Search

Foaming agents are widely used in the processing of polymer materials. The p-toluenesulfonyl hydrazide (TSH), as a foaming agent, generates foams that are fine and uniform. However, the extensive heat produced during the thermal decomposition of foaming agents greatly increases the risk throughout the process. Accidents involving TSH have caused severe economic losses of 300,000 RMB in China. In this study, a differential scanning calorimetry, adiabatic accelerating calorimeter, thermogravimetric-infrared spectrometer, and Gaussian molecular simulation software were adopted to explore the pyrolysis characteristics and decomposition mechanism of TSH and TSH containing impurities (water, urea). Experimental results indicated that the apparent activation energy of pure TSH was 173.39 kJ mol−1. The potential for explosion is high when TSH decomposed, as it releases heat and gaseous products. The addition of water or urea reduces the hazard level of TSH, but urea promotes the decomposition of TSH. The time it takes for a reaction to reach its maximum rate under adiabatic conditions (TMRad) to reach 24 h (TD24) and 8 h (TD8) was 46.8 and 56 °C, respectively. Comparing the experimental results with molecular simulations, the products of thermal decomposition of TSH include nitrogen, water, aryl disulphides, and sulphide sulphonates. [ABSTRACT FROM AUTHOR]

The increasing concerns about health have led to a growing demand for high‐quality fried foods. The potential uses of Ligustrum robustum (Rxob.) Blume, a traditional tea in China, as natural additives to enhance the quality of starchy food during frying was studied. Results indicated that L. robustum polyphenols extract (LREs) could improve the quality of fried starchy food, according to the tests of color, moisture content, oil content, texture property, and volatile flavor. The in vitro digestion results demonstrated that LRE reduced the final glucose content from 11.35 ± 0.17 to 10.80 ± 0.70 mmol/L and increased the phenolic content of fried starch foods from 1.23 ± 0.04 to 3.76 ± 0.14 mg/g. The appearance and polarizing microscopy results showed that LRE promoted large starch bulges on the surface of fried starchy foods. Meanwhile, X‐ray diffraction results showed that LRE increased the intensity of characteristic diffraction peak of fried starch with a range of 21.8%–28%, and Fourier transform infrared results showed that LRE reduced the damage to short‐range order structure of starch caused by the frying process. In addition, LRE increased the aggregation of starch granules according to the SEM observation and decreased the enthalpy of starch gelatinization based on the differential scanning calorimetry results. The present results suggest that LREs have the potential to be utilized as a natural additive for regulating the quality of fried starchy food in food industries. Practical Application: The enhancement of L. robustum polyphenols on the quality of starchy food during frying was found, and its mechanisms were also explored. This work indicated that L. robustum might be used as a novel economic natural additive for producing high‐quality fried foods. [ABSTRACT FROM AUTHOR]

Methylene diphenyl diisocyanate (MDI) serves as a primary component of polyurethane in various applications, including household appliances, architectural structures, automobiles, and adhesives. A recent MDI plant explosion in China highlighted the importance of studying MDI's thermal stability and parameters to prevent accidental thermal decomposition. In this study, an extensive array of analytical techniques, including differential scanning calorimetry, thermogravimetric analysis, and adiabatic accelerating calorimeter, was employed to determine the thermokinetic constants of MDI, providing a solid foundation for further in-depth investigations. The findings revealed that MDI containing water reacts at substantially lower temperatures, while pure MDI can release heat and gases in an adiabatic environment, posing a considerable explosion risk. The kinetic constant of MDI was calculated using the Flynn–Wall–Ozawa method, yielding apparent activation energy values ranging from 51.78 to 96.70 kJ mol−1 across a conversion degree range of 0.05–0.70. The Coats–Redfern model pinpointed the kinetic reaction mechanism as a two-stage chemical process based on the apparent activation energy. Molecular optimization, following the energy minimisation principle, was conducted using Gaussian 09 software, which led to the identification of the optimal pathway for generating carbodiimide and carbon dioxide. This investigation offers valuable insights for the effective management of MDI during production, transportation, and storage, contributing to improve loss prevention practices in the industry. [ABSTRACT FROM AUTHOR]

In recent years, the coagulation properties of inorganic minerals such as kaolin and zeolite have been demonstrated. This study aimed to assess the hemostatic properties of three local clays from China: natural kaolin from Hainan, natural halloysite from Yunnan, and zeolite synthesized by our group. The physical and chemical properties, blood coagulation performance, and cell biocompatibility of the three materials were tested. The studied materials were characterized by using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). All three clays showed different morphologies and particle size, and exhibited negative potentials between pH 6 and 8. The TGA and DSC curves for kaolin and halloysite were highly similar. Kaolin showed the highest water absorption capacity (approximately 93.8% ± 0.8%). All three clays were noncytotoxic toward L929 mouse fibroblasts. Kaolin and halloysite showed blood coagulation effects similar to that exhibited by zeolite, indicating that kaolin and halloysite are promising alternative hemostatic materials. [ABSTRACT FROM AUTHOR]

The sintered permeable brick was prepared using granite waste and burnt coal cinder (BCC) as raw materials to ensure the utmost utilization of both solid wastes. The effect of various parameters, such as the proportion of raw materials, granite particle size and sintering temperatures on the properties of the permeable brick were studied, and the relevant sintering mechanism was clarified. The differential scanning calorimetry curves indicate that the mixture of granite waste and BCC begins to melt at a lower temperature, which is lower than the temperature for melting them alone, so the use of them to prepare sintered bricks will reduce energy consumption. The optimal conditions for the preparation of the permeable bricks were determined as the mass ratio of granite waste to BCC of 80: 20, sintering temperature of 1150–1175°C, and granite particle size of.9–1.25 mm. It was found that the permeability and the flexural strength of the samples can reach 3.41 × 10 −2 cm/s and 4.2 MPa, respectively, which both exceed the requirements specified in the national standard of China. [ABSTRACT FROM AUTHOR]

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Food & Machinery is the property of Food & Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Henan University of Technology Natural Science Edition is the property of Henan University of Technology Journal Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Dabei deep high-pressure condensate gas field occupies the paramount position in the Tarim Oilfield in China, the exploration and developments of which have been progressing. Since the initial development, the wax deposition and plugging in the wellbore and gathering pipeline have been the most bothering issues, resulting in the reduction or even shutdown of condensate gas well production. Therefore, the wax appearance temperature of Dabei condensate oil was studied using the capillary viscometer, differential scanning calorimetry (DSC), and polarizing microscope observation. The wax content was tested by using the DSC and crystallization separation test method. Finally, the wax appearance temperatures of degassed condensate oil and equilibrium condensate oil under different pressures were tested. Experimental results show that the wax appearance temperature measured by polarizing microscope observation was higher than that measured by the DSC and capillary viscometer, the lag of which can be recorded as the cloud point. The wax appearance temperature measured by polarizing microscope observation is of high accuracy. Secondly, the DSC method is not sufficient for measuring wax precipitation at low temperatures, showing a lower wax content than the crystallization separation test method. Thus, the wax content of Dabei condensate oil can be better measured by using the crystallization separation test method. Additionally, the wax precipitation law of equilibrium condensate oil is opposite to that of degassed condensate oil. The wax appearance temperature of equilibrium condensate oil increases as the pressure decreases. The results of wax appearance temperature of equilibrium condensate oil provide a useful and quick index to judge the potential risk of wax precipitation in the Tarim Oilfield, which can provide an efficient strategy for the development of waxy condensate gas reservoirs and the optimization of wax prevention and treatment technology. [ABSTRACT FROM AUTHOR]

The typical combustion mode of underground coal fires (UCFs) is smoldering during which the reaction zone is not exposed to a constant oxygen concentration. Understanding the macro-kinetics of coal-oxygen reactions under varying oxygen concentrations, especially the extremely oxygen-depleted condition, is of both theoretical importance and practical relevance to the control and extinguishment of UCFs. Considering the actual conditions of UCFs, thermal analysis tests under four oxygen concentrations (from 21% to 3%) and three heating rates (1,2 and 5 °C/min) were carried out. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) results were obtained for a bituminous coal sample from Inner Mongolia, China. With the global reaction assumption, the macro-kinetics parameters (the apparent activation energy, the pre-exponential factor and the kinetics model function) were determined. On the profiles of the apparent activation energy (Ea), three peak values were observed, physically interpreted as the depiction of volatiles, the formation of plastic mass and the depiction of char, respectively. This interpretation was verified by characteristic temperatures extracted from the experimental data. With the decrease of the oxygen concentration from 21% to 9%, two peak values diminish gradually. The case with 3% oxygen concentration gives a nearly monotonically declining Ea, indicating that under that particular condition, oxygen diffusion stands as the only limiting factor across all stages of coal-oxygen reactions. The best-fit kinetics model functions suggest that the char oxidation stage fal[s into the kinetics-controlled regime when the oxygen concentration is as low as 9%. For the volatiles burning stage, the universal ignition index (Fz) is found to be effectively related to the reaction regime for a variety of coal ranks. The quantitative results obtained can be integrated into any CFD multi-physics models as a sub-model for chemical kinetics. [ABSTRACT FROM AUTHOR]

With people's awareness of environmental protection, the requirement of eco‐quality is increasingly demanding, particularly a more profound reflection in the field of materials. Polylactic acid (PLA) is a hopeful biodegradable thermoplastic material while its adverse nature restricts the practical applications. In this work, a one‐step reactive extrusion method was adopted to improve some properties of PLA by melt blending with some active additives, including commercial epoxy‐based chain extender, that is, ADR4468 of BASF, Germany; thermoplastic polyurethane thermoplastic polyurethane (TPU) elastomer, that is, DN‐5380 of Dawn, China, and mineral nucleating agent talc, that is, AH250CL of Aihai, China. Their influences on mechanical properties and crystallization behaviors of PLA were explored, and the detailed mechanisms were also discussed. It is found that ADR chain extender played a key role in improving the strength and rigidity of the composites, and methylenediphenyl diisocyanate type TPU elastomer could significantly enhance the toughness and ductility of PLA materials, while talc had a positive impact on regulating the cooling crystallization behavior of PLA. In particular, only trace ADR4468 (0.4 wt%) could effectively enhance its tensile and flexural strengths of neat PLA by 6.3% and 13.4%, respectively. Reactive polyurethane with 5 wt% significantly improved its elongation at break by 36.5%. The micro‐sized talc‐nucleating agent enhanced the cooling crystallization degrees to 24.7% from 4.8% for PLA blended with trace chain extender. The analysis results indicated that the functional group reactions between the active additives and PLA played key roles in improving the related properties. The output has certain reference values for PLA modification strategy, and will pave a route for endowing PLA materials with specific and required nature. [ABSTRACT FROM AUTHOR]

A series of poly (n-alkyl acrylate-maleic anhydride) with different molecular weights were prepared as pour point depressants (PPDs) for JENM waxy crude oil obtained from the China-Myanmar crude oil pipeline. The crystallization temperature, wax morphology, and rheological behavior of crude oil were analyzed by differential scanning calorimetry, polarizing microscope, and rotary rheometer, respectively. The results indicate that the molecular weight significantly affects the performance of the pour point depressant. When the weight-average molecular weight (Mw) of copolymers were ranging from 60,000 to 70,000, it has a better pour point depression effect for JENM crude oil. The added copolymer (MW = 68,300) has achieved optimal performance which decreased the pour point of crude oil from 30 to 19 °C and crystallization temperature from 39.5 to 36.1 °C with the smallest wax crystal size and the 96.7% reduction viscosity. [ABSTRACT FROM AUTHOR]

The thermal characteristic behaviors of two kaolinite samples selected from Qingshuihe region in Inner Mongolia in China were studied through thermogravimetry, derivative thermogravimetry, and differential scanning calorimetry (TG–DTG–DSC), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy. The activation energies of dehydroxylation for the two kaolinite samples (determined as Kaol-1 and Kaol-2) were calculated based on KAS and FWO methods. The XRD results indicated that Kaol-1 and Kaol-2 both were determined as kaolinite, and a small amount of quartz, but the Kaol-2 presented many amorphous organic matters. The TG–DSC results displayed the adsorbed water desorption and dehydroxylation with the temperature increased from 200 to 1100 °C. The dehydroxylation is followed as the intensities decrease in the bands at 3690 cm−1, 3620 cm−1 and 914.0 cm−1 attributing to the stretching mode of inner surface hydroxyls, and which disappeared when the temperature reached at 600 °C. The endothermic peak temperature of dehydroxylation for Kaol-2 presented higher than that of Kaol-1, which may be attributed to present of amorphous organic matter and was in agreement with the XRD data. The maximum endothermic temperature of dehydroxylation increased both for Kaol-1 and Kaol-2 with the increase in heating rate, which was attributed to more sufficient decomposition as the decrease in heating rate. The thermal kinetic analysis indicated that the dehydroxylation reaction of Kaol-1 should be a single kinetic mechanism, but the E of Kaol-2 decreased as α increasing from 0.2 to 0.5 and then gradually increased with the increase of α. The average E of dehydroxylation for Kaol-2 both was lower than that of Kaol-1 based on Kissenger–Akahira–Sunose and Flynn–Wall–Ozawa methods, which was attributed to the relatively higher organic carbon content in Kaol-2. [ABSTRACT FROM AUTHOR]

We developed a novel preparative method for nanoparticle albumin-bound (nab) paclitaxel with high drug loading, which was based on improved paclitaxel solubility in polyethylene glycol (PEG) and self-assembly of paclitaxel in PEG with albumin powders into nanoparticles. That is, paclitaxel and PEG were firstly dissolved in ethanol, which was subsequently evaporated under vacuum. The obtained liquid was then mixed with human serum albumin powders. Thereafter, the mixtures were added into phosphate-buffered saline and nab paclitaxel suspensions emerged after ultrasound. Nab paclitaxel was finally acquired after dialysis and freeze drying. The drug loading of about 15% (W/V) were realized in self-made nab paclitaxel, which was increased by approximately 50% compared to 10% (W/V) in Abraxane. Now this new preparative method has been authorized to obtain patent from China and Japan. The similar characteristics of self-made nab paclitaxel compared to Abraxane were observed in morphology, encapsulation efficiency, in vitro release, X-ray diffraction analysis, differential scanning calorimetry analysis, and circular dichroism spectra analysis. Consistent concentration-time curves in rats, biodistributions in mice, anti-tumor activities in mice, and histological transmutation in mice were also found between Abraxane and self-made nanoparticles. In a word, our novel preparative method for nab paclitaxel can significantly improve drug loading, obviously decrease product cost, and is considered to have potent practical value. [ABSTRACT FROM AUTHOR]

Coal spontaneous combustion (CSC) is a major safety concern affecting not just miners and businesses, but of industry in China generally. Chemical methods are already widely applied in the field of CSC prevention and plays a vital role in suppressing its negative effects. Ionic liquids (ILs) are novel and environmentally friendly solvents that have shown possible inhibitory effects on CSC through controlling the reactive groups in coal's molecular structure. To study the effects of various ILs on CSC more thoroughly, this paper examined several types of IL that had been pre-treated for different periods and examined how they performed during different phases of the combustion process. A long flame coal type was selected and immersed in four ILs [BMIM][BF4], [BMIM][NO3], [BMIM][I], and [EMIM][BF4]. Immersion periods were 2 days, 3 months, and 6 months; a raw coal sample was retained as a control. LFA 457 laser-flash apparatus determined the thermophysical properties of the samples between 30 and 300 °C. The kinetic process of the samples (30–800 °C) was deduced by thermogravimetric–differential scanning calorimetry thermal at various heating rates (2, 5, 10, and 15 °C min−1), and the thermal effect parameters were obtained. Results from this paper show that immersion treatment using ILs has an inhibitory effect on CSC, and the reliability of the thermophysical parameters was verified by uncertainty analysis. The pre-treated samples characteristics and exothermic peak temperature with different degrees of hysteresis were recorded, and statistical analysis verified the conclusions from the thermal physics experiments. The pre-treated sample with the greatest lag over various stages was found, and the apparent activation energy (Ea) of its rapid oxidation stage was calculated by Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose methods. Meanwhile, the two kinetic methods confirm each other and come to a conclusion after joint verification. The greatest Ea found here was for a 6-month immersion coal sample using the IL [BMIM][BF4]. [ABSTRACT FROM AUTHOR]

Summary: Coal gangue spontaneous combustion produces toxic and harmful gases. This research aims to study a new type of polymer nanocomposite inhibitor to prevent and control coal gangue spontaneous combustion. Nanomodification of montmorillonite (MMT) was carried out on high polymer emulsion inhibitor polyacrylamide (PAM) to improve its thermal stability and overcome the short inhibition duration problem. First, through scanning electron microscope (SEM), energy‐dispersive spectrometer (EDS), and proximate analysis experiments, it was found that the coal gangue in the Yangquan mining area was prone to spontaneous combustion. Then, PAM/MMT was produced by an intercalation method. The results of X‐ray diffraction (XRD) and differential scanning calorimetry (DSC) showed that the interval spacing of MMT increased, which was sufficient for the insertion of acrylamide monomer. The vitrification temperatures of PAM and PAM/MMT prove that PAM/MMT exhibited higher thermal stability. The results of Fourier transform infrared spectroscopy (FTIR) experiments indicated that the PAM/MMT composite inhibitor agent effectively inhibited the oxidative activity of reactive groups on the coal gangue surface. As a result, PAM/MMT could suppress coal gangue oxidative spontaneous combustion, so as to reduce environmental problems caused by coal gangue spontaneous combustion. Furthermore, a spraying process is designed for the application of the inhibitor. [ABSTRACT FROM AUTHOR]

Large amounts of silt have been deposited on the seabed in China's coastal areas due to intensive coastal development and marine raft aquaculture, which are the main causes of local marine environmental disasters. In this study, seabed silt was tested as a potential raw material for artificial reefs. The silt was mixed with cement in four proportions to create concrete specimens for use in silt artificial reefs (SARs). The compressive strength development and nutrient dissolution were examined in the SAR specimens. The hydration products of the SAR paste were investigated through X-ray diffraction (XRD), scanning election microscope (SEM), and differential scanning calorimetry (DSC) techniques. The results showed that the compression strength of the SAR specimens was inversely proportional to their seabed silt content. The SAR specimens were able to continuously dissolve nitrogen-containing nutrients. The presence of Ca(OH)2, commonly found in traditional concrete, was not detected, which may help improve the seaweed adhesion and biological effects of artificial reefs. The effective utilization of seabed silt could serve to restore and improve the marine ecological environment. [ABSTRACT FROM AUTHOR]

Moisture sorption isotherms of water caltrop pericarp (WCP) powders were determined at 20, 30, and 40°C over water activity (Aw) range of 0.11 and 0.97. The adsorption isotherms decreased with the increase of temperature and exhibited Type II BET adsorption characteristics. The monolayer moisture content values calculated by the Guggenheim–Anderson–de Bor equation were found to be 0.0561, 0.0509, and 0.0409 g/g solids at 20, 30, and 40°C, respectively. The values of net isosteric heat of adsorption and differential entropy decreased from 26.094 to 0.250 kJ/mol, 76.665 to 0.358 J mol−1 K−1 with water content varying from 0.30 to 0.07 g/g solids, respectively. The isokinetic theory showed that the water adsorption process of WCP powders was governed by enthalpy. The values of specific surface area available for adsorption at 20, 30, and 40°C were 198.95, 180.40, and 145.11 m2/g, respectively. The spreading pressure increased with the increase of Aw values at a fixed temperature and decreased when temperature rising at a given Aw level. The effective pore size for WCP powders increased with the increment of water content and temperature, ranging from 1.648 to 21.761 nm. The glass transition temperature (Tg) of WCP powders was examined by differential scanning calorimetry and its values decreased from 72.34 to 2.42°C as water content ranged from 0.0499 to 0.352 g/g solids. The result showed that WCP powders remained stable at 30°C when the moisture content was lower than 0.149 g/g solids. Practical applications: Water caltrop (Trapa bispinosa Roxb) has been widely cultivated in China and other Southeast Asia because of its medical functions and delicious taste. The micronized water caltrop pericarp (WCP) is an excellent source of dietary fiber and phenolics and has been applied in various food and nonfood sectors. The objectives of this work were to evaluate the thermodynamic properties of water adsorption isotherms of WCP powders. In addition, a state diagram was established based on the water activity concept and glass transition theory. The results documented in this study will help design the energy process for producing WCP powders and predicting storage stability. [ABSTRACT FROM AUTHOR]

Slick water volume fracturing technology is one of the main technologies for the development of high temperature and compact carbonate reservoirs in 'Western China at present. Slick water complex acid is mainly used to form volume acid fracturing fractures to improve the stimulation effect. However, at the present stage of field construction in Western China, high salinity groundwater is used to distribute fluids, while formation temperature is high, the performance of conventional friction reducer is seriously reduced, so it is necessary to develop targeted high- performance polymer friction reducer. Through the optimization of fracturing fluid additives, free radical aqueous solution copolymerization was carried out by using one or more hydrophilic monomers and temperature/salt resistant monomers. In order to optimize the modified monomers and their dosage, infrared spectroscopy, nuclear magnetic resonance and differential scanning calorimetry are used to analyze the newly synthesized polymers. Finally a kind of modified monomers is developed, which has good temperature resistance, fast dissolution rate under high salinity conditions, excellent friction reduction, swelling properties, low formation damage, and the flow-back treatment is simple. It can tolerate high temperature o f 14() °C. • and rapidly dissolve under the salinity of "100,000 mg/L, the resistance reductio n rate is abou t 70%. A new type o f temperature-resistant and salt-resistant slick water fracturing fluid system act as a theoretical foundation and technical support for the development o f ultradeep carbonate rocks [ABSTRACT FROM AUTHOR]

Chinese rice wine (CRW), with its high nutritional value and unique flavor, has been popular in China for thousands of years. The traditional steps of immersion and steam cooking during the brewing of rice wine have several drawbacks, including the long production time, large energy consumption, generation of wastewater and the large production area it occupies. Extrusion puffing has the potential to overcome these drawbacks. In this study, the physicochemical properties of extruded-puffed brown rice obtained under different conditions were analyzed. The puffed extrudates exhibited low bulk density, high water solubility index and higher surface area than the steam-cooked brown rice. Extrusion puffing operates at high temperatures, high pressure and provides mechanical shearing forces, resulting in the puffed extrudates having a higher degree of gelatinization, as determined by X-ray diffractometer (XRD), Fourier transform infrared spectroscopy with attenuated total reflection (FTIR-ATR) and differential scanning calorimetry (DSC), revealed the disruption of the native crystalline structure. The effect of extrusion on enzymatic hydrolysis was evaluated using amylase digestion. The results indicated that puffed extrudates significantly improved the enzymatic hydrolysis rate and yield. Moreover, the catalytic efficiency was evaluated by kinetic constants, with extrusion puffing treatment demonstrating an efficiency18-fold higher than steam-cooked brown rice. Finally, extruded-puffed blown rice was used for Chinese rice wine fermentation. The extruded-puffed blown rice improved alcohol yield during the fermentation process, which increased the wine yield by 12.4% compared to traditional cooking methods. Image 1 • Brown rice had significant changes in physicochemical properties after extrusion. • Structure features analyzed by XRD and FTIR-ATR. • Extrusion puffing highly enhanced the efficiency of saccharification. • Extruded-puffed brown rice used for Chinese rice wine fermentation. • Extrusion puffing showed potential to replace immersion and cooking techniques. [ABSTRACT FROM AUTHOR]

• Three types of asphalt with the largest usage in China were tested. • Rubber# has the best anti-aging performance, followed by SBS# and 70#. • The glass transition temperature and the area ratio of characteristic functional groups increased after aging. • The GPC curve shifts to the macromolecular direction after asphalt aging. To study the effect of thermo-oxidative aging on the physical properties and microstructure of base and modified asphalts, conventional index tests, dynamic shear rheology (DSR), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, and gel permeation chromatography (GPC) were performed. The macro-physical indexes and microstructural changes in the asphalt before and after aging were analyzed. The results show that with an increase in the thermal-oxidative aging degree, the penetration degree of asphalt decreases; the softening point increases, and the high-temperature performance improves. Simultaneously, the asphalt consistency and hardness increase. This results in a significant increase in the initial modulus and glass transition temperature, decrease in the shear resistance, and degradation of the low-temperature performance. Rubber-modified asphalt exhibited the highest anti-aging performance, followed by styrene–butadiene–styrene-modified and 70# asphalts. Thermal-oxidative aging did not change the original functional group species; however, the peak area ratio of the sulfoxide and carbonyl functional groups increased significantly. After aging, the overall molecular weight of the asphalt shifted in the macromolecular direction. Weight-average and number-average molecular weights and polydispersity increased. [ABSTRACT FROM AUTHOR]

As a mining waste, coal gangues are prone to spontaneous combustion after being piled, resulting in a series of hazardous environment problems. By studying the spontaneous combustion characteristics of coal gangues in the Dangtong (DT) and Jincheng (JC) mining areas of Shanxi Province, China, it was shown that the spontaneous combustion of coal gangues is closely related to ventilation rates. However, different ventilation rates (10–40 L/min) play different roles in the high- and low-temperature stages. After conducting an adiabatic oxidation experiment of coal gangues with different particle sizes (0–8 mm), it can be seen that the larger the particle sizes, the greater the activation energy required during oxidation and the lower the heating rate. However, a mixed pile of coal gangues comprising particles of different sizes favors self-heating and oxidation of coal gangues. The thermogravimetric (TG), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR) analyses were applied to study the process of combustion and the factors influencing it. Our test results showed that superabsorbent hydrogels prepared by mixing bentonite powder and acrylamide can be effective to weaken the activities of various oxygen-containing functional groups (such as Si O and O H) in coal gangues. Moreover, use of these hydrogels also inhibits combustion and heat release of coal gangues. By comparing the effects of the hydrogel with nitrogen and water in the fire extinguishing experiments, it was demonstrated that the bentonite–acrylamide superabsorbent hydrogel exhibits both cooling and combustion-control effects. Moreover, these hydrogels can be applied to prevent coal gangues from recombusting. [ABSTRACT FROM AUTHOR]

• Thermal properties of edible oils collected by differential scanning calorimetry. • Adulterations were evidenced through dimension reduction techniques. • K-nearest neighbors model effectively identify even 5% canola oil adulteration. Thermal properties of extra virgin olive oil (EVOO) consumed in China were investigated through differential scanning calorimetry (DSC), Principal Component Analysis (PCA) dimension reduction analysis combined with K-nearest neighbors (KNN) and support vector machine (SVM) models were used to determine whether oil samples would be EVOO. Both models exhibited a 100% ability to distinguish EVOO from non-EVOO. Additionally, the discrimination test of canola oil was still limited from EVOO adulteration due to its similarity of cooling profiles with EVOO. Canola oil was artificially added into EVOO in 5%, 10%, 20% and 30% and DSC test results collected were detected in computer models. Both models effectively identified even 5% canola oil adulterated in EVOO; however, KNN (93.75%) model exhibited much higher accuracy than SVM (43.92%). In conclusion, DSC combined with KMN model analysis was more available for the adulteration detection of EVOO. [ABSTRACT FROM AUTHOR]

[Display omitted] • Materials used in a mural painting tomb of Ming Dynasty were analyzed for the first time. • Analysis technics including Raman, FT-IR, XRD, SEM-EDX and TG-DSC were employed. • Pigments identified as hematite, cinnabar, malachite, yellow ochre, calcite, carbon. • Preparatory layer found to be prepared by fine lime mortar with cotton fiber inside. • Support constructed with sticky rice lime mortar with several kinds of additives. The pigments, surface deposition, preparatory layer and support from a mural painting tomb of Ming Dynasty (1368–1644 CE) were first time analyzed by micro-Raman, Fourier-transform Infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscope with energy-dispersive X-ray microanalysis (SEM-EDX), thermogravimetry and differential scanning calorimetry (TG-DSC) to reach a better understanding of the composition of the materials and the techniques adopted. All the pigments were identified, including hematite, cinnabar, malachite, yellow ochre, calcite and carbon black. The preparatory layer was found to be prepared by fine lime mortar with cotton fiber inside. The crystalline depositions on the mural painting were identified as calcite and dolomite originated from the lime-based preparatory layer. The support was found to be constructed with sticky rice lime mortar with several kinds of additives. The original lime stone was demonstrated to be magnesium-rich and the carbonization results were also discussed. These results revealed significant information on the materials and techniques used to build mural painting tomb in Ming Dynasty. This will benefit the further restoration and conservation works and also provide a methodology solution for the scientific analysis of ancient tomb mural paintings. [ABSTRACT FROM AUTHOR]

Based on the background that a large amount of iron tailings was stockpiled in China, the most appropriate preparation conditions of producing autoclaved aerated concrete (AAC) with iron tailing was studied. The slurry properties were tested to evaluate the effects of the raw material factors on gas forming character. The compressive and specific strengths were measured to assess the feasibility of producing B05, A2.5 AAC blocks. The analysis of morphology, mineral components and thermal property were carried out in order to determine the mineral composition of iron tailing AAC blocks. Leaching toxicity was determined to ensure the environmental safety of iron tailing AAC blocks. The results shows that under the following conditions, cement 8%, quicklime 21%–27%, 20 min ball milled siliceous 62%–68% (with 40%–60% substituted by iron tailings), gypsum 3%, ratio of water to raw material (W/R) 0.6, aluminum (Al) powder 0.14% and at 1.4 MPa steam pressure maintaining for 8 h, the bulk density can be between 490 and 525 kg/m 3 , compressive strength higher than 2.5 MPa and specific strength higher than 4700 N m/kg. The main minerals in the AAC were dough-like CSH gel, flake-like tobermorite and long-strip anhydrate besides quartz and other residual minerals from the iron tailings. The compressive strength is mainly attributed to the interconnected microstructure constituted of CSH gel and tobermorite. The thermal analysis also proved the existing of the main minerals. [ABSTRACT FROM AUTHOR]

The disposal of medical waste has become an increasing environmental issue since the COVID-19 epidemic outbreaks. Conventional disposal methods have produced waste of fossil resources and environmental problems. In this study, the waste medical mask-derived materials were tested as viscosity reducer and pour point depressant to evaluate the possibility of being used as crude oil fluidity improver. The results show that the materials derived from the three parts of the waste medical mask can reduce the viscosity and pour point of each crude oil samples from different oilfields in China. The middle layer of the medical mask (PP-2) displays the highest efficiency, and the viscosity reduction rate and maximum pour point reduction reaches 81% and 8.3 °C at 500 ppm, respectively. A probable mechanism of improving rheological properties of the crude oil samples by the medical mask-derived materials was further proposed after the differential scanning calorimetry (DSC) analysis and the wax crystal morphology analysis. We hope this work could provide a way to solve the current environmental issues under COVID-19. [Display omitted] • Waste medical mask can improve the fluidity of crude oil samples from different oilfields in China. • The middle layer of the medical mask (PP-2) at 500 ppm exhibits the highest effeciency with a viscosity reduction rate of 81%, and the maximum pour point reduction is 8.3 °C. • Differential scanning calorimetry (DSC) and paraffin crystal morphology characterization were conducted to support the possible mechanism. • This work provides a way to solve the current environmental problems caused by COVID-19. [ABSTRACT FROM AUTHOR]

Trapa is one of the most common aquatic genera. In this paper, we investigated the structural and functional properties of starches from four wild Trapa species ( Trapa quadrispinosa , japonica , mammillifera and incisa ) popularly found in South China. The morphology, weight and starch content of fruit and kernel were significantly different among the four species. Starches from the four Trapa species were all oval in shape with smooth surface and central hila, exhibited C A -type crystallinity, and had similar molecular weight distribution. Trapa japonica starch showed the highest swelling power, amylase hydrolysis and digestion, and the lowest water solubility. T. japonica and mammillifera starches showed similar pasting properties, T. quadrispinosa starch had the lowest peak, breakdown and setback viscosities, and Trapa incisa starch had the highest final and setback viscosities. These results would be very useful for exploring the applications of wild Trapa starches in food and nonfood industries. [ABSTRACT FROM AUTHOR]

To achieve carbon neutrality and optimize China's energy structure, pyrolysis (thermal cracking) was selected to recycle the Waste Fischer-Tropsch wax (WFTW) produced in large quantities from Fischer-Tropsch synthesis plants, which has rich hydrocarbon content and high calorific value. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), thermogravimetry-mass spectrometry (TG-MS), and thermogravimetric-infrared spectroscopy (TG-IR) were used to investigate the pyrolysis characteristics and mechanism of WFTW. The TG and DSC showed that the main pyrolysis temperature range of WFTW was 230–480 °C, and the heating rate affected the temperature range greatly. Theoretically, more than 87% of the calorific value in the WFTW can be recovered as liquid fuels, and the most suitable heating rate was 15 °C/min. TG-MS and TG-IR showed pyrolysis products at different stages to further investigate the pyrolysis process and provide a basis for recycling WFTW. The activation energy calculated by Kissinger method is 215 ± 3 kJ/mol, and the mean apparent activation energy calculated by Starink method is 133 ± 14 kJ/mol, showing a good agreement with Kissinger method at a high conversion rate (70–80%). • The pyrolysis characteristics and mechanism of waste Fischer-Tropsch wax were studied through TGA, DSC, TG-MS, and TG-IR. • Oligomerization, volatilization, and thermal cracking are important in the WFTW pyrolysis process. • The pyrolysis activation energy calculated by Starink method agreed with Kissinger method well at high conversion rates. • More than 87% of the energy content can be recovered as liquid fuel theoretically. [ABSTRACT FROM AUTHOR]

According to the recommendations developed by the Kinetics Committee of the International Confederation for Thermal Analysis and Calorimetry (ICTAC), non-isothermal pyrolysis experiments were carried out to analyze and compare two types of oil shale from the northeast of China using simultaneous differential scanning calorimetry (DSC) and thermogravimetric (TG) analysis at temperatures ranging from 40 to 850 °C. The pyrolysis process of oil shale begins with the evaporation of small molecular substances, then continues by the pyrolysis of kerogen, and finally ends mainly with the complete decomposition of carbonates. In this whole process, almost 36 % of overall pyrolytic heat was used for the pyrolysis of kerogen. When retorting air-dried basis oil shale below 520 °C, a considerable proportion of the heat required will have to be used mainly for the evaporation of small molecular substances below 185 °C. Specific heat capacities of two oil shale semicokes were measured below 500 °C by DSC method, showing that specific heat capacity of semicoke will increase with the increase of the temperature, and carbonization of kerogen can bring about a further positive effect on it. Coats-Redfern method was used to calculate kinetic parameters in three pyrolysis stages. [ABSTRACT FROM AUTHOR]

Bamboo processing is faced with increasing requirements of resource reusability in China. A large amount of waste bamboo green produced in bamboo processing needs to be recycled. Waste bamboo green contains a large number of environmentally friendly wax components. In this study, supercritical CO 2 extraction was used to extract bamboo green waste to obtain natural wax. Response surface methodology (RSM) was used to optimize the extraction process and the yield of bamboo green wax under pressure of 20–30 MPa, temperature of 318–328 K, and time of 30–90 min. The extracted bamboo green wax was characterized by gas chromatography and mass spectrometry (GC-MS). RSM optimization shows that under the conditions of 26 MPa, 328 K, and 56 min, the yield of bamboo green wax was the highest at 2.327%. The compositions of esters, fatty acids, sterols and so on in bamboo green wax were characterized by GC-MS. Differential scanning calorimetry (DSC) shows that the melting point of bamboo green wax is 334 K. At last, the economic evaluation of bamboo green wax was made to analyze its potential application prospect. It is supposed that bamboo green waste is a resource for natural wax with potential application value. [ABSTRACT FROM AUTHOR]

Abstract: The effect of wx genes on amylose content, physicochemical properties of wheat starches, and the quality of Chinese crisp stick were investigated using near-isogenic lines (NILs) with null wx alleles in Yangmai 17 and Yangmai 01-2 backgrounds. wx genes showed significant effects on amylose content and other traits. The triple-null genotype had the lowest amylose content among eight genotypes, followed by double-null, single-null, and wild-type genotypes. The triple-null also showed lower flour yield, higher percentage of type B-granules on a volume basis and higher crystallinity than non-waxy genotypes, and showed significant differences in all pasting and thermal transition parameters compared to non-waxy genotypes, except for degree of retrogradation at day 14. For the quality of Chinese crisp stick, the hardness, crispness, fracturability, and specific volume of waxy genotype were 3.91 kg, 11.0, 1.85 mm and 104.4 ml, whereas the corresponding ranges for non-waxy genotypes were 5.39–5.70 kg, 0.5–0.9, 0.69–0.86 mm and 49.5–57.6 ml, respectively, in Yangmai 17 background. This indicates that waxy genotypes showed significantly better crisp stick quality than non-waxy genotypes. A similar trend was also observed in Yangmai 01-2 background. This indicated the potential utilization of waxy wheat for producing traditional products. [Copyright &y& Elsevier]

Abstract: Chinese historic silk fabrics dated from the Warring States Period (B.C. 475–B.C. 221), the Han Dynasty (B.C. 202–A.D. 220) and the Ming Dynasty (A.D. 1368–A.D. 1644) as well as artificial aged silk specimens were examined by SEM, TEM, amino acid analysis, FTIR, WAXD, SAED and DSC to investigate the degradation mechanism for the purpose of conservation. The variations of the relative concentrations of Gly and Ala and the crystallinity revealed that the degradation mainly occurred at the amorphous region at the initial degradation stage; both the amorphous and the crystalline regions were degraded at the same speed at the late degradation stage. Combined with the fact that the mechanical strength decreased over the degradation process, it could be concluded that the degradation of both the amorphous and the crystalline regions contributed to the decrease of the mechanical strength. During the degradation process, the morphology of the cross-section of the silk fiber was found to change from stacking particles to lamellar sheets, with decreasing size of segments of silk fibril. The changes of morphology and degree of orientation during the degradation process exhibited correlations with the change of secondary structure, which was greatly affected by aging method. The change of thermal stability exhibited correlations with both the secondary structure and the degree of orientation. [Copyright &y& Elsevier]

Polylactic fiber (PLA) is a new environment-friendly fiber and has been produced by different plants with wide application, while there are few studies on the difference of the structure and property of PLA fibers produced from these plants in China. The main content in present article is to conduct elementary analysis, gas chromatography mass spectrum, IR spectroscopy, ultraviolet, X-ray, differential scanning calorimetry (DSC), TG, SEM, and tensile tests to obtain the common structure and properties of PLA fibers and to prove that there are no significant difference between the 13 kinds of PLA fibers made by 13 plants in China. The elementary analysis method is used to test the contents of C, H, and O elements, and it has good accordance with the theoretical results. Gas chromatography mass spectrum method proves that the functional groups of PLA fiber are lactide and acetaldehyde as well as 2,3-pentanedione. IR spectroscopy depicts that significant absorbing peaks exist as CO, CO, OH within absorbing wavelength zones. There are no characteristic absorbing peaks of ultraviolet spectrum. Crystallinity and orientation degree in full wave at half maximum and in area are calculated based on X-ray. The peak melting point and pyrogenation peak point are obtained by DSC and TG testings. The tensile property and the surface morphology by SEM are conducted and some typical faults in the surface are observed. In addition, the coefficient of variance of these experimental results between 13 kinds of PLA fibers show that their structure and properties are similar. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

In order to probe CO2-coal interactions, differential scanning calorimetry(DSC) experiment was carried out in the atmosphere of He, N2 and CO2 with coals from Huozhou and Jincheng area in Shanxi Province. The results show that, in a He atmosphere, the curves are straightforward, the curves in the N2 atmosphere are smooth and upward compared with curves in the He atmosphere, however, in a CO2 atmosphere, all the three curves show exothermic peaks and endothermic peaks are irreversible. It is proposed that, as an inert gas, He can't be adsorbed on coal surface, hence no enthalpy released. For N2, physical adsorption occurs, charactered with lower enthalpy releasing. The larger enthalpy variation in a CO2 atmosphere indicates that, except for physical reactions, chemical reactions may also occur. Based on the analysis of coal interactions, CO2 interactions and molecular-scale interactions of CO2 with substances other than coal, the CO2-coal interactions were explained as follows: the C atom of CO2 accepted electrons from coal molecular, and formed an "electron donor-acceptor complex" ( i. e. , an "EDA complex" ), in other words, chemical reactions occurred, hence exothermic peaks occurred. The interconnections of the active sites to other groups in coal molecular are weakened due to the formation of EDA complex, so to be easily broken during heating, hence endothermic peaks occurred. The irreversibility of the curves indicates that coal structure is changed. [ABSTRACT FROM AUTHOR]

As a high priority of waste management and recycling by the Hong Kong government, Recycled Aggregate (RA) has been used in various construction applications, mainly as sub-grade, roadwork, and unbound materials. However, higher-grade applications are rare. The major barrier encountered is the variation of quality within RA, which causes lower strength, resulted from crystallization of Recycled Aggregate Concrete (RAC). Therefore, the objective of this study is to examine the crystallization of RAC in a Two-Stage Mixing Approach. Following are the five areas of interest: (i) investigate the waste problems in construction activities; (ii) examine the crystal development on the hydration of cement paste; (iii) develop a two-stage mixing approach (TSMA) for improving the performance of RAC; (iv) explore the crystallization of TSMA in comparison with the Normal Mixing Approach (NMA) through use of Differential Scanning Calorimetry (DSC); and (v) verify the results obtained from DSC analysis with those obtained from compressive strength testing. This study adopted 0, 20, and 100% RA substitution in virgin aggregate and measured by DSC and compressive strength on both TSMA and NMA. TSMA uses only half the water for mixing, forming a thin layer of cement slurry on the surface of RA that will permeate into the porous old cement mortar and fill old cracks and voids in the pre-mix process. The results from DSC analysis clearly demonstrated that TSMA can give a better crystallization of CaO·SiO 2 ·H 2 O [CSH] and Ca(OH) 2 [CH]. The optimal situation occurs on 20% RA substitution in virgin aggregate, balancing the advantages of each, a finding supported by the results from compressive strength testing. Therefore, TSMA is a superior methodology and opens a wider application for the use of RAC. [ABSTRACT FROM AUTHOR]

The high water content of lignite has raised serious environmental and efficient issues, which are obstacles to its large scale utilization. In this study, hydrothermal dewatering (HTD) method was used to upgrade a lignite from Inner Mongolia in China at 230–330 °C. The combustion behaviors of raw lignite and HTD samples were investigated by thermogravimetry with differential scanning calorimetry (TG-DSC). By changes of mass and heat flow, the lignite combustion process was described from three stages: water evaporation, coal devolatilization and char combustion. Compared with raw lignite, the combustion reactivity of HTD samples upgraded at 230–300 °C was improved, while that of sample upgraded at 330 °C decreased. The temperatures at maximum combustion rate of 230–300 °C samples (below 397.6 °C) were lower and that of 330 °C samples (448.9 °C) was higher than that of raw lignite (399.8 °C). The released heat at char combustion stage increased for HTD samples. Then the physico-chemical structures of lignite before and after HTD process were analyzed to investigate the effect of HTD on coal combustion characteristics. Results showed that HTD process could affect the heat at water evaporation and initial devolatilization stages during coal combustion through removing oxygen functional groups in lignite. The enhancement in aromaticity of lignite after HTD increased activation energy of intrinsic reaction, whereas the large pore volume and high surface area of 230–300 °C samples decreased diffusion activation energy at char combustion stage. The effect of pore structure predominated on combustion reactivity compared with aromaticity for HTD samples. [ABSTRACT FROM AUTHOR]

Cinnamomum camphora seeds are abundant in China. For high value utilization of Cinnamomum camphora seed kernel (CCSK) protein, the effects of phenolic compounds on physicochemical and functional properties of protein isolate (PI) from CCSK were investigated in this study. A total of 12 phenolic compounds in CCSK have, for the first time, been tentatively identified by HPLC-ESI-QTOF-MS2. PI had a higher level of protein content compared to that of protein-phenolic complex (PPC). The formation of PPC resulted in a reduction of free sulfhydryl groups content and surface hydrophobicity as well as an increase of particle size and zeta potential. Fourier-transform infrared spectroscopy showed that the contents of secondary structure of PI and PPC were not obviously different. However, a remarkable increase in β -sheet and a decrease in random coil of PPC compared to PI were found by circular dichroism. Differential scanning calorimetry analysis revealed that PPC was thermally more stable than that of PI. PI and PPC exhibited superior essential amino acid composition and similar protein subunits. Furthermore, PPC exhibited higher solubility, better foaming and emulsifying properties than those of PI. These results suggested that the protein products from CCSK may be used as natural functional materials in the food industry. Image 104850 • Protein products of PI and PPC were prepared from Cinnamomum camphora seed kernel. • Presence of phenolic compounds in PI had a significant effect on its purity. • Physicochemical properties of PI were significant influenced by the formation of PPC. • Both PI and PPC exhibited superior essential amino acid composition. • PPC had the higher solubility, better foaming and emulsifying properties than those of PI. [ABSTRACT FROM AUTHOR]

Damage to concrete structures with gypsum-contaminated aggregate occurs frequently. Aggregates in much of the southern part of China are contaminated with gypsum. Therefore, in this study, the effects of using different quantities of gypsum-contaminated aggregate on the expansion and compressive strength of concrete were investigated over a period of one year. Two groups of concrete were designed with the gypsum-contaminated aggregate containing different parts of fine and coarse aggregate, respectively. The SO3 contents were 0%, 0.5%, 1%, 1.5%, 3%, 5%, and 7% by weight of aggregate. X-ray diffraction (XRD), thermogravimetry (TG), and differential scanning calorimetry (DSC) were used to analyze the change in mineral composition over time. The microstructure was also studied by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The results showed that significant expansion and great loss in compressive strength did not occur in concrete if the content of SO3 lay below 1.5% and 3% in fine and coarse aggregates, respectively. The concentration of sulfate ions in concrete was not enough to form new a phase of gypsum. During the process of internal sulfate attack, the content of gypsum decreased and the content of ettringite increased. Ettringite was the main reason for the expansion damage of concrete. Additionally, the fracture mode of internal sulfate attack on concrete was the crack extension from gypsum to paste; finally, the aggregate separated from the paste. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study was to evaluate the cyclic fatigue resistance of 3 replicalike rotary instruments compared with their original brand systems using continuous rotation and optimum torque reverse (OTR) kinematics., Methods: New F1 rotary instruments (n = 20 per group) from ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland) and ProTaper Gold (Dentsply Maillefer) original brand systems were compared with 3 replicalike instruments (U-File [Dentmark, Ludhiana, India], Super Files [Shenzhen Flydent Medical, Shenzhen, China], and Super Files Blue [Shenzhen Flydent Medical]) regarding cyclic fatigue resistance. In each group, the selected instruments were randomly distributed into 2 subgroups (n = 10) according to the kinematics. In the rotary group (ROT), the instruments were activated with a continuous clockwise rotation (300 rpm, 1.5 Ncm), whereas in the OTR group, asymmetric oscillatory motion was performed setting the OTR function at 300 rpm and adjusting the torque limit at the minimum level using the TriAuto ZX2 motor (J Morita, Kyoto, Japan). The time to fracture was recorded and statistically compared according to the kinematics (ROT × OTR) and the instrument type (replicalike × original brand) using the independent sample t test (α = 0.05). Additionally, the metal alloy characterization of each system was performed by differential scanning calorimetry and energy-dispersive X-ray spectroscopy., Results: Statistical analysis revealed significantly higher time to fracture for all rotary systems tested in OTR motion compared with continuous rotation (P < .05) with a mean percentage increase ranging from 52.1% (ProTaper Gold) to 156.7% (U-File). The replicalike instruments showed a significantly higher time to fracture compared with the respective original brand instruments in either ROT or OTR motion (P < .05). Replicas presented austenitic temperatures above the ones displayed by the original brands and an almost equiatomic ratio between nickel and titanium elements., Conclusions: OTR motion significantly improved the fatigue resistance of both original and replicalike systems. The replicas showed higher cyclic fatigue resistance than original brand instruments and higher transition temperatures to the austenitic phase., (Copyright © 2020 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Biochar amendment may alter the quantity and stability of soil organic matter (SOM), whichcould be quantified using thermogravimetry (TG) and differential scanning calorimetry(DSC) techniques. The present study was to evaluate the thermal stability of SOM after 8-yrconsecutive biochar application in the North China. The experiment consisted of fourtreatments: control (CK), biochar rate at 4.5 t ha−1 yr−1 (B4.5), biochar rate at 9.0 t ha−1yr−1 (B9.0), and crop straw return (SR). Soil samples were collected from the 0-10 cm layer.The results showed that the derivatives of thermogravimetry curves (DTG) andDSC curves had three peaks, near 100, 400 and 500˚ C for both the bulk soils. Thepercentage of thermal labile SOM (weight loss in 200–400˚ C accounting for that in200–550˚ C, %Exo1) followed the order of SR &#x003E; CK &#x003E; B4.5 &#x003E; B9.0. Across thetreatments, the TG-T50(the temperature leading to half of SOM loss) showed the trendof B9.0 &#x003E; B4.5 &#x003E; CK &#x003E; SR. Moreover, a negative correlation between %Exo1and TG-T50 existed (r= -0.975; P &#x003C;0.05). The energy densities (ED) of SOM(energy release per unit SOM) followed the order of B9.0 &#x003E; B4.5 &#x003E; SR &#x003E; CK.We concluded that biochar amendment increased the thermal stability of SOM. [ABSTRACT FROM AUTHOR]

Background: Neohesperidin is an important natural flavanone glycoside distributed in several citrus species. This compound is widely used as a raw material for food additives in the food industry. The request for certified reference materials (CRMs) in dietary supplements was stipulated by the National Administrative Committee for CRMs and was underpinned by the need to improve the accuracy and comparability of measurement data and to establish metrological traceability of analytical results., Results: This paper reports the sample preparation methodology, homogeneity and stability studies, value assignment and uncertainty estimation of a new certified reference material of neohesperidin (GBW09522). Differential scanning calorimetry, coulometric titration and mass balance methods proved to be sufficiently reliable and accurate for certification purposes. The certified value of neohesperidin CRM is 994 g kg(-1) with an expanded uncertainty of 4 g kg(-1) (k = 2). The reference material described above was homogeneous and stable for 12 months at a storage temperature of 25 °C., Conclusion: The new CRM of neohesperidin can be used to validate analytical methods and improve the accuracy of measurement data as well as quality control of neohesperidin-related dietary supplements, foods, traditional herbs and pharmaceutical formulations., (© 2014 Society of Chemical Industry.)