Changes In Content Research Articles

Effect of Ti and Mo content changes on microstructure and properties of laser cladding FeCoCrNiMn high entropy alloy coatings

The HEA coatings of FeCoCrNiMnTixMo1.5-x(x = 0.25, 0.5, 0.75, 1 and 1.25) were prepared by laser cladding. X-ray diffraction (XRD), electron backscatter diffraction (EBSD), and scanning electron microscopy (SEM) were used to characterize the phase and crystal structure. The mechanical properties were tested. The results show that Ti is solidly dissolved in the FCC phase for solid solution strengthening. Mo is precipitated as the second phase σ phase for second phase dispersion strengthening. As x increases, the coating becomes the FCC+σ phase, and the σ phase disappears at x = 1.25. The microhardness and wear resistance of the coating are greatly improved by solution strengthening and second phase precipitation strengthening. The microhardness is up to 3.18 times of the substrate, and the wear resistance is up to 10.9 times of the substrate. Corrosion resistance of all coatings is better than that of 45# steel. With the increase of x, the corrosion resistance of the coating increases first and then decreases. When x = 1, the corrosion resistance of the coating is the best.

The dynamics of development of the Ukrainian-language segment on TikTok: evolution and contemporary challenges

This article examines the dynamics of development of the Ukrainian-language segment on the TikTok platform, evaluates the influence of this social media application on the formation of Ukraine's information space, and identifies key trends and changes in Ukrainian-language content from its inception on the platform to the present day. The study explores the emergence, development, and peculiarities of the TikTok platform in the global and Ukrainian information space, identifying factors contributing to the creation and dissemination of Ukrainian-language content on TikTok. Research delves into the content produced by Ukrainian bloggers on TikTok and considers its potential impact. It is found that TikTok initially served predominantly as a Russian-language entertainment platform upon its introduction to Ukraine, evolving later into a multifunctional tool facilitating the widespread dissemination and consumption of Ukrainian-language content. The growth of the Ukrainian-language segment on TikTok contributes to the formation of national identity and culture, as well as the strengthening of the state language. Ukrainian bloggers utilize the platform to promote Ukrainian values, social initiatives, and mobilize public opinion amidst Russian military aggression. Analysis of TikTok's development dynamics provides grounds to anticipate its increasing influence on our country's information space.

Investigation of the effects of coal properties, environmental conditions, and costs on coal drying method selection using multi-criteria decision-making method (AHP)

In this study, coal properties and environmental characteristics were investigated, and the most suitable coal drying method was determined for four different regions (Armutcuk, Afsin, Can, and Soma) where Türkiye's significant coal reserves are located, using the AHP method (Analytical Hierarchy Process). Installation and operating cost, drying rate, environmental risk, and land area parameters were used as selection criteria in the AHP method. After analyzing the physical and chemical properties of coals from four different regions, changes in moisture content and drying costs were calculated according to various drying methods (rotary, microwave, solar, and air). The results indicated that the solar energy data of the regions were determined to be 1315, 1610, 1400, and 1444 kWh/m²-year for Armutcuk, Afsin, Can, and Soma, respectively. Accordingly, solar energy drying systems are expected to be preferred in regions with high solar energy. However, with the effect of other selection criteria, it was determined that although the Can region receives less solar energy than the Soma region, the microwave drying method should be used for the coal of the Soma region, and the solar energy drying method should be used for the coal of Can region. Microwave and solar energy methods should be preferred for drying the coals of the Armutcuk and Afsin regions, respectively. As in many sectors, multi-criteria decision-making methods are necessary for optimum equipment/method selection in the mining sector. In conclusion, this study showed that the AHP method can be used when appropriate criteria are thoroughly determined.

Antibacterial and Healing Efficacy of Mangiferin-Loaded Silver Nanoparticle and Chitosan-Alginate Membrane Dressings

Mangiferin, a bioactive constituent of Mangifera indica (family Anacardiaceae), has an impressive therapeutic profile, having antioxidant, anti-inflammatory, analgesic, antibacterial, and immunomodulatory properties capable of possessing wound healing potential. Our investigation aims to isolate and characterize mangiferin, green synthesis of silver nanoparticles (Ag-NPs) and production of chitosan alginate (Cs/Alg) film dressing loaded with mangiferin Ag-NPs and assess antibacterial and wound-healing properties against infected excision and burn wounds. The isolated mangiferin was authenticated by estimating melting point, thin layer chromatography (TLC), fourier-transform infrared spectroscopy (FTIR), and high-performance liquid chromatography (HPLC). Ag-NPs were green synthesized and characterized by UV-visible, particle size, zeta potential (ZP), entrapment efficiency (%EE), scanning electron microscope (SEM), transmission electron microscope (TEM), and stability study. Chitosan alginate membrane dressing was prepared by incorporating mangiferin Ag-NPs, and film thickness, pH, film weight, water intake capacity, and in-vitro drug release parameters were estimated. Among the four mangiferin Ag-NP batches, MN3 formed stable polydispersity spherical Ag-NPs with smaller particle size and high %EE. Mangiferin-loaded Cs/Alg film MN-CM4 showed significantly higher (p < 0.001) drug content, wettability, release profile, and favorable pH changes. The mangiferin Ag-NPs embedded Cs/Alg film dressing showed a significantly high antimicrobial effect against the gram-positive bacterial strain of S. aureus, commonly found in wounds. MN3 and MN-CM4 treatment showed the shortest epithelialization period and enhanced wound closure. The hydroxyproline content has significantly (p < 0.001) increased, and myeloperoxidase content was reduced by MN3 and MN-CM4 treatment. MN-CM4 treatment showed complete re-epithelialization reduced inflammatory cells with thicker and denser collagen fiber deposition. The effectiveness of the Cs/Alg film of mangiferin Ag-NPs dressing has a synergistic effect on promoting speedy wound healing. The Cs/Alg film of mangiferin Ag-NPs showed rapid wound healing against infected and burned wounds, enhanced collagen synthesis, and anti-inflammatory and antibacterial efficacy.

In-situ water retention monitoring system of an operational dike

The severe droughts in recent decades and the lack of regular flooding have caused considerable fissures to develop on clay embankments. Previous surveys in Hungary have identified the examined dike section as prone to desiccation cracks. It is essential to determine the possible extent of these desiccation cracks, as they degrade the dikes’ resistance against several failure mechanisms. A representative dike cross-section was equipped with a unique water retention monitoring system comprising 17 sensors, including 14 soil moisture and 3 water potential sensors. These devices were validated with laboratory measurements to obtain accurate results. The gravimetric water content (w) ranged from 8.3 % to 31.3 %, and the matric potential was recorded between 0.1 kPa and 2350.7 kPa over one and a half years. The study examined the differences in soil behaviour under pavement and turf cover, identifying common moisture content distribution patterns and areas of the cross-section prone to desiccation cracking. The uniqueness of the monitoring system lies in the fact that it was established in an operational embankment, which regulates the flow of a river. Furthermore, it was instrumented along the Tisza River, which is among Europe’s most significant watercourses. The results may help better understand the moisture content change in clay embankments and the role of the crest pavement in the moisture content distribution.

Influence of Heat Treatment and Lactic Acid Fermentation on the Physical and Chemical Properties of Pumpkin Juice

Pumpkin is a highly nutritious plant, rich in valuable nutrients that benefit human health. Due to the high perishability of this fruit, the production of pumpkin juice is a practical way to use it effectively. Recently, fermented vegetable juices have been used as a dairy alternative due to their nutritional and potential probiotic properties. This study investigated the fermentation of pumpkin juice using different strains of lactic acid bacteria (LAB), with and without heat treatment. The effects of fermentation on microbial growth, pH, acidity, extract, sugars, carotenoids, polyphenols, and antioxidant properties were analyzed. The heat-treatment process did not greatly impact the dry matter content, pH, acidity, extract, or sugar content. However, it led to a reduction in carotenoid and polyphenol levels. During fermentation, there was a consistent decrease in pH and an increase in total acidity, with no noticeable differences between bacterial strains regarding their influence on these parameters. The study revealed that there were no distinctions between LAB strains in their effects on pH, acidity, and carotenoid content in fermented pumpkin juice. Nonetheless, both L. sakei and L. plantarum proved to be effective in the fermentation process, with L. sakei demonstrating greater adaptability. The expected pH, acidity, and sugar content changes were consistently observed throughout the fermentation process. Overall, results confirm the efficacy of the used Lactobacillus strains in fermenting pumpkin juice and highlight the potential impact of heat treatment on the nutritional composition of the juice. The purpose of thermal processing of pumpkin juice, which is conducted with lactic acid fermentation, is crucial for the food industry. It extends the product’s shelf life, improves its nutritional and taste profiles, and guarantees its microbiological safety.

Polyunsaturated triacylglycerol accumulation mainly attributes to turnover of de novo-synthesized membrane lipids in stress-induced starchless Chlamydomonas.

Assembly of PUFA-attached TAGs is intimately correlated to turnover of newly formed membrane lipids in starch-deficient Chlamydomonas exposed to high light and nitrogen stress under air-aerated mixotrophic conditions. Triacylglycerols (TAGs) rich in polyunsaturated fatty acids (PUFAs) in microalgae have attracted extensive attention due to its promising application in nutraceuticals and other high-value compounds. Previous studies revealed that PUFAs accumulated in TAG primarily derived from the dominant membrane lipids, monogalactosyldiacylglycerolipid, digalactosyldiacylglycerol and diacylglycerol-N,N,N-trimethylhomoserine (DGTS), in the model alga Chlamydomonas reinhardtii. However, their respective contribution to PUFA-attached TAG integration has not been clearly deciphered, particularly in starchless Chlamydomonas that hyper-accumulates TAG. In this study, the starchless C. reinhardtii BAFJ5 was mixotrophically cultivated in photobioreactors aerated with air (0.04% CO2), and we monitored the dynamic changes in growth, cellular carbon and nitrogen content, photosynthetic activity, biochemical compositions, and glycerolipid remodeling under high light and nitrogen starvation conditions. The results indicated that multiple PUFAs continually accumulated in total lipids and TAG, and the primary distributors of these PUFAs gradually shifted from membrane lipids to TAG in stress-induced BAFJ5. The stoichiometry analyses showed that the PUFA-attached TAG assembly attributed to turnover of not only the major glycerolipids, but also the phospholipids, phosphatidylethanolamine (PE) and phosphatidylglycerol. Specifically, the augmented C16:3n3 and C18:3n3 in TAG mainly originated from de novo-synthesized galactolipids, while the cumulative C18:3n6 and C18:4n3 in TAG were intimately correlated with conversion of the newly formed DGTS and PE. These findings emphasized significance of PUFA-attached TAG formation dependent on turnover of de novo assembled membrane lipids in starch-deficient Chlamydomonas, beneficial for enhanced production of value-added lipids in microalgae.

تأثير الشبكات الرقمية الاجتماعية على القيم الاجتماعية للشباب السعودي

Social media networks have emerged among young people in a way that has made digital platforms dominating on virtual reality for many users, which has made them win the bet on media competition between media institutions and communicating platforms to attract more users. In the midst of this demand for digital social platforms, questions arise regarding the nature of the changes and effects that these platforms reflect on users. Despite the fact that this path has been previously addressed by a number of researchers, questions related to these effects still exist due to the change in communication content and the increase in consumption by users, which suggests a change in perceptions, whether negatively or positively. Therefore, many research questions arise here related to intellectual influences in terms of the type of influence that digital social platforms reflect on university student users and to what extent this influence reaches and what are the individual differences due to demographic characteristics. Given that the social aspect is the final result of common customs and traditions, which stem from religious culture, socialization, education and upbringing, this study addresses the intellectual and social effects of digital social media platforms on university students (King Abdulaziz University) due to the great diversity that the university contains in terms of social and cultural backgrounds, which reflects a clearer and more accurate picture than some other universities located in areas with less cultural and social diversity. The study included a diverse sample of university students, numbering around 264 male and female students. The study showed that intellectual effects tend to be largely negative, as variables related to the positive effects of social media networks on social values received a weak approval rate among the study sample, for example: what is published of news and events on social media networks about social values is positive (45.20%), social media networks help in preserving social values (44%), social media networks enhance the building of social values (47.20%), with the emergence of demographic differences due to gender between male and female students in some other variables regardless of academic specializations. The study includes at the end a number of outputs and recommendations that can contribute to reducing the negative effects among university students, which increases the chances of influencing more than being influenced.

Loss of collagen content is localized near cartilage lesions on the day of injurious loading and intensified on day 12.

Joint injury can lead to articular cartilage damage, excessive inflammation, and post-traumatic osteoarthritis (PTOA). Collagen is an essential component for cartilage function, yet current literature has limited understanding of how biochemical and biomechanical factors contribute to collagen loss in injured cartilage. Our aim was to investigate spatially dependent changes in collagen content and collagen integrity of injured cartilage, with an explant model of early-stage PTOA. We subjected calf knee cartilage explants to combinations of injurious loading (INJ), interleukin-1α-challenge (IL) and physiological cyclic loading (CL). Using Fourier transform infrared microspectroscopy, collagen content (Amide I band) and collagen integrity (Amide II/1338 cm-1 ratio) were estimated on days 0 and 12 post-injury. We found that INJ led to lower collagen content near lesions compared to intact regions on day 0 (p < 0.001). On day 12, near-lesion collagen content was lower compared to day 0 (p < 0.05). Additionally, on day 12, INJ, IL, and INJ + IL groups exhibited lower collagen content along most of tissue depth compared to free-swelling control group (p < 0.05). CL groups showed higher collagen content along most of tissue depth compared to corresponding groups without CL (p < 0.05). Immunohistochemical analysis revealed higher MMP-1 and MMP-3 staining intensities localized within cell lacunae in INJ group compared to CTRL group on day 0. Our results suggest that INJ causes rapid loss of collagen content near lesions, which is intensified on day 12. Additionally, CL could mitigate the loss of collagen content at intact regions after 12 days.

Effects of CaF2 and La2O3 on the phase structure of rare earth in CaO–SiO2–La2O3–CaF2 slags

The rare earth in the rare earth slag can be separated and enriched by heating and melting the rare earth slag and then slowly cooling crystallisation. In this process, it is of great significance to study the effect of chemical composition on the crystallisation of rare earth phase in slag and the effect of slag viscosity on crystal growth. The rare earth slag melt samples were prepared according to the main chemical composition of rare earth slag by using an analytical pure reagent. The effects of CaF2 and La2O3 contents on the phase structure and morphology of rare earth phase in CaO–SiO2–La2O3–CaF2 slags were studied by SEM-EDS and XRD. The relationship between the viscosity of the slag and the crystal growth behaviour was studied by measuring the melt viscosity with the cylinder rotation method. The results show that the rare earth in CaO–SiO2–La2O3–CaF2 slags exists in the form of CaLa4(SiO4)3O. The change of CaF2 and La2O3 content has no effect on the structure of rare earth phase, but the size of rare earth crystal phase changes obviously. With the increase of CaF2 and La2O3 content, the size of rare earth crystal phase increases gradually. CaF2 and La2O3 can reduce the viscosity transition temperature of slag melt and increase the crystallisation temperature range of rare earth phase to promote crystal growth.

Effects of pre‐deacidification on 3‐MCPDE and GE contents of high‐acid oils during refining

SummaryCrude fats and oils may have high free fatty acid (FFA) content depending on raw material quality and processing conditions. Their refining is always a challenge due to refining loss and the formation of some process contaminants such as 3‐monochloropropane‐1,2‐diol esters (3‐MCPDE), and glycidyl esters (GE). In this study, crude hazelnut oil having 12.10% FFA was degummed, bleached, and pre‐deacidified by a molecular distillation (MD) unit before neutralisation and deodorisation. Changes in FFA, diglyceride(DG), 3‐MCPDE, GE, and tocopherol contents were monitored. Almost no changes were detected in FFA and DG contents during degumming and bleaching while the latter resulted in the 3‐MCPDE formation and GE reduction. Some tocopherol losses were also observed after these steps. On the other hand, a huge amount of FFA was distilled (from 12.10% to 1.71%) by the MD process performed at 200 °C, 0.25 mbar, as well as with a 53.6% loss of tocopherol. The samples were then subjected to deodorisation before (MD‐PHY) and after neutralisation (MD‐CHE) at 230 °C under 2 mbar absolute pressure for 2, 4, and 8 h. While some 3‐MCPDE and GE formations were detected during MD‐CHE, there were almost no formations in these contaminants after MD‐PHY. When the bleached oil having 12.10% FFA was also directly deodorised at given conditions, no formations but some reductions in 3‐MCPDE and GE contents of the oils were determined, possibly because of esterification of FFA with DGs that are an important precursor of these contaminants.

Molecular Functions and Physiological Roles of Gustatory Receptors of the Silkworm Bombyx mori.

Complete elucidation of members of the gustatory receptor (Gr) family in lepidopteran insects began in the silkworm Bombyx mori. Grs of lepidopteran insects were initially classified into four subfamilies based on the results of phylogenetic studies and analyses of a few ligands. However, with further ligand analysis, it has become clear that plant secondary metabolites are important targets not only for Grs in the bitter subfamily but also for the Drosophila melanogaster Gr43a orthologue subfamily and Grs in the sugar subfamily. Gene knockout experiments showed that B. mori Gr6 (BmGr6) and BmGr9 are involved in the recognition of the feeding-promoting compounds chlorogenic acid and isoquercetin in mulberry leaves by the maxillary palps, suggesting that these Grs are responsible for palpation-dependent host recognition without biting. On the other hand, BmGr expression was also confirmed in nonsensory organs. Midgut enteroendocrine cells that produce specific neuropeptides were shown to express specific BmGrs, suggesting that BmGrs are involved in the induction of endocrine secretion in response to changes in the midgut contents. Furthermore, gene knockout experiments indicated that BmGr6 is indeed involved in the secretion of myosuppressin. On the other hand, BmGr9 was shown to induce signal transduction that is not derived from the intracellular signaling cascade mediated by G proteins but from the fructose-regulated cation channel of BmGr9 itself. Cryogenic electron microscopy revealed the mechanism by which the ion channel of the BmGr9 homotetramer opens upon binding of fructose to the ligand-binding pocket. Research on BmGrs has contributed greatly to our understanding of the functions and roles of Grs in insects.

Estimating cation exchange capacity from hygroscopic water content change

Estimating cation exchange capacity from hygroscopic water content change

Latitudinal trends in an invasive plant: genetic differentiation, phenotypic plasticity, and the effects of heavy metals and herbivores on growth, defence, and reproductive characteristics

Abstract Background and Aims Invasive species usually demonstrate remarkable adaptability across diverse environments, successfully inhabiting a wide variety of regions. This adaptability often links to genetic differentiation and phenotypic plasticity, leading to latitudinal trends in phenotypic traits. In this study, we collected seeds of invasive plant Phytolacca americana from different latitudes and planted them in homogeneous gardens to investigate the latitudinal variation of P. americana phenotypic traits and to evaluate the effects of herbivory and heavy metals on plant growth, defence, and reproductive characteristics. Methods P. americana seeds from different latitudes were planted in a homogeneous garden. For the experimental treatment, the seeds were divided into four groups: a heavy metal treatment group and its corresponding control group, and a cover treatment group with its corresponding control group. After the fruits matured, their growth, reproduction, and defence indicators were measured. Key Results Significant latitudinal trends were observed in P. americana’s growth and defence characteristics, including changes in branch number, underground biomass, total biomass, and leaf tannin content. Compared to previous field surveys on P. americana, our study found that the latitude trends in growth structure and defence traits were consistent. But the latitudinal trend of reproductive structure is different. Moreover, heavy metals and herbivory substantially influenced the plant’s growth, reproduction, and defence mechanisms, further shaping its latitudinal patterns. Conclusions The observed phenotypic variations in P. americana across latitudes can be largely attributed to the synergistic effects of phenotypic plasticity and genetic variation. At a broader geographical scale, adaptations to heavy metal stress and herbivory pressure among different P. americana populations involve distinct trade-offs related to growth, reproduction, and defence strategies.

Qingqianliutianosides A–E: five new sweet dammarane triterpenoid glycosides derived from the leaves of Cyclocarya paliurus – identification, characterization and interactions with T1R2/T1R3 sweet taste receptors

AbstractBACKGROUNDCyclocarya paliurus, as a new food resource, is utilized extensively in human and animal diets due to its bioactive compounds, health benefits, and its highly prized sweet flavor. This study aimed to investigate the sweet‐taste ingredient of C. paliurus leaves.RESULTSFive new dammarane triterpenoid glycosides were isolated and identified as qingqianliutianosides A–E (1–5) by comprehensive spectroscopic data analysis and a single crystal X‐ray diffraction experiment. Qingqianliutianoside A (1) and qingqianliutianoside C (3), present in relatively high quantities in the plant, were shown to exhibit sweetness by sensory evaluation and electronic tongue analysis. Further monitoring was conducted on the content changes in 3 in leaves at different growth stages, indicating that 3 reached its peak content in April and then showed a decreasing trend. Molecular docking studies revealed that T1R2/T1R3 receptors Ser212, Ser105, Thr239, Asn380, Thr305, and Val381 may play critical roles, demonstrating that hydrogen bonding and hydrophobic interactions were the dominant interaction forces between all of the identified compounds and the active sites in the Venus flytrap module of the T1R2/T1R3 receptors.CONCLUSIONQingqianliutianosides A–E are promising natural source sugar substitutes for use in functional foods and beverages. © 2024 Society of Chemical Industry.

Mathematical Modeling of Sorptive Extraction of Lithium Chloride from Lithium-containing Brine of the Aral Sea Region

Introduction The article presents the results of chemical and physicochemical analysis of initial lithium-containing hydromineral raw materials and sorbent based on bentonite clay with titanium oxide addition. Methods It is established that the mineral is montmorillonite group and kaolinite according to the results of the analysis of the microstructure and elemental composition of bentonitic clay of the Darbazinsky deposit. Brine is characterized by the change of lithium chloride content in the range of 403- 1001 mg/l. Physical and mechanical characteristics of the obtained sorbents based on bentonite clay and titanium oxide additive are characterized by a high mechanical strength of 5.31 MPa, density of up to 2,6 g/cm3, and specific surface area of 1572 cm2/g. The technological parameters of sorption extraction of lithium chloride from lithium-containing hydromineral raw materials were optimized using the system analysis “STATISTICA” developed by StatSoft company. It is established that to increase the rate of lithium chloride extraction from brine, it is necessary to maintain the rate of brine flow within 8 l/min at maximum humidity of solution output up to 43g/m3 on the basis of the obtained volumetric graphical dependencies. Results The microstructure of the used sorbents with titanium oxide addition up to 20% is characterized by the predominance of lithium chlorides, which are represented by heap-shaped, prismatic crystals. Conclusion The maximum amount of lithium chloride in the form of clusters of light-white crystals of tabular shape on the surface of the sorbent is observed at increasing the content of titanium oxide up to 40%.

A Comparative Study on the Antioxidative Activity and Phenolic Content of Fresh and Black (Fermented) Allium Vegetables

Allium genus vegetables have significant functional effects on health. In recent years, consumer demand for black forms of these vegetables, produced from fresh Alliums through spontaneous fermentation at high temperature and humidity, has increased, while their functional effects have yet to be fully elucidated. The aim of this study was to compare the antioxidant capacity and total phenol content of various Allium vegetables (yellow onion, red onion, white onion, and garlic) in both their raw and black (fermented) forms. For the production of black onions and black garlic, unpeeled raw forms of these vegetables were kept at 75 °C and 90% humidity for 9 days. Afterward, fresh and fermented samples were lyophilized, dried, and evaluated for total phenol content by the Folin–Ciocalteu method and for antioxidant activity by the ABTS and DPPH methods. The total phenol content increased significantly in all samples after fermentation (p &lt; 0.05), with the highest increases observed in garlic (216%), while the increases in onion species ranged between 44.6% and 118.3%. The increase in antioxidant capacity was also significant in all samples (p &lt; 0.05) and was higher in garlic than in onions. Changes in antioxidant capacity and total phenol content indicate that fermentation improves the nutritional quality of these vegetables.

The contractile efficiency of the mantle muscle of European common cuttlefish (Sepia officinalis) during cyclical contractions

Escape jet propulsion swimming in cuttlefish (Sepia officinalis) is powered by the circular muscles surrounding the mantle cavity. This mode of locomotion is energetically costly compared to undulatory swimmers. The energetic cost of swimming is determined by the mechanical power requirements and the efficiency with which chemical energy is transferred into useful mechanical work. One step in this energy transduction process is the transfer of energy from ATP hydrolysis into mechanical work by the muscles. Here, we determined the efficiency of this step, termed the contractile efficiency. Muscle preparations from the circular muscles of the mantle cavity were subjected to sinusoidal length changes at different cycle frequencies, and stimulated with a phase and duration that maximised initial net work. Changes in ATP, arginine phosphate and octopine content between control and exercised muscles were determined and used to calculate the energy released from ATP hydrolysis (Emet). The maximum contractile efficiency (the ratio of net work to Emet) was 0.37, occurring at the same cycle frequency at which mechanical power was maximal and that was used during jet propulsion swimming, suggesting that cuttlefish muscle is adapted to generate muscular power efficiently. The overall efficiency of cuttlefish jet propulsion swimming was estimated to be 0.17, which is broadly comparable to that measured during animal flight and human-powered pedalled locomotion, indicating the high energetic costs of jet propulsion swimming are not due to inefficient locomotion per se, instead, they result from the relatively high mechanical power requirements.

Impacts of generative AI on user contributions: evidence from a coding Q &amp;A platform

AbstractThis study investigates the short-term impact of generative AI, exemplified by the introduction of ChatGPT, on user contributions in a coding Q&amp;A platform. We find that the introduction of ChatGPT led to a reduction in the number of high-quality answers provided by users, particularly among highly engaged contributors, despite an overall increase in answers. We identify two key mechanisms: (1) increased perceived question sophistication despite no actual change in content and (2) reduced motivation of loyal users in providing answers in the face of AI-generated alternatives. The findings suggest that while generative AI can facilitate value creation on user-generated content (UGC) platforms, it also poses challenges in retaining core contributors and managing content quality. The paper contributes to the literature on the impact of AI adoption on platforms and suggests practical implications for UGC platform management, such as the need for AI content disclosure measures to retain engaged users.

Prediction of mechanical properties of rolled steel based on dual-attention multiscale convolutional neural network

The mechanical properties of carbon steel sheet directly depend on the chemical composition and process parameters of the steel. There is a complex nonlinear relationship between chemical composition, process parameters, and mechanical properties, and the establishment of a model with the ability to automatically distinguish the importance of different parameters, and to have good prediction accuracy and generalisation in different data sets is one of the important issues in the field of carbon steel mechanical properties prediction. In this paper, we proposed a multi-scale convolutional network model based on dual-attention mechanism (DAM-MSDSC), where the dual-attention module mines from features and channels at the same time, making the model focus on the important features. The multiscale feature fusion module effectively improves the model prediction accuracy by mining features from the output of the middle layer of the network to obtain features containing multiscale fusion features. In hot-rolled steel, for the two parameters of carbon content and temperature, it is confirmed that the change of carbon content has a greater impact on TS, while FTT and CT have a greater impact on YS. Through comparative experiments on different datasets, the proposed model had the best prediction performance, in which the correct rates of YS, TS, and EL are 98 %, 98.7 %, and 99.4 %, respectively, in cold rolled steel, and 97.8 %, 98.6 %, and 99.2 %, respectively, in hot rolled steel.