Variation In Content Research Articles

Quantitative hardness‐carbon content‐microstructure correlation in normalized plain carbon steel

AbstractComposition (carbon content) dependent critical structural evolution in correlation to hardness attained is judiciously investigated for plain carbon steel, the most widely used cost‐effective structural material, under normalizing treatment of industrial relevance involving non‐equilibrium still air cooling. The solid state phase transformation under non‐equilibrium still air cooling is conceived in terms of a logarithmic variation of eutectoid carbon content with the gross carbon content of steel in view of maintaining fixed maximum solubility of carbon in α‐iron with an assumption of the prevailing para‐equilibrium condition. Such a unique formulation for non‐equilibrium condition together with consideration of Hall–Petch type relationship and rule of mixture for two prime microconstituents (proeutectoid α‐ferrite and pearlite) finally results in a new mathematical relationship for chemical composition‐structure‐property correlation for the non‐equilibrium normalizing treatment readily practiced in industry. Indeed, a composition dependent structural refinement effect is established that is exemplified with the rise in hardness level in plain carbon steel under conventional normalizing treatment. Most importantly, the experimentally measured overall hardness values closely follow those obtained by the developed mathematical relationship, thereby meeting an ever‐needed requirement of direct determination of steel hardness of practical relevance from microstructural parameters.

Distribution characteristics and influencing factors of soil organic carbon in tidal flat wetland of central Jiangsu, China.

We measured winter and summer soil organic carbon (SOC) contents in two typical coastal wetlands, the Spartina alterniflora salt marsh and the non-vegetation mudflat, on the south side of the Chuandong River Estuary in Yancheng, Jiangsu Province. We investigated the spatiotemporal variations of soil organic carbon contents and its driving factors. The results showed that SOC content ranged from 0.75 to 2.38 g·kg-1 in the mudflat area and from 2.07 to 18.59 g·kg-1 in the S. alterniflora salt marsh area, showing a decreasing trend towards the sea. The SOC content in the S. alterniflora salt marsh area was approximately 2.5 to 3.5 times of that in the mudflat area. Within a depth range of 1 m, there was no vertical variation in SOC content in the mudflat area, but an increasing and then decreasing pattern in the S. alterniflora marsh area with the peak occurring in the depth range of 20 to 30 cm. Soil organic carbon content exhibited significant seasonal difference, with higher value in summer than in winter. The summer SOC content was 5% to 10% higher than that in winter in the S. alterniflora marsh area, while it was 43% higher in summer than in winter in the mudflat area. In the S. alterniflora marsh area, soil organic carbon content was positively correlated with soil moisture and salinity, but negatively correlated with sediment particle size. In contrast, there was no significant correlation between soil organic carbon content and soil physicochemi-cal factors in the mudflat area. Those results indicated that the correlation between various soil physicochemical factors and SOC is established on the basis of vegetation cover in coastal wetlands. Our findings could provide valuable insights for the conservation of blue carbon ecosystems in coastal wetlands in China.

Response of soil stoichiometric characteristics to climatic factors in temperate steppe of Longzhong region, China.

We explored the relationship between climate factors (mean annual precipitation and mean annual temperature) and the contents and stoichiometry of soil carbon (C), nitrogen (N), and phosphorus (P) at different soil depths (0-5, 5-10, 10-20, 20-30, 30-50, 50-70, and 70-100 cm) temperate steppe of Longzhong. The results showed with the increases of soil depth, soil C, N contents, C:P, and N:P gradually decreased from 21.88 g·kg-1, 1.84 g·kg-1, 33.6 and 3.1 to 7.67 g·kg-1, 0.59 g·kg-1, 12.5 and 1.0, respectively. Soil C:N showed an increasing trend from 12.2 to 13.9, while soil P content remained stable with an average of 0.61 g·kg-1. Soil C, N, C:P, and N:P were significantly positively correlated with mean annual precipitation and negatively correlated with mean annual temperature. Soil P content and C:N were not correlated with mean annual precipita-tion and mean annual temperature. With the increases of soil depth, the total explanatory power of the changes in soil C, N and P contents by mean annual precipitation and mean annual temperature decreased and then increased, and that in soil C:P, N:P and C:N did not change significantly. The changes of soil C, N and P contents on the temperature steppe were mainly influenced by mean annual precipitation. The effects and relative contributions of mean annual precipitation and mean annual temperature on the variations of soil nutrient contents and stoichiometry of C, N and P differed at different soil depths.

Thermoformability study of wood flour–HDPE composites with variations in wood content under vacuum forming

Wood–plastic composites (WPCs) have emerged as sought-after substitutes for plastic. However, their use is restricted primarily to linear profiles owing to the lack of techniques for their three-dimensional (3D) forming. Thermoforming is a potential method for the 3D formation of WPCs. Accordingly, the aim of this study was to evaluate the thermoforming behaviour of extruded wood flour–high-density polyethylene composites with two different wood flour compositions (34 % and 54 %) under vacuum forming. This study examined the thermal behaviour of each structure during the forming process and the shape conformability, shape consistency, and surface quality of the formed samples. The findings suggest that increasing the quantity of plastic in composites can improve the obtained shape dimensions. Nevertheless, this improvement is accompanied by an increased level of inconsistency in the acquired profiles due to the distinct stretching rates of plastic and wood. Furthermore, the results reinforced the reliability of thermal analysis as a credible means of evaluating quality.

Investigation of the impact of pyrite content on the terahertz dielectric response of coals and rapid recognition with kernel-SVM

Pyrite promotes the coal spontaneous combustion of coal. Owing to the highly uneven distribution of pyrite in coal seams, different areas of the same coal seam may have significantly different spontaneous combustion tendencies. To mitigate the adverse effects of pyrite, a method for detecting pyrite distribution in coal seams is imperative to be developed. This study employed terahertz time-domain spectroscopy to measure the terahertz dielectric response of coals with varying pyrite contents, focusing on discerning the underlying differences and mechanisms. Results emphasize the coal's metamorphism as a key influencer of terahertz signals. Coals that are more highly metamorphosed generally exhibit higher signal amplitude and lower complex permittivity. Signal peak amplitudes demonstrate a linear attenuation trend with increasing pyrite content, particularly pronounced in highly metamorphic coals. Regarding the complex permittivity, the real part displayed irregular changes with variations in pyrite content, whereas the imaginary part exhibited linear growth. Terahertz waves prove sensitive to pyrite-induced relaxation-type polarization. Moreover, support vector machine classification, employing terahertz imaginary spectrum, achieves an approximately 90 % multiclass accuracy in pyrite estimation across diverse coal types. The conclusions offer valuable theoretical insight for terahertz technology applications, including controlling coal spontaneous combustion, mining associated pyrite, and analyzing coal quality.

Application of 137Cs tracer technique in floodplain deposition research in mesoscale river basins

Floodplain deposition can provide important historical information about river systems. 137Cs tracer measurement is the most widely used technique for studying floodplain deposition. One-time sampling is normally used to date or estimate erosion and deposition rates, while time-interval sampling has rarely been applied. Northeast China is an important grain production area characterized by intense erosion and a low sediment transport ratio. Most studies of the region have focused on slope sedimentation, while floodplain sedimentation has received little attention. In this study, two-time steps of cross-sectional sediment core sample collection were performed to examine the floodplain sedimentation in the river basin of the Laolai River, a tributary of the Songhua River. The potential for using 137Cs to estimate the sediment deposition rate for a given time-interval was also investigated. A total of 18 cross-sections were acquired, and three repeated cross-sections were selected for double sampling. Significant differences were observed between the results obtained from the samples collected in separate rounds, suggesting the presence of internal heterogeneity during floodplain sedimentation and a significant influence of sampling positions on the analysis results. In the basin examined, sedimentation often occurs midstream, upstream, and at the outlet, and was mainly affected by topography, reservoir construction, and land use. Sedimentation occurs easily at wide, flat outlets or river intersections in braided water systems. It was observed that downstream floodplain sedimentation was increased by sediment interception by upstream reservoirs, but reduced by forests near floodplains. Sedimentation rates were significantly different between the 1954 and 1963 time markers, and we found that using rates from 1954 alone would lead to underestimation. When 137Cs sedimentation and floodplain distribution are used to determine flooding occurrence, variations in 137Cs content and particle size distribution should be considered. River bank erosion in this region should be taken into account, and riparian protection is required to reduce erosion and floodplain deposition. Since 137Cs is absent in fine particles when the sediment is predominantly sand, 137Cs measurement may underestimate the sediment deposition rate.

Physical weathering of Gobi Desert sediments under different temperature and humidity conditions

Physical weathering of the Gobi Desert surface sediments involves complex processes. However, our understanding of its main driving factors is still limited, and experimental observations on the weathering intensity of Gobi Desert surface sediments under changing environmental conditions are still insufficient. Surface samples were collected from the Gobi Desert, divided into 0.063–0.125 mm, 0.125–0.25 mm, 0.25–0.5 mm, 0.5–1 mm and 1–2 mm groups, and washed with deionized water. Physical weathering and salt weathering experiments of these groups were conducted under temperature (T) of −40 °C–40 °C and relative humidity (RH) of 20 %–100 %. Salt and mineral analyses, grain size distribution, and morphology analysis of each fraction group before and after the experiments were conducted. The results showed that mean grain sizes for the 0.063–0.125 mm, 0.125–0.25 mm, 0.25–0.5 mm, 0.5–1 mm, and 1–2 mm groups decreased by 0.49 ± 1.09 %, −0.27 ± 2.14 %, 0.41 ± 3.14 %, 2.96 ± 3.14 %, and 0.19 ± 1.29 %, respectively. The mean size of each group decreased ∼ 0.76 ± 1.13 % /10 days, demonstrating a higher physical weathering intensity than the previous estimations. The d0.1 size (i.e., the grain diameter for which 0.1 % of each grain group is smaller) was more sensitive to physical weathering, and the skewness was a good indicator of physical weathering for groups obeying a normal distribution. Physical weathering was still affected by salt weathering, and there was no regular pattern for physical weathering under variations in salt and mineral contents. At present, there are still difficulties in developing an accurate physical weathering intensity model.

Unveiling Apple Diversity: The Quality of Juice Produced from Old vs. Commercial Apple Cultivars.

This research is focused on comparing the compositions of juice produced from old and commercially grown apple cultivars. We examined factors such as pH, total acids, soluble dry matter, polyphenol profile, and antioxidant activity, which impact the attributes, safety, shelf life, and nutritional value of the juice. Our analysis revealed differences between these two groups of cultivars. For instance, pH values ranged from 3.04 (in 'Bobovec') to 3.69 (in 'Fuji'). The proportions of acids varied from 0.07 g/100 mL (in 'Fuji') to 0.19 g/100 mL (in 'Wagener'). Soluble dry matter content ranged from 14.10% (in 'Fuji') to 18.50% (in 'Kraljevčica'). We also observed variations in sugar content and composition among cultivars; for example, sucrose levels varied from 16.11 g/L ('Fuji') to 39.36 g/L ('Golden Delicious). Glucose levels ranged from 4.95 g/L ('Jonagold') to 19.18 g/L ('Fuji'), while fructose levels spanned from 50.78 g/L ('Austrougarka') to 427.97 g/L ('Ilzer Rosenapfel'). Furthermore, old apple cultivars exhibited higher concentrations of phenols and flavonoids compared to commercial ones; we also noted significant variations in flavonol levels among different cultivars. The 'Wagener' and 'Božićnica' apple varieties had levels of myricetin measuring 0.53 and 0.52 µg/mL, respectively. On the other hand, 'Bobovec' stood out for its content of procyanidin B2 with a concentration of 422.61 µg/mL. When examining non-flavonoid compounds, it was found that old apple cultivars had higher concentrations of gallic acid, trans-ferulic acid, and chlorogenic acid. However, commercial cultivars showed dominance in caffeic and p-coumaric. Comparisons of antioxidant capacity using DPPH and ABTS assays clearly demonstrated the superiority of old apple cultivars. Overall, this study highlights the importance of utilizing apple cultivars for juice production. Their distinct compositions and higher antioxidant capacities contribute to potential health benefits. Preserving these cultivars for enhanced juice quality and nutritional value is encouraged. Further research could explore cultivation practices' impact on composition and health benefits.

Corrosion behavior and mechanism of electric arc-sprayed Al-Mg coating and Zn-Al-Mg pseudo-alloy coatings

Pseudo-alloy coatings produced using the electric arc spray method are economical for corrosion protection in large-scale applications. In this study, the corrosion behaviour of two Zn-Al-Mg pseudo-alloy coatings (Al-5%Mg wire + Al-50%Zn wire and Al-5%Mg wire + 99.9%Zn wire) is investigated. A reference coating (Al-5%Mg) is also tested for comparison. The results show that the variation in the Zn content significantly affects the corrosion mechanism, including corrosion kinetics, corrosion development pathway, and corrosion products. Selective dissolution is inevitable in the pseudo-alloy coatings due to the phase segregation caused by multi-galvanic systems. Severe corrosion reactions can occur if these galvanic cells are confined in a limited space, such as in a single colony. If the electrodes of these galvanic cells are relatively large, the dissolution process can be slow but continuous. Both Zn-Al-Mg pseudo-alloy coatings exhibit improved corrosion resistance due to the barrier effect of the AlMg splats and can provide adequate sacrificial protection owing to the more negative corrosion potential of the Zn-rich splats.

Effect of incorporation of multi-walled carbon nanotubes on the CO2/CH4 separation performance of sulfonated poly (ether ether ketone) / polyetherimide composite membranes using design of experiments and molecular dynamics simulation methods

Blend membranes were prepared based on sulfonated poly (ether ether ketone) (SPEEK) and poly (etherimide) (PEI) using different amounts of multi-wall carbon nanotubes (MWCNTs) (up to 2 wt%). PEEK has been sulfonated directly to reach 70 % degree of sulfonation. The manufactured membranes were examined by X-ray diffraction (XRD), scanning field emission electron microscopy (FESEM), Fourier transformed infrared spectroscopy (FTIR). The effect of the composition of SPEEK / PEI on membrane selectivity was investigated under different feed pressures (2 to 8 bar) and temperatures (25 to 55 °C). The values of selectivity and gas permeability were varied between the value of the individual polymers, fluctuating systematically with SPEEK / PEI content variation in the blends. TGA and tensile tests result obtained for prepared membranes shown that the hybrid membrane had good thermal and mechanical properties. The addition of MWCNTs to the blend led to simultaneously improve the selectivity and permeability of the pair gases of CO2 and CH4. The permeability of CO2, as well as CH4/CO2 selectivity for the membrane with the same weight of SPEEK and PEI, and 1 wt% of MWCNTs (coded SP55M1) experienced an increase of about 22 % compared with the neat membrane. Molecular dynamics simulations (MDS) were performed by employing the COMPASS force field to estimate the diffusivity of CH4 and CO2 gases through selected membranes. At last, with compared to the obtained experimetal data, the optimized nanocomposite membrane, integrated with MWCNTs was efficient, which makes it promising platform to separate mixed gase flows of CO2 and CH4 and other related environmental processes.

Экологическая оценка накопления и миграции меди в почве возрастных ампелоценозов в результате длительного применения медьсодержащих фунгицидов в регионе Фрушка Гора Республики Сербия

The data on soil copper accumulation and slope migration due to long-term use of copper-containing pesticides in vineyards over 200 years old with different management systems in the conditions of the Fruska Gora region of the Autonomous Province of Vojvodina, Republic of Serbia are discussed. The study focused on brown forest residual carbonate soils found in sloping landscapes with different length, steepness and exposure. The total copper content in the soil on a permanently vegetated slope with a 10º steepness was 2-4 times higher on the farm with an archaic management system compared to the farm with a traditional management system on a 5º steep slope. The copper content variation ranged from 84.5-136.6, 72.3-189.4, and 41.0-247.5 mg/kg in horizons 0-5, 5-15, and 15-30 cm respectively. Copper migration down the slope was observed in both vineyards, although with different intensities. The coefficient of lateral differentiation for farms with lower slope steepness was between 0.90 and 1.45, while for those with higher steepness, it ranged from 0.96 to 5.57. The highest values of the coefficient were observed in the transaccumulative facies at a depth of 15-30 cm. The total copper content in the topsoil of the transit site of the ampelocenosis slope with archaic cultivation system exceeded by 21-47% the maximum permissible value in the Republic of Serbia, while in the lower part of the slope, in the horizons 5-15 and 15-30 cm, it was 2-3 times higher than the normative value. Keywords: COPPER, COPPER-CONTAINING PESTICIDES, VINEYARDS, AMPELOCENOSIS, ACCUMULATION, LATERAL DIFFERENTIATION, SLOPE, SLOPE STEEPNESS, BROWN FOREST SOIL

Astronomical control on organic matter enrichment of lacustrine mudstones in the first member of the Late Cretaceous Qingshankou Formation, the Songliao Basin, NE China

Astronomical forcing has an important effect on organic matter enrichment in marine mudstones, but this effect remains poorly constrained in lacustrine mudstones. Here, we investigate the astronomical control of organic matter enrichment in lacustrine black mudstone from the first member of the Qingshankou Formation in the Songliao Basin. Detailed mineralogical, lithological, geochemical, and cyclostratigraphic studies were carried out. The results show that there are high-frequency variations in the organic matter content in the mudstones of the Qingshankou Formation. The upper and lower sections are further divided according to the organic matter content level and the variation frequency. The organic matter content in the lower section is high, up to 6.08 wt%, with long-period variation and individual cycles around 10 m. The organic matter content in the upper section is relatively low, the highest organic matter content is only 2.91 wt%, with short-period variation and individual cycles mostly less than 5 m. Cyclostratigraphic studies indicate that significant astronomical signals are recorded in the mudstone stratigraphy. 100 kyr short eccentricity and 38 kyr obliquity strongly control the variation of organic matter content in the lower and upper sections, respectively. Organic matter enrichment has a closely synchronized phase relationship with paleoproductivity, preservation conditions, and dilution indicators. Astronomical cycles influence the depositional conditions of organic matter enrichment by controlling climate change, which eventually forces organic matter enrichment. At high values of eccentricity and obliquity, enhanced insolation, monsoon, precipitation, and river runoff caused lake expansion, increased input of terrestrial nutrients, and increased bottom water reduction conditions, which are conducive to organic matter enrichment. On the contrary, the depositional conditions for organic matter enrichment become poor.

Use of Pyrolysis-Gas Chromatography/Mass Spectrometry as a Tool to Study the Natural Variation in Biopolymers in Different Tissues of Economically Important European Softwood Species.

Intraspecific macromolecule variation in stemwood, knotwood, and branchwood was studied using analytical pyrolysis with the intention of introducing a rapid working method to assess the variance in lignin content using analytical pyrolysis and highlight variability markers. The study was performed on Picea abies, Abies alba, and Pseudotsuga menziesii. Lignin determined via analytical pyrolysis-GC/MS (Py-lignin) can be used to identify variations in lignin content, compared to using classical Klason lignin values as a reference method for lignin determination, which requires a correction factor. Principal component analysis (PCA) was performed to identify biopolymer pyrolysis product markers for different species, tissues, or heights that could help highlight structural differences. Douglas fir was differentiated from spruce and silver fir in the levoglucosan amount. Guaiacol was more present in spruce wood, and creosol was more present in Douglas fir. Knotwood was structurally close to stemwood in spruce and silver fir, but there was a clear transition between stemwood and branchwood tissue in Douglas fir. Knotwood was differentiated by higher furan compounds. Branchwood was clearly separate from stemwood and knotwood and presented the same markers as compression wood in the form of phenylpropanoid lignins (H-lignin) as well as isoeugenol and vinyl guaiacol, the two most produced lignin pyrolysis products.

The Impact of Ultrasound Pre-Treatment on Hot-Air-Drying Kinetics and Quality of Carrot Slices Assessed by Simulations and Experiments

This study investigated experimentally and numerically the influence of ultrasound pre-treatment on the drying kinetics of sliced carrot samples. Drying experiments were performed under different conditions, including scenarios with and without ultrasound pre-treatment at drying temperatures of 30 °C, 40 °C, and 50 °C. A diffusion-based-drying model was developed to study the impact of ultrasound pre-treatment on drying kinetics. The effective moisture diffusivity of carrots was expressed as a function of moisture content and temperature. Given the complexity of the dehydration process in carrot slices, which depends on the spatiotemporal variations in moisture content and temperature, and is challenging to monitor experimentally, the effective moisture diffusivity is computed by minimizing the discrepancy between numerical predictions and experimental moisture-content changes over time. This study revealed that ultrasound pre-treatment significantly enhanced the moisture diffusivity of the samples, increasing it by 43% to 90% at drying temperatures of 40 °C and 50 °C, respectively. To apply this analysis of ultrasound pre-treatment in large-scale dryers where thousands of slices may be involved, the proposed diffusion model was simplified to a characteristic drying-curve model. Afterwards, this characteristic drying-curve model was incorporated into a belt-dryer model. The results indicated a 12% reduction in the length of the belt dryer when ultrasound pre-treatment was applied. Additionally, the color of carrot samples was preserved better with ultrasound pre-treatment. On the basis of these results, the application of ultrasound pre-treatment in the hot-air drying of carrot slices was favored, both in terms of improved drying kinetics and quality aspects.

Liquid Metal Embrittlement Cracking in Uncoated Transformation-Induced Plasticity Steel during Consecutive Resistance Spot Welding

In the automotive production line, a single pair of electrodes is employed to produce hundreds of consecutive welds before undergoing dressing or replacement. In consecutive resistance spot welding (RSW) involving Zn-coated steels, the electrodes undergo metallurgical degradation, characterized by Cu-Zn alloying, which impacts the susceptibility to liquid metal embrittlement (LME) cracking. In the present investigation, the possibility of LME crack formation in uncoated TRIP steel joints during consecutive RSW (involving 400 welds in galvannealed and uncoated TRIP steels) was investigated. The results have shown that different Cu-Zn phases were formed on the electrode surface because of its contamination with Zn from the galvannealed coating. Therefore, during the welding of the uncoated TRIP steel, the heat generated at the electrode/sheet interface would result in the melting of the Cu-Zn phases, thereby exposing the uncoated steel surface to molten Zn and Cu, leading to LME cracking. The cracks exhibited a maximum length of approximately 30 µm at Location A (weld center) and 50 µm at Location B (shoulder of the weld). The occurrence and characteristics of the cracks differed depending on the location as the number of welds increased due to the variation in Zn content. Type A cracks did not form when the number of welds was less than 280. Several cracks with a total length of approximately 30 μm were suddenly formed between 280 and 400 welds. On the other hand, type B cracks began to appear after 40 welds. However, the number and size of these exhibited inconsistency as the number of welds increased. Overall, the results have shown that small LME cracks can form even in uncoated steels during consecutive welding of Zn-coated and uncoated steel joints.

Effect of technological parameters on the process of copper deposition on chemically and chemical-galvanically nickel-plated fibers

Purpose This paper aims to study the possibility of electroplating copper coatings on chemically and chemical-galvanically nickel-plated acrylic fibers, to be further processed into yarn, fabrics, knitwear and nonwoven materials. Design/methodology/approach Electrically conductive fibers with different copper contents have been obtained, and the effect of electrolyte pH, its composition, current strength at the first and second cathodes, as well as the metallization time on the electrophysical, physical and mechanical properties of copper-containing fibers, has been studied. Findings The studies have shown that with an increase in the copper content, the electrical conductivity, the uniformity of the coating and the uniformity of the electrophysical properties (for chemical-galvanically nickel-plated fiber) increase. In the case of copper plating of chemically nickel-plated fiber, the coefficient of variation in electrical resistance increases with increasing plating time, even though the copper content increases, and the coefficient of variation in copper content and electrical resistance decreases. The physical and mechanical properties of copper-containing fibers differ slightly from the original (subjected to copper plating) and industrial Nitron fibers. With copper plating, the strength of the fiber practically does not decrease, and the elongation decreases somewhat, compared with the mass-produced Nitron fiber. Originality/value The physical and mechanical properties of copper-containing fibers are quite high, which makes it possible to be successfully further processed into yarn, fabrics, knitwear and nonwoven materials.

Maximising mobile user experience through self-adaptive content- and ambient-aware display brightness scaling

Display subsystems have become the predominant user interface on mobile devices, serving as both input and output interfaces. For a better quality of user experience (QoE), the display subsystem is expected to provide appropriate resolution and brightness despite its impact on battery life. Existing display brightness approaches either consider content- and ambient-light in isolation or do not account for the user’s expected battery life, thereby failing to maximise the QoE. This paper proposes aCADS, a self-Adaptive Content- and Ambient-aware Display brightness Scaling in mobile devices that maximises QoE while meeting battery life expectations. The approach employs a content- and ambient lighting-aware profiler that learns and classifies each sample into predefined clusters at runtime by leveraging insights on user perceptions of content and ambient luminances variations. We maximise QoE through adaptive scaling of the display’s brightness using an energy model that determines appropriate brightness levels while meeting expected battery life. The evaluation on a commercial smartphone shows that aCADS improves QoE by up to 32.5% compared to state-of-the-art.

The Effect of Air Relative Humidity on the Drying Process of Sanitary Ware at Low Temperature: An Experimental Study

Drying is a thermodynamic process in which the moisture contained in the solid is removed by evaporation through the supply of an appreciable amount of thermal energy. It is recognized as a critical and intricate stage in the manufacturing process of ceramic materials. In general, drying at higher temperatures and lower air-relative humidity provokes severe hydric, thermal, and mechanical fractures in the ceramic parts, thus reducing product quality after the process. Then, this process must be realized under controlled conditions. From an industrial point of view, the drying process of sanitary ware takes place in two stages: drying at low temperatures (less than 40 °C) and drying at high temperatures (above 50 °C). Thus, the purpose of this work is to experimentally investigate the drying process at low temperatures in sanitary toilets. Drying experiments were conducted in an oven with the same temperature (35 °C) and different relative humidity of the drying air. The results of the moisture content, temperature, and dimension variations along the process, as well as drying and heating rates, are reported and analyzed. The results indicate that the higher the air’s relative humidity, the slower the moisture removal. Herein, aspects of the product quality after the drying process are also discussed.

Selenium enrichment in the Dingtoushan carbonate-hosted epigenetic Pb-Zn deposit in the western Yangtze Block, SW China

Selenium (Se) is a typical dispersed element (crust Clarke value only 0.05 × 10-6) and is mainly enriched in black shales (>20 × 10-6). Selenium can also be associated with Pb-Zn and U deposits. In carbonate-hosted epigenetic hydrothermal Pb-Zn deposits, the selenium contents in sulfides are commonly < 50 × 10-6, and the selenium is mainly enriched in galena, whereas the selenium contents in sphalerite are often < 10 × 10-6. There are few studies on Se-rich carbonate-hosted epigenetic hydrothermal Pb-Zn deposits, and the origin of such deposits needs more in-depth exploration. In this study, we selected the Dingtoushan Se-rich Pb-Zn deposit in the western Yangtze Block, SW China, and utilized in-situ trace elements and S-Pb isotopes of Se-rich sphalerite to investigate this issue. There are two textures of sphalerite formed in the Dingtoushan deposit, of which subhedral sphalerite (Sp-I) precipitated during the early stage, whereas euhedral sphalerite (Sp-II) generated during the late stage. The results of trace elements show that the Dingtoushan deposit is significantly enriched in selenium (>22 × 10-6) compared with other carbonate-hosted Pb-Zn deposits (<22 × 10-6, generally < 10 × 10-6) in the Sichuan-Yunnan-Guizhou (SYG) Pb-Zn metallogenic province. In detail, a positive correlation between Se, Cd, In and Cu contents and sulfur isotopes of sphalerite is identified at the deposit scale, but no relationship is observed at the grain scale. In addition, the late stage Sp-II with δ34S values of −7‰ to −3‰ is rich in selenium and other trace elements, whereas the early stage Sp-I with isotopically light sulfur (δ34S = -29 ‰ to −8‰) is depleted of them. This indicates that in the early stage, insufficient addition of hydrothermal fluid resulted in relatively low temperature, and sulfur formed by bacterial sulfate reduction (BSR) was mainly involved in mineralization. With the addition of a large amount of hydrothermal fluid, thermochemical sulfate reduction (TSR) was induced, which leads to the formation of sphalerite in the late stage with relatively high δ34S values. Furthermore, the Pb isotopes reveal that the ore-forming metals were likely derived from the Cambrian black shales. Hence, we infer that fluid mixing is the main sulfide precipitation mechanism and may cause the positive correlation of selenium concentrations and δ34S values. On the other hand, at the grain scale of sphalerite, the variation of selenium contents shows a negative correlation with temperature, suggesting that temperature may play a critical role in selenium enrichment in sphalerite. This study highlights that selenium enrichment in sphalerite is jointly controlled by fluid mixing and temperature. The degree of fluid mixing dominated the selenium concentration in hydrothermal fluid, but high temperature may not be conducive to selenium incorporation into sphalerite. Our new results indicate that sphalerite in the carbonate-hosted epigenetic hydrothermal deposits is also a major host for selenium and such type deposits may have a great economic potential for selenium resource.

Petrogenesis of Neoproterozoic high-K intrusion in the southwestern Yangtze Block, South China: Implication for the recycled subducted-sediment in the mantle source

The study of K-enriched intrusive rocks is essential for deciphering mantle metasomatism beneath active continental arcs. In this contribution, high-precision zircon U–Pb–Hf isotope, whole-rock geochemistry, Sr–Nd isotope, and mineral chemistry analyses were performed to evaluate the petrogenesis and geodynamic system of the Yunnongfeng intrusion on the southwestern margin of the Yangtze Block. The Yunnongfeng intrusion consists of a high-K to shoshonitic rock assemblage with variable lithology from gabbro-diorite to granite. Zircon U–Pb dating gives concordant crystallization ages of ca. 782.5 ± 3.8 Ma for gabbro-diorite, ca. 774 ± 4.1 and 776 ± 4.1 Ma for diorite, ca. 770 ± 4.7 Ma for quartz monzonite, ca. 763 ± 3.4 Ma for quartz syenite, and ca. 764 ± 16 Ma for granite. These samples also show similar Sr–Nd, and Lu–Hf isotopic compositions, implying a common magma source. The similar crystallization age and regular variation of major and trace element contents suggest that these rocks were formed through fractional crystallization of cogenetic primitive mantle magmas. The enriched εNd(t) (−5.7 to − 5.1) and εHf(t) (−6.7 to − 1.2) values, high Rb/Y and Th/La ratios, slight Nd–Hf decoupling, and high-K and Th contents demonstrate that their lithospheric mantle source was enriched by slab-related fluid and sediment-related melt. The samples also exhibit remarkable enrichment in large-ion lithophile elements and depletion in high-field-strength elements, indicative of subduction-related arc magmatism. Taking into account previous studies, we suggest that the western margin of the Yangtze Block experienced a long-term subduction process during the Neoproterozoic, and the Yunnongfeng intrusion formed in an extensional back-arc basin. Based on the K-enriched mafic–intermediate rocks from the western margin of the Yangtze Block commonly show high K2O/Na2O, Rb/Sr, low Ba/Rb ratios, and enriched εNd(t) values, our study, coupled with numerous previous reports, proposes that the K-enrichment resulted from the breakdown of phlogopite, owing to subduction-related sediment melt reacting with peridotite in the mantle source area.