Important Raw Material Research Articles

Evaluation of the Performance of a Composite Water Control Process for Offshore Bottom Water Fractured Gas Reservoirs

Natural gas, as one of the main energy sources of the modern clean energy system, is also an important raw material for the chemical industry, and the stable extraction of natural gas reservoirs is often affected by bottom water. It is difficult to control water in natural gas reservoirs, while fractured gas reservoirs are even more demanding. This is due to the complexity of the seepage laws of gas and water in fractures, resulting in the poor applicability of conventional processes for water control. Continuous research is needed to propose a process with effective control capabilities for bottom-water fractured gas reservoirs. Aiming at the above difficulties, this paper is based on a large-scale three-dimensional physical simulation device to carry out physical model design and simulation results testing and analysis. The water control ability of the combination of density-segmented sieve tubes and continuous packers in fractured gas reservoirs is explored. The physical simulation results show that the fracture distribution characteristics control the upward transportation path of bottom water. According to the segmentation characteristics of the fractures at the horizontal section location, optimizing the number of horizontal well screen tube segments and the density of boreholes reduces the cone-in velocity of bottom water before connecting the fractures to a certain extent. And the combined process has different degrees of water control ability for the three stages of bottom water transportation from the fractured gas reservoir to the production well. As the degree of water in the production well increases, the water control ability of the process gradually decreases. After the implementation of the water control process, the water-free gas production period was extended by about 6.84%, and the total production time was extended by about 6.46%. After the shutdown of the horizontal wells, the reduction in daily water production can still reach 21% compared to the natural extraction. The results of this research can provide process suggestions for water control in offshore fractured reservoirs and further ensure stable production in offshore fractured gas reservoirs.

Enhancing microbial salt tolerance through low-voltage stimulation for improved p-chloronitrobenzene (p-CNB) removal in high-salinity wastewater

As an important raw material for the synthesis of chemical and pharmaceutical, hazardous carcinogen p-chloronitrobenzene (p-CNB) has been widely found in high-salinity wastewater which need to be treated carefully. Due to the high-salinity shock on microorganisms, conventional microbial treatment technologies usually show poor effluent quality. This study initially investigated the p-CNB removal performance of microorganisms stimulated by 1.2 V low-voltage in high-salinity wastewater under facultative anaerobic conditions and further revealed the enhanced mechanisms. The results showed that the p-CNB removal kinetic parameter kp-CNB in the electrostimulating microorganism reactor (EMR) increased by 104.37 % to 155.30 % compared to the microorganism reactor (MR) as the control group under the varying salinities (0–45 g/L NaCl). The secretion of extracellular polymeric substances (EPS) in halotolerant microorganisms mainly enhanced by 1.2 V voltage stimulation ranging from 0 g/L NaCl to 30 g/L NaCl. Protein concentration ratio of EMR to MR in loosely bound EPS achieved maximum value of 1.77 at the salinity of 15 g/L NaCl, and the same ratio in tightly bound EPS also peaked at 1.39 under the salinity of 30 g/L NaCl. At the salinity of 45 g/L NaCl, 1.2 V voltage stimulation mainly enhanced salt-in strategy of halotolerant microorganisms, and the intracellular Na+ and K+ concentration ratio of EMR to MR reached maximum and minimum values of 0.65 and 1.92, respectively. Furthermore, the results of microbial metagenomic and metatranscriptomic analysis showed the halotolerant microorganisms Pseudomonas_A and Nitratireductor with p-CNB removal ability were enriched significantly under 1.2 V voltage stimulation. And the gene expression of p-CNB removal, salt-in strategy and betaine transporter were enhanced under voltage stimulation at varying salinities. Our investigation provided a new solution which combined with 1.2 V voltage stimulation and halotolerant microorganisms for the treatment of high-salinity wastewater.

Cradle-to-grave environmental analysis of an alpaca fiber sweater produced in Peru

Animal fibers are an important raw material for the fashion industry but have recently been discussed due to the environmental impacts related to their production. In order to provide scientific information for decision-making in the Peruvian alpaca sector a cradle to grave carbon footprint of one (01) wear of a 100 % alpaca fiber sweater has been conducted. For the modeling of the fiber procurement stage primary data regarding livestock management and annual production parameters were obtained from interviews with 42 Peruvian alpaca herders from the main producing regions in South and Central Peru. Data for the processing stages (spinning and dyeing, knitting and weaving) were collected by means of interviews and questionnaires from three alpaca fashion companies in Arequipa and Lima. The distribution, use, and end-of-life stages were modeled with secondary data. The resulting carbon footprint of one wear of the alpaca fiber sweater is 0.449 kg CO2 equivalents (CO2e). Most emissions occur during the lifecycle stages of fiber production and distribution (70 % and 14 % of CO2e emissions, respectively). Methane emissions from enteric fermentation account for 87 % of the impact within the fiber procurement stage. The environmental impacts during the distribution stage were dominated by retailing and road transport in the destination countries and export by air and sea (53.1 % and 46.4 % of carbon emissions in this stage, respectively). Other life cycle stages were found to be less relevant emission sources. The study concluded that the main strategies for impact mitigation should focus on improving the efficiency of the fiber procurement systems. Furthermore, several knowledge gaps have been identified and should be addressed by future research regarding methane emissions associated with the main co-products of the livestock systems, ecosystem services in the Andes and especially Andean wetlands and potential mitigation strategies of greenhouse gases related to different pasture management options.

The Impact of the 2020–2022 Crises on EU Countries’ Independence from Energy Imports, Particularly from Russia

The main objective of this article is to evaluate the repercussions of the crises resulting from the COVID-19 pandemic and the war in Ukraine on changes to the European Union’s reliance on energy raw material imports, particularly from Russia. Furthermore, several specific objectives are outlined: to ascertain the EU’s energy balance and any alterations therein, to identify changes in the concentration of energy raw material imports among EU countries during the crises, to determine the level and fluctuations in energy raw material import dependence within the EU and individual member states throughout the crises, and lastly, to assess changes in the concentration of energy raw material imports from Russia in EU countries during the crises. The research encompassed all 27 EU member states as of 31 December 2022, and the examination period spanned 2010 to 2022. The information sources include relevant literature on the subject and data sourced from Eurostat. In conducting the analysis and presenting the data, several methodologies are employed, including descriptive, tabular, and graphical techniques. Additionally, quantitative measures such as the Gini structure concentration coefficient and concentration analysis via the Lorenz curve are utilized. In the initial phase, an analysis of changes to the energy balance of the entire EU in the period before and during the COVID-19 pandemic and the war in Ukraine was carried out. Changes to the concentration of energy imports in EU countries during crises are also shown. Secondly, dependence on imports of individual energy resources for the entire EU was identified. Various changes in this relationship during crises are shown. If the dependence of the entire EU on the import of individual groups of energy resources from Russia were identified, changes in individual EU countries in this respect are indicated. Finally, the changes in the concentration of energy imports from Russia in the EU countries during the crises are shown. During the COVID-19 pandemic, the EU experienced a slight reduction in dependence on energy raw material imports. However, this reduction was short-lived and mainly attributed to the decrease in energy demand caused by the pandemic. Conversely, the war in Ukraine had a substantial impact, leading to a notable surge in energy raw material imports as a result of stockpiling efforts and the need to safeguard against further disruptions in the energy market. Notably, the EU’s reliance on energy imports from Russia was already considerable. Following the outbreak of the conflict in Ukraine, imports of oil, petroleum products, and solid fossil fuels experienced significant decline due to imposed sanctions. Nonetheless, restrictions on natural gas imports were comparatively less severe. In 2023, imports of crude oil instead of petroleum products practically ceased, while restrictions in the case of natural gas were not so drastic.

Effect of the Textures and Particle Sizes of Limestone on the Quicklime Reaction Activity

Quicklime is not only an important raw material for the steel and nano-calcium carbonate industries but also a key carrier for capturing carbon dioxide in the fight against global warming, and its reaction activity plays a vital role in these processes. Recent studies have found that quicklime produced from limestones with similar chemical compositions under the same production process has significantly different reaction activities, which indicates that something other than the chemical composition of limestone affects quicklime reaction activity. To explore the factors affecting quicklime reaction activity, this study analyzed the textures and calcite particle size of limestone collected from different areas of Guangxi, China, and measures the quicklime reaction activity with different calcination times. It has been found that: (1) limestone with a clastic texture is preferred to that with a crystalline texture (including transition type) in yielding quicklime with higher reaction activity; and (2) for limestone with a clastic texture, fine-grained limestone tends to produce the same or higher quicklime reaction activity with lower energy consumption.

Molecular interaction mechanisms and cellular response of superoxide dismutase and catalase to fluoranthene.

As an important raw material and intermediate product of the petrochemical industry, fluoranthene (Fla) can be emitted with industrial activities and has become a typical polycyclic aromatic hydrocarbon enriched in the Chinese topsoil layer, posing a significant threat to sensitive soil biota. Here, multispectral tools and molecular simulation techniques were integrated to elucidate the molecular mechanism of Fla interaction with key antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) at the molecular level. Meanwhile, we further revealed the cellular responses of SOD and CAT and the associated redox states in earthworm (Eisenia fetida) coelomocytes based on the molecular-level results. Our results showed that the exposure to Fla affected the backbone structure of SOD and CAT molecules and resulted in the formation of Fla-SOD polymers as well as an overall reduction in the size of the Fla-CAT binding system. Fla altered the microenvironment around Tyr residues in the SOD molecule and quenched the endogenous fluorescence of Tyr within the CAT molecule. In earthworm coelomocytes, Fla at 60 and 80 μM resulted in a significant elevation of CAT and SOD activities by 114% (p = 0.032) and 6.09% (p = 0.013), respectively. Molecular simulation results suggested that Fla-induced changes in the structure and conformation of SOD and CAT may be the key reason for their altered activities. The related redox homeostasis detection in earthworm coelomocytes indicated that high concentrations (80 μM) of Fla led to a significant accumulation of intracellular ROS (p = 0.018) and resulted in the development of lipid peroxidation. Our work contributes to an in-depth understanding of the biological effect of Fla to sensitive soil fauna, thus providing new ideas for Fla ecological risk prevention and control.

Achieving high relative density and low resistivity in indium tin oxide targets via Bi2O3-CeO2 additive

Indium tin oxide (ITO) target, an important raw material of ITO films, is difficultly prepared by traditional sintering due to the volatilization and partial dissociation at high sintering temperature. In this work, the high-density and low-resistivity ITO targets were prepared with Bi2O3-CeO2 additive at low sintering temperature. The effects of Bi2O3-CeO2 content and sintering temperature on the densification, phase composition, microstructure, mechanical properties and electrical resistivity of ITO targets were systematically investigated. The results revealed that the Bi2O3-CeO2 addition reduced sintering temperature by 50 ℃, and the ITO target with 1.0 wt% Bi2O3-1.0 wt% CeO2 had the maximum relative density of 99.57%, surpassing additive-free ITO target. The dense microstructure at low sintering temperature was attributed that Bi2O3 could convert solid phase sintering into liquid phase sintering. Notably, the ITO target with 1.0 wt% Bi2O3-1.0 wt% CeO2 also had the minimum resistivity of 1.82 × 10−4 Ω·cm, which was due to more free electrons generated by CeO2 doping and the dense microstructure. In addition, the grain growth kinetics was applied to calculate corresponding diffusion data, namely, the grain growth exponent (n = 7.4), growth rate constant (k = 4.211 × 1023) and growth activation energy (Q = 394.79 kJ/mol). This work provides a strategy to prepare high-quality ITO targets and presents great potential for the low-temperature sintering on other ceramic materials.

Preparation and properties of dynamic crosslinked styrene butadiene rubber

Abstract As the second largest synthetic rubber after styrene butadiene rubber, cis-butadiene rubber (BR) is one of the important raw materials for automobile tires and cold-resistant products. Herein, a traditional rubber preparation process was used to introduce dynamic reversible bonds into BR based on an “imitative” click reaction. Compared with traditional complex self-healing techniques, this method is undoubtedly simpler and more efficient. Dynamic reversible bonds are able to break and recombine under the stimulation of external conditions, which endow rubber with self-healing properties. We use the small biological molecule lipoic acid (LA) as a cross-linking agent and cross-link LA and BR through mechanical compounding and hot press vulcanization to obtain self-healing butadiene rubber (BLA). In addition, BLA-(Zn2+) was further prepared by introducing Zn2+ to form metal-oxygen coordination bonds with carboxyl groups. And systematically studied the effect of Zn2+ on the mechanical properties and self-healing properties of cross-linked BR. Through the combined action of disulfide bonds, hydrogen bonds and Zn2+-O coordination bonds, BLA-(Zn2+) has better properties than BLA, the tensile strength can reach 3.76 MPa, and the repair efficiency is about 82 %. This simple preparation process is certainly more cost effective.

PROBLEMS OF DEVELOPMENT OF THE MINERAL RESOURCE BASE OF THE HIGH-TECH INDUSTRY OF RUSSIA

The article considers the problem of self-sufficiency of Russia with import-dependent types (including critical) of strategic mineral raw materials (SMRM). It is shown that in recent years, the Russian Government has been paying much attention to the development of the mineral resource base (MSB) of SMRM: in 2018, the Strategy for the Development of MSB of the Russian Federation until 2035 was approved, and in 2022, the updated List of the main types of SMRM was approved for the first time in 26 years. The article notes that SMRM self-sufficiency has been achieved for most of the items in the List. For 17 items on the List, the industry of the Russian Federation is highly dependent on imports, and for some items this dependence reaches 100%. Despite this, many domestic deposits of SMRM, critically dependent on imports, are not being developed, due to low profitability. The analysis carried out in the article showed that Russia can completely replace the import of mineral raw materials by developing its own SMRM. At the fastest pace, the supply of self-sufficiency can be achieved through the development of placer deposits, weathering crust and recycling

Prospective assessment of the associated minerals complex in the Konksky and Bilozersky iron ore districts from the Middle-Dniprean mega-block of the Ukrainian shield

Purpose.To determine the material composition, formational types and justify the prospects for the development of metallic and non-metallic minerals complex accompanying ore occurrences and iron deposits in the Konksky and Belozersky iron ore regions of the Middle Dnieper megablock of the Ukrainian Shield. Methods.In the process of carrying out research tasks, traditional methods of studying the material composition of minerals were used - petrographic, mineragraphic, interpretation of X-ray diffraction, thermal, and chemical analyzes were carried out. An ore formation analysis of ore occurrences of minerals accompanying iron in the Konksky and Belozersky iron ore regions was carried out. Findings.The features of the geological structure, material composition, and the influence of secondary alterations of rocks and ores on the prospects for the ore content of associated minerals accompanying iron deposits and occurrences in the study areas are characterized. The ore formation types, the genesis of ore occurrences are substantiated, and the prospects for the integrated use of raw materials accompanying iron ore deposits in the Konksky and Belozersky regions are determined. The originality.The systematic generalization of factual material regarding geological and ore formations in the Konkskaya and Belozerskaya greenstone structures, the substantiation of the possibility for using the results for metallogenic forecasting, in particular, hidden ore and the substantiation of the possibility of integrated use of the subsoil of the study areas. Practical implementation is justified by the possibility of using research results in the process of exploration and development work for a complex of associated minerals within the research area. An assessment of the prospects for the use of minerals accompanying deposits of strategically important iron ore raw materials will make it possible to ensure the comprehensive use of the subsoil of iron ore areas.

Increasing the flexibility in aluminum paste dosing system: A comparison between shift pre‐mixing system and batch pre‐mixing system designs

AbstractThe production of autoclaved aerated concrete (AAC) is a multiple industrial process that depends on the quality of the used raw materials, mixing ratios as well as on the consistency between the chemical and mechanical performance of the mixing unit in a mixing tower. Optimizing the mixing process, ratios and many other overlapping elements are important factors for its ideal design to ensure reducing production costs and reducing waste of the basic raw materials, that could be happened due to the inflexibility of the used dosing system design. Since the aluminum paste is one of the most important basic raw materials for the manufacture of autoclaved aerated concrete with a low participation rate in the mixture of about 0.1% (e.g., AAC ‐G4 type), however, in terms of production costs, it constitutes a part of not less than 10% of the total raw materials cost per cubic meter of autoclaved aerated concrete (e.g., AAC‐G4 type), according to several real studies in several factories. Through this research, we present a comparison between two aluminum paste dosing system designs already implemented in several AAC factories: (1) shift pre‐mixing and weighting model and system‐ ASMD, (2) Batch pre‐mixing and weighting Model‐ ABMD. This research will illustrate the differences between the two systems in terms of technical and financial aspects based on the reality of practical experience.

Partial hydrogenation of anisole to cyclohexanone in water medium catalyzed by atomically dispersed Pd anchored in the micropores of zeolite

Cyclohexanone is an important raw material for manufacturing nylon and other chemicals. The sustainable conversion of biomass derived molecules to cyclohexanone is desired but still challenging. Herein, a palladium single atom catalyst anchored in the micropores of zeolite (namely Pd1/ZSM-5) is designed and exhibits remarkable catalytic activity in transforming anisole to cyclohexanone in water medium (H2O), without using of organic solvent or halogen promoter. The selectivity to cyclohexanone is 91.2% and the turnover rate (TOR) is 400.8 h−1 at 453 K. The Pd sites, acid sites, and microporous confinement environment of zeolite cooperate to promote the partial hydrogenation to cyclohexanone, and inhibit further hydrogenation as the side reaction. H2O not only acts as the solvent, but also participates significantly in the partial hydrogenation. Moreover, as revealed by isotope labelled experiments (D2O and H218O), the water participated hydrogenolysis and the consequent partial hydrogenation mechanism is proposed.

A fast and reliable method to quantify neral and geranial (citral) in essential oils using 1H NMR spectroscopy

AbstractCitral (3,7‐dimethyl‐2,6‐octadienal), a mixture of geranial and neral (two stereoisomeric monoterpene aldehydes), is considered an important raw material in the fields of fragrance, pharmaceutical, food and cosmetic industries. It is a well‐known biologically active compound present in various essential oils. A fast and reliable experimental method was developed and validated in order to quantify citral in essential oils using 1H NMR spectroscopy (experiment time at the minute level). The quantitative procedure, using anisole as internal standard, showed a perfect linearity of measurements (R2 = 0.9999), a very good accuracy (relative errors comprised between −1.9% and 0.3%) and an excellent precision (reproducibility 17.8 mg ± 1.0%). The procedure was also checked with three mixtures of weighted monoterpenes and the contents of citral, measured by GC and 1H NMR, were absolutely comparable. Then, the method was successfully applied to measure the contents of citral in 10 commercially available essential oils. Among the investigated samples, citral varied from 2.9% (Zingiber officinalis) to 90.6% (Bakhousia citriodora).

Identification of growth years for Puerariae Thomsonii Radix based on hyperspectral imaging technology and deep learning algorithm

Puerariae Thomsonii Radix (PTR) is not only widely used in disease prevention and treatment but is also an important raw material as a source of starch and other food. The growth years of PTR are closely related to its quality. The rapid and nondestructive identification of growth year is essential for the quality control of PTR and other traditional Chinese medicines. In this study, we proposed a convolutional neural network (CNN)-based classification framework in conjunction with hyperspectral imaging (HSI) technology for the rapid identification of the growth years of PTRs. Traditional treatment methods (i.e., multiplicative scatter correction, standard normal variate, and Savitzky-Golay smoothing) combined with machine learning algorithms (i.e., random forest, logistic regression, naive Bayes, and eXtreme gradient boost) were used as baseline models. Among them, the F1-score of CNN-based models based on PTRs’ outer surfaces was over 90%, outperforming all the other baseline models. These results showed that it was feasible to use a deep learning algorithm in conjunction with HSI technology to identify the growth years of PTR. This method provides a fast, nondestructive, and simple method of identifying the growth years of PTR. It can be easily applied to other scenarios, such as for the identification of the locality or years of growth for other traditional Chinese herbs.

Dual metabolic pathways co-determine the efficient aerobic biodegradation of phenol in Cupriavidus nantongensis X1

Phenol, as an important chemical raw material, often exists in wastewater from chemical plants and pollutes soil and groundwater. Aerobic biodegradation is a promising method for remediation of phenolic wastewater. In this study, degradation characteristics and mechanisms of phenol in Cupriavidus nantongensis X1 were explored. Strain X1 could completely degrade 1.5 mM phenol within 32 h and use it as the sole carbon source for growth. The optimal degradation temperature and pH for phenol by strain X1 were 30 °C and 7.0. The detection of 3-oxoadipate and 4-hydroxy-2-oxopentanoate indicated that dual metabolic pathways coexist in strain X1 for phenol degradation, ortho- and meta-pathway. Genome and transcriptome sequencing revealed the whole gene clusters for phenol biomineralization, in which C12O and C23O were key enzymes in two metabolic pathways. The ribosome proteins were also involved in the regulation of phenol degradation. Meanwhile, the degradation activities of enzyme C23O was 188-fold higher than that of C12O in vitro, which indicated that the meta-pathway was more efficient than ortho-pathway for catechol degradation in strain X1. This study provides an efficient strain resource for phenol degradation, and the discovery of dual metabolic pathways provides new insight into the aerobic biological metabolism and bioremediation of phenol.

Chemometric Analysis-Based Sustainable Use of Different Current Baking Wheat Lots from Romania and Hungary

Wheat is the most important raw material for bakery industries. Real-time grain quality assessment could increase bakery product quality and baking efficiency. The quality assessment of wheat grains can be conducted using modern and non-invasive techniques based on near-infrared spectrophotometry (NIRS) methods for the assessment of gluten content (WetGL), protein content, Zeleny index (ZelenyIdx), grain humidity (Ur), etc. The topic covered in the study is of current interest, is a part of sustainable research, and involves aspects of food quality, one of the concerns addressed by the University of Oradea’s Department of Food Engineering. The present study was carried out in 2020 on eleven wheat lots from Romania and Hungary. Following the NIRS analyses, the results show varied quality for the Romanian and Hungarians wheat lots. The Romanian variety Crisana recorded the highest values for quality parameters, being similar to the Hungarian variety Bekes from Hajdu Bihar County. The statistical analysis was carried out using multivariate analysis (multivariate analysis of variance (MANOVA), canonical variate analysis (CVA) and hierarchical cluster analysis (HCA)), which highlighted which of the batches of wheat grains can be mixed to obtain a raw material of high quality for the bakery industry.

Evaluation of Tamarindus indica L. Seed Tannins

Tannins are water-soluble polyphenols mostly found in vascular plants and are important raw materials in many industries like leather, pharmaceuticals, and food and beverages. Tannins protect the plant and help its growth. In this study, Tamarindus indica L. seeds were extracted for the determination of tannin content and the tanning strength by the hide powder method. Earlier studies showed that Tamarindus indica L. seeds varied in the amount of tannins present. Mimosa was used as a control. The tanning strength was 1.73 for the tamarind seed extract and 2.06 for mimosa. The tannin content was >10% for both the tamarind seed extract and mimosa. It was concluded that both tamarind seed extract and mimosa had sufficient tanning strength exceeding (1.5) the minimum recommended for a tanning agent hence providing insights as a feasible material for the tanning process.

Enzyme and Metabolic Engineering Strategies for Biosynthesis of α-Farnesene in Saccharomyces cerevisiae.

α-Farnesene, a type of acyclic sesquiterpene, is an important raw material in agriculture, aircraft fuel, and the chemical industry. In this study, we constructed an efficient α-farnesene-producing yeast cell factory by combining enzyme and metabolic engineering strategies. First, we screened different plants for α-farnesene synthase (AFS) with the best activity and found that AFS from Camellia sinensis (CsAFS) exhibited the most efficient α-farnesene production in Saccharomyces cerevisiae 4741. Second, the metabolic flux of the mevalonate pathway was increased to improve the supply of the precursor farnesyl pyrophosphate. Third, inducing site-directed mutagenesis in CsAFS, the CsAFSW281C variant was obtained, which considerably increased α-farnesene production. Fourth, the N-terminal serine-lysine-isoleucine-lysine (SKIK) tag was introduced to construct the SKIK∼CsAFSW281C variant, which further increased α-farnesene production to 2.8 g/L in shake-flask cultures. Finally, the α-farnesene titer of 28.3 g/L in S. cerevisiae was obtained by fed-batch fermentation in a 5 L bioreactor.

Enersol Promotes Growth and Yield Performance of Pechay (Brassica rapa L. var. chinensis (L.) Hanelt)

This study presents the results of a field bio-efficacy evaluation to assess the impact of Enersol® LDG, a mineral fertilizer containing leonardite and humic acid, on the growth and yield of pechay (Brassica rapa) in Puypuy, Bay, Laguna, Philippines. In pechay production, there is a need for a plant food supplement that facilitates immediate nutrient absorption. Leonardite-based products have been used to improve soil properties and to help plants withstand biotic and abiotic stresses. Leonardite is an important raw material in the manufacture of commercial products rich in humic and fulvic acids. An experiment in a randomized complete block design with three replications was conducted, with different combinations of Enersol® LDG and inorganic fertilizer applied basally at seed sowing. Results showed that the combination of Enersol® LDG and inorganic fertilizer significantly increased the total fresh yield of pechay compared to other treatments. However, reducing the amount of inorganic fertilizer resulted in lower yields, regardless of the Enersol® LDG application rate. The marketable yield and percent marketable yield were also significantly higher in plants treated with Enersol® LDG and inorganic fertilizer combinations compared to the control and Enersol® LDG alone. Based on these findings, it can be concluded that Enersol® LDG, when combined with inorganic fertilizer, significantly enhanced the growth, and yield of pechay. Further research is recommended to explore optimal dosage and application methods for maximizing pechay production using Enersol® LDG.

Preparation and characterization of the bonding performance of a starch-based water resistance adhesive by Schiff base reaction

Starch is one of the important raw materials for the preparation of biomass adhesives for its good viscosity and low-cost properties. However, the drawbacks of poor water resistance and bonding performance seriously restrict its application in the wood industry. To resolve those problems, an environment-friendly renewable, and high water resistance starch-based adhesive (OSTH) was prepared with oxidized starch and hexanediamine by Schiff base reaction. In order to optimize the adhesive preparation process, the effect of different oxidation times and oxidant addition on the mechanical performance of plywood were investigated. In addition, the curing behavior characteristics, thermomechanical properties, and thermal stability of the OSTH adhesives were analyzed by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermogravimetric analysis (TG). Fourier-transform infrared (FTIR) spectrometry and Liquid Chromatography-Mass Spectrometry (LC-MS) were used to explain the reaction mechanisms involved. The results show this adhesive has an excellent bonding performance at the oxidation time of 12 h with 11 % (w/w, dry starch basis) NaIO4 as an oxidant. The dry shear strength, 24-hour cold water, and 3-hour hot water (63 °C) soaking shear strength of the plywood bonded with this resin were respectively 1.87 MPa, 0.96 MPa, and 0.91 MPa, which satisfied the standard requirement of GB/T 9846-2015 (≥0.7 MPa). Thus, this study provided a potential strategy to prepare starch-based wood adhesives with good bonding performance and water resistance.