bluuebunny/crossref_metadata_2025 huggingface dataset:
Motivations of Volunteers in Danish Grazing Organizations
Authors: Madsen Sari F. , Ekelund Flemming , Strange Niels , Schou Jesper Sølver
Published: July 2021

Global biodiversity is under pressure from human activities, and the effort for nature conservation and restoration and the allocation of economic resources for biodiversity policies remain insufficient. In such a context, volunteers can play an important role as a resource in nature conservation projects if their recreational activities interact with the objectives of nature management. In recent years, the number of volunteers in conservation work has increased in Denmark, with more people volunteering to contribute to nature conservation projects. Ensuring that volunteers remain motivated and engaged is crucial for the success of such conservation projects. In this study, we evaluated the motivation among members of grazing organizations, an activity that represents the most prominent voluntary nature conservation initiative in Denmark. We applied an exploratory factor analysis (EFA) and an ordinal regression to analyze survey data from 25 Danish grazing organizations. We found that five motivational factors determine the engagement of the volunteers, namely social, nature value, instrumental, identification, and personal benefit. Whereas the social, nature value and personal benefit are factors also identified in the existing literature, the instrumental and identification factors add new perspectives to the motivation of environmental volunteers. We found that place attachment is an important driver, and that the chairpersons/coordinators of the grazing organizations especially emphasized the sharing of values and knowledge with their members as a driver. Lastly, volunteers were reluctant to support the idea of forming a more formal setup in terms of a “grazing organization union”.
Comparative Analysis of Shear Strength Parallel to Fiber of Different Local Bamboo Species in the Philippines
Authors: Bautista Brian E. , Garciano Lessandro E. O. , Lopez Luis F.
Published: July 2021

There are limited published studies related to the mechanical properties of bamboo species in the Philippines. In this study, the shear strength properties of some economically viable bamboo species in the Philippines were properly characterized based on 220 shear test results. The rationales of selecting this mechanical property are the following: (1) Shear strength, parallel to the fiber, has the highest variability among the mechanical properties; and (2) Shear is one of the governing forces on joint connections, and such connections are the points of failure on bamboo structures when subjected to extreme loading conditions. ISO 22157-1 (2017) test protocol for shear was used for all tests. The results showed that Bambusa blumeana has the highest average shear strength, followed by Gigantochloa apus, Dendrocalamus asper, Bambusa philippinensis, and Bambusa vulgaris. However, comparative analysis, using One-way ANOVA, showed that shear strength values among these bamboo species have significant differences statistically. A linear regression model is also established to estimate the shear strength of bamboo from the physical properties. Characteristic shear strength is also determined using ISO 12122-1 (2014) for future design reference.
The Balanced Structure of Environmental Identity
Authors: Bruni Coral M. , Schultz P. Wesley , Woodcock Anna
Published: July 2021

Connectedness with nature refers to an individual’s beliefs about their relationship with the natural environment. The current paper integrates connectedness with nature into a broader framework of balanced identity theory as a form of self-concept, and presents new data showing that individuals tend toward balanced-congruity and hold cognitive configurations that balance self-concept, environmental attitudes, and self-esteem. In essence, when an individual scores highly on one of these constructs, it is likely that they will score highly on the other two constructs. Two hundred and seventy-six undergraduate students completed explicit and implicit measures of connectedness with nature, attitudes toward nature, and self-esteem. The balanced-congruity principle was supported with implicit measures (e.g., Implicit Association Test), but not explicitly with self-report measures. Results suggest that attitudes toward nature, connectedness with nature, and self-esteem form a balanced triadic structure of implicit environmental identity. The findings extend our understanding of connectedness with nature, by integrating it into a broader framework that links connectedness, attitudes, and self-esteem as a triadic form of environmental identity. This finding has important implications for practitioners interested in fostering environmental identities and promoting sustainability.
Influence of Housing Resettlement on the Subjective Well-Being of Disaster-Forced Migrants: An Empirical Study in Yancheng City
Authors: Li Yi , Feng Xuanfeng
Published: July 2021

As natural disasters have occurred frequently in recent years, disaster-induced migration has become inevitable. People normally attach great importance to the speed and results of post-disaster reconstruction while ignoring the subjective well-being (SWB) of disaster victims, which represents their quality of life and emotional conditions. Based on a questionnaire survey of 256 respondents from Yancheng’s 17 centralised resettlement communities established after a hurricane in 2016, we used ordinal logistic regression models to discuss the SWB of disaster-induced migrants and its main influencing factors. We found that the SWB of disaster-induced migrants is influenced by resettlement housing conditions and community built and social environments. In light of the housing resettlement conditions, the findings show that disaster migrants are likely to feel happier if they are satisfied with the housing resettlement allocation mode, housing resettlement quality and the living space, and the more housing expenditure related to the resettlement is, the less happy they tend to be. In regard to the community environment, it is found that disaster migrants’ evaluation of community facilities and participation does not have a significant impact on their happiness, but the more highly rated community hygiene and the cadre–mass relationship are, the happier they tend to be.
Investigation of the Formation Mechanism and Environmental Risk of Tire—Pavement Wearing Waste (TPWW)
Authors: Wang Kechen , Chu Xiangyu , Lin Jiao , Yang Qilin , Fan Zepeng , Wang Dawei , Oeser Markus
Published: July 2021

Tire—pavement interaction behaviours result in large amounts of wearing waste matter, which attaches to the surface of the pavement and is directly exposed to the surrounding environment. This kind of matter imposes a great challenge to the environment of the road area. The current study is devoted to carrying out a comprehensive investigation of the formation mechanism of tire—pavement wearing waste (TPWW), as well as the resulting environmental risks. A self-developed piece of accelerated polishing equipment, the Harbin advanced polishing machine (HAPM), was employed to simulate the wearing process between vehicle tires and pavement surfaces, and the TPWW was collected to conduct morphological, physical, and chemical characterisations. The results from this study show that the production rate of TPWW decreases with the increase in polishing duration, and the coarse particles (diameters greater than 0.425 mm) account for most of the TPWW obtained. The fine fraction (diameter smaller than 0.425 mm) of the TPWW comprises variously sized and irregularly shaped rubber particles from the tire, as well as uniformly sized and angular fine aggregates. The environmental analysis results show that volatile alkanes (C9–C16) are the major organic contaminants in TPWW. The Open-Graded Friction Course (OGFC) asphalt mixture containing crumb rubber as a modifier showed the highest risk of heavy metal pollution, and special concern must be given to tire materials for the purpose of improving the environmental conditions of road areas. The use of polyurethane as a binder material in the production of pavement mixtures has an environmental benefit in terms of pollution from both organic contaminants and heavy metals.
Grain Density-Based Approaches to Predict the Mechanical, Thermal and Hygric Properties of Carbon-Negative Aggregate Concretes
Authors: Rahmouni Imen , Promis Geoffrey , Douzane Omar , Rosquoet Frédéric
Published: July 2021

The suitability of replacing mineral aggregate with carbon-negative ones mainly depends on the properties of the aggregates produced from waste recycling, reducing CO2 emissions. This study aimed to investigate the predictive approaches adapted to concrete mixtures where mineral aggregates are replaced by carbonated aggregates (at different substitution rates from 25 to 100% with aggregates of various origins). A large experimental campaign of aggregates and carbonated aggregate concretes highlighted their physical, mechanical, thermal and hygric properties and the influence of density and porosity of aggregates on these properties. Thanks to these results, predictive approaches were formulated to establish the main engineering properties: mechanical compressive strength, elasticity modulus, thermal conductivity, thermal mass capacity and hygric diffusivity. These empirical and analytical models were based on the density of aggregates. Maximum deviations of around 15% were obtained with the experimental data, highlighting the influence of grain density on carbonated aggregate concretes. These models could then be used to optimize the formulation of concrete mixtures with carbonated aggregates, replacing international standards adapted to mineral aggregates.
Environmental Regeneration Integrating Soft Mobility and Green Street Networks: A Case Study in the Metropolitan Periphery of Naples
Authors: Valente Renata , Mozingo Louise , Bosco Roberto , Cappelli Eduardo , Donadio Carlo
Published: July 2021

Public space and street networks form a significant and central determinant of urban quality. The advent of the COVID-19 pandemic has focused their crucial importance in the reorganisation of places that are “safe” because they allow movement through cities with minimal risk of contagion. While addressing the need for social distancing, open air exercise, and mobility without use of public transport, these measures resulted in other environmental and social benefits. Living with the coronavirus pandemic has produced a series of adaptative actions, such as barring or limiting automobile traffic, thereby expanding street space for pedestrians and bicyclists, whose impact is, as yet, difficult to fathom because of their contingent, temporary nature. In this context, this case study proposes a sustainable bicycle network to inform the future, permanent street redesign. Based on topographic, morphologic, and climatic data, it evaluates a series of contiguous road sections, defining redesign capacities and critical conditions to implement sustainable interventions to manage urban runoff, mitigate of extreme heat events, expand pedestrian paths and provide a bicycle network. This holistic approach to sustainable urban design evaluation, supported by reproducible data and parameters, serves as a replicable model for the sustainable redesign of roads in other urban settings. The extent, integration, and complexity of the study engaged an interdisciplinary framework, facilitating detailed planning and design and quantified assessments of environmental outcomes.
Sand- and Clay-Photocured-Geomembrane Interface Shear Characteristics Using Direct Shear Test
Authors: Li Lihua , Yan Han , Xiao Henglin , Li Wentao , Geng Zhangshuai
Published: July 2021

It is well known that geomembranes frequently and easily fail at the seams, which has been a ubiquitous problem in various applications. To avoid the failure of geomembrane at the seams, photocuring was carried out with 1~5% photoinitiator and 2% carbon black powder. This geomembrane can be sprayed and cured on the soil surface. The obtained geomembrane was then used as a barrier, separator, or reinforcement. In this study, the direct shear tests were carried out with the aim to investigate the interfacial characteristics of photocured geomembrane–clay/sand. The results show that a 2% photoinitiator has a significant effect on the impermeable layer for the photocured geomembrane–clay interface. As for the photocured geomembrane–sand interface, it is reasonable to choose a geomembrane made from a 4% photoinitiator at the boundary of the drainage layer and the impermeable layer in the landfill. In the cover system, it is reasonable to choose a 5% photoinitiator geomembrane. Moreover, as for the interface between the photocurable geomembrane and clay/sand, the friction coefficient increases initially and decreases afterward with the increase of normal stress. Furthermore, the friction angle of the interface between photocurable geomembrane and sand is larger than that of the photocurable geomembrane–clay interface. In other words, the interface between photocurable geomembrane and sand has better shear and tensile crack resistance.
Special Issue “Levering Sustainable Food Systems to Address Climate Change (Pandemics and Other Shocks and Hazards): Possible Transformations”
Authors: Spring Andrew , Nelson Erin , Knezevic Irena , Ballamingie Patricia , Blay-Palmer Alison
Published: July 2021

Since we first conceived of this Special Issue, “Levering Sustainable Food Systems to Address Climate Change—Possible Transformations”, COVID-19 has turned the world upside down [...]
Leveraging the 4th Industrial Revolution Technology for Sustainable Development of the Northern Sea Route (NSR)—The Case Study of Autonomous Vessel
Authors: Lee Sung-Woo , Jo Jisung , Kim Sewon
Published: July 2021

The Fourth Industrial Revolution (4IR) technology has been applied to various industrial areas not only to improve economic efficiency but also to obtain environmental and safety benefits. We paid attention to the unresolved issues of Arctic development to establish a balance between economic feasibility and social values and suggest the 4IR technologies as the solution for this. The master concept of application of the 4IR technology to NSR sailing is presented. Further, we conducted a case study for autonomous vessels. A cost breakdown structure model is specified to compare the total costs of traditional and autonomous vessels. Then, we conducted scenario analysis to investigate the economic and social effects of autonomous vessels by season and route. The results show that autonomous vessels have economic benefits compared to the traditional vessel even in the winter season, and if we realize autonomous vessels in the NSR, there are more cost saving effects than in the Suez Canal Route (SCR) in any season. As for the environmental benefits, autonomous vessels have lower gas emissions and reduced water disposal compared to the traditional vessel. Further, autonomous vessels could be a solution to provide a better crew working environment by minimizing the number of people on board. The contribution of this research is that, first, we utilize real fuel oil consumption measurement data to estimate the voyage expenses, and, second, this is a novel attempt of applying the 4IR technology as a solution for the Arctic development issue. In this respect, this research is expected to serve as a cornerstone for future research, and it will help to establish Arctic development strategies in Arctic or non-Arctic countries.
Evaluating Decision Making in Sustainable Project Selection Between Literature and Practice
Authors: Alyamani Rakan , Long Suzanna , Nurunnabi Mohammad
Published: July 2021

A robust project selection process is critical for the selection of sustainable projects that meet the needs of an organization or community. There are multiple factors or criteria that can be considered in the selection of the appropriate sustainable project, but it can be challenging to find sufficient depth of expert opinion to perform a strong evaluation of these criteria. Several researchers have turned to the sustainable project literature as a source of expert opinion to evaluate the criteria used in sustainable project selection and rank them based on importance using different multi-criteria decision-making (MCDM) methodologies. However, using the literature as a source of expert opinion poses a different set of challenges and may not accurately represent the actual opinions of sustainable project subject matter experts (SMEs) and practitioners. In this study, the fuzzy analytic hierarchy process (FAHP) methodology is used to determine the importance of project cost, project maturity, skill and experience, uncertainty, and technology information transfer as selection criteria using collected opinions from academic sustainable project experts and practitioners. The results are then compared with previous research that used the literature to rank these five criteria based on importance when selecting between multiple sustainable project alternatives. The results show that project cost is still considered the major driver of decision making in sustainable project selection by both the literature and practice. However, unlike the literature-as-experts approach, SMEs prioritize skill and experience and technology information transfer over project maturity and uncertainty. Project managers and decision makers can use these findings to best prioritize the types of challenges that may occur depending on inputs for the FAHP analysis.
Enhancement of Biogas Production via Co-Digestion of Wastewater Treatment Sewage Sludge and Brewery Spent Grain: Physicochemical Characterization and Microbial Community
Authors: Mudzanani Khuthadzo , van Heerden Esta , Mbhele Ryneth , Daramola Michael O.
Published: July 2021

The present study intends to evaluate a synergy towards enhanced biogas production by co-digesting municipal sewage sludge (SS) with brewery spent grain (BSG). To execute this, physicochemical and metagenomics analysis was conducted on the sewage sludge substrate. The automatic methane potential test system II (AMPTS II) biochemical methane potential (BMP) batch setup was operated at 35 ± 5 °C, pH range of 6.5–7.5 for 30 days’ digestion time on AMPTS II and 150 days on semi-continuous setup, where the organic loading rate (OLR) was guided by pH and the volatile fatty acids to total alkalinity (VFA/TA) ratio. Metagenomics analysis revealed that Proteobacteria was the most abundant phyla, consisting of hydrolytic and fermentative bacteria. The archaea community of hydrogenotrophic methanogen genus was enriched by methanogens. The highest BMP was obtained with co-digestion of SS and BSG, and 9.65 g/kg of VS. This not only increased biogas production by 104% but also accelerated the biodegradation of organic matters. However, a significant reduction in the biogas yield, from 10.23 NL/day to 2.02 NL/day, was observed in a semi-continuous process. As such, it can be concluded that different species in different types of sludge can synergistically enhance the production of biogas. However, the operating conditions should be optimized and monitored at all times. The anaerobic co-digestion of SS and BSG might be considered as a cost-effective solution that could contribute to the energy self-efficiency of wastewater treatment works (WWTWs) and sustainable waste management. It is recommended to upscale co-digestion of the feed for the pilot biogas plant. This will also go a long way in curtailing and minimizing the impacts of sludge disposal in the environment.
A Socio-Technical Perspective on the Application of Green Ergonomics to Open-Plan Offices: A Review of the Literature and Recommendations for Future Research
Authors: Norton Thomas A. , Ayoko Oluremi B. , Ashkanasy Neal M.
Published: July 2021

Open-plan office (OPO) layouts emerged to allow organizations to adapt to changing workplace demands. We explore the potential for OPOs to provide such adaptive capacity to respond to two contemporary issues for organizations: the chronic challenge of environmental sustainability, and the acute challenges emerging from the great COVID-19 homeworking experiment. We apply a socio-technical systems perspective and green ergonomics principles to investigate the relationship between an OPO environment and the occupants working within it. In doing so, we consider relevant technical and human factors, such as green technology and employee green behavior. We also consider how a green OPO might provide non-carbon benefits such as improving occupant well-being and supporting the emergence of a green organizational culture. Our investigation highlights several avenues through which an OPO designed with green ergonomic principles could benefit occupants, the organizations they work for, and the natural environment of which they are a part and on which they depend. We find reason to suspect that green OPOs could play an important role in sustainable development; and offer a research agenda to help determine whether it is true that OPOs can, indeed, exemplify how “going green” may be good for business.
Sustainability Investigation of Vehicles’ CO2 Emission in Hungary
Authors: Árpád István , Kiss Judit T. , Bellér Gábor , Kocsis Dénes
Published: July 2021

The regulation of vehicular CO2 emissions determines the permissible emissions of vehicles in units of g CO2/km. However, these values only partially provide adequate information because they characterize only the vehicle but not the emission of the associated energy supply technology system. The energy needed for the motion of vehicles is generated in several ways by the energy industry, depending on how the vehicles are driven. These methods of energy generation consist of different series of energy source conversions, where the last technological step is the vehicle itself, and the result is the motion. In addition, sustainability characterization of vehicles cannot be determined by the vehicle’s CO2 emissions alone because it is a more complex notion. The new approach investigates the entire energy technology system associated with the generation of motion, which of course includes the vehicle. The total CO2 emissions and the resulting energy efficiency have been determined. For this, it was necessary to systematize (collect) the energy supply technology lines of the vehicles. The emission results are not given in g CO2/km but in g CO2/J, which is defined in the paper. This new method is complementary to the European Union regulative one, but it allows more complex evaluations of sustainability. The calculations were performed based on Hungarian data. Finally, using the resulting energy efficiency values, the emission results were evaluated by constructing a sustainability matrix similar to the risk matrix. If only the vehicle is investigated, low CO2 emissions can be achieved with vehicles using internal combustion engines. However, taking into consideration present technologies, in terms of sustainability, the spread of electric-only vehicles using renewable energies can result in improvement in the future. This proposal was supported by the combined analysis of the energy-specific CO2 emissions and the energy efficiency of vehicles with different power-driven systems.
Effect of Peatland Siltation on Total and Labile C, N, P and K
Authors: Smolczynski Slawomir , Kalisz Barbara , Urbanowicz Pawel , Orzechowski Miroslaw
Published: July 2021

Large areas of peatlands, in addition to the effect of drainage, were subjected to erosional process and were silted. The objective of the study was to verify whether siltation of peatlands hampers mineralization of remaining peat and alters labile C, N, P and K. Total C and N were measured on a CN analyzer, and total P and K on an ICP spectrometer after microwave digestion. The labile fractions of C, N, P and K were extracted with hot water and measured on the CN analyzer and ICP spectrometer. We noted that labile C, N, P and K concentrations in silted topsoil were lower than the values reported in unsilted topsoil. Higher concentration of labile compounds in peats is a signal of higher biological activity and mineralization of organic matter. A TOC/TP < 300 and TOC/TN of approximately 8 in topsoil suggested diminished mineralization and supported our hypothesis that siltation hampered mineralization of organic matter. The TOC/TK ratio proved to be a fine indicator of the state of organic soils siltation, which enabled the separation of unsilted peats from silted topsoil (on the base of value of 177). It can be assumed that the mineralization of peat layers is hampered by the above lying silted topsoil, which is less biologically active, having less oxygen, and therefore conserving underlying peats against oxidation.
The Socio-Economics Factors in Family Farms with Different Economic Sustainability Levels from Central and Eastern Europe
Authors: Smędzik-Ambroży Katarzyna , Guth Marta , Majchrzak Adam , Muntean Andreea Cipriana , Maican Silvia Ștefania
Published: July 2021

Economic sustainability plays an important role in shaping conditions for economic growth and social development. The importance of answering the question about the level of sustainability of family farms results from the fact that the countries of Central and Eastern Europe, apart from exceptions (e.g., the Czech Republic and Slovakia), are characterized by a fragmented agrarian structure. Hence, the main goal of this article was to answer two questions: (1) whether the countries of Central and Eastern Europe differ in the level of economic sustainability of small family farms; and (2) whether the same socioeconomic factors impact similarly on the level of economic sustainability of small family farms from countries of Central and Eastern Europe. The study was based on surveys conducted in small family farms: in 2018 from Poland (672 farms) and in 2019 in four other countries (Lithuania; 999 farms, Romania; 834 farms, Serbia; 523 farms, Moldova; 530 farms). The publication includes a critical analysis of the literature, structure analysis and correlation analysis. The results show the occurrence of large differences between the economic sustainability of small family farms from the countries of Central and Eastern Europe. The research indicates that the larger the area of a small-scale family farm, the greater its economic sustainability. The productivity of these farms increases with their economic sustainability. The results also prove a negative relationship between the age of the farmer and the economic sustainability of their farm in all analysed countries. These trends were found in all analysed countries of Central and Eastern Europe. The results of the analyses support the conclusion that agricultural policy instruments aimed at increasing the economic sustainability of small family farms should lead to: land consolidation, a decrease in the age of farm owners through generational changes, and a decrease in employment in agriculture, which would lead to a reduction in labour input in the agricultural sector.
Integrating Urban Agriculture and Stormwater Management in a Circular Economy to Enhance Ecosystem Services: Connecting the Dots
Authors: Deksissa Tolessa , Trobman Harris , Zendehdel Kamran , Azam Hossain
Published: July 2021

Due to the rapid urbanization in the context of the conventional linear economy, the vulnerability of the urban ecosystem to climate change has increased. As a result, connecting urban ecosystem services of different urban land uses is imperative for urban sustainability and resilience. In conventional land use planning, urban agriculture (UA) and urban stormwater management are treated as separate economic sectors with different-disconnected-ecosystem services. Furthermore, few studies have synthesized knowledge regarding the potential impacts of integration of UA and stormwater green infrastructures (GIs) on the quantity and quality of urban ecosystem services of both economic sectors. This study provides a detailed analysis of the imperative question—how should a city integrate the developments of both urban agriculture and stormwater green infrastructure to overcome barriers while enhancing the ecosystem services? To answer this question, we conducted an extensive literature review. The results show that integrating UA with GIs can enhance urban food production while protecting urban water quality. This paper provides an initial context and mechanisms for future researchers and city planners regarding the manner in which the synergies between UA and stormwater GIs can create greater value for the wellbeing of urban ecosystems and resilience in the circular economy.
Residents’ Perception of a Collaborative Approach with Artists in Culture-Led Urban Regeneration: A Case Study of the Changdong Art Village in Changwon City in Korea
Authors: Baek Yoonjee , Jung Changmu , Joo Heesun
Published: July 2021

This study asserts that the higher the degree of artists’ and residents’ participation in a culture-led renewal project, the higher the level of residents’ satisfaction. Engaging artist groups and introducing cultural programs can facilitate building a collaborative network between artists and residents. This paper adopts an experimental study method and defines the experimental and control groups as follows: the experimental group (Changwon city) has relatively high artist participation, and the control group (Sacheon, Gimhae, Miryang cities) have relatively low artist involvement. Multiple regression analysis was conducted utilizing 192 valid survey data in R studio software. The significant variables were compared between the experimental group (Model 1) and the control group (Model 2). As a result, the relative effects of “1. experience (or amount) of residents’ participation in urban renewal programs”, “2. reflection of residents’ opinions”, and “3. neighborly trust” on “residents’ satisfaction with urban regeneration projects and expected outcomes” was shown to be greater in the experimental group. The result implies that the involvement of cultural entities and the operation of arts programs increase residents’ will to participate in renewal projects and to build neighborly trust. Further, collection and reflection of residents’ opinions about the renewal works were more smoothly completed when mediated by artist participation and using cultural content.
Electro-Polymerized Titan Yellow Modified Carbon Paste Electrode for the Analysis of Curcumin
Authors: D’Souza Edwin S. , Manjunatha Jamballi G. , Raril Chenthattil , Tigari Girish , Arpitha Huligerepura J. , Shenoy Suvarnalatha
Published: July 2021

A modest, efficient, and sensitive chemically modified electrode was fabricated for sensing curcumin (CRC) through an electrochemically polymerized titan yellow (TY) modified carbon paste electrode (PTYMCPE) in phosphate buffer solution (pH 7.0). Cyclic voltammetry (CV) linear sweep voltammetry (LSV) and differential pulse voltammetry (DPV) approaches were used for CRC detection. PTYMCPE interaction with CRC suggests that the electrode exhibits admirable electrochemical response as compared to bare carbon paste electrode (BCPE). Under the optimized circumstances, a linear response of the electrode was observed for CRC in the concentration range 2 × 10−6 M to 10 × 10−6 M with a limit of detection (LOD) of 10.94 × 10−7 M. Moreover, the effort explains that the PTYMCPE electrode has a hopeful approach for the electrochemical resolution of biologically significant compounds. Additionally, the proposed electrode has demonstrated many advantages such as easy preparation, elevated sensitivity, stability, and enhanced catalytic activity, and can be successfully applied in real sample analysis.
Bayesian Testing Procedure on the Lifetime Performance Index of Products Following Chen Lifetime Distribution Based on the Progressive Type-II Censored Sample
Authors: Wu Shu-Fei , Chang Wei-Tsung
Published: July 2021

With the high demands on the quality of high-tech products for consumers, assuring the lifetime performance is a very important task for competitive manufacturing industries. The lifetime performance index CL is frequently used to monitor the larger-the-better lifetime performance of products. This research is related to the topic of asymmetrical probability distributions and applications across disciplines. Chen lifetime distribution with a bathtub shape or increasing failure rate function has many applications in the lifetime data analysis. We derived the uniformly minimum variance unbiased estimator (UMVUE) for CL, and we used this estimator to develop a hypothesis testing procedure of CL under a lower specification limit based on the progressive type-II censored sample. The Bayesian estimator for CL is also derived, and it is used to develop another hypothesis testing procedure. A simulation study is conducted to compare the average confidence levels for two procedures. Finally, one practical example is given to illustrate the implementation of our proposed non-Bayesian and Bayesian testing procedure.
A Preconditioned Variant of the Refined Arnoldi Method for Computing PageRank Eigenvectors
Authors: Shen Zhao-Li , Yang Hao , Carpentieri Bruno , Gu Xian-Ming , Wen Chun
Published: July 2021

The PageRank model computes the stationary distribution of a Markov random walk on the linking structure of a network, and it uses the values within to represent the importance or centrality of each node. This model is first proposed by Google for ranking web pages, then it is widely applied as a centrality measure for networks arising in various fields such as in chemistry, bioinformatics, neuroscience and social networks. For example, it can measure the node centralities of the gene-gene annotation network to evaluate the relevance of each gene with a certain disease. The networks in some fields including bioinformatics are undirected, thus the corresponding adjacency matrices are symmetry. Mathematically, the PageRank model can be stated as finding the unit positive eigenvector corresponding to the largest eigenvalue of a transition matrix built upon the linking structure. With rapid development of science and technology, the networks in real applications become larger and larger, thus the PageRank model always desires numerical algorithms with reduced algorithmic or memory complexity. In this paper, we propose a novel preconditioning approach for solving the PageRank model. This approach transforms the original PageRank eigen-problem into a new one that is more amenable to solve. We then present a preconditioned version of the refined Arnoldi method for solving this model. We demonstrate theoretically that the preconditioned Arnoldi method has higher execution efficiency and parallelism than the refined Arnoldi method. In plenty of numerical experiments, this preconditioned method exhibits noticeably faster convergence speed over its standard counterpart, especially for difficult cases with large damping factors. Besides, this superiority maintains when this technique is applied to other variants of the refined Arnoldi method. Overall, the proposed technique can give the PageRank model a faster solving process, and this will possibly improve the efficiency of researches, engineering projects and services where this model is applied.
Research on Path Planning Algorithm for Crowd Evacuation
Authors: Wang Zhenfei , Zhang Chuchu , Wang Junfeng , Zheng Zhiyun , Li Lun
Published: July 2021

In recent years, crowded stampede incidents have occurred frequently, resulting in more and more serious losses. The common cause of such incidents is that when large-scale populations gather in a limited area, the population is highly unstable. In emergency situations, only when the crowd reaches the safe exit as soon as possible within a limited evacuation time to complete evacuation can the loss and casualties be effectively reduced. Therefore, the safety evacuation management of people in public places in emergencies has become a hot topic in the field of public security. Based on the analysis of the factors affecting the crowd path selection, this paper proposes an improved path-planning algorithm based on BEME (Balanced Evacuation for Multiple Exits). And pedestrian evacuation simulation is carried out in multi-exit symmetrical facilities. First, this paper optimizes the update method of the GSDL list in the BEME algorithm as the basis for evacuating pedestrians to choose an exit. Second, the collision between pedestrians is solved by defining the movement rule and collision avoidance strategy. Finally, the algorithm is compared with BEME and traditional path-planning algorithms. The results show that the algorithm can further shorten the global evacuation distance of the symmetrical evacuation scene, effectively balance the number of pedestrians at each exit and reduce the evacuation time. In addition, this improved algorithm uses a collision avoidance strategy to solve the collision and congestion problems in path planning, which helps to maximize evacuation efficiency. Whether the setting of the scene or the setting of the exit, all studies are based on symmetric implementation. This is more in line with the crowd evacuation in the real scene, making the experimental results more meaningful.
First-Order Formalism and Thick Branes in Mimetic Gravity
Authors: Xie Qun-Ying , Fu Qi-Ming , Sui Tao-Tao , Zhao Li , Zhong Yi
Published: July 2021

In this paper, we investigate thick branes generated by a scalar field in mimetic gravity theory, which is inspired by considering the conformal symmetry under the conformal transformation of an auxiliary metric. By introducing two auxiliary super-potentials, we transform the second-order field equations of the system into a set of first-order equations. With this first-order formalism, several types of analytical thick brane solutions are obtained. Then, tensor and scalar perturbations are analyzed. We find that both kinds of perturbations are stable. The effective potentials for the tensor and scalar perturbations are dual to each other. The tensor zero mode can be localized on the brane while the scalar zero mode cannot. Thus, the four-dimensional Newtonian potential can be recovered on the brane.
Startup Investment Decision Support: Application of Venture Capital Scorecards Using Machine Learning Approaches
Authors: Bai Sarah , Zhao Yijun
Published: July 2021

This research aims to explore which kinds of metrics are more valuable in making investment decisions for a venture capital firm using machine learning methods. We measure the fit of developed companies to a venture capital firm’s investment thesis with a balanced scorecard based on quantitative and qualitative characteristics of the companies. Collaborating with the management team of Rose Street Capital (RSC), we explore the most influential factors of their balanced scorecard using their retrospective investment decisions of successful and failed startup companies. Our study employs six standard machine learning models and their counterparts with an additional feature selection technique. Our findings suggest that “planning strategy” and “team management” are the two most determinant factors in the firm’s investment decisions, implying that qualitative factors could be more important to startup evaluation. Furthermore, we analyzed which machine learning models were most accurate in predicting the firm’s investment decisions. Our experimental results demonstrate that the best machine learning models achieve an overall accuracy of 78% in making the correct investment decisions, with an average of 87% and 69% in predicting the decision of companies the firm would and would not have invested in, respectively. Our study provides convincing evidence that qualitative criteria could be more influential in investment decisions and machine learning models can be adapted to help provide which values may be more important to consider for a venture capital firm.
Investigation of AgI-Based Solid Solutions with Ag2CO3
Authors: Uchida Kento , Matsushima Yuta
Published: July 2021

The formation phenomena of silver carbonate (Ag2CO3)–silver iodide (AgI) solid solutions were investigated by X-ray diffraction, thermogravimetry-differential thermal analysis, and electrical conductivity measurement. Results revealed that AgI and Ag2CO3 reacted with each other when mixed at room temperature. The reaction products were classified into three types: (1) AgI-based solid solutions in the AgI-rich region for x = 10% or less in x Ag2CO3–(1 − x) AgI; (2) Ag2CO3-based solid solutions in the Ag2CO3-rich region for x = 60% or more; and (3) silver carbonate iodides in the intermediate range for x between 10% and 60%. For the AgI-based solid solutions, the incorporation of Ag2CO3 into the AgI lattice expanded the unit cell and enhanced electrical conductivity. The solubility limit of Ag2CO3 into the AgI lattice estimated from the differential thermal analysis was x ≈ 5%.
Hybrid Electric Vehicles: A Review of Existing Configurations and Thermodynamic Cycles
Authors: León Rogelio , Montaleza Christian , Maldonado José Luis , Tostado-Véliz Marcos , Jurado Francisco
Published: July 2021

The mobility industry has experienced a fast evolution towards electric-based transport in recent years. Recently, hybrid electric vehicles, which combine electric and conventional combustion systems, have become the most popular alternative by far. This is due to longer autonomy and more extended refueling networks in comparison with the recharging points system, which is still quite limited in some countries. This paper aims to conduct a literature review on thermodynamic models of heat engines used in hybrid electric vehicles and their respective configurations for series, parallel and mixed powertrain. It will discuss the most important models of thermal energy in combustion engines such as the Otto, Atkinson and Miller cycles which are widely used in commercial hybrid electric vehicle models. In short, this work aims at serving as an illustrative but descriptive document, which may be valuable for multiple research and academic purposes.
Synthesis of Silver-Impregnated Magnetite Mesoporous Silica Composites for Removing Iodide in Aqueous Solution
Authors: Jo Sang-Eun , Choi Jung-Weon , Choi Sang-June
Published: July 2021

Mag@silica-Ag composite has a high sorption ability for I− in aqueous solution due to its high surface area and strong affinity for the studied anion. The material adsorbed I− rapidly during the initial contact time (in 45 min, η = 80%) and reached adsorption equilibrium after 2 h. Moreover, mag@silica-Ag proved to selectively remove I− from a mixture of Cl−, NO3− and I−. The adsorption behavior fitted the Langmuir isotherm perfectly and the pseudo-second-order kinetic model. Based on the Langmuir isotherm, the maximum adsorption capacity of mag@silica-Ag was 0.82 mmol/g, which is significantly higher than previously developed adsorbents. This study introduces a practical application of a high-capacity adsorbent in removing radioactive I− from wastewaters.
Evaluation of Anti-PT Antibody Response after Pertussis Vaccination and Infection: The Importance of Both Quantity and Quality
Authors: Barkoff Alex-Mikael , Knuutila Aapo , Mertsola Jussi , He Qiushui
Published: July 2021

Pertussis toxin (PT) is considered the main virulence factor causing whooping cough or pertussis. The protein is widely studied and its composition was revealed and sequenced already during the 1980s. The human immune system creates a good response against PT when measured in quantity. However, the serum anti-PT antibodies wane rapidly, and only a small amount of these antibodies are found a few years after vaccination/infection. Therefore, multiple approaches to study the functionality (quality) of these antibodies, e.g., avidity, neutralizing capacity, and epitope specificity, have been investigated. In addition, the long-term B cell memory (Bmem) to PT is crucial for good protection throughout life. In this review, we summarize the findings from functional PT antibody and Bmem studies. These results are discussed in line with the quantity of serum anti-PT antibodies. PT neutralizing antibodies and anti-PT antibodies with proper avidity are crucial for good protection against the disease, and certain epitopes have been identified to have multiple functions in the protection. Although PT-specific Bmem responses are detectable at least five years after vaccination, long-term surveillance is lacking. Variation of the natural boosting of circulating Bordetella pertussis in communities is an important confounding factor in these memory studies.
Co-Occurrence of 35 Mycotoxins: A Seven-Year Survey of Corn Grain and Corn Silage in the United States
Authors: Weaver Alexandra C. , Weaver Daniel M. , Adams Nicholas , Yiannikouris Alexandros
Published: July 2021

Mycotoxins contaminate crops worldwide and play a role in animal health and performance. Multiple mycotoxins may co-occur which may increase the impact on the animal. To assess the multiple mycotoxin profile of corn (Zea mays), we conducted a 7-year survey of new crop corn grain and silage in the United States. A total of 711 grain and 1117 silage samples were collected between 2013 and 2019 and analyzed for the simultaneous presence of 35 mycotoxins using ultra-performance liquid chromatography–tandem mass spectrometry. The measured mean number of mycotoxins per sample were 4.8 (grain) and 5.2 (silage), ranging from 0 to 13. Fusaric acid (FA) was most frequently detected in 78.1 and 93.8% of grains and silages, respectively, followed by deoxynivalenol (DON) in 75.7 and 88.2% of samples. Fumonisin B1 (FB1), fumonisin B2 and 15-acetyl-deoxynivalenol (15ADON) followed. The greatest (p < 0.05) co-occurrence was between FA and DON in 59.1% of grains and 82.7% of silages, followed by FA with FB1, DON with 15ADON, and FA with 15ADON. Although many samples had lower mycotoxin concentrations, 1.6% (grain) and 7.9% (silage) of tested samples had DON ≥ 5000 µg/kg. Fumonisins were detected ≥ 10,000 µg/kg in 9.6 and 3.9% of grain and silage samples, respectively. Concentrations in grain varied by year for eight mycotoxin groups (p < 0.05), while all 10 groups showed yearly variations in silage. Our survey suggest that multiple mycotoxins frequently co-occur in corn grain and silage in the United States, and some of the more prevalent mycotoxins are those that may not be routinely analyzed (i.e., FA and 15ADON). Assessment of multiple mycotoxins should be considered when developing management programs.
Supermassive Black Holes from Bose-Einstein Condensed Dark Matter—Or Black and Dark Separation by Angular Momentum
Authors: Morikawa Masahiro
Published: July 2021

Many supermassive black holes (SMBH) of mass 106∼9M⊙ are observed at the center of each galaxy even in the high redshift (z≈7) Universe. To explain the early formation and the common existence of SMBH, we previously proposed the SMBH formation scenario by the gravitational collapse of the coherent dark matter (DM) composed from the Bose-Einstein Condensed (BEC) objects. A difficult problem in this scenario is the inevitable angular momentum which prevents the collapse of BEC. To overcome this difficulty, in this paper, we consider the very early Universe when the BEC-DM acquires its proper angular momentum by the tidal torque mechanism. The balance of the density evolution and the acquisition of the angular momentum determines the mass of the SMBH as well as the mass ratio of BH and the surrounding dark halo (DH). This ratio is calculated as MBH/MDH≈10−3∼−5(Mtot/1012M⊙)−1/2 assuming simple density profiles of the initial DM cloud. This result turns out to be consistent with the observations at z≈0 and z≈6, although the data scatter is large. Thus, the angular momentum determines the separation of black and dark, i.e., SMBH and DH, in the original DM cloud.