bluuebunny/crossref_metadata_2025 huggingface dataset:
Technical Performance Comparison between U-Shaped and Deep Borehole Heat Exchangers
Authors: Alimonti Claudio
Published: January 2023

The geothermal industry is fronted by a fundamental decade to grow and become an energy supplier in transitioning to a sustainable energy system. The introduction of Closed-Loop Geothermal energy systems (CLG) can overcome the negative social response and increase the attractiveness of geothermal developments. The present work aims to investigate and compare the performance of CLG systems. For the comparison, the case study of Campi Flegrei was chosen. The maximum depth was fixed at 2000 m, and the two configurations were set up to analyse the performance and evaluate the best operational configuration. Both CLG configurations showed decay in the output temperature of the working fluid during the production time. For a U-shaped design, it is possible to find a working condition that allows constant thermal power over time. The DBHE specific power was always more significant, up to 350 kW/m, compared to the U-shaped, which attained a maximum of 300 W/m (15%). The comparison with Beckers et al. analysis highlights the similarity of our results with their base case. The consideration of the CLG system’s length is related to the heat exchange and investment costs. For longer exchangers, there are higher investments and lower specific power.
Development and Analysis of Mathematical Plunger Lift Models of the Low-Permeability Sulige Gas Field
Authors: Cai Wenbin , Zhang Huiren , Huang Zhimin , Mo Xiangyang , Zhang Kang , Liu Shun
Published: January 2023

The Sulige is a low-permeability tight gas sandstone field whose natural gas production has gradually declined with continuous development. The primary reason was that most of the wells in the field flew below their critical rates and liquids started to accumulate in the wellbore at different levels, which resulted in the production reduction due to the wellbore pressure decrease and back pressure increase on the produced gas. An artificial lift was required to remove the liquids from those wells. With the advantages such as simple installation and operation, low cost and high liquid-carrying capacity, the plunger lift has been proven effective in the Sulige Gas Field. In this paper, firstly, a series of mathematical models were developed to investigate plunger displacement and velocity in the uplink and downside phases, fluid leakage in the uplink phase, and the characteristics of tubing pressure and casing pressure in the uplink and pressure build-up phases. Then, taking well X1 and well X2 at Su 59 area of the gas field as an example, the established mathematical models were applied to estimate its tubing and casing pressure, plunger moving displacement and speed, fluid leakage during the uplink phase, and gas production during the plunger lift. Hence, the well production cycle operated by the maximum gas rate was optimized. This study provides a theoretical basis for the optimal design of plunger lift parameters and the improvement of gas production.
Harmonic Distortion Reduction of Transformer-Less Grid-Connected Converters by Ellipsoidal-Based Robust Control
Authors: Soliman Hisham M. , Saleem Ashraf , Bayoumi Ehab H. E. , De Santis Michele
Published: January 2023

A photovoltaic generator connected to a large network and supplying a nonlinear load (source of harmonics) injects distorted current into the grid. This manuscript presents an invariant-ellipsoid set design of a robust controlled active power filter to inject current into the large grid with minimum total harmonic distortion (THD). The nonlinear load current is considered an external disturbance to minimize its effect on the injected grid current. Moreover, the large grid is modeled as a fixed voltage source in a series with a Thevenin impedance whose value changes within an interval. Using the invariant-ellipsoid technique, the problem is cast as a robust disturbance-rejection tracking control. The volume of the ellipsoid is minimized, which results in minimizing the effect of disturbance on system performance and keeping the trajectories as close as possible to the origin. The design is cast into a set of nonlinear matrix inequalities that are linearized by fixing a scalar. The resulting convex optimization is solved iteratively by linear matrix inequalities (LMIs). The simulation and experimental findings show that the proposed design is successful in reducing THD injected into the grid when grid impedance is uncertain and variable loads are applied (balanced and unbalanced cases).
A Comparative Review on Single Phase Transformerless Inverter Topologies for Grid-Connected Photovoltaic Systems
Authors: Kibria Md. Faruk , Elsanabary Ahmed , Tey Kok Soon , Mubin Marizan , Mekhilef Saad
Published: January 2023

The uses of grid-connected photovoltaic (PV) inverters are increasing day by day due to the scarcity of fossil fuels such as coal and gas. On the other hand, due to their superior efficiency, lower cost, smaller size, and lighter weight when compared to inverters with transformers, transformerless inverters for low-voltage single-phase grid-tied photovoltaic (PV) systems have recently attracted more interest. However, there are some specific challenges, especially leakage current issues, which must be adequately addressed to ensure the safety standards of the grid codes. A variety of topologies has been presented in the literature to eliminate the leakage current using the decoupling or clamping technique. However, choosing an appropriate topology after comparison is challenging because each topology has a unique set of parameters. In this paper, the authors have selected a common set of parameters and simulated all the selected eighteen well-known topologies in MATLAB/Simulink to fairly analyze and compare their common mode characteristics and other output parameters. In addition, the power loss distribution of every switch of each of the eighteen topologies was calculated and presented to better understand the insight of the topologies.
CPSOGSA Optimization Algorithm Driven Cascaded 3DOF-FOPID-FOPI Controller for Load Frequency Control of DFIG-Containing Interconnected Power System
Authors: Xie Shihao , Zeng Yun , Qian Jing , Yang Fanjie , Li Youtao
Published: January 2023

This paper proposes a new cascaded fractional-order controller (CC-FOC) to solve the load frequency control (LFC) problem of an interconnected power system. The CC-FOC consists of a three-degree-of-freedom fractional-order proportional-integral-differential (3DOF-FOPID) controller and a fractional-order proportional-integral (FOPI) controller. Each area of the two-area interconnected power system in this study consists of a thermal unit, a hydro unit, a diesel unit, and a doubly-fed induction generator (DFIG). The enhanced particle swarm optimization (PSO) and gravitational search algorithm (GSA) under the chaotic map optimization (CPSOGSA) technique are used to optimize the controller gains and parameters to enhance the load frequency control performance of the cascade controller. Moreover, simulation experiments are conducted for the interconnected power system under load perturbation and random wind speed fluctuations. The simulation results demonstrate that the proposed cascaded fractional-order controller outperforms the traditional proportional-integral-differential (PID) controller and three other fractional-order controllers in terms of LFC performance. The suggested cascade controller displays strong dynamic control performance and the resilience of the cascade fractional-order controller by adjusting the load disturbance and analyzing the system characteristics.
Aggregating Prophet and Seasonal Trend Decomposition for Time Series Forecasting of Italian Electricity Spot Prices
Authors: Stefenon Stefano Frizzo , Seman Laio Oriel , Mariani Viviana Cocco , Coelho Leandro dos Santos
Published: January 2023

The cost of electricity and gas has a direct influence on the everyday routines of people who rely on these resources to keep their businesses running. However, the value of electricity is strongly related to spot market prices, and the arrival of winter and increased energy use owing to the demand for heating can lead to an increase in energy prices. Approaches to forecasting energy costs have been used in recent years; however, existing models are not yet robust enough due to competition, seasonal changes, and other variables. More effective modeling and forecasting approaches are required to assist investors in planning their bidding strategies and regulators in ensuring the security and stability of energy markets. In the literature, there is considerable interest in building better pricing modeling and forecasting frameworks to meet these difficulties. In this context, this work proposes combining seasonal and trend decomposition utilizing LOESS (locally estimated scatterplot smoothing) and Facebook Prophet methodologies to perform a more accurate and resilient time series analysis of Italian electricity spot prices. This can assist in enhancing projections and better understanding the variables driving the data, while also including additional information such as holidays and special events. The combination of approaches improves forecast accuracy while lowering the mean absolute percentage error (MAPE) performance metric by 18% compared to the baseline model.
Advanced Progress of Organic Photovoltaics
Authors: Wu Xinlei , Zhang Yuanpeng , Shi Kaihang , Ma Xiaoling , Zhang Fujun
Published: January 2023

Modern civilization and economic development of humankind have been largely based on the exploitation and utilization of fossil energy [...]
A Transformer Design for High-Voltage Application Using LLC Resonant Converter
Authors: Ondin Umut , Balikci Abdulkadir
Published: January 2023

The inductor–inductor–capacitor (LLC) resonant converter is a suitable topology for wide output voltage and load range applications with limited circuit parameters. One of the most significant design boundaries of an LLC resonant converter in high-voltage applications is the parasitic capacitance effect of the main circuit components, particularly the transformer and junction capacitances of the secondary rectifier network. Parasitic capacitance effects are much higher in high-voltage applications than in low-voltage applications. Therefore, the use of an LLC resonant converter is limited to high-voltage applications. This study proposes to reduce the capacitive effects of high-voltage transformers and rectification networks with a multi-winding transformer with an integrated rectifier design and to use it in high-voltage applications with the advantages of the LLC resonant converter. For the proposed prototype, comparative experimental measurements were conducted using a conventional scheme. The measurements validate the reliability of the LLC converter for high-voltage applications, improving the output regulation performance while significantly reducing parasitic capacitances.
Advances in Oil and Gas Production: A Viewpoint
Authors: Morenov Valentin
Published: January 2023

Nowadays, there is a global trend towards “green” industry, which implies the reduction in carbon emissions from various industrial processes [...]
Heat Transfer Analysis and Operation Optimization of an Intermediate Fluid Vaporizer
Authors: Huang Kun , Zhou Xingyu , Huang Cheng , Wang Lin , Li Dequan , Zhao Jinrei
Published: January 2023

An intermediate fluid vaporizer (IFV) is a typical vaporizer of liquefied natural gas (LNG), which is used in a large number of LNG terminals. Since it requires a large supply of seawater during its operation, it generates a lot of energy consumption. In this study, to reduce the seawater consumption in the regasification system, the heat transfer process was first numerically calculated, and the heat transfer coefficient of the IFV was determined for different seawater inlet temperatures, seawater flow rates, and LNG flow rates. The calculation results of the heat transfer coefficient were integrated into the numerical model in HYSYS, and the minimum seawater flow of the IFV under different working conditions was obtained. For receiving terminals using multiple IFVs, this study programmed calculations based on optimization software. The operating configuration of the IFVs under different operating conditions was optimized to reduce the consumption of seawater in the regasification system of the LNG terminals.
Simulation Analysis of a Single-Phase AC Circuit with a Nonlinear Load
Authors: Wcislik Miroslaw , Strzabala Pawel
Published: January 2023

The IEEE 1459 standard states that: “There is a need to quantify correctly the distortions caused by the nonlinear and parametric loads …” The paper undertakes this problem. The article includes an analysis of selected steady-state properties of a single-phase AC circuit containing a series connection of a resistance, an inductance, and a nonlinear element described by a signum function. The circuit is supplied from a sinusoidal voltage source. The mathematical model of this circuit is described using dimensionless variables. Based on the harmonic balance, a description of the circuit for the fundamental harmonic and the circuit for the remaining harmonics was separated. On the basis of the relationship between the current and voltage waveforms, the solution for all harmonics, the harmonic content coefficients, and the elements of the equivalent scheme of the nonlinear load, were estimated symbolically. Based on the circuit equations, a circuit model and measurement systems were developed in Simulink, as well as a program that controls these models in MATLAB and determines the characteristics of the circuit model. The paper presents selected circuit characteristics as a function of load voltage amplitude and circuit resistance. The conclusions drawn from these studies have practical significance.
SWOT Analysis of Non-Technical and Technical Measures towards “(Nearly) Zero-Emission Stove Technologies”
Authors: Reichert Gabriel , Schmidl Christoph
Published: January 2023

Firewood stoves are widespread and popular for renewable heat supply in Europe. Several new technological measures have been developed recently that aim at improving the appliance performance in terms of emissions and efficiency. In order to support the trend towards “(nearly) zero-emissions technologies”, the objective of this study was to provide a profound overview of the most relevant technical primary and secondary measures for emission reduction and to analyze their functionality, the relevant framework conditions for their application and their costs. Since user behavior is essential for emission and efficiency performance, the state of knowledge about user behavior is summarized and the latest measures for its optimization are evaluated as non-technical primary measures. Primary and secondary measures were analyzed separately, but also potentially promising combinations of primary and secondary optimization were evaluated using SWOT analysis. The results showed that complementary application of primary and secondary measures will be necessary in order to achieve “(nearly) zero-emission technologies”. The paper is useful for manufacturers and provides them with guidance and recommendations for future developments. They can specifically select appropriate measures for their products and applications not only based on technical aspects, but also with a strong focus on user behavior and user comfort.
Production Controls in Heavy Oil and Bitumen Markets: Surplus Transfer Due to Alberta’s Curtailment Policy
Authors: Schaufele Brandon , Winter Jennifer
Published: January 2023

In January 2019, the Canadian province of Alberta enacted limits on crude oil and bitumen production. These production controls, a policy referred to as curtailment, represent a shift for a government that historically avoided market intervention. The policy was designed to shrink a growing and prolonged price differential between the Western Canadian Select price of oil, the key benchmark for Alberta’s heavy oil production, and the West Texas Intermediate benchmark. The curtailment created artificial scarcity, shrinking the price differential from more than $40 USD per barrel in November 2018 to less than $15 USD per barrel in February 2019. In the process, this policy transferred market surplus from refiners, mainly those in the US Midwest, to producers in Alberta. We review this large-scale market intervention and calculate the magnitude of the economic transfer. We find the curtailment increased producer surplus by $659M CAD per month and reduced consumer surplus by $763M per month. At the margin, every $1 reduction in consumer surplus translates into a $0.71 gain in producer surplus. We further show that if the Government of Alberta’s objective was to maximize short-run producer surplus, it should further scale back production, setting the curtailment rate at 25% rather than the initial 8.7%.
An Approach to Quantifying the Influence of Particle Size Distribution on Buried Blast Loading
Authors: Waddoups Ross , Clarke Sam , Tyas Andrew , Rigby Sam , Gant Matt , Elgy Ian
Published: January 2023

Buried charges pose a serious threat to both civilians and military personnel. It is well established that soil properties have a large influence on the magnitude and variability of loading from explosive blasts in buried conditions. In this study, work has been undertaken to improve techniques for processing pressure data from discrete measurement apparatus; this is performed through the testing of truncation methodologies and the area integration of impulses, accounting for the particle size distribution (PSD) of the soils used in testing. Two experimental techniques have been investigated to allow for a comparison between a global impulse capture method and an area-integration procedure from a Hopkinson Pressure Bar array. This paper explores an area-limiting approach, based on particle size distribution, as a possible approach to derive a better representation of the loading on the plate, thus demonstrating that the spatial distribution of loading over a target can be related to the PSD of the confining material.
Preliminary Study on Mini-Modus Device Equipped with a Bioreactor to Purify and Oxygenate a Synthetic Effluent
Authors: Perin Guido , Romagnoli Francesco , Perin Fabrizio , Bonardi Maurizio , Romano Franco , Floretta Caterina , Giacometti Andrea
Published: January 2023

To explore the possibility of recovering a polluted anoxic environment characterized by an elevated organic load, a bench-scale novel technology, called the module for the decontamination of units of sediment (MODUS), was studied. The bench-scale apparatus is able to aerate an effluent by a sparger that uses an air flow. The apparatus was implemented with a bioreactor to biodegrade a synthetic effluent made by glucose, urea, and potassium acid phosphate; an apparatus that will be here referred to as the BIOmini-MODUS. To test its performance, seven series of biodegradation experiments were done, each series corresponding to one of the seven different selected air flows in the range 5–20 L min−1. The purpose was to determine the best operative conditions for the BIOmini-MODUS, especially in terms of energy efficiency. These were found by studying eight parameters deemed particularly crucial: (1) dissolved oxygen concentration of the synthetic effluent, (2) time required to complete the substrate biodegradation, (3) air pressure (head losses) of the pumped air, (4) power needed to pump the air, (5) total energy used during a single biodegradation experiment, (6) biodegradation efficiency, (7) biological oxygen demand BOD as a function of time, and (8) the maximum biodegradation velocity reached by each biodegradation experiment. All of them, except BOD, were a function of the air flow. The air flow resulted in being particularly important to optimize the performance of the BIOmini-MODUS in terms of biodegradation velocity and oxygen concentration at the apparatus exit, in conjunction with energy efficiency. This last one, which showed a sharp maximum for an air flow of 10 L min−1, was determined on the basis of the biodegradation rate. At low air flows, a high biodegradation rate resulted in being a good parameter to indicate high energy efficiency; while, on the other hand, a high oxygen concentration resulted in being a good parameter to determine a high biodegradation rate.
Evaluating Effects of Remotely Sensed Neighborhood Crowding and Depth-to-Water on Tree Height Growth
Authors: Bergmüller Kai O. , Vanderwel Mark C.
Published: January 2023

Previous research on the effects of neighborhood crowding and soil moisture on tree height growth have been limited by time-consuming and sometimes inaccurate ground-based measurements of tree height. Recent developments in unmanned aerial vehicles (UAVs) allow detailed 3D point clouds of the canopy surface to be generated at relatively low cost. Using UAV-derived point clouds, we obtained height measurements of 4386 trees for the years 2019 and 2021. We also calculated four neighborhood crowding indices and a topography-based moisture index (depth-to-water) for these trees. Using initial tree height, neighborhood crowding indices and the depth-to-water index, we developed Bayesian hierarchical models to predict height growth for three tree species (Picea glauca (white spruce), Populus tremoluides (trembling aspen) and Pinus contorta (lodgepole pine)) across different stands. Bayes-R2 values of the final models were highest for white spruce (35%) followed by trembling aspen (28%) and lodgepole pine (25%). Model outputs showed that the effect of crowding and depth-to-water on height growth are limited and species-dependent, adding a maximum of 7% to the Bayes-R2 metric. Comparing different neighborhood crowding indices revealed that no index is clearly superior to others across all three species, as different neighborhood crowding indices resulted in only minor differences in model performance. While height growth can be partially explained by aerially derived neighborhood crowding indices and the depth-to-water index, future studies should focus on identifying relevant site characteristics to predict tree growth with greater accuracy.
Study on the Limit of Moisture Content of Smoldering Humus during Sub-Surface Fires in the Boreal Forests of China
Authors: Yin Sainan , Shan Yanlong , Tang Shuyuan , Douglas Grahame , Yu Bo , Cui Chenxi , Cao Lili
Published: January 2023

A sub-surface forest fire is a kind of fire that spreads slowly with no flames and lower temperatures, and threatens the ecosystem and human life. The moisture content of humus is considered to be an important factor in determining fire occurrence and sustaining. The humus of the Larix gmelinii in the Daxing’an Mountains was selected for the experiment, the limit moisture content condition of sub-surface forest fires was determined by an experiment simulating smoldering, and the prediction model of the probability of sub-surface forest fire occurrence was established. The results will be of great significance for the prevention, monitoring, and fighting of sub-surface forest fires in the boreal forest. The results showed that when the moisture content of humus in the upper layer was low, the smoldering process could be self-sustaining at 20%. For deeper layers of a depth of 18 cm, this increased to 30% moisture content of the humus and was the critical depth for sub-surface fires. The moisture content of 40% was a limit to burning where smoldering can only last for a short duration and is then extinguished. When the moisture content of the humus was 20%, the smoldering temperature was higher and the rate of spread was faster, with smoldering being maintained for longer periods at 30% moisture content. The regression prediction model of the highest temperature and vertical rate of spread in a column of humus was correlated to moisture content and depth, and the model significance was good at p < 0.01. Based on moisture content and depth, the occurrence probability prediction model of sub-surface fires has a good correlation (R2 = 0.93) and high prediction accuracy (AUC = 0.995). The effect of moisture content (Or = 4.008) on the occurrence probability of sub-surface fires is higher than that of depth (Or = 2.948). The results point out that it is necessary to prevent and monitor the occurrence of sub-surface fires when the humus moisture content is less than 40%. In order to reduce the risk of sub-surface fires, the monitoring time of the fire field should be extended after the fire is extinguished due to the slow-burning process of the sub-surface fire. Increasing the moisture content of the humus is an important method to reduce the probability and restrain the spread of sub-surface fires.
Forest Land Resource Information Acquisition with Sentinel-2 Image Utilizing Support Vector Machine, K-Nearest Neighbor, Random Forest, Decision Trees and Multi-Layer Perceptron
Authors: Zhang Chen , Liu Yang , Tie Niu
Published: January 2023

Forestry work involves scientific management and the effective utilization of forest land resources, and finding economical, efficient and accurate acquisition methods for forest land resource information. In previous land-use classification research, machine learning algorithms have achieved good results, and Sentinel public data have been used in various remote sensing applications. However, there is a paucity of research using these data to evaluate the performance of machine learning algorithms in the extracting of complex forest land resource information. Using the Sentinel-2 satellite multispectral image data, the spectral reflectance, vegetation index characteristics and image texture characteristics of different forest land resources in the study area were calculated and compared. Then, based on three groups of features, the performances of the Support Vector Machine (SVM), K-Nearest Neighbor (KNN), Random Forest (RF), decision trees (DT) and Multi-layer Perceptron (MLP) were examined and compared to identify and classify forest land resource types. The research indicates the following: (1) The SVM algorithm achieved the highest OA (95.8%). The average accuracy of the SVM algorithm was much higher than other algorithms (SVM 88.3%, KNN 87.5, RF 85.3%, MLP 85.00% and DT 77.5%). (2) The classification accuracies of each algorithm for coniferous forests were relatively high, and the recognition accuracy was above 95%, whereas the classification accuracies of the other categories varied greatly. (3) Adding texture features can improve the accuracy of the five algorithms. This study reports new references for the qualitative methods of forest land resource distribution. It has also produced more efficient and accurate acquisitions of forest land resource information, scientific management and effective use of forest land resources.
Development and Testing of a Friction-Driven Forestry Electric Monorail Car
Authors: Xu Haoting , Xu Daochun , Zheng Cheng , Bai Xiaopeng , Li Wenbin
Published: January 2023

A friction-driven forestry electric monorail car based on a wheel hub motor is designed with the aim of solving the problems of the low transportation capacity, low running speed, large turning radius, and poor stability of low-slope mountain forestry monorails. The relationships between the minimum turning radius and the steering spring elasticity coefficient, between the body tilt and the anti-tip spring elasticity coefficient, and between the minimum turning radius of the monorail car and the distance between the two chassis and the two steering wheels was provided by the theoretical calculation and analysis of the key parameters of a dual-chassis structure, steering device, and anti-tip device. The dimensional parameters of the key components were determined. The three-dimensional design of the overall car was carried out, and the feasibility of the design was verified in kinematic simulation experiments. A performance test of the monorail car was conducted with the minimum turning radius, maximum load capacity, maximum full load speed, climbing degree, and center of gravity offset as indicators. The test results show that the monorail car has a minimum turning radius of 3.3 m, a maximum load capacity of 300 kg, a maximum speed of 20 km·h−1 fully loaded, a maximum gradient of 21°, and a unilateral vibration amplitude of 8 mm or less. The double-chassis structure and anti-tip device met the design requirements. The good transportation performance of the designed monorail car effectively solves the problems of a large turning radius and unstable driving of current forestry monorails. Additionally, the designed monorail car is environmentally friendly and efficient, meeting the requirements of monorail transporters for low-slope mountain forests and laying the foundation for the intelligent harvesting and transportation of mountain forest fruits.
Is Cross-Laminated Timber (CLT) a Wood Panel, a Building, or a Construction System? A Systematic Review on Its Functions, Characteristics, Performances, and Applications
Authors: De Araujo Victor , Aguiar Fabricio , Jardim Pedro , Mascarenhas Fernando , Marini Lucas , Aquino Vinicius , Santos Herisson , Panzera Tulio , Lahr Francisco , Christoforo André
Published: January 2023

Cross-laminated timber (CLT) has been widely discussed as a relevant industrialized construction solution. Numerous publications have considered CLT as a structural wood-based panel, but other documents have mentioned it as a building or even a construction system. Many authors address its application in multistory buildings, although single-family houses and lower building applications have become desirable topics as well. Given these gaps, this review study addresses a systematic method to evince the functions of cross-laminated timber in construction. The elucidation and discussion were led by technical and scientific contents through publications present in scientific websites and the Google web search engine. Intricate perceptions about the knowledge and reference of CLT functions were identified. From prospections, it was possible to state that CLT is a timber-forest product created in Europe, whose function acts as a structural composite panel of the engineered wood product category. However, CLT has been mentioned by many publications as a building or a construction system. Suggestions were raised to clarify to all readers with respect to misconceptions, and elucidate the construction systems capable of using it as the main resource. Discussions evinced the characteristics and potentials of this wood product. Even with its increasing application in tall buildings, the commercial application of CLT in low-rise buildings may be boosted by the possibility of large-scale production of industrialized houses.
Performance of Skidding Operations in Low-Access and Low-Intensity Timber Removals: A Simulation of Productivity and Fuel Consumption in Mature Forests
Authors: Borz Stelian Alexandru , Mariş Alexandru-Constantin , Kaakkurivaara Nopparat
Published: January 2023

Forest policies aiming for a greener future and decarbonization require scientific support to help in decision making on resource economy and sustainability of forest operations. Timber skidding is one of the most prevalent options in wood extraction around the world. While its operational and environmental performance is affected by several factors, of which the extraction distance, removal intensity, and machine capabilities are of first importance, there are few studies on the subject in low-access and low-intensity removals. Based on a time study which accounted for production and fuel consumption, this work modeled and quantified productivity and fuel consumption for such operational conditions. Dependence of fuel and time consumption on relevant operational factors was modeled by least square stepwise ordinary regression techniques. Then, the developed models and summary statistics were used to simulate productivity and fuel consumption for a wide range of extraction distances. The main results indicate that, for removal intensities in the range of 7 to 15 m3/ha, productivity of skidding operations in mature broadleaved forests depended heavily on the extraction distance. Taking as a reference an extraction distance of 200 m, productivity halved at 800 m, and decreased to one fourth at 2000 m. For the same conditions, fuel consumption increased linearly, being doubled at 800 m and four times higher at 2000 m. Although the unit fuel consumption increased linearly as a function of extraction distance, its magnitude of increment was much lower. The results of this study indicate that shortening the extraction distances may be the best option in increasing the operational and environmental performance of skidding operations. This may be achieved by developing further the forest road network, which, in addition to the benefits for harvesting operations, could support a more sustainable forest management.
Smart Embedded System for Skin Cancer Classification
Authors: Durães Pedro F. , Véstias Mário P.
Published: January 2023

The very good results achieved with recent algorithms for image classification based on deep learning have enabled new applications in many domains. The medical field is one that can greatly benefit from these algorithms in order to help the medical professional elaborate on his/her diagnostic. In particular, portable devices for medical image classification are useful in scenarios where a full analysis system is not an option or is difficult to obtain. Algorithms based on deep learning models are computationally demanding; therefore, it is difficult to run them in low-cost devices with a low energy consumption and high efficiency. In this paper, a low-cost system is proposed to classify skin cancer images. Two approaches were followed to achieve a fast and accurate system. At the algorithmic level, a cascade inference technique was considered, where two models were used for inference. At the architectural level, the deep learning processing unit from Vitis-AI was considered in order to design very efficient accelerators in FPGA. The dual model was trained and implemented for skin cancer detection in a ZYNQ UltraScale+ MPSoC ZCU104 evaluation kit with a ZU7EV device. The core was integrated in a full system-on-chip solution and tested with the HAM10000 dataset. It achieves a performance of 13.5 FPS with an accuracy of 87%, with only 33k LUTs, 80 DSPs, 70 BRAMs and 1 URAM.
Global Solar Radiation Forecasting Based on Hybrid Model with Combinations of Meteorological Parameters: Morocco Case Study
Authors: Belmahdi Brahim , Louzazni Mohamed , Marzband Mousa , El Bouardi Abdelmajid
Published: January 2023

The adequate modeling and estimation of solar radiation plays a vital role in designing solar energy applications. In fact, unnecessary environmental changes result in several problems with the components of solar photovoltaic and affects the energy generation network. Various computational algorithms have been developed over the past decades to improve the efficiency of predicting solar radiation with various input characteristics. This research provides five approaches for forecasting daily global solar radiation (GSR) in two Moroccan cities, Tetouan and Tangier. In this regard, autoregressive integrated moving average (ARIMA), autoregressive moving average (ARMA), feed forward back propagation neural networks (FFBP), hybrid ARIMA-FFBP, and hybrid ARMA-FFBP were selected to compare and forecast the daily global solar radiation with different combinations of meteorological parameters. In addition, the performance in three approaches has been calculated in terms of the statistical metric correlation coefficient (R2), root means square error (RMSE), stand deviation (σ), the slope of best fit (SBF), legate’s coefficient of efficiency (LCE), and Wilmott’s index of agreement (WIA). The best model is selected by using the computed statistical metric, which is present, and the optimal value. The R2 of the forecasted ARIMA, ARMA, FFBP, hybrid ARIMA-FFBP, and ARMA-FFBP models is varying between 0.9472% and 0.9931%. The range value of SPE is varying between 0.8435 and 0.9296. The range value of LCE is 0.8954 and 0.9696 and the range value of WIA is 0.9491 and 0.9945. The outcomes show that the hybrid ARIMA–FFBP and hybrid ARMA–FFBP techniques are more effective than other approaches due to the improved correlation coefficient (R2).
Intravenous-Therapy-Associated Circulatory Overload: A Retrospective Study of Forensic Cases
Authors: Xu Guangtao , Su Ruibing , Lv Junyao , Xu Long , Jin Xin , Chen Deqing , Hu Bo , Yu Xiaojun
Published: January 2023

Background and Objective: Intravenous therapy is widely used in clinics to deliver medications and fluids to patients, and overuse may cause intravenous-infusion-associated circulatory overload (IACO) and death. However, forensic data on deaths from the overuse of intravenous therapy are limited. We performed a retrospective study to identify whether causes of death in forensic practice were associated with IACO. Methods: A total of 572 medical-related cases with a history of intravenous infusion who suffered from injuries or illnesses and died after treatment in hospitals were recruited from two centers of forensic medicine between 2002 and 2018. Results: The results demonstrated that 6.47% of cases (37/572) were exposed to an infusion overdose that resulted in deaths related to IACO, and 43.24% of cases (16/37) had a net fluid retention ranging from 3.0 L/d to 13.8 L/d. The highest case was administered 1.4 L blood products and 13.6 L fluids within 25 h. We observed significant decreases in red blood cells, hematocrit, hemoglobin, and platelets from the time of “on admission” to “before death”, except for white blood cells. Autopsy findings of 16 cases revealed some organ or tissue pathological alterations related to IACO, including pale-yellow liquid overflow under the abdominal epidermis, much transudate in body cavities, and lung edema with a high tissue density and no obvious slurry deposition in the alveolar lumen. Another 21 cases died after a rapid infusion rate ranging from 111 to 293 drops/min, which resulted from viral myocarditis on autopsy. Conclusions: Our data on excessive or irrational use of intravenous therapy indicate a severe circulatory overload, which may eventually result in lethal outcomes. Therefore, the use of improper intravenous therapy should be reduced to ameliorate adverse health consequences during clinical treatment.
Acknowledgment to the Reviewers of Fractal and Fractional in 2022
Authors:   Fractal Fract Editorial Office
Published: January 2023

High-quality academic publishing is built on rigorous peer review [...]
Lie Symmetries and Third- and Fifth-Order Time-Fractional Polynomial Evolution Equations
Authors: Kubayi Jollet Truth , Jamal Sameerah
Published: January 2023

This paper is concerned with a class of ten time-fractional polynomial evolution equations. The one-parameter Lie point symmetries of these equations are found and the symmetry reductions are provided. These reduced equations are transformed into nonlinear ordinary differential equations, which are challenging to solve by conventional methods. We search for power series solutions and demonstrate the convergence properties of such a solution.
Analytical Solutions of the Predator–Prey Model with Fractional Derivative Order via Applications of Three Modified Mathematical Methods
Authors: Areshi Mounirah , Seadawy Aly R. , Ali Asghar , Alharbi Amal F. , Aljohani Abdulrahman F.
Published: January 2023

We have investigated wave solutions of the Predator–Prey (PP) model with fractional derivative order by novel three modified mathematical methods with the help of the Mathematica platform. The derived solutions are in the form of distinct functions such as trigonometric, hyperbolic, exponential and rational functional. For the physical phenomena of fractional model, some solutions are plotted in 2-dimensional and 3-dimensional by inserting specific values to attached parameters under sufficient condition on each solution. Hence, proposed schemes are enormously superbly mathematical tools to review wave solutions of several fractional models in nonlinear science.
Solvability of Mixed Problems for a Fourth-Order Equation with Involution and Fractional Derivative
Authors: Kirane Mokhtar , Sarsenbi Abdissalam A.
Published: January 2023

In the present work, two-dimensional mixed problems with the Caputo fractional order differential operator are studied using the Fourier method of separation of variables. The equation contains a linear transformation of involution in the second derivative. The considered problem generalizes some previous problems formulated for some fourth-order parabolic-type equations. The basic properties of the eigenfunctions of the corresponding spectral problems, when they are defined as the products of two systems of eigenfunctions, are studied. The existence and uniqueness of the solution to the formulated problem is proved.
In Silico Mining and Characterization of High-Quality SNP/Indels in Some Agro-Economically Important Species Belonging to the Family Euphorbiaceae
Authors: Sen Surojit , Rathi Sunayana , Sahu Jagajjit , Mandal Subhash C. , Ray Supratim , Slama Petr , Roychoudhury Shubhadeep
Published: January 2023

(1) Background: To assess the genetic makeup among the agro-economically important members of Euphorbiaceae, the present study was conducted to identify and characterize high-quality single-nucleotide polymorphism (SNP) markers and their comparative distribution in exonic and intronic regions from the publicly available expressed sequence tags (ESTs). (2) Methods: Quality sequences obtained after pre-processing by an EG assembler were assembled into contigs using the CAP3 program at 95% identity; the mining of SNP was performed by QualitySNP; GENSCAN (standalone) was used for detecting the distribution of SNPs in the exonic and intronic regions. (3) Results: A total of 25,432 potential SNPs (pSNP) and 14,351 high-quality SNPs (qSNP), including 2276 indels, were detected from 260,479 EST sequences. The ratio of quality SNP to potential SNP ranged from 0.22 to 0.75. A higher frequency of transitions and transversions was observed more in the exonic than the intronic region, while indels were present more in the intronic region. C↔T (transition) was the most dominant nucleotide substitution, while in transversion, A↔T was the dominant nucleotide substitution, and in indel, A/- was dominant. (4) Conclusions: Detected SNP markers may be useful for linkage mapping; marker-assisted breeding; studying genetic diversity; mapping important phenotypic traits, such as adaptation or oil production; or disease resistance by targeting and screening mutations in important genes.
The Genetic Background of Hearing Loss in Patients with EVA and Cochlear Malformation
Authors: Bałdyga Natalia , Oziębło Dominika , Gan Nina , Furmanek Mariusz , Leja Marcin L. , Skarżyński Henryk , Ołdak Monika
Published: January 2023

The most frequently observed congenital inner ear malformation is enlarged vestibular aqueduct (EVA). It is often accompanied with incomplete partition type 2 (IP2) of the cochlea and a dilated vestibule, which together constitute Mondini malformation. Pathogenic SLC26A4 variants are considered the major cause of inner ear malformation but the genetics still needs clarification. The aim of this study was to identify the cause of EVA in patients with hearing loss (HL). Genomic DNA was isolated from HL patients with radiologically confirmed bilateral EVA (n = 23) and analyzed by next generation sequencing using a custom HL gene panel encompassing 237 HL-related genes or a clinical exome. The presence and segregation of selected variants and the CEVA haplotype (in the 5′ region of SLC26A4) was verified by Sanger sequencing. Minigene assay was used to evaluate the impact of novel synonymous variant on splicing. Genetic testing identified the cause of EVA in 17/23 individuals (74%). Two pathogenic variants in the SLC26A4 gene were identified as the cause of EVA in 8 of them (35%), and a CEVA haplotype was regarded as the cause of EVA in 6 of 7 patients (86%) who carried only one SLC26A4 genetic variant. In two individuals with a phenotype matching branchio-oto-renal (BOR) spectrum disorder, cochlear hypoplasia resulted from EYA1 pathogenic variants. In one patient, a novel variant in CHD7 was detected. Our study shows that SLC26A4, together with the CEVA haplotype, accounts for more than half of EVA cases. Syndromic forms of HL should also be considered in patients with EVA. We conclude that to better understand inner ear development and the pathogenesis of its malformations, there is a need to look for pathogenic variants in noncoding regions of known HL genes or to link them with novel candidate HL genes.
Tempo and Mode of Genome Structure Evolution in Insects
Authors: Alfieri James M. , Jonika Michelle M. , Dulin Jennifer N. , Blackmon Heath
Published: January 2023

The division of the genome into discrete chromosomes is a fundamental characteristic of eukaryotic life. Insect taxonomists’ early adoption of cytogenetics has led to an incredible amount of data describing genome structure across insects. In this article, we synthesize data from thousands of species and use biologically realistic models to infer the tempo and mode of chromosome evolution among insect orders. Our results show that orders vary dramatically in the overall rate of chromosome number evolution (a proxy of genome structural stability) and the pattern of evolution (e.g., the balance between fusions and fissions). These findings have important implications for our understanding of likely modes of speciation and offer insight into the most informative clades for future genome sequencing.
Genetic Factors Implicated in the Investigation of Possible Connections between Alzheimer’s Disease and Primary Open Angle Glaucoma
Authors: Kuang Grace , Salowe Rebecca , O’Brien Joan
Published: January 2023

Both Alzheimer’s disease (AD) and primary open angle glaucoma (POAG) are diseases of primary global neurodegeneration with complex pathophysiologies. Throughout the published literature, researchers have highlighted similarities associated with various aspects of both diseases. In light of the increasing number of findings reporting resemblance between the two neurodegenerative processes, scientists have grown interested in possible underlying connections between AD and POAG. In the search for explanations to fundamental mechanisms, a multitude of genes have been studied in each condition, with overlap in the genes of interest between AD and POAG. Greater understanding of genetic factors can drive the research process of identifying relationships and elucidating common pathways of disease. These connections can then be utilized to advance research as well as to generate new clinical applications. Notably, AD and glaucoma are currently diseases with irreversible consequences that often lack effective therapies. An established genetic connection between AD and POAG would serve as the basis for development of gene or pathway targeted strategies relevant to both diseases. Such a clinical application could be of immense benefit to researchers, clinicians, and patients alike. This paper aims to summarize the genetic associations between AD and POAG, describe common underlying mechanisms, discuss potential areas of application, and organize the findings in a review.