Concentration Of Dust Particles Research Articles

Research on a capacitive particle analysis smoke detector.

Smoke detectors face the challenges of increasing accuracy, sensitivity, and high reliability in complex use environments to ensure the timeliness, accuracy, and reliability of very early fire detection. The improvement and innovation of the principle and algorithm for smoke particle concentration detection provide opportunities for improving the performance of the detector. This study represents a new refinement of the smoke concentration detection principle based on capacitive detection of cell structures, and detection signals are processed by a multiscale smoke particle concentration detection algorithm to calculate smoke concentration. Through experiments, it was found that the detector provides effective detection of smoke particle concentrations ranging from 0 to 10% obs/m; moreover, when the detection accuracy is greater than a certain number of parts per million (PPM), the sensitivity of the detector can reach the PPM level; furthermore, the detector can detect smoke particle concentrations higher than the PPM level accuracy even in an environment with a certain concentration of petroliferous and dust particles of different sizes.

The significant role of Darcy–Forchhiemer with integrated hybrid nanoparticles (Graphene and TiO 2) on dusty nanofluid flow subjected to heat conduction

The thermal analysis of two-phase models that deal with the fluid and dusty phases has been considered. This study instigates the flow of a non-miscible, dusty hybrid nanofluid over a stretching cylinder with Darcy–Forchheimer permeability in the presence of thermal radiation. The mathematical model is based on the single-phase nanofluid model, which features modified thermophysical characteristics. This innovative flow model explores how important it is to enhance the concentration of dust particles in fluid dynamics. Hybrid nanoparticles are substituted for nanoparticles in a conventional case to accelerate the heat transfer rate of the fluid. Therefore, in this study, the magnetohydrodynamic flow of hybrid nanofluids and heat transfer of non-Newtonian dusty fluids with suspensions of hybrid nanoparticles have been examined. The appropriate dimensionless variables are used to convert the governing periodic model into a non-dimensional form. The finite-difference-based bvp5c algorithm is used through Matlab for numerical analysis of the set of obtained ordinary differential equations. The graphs explored the influences of relatable factors over the profiles of mass, heat, and velocity transfers. It is observed that with intensifying values of Eckert number (Ec) and Biot number (Bi), the temperature of both phases increased at a significant level, and the velocity decreased with increasing intensity of the magnetic field. The computational results of velocity, core temperature, and intensity dispersion are significant for both aspects. Furthermore, it is observed that both the fluid and dust phases exhibit declining behavior as a result of the impact of porosity, mass concentration, and magnetism on the flow stream. Moreover, it is noticed that both the dust phase temperature θ p ( η ) and fluid phase temperature θ ( η ) intensified with the high intensity of magnetic field and thermal radiation. The missile nozzles, nuclear power plants for aerospace and gaseous-core nuclear rocket systems, and the radiation are considered for evaluating heating significance.

Short-term and long-term effects of exposure to PM10

IntroductionA dust storm is a harmful event in the environment and human health resulting from certain chemicals in the air that transcend predefined levels. Developing countries, such as Iran, suffer from this basic threat (dust particles) to health. The purpose of the research was to evaluate the effects of PM10 particulate matter on mortality related to cardiovascular diseases (CVD) in the year 2022–2023 in Andimeshk City, with the AirQ + programmed. Material and methodThe recommended approach for evaluating effects on health, as recognized by the world health organization (WHO), uses the Air Quality Health Impact Assessment Software (Air Q 2.2.3). The polluted air information required for model runs was obtained from the Environmental Department of Khuzestan. The Khuzestan Meteorological Organization gave information on the levels of particulate matter for both dusty and non-dusty days. The mortality numbers came from the Iranian Statistics Centre and the Health Ministry. The data was collected in a volumetric manner for the year 2022–2023. ResultThe lowest PM10 concentration reported in a year in Andimeshk city belonged to January 9 (14.19 μg/m3), while the most polluted day of the year was November 6 (5634.61 μg/m3). The total monthly concentration of PM10 for April, May, June, July, August, September, October, November, December, January, and February respectively, 2917.9, 3227.82, 3175.89, 2966.24, 3520.46, 3393.1, 4671.07, 13121.26, 3042.63, 1851.67, 2627.52, and 6758.12 μg/m3. ConclusionThe results of this study showed that the studied area is a polluted city in terms of the concentration of dust particles. So, during a year, only 8 days, PM10 concentration did not exceed the standard. One of the main reasons for air pollution in Andimshek city is the neighborhood of Khuzestan province with Iraq and Saudi Arabia, which have dry areas and dust storms.

ПЛАНИРОВАНИЕ И РЕАЛИЗАЦИЯ СТРОИТЕЛЬНЫХ РАБОТ ПРИ ТОЧЕЧНОЙ ЗАСТРОЙКЕ ДЛЯ ОПРЕДЕЛЕНИЯ УДЕЛЬНЫХ ПЫЛЕВЫХ ВЫБРОСОВ

Abstract. The construction industry is one of the significant sources of environmental damage. The effects of dust pollution have an impact on all stages of the building's life cycle, from the start of work on the construction site to completion, operation and demolition. Despite the fact that the stage of work implementation does not last long in comparison with other stages of the life cycle of an investment and construction project, the construction stage has a number of significant impacts on the environment. The development of the construction industry requires the comprehensive assessment and investigation of the construction site as a source of pollu-tion, identification and evaluation of all sources of dust pollution on the construction site, the processes of dust pollution propagation in an urban environment. 
 The article offers an analysis of data on field studies of the degree of atmospheric air pollution in the territory of Rostov-on-Don, an analysis of the volume of construction dust emissions from construction works, a method for calculating control over the implementation of construction processes and the spread of dust pollution generated in the atmospheric air, indi-cators of the maximum, average daily emission concentration of fine dust PM2.5 and PM10 formed from construction production and the ability to control the level of pollution on the construction site. There are no fundamental studies on the calculation of dust emission from construction works during spot construction. Based on the field studies conducted earlier using the Handheld 3016 particle counter, data on dust emissions from construction processes under various climatic influences were obtained.
 Subject: analysis of data on field studies of the degree of atmospheric air dustiness in the territory of Rostov-on-Don, the volume of emissions of construction dust from construction work on construction sites in urban conditions.
 Materials and methods: conducting systematic measurements of the degree of dust in Rostov-on-Don using the Lighthouse Handheld 3016 IAQ manual particle counter, taking into account typical climatic, heterogeneous factors of the territory on which the city is located. Systematic monitoring of several construction sites where residential complexes similar in technology and conditions were built in the most dusty area of Rostov-on-Don and the selection of five construction sites for the development of a calendar schedule for construction and installation work, taking into account specific emissions of dust particles and climatic conditions for calculating the dust pollution factor.
 Results: an effective approach that can be usefully applied to the determination of dust emissions on the construction site, to calculate the gross emission of dust released on the site from construction work, daily indicators of the maximum single and average daily concentration, as well as to dust dispersion with the determination of zones exceeding the MPC indicators is the use of network modeling with further calendarization to predict these types of indicators during the design and implementation of construction production.
 Conclusions: based on the data obtained, it can be concluded that with the existing implemented organization and technology of work, the concentration of fine dust particles are within the MPC, but given the background concentrations of atmospheric air in Rostov-on-Don, these indicators in a particular area will exceed the permissible MPC. The process of using existing SMR models taking into account specific dust emissions, the development of a schedule of dust pollution of a specific territory taking into account natural and climatic factors and the determination of zones of excess of MPC indicators in the process of modeling the dispersion of fine dust particles beyond the fence boundaries of the construction site will make it possible to draw up a passport of environmental safety of the nearby urbanized territory during spot development. Daily determination of dust pollution indicators will allow you to adjust the schedule of construction work. Modeling the dispersion of construction dust, taking into account the direction and speed of the wind, will make it possible to monitor the zones of exceeding the MPC of the neighboring territory on a daily basis and adjust measures to extinguish dust emissions at the construction site.

Measuring the concentrations of some gaseous air pollutants and dust particles in the western city of Hamzah in Iraq

This research concentrates on studying and analyzing the spatial and temporal variation of the concentrations of air pollutants in the Hamzah-western city during the four seasons of the year 2022 by studying the concentrations of gaseous pollutants in the air, such as NO2, SO2, CO, CO2, and O3, as well as measuring the concentrations of dust particles suspended in the air, such as PM2.5 and PM10. The number of sampling sites reached six, distributed into five different sectors (industrial, residential, transport, agricultural, and a mixed sector combining industry and transportation) in order to show the discrepancies in the concentrations of pollutants and explain their causes. The results of in situ measurements and laboratory analyses showed that there is a spatial and temporal variation in the concentrations of air pollutants. The highest concentrations of carbon monoxide CO, carbon dioxide CO2, and sulfur dioxide SO2 were recorded in sector 1 and during the summer season at concentrations of 38.5, 337, and 2.9 ppm, respectively. While the highest concentrations of nitrogen dioxide (NO2) were recorded in sector (2) with a concentration of 0.65 ppm, and all those concentrations were outside the permissible limits, the lowest concentrations were recorded for gases in sector (6), which covered all the study semesters. As for the concentrations of suspended dust particles in their sizes (PM2.5 and PM10), the highest concentrations were recorded in Sector (2), during all seasons of the study, and at 383.81 and 389.38 ppm concentrations, respectively. While the lowest concentrations of suspended particles of both sizes were recorded in Sector 6, a value of 119.65 ppm was recorded for PM2.5 minutes and 115.65 ppm for PM10 minutes. Thus, all their values during the study period were greater than the permissible limits.

Dusty non-Newtonian nanofluid flow along a stretching curved sheet via chemically reactive and heat source/sink imapct: Two-phase model

The momentousness of studying the similar solution of MHD flow along a curved stretching surface of non-Newtonian Casson nanofluids with suspended dust particles is due to stretching curved sheets applications across various industries and disciplines, additionally potential applications of dusty nanofluid in various fields. chemical reaction factor is tested in addition to sink and heat sources in the thermal boundary layer. The transformed equations (ODE) are obtained with the help of appropriate similarity variables to facilitate numerical processing. The numerical treatment of the reduced equations is performed employing a numerical technique known as MATLAB function bvp4c to solve our problem equations with the help of the Runge–Kutta method of fourth order. This investigation yields significant conclusions, one of which is that sphere-shaped dust particles in suspension cause the velocity to decrease. That is, the movement declines with the increase in the concentration of dust particles in the fluid. The dust phase’s speed drops, whereas the fluid phase velocity boosts with the curvature factor. Furthermore, the terms skin-friction and the numbers of Nusselt Nus and Sherwood Shs were verified and argued numerically as we found that the Non-Newtonian Casson parameter supports skin-friction. In addition, the liquid–particle interaction factor for temperature increases Nus, and Shs improves with the liquid–particle interaction factor for concentration. The curved stretching surface is recently used in this research to investigate the movement of the boundary layer, as well as the mass and heat transformation properties of a non-Newtonian nano liquid containing spherical dust particles.

Expanding the simulation of East Asian super dust storms: physical transport mechanisms impacting the western Pacific

Abstract. Dust models are widely applied over the East Asian region for the simulation of dust emission, transport, and deposition. However, due to the uncertainties in estimates of dust transport, these methods still lack the necessary precision to capture the complexity of transboundary dust events. This study demonstrates an improvement in the Community Multiscale Air Quality (CMAQ) model dust treatment during long-range transport of dust from northwestern China to the South China Sea (SCS). To accomplish this, we considered a super dust storm (SDS) event in March 2010 and evaluated the dust scheme by including adjustments to the recent calibration (Dust_Refined_1) and bulk density (Dust_Refined_2) refinements individually and in combination (Dust_Refined_3). The Dust_Refined_3 normalized mean bias of PM10 was −30.65 % for the 2010 SDS event, which was lower in magnitude compared to Dust_Refined_1 (−41.18 %) and Dust_Refined_2 (−49.88 %). Indeed, Dust_Refined_3 improved the simulated aerosol optical depth (AOD) value during significant dust cases, e.g., in March 2005, March 2006, and April 2009. Dust_Refined_3 also showed more clearly that, in March 2010, a “double plume” (i.e., one plume originating from the Taiwan Strait and the other from the western Pacific) separated by the Central Mountain Range (CMR) of Taiwan affected dust transport on the island of Dongsha in the SCS. On 15–21 April 2021, both CMAQ simulations and satellite data highlighted the influence of Typhoon Surigae on dust transport to downwind Taiwan and the western Pacific Ocean (WPO). The CMAQ Dust_Refined_3 simulations further revealed that many dust aerosols were removed over the WPO due to Typhoon Surigae. Hence, the model indicated a near-zero dust particle concentration over the WPO, which was significantly different from previous dust transport episodes over the Taiwan region. Therefore, our study suggested an effective method to improve dust management of CMAQ under unique topographical and meteorological conditions.

Fractal patterns in fluid flows: A radial basis pseudospectral analysis of CuO-EG water nano, Saffman dusty, and plain Newtonian fluids in immiscible layers of a horizontal channel

Nano and dusty fluids provide new possibilities to improve energy transfer efficiencies. Motivated by immiscible fluids duct flow framework in the filtration of hydrocarbon materials, the objective of this manuscript is to present the numerical study of three immiscible fluids namely, copper oxide-ethylene glycol (CuO-EG) water nano, Saffman dusty, and plain Newtonian fluids in the horizontal channel. For the formulation of the mathematical model, the dusty fluid is positioned between the immiscible layers of the nanofluid and Newtonian fluid. The interface between the immiscible fluids is continuous and non-deformable in nature. The flow is driven by an externally time-dependent pressure gradient. The novel radial basis function pseudospectral (RBFPS) method is employed to solve the governed partial differential equations, and the resulting outcomes are compared with cubic B-spline differential quadrature and finite difference method. The impact of several crucial fluid parameters, comprising the volume percentage of CuO nanoparticles, the dust particle concentration parameter, and various others on velocity profiles, are presented graphically. It is observed that despite being present only in the lower zone, the CuO nanoparticles have an impact on the flow velocities in other zones also. The fluid and particle velocities decrease as the volume fraction of CuO increases.

Atmospheric Air Dust Concentration, Composition And Size Distribution Data At Breathing Heights In Yekaterinburg.

Accurate information on air quality serves as the foundation for making regulatory and legal decisions aimed at reducing air pollution. This study investigates the vertical distribution of dust particle concentration, their elemental composition, and size distribution in the atmospheric surface layer in Yekaterinburg. Over eight days in April 2021, 64 dust samples were collected on filters at heights ranging from 0.5 m to 10 m at a single site using a mobile post. The mass concentration of the dust, characterized by heterogeneous data with a coefficient of variation exceeding 30%, exhibited a weak tendency to decrease with height. The proportion of particles smaller than 1 µm decreased with increasing altitude, except for 10 m, where their proportion increased. Conversely, the concentration of p articles ranging from one to two microns decreased closer to the surface. Dust grains of other sizes were nearly evenly distributed at various heights. Dust particles smaller than PM2.5 accounted for approximately 45% of the total particles. X-ray fluorescence analysis identified 12 elements in dust particles, with S, Ca, and Fe showing the most substantial content. The proportion of most metals and Ca in solid particles decreased with height, while the content of S and As increased. The Cu, Zn, and Sb content in dust particles remained constant at all measured heights.

МАТЕМАТИЧЕСКОЕ ОПИСАНИЕ ДИНАМИКИ ЦЕНТРОБЕЖНОГО ДВУХФАЗНОГО ПОТОКА В ПОМОЛЬНОЙ КАМЕРЕ ДЕЗИНТЕГРАТОРА

Rational control of equipment operating modes in the production of building materials is possible only in the case of a mathematical description of various technological processes. The sequence of calculation methods for determining the design and technological parameters of grinding equipment makes it possible to numerically present the results of calculations of rational operating modes of the equipment. The study presents a mathematical description of the dynamics of a two-phase flow inside the grinding chamber of a disintegrator, with the help of which it is possible to determine the speed characteristics of its operating modes for materials with different physical and mechanical properties. The nature of the change in the tangential components of the velocities of the two-phase flow has been established: the range of the current radius of the grinding chamber Ri has been determined, at which the radial components of the velocities of the carrier flow and particles of the ground material continue to increase. As a result of mathematical modeling, it was confirmed that with an increase in the concentration of dust particles in the increasing volume of the grinding chamber, the value of the tangential component of the velocity of a dynamic two-phase flow decreases in relation to the maximum parameters at Ri = 0.15 m by an average of 15.5%. It has been determined that the maximum velocity values for the tangential component are in the limit of Ri = 0.1-0.15 m and are 131 m/s for air, and 127.5 m/s for an average suspended particle with dsr = 40 μm. In the process of developing a mathematical description, it was established that in the range Ri = 0.15 - 0.3 m the increase in the radial components of the velocities of the air carrier medium and the weighted average particle flow is about 14.5%, which, in turn, indicates an increase in the kinetic energy of the crushed particles during the movement of a dynamic two-phase flow from the center to the periphery of the grinding chamber of the disintegrator.

The effect of human activities on Bali’s Silent Day (Nyepi) in 2022

During Nyepi, all activities are eliminated, including public services, such as closing access to land, sea, and air transportation routes that transit to Bali for one day. In 2022, the BMKG Research and Development Center observed air quality in Nyepi. The measurement aims to determine the relative reduction level of greenhouse gas (GHG) and particulate emissions on Nyepi Day compared to before and after. Greenhouse gases and particulates were measured for seven days, February 28 - March 6, 2022. The measurement locations were over 3 points: Denpasar Regional Office III, Karangasem Geophysics Post, and Jembrana Climatology Station. The results of this field measurement show that daily human activities significantly influence the concentration of pollutant gases and particulates in the air. During Nyepi Day, air concentration improves when all human actions are reduced. This is marked by a decrease in the air’s concentration of pollutant gases (CO, NO2) and dust particles. The reduction in the concentration of pollutant gases and dust particles did vary at each observation location; this was due to the sensitivity of the equipment, the character of each observation location, and the placement of measuring devices. Urban areas filled with community activities have experienced the greatest improvement in air quality compared to suburban areas. Order of measuring instruments close to the location of pollutant sources, even in suburban areas, will decrease the concentration of pollutant gases, similar to that in urban areas. The difference between PM25 data during Nyepi 2022 and the average PM25 for 2020 - 2022 shows a decrease in PM25 concentrations of around 47%, with the highest drop at night.

A numerical approach to two phase Marangoni convection hydromagnetic flow of dusty nanofluids

The aim of the present work is to discuss the effects of magnetohydrodynamic (MHD) Marangoni convection flow of dusty TiO2 + H2O nanofluid past a flat surface. A two phase dusty nanofluid model is considered. The transformed dimensionless equations are solved numerically by 4thorder RK method together along with shooting technique. The outcomes of the current investigation are thatthe volume fraction, magnetic parameter and dust particle concentration parameter contribute decelerated motion. Dust particle concentration parameter plays a prime role in controlling the two-phase flow fields. Further, rise in magnetic parameter from 0.5 to 3 emaciates the heat transfer rate (HTR) by 18.45% while that of thermal dust parameter from 1.2 to 3.6 ameliorates HTR by 14 %.

Dust Under the Radar: Rethinking How to Evaluate the Impacts of Dust Events on Air Quality in the United States

AbstractDust is an important and complex constituent of the atmospheric system, having significant impacts on the environment, climate, air quality, and human health. Although dust events are common across many regions of the United States, their impacts are not often prioritized in air quality mitigation strategies. We argue that there are at least three factors that result in underestimation of the social and environmental impact of dust events, making them receive less attention. These include (a) sparse monitoring stations with irregular spatial distribution in dust‐influenced regions, (b) inconsistency with dust sampling methods, and (c) sampling frequency and schedules, which can lead to missed dust events or underestimation of dust particle concentrations. Without addressing these three factors, it is challenging to characterize and understand the full air quality impacts of dust events in the United States. This paper highlights the need for additional monitoring to measure these events so that we can more fully evaluate and understand their impacts, as they are predicted to increase with climate change.

Research and modeling of the ecological efficiency of drying refractory and building materials in vertical shaft furnaces

Based on the hypothesis of the dominant effect on the environmental efficiency of drying materials in shaft furnaces of the concentration, median diameter, dispersion, temperature and humidity of dust particles at the outlet of the dryer, a device for thermal aeration separation of dust is proposed. The analysis of mathematical modeling of aerothermodynamic processes in a two-phase medium asbestos dust ‒ gas flow confirmed the conclusions of industrial studies on the influence of aerothermodynamic parameters of direct flow on the temperature and humidity of asbestos dust in the pneumatic dryer. Based on the principle of additive classification, a mathematical model of aeration separation of dust particles directly in the dryer of the shaft furnace is constructed, depending on the parameters of the heat carrier and the proposed device.

Vibrational energy transmission in underground continuous mining: Dynamic characteristics and experimental research of field data

Respirable dust exposure is a serious health and safety risk for coal mine workers, with the potential for disabling and fatal conditions. Airborne dust particle concentrations must be reduced through new methods of filtration or capture to reduce this risk, and most mining jurisdictions have legal requirements for respirable dust exposure. As this research area receives growing attention, there is an increased need for fully coupled model development and experiments based on field data to quantify the filtering characteristics, with a focus on the scrubber-mesh system and continuous miner machine. Our previous research has demonstrated that vibrating mesh screens can improve dust collection efficiency. While the vibrating mesh approach has been demonstrated to be effective, the main technical challenge is determining how to provide vibration to the scrubber mesh screen at specific frequency and amplitude levels. We present a novel approach to improving dust filtration by transmission of mechanical vibrations generated by the continuous miner machine during coal mining to the mesh filter. The study's specific goal is to harvest natural vibrations inherent in underground mining equipment and translate them to levels suitable for optimal vibration of the mesh panel. The study first collects vibration data from an underground coal mine's operating continuous miner and analyzes it to identify the most stable vibration spectrums that can be used as an input to the energy transmission system. Multiphysics modeling, based on three-phase computation fluid dynamics, is presented that uses resonance condition to harvest operational vibrations of the continuous miner. Resonance occurs when the natural frequency of the scrubber-mesh system matches the continuous miner's vibration frequency, significantly increasing the amplitude of scrubber-mesh vibrations. The study intends to use this energy transmission system to improve the dust collection efficiency of the flooded-bed dust scrubber, reduce clogging, and reduce the need for frequent panel replacements. Our findings indicate that vibration resonance-based energy transmission is a promising technique for significantly improving the dust collection efficiency of flooded-bed mesh scrubbers, with important implications for the development of self-powered and sustainable systems. This novel approach has significant implications for mining industry occupational health and safety.

Correspondence between Cosmic-Dust-Enriched Sediment Horizons and Geomagnetic Field Excursions

The relationship between spikes in cosmic dust fluxes onto the Earth’s surface (mainly represented by native metal particles) and the behavior of the polarity of the main geomagnetic field has been studied. For this, a search was carried out for horizons of paleodeposits with a high concentration of cosmic dust (exceeding the background concentration by more than an order of magnitude). Such increased concentrations of cosmic dust particles were found in peat deposits corresponding to the Etrussia excursion (2.5–3 ka), as well as in ancient Cretaceous and Paleogene marine deposits. In total, we discovered five horizons with a thickness up to 1 m hosting a high concentration of cosmic dust. Measurements of the paleo‒and petromagnetic parameters of samples selected based on the thickness of sedimentary strata showed that the beginning of accumulation of these horizons coincided with geomagnetic field excursions. In this case, sediment enrichment in dust particles could have lasted somewhat longer than a geomagnetic field excursion. Evidence was obtained that Earth collisions with dense fluxes of cosmic dust could have coincided with short-term disturbances in the polarity of the geomagnetic field, but this had no lasting effect on the geodynamo.

Linear polarization signatures of atmospheric dust with the SolPol direct-sun polarimeter

Abstract. Dust particles in lofted atmospheric layers may present a preferential orientation, which could be detected from the resulting dichroic extinction of the transmitted sunlight. The first indications were provided relatively recently on atmospheric dust layers using passive polarimetry, when astronomical starlight observations of known polarization were found to exhibit an excess in linear polarization, during desert dust events that reached the observational site. We revisit the previous observational methodology by targeting dichroic extinction of transmitted sunlight through extensive atmospheric dust layers utilizing a direct-sun polarimeter, which is capable to continuously monitor the polarization of elevated aerosol layers. In this study, we present the unique observations from the Solar Polarimeter (SolPol) for different periods within 2 years, when the instrument was installed in the remote monitoring station of PANGEA – the PANhellenic GEophysical observatory of Antikythera – in Greece. SolPol records polarization, providing all four Stokes parameters, at a default wavelength band centred at 550 nm with a detection limit of 10−7. We, overall, report on detected increasing trends of linear polarization, reaching up to 700 parts per million, when the instrument is targeting away from its zenith and direct sunlight propagates through dust concentrations over the observatory. This distinct behaviour is absent on measurements we acquire on days with lack of dust particle concentrations and in general of low aerosol content. Moreover, we investigate the dependence of the degree of linear polarization on the layers' optical depth under various dust loads and solar zenith angles and attempt to interpret these observations as an indication of dust particles being preferentially aligned in the Earth's atmosphere.

Environmentally Sustainable Transport: Dust Particles (PM10) on Provincial Roads in South Sulawesi, Indonesia

The research objective was to determine and analyze the concentration of dust particles (PM10) and the relationship between traffic flow and dust particles (PM10). Quantitative research by measuring two parameters, namely the volume of traffic flow and the concentration of dust particles (PM10). Traffic volume data were obtained using a manual count following the Indonesian road capacity manual. Dust particles (PM10) were measured using the BAM1020 instrument and data analysis using SPSS version 16.20 with multiple linear regression (MLR). The concentration of dust particles (PM10) produced at 3 points in Maros City, respectively 155.85 μg / m3, 157.22 μg / m3, 151.77 μg / m3 and 1 point in Pangkep City is 150.25 μg / m3. There is a significant positive relationship between the traffic flow and the concentration of dust particles (PM10) shown from the calculation of PM10, r = 0.693; P <0.001.

Background concentrations of airborne, culturable fungi and dust particles in urban, rural and mountain regions

Geographic location and meteorological factors can affect the content of bioaerosol concentrations. This study was conducted to determine the natural background concentrations of culturable fungal spores and dust particles in three different geographical areas. Focus was given to the dominant airborne genera Cladosporium, Penicillium, Aspergillus and the species Aspergillus fumigatus. The influence of weather conditions on the microorganism concentrations in urban, rural and mountain regions were examined. Possible correlations between particle counts and culturable fungal spore concentrations were investigated.125 measurements of the air were conducted using the air sampler MAS–100NT® and the particle counter Alphasense OPC–N3. The analyses of the collected samples were based on culture methods using different media.The highest median of fungal spore concentrations was detected in the urban region and was of 2.0 × 103 CFU/m3 for xerophilic fungi and 1.7 × 103 CFU/m3 for the genus Cladosporium. The concentrations of fine and coarse particles in rural and urban regions were the highest of 1.9 × 107 pa/m3 and 1.3 × 107 pa/m3, respectively. Little cloud cover and slight wind had a positive influence on the concentration of fungal spores. Furthermore, correlations were observed between air temperature and the concentrations of xerophilic fungi as well as the genera Cladosporium. In contrast, relative humidity correlated negatively with total fungi and Cladosporium and no correlation was found with the other fungi. For the region of Styria in summer and early autumn, the natural background concentration for xerophilic fungi ranged between 3.5 × 102 and 4.7 × 103 CFU/m3 air. No significant differences were detected between the fungal spore concentrations in urban, rural and mountainous regions.The data of this study could be used as a reference to compare the natural background concentrations of airborne culturable fungi in further studies concerning air quality assessment.

Multifield intermittency of dust storm turbulence in the atmospheric surface layer

Dust storms are typical dispersed two-phase atmospheric turbulence involving electrified charged dust particles. Previous observations have demonstrated that clean-air atmospheric turbulence is strongly intermittent. However, the intermittency of the wind velocity, concentration of dust particles with a diameter smaller than $10\ \mathrm {\mu }{\rm m}$ (PM10) and electric fields, known as multifield intermittency, has not been reported or characterized yet. Here, we quantify the small-scale multifield intermittency of dust storms using datasets obtained from the Qingtu Lake Observation Array and a wavelet-based data analysis technique. The results indicate that the probability density functions of the multifield increments are scale dependent, and the scaling exponents of the multifield structure functions exhibit anomalous scaling, suggesting that the multiple fields in dust storms are also highly intermittent. Specifically, the wind velocity during dust storms appears to be more intermittent as compared with clean-air conditions. Among the multiple fields, the small-scale intermittency is strongest for PM10 dust concentration, moderate for electric fields and weakest for wind velocity. Furthermore, the anomalous scaling of multiple fields is well described by the hierarchical structure theory of turbulence. It is theoretically predicted that the wind velocity displays a one-dimensional filamentary structure, while the PM10 dust concentration and electric fields display two-dimensional sheet-like structures. Finally, after removing the coherent components of the observed time series by the proposed wavelet conditioning statistics, Kolmogorov linear scaling is recovered for the multiple fields, suggesting that small-scale multifield intermittency is caused by the presence of small-scale coherent structures.