bluuebunny/crossref_metadata_2025 huggingface dataset:
Digital Authentication System in Avatar Using DID and SBT
Authors: Kim Geunyoung , Ryou Jaecheol
Published: October 2023

Anonymity forms the basis of decentralized ecosystems, leading to an increase in criminal activities such as money laundering and illegal currency trading. Especially in blockchain-based metaverse services, activities such as preventing sexual crimes and verifying the identity of adults are becoming essential. Therefore, avatar authentication and the KYC (Know Your Customer) process have become crucial elements. This paper proposes a mechanism to achieve the KYC process by verifying user identity using smart contracts. Users obtain an SBT (Soul Bound Token) from the metaverse service provider through the DID (Decentralized Identity) credential issued during the KYC process. The identity verification of avatars occurs within smart contracts, ensuring user privacy and protection through ZKP (Zero Knowledge Proof). Tools for generating ZKP are also provided, enabling users, even those who are unfamiliar with ZKP, to use them conveniently. Additionally, an integrated wallet is offered to seamlessly manage DID credentials and SBTs. Furthermore, in case of avatar identity issues, users can request an audit by the issuer through the associated DID tokens.
Soy Protein Isolate–Chitosan Nanoparticle-Stabilized Pickering Emulsions: Stability and In Vitro Digestion for DHA
Authors: Zhao Pengcheng , Ji Yuan , Yang Han , Meng Xianghong , Liu Bingjie
Published: October 2023

The purpose of the study was to investigate the stability and oral delivery of DHA-encapsulated Pickering emulsions stabilized by soy protein isolate–chitosan (SPI-CS) nanoparticles (SPI-CS Pickering emulsions) under various conditions and in the simulated gastrointestinal (GIT) model. The stability of DHA was characterized by the retention rate under storage, ionic strength, and thermal conditions. The oral delivery efficiency was characterized by the retention and release rate of DHA in the GIT model and cell viability and uptake in the Caco-2 model. The results showed that the content of DHA was above 90% in various conditions. The retention rate of DHA in Pickering emulsions containing various nanoparticle concentrations (1.5 and 3.5%) decreased to 80%, while passing through the mouth to the stomach, and DHA was released 26% in 1.5% Pickering emulsions, which was faster than that of 3.5% in the small intestine. After digestion, DHA Pickering emulsions proved to be nontoxic and effectively absorbed by cells. These findings helped to develop a novel delivery system for DHA.
Mental Health and Contraceptive Knowledge in High Schoolers: Comparing Remote and In-Person Learning during COVID-19
Authors: Hinoveanu Denisa , Anastasiu Doru Mihai , Citu Cosmin , Crisan Doru Ciprian , Popa Zoran Laurentiu , Nicolae Nicoleta , Dumitru Catalin , Neda-Stepan Oana , Fericean Roxana Manuela , Stelea Lavinia
Published: October 2023

Background and Objectives: In response to the COVID-19 pandemic’s effects on education, this study delves into the behavioral, mental health, and sexual education characteristics of high school students during 2020–2021 and 2022–2023. Materials and Methods: We evaluated a variety of factors, including substance use, academic performance, sexual activities, mental health support, pandemic-related anxiety levels, and quality of life indicators using standardized instruments such as the SF-36, GAD-7, and WHOQOL-BREF. Furthermore, we addressed specific questions concerning contraception and sexual education during this period. Results: The questionnaires were filled in by 44 students in 2020–2021 and 41 students in 2022–2023. Significant findings included a noteworthy increase in COVID-19 vaccination rates, from 18.2% in 2020–2021 to 39.0% in 2022–2023 (p = 0.033), enhanced perceptions of mental health support during remote learning, from 7.1% to 20.0% (p = 0.044), and a rise in students partaking in reproductive health discussions from 10.7% to 25.0% (p = 0.046). Additionally, there was a marked decline in anxiety regarding the transition back to in-person learning (p = 0.048). Health surveys, such as the SF-36, signaled improvements in both physical and mental health over the years (p = 0.046 and p = 0.019, respectively), while the GAD-7 scores depicted a considerable reduction in anxiety symptoms (p = 0.038). The WHOQOL-BREF results also highlighted a significant uptick in students’ mental well-being in 2022–2023 (p = 0.039). Conclusions: As the COVID-19 pandemic ended, high school students exhibited shifts in behavior, health, and education over four academic years, particularly in areas of contraceptive knowledge and mental health outcomes. The pronounced enhancements in vaccination rates, perceptions of mental health support, participation in health conversations, and overall mental wellness emphasize the adaptability and resilience of students in these tumultuous periods, and a general increase in contraceptive knowledge and quality of life during the end of the pandemic.
Review and Analysis of Heat Transfer in Spacer-Filled Channels of Membrane Distillation Systems
Authors: Schilling Sebastian , Glade Heike
Published: October 2023

Membrane distillation (MD) is an attractive process for the concentration of seawater brines. Modelling and simulation of membrane distillation processes requires a better knowledge of the heat transfer coefficients in spacer-filled channels which are usually determined by applying empirical correlations for the Nusselt number. In this study, first, a comprehensive literature review on heat transfer correlations was conducted. It was found that the empirical correlations often used for MD simulation result in strongly varying Nusselt numbers that differ by up to an order of magnitude at low Reynolds numbers. Then, heat transfer in spacer-filled channels was investigated experimentally in a membrane distillation system using an aluminum plate instead of a flat-sheet membrane. Numerous tests were carried out with sodium chloride solutions in a wide range of salinities, between 1 g/kg and 95 g/kg, and temperatures, between 30 °C and 80 °C, yielding high heat transfer coefficients in a range of 1500 to 8300 W/(m2K) at relatively low Reynolds numbers, between 100 and 1500, clearly showing the influence of the spacers on heat transfer. A new empirical Nusselt correlation (Nu=0.158Re0.652Pr0.277) was derived which represents the experimental data with a deviation of 10% and is valid for 100<Re<1500 and 2<Pr<7. Computational fluid dynamics simulations were performed to analyze the variations of the fluid properties across the boundary layer due to temperature differences. The simulations showed only minor deviations of the heat transfer coefficients in the hot and cold fluid channels for small driving temperature differences.
Study of the Physical, Chemical, and Structural Properties of Low- and High-Methoxyl Pectin-Based Film Matrices Including Sunflower Waxes
Authors: Chalapud Mayra C. , Salgado-Cruz Ma. de la Paz , Baümler Erica R. , Carelli Amalia A. , Morales-Sánchez Eduardo , Calderón-Domínguez Georgina , García-Hernández Alitzel B.
Published: October 2023

The development of bio-based materials remains one of the most important alternatives to plastic materials. Although research in this field is growing, reporting various materials and methodologies, it is still necessary to increase exploration. The aim of this work was to expand and complement previous research on the preparation and characterization of high- and low-methoxyl pectin films obtained by casting, with the addition of commercial and recovered sunflower waxes. The results showed that the addition of sunflower waxes to the pectin matrix generated some discontinuity in the aggregate, increasing the thickness and roughness of the film. However, due to their hydrophobic nature, the waxes contributed to lower vapor transmission rate values of the films. On the other hand, the low-methoxyl pectin films had a more crystalline structure, which could help to diminish water vapor permeability values, mechanical resistance and rigidity, and improve their elongation. Regarding chemical characteristics, most of the raw materials’ chemical groups were found in the resulting films, and the presence of C-H bending due to pectin gelation was observed. Finally, the compatibility and contribution of pectin and sunflower waxes to the production of the films were demonstrated, as well as the possibility of using materials from industrial waste in food packaging applications.
Nonconventional Tether Structure for Quality Factor Enhancement of Thin-Film-Piezoelectric-on-Si MEMS Resonator
Authors: Awad Mohammed , Workie Temesgen Bailie , Bao Jingfu , Hashimoto Ken-ya
Published: October 2023

This article presents a new design of supporting tethers through the concept of force distribution. The transmitted force applied on tethers will be distributed on the new tether design area, resulting in low acoustic energy transferred to anchor boundaries and stored energy enhancement. This technique achieves an anchor quality factor of 175,000 compared to 58,000 obtained from the conventional tether design, representing a three-fold enhancement. Furthermore, the unloaded quality factor of the proposed design improved from 23,750 to 27,442, representing a 1.2-fold improvement.
Detection and Quantification of the Epstein-Barr Virus in Lymphoma Patients from Ethiopia: Molecular and Serological Approaches
Authors: Teshome Seifegebriel , Zealiyas Kidist , Abubeker Abdulaziz , Tadesse Fisihatsion , Balakrishna Jayalakshmi , Weigel Christoph , Abebe Tamrat , Ahmed Elshafa Hassan , Baiocchi Robert A.
Published: October 2023

The Epstein-Barr virus (EBV) is a known oncogenic virus associated with various lymphoma subtypes throughout the world. However, there is a lack of information regarding EBV prevalence in lymphoma patients, specifically in Ethiopia. This study aimed to investigate the presence of the EBV and determine its viral load in lymphoma patients from Ethiopia using molecular and serological approaches. Lymphoma patient samples were collected from the Ethiopian population. DNA and serum samples were extracted and subjected to molecular detection methods, including quantitative polymerase chain reaction (qPCR) analysis targeting the EBNA1 gene. Serological analyses were performed using an enzyme-linked immunosorbent assay (ELISA) to detect EBV viral capsid antigen IgG antibodies. EBV DNA was detected in 99% of lymphoma patients using qPCR, and serological analyses showed EBV presence in 96% of cases. A high EBV viral load (>10,000 EBV copies/mL) was observed in 56.3% of patients. The presence of high EBV viral loads was observed in 59.3% of HL patients and 54.8% of NHL patients. This study provides important insights into the prevalence and viral load of the EBV among lymphoma patients in Ethiopia. The findings contribute to the limited knowledge in this area and can serve as a foundation for future research.
Biomineralization and Characterization of Calcite and Vaterite Induced by the Fungus Cladosporium sp. YPLJS-14
Authors: Ye Peilin , Xiao Feirong , Wei Shiping
Published: October 2023

Microbially induced calcium carbonate precipitation (MICP) by the urease-producing bacteria has wide applications in the field of geology and environmental engineering. Compared to bacteria, fungi usually possess more tolerance to high salts and heavy metals, enabling MICP induced by the urease-producing fungi to be applied to harsh environments. In this study, the carbonate minerals, induced by the urease-producing fungi isolated from marine sediments, were investigated. One of the urease-producing fungi, designated as YPLJS-14, was identified with the high efficiency of precipitating calcium carbonate. The ITS sequence of YPLJS-14 revealed that it belongs to the genus of Cladosporium. The precipitates induced by this strain were characterized by XRD, SEM, TEM, SAED, and FTIR, respectively. The results show that the mineral phase of fungal precipitates is composed of calcite and vaterite. SEM, TEM, and SAED confirm that the minerals in rhombohedral morphology are calcite and the spherical minerals are vaterite. Thermogravimetric and derivative thermogravimetric (TG/DTG) analyses show that vaterite is a thermodynamically unstable mineral phase compared to calcite and easily decomposes at lower temperatures. These findings provide a foundation for understanding the mineralization mechanism of the urease-producing fungi and the potential applications in environmental engineering.
Distinct Extraction Behaviors of La/Ce and Sc/Y in the Phosphoric Acidic Leachate of Bauxite Residues and Their Sequential Extraction with Di-(2-Ethylhexyl) Phosphoric Acid as Extractant
Authors: Li Bowen , Deng Bona , Yao Yuqi , Wang Chuanli , Ruan Yaoyang , Zhou Fang , Chi Ru’an , Zhang Hanquan
Published: October 2023

Bauxite residue is a hazardous solid waste produced in the alumina production process and has also become a significant rare earth resource. The extraction behaviors of La, Ce, Sc and Y solubilized in the phosphoric acidic leachate of bauxite residue were investigated in this study with di-(2-ethylhexyl) phosphoric acid as the extractant. With a relatively low concentration of 2% at an aqueous solution pH of 1.5, 90% Sc and 98% Y were extracted by di-(2-ethylhexyl) phosphoric acid. Less than 5% La and Ce and impurities of Fe, Al, Ti and Ca were extracted in this situation. As the concentration of di-(2-ethylhexyl) phosphoric acid increased to 20%, almost all the Sc and Y were extracted and the extraction ratios of La and Ce were 87% and 95%, respectively. A good separation of REEs against impurities was simultaneously obtained in the solvent extraction process and their separation coefficients were much higher than 1. A stepwise extraction process was proposed and established to extract Sc/Y and La/Ce sequentially from the phosphoric acidic leachate. It was further revealed that the Sc and Y in the acidic leachate were extracted by di-(2-ethylhexyl) phosphoric acid through an ion exchange process, and that the extraction of La and Ce was due to an antagonistic process where both an ion exchange reaction and a solvation reaction occurred.
Efficient Copper Recovery from Chalcopyrite Using an «Isopropanol–Sulfuric Acid–Sodium Dodecyl Sulfate» System
Authors: Kenzhaliyev Bagdaulet , Ketegenov Tlek , Kamunur Kaster , Batkal Aisulu , Nadirov Rashid
Published: October 2023

In this study, SDS is used to enhance the sulfuric acid leaching of chalcopyrite in aqueous and isopropanol media. The presence of SDS increased copper extraction into the solution in both solvents. However, it was the “isopropanol–sulfuric acid–SDS” system that proved to be particularly effective for copper recovery from chalcopyrite. The positive effect of SDS can be attributed to the reduction in the solution’s surface tension and the enhancement of mineral wetting. Additionally, the presence of SDS as a surfactant induces changes in the adsorption patterns of formed sulfur species on the mineral surface. SDS competes with sulfur for occupancy on the surface binding sites. This competitive interaction has the potential to diminish the formation of a substantial sulfur layer on the mineral surface. Under optimal conditions (isopropanol media, 2 M H2SO4, 65 °C, 120 min, 0.6 g/L SDS), copper recovery into the solution was 83%, and this is a considerable achievement for chalcopyrite leaching at ambient pressure in the absence of strong oxidizers.
Effect of Polybutylene Succinate Additive in Polylactic Acid Blend Fibers via a Melt-Blown Process
Authors: Tangnorawich Benchamaporn , Magmee Areerut , Roungpaisan Nanjaporn , Toommee Surachet , Parcharoen Yardnapar , Pechyen Chiravoot
Published: October 2023

This work aimed to study the influence of the polybutylene succinate (PBS) content on the physical, thermal, mechanical, and chemical properties of the obtained polylactic acid (PLA)/PBS composite fibers. PLA/PBS blend fibers were prepared by a simple melt-blown process capable of yielding nanofibers. Morphological analysis revealed that the fiber size was irregular and discontinuous in length. Including PBS affected the fiber size distribution, and the fibers had a smoother surface with increased amounts of added PBS. Differential scanning calorimetry analysis (DSC) revealed that the crystallization temperature of the PLA sheet (105.8 °C) was decreased with increasing PBS addition levels down to 91.7 °C at 10 wt.% PBS. This suggests that the addition of PBS may affect PLA crystallization, which is consistent with the X-ray diffraction analysis that revealed that the crystallinity of PLA (19.2%) was increased with increasing PBS addition up to 28.1% at 10 wt% PBS. Moreover, adding PBS increased the tensile properties while the % elongation at break was significantly decreased.
Chronic Illness, Nutritional Status, and Factors Associated with Malnutrition among Various Age Groups Residing in Urban Areas of Telangana and Rural Areas of Andhra Pradesh
Authors: Ramanujam Karthikeyan , Mergu Nagaraju , Kondeth Henna , Reddy Garlapati Venkat Raji , Venkata Prasad Upadrasta , Sadasivuni Renuka , Geddam Jagajeevan Babu , Rajkumar Hemalatha , Reddy Nusi Samarasimha
Published: October 2023

Malnutrition includes both under-nutrition and over-nutrition, which have negative health impacts and social consequences. The present study aims to understand the demographic dynamics, burden of chronic illnesses, and risk factors associated with malnutrition (stunting, thinness, and obesity) among different age groups in urban and rural areas. Data were collected through a cross-sectional study conducted in an urban area in Hyderabad and four rural villages in Andhra Pradesh. A multivariable mixed-effect logistic regression was used to assess the risk factors associated with malnutrition among different age groups. The final analysis included the data of 10,350 individuals, consisting of 8317 (80.4%) from urban areas and 2033 (19.6%) from rural areas. The number of known cases of hypertension in the urban area was 926 (11.1%) and 114 (5.6%) in the rural areas, and that of diabetes was 511 (6.1%) in the urban area and 104 (5.1%) in the rural areas. The burden of stunting among under-five children and obesity among adults was 33.7% (95% CI; 29.7–37.9) and 47.4% (95% CI; 45.8–49.1), respectively. Adults aged 40–59 years (AOR 1.91; 1.59–2.28) and belonging to a clerical/skilled (AOR 1.32; 1.03–1.71) occupation were at higher odds of obesity compared to their counterparts. Policymakers and health practitioners should consider the insights from our findings to tailor effective interventions to address malnutrition.
Snacking Behaviours of Australian Young Adults: Secondary Analysis of the MYMeals Cross-Sectional Study
Authors: Han Jae Youn (Lisa) , Morris Katrina , Wellard-Cole Lyndal , Davies Alyse , Rangan Anna , Allman-Farinelli Margaret
Published: October 2023

Snacking outside main meals may contribute to the high intakes of discretionary foods (i.e., unhealthful foods) among young adults. This study assessed the snacking behaviours of Australian young adults including the contribution of snacking to energy and nutrient intakes, the main foods consumed, and portion sizes. A secondary analysis of the MYMeals study of adults aged 18–30 years who consumed at least one snack food during the recording period (n = 889) was conducted. All food consumed over 3 consecutive days was recorded using a purpose-designed smartphone app. Snack foods contributed 13.2% of energy, 23.4% of total sugars, and 16.2% of saturated fat. Females consumed more energy (13.8% vs. 12.2%, p = 0.007) and total sugars (25.8% vs. 20.8%, p = 0.009), from snacking than males. Fruit (20.2%), chocolate (9.9%), cake-type desserts (8.4%), sweet biscuits (6.1%), and ice-cream-type desserts (5.6%) were the most frequently consumed snacks by young adults. The median portion sizes for the top five snack foods consumed were fruit—106 g (IQR: 73), chocolate—26 g (IQR: 36), cake—95 g (IQR: 88), sweet biscuits—26 g (IQR: 29), and ice cream—75 g (IQR: 42). The current findings may inform population-wide strategies to encourage healthful snacks such as fruit, inform portion control by individuals, and persuade the food industry to reduce the serving size of discretionary snack foods such as cake.
Nutrition Status of Female Winter Sports Athletes
Authors: Jiménez-Casquet María José , Conde-Pipó Javier , Valenzuela-Barranco Ignacio , Rienda-Contreras Raquel , Olea-Serrano Fátima , Bouzas Cristina , Tur Josep A. , Mariscal-Arcas Miguel
Published: October 2023

Eating disorders, especially restrictive eating, are common among female athletes. There are two main types of winter sports: those that are practiced outdoors on snow (−25 to +5 °C and 2500 m), such as alpine skiing and snowboarding, and those that are practiced indoors on ice (5–10 °C at low altitude), such as figure skating and ice hockey. The aim of this research was to identify the nutritional status and potential risk of female athletes practicing winter sports, considering the altitude of training. The sample was composed of 58 women (aged 19.81 years (SD: 12.61)) who were competitors in some winter sports. Anthropometrics and nutritional variables were taken. Statistically significant differences were found between HA and LA groups for all the characteristics except thigh skinfold, and neither group had an energy intake (EI) that matched their total energy expenditure (TEE). Both groups met at least two-thirds of the RDI for all minerals and vitamins except iodine, fluorine, vitamin D, vitamin E, and retinol. This study suggests that female winter sports athletes have insufficient energy, vitamin, and mineral intake, which can be worsened with altitude.
Rectus Femoris Cross-Sectional Area and Phase Angle asPredictors of 12-Month Mortality in Idiopathic Pulmonary Fibrosis Patients
Authors: Fernández-Jiménez Rocío , Cabrera Cesar Eva , Sánchez García Ana , Espíldora Hernández Francisco , Vegas-Aguilar Isabel M. , Amaya-Campos Maria del Mar , Cornejo-Pareja Isabel , Guirado-Peláez Patricia , Simón-Frapolli Victor , Murri Mora , Garrido-Sánchez Lourdes , Martínez Mesa Alvaro , Piñel-Jimenez Lorena , Benítez-Cano Gamonoso Miguel , Dalla-Rovere Lara , García Olivares Maria , Velasco-Garrido Jose Luis , Tinahones-Madueño Francisco , García-Almeida José Manuel
Published: October 2023

Background: The value of the phase angle (PhA), measured via bioelectrical impedance analysis (BIA), could be considered a good marker of the cell mass and the cell damage of a patient; however, there are new techniques, such as muscle ultrasonography, that allow the quantity and quality of muscle to be assessed in a minimally invasive way. The aim of this study is to determine the prognostic value of morphofunctional techniques in the prognosis of mortality in patients with idiopathic pulmonary fibrosis (IPF). Methods: This multicenter, cross-sectional study included 86 patients with idiopathic pulmonary fibrosis with a mean age of 71 years, 82.7% of whom were male. The nutritional risk of the patients was assessed by means of questionnaires, such as the Subjective Global Assessment (SGA), and non-invasive functional techniques, including BIA, nutritional ultrasound, and hand grip strength (HGS). Statistical analysis of the sample was performed using JAMOVI version 2.3.22. Results: Correlations were made between the RF-CSA techniques with PhA (r = 0.48, p < 0.001), BCM (r = 0.70, p < 0.001), SMI (r = 0.64, p < 0.001), and HGS (r = 0.54, p < 0.001). The cut-off points for 12-month mortality were PhA = 4.5° (AUC = 0.722, sensitivity of 72.7% and specificity of 66.6%), BCM = 28.8 kg (AUC = 0.609, sensitivity of 32.4% and specificity of 100.0%), RF-CSA = 3.00 cm2 (AUC = 0.857, sensitivity of 64.4% and specificity of 100.0%), 6MMW = 420 m (AUC = 0.830, sensitivity of 63.27% and specificity of 100.0%), and TUG = 7.2 s (AUC = 0.771, sensitivity of 100.0% and specificity of 56.67%). In addition, a multivariate analysis was performed with RF-CSA, HR = 8.11 (1.39–47.16, p = 0.020), and PhA of 6.35 (1.29–31.15, p = 0.023), taking into account age, sex, and BMI to determine mortality. Finally, a Kaplan–Meier survival analysis was conducted with low or normal values for classical parameters (GAP and T6MM) and new parameters (PhA, BCM, RF-CSA, and TUG). Conclusion: RF-CSA and PhA were shown to be good prognostic markers of 12-month mortality and could, therefore, be useful screening tools to complement the nutritional assessment of IPF patients.
A Continuous Centennial Late Glacial-Early Holocene (15–10 cal kyr BP) Palynological Record from the Iberian Pyrenees and Regional Comparisons
Authors: Rull Valentí , Blasco Arnau , Calero Miguel Ángel , Blaauw Maarten , Vegas-Vilarrúbia Teresa
Published: October 2023

This paper presents the first continuous (gap-free) Late Glacial-Early Holocene (LGEH) pollen record for the Iberian Pyrenees resolved at centennial resolution. The main aims are (i) to provide a standard chronostratigraphic correlation framework, (ii) to unravel the relationships between vegetation shifts, climatic changes and fire, and (iii) to obtain a regional picture of LGEH vegetation for the Pyrenees and the surrounding lowlands. Seven pollen assemblage zones were obtained and correlated with the stadial/interstadial phases of the Greenland ice cores that serve as a global reference. Several well-dated datums were also derived for keystone individual taxa that are useful for correlation purposes. Four vegetation types were identified, two of them corresponding to conifer and deciduous forests (Cf, Df) and two representing open vegetation types (O1, O2) with no modern analogs, dominated by Artemisia-Poaceae and Saxifraga-Cichorioideae, respectively. Forests dominated during interstadial phases (Bølling/Allerød and Early Holocene), whereas O1 dominated during stadials (Oldest Dryas and Younger Dryas), with O2 being important only in the first half of the Younger Dryas. The use of pollen-independent proxies for temperature and moisture allowed the reconstruction of paleoclimatic trends and the responses of the four vegetation types defined. The most relevant observation in this sense was the finding of wet climates during the Younger Dryas, which challenges the traditional view of arid conditions for this phase on the basis of former pollen records. Fire incidence was low until the Early Holocene, when regional fires were exacerbated, probably due to the combination of higher temperatures and forest biomass accumulation. These results are compared with the pollen records available for the whole Pyrenean range and the surrounding lowlands within the framework of elevational, climatic and biogeographical gradients. Some potential future developments are suggested on the basis of the obtained results, with an emphasis on the reconsideration of the LGEH spatiotemporal moisture patterns and the comparison of the Pyrenees with other European ranges from different climatic and biogeographical regions.
Mechanical Pressing of Coconut Oil and Evaluation of Its Lubricant Properties
Authors: Mizera Čestmír , Aleš Zdeněk , Herák David , Hrabě Petr , Kabutey Abraham , Napitupulu Richard A. M. , Ungureanu Nicoleta
Published: October 2023

Vegetable oils represent an important element in protecting a sustainable environment. The pursuit of environmentally friendly solutions and the ever-increasing costs of synthetic oil production are increasing the interest in natural vegetable oils. This paper presents and discusses the possibilities of using the oils obtained from coconuts (Cocos nucifera L.) harvested in Indonesia (North Sumatra region), with three maturity levels (green, yellow, and brown), as lubricants. The specific mechanical energy for linear pressing of the green, yellow, and brown types was 22.3, 20.7, and 18.5 J·goil−1, respectively. The water content of the oils obtained from the green, yellow, and brown types was 1786, 2033, and 1902 mg H2O·g−1, respectively. The mathematical models for linear pressing were established. The sizes of the wear area for the green, yellow, and brown types were 25.7, 24.4, and 34.3 mm2, respectively. The UV–visible spectral curves of the oils, in the range of 180–320 nm, were determined. The results of the lubrication properties of the Reichert test showed that better lubrication properties were exhibited by the green and yellow types, which are comparable to the lubricating properties of engine oils. The results from the SEM images also showed a better structure of the worn surface and fewer traces of abrasive wear.
Electrocatalytic Ni-Co Metal Organic Framework for Efficient Urea Oxidation Reaction
Authors: Yu Hua , Xu Wei , Chang Hongchao , Xu Guangyao , Li Lecong , Zang Jiarong , Huang Rong , Zhu Luxia , Yu Binbin
Published: October 2023

Energy shortage and environmental pollution have become the most serious problems faced by human beings in the 21st century. Looking for advanced clean energy technology to achieve sustainable development of the ecological environment has become a hot spot for researchers. Nitrogen-based substances represented by urea are environmental pollutants but ideal energy substances. The efficiency of urea-based energy conversion technology mainly depends on the choice of catalyst. The development of new catalysts for urea oxidation reaction (UOR) has important application value in the field of waste energy conversion and pollution remediation based on UOR. In this work, four metal–organic framework materials (MOFs) were synthesized using ultrasound (NiCo-UMOFs) and hydrothermal (NiCo-MOFs, Ni-MOFs and Co-MOFs) methods to testify the activity toward UOR. Materials prepared using the hydrothermal method mostly form large and unevenly stacked block structures, while material prepared using ultrasound forms a layer-by-layer two-dimensional and thinner structure. Electrochemical characterization shows NiCo-UMOFs has the best electrocatalytic performance with an onset potential of 0.32 V (vs. Ag/AgCl), a Tafel slope of 51 mV dec−1, and a current density of 13 mA cm−2 at 0.5 V in a 1 M KOH electrolyte with 0.7 M urea. A prolonged urea electrolysis test demonstrates that 45.4% of urea is removed after 24 h.
Satellite-Based Evaluation of Submarine Permafrost Erosion at Shallow Offshore Areas in the Laptev Sea
Authors: Osadchiev Alexander , Adamovskaya Polina , Myslenkov Stanislav , Dudarev Oleg , Semiletov Igor
Published: October 2023

Large areas of the seafloor in the Laptev Sea consist of submarine permafrost, which has experienced intense degradation over the last decades and centuries. Thermal abrasion of the submarine permafrost results in upward advection of suspended matter, which could reach the surface layer in shallow areas. This process is visually manifested through increased turbidity of the sea surface layer, which is regularly detected in optical satellite imagery of the study areas. In this study, satellite data, wind and wave reanalysis, as well as in situ measurements are analyzed in order to reveal the main mechanisms of seafloor erosion in shallow areas of the Laptev Sea. We describe the synoptic variability in erosion at the Vasilyevskaya and Semenovskaya shoals in response to wind and wave conditions. Finally, using reanalysis data, daily suspended matter flux from this area was evaluated during ice-free periods in 1979–2021, and its seasonal and inter-annual variabilities were described. The obtained results contribute to our understanding of subsea permafrost degradation, the sediment budget, and carbon and nutrient cycles in the Laptev Sea.
Phased Feature Extraction Network for Vehicle Search Tasks Based on Cross-Camera for Vehicle–Road Collaborative Perception
Authors: Wang Hai , Niu Yaqing , Chen Long , Li Yicheng , Luo Tong
Published: October 2023

The objective of vehicle search is to locate and identify vehicles in uncropped, real-world images, which is the combination of two tasks: vehicle detection and re-identification (Re-ID). As an emerging research topic, vehicle search plays a significant role in the perception of cooperative autonomous vehicles and road driving in the distant future and has become a trend in the future development of intelligent driving. However, there is no suitable dataset for this study. The Tsinghua University DAIR-V2X dataset is utilized to create the first cross-camera vehicle search dataset, DAIR-V2XSearch, which combines the cameras at both ends of the vehicle and the road in real-world scenes. The primary purpose of the current search network is to address the pedestrian issue. Due to varying task scenarios, it is necessary to re-establish the network in order to resolve the problem of vast differences in different perspectives caused by vehicle searches. A phased feature extraction network (PFE-Net) is proposed as a solution to the cross-camera vehicle search problem. Initially, the anchor-free YOLOX framework is selected as the backbone network, which not only improves the network’s performance but also eliminates the fuzzy situation in which multiple anchor boxes correspond to a single vehicle ID in the Re-ID branch. Second, for the vehicle Re-ID branch, a camera grouping module is proposed to effectively address issues such as sudden changes in perspective and disparities in shooting under different cameras. Finally, a cross-level feature fusion module is designed to enhance the model’s ability to extract subtle vehicle features and the Re-ID’s precision. Experiments demonstrate that our proposed PFE-Net achieves the highest precision in the DAIR-V2XSearch dataset.
Adaptive Output Containment Tracking Control for Heterogeneous Wide-Area Networks with Aperiodic Intermittent Communication and Uncertain Leaders
Authors: Shi Yanpeng , Hu Jiangping , Ghosh Bijoy Kumar
Published: October 2023

This paper proposes an adaptive distributed hybrid control approach to investigate the output containment tracking problem of heterogeneous wide-area networks with intermittent communication. First, a clustered network is modeled for a wide-area scenario. An aperiodic intermittent communication mechanism is exerted on the clusters such that clusters only communicate through leaders. Second, in order to remove the assumption that each follower must know the system matrix of the leaders and achieve output containment, a distributed adaptive hybrid control strategy is proposed for each agent under the internal model and adaptive estimation mechanism. Third, sufficient conditions based on average dwell-time are provided for the output containment achievement using a Lyapunov function method, from which the exponential stability of the closed-loop system is analyzed. Finally, simulation results are presented to demonstrate the effectiveness of the proposed adaptive distributed intermittent control strategy.
Loop Closure Detection Method Based on Similarity Differences between Image Blocks
Authors: Huang Yizhe , Huang Bin , Zhang Zhifu , Shi Yuanyuan , Yuan Yizhao , Sun Jinfeng
Published: October 2023

Variations with respect to perspective, lighting, weather, and interference from dynamic objects may all have an impact on the accuracy of the entire system during autonomous positioning and during the navigation of mobile visual simultaneous localization and mapping (SLAM) robots. As it is an essential element of visual SLAM systems, loop closure detection plays a vital role in eradicating front-end-induced accumulated errors and guaranteeing the map’s general consistency. Presently, deep-learning-based loop closure detection techniques place more emphasis on enhancing the robustness of image descriptors while neglecting similarity calculations or the connections within the internal regions of the image. In response to this issue, this article proposes a loop closure detection method based on similarity differences between image blocks. Firstly, image descriptors are extracted using a lightweight convolutional neural network (CNN) model with effective loop closure detection. Subsequently, the image pairs with the greatest degree of similarity are evenly divided into blocks, and the level of similarity among the blocks is used to recalculate the degree of the overall similarity of the image pairs. The block similarity calculation module can effectively reduce the similarity of incorrect loop closure image pairs, which makes it easier to identify the correct loopback. Finally, the approach proposed in this article is compared with loop closure detection methods based on four distinct CNN models with a recall rate of 100% accuracy; said approach performs significantly superiorly. The application of the block similarity calculation module proposed in this article to the aforementioned four CNN models can increase the recall rate’s accuracy to 100%; this proves that the proposed method can successfully improve the loop closure detection effect, and the similarity calculation module in the algorithm has a certain degree of universality.
FilterformerPose: Satellite Pose Estimation Using Filterformer
Authors: Ye Ruida , Wang Lifen , Ren Yuan , Wang Yujing , Chen Xiaocen , Liu Yufei
Published: October 2023

Satellite pose estimation plays a crucial role within the aerospace field, impacting satellite positioning, navigation, control, orbit design, on-orbit maintenance (OOM), and collision avoidance. However, the accuracy of vision-based pose estimation is severely constrained by the complex spatial environment, including variable solar illumination and the diffuse reflection of the Earth’s background. To overcome these problems, we introduce a novel satellite pose estimation network, FilterformerPose, which uses a convolutional neural network (CNN) backbone for feature learning and extracts feature maps at various CNN layers. Subsequently, these maps are fed into distinct translation and orientation regression networks, effectively decoupling object translation and orientation information. Within the pose regression network, we have devised a filter-based transformer encoder model, named filterformer, and constructed a hypernetwork-like design based on the filter self-attention mechanism to effectively remove noise and generate adaptive weight information. The related experiments were conducted using the Unreal Rendered Spacecraft On-Orbit (URSO) dataset, yielding superior results compared to alternative methods. We also achieved better results in the camera pose localization task, indicating that FilterformerPose can be adapted to other computer vision downstream tasks.
Lightweight 3D Dense Autoencoder Network for Hyperspectral Remote Sensing Image Classification
Authors: Bai Yang , Sun Xiyan , Ji Yuanfa , Fu Wentao , Duan Xiaoyu
Published: October 2023

The lack of labeled training samples restricts the improvement of Hyperspectral Remote Sensing Image (HRSI) classification accuracy based on deep learning methods. In order to improve the HRSI classification accuracy when there are few training samples, a Lightweight 3D Dense Autoencoder Network (L3DDAN) is proposed. Structurally, the L3DDAN is designed as a stacked autoencoder which consists of an encoder and a decoder. The encoder is a hybrid combination of 3D convolutional operations and 3D dense block for extracting deep features from raw data. The decoder composed of 3D deconvolution operations is designed to reconstruct data. The L3DDAN is trained by unsupervised learning without labeled samples and supervised learning with a small number of labeled samples, successively. The network composed of the fine-tuned encoder and trained classifier is used for classification tasks. The extensive comparative experiments on three benchmark HRSI datasets demonstrate that the proposed framework with fewer trainable parameters can maintain superior performance to the other eight state-of-the-art algorithms when there are only a few training samples. The proposed L3DDAN can be applied to HRSI classification tasks, such as vegetation classification. Future work mainly focuses on training time reduction and applications on more real-world datasets.
ECG Multi-Emotion Recognition Based on Heart Rate Variability Signal Features Mining
Authors: Wang Ling , Hao Jiayu , Zhou Tie Hua
Published: October 2023

Heart rate variability (HRV) serves as a significant physiological measure that mirrors the regulatory capacity of the cardiac autonomic nervous system. It not only indicates the extent of the autonomic nervous system’s influence on heart function but also unveils the connection between emotions and psychological disorders. Currently, in the field of emotion recognition using HRV, most methods focus on feature extraction through the comprehensive analysis of signal characteristics; however, these methods lack in-depth analysis of the local features in the HRV signal and cannot fully utilize the information of the HRV signal. Therefore, we propose the HRV Emotion Recognition (HER) method, utilizing the amplitude level quantization (ALQ) technique for feature extraction. First, we employ the emotion quantification analysis (EQA) technique to impartially assess the semantic resemblance of emotions within the domain of emotional arousal. Then, we use the ALQ method to extract rich local information features by analyzing the local information in each frequency range of the HRV signal. Finally, the extracted features are classified using a logistic regression (LR) classification algorithm, which can achieve efficient and accurate emotion recognition. According to the experiment findings, the approach surpasses existing techniques in emotion recognition accuracy, achieving an average accuracy rate of 84.3%. Therefore, the HER method proposed in this paper can effectively utilize the local features in HRV signals to achieve efficient and accurate emotion recognition. This will provide strong support for emotion research in psychology, medicine, and other fields.
Important Perspectives and Concepts to Teach in Ethics Education
Authors: Lilja Annika
Published: October 2023

In the field of ethics, which is a part of the subject religious education (RE) in Sweden, there is still insufficient research related to powerful knowledge. The aim of this article is to contribute knowledge to the field by examining what teachers see as important perspectives and concepts in ethics education. To fulfil this aim, eight teachers in Swedish compulsory schools have been interviewed about central perspectives and concepts related to their teaching in ethics. The results show that the interviewed teachers emphasize three perspectives which concern: (1) society locally and globally, (2) different ethical dilemmas and (3) the students’ experiences in school and at home. The teachers also believe that certain concepts are needed for students to understand what a democratic society means, to succeed in subsequent stages of education and to understand their own lives. The teachers’ descriptions of what they view as important perspectives and concepts relate to knowledge that has power and potential for social justice. They want to prepare and engage their students in relation to questions that they may face both now and in their futures.
Anaerobic Membrane Bioreactors for Municipal Wastewater Treatment, Sewage Sludge Digestion and Biogas Upgrading: A Review
Authors: Li Yemei , Ren Yuanyuan , Ji Jiayuan , Li Yu-You , Kobayashi Takuro
Published: October 2023

Anaerobic membrane bioreactors (AnMBRs) are formed through the combination of anaerobic digestion and membrane technology. The upgraded technology separates SRT from HRT in the anaerobic digester, shortening the treatment period, reducing the digester’s volume and improving effluent quality. Furthermore, AnMBRs have a strong tolerance for the existing forms of objects and can handle liquids, high-solid materials and gases. Up to now, AnMBRs have been utilized in the treatment of various types of industrial and municipal wastewater, organic solid waste and also biogas upgrading, and they have achieved excellent performance. However, there are few studies which have discussed their multiple utilization, especially following the flow of wastewater treatment. This study summarizes the application of AnMBRs in their diverse roles in the municipal wastewater treatment process. The discussion revolves around energy generation and the fouling issue of AnMBRs in the treatment of municipal wastewater, the digestion of sewage sludge generated in conventional municipal wastewater treatment and the upgrading of biogas after anaerobic digestion. In addition to controlling operating parameters, strategies used to improve the treatment effectiveness are also introduced. Lastly, online methods for preventing membrane fouling, which is the main operational obstacle to AnMBRs’ wider spread, are also discussed. This review aims to provide a fresh perspective on how AnMBRs are utilized in waste treatment.
Systems Thinking Skills and the ICT Self-Concept in Preschool Teachers for Sustainable Curriculum Transformation
Authors: Kurent Brina , Avsec Stanislav
Published: October 2023

The importance of early learning is even greater today if we are to prepare children for the 21st century by developing several lifelong competencies. With the advent of digitalization, some educators already integrate information communication technology (ICT) into early childhood, whereas others also have concerns about early implementation. However, the introduction of digital competencies from the perspective of systems thinking among preservice and in-service preschool teachers has not yet been demonstrated. The purpose of this study is to identify preschool teachers’ systems thinking skills and their ICT self-concept and to develop a pathway model for developing an ICT self-concept for sustainable and digital preschool education using systems thinking. An empirical research design with advanced statistical analysis and structural equation modeling was used. The sample consists of 172 preschool teachers. The results showed small differences between the preservice and in-service preschool teachers in the areas of “sequence of events” and “communication” in favor of preservice preschool teachers. Regardless of the group of preschool teachers, systems thinking develops self-concept in relation to ICT equally. The pathway diagram shows that “understanding the relationships between patterns” is the strongest predictor of the ICT self-concept, that only perceiving and understanding the inter-relationships of factors influence problem solving, and that understanding variations of different types (random/specific) and causal sequences alone has predictive power for “process and store” in the context of the ICT self-concept. The developed model will help educators, researchers, and curriculum designers to improve preschool education practices and transform the curriculum in a sustainable way.