Changes In Chemical Composition Research Articles

Changes in Blue Color of Sapphire Compared with Oxidation State Changes

Blue sapphire has long been treated with heat to modify its blue color and attain greater value. However, the process of modifying the blue color in sapphire remains not well understood. The color-changing mechanism has traditionally been explained using the Intervalence Charge Transfer (IVCT) (Fe2+-Ti4+ and/or Fe2+-Fe3+) theory, wherein the blue color can be diminished by heat treatment in an oxidizing environment which alters Fe2+ (FeO) to Fe3+ (Fe2O3) and decreases the occurrence of the IVCT process. However, recently, the band gap theory has been proposed, suggesting that iron (Fe) in sapphire is always in the Fe3+ state, the blue color is caused by Fe3+-Ti4+ pair and the heat treatment does not affect Fe oxidation state. Therefore, in this study, eight magmatic sapphires from four localities were investigated for changes in blue color via color analysis, changes in spectra using XANES, and changes in chemical composition using PIXE both before and after heat treatment. The color analysis reveals a slight reduction in saturation (fading of blue) and a noticeable lightening after heat treatment, which corresponds with the high content of solid inclusions or trapiche samples. XANES data analysis using the LCF technique indicated insignificant changes in Fe oxidation state from 2+ to 3+ after heat treatment across all samples. However, when comparing the XANES data with color parameter L*a*b*, it is noted that the percentage of Fe oxidation state changes does not show a positive relationship with changes in blue based on color parameter b* (blue–yellow); rather, it shows a positive relationship with parameter L* (lightness). Microscopic observations also reveal the dissolution of clouds or minute particles around planes of ilmenite needles. It could be suggested that the changes in Fe oxidation state may not be directly related to changes in blue color but could be linked to the partial dissolution of Fe-bearing inclusions.

Влияние молотой серы на альгоцианофлору щелочных засолённых почв

The paper considers the impact of ground sulphur (S 0 ) used as a chemical ameliorant for alkali-saline soils, as well as of sulphur with mineral and organic fertilizers, on species diversity and abundance of soil phototrophic microorganisms – algae and cyanobacteria. The research was carried out in laboratory conditions through the example of alkali soil. The alkali type is automorphic, its subtype is brown semiarid. Application of ground sulphur, as well as sulphur with mineral and organic fertilizer additives to alkali-saline soil caused considerable change in its chemical and physical-chemical properties: рН decrease, and increase in conductivity and phosphorus, potassium, magnesium, and calcium content in soil extract. Soluble carbonates and hydrocarbonates content decreased. Changes in soil properties and chemical composition effected species composition and abundance of soil algocyanoflora. 16 species, including Cyanobacteria – 10, Bacillariophyta – 4, Chlorophyta – 2, were found in the control soil. 25 species of soil microphototrophs, such as Cyanobacteria – 14, Chlorophyta – 4, Bacillariophyta – 7, were found in the soil of experiment variants. Algocyanoflora species composition of control and experiment variants remains mostly the same (64%). Application of mineral and organic additives caused growth of algocyanoflora species diversity in soil. Sulphur application contributed to microphototrophs cells increasing in number. The highest species diversity of microphototrophs found in the variant with sulfur and a complex of mineral and organic fertilizers.

UPLC-Q-TOF/MS analysis of chemical components of single decoction and combined decoction of Qige decoction reveals the differences between various preparation processes.

The aim of this work was to explore the differences between various pharmaceutical processes in combined solutions of a single decoction (QGHBY) and a combined decoction (QGHJY) of Qi-Ge decoction from the perspective of chemical composition changes, so as to further guide the clinical application of drugs. A combined solution of a single decoction and a combined decoction of Astragali Radix, Puerariae Lobatae Radix and Citri Reticulatae Chachiensis Pericarpium was prepared with the same technological parameters. The chemical components of the two were detected and identified based on UPLC-Q-TOF/MS, and the different components were determined by principal component analysis. Eighty-eight compounds were identified in the pharmaceutical solution of Qi-Ge decoction. Principal component analysis revealed 11 different components of QGHBY and QGHJY with the conditions of Variable Importance in Projection (VIP) ≥ 1, fold change ≥ 2 and p < 0.05, among which hesperidin, hesperitin, isosinensetin, sinensetin and 5-demethylnobiletin were the components of Citri Reticulatae Chachiensis Pericarpium. The levels of these 11 different components in QGHJY were higher than those of QGHBY. The combined decoction is beneficial for the dissolution of flavonoids and other chemical components, and there is a significant difference in the content of chemical components between modern herbal concentrate granules and traditional decoctions.

Plasma Treatment Modifies Element Distribution in Seed Coating and Affects Further Germination and Plant Growth through Interaction with Soil Microbiome.

This study investigates the impact of plasma-seed interaction on germination and early plant development, focusing on Arabidopsis thaliana and Brassica napus. The investigation delves into changes in chemical composition, water absorption, and surface morphology induced by plasma filaments generated in synthetic air. These analyses were conducted using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Although plasma treatment enhanced water absorption and modified surface chemistry, its impact on germination demonstrated species- and context-dependent variations. Notably, the accelerated germination and morphogenesis of seedlings in microbiome-enriched (MB+) soil could be achieved also in microbiome-deprived (MB-) soil by short-term plasma treatment of seeds. Remarkably, the positive effects of plasma treatment on early developmental events (germination, morphogenesis) and later events (formation of inflorescences) were more pronounced in the context of MB- soil but were accompanied by a slight decrease in disease resistance, which was not detected in MB+ soil. The results underscore the intricate dynamics of plasma-plant interactions and stress the significance of accounting for the soil microbiome while designing experiments with potential field application.

Effect of metal organic framework alginate aerogel composite sponge on adsorption of tartrazine from aqueous solutions: Adsorption models, thermodynamics and optimization via Box-Behnken design

La-MOF has an excellent chance of eliminating food and industrial coloring pollutants from water because it is a typical metal-organic framework material. Nevertheless, the challenging liquid recovery has restricted the use of this powdered adsorbent. In order to solve this shortcoming, we created composite beads (La-MOF@CA aerogel composite sponge) by solidifying sodium alginate and La-MOF together. A common technique to boost an adsorbent material's adsorption capability is to modify its composition; this is especially true for adsorbents composed of metal organic framework. The effects of La-MOF@CA aerogel composite sponge on the adsorption and elimination of tartrazine (TZ) were examined in this study. Following thorough characterization, the following tests were performed: X-ray diffraction (XRD), energy-dispersive X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller surface area (BET). The La-MOF@CA aerogel composite sponge has a significant high surface area of 1244.68 m2/g and this surface area was decrease after adsorption of TZ to be 768.98 m2/g. the greatest adsorption capacity (qmax) of for TZ, 710.75 mg/g. Examine how the adsorption process is impacted by factors like temperature, adsorbent dosage, pH, and TZ concentration. The pHZPC was 5.18 and optimum pH for adsorption and removal of TZ was 4. The adsorption process was fitted to the pseudo-second-order equation kinetically, and to the Langmuir equation isothermally. As the adsorption energy Ea was 22.76 kJ/mol indicated that the adsorption process was chemisorption. The adsorption process was thought to be endothermic and spontaneous based on adsorption thermodynamics. The temperature increased in tandem with the amounts of materials absorbed. With good efficiency, no change in chemical composition, and similar XRD and XPS data before and after reuse, the La-MOF@CA aerogel composite sponge was reused five times. Examine the interaction mechanism between the heavy TZ and the La-MOF@CA aerogel composite sponge. Box Behnken-design was used to maximize the adsorption results (BBD).

Imidazole as a new strategy in the lignocellulosic pretreatment: An application in corn sub-products with a focus on bioenergy production

To enhance the efficiency of pretreatment processes for lignocellulosic biomass, this study utilized the green solvent imidazole to pretreat residual corn biomass (corn straw (CS) and corncob (CC)) with a focus on cellulose recovery for ethanol production. The pretreatment involved varying temperatures (ranging from 120 to 180 °C) and times (30 and 60 min) with biomass:imidazole ratio of 1:9 (w.w−1). The effects of imidazole pretreatment on the biomasses were examined by analyzing the chemical composition, surface morphology, cellulose crystallinity, and compositional changes. The results demonstrated a significant alteration of the lignocellulosic complex due to imidazole pretreatment, resulting in a reduction of the lignin content, reaching 81.47 % and 74 % for CS (180°C-60min) and CC (180°C-30min), respectively. Moreover, the cellulose content in the pretreated solids increased by approximately 1.5 times compared to the raw biomass. The pretreated biomasses were subjected to enzyme hydrolysis (after pretreated at a higher temperature (150–180 °C)), which led to a high glucose yield. CC achieved a glucose yield of 100 %, while CS yielded 77 %. Alcoholic fermentation was carried out using Saccharomyces cerevisiae CAT-1, resulting in an ethanol yield of 82 % in 12 h for CC (180 °C for 30 min) and 66 % for CS (150 °C for 1 h).

Chemical composition and microbiota changes across musk secretion stages of forest musk deer.

Forest musk deer is the most important animal for natural musk production, and the musk composition changes periodically during musk secretion, accompanied by variation in the com-position of deer-symbiotic bacteria. GC-MS and 16S rRNA sequencing were conducted in this study, the dynamic changes to correlated chemical composition and the microbiota across musk secretion periods (prime musk secretion period, vigorous musk secretion period and late musk secretion period) were investigated by integrating its serum testosterone level in different mating states. Results showed that the testosterone level, musk composition and microbiota changed with annual cycle of musk secretion and affected by its mating state. Muscone and the testosterone level peaked at vigorous musk secretion period, and the microbiota of this stage was distinct from the other 2 periods. Actinobacteria, Firmicutes and Proteobacteria were dominant bacteria across musk secretion period. PICRUSt analysis demonstrated that bacteria were ubiquitous in musk pod and involved in the metabolism of antibiotics and terpenoids in musk. "Carbohydrates and amino acids," "fatty acids and CoA" and "secretion of metabolites" were enriched at 3 periods, respectively. Pseudomonas, Corynebacterium, Clostridium, Sulfuricurvum were potential biomarkers across musk secretion. This study provides a more comprehensive understanding of genetic mechanism during musk secretion, emphasizing the importance of Actinobacteria and Corynebacterium in the synthesis of muscone and etiocholanone during musk secretion, which required further validation.

The Influence of the Changes in Natural Gas Supplies to Poland on the Amount of Hydrogen Produced in the SMR Reactor

Thanks to investments in diversifying the supply of natural gas, Poland did not encounter any gas supply issues in 2022 when gas imports from Russia were ceased due to the Russian Federation’s armed intervention in Ukraine. Over the past few years, the supply of gas from routes other than the eastern route has substantially grown, particularly the supplies of liquefied natural gas (LNG) via the LNG terminal in Świnoujście. The growing proportion of LNG in Poland’s gas supply leads to a rise in ethane levels in natural gas, as verified by the review of data taken at a specific location within the gas system over the years 2015, 2020, and 2022. Using measurements of natural gas composition, the effectiveness of the steam hydrocarbon reforming process was simulated in the Gibbs reactor via Aspen HYSYS. The simulations confirmed that as the concentration of ethane in the natural gas increased, the amount of hydrogen produced, and the heat required for reactions in the reformer also increased. This article aims to analyze the influence of the changes in natural gas quality in the Polish transmission network caused by changes in supply structures on the mass and heat balance of the theoretical steam reforming reactor. Nowadays, the chemical composition of natural gas may be significantly different from that assumed years ago at the plant’s design stage. The consequence of such a situation may be difficulties in operating, especially when controlling the quantity of incoming natural gas to the reactor based on volumetric flow without considering changes in chemical composition.

Chemical characterization and sources of background aerosols in the eastern Mediterranean

Measurements of the composition of the gas and particulate phases were conducted from May 9 to June 4 of 2016 at the Finokalia (Greece) remote coastal site in the eastern Mediterranean, continuing the effort to track long term changes of the atmospheric chemical composition in the area. Finokalia is influenced by air masses arriving in the site from regional sources in Europe, Africa, and other locations. In this study, a series of instruments and analysis techniques were used for the first time at the Finokalia site to characterize the composition of the organic aerosol (OA). The PM1 was composed of ammonium sulfate/bisulfate (60%), followed by organics (35%) and black carbon (BC) (4%). The OA was highly oxidized with an average oxygen-to-carbon (O:C) ratio of 0.81. Source apportionment of high-resolution organic aerosol mass spectra via positive matrix factorization (PMF) identified four factors: less oxidized oxygenated organic aerosol (LO-OOA), more oxidized oxygenated organic aerosol (MO-OOA), marine-related oxygenated organic aerosol (marine-OOA) and hydrocarbon-like organic aerosol (HOA). The LO-OOA (O:C = 0.92) was the dominant factor for most of the campaign (51% of the PM1 OA), while the MO-OOA (O:C = 1.1) was responsible for 11% of the OA. The marine-OOA factor was also highly oxidized (O:C = 1.03), contributing on average 24% to the total OA and was found to be well correlated with sulfate (R2 = 0.83). The anthropogenic HOA factor (O:C = 0.36) was related to activities in the island of Crete. Its mass spectrum was quite similar (R2 = 0.86–0.95) to those of other HOA factors in the literature and its average concentration was 0.2 μg m−3 (14% of OA). High molecular weight compounds were found, suggesting the presence of oligomers in agreement with the presence of a highly oxidized quenching agent. Aromatic VOCs, like benzene, toluene, and xylenes were on average 0.17, 0.66 and 0.36 ppb, respectively with toluene concentrations indicating the presence of a local source despite the remote nature of the site. New particle formation (NPF) was observed during 26% of the days. The air masses during NPF events passed over the island of Crete and the Balkans and were characterized by a low condensation sink (5.9 ± 2.2 10−3 s−1). Nucleation mode particle concentrations during NPF days had an additional evening peak between 17:00 and 22:00, which was accompanied by an HOA peak implying the influence of a source of sub-25 nm particles in the extended area. These findings show that even a relatively remote site like Finokalia is occasionally affected by sources located tens of kilometers away, something that should be taken into account in the interpretation of past and future measurements in this location.

Two‐Dimensional Heterostructure Complementary Logic Enabled by Optical Writing

Integrated logic circuits using atomically thin, two‐dimensional (2D) materials offer several potential advantages compared to established silicon technologies such as increased transistor density, circuit complexity, and lower energy dissipation leading to scaling benefits. In this article, a novel approach to achieve tunable doping in 2D semiconductors is explored to achieve complementary transistors and logic integration. By selectively transferring WSe2 onto hBN and SiO2 substrates, complementary transistor behavior (n‐ and p‐type) was achieved using a UV light source and electrostatic activation. Furthermore, advanced characterization techniques, including high‐resolution transmission electron microscopy (HRTEM) and Kelvin probe force microscopy (KPFM), provided insights into the chemical composition and surface potential changes after UV writing. Finally, a logic inverter was successfully implemented using selectively photo‐induced doped WSe2 transistors, showcasing the potential for practical logic applications. This innovative method opens new avenues for designing energy‐efficient and reconfigurable 2D semiconductor circuits, addressing key challenges in modern electronics.

Chemical Composition and Optical Properties of Secondary Organic Aerosol from Photooxidation of Volatile Organic Compound Mixtures.

The chemical and optical properties of secondary organic aerosols (SOA) have been widely studied through environmental chamber experiments, and some of the results have been parametrized in atmospheric models to help understand their radiative effects and climate influence. While most chamber studies investigate the aerosol formed from a single volatile organic compound (VOC), the potential interactions between reactive intermediates derived from VOC mixtures are not well understood. In this study, we investigated the SOA formed from pure and mixtures of anthropogenic (phenol and 1-methylnaphthalene) and/or biogenic (longifolene) VOCs using continuous-flow, high-NOx photooxidation chamber experiments to better mimic ambient conditions. SOA optical properties, including single scattering albedo (SSA), mass absorption coefficient (MAC), and refractive index (RI) at 375 nm, and chemical composition, including the formation of oxygenated organic compounds, organic-nitrogen compounds (including organonitrates and nitro-organics), and the molecular structure of the major chromophores, were explored. Additionally, the imaginary refractive index values of SOA in the multi-VOC system were predicted using a linear-combination assumption and compared with the measured values. When two VOCs were oxidized simultaneously, we found evidence for changes in SOA chemical composition compared to SOA formed from single-VOC systems, and this change led to nonlinear effects on SOA optical properties. The nonlinear effects were found to vary between different systems.

Changes in Chemical Composition of Red and Black Currant Fruits and Leaves During Berry Ripening

ABSTRACT The composition and variations of sugars, organic acids and phenolic compounds of red and black currant fruits and leaves were studied during the last four weeks of ripening. The results showed that sugar content increased during berry ripening in both species. In comparison, organic acids decreased in red currant, whereas no differences between sampling dates were observed in black currant. Forty-seven individual phenolic compounds, belonging to anthocyanins, flavonols, flavanols, hydroxycinnamic acid derivatives and flavanones were identified in red currant fruits and 52 in black currant fruits by HPLC-MS analysis. In black currant fruits, the major phenolic compounds were anthocyanins (81.51–85.15% of total phenolics), which increased during ripening until the last sampling date. In both red and black currant leaves, 47 phenolic compounds were identified. The content of phenolic compounds in red currant leaves was 1.31-fold to 1.90-fold higher compared to the content in black currant leaves. The most abundant phenolics in both currant leaves were flavonol glycosides, accounting for 58.5–67.9% of total phenolics, and their content was the highest at the end of berry ripening.

Improvement in persistent room temperature phosphorescence of polymeric systems via a melt‐pressing method

AbstractPolymer‐based afterglow materials with persistent room temperature phosphorescence (pRTP) have attracted ever‐increasing attention due to their excellent mechanical property, suitability for large‐area production, and diverse processing methods. However, most pRTP polymers were solution‐processed into the films via casting. Herein, a simple processing method of melt‐pressing was proposed, which can improve the phosphorescence of various emitters when doped into polyamide‐12 (PA12) or its copolymer PA4 matrix. Notably, for Be@PA4 and Ch@PA4 (benzo[c]phenanthrene, Be and chrysene, Ch), their casted films did not show any afterglow, while the melt‐pressed ones exhibited bright afterglow of over 4.0 s, even if there were no hydrogen or ionic interaction between the emitters and the matrix. Detailed investigations demonstrate the melt‐pressing procedure can increase the non‐covalent interaction among the matrix as well as offer a rigid and dense environment. The melt‐pressed RTP improvement strategy was also applied to other polar polymers. Additionally, the melt‐pressing method would be of great potential in high‐level anti‐counterfeiting like preparing colorful camouflage patterns. Therefore, we offered a feasible method of melt‐pressing to improve the phosphorescence of polymeric materials without a change in chemical composition or feeding ratio. This work also gained a deeper understanding of the luminescence of polymer‐based systems.

Investigation of atomic layer deposition methods of Al2O3 on n-GaN

In this work, three atomic layer deposition (ALD) approaches are used to deposit an Al2O3 gate insulator on n-GaN for application in vertical GaN power switches: thermal ALD (ThALD), plasma-enhanced ALD (PEALD), and their stacked combination. The latter is a novel method to yield the most ideal insulating layer. Also, the influence of an in situ NH3 or H2 plasma pre-treatment is studied. Planar MIS capacitors are used to investigate the electrical properties and robustness of the gate insulators. In vacuo x-ray photoelectron spectroscopy (XPS) is used to study the changes in chemical composition after every surface treatment. XPS shows that all plasma pre-treatments efficiently remove all carbon contamination from the surface, but only NH3 plasma is observed to additionally remove the native oxide from the n-GaN surface. The water precursor step in the ThALD process does not completely remove the CH3 ligands of the trimethylaluminum precursor step, which might electrically be associated with a reduced forward bias robustness. The O2 plasma step in the PEALD process is associated with the removal of carbon and a tremendous increase of the O content in the GaN surface region. Electrically, this strongly correlates to an enhanced forward bias robustness and an increased forward bias hysteresis, respectively. The ThALD/PEALD stack method mitigates the shortcomings of both ALD processes while maintaining its advantages. Electrical measurements indicate that the stack method alongside NH3 plasma pretreatment provides the best characteristics in terms of hysteresis, threshold voltage, forward bias robustness, and interface trap density of states.

Volatile Compound Markers in Beef Irradiated with Accelerated Electrons.

This study focuses on the behavior of volatile organic compounds in beef after irradiation with 1 MeV accelerated electrons with doses ranging from 0.25 kGy to 5 kGy to find reliable dose-dependent markers that could be used for establishing an effective dose range for beef irradiation. GC/MS analysis revealed that immediately after irradiation, the chemical yield and accumulation rate of lipid oxidation-derived aldehydes was higher than that of protein oxidation-derived aldehydes. The nonlinear dose-dependent relationship of the concentration of volatile organic compounds was explained using a mathematical model based on the simultaneous occurrence of two competing processes: decomposition of volatile compounds due to direct and indirect action of accelerated electrons, and accumulation of volatile compounds due to decomposition of other compounds and biomacromolecules. A four-day monitoring of the beef samples stored at 4 °C showed that lipid oxidation-derived aldehydes, protein oxidation-derived aldehydes and alkanes as well as alcohol ethanol as an indicator of bacterial activity were dose-dependent markers of biochemical processes occurring in the irradiated beef samples during storage: oxidative processes during direct and indirect action of irradiation, oxidation due to the action of reactive oxygen species, which are always present in the product during storage, and microbial-enzymatic processes. According to the mathematical model of the change in the concentrations of lipid oxidation-derived aldehydes over time in the beef samples irradiated with different doses, it was found that doses ranging from 0.25 kGy to 1 kGy proved to be most effective for beef irradiation with accelerated electrons, since this dose range decreases the bacterial content without considerable irreversible changes in chemical composition of chilled beef during storage.

Genome-Wide Characterization of Differentially Expressed Scent Genes in the MEP Control Network of the Flower of Lilium 'Sorbonne'.

Fragrance is an important feature of ornamental lilies. Components of volatile substances and important genes for monoterpene synthesis in the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway were examined in this study. Twenty volatile compounds (2 in the budding stage, 3 in the initial flowering stage, 7 in the semi-flowering stage, 17 in the full-flowering stage, and 5 in withering stage) were detected in the Oriental lily 'Sorbonne' using gas chromatography-mass spectrometry. The semi- and full-flowering stages were key periods for volatile substance production and enzyme function. Sequence assembly from samples collected during all flowering stages resulted in the detection of 274,849 genes and 129,017 transcripts. RNA sequencing and heatmapping led to the detection of genes in the MEP monoterpene metabolism pathway. Through gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis, we extracted key genes (LiDXS2, LiLIS, and LiMYS) and transcription factors (in the bHLH, MYB, HD-ZIP, and NAC families) associated with the MEP pathway. Tissue localization revealed that LiDXS2, LiLIS, and LiMYS were expressed in Lilium 'Sorbonne' petals in the full-flowering stage. Genes regulating the 1-deoxy-D-X-lignone-5-phosphate synthase family of rate-limiting enzymes, involved in the first step of monoterpene synthesis, showed high expression in the semi- and full-flowering stages. LiDXS2 was cloned and localized in chloroplast subcells. The relative expression of terpene-related genes in the MEP and mevalonic acid pathways of wild-type and LiLIS/LiMYS transgenic Arabidopsis thaliana, and changes in chemical composition, confirmed that LiLIS/LiMYS regulates the monoterpene synthesis pathway. The results of this study provide a theoretical basis for the synthesis of lily aromatic substances and the cultivation of new garden flower varieties.

Additive manufactured corrosion-resistant SS316L/IN625 functionally graded multi-material in hydrofluoric acid (HF) environment

Multi-materials were designed for the severe corrosion environment in fluorine chemical industry. Directed energy deposition with laser beam (DED-LB) was used to manufacture SS316L/IN625 multi-materials with direct combination (DC) and graded transition (GT) structures. Partial immersion tests in 40% HF solution were conducted. The corrosion rate of SS316L/IN625 multi-materials was less than 1 mm/y. However, localized galvanic corrosion was observed in the DC samples because of the sudden change in chemical composition at the interface. The GT samples effectively eliminated this issue by gradually increasing Ni, showing good economic efficiency and reliability for the multi-phase HF corrosion environment.

Improved adhesion of rubber composites by developing environmentally friendly fiber impregnation coatings with good interfacial modulus transition gradients

Polyester (PET) fibers must undergo impregnation with a resorcinol-formaldehyde-latex (RFL) solution to ensure efficient adhesion with rubber. However, the harmful, carcinogenic resorcinol-formaldehyde (RF) resin in RFL impregnation solution negatively affects human health. In this paper, PET was pretreated with blocked isocyanate and epoxy resins to activate the fibers, and a new environmentally friendly fiber impregnation coating was developed. In the new impregnation coatings, ethylene glycol diglycidyl ether (EGDE) and m-xylylenediamine (MXDA) were applied to replace the resorcinol and formaldehyde. Moreover, glycidyl methacrylate (GMA) containing epoxy groups and double bonds was introduced to enhance interaction with rubber further, and then styrene-butadiene-vinyl-pyridine (VP) latex was mixed. The results show that the peel strength of the impregnated PET/rubber composites with the new impregnation coatings can reach 14.0 N/mm, representing an increase of 30.8 % compared to that of the sample with the pure RFL impregnation coatings, whose peel strength is only 10.7 N/mm. Furthermore, the mechanism for enhancing the interfacial adhesive properties of PET/rubber composites was performed by analyzing the chemical composition and morphological changes of the impregnated PET surface, as well as the change of sulfur content at the interface of the impregnated PET/rubber composites and the transition gradient of interfacial modulus.

Chemical Composition of Healthy and Raspberry Leaf Blotch Emaravirus-Infected Red Raspberry ‘Willamette’ Fruits

The aim of this study was to determine the changes in chemical composition of fresh red raspberry ‘Willamette’ fruits caused by the presence of raspberry leaf blotch emaravirus (RLBV). In three experimental orchards of ‘Willamette’ raspberry, fruits were harvested from RLBV-free and RLBV-infected plants in 2019 and 2020. Fruits were collected at appropriate maturity stages and further analyzed in terms of total phenolics, total anthocyanins, and selected individual phenolics. In all three experimental orchards, the phenolic profiles of the infected and uninfected fruit samples were considerably different during both studied years. Nonetheless, the intensity of the modifications varied greatly depending on the location and harvest year. Statistical analysis revealed that the influence of RLBV infection on the studied features was undeniable, although the influences of weather conditions and soil composition outweighed the influence of RLBV. Taking into consideration all the experimental and statistical data, it can be concluded that RLBV had an impact on the phenolic profile of raspberry ‘Willamette’ fruits, while sensitivity to environmental conditions and soil composition is emphasized.

Influence of different heat treatment regimes on the change of chemical composition and antibacterial activity of bee honey

The studies of the chemical composition and antibacterial activity of heather honey (Calluna vulgaris) subjected to heat treatment at 35–40°C for 12 hours were carried out. The temperature range (38–40°C), at which decrease in the H2O2 concentration, decrease in D-glucose-1-oxidase activity and increase in the 5-hydroxymethylfurfural content, was identified. The degree of chemical changes was directly proportional to the temperature and time of thermal exposure. The correlation between changes in the chemical composition and antibacterial activity of honey against test microorganisms Escherichia coli (strain 1257), Staphylococcus aureus (strain 209-P) and Bacillus cereus (strain 96) was established. The obtained results showed that heating honey to 37 °C even for 12 hours didn’t cause undesirable changes in its chemical composition and decrease in antibacterial activity. Thus, this temperature regime can be considered more gentle and recommended for use in the heat treatment of this food product.