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Found 6674 publications
Use of Hybrid Flame Retardants in Chemically Foamed rPET Blends
Publication Name: Crystals
Publication Date: 2025-01-01
Volume: 15
Issue: 1
Page Range: Unknown
Description:
The foamed structure of recycled polyethylene-terephthalate (rPET) is a promising solution for industrial applications; however, the remedy for its inherent melt-dripping property is still a challenging topic. In our research, we were able to improve the flame retardancy of the endothermic–exothermic hybrid rPET foam by adding a different mixture of flame retardants to the formula. Three different kinds of halogen-free flame retardant agents were used: ammonium polyphosphate-based Exolit AP 422 (AP), organic aluminum phosphate in the form of Exolit OP 1240 (OP), and Budit 342 containing melamine polyphosphate (MPP). The hybrid flame retardant mixture, by combining the swelling and charring mechanism, increased the flame retardancy of the samples. The sample made with 15 phr OP and 5 phr MPP displayed outstanding performance, where five samples were capable of self-extinguishing in 5 s, while only slightly decreasing the tensile and flexural strength properties and simultaneously increasing the Young and flexural modulus compared to the reference sample. The addition of MPP reduced the porosity in many cases, while preventing cell coalescence. Our results prove that the hybrid flame retardant agent frameworks efficiently increase the flame retardancy of rPET foams, facilitating their application in industrial sectors such as the aerospace, packaging, renewable energy, and automotive industries to realize sustainability goals. The utilization of halogen-free flame retardants is beneficial for better air quality, reducing toxic gas and smoke emissions.
Open Access: Yes
In search of the nature of specific nucleic acid-protein interactions
Publication Name: Acta Physiologica Hungarica
Publication Date: 2005-06-23
Volume: 92
Issue: 1
Page Range: 1-10
Description:
The theory of "codon-amino acid coevolution" was first proposed by Woese in 1967. It suggests that there is a stereochemical matching - that is, affinity - between amino acids and certain of the base triplet sequences that code for those amino acids. We have constructed a Common Periodic Table of Codons and Amino Acids, where the Nucleic Acid Table showed perfect axial symmetry for codons and the corresponding Amino Acid Table also displayed periodicity regarding the biochemical properties (charge and hydrophobicity) of the 20 amino acids and the position of the stop signals. The Table indicates that the middle (2nd) amino acid in the codon has a prominent role in determining some of the structural features of the amino acids. The possibility that physical contact between codons and amino acids might exist was tested on restriction enzymes. Many recognition site-like sequences were found in the coding sequences of these enzymes and as many as 73 examples of codon-amino acid co-location were observed in the 7 known 3D structures (December 2003) of endonuclease-nucleic acid complexes. These results indicate that the smallest possible units of specific nucleic acid-protein interaction are indeed the stereochemically compatible codons and amino acids. © 2005 Akadémiai Kiadó.
Open Access: Yes
Investigation of the Tribological Effects of Nano-Sized Transition Metal Oxides on a Base Oil Containing Pour Point Depressant and Viscosity Modifier
Publication Name: Chemengineering
Publication Date: 2025-02-01
Volume: 9
Issue: 1
Page Range: Unknown
Description:
This study investigates the tribological effects of nano-sized metal oxides (ZrO2 , CuO, Y2 O3 and TiO2 ) in Group III type base oil containing 0.3% pour point depressant (PPD) and 5% viscosity modifier (VM) to enhance friction and wear performance. The homogenized lubricant samples with varying concentrations of oxide nanoparticles (0.1–0.5 wt%) on a linear oscillating tribometer performed static and dynamic frictional tests. Optical and confocal microscopy surface analysis evaluated the wear of the specimen, and SEM and EDX analyses characterized the wear tracks, nanoparticle distributions, and quantification. The cooperation between PPD and nanoparticles significantly improved friction and wear values; however, the worn surface suffered extensively from fatigue wear. The collaboration between VM and nanoparticles resulted in a nanoparticle-rich tribofilm on the contact surface, providing excellent wear resistance that protects the component while also favorably impacting friction reduction. This study found CuO reduced wear volume by 85% with PPD and 43% with VM at 0.5 wt%, while ZrO2 achieved 80% and 63% reductions, respectively. Y2 O3 reduced wear volume by 82% with PPD, and TiO2 reduced friction by 20% with VM. These nanoparticles enhanced tribological performance at optimal concentrations, but high concentrations caused tribofilm instability, highlighting the need for precise optimization.
Open Access: Yes
NEW OCCURRENCES OF TWO RARE UROPODINA (ACARI: MESOSTIGMATA) SPECIES FROM IRANIAN FRUIT PLANTATIONS
Publication Name: Acarina
Publication Date: 2024-01-01
Volume: 32
Issue: 2
Page Range: 175-178
Description:
Two rare Uropodina species are reported from Iran: Macrodinychus iranicus Babaeian and Khalili-Moghadam, 2021 from soil in an apricot plantation; Oplitis iranicus Kazemi and Kontschán, 2007 from soils in orange plantations.
Open Access: Yes
Global Sustainability Reporting in the Automotive Industry via the eXtensible Business Reporting Language
Publication Name: Chemical Engineering Transactions
Publication Date: 2021-01-01
Volume: 88
Issue: Unknown
Page Range: 1087-1092
Description:
Sustainability measurement has become one of the most important topics for automotive manufacturers. The financial reporting practice has been faced with an increased digitization and standardization process, which was enabled by the either voluntary or required implementation of the eXtensible Business Reporting Language (XBRL) platform. The obligatory adaption appeared in European legislation, which covers both financial, and non-financial information. In the current study, we have made a comparison of the most significant European and American automakers' sustainability reports data content to utilize the sustainability XBRL taxonomy adaptation. Using literature, the development of disclosure requirements was reviewed, following which the adaptation to global sustainability standards (GRI, SASB) in reporting was examined from a qualitative point of view, using a text mining methodology. It has been concluded that by the biggest automotive manufacturers the conditions are currently met to a limited extent, but the most significant obstacle is the lack of linking sustainability information to financial impacts. If the financial regulations require OEMs to adapt, and potentially disclose negative information (such as pollution data, penalties) may negatively affect investor perception. Based on the review XBRL is capable to become a global standard, however, reported contents should be carefully audited and linked to objectively verifiable financial data to provide relevant information to investors, decision-makers.
Open Access: Yes
DOI: 10.3303/CET2188181
Complex pattern of nexus between global mining consortiums and sustainability in the Middle East and North Africa region
Publication Name: Resources Policy
Publication Date: 2024-10-01
Volume: 97
Issue: Unknown
Page Range: Unknown
Description:
This research investigates the intricate interplay between major global mining entities and sustainability initiatives in the Middle East and North Africa (MENA) region, as a key part of Global South countries. The study conducts a comprehensive analysis of the global mining industry at five distinct levels: mining, mining cap-weighted, mining coal exclusion, global gold mining tracker, and global electrification minerals mining. The objective is to comprehend the multi-fractal patterns and implications of their interconnectedness with sustainability and conventional investments. By employing a time-varying parameter vector autoregressive (TVP-VAR) approach to identify the degree of nexus between each pair consisting of a mining index and sustainability or conventional investments, and utilizing the generalized Hurst exponent of a multiscale multi-fractal analysis (MMA) from September 18, 2017, to July 3, 2023, the study reveals that none of the bi-variate interconnectedness adheres to a random walk process, thereby confirming their inefficient behavior. The level of efficiency among pairs varies, demonstrating heterogeneity across the connections. The analysis indicates a relatively lower level of inefficiency in pairs of pairwise connectedness indices (PCIs) related to sustainable investments compared to conventional investments. Generally, conventional investments exhibit more distinct trends or predictability over various time scales, suggesting a less complex and unpredictable pattern compared to sustainable investments. Additionally, the persistence level in PCIs linked to conventional sustainable investments is higher than that of sustainable investments, implying that conventional investments have more predictable associations with mining consortiums. These findings provide valuable insights into the dynamic relationships between global mining entities and sustainability initiatives in the MENA region, with implications for investors, policymakers, and industry stakeholders. The clarity observed in connectivity patterns with conventional investments presents strategic opportunities for investors, potentially influencing regulatory adjustments for sustainable resource governance. The identified inefficiencies create opportunities for refining risk management tools and optimizing investment strategies. Furthermore, the study highlights the stability of connections between conventional sustainable investments and mining consortiums over time, providing guidance for long-term planning and risk mitigation.
Open Access: Yes
Economic development and growth in central and Eastern Europe
Publication Name: Comparative Economic Research
Publication Date: 2021-01-01
Volume: 24
Issue: 4
Page Range: 69-84
Description:
The study investigates the economic growth in Central and Eastern Europe in the last 25 years. The economy can be regarded as a substantial topic in any country, but it is even more interesting in developing countries. One of the basic ideas of the European Union is the convergence between member states, namely the reduction of development disparities, which can be achieved through faster economic growth in less-developed countries. Growth theory is one of the main topics in economics. Its significant importance is because the desire for development is one of the main driving forces of mankind. The aim of the study is to reveal the crucial differences and common features between the growth paths of the eleven Central and Eastern European member states of the European Union. After presenting growth theories, the growth performance of the examined Central and Eastern European member states is pinpointed. During the research, GDP per capita, population, migration, activity rate, employment rate, unemployment rate, foreign direct investment and foreign trade openness are considered.
Open Access: Yes
Evaluating 3D-Printed Polylactic Acid (PLA)-Reinforced Materials: Mechanical Performance and Chemical Stability in Concrete Mediums
Publication Name: Applied Sciences Switzerland
Publication Date: 2025-02-01
Volume: 15
Issue: 4
Page Range: Unknown
Description:
The optimization and evaluation of 3D-printed polylactic acid (PLA) materials for reinforcing concrete elements present a promising avenue for advancing sustainable construction methods. This study addresses the challenges associated with PLA’s dual nature—biodegradable yet mechanically limited for long-term applications—while leveraging its potential to enhance concrete reinforcement. The research identifies gaps in understanding PLA’s mechanical and chemical behavior in alkaline environments, particularly its interactions with concrete matrices. To bridge this gap, four distinct PLA variants (high-impact PLA, engineering PLA, electrical ESD PLA, and gypsum PLA) and ABS (acrylonitrile butadiene styrene) were subjected to dissolution tests in NaOH solutions (pH 12 and 12.55) and mechanical evaluation under three-point bending using digital image correlation (DIC) technology. Test specimens were prepared using optimized 3D printing strategies to ensure structural consistency and were embedded in concrete beams to analyze their reinforcement potential. Force–displacement data and GOM ARAMIS measurements revealed significant differences in mechanical responses, with peak loads ranging from 0.812 kN (high-impact PLA) to 1.021 kN (electrical ESD PLA). Notably, electrical ESD PLA exhibited post-failure load-bearing capacity, highlighting its reinforcement capability. Chemical dissolution tests revealed material-specific degradation patterns, with high-impact and Gypsum PLA showing accelerated surface changes and precipitation phenomena. Observations indicated white crystalline precipitates, likely lime (calcium hydroxide—Ca(OH)2 ), residue from the dissolution tests (sodium hydroxide—NaOH), or material-derived residues formed on and near PLA elements, suggesting potential chemical interactions. These findings underline the critical role of material selection and optimization in achieving effective PLA–concrete integration. While PLA’s environmental sustainability aligns with industry goals, its structural reliability under long-term exposure remains a challenge. The study concludes that electrical ESD PLA demonstrates the highest potential for application in reinforced concrete, provided its chemical stability is managed, as its peak value (1.021 kN) showed 25.7% higher load-bearing capacity than high-impact PLA (0.812 kN) and did not lose any of its structural stability in the dissolution tests. This work advances the understanding of PLA as a sustainable alternative in construction, offering insights for future material innovations and applications.
Open Access: Yes
DOI: 10.3390/app15042165
Number archetypes, symbolic coding letters and "background communication theory" in Saint Stephen's royal mirror
Publication Name: Iccc 2009 IEEE 7th International Conference on Computational Cybernetics
Publication Date: 2009-12-01
Volume: Unknown
Issue: Unknown
Page Range: 201-211
Description:
Following Pauli's approach to the analysis of the Kepler's works, the paper attempts to identify patterns in the creative background cognitive processes related to a "background system and communication theory" in the thousand-year-old great Latin opus of St Stephen's Royal Mirror. Our paper is dedicated to the blessed memory of Prof. S. Csibi, the great scholar of communication theory, who creatively participated in this endeavour. ©2009IEEE.
Open Access: Yes
