bluuebunny/crossref_metadata_2025 huggingface dataset:
Recovery and Utilization of Lead in Lead–Containing Waste Residue from Electrolytic Manganese Production
Authors: Song Xiaosan , Fan Jishuo , Zhou Jie
Published: September 2023

As a metallurgical and chemical raw material, electrolytic manganese is an important strategic resource. However, with the rapid development of the electrolytic manganese industry, the correct disposal of anode slime has become a serious problem. The purpose of this experiment was to reduce the occupation of land resources by the lead–containing waste residue of electrolytic manganese, reduce the pollution caused by the lead–containing waste residue to the environment and provide a reference for the research on the treatment technology and resource utilization of lead–containing waste residue in China. In this experiment, a special process was studied for the composition characteristics of lead–containing waste residues produced by electrolytic manganese. The acid leaching–enrichment–membrane electrolysis process was used to recover the lead in the lead–containing waste residues of electrolytic manganese and to recover the acid, so as to maximize the utilization of resources. In this experiment, the pretreated lead–containing waste residue was leached, enriched and concentrated, and then the enriched Pb2+ solution was used as cathode solution and dilute nitric acid as anode solution to recover lead by membrane electrolysis. The membrane electrolysis experiment uses lead plate as cathode, selects the best anion exchange membrane and anodic electrolysis material, and then takes lead recovery, acid recovery, current efficiency, voltage and power consumption as investigation indexes to explore and analyze the influence of many factors such as Pb2+ concentration and current density on the experiment, so as to determine the best membrane electrolysis process parameters. The optimum process parameters of lead recovery by membrane electrolysis were determined as follows: Pb2+ concentration was 40 g/L, current density was 30 mA/cm2, reaction temperature was 60 °C, cathodic pH value was 4.0, anodic HNO3 concentration was 0.5 mol/L, and cathodic ammonium nitrate concentration was 50 g/L. Under the optimal conditions, the current efficiency was 85.6%, the acid recovery was 73.03%, the lead recovery was 99.2%, the voltage was 3.8 V, and the power consumption was 1148.4 kW·h·t−1. Through the three steps of acid leaching–enrichment–membrane electrolysis, 78.53% of the Pb2+ in the original lead–containing waste residue can be recovered in the form of metal lead element, and the HNO3 recovered in the anode chamber can also be used again in the acid leaching process, which can not only solve the problem of environmental pollution caused by lead–containing waste residue but also achieve the recovery and utilization of resources, with good social and economic benefits.
Investigating the Static Recrystallization Behavior of 22MnB5 Manganese–Boron Steel through Stress Relaxation Analysis
Authors: Birnbaum Peter , Pilz Stefan , Neufeld Kai , Kunke Andreas
Published: September 2023

A constitutive model was developed to characterize the static recrystallization (SRX) and evolution of the grain size of the industrially relevant press-hardening steel, 22MnB5, subsequent to the hot forming of sheet metal. Isothermal stress relaxation tests were conducted using the BAEHR 805 A/D thermomechanical simulator, encompassing a temperature range of 950 to 1050 °C, prestrain levels ranging from 0.01 to 0.1, and strain rates spanning from 0.01 to 0.8 s−1. The results obtained from the isothermal stress relaxation tests facilitated the formulation of an Avrami equation-based model, which aptly describes the kinetics of SRX in relation to the temperature, prestrain, and strain rate. Notably, an increase in temperature led to accelerated recrystallization kinetics, signifying temperature-dependent behavior. When the temperature increased from 950 to 1050 °C, the recrystallization time was reduced to approximately one-third. Additionally, the prestrain exhibited a positive influence on the acceleration of SRX kinetics. A quintupling of the prestrain from 0.01 to 0.05 resulted in a reduction of the static recrystallization duration to approximately one-fifth. Among the parameters studied, the strain rate had the least impact on the SRX kinetics, as doubling the strain rate from 0.01 to 0.8 only resulted in a halving of the recrystallization duration. Moreover, an analysis of the microstructural evolution in response to the forming parameters was undertaken. While the grain-size investigation post-isothermal stress relaxation tests provided results in line with the SRX kinetics calculations, the observed effects were comparatively subdued. Furthermore, a comprehensive examination was conducted using electron backscatter diffraction (EBSD) analysis, aiming to explore the effects of specific stress relaxation states on the morphology of martensite. The findings reveal fully recrystallized globulitic microstructures, characterized by relatively minor differences among them.
Logging Identification and Distribution of Bauxite in the Southwest Ordos Basin
Authors: Zhang Peng , Jing Xianghui , Pu Renhai , Wang Aiguo , Huang Xueping
Published: September 2023

In recent years, with the discovery of oil and gas in the Carboniferous bauxite reservoir in the Ordos basin, the formation and distribution of bauxite and bauxite reservoirs have attracted the attention of oil and gas explorers. Based on the slightly equidistant core testing of minerals and the porosity on the formation and calibration on the logging curves, we established a logging identification method for bauxite in the study area and fitted the formula for calculating the diaspore content and porosity using logging data. By applying this formula and a large amount of logging data, thickness and porosity maps of the Taiyuan formation of bauxite in the southeastern part of the basin were produced. Then, according to the thickness of the earliest deposited Taiyuan formation on the unconformity surface, we analyzed the paleogeomorphology of the bauxite deposition. Finally, a sedimentary facies map of the Taiyuan formation was developed based on the content of sandstone, coal seams, and carbonate rocks contained there. The results show that the diaspore content of bauxite is positively correlated with the natural gamma logging (GR) values. According to the diaspore contents and the GR values, the aluminiferous rocks in the Taiyuan formation can be divided into three categories: ① Bauxite for GR values > 450 API and diaspore content >70%; ② Argillaceous bauxite for GR values = 300–450 API and diaspore content = 25%–70%; and ③ Bauxitic mudstone for GR values = 220–300 API and diaspore content = 0%–25%. Bauxite mainly occurred in the middle and deep lagoon environments in the lower part of the Taiyuan formation. The lagoon is distributed along the paleokarst groove in the NW strike, with a width of approximately 30–40 km and a length of approximately 150–200 km, among which the thickness of pure bauxite is 9 m, argillaceous bauxite 26 m and alumina mudstone 6 m. Bauxite with a high porosity mainly existed in pure bauxite. The lagoon bauxite in the lower part of the Taiyuan formation gradually changes upward into a tidal flat swamp and carbonate platform environment.
The Influence of TiO2 Nanoparticles Morphologies on the Performance of Lithium-Ion Batteries
Authors: Luo Wenpo , Blanchard Juliette , Xue Yanpeng , Taleb Abdelhafed
Published: September 2023

Anode materials based on the TiO2 nanoparticles of different morphologies were prepared using the hydrothermal method and characterized by various techniques, such as X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and N2 absorption. The TiO2 nanoparticles prepared were used as anode materials for lithium-ion batteries (LIBs), and their electrochemical properties were tested using discharging/charging measurements. The results showed that the initial morphology of the nanoparticles plays a minor role in battery performance after the first few cycles and that better capacity was achieved for TiO2 nanobelt morphology. The sharp drop in the specific capacity of LIB during their first cycles is examined by considering changes in the morphology of TiO2 particles and their porosity properties in terms of size and connectivity. The performance of TiO2 anode materials has also been assessed by considering their phase.
24-Hour Dietary Recall in the Expanded Food and Nutrition Education Program: Perspective of the Program Coordinator
Authors: Roe Annie J. , Sankavaram Kavitha , Baker Susan , Franck Karen , Puglisi Michael , Earnesty Dawn , Henson Teresa
Published: September 2023

The purpose of this study was to determine how the 24-hour dietary recall (24HDR) is administered and how the Expanded Food and Nutrition Education Program (EFNEP) peer educators and other staff are trained on the data collection and entry process, from the EFNEP coordinators’ perspectives. This cross-sectional, quantitative study utilized an online survey to collect information from EFNEP coordinators representing 61 of 76 EFNEP programs. While 56% of the programs collected the 24HDR data starting with the first thing eaten the previous day, 49% of them started collecting data at the time of class, going backwards. Most programs, i.e., 72%, reported using a multiple-pass method; however, only one-third of them reported using the standard five-pass method. Almost all programs, i.e., 97%, reported one peer educator collecting data from a group of 2–12 clients. All programs reported collecting the 24HDR data in a group setting, with about one-third of the programs also collecting data one-on-one. Most programs, i.e., 57%, reported spending ≤4 h on the initial training of staff in how to collect 24HDR data, and 54% of them reported that the peer educators entered the data themselves. This study found that the methods used to collect answers, train the staff, and enter the 24HDR data varied across EFNEP programs and that there is a need to standardize or revise the collection of 24HDR data.
Dolichos Lablab Linné Inhibits Bone Density Loss and Promotes Bone Union in Senile Osteoporosis through Osteogenesis
Authors: Kim Minsun , Kim Jae-Hyun , Hong Sooyeon , Lee Sumin , Lee Seung Hoon , Choi Jun Won , Jung Hyuk-Sang , Sohn Youngjoo
Published: September 2023

As populations continue to age, osteoporosis has emerged as an increasingly critical concern. Most advancements in osteoporosis treatment are predominantly directed toward addressing abnormal osteoclast activity associated with menopause, with limited progress in developing therapies that enhance osteoblast activity, particularly in the context of aging and fractures, and serious side effects associated with existing treatments have highlighted the necessity for natural-product-based treatments targeting senile osteoporosis and fractures. Dolichos lablab Linné (DL) is a natural product traditionally used for gastrointestinal disorders, and its potential role in addressing bone diseases has not been extensively studied. In this research, we investigated the anti-osteoporosis and bone-union-stimulating effects of DL using the SAMP6 model, a naturally aged mouse model. Additionally, we employed MC3T3-E1 cells to validate DL’s osteoblast-promoting effect and to assess the involvement of core mechanisms such as the BMP-2/Smad and Wnt/β-catenin pathways. The experimental results revealed that DL promoted the formation of osteoblasts and calcified nodules by upregulating both the BMP-2/Smad and Wnt/β-catenin mechanisms. Based on its observed effects, DL demonstrated the potential to enhance bone mineral density in aged osteoporotic mice and promote bone union in fractured mice. These findings indicate the promising therapeutic potential of DL for the treatment of osteoporosis and bone-related conditions, thus warranting further investigation and potential clinical applications.
Drilling of Cross-Ply UHMWPE Laminates: A Study on the Effects of the Tool Geometry and Cutting Parameters on the Integrity of Components
Authors: Díaz-Álvarez Antonio , Rodríguez-Millán Marcos , Rubio Ignacio , Kim Daekyum , Díaz-Álvarez José
Published: September 2023

Ultrahigh-molecular-weight polyethylene (UHMWPE) is used in the defence industry mainly owing to its properties, such as excellent dimensional stability, excellent ballistic performance, and light weight. Although UHMWPE laminates are generally studied under impact loads, it is crucial to understand better the optimal machining conditions for assembling auxiliary structures in combat helmets or armour. This work analyses the machinability of UHMWPE laminates by drilling. The workpiece material has been manufactured through hot-pressing technology and subjected to drilling tests. High-speed steel (HSS) twist drills with two different point angles and a brad and spur drill that is 6 mm in diameter have been used for this study. Cutting forces, failure, and main damage modes are analysed, making it possible to extract relevant information for the industry. The main conclusion is that the drill with a smaller point angle has a better cutting force performance and less delamination at the exit zone (5.4 mm at a 60 m/min cutting speed and a 0.05 mm/rev feed) in the samples. This value represents a 46% improvement over the best result obtained in terms of delamination at the exit when using the tool with the larger point angle. However, the brad and spur drill revealed a post-drilling appearance with high fuzzing and delamination.
Vitamin Compatibility with the Marek’s Disease Vaccine
Authors: Fatemi Seyed Abolghasem , Williams Christopher J. , Deines Joshua , Peebles Edgar David
Published: September 2023

In ovo injection of the Marek’s disease (MD) vaccine (MDV) has been widely practiced in commercial US hatcheries. However, the MDV is very sensitive and may not be compatible with some nutrients when administered together by in ovo injection. When individually administered by in ovo injection, L-Ascorbic acid (L-AA) and 25-hydroxyvitamin D3 (25OHD3) have previously exhibited very promising results on the post-hatch physiological and immunological characteristics of broilers subjected to stressful commercial conditions. However, the compatibility of the MDV with these vitamins has not been previously explored. Their compatibility must first be established before their combined administration by in ovo injection can be considered. Therefore, the objective in this study was to determine the compatibility of the MDV with various levels of 25OHD3 or L-AA. The treatments employed were MDV-alone, MDV in combination with 0.6 (low) or 2.4 (high) μg doses of 25OHD3, or MDV in combination with 1.2 (low) or 12 (high) mg doses of L-AA. The live and dead ratio of primary chick embryo fibroblast cells infected by the MD virus (CEF-MDV) in each treatment was determined every 30 min for 2 h. The L-AA at both the low and high doses resulted in a 70% death of CEF-MDV within 1 h, but either dose of the 25OHD3 exhibited only an approximate 5% lower CEF-MDV survival as compared to those in the MDV-alone treatment. Therefore, it is suggested that the two designated doses of 25OHD3 have the potential to be effectively combined with the MDV for subsequent administration by in ovo injection.
Establishment of Technical Standard Database for Surface Engineering Construction of Oil and Gas Field
Authors: Xia Taiwu , Dai Zhixiang , Huang Zhan , Liu Li , Luo Ming , Wang Feng , Zhang Wei , Zhou Dan , Zhou Jun
Published: September 2023

In recent years, oil and gas field surface engineering construction projects tend to be large in scale, large in quantity, and short in cycle. The task of surface construction management has increased significantly. In the process of project construction, corresponding standards and specifications are required to provide sufficient technical guidance and support for design, construction, and management personnel to ensure project management and control towards compliance, safety, and quality. However, the oil and gas field engineering standards are numerous and specialized, involving different levels of national standards, enterprise standards, and industry standards, which leads to the inefficiency of the actual use of standards and specifications. To solve them, this paper uses knowledge graph technology, OCR recognition, and natural language processing technology to conduct systematic research on the knowledge classification mechanism, data extraction, database construction mechanism, data structuring, and intelligent retrieval matching of oil-gas field surface engineering construction standards. In this study, the structured identification, storage, and information warehousing of standards are realized, and a highly sharable library of standards and specifications is formed, which realizes the intelligent retrieval and pushing of technical standards for surface engineering construction. This paper creates conditions for the realization of intelligent push and benchmarking management of standards and specifications, providing support for digital transformation and intelligent development of oil–gas fields.
Exploring International Perspective on Factors Affecting Urban Socio-Ecological Sustainability by Green Space Planning
Authors: Teimouri Raziyeh , Karuppannan Sadasivam , Sivam Alpana , Gu Ning , Yenneti Komali
Published: September 2023

Urban green space (UGS) is one of the most important components of urban systems to create sustainable cities. This crucial urban element performs many social and ecological functions to facilitate a better quality of life for urban residents. The main aim of this study is to identify the most critical factors contributing to cities’ social and ecological sustainability through UGS planning and development. To achieve this aim, an integrated socio-ecological approach was followed to collect and analyse the data, which comprised context analysis and an international experts survey. Therefore, firstly, the main influencing factors for urban social and ecological sustainability that can be achieved by UGS planning were extracted by reviewing the related literature. In the next step, to find the most critical factors, an online international survey of academicians and experts drawn from a number of countries was conducted. Based on the experts’ opinions, twenty-two factors out of sixty-five, including twelve social factors and ten ecological factors, achieved the highest scores. According to the results, the key factors of accessibility from the social sustainability category and protection from the ecological sustainability category play the most important roles in maximising the social and ecological benefits of UGS.
Flood Risk Management via Risk Communication, Cognitive Appraisal, Collective Efficacy, and Community Action
Authors: Lin Carolyn A.
Published: September 2023

Climate change and more frequent severe storms have caused persistent flooding, storm surges, and erosion in the northeastern coastal region of the United States. These weather-related disasters have continued to generate negative environmental consequences across many communities. This study examined how coastal residents’ exposure to flood risk information and information seeking behavior were related to their threat appraisal, threat-coping efficacy, and participation in community action in the context of building social resilience. A random sample of residents of a coastal community in the Northeastern United States was selected to participate in an online survey (N = 302). Key study results suggested that while offline news exposure was weakly related to flood vulnerability perception, online news exposure and mobile app use were both weakly associated with flood-risk information seeking. As flood vulnerability perception was strongly connected to flood severity perception but weakly linked to lower self-efficacy beliefs, flood severity perception was weakly and moderately associated with response-efficacy beliefs and information seeking, respectively. Furthermore, self-efficacy beliefs, response efficacy beliefs, and flood-risk information seeking were each a weak or moderate predictor of collective efficacy beliefs. Lastly, flood risk information-seeking was a strong predictor and collective efficacy beliefs were a weak predictor of community action for flood-risk management. This study tested a conceptual model that integrated the constructs from risk communication, information seeking, and protection motivation theory. Based on the modeling results reflecting a set of first-time findings, theoretical and practical implications are discussed.
Olive Ridley Sea Turtle Incubation in Natural Conditions Is Possible on Guatemalan Beaches
Authors: Morales-Mérida B. Alejandra , Morales-Cabrera Alejandra , Chúa Carlos , Girondot Marc
Published: September 2023

The Guatemalan strategy for sea turtle conservation was defined by the National Council of Protected Areas (CONAP) in 1989. Hatcheries lie at the core of this strategy: egg collectors are allowed to deliver 20% of a nest to a hatchery in exchange for selling or eating the remaining eggs. Consequently, nearly 100% of nests are collected, with no nests being left on the beaches. Hatchery design promotes shading using roofs made from vegetation. The logic behind this recommendation is that the natural incubation of eggs is supposedly impossible due to the overly high temperatures on the beach. However, changing the incubation temperature of sea turtle eggs can profoundly alter the sex ratio in sea turtles with temperature-dependent sex determination. It can also modify the physiology or behavior of juvenile turtles. Here, we test whether incubation in natural conditions is possible on Guatemalan beaches, and for the first time, we determine the thermal reaction norm of embryo growth to ensure hatching success in sea turtles. We show that incubation in natural conditions is possible since three out of the four monitored nests produced hatchlings. We urge the Guatemala National Council of Protected Areas to reevaluate its strategy for sea turtle conservation in Guatemala in light of these results.
Optimum Conditions for Enhancing Chitosan-Assisted Coagulation in Drinking Water Treatment
Authors: Takaara Tomoko , Kurumada Kenichi
Published: September 2023

Coagulant aids are useful chemicals that enhance the efficiency of coagulation sedimentation treatment. For this purpose, it is necessary to choose safe chemicals to avoid various risks to the health of those who use the treated water. The use of chitosan, an abundant natural polysaccharide, as a coagulant aid is significant not only for safe water treatment but also for the effective utilization of unused natural water resources, which are mostly wasted. We experimentally determined the optimal treatment conditions for using chitosan as a coagulant aid in water treatment. The most efficient use was identified as adding chitosan at the stage of rapid stirring after the addition of coagulant accelerated initial dispersion. When used with the main coagulant polyaluminum chloride (PACl), the optimal concentration of chitosan was 0.8 mg L−1, as estimated using the ζ potential showing isoelectricity at the optimal chitosan concentration. Determining the chitosan concentration using the minimum ζ potential was also valid for estimating the optimum concentration of chitosan, which is an extension of the method used at much higher turbidity, as seen in wastewater. Thus, the ζ potential-based prediction of the optimum chitosan concentration was effective even when the effect of sweep coagulation, which is normally induced at higher turbidity, was negligible. The superiority of using the coagulant PACl in combination with chitosan as the coagulant aid was demonstrated by comparing the in situ-observed coagulation process to cases with other coagulants and coagulant aids using direct time-series observation of the coagulation process. The use of chitosan with PACl was found to make the flocs easier to remove because it resulted in the largest mass fraction of the resultant floc sedimentation on the bottom of the vessel. In this study, using the PACl coagulant in combination with chitosan as the coagulant aid was found to be as viable as using the current popular combination of aluminum sulfate and polyacrylamide. Replacing polyacrylamide with chitosan contributed to reducing the potential risk to the health of those to use the treated water.
Assessment and Characterization of Duck Feathers as Potential Source of Biopolymers from an Upcycling Perspective
Authors: Alvarez Sandra , Raydan Nidal Del Valle , Svahn Isabelle , Gontier Etienne , Rischka Klaus , Charrier Bertrand , Robles Eduardo
Published: September 2023

A comprehensive characterization of the physical and chemical properties of whole duck feathers from French mulard species, including their various categories and fractions (barbs, rachis, and calamus), was conducted to explore potential ways for utilizing this waste product. This analysis aimed to identify opportunities for valorizing these feathers and unlocking their untapped potential. Hence, the duck feathers were thoroughly characterized by a proximate analysis to determine their composition and theoretical heating value. Additionally, feathers underwent other analyses as Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE) analysis, solvent behavior and chemical durability assessment, hydrophobicity testing, Fourier Transform Infrared (FT-IR) spectroscopy, Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM). The analyses revealed duck feather composition, molecular weight, stability in different environments, hydrophobicity, functional groups present, thermal behavior, crystallinity, and structural arrangement. Upon analysis, it was determined that duck feathers contain pure fiber keratin and possess characteristics that make them suitable for the production of high-value keratin-based products, including cosmetics, activated carbon for purification, materials for waterproofing, lightweight construction, and textile innovations, underscoring their potential to support sustainable and eco-friendly initiatives across various sectors.
Water Conflicts in Chile: Have We Learned Anything from Colonial Times?
Authors: Blanco Elisa , Donoso Guillermo , Camus Pablo
Published: September 2023

The number of disputes related to water that reach courts in Chile has increased in the last decades, the topics of these disputes have become more complex, and the current conflict resolution system has not been able to adjust to this situation. This study analyzes colonial texts from water-related conflicts that were addressed at the Royal Hearings in Santiago (1691–1800) and from the Cabildo gatherings (1541–1802), using an adaptation of the Institutional Analysis and Development framework. The research shows a strong institutional system surrounding conflict resolution during colonial times, with nested schemes and empowered figures appointed in leading roles. However, a lack of equity and inclusion of all actors is also visible, reducing its legitimacy. At present, the increasing value of water and a sense of distrust in the institutional system have led to longer and more complex conflict resolution processes. Here, learning from past times about the empowerment of the institutional system for solving water disputes could be useful. An increased support towards initial conflict resolution mechanisms, giving space for local knowledge and generating stronger participation in these initial steps, is a lesson for the future.
Applying Data Analytics to Analyze Activity Sequences for an Assessment of Fragmentation in Daily Travel Patterns: A Case Study of the Metropolitan Region of Barcelona
Authors: Montero Lídia , Mejía-Dorantes Lucía , Barceló Jaume
Published: September 2023

Sequence analysis is a robust methodological approach that has gained popularity in various fields, including transportation research. It provides a comprehensive way to understand the dynamics and patterns of individual behaviors over time. In the context of the Metropolitan Region of Barcelona, applying sequence analysis to mobility surveys offers valuable insights into the sequencing of travel activities and modes, shedding light on the complex interrelationship between individuals and their travel choices and the built environment. Sequence analysis allows us to examine travel behaviors as dynamic processes and reveal the underlying structure and evolution of travel patterns over a day. Here, we describe a data analytics approach that enables the identification of common travel patterns and the exploration of variations across demographic groups or geographical regions. We propose a method for discovering similarities in travel behavior segments from diaries included in travel surveys in order to refine transport policies for selected segments. Unfortunately, the data collected by the authorities in the analyzed travel surveys do not include family structure, which seems critical in explaining the segmentation of travel sequences.
Digital Rural Construction and Rural Household Entrepreneurship: Evidence from China
Authors: Zhou Yunwen , Cai Zhijian , Wang Jie
Published: September 2023

Promoting rural entrepreneurship is an important approach to achieving rural revitalization, accelerating the construction of a new development pattern, and enhancing the well-being of farmers. Based on the County Digital Rural Index (CDRI) and the China Household Finance Survey (CHFS), we empirically examine the impact and role of digital rural construction (DRC) on rural household entrepreneurship. Our findings are as follows: (1) DRC plays a vital role in facilitating entrepreneurial behaviors (EB) and entrepreneurial performance (EP) among rural households. (2) DRC indirectly fosters rural household entrepreneurship by facilitating resource acquisition and opportunity identification. (3) Our heterogeneity analysis reveals that DRC’s promotion effect is stronger among local entrepreneurs and individuals with risk-averse tendencies. Additionally, DRC has a more pronounced effect in stimulating EB within lower-income families, while its impact on EP shows the opposite trend. Furthermore, DRC’s influence on rural household entrepreneurship is particularly significant in regions with more advanced digital rural development. (4) Additionally, we observe a significant positive impact of the four dimensions of DRC on rural household entrepreneurship, further affirming the role of DRC in driving rural household entrepreneurship. In the digital economy era, this study provides empirical evidence to promote the integration of digital technology and rural entrepreneurship, offering valuable insights for advancement in this domain.
Decoding Urban Archetypes: Exploring Mobility-Related Homogeneity among Cities
Authors: von Behren Sascha , Turek Maximilian , Barthelmes Lukas , Scholta Hanna , Hansen Frank , Kagerbauer Martin , Eisenmann Christine
Published: September 2023

To make cities more sustainable and livable and to achieve climate targets in transportation, cities around the globe must undergo sustainable transformations. However, disparities in initial conditions pose challenges when trying to implement these sustainable changes. Identifying these differences aids in the comprehension of future developments. In this study, we establish an international comparison by decoding the mobility-related characteristics of cities and determining urban archetypes. Using publicly accessible data, we analyze and classify 96 cities in different countries. Therefore, we utilize principal component analysis to simplify the data. The emerging components serve as input for segmentation. This approach yields nine unique urban archetypes, ranging from Well-Functioning and Ancient Hybrid Cities in Europe to Paratransit and Traffic-Saturated Cities in the southern hemisphere. Our results show that there is a significant advantage to using a multidimensional segmentation basis, which we identify in an extensive literature review. The result is a finer segmentation, which is especially clear for European cities that demonstrate four different clusters. We discuss that the effect of future restrictions on private car usage will vary widely between the urban archetypes.
Research on the Ecological Innovation Efficiency of the Zhongyuan Urban Agglomeration: Measurement, Evaluation and Optimization
Authors: Yang Yang , Li Simo , Su Zhaoxian , Fu Hao , Wang Wenbin , Wang Yun
Published: September 2023

The objective of carbon peaking and carbon neutralization put forward higher requirements for the intensive use of energy and resources, and green and efficient development has become an essential part of high-quality development. Ecological innovation focuses on resource preservation and application and the improvement of the ecological environment while driving economic development through innovation; therefore, ecological innovation has become a solution to balance resource conservation, environmental protection, and efficient development effectively and has received widespread attention. This research takes 30 cities of the Zhongyuan Urban Agglomeration as research subjects and constructs an urban agglomeration’s evaluation index system to measure ecological innovation efficiency. By utilizing the entropy-weight TOPSIS model and super-efficiency SBM-DEA model, the ecological innovation performance of the Zhongyuan Urban Agglomeration is measured and evaluated from 2006 to 2020; then, redundancy analysis is applied to analyze the correlation between ecological innovation inputs and outputs. The final results illustrate that: (1) The overall ecological innovation performance level of the Zhongyuan urban agglomeration is relatively low, and the ecological innovation ability of some cities is inadequate; (2) From the temporal perspective, the temporal evolution of the Zhongyuan urban agglomeration showed a less obvious U-shaped trend, and the innovation output benefits of the core development region are considerably superior to those of the co-development region, and the ecological innovation transformation efficiency of the Zhongyuan urban agglomeration shows a fluctuating trend; (3) From the spatial perspective, there are eight cities at the “high output and high efficiency” level but 19 cities at the “low output and low efficiency” level, and the ecological innovation performance of most cities in the north is obviously better than that in the south from the perspective of spatial distribution. Therefore, to further improve the ecological innovation ability and performance of the Zhongyuan urban agglomeration, relevant policies should be fully practiced and implemented, such as building Nanyang as a sub-central city, constructing an efficient ecological economy demonstration area in the south of Henan province, effectively integrating Zhengzhou and Kaifeng, and the innovative radiation of Zhengzhou as a national central city to other cities.
Interaction of the Cosmic Dark Fluid with Dynamic Aether: Parametric Mechanism of Axion Generation in the Early Universe
Authors: Balakin Alexander , Ilin Alexei , Shakirzyanov Amir
Published: September 2023

We consider an isotropic homogeneous cosmological model with five interacting elements: first, the dynamic aether presented by a unit timelike vector field; second, the pseudoscalar field describing an axionic component of the dark matter; third, the cosmic dark energy, described by a rheologic fluid; fourth, the non-axionic dark matter coupled to the dark energy; and fifth, the gravity field. We show that the early evolution of the Universe described by this model can include two specific epochs: the first one can be characterized as a super-inflation epoch; the second epoch is associated with an oscillatory regime. The dynamic aether carries out a regulatory mission; the rheologic dark fluid provides the specific features of the spacetime evolution. The oscillations of the scale factor and of the Hubble function are shown to switch on the parametric (Floquet-type) mechanism of the axion number growth.
Solving the Hydrodynamical System of Equations of Inhomogeneous Fluid Flows with Thermal Diffusion: A Review
Authors: Ershkov Sergey V. , Prosviryakov Evgeniy Yu. , Burmasheva Natalya V. , Christianto Victor
Published: September 2023

The present review analyzes classes of exact solutions for the convection and thermal diffusion equations in the Boussinesq approximation. The exact integration of the Oberbeck–Boussinesq equations for convection and thermal diffusion is more difficult than for the Navier–Stokes equations. It has been shown that the exact integration of the thermal diffusion equations is carried out in the Lin–Sidorov–Aristov class. This class of exact solutions is a generalization of the Ostroumov–Birikh family of exact solutions. The use of the class of exact solutions by Lin–Sidorov–Aristov makes it possible to take into account not only the inhomogeneity of the pressure field, the temperature field and the concentration field, but also the inhomogeneous velocity field. The present review shows that there is a class of exact solutions for describing the flows of incompressible fluids, taking into account the Soret and Dufour cross effects. Accurate solutions are important for modeling and simulating natural, technical and technological processes. They make it possible to find new physical mechanisms of momentum transfer for the design of new types of equipment.
On (α,p)-Cyclic Contractions and Related Fixed Point Theorems
Authors: Asem Victory , Singh Yumnam Mahendra , Khan Mohammad Saeed , Sessa Salvatore
Published: September 2023

Lipschitz mapping appears inevitably in many branches of mathematics, especially in functional analysis, and leads to the study of new results in metric fixed point theory. Goebel and Sims (resp. Goebel and Japon-Pineda) introduced a class of the Lipschitz mappings termed as (α,p)-Liptschitz mappings and studied not only the modified form of the Lipschitz condition, but also the behavior of a finite number of their iterates. The purpose of this paper is to discuss the various types of (α,p)-contractions with cyclic representation that extend the results due to Banach, Kannan, and Chatterjea. Moreover, based on such types of contractions and the property of symmetry, we obtain some related fixed-point results in the setting of metric spaces. Some examples are studied to illustrate the validity of our obtained results. As an application of our results, we establish the existence of the solution to a class of Fredholm integral equations.
Isotope Discrimination of Source Waters, Flowpaths, and Travel Times at an Acid-Generating, Lead–Zinc–Silver Mine, Silver Valley, Idaho, USA
Authors: Langman Jeff B. , Gaddy Ethan , Link Timothy E. , Boll Jan , Barnett Bradley , Hill Morgan
Published: September 2023

Precipitation infiltrates into the lead–zinc–silver Bunker Hill Mine, oxidizes pyrite, and produces acidic waters that discharge from the mine portal. The metasedimentary geology and alteration from 100+ yr of mining provide a heterogeneous environment for source water infiltration and flow within the mine. A university–industry partnership was developed to trace the mine water sources, flowpaths, and travel times to identify potential areas for infiltration reduction. Snowpack, creek, and mine water samples were collected over a 1-year period for the analysis of δ2H, δ18O, and 3H, along with the in situ measurement of temperature, specific conductance, pH, dissolved oxygen, and flow. The isotope tracers were used to identify the source waters, unmix mine water as it moved deeper in the mine, and examine flowpaths in and near the acid-generating pyritic zone. The results indicate creek water infiltrating relatively quickly through the anthropogenically-modified pathways and causing the largest amount of acidic water in the upper levels of the mine. Slower, natural pathways associated with faults, fractures, and bedding planes produce mostly neutral waters with the source waters typically originating at higher elevations. Travel times ranged from <1 to 22 years with shorter pathways to the upper levels of the mine and increasing contributions deeper in the mine from pathways containing older, higher-elevation snowmelt. These slower and older inflows were identified by depleted δ18O values, smaller 3H concentrations, the dampening of the variability of the isotope signals, and pH increases. Reduction of infiltration zones near the upper workings of the mine likely will decrease the acidic waters in the upper levels of the mine, but the higher elevation infiltration zones will continue to contribute snowmelt-derived waters at all mine levels.
Investigations on Flexural Strength of a Columnar Saline Model Ice under Circular Plate Central Loading
Authors: Tian Yukui , Zhao Weihang , Yu Chaoge , Gang Xuhao , Lu Peng , Yue Qianjin
Published: September 2023

The properties of ice strength have a significant impact on the design and safety of structures in ice-infested waters. To analyze the flexural strength of columnar saline model ice, we conducted circular plate center loading tests at the Small Ice Model Basin of the China Ship Scientific Research Center (CSSRC SIMB) in China. The tests involved varying the loading rate and ice temperature, and a numerical model was developed using FEM and LS-DYNA for validation and comparison. The results of the tests revealed the crack propagation process, stress distribution, load response, and failure mode of the model ice. The model ice displayed typical brittle failure, and the flexural strength was linearly related to ice temperature but not significantly correlated with loading rate. The porosity of the model ice affected the load response and time of failure but not the failure mode. The model ice with 7% porosity had a 7.8% reduction in load response compared to the nonporous model ice. This study provides a reliable method for measuring and analyzing the flexural strength of model ice. It also serves as a foundation for further research on the interaction between structures and ice sheets.
L’Homère de Pléthon
Authors: Pontani Filippomaria
Published: September 2023

A short treatise on Homer by George Gemistus Pletho is here published for the first time : new information is given on the manuscript witnesses (especially the ms. Naples, Girolamini C. F. 2.11, partly copied by the learned John Dokeianos, who played a role in the production and preservation of several books of Pletho -the ones now in Venice are examined in some detail) as well as on the content of the text, which deals with Homer’s biography, with the allegorical reading of the gods in the Iliad, and with the need to athetise the most dangerous parts of the poem.
The Multidimensional Role of Social Entrepreneurship: A Case Study Approach Within an International Project Context
Authors: Ferreiro Maria de Fátima , Sousa Cristina , Vale Sofia , Sousa Maria José
Published: September 2023

Social entrepreneurship creates social value and has a multidimensional impact (e.g. economic, environmental, cultural). This is related to the complexity and multidimensional approaches to current societal problems such as climatic changes and socioeconomic crises. The paper explores this multidimensionality by presenting three Portuguese case studies of social entrepreneurship operating in diverse domains. The study is based on primary and secondary data on the selected social enterprises. The analysis explores the motivations and constraints in forming a social enterprise and the impact of entrepreneurial activity. There is evidence of multiple roles played by these entrepreneurial agents, and, therefore, their critical role in the response to the problems that current societies face.
Portuguese SMEs: Strategies for Collaborative R&D and Participation in the Framework Programme
Authors: Abreu Ricardo , Antunes Jorge , Escada Mafalda , Pádua Maria , Patrício Maria Teresa
Published: September 2023

The European Union Framework Programme can create and/or strengthen research networks and cooperation, namely between SMEs and higher education institutions. However, in Portugal, SMEs represent only 16,7% of allocated funds, falling below the European Commission’s target (Agência Nacional de Inovação, 2020). Low SME participation can result from factors particularly related to SMEs, such as organizational characteristics and past R&D experience. In fact, previous collaborative R&D experience is an important factor determining participation in Framework Programmes (Barajas & Huergo, 2010), suggesting a virtuous cycle. How and why do SME gain collaborative experience with HEI? In what kind of collaborative experiences with HEIs do SMEs engage? What are the characteristics of SMEs that engage in these experiences? What obstacles and risks do SMEs face when applying for the FP and which strategies do they adopt to face them? To answer these questions, we conducted an exploratory survey with SMEs that collaborate with HEIs (N = 26). Additionally, we conducted semi-structured interviews with three H2020 participant SMEs and three non-participants to further explore their collaborative practices and R&D strategies.
Towards Carbon Neutrality Through Innovation: Empirical Insights in European Countries
Authors: Bajcan Jan , Trubač Dominik
Published: September 2023

In the current era where innovation and sustainability are at the forefront, businesses need to become increasingly active in implementing environmentally sustainable projects. The aim of this paper is to set initiative-taking activities for small and medium sized enterprises (SMEs) which would increase their level of engagement in innovative and environmentally responsible projects. Achieving environmental goals has never been easy given the fact that SMEs are the biggest polluters of the environment. Therefore, there is an urgent need for the leaders of these businesses to start implementing eco-innovation solutions to respond to these challenges. Our research consists of examining the current situation of the European Union's member states and responding to the objectives which have been set for them, by proposing strategic solutions for SMEs. Research also compares data between Human Development Index and Innovation Index to identify areas where there is room for improvement. These objectives concern the green development of countries, and the achievement of carbon neutrality by 2055. The results of the work points to increased attention for countries with low levels of development capability and refers to the adoption of measures taken by SMEs to help achieve the goals set. Final recommendations will describe how SMEs could implement initiatives in their businesses and where to look for sustainable and green change in their environment. Marked changes need to be made immediately in order for SMEs to adapt to these changes in order to fulfil objectives set by the European Union in a widely discussed program, Fit For 55.