Hot Water Treatment Research Articles

Quantitative design criterion for mechanical interface functionalization regarding adhesion strength in chemically pre-treated polymer-metal hybrids using fractal dimension

ABSTRACT Polymer-metal hybrids (PMH) are common lightweight materials, whereas adhesion between metal and polymer is largely determined by the metallic surface design. Approaches in interface functionalization comprise both, mechanical and chemical surface modification. Therefore, surface modification on aluminum EN AW-6082 has been conducted prior to thermal joining to glass-fiber reinforced polyamide 6. Laser beam machining with a variation of structure density was carried out to produce defined groove structures. In addition, chemical surface modification by Boehmite hot water treatment as well as organo-silane couple agents were realized. Subsequently, the joint strength was assessed in lap shear tests. In order to quantitatively correlate the features of surface structure to the joint strength, regression analysis considering different chemical states were conducted. Hereby, the surface structure was represented on the one hand by the structure density and on the other hand by the calculated fractal dimension on cross-sectional images. The results revealed that using both, mechanical and chemical surface modification by laser machining as well as silanization, not only added together but moreover acted beneficial to each other. In addition, the fractal dimension proved to be a promising design criterion for linear correlation of joint strength independent of the chemical state.

Structural and Optical Properties of Al2O3 Nanostructures Prepared by Hot Water Treatment Method

Structural and Optical Properties of Al2O3 Nanostructures Prepared by Hot Water Treatment Method

Eliminating leaf scald disease in sugarcane: efficacy of hot water and cold soak treatments

Eliminating leaf scald disease in sugarcane: efficacy of hot water and cold soak treatments

Seed Disinfection Treatments Minimized Microbial Load and Enhanced Nutritional Properties of Fenugreek Sprouts Which Alleviated Diabetes-Negative Disorders in Diabetic Rats.

Sprouts are an attractive food product that contains high amounts of nutritional substances and has pro-health features. Sprout consumption has strongly increased despite its potential risk to health due to its microbial load. Both the safety and shelf life of sprouts may be negatively affected by a high microbial load. To reduce the microbial contamination in sprouts before consumption, the initial microbial load on the seeds needs to be controlled. Many herbal sprouts have been recommended for diabetes, and fenugreek is one of these sprouts. Thus, the current experiment aimed at disinfecting fenugreek seeds using microwave (5, 10, and 20 s) and hot water (30, 45, and 60 s) treatments for different durations. The best-disinfected sprouts with the highest nutritional properties were used to evaluate their influence on streptozocin-induced diabetic rats in comparison with fenugreek seed feeding. Microwave treatments showed the highest sprout length, fresh weight, total free amino acids, antioxidants, reducing sugars, and total phenols. Additionally, microwave seed treatments showed the lowest bacteria and mold counts on sprouts produced relative to hot water treatments, and the best seed treatment was a microwave for 20 s, which gave the best values in this respect. Feeding diabetic rats with different fenugreek seeds or sprout rates (0, 5, 7.5, and 10% w/w) improved body weight, restricted the growth of glucose levels, lowered total cholesterol and triglycerides, and improved HDL compared with the positive control group, and fenugreek sprouts at higher rates showed the maximum improvements in blood glucose, total cholesterol, and triglycerides. Treating fenugreek seed with microwave radiation for 20 s to disinfect the seeds before sprouting is recommended for lowering the microbial load with optimum nutritional and antioxidant activity, and feeding diabetic rats with these sprouts at the rate of 7.5 and 10% had promising effects on hyperglycemia and associated disorders.

The Compatibility of Cement Bonded Fibreboard Through Dimensional Stability Analysis: A Review

Natural fibre in cement matrix was used to reinforce, increase tensile strength, and protect against matrix cracking. The various properties of the matrix, which were introduced by the shrinkage and thermal stresses, can be attributed to the microcracks on the composites. The composites experienced significant negative changes due to the spread of microcracks. Changes in moisture have an impact on the dimensional stability of cement-bonded fibreboards. The increasing moisture content caused the expansion of cement-bonded fibreboard, whereas shrinkage was caused by the moisture being evaporated. Since natural fibres connect ineffectively with the cement matrix due to their hydrophilicity, fibre-cement composites are dimensionally unstable. Hot water treatments operate by clearing the fibre’s surface of volatile compounds, impurities, and waxy elements and facilitating water absorption. Numerous variables, including the mixing ratio, the targeted density, and the pre-treatment technique used on natural fibre, influence the dimensional stability of cement-bonded fibreboard. The compatibility of cement-bonded fibreboard increases with increasing cement/fibre mixing ratio, density of cement-bonded fibreboard, hot water treatment temperature and duration.

Effects of Different Extraction Methods on the Structural and Functional Properties of Soluble Dietary Fibre from Sweet Potatoes.

In this study, hot water treatment (WT), ultrasonic treatment (UT), ultrasonic-sodium hydroxide treatment (UST), ultrasonic-enzyme treatment (UET), and ultrasonic-microwave treatment (UMT) were used to treat sweet potatoes. The structural, physicochemical, and functional properties of the extracted soluble dietary fibres (SDFs) were named WT-SDF, UT-SDF, UST-SDF, UET-SDF, and UMT-SDF, respectively. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal properties, and Brunauer-Emmett-Teller (BET) analysis were employed. The structural results indicated that the UST-SDF exhibited the best thermal stability, highest crystallinity, and maximum specific surface area. Moreover, compared to hot water extraction, ultrasonic extraction, or ultrasonic extraction in combination with other methods, enhanced the physicochemical and functional properties of the SDF, including extraction yield, water-holding capacity (WHC), oil-holding capacity (OHC), glucose adsorption capacity (GAC), glucose dialysis retardation index (GDRI), sodium cholate adsorption capacity (SCAC), cholesterol adsorption capacity (CAC), nitrite ion adsorption capacity (NIAC), and antioxidant properties. Specifically, the UST-SDF and UMT-SDF showed better extraction yield, WHC, OHC, GAC, CAC, SCAC, and NIAC values than the other samples. In summary, these results indicate that UST and UMT could be applied as ideal extraction methods for sweet potato SDF and that UST-SDF and UMT-SDF show enormous potential for use in the functional food industry.

Influence of Substrate Location and Temperature Variation on the Growth of ZnO Nanorods Synthesized by Hot Water Treatment.

Hot water treatment (HWT) is a versatile technique for synthesizing metal oxide nanostructures (MONSTRs) by immersing metal substrates in hot water, typically in glass beakers. The proximity of substrates to the heat source during HWT can influence the temperature of the substrate and subsequently impact MONSTR growth. In our study, zinc (Zn) substrates underwent HWT at the base of a glass beaker in contact with a hot plate and at four different vertical distances from the base. While the set temperature of deionized (DI) water was 75.0 °C, the substrate locations exhibited variations, notably with the base reaching 95.0 °C. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Raman spectroscopy showed stoichiometric and crystalline zinc oxide (ZnO) nanorods. ZnO rods on the base, exposed to higher temperatures, displayed greater growth in length and diameter, and higher crystallinity. Nanorods with increasing vertical distances from the base exhibited a logarithmic decrease in length despite identical temperatures, whereas their diameters remained constant. We attribute these findings to crucial HWT growth mechanisms like surface diffusion and "plugging", influenced by temperature and water flow within the beaker. Our results provide insights for optimizing synthesis parameters to effectively control MONSTR growth through HWT.

Sequential utilization of birch sawdust using a two-step hot water treatment

Sequential utilization of birch sawdust using a two-step hot water treatment

Genome-wide identification of gene families related to miRNA biogenesis in Mangifera indica L. and their possible role during heat stress.

Mango is a popular tropical fruit that requires quarantine hot water treatment (QHWT) for postharvest sanitation, which can cause abiotic stress. Plants have various defense mechanisms to cope with stress; miRNAs mainly regulate the expression of these defense responses. Proteins involved in the biogenesis of miRNAs include DICER-like (DCL), ARGONAUTE (AGO), HYPONASTIC LEAVES 1 (HYL1), SERRATE (SE), HUA ENHANCER1 (HEN1), HASTY (HST), and HEAT-SHOCK PROTEIN 90 (HSP90), among others. According to our analysis, the mango genome contains five DCL, thirteen AGO, six HYL, two SE, one HEN1, one HST, and five putative HSP90 genes. Gene structure prediction and domain identification indicate that sequences contain key domains for their respective gene families, including the RNase III domain in DCL and PAZ and PIWI domains for AGOs. In addition, phylogenetic analysis indicates the formation of clades that include the mango sequences and their respective orthologs in other flowering plant species, supporting the idea these are functional orthologs. The analysis of cis-regulatory elements of these genes allowed the identification of MYB, ABRE, GARE, MYC, and MeJA-responsive elements involved in stress responses. Gene expression analysis showed that most genes are induced between 3 to 6 h after QHWT, supporting the early role of miRNAs in stress response. Interestingly, our results suggest that mango rapidly induces the production of miRNAs after heat stress. This research will enable us to investigate further the regulation of gene expression and its effects on commercially cultivated fruits, such as mango, while maintaining sanitary standards.

Durability of metal oxide nanostructures synthesized by hot water treatment

Metal oxide nanostructures (MONSTRs) have become popular in various fields. This study investigates the durability of MONSTRs synthesized through hot water treatment (HWT) using copper, aluminum, and zinc as the source metals of choice. The physical durability tests include pressure, scratch, and scotch tape adhesion tests, and chemical durability tests such as corrosion resistance tests, heat resistance, and solar exposure tests. Results showed that MONSTRs synthesized from HWT are highly durable under the tested conditions except for NaOH and HCl immersion tests for copper oxide and zinc oxide. The study concluded that HWT is a sustainable synthesis method for MONSTRs.Graphical

Impact of seedbed types and scarification methods on germination percentage and growth performance of Bambara groundnut (Vigna subterranea (L.) Verdc.) in the Sudan Savanna zone of Nigeria

The field experiments were conducted during the 2021 and 2022 wet seasons at The National Institute for Horticultural Research, Bagauda, and Hadejia-Jama’are River Basin Development Authority, Wudil, both in Kano State within the Sudan Savannah agro-ecological zone of Nigeria. The study aimed to find a better seedbed arrangement and the best scarification methods for good germination and growth of Bambara groundnut cultivars. The treatments consisted of four seedbed types (ridge, ridge+earthing, flat, and flat+earthing), four scarification methods (zero, mechanical, acid, and hot water treatments), and three cultivars (cream, black, and speckled). The treatments were factorially combined and laid out in a split-split plot design with three replications. Seedbed was assigned to the main plot, scarification methods were assigned to the subplot, and cultivars were assigned to the sub-subplot. Data collected were days to first emergence, establishment count (%), canopy height (cm), and kernel yield (kg ha-1). The result indicated that mechanically scarified Bambara groundnut seeds resulted in a higher establishment count and uniform canopy height (cm), which led to more dry matter accumulation and a higher kernel yield (kg ha-1).

Cooking Recipe as a Determinant of Glycemic Index Variation in Commercial and Natural Wheat Flour

An in vivo study was conducted with various cooking recipes to select suitable wheat flour in view point of glycemic index (GI) value from the commercially available whole and plain wheat flour by comparing with natural wheat flour. We assessed the glycemic responses of 10 healthy individuals with reference food (50 g glucose) and cooked wheat roti, equivalent to 50 g carbohydrate, in hot (100°C) and normal water (25°C) recipes. To prevent residual effects, the individuals were kept overnight fasting throughout the study period. Capillary glucose levels at 0, 15, 30, 45, 60, 90 and 120 minutes after consuming the meals were assessed and used to determine the Incremental Area Under Curve (IAUC). Results showed a significant decrease (p<0.001 and p<0.005) in glucose levels of the test foods compared to reference food. The measured GI values of the samples processed with normal water were categorized as low (plain wheat flour, 52), medium (56 for whole wheat flour) and high (natural flour, 73). But all the samples were in low GI class when processed with hot water; GI was 43, 47 and 44 for whole wheat flour, plain wheat flour, and natural wheat flour, respectively. The temperature differences in the recipes are believed to be the primary cause of variation in GI. Hot water treatment provided low GI in the recipes that may be good for both healthy and diabetic people. J Bangladesh Agril Univ 22(2): 257-266, 2024

3D printing technology for the design of eco-friendly palisade solar evaporators for enhanced desalination and wastewater treatment

Solar-driven desalination represents a promising solution to the global water scarcity challenge, offering a sustainable and efficient method for water purification. However, traditional solar evaporation techniques face several hurdles, including prohibitive costs, intricate fabrication processes, and suboptimal solar-to-thermal energy conversion efficiencies. Addressing these issues, our study introduces an innovative, low-cost, and high-efficiency palisade solar evaporator, created using a one-step fused deposition modeling (FDM) 3D printing process. This method requires only a straightforward hot water treatment for post-fabrication conditioning, avoiding the need for complex preparations or modifications. The evaporators are very eco-friendly, as they are printed using commercial and biodegradable polylactic acid (PLA) containing carbon fibers. The structural parameters of palisade solar evaporators, including height and gap size, were well optimized. The palisade solar evaporator with height of 18 mm and gap width of 0.6 mm exhibits a solar-driven water evaporation rate of 2.52 kg m−2 h−1 under one sun illumination. Moreover, the device demonstrates exceptional salt resistance, maintaining its efficiency without salt buildup or performance degradation over prolonged use. This investigation validates the feasibility of utilizing commercial and biodegradable PLA in 3D printing to develop cost-effective, eco-conscious, and efficient solar evaporators for desalination and wastewater treatment.

Combined application of hot water and hexanal-based formulations preserves the postharvest quality of mango fruits.

Mango fruits undergo numerous postharvest quality losses during storage. Hence, the present study aimed to increase the shelf life of mango fruits by applying hexanal-based enhanced freshness formulations (EFF) in combination with hot water treatment (HWT). The findings revealed that, among all the tested applications, the combination of EFF 1.0% + HWT reduced the weight loss, decay incidence, and activity of cell wall degrading enzymes of mango fruits. Also, the combined treatment was effective in maintaining the fruit quality parameters such as soluble solid contents, titratable acidity, ascorbic acid and activity of antioxidant compounds. The present study concludes that the postharvest application of EEF 1.0% in combination with HWT can be used in extending the shelf life of mango cv. 'Langra,' fruits stored at 12° C and 85-90% relative humidity for 35 days. © 2024 Society of Chemical Industry.

Hot Water Treatment Preserves Chinese Chestnut (Castanea mollissima Blume) Quality during Storage by Increasing Its Sugar Accumulation and ROS-Scavenging Ability

Heat treatment is a widely used physical technology for postharvest fruit and crops. The Chinese chestnut cultivar “Kuili” has high sugar and amylose contents, and is popular among people. However, the chestnut quality decreases quickly after harvest. In order to maintain the chestnuts’ quality during storage, this study explores five hot water treatments for chestnuts: T1 (control, no treatment), T2 (50 °C), T3 (65 °C), T4 (75 °C), and T5 (90 °C) for 45 min. T1 was dried at ambient temperature, while the other heat treatments were dried at 30 °C for 30 min. After treatment, chestnuts were placed in plastic trays, covered with a 15 μm thick PVC film, and stored at 4 °C with 70% relative humidity; they remained in the same air for 120 days. Results indicated that T3 and T4 showed slight color changes while maintaining shell and kernel firmness, and their weight loss was reduced (+5–8%), as well as their decay rate (limited to within 20%). The T3, T4, and T5 treatments (from days 60 to 120) decreased their pest survival rates to <2%. Additionally, heat treatments facilitated the accumulation of total soluble sugar and increased the expression of sugar biosynthesis-related genes. Meanwhile, T3 and T4 delayed starch reduction (they maintained relatively higher contents, from 288 to ~320 mg g−1 DW) and altered some starch biosynthesis genes. Furthermore, T2, T3, and T4 exhibited higher antioxidant activity and lower hydrogen peroxide (H2O2) and superoxide anions (O2−) contents than T1. At the end of storage, the scores of T3 and T4 treatments were 55.1 and 52.3, and they ranked first and second among the five treatments, respectively. Therefore, these findings provide valuable insights for controlling postharvest losses in chestnuts.

MaHsf24, a novel negative modulator, regulates cold tolerance in banana fruits by repressing the expression of HSPs and antioxidant enzyme genes.

Transcriptional regulation mechanisms underlying chilling injury (CI) development have been widely investigated in model plants and cold-sensitive fruits, such as banana (Musa acuminata). However, unlike the well-known NAC and WRKY transcription factors (TFs), the function and deciphering mechanism of heat shock factors (HSFs) involving in cold response are still fragmented. Here, we showed that hot water treatment (HWT) alleviated CI in harvested banana fruits accomplishing with reduced reactive oxygen species (ROS) accumulation and increased antioxidant enzyme activities. A cold-inducible but HWT-inhibited HSF, MaHsf24, was identified. Using DNA affinity purification sequencing (DAP-seq) combined with RNA-seq analyses, we found three heat shock protein (HSP) genes (MaHSP23.6, MaHSP70-1.1 and MaHSP70-1.2) and three antioxidant enzyme genes (MaAPX1, MaMDAR4 and MaGSTZ1) were the potential targets of MaHsf24. Subsequent electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation coupled with quantitative PCR (ChIP-qPCR) and dual-luciferase reporter (DLR) analyses demonstrated that MaHsf24 repressed the transcription of these six targets via directly binding to their promoters. Moreover, stably overexpressing MaHsf24 in tomatoes increased cold sensitivity by suppressing the expressions of HSPs and antioxidant enzyme genes, while HWT could recover cold tolerance, maintaining higher levels of HSPs and antioxidant enzyme genes, and activities of antioxidant enzymes. In contrast, transiently silencing MaHsf24 by virus-induced gene silencing (VIGS) in banana peels conferred cold resistance with the upregulation of MaHSPs and antioxidant enzyme genes. Collectively, our findings support the negative role of MaHsf24 in cold tolerance, and unravel a novel regulatory network controlling bananas CI occurrence, concerning MaHsf24-exerted inhibition of MaHSPs and antioxidant enzyme genes.

Modification of PVA Nanofiber by Simple Hot Water Treatment and Application on the Removal of Malachite Green Dye From Aqueous Solutions.

In this study, the crosslinking of PVA nanofiber was increased using solvent vapor treatment. Then, Fe3O4 nanoparticles were synthesized by a simple hot water technique and composited with the nanofiber. The study focuses on applying the modified PVA nanofibers to remove malachite green (MG) from water using different pH, contact times, and dye initial concentrations. The surface morphology of the nanofiber was determined using SEM, FTIR, and XRD techniques. SEM showed that the crosslinking was increased, and Fe3O4 nanoparticles appeared as agglomerates on the surface of the nanofiber. The removal percentages at optimal pH and contact time were 99.76%, and 99.5%, respectively. Thereafter, kinetics was studied by the linear pseudo-first order, pseudo-second order, Elovich equation, and Intraparticle diffusion models. Results demonstrated that the adsorption kinetics follow the pseudo-second order. Moreover, the adsorption isotherm was discussed using Langmuir and Freundlich equations. The Langmuir equation best described the adsorption with R2 value of 0.9771, and the maximum removal was 128.205 mg/g. As a result, the MG dye molecules covered the PVA nanofiber/Fe3O4 nanoparticles in a monolayer and homogenous coverage. The results of this study are significant for industries' wastewater treatment as they provide a potential solution for the removal of MG dye from textile, paper, cosmetics, food, and aquaculture industries' wastewater.

Plastic takeaway food containers may cause human intestinal damage in routine life usage: Microplastics formation and cytotoxic effect

The microplastics and organic additives formed in routine use of plastic takeaway food containers may pose significant health risks. Thus, we collected plastic containers made of polystyrene, polypropylene, polyethylene terephthalate, polylactic acid and simulated two thermal usages, including hot water (I) and microwave treatments (M). Nile Red fluorescence staining was developed to improve accurate counting of microplastics with the aid of TEM and DLS analysis. The quantity of MPs released from thermal treatments was determined ranging from 285.7 thousand items/cm2 to 681.5 thousand items/cm2 in containers loaded with hot water with the following order: IPS>IPP>IPET>IPLA, while microwave treatment showed lower values ranging from 171.9 thousand items/cm2 to 301.6 thousand items/cm2. In vitro toxicity test using human intestinal epithelial Caco-2 cells indicated decrease of cell viability in raw leachate, resuspended MPs and supernatants, which might further lead to cell membrane rupture, ROS production, and decreased mitochondrial membrane potential. Moreover, the leachate inhibited the expression of key genes in the electron transport chain (ETC) process, disrupted energy metabolism. For the first time, we isolate the actually released microplastics and organic substances for in vitro toxicity testing, and demonstrate their potential impacts to human intestine. SynopsisPlastic take-out containers may release microplastics and organic substances during daily usage, both of which can cause individual and combined cytotoxic effects on human colon adenocarcinoma cells Caco-2.

Investigation of Hydrothermal Carbonization of Exhausted Chestnut from Tannin Extraction: Impact of Process Water Recirculation for Sustainable Fuel Production

This study explores the hydrothermal carbonization (HTC) process applied to the exhausted chestnut produced by the tannin extraction industry, utilizing process water recirculation to enhance the efficiency and sustainability of the conversion process. Tannin extraction from wood typically involves hot water treatment, leaving behind residual wood biomass known as exhausted wood. These by-products maintain their renewable properties because they have only been exposed to hot water under a high pressure, which is unlikely to cause major alterations in their structural components. Hydrothermal treatment was carried out at temperatures of 220 °C and 270 °C for 1 h, with process water being recirculated four times. This investigation focused on analyzing the effects of recirculation on the yield and fuel properties of hydrochar, as well as characterizing the combustion behavior of the obtained hydrochar. The results indicated that recirculation of process water led to improvements in both the mass and energy yields of hydrochar. The mass yield of the hydrochar samples increased by 5–6%, and the ERE of the hydrochar samples increased by 5–8% compared to the HTC reference sample. However, alterations in the combustion characteristics were observed, including decreases in ignition temperature and combustion reactivity. The results indicate that, with PW recirculations, the combustion index decreased by about 14% and 18% for 220 °C and 270 °C, respectively. Overall, this research demonstrates the potential of utilizing HTC on chestnut tannin residue with process water recirculation to produce stable solid fuel and provides insights into the combustion behavior of the resulting hydrochar.

Micro-blasting & Hot Water Treatment: Surface Texturing for Metal-Polymer Direct Joining

Micro-blasting & Hot Water Treatment: Surface Texturing for Metal-Polymer Direct Joining