Influence Of Chemical Components Research Articles

The influence of SBS modification on the rheological property of asphalt before and after regeneration

In this article, the author intends to explore the different aging process of SBS modified asphalt, and the influence of chemical components on the rheological property by adding regeneration agents. To this end, the samples of different degrees of aging need to be prepared so as to simulate the aging behaviors during the processes of SBS modified asphalt, namely, mixing, transport, operation, and service. The Fourier transform infrared (FT-IR), dynamic shear rheology (DSR), and bending beam rheology (BBR) are conducted to study the different degrees of aging and the influence of regeneration agents on the rheological property of SBS modified asphalt and its micro components. The author has conducted quantitative analysis on different degrees of aging and the micro components of SBS modified asphalt after regeneration based on rheological property. Besides, the article discussed the rheological property parameter and the influence of regeneration agents on SBS modified asphalt and micro components. The result of research indicated that, as the aging degree increased, the complex modulus, phase angle, and creep rate of SBS modified asphalt decreased. Besides, the creep stiffness modulus increased, with obvious growth of carbonyl index (CI) and sulfoxide index (SI) and decrease of butadiene index (BI); when the regeneration agents are added, the rheological property index of recycled asphalt, the content change of characteristic functional group are opposite to that of aging asphalt. Based on the grey relational analysis, carbonyl is the most seriously affected in terms of how the change of recycled asphalt’s chemical components influence high temperature rheology property parameter, followed by sulfoxide and butadiene. In terms of the stiffness modulus, the most seriously affected is carbonyl, followed by sulfoxide and then butadiene. In terms of the creep rate, the most seriously affected is butadiene, followed by sulfoxide and then carbonyl.

Effect of chemical composition of calcined bauxite aggregates on mechanical and physical properties for high friction surface course

This paper attempts to show the impact of chemical components on the mechanical and physical performance of calcined bauxite, especially the long-term skid resistance. Firstly, the mechanical and physical properties of five types of calcined bauxites including, the polished stone value (PSV), crush value, Los Angeles Abrasion value (LAA), adhesion property, bulk density and water absorption were tested. The X-ray fluorescence (XRF) and X-ray diffraction (XRD) were applied to examine the chemical and mineral components of aggregate. The Pearson correlation coefficient and Pearson correlation coefficient matrix by Statistic Package for Social Science (SPSS) were utilized to study the relationship between chemical components and mechanical, physical properties of calcined bauxite. Then, the long-term skid resistance of calcined bauxite aggregate was carried out in the laboratory by accelerated polish machine and British Pendulum Tester. The polishing mechanism and the influence of chemical components on the skid resistance of calcined bauxite aggregates were gained by linear regression methods. The asymptotic model was adopted to fit the relationship between British pendulum number (BPN) and polish times. The results indicate that the chemical compositions of calcined bauxite aggregate including Al2O3 and SiO2 along with indicator SiO2/Al2O3 show significant impact on the mechanical and physical properties of calcined bauxites. The final value of PSV (PSVf) is significantly correlated with average grain size (D), corundum, mullite and Aggregate Hardness Parameter (AHP) of calcined bauxite. The asymptotic model can describe the decay process of polish of calcined bauxite with polish time. The PSVn can be expressed with PSVf and SiO2/Al2O3 by linear equation. In addition, the incorporation of calcined bauxite improves MPD (Mean Profile Depth) and BPN of limestone asphalt mixture. This provides a new and interesting way for selecting suitable aggregate used in the pavement surface layer.

Contemporary methods for production of Prussian blue

Prussian blue, a blue-coloured pigment, has found a wide application in various branches of production, including such industries as construction and transport, where Prussian blue is applied as a coloured coating, and also in agriculture and medicine. A typical technological process for production of Prussian blue includes nucleation, enlargement of formed crystals, aggregation of formed crystals, and, finally, recrystallization followed by further oxidation, rinsing of impurities and drying. A typical technological process for production of Prussian blue is observed, its features are studied, and the influence of chemical components on the properties of the obtained pigment are examined. Recommendations on the mole ratio and concentrating of chemical components are given. The pigment produced by the given recommendations is superior in quality to foreign counterparts.

Prosopis spp. powder: influence of chemical components in water adsorption properties

SummaryProsopis alba and Prosopis nigra powders from pods were evaluated through chemical and mineral composition and other healthy food compounds such as polyphenols and fatty acids exhibiting antioxidant activity. P. nigra presented higher content of lipids and polyphenols leading to a higher antioxidant activity than P. alba. Although P. nigra presented lower amount (%) of fibre (20.1 vs. 23.3), the amount of total soluble sugars responsible of water retention was slightly higher (PN: 57.1, PA: 56.7). Moisture content, water activity and water absorption behaviours were different between both powders due to differences in their chemical composition. P. nigra powder presented higher amounts of polyphenols, antioxidant activity and lower initial equilibrium moisture content (aw = 0.7), with a lower aw at 20 °C at the same water content, suggesting that P. nigra powder would have less possibility of deterioration during storage.

Influence of pollution chemical components on AC flashover performance of various types of insulators

The pollution on insulators is composed of various chemical components, which threaten the stability of external insulation. However, the existing insulation designs have not taken this issue into consideration. This work aimed to study the influence of pollution chemical components on flashover performance of insulators with various materials. Flashover tests of porcelain, glass and silicone rubber insulators polluted by eight types of common contaminants were conducted. Based on the test data, the influence of chemical components and their solubility on equivalent salt deposit density (ESDD) and insulator flashover performance were analysed; and the electrical properties of different types of insulators were compared. Results show that the ESDD contribution rate changes with chemical components. The dissolution characteristic has a significant influence on the measurement of ESDD; slightly soluble contaminants need to be considered separately. The corresponding insulator flashover gradient for ions can be summarised as Cl− < NO3 − < SO4 2−, K+ < Na+, NH4 + < Ca2+. For a glass insulator, the flashover gradient is 4.9–17.0% higher than that of a porcelain insulator. For a silicone rubber insulator, this gap reaches 14.6–24.4 and 83.3–90% for freely soluble pollution and CaSO4, respectively, this phenomenon can be explained by the combined action of the slightly soluble character of CaSO4 and hydrophobicity transference of silicone rubber.

Effects of autohydrolysis of Eucalyptus urograndis and Eucalyptus grandis on influence of chemical components and crystallinity index

Samples of Eucalyptus urograndis and Eucalyptus grandis sawdust were autohydrolyzed in aqueous conditions to reach temperatures in the range 110–190°C and reaction times of 0–150min in a minireactor. In each minireactor were used a liquor:wood ratio (10:1 L:kg dry wood), in order to assess the effects of the autohydrolysis severity and the crystalline properties of cellulose. The content of extractives, lignin, holocellulose, cellulose, hemicelluloses and crystallinity index obtained from the solid fraction after autohydrolysis of sawdust were determined. This study demonstrated that the hemicelluloses were extensively removed at 170 and 190°C, whereas cellulose was partly degraded to Eucalyptus urograndis and Eucalyptus grandis sawdust. The lignin content decreased, while the extractives content increased. It was defined that during autohydrolysis, had a slight decreased on crystalline structure of cellulose of Eucalyptus urogandis and Eucalyptus grandis.

月粉じんの有害性評価手法の開発

In order to explore whether lunar regolith induce airway hyperreactivity or bronchial asthma or not, we examined cellular influences of lunar regolith simulant whose component are similar to that of the lunar regolith. Particularly, we focused chemical component and particle size because the difference in the gravity between earth and moon, affect the different in the particle size of respirable dusts. The regolith simulant was fractionated to <10 μm, <25 μm and 10–25 μm by gravitational sedimentation in suspensions. The particle size with less than 10 μm means the respirable dust in earth, and particle size with less than 25 μm means respirable dusts in moon by calculating the one sixth of gravity of earth. Additionally, we also examined cellular influences of fine regolith simulant. Human lung carcinoma A549 cells were incubated at concentration of 0.1 and 1.0 mg/ml of these regolith simulants. After 24 h exposure, cytotoxicity, oxidative stress and immune response were examined. When the concentration was 1.0 mg/ml, cell membrane damage, mitochondrial dysfunction and induction of IL-8 were observed. Compared with crystalline silica which is positive control, cellular influences of the regolith simulant at concentration of 0.1 mg/ml were little. Secretion of IL-1β and TNF-α was observed at concentration of 1.0 mg/ml, however, induction of their gene expression did not observed at 24 h after exposure. Induction of cellular oxidative stress was small. Although the cell influence tended to be strong in the <10 μm particles, there was no remarkable difference. These results suggest that influence of chemical components and particles size on the cellular influence of lunar regolith simulant is small.

Morphology and Precipitation Kinetics of MnS in Low-Carbon Steel During Thin Slab Continuous Casting Process

The morphology of manganese sulfide formed during thin slab continuous casting process in low-carbon steel produced by compact strip production (CSP) technique was investigated. Using transmission electron microscopy analysis, it was seen that a majority of manganese sulfides precipitated at austenite grain boundaries, the morphologies of which were spherical or close to the spherical shape and the size of MnS precipitates ranged from 30 nm to 100 nm. A mathematical model of the manganese sulfide precipitation in this process was developed based on classical nucleation theory. Under the given conditions, the starting and finishing precipitation temperatures of MnS in the continuous casting thin slab of the studied low-carbon steel are 1 189 °C and 1 171 °C, respectively, and the average diameter of MnS precipitates is about 48 nm within this precipitation temperature range. The influences of chemical components and thermo-mechanical processing conditions on the precipitation behavior of MnS in the same process were also discussed.

Cytotoxicity of selected magnetic fluids on human adenocarcinoma cells

Based on the knowledge that the magnetite particles seem to be well tolerated by the human body, the cytotoxic potential of coated particles was investigated, which had been selected for potential applications regarding the minimal-invasive elimination of breast tumors by magnetic thermoablation. Human adenocarcinoma cells (BT-20) were exposed (24, 48 and 72 h) to different magnetite particles with diverging total size (8, 10 and 220 nm) and coating (cationic and anionic). One sample contained only non-coated magnetite particles. The magnetite concentration ranged between 0.2 and 20 ng/cell. Cytotoxicity was estimated by measuring the succinate dehydrogenase activity. The morphologic features resulting from the interaction of magnetic fluids with BT-20 cells was determined by transmission electron microscopy. As opposed to the non-coated magnetic particles, cationic particles induced the strongest decrease in cell survival rates depending on time and concentration. Morphologically, the cationic particle samples exerted a strong binding to cellular membranes. Changes in the subcellular structure were found in relation to the coated magnetic particles. In conclusion, our results show that the coated prototype magnetic particles, particularly those with a cationic surfactant, are cytotoxic to BT-20 cells. The cytotoxicity is attributed to electrostatic bindings with cellular membranes, influences of chemical components or non-physiologic pH. Considering the in vivo applications, adverse systemic effects are conceivable and more biocompatible coatings for the selected magnetic particles should be elaborated.

The Influence of Chemical Components on Firmness of Boiled Tuber of Taro

The Influence of Chemical Components on Firmness of Boiled Tuber of Taro

Role of chemical components of resistant and susceptible genotypes of cotton and okra in ovipositional preference of cotton leafhopper

Ovipositional preference of cotton leafhopper,Amrasca biguttula biguttula (Ishida) on resistant and susceptible genotyps of cotton and okra was found under the influence of chemical components. The non-reducing sugars, tannins, silica and free gossypol in the leaves showed significant and negative correlation with the number of leafhopper eggs.