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The fine particle liquid–solid flow in porous media is involved in many industrial processes such as oil exploitation, geothermal reinjection and particle filtration. Understanding the migration characteristics of single fine particles in liquid–solid flow in porous media can provide micro-detailed explanations for the fine particle liquid–solid flow in porous media. In this paper, an existing lattice Boltzmann method–discrete element method (LBM-DEM) is improved by introducing a new boundary thickening direct forcing (BTDF) immersed boundary method (IBM) to replace the classical IBM. The new method is used to investigate the migrations of one, two or three fine particles in a flow field in porous media and the reactions of one, two or three fine particles on the flow field. It is found that the movement distance of a fine particle in porous media does not show a linear correlation with the fine particle's density. A fine particle with a higher density may move a shorter distance and then stagnates. Although a fine particle with a smaller diameter has a better following performance in a flow field, it is also likely to be stranded in a low-infiltration area in porous media. Under the same increase ratio, the increase in the diameter of a fine particle causes an increased pressure drop of the liquid–solid flow. In some cases, the increase in the quantity of fine particles can intensify the disturbance of fine particles on the flow field, improving the movement of fine particles. [ABSTRACT FROM AUTHOR]

The interaction between fine particles is widespread in nature and plays a crucial role in regulating various interfaces for minerals. In coal preparation wastewater treatment, the intricate mechanism of interaction between multi-component fine particles in coal slurry water (denoted as CSW) is a fundamental aspect in addressing the challenges of coal slurry water agglomeration, selective separation, and difficult dewatering. This paper presents a summary of the necessity, current research status, and progress in studying the microscopic interaction between mineral particles in CSW systems. It overviews theoretical calculation formulas for particle-particle interaction, factors that influence such interaction, and modern analysis techniques for studying microscopic particle interaction. These findings enhance and refine relevant theories, establish a theoretical foundation, and offer technical support for stabilizing and optimizing the performance of CSW systems. Additionally, it elucidates the mechanism of particle-particle interaction in CSW, which is of significant importance in achieving efficient separation of CSW. [ABSTRACT FROM AUTHOR]

Particle dampers (PD) can be embedded in structures fabricated via selective laser melting (SLM) because the raw powder (particle diameter : several tens of micrometers) remains in closed spaces during SLM. However, most PD studies have focused on coarse particle sizes larger than 1 mm and low frequencies below 100 Hz; there is insufficient evaluation of PD attenuation characteristics and particle behavior for particle sizes from tens of micrometers to sub-millimeters and in the 100 to 1000 Hz band. In this study, the equivalent viscous damping coefficients of spherical zirconia balls with nominal sizes of 0.05, 0.10, 0.20, and 0.40 mm are measured under different vibration accelerations (from 9 to 148 m/s2(rms)) and frequencies (from 100 to 800 Hz) to experimentally investigate the effect of fine particle diameters on the damping properties. It is deduced that in the frequency range above 200 Hz, the equivalent viscous damping coefficients of the coarse particle diameter are greater than those of fine particles at accelerations below the range of 15.7–22.4 m/s2(rms). In contrast, the equivalent viscous damping coefficients of the fine particles are greater than those of the coarse particles at accelerations above the 15.7–22.4 m/s2(rms) range. In addition, to determine the reason for these tendencies, the behavior of particles with a nominal size of 0.05 mm, which is close to the raw powder, is observed through a window using a high-speed microscope camera. The results reveal that in the low acceleration range, the inertial force does not overcome the static friction force owing to poor flowability caused by adhesion force, and the particles are always stationary with respect to the sealed container.

Laboratory filtration experiments are employed to investigate effective well killing while minimizing its impacts on surrounding rocks. The novelty of this experimental study lies in the prolonged exposure of rock samples to the killing fluid for seven days, corresponding to the average duration of well workovers in the oilfields in Perm Krai, Russia. Our findings indicate that critical factors influencing the interactions between rocks and the killing fluid include the chemical composition of the killing fluid, the mineralogical composition of the carbonate rocks, reservoir pressure and temperature, and the contact time. Petrophysical analyses using multi-scale X-ray computed tomography, field emission scanning electron microscopy, and X-ray diffraction were conducted on samples both before and after the well killing simulation. The experiments were performed using real samples of cores, crude oil, and the killing fluid. The results from this study indicate that low-mineralized water (practically fresh water) is a carbonate rock solvent. Such water causes the dissolution of rock components, the formation of new calcite crystals and amoeba-like secretions, and the migration of small particles (clay, quartz, and carbonates). The formation of deep channels was also recorded. The assessment reveals that the change in the pH of the killing fluid indicates that the observed mineral reactions were caused by carbonate dissolution. These combined phenomena led to a decrease in the total number of voids in the core samples, which was 25% on average, predominantly among voids measuring between 45 and 70 μm in size. The change in the pore distribution in the bulk of the samples resulted in decreases in porosity of 1.8% and permeability of 67.0% in the studied core samples. The results from this study indicate the unsuitability of low-mineralized water as a well killing fluid in carbonate reservoirs. The composition of the killing fluid should be optimized, for example, in terms of the ionic composition of water, which we intend to investigate in future research.

Thermal expansion, by which a material’s volume increases when heated, is a universal phenomenon deriving from the thermal vibration of the atoms that constitute solids. Since the discovery of low thermal expansion in Invar alloys at the end of the 19th century, the “abnormality” of thermal expansion has given birth to new sciences and technologies. This article describes studies of thermal expansion anomalies from low thermal expansion of Invar alloys to the giant negative thermal expansion (giant NTE) materials recently discovered. Moreover, prospects for future research are presented. One turning point is the large isotropic NTE of ZrW2O8 discovered in 1996. Starting with manganese nitride in 2005, various materials have been found to have negative linear expansion coefficients that are many times larger than those of conventional NTE materials, although some operating-temperature constraints exist. These achievements have overturned the conventional wisdom which holds that negative coefficients of linear expansion do not engender large values. Additionally, the achievements established the concept of “giant” or “colossal” NTE. This article emphasizes recent important findings of enhanced NTE caused by material microstructural effects that are peculiar to ceramic bodies, and “hybrid” NTE by which multiple mechanisms work simultaneously. Additionally, this article introduces an attempt to produce fine particles of NTE material and use them as a thermal expansion compensator, especially for thermal-expansion control of resin. [ABSTRACT FROM AUTHOR]

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Hyporheic exchange (HE), fine particle deposition and clogging are tightly coupled processes that control ecosystem services in rivers. While HE is assumed to be induced primarily by riverbed topography, surface flow turbulence also drives significant exchange. We show that turbulence‐driven HE produces large interfacial fluxes and drives long‐term feedback between HE and fine suspended particles via bed clogging. Turbulence significantly increases total HE fluxes as it rapidly delivers suspended particles into porewater over the entire interface, whereas advective pumping exchange only delivers particles into focused downwelling regions on the upstream side of bedforms. While turbulence is associated with rapid fluctuations and shallow HE, it is key on longer‐timescale outcomes, namely bed clogging. However, beyond the general effect of clogging in attenuating HE, turbulence‐driven HE will also be important for other river‐borne materials that are retained and transformed within hyporheic zones, such as nutrients and organic pollutants. Plain Language Summary: Fine natural sediments like clay particles are transported in rivers and deposited in riverbeds. Clay deposition is important to river ecosystems because it controls habitat conditions within riverbeds. In this research, new computational simulations show that turbulent river flow controls clay deposition in riverbeds. These new simulations incorporate turbulence, and they are able to correctly predict patterns of clay deposits. They also predict how clay deposits clog the riverbed and reduce the exchange of water between the river and bed. These simulation capabilities are important to protect river ecosystems and to manage contaminants that interact with riverbeds, because clogging is a common process that damages river ecosystems. Key Points: Turbulence accounts for a significant fraction of fine particle delivery to the hyporheic zoneTurbulent transport of fine particles contributes substantially to interfacial clogging that attenuates Hyporheic exchange (HE)A numerical model is presented that integrates interfacial turbulence, HE of suspended particles and bed clogging [ABSTRACT FROM AUTHOR]

Nitrogen (N) is a constituent element of ambient organic aerosol; however, we have limited knowledge of the total quantity of organic N (ON) and its relative importance to aerosol N due to a lack of effective analytical methods for ON. Here, we report first online measurements of ON in particulate matter (PM2.5) in urban Shanghai in summer of 2021 using a newly developed aerosol nitrogen analyzer. ON accounted for an average of 25% of total aerosol N and varied in the range of 5%–64% on the hourly scale. Hourly variations identified four distinct types of ON episodes that occurred in different hours of a day. Analysis aided by concurrently measured source indicative pollutants revealed that vehicular emissions, nocturnal chemistry, daytime photochemistry or combined primary sources, and secondary chemistry could drive up ON under different day‐to‐day atmospheric conditions. Our results help bridge the knowledge gap in the emissions and formation of organic aerosol. Plain Language Summary: Atmospheric particulate matter (PM) exerts profound influences on urban air quality and human health. A large fraction of ambient aerosol is organic matter, in which nitrogen (N)‐containing molecules are known constituents. However, our knowledge is extremely limited about the abundance and sources of nitrogenous organics due to a lack of convenient measurement tools to quantify the total aerosol organic nitrogen (ON) in the past. This hurdle has been lifted through our recently developed aerosol nitrogen analyzer that can provide sensitive and simultaneous determinations of aerosol organic and inorganic N. Here, we present a first report of bihourly measured ON at an urban site of Shanghai, a megacity in China during a period of two and a half summer months. ON represented 25% of aerosol N on average and hourly data varied from 5% to 64%. The results indicated importance of ON comparable to that of inorganic N species (i.e., NH4+ ${\text{NH}}_{4}^{+}$, NO3− ${\text{NO}}_{3}^{-}$) and that the sources/chemistry of ON molecules are considerably dynamic. Past attention has been predominantly placed on inorganic N pollutants or carbonaceous materials in addressing urban PM pollution. This work highlights the need to consider the role of ON, especially as efforts of decarbonization in energy sources unfold. Key Points: First hourly observation of aerosol total organic nitrogen (ON) at an urban site revealed ON made up 5%–64% of total aerosol nitrogenHourly data identified distinct ON episode types that occurred in different hours of a day linked to dominant sources of varying originsSource indicators revealed vehicle emissions, coal combustion, nocturnal chemistry and daytime photochemistry were major sources of urban ON [ABSTRACT FROM AUTHOR]

Fine and ultrafine particles possess great potential for industrial applications ascribed from their huge specific surface area and ability to provide good gas–solid contact. However, these powders are inherently cohesive, making it challenging to achieve smooth flow and fluidization. This challenge can be well-resolved by nanoparticle modulation (nano-modulation), where a small amount of nanoparticles is uniformly mixed with the cohesive fine/ultrafine powders. Through nano-modulation, the fluidization system of cohesive powders exhibits distinguishable minimum fluidization velocity, enlarged bed expansion ratio (particularly the dense phase expansion), and scarcer, smaller, and slower moving bubbles, indicating improved flow and fluidization quality. The purpose of the current work is to systematically summarize the state-of-the-art progress in the fluidization and utilization of fine and ultrafine particles via the nanoparticle modulation method. Accordingly, a broader audience can be enlightened regarding this promising fine/ultrafine particle fluidization technology, so as to provoke their attention and encourage interdisciplinary integration and industry-academia collaborative research. [ABSTRACT FROM AUTHOR]

Although meteorological conditions play a significant role in air pollution, research on their effects on the relationship between air pollutants is limited. In this study, trends of six criteria air pollutants were investigated from 15 air quality monitoring stations (AQMSs) in Ulsan, a multi-industrial city in South Korea, during 2015–2019. Unlike CO and O3, SO2, NO2, PM10, and PM2.5 showed statistically significant decreasing trends over the period. The companion relationship between PM2.5 and gaseous pollutants was evaluated by their correlations [R (PM2.5–GPs)]. R (PM2.5–NO2) was relatively high at almost all AQMSs, whereas high R (PM2.5–SO2) was observed near the petrochemical industrial complex, suggesting a great influence of local emissions (vehicles and industries). R (PM2.5–CO) and the standardized regression coefficients of CO obtained from the multiple linear regression model were the highest, indicating that combustion processes may significantly contribute to PM2.5. The effect of temperature (T) was more apparent on R (PM2.5–GPs) than that of relative humidity, with significant values under T > 15 °C. Moreover, R (PM2.5–O3) was positive at the T range of 12–18 °C, suggesting that reducing GPs emitted by industrial facilities during May–June may control PM2.5 and O3 in Ulsan. The methodology demonstrated in this study can be further used for a better understanding of the influences of environmental factors on the secondary PM2.5 formation from gaseous precursors and the R (PM2.5–O3). [ABSTRACT FROM AUTHOR]

PM2.5 concentration declined significantly nationwide, while O3 concentration increased in most regions in China in 2013–2020. Recent evidences proved that peak season O3 is related to increased death risk from non-accidental and respiratory diseases. Based on these new evidences, we estimate excess deaths associated with long-term exposure to ambient PM2.5 and O3 in China following the counterfactual analytic framework from Global Burden Disease. Excess deaths from non-accidental diseases associated with long-term exposure to ambient O3 in China reaches to 579 (95% confidential interval (CI): 93, 990) thousand in 2020, which has been significantly underestimated in previous studies. In addition, the increased excess deaths associated with long-term O3 exposure (234 (95% CI: 177, 282) thousand) in 2013–2020 offset three quarters of the avoided excess deaths (302 (95% CI: 244, 366) thousand) mainly due to PM2.5 exposure reduction. In key regions (the North China Plain, the Yangtze River Delta and the Fen-Wei Plain), the former is even larger than the latter, particularly in 2017–2020. Health benefit of PM2.5 concentration reduction offsets the adverse effects of population growth and aging on excess deaths attributed to PM2.5 exposure. Increase of excess deaths associated with O3 exposure is mainly due to the strong increase of O3 concentration, followed by population aging. Considering the faster population aging process in the future, collaborative control, and faster reduction of PM2.5 and O3 are needed to reduce the associated excess deaths. [ABSTRACT FROM AUTHOR]

Thermal expansion, by which a material’s volume increases when heated, is a universal phenomenon deriving from the thermal vibration of the atoms that constitute solids. Since the discovery of low thermal expansion in Invar alloys at the end of the 19th century, the “abnormality” of thermal expansion has given birth to new sciences and technologies. This article describes studies of thermal expansion anomalies from low thermal expansion of Invar alloys to the giant negative thermal expansion (giant NTE) materials recently discovered. Moreover, prospects for future research are presented. One turning point is the large isotropic NTE of ZrW2O8 discovered in 1996. Starting with manganese nitride in 2005, various materials have been found to have negative linear expansion coefficients that are many times larger than those of conventional NTE materials, although some operating-temperature constraints exist. These achievements have overturned the conventional wisdom which holds that negative coefficients of linear expansion do not engender large values. Additionally, the achievements established the concept of “giant” or “colossal” NTE. This article emphasizes recent important findings of enhanced NTE caused by material microstructural effects that are peculiar to ceramic bodies, and “hybrid” NTE by which multiple mechanisms work simultaneously. Additionally, this article introduces an attempt to produce fine particles of NTE material and use them as a thermal expansion compensator, especially for thermal-expansion control of resin. [ABSTRACT FROM AUTHOR]

Abstract Hyporheic exchange (HE), fine particle deposition and clogging are tightly coupled processes that control ecosystem services in rivers. While HE is assumed to be induced primarily by riverbed topography, surface flow turbulence also drives significant exchange. We show that turbulence‐driven HE produces large interfacial fluxes and drives long‐term feedback between HE and fine suspended particles via bed clogging. Turbulence significantly increases total HE fluxes as it rapidly delivers suspended particles into porewater over the entire interface, whereas advective pumping exchange only delivers particles into focused downwelling regions on the upstream side of bedforms. While turbulence is associated with rapid fluctuations and shallow HE, it is key on longer‐timescale outcomes, namely bed clogging. However, beyond the general effect of clogging in attenuating HE, turbulence‐driven HE will also be important for other river‐borne materials that are retained and transformed within hyporheic zones, such as nutrients and organic pollutants.

BackgroundCombustion of solid biomass fuels using traditional stoves which is the daily routine for 3 billion people emits various air pollutants including fine particulate matter which is one of the widely recognized risk factors for various cardiorespiratory and other health problems. But, there is only limited evidences of kitchen PM2.5 concentrations in rural Ethiopia.ObjectiveThis study is aimed to estimate the 24-h average kitchen area concentrations of PM2.5 and to identify associated factors in rural households of northwest Ethiopia.MethodThe average kitchen area PM2.5 concentrations were measured using a low-cost light-scattering Particle and Temperature Sensor Plus (PATS+) for a 24-h sampling period. Data from the PATS+ was downloaded in electronic form for further analysis. Other characteristics were collected using face-to-face interviews. Independent sample t-test and one-way analysis of variance were used to test differences in PM2.5 concentrations between and among various characteristics, respectively.ResultMixed fuels were the most common cooking biomass fuel. The 24-h average kitchen PM2.5 concentrations was estimated to be 405 μg/m3, ranging from 52 to 965 μg/m3. The average concentrations were 639 vs. 336 μg/m3 (p

Recent years have witnessed growing research interest in applying rheology in grinding and flotation treatment of finely disseminated ores. Slurry rheology has long been identified as the comprehensive effect of inter-particle interactions, including their aggregation and dispersion states in slurry, which are more impactive under the fine-particle effect. In this regard, rheology has the potential to play a significant role in interpreting the flowing and deforming phenomena of inter-particle aggregates, particle-bubble aggregates, and flotation froth. Though much attention has been paid to the rheological effect in industrial suspension, this has not been the case for mineral grinding and flotation for fine particles. The influential mechanism of rheology on the sub-processes of mineral processing has not been systemically determined nor revealed thoroughly, thus the underpinning mechanism for enhancing the processing efficiency has been difficult to discover. This paper reviews the current application and importance of rheology in fine mineral processing, and the potential research direction in the field is proposed. [ABSTRACT FROM AUTHOR]

PM2.5 samples were collected from a semi-rural site in the industrial city of Ulsan, South Korea during 2018–2019 to characterize the chemical composition and determine source contributions on polluted and normal days. The daily PM2.5 concentration exceeded the United States National Ambient Air Quality Standards (35 µg/m3) on 11 of the 56 days. The mean concentration of Σ9 water-soluble inorganic ions (WSIIs) was 17.1 and 6.07 µg/m3 on polluted and normal days, respectively, with SO42–, NO3–, and NH4+ the dominant species. The elements were dominated by Mg and Fe, with a mean concentration of Σ11 elements of 1973 and 855 ng/m3 on polluted and normal days, respectively. The mean concentration of Σ21 polycyclic aromatic hydrocarbons (PAHs) was 4.44 and 3.26 ng/m3 on polluted and normal days, respectively, indicating a higher human health risk on polluted days. High PM2.5 concentrations were due to an increase in the concentration of almost all WSIIs, elements, and PAHs on polluted days. Potential sources of PM2.5 were identified using positive matrix factorization (PMF), the conditional bivariate probability function (CBPF), and the potential source contribution function (PSCF). According to PMF results, secondary inorganic aerosols (39.8%), primary sulfate (18.2%), and coal/biomass burning (16.3%) were dominant on polluted days, whereas marine sources (23.1%), secondary inorganic aerosols (19.3%), and primary sulfate (16.2%) were the largest contributors to PM2.5 on normal days. Results from the CBPF and PSCF indicate that polluted days may be influenced by both long-range atmospheric transport (LRAT) and local emission sources, while LRAT became more important on normal days. Based on these findings, other studies are necessary to further investigate and distinguish the PM2.5 source contributions in industrial and urban areas. [ABSTRACT FROM AUTHOR]

According to the International Agency for Research on Cancer (IARC), airborne fine particulate matter (PM2.5), which is categorized as a Group I carcinogen, was found to lead to predominantly lung as well as other cancer types in humans. Hepatocellular carcinoma (HCC) is endemic in Taiwan where it is the second and fourth foremost cause of cancer deaths in men and women, respectively. Taiwan's mortality rates for liver cancer vary considerably from one region to another, suggesting that the environment may exert some influence on deaths attributed to liver cancer. The aim of this investigation was to perform an ecologic study to examine the possible link between ambient PM2.5 levels and risk of liver cancer in 66 in Taiwan municipalities. To undertake this investigation, annual PM2.5 levels and age-standardized liver cancer mortality rates were calculated for male and female residents of these areas from 2010 to 2019. Data were tested using weighted-multiple regression analyses to compute adjusted risk ratio (RR) controlling for urbanization level and physician density. Annual PM2.5 levels of each municipality were divided into tertiles. The adjusted RRs for males residing in those areas with intermediate tertile levels (21.85 to 28.21 ug/m3) and the highest tertiles levels (28.22–31.23 ug/m3) of PM2.5 were 1.29 (95% CI = 1.25–1.46) and 1.41 (95% CI = 1.36–1.46), respectively. Women in these locations shared a similar risk, 1.32 (1.25–1.4) and 1.41 (1.34–1.49), respectively. Evidence indicated that PM2.5 increased risk of mortality rates attributed to liver cancer in both men and women in Taiwan. [ABSTRACT FROM AUTHOR]

In view of the difficulty and low efficiency of fine hematite flotation, nanobubbles with special interfacial properties were applied to reverse the flotation of hematite to improve the flotation behavior and separation performance of fine particles. The Box-Behnken response surface method was used to design the experiments and optimize the reagent dosage for reverse nanobubble flotation of hematite from the flotation feed at Anqian Mineral Processing Plant by specifically analyzing the effect of each factor and the interactions between factors on the flotation performance. The results show that collector TD-Ⅱ and corn starch had more significant impacts on grade and recovery than lime and the interactions between starch, lime, and collector TD-Ⅱ had significant effects on iron grade. The iron recovery is 82.27 % and the iron grade is 67.32 % for the concentrate when 3.0 kg/t corn starch, 1.5 kg/t lime, and 0.78 kg/t collector TD-Ⅱ are added. The kinetic flotation experiments confirm that the introduction of nanobubbles in flotation can improve flotation kinetics and concentrate recovery. The application of the nanobubble flotation process will help resolve the difficulty in the efficient flotation of fine particles, which is of great significance to improving the technical performance indicators and economic benefits of the mineral processing plant. [ABSTRACT FROM AUTHOR]

In this study, the water-soluble inorganic ions (WSIIs) composition of fine particulate matter (PM2.5) was measured in the northern Nanjing city from 2015 to 2021. NH4+, NO3− and SO42− concentrations dominated in total WSIIs (Na+, NH4+, K+, Mg2+, Ca2+, Cl−, NO3− and SO42−), accounting for 87.8%. The nitrate with highest average concentration among all ions was 11.0 μg·m−3. Total WSIIs concentrations were higher in winter and lower in summer, with the highest levels in December (45.6 μg·m−3) and the lowest levels in August (15.1 μg·m−3). NO3−/SO42− was higher than 1, indicating the important contribution of mobile sources. The aerosols exhibited a weak acidic by the molar ratio of water-soluble anions and cations. Positive matrix factorization (PMF) analysis results showed that secondary nitrate and sulfate were the major pollution sources in December 2016 and 2020. The contribution of secondary nitrate in 2020 increased by 47.6% compared to 2016, while that of secondary sulfate decreased by 42.4%. The potential source contribution results demonstrated that for secondary aerosol concentrations, the contribution of regional transport from north of Anhui increased, while the contribution of local emissions decreased. The results from this study could contribute to the better prevention and control of regional air pollution in the future. [ABSTRACT FROM AUTHOR]

To improve the removal efficiency of flue gas fine particles in the desulfurization tower by wet desulfurization technology, a new set of purging electrically charged atomization nozzle device was designed and applied to the visual desulfurization tower model test bed. The effects of operating parameters on the particle removal efficiency were systematically investigated. The results show that the charge effect of spray droplets is greatly affected by spray flow rate and spray angle, and there is an optimal charge effect working condition value. With the increasing of particle size, the overall particle classification removal efficiency is increased. The particle removal efficiency is increased with the increasing of fluid flow rate and decreased with the increasing of flue gas flow rate, which is increased firstly with latter decreasing by increasing the dust concentration. The removal efficiency of particulate matter can be further improved after the droplet is charged, and the purpose of efficient removal of fine particulate matter can be realized. [ABSTRACT FROM AUTHOR]

The enrichment of polymetallic sulfide ore is a complex task. Fine grinding is carried out to reveal useful minerals, resulting in the formation of microparticles. It is difficult to achieve the floatation of microparticles and fine useful minerals are lost with flotation tailings. The problem of microparticle flotation can be solved by using air bubbles smaller than 50 µmin for the flotation process. Water-air microemulsion (WAME)of a frothersolution obtained using the generator was used as microbubbles. The effect of WAME on flotation was studied on polymetallic ores and gold-bearing ore from Kazakhstan deposits.The use of WAMEin the processing of polymetallic ore allowed for themaintenance of the quality of rougher concentrates, to increase the copper extraction in Cu-Pb rougherconcentrate by 7.41%, of lead by 5.98% in the copper-lead flotation cycle (Cu-Pb-Zn-Fe ore), copper extraction in Cu-Mo rougherconcentrate by 5.2%, and molybdenum by 4.7% in the copper-molybdenum flotation cycle (Cu-Mo ore). The indicators of flotation gold extraction into the gold-containing concentrate significantly improved in comparison with the basic mode when using the generator in rougher and scavenger flotation cycles: the quality increased by 5.3 g/t, and the extraction increased by 4.27%. [ABSTRACT FROM AUTHOR]

In this paper, −10 μm rutile and −30 μm garnet particles were selected as samples. The effects of different reagents on the flotation of rutile and garnet single minerals were studied, and the mechanism was analyzed by the contact angle, zeta potential, and Fourier transform infrared (FTIR) measurements. The flotation results show that an optimal recovery is obtained with benzohydroxamic acid (BHA) as the collector for rutile and sodium silicofluoride (SSF) as the inhibitor for garnet. Even with BHA having a good collecting performance for both rutile and garnet, there are still some differences. BHA greatly improves the hydrophobicity of rutile and garnet, and changes the chemical environment of rutile but not garnet. SSF significantly reduces the hydrophobicity of rutile and garnet, and slightly affects the environment in which BHA interacts with rutile. However, the above reagents and combinations have little effect on the surface chemical environment of garnet. [ABSTRACT FROM AUTHOR]

Modern pharmaceutical manufacturing emphasizes the need for sustainable technologies. Fine particles, including nano and micro-sized crystals, are increasingly important, particularly in the production of inhalation medicines. A novel application of freeze-dissolving technology has been demonstrated in the production of metronidazole, a model drug. This process involves creating frozen spherical particles by introducing a tert-butanol solution containing dissolved metronidazole into liquid nitrogen. Various antisolvents, such as n-hexane, n-heptane, ethanol, n-propanol, n-butanol, or n-pentanol, were employed to dissolve these frozen templates at temperatures ranging from 248.15 to 278.15 K. During this process, pre-formed metronidazole fine particles within the frozen template were released into the antisolvent solution. An alternative method involved placing these frozen particles into a vacuumed freeze dryer to extract the fine particles. The new freeze-dissolving technology can save 99% both energy and time compared to the traditional freeze-drying method, demonstrating a significantly more efficient and sustainable pharmaceutical manufacturing approach. The freeze-dissolving method is to dissolve the frozen solvent molecules in an antisolvent of the target medicine molecules, and, therefore, the solvent molecules is fast dissolved, but the fine particles will remain. The new technology has potential for large-scale manufacturing in pharmaceutical manufacturing, with low cost and high efficiency and suitability. [Display omitted] • A novel green and efficient method in production of nano and micro medicine crystals • Freeze-dissolving method: 99% less time and energy required as freeze-drying method • Metronidazole crystals were produced and separated by freeze-dissolving method • Metronidazole crystals were similar or smaller than those by freeze drying method [ABSTRACT FROM AUTHOR]

Monthly particle-phase ambient samples collected at six sampling locations in Yuxi, a high-altitude city on the edge of Southeast Asia, were measured for particle-associated PAHs. As trace substances, polycyclic aromatic hydrocarbons (PAHs) are susceptible to the influences of meteorological conditions, emissions, and gas-particulate partitioning and it is challenging job to precise quantify the source and define the transmission path. The daily concentrations of total PM2.5-bound PAHs ranged from 0.65 to 80.76 ng/m3, with an annual mean of 11.94 ng/m3. Here, we found that the concentration of PM2.5-bound PAHs in winter was significantly higher than that in summer, which was mainly due to source and meteorology influence. The increase of fossil combustion and biomass burning in cold season became the main contributors of PAHs, while precipitation and low temperature exacerbated this difference. According to the concentration variation trend of PM2.5-bound PAHs and their relationship with meteorological conditions, a new grouping of PAHs is applied, which suggested that PAHs have different environmental fates and migration paths. A combination of source analysis and trajectory model supported local sources from combustion of fossil fuel and vehicle exhaust contributed to the major portion on PAHs in particle, but on the Indochina Peninsula the large number of pollutants emitted by biomass burning during the fire season would affect the composition of PAHs through long-range transporting. Risk assessment in spatial and temporal variability suggested that citizens living in industrial areas were higher health risk caused by exposure the PM2.5-bound PAHs than that in other regions, and the risk in winter was three times than in summer. [ABSTRACT FROM AUTHOR]

For a winter pollution episode in Yinchuan, a city in Northwestern China, ambient aerosols were characterized using a real-time single-particle aerosol mass spectrometer (SPAMS). More than 160,000 individual particles analyzed with the SPAMS were classified into eight major categories on the basis of their mass spectral patterns: traffic emissions, biomass burning, dust, coal burning, industrial emissions, secondary inorganic, cooking, and others, all of which contribute to fine particles. The results revealed that coal burning (29.6%) and traffic emissions (23.4%) were the main sources during the monitoring period. Industrial emissions and secondary inorganic aerosols accounted for 16.6% and 14.0%, respectively. The SPAMS data indicated that the number concentration of the eight types of particles was markedly different in the different pollution cases, and higher number concentrations were discovered more often during pollution episodes. The three pollution cases were mainly caused by the accumulation of fine particles, mainly from traffic emissions, industrial emissions, and increased secondary inorganic conversion. [ABSTRACT FROM AUTHOR]

Because of growing demands for thermal expansion control in a local region, typically inner components of electronic devices, there is currently a great deal of interest in negative thermal expansion (NTE) fine particles. The spray-drying method without grinding produced micrometer-scale fine particles of pyrovanadate Cu1.8Zn0.2V2O7 showing a large negative coefficient of linear thermal expansion αL ~ –14 ppm/K equivalent to that of the bulk body. The solid-solution system Cu1.8Zn0.2V2–xPxO7 maintains the NTE functionality in a wide x compositional range. Phosphorus substitution contributes to cost reduction and to improvement of electrical insulation. Control of the structural phase transition in the phosphate analog Zn2P2O7 by substituting Mg for Zn realized a huge negative αL exceeding –60 ppm/K over a wide temperature range including room temperature. Because small particles are obtainable even with the conventional solid-phase reaction, the 1 μm level fine particles were obtained successfully using the pulverization method without degrading the function. It has high practicality because it is composed only of inexpensive and environmentally friendly elements such as Zn, Mg, and P. These NTE fine particles are expected to support great progress in thermal expansion control engineering. [ABSTRACT FROM AUTHOR]

In order to explore the mechanism of haze formation, the meteorological effect and chemical reaction process of the explosive growth (EG) of PM2.5 were studied. In this study, the level of PM2.5, water-soluble inorganic ions, carbonaceous aerosols, gaseous precursors, and meteorological factors were analyzed in Shanghai in 2018. The EG event is defined by a net increase of PM2.5 mass concentration greater than or equal to 100 μg m−3 within 3, 6, or 9 h. The results showed that the annual average PM2.5 concentration in Shanghai in 2018 was 43.2 μg m−3, and secondary inorganic aerosols and organic matter (OM) accounted for 55.8% and 20.1% of PM2.5, respectively. The increase and decrease in the contributions of sulfate, nitrate, ammonium (SNA), and elemental carbon (EC) to PM2.5 from clean days to EG, respectively, indicated a strong, secondary transformation during EG. Three EG episodes (Ep) were studied in detail, and the PM2.5 concentration in Ep3 was highest (135.7 μg m−3), followed by Ep2 (129.6 μg m−3), and Ep1 (82.3 μg m−3). The EG was driven by stagnant conditions and chemical reactions (heterogeneous and gas-phase oxidation reactions). This study improves our understanding of the mechanism of haze pollution and provides a scientific basis for air pollution control in Shanghai. [ABSTRACT FROM AUTHOR]

Recent years have witnessed growing research interest in applying rheology in grinding and flotation treatment of finely disseminated ores. Slurry rheology has long been identified as the comprehensive effect of inter-particle interactions, including their aggregation and dispersion states in slurry, which are more impactive under the fine-particle effect. In this regard, rheology has the potential to play a significant role in interpreting the flowing and deforming phenomena of inter-particle aggregates, particle-bubble aggregates, and flotation froth. Though much attention has been paid to the rheological effect in industrial suspension, this has not been the case for mineral grinding and flotation for fine particles. The influential mechanism of rheology on the sub-processes of mineral processing has not been systemically determined nor revealed thoroughly, thus the underpinning mechanism for enhancing the processing efficiency has been difficult to discover. This paper reviews the current application and importance of rheology in fine mineral processing, and the potential research direction in the field is proposed.

In this study, commercially available, milled, and heat-treated Mg(OEt)2 were used as the precursors in the synthesis procedure of industrially-favorable supported Ziegler–Natta catalysts. The effects of milling and heat-treatment of the support were completely investigated during the catalyst synthesis and polymerization using SEM, PSD, BET, DCS, and XRD techniques. It was found that despite the support treatments had no significant effect on the elemental analysis results of the catalysts, the morphology of the catalyst pores was very sensitive to support manipulation, and bottleneck-type pores were predominated in the catalysts which were made using the non-manipulated supports. On the other hand, the catalysts which were made using the milled and not-milled supports showed a clear difference between the activity, particle size, and particle size distribution of the catalysts. Also, a high level of stacking disorder and high grain size was observed in the crystal structure of the catalyst made using the commercially available support. In the following, competition between fragmentation and replication was investigated in the synthesized samples, and an attempt was made to link the stacking disorder (in the catalyst structure) to the ease of the fragmentation process. Finally, using practical observation, a mechanism was proposed to justify the changes in the morphology of the catalysts during synthesis procedures. We claimed that milling and especially heat-treating of the support leads to the ordering of the MgCl2 stacking structure. [ABSTRACT FROM AUTHOR]

• Fine particles control the exchangeable silica mobilization in the river. • Current sediment in the estuary contain less reactive silica than historical level. • Increased fine particle fraction affect silica sediment with forms variation in estuary. Changes in riverine sediment transport are an important part of land-sea geochemical cycling and further impact geochemical element fluxes in turbid rivers. However, as a vital nutrient element supporting primary productivity, silica mobilization from drainage in turbid rivers is overlooked. The turbid Yellow River has a strong ability to adsorb reactive silica, thereby exerting a substantial impact on the estuarine deposition of silica. Through an integration of monitoring databases, field sampling and historical hydrological data, we concluded that riverine fine particles control the exchangeable silica in the river and its estuary under soil erosion. Indoor simulation further revealed that the adsorbed content of exchangeable silica (ex-Si) in fine sediment constituted 35 % of total sediment matter. In addition, the transport of phosphorus and ex-Si was jointly regulated by fine sediment in global fluvial sediment transport, thereby exerting additional influence on the trophic structure of estuarine ecosystems. Against the backdrop of sediment budget deficit in the estuary, the heightened content of fine particles is depleting the silica storage from estuarine sediments. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Different particle size collocation of rutile and garnet affects on separation. • Sodium fluorosilicate selectively inhibits garnet, especially −15 μm size. • A 1:1 mixture of −74 μm rutile and −15 μm garnet was separated successfully. • A recovery of rutile with 92.33% was obtained. • Size ratio provided scientific direction for rutile and garnet separation. The flotation separation of fine minerals, including rutile, has long been a challenging research focus. This study selected rutile and garnet samples with size fractions of −15, −38, and −74 μm to investigate the impact of particle size on flotation separation. Infrared spectroscopy, Zeta potential analysis, adsorption capacity measurements, and high-speed camera were utilized to analyze the mechanism. Results indicate that a high-grade concentrate with recovery of 92.33 % was achieved by mixing −74 μm rutile and −15 μm garnet in a 1:1 ratio. Benzohydroxamic acid (BHA) collector primarily chemisorbs onto the surface of rutile particles. BHA's adsorption capacity on each particle size's rutile surface is significantly higher than that of garnet. Meanwhile, sodium fluorosilicate (SSF) exhibits the strongest inhibitory effect on −15 μm garnet particles. Additionally, adhesion between bubbles and −74 μm rutile is much stronger than that between bubbles and fine particles overall. These findings have significant reference value for improving eclogite-type rutile ore's fine particle separation. [ABSTRACT FROM AUTHOR]

In this study, the water-soluble inorganic ions (WSIIs) composition of fine particulate matter (PM2.5) was measured in the northern Nanjing city from 2015 to 2021. NH4+, NO3− and SO42− concentrations dominated in total WSIIs (Na+, NH4+, K+, Mg2+, Ca2+, Cl−, NO3− and SO42−), accounting for 87.8%. The nitrate with highest average concentration among all ions was 11.0 μg·m−3. Total WSIIs concentrations were higher in winter and lower in summer, with the highest levels in December (45.6 μg·m−3) and the lowest levels in August (15.1 μg·m−3). NO3−/SO42− was higher than 1, indicating the important contribution of mobile sources. The aerosols exhibited a weak acidic by the molar ratio of water-soluble anions and cations. Positive matrix factorization (PMF) analysis results showed that secondary nitrate and sulfate were the major pollution sources in December 2016 and 2020. The contribution of secondary nitrate in 2020 increased by 47.6% compared to 2016, while that of secondary sulfate decreased by 42.4%. The potential source contribution results demonstrated that for secondary aerosol concentrations, the contribution of regional transport from north of Anhui increased, while the contribution of local emissions decreased. The results from this study could contribute to the better prevention and control of regional air pollution in the future.

In the process of natural gas purification, common baffle demister has the problem of low separation efficiency and incomplete separation of fine droplets with the particle size in the range of 5–25 μm. This situation not only affects the quality of natural gas, but also causes corrosion and damage to gas equipment, and even seriously affects normal production. In order to solve these problems, we have carried out an innovative design for its structure. Based on the single‐stage baffle, vortex blades are added at the first straight plate section from the inlet and the second straight plate section in the middle to enhance the turbulent vortex degree and complexity of the flow field in this area and improve the probability of collision of small particles with the wall, thus achieving the purpose of improving the demisting efficiency. In this paper, performance of the new mist eliminator is analyzed and evaluated by means of experimental study and computational fluid dynamics (CFD) numerical simulation. The results show that when the flow rate is 3.5–5.5 m/s, total separation efficiency of the new mist eliminator for fine particles with a particle size of 5–25 μm is about 51.72%–86.13%, which is about 38.57%–55.76% higher than ordinary baffled mist eliminator. The separation efficiency of particles with a diameter of 5 μm is about 31.79%, increased about 26.15%. The separation efficiency of particles with a diameter of 10 μm is about 52.09%, increased about 37.21%. In addition, when the flow rate is 3.5–5.5 m/s, the pressure drop is increased by about 41.68–135.97 Pa. It could be concluded that the new type of mist eliminator could effectively improve the demisting efficiency of fine droplets. [ABSTRACT FROM AUTHOR]

In a flotation process, the particle–bubble and particle–particle interactions are key factors influencing collection efficiencies. In this work, the generalized Sutherland equation collision model and the modified Dobby–Finch attachment model for potential flow conditions were used to calculate the efficiencies of particle–bubble collision and attachment, respectively, for a flotation particle size of 80 μm. The negative effects of increase in the suspension viscosity due to the presence of fine particles on the flotation performance of fine particles have been reported, but there is no overarching model coupling the suspension viscosity and the flotation performance in the literature. Therefore, our study addressed this very important research gap and incorporated the viscosity model as a function of solid concentration, shear rate, and particle size into a flotation rate constant model that was proposed and conducted for the first time. This is quite a unique approach because the previously developed flotation rate constant model has never been coupled with a suspension rheology model taking into account the solid particle concentration and shear rate, although they are very important flotation variables in practice. The effect of the presence of ultra-fine/fine particles on the viscosity of the suspension and the flotation efficiencies and rate constant of flotation particle size of 80 μm were also investigated in order to better understand the mechanism of the problematic behavior of ultra-fine/fine particles in flotation. This coupling study started with the simplest case: flowing suspensions of inert, rigid, monomodal spherical particles (called hard spheres). Even for hard spheres, the effect of shear rate and particle size which produces deviation from the ideal case (constant viscosity at constant temperature regardless of shear rate) was clearly identified. It was found that the suspension viscosity increases with the decrease in fine/ultra-fine particle size (i.e., 1 µm–8 nm) and at higher solid particle concentration. Then, the colloidal particle suspensions, where interparticle forces play a significant role, were also studied. The suspension viscosity calculated for both cases was incorporated into the flotation efficiencies and rate constant models and discussed in terms of the effects of the presence of ultra-fine and fine particles on the flotation kinetics of flotation particle size of 80 μm. [ABSTRACT FROM AUTHOR]

Background: Our hypothesis was that exposure to fine particulate matter (PM2.5) is related to abnormal cord insertion, which is categorized as a form of placental implantation abnormality. We investigated the association between exposure to total PM2.5 and its chemical components over the first trimester and abnormal cord insertion, which contributes to the occurrence of adverse birth outcomes.Methods: From the Japan Perinatal Registry Network database, we used data on 83 708 women who delivered singleton births at 39 cooperating hospitals in 23 Tokyo wards (2013-2015). We collected PM2.5 on a filter and measured daily concentrations of carbon and ion components. Then, we calculated the average concentrations over the first trimester (0-13 weeks of gestation) for each woman. A multilevel logistic-regression model with the hospital as a random effect was used to estimate the odds ratios (ORs) of abnormal cord insertion.Results: Among the 83 708 women (mean age at delivery = 33.7 years), the frequency of abnormal cord insertion was 4.5%, the median concentration [interquartile range (IQR)] of total PM2.5 was 16.1 (3.61) μg/m3 and the OR per IQR for total PM2.5 was 1.14 (95% confidence interval = 1.06-1.23). In the total PM2.5-adjusted models, total carbon, organic carbon, nitrate, ammonium and chloride were positively associated with abnormal insertion. Organic carbon was consistently, and nitrate tended to be, associated with specific types of abnormal insertion (marginal or velamentous cord insertion).Conclusions: Exposure to total PM2.5 and some of its components over the first trimester increased the likelihood of abnormal cord insertion. [ABSTRACT FROM AUTHOR]

Biocompatible polymer fine particles would be promising carriers for a drug delivery system. Although biocompatible polymer fine particles containing active pharmaceutical ingredients are typically produced by oil in water (O/W) emulsion castings, this method has several limitations, such as the significant solubility of both the polymer and API being studied in typical less-polar solvents that are immiscible with aqueous media is required to form O/W emulsions. Herein, we demonstrate that ternary system-based oil in oil emulsion castings can produce porous and spherical fine particles of biocompatible ethyl cellulose (EC) with a narrow size distribution. The fine particles possess macropores with average diameter of 0.43 μm and are quantitatively obtained from commercial EC. Several analytical techniques, including transmission electron microscopy, scanning electron microscopy in combination with energy dispersive X-ray spectroscopy, and X-ray computed tomography scan have revealed that pore networks are constructed throughout the particles, which provides the large pore volumes. [Display omitted] • Porous and spherical biocompatible ethyl cellulose fine particles are produced. • The fine particles have a narrow size distribution. • The fine particles possess macropores with average diameter of 0.43 μm. • The fine particles are thoroughly studied using several analytical techniques. • A ternary system-based emulsion casting is a key enabler for the work. [ABSTRACT FROM AUTHOR]

Abstract Background While many studies reported the association between long-term exposure to particulate matter air pollution (PM) and cardiovascular disease (CVD), few studies focused on incidence with relatively high-dose exposure using a nationwide cohort. This study aimed to investigate the association between long-term exposure to PM10 and PM2.5 and incidence of CVD in a nationwide and population-based cohort in South Korea where the annual average concentration of PM2.5 is above 20 μg/m3. Methods We selected 196,167 adults in the National Health Insurance Service-National Sample Cohort (NHIS-NSC) constructed based on the entire South Korean population. Incidence of four CVD subtypes including ischemic heart disease (IHD), myocardial infarction, heart failure, and stroke, and total CVD including all four was identified as the first diagnosis for 2007–2015. To assess individual exposures, we used annually-updated district-level residential addresses and district-specific PM concentrations predicted by a previously developed universal kriging prediction model. We computed individual-level long-term PM concentrations for four exposure windows: previous 1, 3, and 5 year(s) and 5 years before baseline. We applied time-dependent Cox proportional hazards models to estimate hazard ratios (HRs) of incident CVDs per 10 μg/m3 increase in PM10 and PM2.5 after adjusting for individual- and area-level characteristics. Results During 1,578,846 person-year, there were 33,580 cases of total incident CVD. Average PM10 and PM2.5 concentrations for the previous 5 years were 52.3 and 28.1 μg/m3, respectively. A 10 μg/m3 increase in PM2.5 exposed for the previous 5 years was associated with 4 and 10% increases in the incidence of total CVD (95% confidence interval: 0–9%) and IHD (4–16%), respectively. HRs tended to be higher with earlier exposure for IHD and more recent exposure for stroke. The estimated shape of the concentration-response relationship showed non-linear patterns. We did not find evidence of the association for PM10. Conclusions Using a population-based nationwide cohort exposed to relatively high PM concentration, this study confirmed the association between PM2.5 and CVD incidence that was reported in previous studies mostly with low-dose environments. The magnitude and the shape of the association were generally consistent with previous findings.

Zhengzhou is one of the most heavily polluted cities in China. This study collected samples of PM2.5 (atmospheric fine particulate matter with aerodynamic diameter ≤ 2.5 μm) at five sites in different functional areas of Zhengzhou in 2016 to investigate the chemical properties and sources of PM2.5 at three pollution levels, i.e., PM2.5 ≤ 75 μg/m3 (non-pollution, NP), 75 μg/m3 < PM2.5 ≤ 150 μg/m3 (moderate pollution, MP), and PM2.5 > 150 μg/m3 (heavy pollution, HP). Chemical analysis was conducted, and source categories and potential source region were identified for PM2.5 at different pollution levels. The health risks of toxic elements were evaluated. Results showed that the average PM2.5 concentration in Zhengzhou was 119 μg/m3, and the sum of the concentrations of SO42−, NO3−, and NH4+ increased with the aggravation of pollution level (23, 42, and 114 μg/m3 at NP, MP, and HP days, respectively). Positive Matrix Factorization analysis indicated that secondary aerosols, coal combustion, vehicle traffic, industrial processes, biomass burning, and dust were the main sources of PM2.5 at three pollution levels, and accounted for 38.4%, 21.6%, 16.7%, 7.4%, 7.7%, and 8.1% on HP days, respectively. Trajectory clustering analysis showed that close-range transport was one of the dominant factors on HP days in Zhengzhou. The potential source areas were mainly located in Xinxiang, Kaifeng, Xuchang, and Pingdingshan. Significant risks existed in the non-carcinogenic risk of As (1.4–2.3) for children at three pollution levels and the non-carcinogenic risk of Pb (1.0–1.4) for children with NP and MP days. [ABSTRACT FROM AUTHOR]

In this study, the flotation of rhodochrosite fines induced by octyl hydroxamic acid (OHA) as hydrophobic agglomerates was investigated through the measurements of micro-flotation, laser diffraction, microscopy observations and zeta potential. The experimental results showed that the apparent particle size and morphology of rhodochrosite agglomerates were greatly affected by OHA concentration and stirring speed. Bigger agglomeration particle size and more regular agglomerates could be obtained at the OHA concentration of 60 mg/L, and appropriate stirring speed was required to form an optimum particle size of agglomerates for micro-flotation. The increased apparent particle size of rhodochrosite was favorable for micro-flotation recovery even though the particles were negatively charged in the presence of OHA. It's considered that OHA adsorbed on the surface of rhodochrosite through zeta potential results as well as the species distribution analysis of OHA and rhodochrosite. [Display omitted] • Rhodochrosite agglomeration induced by OHA was investigated. • Agglomerates size was closely related to mechanical agitation. • Correlation of rhodochrosite aggregation with flotability was presented. • OHA could be well adsorbed on the surface of rhodochrosite. [ABSTRACT FROM AUTHOR]

Algae contain essential plant nutrients, various microelements and bioactive substances promoting full supply of nutritious substances to plants during their entire vegetation period. They are attractive because their cultivation does not require plots of agricultural land, and they use carbon dioxide as well as nitrogen and phosphorus compounds to accumulate biomass. Besides, they are environment-friendly and their use makes it possible to create a closed cycle. Chemical composition of algae shows that they are suitable for use as a fertilizer component, because they have no aluminium or silicon, and heavy metal concentration does not exceed permitted limits. The particles 106 – 212 μm in size contain mostly (65.4 %) algae, and are irregular in shape. By using algae, fine sediment remains in suspension 4 times longer and settles slowly to the bottom (with 4 % clay additive, the solid phase settles in 40 min, and with 4 % algae – in 130 min). Stable NPK 12-4-18 suspension fertilizers suitable for use during a warm period were obtained with 3.5 % algae additive. The main properties of such suspensions are: pH 6.3; crystallization temperature + 8.21 °C; density – 1226 kg/m3, viscosity – 7.32 mm2/s.

Exposure to airborne particulate matter (PM) is related to the increased risk of several diseases, including chronic and allergic rhinitis. We have previously shown that atmospheric endotoxin level was positively associated with the number of emergency department visits for asthma even after adjusting for meteorological factors, suggestive of the significant association between atmospheric endotoxin level and asthma exacerbation. Whether atmospheric endotoxin level is related to inflammatory response induction is, however, unclear. Here, we established stable cell lines to determine the promoter activity of the genes encoding pro-inflammatory cytokines such as tumor necrosis factor alpha, interleukin 6 (IL6), and IL33 by transfection of each reporter plasmid into rat tracheal epithelial EGV-4 T cells. These cells could measure the inflammatory response induced by endotoxin treatment more easily, rapidly, and sensitively than the conventional system using immunodetection assays. Furthermore, we revealed a relationship between atmospheric endotoxin level and inflammatory response induction. Thus, the system established herein may serve as a promising tool to monitor inflammatory response induced upon PM exposure.

The main objectives of this study are to directly prepare surfactant-free aqueous dispersions of submicron-sized ferrocene (ADSMFs) via an antisolvent-crystallization technique and to explore their fire-suppression ability. In this study, for the antisolvent crystallization, alcohol (ethanol and 1-propanol) and water were used as solvents and antisolvent, respectively. Particle-size measurements confirmed that the ferrocene diameters in most ADSMFs were in submicrometer (410 nm–2.92 μm). Spray droplet-size and spray flux measurements demonstrated no significant variations among the sprayed ADSMFs, allowing a direct comparison of the fire-suppression abilities among the ADSMFs. Fire-suppression tests involving n-heptane pool fires indicated that (i) the ADSMFs exhibited shorter extinguishing times by a factor of ca. 5 than the conventional wet-chemical agent and (ii) the fire-extinguishing ability was improved by reducing the ferrocene-particle sizes from microns to submicrons; however, no significant effects of the ferrocene concentration and diameter on the ADSMF's extinguishing times were observed in the ferrocene diameter range of submicrons. The interesting finding (ii) probably arises from the ease with which ferrocene readily decomposes/breaks down and then generates active inhibiting iron species in flames.

The enrichment of polymetallic sulfide ore is a complex task. Fine grinding is carried out to reveal useful minerals, resulting in the formation of microparticles. It is difficult to achieve the floatation of microparticles and fine useful minerals are lost with flotation tailings. The problem of microparticle flotation can be solved by using air bubbles smaller than 50 µmin for the flotation process. Water-air microemulsion (WAME)of a frothersolution obtained using the generator was used as microbubbles. The effect of WAME on flotation was studied on polymetallic ores and gold-bearing ore from Kazakhstan deposits.The use of WAMEin the processing of polymetallic ore allowed for themaintenance of the quality of rougher concentrates, to increase the copper extraction in Cu-Pb rougherconcentrate by 7.41%, of lead by 5.98% in the copper-lead flotation cycle (Cu-Pb-Zn-Fe ore), copper extraction in Cu-Mo rougherconcentrate by 5.2%, and molybdenum by 4.7% in the copper-molybdenum flotation cycle (Cu-Mo ore). The indicators of flotation gold extraction into the gold-containing concentrate significantly improved in comparison with the basic mode when using the generator in rougher and scavenger flotation cycles: the quality increased by 5.3 g/t, and the extraction increased by 4.27%.

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From a public health point of view, years of life lost (YLL) is a more important index than the number of deaths to evaluate the effect of risk factors. The objective of the present study was to estimate the burden of disease including years of life lost (YLL) and expected life remaining (ELR) attributed to long-term exposure to PM2.5 in Ahvaz, one of the most polluted cities of the world, during March 2014 through March 2017. AirQ + software was used for the estimation of YLL and ELR due to all natural causes of death. Hourly concentrations of PM2.5 were acquired from the Department of Environment (DoE) of Ahvaz. Several steps were performed to validate the raw air quality data. Only the monitors were included that had minimum data completeness of 75%. Two age groups were selected for this study, including 0–64 and 65 < years. The life table approach was used to estimate YLL and ELR. Annual averages of PM2.5 were 5.2–8 times higher than the air quality guideline (10 μg/m3) set by WHO for long-term exposure to PM2.5. In total, PM2.5 has caused 234,041 years of life lost due to mortality. About 84% of YLLs were attributed to people older than 65 years old. The YLLs of men were higher than those for women. The YLLs in the third year were greater than the first two years. PM2.5 has caused the average age of total population, people aged 0–64 years old, and people > 65 years old decreased by 2.5, 3, and 1.6 years, respectively. These studies indicated that people in a city that the air quality is highly affected by dust storms, industrial emissions, and urban air pollution are significantly at risk. Air pollution control strategies and actions should be designed and executed to improve the quality of ambient air. [ABSTRACT FROM AUTHOR]

Background: Ambient fine particle (PM2.5) pollution is an important public health problem in China. Short-term ambient PM2.5 exposure is associated with increased mortality of respiratory diseases. However, few evidence was available on the effect of exposure to ambient PM2.5 on the years of life lost (YLL) from respiratory diseases in the elderly. Furthermore, birth season which is frequently applied as a proxy for environmental exposure in early life may influence the health outcome in the later life. Nevertheless, the modification effect of birth season on the relationship of PM2.5 exposure and respiratory health need to be explored. Methods: A time-stratified case-crossover design was used to analyze YLL from respiratory diseases in the elderly related to ambient PM2.5 exposure between 2013 and 2016 in Ningbo, China. The modification effect of birth season was explored by subgroup comparisons between different birth seasons. Results: Each 10 μg/m3 increase in daily ambient PM2.5 was associated with an increment of 1.61 (95% CI 0.12, 3.10) years in YLL from respiratory diseases in the elderly population. Individuals who were born in winter had significantly higher YLL from respiratory diseases associated with ambient PM2.5 exposure than those who were born in other seasons. Conclusions: Birth season which reflects the early-life PM2.5 exposure level that may influence the lung development has a potential effect on the disease burden of respiratory diseases related to ambient PM2.5 exposure in later life. The results would provide theoretical basis to protect vulnerable population defined by birth season when exploring the adverse effects of ambient PM2.5 in the respiratory health. [ABSTRACT FROM AUTHOR]