Effect Of Thermal Treatment Research Articles

Technical note: Effects of chemical, radiational, and thermal treatment of bone tissue on material stiffness and anisotropy.

We evaluated the effects of four treatments for pathogen inactivation in bone tissue (ethanol storage, formalin fixation, gamma irradiation, and heat treatment via autoclave) on stiffness and anisotropy values in bone samples. Cortical bone samples from the humerus of 14 bovine specimens were subjected to Knoop microindentation analysis in longitudinal and transverse planes of section and four indenter orientations within each section. From each specimen, individual samples were assigned to one of five treatment conditions: 50% ethanol-saline solution, formalin immersion, gamma irradiation, autoclave, and buffered saline (controls). Each sample was microindented 100 times and the resultant stiffness data were analyzed by a resampled factorial analysis of variance. First- and second-order interactions as well as main effects of indenter orientation, treatment, and specimen were significant for both transverse and longitudinal sections, with the sole exception that indenter orientation-treatment interaction was nonsignificant for longitudinal sections. Interaction plots reveal that thermal (autoclave) and irradiation treatments depress stiffness values the most, while patterns of indentation stiffness at different orientations are relatively unaffected. Patterns of anisotropy are relatively unaffected by preservative treatments, but elastic modulus changes are consistent and unambiguous. Formalin and ethanol treatments are most comparable to controls and represent the best preservative media for mechanical testing. These options, however, are likely to be the least effective for ensuring the inactivation or sterilization of potentially contaminated samples.

The effect of thermal and non-thermal treatments on shelf-life of ready to drink whey-based functional beverages

Whey protein-based beverages are popular because of their many health benefits, high protein, pleasant flavor and vibrant hue. The hue of protein beverages is the most reliable barometer of how various quality characteristics will influence buyers' decisions. Protein beverages are typically processed using conventional thermal treatment, which diminishes their nutritional content and alters their appearance. Controlling the protein beverage quality and approximating the nutritional change can be achieved by examining microbial load during storage. This study analyzed the total microbial load such as coliform, yeast and molds of protein beverages, along with the impacts of various thermal (microwave, retort-pasteurization) and nonthermal (ultrasonication) treatments. The microbiological evaluation of the protein beverage was carried out at regular intervals (weekly) during the storage period under refrigeration and room temperature. In results, the protein beverage remained good in terms of overall acceptability and maintained the quality up to 90 days and 65 days after thermosonication treatment and was stored at refrigerated temperature (4 °C) followed by room temperature (28 °C) respectively. Hence, this study focuses on maximizing the shelf-life efficiency and maintaining protein beverage quality by using thermal and non-thermal procedures in tandem.

Fracture Mode and Thermal Damage Evolution of Sandstone Under the Coupling Effect of Thermal Treatment and Impact Load

The dynamic properties of high-temperature sandstone quickly deteriorate with different cooling methods, which leads to the instability of underground engineering rock structures. Therefore, it is of great significance to quantify the changes in the dynamic characteristics of high-temperature cooled sandstone under impact loads. Therefore, the sandstone is heated to different temperatures and cooled using three methods. A dynamic tensile test is performed using the Splitting Hopkinson Pressure Bar (SHPB) test set for high-temperature cooled sandstone. At the same time, the transient process of rock failure was examined using high-speed cameras. The influence of different temperatures and cooling methods on the thermal damage value of sandstone was analyzed, and the prediction equation was formed. The change in rock energy during rock failure under impact load was calculated.

An Investigation on Laser Machining of 7075 T6 Aluminium Alloy and Effect of Thermal Treatment on its Mechanical Property

An Investigation on Laser Machining of 7075 T6 Aluminium Alloy and Effect of Thermal Treatment on its Mechanical Property

Utilization of pretreated green liquor dregs as an activator for blast furnace slag: Effect on hydration, phase assemblage, and rheology

This study explores the utilization of calcium- and magnesium-rich pulp mill residues, i.e., green liquor dregs (GLDs), as an activator for ground granulated blast furnace slag (BFS). The aim of this study is to examine the potential of this unutilized residue when used as a part of alkali-activated materials (AAMs) and in this way enhance the exploitation of GLD. This study focuses on the fresh- and hardened-state properties of the produced paste and mortar samples, where 70% of BFS and 30% of GLD have been incorporated. Two different-sourced and thermally pretreated (105 °C, 300 °C, and 525 °C) GLDs have been used. The effect of thermal treatment on the utilization possibility of GLDs with respect to viscosity, setting times, reactivity, mineralogy, and microstructure is analyzed using the paste samples, while its effect on workability, and strength gain is measured using the mortar samples. Results show that both GLDs enhance the hydration of BFS and that the early-age hydration and strength increase when the GLDs have undergone pretreatment at the highest temperature (525 °C). However, at the later age (28 days), the samples activated with the GLDs treated at 300 °C achieve the highest strength. The addition of both GLDs treated at any temperature increases the viscosity of the composite samples and reduces their workability; however, it should be noted that optimization of water to binder ratio was not the objective of this study. The results of this study show that GLD, previously considered unreactive, can potentially become a reactive component of AAMs.

The Influence of Thermal Treatment of Activated Carbon on Its Electrochemical, Corrosion, and Adsorption Characteristics

Activated carbons can be applied in various areas of our daily life depending on their properties. This study was conducted to investigate the effect of thermal treatment of activated carbon on its properties, considering its future use. The characteristics of activated carbon heat-treated at temperatures of 1500, 1800, and 2100 °C based on its future use are presented. The significant effect of the treatment temperature on morphological, adsorption, electrochemical, and corrosion properties was proved. Increasing the temperature above 1800 °C resulted in a significant decrease in the specific surface area (from 969 to 8 m2·g−1) and material porosity—the formation of mesopores (20–100 nm diameter) was observed. Simultaneously, adsorption capability, double layer capacity, and electrochemically active surface area also decreased, which helped to explain the shape of cyclic voltammograms recorded in 2,4-dichlorophenoxyacetic acid and in supporting electrolytes. However, a significant increase in corrosion resistance was found for the carbon material treated at a temperature of 2100 °C (corrosion current decreased by 23 times). Comparison of morphological, adsorption, corrosion, and electrochemical characteristics of the tested activated carbon, its applicability as an electrode material in electrical energy storage devices, and materials for adsorptive removal of organic compounds from wastewater or as a sensor in electrochemical determination of organic compounds was discussed.

High-temperature anaerobic calcination for stabilizing environmentally stressful elements in phosphoric acid production by-products

Phosphorus tailings (P) refer to the waste materials left over after the extraction of phosphorus from phosphate rock during mining and processing. phosphogypsum (PG) is typical by-products of phosphoric acid production (PPB), containing numerous environmentally hazardous elements (EHE) that pose significant risks to ecological safety. In this study, we examined the impact of high-temperature anaerobic calcination on the migration and immobilization of EHE in PPB. The results indicated that higher temperature ranges favorably controlled the leaching toxicity of PPB. In the calcination products of P and PG, the inhibition efficiency of Pb leaching toxicity reached 84.93% and 89.33%, respectively. Under higher temperature conditions (P at 700 °C, PG at 600 °C), the inhibition of Cr leaching toxicity reached 100%. The inhibitory effects of high-temperature environments on EHE in PPB were ranked as fluorine > phosphorus > heavy metals. The mechanisms of migration and transformation of EHE in PPB under high-temperature anaerobic calcination were elucidated in three aspects, ranked from strongest to weakest. Firstly, the encapsulation of EHE by a shell-like structure, attributed to the “melt-wrap” phenomenon. Secondly, the decomposition-gasification phenomenon induced by high-temperature conditions. Thirdly, the effect of high temperature on the transformation of the storage forms of EHE. This study fills a research gap in the field of thermal treatment of PPB, enhancing the understanding of the specific effects of thermal treatment on the transformation of EHE in PPB, and provides theoretical and data support for the high-temperature thermal treatment of solid wastes.

Hydrogen Bond Integration in Potato Microstructure: Effects of Water Removal, Thermal Treatment, and Cooking Techniques

Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Scanning electron microscopy (SEM) were used to study the effects of heat treatments and water removal by freeze-drying after different time intervals (6, 12, 24, 48, and 72 h) on the molecular structure of potato tubers. SEM images show structural differences between raw (RP), microwaved (MP), and boiled potato (BP). MP showed a cracked structure. BP was able to re-associate into a granule-like structure after 6 h of freeze-dying, whereas RP had dried granules within a porous matrix after 24 h of freeze-drying. These results are consistent with the moisture content and FTIR results for MP and BP, which demonstrated dried spectra after 6 h of freeze-drying and relatively coincided with RP results after 24 h of freeze-drying. Additionally, three types of hydrogen bonds have been characterized between water and starch, and the prevalence of water very weakly bound to starch has also been detected. The relative crystallinity (RC) was increased by thermal treatment, whereby microwaving recorded the highest value. A comparison of the FTIR and XRD results indicated that freeze-drying treatment overcomes heat effects to generate an integral starch molecule.

THERMAL TREATMENT OF AGRICULTURAL WASTE AS AN ALTERNATIVE FOR PRODUCING SOLID BIOFUELS

Brazil stands out in terms of the composition of its energy matrix, with biofuels playing an important role, with many different raw materials requiring study. This article seeks to evaluate thermal treatment's effect on different biomass species to improve their energy characteristics, through an analysis of immediate chemical composition (as standardized by the American Society for Testing and Materials), spectroscopy in the infrared region, and thermogravimetry. This paper details the energy potential for each biomass, establishing the torrefaction processes with the best yield from agricultural residue of peanuts (Arachis hypogaea L.), cacao (Theobroma cacao L.), sugarcane (Saccharum spp.), coconut (Cocos nucifera L.), palm oil (Elaeis guineensis Jacq.), and papaya (Carica papaya L.). The thermal treatment of biomass proved effective in obtaining a solid biofuel with a higher heating value, as diagnosed through immediate chemical analyses.

Effect of cryogenic thermal cycling treatment on the mechanical properties of FINEMET amorphous nanocrystalline alloy

The brittleness of FINEMENT amorphous nanocrystalline alloys caused by annealing is an urgent problem to be solved because it limits the scope of their engineering application. We are herein to investigate the rejuvenation behavior of the as-annealed samples that not only are in a relaxed state but also the nanocrystals are precipitated in the amorphous matrix. The results show that the thermal temperature for cryogenic thermal cycling (CTC) treatment should not be larger than 483 °C in order to recover the enthalpy of relaxation. Further, the more suitable temperature for CTC treatment differs with the time that the as-annealed ribbon is employed. Meanwhile, the improvement of mechanical properties of the rejuvenated samples was examined with the help of hardness, flat plate bending, and nanoindentation experiments, and the results correspond well to the maximum of the relaxation enthalpy recovery. In addition, molecular dynamics simulations were used to visualize the changes in the local structure and found that the increased local five-fold symmetric clusters have increased the amorphousness of the amorphous nanocrystalline ribbon through CTC treatment.

Effect of thermal treatment on unloading-induced fracture activation of granites during triaxial shear slip experiments

Effect of thermal treatment on unloading-induced fracture activation of granites during triaxial shear slip experiments

The influence of functional groups on the pyrolysis of per- and polyfluoroalkyl substances

Thermal treatment is a widely used remediation strategy for PFAS-contaminated materials such as soil, spent sorbents, and domestic waste. To better understand the effectiveness and environmental impact of thermal treatments for PFAS-contaminated materials, a fundamental understanding of PFAS thermal degradation mechanisms is required. This work aims to study the pyrolysis of six representative PFAS compounds, all of which have an eight-carbon length but with different functional groups. To assess the thermal stability and pyrolysis products of these six PFAS compounds, evolved gas analysis (EGA) was performed using thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) coupled with an infrared spectrometer (IR) and a mass spectrometer (MS), as well as pyrolysis-GCMS (Pyr-GCMS). The EGA data demonstrates that compounds with lower estimated vapor pressures were generally found to be more thermally labile, and the presence of an ionic bond necessitates higher temperatures for pyrolysis. Pyrolysis at 900 °C yielded a variety of fluorinated organic compounds at significant signals. Tetrafluoroethene constituted the majority of the Pyr-GCMS signal for all the compounds. Moreover, a significant fraction of detected products was unable to be identified, underscoring a need for better tools to help with the identification of unknowns. Pyrolysis can occur through random chain scission, scission of the functional group, scission of the terminal CF3 group, and HF elimination. Some compounds may undergo more complete beta-scission to produce smaller pyrolysis products compared to others. The presence of acidic protons within the functional group can help facilitate HF elimination, whereas the salt form of a PFAS compound is less likely to undergo HF elimination. Termination of radical intermediates can either be recombination with a CF3 radical or hydrogen abstraction (H-abstraction). Observed hydrogen-substituted products indicate that functional groups with higher hydrocarbon character may lead to more H-abstraction terminated products. Overall findings show that the functional group of a PFAS may decrease or increase its thermal stability and lead to different profiles of pyrolysis products.

Effect of different thermal processing methods and thermal core temperatures on the protein structure and in vitro digestive characteristics of beef

This study aimed to investigate the effect of different thermal processing treatments on the protein digestion characteristics of beef. The beef samples were subjected to different cooking methods, namely steaming, boiling, and roasting, and different core temperatures (75 °C, 80 °C, 85 °C, and 90 °C), and were subjected to in vitro gastrointestinal digestion simulation. All the thermal processing treatments increased the protein digestibility; the samples that were steamed at 85 °C (S85), boiled at 80 °C (B80), and roasted at 80 °C (R80) showed the biggest gains. The S85 released more peptide species after gastrointestinal digestion, according to peptididomic studies. These differences were closely related to protein structure. Thermal processing treatments resulted in a higher degree of proteolysis and looser protein conformation, as evidenced by decreased intrinsic fluorescence and electrophoretic band intensity, increased surface hydrophobicity, and the change in protein secondary structure from α-helix to β-sheet and random coil. Based on the results, S85 was identified as the optimal thermal processing treatment for enhancing the digestibility of beef protein. The results provide valuable insights into the nutritional qualities and digestion of heat-processed beef protein.

Optimization and characterization of doped photoactive layer P3HT: ICBA for organic optoelectronic applications

A doped bulk heterojunction P3HT: ICBA active layer was studied, aiming at the effects of chromium chloride (CrCl2) and Cobalt chloride (CoCl2) doping. The study involved linear optical and electrical characterization to analyze the impact of these additives on the photoactive layer's performance. The electrical properties of doped P3HT: ICBA revealed enhancements with CrCl2(5%wt), CrCl2(10%wt), CoCl2(5%wt), and CoCl2(5%wt) (5%wt) by 8.5x, 11x, 10x, and 14x respectively, compared to pure P3HT:ICBA under dark/light conditions. This improvement is attributed to enhanced internal charge generation. The study also examined the effect of thermal treatment on the active layer from 20 ºC to 65 ºC under dark/light conditions. Additionally, the doped photoactive layer samples were tested as optical sensors under white, green, and red light, with a slightly higher optical response under white light. The findings confirm that doping P3HT: ICBA with CoCl2 and CrCl2 improves optical and electrical responses due to better charge transfer and generation.

Effect of Hydrothermal and Non Thermal Treatments on Nutritional and Functional Properties of Pearl Millet Grain and Flour

Effect of Hydrothermal and Non Thermal Treatments on Nutritional and Functional Properties of Pearl Millet Grain and Flour

Thermally processed rice starch impacts glucose homeostasis in mice to different degrees via disturbing gut microbial structure and intestinal barrier function

Long-term intake of thermally processed starch-based foods may impact glucose homeostasis, but the consistency of the effects of various thermal treatments and the reasons are not clear. In this study, thermal treatments, especially boiling, damaged the crystal structure and inter-molecular hydrogen bonds of starch-based blends, thus decreasing the structural order and stability. These thermally treated starch-based blends increased the appetite of mice, promoted food digestion, and enhanced postprandial glucose response. Normal C57BL/6J mice were treated with boiled, baked, and fried starch-based diets for ten weeks. Compared to the baked and fried starch-based diets, the boiled starch-based diet significantly (p < 0.05) elevated random blood glucose levels and disrupted insulin homeostasis, primarily due to the remarkable decrease in gut microbial diversity. Both baked and fried starch-based diets resulted in relatively high intestinal epithelial permeability (plasma lipopolysaccharide increased by 28.67 % and 21.85 %, respectively). They adversely affected islet β-cell function and evoked glucose metabolism disorder. Overall, results demonstrate a clear connection among the thermal processing of starch-based diets, disruption of intestinal homeostasis, and adverse glucose metabolism. This study lays a theoretical foundation for the formulation of food processing strategies to mitigate the adverse effects of thermally treated food on glucose homeostasis.

Controlled hydrolysis with preheating treatment and glutathione addition for enhanced foaming properties of soy protein isolate

This study investigates the effects of thermal treatment and glutathione addition on soy protein isolate (SPI) before pepsin-driven hydrolysis to obtain desirable hydrolysis with a high yield of soluble protein and good foaming properties. Various properties of SPI hydrolysates were measured to understand the change of SPI molecular composition related to foaming properties. The results revealed that the combination of glutathione and 55 °C thermal treatment yielded the most favorable SPI hydrolysate, characterized by excellent foaming capability (191.3%) and stability (93.1%), attributed to the highest relative composition (50.2%) of 7S. With the treatment temperature increasing from 55 °C to 75 °C, the reduction of 7S and generation of small molecular weight peptides negatively affected the foaming properties of SPI hydrolysates. The application of glutathione as a modulator, alongside mild thermal treatment, optimizes SPI hydrolysates for applications needing improved foaming and interfacial properties to achieve desirable foaming capability and stability. The study's findings offer promising potential for improving food products and formulations requiring enhanced foaming properties, with applications in industries like bakery and confectionery, leading to better texture, stability, and overall product quality.

Exploring the potential of graphite felt electrodes for electrochemical sensing of bisphenol A: An experimental and computational study

Considering the seriously detrimental effects of bisphenol A (BPA) on human beings and environment, efforts have been devoted to search for its effective and efficient electrochemical detection. This study explores the potential of Polyacrylonitrile (PAN)- and Rayon-based graphite felts for electrochemical sensing of BPA. Effect of thermal treatment on the physicochemical and electrochemical properties of the graphite felts (GF) is also comprehensively investigated. The felts were thermally activated to increase the hydrophilicity and then characterized by Fourier transform infra-red (FT-IR) spectroscopy, Raman spectrometry, thermal gravimetric analysis (TGA), scanning electron microscopy (SEM) and electrochemical methods. Furthermore, the electrochemical behavior of BPA was investigated on the graphite felt electrodes in phosphate buffer solution using cyclic voltammetry (CV) technique. Electrochemical measurements using cyclic voltammetry revealed the superior activity of thermally activated PAN-based GF (T-PGF) as an electroactive substrate for BPA sensing. Under optimized conditions, the CV response of T-PGF towards BPA showed two linear relationships within concentration ranges of 1–100 µM and 100–1000 µM and low limit of detection (0.13 µM at S/N = 3). The experimental results were also validated by density functional theory (DFT) studies. Compared with other sensing substrates for BPA such as glassy carbon electrode, GF with a simple surface modification by thermal treatment appears as a promising and reliable method for rapid detection of BPA and will help in its removal and mitigate its harmful effects.

Effect of pilot-scale high-temperature short-time processing on the retention of key micronutrients in a fortified almond-based beverage: implications for fortification of plant-based milk alternatives.

The effect of thermal processing treatments on key micronutrients in fortified almond-based beverages has not been well characterized. An almond-based beverage was produced in a pilot plant, fortified with vitamin A palmitate, vitamin D2, riboflavin (vitamin B2), calcium carbonate, and zinc gluconate, and was processed using various high-temperature short-time (HTST) pasteurization treatments. Naturally present micronutrients in the base ingredients included several B vitamins (vitamin B1 [thiamin], total vitamin B3 [sum of nicotinamide and nicotinic acid], and total vitamin B6 [sum of pyridoxal, pyridoxamine, and pyridoxine]) and minerals (magnesium, phosphorus, and potassium). The prepared almond-based beverage was homogenized and thermally processed using HTST pasteurization with a temperature range from ~94 to 116°C for a constant time of 30 s. The samples were analyzed for vitamin A palmitate, vitamin D2, target B vitamins (thiamin, riboflavin, total vitamin B3, and total vitamin B6), and minerals (magnesium, phosphorus, potassium, calcium, and zinc). The results showed that amounts of vitamin A, vitamin D2, riboflavin, and total vitamin B6 did not significantly (p > 0.05) change after the HTST treatments, whereas thiamin significantly (p < 0.05) decreased by 17.9% after HTST treatment at 116°C. Interestingly, total vitamin B3 content significantly (p < 0.05) increased by 35.2% after HTST treatment at 116°C. There was no effect of processing on the minerals that were monitored. The results from this study indicate that the majority of key micronutrients assessed in this study are stable during HTST processing of an almond-based beverage and that fortification of plant-based milk alternatives may be a viable process to enhance the micronutrient content consumers receive from these products.

The role of processing on phenolic bioaccessibility and antioxidant capacity of apple derivatives

Fruit derivatives are commonly obtained by applying processing operations deemed responsible for the loss of phenol compounds, but very little information is available on the fate of phenols upon digestion of these products. The present study evaluated the effect of thermal and mechanical treatments, commonly applied to turn apple pulp into puree and homogenate, on phenolic bioaccessibility and antioxidant activity.Despite a 20 % decrease in polyphenols due to processing, their bioaccessibility was higher in apple derivatives (>20 %) compared to pulp (∼2 %). Polyphenol oxidase (PPO), inactivated by thermal treatments in apple derivatives but not in the pulp, was hypothesized to be responsible for this difference. Results acquired on an unprocessed PPO-free apple model, only featuring quercetin-3-glucoside and pectin, actually exhibited similar bioaccessibility as processed derivatives.The radical scavenging capacity was unaffected by the structural integrity of apples, indicating independence from the plant tissue's hierarchical arrangement. After digestion, radical scavenging capacity decreased in the real apple matrices, correlating with phenolic content, while it was retained in the apple model, further suggesting the pivotal food matrix role in modulating polyphenols bioaccessibility and subsequent biological activity.Translating these results to an industrial scale, processing conditions can be optimized not only to guarantee that the quality requirements are met, but also to achieve desired nutritional benefits.