bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing Virtual Reality Head Mounted Display (HMD) Set-Up for Thoracoscopic Surgery of Complex Congenital Lung MalFormations in Children
Authors: Pelizzo Gloria , Costanzo Sara , Roveri Margherita , Lanfranchi Giulia , Vertemati Maurizio , Milani Paolo , Zuccotti Gianvincenzo , Cassin Simone , Panfili Sebastiano , Rizzetto Francesco , Campari Alessandro , Camporesi Anna , Calcaterra Valeria
Published: January 2022

Video assisted thoracoscopic surgery (VATS) has been adopted in pediatric age for the treatment of congenital lung malformations (CLM). The success of VATS in pediatrics largely depends on the surgeon’s skill ability to understand the airways, vascular system and lung parenchyma anatomy in CLM. In the last years, virtual reality (VR) and 3-dimensional (3D) printing of organ models and VR head mounted display (HMD) technologies have been introduced for completion of preoperative planning in adult patients. To date no reports about the use of VR HMD technologies in a pediatric setting are available. The aim of this report is to introduce a VR HMD model in VATS procedure to improve the quality of care in children with CLM. VR HMD set-up for planning thoracoscopic surgery was performed in a series of pediatric patients with diagnosis of CLM. The preoperative VR HMD evaluation allowed a navigation into the malformation with the aim to explore, interact, and make the surgeon more confident and skilled to answer to the traps. A development of surgical simulations models and teaching program dedicated to education and training in pediatric VATS is suitable among the pediatric surgery community. Further studies should demonstrate all the benefits of such technology in pediatric patients submitted to VATS procedure.
A Unique Case of Multicentric Infantile Myofibromatosis with Radiologic-Pathologic Correlation
Authors: Pušnik Luka , Šekoranja Daja , Plut Domen
Published: January 2022

Infantile myofibromatosis (IM) is a rare condition with a variable clinical presentation that characteristically affects young children. Most frequently it presents as one or more benign nodules of the skin, bones, soft tissues, or, rarely, visceral organs. According to the location and number of lesions, there are three different forms: solitary, multicentric without visceral involvement, and multicentric with visceral involvement (generalised), with the latter having the least favourable prognosis. We present a unique case of severe congenital generalised IM in a new-born male who required intubation and mechanical ventilation immediately after the birth due to respiratory distress. A chest radiograph showed numerous tumours involving the entire lung, resembling a metastatic lung disease. Additionally, the neonate had multiple, bluish, papular skin nodules and a biopsy of a skin nodule ultimately led to the diagnosis of IM. Diffuse lung involvement prevented adequate ventilation which resulted in multiorgan failure and death before targeted treatment could have been initiated. The presented case is unique, as such atypical extensive involvement of the lung and leptomeninges in IM has not been reported before. In this brief report, we present the findings of radiographic and ultrasonographic examinations in correlation with autopsy and histopathology.
The Effect of Age, Biological Maturation and Birth Quartile in the Kinanthropometric and Physical Fitness Differences between Male and Female Adolescent Volleyball Players
Authors: Albaladejo-Saura Mario , Vaquero-Cristóbal Raquel , García-Roca Juan Alfonso , Esparza-Ros Francisco
Published: January 2022

Background: Differences in kinanthropometric and physical fitness performance between boys and girls usually start during adolescence, as a result of the changes in the hormonal environment that occur with the advance of age and biological maturation; Methods: A total of 96 1st Regional Division players adolescent volleyball players, 48 males, (age = 14.17 ± 1.00 years-old) and 48 females (age = 14.41 ± 1.21 years-old) underwent a kinanthropometric assessment, were asked to perform different physical fitness test and to complete a questionnaire. Chronological age, maturity offset, age at peak height velocity (APHV), and birth quartile were calculated; Results: Statistical differences were observed between male and female players in the APHV (p < 0.001). Male players showed higher values in the bone and muscle-related variables (p < 0.001–0.040), as well as in the strength and power production-related physical tests (p < 0.001–0.012), while the female showed higher values in the fat-related variables (p = 0.003–0.013), and performed better in the flexibility tests. Age, maturity offset, and birth quartile showed to have statistical influence in the differences found between sex groups; Conclusions: There is a clear influence of age and biological maturation on the differences found between sexes in adolescent volleyball players that could be taken into account regarding grouping in early stages.
Solar Photovoltaic System-Based Reduced Switch Multilevel Inverter for Improved Power Quality
Authors: Andela Madhu , Shaik Ahmmadhussain , Beemagoni Saicharan , Kurimilla Vishal , Veramalla Rajagopal , Kodakkal Amritha , Salkuti Surender Reddy
Published: January 2022

This paper deals with a reduced switch multi-level inverter for the solar photovoltaic system-based 127-level multi-level inverter. The proposed technique uses the minimum number of switches to achieve the maximum steps in staircase AC output voltage when compared to the flying capacitor multi-level inverter, cascaded type multilevel inverter and diode clamped multi-level inverter. The use of a minimum number of switches decreases the cost of the system. To eliminate the switching losses, in this topology a square wave switch is used instead of pulse width modulation. Thereby the total harmonic distortion (THD) and harmonics have been reduced in the pulsating AC output voltage waveform. The performance of 127-level MLI is compared with 15 level, 31-level and 63-level multilevel inverters. The outcomes of the solar photovoltaic system-based 127-level multi-level inverter have been simulated in a MATLAB R2009b environment.
Effect of Corrosion and Wall Textures on Wettability and Heat Flux at Non-Isothermal Conditions
Authors: Misyura Sergey Y.
Published: January 2022

The corrosion behavior, evaporation and heat transfer of aluminum alloy during droplet evaporation of an aggressive solution of NaCl and hydrogen peroxide in water have been studied experimentally. To date, the effect of corrosion on the evaporation and heat transfer of droplet salt solutions on textured surfaces remains insufficiently explored. The corrosion resistance of the material and the contact angle increase with an increase in the number of laser penetrations after laser texturing. Studies conducted using an electron microscope and Energy-Dispersive X-ray Spectroscopy (EDS) mapping show that the maximum amount of adsorbed hydrocarbon impurities falls on areas with a large number of pits. In the process of metal corrosion, wettability and heat transfer change. In spite of the fact that laser exposure significantly increases the corrosion resistance, the wettability of the wall changes significantly due to corrosion. The wetted diameter of a droplet changes over time, which leads to an increase in the evaporation rate and heat flux. The heat flux during evaporation of a droplet on a heated wall depends on the water droplet diameter, the texture of the wall and the corrosion resistance.
Recent Developments on Relaxor-PbTiO3 Ferroelectric Crystals
Authors: Baasandorj Lkhagvasuren , Chen Zibin
Published: January 2022

Numerous investigations on the development of the relaxor-PbTiO3 ferroelectric crystals have been carried out since their extraordinary properties were revealed. Recent developments on these crystals have offered further advances in electromechanical applications. In this review, recent developments on relaxor-PbTiO3 crystals and their practical applications are reviewed. The single crystal growth methods are first discussed. Two different strategies, poling and doping, for piezoelectric improvement are surveyed in the following section. After this, the anisotropic features of the single crystals are discussed. Application perspectives arising from the property improvements for electromechanical devices are finally reviewed.
Cydalima perspectalis in Poland—8 Years of Invasion against the Background of Three Other Invasive Species
Authors: Bereś Paweł K. , Ziętara Patrycja , Nakonieczny Mirosław , Kontowski Łukasz , Grzbiela Michał , Augustyniak Maria
Published: January 2022

The box tree moth (Cydalima perspectalis) origins from East Asia. In Europe, it was recorded for the first time in 2007, and in Poland in 2012. By the end of 2020, it was found all over Poland. There are no published data on the range of C. perspectalis occurrence in Poland because it is not a quarantine pest in the European Union and is not subject to official monitoring. Data collected in 2018–2020 via a website dedicated to monitoring, for the first time, illustrate the current range and its largest concentrations in southern and central Poland. The monitoring confirmed that the main directions of the invasion are related to the main communication routes of Poland (south-north) and are of a long-distance character. The dispersal pattern corresponds to the model developed for Cameraria ohridella: a stratified dispersal model that considers long-distance road/rail transport. The second important factor contributing to the invasion of C. perspectalis are large human communities enabling rapid local dispersion (a diffusion model). Comparing its invasion with the monitoring data from 2007–2013 of two other invasive pests of Poland: Ostrinia nubilalis and Diabrotica virgifera, shows that a diffusion model best describes the spatial spread of these pests only to uninhabited neighboring areas.
Diversity of Land Snail Tribe Helicini (Gastropoda: Stylommatophora: Helicidae): Where Do We Stand after 20 Years of Sequencing Mitochondrial Markers?
Authors: Korábek Ondřej , Juřičková Lucie , Petrusek Adam
Published: January 2022

Sequences of mitochondrial genes revolutionized the understanding of animal diversity and continue to be an important tool in biodiversity research. In the tribe Helicini, a prominent group of the western Palaearctic land snail fauna, mitochondrial data accumulating since the 2000s helped to newly delimit genera, inform species-level taxonomy and reconstruct past range dynamics. We combined the published data with own unpublished sequences and provide a detailed overview of what they revealed about the diversity of the group. The delimitation of Helix is revised by placing Helix godetiana back in the genus and new synonymies are suggested within the genera Codringtonia and Helix. The spatial distribution of intraspecific mitochondrial lineages of several species is shown for the first time. Comparisons between species reveal considerable variation in distribution patterns of intraspecific lineages, from broad postglacial distributions to regions with a fine-scale pattern of allopatric lineage replacement. To provide a baseline for further research and information for anyone re-using the data, we thoroughly discuss the gaps in the current dataset, focusing on both taxonomic and geographic coverage. Thanks to the wealth of data already amassed and the relative ease with which they can be obtained, mitochondrial sequences remain an important source of information on intraspecific diversity over large areas and taxa.
Ubiquitous but Ignored? A Case of Water Beetle in Southeastern Europe
Authors: Mičetić Stanković Vlatka , Bruvo Mađarić Branka , Kučinić Mladen
Published: January 2022

Although freshwater habitats, especially springs, are widely recognized as top-priority habitats for monitoring and conservation procedures, their fauna, especially water beetles, are still poorly studied in the southeastern part of Europe. Thus, the dominant water beetle in these habitats, E. bosnica (Zaitzev, 1908) (Insecta: Coleoptera: Elmidae), has been completely ignored and misidentified. This study represents the first review of its taxonomy and its population and ecological traits. Both published and unpublished data are presented and discussed, as well as the results of field sampling in 46 springs and other waterbodies conducted in this region from 2004 to 2019. The identification characters of the male genitalia and the first DNA barcode of the species are presented. The results confirm the close phylogenetic relationship of E. bosnica with E. aenea (Müller, 1806) and E. rioloides (Kuwert, 1890). The species proved to be a useful environmental descriptor and can easily be used as a biological indicator due to its easy identification. The species shows remarkable sensitivity to environmental conditions and inhabits sites that are potentially under increased anthropogenic pressure and could disappear at an alarming rate. Thus, karstic habitats should be included in future conservation and monitoring procedures in this part of Europe.
Butterfly Community Diversity in the Qinling Mountains
Authors: Ren Jinze , Li Shuying , He Mengdi , Zhang Yalin
Published: January 2022

The Qinling Mountains are one of the oldest mountain ranges in China and a global biodiversity research and conservation hotspot. However, there is a lack of systematic research and survey of butterfly diversity in this region. Based on the butterfly taxa, combined with the changes in natural climate, altitude gradient and season in the Qinling Mountains, the butterfly diversity and community structure changes in 12 counties in the middle Qinling Mountains were analyzed by transect surveys and platform data analyses. A total of 9626 butterflies were observed, belonging to 427 species across 175 genera and 5 families. The species richness on the southern slope of the Qinling Mountains was higher than on the northern slope. We also studied the variation in alpha and beta diversity of butterflies. The results show that butterfly species were abundant and the highest diversity was found at the middle altitudes (1000–2000 m). Moreover, there were obvious seasonal differences in both species and number of butterflies. The community similarity in spring, summer and autumn was low, with limited species co-existing. The butterflies in the Qinling Mountains reserve area were the most abundant, exhibiting no significant difference with those in the ecotone and the farm area. Finally, we did an assessment of butterflies as endangered and protected species. In conclusion, our long-term butterfly survey data show that human disturbance and climate and environmental changes jointly shape the butterfly diversity in the middle of the Qinling Mountains.
Lack of PRAME Expression in Cutaneous T-Cell Lymphomas
Authors: Bui Chau M. , Kitahara Sumire , Shon Wonwoo , Pukhalskaya Tatsiana , Smoller Bruce R.
Published: January 2022

Cutaneous T-cell lymphomas (CTCLs) are rare tumors with no established markers that can reliably distinguish between benign and malignant lesions. Preferentially Expressed Antigen in Melanoma (PRAME) is a cancer/testis antigen that is found in many solid and hematologic malignancies. PRAME overexpression typically portends a poor prognosis and lower chemotherapeutic response. To date, no studies have established a role for PRAME in CTCL. An analysis was performed on 47 cases definitively diagnosed as CTCL: 25 cases of mycosis fungoides, 2 of Sezary syndrome, 5 of CD30+ lymphoproliferative disorder, 7 of primary cutaneous anaplastic large T-cell lymphoma, 3 of primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder, 1 of subcutaneous panniculitis-like T-cell lymphoma, and 4 of angiocentric T-cell lymphoma. PRAME immunohistochemistry was completely negative in all cases. PRAME expression was not found in any CTCL subtypes, suggesting that the pathogenesis of CTCL is not mediated by PRAME. Further study is required to identify biomarkers that might aid in the diagnosis and prognostication of CTCLs.
Matrix of Affordable Housing Assessment: A Development Process
Authors: Chohan Afaq Hyder
Published: January 2022

The United Arab Emirates (UAE) is a multiracial society with diverse housing and a potential real estate market. This study focused on users’ perceptions of the designs of available and affordable private housing stock in Dubai, Sharjah, and Ajman, which are the most populated states (emirates) of the UAE. A literature review and case studies of low- to medium-rise residential buildings were used to determine the parameters defining affordable housing design, and a model was developed of 7 design segments (independent variables) with 39 dependent variables. The model consists of a matrix of 39 design variables, in which each variable is set in a survey tool with a Likert scale to evaluate user satisfaction levels with the designs of their respective buildings. Questionnaires were distributed among the inhabitants of several buildings at different locations in the emirates. This study found that 16 anomalous design factors failed to satisfy users. It is likely that the results of this study will provide a blueprint for dialogue between regional building designers and end users to improve the designs of new buildings. The resulting design assessment matrix can be used for the analysis of residential buildings in other parts of the Gulf Cooperation Council region.
A Photon Force and Flow for Dissipative Structuring: Application to Pigments, Plants and Ecosystems
Authors: Michaelian Karo , Cano Mateo Ramón Eduardo
Published: January 2022

Through a modern derivation of Planck’s formula for the entropy of an arbitrary beam of photons, we derive a general expression for entropy production due to the irreversible process of the absorption of an arbitrary incident photon spectrum in material and its dissipation into an infrared-shifted grey-body emitted spectrum, with the rest being reflected or transmitted. Employing the framework of Classical Irreversible Thermodynamic theory, we define the generalized thermodynamic flow as the flow of photons from the incident beam into the material and the generalized thermodynamic force is, then, the entropy production divided by the photon flow, which is the entropy production per unit photon at a given wavelength. We compare the entropy production of different inorganic and organic materials (water, desert, leaves and forests) under sunlight and show that organic materials are the greater entropy-producing materials. Intriguingly, plant and phytoplankton pigments (including chlorophyll) reach peak absorption exactly where entropy production through photon dissipation is maximal for our solar spectrum 430<λ<550 nm, while photosynthetic efficiency is maximal between 600 and 700 nm. These results suggest that the evolution of pigments, plants and ecosystems has been towards optimizing entropy production, rather than photosynthesis. We propose using the wavelength dependence of global entropy production as a biosignature for discovering life on planets of other stars.
The Effect of Management Characteristics on Audit Report Readability
Authors: Salehi Mahdi , Zimon Grzegorz , Seifzadeh Maryam
Published: January 2022

The present study investigates the relationship between management characteristics (managerial entrenchment, CEO narcissism, overconfidence, board effort, real and accrual-based earnings management) and the audit report readability of listed firms. In other words, this paper seeks to answer the question of “whether management characteristics can have a favourable effect on the audit report readability or not.” The multivariate regression model is used for this study. Research hypotheses were also examined using a sample of 1004 observations on the Tehran Stock Exchange during 2012–2018 and by employing multiple regression patterns based on a panel data technique and fixed effects model. The results show a negative and significant relationship between managerial entrenchment and real and accrual-based earnings management and the audit report readability, based on the FOG index, and a positive and significant relationship between management narcissism, CEO overconfidence, and board effort and the audit report readability, based on the FOG index. Moreover, a negative and significant relationship exists between management entrenchment, CEO overconfidence, real and accrual-based earnings management, and audit report readability based on text length and Flesch indices. A positive and significant relationship was evident between CEO narcissism and board effort and audit report readability based on the same indices. Besides, research models were also examined for more confidence using other additional methods, including FE, T + 1, ABB, and GMM, which confirm the study’s preliminary results. Since the present study is the first paper to investigate such a topic in the emergent markets, it provides valuable information about intrinsic and acquisitive characteristics of management for users, analysts, and legal institutions that contribute significantly to financial statement readability.
Log Periodic Power Analysis of Critical Crashes: Evidence from the Portuguese Stock Market
Authors: Gonçalves Tiago Cruz , Borda Jorge Victor Quiñones , Vieira Pedro Rino , Matos Pedro Verga
Published: January 2022

The study of critical phenomena that originated in the natural sciences has been extended to the financial economics’ field, giving researchers new approaches to risk management, forecasting, the study of bubbles and crashes, and many kinds of problems involving complex systems with self-organized criticality (SOC). This study uses the theory of self-similar oscillatory time singularities to analyze stock market crashes. We test the Log Periodic Power Law/Model (LPPM) to analyze the Portuguese stock market, in its crises in 1998, 2007, and 2015. Parameter values are in line with those observed in other markets. This is particularly interesting since if the model performs robustly for Portugal, which is a small market with liquidity issues and the index is only composed of 20 stocks, we provide consistent evidence in favor of the proposed LPPM methodology. The LPPM methodology proposed here would have allowed us to avoid big loses in the 1998 Portuguese crash, and would have permitted us to sell at points near the peak in the 2007 crash. In the case of the 2015 crisis, we would have obtained a good indication of the moment where the lowest data point was going to be achieved.
Aspects of Energy Saving of Oil-Producing Enterprises
Authors: Midor Katarzyna , Ivanova Tatyana N. , Molenda Michał , Biały Witold , Zakharov Oleg V.
Published: January 2022

Increasing energy efficiency is included in the UN Sustainable Development Goals (SDGs) to be achieved by the year 2030. Enhancing energy efficiency is also one of the priority areas for improving the operational efficiency of any oil production enterprise. The energy management system of enterprises has been founded and implemented on the basis of the international standard ISO 50001:2018 and it works successfully. The energy efficiency strategy is formulated in the energy policy and integrated into the business model of the companies. Companies receive significant energy savings in the exploration and production segments through technical, technological, and organizational measures. This article shows the main directions for improving the energy efficiency of the artificial lift well stock and the results of their implementation. The main constraints on the implementation of the energy efficiency policy of oil-producing enterprises have been identified and directions for improvement of energy-saving structure have been proposed. The article proposes strategic-level classification of energy-saving measures, which is based on assessment and comparison of implementation costs, payback period, and takes into account investments into artificial lift technology, therefore allowing investment priorities in the energy management sphere to be distinguished. Advanced directions for investment in oil-production technology have been identified, and an algorithm of development and implementation of key indicators of energy consumption efficiency has been proposed.
The Effect of Inert Fuel Compounds on Flame Characteristics
Authors: Hudák Igor , Skryja Pavel , Bojanovský Jiří , Jegla Zdeněk , Krňávek Martin
Published: January 2022

To describe the effects of inert compounds in gaseous fuel, experiments on three different process burners (staged fuel burner, staged air burner, and low-calorific burner) were carried out. The tested burners are commercially available, but they were specially designed for experimental usage. Tests were carried out in the semi-industrial burner testing facility to investigate the influence of inert gases on the flame characteristics, emissions, and heat flux to the combustion chamber wall. Natural gas was used as a reference fuel, and, during all tests, thermal power of 500 kW was maintained. To simulate the combustion of alternative fuels with lower LHV, N2 and CO2 were used as diluents. The inert gas in the hydrocarbon fuel at certain conditions can lower NOx emissions (up to 80%) and increase heat flux (up to 5%). Once incombustible compounds are present in the fuel, the higher amount of fuel flowing through nozzles affects the flow in the combustion chamber by increasing the Reynolds number. This can change the flame pattern and temperature field, and it can be both positive and negative, depending on actual conditions.
Effects of Pressure and Coal Rank on the Oxy-Fuel Combustion of Pulverized Coal
Authors: Qin Dingyi , Chen Qianyun , Li Jing , Liu Zhaohui
Published: January 2022

Pressurized oxy-fuel combustion technology is the second generation of oxy-fuel combustion technology and has low energy consumption and low cost. In this research, a visual pressurized flat-flame reaction system was designed. A particle-tracking image pyrometer (PTIP) system based on a high-speed camera and an SLR camera was proposed. Combining the experimental system and data-processing method developed, the ignition and combustion characteristics of a single coal particle between 69 and 133 μm in size were investigated. The results indicated that at atmospheric pressure, the ignition delay time of ShanXi (SX) anthracite coal was longer than that of ShenHua (SH) bituminous coal, while that of PRB sub-bituminous coal was the shortest. As the pressure rose, the ignition delay time of the PRB sub-bituminous coal and SX anthracite coal showed a continuous increasing trend, while the ignition delay time of SH bituminous coal showed a trend of first increasing and then decreasing. Moreover, pressure also affects the pyrolysis process of coal. As the pressure increases, it became more difficult to release the volatiles produced by coal pyrolysis, which reduced the release rate of volatiles during the ignition stage, and prolonged the release time and burning duration time of volatiles.
Space Vector Modulation (SVM)-Based Common-Mode Current (CMC) Reduction Method of H8 Inverter for Permanent Magnet Synchronous Motor (PMSM) Drives
Authors: Jeong Won-Sang , Lee Yoon-Seong , Lee Jung-Hyo , Lee Chang-Hee , Won Chung-Yuen
Published: January 2022

This paper proposes a space vector modulation (SVM)-based common-mode (CM) currents reduction method of an H8 inverter for permanent magnet synchronous motor (PMSM) drives. There are power quality issues in the PMSM drive systems, such as current distortions and CM electromagnetic interference (EMI) due to the fast-switching operation of the inverter. These issues are related to CM voltage (CMV) and CM current (CMC). Although several studies have been conducted to reduce the CMV and CMC, some CMV variations and CMCs are still generated in the real implementation. Unlike conventional methods, the proposed method selects the voltage vectors with similar CMV levels and arranges them considering the series-connected switch operation of the H8 inverter in a voltage vector modulation sequence. At a low modulation index (MI), the proposed method completely restricts the CMV variations into six times. At high MI, the proposed method synthesizes the reference voltage vector differently, depending on the position of the reference vector, to reduce both current distortions and CMCs. The validity of the proposed method is verified through simulations and experimental results.
Model Reference Tracking Control Solutions for a Visual Servo System Based on a Virtual State from Unknown Dynamics
Authors: Lala Timotei , Chirla Darius-Pavel , Radac Mircea-Bogdan
Published: January 2022

This paper focuses on validating a model-free Value Iteration Reinforcement Learning (MFVI-RL) control solution on a visual servo tracking system in a comprehensive manner starting from theoretical convergence analysis to detailed hardware and software implementation. Learning is based on a virtual state representation reconstructed from input-output (I/O) system samples under nonlinear observability and unknown dynamics assumptions, while the goal is to ensure linear output reference model (ORM) tracking. Secondary, a competitive model-free Virtual State-Feedback Reference Tuning (VSFRT) is learned from the same I/O data using the same virtual state representation, demonstrating the framework’s learning capability. A model-based two degrees-of-freedom (2DOF) output feedback controller serving as a comparisons baseline is designed and tuned using an identified system model. With similar complexity and linear controller structure, MFVI-RL is shown to be superior, confirming that the model-based design issue of poor identified system model and control performance degradation can be solved in a direct data-driven style. Apart from establishing a formal connection between output feedback control, state feedback control and also between classical control and artificial intelligence methods, the results also point out several practical trade-offs, such as I/O data exploration quality and control performance leverage with data volume, control goal and controller complexity.
Perovskite-Based Nanocomposite Electrocatalysts: An Alternative to Platinum ORR Catalyst in Microbial Fuel Cell Cathodes
Authors: Nandikes Gopa , Gouse Peera Shaik , Singh Lakhveer
Published: January 2022

Microbial fuel cells (MFCs) are biochemical systems having the benefit of producing green energy through the microbial degradation of organic contaminants in wastewater. The efficiency of MFCs largely depends on the cathode oxygen reduction reaction (ORR). A preferable ORR catalyst must have good oxygen reduction kinetics, high conductivity and durability, together with cost-effectiveness. Platinum-based electrodes are considered a state-of-the-art ORR catalyst. However, the scarcity and higher cost of Pt are the main challenges for the commercialization of MFCs; therefore, in search of alternative, cost-effective catalysts, those such as doped carbons and transition-metal-based electrocatalysts have been researched for more than a decade. Recently, perovskite-oxide-based nanocomposites have emerged as a potential ORR catalyst due to their versatile elemental composition, molecular mechanism and the scope of nanoengineering for further developments. In this article, we discuss various studies conducted and opportunities associated with perovskite-based catalysts for ORR in MFCs. Special focus is given to a basic understanding of the ORR reaction mechanism through oxygen vacancy, modification of its microstructure by introducing alkaline earth metals, electron transfer pathways and the synergistic effect of perovskite and carbon. At the end, we also propose various challenges and prospects to further improve the ORR activity of perovskite-based catalysts.
Studying Four Different Permanent Magnet Eddy Currents Heaters with Different Magnet Areas and Numbers to Produce Heat Directly from a Vertical Axis Wind Turbine
Authors: Khanjari Ali , Kang Sangkyun , Lee Daeyong , Jung Dae-Yi , Lee Jang-Ho
Published: January 2022

Changing the magnetic field on a conductor metal can induce eddy currents, which cause heat generation. In this paper, we use this idea to convert wind energy into thermal energy directly. This system contains a vertical axis wind turbine and an eddy currents heat generator. The eddy currents heat generator has two parts. The first part is a rotor with some permanent magnets causing the magnetic field changes, and the second part is a stator that acts as a conductor. The magnetic field changes in the heat generator play an important role in power output; therefore, we test four different magnet arrangements with different pole numbers on the rotor at different rotational speeds from 100 rpm to 500 rpm to measure the input torque and power needed to rotate each model. Then, based on the measured data, the wind turbine is designed by Qblade software based on the blade element momentum theory. It is shown that compared to the weight of the heat generator and the area of magnetization, designing a proper magnet arrangement for the heat generator can change the output power considerably as it can trigger the magnetic field fluctuation along the direction of rotation. For example, opting for a proper arrangement on the rotor decreases the number of poles from 120 to 24 but increases the power input from 223 W to 1357 W.
Processes of Modernization of Consumption in Poland in the Context of the Sustainable Consumption and the Functioning of the Renewable Energy Market
Authors: Sobocińska Magdalena
Published: January 2022

The process of consumption modernization can be expressed by adopting the principles of sustainable development within the sphere of consumption. It should be emphasized that the implementation of a sustainable consumption model becomes especially important when considering the fact that not only various types of enterprises but also consumers participate in the excessive consumption of natural resources. The processes of sustainable consumption that are related to its humanization and the formation of a responsible society are a response to the overconsumption of goods and services, which is not determined by actual human needs and does not consider social and ecological costs. The aim of the paper is to present a process of consumption modernization in Poland in the context of the functioning of the renewable energy market. Special attention is paid to behaviours that are consistent with the sustainable consumption model, as well as with the motives for using renewable energy sources by Polish consumers and the perception of barriers to increasing the use of renewable energy sources in Poland. This paper is based on literature studies, as well as on the results of an empirical study of quantitative character that was performed in 2021 on a nationwide representative sample of 1020 people. The contribution of the article is represented by showing the motivation of Polish consumers to use renewable energy sources and by indicating barriers to the development of the use of renewable energy sources by consumers in Poland. The analysis of the research results shows that the aspect of saving money plays a significant role among the motives for using renewable energy sources. At the same time, high investment costs in devices that enable the use of renewable energy sources are the main factor that is limiting the increase in the use of renewable energy sources in Poland.
Uncovering Contributing Factors to Interruptions in the Power Grid: An Arctic Case
Authors: Eikeland Odin Foldvik , Maria Bianchi Filippo , Holmstrand Inga Setså , Bakkejord Sigurd , Santos Sergio , Chiesa Matteo
Published: January 2022

Electric failures are a problem for customers and grid operators. Identifying causes and localizing the source of failures in the grid is critical. Here, we focus on a specific power grid in the Arctic region of Northern Norway. First, we collected data pertaining to the grid topology, the topography of the area, the historical meteorological data, and the historical energy consumption/production data. Then, we exploited statistical and machine-learning techniques to predict the occurrence of failures. The classification models achieve good performance, meaning that there is a significant relationship between the collected variables and fault occurrence. Thus, we interpreted the variables that mostly explain the classification results to be the main driving factors of power interruption. Wind speed of gust and local industry activity are found to be the main controlling parameters in explaining the power failure occurrences. The result could provide important information to the distribution system operator for implementing strategies to prevent and mitigate incoming failures.
Method of Selecting Energy-Efficient Parameters of an Electric Asynchronous Traction Motor for Diesel Shunting Locomotives—Case Study on the Example of a Locomotive Series ChME3 (ЧMЭ3, ČME3, ČKD S200)
Authors: Kuznetsov Valeriy , Kardas-Cinal Ewa , Gołębiowski Piotr , Liubarskyi Borys , Gasanov Magomedemin , Riabov Ievgen , Kondratieva Lilia , Opala Michał
Published: January 2022

One of the assumptions made during the modernization process of diesel shunting locomotives is the replacement of a diesel traction motor with a DC generator with an electric asynchronous traction motor. The article aimed to develop a method of selecting energy-efficient parameters of an asynchronous electric traction motor for diesel shunting locomotives, which will ensure that its operating energy efficiency will be as high as possible. The method was verified on the example of a locomotive series ChME3 (ЧMЭ3, ČME3, ČKD S200). It has been found that using a traction asynchronous electric drive on a ChME3 locomotive, its efficiency increases in comparison with DC electric motors by 3–5% under the long-term operation modes and by 7–10% during locomotive operation with traction at the adhesion limit. Using a new traction gearbox with a higher gear ratio expands the speed range in which the asynchronous traction drive operates with a high-efficiency factor. It is effective to use a traction asynchronous electric drive to modernize ChME3 diesel locomotives in case of their use under the modes requiring the implementation of maximum traction forces at low speeds. A further increase in the efficiency of the traction asynchronous electric drive is possible based on the optimal design of the wheel-motor unit and the asynchronous traction electric drive.
A Quasi-Nondestructive Evaluation Method for Physical-Mechanical Properties of Fragile Archaeological Wood with TMA: A Case Study of an 800-Year-Old Shipwreck
Authors: Wu Mengruo , Han Xiangna , Qin Zhenfang , Zhang Zhiguo , Xi Guanglan , Han Liuyang
Published: January 2022

Archaeological wood is a kind of ‘new material’ that has deteriorated due to long-term degradation. The existing wood science theory and evaluation methods are not fully applicable to archaeological wood. Moreover, current physical-mechanical evaluation methods are inadequate for fragile archaeological wood due to their insufficient accuracy and the large sample amount required, causing difficulties in many necessary physical-mechanical repeatability tests. In light of these limitations, the representative samples on Nanhai No. 1, a merchant shipwreck in the Song Dynasty, were selected as the research objects in this paper. The shipwreck is a typical waterlogged wooden artifact. A quasi-nondestructive physical-mechanical evaluation technique for archaeological wood was developed with the thermomechanical analyzer (TMA). This study used TMA to evaluate the bending strength of representative waterlogged archaeological samples of Nanhai No. 1 shipwreck and sound wood with the same species. Besides, the thermal linear expansion coefficients in the ambient temperature range were obtained. The sizes of the samples used in the tests were only 2 mm × 8 mm × 0.3 mm and 1 cm × 1 cm × 1 cm, respectively. Bending strength results of archaeological wood by the TMA method conformed to the tendency that the bending strength decreases with the increase of decay degree. In addition, the longitudinal linear expansion coefficients of archaeological wood reached 80%–115% of those in the transverse grain direction, which were about 10 times higher than those of the sound wood. The linear expansion coefficients of archaeological wood in three directions were similar. Based on the results of Fourier transform infrared analysis (FT-IR), the significant differences in the physical-mechanical properties of the archaeological wood and the sound wood were induced to be mainly ascribed to the decomposition and the loss of hemicellulose in the archaeological wood. The cell wall substrate could not stabilize the cellulose skeleton, which led to the instability of the tracheid structure of the archaeological wood. This study provided a proven quasi-nondestructive method for the preservation state evaluation of waterlogged archaeological wood (WAW) from the Nanhai I shipwreck and other similar waterlogged wooden relics.
Effects of Buried Wood on the Development of Populus tremuloides on Various Oil Sands Reclamation Soils
Authors: Trepanier Kaitlyn E. , Manchola-Rojas Laura , Pinno Bradley D.
Published: January 2022

Buried wood is an important but understudied component of reclamation soils. We examined the impacts of buried wood amounts and species on the growth of the common reclamation tree species trembling aspen (Populus tremuloides). In a greenhouse study, aspen seedlings were planted into four soil types, upland derived fine forest floor-mineral mix (fFFMM), coarse forest floor-mineral mix (cFFMM), and lowland derived peat and peat-mineral mix (PMM), that were mixed with either aspen or pine wood shavings at four concentrations (0%, 10%, 20% and 50% of total volume). Height and diameter growth, chlorophyll concentration, and leaf and stem biomass were measured. Soil nutrients and chemical properties were obtained from a parallel study. Buried wood primarily represents an input of carbon to the soil, increasing the C:N ratio, reducing the soil available nitrogen and potentially reducing plant growth. Soil type had the largest impact on aspen growth with fFFMM = peat > PMM > cFFMM. Buried wood type, i.e., aspen or pine, did not have an impact on aspen development, but the amount of buried wood did. In particular, there was an interaction between wood amount and soil type with a large reduction in aspen growth with wood additions of 10% and above on the more productive soils, but no reduction on the less productive soils.
Tissue Structure Changes of Aquilaria sinensis Xylem after Fungus Induction
Authors: Liu Yuxin , Qiao Mengji , Fu Yunlin , Wei Penglian , Li Yingjian , Liu Zhigao
Published: January 2022

In this study, we analyzed the mechanism and the process of fungal-induced agarwood formation in Aquilaria sinensis and studied the functional changes in the xylem structure after the process. The microscopic structure of the white zone, transition zone, agarwood zone, and decay zone of 12-and 18-months of inoculation A. sinensis xylem was studied. The distribution of nuclei, starch grains, soluble sugars, sesquiterpenes, fungal propagules, and mycelium in xylem tissues was investigated by histochemical analysis. The results show that the process of agarwood formation was accompanied by apoptosis of parenchyma cells such as interxylary phloem, xylem rays, and axial parenchyma. Regular changes in the conversion of starch grains to soluble sugars, the production of sesquiterpenoids, and other characteristic components of agarwood in various types of parenchyma cells were also observed. The material transformation was concentrated in the interxylary phloem, providing a structural and material basis for the formation of agarwood. It is the core part of the production of sesquiterpenoids and other characteristic products of agarwood. Compared with the A. sinensis inoculated for 12 months, the xylem of the A. sinensis inoculated for 18 months was more vigorous. There were no significant differences between the 12 and 18 months of inoculation in terms of sugars and agarwood characteristic products. In production, harvesting after 12 months of inoculation can improve harvesting efficiency.
Evaluation of Vegetation Configuration Models for Managing Particulate Matter along the Urban Street Environment
Authors: Jeong Na-Ra , Han Seung-Won , Kim Jeong-Hee
Published: January 2022

As a green infrastructure component, urban street vegetation is increasingly being utilized to mitigate air pollution, control microclimates, and provide aesthetic and ecological benefits. This study investigated the effect of vegetation configurations on particulate matter (PM) flows for pedestrians in road traffic environments via a computation fluid dynamics analysis based on the road width (four and eight-lane) and vegetation configuration (single-, multi-layer planting, and vegetation barrier). Airflow changes due to vegetation influenced PM inflow into the sidewalk. Vegetation between roadways and sidewalks were effective at reducing PM concentrations. Compared to single-layer planting (trees only), planting structures capable of separating sidewalk and roadway airflows, such as a multi-layer planting vegetation barrier (trees and shrubs), were more effective at minimizing PM on the sidewalk; for wider roads, a multi-layer structure was the most effective. Furthermore, along a four-lane road, the appropriate vegetation volume and width for reducing PM based on the breathing height (1.5 m) were 0.6 m3 and 0.4 m, respectively. The appropriate vegetation volume and width around eight-lane roads, were 1.2–1.4 m3 and 0.8–0.93 m, respectively. The results of this study can provide appropriate standards for street vegetation design to reduce PM concentrations along sidewalks.
Visual Behaviour and Cognitive Preferences of Users for Constituent Elements in Forest Landscape Spaces
Authors: Zhou Sitong , Gao Yu , Zhang Zhi , Zhang Weikang , Meng Huan , Zhang Tong
Published: January 2022

Background: Elements of forest landscape spaces are important media through which landscape information is conveyed. Therefore, it is very important for designers and managers of forests to explore the relationship among visual behaviour, landscape preferences, and element characteristics. Purpose: This study took forest landscape spaces as the subject, discussed the characteristics of visual behaviour and cognitive preferences for landscape elements, and analysed the relationship among element characteristics, visual behaviour, and cognitive preferences in forest landscape spaces. The findings will help designers better plan the spatial composition of forest landscapes. Methods: We collected data from 53 graduate and undergraduate students and then used Spearman’s rho correlation analysis and multiple linear regressions to analyse the experimental data. Main results: 1. As the composition of forest landscape spaces varies and landscape elements are combined in different ways, visual behaviour towards landscape elements also differs. 2. People are easily attracted by highly fascinating landscape elements, but they will spend more time on low fascinating landscape elements. 3. Element characteristics significantly affect visual behaviour and cognitive preferences. Elements with high complexity or a large proportion of elements take more time for the participants to recognize, which reduces the evaluation of satisfaction.