bluuebunny/crossref_metadata_2025 huggingface dataset:
Trained Lifeguards Performing Pediatric Cardiopulmonary Resuscitation While Running: A Pilot Simulation Study
Authors: Santos-Folgar Myriam , Rodriguez-Nunez Antonio , Barcala-Furelos Roberto , Otero-Agra Martín , Martínez-Isasi Santiago , Fernández-Méndez Felipe
Published: August 2023

The aim of this study was to compare the quality of standard infant CPR with CPR in motion (i.e., walking and running) via performing maneuvers and evacuating the infant from a beach. Thirteen trained lifeguards participated in a randomized crossover study. Each rescuer individually performed three tests of 2 min each. Five rescue breaths and cycles of 30 chest compressions followed by two breaths were performed. Mouth-to-mouth-and-nose ventilation was carried out, and chest compressions were performed using the two-fingers technique. The manikin was carried on the rescuer’s forearm with the head in the distal position. The analysis variables included compression, ventilation, and CPR quality variables, as well as physiological and effort parameters. Significantly lower compression quality values were obtained in running CPR versus standard CPR (53% ± 14% versus 63% ± 15%; p = 0.045). No significant differences were observed in ventilation or CPR quality. In conclusion, lifeguards in good physical condition can perform simulated infant CPR of a similar quality to that of CPR carried out on a victim who is lying down in a fixed position.
Psychological Difficulties in Children and Adolescents during the COVID-19 Lockdown: The Effects of Spending Free Time with Parents or Using Digital Devices
Authors: Di Norcia Anna , Mascaro Chiara , Bianchi Dora , Cannoni Eleonora , Szpunar Giordana , Laghi Fiorenzo
Published: August 2023

The present study investigated protective and risk factors for psychological difficulties in children and adolescents during the COVID-19 lockdown. Specifically, the role of increased use of digital devices (DDs) for recreational purposes and the role of free time spent with parents were explored. Furthermore, the possible mediating effect of increased use of DDs in the relationship between free time spent with parents and psychological difficulties was tested. Participants were 4412 Italian children and adolescents, divided into two groups: children aged 6–10 years (n = 2248) and adolescents aged 11–18 years (n = 2164). Data were collected in Italy during the national lockdown and questionnaires were completed online by parents, who reported on their children’s habits. The daily use of DDs increased significantly during the lockdown compared to the previous period, in both children and adolescents. Additionally, psychological difficulties increased in both children and adolescents during the lockdown, with a more severe impairment for children. Increased use of DDs during the lockdown positively predicted psychological difficulties (children: beta = 0.18, p < 0.001; adolescents: beta = 0.13, p < 0.001), while free time spent with parents was protective (children: beta = −13, p < 0.001; adolescents: beta = −0.12, p < 0.001). For children (but not adolescents), increased use of DDs mediated the effects of free time spent with parents on psychological difficulties (children: beta = −0.01, 95% CI [−0.018, −0.002]; adolescents: beta = −0.003, 95% CI [−0.009, 0.003]). The findings provide new insights for education and research.
Phenotypic Characterization and Comparative Genomic Analyses of Mycobacteriophage WIVsmall as A New Member Assigned to F1 Subcluster
Authors: Guo Xinge , Zhang Jing , Wang Yuhan , Zhou Fang , Li Qiming , Teng Tieshan
Published: August 2023

In this study, we conducted the morphological observation, biological and genomic characterization, evolutionary analysis, comparative genomics description, and proteome identification of a recently isolated mycobacteriophage, WIVsmall. Morphologically, WIVsmall is classified as a member of the Siphoviridae family, characterized by a flexible tail, measuring approximately 212 nm in length. The double-stranded phage genome DNA of WIVsmall spans 53,359 base pairs, and exhibits a G + C content of 61.01%. The genome of WIVsmall comprises 103 protein-coding genes, while no tRNA genes were detected. The genome annotation unveiled the presence of functional gene clusters responsible for mycobacteriophage assembly and maturation, replication, cell lysis, and functional protein synthesis. Based on the analysis of the phylogenetic tree, the genome of WIVsmall was classified as belonging to subgroup F1. A comparative genomics analysis indicated that the WIVsmall genome exhibited the highest similarity to the phage SG4, with a percentage of 64%. The single-step growth curve analysis of WIVsmall revealed a latent period of 120 min, and an outbreak period of 200 min.
Cinnamon Essential-Oil-Loaded Fish Gelatin–Cellulose Nanocrystal Films Prepared under Acidic Conditions
Authors: Golmohammadi Abdollah , Razavi Mahsa Sadat , Tahmasebi Mohammad , Carullo Daniele , Farris Stefano
Published: August 2023

The aim of this study was to characterize films obtained from fish gelatin (GelA, 3% w/w), encapsulated with cinnamon essential oil (CEO, 0.03–0.48% v/w), and loaded with bacterial cellulose nanocrystals (BCNCs, 0.06% w/w) at pH = 3.5. CEO-GelA/BCNC films were prepared by casting, and thickness, light transmittance (TT) and haze (H), surface hydrophobicity, tensile properties, chemical composition, and water solubility (WS) thereof were assessed. All films displayed outstanding optical properties (TT > 89.4%), with haze slightly exceeding a 3% value only at the highest CEO loading within the nanoemulsion formulation. The CEO plasticizing effect increased the elongation at break (EAB, from 0.84% up to 3.79%) and decreased the tensile strength (TS, from 8.98 MPa down to 1.93 MPa). The FT-IR spectra of films revealed good interaction among nanoemulsion components via hydrogen bonding. The CEO hydrophobic nature negatively impacted the WS (from 52.08% down to 8.48%) of the films. The results of this work confirmed the possibility of producing packaging systems from renewable sources to be potentially used in the form of edible films/coatings for the preservation of water-sensitive food products, both vegan-based (fruits/vegetables) and animal-based (meat/seafood).
Experimental Study on the Corrosion of Fulvic Acid to Cement-Soil and Its Microstructures in the Peat Soil Environment
Authors: Cao Jing , Lei Shuyu , Liu Wenlian , Song Yunfei , Sui Sugang , Xu Hanhua , Guo Yongfa , Ding Wenyun
Published: August 2023

In underground engineering, cement-soil reinforcement beneath a peat soil environment is a significant challenge. To investigate the corrosiveness of fulvic acid on cement-soil and its micro and fine structure changes under the peat soil environment (PSE), an experiment was conducted to prepare peat soil by mixing humic acid (HA) into an alluvial clayey soil and then adding cement to make a cement-soil specimen, which was soaked in a fulvic acid (FA) solution and deionized water to simulate the different working of the cement-soil. The experiment was carried out by a scanning electron microscopy (SEM) test, mercury intrusion porosimetry (MIP) test, pore (particle) and fracture image recognition and analysis (PCAS), and unconfined compressive strength (UCS) test on cement-soil with soaking time as the variation factor. The results show that: In the deionized water environment, the structural characteristics of the cement-soil exhibited a gradual enhancement followed by a slight weakening. Conversely, when placed in a peat soil environment, the strength of the cement-soil initially increased at a slow rate due to the gelling and filling impact of fulvic acid. However, in the later stages, the corrosive influence of fulvic acid became dominant. This led to an enlargement of the pore space within the cement-soil, resulting in a gradual deterioration of its structure. Consequently, the strength of the cement-soil displayed a pattern of slow initial increase followed by a rapid decrease.
Effects of Tetrafluorocyclohexa-1,3-Diene Ring Position on Photoluminescence and Liquid-Crystalline Properties of Tricyclic π-Conjugated Molecules
Authors: Ohsato Haruka , Yamada Shigeyuki , Yasui Motohiro , Konno Tsutomu
Published: August 2023

Tetrafluorocyclohexa-1,3-diene ring-containing tricyclic π-conjugated molecules are promising negative-dielectric-anisotropy guest species for vertical-alignment-type liquid-crystalline (LC) displays. Building on our previous work reporting the excellent photoluminescence (PL) properties of tricyclic π-conjugated molecules with central tetrafluorocyclohexa-1,3-diene rings, we herein synthesized four analogous molecules with terminal tetrafluorocyclohexa-1,3-diene rings from commercially available precursors and investigated the effects of substituent type and diene ring position on PL and LC properties using microscopic and spectroscopic methods. One of the prepared molecules exhibited a relatively planar molecular structure and formed herringbone-type aggregates via π/F and CH/π interactions instead of forming stacked aggregates via π/π stacking interactions, thus exhibiting relatively strong PL in solution and crystalline states. Moreover, the PL color of this compound depended on the electronic character of its terminal substituents along the long molecular axis. Of the four prepared species, two featured terminal ethyl groups and formed one or more LC phases. The PL properties of these phases indicated that the related phase transition induced changes in the aggregate structure, PL wavelength, and PL color. Our results expand the applicability of CF2CF2 moiety-containing tricyclic compounds as functional molecules for the fabrication of next-generation PL, LC, and PL-LC materials.
A Multi-Centre Randomized Study Comparing Two Standard of Care Chemotherapy Regimens for Lower-Risk HER2-Positive Breast Cancer
Authors: Fernandes Ricardo , Ng Terry L. , Alzahrani Mashari Jemaan , Raphael Jacques , Blanchette Phillip , Black Morgan , Stober Carol , Pond Gregory R. , Cella David , Vandermeer Lisa , Ibrahim Mohammed , Clemons Mark
Published: August 2023

Background: Neither paclitaxel plus trastuzumab (P-H) nor docetaxel-cyclophosphamide plus trastuzumab (TC-H) have been prospectively compared in HER2-positive early-stage breast cancer (EBC). A randomized trial was performed to assess the feasibility of a larger study. Methods: Lower-risk HER2-positive EBC patients were randomized to either P-H or TC-H treatment arms. The co-primary feasibility outcomes were: ≥75% patient acceptability rate, active trial participation of ≥50% of medical oncologists, ≥75% and ≥90% treatment completion, and receipt rate of planned cycles of chemotherapy, respectively. Secondary outcomes: Febrile neutropenia (FN) rate, treatment-related hospitalizations, health-related quality of life (HR-QoL) questionnaires. Analyses were performed by per protocol and intention-to-treat. Results: Between May 2019 and March 2021, 49 of 52 patients agreed to study participation (94% acceptability rate). Fifteen (65%) of 23 medical oncologists approached patients. Rates of FN were higher (8.3% vs. 0%) in the TC-H vs. P-H arm. Median (IQR) changes in scores from baseline in FACT-Taxane Trial Outcome Index at 24 weeks were −4 (−10, −1) vs. −6.5 (−15, −2) for TC-H and P-H arms, respectively. Conclusions: A randomized trial comparing P-H and TC-H was feasible. Expansion to a larger trial would be feasible to explore patient-reported outcomes of these adjuvant HER2 chemotherapy regimens.
Do Cancer Genetics Impact Treatment Decision Making? Immunotherapy and Beyond in the Management of Advanced and Metastatic Urothelial Carcinoma
Authors: Hui Gavin , Stefanoudakis Dimitrios , Zektser Yuliya , Isaacs Dayna Jill , Hannigan Christopher , Pantuck Allan J. , Drakaki Alexandra
Published: August 2023

Bladder cancer is one of the most commonly diagnosed genitourinary malignancies. For many years, the primary treatment for metastatic urothelial cancer (mUC) was predicated on the use of platinum-based chemotherapy. More recently, immune checkpoint inhibitors (ICIs) were approved by regulatory agencies such as the US FDA for use in both the first- and second-line settings. This review outlines the approved ICIs for mUC in the second-line setting and as an alternative to chemotherapy in the first-line setting, as well as the novel agents that have also been incorporated into the treatment of this malignancy. Single-agent ICIs are often used in second-line settings in mUC, and there are three drugs currently approved for those who progress after receiving platinum-based chemotherapy. In the first-line setting, the preferred treatment regimen remains cisplatin-based chemotherapy. However, single-agent ICI can be an alternative first-line treatment for those who are not candidates for cisplatin-based therapy. There are also clinical trials adding ICIs to chemotherapy as combination regimens. However, treatment for mUC has now expanded even beyond immunotherapy. Newer targeted agents such as erdafitinib, a fibroblast growth factor receptor inhibitor, and two antibody–drug conjugates, enfortumab vedotin and sacituzumab govitecan, have been recently approved. As new drug agents are discovered, it will be important to assess both the treatment outcomes as well as the effects on patients’ quality of life. Furthermore, integrating genetic and molecular information can help guide treatment decisions as next-generation sequencing is more commonly acquired during the evaluation of newly diagnosed patients with advanced and metastatic cancer.
VEPL Dataset: A Vegetation Encroachment in Power Line Corridors Dataset for Semantic Segmentation of Drone Aerial Orthomosaics
Authors: Cano-Solis Mateo , Ballesteros John R. , Branch-Bedoya John W.
Published: August 2023

Vegetation encroachment in power line corridors has multiple problems for modern energy-dependent societies. Failures due to the contact between power lines and vegetation can result in power outages and millions of dollars in losses. To address this problem, UAVs have emerged as a promising solution due to their ability to quickly and affordably monitor long corridors through autonomous flights or being remotely piloted. However, the extensive and manual task that requires analyzing every image acquired by the UAVs when searching for the existence of vegetation encroachment has led many authors to propose the use of Deep Learning to automate the detection process. Despite the advantages of using a combination of UAV imagery and Deep Learning, there is currently a lack of datasets that help to train Deep Learning models for this specific problem. This paper presents a dataset for the semantic segmentation of vegetation encroachment in power line corridors. RGB orthomosaics were obtained for a rural road area using a commercial UAV. The dataset is composed of pairs of tessellated RGB images, coming from the orthomosaic and corresponding multi-color masks representing three different classes: vegetation, power lines, and the background. A detailed description of the image acquisition process is provided, as well as the labeling task and the data augmentation techniques, among other relevant details to produce the dataset. Researchers would benefit from using the proposed dataset by developing and improving strategies for vegetation encroachment monitoring using UAVs and Deep Learning.
Predictors of New and Persistent New Left Bundle Branch Block One Year after the Implantation of a Sutureless and Rapid-Deployment Aortic Valve Prosthesis
Authors: Januszek Rafał , Balan Robert
Published: August 2023

Introduction: Conduction disorders following aortic valve replacement therapy (AVR), either surgical or percutaneous, are related to a higher risk of complete atrioventricular block and permanent pacemaker implantation (PPI). Aim: The objective of this study was to assess risk factors regarding the incidence of new postoperative and persistent new left bundle branch block (LBBB) 1 year after the implantation of a sutureless/rapid-deployment (SURD) aortic valve prosthesis. Material and Methods: The current study included 200 consecutive patients treated with isolated or concomitant AVR between May 2014 and May 2017 at the Department of Cardiac Surgery in Pasawa with SURD aortic valve EDWARDS INTUITY EliteTM implantation. The patients were divided according to the presence of new postoperative LBBB (67 patients, 33.5%) and persistent new LBBB 1 year after AVR (35 patients, 17.5%). A comparative analysis was performed between patients with and without new LBBB after AVR and those with and without persistent LBBB 1 year after AVR. Univariate and multivariate regression analyses were conducted to extract the risk factors of LBBB occurrence. Results: Among the risk factors for the lack of new LBBB development after AVR, Euroscore II (p < 0.001) was found, while for the occurrence of persistent new LBBB 1 year after AVR, atrial fibrillation (p = 0.001), length of hospital stay (p = 0.001) and body mass index (p = 0.004) were noted. Conclusions: Patients with new or persistent new LBBB 1 year after AVR had lower mean Euroscore II and BMI values. Their stay at the hospital was also shorter.
The Association of Cytomegalovirus and Allostatic Load by Country of Birth and Length of Time in the United States
Authors: Hill Matthew , Mostafa Sayed , Muganda Perpetua M. , Jeffers-Francis Liesl K. , Obeng-Gyasi Emmanuel
Published: August 2023

Background: Cytomegalovirus (CMV) is a highly prevalent virus with a worldwide distribution. It typically remains dormant in most individuals until reactivation. Immunocompromised states are known to be potential causes for CMV reactivation. Current research has shown a link in the decline of immigrant health among those living in the US for an extended period, though the impact of CMV on this is not clear. Methods: This study investigated the association between country of birth, duration of US residency, allostatic load, and latent cytomegalovirus infection (CMV IgG) in a sample of US adults aged 20–49. The data utilized for our analysis was obtained from the National Health and Nutrition Examination Survey (NHANES) conducted between 2001 and 2004. Allostatic load, an index measuring the cumulative physiological strain on the body as it strives to regain stability in the presence of chronic stress, provided a valuable approach to assess stress within the context of CMV exposure. Logistic regression modeling was employed to estimate odds ratios and confidence intervals for the analysis. The chi-square test of association and Cramer’s V statistic were used to assess the correlation among categorical variables, while Pearson’s correlation coefficient was applied to evaluate the relationship between continuous variables. The results revealed that individuals born outside the US and those with less than 20 years of residency in the US exhibited significantly higher proportions of positive CMV IgG compared to individuals born in the US. Specifically, individuals born outside the US had more than triple the odds of CMV IgG when adjusting for the AL index (OR = 3.69, p-value = 0.0063). A similar trend was observed when examining AL risk based on the duration of US residency. Furthermore, age and sex were identified as significant predictors (p-value < 0.05) of AL risk, considering the individual’s country of birth. In summary, the findings of this study significantly enhance our comprehension of the intricate interplay between cytomegalovirus (CMV) and allostatic load (AL). The investigation sheds light on how CMV and AL interact within specific demographic contexts, providing valuable insights into the underlying risk factors for CMV infection.
Dynamics Differences between Minimal Models of Second and First-Order Chemical Self-Replication
Authors: Moseley Lauren A. , Peacock-López Enrique
Published: August 2023

To further explore the origins of Life, we consider three self-replicating chemical models. In general, models of the origin of Life include molecular components that can self-replicate and achieve exponential growth. Therefore, chemical self-replication is an essential chemical property of any model. The simplest self-replication mechanisms use the molecular product as a template for its synthesis. This mechanism is the so-called First-Order self-replication. Its regulatory limitations make it challenging to develop chemical networks, which are essential in the models of the origins of Life. In Second-Order self-replication, the molecular product forms a catalytic dimer capable of synthesis of the principal molecular product. In contrast with a simple template, the dimers show more flexibility in forming complex chemical networks since the chemical activity of the dimers can be activated or inhibited by the molecular components of the network. Here, we consider three minimal models: the First-Order Model (FOM), the Second-Order Model (SOM), and an Extended Second-Order Model (ESOM). We construct and analyze the mechanistic dimensionless ordinary differential equations (ODEs) associated with the models. The numerical integration of the set of ODEs gives us a visualization of these systems’ oscillatory behavior and compares their capacities for sustained autocatalytic behavior. The FOM model displays more complex oscillatory behavior than the ESOM model.
On Optimal and Quantum Code Construction from Cyclic Codes over
FqPQ with Applications
Authors: Ali Shakir , Alali Amal S. , Sharma Pushpendra , Wong Kok Bin , Öztas Elif Segah , Jeelani Mohammad
Published: August 2023

The key objective of this paper is to study the cyclic codes over mixed alphabets on the structure of FqPQ, where P=Fq[v]⟨v3−α22v⟩ and Q=Fq[u,v]⟨u2−α12,v3−α22v⟩ are nonchain finite rings and αi is in Fq/{0} for i∈{1,2}, where q=pm with m≥1 is a positive integer and p is an odd prime. Moreover, with the applications, we obtain better and new quantum error-correcting (QEC) codes. For another application over the ring P, we obtain several optimal codes with the help of the Gray image of cyclic codes.
Superimposed Perfect Binary Array-Aided Channel Estimation for OTFS Systems
Authors: Tang Zuping , Kong Hengyou , Wu Ziyu , Wei Jiaolong
Published: August 2023

Orthogonal time-frequency space (OTFS) modulation outperforms orthogonal frequency-division multiplexing in high-mobility scenarios through better channel estimation. Current superimposed pilot (SP)-based channel estimation improves the spectral efficiency (SE) when compared to that of the traditional embedded pilot (EP) method. However, it requires an additional non-superimposed EP delay-Doppler frame to estimate the delay-Doppler taps for the following SP-aided frames. To handle this problem, we propose a channel estimation method with high SE, which superimposes the perfect binary array (PBA) on data symbols as the pilot. Utilizing the perfect autocorrelation of PBA, channel estimation is performed based on a linear search to find the correlation peaks, which include both delay-Doppler tap information and complex channel gain in the same superimposed PBA frame. Furthermore, the optimal power ratio of the PBA is then derived by maximizing the signal-to-interference-plus-noise ratio (SINR) to optimize the SE of the proposed system. The simulation results demonstrate that the proposed method can achieve a similar channel estimation performance to the existing EP method while significantly improving the SE.
NRVC: Neural Representation for Video Compression with Implicit Multiscale Fusion Network
Authors: Liu Shangdong , Cao Puming , Feng Yujian , Ji Yimu , Chen Jiayuan , Xie Xuedong , Wu Longji
Published: August 2023

Recently, end-to-end deep models for video compression have made steady advancements. However, this resulted in a lengthy and complex pipeline containing numerous redundant parameters. The video compression approaches based on implicit neural representation (INR) allow videos to be directly represented as a function approximated by a neural network, resulting in a more lightweight model, whereas the singularity of the feature extraction pipeline limits the network’s ability to fit the mapping function for video frames. Hence, we propose a neural representation approach for video compression with an implicit multiscale fusion network (NRVC), utilizing normalized residual networks to improve the effectiveness of INR in fitting the target function. We propose the multiscale representations for video compression (MSRVC) network, which effectively extracts features from the input video sequence to enhance the degree of overfitting in the mapping function. Additionally, we propose the feature extraction channel attention (FECA) block to capture interaction information between different feature extraction channels, further improving the effectiveness of feature extraction. The results show that compared to the NeRV method with similar bits per pixel (BPP), NRVC has a 2.16% increase in the decoded peak signal-to-noise ratio (PSNR). Moreover, NRVC outperforms the conventional HEVC in terms of PSNR.
Future Technologies for Recycling Spent Lithium-Ion Batteries (LIBs) from Electric Vehicles—Overview of Latest Trends and Challenges
Authors: Giza Krystyna , Pospiech Beata , Gęga Jerzy
Published: August 2023

The work describes the construction of lithium-ion batteries, with particular emphasis on metals that can be obtained as secondary raw materials. The work presents the latest trends in the recycling of lithium-ion batteries, using pyro- and hydrometallurgical methods, or their combination. The ecological aspect of the impact of the recycling processes on the environment is shown, as well as the challenges and expectations for the future in the field of recycling processes.
The Impact of Full-System Decontamination of Kori Unit 1 on the Radioactive Waste Classification of Steam Generator Tubes
Authors: Kang Su-Hyun , Kim Chang-Lak
Published: August 2023

Kori Unit 1, which was permanently shut down on 18 June 2017, is planned to undergo full-system decontamination prior to major decommissioning activities. One of the advantages of performing FSD is the downgrading of the classification level of radioactive waste. From this perspective, the impact on the steam generator (SG) tubes, which account for a considerable portion of the total surface area during FSD operation, was examined. Initially, the CRUDTRAN code was used to predict the radioactivity inventory of the Kori Unit 1 SG tubes, which turned out to be approximately 21% more conservative than the measured value. To estimate the radioactivity in the tubes after FSD, decontamination factor values from overseas cases in the SG tubes section were selected and applied. Then, the regulations for radioactive waste in Korea were reviewed, and the specific activity was calculated by predicting the mass of the SG tubes. As a conclusion, it was confirmed that the SG tubes will be classified as low-level radioactive waste, whether FSD is performed or not. Furthermore, it was observed that even if a high efficiency of FSD is achieved, if stored, it would take more than 50 years for clearance.
The Circular Economy in Corporate Reporting: Text Mining of Energy Companies’ Management Reports
Authors: Santos Márcia , Rolo Ana , Matos Dulce , Carvalho Luisa
Published: August 2023

This paper explores the implementation of the circular economy in the energy sector. The research findings contribute to our understanding of the practical application of the circular economy, enabling policymakers and stakeholders to make informed decisions and develop targeted strategies. The study analyzes 88 Portuguese companies’ reports, examining the presence of circular economy strategies and initiatives. The results reveal that energy sector companies tend to prioritize reporting their greenhouse gas reduction efforts over their circular economy strategies. The findings align with previous studies in the oil and gas industry, emphasizing the significance of sustainability reporting and potential biases in reporting practices. The study also identifies a gap between circular economy terminology and its representation in reports, indicating the need for greater incorporation of circular economy-oriented initiatives in the energy sector. The research highlights the role of technology in fostering innovation and calls for strategic alliances and knowledge sharing to drive circular economy practices. Further research is recommended to understand the barriers to implementing circular economy practices and identify effective solutions. Overall, this paper provides valuable insights for advancing the circular economy in the energy sector and achieving broader sustainability goals.
Enhancing Wind Turbine Performance: Statistical Detection of Sensor Faults Based on Improved Dynamic Independent Component Analysis
Authors: Kini K. Ramakrishna , Harrou Fouzi , Madakyaru Muddu , Sun Ying
Published: August 2023

Efficient detection of sensor faults in wind turbines is essential to ensure the reliable operation and performance of these renewable energy systems. This paper presents a novel semi-supervised data-based monitoring technique for fault detection in wind turbines using SCADA (supervisory control and data acquisition) data. Unlike supervised methods, the proposed approach does not require labeled data, making it cost-effective and practical for wind turbine monitoring. The technique builds upon the Independent Component Analysis (ICA) approach, effectively capturing non-Gaussian features. Specifically, a dynamic ICA (DICA) model is employed to account for the temporal dynamics and dependencies in the observed signals affected by sensor faults. The fault detection process integrates fault indicators based on I2d, I2e, and squared prediction error (SPE), enabling the identification of different types of sensor faults. The fault indicators are combined with a Double Exponential Weighted Moving Average (DEWMA) chart, known for its superior performance in detecting faults with small magnitudes. Additionally, the approach incorporates kernel density estimation to establish nonparametric thresholds, increasing flexibility and adaptability to different data types. This study considers various types of sensor faults, including bias sensor faults, precision degradation faults, and freezing sensor faults, for evaluation. The results demonstrate that the proposed approach outperforms PCA and traditional ICA-based methods. It achieves a high detection rate, accurately identifying faults while reducing false alarms. It could be a promising technique for proactive maintenance, optimizing the performance and reliability of wind turbine systems.
Experimental Validation of 40 kW EV Charger Based on Vienna Rectifier and Series-Resonant Dual Active Bridge
Authors: Wrona Grzegorz , Zdanowski Mariusz , Trochimiuk Przemysław , Rąbkowski Jacek , Sobieski Radosław
Published: August 2023

This work presents the experimental validation of a 40 kW electric vehicle (EV) charger. The proposed system comprises two 20 kW modules connected in parallel at the input and output. Each module has two stages—as a grid converter Vienna Rectifier (VR) was chosen, and as an isolated DC/DC stage, two Series-Resonant Dual-Active-Bridges (SRDABs) in input-series-output-parallel (ISOP) configurations were applied. The AC/DC and DC/DC stages were enclosed in 2U rack standard housing. A bipolar DC-link with ±400 V DC voltage was employed to connect both stages of the charger module while the charger’s output is dedicated to serving 800 V batteries. VRs operated at 66 kHz switching frequency and the SRDABs operated at 100 kHz. The converters used in the charger structure were based on silicon carbide (SiC) power devices. The description and parameters of the built hardware prototypes of both—AC/DC and DC/DC—converters are provided. Moreover, the experimental validation of each stage and the whole charging system, including oscilloscope waveforms and power analyzer measurements at nominal power, are included. Such a configuration enables energy conversion with high efficiency without a negative impact on the grid and high-quality grid waveforms.
Comparison and Enhancement of Machine Learning Algorithms for Wind Turbine Output Prediction with Insufficient Data
Authors: Im Subin , Lee Hojun , Hur Don , Yoon Minhan
Published: August 2023

As the penetration of renewable energy sources into a power system increases, the significance of precise short-term forecasts for wind power generation becomes paramount. However, the erratic and non-periodic nature of wind poses challenges in accurately predicting the output. This paper presents a comprehensive investigation into forecasting wind power generation for the following day, using three machine learning models: long short-term memory (LSTM), convolutional neural network-bidirectional LSTM (CNN-biLSTM), and light gradient boosting machine (LGBM). In addition, this paper proposes a method to improve the prediction performance of LGBM by separating data according to the distribution of features, and training and testing each separated dataset with a distinct model. This study includes a comparative analysis of the performance of the proposed models in predicting wind turbine output, offering valuable insights into their respective efficiencies. The results of this investigation were analyzed for two geographically distinct wind farms (Korea and the UK). The findings of this study are expected to facilitate the selection of efficient prediction models within the forecast accuracy auxiliary service market and assist grid operators in ensuring reliable power supply for the grid.
Spatial Analysis of Dense LiDAR Point Clouds for Tree Species Group Classification Using Individual Tree Metrics
Authors: Slavík Martin , Kuželka Karel , Modlinger Roman , Surový Peter
Published: August 2023

This study presents a method of tree species classification using individual tree metrics derived from a three-dimensional point cloud from unmanned aerial vehicle laser scanning (ULS). In this novel approach, we evaluated the metrics of 1045 trees using generalized linear model (GLM) and random forest (RF) techniques to automatically assign individual trees into either a coniferous or broadleaf group. We evaluated several statistical descriptors, including a novel approach using the Clark–Evans spatial aggregation index (CE), which indicates the level of clustering in point clouds. A comparison of classifiers that included and excluded the CE indicator values demonstrated their importance for improved classification of the individual tree point clouds. The overall accuracy when including the CE index was 94.8% using a GLM approach and 95.1% using an RF approach. With the RF approach, the inclusion of CE yielded a significant improvement in overall classification accuracy, and for the GLM approach, the CE index was always selected as a significant variable for correct tree class prediction. Compared to other studies, the above-mentioned accuracies prove the benefits of CE for tree species classification, as do the worse results of excluding the CE, where the derived GLM achieved an accuracy of 92.6% and RF an accuracy of 93.8%.
Inhibitory Effects of Ammonia on Archaeal 16S rRNA Transcripts in Thermophilic Anaerobic Digester Sludge
Authors: Wang Shenghui , Song Caihong , Li Jie , Zhang Chen , Li Peng
Published: August 2023

High temperatures exacerbate the ammonia inhibition of anaerobic digestion coupled with methanogenesis. The inhibition of methane production by ammonia has been observed in other studies. However, the underlying mechanism is not well understood and requires further investigation. This study explored the effect of ammonia stress on archaeal 16S rRNA transcripts in thermophilic anaerobic digester sludge. Different ammonium concentrations were checked for their influence on the methanogenic rate and hydrogen accumulation. Quantitative PCR was used to compare the changes in total archaeal 16S rRNA expression. A Monte Carlo permutation test within redundancy analysis (RDA) was adopted for exploring the relationship between environmental variables and archaeal 16S rRNA and their transcripts. The results showed that with the increase in ammonium concentration, the methanogenic rate decreased and hydrogen accumulation occurred. The total archaeal 16S rRNA genes and transcripts copy numbers decreased significantly in treatments with higher ammonium concentrations (7 and 10 g NH4+-N/L), but did not change much at lower ammonia concentrations (3 g NH4+-N/L) compared with the 0 g NH4+-N/L treatment. The RDA analysis further revealed that most environmental variables, including ammonia and methane, except for formate, were significantly correlated with the community structure activity of archaeal 16S rRNA transcripts rather than the community structure of their genes. The composition of archaeal 16S rRNA transcripts showed that the hydrogenotrophic methanogen Methanothermobacter dominated the methanogenic community activity in all incubations. It exhibited sensitivity to ammonia stress and should be responsible for the methanogenic inhibition under thermophilic conditions. Our findings suggested that archaeal 16S rRNA transcripts, rather than 16S rRNA genes, are key indicators of ammonia stress and methanogenic activity.
Exploring the Possibility of Enriching Fermented Milks with Young Barley Leaves Powder Preparation
Authors: Kozłowska Mariola , Ziarno Małgorzata , Zaręba Dorota , Ścibisz Iwona
Published: August 2023

Barley (Hordeum vulgare L.) is one of the first cereals that humans began to cultivate. This study aimed to investigate the possibility of enriching fermented dairy products, using fermented milk as an example, with young barley leaves powder (YBLP) preparation including different starter cultures of lactic acid bacteria (LAB). The addition of YBLP did not affect the maximum rate of acidification and the time at which the maximum acidification rate was achieved. However, it did impact the time required to reach the desired pH level (4.6) for specific starter cultures. Over a 28-day storage period, gradual acidification of the fermented milk was observed. The addition of YBLP has a limited effect on the pH of the fermented milk, with the pH value primarily dependent on the type of starter culture and storage time. The addition of YBLP may have a positive effect on the survival of bacterial cells during the storage of the fermented milk; however, a gradual decrease in the number of LAB cells was observed during refrigerated storage. Furthermore, the addition of YBLP had a significant effect on the hardness, adhesion, and water-holding capacity of some fermented milk immediately after fermentation, depending on the specific starter culture used.
Wildfires in the Larch Range within Permafrost, Siberia
Authors: Kharuk Viacheslav I. , Shvetsov Evgeny G. , Buryak Ludmila V. , Golyukov Alexei S. , Dvinskaya Maria L. , Petrov Il’ya A.
Published: August 2023

Throughout the larch range, warming leads to frequent fires and an increase in burned areas. We test the hypothesis that fires are an essential natural factor that reset larch regeneration and support the existence of larch forests. The study area included Larix sibirica and L. gmelinii ranges within the permafrost zone. We used satellite-derived and field data, dendrochronology, and climate variables analysis. We found that warming led to an increase in fire frequency and intensity, mean, and extreme (>10,000 ha) burned areas. The burned area is increasing in the northward direction, while fire frequency is decreasing. The fire rate exponentially increases with decreasing soil moisture and increasing air temperature and air drought. We found a contrasting effect of wildfire on regeneration within continuous permafrost and within the southern lowland boundary of the larch range. In the first case, burnt areas regenerated via abounded larch seedlings (up to 500,000+ per ha), whereas the south burns regenerated mostly via broadleaf species or turned into grass communities. After the fire, vegetation GPP was restored to pre-fire levels within 3–15 years, which may indicate that larch forests continue to serve as carbon stock. At the southern edge of the larch range, an amplified fire rate led to the transformation of larch forests into grass and shrub communities. We suggested that the thawing of continuous permafrost would lead to shrinking larch-dominance in the south. Data obtained indicated that recurrent fires are a prerequisite for larch forests’ successful regeneration and resilience within continuous permafrost. It is therefore not necessary to suppress all fires within the zone of larch dominance. Instead, we must focus fire suppression on areas of high natural, social, and economic importance, permitting fires to burn in vast, larch-dominant permafrost landscapes.
Numerical Analysis of Direct and Inverse Problems for a Fractional Parabolic Integro-Differential Equation
Authors: Koleva Miglena N. , Vulkov Lubin G.
Published: August 2023

A mathematical model consisting of weakly coupled time fractional one parabolic PDE and one ODE equations describing dynamical processes in porous media is our physical motivation. As is often performed, by solving analytically the ODE equation, such a system is reduced to an integro-parabolic equation. We focus on the numerical reconstruction of a diffusion coefficient at finite number space-points measurements. The well-posedness of the direct problem is investigated and energy estimates of their solutions are derived. The second order in time and space finite difference approximation of the direct problem is analyzed. The approach of Lagrangian multiplier adjoint equations is utilized to compute the Fréchet derivative of the least-square cost functional. A numerical solution based on the conjugate gradient method (CGM) of the inverse problem is studied. A number of computational examples are discussed.
Design Optimization of Improved Fractional-Order Cascaded Frequency Controllers for Electric Vehicles and Electrical Power Grids Utilizing Renewable Energy Sources
Authors: El-Sousy Fayez F. M. , Alqahtani Mohammed H. , Aljumah Ali S. , Aly Mokhtar , Almutairi Sulaiman Z. , Mohamed Emad A.
Published: August 2023

Recent developments in electrical power grids have witnessed high utilization levels of renewable energy sources (RESs) and increased trends that benefit the batteries of electric vehicles (EVs). However, modern electrical power grids cause increased concerns due to their continuously reduced inertia resulting from RES characteristics. Therefore, this paper proposes an improved fractional-order frequency controller with a design optimization methodology. The proposed controller is represented by two cascaded control loops using the one-plus-proportional derivative (1 + PD) in the outer loop and a fractional-order proportional integral derivative (FOPID) in the inner loop, which form the proposed improved 1 + PD/FOPID. The main superior performance characteristics of the proposed 1 + PD/FOPID fractional-order frequency controller over existing methods include a faster response time with minimized overshoot/undershoot peaks, an ability for mitigating both high- and low-frequency disturbances, and coordination of EV participation in regulating electrical power grid frequency. Moreover, simultaneous determination of the proposed fractional-order frequency controller parameters is proposed using the recent manta ray foraging optimization (MRFO) algorithm. Performance comparisons of the proposed 1 + PD/FOPID fractional-order frequency controller with existing PID, FOPID, and PD/FOPID controllers are presented in the paper. The results show an improved response, and the disturbance mitigation is also obtained using the proposed MRFO-based 1 + PD/FOPID control and design optimization methodology.
The Genealogical Message of Beatrix Frangepán
Authors: Berzeviczy Klára , Liska András , Pályi Gyula
Published: August 2023

Beatrix Frangepán (* c. 1480, +(27 March) 1510) from the Counts of Veglia (Krk), Modrus and Zengg was a descendant from one of the leading families of the Hungarian–CroatianHungarian–Croatian late Medieval Kingdom. She became wife of Crown Prince János Corvinus-Hunyadi and later of Margrave Georg Hohenzollern-Brandenburg. From her first marriage, she had three children. One of these, Kristóf, who died young, was buried together with his father in Lepoglava (Croatia). Recently, successful archaeogenetic analyses have been performed on the remains of János and Kristóf Corvinus-Hunyadi; and in the course of these studies, the family background of Kristóf’s mother, Beatrix Frangepán, became an important factor. The present study provides a nine-generation family tree of Beatrix Frangepan as a complementary data pool for an eventual expansion of the archaeogenetic studies. Preliminary results of archaeological study of the supposed grave of Beatrix Frangepán are also reported.
16p11.2 Microduplication Syndrome with Increased Fluid in the Cisterna: Coincidence or Phenotype Extension?
Authors: Nascimento Lívia Polisseni Cotta , Mergener Rafaella , Nunes Marcela Rodrigues , Muniz Victória Feitosa , Catao Juliana Rossi , Silveira Ana Kalise Böttcher da , Dorfman Luiza Emy , Graziadio Carla , Zen Paulo Ricardo Gazzola
Published: August 2023

We report the first case of a child with 16p11.2 microduplication syndrome with increased fluid in the cisterna magna seen on magnetic resonance imaging (MRI). This finding may correspond to a Blake’s Pouch Cyst (BPC) or a Mega Cisterna Magna (MCM), being impossible to differentiate through image examination. The molecular duplication was diagnosed using chromosomal microarray analysis with single nucleotide polymorphism (SNP). We review the clinical and neuroimaging features in published case reports in order to observe the findings described in the literature so far and present a skull three-dimensional model to contribute to a better understanding. Despite the variable expressivity of the syndrome being well known, there is no case described in the available literature that mentions the association of 16p11.2 microduplication and the presence of BPC or MCM seen in neuroimaging exams. This finding may represent an extension of the phenotype not yet reported or may present itself as a coincidence in a child with various malformations.
Analysis of Reports Sent to the Portuguese Pharmacovigilance System and Published Literature Regarding the Safety of Metformin in the Elderly
Authors: Esteves Beatriz , Monteiro Cristina , Duarte Ana Paula Coelho
Published: August 2023

The first line medication for the treatment of type 2 diabetes is metformin. This study aims to investigate the safety profile of metformin and metformin combination medications in older adults using pharmacovigilance data. A literature search was used to identify published clinical studies reporting safety of metformin in older patients (age ≥ 65 years old), which were then thoroughly evaluated. Additionally, a deep analysis was performed, taking into account suspected adverse drug reaction (ADR) reports submitted to the Portuguese Pharmacovigilance System involving patients with 65 years old or older, with metformin or metformin combination as the suspected drug. The results suggest that metformin is safer when used in combination with other antidiabetics than when used in monotherapy. Metformin prolonged-release tablets have a lower incidence of adverse effects compared to treatment with immediate-release metformin tablets. The analysis of the reports showed that “gastrointestinal disorders” was one of the most common classes reported, and metformin alone was the drug most commonly associated with serious gastrointestinal reactions that resulted in hospitalization. In addition, it was the drug most commonly associated with the lactic acidosis ADR. Even though most ADRs in the reports were serious, the majority progressed to cure. According to the analysis performed, the results suggest that the patient’s renal function should be considered in order to prevent ADRs associated with metformin, such as lactic acidosis. Therefore, monitoring the safety profile of metformin remains essential to prevent serious ADRs.