bluuebunny/crossref_metadata_2025 huggingface dataset:
Tracking the Origins of Pseudomonas aeruginosa Phylogroups by Diversity and Evolutionary Analysis of Important Pathogenic Marker Genes
Authors: Quiroz-Morales Sara E. , García-Reyes Selene , Ponce-Soto Gabriel Yaxal , Servín-González Luis , Soberón-Chávez Gloria
Published: April 2022

Pseudomonas aeruginosa is a widespread environmental bacterium and an opportunistic pathogen that represents a health hazard due to its production of virulence factors and its high antibiotic resistance. The genome of most of the strains belonging to this bacterial species is highly conserved, and genes coding for virulence-associated traits are part of the species core-genome. Recently, the existence of phylogroups has been documented based on the analysis of whole genome sequences of hundreds of isolates. These clades contain both clinical and environmental strains, which show no particular geographical distribution. The major phylogroups (clades 1 and 2) are characterized by the nearly mutually exclusive production of the virulence effectors secreted by the type three secretion system (T3SS) ExoS and ExoU, respectively. Clade 3 is the most genetically diverse and shares with clade 5, which is closely related to clades 1 and 2, the production of the pore-forming exolysin A, and the lack of T3SS, among other characteristics. Here we analyze the 4955 P. aeruginosa genomes deposited in the Pseudomonas Genome Database and present some hypotheses on the origins of four of the five phylogroups of this bacterial species.
Electrical Impedance Spectroscopy Improves Skin Cancer Detection and Reduces the Number of Biopsies
Authors: Liebich Christoph , Bartsch Jana Nadine , Schubert Irene , von Bruehl Marie-Luise , Sander Christian
Published: April 2022

There has recently been an increased interest in the use of novel automated technologies for the early detection of skin malignancies. We performed a retrospective analysis of the clinical effectiveness of electrical impedance spectroscopy (EIS) in detecting malignancies in an everyday clinical setting. After a thorough visual examination and dermoscopy, 909 abnormal lesions suspicious for malignancy were detected in 481 patients who presented in a private dermatology practice between 2015 and 2017 and evaluated with the EIS system. The histopathological results of the excised lesions were compared to the Neviscore, the output of the device. In total, 443 lesions (49%) received a negative Neviscore and were thus benign. On the other hand, 466 lesions received a positive Neviscore, indicating aberrations of the physiological cell structure. Of the 909 lesions, 45% were excised after visual and EIS examination. Of the excised lesions, 16% were diagnosed histopathologically as malignant. The EIS detected melanomas with 100% accuracy. The number needed to excise decreased from 17.5 to 7.8. The predictive value for a negative Neviscore was 98.9% (true negative results). EIS was found to be a valuable adjunct support tool when making clinical assessments of potentially malignant lesions.
Comparison of Nonclassic and Classic Phenotype of Hypertrophic Cardiomyopathy Focused on Prognostic Cardiac Magnetic Resonance Parameters: A Single-Center Observational Study
Authors: Stachera Magdalena , Przybyło Paweł , Sznajder Katarzyna , Gierlotka Marek
Published: April 2022

Patients with nonclassic phenotypes (NCP)—more advanced stages of hypertrophic cardiomyopathy (HCM)—constitute an intriguing and heterogeneous group that is difficult to diagnose, risk-stratify, and treat, and often neglected in research projects. We aimed to compare cardiac magnetic resonance (CMR) parameters in NCP versus classic phenotypes (CP) of HCM with special emphasis given to the parameters of established and potential prognostic importance, including numerous variables not used in everyday clinical practice. The CMR studies of 88 patients performed from 2011 to 2019 were postprocessed according to the study protocol to obtain standard and non-standard parameters. In NCP, the late gadolinium enhancement extent expressed as percent of left ventricular mass (%LGE) and left ventricular mass index (LVMI) were higher, left atrium emptying fraction (LAEF) was lower, minimal left atrial volume (LAV min) was greater, and myocardial contraction fraction (MCF) and left ventricular global function index (LVGFI) were lower than in CP (p < 0.001 for all). In contrast, HCM risk score and left ventricular maximal thickness (LVMT) were similar in NCP and CP patients. No left ventricular outflow tract obstruction (LVOTO) was observed in the NCP group. Left ventricular outflow tract diameter (LVOT), aortic valve diameter (Ao), and LVOT/Ao ratio were significantly higher and anterior mitral leaflet (AML)/LVOT ratio was lower in the NCP compared to the CP group. In conclusion, significant differences in nonstandard CMR parameters were noted between the nonclassic and classic HCM phenotypes that may contribute to future studies on disease stages and risk stratification in HCM.
Design of Gold Nanoparticle Vertical Flow Assays for Point-of-Care Testing
Authors: Lei Rongwei , Wang David , Arain Hufsa , Mohan Chandra
Published: April 2022

Vertical flow assays (VFAs) or flow-through assays have emerged as an alternate type of paper-based assay due to their faster detection time, larger sample volume capacity, and significantly higher multiplexing capabilities. They have been successfully employed to detect several different targets (polysaccharides, protein, and nucleic acids), although in a limited number of samples (serum, whole blood, plasma) compared to the more commonly known lateral flow assays (LFAs). The operation of a VFA relies mainly on gravity, coupled with capillary action or external force to help the sample flow through layers of stacked pads. With recent developments in this field, multiple layers of pads and signal readers have been optimized for more user-friendly operation, and VFAs have achieved a lower limit of detection for various analytes than the gold-standard methods. Thus, compared to the more widely used LFA, the VFA demonstrates certain advantages and is becoming an increasingly popular platform for obtaining qualitative and quantitative results in low-resource settings. Considering the wide application of gold nanoparticles (GNPs) in VFAs, we will mostly discuss (1) the design of GNP-based VFA along with its associated advantages/disadvantages, (2) fabrication and optimization of GNP-based VFAs for applications, and (3) the future outlook of flow-based assays for point-of-care testing (POCT) diagnostics.
Can EEG Correlates Predict Treatment Efficacy in Children with Overlapping ASD and SLI Symptoms: A Case Report
Authors: Maksimović Slavica , Jeličić Ljiljana , Marisavljević Maša , Fatić Saška , Gavrilović Aleksandar , Subotić Miško
Published: April 2022

Evaluation of the rehabilitation efficacy may be an essential indicator of its further implementation and planning. The research aim is to examine whether the estimation of EEG correlates of auditory-verbal processing in a child with overlapping autism spectrum disorder (ASD) and specific language impairment (SLI) symptoms may be a predictor of the treatment efficacy in conditions when behavioral tests do not show improvement during the time course. The prospective case report reports follow-up results in a child aged 36 to 66 months. During continuous integrative therapy, autism risk index, cognitive, speech–language, sensory, and EEG correlates of auditory-verbal information processing are recorded in six test periods, and their mutual interrelation was analyzed. The obtained results show a high statistically significant correlation of all observed functions with EEG correlates related to the difference between the average mean values of theta rhythm in the left (F1, F3, F7) and right (F2, F4, F8) frontal region. The temporal dynamics of the examined processes point to the consistency of the evaluated functions increasing with time flow. These findings indicate that EEG correlates of auditory-verbal processing may be used to diagnose treatment efficacy in children with overlapping ASD and SLI.
Dynamic Operation Loss Minimization for Permanent Magnet Synchronous Generator Based on Improved Model Predictive Direct Torque Control
Authors: Miao Lei , Lin Fengqin , Jiang Yuan , Li Qing , Sun Wenwei
Published: April 2022

During permanent magnet synchronous generator (PMSG) operation, aside from improving the rapid response of torque and reducing the rippling of torque and flux to guarantee the operational reliability, the loss of the PMSG itself cannot be ignored either. Aiming at this problem, an improved model predictive direct torque control (MPDTC) method is proposed, which suppresses the torque ripple and achieves PMSG efficiency optimization. Firstly, based on the conventional MPDTC and the loss model of PMSG, the predicted stator active current is determined, which is utilized for obtaining the predicted torque. Secondly, combined with the generator loss model, the set value of the stator energetic current is obtained; combined with the wind power system maximum power point tracking method, the set value of generator torque is obtained. Thirdly, by converting the torque control error and current control error into a per unit value, the influence of the weight coefficient in the cost function on the control effect is reduced. Finally, the key results verified the effectiveness and superiority of the proposed control scheme by simulation and experiment.
Method for Measuring Interface Pressure of High-Voltage Cables
Authors: Lyu Chao , Wang Shuang , Liu Shuang , Guo Yi
Published: April 2022

In high-voltage cables, because of the close fit of their internal structures, interface pressure is generated between conductor and insulator, which affects the performance of the cable. Studies on the calculation and testing of the interfacial pressure of cable conductors are scarce because of the lack of a unified formula and the difficulty of direct measurement. As such, in this study, we devised two methods for calculating and measuring the interface pressure of cable conductors. In the first, we used two physical experimental methods. We used the friction between cable components to perform the calculation and create an experimental method for determining cable conductor interface pressure; on the basis of the equation of the pressure inside and outside a thick-walled cylinder using elasticity mechanics, we calculated the interface pressure on the basis of the measurement of the strain state of the inner and outer diameters of each layer of the cable under different assembly and stripping conditions. We verified the effectiveness of the methods through physical tests and simulations using a YJLW03 1 × 1200 high-voltage cable. Then, we used simulation software ANSYS and SolidWorks to calculate the interface pressure. With different simulation settings, we obtained results regarding interface pressure. Lastly, these simulated values were individually compared with two physical tests, and the error was calculated. Results obtained in the ANSYS environment showed that interface pressure values determined by the geometric interference normal stress, geometric interference pressure, contact interference normal stress, and contact interference pressure methods were 39.75, 36.84, 5.76, and 36.57 MPa, respectively. In SolidWorks software, we used the contact-stress and X-axis normal stress methods. Results were all 37.36 MPa. Then, simulation results and experimental results were compared, and error was calculated. The comparison showed that the X-axis orthogonal stress method was the most accurate. Errors between the X-axis orthogonal stress method and the two physical experiments were 1.5% and 0.48%. Through the above simulation and physical experiments, we determined the interface pressure between conductors and insulators in a high-voltage power cable. We obtained the cable interface pressure value through two kinds of physical experiments, and these two methods were clearly reliable. Simulation experiments showed that using SolidWorks software to simulate this problem obtained better results. Research results provide technical support and reference for the calculation and measurement of cable interface pressure and the optimization of cable performance.
Bias Temperature Instability of MOSFETs: Physical Processes, Models, and Prediction
Authors: Zhang Jian Fu , Gao Rui , Duan Meng , Ji Zhigang , Zhang Weidong , Marsland John
Published: April 2022

CMOS technology dominates the semiconductor industry, and the reliability of MOSFETs is a key issue. To optimize chip design, trade-offs between reliability, speed, power consumption, and cost must be carried out. This requires modeling and prediction of device instability, and a major source of instability is device aging, where defects gradually build up and eventually cause malfunction of circuits. This paper first gives an overview of the major aging processes and discusses their relative importance as CMOS technology developed. Attentions are then focused on the negative and positive bias temperature instabilities (NBTI and PBTI), mainly based on the early works of the authors. The aim is to present the As-grown-Generation (AG) model, which can be used not only to fit the test data but also to predict long-term BTI at low biases. The model is based on an in-depth understanding of the different types of defects and the experimental separation of their contributions to BTI. The new measurement techniques developed to enable this separation are reviewed. The physical processes responsible for BTI are explored, and the reasons for the failure of the early models in predicting BTI are discussed.
FPGA-Based BNN Architecture in Time Domain with Low Storage and Power Consumption
Authors: Zhang Longlong , Tang Xuebin , Hu Xiang , Zhou Tong , Peng Yuanxi
Published: April 2022

With the increasing demand for convolutional neural networks (CNNs) in many edge computing scenarios and resource-limited settings, researchers have made efforts to apply lightweight neural networks on hardware platforms. While binarized neural networks (BNNs) perform excellently in such tasks, many implementations still face challenges such as an imbalance between accuracy and computational complexity, as well as the requirement for low power and storage consumption. This paper first proposes a novel binary convolution structure based on the time domain to reduce resource and power consumption for the convolution process. Furthermore, through the joint design of binary convolution, batch normalization, and activation function in the time domain, we propose a full-BNN model and hardware architecture (Model I), which keeps the values of all intermediate results as binary (1 bit) to reduce storage requirements by 75%. At the same time, we propose a mixed-precision BNN structure (model II) based on the sensitivity of different layers of the network to the calculation accuracy; that is, the layer sensitive to the classification result uses fixed-point data, and the other layers use binary data in the time domain. This can achieve a balance between accuracy and computing resources. Lastly, we take the MNIST dataset as an example to test the above two models on the field-programmable gate array (FPGA) platform. The results show that the two models can be used as neural network acceleration units with low storage requirements and low power consumption for classification tasks under the condition that the accuracy decline is small. The joint design method in the time domain may further inspire other computing architectures. In addition, the design of Model II has certain reference significance for the design of more complex classification tasks.
Design and Control of a Three-Level Rectifier in LCC/S-Compensated IPT for Wide Output Voltage Regulation over Various Magnetic Couplings
Authors: Li Jianting , Wang Jinquan , Wang Puyu , Li Jianke , Chen Jingjing , Chen Shu
Published: April 2022

Conventional inductive power transfer (IPT) employs primary control via phase shift, frequency tuning, or voltage tuning, whereas closed-loop control requires real-time wireless feedback communication. However, the long propagation delay results in small bandwidth. In this paper, a three-level (TL) rectifier is studied to implement secondary control and wide output voltage regulation in an inductor–capacitor–capacitor/series (LCC/S)-compensated IPT system over various magnetic couplings. The periodical operation behavior is analyzed, and a generic analytical expression of the system voltage gain including the TL rectifier is derived based on the Fourier series. A control strategy of an optimal control trajectory is proposed to maximize the power factor in the TL rectifier. The control variables are the duty cycles of the zero-level and one-level voltage in the TL rectifier. Either one remains at zero, while another one is utilized to modulate the output voltage in the proposed control strategy. A 2 kW prototype is designed and built to validate the theoretic analysis. The wide output voltage range between 100 V and 200 V under different magnetic coupling coefficients (0.16 and 0.23), a peak efficiency of 95.8% at 100 V and misaligned position, as well as a faster response of 1.3 ms are experimentally validated.
Modeling a Hybrid Reformed Methanol Fuel Cell–Battery System for Telecom Backup Applications
Authors: Martinho Diogo Loureiro , Simon Araya Samuel , Sahlin Simon Lennart , Liso Vincenzo , Li Na , Berg Thomas Leopold
Published: April 2022

In this paper, a hybrid reformed methanol fuel cell–battery system for telecom backup applications was modeled in MATLAB Simulink. The modeling was performed to optimize the operating strategy of the hybrid system using an energy management system with a focus on a longer lifetime and higher fuel efficiency for the fuel cell, while also keeping the state-of-charge (SOC) of the battery within a reasonable range. A 5 kW reformed methanol fuel cell stack and a 6.5 kWh Li-ion battery were considered for the hybrid model. Moreover, to account for the effects of degradation, the model evaluated the performance of the fuel cell both in the beginning of life (BOL) and after 1000 h and 250 start–stop cycling tests (EOT). The energy management system (EMS) was characterized by 12 operating conditions that used the battery SOC, load requirements and the presence or absence of grid power as the inputs to optimize the operating strategy for the system. Additionally, the integration of a 400 W photovoltaic (PV) system was investigated and was able to supplement the battery SOC, thereby increasing the stability and reliability of the system. However, extensive power outages during the night could lead to low battery SOC and, therefore, critical operating conditions and the extended use of the fuel cell. The model also predicted the methanol consumption for different scenarios.
Multiscale Full-Waveform Inversion with Land Seismic Field Data: A Case Study from the Jizhong Depression, Middle Eastern China
Authors: Wang Kai , Feng Xuan , Malcolm Alison , Williams Christopher , Wang Xiaojiang , Zhang Kai , Zhang Baowei , Yue Hangyu
Published: April 2022

The Jizhong depression contains several geothermal reservoirs that are characterized by localized low-velocity anomalies. In this article, full-waveform inversion (FWI) is used to characterize these anomalies and determine their extent. This is a challenging problem because the reservoirs are quite small and the available data have usable frequencies only down to 5 Hz. An accurate-enough starting model is carefully built by using an iterative travel time tomography method combined with a cycle-skipping assessment method to begin the inversion at 5 Hz. A multiscale Laplace–Fourier-domain FWI with a layer-stripping approach is implemented on the starting model by gradually increasing the maximum offset. The result of overlapping the recovered velocity model on the migrated seismic profile shows a good correlation between the two results. The recovered model is assessed by ray tracing, synthetic seismogram modeling, checkerboard testing and comparisons with nearby borehole data. These tests indicate that low-velocity anomalies down to a size of 0.3 km × 0.3 km at a maximum depth of 2 km can be recovered. Combined with the well log data, the resulting velocity model allows us to delineate two potential geothermal resources, one of which was previously unknown.
A Review of EV Battery Utilization in Demand Response Considering Battery Degradation in Non-Residential Vehicle-to-Grid Scenarios
Authors: Leippi Andre , Fleschutz Markus , Murphy Michael D.
Published: April 2022

Integrating fleets of electric vehicles (EVs) into industrial applications with smart grids is an emerging field of important research. It is necessary to get a comprehensive overview of current approaches and proposed solutions regarding EVs with vehicle-to-grid and smart charging. In this paper, various approaches to battery modeling and demand response (DR) of EV charging in different decentralized optimization scenarios are reviewed. Modeling parameters of EVs and battery degradation models are summarized and discussed. Finally, optimization approaches to simulate and optimize demand response, taking into account battery degradation, are investigated to examine the feasibility of adapting the charging process, which may bring economic and environmental benefits and help to alleviate the increasing demand for flexibility. There is a lack of studies that comprehensively consider battery degradation for EV fleets in DR charging scenarios where corresponding financial compensation for the EV owners is considered. Therefore, models are required for estimating the level of battery degradation endured when EVs are utilized for DR. The level of degradation should be offset by providing the EV owner with subsidized or free electricity provided by the company which is partaking in the DR. This trade-off should be optimized in such a manner that the company makes cost savings while the EV owners are compensated to a level that is at least commensurate with the level of battery degradation. Additionally, there is a lack of studies that have examined DR in smart grids considering larger EV fleets and battery degradation in multi-criteria approaches to provide economic and environmental benefits.
An Efficient Method for Computing the Power Potential of Bypass Hydropower Installations
Authors: Cleynen Olivier , Powalla Dennis , Hoerner Stefan , Thévenin Dominique
Published: April 2022

Small-scale hydropower installations make possible a transition towards decentralized electrical power production with very low ecological footprint. However, the prediction of their power potential is difficult, because the incoming flow velocity and the inlet and outlet water heights are often outside of the control of the operator. This leads to a need for a method capable of calculating an installation’s power potential and efficiency rapidly, in order to cover for many possible load cases. In this article, the use of a previously-published theoretical framework is demonstrated with the case of a mid-scale hydropower device, a 26 m long water vortex power plant. It is shown that a simplified CFD simulation with a single output (the mass flow rate) is sufficient to obtain values for the two coefficients in the model. Once this is done, it becomes possible to evaluate the device’s real-life performance, benchmarking it against reference values anchored in physical principles. The method can be used to provide design guidance and rapidly compare different load cases, providing answers that are not easily obtained using intuition or even experiments. These results are obtained for a computing cost several orders of magnitude smaller than those associated with a full description of the flow using CFD methods.
Implementation of Non-Destructive Condition Monitoring Techniques on Low-Voltage Nuclear Cables: II. Thermal Aging of EPR/CSPE Cables
Authors: Mustafa Ehtasham , Afia Ramy S. A. , Nawaz Aamir , Nouini Oumaima , Tamus Zoltán Ádám
Published: April 2022

Determining the aging state of low-voltage nuclear power plant cables using a nondestructive and reliable condition monitoring technique is highly desirable as the cables experience multiple aging stresses during the service period. This paper deals with the implementation and investigation of such nondestructive techniques, which can detect the overall aging state of low-voltage instrumentation and control (I&C) cables, which are subjected to accelerated thermal aging. The dielectric spectroscopy, extended voltage response, and polarization–depolarization current as nondestructive electrical aging techniques were used for the investigation purpose, while the elongation at break was also adopted as a mechanical measurement and for comparison. Prominent variations in the electrical parameters for the insulation and jacket were observed, whereas the elongation at break for both materials also decreased under thermal aging. Based on the electrical techniques, aging markers were selected that showed a strong correlation with the aging and elongation at break, proving the ability of the adopted electrical methods as a nondestructive condition monitoring technique.
Development of CO2 Concentration Prediction Tool for Improving Office Indoor Air Quality Considering Economic Cost
Authors: Lee Yeo-Kyung , Kim Young Il , Lee Woo-Seok
Published: April 2022

Ventilation is becoming increasingly important to improve indoor air quality and prevent the spread of COVID-19. This study analyzed the indoor air quality of office spaces, where occupants remain for extended periods, among multi-use facilities with an increasing need for ventilation system application. A “tool for office space CO2 prediction and indoor air quality improvement recommendation” was developed. The research method was divided into four steps. Step 1: Analysis of indoor air quality characteristics in office spaces was carried out with a questionnaire survey and indoor air quality experiment. Based on the CO2 concentration, which was found to be a problem in the indoor air quality experiment in the office space, Step 2: CO2 concentration prediction tool for office spaces, which requires inputs of regional and spatial factors and architectural and equipment elements, was developed. In Step 3: Development and verification of prediction tool considering economic feasibility, the cost of energy recovery ventilation systems based on the invoices of the energy recovery ventilation manufacturers was analyzed. In Step 4: Energy recovery ventilation proposal and indoor CO2 forecast, Office Space B, which can accommodate up to 15 people, was derived as an example of the proposed tool. As a result of the prediction, the optimal air volume of the energy recovery ventilation was determined according to the “office CO2 prediction and indoor air quality improvement recommendations”. This study introduced simple tools, which can be used by non-experts, that are capable of showing changes in indoor air quality, CO2 concentration and cost according to activities.
Dual Heuristic Dynamic Programming Based Energy Management Control for Hybrid Electric Vehicles
Authors: Wang Yaqian , Jiao Xiaohong
Published: April 2022

This paper investigates an adaptive dynamic programming (ADP)-based energy management control strategy for a series-parallel hybrid electric vehicle (HEV). This strategy can further minimize the equivalent fuel consumption while satisfying the battery level constraints and vehicle power demand. Dual heuristic dynamic programming (DHP) is one of the basic structures of ADP, combining reinforcement learning, dynamic programming (DP) optimization principle, and neural network approximation function, which has higher accuracy with a slightly more complex structure. In this regard, the DHP energy management strategy (EMS) is designed by the backpropagation neural network (BPNN) as an Action network and two Critic networks approximating the control policy and the gradient of value function concerning the state variable. By comparing with the existing results such as HDP-based and rule-based control strategies, the equivalent consumption minimum strategy (ECMS), and reinforcement learning (RL)-based strategy, simulation results verify the robustness of fuel economy and the adaptability of the power-split optimization of the proposed EMS to different driving conditions.
Multi-Parameter Analysis of Gas Losses Occurring during the Determination of Methane-Bearing Capacity in Hard Coal Beds
Authors: Karbownik Marcin , Dudzińska Agnieszka , Strzymczok Jarosław
Published: April 2022

The content of natural methane in hard coal seams, called methane-bearing capacity, is the basic parameter that enables the level of methane hazard to be determined in hard coal mines. This parameter is also used to determine the potential quantities of methane that can be collected and used for energy purposes and the amount of its harmful emission to the atmosphere. Direct methods are most often used to determine methane-bearing capacity. An important aspect that has a great influence on the final result of the research is the gas losses generated at the stage of sampling. Under the conditions of the Polish mining industry, the direct drill cuttings method is used to determine the methane-bearing capacity. Gas losses are compensated for in this method with the use of the coefficient 1.12, by which the obtained result is multiplied. In this paper, a multi-parameter analysis of gas loss in the determination of methane-bearing capacity in hard coal seams has been carried out. Several experiments were performed to identify the most important aspects to be taken into account to obtain a correct result. A methane-bearing capacity test was conducted using two direct methods: the direct drill cuttings method, otherwise known as the single-phase vacuum degassing method, and a method based on the United States Bureau of Mines standards. Sorption studies, such as methane sorption kinetics tests, were also conducted in which sorption properties, such as sorption capacity, effective diffusion coefficient, and half sorption time, were determined. Methane sorption isotherms were also determined, and pore structure was analysed. Based on the obtained test results, an analysis was carried out which made it possible to present appropriate conclusions concerning the gas losses during the methane-bearing capacity test, generated at the stage of sampling. The final result of the work was the proposal of a new gas loss coefficient for the direct drill cuttings method of methane-bearing capacity determination.
A Comparison of Adaptive Ultrasound Reflectometry Calibration Methods for Use in Lubrication Films
Authors: Hansen Elias Vagn , Johansen Per
Published: April 2022

Adaptive calibration for ultrasound reflectometry methods used in the detection of lubrication film thickness is of great research interest. This is mainly due to the versatile non-destructive implementation of the technology in industrial applications, allowing for measurements of the lubrication film thickness, which directly relates to the friction, wear, and overall efficiency of the system. This study reviews and compares a curve fitting, extended Kalman filter, and resonance frequency detection adaptive calibration approach. Furthermore, the study compares two different regression models, used for the curve fitting and the extended Kalman filter approach. The study compares the methods and regression models based on both a theoretical and experimental analysis. The experimental analysis is based on data with varying lubrication film thickness. The lubrication film thickness is varied such that the resonance frequency is both detectable and non-detectable within the ultrasound transducer bandwidth. It is found that all three methods give results very similar to those achieved through manual calibration. However, since the extended Kalman filter approach is the only method that allows for continuous calibration, this method is found to have the greatest potential of the methods compared.
Evaporated Alkali Carbonate Effect on an Aluminum Diffusion Coated 253MA Vessel after 4000 h Discontinuous Operation—Lessons Learned
Authors: Hamdy Esraa , Wagné Angelina , Geers Christine
Published: April 2022

A vessel of a laboratory setup for hosting molten alkali carbonate immersion experiments was recently decommissioned after about 4000 h discontinuous operation at 800 °C. In this article, we want to describe the long-term damage of the vessel caused by evaporated alkali carbonate species in a carbon dioxide gas environment. The vessel is made of alloy 253MA and coated by an aluminum powder pack diffusion process. The degree of material loss and internal degradation did not correlate with the temperature profile across the vessel but rather with the vicinity to the gas and salt evaporation source. One millimeter of the vessel’s initial 5 mm wall thickness was completely consumed at the strongest attacked location plus another 800 µm of internal attack beneath the metal–oxide interface.
Acoustic Signature and Impact of High-Speed Railway Vehicles in the Vicinity of Transport Routes
Authors: Polak Krzysztof , Korzeb Jarosław
Published: April 2022

In this paper, an attempt is undertaken to identify the acoustic signature of railway vehicles travelling at 200 km/h. In the framework of conducted experimental research, test fields were determined, measurement apparatus was selected and a methodology for making measurements was specified, including the assessment of noise emission on curved and straight track for electric multiple units of Alstom type ETR610-series ED250, the so-called Pendolino. The measurements were made with the use of an acoustic camera and a 4 × 2 microphone array, including four equipped measurement points and two microphones located at the level of the head of the rail and at a height of 4 m above this level. As a result of the conducted experimental research, the dominant noise sources were identified and amplitude–frequency characteristics for these sources were determined by dividing the spectrum into one-third octave bands in the range from 20 Hz to 20 kHz. The paper also considers issues related to the verification of selected models of noise assessment in terms of their most accurate reflection of the phenomenon of propagation in close surroundings. On the basis of conducted experimental studies, the behaviour of selected models describing the change of sound level with frequency division into one-third octave bands as a function of variable distance of observer from the railway line on which high-speed railway vehicles are operated was verified. In addition, the author’s propagation model is presented together with a database built within the scope of the study, containing the actual waveforms in the time and frequency domain.
Characterization of Sampled Value Streams in Non Real-Time Calibration Systems
Authors: Agustoni Marco , Frigo Guglielmo
Published: April 2022

The digital transformation of electrical substations relies on the communication protocols introduced in the IEC Std 61850. In particular, the Sampled Value data format is expected to be employed in an ever-increasing number of measurement applications and devices. In this context, National Metrological Institutes are required to develop calibration infrastructures capable of dealing with synchronous analog and digital input and output channels. In this paper, we characterize the performance of the METAS calibrator in terms of transmission latency and publishing rate stability. In particular, we discuss the feasibility of meeting the stringent requirements of meterological applications even in a non real-time operating system. To this end, an enhanced software library and measurement procedure are introduced. The proposed results confirm the quasi-deterministic behavior of the calibrator and proves its refined precision and stability with respect to commercial devices.
Genetic Parameters of Diameter Growth Dynamics in Norway Spruce Clones
Authors: Zeltiņš Pauls , Kangur Ahto , Katrevičs Juris , Jansons Āris
Published: April 2022

The breeding of Norway spruce in northern Europe has substantially contributed to the production of high-quality wood. The vegetative propagation of robust elite clones could help to sustain the provision of high-quality timber in the face of changing climates. For the adequate evaluation of genetic gains, the altered tree growth dynamics of the clones need to be understood, yet essential information about the long-term growth dynamics of improvedboreal trees is still lacking. We examined a 50-year-old clonal plantation in Latvia to distinguish the clonal effects on diameter growth function parameters and estimate the genetic parameters. A mixed-effect modelling approach was used, in which the clones were applied as random effects on the parameters of the Chapman–Richard equation. All model parameters showed significant variance in the genotypic coefficients of variation CVg which ranged between 11.0 and 17.1%, with the highest being for the growth rate. The heritability (H2) of the diameter at breast height (DBH) reached 0.35 at the age of 40, while CVg decreased from 12.9% to 7.8% between the ages of 20 and 45. Age–age genotypic correlations were positive and were strong or very strong (>0.76). The realised genetic gain varied from −6.3 to +24.0% around the trial mean. A substantial improvement in DBH was indicated when elite clones were selected for vegetative propagation based not only on early measurements, but also considering the genetic variance in the model parameters.
The Genetics and Ecology of Post-Fire Eucalyptus globulus Recruitment in an Isolated Stand in Central Portugal
Authors: Costa Joana , Silva Joaquim S. , Deus Ernesto , Pinho Simão , Pinto Joaquim F. , Borralho Nuno
Published: April 2022

Eucalyptus globulus Labill. is a widespread forest tree species, reported as naturalized across the introduced range, often showing abundant natural regeneration after wildfires. This paper studies a post-fire cohort of seedlings derived from a small, isolated E. globulus stand in central Portugal. The aim is to better understand the genetic dynamics and dispersal mechanisms of naturally established E. globulus populations in the introduced range. The seedling density at 55 m from adult trees was 12,000 ha−1, the farthest seedling being registered at 101 m. Post-fire expansion occurred in a southward direction, in accordance with predominant wind. Seedlings had significantly lower levels of genetic diversity (Ae = 5.8.; He = 0.8) than adult trees (Ae = 6.5; He = 0.8). Crossings were strongly unbalanced, with only eight trees contributing to the sampled seedlings, and one single tree contributing to 52% of these seedlings. Moreover, the co-ancestry amongst seedlings more than doubled (from θ = 0.03 to 0.076), and the population status number was around one third of the value registered for the adult population (from Ns = 16.2 to 6.6). Despite its isolation, external pollen was detected in the stand, and appears to have travelled at least 700 m, contributing to 22% of the offspring. Overall, the seedling cohort is much less diverse than the parent trees, with expected lower resilience and persistence to environmental stresses.
Response of Leaf Functional Traits of Landscape Plants to Urban Green Space Environment in Lanzhou, China
Authors: Huang Rong , Tian Qing , Zhang Yue , Wu Yonghua , Li Zizhen , Tang Zitong , Zhou Anyue
Published: April 2022

Leaf functional traits are the essential components of adaption plant strategies and have different responses to various environments, but our knowledge of how plants adapt to highly complex urban environments through coordinated changes in leaf functional traits is limited. In this study, we studied the response of landscape plants to the environments of sports field (SF), park (PAR), residential green space (RES), and greenway (GW), and analyzed the effects of the different green space environments on trade-off strategies of plants based on leaf functional traits. The results showed that leaf functional traits of plants and adaptation strategies varied among different urban environments in Lanzhou, China. Leaf length (LL), width (LW), area (LA), and special leaf area (SLA) were PAR > SF > RES > GW. Leaf nitrogen (LNC) and phosphorus content (LPC) were SF > PAR > RES > GW. Leaf carbon content (LCC), leaf dry matter content (LDMC), the ratio of leaf carbon and nitrogen (C/N), and the ratio of leaf carbon and phosphorus (C/P) was GW > RES > PAR > SF. The landscape plants in SF and PAR were more adaptive to the urban environment than those in RES and GW. Among different green space environments, landscape plants in SF and PAR tended to have an acquisitive strategy with high LL, LW, LA, SLA, LNC, and LPC. In contrast, plants in RES and GW tended to have a conservative strategy with a high level of concentration of LCC, LDMC, C/N, and C/P.
Use of Battery- vs. Petrol-Powered Chainsaws in Forestry: Comparing Performances on Cutting Time
Authors: Neri Francesco , Laschi Andrea , Marchi Enrico , Marra Elena , Fabiano Fabio , Frassinelli Niccolò , Foderi Cristiano
Published: April 2022

The use of battery tools is very common in many fields of work. In fact, the electric engine and batteries have several advantages over traditional endothermic engines, including low emissions, in terms of pollutants, vibration and noise. In this context, the chainsaw market started producing electric models powered by batteries. These machines can be useful in forestry, but information on their performance is scarce. The aim of this work was to compare the performance, in terms of cutting times, of three Stihl chainsaw models: the MS 220C-B (battery powered), and the MS 201 C-M and MS 261 C-M (both petrol powered). The study was carried out on five different wood species, also taking into consideration the presence/absence of wood defects in the cutting. More than 800 cuts on 15 m × 15 cm wood beams were video recorded, and the cutting times were later obtained to a resolution of 4/100 of a sec, using video-editing software. The results showed a poorer performance of the battery chainsaw than the petrol chainsaws, especially on certain wood species. However, this difference has been reduced when compared with older models. In conclusion, battery chainsaws need some additional improvements to be introduced into forestry, but their high potential is evident.
An Ecological-Economic Approach to Assess Impacts of the Expansion of Eucalyptus Plantations in Agroforest Landscapes of Northern Ethiopia
Authors: Abate Dagm , Borges José G. , Marques Susete , Bushenkov Vladimir
Published: April 2022

The conversion of fertile croplands to Eucalyptus woodlots in Ethiopian highlands, due to its business attractiveness to smallholders, raises concerns related to food production, water resources, carbon and other ecosystem services. This study was therefore designed to examine land allocation and plantation management decisions. Our emphasis was on the analysis of tradeoffs between the economic gains obtained from harvesting Eucalyptus timber and food production, carbon and water use. For that purpose, we considered a 1987 ha agroforest landscape in the Amhara region, Northern Ethiopia. With a planning horizon covering nine one-year periods, we developed and used nine Model I single objective linear programming (LP) models, and analyzed tradeoffs between objectives (e.g., land expectation value (LEV), Carbon, volume of ending inventory (VolEI), crop production and water use) using an LP-based Pareto frontier approach. The study revealed that the objective of maximizing the total economic gain from the sale of Eucalyptus wood poles favored a complete conversion of the available cropland into Eucalyptus woodlots. To meet the minimum annual crop production/consumption/requirements of households in the study area, the land under Eucalyptus should be limited to 1772 ha, with a sequestration potential of 1.5 to 1.57 × 107 kg yr−1 of carbon in the aboveground biomass. However, this land cover limit should be decreased to 921 ha so as to limit the total annual water use (for biomass production) below the amount available from rainfall (11,000 m3 ha−1 yr−1). Moreover, the study highlighted that maximizing the harvested wood volume or LEV would come at the cost of a decreased aboveground carbon stock and volume of ending inventory and higher total water use. It also provided alternative optimal Pareto-front points, among which decision makers will be able to select their preferred targets. The current study also showed the potential for the application of Pareto frontier approaches to support the development of effective ecological/economic management strategies and the design of land use policies in an Ethiopian context.
Weather Research and Forecasting—Fire Simulated Burned Area and Propagation Direction Sensitivity to Initiation Point Location and Time
Authors: DeCastro Amy , Siems-Anderson Amanda , Smith Ebone , Knievel Jason C. , Kosović Branko , Brown Barbara G. , Balch Jennifer K.
Published: April 2022

Wildland fire behavior models are often initiated using the detection information listed in incident reports. This information carries an unknown amount of uncertainty, though it is often the most readily available ignition data. To determine the extent to which the use of detection information affects wildland fire forecasts, this research examines the range of burned area values and propagation directions resulting from different initiation point locations and times. We examined the forecasts for ten Colorado 2018 wildland fire case studies, each initiated from a set of 17 different point locations, and three different starting times (a total of 520 case study simulations). The results show that the range of forecast burned area and propagation direction values is strongly affected by the location of the initiation location, and to a lesser degree by the time of initiation.
The Impact of Premortality Stress on Some Quality Parameters of Roe Deer, Wild Boar, and Red Deer Meat
Authors: Tomljanović Kristijan , Grubešić Marijan , Medić Helga , Potočnik Hubert , Topolovčan Tomislav , Kelava Ugarković Nikolina , Marušić Radovčić Nives
Published: April 2022

The specifics of meat production from free-ranging animals include the killing of animals in the wild with firearms. This type of uncontrolled killing sometimes leads to the phenomenon that the game does not die immediately but after a certain time from the shot to death, which may ultimately affect the quality of the meat. During one hunting year on free-ranging red deer (Cervus elaphus) (RD), roe deer (Capreolus capreolus) (RoD), and wild boar (Sus scrofa) (WB), the effect of time from shot to death on final pH, water-holding capacity (WHC), water content, and colour (L*, a*, b*) was investigated. All analyses were performed on Musculus biceps femoris (BF). After shooting, the animals were divided into two categories (A = time from shot to death ≤ 1 min; B = time from shot to death > 1 min). In RD, group B had significantly lower (p < 0.05) water content. In RoD, group B had significantly lower (p < 0.05) values of L* and b*. In WB, group B had significantly lower (p < 0.05) L* value and significantly higher (p < 0.05) pH value. The study proves that in BF of the three studied game species, the time extension from shot to death significantly affects the final water content values in RD, L* and b* in RoD and pH and L * in WB.