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We have studied soils of the western coast of the Chivyrkui and Barguzin bays on the Svyatoi Nos Peninsula, which is the largest peninsula of Lake Baikal in the Republic of Buryatia. Morphogenetic characteristics of soils on the main types of coasts of the peninsula—low abrasion with isolated lagoons, low abrasion, accumulative, and ingression—are given. Rocks in the basis of the coasts of the bays are an important factor of soil formation. It is shown that the genesis of soils depends on the distance from the lake and the altitude, resulting in the difference in their structure and properties. The soils are not directly affected and flooded by lake water due to high mountainous coasts, which are often rocky with steep slopes. Soil formation beyond the floodplain regime is also typical for soils of the closest to the lake level: soddy podzols, which occupy low shores of accumulative types. The particle-size composition of the studied soils varies widely from loose sand to light clay. The common properties of soils include acid and weakly acid reaction, the regressive-accumulative type of humus distribution, and differentiation of bulk oxides along the profile. The revealed evidences of podzolization in Al–Fe-humus soils and of clay accumulation in brown soils are related to sufficient moistening of the coasts and the warming effect of the lake water mass. The research results may be used in landscape planning in territorial organization and monitoring work in recreation areas. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar could reduce 6% CO 2 , 66% CH 4 and 32% NH 3 emissions. • Particle size distributions of compost tend to be smaller. • Wheat straw biochar improves proportion of < 200 μm size distributions. • Wheat straw biochar improves aerobic layer thickness (Lp) and oxygen infiltration. • Along the compost material to biochar, aromatic compounds are gradually increasing. In recent research, biochar has been proven to reduce the greenhouse gases and promote organic matter during the composting. However, gas degradation may be related to the microstructure of compost. To investigate the mechanism of biochar additive, composting was performed using swine manure, wheat straw and biochar and representative solid compost samples were analyzed to characterize the mixed biochar and compost particles. We focused on the microscale, such as the particle size distributions, surface morphologies, aerobic layer thicknesses and the functional groups. The biochar and compost particle agglomerations gradually became weaker and the predominant particle size in the experiment group was < 200 μm. The aerobic layer thickness (Lp) was determined by infrared spectroscopy using the wavenumbers 2856 and 1568 cm−1, which was 0–50 μm increased as composting proceeded in both groups. The biochar increased Lp and facilitated oxygen penetrating the compost particle cores. Besides, in the biochar-swine manure particle interface, the aliphatic compound in the organic components degraded and the content of aromaticity increased with the composting process, which was indicated by the absorption intensity at 2856 cm−1 decreasing trend and the absorption intensity at 1568 cm−1 increasing trend. In summary, biochar performed well in the microscale of compost pile. [ABSTRACT FROM AUTHOR]

Summary: The feasibility of predicting at laboratory‐scale the fouling propensity of orange juice suspended particles based on their physical properties, was investigated. Samples were generated from mixtures of two selected size class of large and fine particles. The particle‐size distribution, rheological and textural properties of these samples were characterised as well as their fouling propensity using permeability test. Qualitative and quantitative statistical analyses revealed significant correlations between specific resistance to filtration (SRF) and hydration velocity (Vh), statistical diameter (D90) and shear strain at flow point (ɣf). Partial Least Square method allowed to discriminate contrasted values of log(SRF) of suspended particles using a simplified model (R2 = 0.79; RMSEC; RMSECV <20% of SRF mean; RPD = 1.6), based on 5 predictor variables (Vh, ɣf, D90, D[4;3] and Ec). These findings, offer new prospects to guide the choice of pretreatment or specific operating conditions to improve the performance of fruit juices microfiltration. [ABSTRACT FROM AUTHOR]

Karst aquifers are important resources for drinking water supply and are very vulnerable to contamination. Microbial concentrations at karst springs, in particular, often vary quickly over a short period of time. In this study, the response of microbial water quality and particle-size distribution of two alpine karst springs to rainfall events was investigated to test and validate parameters that can be used as early-warning systems for fecal contamination. At both investigated karst springs, total organic carbon, particle-size distribution (especially small particle fractions), and particle load show a good correlation to the fecal indicator bacteria E. coli and can therefore be used as a real-time indicator of fecal contamination at the investigated springs. In addition to conventional bacterial determination methods, the β-D-glucuronidase activity, which can be measured in near real-time, was used as a novel indicator parameter for fecal contamination. At the event scale, the β-D-glucuronidase (GLUC) activity shows a good correlation to E. coli and can be used as an additional real-time indicator of fecal contamination. For the studied springs, when they show two peaks in turbidity and small particles, these two parameters are suitable for an early warning system because the bacterial contamination occurs during the secondary peak of these parameters. These results highlight the vulnerability of karst aquifers and demonstrate the applicability of advanced measurement techniques in detecting fecal contamination in real-time, which is especially important given the time-consuming nature of conventional bacterial detection methods. [ABSTRACT FROM AUTHOR]

The quality of lime is generally estimated by traditional methodologies, which consist of coarse granulometry and chemical reactivity determinations. Performing a detailed chemical/mineralogical and fine granulometric characterization is the objective of this study. Fifteen lime samples, from an original 52 commercial samples, were analyzed by their granulometric profile (GP) and chemical-mineralogical compositions to discuss limestone quality inside the tree group of traditional efficiency neutralizing power (ENP) and Mg contents. The lime reactivity was estimated using laser diffraction under water and acid solution (1 mol L−1 HCl). The grain-size distribution ranged from 0.563 to 1124 µm and the GP was associated with the chemical and mineralogical compositions. Samples with high ENP (>99%) presented differences in GP regarding Mg contents. Lime with low ENP presents the most varied mineral assemblage, while calcite and dolomite were the predominant minerals in high-ENP samples. Samples containing high Mg were the most sensitive to the acid solution, suggesting great reactivity. This work contributes to a better understanding of limestone quality than routine analyses performed so far. Additionally, the use of the laser diffraction method promotes a rapid lime reactivity test for liming purposes. [ABSTRACT FROM AUTHOR]

The effect of temperature in the range from 4 to 50°C on the water retention curves in five soil samples of different textures was studied. The method of thermostatic centrifugation on the basis of a laboratory centrifuge Sigma 2-KHL (Germany) was used, which made it possible for the first time to evaluate the influence of the temperature factor in a wide range of the thermodynamic potential of water from 0 to 3000 J/kg. Using statistical methods, two physically-based hypotheses of the relationship between temperature and thermodynamic potential—"capillary" (a decrease in water retention with increasing temperature) and "surface forces" (temperature invariance of water retention)—were evaluated. A representative analysis of 4–8 repetitions of each experiment did not reveal a statistically significant effect of the temperature factor on the water retention curves in all the studied samples. A fundamental explanation of the obtained results is proposed on the basis of Polanyi's potential theory and the ion-electrostatic mechanism of disjoining water pressure according to Deryagin. [ABSTRACT FROM AUTHOR]

This study introduced a four-way CFD-DEM coupling approach to simulate the shear-induced particle migration (SIPM) mechanism leading to formation of the lubrication layer (LL) during concrete pumping. The CFD-DEM simulations considered the coupled effect of concentration (10 %–40 %) and wide size distribution (1–17 mm) of aggregate and rheology of the mortar for forces between the suspending matrix and the particles (and vice versa), as well as force transmission directly between particles (and the pipe wall). The formation of the LL was successfully simulated through a more realistic understanding the SIPM mechanism and rheological evaluation across the pipe with comparable calculation times compared to the one-way coupled DEM approach, especially for high concentrations. The simulated LL thicknesses of 0.8–2.7 mm compared well with experimental values. The flow rate and rheological heterogeneity of pumped concrete, and rheology of the LL, were found mostly controlled by the granular-skeleton characteristics rather than the suspending-matrix rheology. • Four-way CFD-DEM coupling to simulate concrete pumping as a multiphasic suspension • Modeling shear-induced particle migration leading to formation of lubrication layer • Superior accuracy of CFD-DEM coupling approach to simulate SIPM compared to DEM • Coupled effect of PSD and φ/φ max of aggregate and mortar rheology on pumpability • Characterization of lubrication layer in terms of rheological properties and thickness [ABSTRACT FROM AUTHOR]

[Display omitted] • Modelling of H 2 -TPR patterns considering the effect of particle size distribution. • Three pure metal oxides were used to selecte the kinetic reaction models. • Three reaction kinetic models were considered. • Information of the metal oxide is derived from the Prout and Tompkins model. Hydrogen temperature-programmed reduction (H 2 -TPR) has become a very useful and common technique for the chemical characterization of solids as it is sensitive to the study of reducible species in catalysis and is considered to be a fingerprint for the reducibility of metal oxide catalysts. However, although modeling of H 2 -TPR patterns has been extensively studied, little attention has been paid to the effect of particle-size distribution (PSD). The complexity of modeling H 2 -TPR patterns arises from the fact that the chemistry of metal oxide reduction depends on several factors, including particle size, nature of the support material and confinement within the porous structure, amongst others. In order to identify the kinetic reaction model governing the reduction of certain metal oxides and to explore the effect of PSD, pure metal oxides that only exhibited the particle size difference effect were used to model the H 2 -TPR patterns. Kinetic and thermodynamic data, which are very useful for characterizing heterogeneous catalysts, were obtained from this study. This work presents a simple procedure for modeling H 2 -TPR patterns of various metal oxides (i.e., CuO, Ag 2 O, and NiO) used as active phases in several reactions of environmental and energetic interest using several solid-state reaction kinetic models and considering their PSDs. The results obtained show that modeling the H 2 -TPR profiles provides information regarding the PSD of metal oxide catalysts that undergo a single-step reduction and only present the particle size difference effect. [ABSTRACT FROM AUTHOR]

In order to study the relationship between multifractal characteristics of particle-size distribution (PSD) and unsaturated hydraulic conductivity, taking the Hunan clay as the research object, we analysed the particle composition of the whole particle size range by a laser particle size analyser, and discussed the multifractal characteristics of PSD by using the fractal theory. The soil–water characteristic curve (SWCC) and unsaturated hydraulic conductivity were measured by the pressure plate instrument and instantaneous profile method, and the unsaturated hydraulic conductivity was predicted by the fractal model. The results show that the fractal dimension D is not a fixed value for the Hunan clay with the whole particle size range, which exhibits obvious multifractal characteristics. The value of fractal dimension D is closely related to the investigated particle size range. The larger the particles in the particle size range, the larger the corresponding fractal dimension D. By comparing the measured and predicted values of the unsaturated hydraulic conductivity, it is found that the prediction results of fractal dimension D for unsaturated hydraulic conductivity with different particle size ranges are quite different, and that those results with larger particle size ranges are more reasonable. [ABSTRACT FROM AUTHOR]

In this study, sodium methylsilicate and lime were selected to prepare the same proportion of Imitation Site Soil, and according to the principle of carbonation reaction of restoration materials, the effect of carbonation reaction on the performance of restoration soil of earthen sites was studied. The study has good significance for the conservation and restoration of earthen sites. The samples were cured with CO2 concentration and curing age as variables. After curing, the samples were tested to determine their water-resistant properties, uniaxial compressive strength, and pH value and a micro scanning electron microscope was used. The results indicated that the carbonation reaction can quickly improve the water resistance and compressive strength of imitation site soil, and reduced the water absorption by 16.67% compared to the specimens conditioned at 0.03% CO2 concentration. The UCS of specimens at 5%, 10%, and 15% CO2 concentrations increased by 72.22%, 131.19%, and 219.27%, respectively, compared with those at 0.03% CO2 concentration after the specimens were environmentally maintained in the carbonation chamber at 0.03%, 5%, 10%, and 15% CO2 concentrations for 120 h, respectively. The internal particle gradation of the imitation site soil improved after carbonation. These results provide a basis for improving the restoration technology of earthen sites. [ABSTRACT FROM AUTHOR]

This article deals with the fractionation of wood dust by sieve after sanding. Dust from untreated beechwood was compared to dust from thermally modified beechwood (at 200 °C for 3 h). The authors hypothesized that the thermal modification changes the particle size distributions of the dust sieve fractions and that all the dust sieve fractions contain the finest particles, which are suspendable in the air and are potentially respirable. To obtain dust for testing, both wood materials were sanded with P120 paper at a belt speed of 14.5 m/s and a pressure of 0.65 N/cm² . A set of sieves with aperture sizes of 25, 80, and 250 µm were used to separate the dust into sieve fractions with grain sizes less than 25 µm, 25 to 80 µm, 80 to 250 µm, and greater than 250 µm. The content of the finest particles in the fractions was measured via a laser particle sizer. Both dusts had similar particle size distributions. In addition, each investigated fraction of both dusts contained the finest particles, i.e., less than 10 µm. It follows that the laser analysis method may be necessary to correctly assess the occupational risk at a sanding. [ABSTRACT FROM AUTHOR]

For a diesel engine, it is crucial and difficult to reduce the original particle matter emissions. Although the emission of particle matter can be reduced effectively, the engine internal purification and external purification measures can increase the cost and manufacturing process. Therefore, designing and improving oil products has become the most effective way to reduce emissions. This study compared the combustion and particle matter characteristics of diesel, diesel–rocket propellant-3 (RP3) (WDBF) with 20%, 40%, and 60% rocket propellant-3 in a single-cylinder compression ignition engine. The brake power, brake thermal efficiency (BTE), and particle matter concentration of the diesel engine were determined experimentally at three speeds (2,000, 2,700, and 3,600 r·min−1) at engine loads of 10%, 50%, and 100%. The results demonstrated that with the increase of the RP3 blending ratio, the density, cetane number, kinematic viscosity, and surface tension of diesel–RP3 WDBF decreased, whereas the low heating value increased, and T10, T50, and T90 (10%, 50%, and 90% volume distillation temperatures, respectively) decreased. The addition of RP3 to diesel increased the peak number concentration of small particles under the test conditions. The total particle number concentration (TPNC), total particle volume concentration (TPVC), and total particle mass concentration (TPMC) decreased by 14.1%–53.4%, 22.5%–75.3%, and 21.3%–39.3%, respectively, compared with that of using diesel. The change was obvious with the increase of the RP3 ratio and without impact on brake power and BTE. [ABSTRACT FROM AUTHOR]

A new method to estimate the size distribution of non‐interacting colloidal particles from small‐angle scattering data is presented. The method demonstrates that the distribution can be efficiently retrieved through features of the scattering data when plotted in the Porod representation, thus avoiding the standard fitting procedure of nonlinear least squares. The present approach is elaborated using log‐normal and Weibull distributions. The method can differentiate whether the distribution actually follows the functionality of either of these two distributions, unlike the standard fitting procedure which requires a prior assumption of the functionality of the distribution. After validation with various simulated scattering profiles, the formalism is used to estimate the size distribution from experimental small‐angle X‐ray scattering data from two different dilute dispersions of silica. At present the method is limited to monomodal distributions of dilute spherical particles only. [ABSTRACT FROM AUTHOR]

Particle-size distribution is a critical part of soil description, which is commonly measured using pipette and hydrometer methods. However, a recently developed technique, called the integral suspension pressure method, allows for the measurement of continuous particle-size distribution based on Stokes' law. The objective of this study was to evaluate the applicability of the integral suspension pressure method for measuring particle-size distribution, as an alternative to the standard hydrometer procedure. The integral suspension pressure method was tested by using a soil dataset with a wide range of organic matter contents (0.22-12.0%). Forty-nine samples were analysed with a hydrometer after organic matter removal and the results were compared with those obtained using the integral suspension pressure method. Through comparing the integral suspension pressure and hydrometer measurements, root mean square error values of 8.9, 8.1, and 11.9% were observed for sand, silt, and clay, respectively. The clay fraction was underestimated throughout the entire range of measurements. Conversely, the silt content was overestimated over the whole range of measurements, especially in samples with more than 36% silt. When compared to the hydrometer method, integral suspension pressure integral suspension pressure exhibited a tendency to misclassify the soil texture of clay loam samples but was accurate for sandy loams. [ABSTRACT FROM AUTHOR]

The capillary effect in polydisperse porous systems of soils and sediments is discussed. This effect is quantified using a new fundamental model of capillary rise depending on the parameters of dispersion of soil particles, soil bulk density, density of soil solid phase, wettability, and the amount of tightly bound water. In contrast to a well-known Jurin's law, the model takes into account the particle-size distributions and the change in pore size associated with soil density. The model adequately predicts the capillary rise in both artificial monodisperse porous systems and real soils with the particle size ranging from 0.006 to 1 mm. The effects of natural and synthetic hydrophobizers on the kinetics and maximum height of capillary rise are examined. The laboratory and field data on the efficiency of imperfect (with hydraulic connection) and perfect (with its rupture) capillary barriers are compared to the Hydrus-1D predictive modeling data. The results are used to evaluate the capillarity in soils and to design soil constructions with capillary barriers. [ABSTRACT FROM AUTHOR]

A mathematical model reflecting the evolution of both particle breakage and particle-size distribution (PSD) for rockfill subjected to triaxial shear has been proposed in this article. First, the PSD of a soil is expressed by a gradation equation which has been shown to be widely applicable by comparison with a large amount of test data from soils encountered in practice. Then two particle breakage factors Bg and Br are suggested and proved to be two suitable breakage factors in the model. Mathematical relationships between Bg, Br and the gradation equation's parameters b and m are derived. Then, correlations between the two breakage factors, effective mean normal stress and generalised shear strain during shearing are expressed by empirical functions, with several drained triaxial compression test data verifying the applicability. The inter-relationships of particle breakage, PSD and stress state of rockfill are thereby established, providing what is termed the PSD evolution model. Additionally, the proposed PSD evolution model is verified by successfully predicting the particle breakage factors and PSDs of rockfill triaxial specimens. [ABSTRACT FROM AUTHOR]

The particle size distribution of the soil fines content and mean particle size (d50) are used in a number of soil property relationships and in the soil classification. To analyze and model particle size distribution (PSD) using a modified version of Vipulanandan p-q model, some data collected from several research studies and the results of prediction were compared with the Fredlund and Logistic Growth models used in the literature. The Vipulanandan p-q model parameters were correlated very well to various indices of PSDs such as the diameter in the particle size distribution curve corresponding to 10%, 30%, 60%, and 90% of finer (d10, d30, d60, and d90 respectively), mean particle size the diameter in the particle size distribution curve corresponding to 50% finer (d50), and fines content (F%). There was no correlation between Fredlund model and Logistic Growth model parameters with soil PSD properties. Based on the coefficient of determination (R2) and root mean square error (RMSE), the proposed Vipulanandan p-q model was in a very good agreement with the experimental results. The relationship between fines content and d50 were also generalized using the Vipulanandan p-q model to quantify the upper and lower groutability limits for sandy soils. [ABSTRACT FROM AUTHOR]

A printed-circuit board (PCB) powder sample obtained by cryo-milling was characterized to elucidate its elemental composition and the chemical states of its components for metal recovery. The major elements (Al, Si, Ca, Fe, Ni, Cu, Sn, Ba, and Pb) were characterized by X-ray fluorescence and X-ray diffraction analyses. The particle-size distribution histogram of the ground PCB exhibited two high frequencies corresponding to the 27–45 μm and 250–500 μm fractions, and the median size was 125 μm. The elemental components of the PCB particles were categorized into four groups: (1) the elements concentrated in the coarse-particle fraction (Cu), (2) elements tending to accumulate in the moderately sized-particle fraction (Br and Sn), (3) elements concentrated in the fine-particle fraction (Fe), and (4) elements that prefer to concentrate in both the coarse- and fine-particle fractions or no particular fraction (Al, Si, Ca, Ni, Ba, and Pb). Based on the diffraction patterns of each fraction, Al existed as metallic Al and Al 2 O 3 (corundum), Si as metallic Si, Ca as CaCO 3 (calcite), Fe as Fe 3 O 4 (magnetite), Ni as metallic Ni, Cu as metallic Cu, Ba as BaTiO 3 (barium titanate), and Pb as PbZrO 3 (lead zirconate). Moreover, multivariate statistical analyses (principal component and cluster analyses) revealed that the amorphous components comprised mainly Si, Ca, Br, and Sn. The elemental composition and crystalline-phase analyses revealed the following: (1) the metallic components were durable because of their high ductility and malleability; (2) the ceramic materials were concentrated in the fine-particle fraction owing to their fragile nature; (3) the PCB components exhibited different durability properties depending on their chemical states. [Display omitted] • A printed-circuit board was ground by cryo-milling for efficient metal recovery. • X-ray fluorescence and X-ray diffraction analyses were conducted for printed-circuit board characterization. • Some elements correlated with the amorphous components of the cryo-milled PCB. • Elemental compositions and chemical state of the PCB powder were investigated. [ABSTRACT FROM AUTHOR]

• Traditional methods for soil specific surface area (SSA) are costly and laborious. • We propose models to estimate SSA from a single hygroscopic water content (w h) • Separate SSA models are developed for soil samples grouped by clay mineralogy. • Considering soil clay mineralogy in SSA models significantly improved performance. • Models based on w h were superior to models based on texture, carbon or CEC. The soil specific surface area (SSA) is an important variable for soil science and geoenvironmental engineering applications, but traditional measurement methods are difficult and time-consuming. Regression models or pedotransfer functions are often used to estimate SSA from other soil properties (e.g., clay content and cation exchange capacity), but these models do not consider the impact of clay mineralogy. Hygroscopic water content (w h) is intimately linked to these soil properties, which suggests that w h may be a better parameter for SSA estimation. This study (i) proposes regression models that estimate SSA from w h at different relative humidity values (5 to 90%) for kaolinite-rich samples (KA), illite-rich or mixed clay samples (IL/MC), montmorillonite-rich samples (ML), and a combination of all samples (ALL) and (ii) compares the performance of the w h models to other published models that comprise clay, silt and soil organic carbon contents and cation exchange capacity. We found that the sample-specific w h regression models accurately estimated SSA for KA, IL/MC and ML samples. For KA and IL/MC samples, the performance of the KA model (e.g., for adsorption, average RMSE = 10.5 m2/g) and IL/MC model (average RMSE = 21.3 m2/g) were better than the ALL-calibration model (KA: average RMSE = 18.7 m2/g; ML: average RMSE = 22.4 m2/g). For ML samples, similar model performance between the ML-calibration model (average RMSE = 41.4 m2/g) and the ALL-calibration model (average RMSE = 41.1 m2/g) was observed. In addition, the model performance of regression models based on w h was superior to models published in the literature that are based on clay, silt and soil organic carbon contents and cation exchange capacity. Overall, this study confirms that a single measure of w h can provide reliable estimates of the SSA while revealing a significant impact of clay mineralogy on model performance. [ABSTRACT FROM AUTHOR]

Unit operation (UO) systems have proliferated to sequester urban drainage particulate matter (PM) and PM-bound constituents. PM has been a primary focus of testing and certification. A nominal class of UOs, hydrodynamic separator (HS) systems require less area compared with nonproprietary UOs such as basins. Physical UO testing can be costly, with years to certification. Despite protocols, controlled certification tests are subject to variability, errors, and bias and could therefore be nonrepresentative, potentially negating accurate comparisons of results. Study objectives are to develop and then test computational fluid dynamics (CFD) models as a potential complementary tool for physical test–based UO certification programs. To facilitate this objective, publically available controlled physical tests of 21 HS systems and 154 test results based on two common certification programs are synthesized, and the variability examined. PM separation from two physical-validated CFD models are compared with the results synthesized from published certification reports. Synthesized results illustrate large variability across HS systems, up to 36.9%. Additionally, results of identical HS systems are inconsistent between certification programs, with a mean relative percent difference (MPRD) as high as 32.5%. In the CFD simulations of a physically tested full-scale HS system, Eulerian-equilibrium Eulerian (EE) and Eulerian-Lagrangian (EL) models reproduce PM separation with MRPD of 2.5% and 4.4%. In conclusion, simulations of publically reported HS systems illustrate the potential of CFD models as an adjuvant evaluation tool complementing physical testing. CFD models can also provide an efficient, economical, consistent, and revisable platform for UO systems. [ABSTRACT FROM AUTHOR]

The assessment of the agricultural landscape state of natural forage lands was carried out in 1997-2018 based on several components. The main ones that determine the essence of ecosystems of this type are the features of their formation, the development of a reaction to an anthropogenic process, are the genesis of natural forage lands, the degree of disturbance, resistance to external anthropogenic factors. The distribution of natural forage lands, into conditionally indigenous and production (post-forest), show not only the degree of disturbance of natural vegetation, but also more accurately assess the resistance of ecosystems to grazing, since production, communities, as initially disturbed, are in an unstable state. Field surveys are considered and presented in order to study the vegetation and soil cover of natural forage lands - hayfields and pastures of Kazakhstan in forest-steppe, steppe, semi-desert, desert, mountain zones, their yield and quality of the resulting forage for their rational use are shown. Protection and development of recommendations. The survey determined the agroecological state of natural forage lands, the occupied area, revealed the structure and communities of vegetation cover, typological composition, agrolandscape with territorial distribution of forage lands, modern use of natural forage lands, opportunities for rational use. [ABSTRACT FROM AUTHOR]

Porcelain stoneware tile is the best class of ceramic tiles regarding technical performance. Low porosity and high glass content are some of its highlighted characteristics. The manufacturing cost is highly dependent on the feldspar content and the processing flow rate. Certain technical bottlenecks in the manufacturing steps, such as milling, forming, and firing, are intrinsically associated with limitations in the processing properties, such as the dry strength, bulk density, and pyroplastic deformation. In this work, improvements in these properties were achieved using high‐energy milling (HEM) after conventional milling (CM). This study was carried out on a pilot industrial scale in the milling stage. Six experimental runs were evaluated. Slurries were spray‐dried. The powders were humidified with 6.5% moisture. Specimens were conformed under a specific pressure of 45 MPa. The firing was performed using temperature ranging from 1150 to 1230°C. The use of HEM, in comparison to traditional milling for the similar particle‐size distributions, has increased the dry density, +0.2 g.cm−3, dry bending strength, +1.0 MPa, and decreased the pyroplastic deformation index, −1.10−5 cm−1. These results allow an estimated thickness reduction of 10%. [ABSTRACT FROM AUTHOR]

Loess-paleosol sequences preserve information that can be used to reconstruct paleoenvironments. A dense network of reliably analyzed sequences from different geographic locations is crucial to address ecological and climatic trends, which occurred during the Pleistocene. This paper focuses on a loess-paleosol sequence in Bůhzdař, situated 9 km NW of Prague, Czech Republic. Geochemical approaches (total organic carbon, XRF elemental analyses, XRD mineralogy, 13C and 18O stable isotopes) are combined with grain-size distributions and optically stimulated luminescence (OSL) to assess the climatic conditions at the time of formation of the strata. The oldest loess at this location was formed circa 200 ka ago (MIS 7), making it the oldest loess in Central Bohemia for now. The Bůhzdař loess-paleosol sequence was highly affected by several erosion events, Eemian paleosols (MIS 5e) being completely missing. The partly relocated paleosols situated at the lower part of the Bůhzdař sequence represent a period of increased humidity during late MIS 7 and MIS 6. Despite the fact that the Bůhzdař profile is not particularly thick (5 m), significant changes in paleoclimate reconstructions have been detected. [ABSTRACT FROM AUTHOR]

The long-debated effective stress definition of unsaturated soils is believed to be correlated to suction, the degree of saturation, and the less mentioned interfacial areas. The tensile strength of unsaturated soils is directly associated with the effective stress definition in theory, and it is also crucial in engineering practices. For unsaturated soils, the relationship between suction and degree of saturation can be described as the water retention curve (WRC), which is related to the pore-size distribution. In the meanwhile, the air–water interfacial area is also regarded as a function of the degree of saturation, and parameters of the function are determined by the soil's pore structures. For granular soils, the pore-size distribution is usually in a unimodal shape and, therefore, the strength properties can also be related to the particle gradation parameters. In this study, a preliminary estimation method is proposed for the tensile strength of unsaturated sandy soils based on basic particle gradation parameters. In this method, with basic physical features considered, WRC is estimated from a characteristic grain diameter (d60) and the coefficient of uniformity (Cu). The function to determine the air–water interfacial area is also formulated by soil gradation parameters of the mean grain-size (d50), the coefficient of uniformity (Cu), and the void ratio. The proposed tensile strength estimation is compared with experimental measurements on sandy soils, which shows fair agreement, especially for the conventional split plate method. Qualitatively, the tensile strength is inversely proportional to soil mean grain-size and is increased with particle-size polydispersity. [ABSTRACT FROM AUTHOR]

Tsunami deposits preserved in the geological record provide a more comprehensive understanding of their patterns of frequency and intensity over longer timescales; but recognizing tsunami deposits can prove challenging due to post‐depositional changes, lack of contrast between the deposits and surrounding sedimentary layers, and differentiating between tsunami and storm deposition. Modern baseline studies address these challenges by providing insight into modern spatial distributions that can be compared with palaeotsunami deposits. This study documents the spatial fingerprint of grain size and foraminifera from Hasunuma Beach and the Kujukuri shelf to provide a basis from which tsunami deposits can be interpreted. At Hasunuma Beach, approximately 50 km east of Tokyo, the spatial distribution of three common proxies (foraminiferal taxonomy, foraminiferal taphonomy and sediment grain size) for tsunami identification were mapped and clustered using Partitioning Around Medoids cluster analysis. Partitioning Around Medoids cluster analysis objectively discriminated two coastal zones corresponding to onshore and offshore sample locations. Results show that onshore samples are characterized by coarser grain sizes (medium to coarse sand) and higher abundances of Pararotalia nipponica (27 to 63%) than offshore samples, which are characterized by finer grain sizes (fine to medium sand), lower abundances of Pararotalia nipponica (2 to 19%) and Ammonia parkinsoniana (0 to 10%), higher abundances of planktonics (15 to 58%) and species with fragile tests including Uvigerinella glabra. When compared to grain‐size and foraminiferal taxonomy, foraminiferal taphonomy; i.e. surface condition of foraminifera, a proxy not commonly used to identify tsunami deposits, was most effective in discriminating modern coastal zones (identified supratidal, intertidal and offshore environments) and determining sediment provenance for tsunami deposits at Kujukuri. This modern baseline study assists the interpretation of tsunami deposits in the geological record because it provides a basis for sediment provenance to be determined. [ABSTRACT FROM AUTHOR]

The paper studies the influence of micro- and nanoparticles of metals and metal oxides on physicochemical properties of high-energy materials comprising cyclic nitroamine crystals. The micro- and nanoparticle encapsulation technique is developed for such cyclic nitroamines as 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) and 2,4,6,8-tetranitro-2,4,6,8- tetraazaicyclooctane (octogen, HMX). Studied and analyzed are physicochemical properties of the novel high-energy materials comprising crystals of cyclic nitroamines. It is found that among the main parameters affecting the particle-size distribution in the crystals and the volume fraction of the metal inclusions, of critical importance is the stirring rate of the reaction mixture when distilling off the solvent. The low stirring rate leads to the formation of polycrystalline structures with the branched surface and multiple defects. Although the conditions of the CL-20 crystallization (solvent/precipitator ratio, temperature, a mixer type, distillation rate) are similar for different aluminum grades (ASD-6 and ALEXTM), the shape and size of the synthesized crystals strongly differ in both cases. The CL-20Alex crystal is characterized by the lower size (~100–150 μm), more tapered sides and greater number of the surface defects than crystals with other inclusions. This is probably because the effect from metallic particles acting as inoculating crystals. [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate the effects of drying, grinder type, and moistening conditions on the interparticle porosity of feed material and the torque supplied to the screw during the single-screw extrusion processing of brown rice. The grains were dried at 60 °C up to moisture contents of 9 and 6% and then milled using two grinder types (disc and roller). The milled products were moistened at levels to produce extruded snacks (11 and 14%). Irrespective of drying the grains, lower particle diameters in the fine and coarse fractions, and narrower distributions were obtained by grinding brown rice in a roller mill than in a disc mill. The disc mill products presented lower interparticle porosity and generated higher torque values than the roller mill products. A reduction in grain moisture from 9 to 6% only decreased the interparticle porosity of disc mill products and increased the torque. An increase in feed moisture from 11 to 14% only increased the interparticle porosity of roller mill products and decreased the torque regardless of grain moisture. This work contributed to understanding the impact of the morphology of the particles in the torque variability during the extrusion processing of brown rice. Few published works correlate physical properties of the feed material with extrusion dependent variables. In the present study, feed materials with high interparticle porosity were produced with roller mill and when extruded they generated low variabilities in the torque. [ABSTRACT FROM AUTHOR]

For many powder processes, the particle size distribution (PSD) is a key quality attribute of the flow properties of the process powders. This paper presents a method for estimating the PSD with acoustic emissions (AE) by implementing a time domain-based threshold approach followed by the extraction of the amplitude mean from each set threshold and correlation to particle size. The experiments were carried out using a powder-free fall experimental rig, and a set of glass beads, while the acquired data were analyzed with a designed signal analysis method. The results of the experiments showed that the PSD of the particle mixtures being investigated could be identified with an average absolute error of 10%. The main advantage of the designed signal analysis method was identified as the requirement for a low hardware complexity due to a simpler algorithm than its predecessors. In an attempt to benchmark the performance of the system, the performance of the designed approach was compared to a wavelet-based analysis designed by Ren et al. From this it was seen that the approach used by Ren et al. is reliant on a tuning process to aid the algorithm in making the size estimation, suggesting that Ren's approach would prove to be inefficient in a process where powder segregation occurred due to poor mixing. [ABSTRACT FROM AUTHOR]

There are global aspirations to harmonize soil particle- size distribution data measured by the laser diffraction method and by traditional sedimentation techniques, e.g. sieve-pipette methods. The need has arisen therefore to build up a database, containing particle-size distribution values measured by the sieving and pipette method according to the Hungarian standard (sieve-pipette methods-MSZ) and the laser diffraction method according to a widespread and widely used procedure. In our current publication, 155 soil samples measured with sieve-pipette methods-MSZ and laser diffraction method (Malvern Mastersizer 2000, HydroG dispersion unit) were compared. Through the application of the usual size limits at the laser diffraction method, the clay fraction was under- and the silt fraction was overestimated compared to the sieve-pipette methods-MSZ results, and subsequently the soil texture classes were determined according to the results of both methods also differed significantly from each other. Based on our previous experience, the extension of the upper size limit of the clay fraction from 2 to 7 µm increases the comparability of sievepipette methods-MSZ and laser diffraction method, in this way the texture classes derived from the particle-size distributions were also more in accordance with each other. The difference between the results of the two kinds of particle-size distribution measurement methods could be further reduced with the pedotransfer functions presented. [ABSTRACT FROM AUTHOR]

Lately, interesting features of lighting Rare Earths doped phosphorus have gained much attention and became favorite research matter among various groups of scientists. In this context, polycrystalline powders of Na 3 La(PO 4) 2 : Er (0%, 2,5%) have been prepared by the solid state method. Powder X-ray diffraction, infrared spectroscopy have been used to identify these materials. The spectroscopic properties of Na 3 La(PO 4) 2 : Er (2,5%) have been investigated through absorption, excitation, emission spectra and decay curves of Er3+ at room temperature. The decay time reveal that Na 3 La(PO 4) 2 : Er (2,5%) possesses a radiative transition and the lifetime value for the transition 4F 9/2 → 4I 15/2 is found equal to 144.92 μs. All obtained results have been presented, compared and discussed with last reported works. The CIE chromaticity coordinates have been highlighted. They reveal that Na 3 La(PO 4) 2 : Er (2,5%, 10%, 20% and 50%) phosphor can be a promising green and yellow-orange luminophore for application in LED. [ABSTRACT FROM AUTHOR]

[Display omitted] • Quantified the effect of the sediment particle-size distribution and microtopography on rill erosion at hillslope scale. • Upslope sediment-laden inflow induced the microtopographic heterogeneity is related to the coarser particles. • Considered the interaction between microtopography and sediment sorting can effectively assess the erosive behaviors. Upslope drainage area contributing inflow to downslope rill erosion can be affected by the dynamics of eroded sediment and soil surface microtopography. However, limited information has previously not recognized the variation of the sediment particles and microtopography on hillslopes where upslope inflow perpetually exists. A series of scouring flume experiments were performed on a 15° slope under upslope inflow rates (4, 6 and 8 L min−1) to investigate the inflow-driven microtopography and sediment particle-size distribution (PSD) during the rill erosion process. The results indicated that the surface elevation decay mostly occurred in the later stage of rill erosion. The spatial variability of microtopography increased gradually with increasing inflow rates, and obvious microtopography sharpness intensified with the development of rill erosion. The surface runoff under the 8 L min−1 inflow rate increased by 15.03 % and 90.14 % for 6 and 4 L min−1, respectively, and the sediment yield reached a maximum at the rill stabilization stage (RS). The overall particle-size distribution was mainly composed of silt-sized particles, accounting for approximately 40.97 %−50.15 % of the total eroded sediment. Considerable depletion of clay fractions occurred in the rill erosion process. High inflow rate significantly enhanced variation amplitude of critical hydrodynamic parameters (e.g., flow velocity, flow shear stress and Reynolds number). The spatial heterogeneity of microtopography was correlated with the coarser fraction of sediment PSD in rill erosion, suggesting that erosion processes were affected by the interaction between eroded sediment distribution and roughness. These findings highlight the importance of the PSD of eroded sediment and the development of soil surface structure for an in-depth understanding of the purple soil erosion mechanism at the hillslope scale. [ABSTRACT FROM AUTHOR]

The effects of TiO2 layer arrangement as photo-anode on the efficiency of dye-sensitized solar cells were investigated and presented. Four TiO2 nanoparticles being different from the TiO2 particle sizes and phases were prepared and characterized with TEM, AFM and XRD analyses. These TiO2 particles were used to prepare three-layered photo-anode with different layer arrangements. The J–V measurements and impedance spectroscopy of the assembled solar cells with these photo-anodes and N3 dye were investigated and interpreted. The photo-anode in which the particles were arranged from large to small (CBA) and the photo-anode in which the particle size is equal (BBB) presented the best efficiency. The BBB performance was related to the appropriate particle size in the B layer and was a driving force for electron transfer, which is inducted by the oxidized dyes. In the CBA sample, this driving force was enhanced by the different particle sizes in the layer interfaces. [ABSTRACT FROM AUTHOR]

The influence of the synthesis temperature on the phase composition, size distribution, and morphology of AlMgB14 particles, obtained by direct interaction of powders of elementary Al, Mg, and B with the addition of free carbon in vacuum 10 – 2 Pa at 1200 – 1400°C, was studied. The synthesized powders were analyzed by means of x-ray diffraction, SEM, EDX, and laser diffraction. The highest mass content of the main phase AlMgB14 (94%) was obtained at synthesis temperature 1200 – 1300°C with 1 h soaking. Impurity MgAl2O4 as well as magnesium-depleted spinel and AlB12 were recorded at soaking temperature above 1300°C. [ABSTRACT FROM AUTHOR]

Soil structural traits provide links between soil structure and ecosystem functioning. The size and stability of soil aggregates are assumed to provide information on aggregate formation and turnover. A standard method to analyse these traits is to determine the mass distribution on sieves. The major drawback of this method is the small size resolution because of a small number of size classes. A promising, yet still unexplored, method for size distribution analysis in soil science, is dynamic image analysis, which foremost allows a much larger diameter resolution and the assessment of both size and shape distributions. The aim of our study was to validate the applicability of dynamic digital image analysis in combination with sonication to characterize the size and shape distribution and the stability of aggregates. We used two different heterogeneous reference materials and three different soil samples with different aggregate stabilities to test this method. The soil samples were chosen based on increasing clay, humus and calcium carbonate contents. The method yielded reproducible results for diameter and shape distributions for both reference materials and soil samples. The most important improvement compared to well‐established methods was the extremely large size resolution. This allows specification of the pattern of diameter‐dependent breakup curves by relating them to specific soil properties. The information on sphericity adds supplementary information on the aggregates released. We found much lower sphericity of 1‐mm aggregates mobilized from topsoil samples formed from the activity of living organisms than aggregates mobilized from subsoil samples formed mainly by physicochemical processes. Highlights: Our aim was to validate dynamic digital image analysis to characterize soil aggregates.Dynamic image analysis allows high resolution and shape analysis compared to established methods.The method yielded reproducible results for diameter and shape distributions.We established high‐resolution disruption patterns of aggregates enabling new approaches in future research. [ABSTRACT FROM AUTHOR]

A brief review of world experience in mapping the mineralogical composition of soils is given; in particular, the results gained in Great Britain (England and Wales), Canada, the United States, Australia, Hungary, the former Soviet Union, and Russia are analyzed. In the majority of countries, the composition of clay minerals was the only object of mapping, except for the United States, for which the data on the mineral composition of coarse fractions were included. This publication is aimed at the analysis of the experience in mapping the mineralogical composition of soils in Moldova—a small country with steppe and forest-steppe landscapes—and elucidates the achievements and problems in this area. Unlike other countries, where the associations of clay mineral were the object of mapping, the specific mineralogical composition of soils and parent materials in Moldova, together with the development and application of appropriate analytical methods and databases, made it possible to compile the maps reflecting the contents of individual minerals both in the clay and coarse fractions. For the first time, digital maps of the contents of various minerals in soils of Moldova were developed on the basis of data of quantitative X-ray diffractometry and their statistical analysis. A close relationship was found between the content of certain minerals and the particle-size distribution data, which permitted us to perform mapping of the mineralogical composition of soils with due account for their textures. As an example, digital maps of the contents of clay minerals (smectite and illite) in the A horizon and in the parent material of Moldavian chernozems and forest soils on a scale of 1 : 3 M are presented. Statistical data on the contents of these minerals in the soils of different textures are discussed. The content of smectite varies within 6–43%, and the content of illite varies within 3–16%. Their distribution in the soil profiles attests to a statistically reliable difference between the contents of these minerals in the A horizon and in the parent material. The mapping procedure is described, and the areas of the practical application of such maps are specified. [ABSTRACT FROM AUTHOR]

Abstract Water soluble organic carbon significantly contributes to aerosol's carbon mass and its chemical composition is poorly characterized due to the huge number of species. In this study, we determined 94 water-soluble compounds: inorganic ions (Cl−, Br−, I−, NO 3 −, SO 4 2−,K+, Mg+, Na+, NH 4 +, Ca2+), organic acids (methanesulfonic acid and C 2 -C 7 carboxylic acids), monosaccharides, alcohol-sugars, levoglucosan and its isomers, sucrose, phenolic compounds, free l - and d -amino acids and photo-oxidation products of α-pinene (cis-pinonic acid and pinic acid). The sampling was conducted using a micro-orifice uniform deposit impactor (MOUDI) at the urban area of Mestre-Venice from March to May 2016. The main aim of this work is to identify the source of each detected compound, evaluating its particle size distribution. Clear differences in size distributions were observed for each class of analyzed compounds. The positive matrix factorization (PMF) model was used to identify six factors related to different sources: a) primary biogenic aerosol particles with particle size > 10 μm; b) secondary sulfate contribution; c) biomass burning; d) primary biogenic aerosol particles distributed between 10 and 1 μm; e) an aged sea salt input and f) SOA pinene. Each factor was also characterized by different composition in waters soluble compounds and different particles size distribution. Graphical abstract Unlabelled Image Highlights • Determination of 94 water soluble compounds in ultrafine, fine and coarse aerosol • Particle size distribution of l - and d -amino acids in urban aerosol • Factor analysis identified different sources for free amino acids and sugars. • Six different sources were identified with positive matrix factorization. • Each identified source had a specific particle size distribution. [ABSTRACT FROM AUTHOR]

Abstract In the context of global climate change as well as local climate warming and drying on the Loess Plateau of China, understanding the relationship between soil particle size and soil water distribution during years of atypical precipitation is important. In this study, fractal geometry theory is used to describe the mechanical composition and texture of soils to improve our understanding of hydropedology and ecohydrology in the critical zone on the Loess Plateau. One grassland slope and two shrubland slopes were selected in the hilly and gully region of the Loess Plateau, and soils were sampled along hillslope transects at depths of 0–500 cm. Fractal theory and redundancy analysis (RDA) were used to identify relationships between the fractal dimension of soil particle-size distributions and the corresponding van Genuchten parameters for the soil-water-characteristic curves. The oven-drying method was used to measure soil water content, and the high-speed centrifugation method was used to generate soil-water-characteristic curves. The results show that (1) the soil water that can be used by Caragana korshinskii during a drought year is distributed below 2 m from the surface, whereas the soil water that can be used by grass is below 1.2 m; (2) Caragana korshinskii promotes the conservation of fine soil particles more than does natural restored grass, and the soil particle-size distribution fractal dimension changes with depth and position; and (3) soil hydraulic properties correlate strongly with soil pedological properties such as bulk density and the soil particle-size distribution fractal dimension. These results provide a case study of the relationships among soil distributions, hydrologic and geomorphic processes for vegetation restoration in drylands with a thick vadose zone. More studies on soil property changes are needed to provide case studies and empirical support for ecological restoration in the Loess Plateau of China. Graphical abstract Unlabelled Image Highlights • Fractal dimension analysis is a useful tool for understanding hydropedology. • Shrub and grass used soil water below 2 m and 1.2 m respectively in a drought year. • Shrub reduces erosion of fine particles but consumes water stored in deep layers. [ABSTRACT FROM AUTHOR]

Transformation of particle-size composition, structure, and density of soils upon urbopedogenesis is considered for Rostov agglomeration. Various soils are compared by horizons. It is found that the share of sand fractions increases in upper and middle horizons of migration-segregation chernozems (Calcic Chernozem (Hyperhumic, Loamic)), above all, at the expense of particles of 0.05—0.001 mm in size; with the coarse medium sand fraction 1-0.25 mm being diagnostic for urbopedogenesis. The reason is the introduction of sandy particles upon urban construction, arranging water conduits and other utility lines, as well as the use of icing-control sandy mixtures. The Dolgov-Bakhtin schedule appears to be the most appropriate for assessing the structure of urban soils. Dry sieving testified to the decreasing amount of agriculturally valuable aggregates in all compared pairs of horizons in the sequence of urban soils: under forest vegetation → under steppe vegetation → in the buried massif of urbosoils. The water stability of aggregates decreases in the sequence: soils under steppe vegetation → buried horizons of urbosoils → soils under forest vegetation. The following sequence of urbic horizons (UR and RAT) shows a decrease in the share of agriculturally valuable fractions and an increase in their water stability: heavy-textured UR → light-textured UR → RAT. The density of natural soils varies insignificantly within the city territory, with its urbostratified soils (Calcic Chernozem Novic (Technic Loamic) in residential areas often manifesting the maximal density. [ABSTRACT FROM AUTHOR]

Abstract: The research sought to develop and test a forensic database of surface soil variability within previously mapped geologic and soil units in southern California. This type of database could be used to link suspects to crime scenes or determine source locations of soil sample evidence. Variability was evaluated using (i) color, (ii) magnetic susceptibility, and (iii) particle‐size distribution. Soil properties were analyzed for their ability to discriminate source areas using stepwise discriminant analysis. The percent correct predictions for geologic unit groups ranged from 30% to 100%. A blind study experiment matched four of the 18 samples to their unit of origin with the first choice by stepwise discriminant analysis, and eight were matched as second and third choices. The probability of selecting the appropriate unit of origin increased by 54% over random chance and eliminated as much as 99% of the field area as a potential search location. [ABSTRACT FROM AUTHOR]

The paper seeks to better understand the particulate mechanics giving rise to the lubrication layer (LL) in flows with wide particle-size distributions (PSD) typical of concrete pumping applications. The study uses a soft-sphere discrete element method (DEM) to simulate the shear-induced particle migration (SIPM) mechanism of formation of the LL. To provide realistic understanding of SIPM and rheological heterogeneity of concrete, three wide PSDs (fine, medium, and coarse) and three different concentrations (10 %–40 %) of five spherical-particle subclasses (1–17 mm diameter) were investigated. The radial evolution of concentration and particle distribution was simulated over time and the LL formation was successfully simulated. The predicted LL thicknesses compared well with experimental values. The coupled effect of PSD, concentration, and mean diameter of particles on wall effect, SIPM, and rheological heterogeneities across the pipe was evaluated. Higher rheological heterogeneity across the pipe was obtained for higher concentration and coarser particle size distributions. [ABSTRACT FROM AUTHOR]

A field investigation of the Huangtupo landslide in the Three Gorges Reservoir area, China, indicated that the particle-size distribution—characterized by an index termed the fractal dimension—varied along the main sliding direction: the fractal dimension tended to increase in this direction. A preliminary study of the spatial variability of the slip zone based upon the fractal dimension was performed. Remolded soil samples with various fractal dimensions obtained from the Huangtupo landslide were prepared for laboratory testing that was carried out to determine the effect of the fractal dimension on the micro and macro behavior of the soils. The microstructure of each soil sample was determined using scanning electron microscopy, while its macromechanical properties were evaluated via consolidated undrained triaxial tests. The results showed that there were close relationships of the fractal dimension with the microstructure, stress-strain behavior, and shear strength. The test results were also consistent with the results of the field investigation of the Huangtupo landslide. Thus, the fractal dimension can be used as an indicator of the spatial variability of the slip zone of a landslide. [ABSTRACT FROM AUTHOR]

This letter reports an extended effective medium theory (EMT) including particle-size distribution functions to maximize the magnetic properties of magneto-dielectric composites. It is experimentally verified by Co-Ti substituted barium ferrite (BaCo x Ti x Fe 12−2 x O 19 )/wax composites with specifically designed particle-size distributions. In the form of an integral equation, the extended EMT formula essentially takes the size-dependent parameters of magnetic particle fillers into account. It predicts the effective permeability of magneto-dielectric composites with various particle-size distributions, indicating an optimal distribution for a population of magnetic particles. The improvement of the optimized effective permeability is significant concerning magnetic particles whose properties are strongly size dependent. [ABSTRACT FROM AUTHOR]

Karst springs, especially in alpine regions, are important for drinking water supply but also vulnerable to contamination, especially after rainfall events. This high variability of water quality requires rapid quantification of contamination parameters. Here, we used a fluorescence-based multi-parameter approach to characterize the dynamics of organic carbon, faecal bacteria, and particles at three alpine karst springs. We used excitation emission matrices (EEMs) to identify fluorescent dissolved organic material (FDOM). At the first system, peak A fluorescence and total organic carbon (TOC) were strongly correlated (Spearman's r s of 0.949), indicating that a large part of the organic matter is related to humic-like substances. Protein-like fluorescence and cultivation-based determination of coliform bacteria also had a significant correlation with r s = 0.734, indicating that protein-like fluorescence is directly related to faecal pollution. At the second system, which has two spring outlets, the absolute values of all measured water-quality parameters were lower; there was a significant correlation between TOC and humic-like fluorescence (r s = 0.588–0.689) but coliform bacteria and protein-like fluorescence at these two springs were not correlated. Additionally, there was a strong correlation (r s = 0.571–0.647) between small particle fractions (1.0 and 2.0 μm), a secondary turbidity peak and bacteria. At one of these springs, discharge was constant despite the reaction of all other parameters to the rainfall event. Our results demonstrated that i) all three springs showed fast and marked responses of all investigated water-quality parameters after rain events; ii) a constant discharge does not necessarily mean constant water quality; iii) at high contamination levels, protein-like fluorescence is a good indicator of bacterial contamination, while at low contamination levels no correlation between protein-like fluorescence and bacterial values was detected; and iv) a combination of fluorescence measurements and particle-size analysis is a promising approach for a rapid assessment of organic contamination, especially relative to time-consuming conventional bacterial determination methods. [ABSTRACT FROM AUTHOR]

Fifteen polycyclic aromatic hydrocarbons (PAHs) were analyzed in two fractions (< 63 μm and 63–850 μm) of street dust samples collected in different urban areas of Rio de Janeiro and Niterói cities, Brazil. Individual PAH concentrations and total PAH concentrations (∑ PAH) were evaluated considering geographic and particle size distributions, PAH source and cancer risk. In 53% of the samples, ∑ PAH values were higher in the smallest particles than in the largest ones, whereas the inverse was true for 23.5% of the samples. In 23.5% of the samples, both classes of particles showed comparable ∑ PAH. The highest ∑ PAH concentrations were found in areas of limited air dispersion, resulting in PAH accumulation in street dust. The diagnostic ratios and principal component analysis (PCA) indicated a strong influence of pyrogenic sources on PAH concentration, mainly of vehicular emissions. The cancer risk levels for children and adults, for both particulate size fractions (< 63 μm and 63 μm–850 μm), were comparable for dermal contact and by ingestion, and ranged from 10 − 8 to 10 − 6 , whereas in certain cases the cancer risk level for adults by dermal contact was 2 to 3 times larger than for children. The cancer risk levels via inhalation always ranged from 10 − 13 to 10 − 10 , so this exposure pathway was almost 10 4 less severe than through ingestion and dermal contact, and thus negligible. [ABSTRACT FROM AUTHOR]

For packaging processes of food and drug powders safety and cleanliness of the final product is one main aspect of the manufacturing process. To reach longer life periods of the products many of these processes are using inert gases during dosing procedure. To examine the entrainment of different kinds of gas species by free-falling bulk material during the dosing process an experimental setup was built. Therefore different particle-size distributions as well as different falling heights were analysed. The achieved results are used for the validation of numerical simulations based on different numerical methods. [ABSTRACT FROM AUTHOR]

Here we used Functional Data Analysis (FDA) to examine particle-size distributions (PSDs) in a beach/shallow marine sedimentary environment in Gijón Bay (NW Spain). The work involved both Functional Principal Components Analysis (FPCA) and Functional Cluster Analysis (FCA). The grainsize of the sand samples was characterized by means of laser dispersion spectroscopy. Within this framework, FPCA was used as a dimension reduction technique to explore and uncover patterns in grain-size frequency curves. This procedure proved useful to describe variability in the structure of the data set. Moreover, an alternative approach, FCA, was applied to identify clusters and to interpret their spatial distribution. Results obtained with this latter technique were compared with those obtained by means of two vector approaches that combine PCA with CA (Cluster Analysis). The first method, the point density function (PDF), was employed after adapting a log-normal distribution to each PSD and resuming each of the density functions by its mean, sorting, skewness and kurtosis. The second applied a centered-log-ratio (clr) to the original data. PCA was then applied to the transformed data, and finally CA to the retained principal component scores. The study revealed functional data analysis, specifically FPCA and FCA, as a suitable alternative with considerable advantages over traditional vector analysis techniques in sedimentary geology studies. [ABSTRACT FROM AUTHOR]

In terms of sulfide copper-molybdenum ore of Sorsk stockwork deposit (Republic of Khakasia), the authors discuss the option of selective dissociation of minerals. The scope of the discussion embraces the effect of pulsed-discharge treatment on particle-size indexes, structural and chemical properties and floatability of objects of the study. It is shown that the pulse-discharge treatment in a greater degree influences copper sulfides and levels their floatability while surface of molybdenite undergoes minor alteration. The pulse-discharge treatment allows enhancing flotation selectivity in separation of copper sulfides and molybdenite, and promotes removal of hydrophobic molybdenite film from quartz surface, which results in production of high-quality molybdenite concentrates. [ABSTRACT FROM AUTHOR]

Inhalation exposure to elevated particulate matter levels is correlated with deleterious health and well-being outcomes. Despite growing evidence that identifies humans as sources of coarse airborne particles, the extent to which personal exposures are influenced by particle releases near occupants is unknown. In a controlled chamber, we monitored airborne total particle levels with high temporal and particle-size resolution for a range of simulated occupant activities. We also sampled directly from the subject's breathing zone to characterize exposures. A material-balance model showed that a sitting occupant released 8 million particles/h in the diameter range 1-10 μm. Elevated emissions were associated with increased intensity of upper body movements and with walking. Emissions were correlated with exposure, but not linearly. The personal PM10 exposure increment above the room-average levels was 1.6-13 μg/m3 during sitting, owing to spatial heterogeneity of particulate matter concentrations, a feature that was absent during walking. The personal cloud was more discernible among larger particles, as would be expected for shedding from skin and clothing. Manipulating papers and clothing fabric was a strong source of airborne particles. An increase in personal exposure was observed owing to particle mass exchange associated with a second room occupant. [ABSTRACT FROM AUTHOR]