bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic Control of MAP3K1 in Eye Development and Sex Differentiation
Authors: Wang Jingjing , Kimura Eiki , Mongan Maureen , Xia Ying
Published: December 2021

The MAP3K1 is responsible for transmitting signals to activate specific MAP2K-MAPK cascades. Following the initial biochemical characterization, genetic mouse models have taken center stage to elucidate how MAP3K1 regulates biological functions. To that end, mice were generated with the ablation of the entire Map3k1 gene, the kinase domain coding sequences, or ubiquitin ligase domain mutations. Analyses of the mutants identify diverse roles that MAP3K1 plays in embryonic survival, maturation of T/B cells, and development of sensory organs, including eye and ear. Specifically in eye development, Map3k1 loss-of-function was found to be autosomal recessive for congenital eye abnormalities, but became autosomal dominant in combination with Jnk and RhoA mutations. Additionally, Map3k1 mutation increased eye defects with an exposure to environmental agents such as dioxin. Data from eye developmental models reveal the nexus role of MAP3K1 in integrating genetic and environmental signals to control developmental activities. Here, we focus the discussions on recent advances in understanding the signaling mechanisms of MAP3K1 in eye development in mice and in sex differentiation from human genomics findings. The research works featured here lead to a deeper understanding of the in vivo signaling network, the mechanisms of gene–environment interactions, and the relevance of this multifaceted protein kinase in disease etiology and pathogenesis.
Fluorescence Microscopy—An Outline of Hardware, Biological Handling, and Fluorophore Considerations
Authors: Hickey Shane M. , Ung Ben , Bader Christie , Brooks Robert , Lazniewska Joanna , Johnson Ian R. D. , Sorvina Alexandra , Logan Jessica , Martini Carmela , Moore Courtney R. , Karageorgos Litsa , Sweetman Martin J. , Brooks Douglas A.
Published: December 2021

Fluorescence microscopy has become a critical tool for researchers to understand biological processes at the cellular level. Micrographs from fixed and live-cell imaging procedures feature in a plethora of scientific articles for the field of cell biology, but the complexities of fluorescence microscopy as an imaging tool can sometimes be overlooked or misunderstood. This review seeks to cover the three fundamental considerations when designing fluorescence microscopy experiments: (1) hardware availability; (2) amenability of biological models to fluorescence microscopy; and (3) suitability of imaging agents for intended applications. This review will help equip the reader to make judicious decisions when designing fluorescence microscopy experiments that deliver high-resolution and informative images for cell biology.
Molecular Mechanisms and Regulation of Mammalian Mitophagy
Authors: Choubey Vinay , Zeb Akbar , Kaasik Allen
Published: December 2021

Mitochondria in the cell are the center for energy production, essential biomolecule synthesis, and cell fate determination. Moreover, the mitochondrial functional versatility enables cells to adapt to the changes in cellular environment and various stresses. In the process of discharging its cellular duties, mitochondria face multiple types of challenges, such as oxidative stress, protein-related challenges (import, folding, and degradation) and mitochondrial DNA damage. They mitigate all these challenges with robust quality control mechanisms which include antioxidant defenses, proteostasis systems (chaperones and proteases) and mitochondrial biogenesis. Failure of these quality control mechanisms leaves mitochondria as terminally damaged, which then have to be promptly cleared from the cells before they become a threat to cell survival. Such damaged mitochondria are degraded by a selective form of autophagy called mitophagy. Rigorous research in the field has identified multiple types of mitophagy processes based on targeting signals on damaged or superfluous mitochondria. In this review, we provide an in-depth overview of mammalian mitophagy and its importance in human health and diseases. We also attempted to highlight the future area of investigation in the field of mitophagy.
Resveratrol Analog 4-Bromo-Resveratrol Inhibits Gastric Cancer Stemness through the SIRT3-c-Jun N-Terminal Kinase Signaling Pathway
Authors: Tai Yun-Shen , Ma Yi-Shih , Chen Chun-Lin , Tsai Hsin-Yi , Tsai Chin-Chuan , Wu Meng-Chieh , Chen Chih-Yi , Lin Ming-Wei
Published: December 2021

Chemotherapy is the treatment of choice for gastric cancer, but the currently available therapeutic drugs have limited efficacy. Studies have suggested that gastric cancer stem cells may play a key role in drug resistance in chemotherapy. Therefore, new agents that selectively target gastric cancer stem cells in gastric tumors are urgently required. Sirtuin-3 (SIRT3) is a deacetylase that regulates mitochondrial metabolic homeostasis to maintain stemness in glioma stem cells. Targeting the mitochondrial protein SIRT3 may provide a novel therapeutic option for gastric cancer treatment. However, the mechanism by which stemness is regulated through SIRT3 inhibition in gastric cancer remains unknown. We evaluated the stemness inhibition ability of the SIRT3 inhibitor 4′-bromo-resveratrol (4-BR), an analog of resveratrol in human gastric cancer cells. Our results suggested that 4-BR inhibited gastric cancer cell stemness through the SIRT3-c-Jun N-terminal kinase pathway and may aid in gastric cancer stem-cell–targeted therapy.
Particle-Size-Dependent Anticorrosion Performance of the Si3N4-Nanoparticle-Incorporated Electroless Ni-P Coating
Authors: Dhakal Dhani Ram , Kshetri Yuwaraj K. , Chaudhary Bina , Kim Tae-Ho , Lee Soo Wohn , Kim Bum Sung , Song Yoseb , Kim Hak Soo , Kim Hak Hee
Published: December 2021

Electroless Nickel–Phosphorus (Ni-P) coating is recognized mostly for its outstanding corrosion and wear-resistant behavior. The intrinsic corrosion and wear-resistant properties of Ni-P-based coating could be further upgraded by incorporating appropriate second-phase additive particles into the coating matrix. However, such properties of the Ni-P-based coating greatly rely on the surface and microstructural evolution arising with the co-deposition of the additive particles. In this study, submicron Si3N4 (average size ~200 nm) and nano Si3N4 (average size ~20 nm) particles were incorporated while depositing a Ni-P alloy in a low-carbon steel substrate to develop the Ni-P-Si3N4 composites through the electroless coating method. The 20 nm Si3N4-incorporated composite coating constituted fewer defects such as cavities and micropores on the surface, but such defects significantly appeared on the surface of the composite after the incorporation of 200 nm Si3N4 nanoparticles. Subsequently, the composite Ni-P-Si3N4, developed with the co-deposition of 20 nm nanoparticles, is enriched with enhanced anticorrosion characteristics compared with the composite developed with 200 nm nanoparticles. The enhancement of anticorrosion behavior was attributed mainly to the Si3N4 nanoparticles that covered the substantial volume of the coating and led to inhibit the formation of corrosion active sites such as defects and metallic Ni phase.
Stable and Efficient Photoinduced Charge Transfer of MnFe2O4/Polyaniline Photoelectrode in Highly Acidic Solution
Authors: Alsultan Mohammed , Al-Rubaye Shaymaa , Al-Keisy Amar , Swiegers Gerhard F. , Taha Intisar Ghanim
Published: December 2021

Tailoring conductive polymers with inorganic photocatalysts, which provide photoinduced electron-hole generation, have significantly enhanced composites leading to excellent photoelectrodes. In this work, MnFe2O4 nanoparticles prepared by a hydrothermal method were combined with polyaniline to prepare mixed (hybrid) slurries, which were cast onto flexible FTO to prepare photoelectrodes. The resulting photoelectrodes were characterized by XRD, FESEM, HRTEM and UV-VIS. The photoelectrochemical performance was investigated by linear sweep voltammetry and chronoamperometry. The photocurrent achieved by MnFe2O4/Polyaniline was 400 μA/cm2 at 0.8 V vs. Ag/AgCl in Na2SO4 (pH = 2) at 100 mW/cm2, while polyaniline alone achieved only 25 μA/cm2 under the same conditions. The best MnFe2O4/Polyaniline displayed an incident photon-to-current conversion efficiency (IPCE) and applied bias photon-to-current efficiency (ABPE) of 60% at 405 nm wavelength, and 0.17% at 0.8 V vs. Ag/AgCl, respectively. High and stable photoelectrochemical performance was achieved for more than 900 s in an acidic environment.
Editorial for the Special Issue on Robust Microelectronic Devices
Authors: Waltl Michael
Published: December 2021

Integrated electronic circuits have influenced our society in recent decades and become an indispensable part of our daily lives [...]
A New L-Proline Amide Hydrolase with Potential Application within the Amidase Process
Authors: Martinez-Rodríguez Sergio , Contreras-Montoya Rafael , Torres Jesús M. , de Cienfuegos Luis Álvarez , Gavira Jose Antonio
Published: December 2021

L-proline amide hydrolase (PAH, EC 3.5.1.101) is a barely described enzyme belonging to the peptidase S33 family, and is highly similar to prolyl aminopeptidases (PAP, EC. 3.4.11.5). Besides being an S-stereoselective character towards piperidine-based carboxamides, this enzyme also hydrolyses different L-amino acid amides, turning it into a potential biocatalyst within the Amidase Process. In this work, we report the characterization of L-proline amide hydrolase from Pseudomonas syringae (PsyPAH) together with the first X-ray structure for this class of L-amino acid amidases. Recombinant PsyPAH showed optimal conditions at pH 7.0 and 35 °C, with an apparent thermal melting temperature of 46 °C. The enzyme behaved as a monomer at the optimal pH. The L-enantioselective hydrolytic activity towards different canonical and non-canonical amino-acid amides was confirmed. Structural analysis suggests key residues in the enzymatic activity.
Weakly Supervised Ternary Stream Data Augmentation Fine-Grained Classification Network for Identifying Acute Lymphoblastic Leukemia
Authors: Liu Yunfei , Chen Pu , Zhang Junran , Liu Nian , Liu Yan
Published: December 2021

Due to the high incidence of acute lymphoblastic leukemia (ALL) worldwide as well as its rapid and fatal progression, timely microscopy screening of peripheral blood smears is essential for the rapid diagnosis of ALL. However, screening manually is time-consuming and tedious and may lead to missed or misdiagnosis due to subjective bias; on the other hand, artificially intelligent diagnostic algorithms are constrained by the limited sample size of the data and are prone to overfitting, resulting in limited applications. Conventional data augmentation is commonly adopted to expand the amount of training data, avoid overfitting, and improve the performance of deep models. However, in practical applications, random data augmentation, such as random image cropping or erasing, is difficult to realistically occur in specific tasks and may instead introduce tremendous background noises that modify actual distribution of data, thereby degrading model performance. In this paper, to assist in the early and accurate diagnosis of acute lymphoblastic leukemia, we present a ternary stream-driven weakly supervised data augmentation classification network (WT-DFN) to identify lymphoblasts in a fine-grained scale using microscopic images of peripheral blood smears. Concretely, for each training image, we first generate attention maps to represent the distinguishable part of the target by weakly supervised learning. Then, guided by these attention maps, we produce the other two streams via attention cropping and attention erasing to obtain the fine-grained distinctive features. The proposed WT-DFN improves the classification accuracy of the model from two aspects: (1) in the images can be seen details since cropping attention regions provide the accurate location of the object, which ensures our model looks at the object closer and discovers certain detailed features; (2) images can be seen more since erasing attention mechanism forces the model to extract more discriminative parts’ features. Validation suggests that the proposed method is capable of addressing the high intraclass variances located in lymphocyte classes, as well as the low interclass variances between lymphoblasts and other normal or reactive lymphocytes. The proposed method yields the best performance on the public dataset and the real clinical dataset among competitive methods.
Noninvasive Assessment of Interstitial Fibrosis and Tubular Atrophy in Renal Transplant by Combining Point-Shear Wave Elastography and Estimated Glomerular Filtration Rate
Authors: Qin Chi , Jin Hailong , Zhang Haixiang , Zhang Yun , Guan Zhaojie , Gao Yongyan
Published: December 2021

The purpose of this study was to evaluate the feasibility of the combination of point-shear wave elastography (p-SWE) and estimated glomerular filtration rate (eGFR) for assessing different stages of interstitial fibrosis and tubular atrophy (IF/TA) in patients with chronic renal allograft dysfunction (CAD). From September 2020 to August 2021, 47 patients who underwent renal biopsy and p-SWE examinations were consecutively enrolled in this study. The areas under the receiver operating characteristic curves (AUCs) were calculated to evaluate overall accuracy and to identify the optimal cutoff values for different IF/TA stages. A total of 43 patients were enrolled in this study. The renal cortical stiffness and eGFR showed a significant difference between IF/TA Grade 0–1 and Grade 2–3 (p < 0.001). Additionally, renal stiffness and eGFR were independent predictors for moderate-to-severe IF/TA (Grade ≥ 2) according to multiple logistic regression analysis. The combination of p-SWE and eGFR, with an optimal cutoff value of −1.63, was superior to eGFR alone in assessing moderate-to-severe interstitial fibrosis (AUC, 0.86 vs. 0.72, p = 0.02) or tubular atrophy (AUC, 0.88 vs. 0.74, p = 0.02). There was no difference between p-SWE and eGFR in assessing moderate-to-severe IF/TA (AUC, 0.85 vs. 0.79, p = 0.61). Therefore, combining p-SWE and eGFR is worthy of clinical popularization and application.
COVID-Net CXR-S: Deep Convolutional Neural Network for Severity Assessment of COVID-19 Cases from Chest X-ray Images
Authors: Aboutalebi Hossein , Pavlova Maya , Shafiee Mohammad Javad , Sabri Ali , Alaref Amer , Wong Alexander
Published: December 2021

The world is still struggling in controlling and containing the spread of the COVID-19 pandemic caused by the SARS-CoV-2 virus. The medical conditions associated with SARS-CoV-2 infections have resulted in a surge in the number of patients at clinics and hospitals, leading to a significantly increased strain on healthcare resources. As such, an important part of managing and handling patients with SARS-CoV-2 infections within the clinical workflow is severity assessment, which is often conducted with the use of chest X-ray (CXR) images. In this work, we introduce COVID-Net CXR-S, a convolutional neural network for predicting the airspace severity of a SARS-CoV-2 positive patient based on a CXR image of the patient’s chest. More specifically, we leveraged transfer learning to transfer representational knowledge gained from over 16,000 CXR images from a multinational cohort of over 15,000 SARS-CoV-2 positive and negative patient cases into a custom network architecture for severity assessment. Experimental results using the RSNA RICORD dataset showed that the proposed COVID-Net CXR-S has potential to be a powerful tool for computer-aided severity assessment of CXR images of COVID-19 positive patients. Furthermore, radiologist validation on select cases by two board-certified radiologists with over 10 and 19 years of experience, respectively, showed consistency between radiologist interpretation and critical factors leveraged by COVID-Net CXR-S for severity assessment. While not a production-ready solution, the ultimate goal for the open source release of COVID-Net CXR-S is to act as a catalyst for clinical scientists, machine learning researchers, as well as citizen scientists to develop innovative new clinical decision support solutions for helping clinicians around the world manage the continuing pandemic.
Virtual Gene Concept and a Corresponding Pragmatic Research Program in Genetical Data Science
Authors: Huminiecki Łukasz
Published: December 2021

Mendel proposed an experimentally verifiable paradigm of particle-based heredity that has been influential for over 150 years. The historical arguments have been reflected in the near past as Mendel’s concept has been diversified by new types of omics data. As an effect of the accumulation of omics data, a virtual gene concept forms, giving rise to genetical data science. The concept integrates genetical, functional, and molecular features of the Mendelian paradigm. I argue that the virtual gene concept should be deployed pragmatically. Indeed, the concept has already inspired a practical research program related to systems genetics. The program includes questions about functionality of structural and categorical gene variants, about regulation of gene expression, and about roles of epigenetic modifications. The methodology of the program includes bioinformatics, machine learning, and deep learning. Education, funding, careers, standards, benchmarks, and tools to monitor research progress should be provided to support the research program.
Uncertainty Relations in the Madelung Picture
Authors: Bonilla-Licea Moise , Schuch Dieter
Published: December 2021

Madelung showed how the complex Schrödinger equation can be rewritten in terms of two real equations, one for the phase and one for the amplitude of the complex wave function, where both equations are not independent of each other, but coupled. Although these equations formally look like classical hydrodynamic equations, they contain all the information about the quantum system. Concerning the quantum mechanical uncertainties of position and momentum, however, this is not so obvious at first sight. We show how these uncertainties are related to the phase and amplitude of the wave function in position and momentum space and, particularly, that the contribution from the phase essentially depends on the position–momentum correlations. This will be illustrated explicitly using generalized coherent states as examples.
Double Feature Extraction Method of Ship-Radiated Noise Signal Based on Slope Entropy and Permutation Entropy
Authors: Li Yuxing , Gao Peiyuan , Tang Bingzhao , Yi Yingmin , Zhang Jianjun
Published: December 2021

In order to accurately identify various types of ships and develop coastal defenses, a single feature extraction method based on slope entropy (SlEn) and a double feature extraction method based on SlEn combined with permutation entropy (SlEn&PE) are proposed. Firstly, SlEn is used for the feature extraction of ship-radiated noise signal (SNS) compared with permutation entropy (PE), dispersion entropy (DE), fluctuation dispersion entropy (FDE), and reverse dispersion entropy (RDE), so that the effectiveness of SlEn is verified, and SlEn has the highest recognition rate calculated by the k-Nearest Neighbor (KNN) algorithm. Secondly, SlEn is combined with PE, DE, FDE, and RDE, respectively, to extract the feature of SNS for a higher recognition rate, and SlEn&PE has the highest recognition rate after the calculation of the KNN algorithm. Lastly, the recognition rates of SlEn and SlEn&PE are compared, and the recognition rates of SlEn&PE are higher than SlEn by 4.22%. Therefore, the double feature extraction method proposed in this paper is more effective in the application of ship type recognition.
Stock Market Reactions during Different Phases of the COVID-19 Pandemic: Cases of Italy and Spain
Authors: Keliuotyte-Staniuleniene Greta , Kviklis Julius
Published: December 2021

The COVID-19 pandemic and pandemic-induced lockdowns and quarantine establishments have inevitably affected individuals, businesses, and governments. At the same time, the spread of the COVID-19 pandemic had a dramatic impact on financial markets all over the world and caused an increased level of uncertainty; the stock markets were no exception either. Most of the studies on the impact of the COVID-19 pandemic on stock markets are based either on the analysis of a relatively short period (the beginning of pandemic) or a longer period, which, in turn, is very heterogeneous in terms of both the information available on the COVID-19 virus and the measures taken to contain the virus and address the consequences of the pandemic. However, it is very important to assess the impact not only at the beginning of the pandemic but also in the subsequent periods and to compare the nature of this impact; the studies of this type are still fragmentary. Therefore, this research aims to investigate the impact of the COVID-19 pandemic on stock markets of two of the most severely affected European countries—Italy and Spain. To reach the aim of the research OLS regression models, heteroscedasticity-corrected models, GARCH (1,1) models, and VAR-based impulse response functions are employed. The results reveal that the stock market reaction to the spread of the COVID-19 pandemic differs depending on the country and period analyzed: OLS regression and heteroscedasticity-corrected models have not revealed the statistically significant impact of the spread of the COVID-19 pandemic, while impulse response functions demonstrated the non-zero primary response of analyzed markets to the COVID-19 shock, and GARCH models (in the case of Spain) confirmed that the COVID-19 pandemic increased the volatility of stock market return. This research contributes to the literature by providing a comprehensive impact assessment both during the whole pre-vaccination period of the pandemic and during different stages of this period.
A Change of Paradigm for the Design and Reliability Testing of Touch-Based Cabin Controls on the Seats of Self-Driving Cars
Authors: Custódio Tiago , Alves Cristiano , Silva Pedro , Silva Jorge , Rodrigues Carlos , Lourenço Rui , Pessoa Rui , Moreira Fernando , Marques Ricardo , Tomé Gonçalo , Falcao Gabriel
Published: December 2021

The current design paradigm of car cabin components assumes seats aligned with the driving direction. All passengers are aligned with the driver that, until recently, was the only element in charge of controlling the vehicle. The new paradigm of self-driving cars eliminates several of those requirements, releasing the driver from control duties and creating new opportunities for entertaining the passengers during the trip. This creates the need for controlling functionalities that must be closer to each user, namely on the seat. This work proposes the use of low-cost capacitive touch sensors for controlling car functions, multimedia controls, seat orientation, door windows, and others. In the current work, we have reached a proof of concept that is functional, as shown for several cabin functionalities. The proposed concept can be adopted by current car manufacturers without changing the automobile construction pipeline. It is flexible and can adopt a variety of new functionalities, mostly software-based, added by the manufacturer, or customized by the end-user. Moreover, the newly proposed technology uses a smaller number of plastic parts for producing the component, which implies savings in terms of production cost and energy, while increasing the life cycle of the component.
Sub-Milliwatt Transceiver IC for Transcutaneous Communication of an Intracortical Visual Prosthesis
Authors: Omisakin Adedayo , Mestrom Rob , Radulov Georgi , Bentum Mark
Published: December 2021

An intracortical visual prosthesis plays a vital role in partially restoring the faculty of sight in visually impaired people. Reliable high date rate wireless links are needed for transcutaneous communication. Such wireless communication should receive stimulation data (downlink) and send out neural recorded data (uplink). Hence, there is a need for an implanted transceiver that is low-power and delivers sufficient data rate for both uplink and downlink. In this paper, we propose an integrated circuit (IC) solution based on impulse radio ultrawideband using on-off keying modulation (OOK IR-UWB) for the uplink transmitter, and binary phase-shift keying (BPSK) with sampling and digital detection for the downlink receiver. To make the solution low-power, predominantly digital components are used in the presented transceiver test-chip. Current-controlled oscillators and an impulse generator provide tunability and complete the on-chip integration. The transceiver test-IC is fabricated in 180 nm CMOS technology and occupies only 0.0272 mm2. At 1.3 V power supply, only 0.2 mW is consumed for the BPSK receiver and 0.3 mW for the IR-UWB transmitter in the transceiver IC, while delivering 1 Mbps and 50 Mbps, respectively. Our link budget analysis shows that this test chip is suitable for intracortical integration considering the future off-chip antennas/coils transcutaneous 3–7 mm communication with the outer side. Hence, our work will enable realistic wireless links for the intracortical visual prosthesis.
Physical Layer Secrecy by Power Splitting and Jamming in Cooperative Multiple Relay Based on Energy Harvesting in Full-Duplex Network
Authors: Sehito Nabila , Yang Shouyi , Ali Esraa Mousa , Khan Muhammad Abbas , Larik Raja Sohail Ahmed , Bari Inam , Kamal Mian Muhammad , Khan Salahuddin , Alibakhshikenari Mohammad , Limiti Ernesto
Published: December 2021

In this article, we investigated the secrecy performance of a three-hop relay network system with Power Splitting (PS) and Energy Harvesting (EH). In the presence of one eavesdropper, a signal is transferred from source to destination with the help of a relay. The source signal transmits in full-duplex (FD) mood, jamming the relay transfer signals to the destination. The relay and source employ Time Switching (TS) and Energy Harvesting (EH) techniques to obtain the power from the power beacon. In this study, we compared the Secrecy Rate of two Cooperative Schemes, Amplify and Forward (AF) and Decode and Forward (DF), for both designed systems with the established EH and PS system. The Secrecy Rate was improved by 50.5% in the AF scheme and by 44.2% in the DF scheme between the relay and eavesdropper at 40 m apart for the proposed system in EH and PS. This simulation was performed using the Monto Carlo method in MATLAB.
Application of Porous Materials for CO2 Reutilization: A Review
Authors: Parvanian Amir Masoud , Sadeghi Nasrin , Rafiee Ahmad , Shearer Cameron J. , Jafarian Mehdi
Published: December 2021

CO2 reutilization processes contribute to the mitigation of CO2 as a potent greenhouse gas (GHG) through reusing and converting it into economically valuable chemical products including methanol, dimethyl ether, and methane. Solar thermochemical conversion and photochemical and electrochemical CO2 reduction processes are emerging technologies in which solar energy is utilized to provide the energy required for the endothermic dissociation of CO2. Owing to the surface-dependent nature of these technologies, their performance is significantly reliant on the solid reactant/catalyst accessible surface area. Solid porous structures either entirely made from the catalyst or used as a support for coating the catalyst/solid reactants can increase the number of active reaction sites and, thus, the kinetics of CO2 reutilization reactions. This paper reviews the principles and application of porous materials for CO2 reutilization pathways in solar thermochemical, photochemical, and electrochemical reduction technologies. Then, the state of the development of each technology is critically reviewed and evaluated with the focus on the use of porous materials. Finally, the research needs and challenges are presented to further advance the implementation of porous materials in the CO2 reutilization processes and the commercialization of the aforementioned technologies.
Dynamic Model of Impact Energy Absorption by a Conveyor Belt in Interaction with the Support System
Authors: Marasova Daniela , Andrejiova Miriam , Grincova Anna
Published: December 2021

Measurements of the dynamic load of conveyor belts of identical strengths were used to evaluate and compare the data for belts with and without a support system. The goal was to identify the effects of the support system in terms of a relative amount of impact energy absorbed by a conveyor belt. A dynamic model was designed based on selected parameters of the impact process. Damage to conveyor belts, caused by the absorption of impact energy, was evaluated using the applied methods of mathematical statistics.
Designing for the Environment: An Example of Multi-Criteria Analysis Used for Solar Hot Water System Selection
Authors: Żelazna Agnieszka , Gołębiowska Justyna
Published: December 2021

In the European Union, the building sector accounts for more than 40% of final energy consumption, contributing to the deterioration of the quality of the environment. Among the various solutions that aim to reduce the negative environmental impact caused by the operation of buildings, solar hot water systems (SHW) are popular. The choice of a SHW system is associated with the comfort of use and the access to low-cost energy. The design guidelines include the technical parameters for system operation such as materials, dimensions, sizing and operation temperatures. However, the legitimacy of choosing a particular solution and the available technical parameters are key issues. In the presented study, a multi-criteria analysis was proposed as a basis for the proper selection of system parameters, e.g., collector type, solar tank volume. A model of the SHW system was used to calculate the possible solutions, ensuring the same comfort of usage for several design options. The analyzed model was then used for the calculation of three various indicators: Simple Payback Time (SPBT), Primary Energy consumption (PE) and IMPACT 2002+. The application of a multi-criteria analysis based on a Life Cycle Assessment allowed for beneficial solutions to be found from the point of view of economics, non-renewable resources and environmental protection.
Design Procedure Based on Maximum Efficiency for Wireless Power Transfer Battery Chargers with Lightweight Vehicle Assembly
Authors: Simonazzi Mattia , Campanini Alessandro , Sandrolini Leonardo , Rossi Claudio
Published: December 2021

This paper analyzes two different design procedures for a series-parallel compensated WPT battery charger, based on different definitions of the operating resonant frequency in the condition of maximum link efficiency. The behaviour of the voltage gain magnitude and the input impedance angle of the resulting WPT links is studied for different loads and coupling coefficients. The design algorithms are supported by analytical formulas derived from an exact circuit analysis of the WPT link, avoiding approximations as far as possible. To support the theoretical approach a case study is proposed, in which both design procedures are implemented considering specifications in line with the actual automotive standards. To conclude, a characterization of the efficiency in both cases is derived.
Sliding-Mode-Based Current and Speed Sensors Fault Diagnosis for Five-Phase PMSM
Authors: Bensalem Yemna , Kouzou Abdellah , Abbassi Rabeh , Jerbi Houssem , Kennel Ralph , Abdelrahem Mohamed
Published: December 2021

The present paper deals with an active fault-tolerant speed tracking of a five-phase permanent magnet synchronous motor with currents and speed sensor failures. The active fault tolerant control scheme, integrating a sliding mode observer and backstepping controllers, is proposed to provide a continuous drive operation of the five-phase permanent magnet synchronous motor, even during more than one sensor fault occurrence. The sliding mode observer is designed to generate the residual signal necessary for the detection stage, whereas speed and current backstepping controllers handle the operation of the five-phase permanent magnet synchronous motor thanks to their ability to consider the nonlinearities of the system model in generating a control law that is robust enough in healthy and faulty cases. Furthermore, the FTC strategy uses the information received from the fault-tolerant switching block in terms of the measured and the observed currents and speed signals. To gain the maximum benefit of the sliding mode observer’s robustness to random noises and its ease of implementation, the observed currents and speed of the five-phase permanent magnet synchronous motor have been estimated. The simulation results are conducted to show the effectiveness of the proposed FTC control scheme and to prove its high performance in fault detection and tolerant control for the five-phase permanent magnet synchronous motor, since it significantly outperforms the performance provided by traditional methods.
Predictive Control-Based NADIR-Minimizing Algorithm for Solid-State Transformer
Authors: Fuentes Carlos , Chavez Hector , Paternina Mario R. Arrieta
Published: December 2021

Solid-state transformers (SSTs) are becoming an important solution to control active distribution systems. Their significant flexibility in comparison with traditional magnetic transformers is essential to ensure power quality and protection coordination at the distribution level in scenarios of large penetration of distributed energy resources such as renewables, electric vehicles and energy storage. However, the power electronic interface of SSTs decouples the nature of the inertial and frequency responses of distribution loads, deteriorating the frequency stability, especially under the integration of large-scale solar and wind power plants. Despite the virtual inertia/voltage sensitivity-based algorithms that have been proposed, the frequency sensitivity of loads and the capability of guaranteeing optimal control, considering the operating restrictions, have been overlooked. To counteract this specific issue, this work proposes a predictive control-driven approach to provide SSTs with frequency response actions by a strategy that harnesses the voltage and frequency sensibility of distribution loads and considers the limitations of voltage and frequency given by grid codes at distribution grids. In particular, the control strategy is centered in minimizing the NADIR of frequency transients. Numerical results are attained employing an empirically-validated model of the power system frequency dynamics and a dynamic model of distribution loads. Through proportional frequency control, the results of the proposed algorithm are contrasted. It is demonstrated that the NADIR improved about 0.1 Hz for 30% of SST penetration.
Performance Investigation Based on Vital Factors of Agricultural Feeder Supported by Solar Photovoltaic Power Plant
Authors: Padole Nivedita , Moharil Ravindra , Munshi Anuradha
Published: December 2021

Solar photovoltaic (SPV) installations are growing in the distribution network due to the continuously decreasing prices of solar photovoltaic panels. Installing the SPV Plant on the distribution feeder supplying to the agricultural pumps is a challenging task due to the varying agricultural load pattern of the Agricultural Feeder (AG Feeder). Supply of power and demand creates potential challenges in the low voltage (LV) distribution system. This paper presents a case study of a 2 MW SPV connected to an agricultural feeder in India. Performance analysis has been carried out using field measurement data. The key parameters such as PV Penetration and Capacity Utilization Factor (CUF) are calculated for analysis. Parameters such as Grid Dependency of the load and PV Contribution have been introduced in this paper, which relates to the SPV system behavior more aptly. It is recommended that the Time of Day (ToD) metering with the lowest cost during the solar generation hours will make agricultural consumers shift their demand matching with solar generation hours. Extensive analysis of agricultural feeder connected SPV power plant indicates that the power supply has improved for the feeder during winter and summer months.
Mechanical Durability Assessment of an Energy-Harvesting Piezoelectric Inverted Flag
Authors: Yang Kaidong , Cioncolini Andrea , Nabawy Mostafa R. A. , Revell Alistair
Published: December 2021

This paper presents results from a practical assessment of the endurance of an inverted flag energy harvester, tested over multiple days in a wind tunnel to provide first insights into flapping fatigue and failure. The inverted flag is a composite bimorph, composed of PVDF (polyvinylidene difluoride) strips combined with a passive metallic core to provide sufficient stiffness. The flag, derived from an earlier, more extensive study, flaps with a typical amplitude of ~120 degrees and a frequency of ~2 Hz, generating a constant power of ~0.09 mW in a wind velocity of 6 m/s. The flag was observed to complete ~5×105 cycles before failure, corresponding to ~70 h of operation. The energy generated over this lifespan is estimated to be sufficient to power a standard low-power temperature sensor for several months at a sampling rate of one sample/minute, which would be adequate for applications such as wildfire detection, environmental monitoring, and agriculture management. This study indicates that structural fatigue may present a practical obstacle to the wider development of this technology, particularly in the context of their usual justification as a ‘deploy and forget’ alternative to battery power. Further work is required to improve the fatigue resistance of the flag material.
Genesis of Coalbed Methane and Its Storage and Seepage Space in Baode Block, Eastern Ordos Basin
Authors: Chen Hao , Tian Wenguang , Chen Zhenhong , Zhang Qingfeng , Tao Shu
Published: December 2021

The Baode block on the eastern margin of the Ordos Basin is a key area for the development of low-rank coalbed methane (CBM) in China. In order to find out the genesis of CBM and its storage and seepage space in Baode block, the isotopic testing of gas samples was carried out to reveal the origin of CH4 and CO2, as well, mercury intrusion porosimetry, low temperature nitrogen adsorption, and X-ray CT tests were performed to characterize the pores and fractures in No. 4 + 5 and No. 8 + 9 coal seams. The results showed that the average volume fraction of CH4, N2, and CO2 is 88.31%, 4.73%, and 6.36%, respectively. No. 4 + 5 and No. 8 + 9 coal seams both have biogenic gas and thermogenic methane. Meanwhile, No. 4 + 5 and No. 8 + 9 coal seams both contain CO2 generated by coal pyrolysis, which belongs to organic genetic gas, while shallow CO2 is greatly affected by the action of microorganisms and belongs to biogenic gas. The average proportion of micropores, transition pores, mesopores, and macropores is 56.61%, 28.22%, 5.10%, and 10.07%, respectively. Samples collected from No. 4 + 5 coal seams have developed more sorption pores. Meanwhile, samples collected from No. 8 + 9 coal seams exhibited a relatively low degree of hysteresis (Hg retention), suggesting good pore connectivity and relatively high seepage ability, which is conducive to gas migration. The connected porosity of coal samples varies greatly, mainly depending on the relative mineral content and the proportion of connected pores.
Modelling the Transition towards a Carbon-Neutral Electricity System—Investment Decisions and Heterogeneity
Authors: Yang Jinxi , Azar Christian , Lindgren Kristian
Published: December 2021

To achieve the climate goals of the Paris Agreement, greenhouse gas emissions from the electricity sector must be substantially reduced. We develop an agent-based model of the electricity system with heterogeneous agents who invest in power generating capacity under uncertainty. The heterogeneity is characterised by the hurdle rates the agents employ (to manage risk) and by their expectations of the future carbon prices. We analyse the impact of the heterogeneity on the transition to a low carbon electricity system. Results show that under an increasing CO2 tax scenario, the agents start investing heavily in wind, followed by nuclear and to some extent in natural gas fired power plants both with and without carbon capture and storage as well as biogas fired power plants. However, the degree to which different technologies are used depend strongly on the carbon tax expectations and the hurdle rate employed by the agents. Comparing to the case with homogeneous agents, the introduction of heterogeneity among the agents leads to a faster CO2 reduction. We also estimate the so called “cannibalisation effect” for wind and find that the absolute value of wind does not drop in response to higher deployment levels, but the relative value does decline.
Process Analysis of PMMA-Based Dental Resins Residues Depolymerization: Optimization of Reaction Time and Temperature
Authors: dos Santos Paulo Bisi , Ribeiro Haroldo Jorge da Silva , Ferreira Armando Costa , Ferreira Caio Campos , Bernar Lucas Pinto , Assunção Fernanda Paula da Costa , de Castro Douglas Alberto Rocha , Santos Marcelo Costa , Duvoisin Sergio , Borges Luiz Eduardo Pizarro , Machado Nélio Teixeira
Published: December 2021

This work aims to optimize the recovery of methyl methacrylate (MMA) by depolymerization of polymethyl methacrylate (PMMA) dental resins fragments/residues. In order to pilot the experiments at technical scale, the PMMA dental resins scraps were submitted by thermogravimetric analysis (TG/DTG/DTA). The experiments were conducted at 345, 405, and 420 °C, atmospheric pressure, using a pilot scale reactor of 143 L. The liquid phase products obtained at 420 °C, atmospheric pressure, were subjected to fractional distillation using a pilot scale column at 105 °C. The physicochemical properties (density, kinematic viscosity, and refractive index) of reaction liquid products, obtained at 345 °C, atmospheric pressure, were determined experimentally. The compositional analysis of reaction liquid products at 345 °C, 30, 40, 50, 60, 70, 80, and 110 min, at 405 °C, 50, 70, and 130 min, and at 420 °C, 40, 50, 80, 100, 110, and 130 min were determined by GC-MS. The morphology of PMMA dental resins fragments before and after depolymerization was performed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX). The experiments show that liquid phase yields were 55.50%, 48.73%, and 48.20% (wt.), at 345, 405, and 420 °C, respectively, showing a first order exponential decay behavior, decreasing with increasing temperature, while that of gas phase were 31.69%, 36.60%, and 40.13% (wt.), respectively, showing a first order exponential growth, increasing with temperature. By comparing the density, kinematic viscosity, and refractive index of pure MMA at 20 °C with those of liquid reaction products after distillation, one may compute percent errors of 1.41, 2.83, and 0.14%, respectively. SEM analysis showed that all the polymeric material was carbonized. Oxygenated compounds including esters of carboxylic acids, alcohols, ketones, and aromatics were detected by gas chromatography/mass spectrometry (GC-MS) in the liquid products at 345, 405, and 420 °C, atmosphere pressure. By the depolymerization of PMMA dental resins scraps, concentrations of methyl methacrylate between 83.454 and 98.975% (area.) were achieved. For all the depolymerization experiments, liquid phases with MMA purities above 98% (area.) were obtained between the time interval of 30 and 80 min. However, after 100 min, a sharp decline in the concentrations of methyl methacrylate in the liquid phase was observed. The optimum operating conditions to achieve high MMA concentrations, as well as elevated yields of liquid reaction products were 345 °C and 80 min.
Does Deterioration of Aerodromes’ Economic Situation Influence the Level of Safety in Civil Aviation? What Can Be Done to Prevent It in Line with a Sustainable Transport Systems Approach?
Authors: Dudek Ewa , Pietrzak Maria
Published: December 2021

Aviation has been one of the key engines of the globalization process and, at the same, time one of the industries most affected by the COVID-19 pandemic and the parallel economic crisis. As safety seems to be the key issue at aerodromes, the aim of this article is to analyze what kind of safety hazards have the coronavirus slowdown created and which of them pose the greatest risk for aerodrome safety in the long run. What is more, the goal of the paper is to direct managers’ attention to proper crisis management in line with sustainability. The main findings are that all classified hazards cause, according to an expert’s assessment, similar safety risk at aerodromes, though limited workforce training and development are perceived as posing the greatest risk. The recommended solution to minimize the occurrence of the hazard is proactive risk management, which means that managers try to anticipate possible hazards in advance and act accordingly, which requires continual controlling combined with internal and external environment analysis and a consistent learning process. That should be accompanied by constant staff development. All these seem to effectively minimize most risks and make ground for a sustainable and safe transport system.
Bioremediation Capacity of Edaphic Cyanobacteria Nostoc linckia for Chromium in Association with Other Heavy-Metals-Contaminated Soils
Authors: Cepoi Liliana , Zinicovscaia Inga , Valuta Ana , Codreanu Liviu , Rudi Ludmila , Chiriac Tatiana , Yushin Nikita , Grozdov Dmitrii , Peshkova Alexandra
Published: December 2021

Anthropogenic activity is the main factor contributing to soil pollution with various toxic metals, including Cr(VI), which dictates the need for decontamination. Often, the traditionally used remediation methods (soil removal, stabilization/solidification, physicochemical extraction, and soil washing) are not sufficiently efficient. Among gentle soil remediation, options can be considered. The aim of this study is to assess the ability of Nostoc linckia to remediate soils contaminated with Cr(VI) in association with other metals. Metal uptake by biomass was assessed using neutron activation analysis, while the components of Nostoc biomass were determined using specific methods. The capacity to accumulate chromium from the contaminated environment (Cr in association with Fe, Ni, Cu, and Zn) by the Nostoc linckia is kept at a high level for three generations of cyanobacterium, and the capacity to accumulate Fe, Ni, Cu, and Zn is growing over the cultivation cycles. The process of accumulation of heavy metals is associated with significant changes in the biochemical composition of Nostoc biomass. Due to the high bioaccumulation capacity and the specific growth mode with the formation of crusts on the soil surface, the edaphic cyanobacteria Nostoc linckia is an important candidate for the bioremediation of soil contaminated with chromium in association with other metals.