Material Content Research Articles

Sown Diversity Effects on the C and N Cycle and Interactions with Fertilization

A better understanding of the role of plant composition and N cycle on agroecosystems is necessary, as these will be affected by future developments in agriculture intensification. To explore the effect of plant diversity on yield and carbon (C) and nitrogen (N) balances in forage mixtures, identifying potential co-benefits between functions. We analyzed results from a field experiment where plants of three forage species (a grass, a legume, and a non-legume forb) were cultivated in monocultures and mixtures. Three years after sward establishment, dry matter yield, together with δ15N, δ13C, and C and N content in plant and soil material were measured. In addition, we analyzed a second scenario to investigate the effect of fertigation with pig slurry (δ15N = +8.4‰) on the C and N balances of forage species. Results support the hypothesis that C and N allocation is affected by plant diversity. Plant composition affected N source (% N derived from air, % N derived from soil, and % N transferred in mixtures). In addition, sown diversity increased yield and modulated C and N balances. The δ15N of samples was affected by both plant composition and fertigation. These results are consistent with previous work showing strong plant composition effects on N-balances, and the potential role that legumes play in enhancing nitrogen sources (derived from the atmosphere) into forage mixture systems. This study contributes to the prediction of suitable sown plant community composition and N management for the optimum agriculture with increased productivity and at the same time reduced environmental impact.

Thermal Decomposition of Date Seed/Polypropylene Homopolymer: Machine Learning CDNN, Kinetics, and Thermodynamics

The buildup of abandoned plastics in the environment and the need to optimize agricultural waste utilization have garnered scrutiny from environmental organizations and policymakers globally. This study presents an assessment of the thermal decomposition of date seeds (DS), polypropylene homopolymer (PP), and their composites (DS/PP) through experimental measurements, machine learning convolutional deep neural networks (CDNN), and kinetic and thermodynamic analyses. The experimental measurements involved the pyrolysis and co-pyrolysis of these materials in a nitrogen-filled thermogravimetric analyzer (TGA), investigating degradation temperatures between 25 and 600 °C with heating rates of 10, 20, and 40 °C.min−1. These measurements revealed a two-stage process for the bio-composites and a decrease in the thermal stability of pure PP due to the moisture, hemicellulose, and cellulose content of the DS material. By utilizing machine learning CDNN, algorithms and frameworks were developed, providing responses that closely matched (R2~0.942) the experimental data. After various modelling modifications, adjustments, and regularization techniques, a framework comprising four hidden neurons was determined to be most effective. Furthermore, the analysis revealed that temperature was the most influential parameter affecting the thermal decomposition process. Kinetic and thermodynamic analyses were performed using the Coats–Redfern and general Arrhenius model-fitting methods, as well as the Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose model-free approaches. The first-order reaction mechanism was identified as the most appropriate compared to the second and third order F-Series solid-state reaction mechanisms. The overall activation energy values were estimated at 51.471, 51.221, 156.080, and 153.767 kJ·mol−1 for the respective kinetic models. Additionally, the kinetic compensation effect showed an exponential increase in the pre-exponential factor with increasing activation energy values, and the estimated thermodynamic parameters indicated that the process is endothermic, non-spontaneous, and less disordered.

ВЫБОР ЛЬНЯНОГО СЫРЬЯ ДЛЯ ПОЛУЧЕНИЯ ОСНОВЫ РАСТИТЕЛЬНОГО НАПИТКА

The purpose of the study is the choice of flax raw materials for obtaining the basis of a vegetable drink. Tasks: to obtain the basis of a milk-type drink from linseed raw materials; to analyze the physico-chemical parameters of the obtained model samples; choose linseed raw materials to obtain the basis of a drink such as milk. The studies were carried out on the basis of the laboratory for the processing of bast crops of the Federal Scientific Center for Bast Crops in Tver. Varietal flax seeds were used, as well as products of their processing in the form of flax cake and mucilage-free seeds. The basis of the vegetable drink was obtained in several stages: maximum grinding in a laboratory mill, additional grinding in a laboratory mortar, and mixing with an extractant using a blender. Extraction was carried out with a low-salt solution (0.6 % NaCl) with constant stirring for 1 h at 40 °C. The resulting extract was separated from the plant mass by centrifugation (3500 rpm, 30 min). Physicochemical parameters were determined by standard methods of analysis. It was revealed that flax seeds and linseed cake are high-quality raw materials for obtaining a vegetable drink such as milk. A sample of the base for a drink from seeds of the LM-98 variety was characterized by the highest protein yield (54.47 ± 2.72 %) and fairly high protein content in dry matter (33.77 ± 1.69 %).The base for the drink, obtained from linseed cake, was characterized by the maximum protein content of all the studied samples – 1.55 ± 0.08 % and the highest protein content in dry matter – 41.67 ± 2.08 %. It is shown that the yield of extractives, determined by the value of the dry residue of extracts, depends not only on the protein content in the raw material, but also on the polysaccharide complex of linseed mucus (its composition and quantity). The highest organoleptic indicators were characterrized by the base of the drink made from flax seeds of the Severny variety.

Integrated learning technology as a means of forming the general cultural competence of students

The methodological basis of modern teaching is integration, which makes it possible to show students the «world as a whole», overcoming the differentiation of scientific knowledge by disciplines. The purpose of this article is to define the essence of the concept of a binary lesson, to consider its forms, to define the goals and objectives of binary lessons, to find out the reasons for the need for such lessons, and also what are the features in their preparation, organization and conduct. The authors show the features of the organization, development and preparation of a modern integrated lesson. It is shown that integrated lessons can be conducted at several levels: binary (simultaneous learning), conceptual and informational (coordination of information by teachers of different disciplines and conducting lessons separately) and remote (network). It is emphasized that an integrated lesson is not a simple addition, but an interpenetration of two or more disciplines, with the specifics of the educational material studied on it. Most often, the subject of analysis within the framework of integrated lessons are multidimensional objects, information about the essence of which is contained in various academic disciplines. The teacher needs to be able to find common ground between subjects and carefully select the content of the lesson material. The article also presents practical experience of conducting integrated lessons in Russian literature and music. As a result of the research, certain conclusions were drawn that an integrated lesson in a modern Russian school is a special type of lesson that combines teaching in several disciplines simultaneously while studying a single concept, topic or phenomenon.

Unveiling molecular DOM reactomics and transformation coupled with multifunctional nanocomposites under anaerobic conditions: Tracking potential metabolomics and pathways.

Anaerobic digestion (AD) offers great potential for pollutant removal and bioenergy recovery. However, it faces challenges when using livestock manure (LSM) as a feedstock given its high content of refractory materials (e.g., lignocellulose, long-chain carbohydrates, lipids, and crude protein). This would significantly inhibit AD-microbial activities, reduce organic transformation efficiency and limit gas production. To overcome this, multifunctional metal-doped hydrochars (HCs) were introduced here as AD supplements/accelerators, given that LSM degradation under AD results in complex dissolved organic matter (DOM). To assess this, the current study investigates the molecular interactions/transformations within DOM during LSM-AD coupled with metal-doped HCs, via batch-mode experiments. Expansive data mining techniques were employed to analyze DOM using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Substantial increments in peptide-like along with decrements in highly unsaturated-like molecules were observed in HC@MnCl2 containing-system. This indicates an increased capability for substrate hydrolysis and potential utilization of soluble microbial products (SMPs) (i.e., highly unsaturated-like molecules), leading to enhanced methane recovery (223.23 mL/g-VSadded, 1.77 times more than the control). However, accumulation of DOM-highly unsaturated molecules (i.e., a lack of SMPs' degradation) accompanied with low methane production (39.68 mL/g-VSadded) was noticed for HC@NiFe2O4. DOM reactivity during LSM-AD was validated via paired mass difference molecular network, indicating predominance of CHO and N-containing groups' transformations for HC@MnCl2 and HC@NiFe2O4, respectively. Potential metabolites and abundant pathways were verified via KEGG database. This study improves our understanding of LSM-AD-DOM complex transformation matrix, the fate of bioavailable/recalcitrant compounds, and identification of potential DOM regulators from thousands of molecules.

Development of E-Handout Based on Audiovisual Fiqih Material for Women as an Effort to Provide Religious Character in Class IV Students of Primary Schools and Madrasah Ibtidaiyah

Education is a planned effort so that each individual is able to achieve various life achievements, including spiritual achievements. One of the religious characters is obedience to God Almighty. This character can be achieved if students have a good understanding of obedience material, one of which is women's jurisprudence. Based on observations, 78% of class IV students at SD Bojonegoro do not understand this material well. Apart from that, the content of material about women's jurisprudence in class IV students of primary schools and madrasah ibtidaiyah textbooks is very minimal, so accompanying teaching materials are needed. Then, students' interest in reading using books or worksheets is very low, students prefer to use devices, because there are videos, pictures and animations. Therefore, developing audio-visual based teaching materials via the Google site is considered very necessary. This teaching material is presented in electronic form by displaying videos, images and animations. This research aims to determine the results of the development of an e-handout on women's fiqh material. The research method used is the Borg & Gall model Research and Development (R&D) method. The results of the development of an audio-visual based e-handout on women's jurisprudence material were declared suitable for use. This is proven by the material expert validation results being 80% (feasible), the media expert validation results being 77% (valid category), and the language expert validation being 76% (feasible), then the question expert validation results being 86% (very feasible) and the student response results were 83% (very interesting).

Tire-Pavement Interaction Noise: Recent Research on Concrete Pavement Surface Type and Texture

Several solutions have been proposed for quieter riding surfaces, including porous pavements, tining, and grinding. This paper deals with certain aspects of a recent large-scale research that has been carried out to examine the influence of cement concrete pavement surface type and texture on noise generation. One pavement surface type (Enhanced Porosity Concrete – EPC), and one surface texturing method (transverse tining) is dealt with in detail in this paper. Experimental studies to ascertain the physical (porosity and pore size), mechanical (strength), and acoustical (acoustic absorption using impedance tube) properties of EPC are discussed. It is shown in this paper that, with careful selection of aggregate gradation and cementing materials content, it is possible to generate a system of optimally-sized pores in the material to maximize acoustic absorption. Mathematical modeling of noise to evaluate the influence of transverse tine geometry (depth, width, and shape) on noise reduction characteristics is explained in the second part of this paper. A mathematical model has been used to determine the stress distribution between the concrete pavement and the tire. The stress distribution model is used to describe the stress and ultimately noise generated by various geometries of tining patterns. Experiments on Tire-Pavement test apparatus are also discussed.

Axolotls, environmentally conscious mayors and watermills: Didactic proposals for raising awareness on water conservation through pedagogical translation

The present article explores the possibilities of integrating Sustainable Development Goal (SDG) #6 (Clean water and sanitation) in the content of materials designed for Spanish as a second or foreign language (S2/FL) learners in a Mexican context. The idea arose from the recent severe droughts in the country that affected water consumption in certain cities. For immersion students studying S2/FL in Mexico, this became a reality rarely discussed in the classroom. In addition, the use of pedagogical translation is proposed to take advantage of the opportunities offered by the learners’ already existing linguistics skills. Considering the particularities of the context where the project was developed, the material design stage was preceded by two smaller enquiries into the perception of Mexico and Mexican culture abroad as well as the country’s representation in existing S2/FL materials. One specific point of interest was if everyday realities where the lack of water received mention in the foreign press and / or if S2/FL textbooks. The resulting activities propose to cover these rather complex topics through a ludic perspective that can be replicated and adapted to a variety of contexts and any one of the SDG.

Специфика формирования учебных материалов по языку специальности для иностранных студентов-медиков

The article deals with the features of teaching Russian as a foreign language within the framework of the professionally oriented training of foreign students of medical universities. The purpose of the work is to consider methodological approaches, tools and techniques that ensure effective language teaching in the medical and biological specialty. The main attention is paid to the requirements for the content, selection and development of educational materials for the effective formation of the communicative competence of future doctors, the quality of which is associated with the need to master not only the lexical and grammatical aspects of the language, but also the skills of speech behavior, conditioned by the peculiarities of medical discourse. Based on this, the main characteristics of the scientific style in general and medical terminology in particular, significant from the point of view of the substantive aspect of teaching language for special purposes (LSP), are covered. Based on the analysis of scientific and the most popular educational and methodological literature in medical universities, the authors derive typological principles for the implementation of the textological approach in teaching Russian for special purposes. The scientific novelty of the work lies in an attempt to generalize and systematize the methods and techniques of LSP teaching used in modern practice, on the basis of which a practical model for organizing educational materials for the systematic development of professional and communicative competence of medical students is proposed. The results of the study are practice-oriented in nature and can be used as a template for further improvement of the principles of organizing the educational process in the field of teaching Russian language in the medical and biological profile.

Preparation, Modification, Quantitation, and Dentin Biomodification Activity of Selectively Enriched Proanthocyanidins.

To date, quantitative analysis of proanthocyanidin (PAC) containing materials including plant extracts and fractions depends on colorimetric assays or phloroglucinolysis/thiolysis combined with UV-HPLC analysis. Such assays are of limited accuracy, particularly lack specificity, require extensive sample preparation and degradation, and need appropriate physical reference standards. To address this analytical challenge and toward our broader goal of developing new plant-sourced biomaterials that chemically and mechanically modulate the properties of dental tissue for clinical interventions, we have characterized 12 different PAC DESIGNER (Depletion and Enrichment of Select Ingredients Generating Normalized Extract Resources) materials. The DESIGNER approach is carried out by using either centrifugal partition chromatography (CPC) or size-exclusion chromatography (SEC) for the selective enrichment of trimeric and tetrameric PACs. Moreover, the rare but biologically interesting A-type PAC DESIGNERs can now be generated successfully from their natural AB-type PAC precursors via phenol-oxidative intramolecular coupling initiated by a mixture of the stable radicals, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). Furthermore, to ensure the quality and stability of PAC DESIGNER materials, we developed a quantitative analysis of the total PAC content of the DESIGNER materials in the form of a quantitative NMR (qNMR) method using a non-PAC internal calibrant combined with diol-HPLC. The total PAC content was, thus, determined to be in a range of 67.5-96.9% by qNMR. We highlight the complementarity of diol-HPLC and qNMR to accurately assess the amount of PACs across a range of concentrations and PAC stability in the DESIGNER materials. This quantitative methodology paves the way to generate standardized DESIGNER and other PAC-containing materials and to perform rigorous quality control for dental (pre)clinical studies of PACs.

Development of Fukado Learning Media on Mathematics Content of Space Building Materials on The Improvement of Student Results Class VI at SD Negeri Sadeng 01 Semarang City

The purpose of this study was to develop Fukado media with Borg and Gall's development theory through 10 stages of development so that the developed media can be used to achieve learning objectives, namely improving student learning outcomes. The research subjects used 6th-grade students at SD Negeri Sadeng 01 Semarang City with 27 students. Augmented reality is one of the media that can help with learning. The development of this media is done by analyzing problems, designing media, media validated by experts, and testing on learning. The effectiveness of this learning media is seen with assessment instruments on validity, effectiveness, and practicality. Media development that has gone through various stages of development is declared successful with a level of validity of media, material, and language of 88%, 95%, and 91% respectively, The effectiveness of the media can be seen from the increase in learning outcomes in mathematics learning with the difference in the average student score reaching 15 from the original 61 to 76 obtained from trials with pretest and posttest.

Preparation and properties of compatible polybutylene adipate‐co‐terephthalate composites with high rice husk content

AbstractTo deal with the severe issue of non‐degradable “white pollution”, it is essential to use cheap and readily available biomass fillers and biodegradable polymers to prepare green plastics with good compatibility and excellent comprehensive properties. In this work, polybutylene adipate‐co‐terephthalate (PBAT) as the matrix, and polycaprolactone‐based polyurethane prepolymers (PCLPU) as compatibilizer were used to prepare bio‐composite materials with a high husk powder content. SEM results indicated that a compatible interface structure had been successfully established. The compatibility of the composite materials was achieved through novel interface structures with physical crosslinking and urethane bonds. Furthermore, compared with the control without compatibilizer, a significant increase in elongation at break from 2.01% to 31.98% was demonstrated, indicating a nearly 15‐fold improvement. A notable increase in impact strength from 3.33 to 11.67 KJ/m2 was observed, suggesting that the toughness and strength were enhanced by adding polyurethane prepolymer. Furthermore, it was revealed through thermogravimetric and water resistance tests that the addition of PCLPU enhanced the thermal stability and hydrophobicity of the composite material. The biomass content of composite materials can reach as high as 80%, significantly reducing their cost.Highlights The rice husk powder as a filler can be up to 80%, significantly reducing the cost of the composite materials. Both strength at break and elongation at break of the biocompsite were improved obviously with PCLPU as compatibilizer. The thermal stability and hydrophobicity of composite materials enhanced with the adding of PCLPU. The compatibility of the composites was achieved through innovative interfacial structures, including physical crosslinking and urethane bonds. The high‐biomass rice husk powder/PBAT composites showed excellent mechanical properties for its good compatibility.

CYSTIC LESIONS OF THE SALIVARY GLANDS(Report of 3 cases)

At least one-third of cystic salivary gland lesions are neoplastic. Cystic lesion of the salivary gland requires only surgery, because regardless of the type and location, drug therapy is not possible with this diagnosis.. If the cystic neoplasm is localized in a hard-to-reach place and if it is localized in the parotid gland, the surgical manipulation is performed from the outside, it is removed simultaneously with the parenchyma of the salivary gland. The FNA specimens from salivary gland cystic lesions can be no informative very often, because FNA of these lesions demonstrates hypocellular mucinous material contents, possibly with inflammatory cells and also scant epithelial cells. For example, the presence of mucin and admixed lymphocytes in cyst fluid can be demonstrated both in the benign inflammatory cysts and cystic neoplasms. A definitive diagnosis of cystic neoplasms of the salivary glands is possible only through histological examination of the neoplastic tissue. Prevention of cystic neoplasms of the salivary gland consists of preventing injuries and inflammations of the oral cavity, careful hygiene and regular visits to the dentist. This article presents cases of the salivary glands cystic neoplasms, which are the clinical interest.

The Addition of Tomato and Spinach Powder to Semolina Pasta: A Study of the Impact of the Production Process and Cooking on Phenolic Compounds

Pasta is a staple food with daily recommended consumption; thus, it can be an excellent vehicle for delivering bioactive compounds like phenols. However, the high-temperature drying process in pasta production, combined with cooking in boiling water, can significantly reduce the concentration of phenolic compounds. This study aimed to enhance the phenolic content of traditional semolina pasta by incorporating tomato and spinach powder into the recipe. High-performance liquid chromatography–electrospray ionization triple quadrupole mass spectrometry (HPLC-ESI-QqQ-MS) was employed to analyse the free and bound phenolic content in the raw materials, as well as in both dried uncooked and cooked pasta. The addition of tomato and spinach powders, known for their high content in bioactive compounds, increased the overall phenolic content of the final enriched pasta by three and two times, respectively, compared to the semolina and whole-wheat semolina pasta. These findings suggest that pasta enriched with tomato and spinach could serve as a functional food with a greater nutritional profile and health benefits through the enhanced delivery of phenolic compounds.

Train-the-Educator: Boosting Knowledge and Confidence for Conducting Substance Use Prevention Education.

School-based substance use prevention is important, yet many educators are not trained in the curriculums. The purpose of this study was to assess changes in educators' knowledge about substances and confidence in delivering drug education before and after participating in educator trainings, as well as overall perceptions of the trainings, for three curriculums: tobacco, cannabis, and all drugs prevention. We conducted one-arm pre-post analyses evaluating educators' changes in knowledge about products and confidence to deliver curriculums. A total of 1064, 648, and 171 educators participated in the trainings and completed surveys (June 2021-November 2023) about drug knowledge (closed-ended, three items for tobacco, five for cannabis), confidence to deliver curriculums (Likert, four items for all trainings), and perceptions of the trainings (open-ended, four items for all trainings). Paired-sample t-tests and McNemar tests of paired proportions were conducted for the matched sample. Two coders double-coded open-ended responses to identify key themes. The training for tobacco was associated with pre-post improvements on all knowledge questions (p's ≤ 0.001). Trainings for all three curriculums were associated with pre-post improvements for all confidence questions (p's < 0.007). Participants qualitatively reported wanting longer trainings with more in-depth content and navigation of materials. Our findings suggest that trainings are a promising method that may improve the knowledge and confidence of educators who deliver drug education curriculums. Educator trainings will likely benefit from detailed content on various substances, interactive activities, and show educators how to tailor curriculums based on their students' specific needs.

Motivation of students as a factor in the formation of a future specialist and ways to improve it

In psychological and pedagogical science and practice, special attention is paid to the motivation of learning activities, as it affects the quality of learning activities. The predominance of external, utilitarian motives among modern youth leads to the fact that learning becomes formal, there is no creative approach, no independent setting of learning goals. It is known that a negative or indifferent attitude to learning can be the reason for a student's poor performance or failure. The article considers professional self-consciousness as an independent psychological and acmeological category, as a developing system, as a personal formation inherent in a particular subject of activity. The manifestation of professional self-consciousness is personal qualities that are refracted through professional knowledge and demonstrated in the situation of professional life. The defining component of the organization of learning activities is motivation. The main factors that influence the formation of positive motivation for learning activities are: the content of the educational material, the organization of learning activities, collective forms of learning activities, assessment of learning activities and the style of pedagogical activity of the teacher. Cognitive activity is the leading sphere of human life. Hence, the cognitive motive is formed - the main factor in the success of cognitive activity, through which the natural human need for development is realized. The groups of cognitive activity motives are analyzed. The study of motivation for professional activity examines the relationship between professional skills and various factors, among which the needs of the individual, the level of achievement motivation and the social prestige of the activity are particularly emphasized. Thus, prestige positively correlates with high motivation (including achievement rather than avoidance of failure), self-esteem, confidence in the future, and the importance of the activity and its results. Activities are never motivated by only one motive. It matters which motive is the main, determining, and which is secondary. The main motive in students' learning activities should be educational and cognitive interest. Only then will learning activities be effective.

Not that Innocent: Chemical and Toxicological Evaluation of Glycerin and Propylene Glycol Used in Vape Liquid Production

This work evaluated the elemental content and toxicology of the primary materials of the e-liquids without adding nicotine and other additives. Elemental content was determined through inductively coupled plasma mass spectrometry (ICP-MS) analyses, and biological effects were evaluated in Saccharomyces cerevisiae and H9c2 cells. Elemental analysis did not detect toxic elements above the limit of quantification (LOQ). Toxic concentration with significant difference (p &lt; 0.05) between the samples and the non-exposed cells for glycerin (7.5% m/v) and propylene glycol (12.5% m/v) and at 70/30 proportions (12.5% m/v), 50/50 (12.5% m/v), and 30/70 (6.25% m/v) were encountered. Yeast toxicity presented a concentration-dependent relation with growth inhibition and lethality. Cytotoxicity tests in mammalian cells presented significant differences (p &lt; 0.05) at low concentrations of glycerin and propylene glycol exposition (1.25 and 0.25% m/v, respectively). High concentrations of glycerin and propylene glycol induced increased reactive oxygen species/lactate dehydrogenase, decreased catalase activity, and interference in cell viability. On acute exposure, pure glycerin and propylene glycol are toxic for yeast and H9c2 cells, increasing with proportions of glycerin/propylene glycol and the increased amount of propylene glycol in the solution. No correlation between elemental content and toxicity was observed.

Chemical characterization of polymer and chloride content in waste plastic materials using pyrolysis - direct analysis in real time - high-resolution mass spectrometry.

The increasing global demand for plastic has raised the need for effective waste plastic management due to its long lifetime and resistance to environmental degradation. There is a need for rapid plastic identification to improve the mechanical waste plastic sorting process. This study presents a novel application of Temperature-Programmed Desorption-Direct Analysis in Real Time-High Resolution Mass Spectrometry (TPD-DART-HRMS) that enables rapid characterization of various plastics. This technique was applied on four commercially available reference polymers (polyethylene, polypropylene, polystyrene, polyvinyl chloride) as well as three "waste" plastic samples of mixed origin. These waste plastic samples were obtained as discards from various industrial processes with limited analytical characterization data. Through the application of CH2 Kendrick mass defect (KMD) grouping, characteristic trends in the mass spectra of each sample were identified, allowing for a simplified numerical comparison. This approach utilized a robust statistical approach using the Tanimoto coefficient, allowing for the quantitative measures of similarity between standards and unknown samples. The application of this mathematical evaluation methodology was used to identify plastic types and to distinguish structurally similar polymers. Additionally, we report that a chloride ion clustering effect with copper substrate can identify chlorinated polymer PVC (polyvinyl chloride) utilizing pyro-(-)DART-HRMS mode. PVC polymer is of particular interest in recycling due to its high chloride content, which can present technical challenges for some types of recycling. We found that chloride ion clusters are a good screening marker for the presence of chlorinated polymers in mixed waste plastic samples. This study can possibly help advance rapid and accurate analytical techniques for identifying the composition of waste plastics to advance the effectiveness of the waste plastic sorting process.

Preparation and mechanical-electrical characterization of new complex-phase conductive concrete

The transmission line tower foundation is the key to determining the safe and stable operation of transmission lines under high current impact, and conductive concrete plays a vital role in the safe and stable operation of transmission lines. However, the mechanical and electrical properties of conductive concrete have a competitive relationship, and balancing these properties simultaneously is a current research problem. This paper proposes a new method for the preparation of novel multiphase electrically conductive concrete fiber composites and elucidates the mechanism of its electrical resistivity and compressive and flexural properties. The effects of concrete, graphite and stainless steel fibers as conductive phase materials on the changing law of physical properties of conductive concrete were compared, and the optimal ratio of the content of conductive phase materials was explored. A numerical calculation model of multi-field coupling of a new type of conductive concrete under high current impact was established. The results demonstrate that when the graphite content is 20% and the stainless steel fiber content is 2.75% ± 0.1%, the mechanical and electrical properties ratio is the best. The resistivity was reduced by 54%, the compressive strength was increased by 47.4%, and the flexural strength was increased by 151.4% compared to graphite conductive concrete. The new conductive concrete has promising frontiers of steady-state electricity and transient heat under 20 kA high current impingement, with its current density value dropping to 3280A/m3 and the maximum module temperature dropping to 2270 K. Relevant research provides a theoretical reference for guaranteeing the safe operation of power systems.

Evaluation of EPDM scrap/ natural fiber vulcanization by solvent swelling analysis

In the rubber industry there is an opportunity to reuse unvulcanized rubber scrap generated during the formulation process, as well as to find alternatives for its use. For this reason, in this work the characterization of EPDM/natural fiber scrap with different proportions is studied through rheological and swelling studies according to the Flory Rehner Equation. The solvents used were distilled water, cyclohexane and toluene at different exposure times. The results found allow us to conclude that the fiber content in EPDM rubber does not affect the scorch time, the maximum vulcanization time. In the case of swelling analysis, the observed changes had a maximum increase of approximately 3% when the fiber content in the composite material increased when they were exposed to water and toluene, this was attributed to the characteristics of the EPDM studied in this work.