bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterizing Particle-Scale Acceleration of Mud-Pumping Ballast Bed of Heavy-Haul Railway Subjected to Maintenance Operations
Authors: Wang Meng , Xiao Yuanjie , Li Wenqi , Zhao Hongjun , Hua Wenjun , Jiang Yu
Published: August 2022

Fouling and mud-pumping problems in ballasted track significantly degrade serviceability and jeopardize train operational safety. The phenomenological approaches for post hoc forensic investigation and remedies of mud pumps have relatively been well studied, but there still lacks studies on inherent mechanisms and ex ante approaches for early-age detection of mud pumps. This paper was aimed to exploring the feasibility of using particle acceleration responses to diagnose and identify early-age mud-pumping risks in real-world field applications. The innovative wireless sensors with 3D-printed shells resembling real shape of ballast particles were instrumented in the problematic railway section to monitor ballast particle movement prior to, during, and after maintenance operations, respectively. The real-time particle-scale acceleration data of ballast bed under both degraded and maintenance-restored clean conditions were recorded. The time histories, power spectra, and marginal spectra of 3D acceleration were comparatively analyzed. The results showed the 3D acceleration of ballast particles underneath rail-supporting tie plates displayed relatively clear periodicity of about 0.8 s with adjacent bogies regarded as a loading unit. The tamping operation was effective for compacting ballast bed laterally and improving the lateral interlocking of ballast particles, whereas the stabilizing operation was effective mainly in the lateral direction and for ballast particles underneath the sleepers. The mud pumps caused intensive particle-scale acceleration, and ballast particles underneath the sleepers were affected more severely than those in between adjacent sleepers. The ballast particles directly underneath tie plates exhibit dramatic acceleration variations due to maintenance operations as compared to those in other positions studied; hence, it seems promising to use particle-scale acceleration underneath tie plates as readily-implementable indicators for smart in-service track health monitoring.
Dynamic Warning Method for Structural Health Monitoring Data Based on ARIMA: Case Study of Hong Kong–Zhuhai–Macao Bridge Immersed Tunnel
Authors: Chen Jianzhong , Jiang Xinghong , Yan Yu , Lang Qing , Wang Hui , Ai Qing
Published: August 2022

Structural health monitoring (SHM) is gradually replacing traditional manual detection and is becoming a focus of the research devoted to the operation and maintenance of tunnel structures. However, in the face of massive SHM data, the autonomous early warning method is still required to further reduce the burden of manual analysis. Thus, this study proposed a dynamic warning method for SHM data based on ARIMA and applied it to the concrete strain data of the Hong Kong–Zhuhai–Macao Bridge (HZMB) immersed tunnel. First, wavelet threshold denoising was applied to filter noise from the SHM data. Then, the feasibility and accuracy of establishing an ARIMA model were verified, and it was adopted to predict future time series of SHM data. After that, an anomaly detection scheme was proposed based on the dynamic model and dynamic threshold value, which set the confidence interval of detected anomalies based on the statistical characteristics of the historical series. Finally, a hierarchical warning system was defined to classify anomalies according to their detection threshold and enable hierarchical treatments. The illustrative example of the HZMB immersed tunnel verified that a three-level (5.5 σ, 6.5 σ, and 7.5 σ) dynamic warning schematic can give good results of anomalies detection and greatly improves the efficiency of SHM data management of the tunnel.
MRI-Compatible Microcirculation System Using Ultrasonic Pumps for Microvascular Imaging on 3T MRI
Authors: Jung Ju-Yeon , Seo Dong-Kyu , Lee Yeong-Bae , Kang Chang-Ki
Published: August 2022

The diagnosis of small vessel disease is attracting interest; however, it remains difficult to visualize the microvasculature using 3 Tesla (T) magnetic resonance imaging (MRI). Therefore, this study aimed to visualize the microvascular structure and measure a slow flow on 3T MRI. We developed a microcirculation system using piezoelectric pumps connected to small tubes (0.4, 0.5, 0.8, and 1.0 mm) and evaluated various MR sequences and imaging parameters to identify the most appropriate acquisition parameters. We found that the system could image small structures with a diameter of 0.5 mm or more when using a 1 m-long tube (maximal signal intensity of 241 in 1 mm, 199 in 0.8 mm, and 133 in 0.5 mm). We also found that the highest signal-to-noise ratio (SNR) appeared on 2-dimensional time-of-flight low-resolution imaging and that the flow velocity (10.03 cm/s) was similar to the actual velocity (11.01 cm/s in a flowmeter) when velocity encoding of 30 cm/s was used in a 0.8 mm-diameter tube. In conclusion, this study demonstrates that a microcirculation system can be used to image small vessels. Therefore, our results could serve as a basis for research on vessels’ anatomical structure and pathophysiological function in small vessel disease.
Robust Handover Optimization Technique with Fuzzy Logic Controller for Beyond 5G Mobile Networks
Authors: Alraih Saddam , Nordin Rosdiadee , Abu-Samah Asma , Shayea Ibraheem , Abdullah Nor Fadzilah , Alhammadi Abdulraqeb
Published: August 2022

Mobility management is an essential process in mobile networks to ensure a high quality of service (QoS) for mobile user equipment (UE) during their movements. In fifth generation (5G) and beyond (B5G) mobile networks, mobility management becomes more critical due to several key factors, such as the use of Millimeter Wave (mmWave) and Terahertz, a higher number of deployed small cells, massive growth of connected devices, the requirements of a higher data rate, and the necessities for ultra-low latency with high reliability. Therefore, providing robust mobility techniques that enable seamless connections through the UE’s mobility has become critical and challenging. One of the crucial handover (HO) techniques is known as mobility robustness optimization (MRO), which mainly aims to adjust HO control parameters (HCPs) (time-to-trigger (TTT) and handover margin (HOM)). Although this function has been introduced in 4G and developed further in 5G, it must be more efficient with future mobile networks due to several key challenges, as previously illustrated. This paper proposes a Robust Handover Optimization Technique with a Fuzzy Logic Controller (RHOT-FLC). The proposed technique aims to automatically configure HCPs by exploiting the information on Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), and UE velocity as input parameters for the proposed technique. The technique is validated through various mobility scenarios in B5G networks. Additionally, it is evaluated using a number of major HO performance metrics, such as HO probability (HOP), HO failure (HOF), HO ping-pong (HOPP), HO latency (HOL), and HO interruption time (HIT). The obtained results have also been compared with other competitive algorithms from the literature. The results show that RHOT-FLC has achieved considerably better performance than other techniques. Furthermore, the RHOT-FLC technique obtains up to 95% HOP reduction, 95.8% in HOF, 97% in HOPP, 94.7% in HOL, and 95% in HIT compared to the competitive algorithms. Overall, RHOT-FLC obtained a substantial improvement of up to 95.5% using the considered HO performance metrics.
Potentiometric Electronic Tongue for Quantitative Ion Analysis in Natural Mineral Waters
Authors: Cuartero María , Ruiz Alberto , Galián Manuel , Ortuño Joaquín A.
Published: August 2022

The present paper addresses the development and use of a new potentiometric electronic tongue for both qualitative and quantitative characterization of natural mineral waters. The electronic tongue is particularly related to the conductivity and ion content of/in the water sample. The analytical system is based on six ion-selective electrodes whose membranes are formulated to provide either cationic or anionic response and considering plasticizers with different dielectric constants (bis(2-ethylhexyl) sebacate, 2-nitrophenyl octyl ether or tricresylphosphate), while keeping the polymeric matrix, i.e., poly(vinyl chloride). Notably, the absence of any ionophore in the membrane provides a general response profile, i.e., no selectivity toward any special ion, which is convenient for the realization of an effective electronic tongue. The dynamic response of the tongue toward water samples of different chemical compositions and geographical locations has been obtained. At the optimized experimental conditions, the tongue presents acceptable repeatability and reproducibility (absence of hysteresis). The principal component analysis of the final potential values observed with the six electrodes allows for the differentiation and classification of the samples according to their conductivity, which is somehow related to the mineralization. Moreover, quantitative determination of the six main ions in the water samples (i.e., chloride, nitrate, hydrogen carbonate, sulfate, sodium, calcium, and magnesium) is possible by means of a simple linear calibration (and cross-validation) model.
Inter-User Distance Estimation Based on a New Type of Fingerprint in Massive MIMO System for COVID-19 Contact Detection
Authors: Yang Siyuan , Bouazizi Mondher , Cao Yuwen , Ohtsuki Tomoaki
Published: August 2022

In this paper, we address the challenging task of estimating the distance between different users in a Millimeter Wave (mmWave) massive Multiple-Input Multiple-Output (mMIMO) system. The conventional Time of Arrival (ToA) and Angle of Arrival (AoA) based methods need users under the Line-of-Sight (LoS) scenario. Under the Non-LoS (NLoS) scenario, the fingerprint-based method can extract the fingerprint that includes the location information of users from the channel state information (CSI). However, high accuracy CSI estimation involves a huge overhead and high computational complexity. Thus, we design a new type of fingerprint generated by beam sweeping. In other words, we do not have to know the CSI to generate fingerprint. In general, each user can record the Received Signal Strength Indicator (RSSI) of the received beams by performing beam sweeping. Such measured RSSI values, formatted in a matrix, could be seen as beam energy image containing the angle and location information. However, we do not use the beam energy image as the fingerprint directly. Instead, we use the difference between two beam energy images as the fingerprint to train a Deep Neural Network (DNN) that learns the relationship between the fingerprints and the distance between these two users. Because the proposed fingerprint is rich in terms of the users’ location information, the DNN can easily learn the relationship between the difference between two beam energy images and the distance between those two users. We term it as the DNN-based inter-user distance (IUD) estimation method. Nonetheless, we investigate the possibility of using a super-resolution network to reduce the involved beam sweeping overhead. Using super-resolution to increase the resolution of low-resolution beam energy images obtained by the wide beam sweeping for IUD estimation can facilitate considerate improvement in accuracy performance. We evaluate the proposed DNN-based IUD estimation method by using original images of resolution 4 × 4, 8 × 8, and 16 × 16. Simulation results show that our method can achieve an average distance estimation error equal to 0.13 m for a coverage area of 60 × 30 m2. Moreover, our method outperforms the state-of-the-art IUD estimation methods that rely on users’ location information.
Trust and Mobility-Based Protocol for Secure Routing in Internet of Things
Authors: Muzammal Syeda Mariam , Murugesan Raja Kumar , Jhanjhi NZ , Hossain M. Shamim , Yassine Abdulsalam
Published: August 2022

In the Internet of Things (IoT), the de facto Routing Protocol for Low Power and Lossy Networks (RPL) is susceptible to several disruptive attacks based on its functionalities and features. Among various RPL security solutions, a trust-based security is easy to adapt for resource-constrained IoT environments. In the existing trust-based security for RPL routing attacks, nodes’ mobility is not considered or limited to only the sender nodes. Similarly, these trust-based protocols are not evaluated for mobile IoT environments, particularly regarding RPL attacks. Hence, a trust and mobility-based secure routing protocol is proposed, termed as SMTrust, by critically analysing the trust metrics involving the mobility-based metrics in IoT. SMTrust intends to provide security against RPL Rank and Blackhole attacks. The proposed protocol is evaluated in three different scenarios, including static and mobile nodes in an IoT network. SMTrust is compared with the default RPL objective function, Minimum Rank with Hysteresis Objective Function (MRHOF), SecTrust, DCTM, and MRTS. The evaluation results indicate that the proposed protocol outperforms with respect to packet loss rate, throughput, and topology stability. Moreover, SMTrust is validated using routing protocol requirements analysis to ensure that it fulfils the consistency, optimality, and loop-freeness.
Research on SSA-LSTM-Based Slope Monitoring and Early Warning Model
Authors: Yang Shasha , Jin Anjie , Nie Wen , Liu Cong , Li Yu
Published: August 2022

For geological disasters such as landslides, active prevention and early avoidance are the main measures to avoid major losses. Therefore, landslide early warning is an effective means to prevent the occurrence of landslide disasters. In this paper, based on geological survey and monitoring data, a landslide monitoring and early warning model based on SSA-LSTM is established for the landslide in Yaoshan Village, Xiping Town, Anxi County, Fujian Province, China. In the early warning model, the hyper parameters of the LSTM neural network are optimized using the SSA algorithm in order to achieve high-accuracy displacement prediction of the LSTM displacement prediction model, and are compared with the unoptimized LSTM, and the results show that the prediction effect of the optimized SSA-LSTM model is significantly improved. Since landslide monitoring and early warning is a long-term work, the model trained by the traditional offline learning method will inevitably have distortion of the prediction effect as the monitoring time becomes longer, so the online migration learning method is used to update the displacement prediction model and combine with the tangent angle model to quantify the warning level. The monitoring and early warning model put forth in this research can be used as a guide for landslide disaster early warning.
The Development of Anammox and Chloroflexi Bacteria during the Composting of Sewage Sludge
Authors: Stegenta-Dąbrowska Sylwia , Sobieraj Karolina , Rosik Joanna , Sidełko Robert , Valentin Marvin , Białowiec Andrzej
Published: August 2022

The C/N ratio is an extremely important parameter in the composting process and is directly responsible for the growth of microorganisms. A low C/N ratio contributes to higher emissions of greenhouse gases and odorous substances, such as ammonia (NH3), which is formed by nitrogen mineralization. Due to the highly toxic effects of ammonia, it is a particularly unwanted by-product that can disrupt the composting process since it poisons microorganisms and causes environmental issues. The activity of anammox bacteria, so far analyzed only in wastewater treatment processes, is a particularly efficient method of nitrogen removal, having an advantage over the conventional methods used previously. This study shows the presence of anammox bacteria during composting, which allows for an opportunity to improve the process and reduce its impact on atmospheric pollution. Despite the aerobic nature of this process, the composted mass of waste presents conditions conducive to the development of these ammonia-oxidizing bacteria, as well as the other strains of microorganisms cooperating with them. This makes it possible to compost at a low C/N ratio; in addition, there is no need for an additional energy supply through aeration, as the processes carried out by anammox bacteria do not require oxygen. Therefore, more in-depth research is necessary to evaluate the low C/N effect on anammox and Chloroflexi bacteria growth and its effect on nitrogen balance during composting.
End-of-Life Textile Recognition in a Circular Economy Perspective: A Methodological Approach Based on Near Infrared Spectroscopy
Authors: Bonifazi Giuseppe , Gasbarrone Riccardo , Palmieri Roberta , Serranti Silvia
Published: August 2022

The life cycle of textiles (i.e., fabrics and apparel products) generates many environmental impacts, such as resource consumption, water, soil, and air pollution through the dispersion of chemical substances and greenhouse gases. For these reasons, in 2019, textiles were identified as a “priority product category for the circular economy” by the European Commission that proposed a new circular economy action plan focusing on recycling. An in-depth characterization of textile fabrics could lead to an ad hoc recycling procedure, reducing resource consumption and chemicals utilization. In this work, NIR (1000–1650 nm) spectroscopy was applied to extract information regarding fabric composition, with reference to cotton, silk, viscose, and some of their blends, using two different devices: a hyperspectral imaging (HSI) platform and a portable spectroradiometer. The different fabrics were correctly classified based on their spectral features by both detection instruments. The proposed methodological approach can be applied for quality control in the textile recycling sector at industrial and/or laboratory scale thanks to the easiness of use and the speed of detection.
Optimal Evacuation Route Planning of Urban Personnel at Different Risk Levels of Flood Disasters Based on the Improved 3D Dijkstra’s Algorithm
Authors: Zhu Yang , Li Hong , Wang Zhenhao , Li Qihang , Dou Zhan , Xie Wei , Zhang Zhongrong , Wang Renjie , Nie Wen
Published: August 2022

In the event of a flood, the choice of evacuation routes is vital for personnel security. This is particularly true when road factors play an important role in evacuation time. In this study, the traditional Dijkstra algorithm for route planning is improved, and the evacuation model is improved from 2D to 3D. At the same time, the Lasso regression method is adopted to take the road factors into account in the pedestrian speed, and the location of shelter is selected and optimized through the calculation results, and then based on the improved 3D Dijkstra’s algorithm, an optimal evacuation route method in different flood disasters risk levels is proposed, which can make pedestrians reach the shelters within the shortest time. After taking into account road factors (road width, slope, non-motorized lane width, and pedestrian density), through the calculation of the pedestrian speed formula, the estimated evacuation time of pedestrians is obtained. By combining available shelters with evacuation routes, the optimized algorithm improves the evacuation efficiency facing different risk levels of flood disasters. The results show that when residents are confronted with flood disasters of once-in-20-year, once-in-50-year, and once-in-100-year, the proposed optimization algorithm can save 7.59%, 11.78%, and 17.78% of the evacuation time. Finally, according to the verification of the actual effect in Meishan Town, the proposed method of optimal evacuation route planning can effectively reduce the evacuation time of pedestrians, evaluate, and optimize the location of existing shelter, and provide suggestions for urban road reconstruction.
Occupational Exposure to Silica Nanoparticles: Evaluation of Emission Fingerprints by Laboratory Simulations
Authors: Natale Claudio , Ferrante Riccardo , Boccuni Fabio , Tombolini Francesca , Sarto Maria Sabrina , Iavicoli Sergio
Published: August 2022

Silica nanoparticles (SiO2 NPs), due to their chemical-physical properties, are among the most widely produced nanomaterials (NMs) in the world, and therefore used in a wide range of industries. Such widespread use, however, draws attention to the health of workers during the production of such NMs and the need for techniques to assess occupational exposure. In the present study, laboratory simulation techniques were used to reproduce a critical work activity in a controlled environment in order to identify emission profiles useful for studying exposure during NM handling in the workplace. Weighing activity inside a glove box isolated from the external environment background and any pollutants was simulated. Real-time instrumentation was used to calculate the concentration, size distribution and surface area of the particles generated during the simulation, and time-integrated instrumentation was used to collect dust for off-line analysis.
Network Analysis of the Disaster Response Systems in the Waste of Electrical and Electronic Equipment Recycling Center in South Korea
Authors: Kim Sudong , Park Jihwan
Published: August 2022

Since dust and flammable gas are generated during the waste recycling process, there is always a risk of a fire accident. However, research on disaster management at recycling facilities deals only with the problem of processing systems from a technical standpoint and does not suggest concrete alternatives from a management aspect. Therefore, this study analyzed the influence of the disaster response network of a Waste of Electrical and Electronic Equipment (WEEE) recycling center at the organizational level based on the concept of the cognitive accuracy of a network considering administrative aspects. Accordingly, a survey was conducted using a structured questionnaire targeting 47 employees at the WEEE recycling center in South Korea and by applying the two-mode network analysis method using UCINET software, the centrality of the actor and the density of the network were quantitatively analyzed. Through this analysis, we confirmed that factors affecting the influence of the network exist, such that the entire network and the networks of different levels of position are different. We suggest that this can be improved by deploying safety and health management managers who perform formal tasks at the center of the network so that everyone can agree on the political approach and by empowering the safety and health management manager to conduct active education and training. Furthermore, we suggest that the network structure should be reorganized, centering on the person in charge of safety and health management to have a network system that matches each position.
Developing A Conceptual Passive Contact Tracing System for Commercial Buildings Using WiFi Indoor Positioning
Authors: Vosoughkhosravi Sorena , Jafari Amirhosein
Published: August 2022

Contact tracing is one of the critical tools for fighting against pandemic disease outbreaks, such as the fast-growing SARS-CoV-2 virus and its different variants. At present, automated contact tracing systems face two main challenges: (1) requiring application installation on smart devices and (2) protecting the users’ privacy. This study introduces a conceptual passive contact tracing system using indoor WiFi positioning to address these challenges and investigate the role of such a system in commercial buildings. In this regard, this study uses a simulated small-office layout in a case study to demonstrate the applicability of the proposed system. The special use of the proposed contact tracing system could be academic facilities and office buildings, where (1) the WiFi infrastructure already exists and therefore implementing such a system could be cost-effective, and (2) the same users use the facility regularly, enabling the system to notify the users upon a confirmed case once they are back in the building and connected to the WiFi system. Such technology can not only enhance the current automated contact tracing system in commercial buildings by illuminating the need to use smartphone applications while protecting users’ privacy, but could also reduce the risk of infection in indoor environments. The developed system can benefit facility managers, business owners, policy makers, and authorities in assisting to find occupants’ high-risk contacts and control the spread of SARS-CoV-2 or similar infectious diseases in commercial buildings, particularly university campuses and office buildings.
Disaster Risk Assessment of Informal Settlements in the Global South
Authors: Quesada-Román Adolfo
Published: August 2022

More than a billion people live in informal settlements worldwide. Their high exposure and vulnerability increase the risk of disaster in their lives. Global changes challenge the capacity to seek practical and quick solutions for the most disadvantaged groups. Most people in Costa Rica reside in the Greater Metropolitan Area (GAM, or Gran Área Metropolitana in Spanish), and nearly half of the informal settlements of the country are also located there. This paper aims to determine the disaster risk of every informal settlement of the GAM in Costa Rica. The study merges the official information that is available to calculate the hazard, exposure, vulnerability, and the risk levels of every informal settlement in the GAM. Moreover, a risk index for informal settlements in the GAM was created using a Pearson correlation technique, normalizing, and spatially distributing the results in three groups (high, medium, and low). The study outputs indicate that municipalities with a greater number of informal settlements also concentrate the higher risk unit’s percentage. Moreover, a direct statistical relationship is present between the historical number of disaster events in the municipalities with more informal settlements. The urban context proves useful to apply a methodology that could determine the disaster risk level of informal settlements in less-developed countries where baseline information for hazard, exposure, and vulnerability calculation is usually scarce, limited, or low in quality. This research shows the conditions of dozens of countries belonging to the Global South and constitutes a useful example for all of the stakeholders of disaster risk reduction worldwide.
Sustainable Employability: Precariousness, Capabilities, and Functioning of Special Education Teachers in Namibia
Authors: Murangi Annelisa , Rothmann Sebastiaan , Nel Mirna
Published: August 2022

Institutions cannot ignore the need for the sustainable employability of people. This study aimed to investigate the sustainable employability of special education teachers from the perspective of employment precariousness, capabilities, and functioning (flourishing and intention to leave) of special education teachers in Namibia. Using a cross-sectional survey design, teachers (n = 200) across seven Namibia regions took part in this study. The Precarity Position Profile, Capability for Work Questionnaire, Flourishing at Work Questionnaire, and Intention to Leave Questionnaire were administered. The results showed that precarious employment was negatively associated with the capability set and with flourishing (emotional, psychological, and social well-being) and positively associated with intention to leave. Low job insecurity and the capability set were associated with emotional well-being. Moreover, low job insecurity, professional development, and the capability set were associated with psychological well-being. Furthermore, precarious work conditions, job insecurity, low professional development, and low scores on the capability set were associated with low social well-being. Precarious work conditions and low scores on the capability set were associated with teachers’ intentions to leave. Two dimensions of precarious employment, namely salary and precarious work conditions, indirectly affected teachers’ emotional, psychological, and social well-being via the capability set.
A Review on Characteristics, Techniques, and Waste-to-Energy Aspects of Municipal Solid Waste Management: Bangladesh Perspective
Authors: Roy Hridoy , Alam Samiha Raisa , Bin-Masud Rayhan , Prantika Tonima Rahman , Pervez Md. Nahid , Islam Md. Shahinoor , Naddeo Vincenzo
Published: August 2022

Municipal solid waste (MSW) management has become a major concern for developing countries. The physical and chemical aspects of MSW management and infrastructure need to be analyzed critically to solve the existing socio-economic problem. Currently, MSW production is 2.01 billion tonnes/yr. In developing countries, improper management of MSW poses serious environmental and public health risks. Depending on the socio-economic framework of a country, several MSW management procedures have been established, including landfilling, thermal treatment, and chemical treatment. Most of the MSW produced in underdeveloped and developing countries such as Bangladesh, India, and Pakistan is dumped into open landfills, severely affecting the environment. Waste-to-Energy (WTE) projects based on thermal treatments, e.g., incineration, pyrolysis, and gasification, can be feasible alternatives to conventional technologies. This research has explored a comprehensive method to evaluate MSW characteristics and management strategies from a global and Bangladesh perspective. The benefits, challenges, economic analysis, and comparison of MSW-based WTE projects have been analyzed concisely. Implementing the WTE project in developing countries can reduce unsupervised landfill and greenhouse gas (GHG) emissions. Alternative solutions and innovations have been discussed to overcome the high capital costs and infrastructural deficiencies. By 2050, Bangladesh can establish a total revenue (electricity sales and carbon credit revenue) of USD 751 million per year in Dhaka and Chittagong only. The landfill gas (LFG) recovery, waste recycling. and pyrolysis for energy production, syngas generation, and metal recovery are possible future directions of MSW management. The MSW management scenario in developing countries can be upgraded by improving waste treatment policies and working with government, academicians, and environmentalists together.
Sorghum Production in Northern Namibia: Farmers’ Perceived Constraints and Trait Preferences
Authors: Wanga Maliata Athon , Shimelis Hussein , Mengistu Girma
Published: August 2022

Sorghum (Sorghum bicolor [L.] Moench) is a valuable crop in the dry regions of the world, including Namibia. Due to the intensity and recurrence of drought and heat stress in the traditional sorghum growing areas, there is a need to breed and deploy new generation farmer-preferred and climate-smart cultivars to serve the diverse value chains. Therefore, the objectives of this study were to assess the present state of sorghum production in northern Namibia and document farmers’ perceived production constraints and trait preferences in new varieties to guide drought-tolerance breeding. A survey was conducted using a participatory rural appraisal in the following six selected sorghum-growing constituencies in Namibia: Kapako and Mpungu (Kavango West Region), Eenhana and Endola (Ohangwena Region), and Katima Mulilo Rural and Kongola (Zambezi Region). Data were collected using a structured questionnaire involving 198 farmers in 14 sampled villages across the regions. Results revealed variable trends in sorghum production among respondent farmers when disaggregated by gender, age, number of households, education level, cropping systems, types of varieties grown, and perceived production constraints. An equal proportion of male and female respondent farmers cultivate sorghum, suggesting the value of the crop to both genders in Namibia. Most respondent farmers (63.6%) were in productive age groups of <40 years old. In the study areas, low-yielding landrace varieties, namely Ekoko, Okambete, Makonga, Kamburo, Nkutji, Katoma, Fuba, Dommy, Kawumbe, and Okatombo, were widely cultivated, and most of the farmers did not use chemical fertilizers to cultivate sorghum. Farmers’ perceived sorghum production constraints in the study areas included recurrent drought, declining soil fertility, insect pest damage, high cost of production inputs, unavailability of improved seed, lack of alternative improved varieties with farmers’ preferred traits, lack of organic manure, limited access to market and limited extension service. The key farmers’ preferred traits in a new sorghum variety included high grain yield, early maturity, and tolerance to drought, in the field and storage insect pests. The study recommends genetic improvement and new variety deployment of sorghum with the described farmers-preferred traits to increase the sustainable production of the crop in Namibia.
The Search for Sustainable Architecture in Asia in the Oeuvre of Antonin Raymond: A New Attunement with Nature
Authors: Cabeza-Lainez Joseph , Almodovar-Melendo Jose-Manuel , Rodríguez-Cunill Inmaculada
Published: August 2022

The American architect Antonin Raymond carried out intense work in Japan from 1920 to 1970. Firstly, coming to Japan to collaborate with Frank Lloyd Wright in the Imperial Hotel almost as an apprentice; unexpectedly, he was to change the game for Nipponese design and construction arts, creating at the same time the path to what currently stands out as a key example of modern environmentally conscious architecture. Due in part to his advanced stance in the profession, architects who now seem pivotal to the rising of a progressive movement in the island-nation were related to Raymond’s wake and influence, including Junzô Yoshimura, Kunio Maekawa, and Kenzô Tange. For these reasons, and given the fact that most of the building typologies he designed were previously nonexistent, his oeuvre caused a great impact and consideration, straddled as it is between nature and culture. Such prominent and visionary work, ahead of stylistic Western postulates, often related to mere abstraction, has not been sufficiently recognized in the history of building design. Consequently, the authors propose to settle in this article some of the most significant developments of Raymond’s work through his projects and ideas that intended to preserve the environment, such as integrated landscape and orientation to benefit from the sun and breezes, favoring ventilation through adroit design and extensive use of local material left untreated. These hard to assimilate notions would show that Raymond embodied in his work a profound respect for nature and traditions, rooted by its part in Daoism and Shintoism, which paved the way for subsequent innovations of early sustainability in the architectural domain.
Smart and Sustainable Management of Shoe Machinery Companies in Taiwan during the COVID-19 Pandemic—Case Studies of the Tung Sheng Company and Strong Basic Enterprise Limited Company
Authors: Tu Ming-Ta , Gau Li-Shiue , Park Ji-Hwan , Huang Wen-Shin , Duong Pham Thuy , Kim Jong-Chae
Published: August 2022

This case report combined PEST, SWOT, a business model canvas, and knowledge management to develop a theoretical framework for assessing business models, and smart and sustainable management of two case study companies—Tung Sheng and Strong Basic—in Taiwan during the COVID-19 pandemic. A case study and heuristic inquiry research design was adopted. Secondary data and interviews with top managers were used to triangulate within the same cases. The results show that the case study companies owned capabilities in R&D as a foundation to further apply new smart ICT (information and communication technology) and execute green manufacturing. Strong key partnerships were useful resources to diversify business investment, although current qualified employees were not sufficient. Resilient practices included adopting new and green technology to mitigate the negative impacts of the COVID-19 pandemic. This study establishes a useful framework for case study research and provides practical information about business models, and smart and sustainable management in two case studies.
Overcoming Growth Challenges of Sustainable Ventures in the Fashion Industry: A Multinational Exploration
Authors: Hofmann Kay H. , Jacob Axel , Pizzingrilli Massimo
Published: August 2022

Over the past decade, the proliferation of entrepreneurial ventures and small firms with sustainable business models have pushed the sustainability agenda in the fashion industry. Despite prominent success stories, these companies often encounter significant operative challenges that hinder growth or even cause business failure. This paper adopts a qualitative research design and uses data gathered during 18 expert interviews with entrepreneurs and executive managers of 18 firms from 13 countries to identify and explore the dominant challenges that micro- and small-sized sustainable fashion companies struggle with. The results indicate that communicating with consumers is perceived as surprisingly difficult, especially because sustainable brands need to justify higher prices and explain the added benefits of their products. Second, resource constraints lead to operative friction and overburdening of the decision makers and their small management teams. Third, sustainable sourcing and production processes are economically difficult in an industry that continues to occupy a mass and low-cost logic. Against the background of these insights, a range of managerial recommendations are developed and contextualized in the framework of the Business Model Canvas. This novel approach makes the suggestions which are rooted in the resource-based view actionable and supports sustainable businesses to better manage their operations and achieve growth. For example, collaborative approaches with different stakeholders may mitigate constraints across all three identified problem areas.
Phase Shift-Controlled Dual-Frequency Multi-Load Converter with Independent Power Control for Induction Cooking Applications
Authors: Vishnuram Pradeep , Kumar Sudhanshu , Singh Vivek Kumar , Babu Thanikanti Sudhakar , Kannan Ramani , Hasan Khairul Nisak Bt Md
Published: August 2022

Induction heating (IH) applications, assisted with converter topology and their control, have become very attractive in recent years. Independent power control for any induction cooking application with simple converter topology, multi-load handling capacity, and a control technique is still a research hot spot. This paper focuses on developing the dual-frequency converter for delivering power to two loads independently. The switching frequencies of the converter for loads 1 and 2 are selected as 20 and 80 kHz, respectively, and the inverter is operated by multiplexing two switching frequencies. The independent power control is performed using a phase shift control scheme and validated in real-time using a PIC16F877A microcontroller. The prototype of 1 kW is developed and load 1 is operated with 550 W and load 2 is operated with 270 W output power. The independent power control is verified for various values of the control angle (ϕ) and it is noticed that the efficiency is 91% at 0∘ and it is above 80% for other values of ϕ. The thermal model of the proposed system is studied using COMSOL multiphysics software and the experimental image is recorded using a FLIR thermal imager. It is noted that the temperature rise in the load is 78 ∘C and 38.5 ∘C for loads 1 and 2, respectively, at time t = 180 s.
Roof Fractures of Near-Vertical and Extremely Thick Coal Seams in Horizontally Grouped Top-Coal Drawing Method Based on the Theory of a Thin Plate
Authors: Zhang Guojun , Li Quansheng , Xu Zhuhe , Zhang Yong
Published: August 2022

During the mining process of the near-vertical seam, there will be movement and collapse of the “roof side” rock layer and the “overlying coal seam,” as well as the emergence of the “floor side” rock layer roof which is more complicated than the inclined and gently inclined coal seams, which causes problems with slippage or overturning damage. With the increase of the inclination of the coal seam, the impact of the destruction of the immediate roof on the stope and roadway gradually becomes prominent, while the impact of the destruction of the basic roof on the stope and the roadway gradually weakens. The destruction of the immediate roof of the near-vertical coal seam will cause a large area of coal and rock mass to suddenly rush to the working face and the two lanes, resulting in rapid deformation of the roadway, overturning of equipment, overturning of personnel, and even severe rock pressure disaster accidents, all of which pose a serious threat to coal mine safety and production. It is necessary to carry out research on the mechanical response mechanism of the immediate roof of near-upright coal seams, to analyse the weighting process of steeply inclined thick coal seam sub-level mining. A four fixed support plate model and top three clamped edges simply supported plate model for roof stress distribution are established before the first weighting of the roof during the upper and lower level mining process. The bottom three clamped edges simply supported plate model and two adjacent edges clamped on the edge of a simply supported plate model are established for roof stress distribution before periodic weighting of the roof during the upper and lower level mining process. The Galerkin method is used to make an approximate solution of deflection equation under the effect of sheet normal stress, and then roof failure criterion is established based on the maximum tensile stress strength criterion and generalized Hooke law. This paper utilizes FLAC3D finite element numerical simulation software, considering the characteristics of steeply inclined thick coal seam sub-level mining. It undertakes orthogonal numerical simulation experiment in three levels with different depths, coal seam angles, lateral pressure coefficient, and orientation of maximum horizontal principal stress, and translates roof stress of corresponding 9 simulation experiment into steeply inclined roof normal stress. We conclude that the distribution law of normal stress along dip and dip direction of a roof under the circumstance of different advancing distances and different sub-levels. The caving pace of first weight and periodical weight were counted under the effect of the roof uniform normal stress. It can better predict the weighting situation of the working face and ensure the safe, efficient, and sustainable mining of coal mines.
Study on Propagation Characteristics of Ground Penetrating Radar Wave in Dikes and Dams with Polymer Grouting Repair Using Finite-Difference Time-Domain with Perfectly Matched Layer Boundary Condition
Authors: Dong Zhifeng , Xue Binghan , Lei Jianwei , Zhao Xiaohua , Gao Jianglin
Published: August 2022

Non-aqueous reactive polymer grouting technology has been widely used in the repair engineering of dikes and dams with shallow diseases. By using the finite difference time-domain method and perfectly matched layer boundary conditions, the calculation model of dikes and dams with shallow diseases such as water-filled cave, air-filled cave and incompact area is established. The propagation process of electromagnetic waves of ground-penetrating radar in dikes and dams with shallow diseases using polymer grouting repair is simulated, and the forward simulation profiles and single-channel waveforms are obtained. The propagation characteristics such as waveform amplitude, waveform shape, transmission time, and reflection time are compared and analyzed. The results show that the forward simulation profiles of dikes and dams with water-filled caves before and after polymer grouting repair present two clusters of hyperbolas, but three clusters of hyperbolas with different amplitudes were observed at 50% repair. The amplitude of the hyperbola and the single-channel reflected waves before repair and 50% repair of the cave and incompact area are greater than those of 100% repair. The propagation characteristics of ground-penetrating radar can effectively explain the degree of polymer grouting repair for dikes and dams with shallow diseases, and provide a theoretical basis for using the ground-penetrating radar to evaluate the effect of polymer grouting technology to repair dikes and dams with shallow diseases.
Analysis of the Population Structure and Dynamic of Endemic Salvia ceratophylloides Ard. (Lamiaceae)
Authors: Laface Valentina Lucia Astrid , Musarella Carmelo Maria , Sorgonà Agostino , Spampinato Giovanni
Published: August 2022

Understanding how changes of any origin interact with the structure and survival of entire populations is very important for the protection and conservation of threatened, rare and/or endemic species. In this study, structure and population dynamics of Salvia ceratophylloides Ard., a precious endemic species, belonging to the subgenus Sclarea (Moench) Benth., section Plethiosphace Benth. (Lamiaceae) exclusive to the suburban environments of Reggio Calabria (Southern Italy), was analysed. Interactions between this species and its different growth habitats were examined. Moreover, the disturbance factors which directly affect the demographic viability of the species, influencing its growth, reproduction and distribution in its distribution area were identified. From 2019 to 2021, a census by counting individuals of all the known stations, recorded according to a specific protocol, was carried out. The recorded data were statistically analysed and compared with those of the phytosociological surveys carried out using the Braun-Blanquet method and summarised in phytosociological classes, in accordance with the hierarchical floristic classification system of vascular plant communities, accepted at national and European levels. The structure of the different populations was also related to the different threat factors that afflict S. ceratophylloides. It was observed that the most structured populations of S. ceratophylloides were found in natural and semi-natural environments where the anthropogenic disturbance was minor, while populations with an irregular structure were found in sites exposed to disturbances of various origins. The different phytosociological classes do not interact directly on population structure. The most important factors affecting structure and distribution are disturbances of various origins, in particular anthropogenic and phytosanitary disturbances. In order to keep populations balanced and stable over time, it would be useful to adopt conservation measures for the species and the habitat in which they live, with practical solutions for the following: (a) to limit infestations by insects that parasitize stems and seeds; (b) to prevent mowing, fires, grazing and the introduction of invasive alien species.
Searching for Novel Sustainability Initiatives in Amazonia
Authors: Medina Gabriel , Pereira Cassio , Ferreira Joice , Berenguer Erika , Barlow Jos
Published: August 2022

Amazonia is facing growing environmental pressures and deep social injustices that prompt questions about how sustainable development may emerge. This study sought novel sustainability initiatives in the Brazilian Amazon based on interviews conducted with diverse practitioners in 2021 using a horizon-scanning approach and snowball sampling for selecting interviewees, who then described the initiative most familiar to them. The interviews resulted in 50 described initiatives and 101 similar initiatives that were listed but not described. The results reveal the emergence of a range of sustainability initiatives, which we classify into seven types of new seeds of change ranging from eco-business opportunities, territorial protection by grassroots movements, and novel coalitions promoting sustainability. However, most of these new seeds are still being established and have a limited or uncertain potential for replication, and most offer only incremental rather than transformative development. Therefore, although these initiatives provide weak yet real signals for alternative futures, they also suggest that much more needs to be done to support the needed transformation toward sustainable and equitable development.