bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Manufacturing Process in Structural Health Monitoring and Mechanical Behaviour of CNT Reinforced CFRP and Ti6Al4V Multi-Material Joints
Authors: Dasilva S. , Jimenez-Suarez A. , Rodríguez E. , Prolongo S. G.
Published: July 2021

Co-cured multi-material metal–polymer composites joints are recent interesting structural materials for locally reinforcing a structure in specific areas of high structural requirements, in fibre metal laminates and lightweight high-performance structures. The influence of manufacturing processes on the morphological quality and their mechanical behaviour has been analysed on joints constituted by sol-gel treated Ti6Al4V and carbon fibre reinforced composites (CFRP). In addition, carbon nanotubes (CNT) have been added to an epoxy matrix to develop multiscale CNT reinforced CFRP, increasing their electrical conductivity and allowing their structural health monitoring (SHM). Mechanical behaviour of manufactured multi-material joints is analysed by the measurement of lap shear strength (LSS) and Mode I adhesive fracture energy (GIC) using double cantilever beam specimens (DCB). It has been proven that the addition of MWCNT improves the conductivity of the multi-material joints, even including surface treatment with sol-gel, allowing structural health monitoring (SHM). Moreover, it has been proven that the manufacturing process affects the polymer interface thickness and the porosity, which strongly influence the mechanical and SHM behaviour. On the one hand, the increase in the adhesive layer thickness leads to a great improvement in mode I fracture energy. On the other hand, a lower interface thickness enhances the SHM sensibility due to the proximity between MWCNT and layers of conductive substrates, carbon woven and titanium alloy.
The Low Breaking Fiber Mechanism and Its Effect on the Behavior of the Melt Flow of Injection Molded Ultra-Long Glass Fiber Reinforced Polypropylene Composites
Authors: Huang Po-Wei , Peng Hsin-Shu , Hwang Sheng-Jye , Huang Chao-Tsai
Published: July 2021

In this study, fiber breaking behavior, fiber orientation, length variation, and changes in melt flow ability of long glass fiber reinforced polypropylene (L-FRP) composites under different mold cavity geometry, melt fill path, and plasticization parameters were investigated. The matrix material used was polypropylene and the reinforcement fibers were 25 mm long. An ultra-long-fiber composite injection molding machine (with a three-stage plunger and injection mechanism design) was used with different mold cavity geometry and plasticization parameters. Different screw speeds were used to explore the changes in fiber length and to provide a reference for setting fiber length and parameter combinations. Flow-length specimen molds with different specimen thickness, melt fill path, and gate design were used to observe the effect of plasticizing properties on the flow ability of the L-FRP composite materials. The experimental results showed that the use of an injection molding machine with a mechanism that reduced the amount of fiber breakage was advantageous. It was also found that an increase in screw speed increased fiber breakage, and 25 mm long fibers were shortened by an average of 50% (to 10 mm). Long fibers were more resistant to melt filling than short fibers. In addition, the thickness of the specimen and the gate design were also found to affect the filling process. The rounded angle gate and thick wall product decreased the flow resistance and assisted the flow ability and fiber distribution of the L-FRP injection molding.
Synthesis and Characterization of New Ferrite-Lignin Hybrids
Authors: Spiridon Iuliana , Dascalu Ioan-Andrei , Coroaba Adina , Apostol Irina , Palamaru Mircea Nicolae , Iordan Alexandra Raluca , Borhan Adrian Iulian
Published: July 2021

The paper presents the synthesis and characterization of new cobalt ferrite-lignin hybrids. The hybrids were obtained through the combustion of cobalt nitrate and ferric nitrate, two kinds of lignin being used as combustion agents. The temperatures of calcination were 500 °C and 900 °C, respectively. The hybrids were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and X-ray photoelectron spectroscopy (XPS). The magnetic properties were also assessed by vibrating sample magnetometer system (VSM). This facile synthesis method made it possible to obtain cobalt ferrite-lignin hybrids with a spinel structure. Their particle sizes and crystallite sizes have increased with an increment in the calcination temperature. A different occupancy of cations at octahedral and tetrahedral sites also occurred upon the increase in temperature. The hybrids comprising organic lignin presented the best magnetic properties.
Photochromic Polyamide 6 Based on Spiropyran Synthesized via Hydrolyzed Ring-Opening Polymerization
Authors: Tian Shiyou , Zhang Jicong , Zhou Qiong , Shi Limei , Wang Wenwen , Wang Dong
Published: July 2021

We report photochromic polyamide 6 (PA6) which was synthesized by hydrolyzed ring-opening polymerization of ε-caprolactam with spiropyran (SP) embedded in the polymer chains. It indicated that crystallinity degree of the resulting copolymers was decreased since only PA6 segments can crystallize with increasing content of SP modifier. Meanwhile, toughness of photochromic PA6 was decreased. The photochromic property analysis indicated that the sample with more flexibility and more content of SP was more sensitive to UV light at the beginning of irradiation than other samples and its color after being irradiated for 1 min tended to reddish. Investigation revealed that the UV-vis absorbance of SP-PA6-3 had negligible decay after 10 cycles, which indicated SP-modified PA6 possessed excellent photoresponse reversibility and fatigue resistance.
The Effect of Clarithromycin Toxicity on the Growth of Bacterial Communities in Agricultural Soils
Authors: Rodríguez-González Laura , Santás-Miguel Vanesa , Campillo-Cora Claudia , Arias-Estévez Manuel , Fernández-Calviño David
Published: July 2021

The presence of antibiotics in different environmental matrices is a growing concern. The introduction of antibiotics into the soil is mainly due to sewage treatment plants. Once in the soil, antibiotics may become toxic to microbial communities and, as a consequence, can pose a risk to the environment and human health. This study evaluates the potential toxicity of the antibiotic clarithromycin (CLA) in relation to the bacterial community of 12 soils with different characteristics. Bacterial community growth was evaluated in soils spiked in the laboratory with different concentrations of CLA after 1, 8, and 42 incubation days. The results indicated that the addition of clarithromycin to the soil may cause toxicity in the bacterial communities of the soil. In addition, it was observed that toxicity decreases between 1 and 8 incubation days, while the bacterial community recovers completely in most soils after 42 incubation days. The results also show that soil pH and effective cation exchange capacity may influence CLA toxicity.
Effects of Dynamic Pricing on the Design and Operation of Distributed Energy Resource Networks
Authors: Sidnell Tim , Dorneanu Bogdan , Mechleri Evgenia , Vassiliadis Vassilios S. , Arellano-Garcia Harvey
Published: July 2021

This paper presents a framework for the use of variable pricing to control electricity imported/exported to/from both fixed and unfixed residential distributed energy resource (DER) network designs. The framework shows that networks utilizing much of their own energy, and importing little from the national grid, are barely affected by dynamic import pricing, but are encouraged to sell more by dynamic export pricing. An increase in CO2 emissions per kWh of energy produced is observed for dynamic import and export, against a baseline configuration utilizing constant pricing. This is due to feed-in tariffs (FITs) that encourage CHP generation over lower-carbon technologies. Furthermore, batteries are shown to be expensive in systems receiving income from FITs and grid exports, but for the cases when they sell to/buy from the grid using dynamic pricing, their use in the networks becomes more economical.
Mean-Reverting 4/2 Principal Components Model. Financial Applications
Authors: Escobar-Anel Marcos , Gong Zhenxian
Published: July 2021

In this paper, we propose a new multivariate mean-reverting model incorporating state-of-the art 4/2 stochastic volatility and a convenient principal component stochastic volatility (PCSV) decomposition for the stochastic covariance. We find a quasi closed-form characteristic function and propose analytic approximations, which aid in the pricing of derivatives and calculation of risk measures. Parameters are estimated on three bivariate series, using a two-stage methodology involving method of moments and least squares. Moreover, a scaling factor is added for extra degrees of freedom to match data features. As an application, we consider investment strategies for a portfolio with two risky assets and a risk-free cash account. We calculate value-at-risk (VaR) values at a 95% risk level using both simulation-based and distribution-based methods. A comparison of these VaR values supports the effectiveness of our approximations and the potential for higher dimensions.
Improved Gridded Precipitation Data Derived from Microwave Link Attenuation
Authors: Silver Micha , Karnieli Arnon , Fredj Erick
Published: July 2021

The motivation for improving gridded precipitation data lies in weather now-casting and flood forecasting. Therefore, over the past decade, Commercial Microwave Link (CML) attenuation data have been used to determine rain rates between microwave antennas, and to produce more accurate countrywide precipitation grids. CML networks offer a unique advantage for precipitation measurements due to their high density. However, these data experience uncertainty from several sources as reported in earlier research. This current work determines the reliability of rainfall measurements for each link by comparing CML-derived rain rates to adjusted weather radar rainfall at the link location, over three months. Dynamic Time Warping (DTW) is applied to the pair of CML/radar time-series data in two study areas, Israel and Netherlands. Based on the DTW amplitude and temporal distance, unreliable links are identified and flagged, and interpolated gridded precipitation data are derived in each country after filtering out those unreliable links. Correlations between CML-derived grids and rain observations from an independent set of gauges, tested over several rain events in both study areas, are higher for the reliable subset of CML than the full set. For certain storm events, the Kendall rank correlation for the set of reliable CML is almost double that of the complete set, demonstrating that improved gridded precipitation data can be obtained by removing unreliable links.
3D Imaging Algorithm of Directional Borehole Radar Based on Root-MUSIC
Authors: Wang Wentian , Liu Sixin , Shen Xuzhang , Zheng Wenjun
Published: July 2021

A directional borehole radar consists of one transmitting antenna in the borehole and four receiving antennas distributed at equal angles in a ring. The receiving antennas can determine the depth and orientation of targets beside the borehole. However, the problem of target orientation determination and 3D imaging algorithms remains a technological challenge. The MUSIC (multiple signal classification) algorithm requires a peak search, so the accuracy of the operation is limited by the angle interval. Based on the MUSIC algorithm, the Root-MUSIC algorithm is proposed and implemented. By replacing the spectral peak search with calculating the roots of the polynomials greatly improves the orientation recognition accuracy. Finally, the results obtained using the above algorithm are verified with synthetic data and compared with the results of the MUSIC algorithm. The results show that both the MUSIC algorithm and the Root-MUSIC algorithm can achieve very good orientation determination and 3D imaging results. In terms of accuracy, the Root-MUSIC algorithm has an obvious improvement compared with the MUSIC algorithm.
Effect of Attention Mechanism in Deep Learning-Based Remote Sensing Image Processing: A Systematic Literature Review
Authors: Ghaffarian Saman , Valente João , van der Voort Mariska , Tekinerdogan Bedir
Published: July 2021

Machine learning, particularly deep learning (DL), has become a central and state-of-the-art method for several computer vision applications and remote sensing (RS) image processing. Researchers are continually trying to improve the performance of the DL methods by developing new architectural designs of the networks and/or developing new techniques, such as attention mechanisms. Since the attention mechanism has been proposed, regardless of its type, it has been increasingly used for diverse RS applications to improve the performances of the existing DL methods. However, these methods are scattered over different studies impeding the selection and application of the feasible approaches. This study provides an overview of the developed attention mechanisms and how to integrate them with different deep learning neural network architectures. In addition, it aims to investigate the effect of the attention mechanism on deep learning-based RS image processing. We identified and analyzed the advances in the corresponding attention mechanism-based deep learning (At-DL) methods. A systematic literature review was performed to identify the trends in publications, publishers, improved DL methods, data types used, attention types used, overall accuracies achieved using At-DL methods, and extracted the current research directions, weaknesses, and open problems to provide insights and recommendations for future studies. For this, five main research questions were formulated to extract the required data and information from the literature. Furthermore, we categorized the papers regarding the addressed RS image processing tasks (e.g., image classification, object detection, and change detection) and discussed the results within each group. In total, 270 papers were retrieved, of which 176 papers were selected according to the defined exclusion criteria for further analysis and detailed review. The results reveal that most of the papers reported an increase in overall accuracy when using the attention mechanism within the DL methods for image classification, image segmentation, change detection, and object detection using remote sensing images.
Sensor-Enabled Multi-Robot System for Automated Welding and In-Process Ultrasonic NDE
Authors: Vasilev Momchil , MacLeod Charles N. , Loukas Charalampos , Javadi Yashar , Vithanage Randika K. W. , Lines David , Mohseni Ehsan , Pierce Stephen Gareth , Gachagan Anthony
Published: July 2021

The growth of the automated welding sector and emerging technological requirements of Industry 4.0 have driven demand and research into intelligent sensor-enabled robotic systems. The higher production rates of automated welding have increased the need for fast, robotically deployed Non-Destructive Evaluation (NDE), replacing current time-consuming manually deployed inspection. This paper presents the development and deployment of a novel multi-robot system for automated welding and in-process NDE. Full external positional control is achieved in real time allowing for on-the-fly motion correction, based on multi-sensory input. The inspection capabilities of the system are demonstrated at three different stages of the manufacturing process: after all welding passes are complete; between individual welding passes; and during live-arc welding deposition. The specific advantages and challenges of each approach are outlined, and the defect detection capability is demonstrated through inspection of artificially induced defects. The developed system offers an early defect detection opportunity compared to current inspection methods, drastically reducing the delay between defect formation and discovery. This approach would enable in-process weld repair, leading to higher production efficiency, reduced rework rates and lower production costs.
Development of an Easy-to-Operate Underwater Raman System for Deep-Sea Cold Seep and Hydrothermal Vent In Situ Detection
Authors: Liu Qingsheng , Guo Jinjia , Ye Wangquan , Cheng Kai , Qi Fujun , Zheng Ronger , Sun Zhilei , Zhang Xilin
Published: July 2021

As a powerful in situ detection technique, Raman spectroscopy is becoming a popular underwater investigation method, especially in deep-sea research. In this paper, an easy-to-operate underwater Raman system with a compact design and competitive sensitivity is introduced. All the components, including the optical module and the electronic module, were packaged in an L362 × Φ172 mm titanium capsule with a weight of 20 kg in the air (about 12 kg in water). By optimising the laser coupling mode and focusing lens parameters, a competitive sensitivity was achieved with the detection limit of SO42− being 0.7 mmol/L. The first sea trial was carried out with the aid of a 3000 m grade remotely operated vehicle (ROV) “FCV3000” in October 2018. Over 20,000 spectra were captured from the targets interested, including methane hydrate, clamshell in the area of cold seep, and bacterial mats around a hydrothermal vent, with a maximum depth of 1038 m. A Raman peak at 2592 cm−1 was found in the methane hydrate spectra, which revealed the presence of hydrogen sulfide in the seeping gas. In addition, we also found sulfur in the bacterial mats, confirming the involvement of micro-organisms in the sulfur cycle in the hydrothermal field. It is expected that the system can be developed as a universal deep-sea survey and detection equipment in the near future.
Aircraft Detection Using Phase-Sensitive Optical-Fiber OTDR
Authors: Cai Yunpeng , Ma Jihui , Yan Wenfa , Zhang Wenyi , An Yuhang
Published: July 2021

Aircraft detection plays a vital role in aviation management and safe operation in the aviation system. Phase-Sensitive Optical Time Domain Reflectometry (Φ-OTDR) technology is a prevailing sensing method in geophysics research, structure inspection, transportation detection, etc. Compared with existing video- or radio-based detection methods, Φ-OTDR is cost-effective, suitable for long-distance detection, and resistant to severe weather conditions. We present a detection system using Φ-OTDR technology and analyze the character of the acoustic signal of aircraft. Instead of runway monitoring in the airport or noise detection in the air, this study focuses on the detection of seismic vibration signal excited by the sound of aircraft. The Chebyshev filter is adopted to eliminate the impact of background noise and random noise from the original vibration signal; the short-time Fourier transform is used for time-frequency analysis. The experimental results showed that the seismic vibration signal excited by the aircraft sound is mainly low-frequency, which is under 5 Hz. Time delay of aircraft vibration signal in different locations of the optic fiber is recorded by the sensing system. The Doppler effect is also revealed by the time-domain analysis: the frequency increases when the aircraft is approaching and decreases when the aircraft moves away.
A Performance Benchmark for Dedicated Short-Range Communications and LTE-Based Cellular-V2X in the Context of Vehicle-to-Infrastructure Communication and Urban Scenarios
Authors: Petrov Tibor , Sevcik Lukas , Pocta Peter , Dado Milan
Published: July 2021

For more than a decade, communication systems based on the IEEE 802.11p technology—often referred to as Dedicated Short-Range Communications (DSRC)—have been considered a de facto industry standard for Vehicle-to-Infrastructure (V2I) communication. The technology, however, is often criticized for its poor scalability, its suboptimal channel access method, and the need to install additional roadside infrastructure. In 3GPP Release 14, the functionality of existing cellular networks has been extended to support V2X use cases in an attempt to address the well-known drawbacks of the DSRC. In this paper, we present a complex simulation study in order to benchmark both technologies in a V2I communication context and an urban scenario. In particular, we compare the DSRC, LTE in the infrastructural mode (LTE-I), and LTE Device-to-Device (LTE-D2D) mode 3 in terms of the average end-to-end delay and Packet Delivery Ratio (PDR) under varying communication conditions achieved through the variation of the communication perimeter, message generation frequency, and road traffic intensity. The obtained results are put into the context of the networking and connectivity requirements of the most popular V2I C-ITS services. The simulation results indicate that only the DSRC technology is able to support the investigated V2I communication scenarios without any major limitations, achieving an average end-to-end delay of less than 100 milliseconds and a PDR above 96% in all of the investigated simulation scenarios. The LTE-I is applicable for the most of the low-frequency V2I services in a limited communication perimeter (<600 m) and for lower traffic intensities (<1000 vehicles per hour), achieving a delay pf less than 500 milliseconds and a PDR of up to 92%. The LTE-D2D in mode 3 achieves too great of an end-to-end delay (above 1000 milliseconds) and a PDR below 72%; thus, it is not suitable for the V2I services under consideration in a perimeter larger than 200 m. Moreover, the LTE-D2D mode 3 is very sensitive to the distance between the transmitter and its serving eNodeB, which heavily impacts the PDR achieved.
Educating for the Environment: The Role of the Host Destination in Education Travel Programs
Authors: Hale Brack W.
Published: July 2021

The benefits from educational travel programs (ETPs) for students have been well-documented in the literature, particularly for programs looking at sustainability and environmental issues. However, the impacts the ETPs have on the destinations that host them have been less frequently considered; most of these studies focus, understandably, on destinations in the Global South. This paper draws on a framework of sustainable educational travel to examine how ETPs affect their host destinations in two case study destinations, based on the author’s professional experience in these locations, interviews with host organizations that use the lens of the pandemic, and information from government databases. The findings highlight an awareness of the sustainability of the destination, the importance of good, local partnerships with organizations well-connected in their communities, and educational activities that can benefit both students and hosts. Nonetheless, we have a long way to go to understand the full impacts of ETPs on their host destinations and thus truly learn to avoid them.
An Inclusive Model for Assessing Age-Friendly Urban Environments in Vulnerable Areas
Authors: Agost-Felip Raquel , Ruá María José , Kouidmi Fatiha
Published: July 2021

Population aging is becoming a major challenge in many countries. This paper deals with the elderly’s specific needs in the public open space as it can play a significant role in their social inclusion and could be especially relevant in deprived areas. The main goal is to build a model to evaluate the vulnerability of the public space by focusing on the elderly’s needs, using indicators. A previous analysis of the scientific and policy-oriented literature and of the technical standards and regulations linked with accessibility and social aspects that affect the elderly in urban areas was performed to identify the main dimensions for evaluation. The interjudge agreement technique was applied to validate the indicators with a panel of experts in technical and social disciplines. The model was applied to a vulnerable area in Castellón (East Spain), based on indicators adapted to the specific context features. The agreement level reached by experts was used to weight the indicators. The application of the model permitted the vulnerability in the suggested dimensions to be estimated and a global integrated index of vulnerability in the area to be calculated. It could assist in urban planning decision making toward age-friendly and, therefore, inclusive cities.
Circular Economy Strategies: Use of Corn Waste to Develop Biomaterials
Authors: Castrillón Hernán Darío Castaño , Aguilar Carlos Mario Gutiérrez , Álvarez Beatriz Elena Angel
Published: July 2021

The circular economy is a process through which elements that have already been used are reincorporated and given a second use so that they can reduce the consumption of virgin raw materials. This article shows how, from the reuse of an agro-industrial waste such as corn husks, a biomaterial can be developed that manages to standardize the properties of materials such as paper and cardboard, thus allowing the development of single-use products that replace the excessive expense of materials such as polymers. In this article, it will be possible to show how from the process of transforming an agro-industrial waste into a raw material base, it is possible not only to reduce the number of raw materials discarded but also to redesign a product that not only contributes to the environmental component but also facilitates the processes of economic sustainability when generating products. As a practical case, a comparison is made between traditional fast-food packaging and how from these, a new packaging proposal can be generated, which starts from the principles of circular economy and complements sustainable design processes to make more efficient manufacturing of the mentioned product.
Perceptions about Tourism and Tourists in Historic Neighborhoods: The Case of Alfama
Authors: Madeira Arlindo , Palrão Teresa , Mendes Alexandra Sofia , López-Morales Ernesto
Published: July 2021

Tourism makes destinations adapt to receive those who visit them, with a great impact among traditional residents. Overtourism affects picturesque places, and these areas end up losing their authenticity, submitting themselves to the consumption needs of tourists. Neighborhoods’ traditional residents also see their routine completely changed due to the different habits of tourists, and displacement rates rise. This study aims to understand how local people perceive tourism in Alfama, one of the most unique and tourist-oriented neighborhoods of Lisbon. Our study involves a questionnaire to old long-term residents and content analysis of their responses. We used Leximancer software to create categories of analysis depending on frequency of mentions and the way themes are related. Our interviewees testified that overtourism in Alfama generates perceptions that range from a generalized acceptance for the benefits that an improved safety associated to an increased street-life and a cleaner neighborhood generate, and on the other hand the grievance for the loss of a pre-existing community. We also conclude that the benefits of tourist-led gentrification are relevant for the gentrification analysis because they show the contradictions that the remaining residential community experience as tourist-led gentrification unfolds.
Why Is Collaborative Apparel Consumption Gaining Popularity? An Empirical Study of US Gen Z Consumers
Authors: McCoy Lindsay , Wang Yuan-Ting , Chi Ting
Published: July 2021

Apparel rental, also known as collaborative apparel consumption, has created an innovative and popular business model, providing consumers with the ability to focus on using their products instead of ownership. Recent surveys show that sustainability is driving demand and customer loyalty in the US. Among all generations, Gen Z consumers lead the way. To better understand the emerging popularity of apparel rental services among Gen Z consumers who are becoming a major driving force for retail growth and the sustainability movement, this study aimed to identify the factors significantly influencing Gen Z consumers’ intention to use apparel rental services; 362 eligible responses were gathered via a questionnaire survey. The psychometric properties of the proposed model were examined, and the multiple regression method was applied to test the hypotheses. Attitude, subject norms, perceived consumer effectiveness, past environmental behavior, and fashion leadership significantly affected Gen Z consumers’ intentions to use apparel rental services. Attitude plays a mediating role between Gen Z consumers’ environmental knowledge, fashion leadership, need for uniqueness, and their intention to use apparel rental services. The proposed research model exhibited good explanatory power, accounting for 58.6% of the variance in Gen Z consumers’ use intention toward apparel rental services.
Nexus between Natural Resources and Environmental Degradation: Analysing the Role of Income Inequality and Renewable Energy
Authors: Wang Yongming , Uddin Irfan , Gong Yingmei
Published: July 2021

Globally, as the environment deteriorates, use of renewable energy is increasing. The discrepancy between inequalities, sustainable sources, and natural resources, on the other hand, is enormous. As a consequence, the current research simulated the link between income inequality, renewable energy, and carbon emissions from 1990 to 2018. The long run and short run interaction were estimated using an autoregressive distribution lag (ARDL) model. According to the study’s findings, improvements in sustainable power, as well as income inequality, are producing a rise in environmental quality. Natural resources seem to have a significantly positive influence on the environment’s quality. Furthermore, the study found that financial development and environmental quality have a bidirectional causal link. According to the conclusions of this study, government authorities should support the use of renewable energy, i.e., sources to optimize carbon release.
Determining Factors Affecting Acceptance of E-Learning Platforms during the COVID-19 Pandemic: Integrating Extended Technology Acceptance Model and DeLone & McLean IS Success Model
Authors: Prasetyo Yogi Tri , Ong Ardvin Kester S. , Concepcion Giero Krissianne Frances , Navata Francheska Mikaela B. , Robles Raphael Andrei V. , Tomagos Isaiash Jeremy T. , Young Michael Nayat , Diaz John Francis T. , Nadlifatin Reny , Redi Anak Agung Ngurah Perwira
Published: July 2021

Online meeting platforms have been widely utilized during the COVID-19 pandemic due to the current shift from traditional learning. However, the acceptance of the different online meeting platforms for e-learning has been underexplored. The purpose of this study was to determine the factors for acceptance of an online learning platform among students during the COVID-19 pandemic. A total of 500 senior high school students voluntarily participated to answer constructs under the Extended Technology Acceptance Model (ETAM) and Delone and McLean IS Success Model. Several latent including user interface (UI), perceived ease of use (PEU), perceived usefulness (PU), information quality (IQ), system quality (SQ), behavioral intentions (BI), and actual use were analyzed by Structural Equation Modeling (SEM). The results indicated that PEU was found to have the greatest on actual use (AU), followed by UI and SQ towards PEU, which subsequently led to BI and AU. Finally, IQ was found to have a significant effect on PU, which led to BI and AU. The level of student acceptability considers the ease of use, user interface, system quality, information quality, leading to a positive behavioral intention for actual use. With that, it would be of best interest to consider the factors that would lead students towards accepting the platforms utilized and therefore the current education system. Moreover, this will lead to their acceptance and promote learning even with the COVID-19 pandemic. Finally, the model construct can be applied and utilized to analyze the online learning platforms in other countries.
Domestic Food Waste and Covid-19 Concern: An Application of the Theory of Planned Behaviour
Authors: Amato Mario , Verneau Fabio , Coppola Adele , La Barbera Francesco
Published: July 2021

The ongoing Covid-19 pandemic rapidly and dramatically disrupted household behaviours in almost all areas and, among these, eating behaviours and daily food patterns have also been radically altered. All reported changes have potential effects in terms of food waste, which is a global problem that mainly occurs at household level. Many scholars attempted to understand the antecedents of food waste in the framework of Theory of Planned Behaviour (TPB). In this paper we follow this strain of research by focussing on two different behaviours, suggested by the Waste Framework Directive of the EU, namely (a) reducing servings and (b) using leftovers, which may be predicted by the intention to reduce food waste. An online questionnaire containing the key constructs of the TPB and the concern towards the pandemic was administered to a sample of 201 Italian consumers. Results show that the TPB model was confirmed for both behaviours while the Covid-19 concern had no direct effect. However, in the case of portion reduction, there is a significant interaction between concern and intention not to waste food. That is, the effect of intention on reducing servings is increasing as the level of concern increases. Therefore, some indications on how to address food waste policies are drawn.
Environmental Impacts of Using Municipal Biosolids on Soil, Plant and Groundwater Qualities
Authors: Ali Majeed , Ahmed Talaat , Abu-Dieyeh Mohammed , Al-Ghouti Mohammad
Published: July 2021

This study was conducted to evaluate the effect of three different rates of municipal biosolids produced in Qatar on plant characteristics and soil texture and its potential impacts on groundwater. Petunia atkinsiana, was used in this study. The experiment took place in a greenhouse in pots with soil mixed with 0, 3, 5, and 7 kg/m2 biosolids. Pelletized class A biosolids from the Doha North Sewage Treatment Plant were used. Results revealed significant differences in all measured parameters, which were affected by biosolid treatments compared to the control treatment. Electrical conductivity, pH, macro and micronutrients and heavy metals were significantly affected by biosolid treatments. The comparison of the discovered levels against the international acceptable ceilings of pollutants indicated the advantages of utilizing class A biosolids, as they were well below the international acceptable levels and showed the best test rates, indicating that the product is a sustainable and efficient organic fertilizer for ornamental plants. Furthermore, the results highlight no potential significant impacts on groundwater due to trace presence of heavy metals, owing to the nature of deep groundwater in Qatar and the usage of modern irrigation devices that fulfil the exact needs of plants in a harsh climate and high evaporation rate.
Halotolerant Microbial Consortia for Sustainable Mitigation of Salinity Stress, Growth Promotion, and Mineral Uptake in Tomato Plants and Soil Nutrient Enrichment
Authors: Kapadia Chintan , Sayyed R. Z. , El Enshasy Hesham Ali , Vaidya Harihar , Sharma Deepshika , Patel Nafisa , Malek Roslinda Abd , Syed Asad , Elgorban Abdallah M. , Ahmad Khurshid , Zuan Ali Tan Kee
Published: July 2021

Salinity significantly impacts the growth, development, and reproductive biology of various crops such as vegetables. The cultivable area is reduced due to the accumulation of salts and chemicals currently in use and is not amenable to a large extent to avoid such abiotic stress factors. The addition of microbes enriches the soil without any adverse effects. The effects of microbial consortia comprising Bacillus sp., Delftia sp., Enterobacter sp., Achromobacter sp., was evaluated on the growth and mineral uptake in tomatoes (Solanum Lycopersicum L.) under salt stress and normal soil conditions. Salinity treatments comprising Ec 0, 2, 5, and 8 dS/m were established by mixing soil with seawater until the desired Ec was achieved. The seedlings were transplanted in the pots of the respective pH and were inoculated with microbial consortia. After sufficient growth, these seedlings were transplanted in soil seedling trays. The measurement of soil minerals such as Na, K, Ca, Mg, Cu, Mn, and pH and the Ec were evaluated and compared with the control 0 days, 15 days, and 35 days after inoculation. The results were found to be non-significant for the soil parameters. In the uninoculated seedlings’ (control) seedling trays, salt treatment significantly affected leaf, shoot, root dry weight, shoot height, number of secondary roots, chlorophyll, and mineral contents. While bacterized seedlings sown under saline soil significantly increased leaf (105.17%), shoot (105.62%), root (109.06%) dry weight, leaf number (75.68%), shoot length (92.95%), root length (146.14%), secondary roots (91.23%), and chlorophyll content (−61.49%) as compared to the control (without consortia). The Na and K intake were higher even in the presence of the microbes, but the beneficial effect of the microbe helps plants sustain in the saline environment. The inoculation of microbial consortia produced more secondary roots, which accumulate more minerals and transport substances to the different parts of the plant; thus, it produced higher biomass and growth. Results of the present study revealed that the treatment with microbial consortia could alleviate the deleterious effects of salinity stress and improve the growth of tomato plants under salinity stress. Microbial consortia appear to be the best alternative and cost-effective and sustainable approach for managing soil salinity and improving plant growth under salt stress conditions.
Sustainable Development of a Mobile Payment Security Environment Using Fintech Solutions
Authors: Hwang Yoonyoung , Park Sangwook , Shin Nina
Published: July 2021

Financial technology (fintech) services have come to differentiate themselves from traditional financial services by offering unique, niche, and customized services. Mobile payment service (MPS) has emerged as the most crucial fintech service. While many studies have addressed the essential role of security when service providers and users choose to engage in financial transactions, the relationship between users distinct perceptions of security and MPS success determinants are yet to be examined. Thus, this study primarily aims to uncover the distinctive roles of platform and technology security by investigating how users react differently to their varying understandings of the MPS usage environment. This study proposes a research model comprising two security dimensions (platform and technology) and three MPS success determinants (convenience, interoperability, and trust). We evaluated the proposed model empirically by using an online survey of 356 users. The survey accounts users experiences of the selected MPS. The results show that a security driven MPS can essentially enhance or deteriorate users positive perceptions of MPS success determinants while they use it for financial transactions. To further understand how this recent trend of user perception of security affects the overall MPS usage experience, this study provides theoretical insights into the roles of platform and technology securities. Managerial insights on the design strategies of MPS providers are also provided based on the potential implications of users subjective and objective perceptions of MPS security environment.
What Stirs Consumers to Purchase Carbon-Friendly Food? Investigating the Motivational and Emotional Aspects in Three Studies
Authors: Penz Elfriede , Hofmann Eva
Published: July 2021

As part of diminishing climate change, food consumption needs to be addressed to reduce greenhouse gases. In order to change food consumption habits to carbon-friendly eating patterns, consumers may be targeted by information campaigns and legal regulation. The current paper studies consumers’ diets and food purchase behavior. In particular, it aims to understand consumers’ motivational and emotional aspects that influence their behavior. Study 1, an interview study, aims to understand the development of and motivations for climate-friendly nutrition. Identifying eco-friendly motives also revealed that emotions seem to play an important role in nutrition and the purchase of climate-friendly products. Study 2 aims at identifying consumers’ positive and negative emotions when it comes to consuming carbon-friendly food. Again, qualitative interviews revealed a variety of positive and negative emotions. Study 3 quantitatively tested the theory of planned behavior, including positive and negative emotions and predicted carbon-friendly food purchases. The results show that attitudes, perceived behavioral control and positive emotions predict carbon-friendly food purchases. Derived from these findings, recommendations for information campaigns and legislation to foster carbon-friendly food purchases are presented.
What Makes Me Want You Here? Refugee Integration in a Zambian Settlement Setting
Authors: Gronau Steven , Ruesink Brigitte
Published: July 2021

Many of the world’s refugees remain in Africa, where they stay long-term, mainly in neighboring countries. The present directions point to integration, in which the host society and the political surroundings play a key role. This paper aims to investigate the ways in which public opinion towards and contact with refugees support integration processes. We apply this research to a settlement setting in rural Zambia, a recent dataset of 275 households from 2018, and an econometric analysis. This is the first study dealing with a set of factors that affect the hosts’ opinion towards and contact with refugees in an African settlement context, and with respect to the Comprehensive Refugee Response Framework produced by the United Nations. Our results show, particularly, the religiosity, group membership, life satisfaction, food insecurity, agricultural ownership and natural resource uses of the host society to be the main factors that need policy consideration for the promotion of refugee integration. Stakeholders dealing in host–refugee settings and seeking for durable solutions should roll out community programs to address threat perceptions and interaction improvements.
Indigenous Environmental Justice and Sustainability: What Is Environmental Assimilation?
Authors: Tsuji Stephen R. J.
Published: July 2021

Canada has a long history of assimilative efforts with respect to Indigenous peoples. Legal assimilation efforts occurred on two fronts: the voluntary and involuntary enfranchisement of First Nations people, and the dissolution of First Nations reserve lands. Cultural assimilation occurred through the residential school system, and the removal of Indigenous children from their homes by Canadian child welfare agencies in the “sixties scoop”. Another form of assimilation is through environmental assimilation. I define environmental assimilation as changes to the environment through development, to the extent whereby the environment can no longer support Indigenous cultural activities. Herein, I examine environmental assimilation in northern Ontario, Canada. The “taken-up” clause in Treaty No. 9, the “Exemption Orders” in the Far North Act, the “Except” stipulation in the Mining Amendment Act, and the unilateral streamlining of projects in the Green Energy Act and the COVID-19 Economic Recovery Act—these pieces of legislation pose threats to the environment and serve to facilitate the reality of contemporary environmental assimilation of First Nations.
Study of the Properties of Full Component Recycled Dry-Mixed Masonry Mortar and Concrete Prepared from Construction Solid Waste
Authors: Hu Zhenwen , Kong Zhe , Cai Guisheng , Li Qiuyi , Guo Yuanxin , Su Dunlei , Liu Junzhe , Zheng Shidong
Published: July 2021

Solutions are needed to solve the problem of a large amount of construction solid waste and a shortage of natural aggregate (coarse and fine aggregates). In this paper, simple-crushed coarse aggregate (SCRCA) and simple-crushed fine aggregate (SCRFA) were obtained by simple-crushing of construction solid waste. On this basis, SCRCA and SCRFA were treated with particle-shaping to obtain particle-shaping coarse aggregate (PSRCA) and particle-shaping fine aggregate (PSRFA), and the recycled powder (RP) produced in the process of particle-shaping was collected. Under the condition of a 1:4 cement-sand ratio, RP was used to replace cement with four substitution rates of 0, 10%, 20%, and 30%, and dry-mixed masonry mortar was prepared with 100% SCRFA, PSRFA, and river sand (RS). The basic and mechanical properties and microstructure of hydration products of dry-mixed mortar were analyzed, and the maximum substitution rate of RP was determined. Under the condition that the amount of cementitious material is 400 kg/m3 and the RP is at the maximum replacement rate, three different aggregate combinations to prepare concrete are the 100% use of SCRCA and SCRFA, PSRCA and PSRFA, and RS and natural aggregate (NCA); the workability, mechanical properties, and aggregate interface transition zone of the prepared concrete were analyzed. The results show that when the replacement rate of RP is less than 20%, it has little effect on the properties of products. The performance of PSRCA and PSRFA after treatment is better than that of SCRCA and SCRFA. Under different RP substitution rates, the performance of dry-mixed mortar prepared with PSRFA is very close to that prepared with RS. The performance of recycled concrete prepared with PSRCA and PSRFA is also very close to that of products prepared with NCA and RS. The failure morphology of PSRCA and RSRFA concrete is also similar to that of NCA and RS concrete.
R & D Attention and Profit Performance—An Empirical Study on Listed Companies in China’s Electric Power and Electrical Industries
Authors: Jing Shiyin , Li Yanbin , Sun Yulong
Published: July 2021

The electric power and electric industries are basic and strategic emerging industries in China’s national economy. Based on the data of listed companies in China’s electric power and electric industries from 2015 to 2019, this paper empirically studies the impact of research and development (R & D) attention on corporate profitability. The results show that attention to R & D by listed companies in electric power and electric industries will significantly improve enterprise’s profit performance, and this kind of effect has yearly heterogeneity. From 2015 to 2017, R & D attention gradually improved the profit performance of enterprises, but the profit spillover effect of R & D investment in recent years needs to be further strengthened. Further study found that R & D attention has a significant effect on corporate profitability in the private enterprise group, the R & D attention of state-owned enterprises and R & D structure adjustment should be paid more attention; R & D investment can significantly improve the profitability of the electrical industry, but the promotion effect was relatively slow in recent years, and R & D investment has a significant effect on the profitability of listed companies in the electric power industry. Although the promotion effect is not obvious, it shows a steady improvement trend. After variable and model replacement, the empirical regression conclusion of this paper is still robust. The results of this paper help to deepen the understanding of the stage characteristics of the impact of R & D attention on profit performance, and it is of great significance to optimize the efficiency of R & D investment and pay attention to the adjustment of R & D structure in the electric power and electrical industries.