Increasing Treatment Temperature Research Articles

Effects of Heating Treatment on Functional and Structural Properties of Liquid Whole Egg

Liquid whole egg (LWE) products have many advantages such as convenient transportation, easy production and are safe. However, LWE has a short shelf life and high thermal sensitivity, so suitable heating treatment is the key to the production of LWE products. The aim of this study is to investigate the effects of heating treatments conditions (at 55-67 °C for 0-10 min) on the emulsification, foaming activity and rheological properties of LWE. The results indicated that the emulsifying activity of LWE had no significant change after 55-64 °C heating treatment, while it decreased significantly after heating treatment at 67 °C. The foaming property of LWE increased significantly after 55 °C to the 64 °C heating treatment; while the foaming property showed a downward trend with the increase in heat treatment temperature, it can significantly improve the foam stability of LWE. The heating treatment thoroughly changed the molecular weight distribution of LWE protein, thus promoted the protein surface hydrophobicity, hydrophobicity activity and rheological properties. The heating treatment at 61 °C for 6 min had a better effect on the functional properties than that of the other heating groups. In addition, the results of this study provide the change in rules of LWE under different heating treatment conditions and provide theoretical guidance for the production and processing of LWE.

Unusual Acid Sites in LSX Zeolite: Formation Features and Physico-Chemical Properties

The advanced approach for the preparation of the NH4 form of highly crystalline LSX zeolite under gentle drying conditions (40 °C, membrane pump dynamic vacuum) is discussed. Decationization of this form at moderate temperatures led to the formation of Brønsted acid sites (BASs), whose concentration and strength were characterized by IR spectroscopy. It was found that a maximum concentration of three BASs per unit cell can be achieved at 200 °C prior to the initiation of zeolite structure degradation. The proton affinity of BASs is unusual, and aspires 1240 kJ/mol, which is significantly higher compared to faujasites with higher moduli. The increase in temperature of the heat treatment (up to 300 °C) resulted in thermal decomposition of BASs and the manifestation of amorphous phase with corresponding Lewis acid sites (LASs) as well as terminal Si-OH groups. Both the destruction of BASs and formation of the LAS-containing amorphous phase are the key reasons for the significant decrease in the adsorption capacity in the micropore region revealed for the sample decationized at 300 °C.

Study on the phase structure of the interface zone of Cu–Al composite plate in cast-rolling state and different heat treatment temperatures based on EBSD

The phase structure in the interface zone of Cu–Al composite plate was studied by EBSD after casting and rolling and different heat treatment temperatures. The grain sizes of the matrix and intermetallic compounds in the interface zone were analyzed statistically. The spatial distribution characteristics of the transverse, rolled, normal and various phases were characterized by inverse pole diagram. The results show that with the increase of heat treatment temperature, the phase of the interfacial area of the composite plate is rearranged, the residual stress can be released, and the zero resolution decreases. The interface zone of cast-rolled Cu–Al composite plate is composed of a layer of intermetallic compound, which is Al2Cu; Two layers of intermetallic compounds, both Al, were formed in the interfacial area after heat treatment at 300 °C and 400 °C Al2Cu and Al4Cu9;After heat treatment at 450 °C, the interface region is composed of three layers of intermetallic compounds, which is Al2Cu, AlCu, Al4Cu9;The grain size of copper matrix is obviously larger than that of aluminum matrix. Matrix aluminum, matrix copper, Al2Cu.The average grains of Cu are mostly large Angle grain boundaries, and the orientation difference of adjacent grains in aluminum layer is much smaller than that in copper layer. After heat treatment at 300 °C for 1 h, the recrystallization degree of the interface zone of Cu–Al composite plate is low. After heat treatment at 400 °C for 1 h, the recrystallization in the interfacial zone of Cu–Al composite plate is not complete; After annealing at 450 °C for 1 h, the subgrain boundaries in the aluminum layer grow up, and LAGB is basically converted to HAGB. The distribution characteristics of the characteristic appearance direction in the crystal space of each phase were characterized under the conditions of casting and rolling and different heat treatment temperatures. At the same time, the research results provide theoretical basis and scientific title for optimizing the preparation process and high-end application of Cu–Al composite plate.

Effect of solution treatments on microstructure and mechanical properties of Ti–6Al–4V alloy hot rolled sheet

The solution and aging treatment were carried out with the hot rolled sheet Ti–6Al–4V alloy sheet, and the effects of solution treatments on the microstructure and mechanical properties were mainly studied. In the solution treatment process, α→β→βt transformation occurred. With the increase of solution treatment temperature and time, the α phase gradually changed from long strip to equiaxed morphology, and the fraction of equiaxed α and β phases gradually increased. The bimodal microstructure of αp and βt was obtained during the solution treatments. Among them, βt is mainly composed of high-density nano-needle αs with different orientations, which has a significant contribution to the strength of Ti–6Al–4V alloy. The strength of bimodal microstructure increases with the increase of βt content, but its influence on ductility is complicated. When βt content exceeds a certain amount, it is easy to lead to brittleness. It is found that when the specimens are treated at 930 °C for 60min or 960 °C for 30min, the best strength-ductility matching can be obtained. In this case, the volume fractions of αp and βt are almost equal, and the PSE of Ti–6Al–4V alloy reaches more than 14500 MPa⋅%.

Revealing the intensified preferred orientation and factors dominating the anisotropic mechanical properties of laser powder bed fusion Ti‐6Al‐4V alloy after heat treatment

Heat treatment is a general process to modify the unsatisfactory microstructure and properties of laser powder bed fusion (LPBF) Ti‐6Al‐4V. However, the effects of heat treatment on the preferred orientation and anisotropic mechanical properties have not been clarified yet. The main objective of this study was to identify the roles of heat treatment in the preferred orientation and mechanical properties of LPBF Ti‐6Al‐4V. The results indicated that α′-martensite with a weak {112̅0}α′ preferred orientation and minor retained β phase with a strong {100}β preferred orientation along the prior columnar β grains existed in the as-built specimen. After 750 °C heat treatment, α′-martensite was fully decomposed to α + β phases, and the {112̅0}α preferred orientation gradually intensified with increases in the heat treatment temperature, particularly after 950 °C heat treatment. The mechanism of the intensified {112̅0}α preferred orientation was proposed and verified by the Burgers orientation relationship and parent phase reconstruction using electron backscatter diffraction.Furthermore, the factors dominating the anisotropic mechanical properties of LPBF Ti‐6Al‐4V after heat treatment were investigated in this study. The results showed that, in the as-built, 750 °C, and 850 °C heat-treated conditions, the ultimate tensile strength and elongation of the horizontally-built specimens were slightly higher than those of the vertically-built ones due to the large spatter-induced disk-shaped pores. However, after 950 °C heat treatment, the elongation of the vertically-built samples exceeded that of the horizontally-built ones. This trend can be attributed to the significant intensification of the preferred orientation by the 950 °C heat treatment, which contributed to the higher Schmid factor and ductility of the vertically-built specimens.

Efficient photoluminescence from Cu2+ doped ZnSe/ZnS core-shell quantum dots in silicate glass

As a nontoxic and harmless photoelectric material, ZnSe quantum dots (QDs) have a broad application prospect. Incorporation of ZnSe QDs into glass provides a stable and robust substrate for QDs, but the low fluorescence efficiency of ZnSe QDs in glass limits their application. In this work, ZnSe/ZnS core-shell structure QDs is prepared in silicate glass by melt quenching and subsequent heat treatment, which is evidenced by XRD, TEM and Raman results. The surface defects of ZnSe QDs are passivated by the ZnS shell, which enhanced the luminescence of ZnSe QDS and increased the PL quauntum yeilds (PLQY) to 1.2%. With the introduction of Cu2+, two PL spectra around 500 nm and 650 nm appear simultaneously. The PL spectrum at 500 nm shows obvious size dependence, which is due to the energy transfer between ZnSe QDs and the D orbital of Cu2+, while the spectrum at 650 nm is attributed to a deeper defect. With the increase of heat treatment temperature and Cu2+ concentration, the defect luminescence gradually weakened and PLQY further increased to 4.62%.

Preparation of monodispersed SiO2-Al2O3 microspheres based on fly ash by thermally induced phase separation

In this study, we successfully prepared fly ash-based SiO2-Al2O3 microspheres using phase separation followed by acid leaching. Thermal analysis and X-ray diffraction were used to identify the optimal temperature range of heat treatment. The chemical composition and surface property of the microspheres were analyzed using X-ray fluorescence and contact angle measurements, and scanning electron microscopy was used to characterize the appearance of the microspheres. The results showed that the SiO2-Al2O3 microspheres were composed of 60–80 wt% SiO2 and 10–12 wt% Al2O3 with a uniform particle size, a hydrophilic surface, and high alkali resistance. Heat treatment studies revealed that the phase separation temperature should not exceed 900 °C to avoid crystallization. The mean particle size of the SiO2-Al2O3 microspheres decreased with an increase in the heat treatment temperature. Additionally, observing the evolution of the phase structure at 800 °C showed that there was fusion between the SiO2-Al2O3-enriched phases via interfacial tension in the later stage, resulting in larger spherical phase structures. Further, an increase in the Al2O3, Fe2O3, and CaO composition decreased the SiO2-Al2O3 microspheres particle size, and therefore inhibited phase separation.

Enhancement of properties of walnut shell/attapulgite/polyvinyl chloride composites with ultrasonic and hydrothermal treatment

The effects of ultrasonic and hydrothermal treatment on the physical, mechanical, wear resistance, water absorption and thermal stability of the walnut shell (WS)/attapulgite (ATP)/polyvinyl chloride (PVC) composite and its enhancement mechanism were investigated. WS was treated by ultrasound and hydrothermal treatment and mixed with PVC and ATP, and the WS/ATP/PVC composites were prepared by melt extrusion. The properties of composites were characterized, and the results showed that after ultrasonic and hydrothermal treatment, the main chemical structure of composites was not changed significantly. Compared with untreated composites, the wear resistance after ultrasonic treatment for 10 min is the best. After ultrasonic treatment for 15 min, the bending strength, tensile strength and impact strength of the composite are increased by 8.9%, 10.3% and 46.2%, respectively. Hydrothermal treatment at appropriate temperatures also improved some properties of the composites. The composites after hydrothermal treatment at 110°C had the best thermal stability and highest hardness, and the bending strength and tensile strength values were increased by 5.9% and 5.2%, respectively. The impact strength of the composite increased with the increase of hydrothermal treatment temperature. The results showed that ultrasonic and hydrothermal treatments have the potential to improve the performance of wood–plastic composites as environmentally friendly pretreatment methods.

Modulating photothermal properties by integration of fined Fe–Co in confined carbon layer of SiO2 nanosphere for pollutant degradation and solar water evaporation

Environmental governance by photothermal materials especially for the separation of organic pollutants and regeneration of freshwater afford growing attention owing to their special solar-to-heat properties. Here, we construct a special functional nanosphere composed of an internal silica core coated by a thin carbon layer encapsulated plasmonic bimetallic FeCo2O4 spinel (SiO2@CoFe/C) by a facile self-assembled approach and tuned calcination. Through combining the advantage of bimetallic Fe–Co and carbon layer, this obtained nanosphere affords improved multiple environmental governing functions including peroxymonosulfate (PMS) activation to degrade pollutants and photothermal interfacial solar water evaporation. Impressively, fined bimetal (FeCo) species (20 nm) acted as main catalytic substance were distributed on the N-doping carbon thin layer, which favors electron transfer and reactive accessibility of active metals. The increasing treatment temperature of catalysts caused the optimization of the surface active metal species and tuning catalytic properties in the AOPs. Besides, the incorporation of Co in the SiO2@CoFe/C-700 could enable the improved PMS activation efficiency compared to SiO2@Fe/C-700 and the mixed SiO2@Co/C-700 and SiO2@Fe/C-700, hinting a synergetic promotion effect. The bimetal coupled catalyst SiO2@CoFe/C-700 affords enhanced photothermal properties compared to SiO2@Co/C-700. Furthermore, photothermal catalytic PMS activation using optimal SiO2@CoFe/C-700 was further explored in addressing stubborn pollutants including oxytetracycline, sulfamethoxazole, 2, 4-dichlorophenol, and phenol. The free radical quenching control suggests that both the sulfate radical, hydroxyl radical, superoxide radical, and singlet oxygen species are involved in the degradation, while the hydroxyl radical and singlet oxygen play a dominant role. Furthermore, the implementation of a solar-driven interfacial water evaporation model using SiO2@CoFe/C-700 was further studied to obtain freshwater regeneration (1.26 kg m−2 h−1, 76.81% efficiency), indicating the comprehensive ability of the constructed nanocomposites for treating complicated environmental pollution including organics removal and freshwater regeneration.

Preparation and characterization of fiber braided tube reinforced polyethylene hollow fiber membranes via thermally induced phase separation

In wastewater treatment applications, mechanical strength of the membranes often cannot meet practical requirements due to the disturbance of aeration flow or the damage of high-pressure cleaning. In this work, fiber braided tube reinforced polyethylene (BR PE) hollow fiber membranes with desirable filtration performance and high tensile strength were successfully prepared via fiber braided tube reinforcement (BR) and thermally induced phase separation (TIPS) methods. Especially, the effect of heat treatment temperature on structure and properties of the membranes was discussed. The results exhibited that tensile strength and interfacial bonding state between the surface separation layer and the fiber braided tube reinforcement were improved with the increase of heat treatment temperature. While the heat treatment temperature was 130 °C, BR PE hollow fiber membranes exhibited favorable interfacial bonding state, and tensile strength was up to 204.4 MPa, which was significantly higher than that of previously reported PE membranes. Moreover, the increase of heat treatment temperature could decrease the membrane pore size and improve filtration performance. Comprehensive consideration, the optimal heat treatment temperature of BR PE hollow fiber membranes was 110 °C. This work can provide scientific and practical basis for large-scale development of BR hollow fiber membranes with good comprehensive performance.

Carbon and oxygen co-doped phosphotungstate for high performance photocatalytic degradation of imidacloprid

Carbon and oxygen co-doped phosphotungstate were successfully prepared by one-pot thermal treatment with phosphotungstic acid (HPW) and melamine-cyanuric acid supramolecule (MCA) as precursors. Based on the results of X-ray photoelectron spectra (XPS), UV–visible diffuse reflectance spectroscopy (UV–vis DRS), and Photoluminescence (PL) measurements, the existence of CO in CNPW-8-420 has been confirmed. Carbon and oxygen which are co-doped as CO in the Keggin structure of phosphotungstate are contributed to the separation of charge carriers and can increase the amount of the photocatalysis active sites. With the amount of HPW increasing, MCA decomposed in CNPW-8-420 and CNPW-20-420 without synthesizing g-C3N4, leading to in-situ doped of CO. Furthermore, the increase of treatment temperature can cause the supramolecular structure of MCA to overbreak, leading to carbon and nitrogen elements doped in CNPW-8-500. The photocatalytic degradation efficiency rate constant of CNPW-8-420 is 0.40 h−1 and it can be reused 3 times with no obvious change. LC−MS/MS revealed the most likely photocatalytic degradation pathway and intermediates of imidacloprid including imidacloprid olefin, guanidine-type imidacloprid, imidacloprid urea, 6-chloronicotinic acid, 5-hydroxy-imidacloprid, and 4,5-dihydroxy-imidacloprid. This study provides a promising strategy for the construction of co-doped POMs photocatalysts using different supramolecule precursors.

The class B heat shock factor HSFB1 regulates heat tolerance in grapevine.

Grape is a widely cultivated crop with high economic value. Most cultivars derived from mild or cooler climates may not withstand increasing heat stress. Therefore, dissecting the mechanisms of heat tolerance in grapes is of particular significance. Here, we performed comparative transcriptome analysis of Vitis davidii 'Tangwei' (heat tolerant) and Vitis vinifera 'Jingxiu' (heat sensitive) grapevines after exposure to 25°C, 40°C, or 45°C for 2h. More differentially expressed genes (DEGs) were detected in 'Tangwei' than in 'Jingxiu' in response to heat stress, and the number of DEGs increased with increasing treatment temperatures. We identified a class B Heat Shock Factor, HSFB1, which was significantly upregulated in 'Tangwei', but not in 'Jingxiu', at high temperature. VdHSFB1 from 'Tangwei' and VvHSFB1 from 'Jingxiu' differ in only one amino acid, and both showed similar transcriptional repression activities. Overexpression and RNA interference of HSFB1 in grape indicated that HSFB1 positively regulates the heat tolerance. Moreover, the heat tolerance of HSFB1-overexpressing plants was positively correlated to HSFB1 expression level. The activity of the VdHSFB1 promoter is higher than that of VvHSFB1 under both normal and high temperatures. Promoter analysis showed that more TATA-box and AT~TATA-box cis-elements are present in the VdHSFB1 promoter than the VvHSFB1 promoter. The promoter sequence variations between VdHSFB1 and VvHSFB1 likely determine the HSFB1 expression levels that influence heat tolerance of the two grape germplasms with contrasting thermotolerance. Collectively, we validated the role of HSFB1 in heat tolerance, and the knowledge gained will advance our ability to breed heat-tolerant grape cultivars.

Investigations on the rheological and swelling-degradation behavior of crumb rubber within the bituminous matrix

This paper focuses on the rheological and swelling-degradation behavior of crumb rubber within the bituminous matrix. Three different penetration-grade asphalts were modified by crumb rubber in a four-paddle mixer at various curing times and treatment temperatures. Rotational viscosity, dynamic shear rheometer, solubility and gel permeation chromatography tests were conducted to evaluate the viscosity, rheological property, crumb rubber solubility and molecular weight distribution of the rubber-modified asphalts, respectively. Moreover, the microstructure of the rubber-modified asphalts was characterized by fluorescence microscopy and Fourier transform infrared spectroscopy tests. The results reveal that the viscosity and complex modulus of the rubber-modified asphalts decrease and the infiltrating ability of crumb rubber within the bituminous matrix increases with increasing treatment temperature (or curing time). However, serious degradation of crumb rubber and asphalt ageing happen with the increased treatment temperature or prolonged curing time, which causes a noticeable increase in viscosity and stiffness. The increase in asphaltenes content within the bituminous matrix causes an enhancement in viscosity and complex modulus, and releases of the large (or medium) molecules, improving rutting deformation resistance. There is no obvious difference in small molecules, illustrating that asphalt type does not affect the distribution of small molecular size. When the treatment temperature increases from 200 °C to 220 °C, the curing time required to achieve 60 % solubility of crumb rubber in asphalt X is from 25 h to 15 h, which indicates that the higher the treatment temperature, the shorter the curing time required to reach the maximum solubility. Moreover, the swollen crumb rubber molecules are degraded into some small molecule substances dissolving into asphalt binder for modification. It makes the adsorption peaks of typical function groups increase significantly. The outputs from this study can provide the guidance for the selection of preparation conditions and asphalt binders that fabricate the rubber-modified asphalt with desired properties.

Introducing micropores into carbon nanoparticles synthesized via a solution plasma process by thermal treatment and their charge storage properties in supercapacitors.

Carbon materials synthesized via a solution plasma process (SPP) have recently shown great potential for various applications. However, they mainly possess a meso-macroporous structure with a lack of micropores, which limits their applications for supercapacitors. Herein, carbon nanoparticles (CNPs) were synthesized from benzene via SPP and then subjected to thermal treatment at different temperatures (400, 600, 800, and 1000 °C) in an argon environment. The CNPs exhibited an amorphous phase and were more graphitized at high treatment temperatures. A small content of tungsten carbide particles was also observed, which were encapsulated in CNPs. An increase in treatment temperature led to an increase in the specific surface area of CNPs from 184 to 260 m2 g-1 through the development of micropores, while their meso-macropore structure remained unchanged. The oxygen content of CNPs decreased from 14.72 to 1.20 atom% as the treatment temperature increased due to the degradation of oxygen functionality. The charge storage properties of CNPs were evaluated for supercapacitor applications by electrochemical measurements using a three-electrode system in 1 M H2SO4 electrolyte. The CNPs treated at low temperatures exhibited an electric double layer and pseudocapacitive behavior due to the presence of quinone groups on the carbon surface. With increasing treatment temperature, the electric double layer behavior became more dominant, while pseudocapacitive behavior was suppressed due to the quinone degradation. Regarding cycling stability, the CNPs treated at high temperatures (with a lack of oxygen functionality) were more stable than those treated at low temperatures. This work highlights a way of introducing micropores into CNPs derived from SPP via thermal treatment, which could be helpful for controlling and adjusting their pore structure for supercapacitor applications.

Research on macroscopic mechanical properties and microscopic evolution characteristic of sandstone in thermal environment

To study macro and micro characteristics of rock and their correlation in high temperature environment, uniaxial compression experiment is conducted to analyze macroscopic mechanical properties of sandstone samples after different temperature treatment, and AE source location technology is used to study corresponding microscopic evolution characteristics. Then, the correlation between macroscopic mechanical properties and microscopic evolution characteristics is discussed qualitatively, and their quantitative relationship is revealed further. The research results show that the brittleness of the sandstone sample experiences transform process of “first increasing and then decreasing” as treatment temperature increases from room temperature to 1000 °C and turning point is 400 °C, according to the change trend in peak stress, peak strain and fracture characteristics. Based on the variations of fractal dimension and microfracture type of AE events, it is evident that the microcrack system of the sandstone sample experiences the change process of “first simple and then complex” with an increase of treatment temperature. The reason for these variations is that treatment temperature can change microcrack system through the game process of thermal healing effect and thermal fracture effect, resulting in the difference of macroscopic mechanical properties. As treatment temperature increases from room temperature to 400 °C, thermal healing effect is always stronger than thermal fracture effect and the difference enlarges continuously. The microcrack system shrinks gradually, and the sandstone sample presents less properties of the microcrack system and its brittleness increase. As treatment temperature is above 400 °C, a continued increase in treatment temperature makes the difference between the two effects start to decreases until thermal fracture effect exceeds thermal healing effect, then their difference enlarges again. The microcrack system develops gradually, and the sandstone sample presents more properties of the microcrack system and its brittleness decrease. Further, according to data fitting analysis, it can be considered that thermal healing effect presents a linear correlation with treatment temperature during the game process and thermal fracture effect shows an nonlinear correlation with treatment temperature. The difference in the increase rate of these two effects results in nonlinear relationship between the microcrack system and treatment temperature. Then, the linear relationship between the microcrack system and macroscopic mechanical properties is reveal and quantitative relationship model between macroscopic mechanical properties and treatment temperature is established, which has good agreement with the experimental data. This research is helpful to know the correlation of macro and micro variations of the sandstone sample in high temperature environment. It possesses important guiding significance and reference value for ensuring stability of the surrounding rock in deep underground engineering.

Role of Heat Treatment on the Texture Evolution of M789 Steel Developed by LPBF Process

A laser powder bed fusion (LPBF) of M789 ally steel has been carried out using an EOS M290 machine. The ideal orientations of M789 alloy were established using an electron backscatter diffraction (EBSD) technique. The analysis through ideal orientation and ODF analysis pointed out that as the heat treatment temperature is increased, the texture becomes strong. Analysis done through recrystallization map concluded that as the heat treatment temperature increases, the recrystallized grains increase which clearly explains the reason for strong texture at high temperature heat treatment. The results from this work can be used to control the texture of the M789 alloy to improve various physical and mechanical properties of the material.

Effects of Heat Treatment on the Microstructure and Properties of a Cast Nickel-Based High-Cr Superalloy

The effect of solution treatment and intermediate heat treatment on the microstructure and properties of a new cast nickel-based high-Cr superalloy was investigated in this paper. The results indicate that the tensile strength and elongation at 900 °C increase when the solution temperature increases from 1160 °C to 1180 °C and then decrease when the solution temperature changes from 1180 °C to 1200 °C and 1220 °C. The stress rupture test results of the high-Cr superalloy under conditions of 900 °C/275 MPa shows that the rupture time, elongation, and reduction of area initially increased and then decreased with the increase in solution treatment temperatures. The results of stress rupture tests for the alloy after intermediate heat treatment followed by furnace-cooling, air-cooling, and water-cooling show that the morphology and distribution of γ’ phase have a great influence on the tensile test results at 900 °C of the alloy but no obvious influence on the test at 900 °C/275 MPa. The microstructure analysis of the superalloy after heat treatment shows that: when the solution treatment temperatures are at 1200 °C and 1220 °C, the incipient melting appears in the interdendritic region, which can severely deteriorate mechanical properties; the morphology of γ′ phase changes gradually from cube to spherical; and a large number of fine γ’ phase precipitates in the γ channel are found with increasing cooling rate after intermediate heat treatment.

STUDY OF THE PROCESS OF CARBONIZATION OF POWDERED CELLULOSE GRANULES IMPREGNATED WITH AgNO3 AND Pd(NO3)2

A comparative study of the process of carbonization of powdered cellulose granules and powdered cellulose granules impregnated with silver and palladium nitrate salts was carried out. The process was carried out in the temperature range 200–600 °С. The influence of the presence of metals on the course of carbonization of powdered cellulose and the features of the reduction of silver and palladium during carbonization were studied by IR spectroscopy and X-ray phase analysis. It has been established that the presence of silver in powdered cellulose does not affect the yield of carbonized material. The presence of palladium in powdered cellulose leads to the fact that the yield of carbonizate in the temperature range of 300–600 °C is reduced relative to the yield of carbonizate simply from powdered cellulose. It has been established by IR spectroscopy that impregnation with salts and subsequent drying at 90 °C of powdered cellulose granules leads to the appearance of carboxyl groups in it, which are not observed in unimpregnated powdered cellulose. With an increase in the heat treatment temperature to 200 °C, the amount of these groups in the silver-containing material increases sharply, while in the palladium-containing material it remains unchanged. A significant increase in the number of C=O groups in the palladium-containing material begins at 300 °C. The increased relative content of C=O groups in the metal-containing material is also preserved in the temperature range of 300–500 °C. The presence of metals in powdered cellulose at pyrolysis temperatures of 300–500 °C leads to a decrease in the content of C=C groups in the carbon matrix relative to methylene (methine) groups. At 600 °C, the carbon matrix of all coals is completely carbonized. X-ray diffraction analysis recorded the appearance of metallic silver and palladium in metal-containing coals at a temperature of 300 °C As the carbonization temperature increases, the content of crystalline Ag(0) and Pd(0) in coals increases. No other forms of silver and palladium are found in the temperature range of 300–600 °С. Testing of metal-containing coals in a model reaction of hydrogen peroxide decomposition showed: in silver-containing carbonizates, the availability of silver particles for H2O2 increases due to an increase in the pyrolysis temperature; in Pd/C, an additional factor that increases the availability of metal particles is the interaction of palladium with carbonizate during pyrolysis.

The Effects of Thermal Treatment on Lipid Oxidation, Protein Changes, and Storage Stabilization of Rice Bran.

Rice bran is a nutrient-rich and resource-dense byproduct of rice milling. The primary cause of rice bran utilization limitation is oxidative deterioration and inadequate storage facilities. Improving stability to extend the shelf-life of rice bran has thus become an utmost necessity. This study aimed to stabilize raw fresh rice bran (RB) by using dry heat methods at 120 °C (233, 143, and 88 min) and 130 °C (86, 66, and 50 min). The results indicated that after dry heat pretreatment, peroxidase levels were at 90%, and the storage stability of dry-heat-stabilized RB was better. However, with an increase in treatment temperature and time, the peroxidase activity improved while the lipase activity decreased to a certain extent without significant changes. The total saturated and unsaturated fatty acids were significantly unchanged during storage, while oleic/linoleic acid increased substantially by 1% at 120 °C for 88 min. The increase in treatment time and temperature was beneficial in controlling the fatty acid values. However, extended treatment time caused an increase in the peroxide value and MDA. The essential and non-essential amino acid ratios, which evaluate a protein's nutritional value, remained relatively stable. The essential subunit of rice bran protein was not affected by the temperature and time of dry heat treatment and storage time.

Formation, characterization, and antigenicity of lecithin-β-conglycinin complexes

Lipid binding has been proposed to represent a functional property of many allergenic proteins. This study investigated the formation, characterization, and antigenicity of lecithin-β-conglycinin complexes. The results indicate that lecithin was combined with β-conglycinin via static quenching and primarily driven by hydrogen bonds and van der Waals forces. In addition, heat treatment reduced the antigenicity of complexes, as evidenced by changes in molecular weight and secondary and tertiary structures. It revealed that large aggregates developed and more hydrophobic regions were exposed for complexes after heat treatment, as well as a decrease in the β-sheet contents and an increase in the β-turn and random coil contents. Furthermore, the average particle size of the complexes increased with increased temperature treatment, and the morphology of the complexes exhibited an amorphous polymer. These findings shedlight on the interaction between lecithin and β-conglycinin and help us understand the role of lecithin in allergic reactions.