bluuebunny/crossref_metadata_2025 huggingface dataset:
Coronary Tortuosity Index vs. Angle Measurement Method for the Quantification of the Tortuosity of Coronary Arteries in Non-Obstructive Coronary Disease
Authors: Zebic Mihic Petra , Arambasic Jerko , Mlinarevic Drazen , Saric Sandra , Labor Marina , Bosnjak Ivica , Mihaljevic Ivica , Bilic Curcic Ines , Juric Iva
Published: December 2023

Coronary tortuosity has been recognized as a potential pathophysiological mechanism in the development of non-obstructive coronary artery disease (CAD). The aim of this study was to examine the role of two coronary tortuosity measurement methods in the detection of clinically significant coronary tortuosity. The study included 160 patients with angina symptoms and myocardial ischemia detected by cardiac stress tests in chronic settings and those diagnosed with acute coronary syndrome. After coronary angiography, tortuosity of coronary arteries was assessed by two methods, including measurement of tortuosity angles and calculating of tortuosity index. Significantly more tortuous coronary arteries were detected in the group with non-obstructive CAD (p < 0.01 for all three arteries), with significantly higher tortuosity index (TI) for all three coronary arteries in this group of patients, compared to patients with obstructive CAD. The highest TI for LCX was found in patients with lateral ischemia (p < 0.001) and for LAD in patients with anterior ischemia (p < 0.001). When measured by the angle method, the only association was found between LCX tortuosity and lateral ischemia (OR 4.9, p = 0.046). In conclusion, coronary tortuosity represents a pathophysiological mechanism for myocardial ischemia in non-obstructive CAD. The coronary tortuosity index could be a reliable and widely applicable tool for the quantification of coronary tortuosity.
Normal Distal Tibiofibular Syndesmosis Assessment Using Postmortem Computed Tomography (PMCT)
Authors: Kim Jahyung , Park Jeong-Hyun , Kwon Hyung-Wook , Lee Mijeong , Kim Digud , Choi Yu-Jin , Park Kwang-Rak , Lee Sookyoung , Cho Jaeho
Published: December 2023

Background: Distal tibiofibular syndesmotic injuries, often misdiagnosed, can lead to substantial morbidity. This study utilized postmortem computed tomography (PMCT) to define normal syndesmotic relationships in 131 subjects. Methods: Three parameters were measured: fibular rotation (FR), sagittal translation (ST), and incisura depth (ID). Results: Interobserver reliability was excellent for FR and ID but moderate for ST. Anatomical variability was wide, with FR ranging from −0.4° to 16.6°, ST from 0.33 mm to 3.49 mm, and ID from 1.89 mm to 6.05 mm. Side-to-side variability within subjects was minimal. Gender-specific differences were observed in ST, possibly due to size variations, highlighting the need for gender-specific diagnostic criteria. Conclusions: Although establishing universal reference values is challenging, using contralateral ankles for comparison can enhance diagnostic accuracy in syndesmotic injuries. This study, the first of its kind, offers valuable insights into normal distal tibiofibular syndesmotic relationships based on PMCT data. Future validation studies in patients with syndesmotic injuries can further improve diagnostic accuracy.
mTOR Pathway Substrates Present High Activation in Vascular Malformations and Significantly Decrease with Age
Authors: Kopeć Jakub , Sałacińska-Łoś Elżbieta , Orzechowska Magdalena , Sokolnicka Monika , Gawłowska-Marciniak Aleksandra , Przemysław Przewratil
Published: December 2023

Background: Vascular anomalies often result in aesthetic flaws, pain, and impair the quality of life. They require challenging treatments that frequently do not provide the desired results. The mammalian target of rapamycin (mTOR) is directly involved in the development of these malformations. However, the exact mechanism behind mTOR dysregulation has not been unambiguously defined. The purpose of this study is to investigate the activation of selected substrates of mTOR to partially assess its involvement in the disease process. Methods: We analyzed tissue samples collected from patients with vascular anomalies treated in our department. We included patients with histopathological diagnoses of lymphatic, venous, capillary malformations, mixed lesions, and a control group of healthy skin samples. We stained the samples using H and E and immunohistochemistry. We used primary antibodies against p70 S6 Kinase, 4EBP1, and p-4EBP1. We graded their color reactions. The statistical analyses were performed using the FactoMineR and factoextra R v.4.1 packages. p-values < 0.05 were considered statistically significant. Results: The analysis of 82 patients showed that healthy tissue vessels expressed lower levels of tested mTOR pathway substrates compared to high activation in vascular malformations. Elevated substrate expression in a comparison between sexes revealed higher P-4EBP1 expression in the female malformation group. We observed a decrease in mTOR substrate expression with age. Conclusion: The higher expression of mTOR substrates in vascular malformations compared to healthy tissue confirms their involvement in abnormal vascular development. Age-related changes in mTOR substrate expression highlight the need for timely intervention. Our study contributes to the understanding of the mTOR signaling pathway in vascular malformations and highlights its potential as a therapeutic target, contributing to personalized medicine.
Predictors of Intra-Operative and Post-Operative Pain Associated with Routine Dental Procedures in Children: A Systematic Review and Meta-Analysis
Authors: Alzubaidi Mohammed A. , Drummond Bernadette K. , Wu Jianhua , Jones Adam , Tahmassebi Jinous F. , Aggarwal Vishal R.
Published: December 2023

Background: Understanding predictors of pain associated with paediatric dental procedures could play an important role in preventing loss of cooperation, which often leads to the procedure having to be performed under general anaesthesia. Aim: We aimed to identify predictors of intra-operative and post-operative pain associated with routine dental procedures in children. Materials and Methods: A systematic review of observational studies was performed using electronic searches on MEDLINE, EMBASE, PsycINFO, Global Health via OVID, PubMed, Scopus, and SciELO. The NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies was used to evaluate the quality of the included studies, which were meta-analysed to estimate the impact of dental procedures and anxiety on children’s pain perception. A meta-regression analysis was also performed to determine the relative effect of predictors on children’s pain perception measured as mean differences on a visual analogue scale (VAS). Results: The search identified 532 articles; 53 were retrieved for full-text screening; 6 studies were included in the review; and 4 were eligible for the meta-analysis. The meta-analysis showed the types of procedures that predicted intra-operative pain, with dental extractions being the most painful (Mean VAS Difference [MD] 46.51 mm, 95% confidence interval [CI] 40.40 to 52.62 mm). The meta-regression showed that pain scores for dental extractions were significantly higher than polishing (the least painful procedure (reference category)) by VAS MD = 23.80 mm (95% CI 5.13–42.46 mm, p-value = 0.012). It also showed that highly anxious children reported significantly higher pain scores during dental procedures by a 12.31 mm MD VAS score (95% CI 5.23–19.40 mm, p-value = 0.001) compared to those with low anxiety levels. Conclusions: This systematic review demonstrates that the strongest predictors of intra-operative pain associated with paediatric dental procedures are dental extractions followed by drilling. Children with high anxiety also reported more pain for similar procedures. Tailoring interventions to reduce pain associated with paediatric dental procedures should be a priority for future research, as reducing pain can impact compliance and could reduce the need for general anaesthesia in dental treatment.
Turing–Hopf Bifurcation Analysis in a Diffusive Ratio-Dependent Predator–Prey Model with Allee Effect and Predator Harvesting
Authors: Chen Meiyao , Xu Yingting , Zhao Jiantao , Wei Xin
Published: December 2023

This paper investigates the complex dynamics of a ratio-dependent predator–prey model incorporating the Allee effect in prey and predator harvesting. To explore the joint effect of the harvesting effort and diffusion on the dynamics of the system, we perform the following analyses: (a) The stability of non-negative constant steady states; (b) The sufficient conditions for the occurrence of a Hopf bifurcation, Turing bifurcation, and Turing–Hopf bifurcation; (c) The derivation of the normal form near the Turing–Hopf singularity. Moreover, we provide numerical simulations to illustrate the theoretical results. The results demonstrate that the small change in harvesting effort and the ratio of the diffusion coefficients will destabilize the constant steady states and lead to the complex spatiotemporal behaviors, including homogeneous and inhomogeneous periodic solutions and nonconstant steady states. Moreover, the numerical simulations coincide with our theoretical results.
Engineering Transport via Collisional Noise: A Toolbox for Biology Systems
Authors: Civolani Alessandro , Stanzione Vittoria , Chiofalo Maria Luisa , Yago Malo Jorge
Published: December 2023

The study of noise assisted-transport in quantum systems is essential in a wide range of applications, from near-term NISQ devices to models for quantum biology. Here, we study a generalized XXZ model in the presence of stochastic collision noise, which allows describing environments beyond the standard Markovian formulation. Our analysis through the study of the local magnetization, the inverse participation ratio (IPR) or its generalization, and the inverse ergodicity ratio (IER) showed clear regimes, where the transport rate and coherence time could be controlled by the dissipation in a consistent manner. In addition, when considering various excitations, we characterized the interplay between collisions and system interactions, identifying regimes in which transport was counterintuitively enhanced when increasing the collision rate, even in the case of initially separated excitations. These results constitute an example of an essential building block for the understanding of quantum transport in structured noisy and warm-disordered environments.
Quantifying the Resilience of a Healthcare System: Entropy and Network Science Perspectives
Authors: Klemann Désirée , Winasti Windi , Tournois Fleur , Mertens Helen , van Merode Frits
Published: December 2023

In this study, we consider the human body and the healthcare system as two complex networks and use theories regarding entropy, requisite variety, and network centrality metrics with resilience to assess and quantify the strengths and weaknesses of healthcare systems. Entropy is used to quantify the uncertainty and variety regarding a patient’s health state. The extent of the entropy defines the requisite variety a healthcare system should contain to be able to treat a patient safely and correctly. We use network centrality metrics to visualize and quantify the healthcare system as a network and assign the strengths and weaknesses of the network and of individual agents in the network. We apply organization design theories to formulate improvements and explain how a healthcare system should adjust to create a more robust and resilient healthcare system that is able to continuously deal with variations and uncertainties regarding a patient’s health, despite possible stressors and disturbances at the healthcare system. In this article, these concepts and theories are explained and applied to a fictive and a real-life example. We conclude that entropy and network science can be used as tools to quantify the resilience of healthcare systems.
Few-Shot Fault Diagnosis Based on an Attention-Weighted Relation Network
Authors: Xue Li , Jiang Aipeng , Zheng Xiaoqing , Qi Yanying , He Lingyu , Wang Yan
Published: December 2023

As energy conversion systems continue to grow in complexity, pneumatic control valves may exhibit unexpected anomalies or trigger system shutdowns, leading to a decrease in system reliability. Consequently, the analysis of time-domain signals and the utilization of artificial intelligence, including deep learning methods, have emerged as pivotal approaches for addressing these challenges. Although deep learning is widely used for pneumatic valve fault diagnosis, the success of most deep learning methods depends on a large amount of labeled training data, which is often difficult to obtain. To address this problem, a novel fault diagnosis method based on the attention-weighted relation network (AWRN) is proposed to achieve fault detection and classification with small sample data. In the proposed method, fault diagnosis is performed through the relation network in few-shot learning, and in order to enhance the representativeness of feature extraction, the attention-weighted mechanism is introduced into the relation network. Finally, in order to verify the effectiveness of the method, a DA valve fault dataset is constructed, and experimental validation is performed on this dataset and another benchmark PU rolling bearing fault dataset. The results show that the accuracy of the network on DA is 99.15%, and the average accuracy on PU is 98.37%. Compared with the state-of-the-art diagnosis methods, the proposed method achieves higher accuracy while significantly reducing the amount of training data.
Detection of Blood CO2 Influences on Cerebral Hemodynamics Using Transfer Entropy
Authors: Fernández-Muñoz Juan , Haunton Victoria J. , Panerai Ronney B. , Jara José Luis
Published: December 2023

Cerebral hemodynamics describes an important physiological system affected by components such as blood pressure, CO2 levels, and endothelial factors. Recently, novel techniques have emerged to analyse cerebral hemodynamics based on the calculation of entropies, which quantifies or describes changes in the complexity of this system when it is affected by a pathological or physiological influence. One recently described measure is transfer entropy, which allows for the determination of causality between the various components of a system in terms of their flow of information, and has shown positive results in the multivariate analysis of physiological signals. This study aims to determine whether conditional transfer entropy reflects the causality in terms of entropy generated by hypocapnia on cerebral hemodynamics. To achieve this, non-invasive signals from 28 healthy individuals who undertook a hyperventilation maneuver were analyzed using conditional transfer entropy to assess the variation in the relevance of CO2 levels on cerebral blood velocity. By employing a specific method to discretize the signals, it was possible to differentiate the influence of CO2 levels during the hyperventilation phase (22.0% and 20.3% increase for the left and right hemispheres, respectively) compared to normal breathing, which remained higher during the recovery phase (15.3% and 15.2% increase, respectively).
Thermodynamic Analysis of Financial Markets: Measuring Order Book Dynamics with Temperature and Entropy
Authors: Li Haochen , Xiao Yue , Polukarov Maria , Ventre Carmine
Published: December 2023

This study bridges finance and physics by applying thermodynamic concepts to model the limit order book (LOB) with high-frequency trading data on the Bitcoin spot. We derive the measures of Market Temperature and Market Entropy from the kinetic and potential energies in the LOB to provide a deeper understanding of order activities and market participant behavior. Market Temperature emerges as a robust indicator of market liquidity, correlating with liquidity measures such as Active Quote Volume, bid–ask spread and match volume. Market Entropy, on the other hand, quantifies the degree of disorder or randomness in the LOB, providing insights into the instantaneous volatility of price in the high-frequency trading market. Our empirical findings not only broaden the theoretical framework of econophysics but also enhance comprehensive understanding of the market microstructure and order book dynamics.
Comparisons of Twelve Freshwater Mussel Bed Assemblages Quantitatively Sampled at a 15-year Interval in the Buffalo National River, Arkansas, USA
Authors: Pieri Anna M. , Harris John L. , Matthews Mickey W. , Hodges Shawn W. , Rodman Ashley R. , Bouldin Jennifer L. , Christian Alan D.
Published: December 2023

Historically, 23 freshwater mussel species have been documented from the Buffalo National River (BNR), a 246 km, free-flowing river in northern Arkansas. The potential threats to BNR include land use/land cover changes, eutrophication, recreation, physical habitat changes, and various climate change-related effects. Twelve quantitative mussel bed sites were established and then sampled using a stratified random sampling protocol to evaluate the long-term changes between 2006 and 2020–2021 in population and assemblage characteristics. We compared (1) overall mussel bed persistence, sampling confidence levels and study-wide relative abundances, and compared species’ size and size-frequency distributions; (2) 10 overall site assemblage variables using paired t-tests; (3) site-level mean density, richness, and diversity indices using pair-wise Mann–Whitney U statistics; and (4) assemblage composition using Non-Metric Multidimensional Scaling. The major findings included the following: (1) sampling efforts based on a targeted 80% confidence level appears relatively robust, (2) BNR mussel assemblage composition and structure were relatively stable (however, small mussel bed persistence is a concern), (3) 7 of 23 sites were outliers based on freshwater mussel composition and habitat characteristics, and (4) assemblage composition changed with three species declining (Actinonaias ligamentina, Lasmigona costata, and Ptychobranchus occidentalis) and four species increasing (Cambarunio hesperus, Cyclonaias tuberculata, Eurynia dilatata, and Venustaconcha pleasii) between monitoring events.
A Novel OFDM-Based Time Domain Quadrature GSM for Visible Light Communication System
Authors: Shi Zichun , Miao Pu , Pang Liyuan , Zhang Yudong
Published: December 2023

In order to improve the spectral efficiency (SE) as well as the receiver performance of band-limited visible light communications (VLCs), two orthogonal frequency division multiplexing (OFDM)-based quadrature generalized multiple-input multiple-output (QG-MIMO) transmission schemes, including time domain (TD) quadrature generalized spatial modulation (TD-QGSM) and TD quadrature generalized spatial multiplexing (TD-QGSMP), are proposed in this paper. Firstly, the constellation symbols in the frequency domain are split into in-phase and quadrature components to perform the OFDM modulation separately. Then, the corresponding time domain signal is spatially mapped on different light emitting diodes (LEDs) for achieving the diversity or multiplexing. In addition, we also propose an illegal vector correction (IVC)-based orthogonal matching pursuit (OMP) detection algorithm to deal with the error propagation and noise amplification effect, where a novel correction criterion is involved for assisting the index vectors estimation and thus for improving the demodulation performance. The simulation results demonstrate that the SE can be significantly improved by the proposed schemes as compared with the existing OFDM-based generalized MIMO schemes, with the TD-QGSM increasing by at least 56.5% and the TD-QGSMP increasing by at least 72.3%. Moreover, the bit error rate (BER) performance can be further improved when applying the proposed IVC-OMP detection method, which outperforms the traditional maximum-likelihood and maximum ratio combining (ML-MRC) detection by at least 62.5%.
Fault Classification and Diagnosis Approach Using FFT-CNN for FPGA-Based CORDIC Processor
Authors: Xie Yu , Chen He , Zhuang Yin , Xie Yizhuang
Published: December 2023

Within the realm of digital signal processing and communication systems, FPGA-based CORDIC (Coordinate Rotation Digital Computer) processors play pivotal roles, applied in trigonometric calculations and vector operations. However, soft errors have become one of the major threats in high-reliability FPGA-based applications, potentially degrading performance and causing system failures. This paper proposes a fault classification and diagnosis method for FPGA-based CORDIC processors, leveraging Fast Fourier Transform (FFT) and Convolutional Neural Networks (CNNs). The approach involves constructing fault classification datasets, optimizing features extraction through FFT to shorten the time of diagnosis and improve the diagnostic accuracy, and employing CNNs for training and testing of faults diagnosis. Different CNN architectures are tested to explore and construct the optimal fault classifier. Experimental results encompassing simulation and implementation demonstrate the improved accuracy and efficiency in fault classification and diagnosis. The proposed method provides fault prediction with an accuracy of more than 98.6% and holds the potential to enhance the reliability and performance of FPGA-based CORDIC circuit systems, surpassing traditional fault diagnosis methods such as Sum of Square (SoS).
Prioritization of Scheduled Surgeries Using Fuzzy Decision Support and Risk Assessment Methods
Authors: Fabisiak Luiza
Published: December 2023

The aim of this study was to develop a method to minimize the risk of cancellation of planned surgery in hospital orthopedic departments. The paper proposes a method that combines multi-criteria and multi-faceted risk assessment. Two data sources are used: a fuzzy FTOPSIS method, combined with FMEA assessment. The FMEA method presented in this paper uses the technique of prioritizing preferences according to FTOPSIS similarity to the ideal solution and belief structure, in order to overcome the shortcomings of traditional FMEA indicators. Finally, a numerical case study of process optimization for elective surgery in a Polish clinic is presented. The focus was on planned hip replacements. The effectiveness of the method in assessing the main factors influencing cancellation of elective surgery is demonstrated. A high accuracy of the results and wide adaptability of the method to other areas are features of the combination of the abovementioned methods. The problem addressed in this publication is the high rate of cancellation of elective surgery. The selection of relevant criteria, their importance, and the preferences of the patients were studied. The results of the method provide a viable action plan for the proposed research problem. The proposed method is multifaceted and can be part of an information system to support reorganization, restructuring, and modification of an operational process.
MLPPF: Multi-Label Prediction of piRNA Functions Based on Pretrained k-mer, Positional Embedding and an Improved TextRNN Model
Authors: Liu Yajun , Li Ru , Lu Yang , Li Aimin , Wang Zhirui , Li Wei
Published: December 2023

PIWI-interacting RNAs (piRNAs) are a kind of important small non-coding RNAs and play a vital role in maintaining the stability of genome. Previous studies have revealed that piRNAs not only silence transposons, but also mediate the degradation of a large number of mRNAs and lncRNAs. Existing computational models only focus on mRNA-related piRNAs and rarely concentrate on lncRNA-related piRNAs. In this study, we propose a novel method, MLPPF, which is designed for multi-label prediction of piRNA functions based on pretrained k-mer, positional embedding and an improved TextRNN model. First, a benchmark dataset, which contains two types of functional labels, namely mRNA-related and lncRNA-related piRNAs, was constructed by processing piRNA-function-annotated data and sequence data. Moreover, pretrained k-mer embedding fused with positional embedding was applied to get the sequence representation with biological significance. Finally, an improved textRNN model with Bi-GRU and an attention mechanism was employed for implementing the piRNA functional label prediction task. Experiments substantiate that our model can effectively identify the piRNA functional labels, reveal the key factors of its subsequences and be helpful for in-depth investigations into piRNA functions.
Advances in Short-Term Solar Forecasting: A Review and Benchmark of Machine Learning Methods and Relevant Data Sources
Authors: Pandžić Franko , Capuder Tomislav
Published: December 2023

Solar forecasting is becoming increasingly important due to the exponential growth in total global solar capacity each year. More photovoltaic (PV) penetration in the grid poses problems for grid stability due to the inherent intermittent and variable nature of PV power production. Therefore, forecasting of solar quantities becomes increasingly important to grid operators and market participants. This review presents the most recent relevant studies focusing on short-term forecasting of solar irradiance and PV power production. Recent research has increasingly turned to machine learning to address this challenge. The paper provides a discussion about building a solar forecasting model, including evaluation measures and machine learning method selection through analysed literature. Given that machine learning is data-driven, the focus of this review has been placed on data sources referenced in the literature. Open-access data sources have been compiled and explored. The main contribution of this paper is the establishment of a benchmark for assessing the performance of solar forecasting models. This benchmark utilizes the mentioned open-source datasets, offering a standardized platform for future research. It serves the crucial purpose of streamlining investigations and facilitating direct comparisons among different forecasting methodologies in the field of solar forecasting.
Biodiesel from Bark and Black Liquor—A Techno-Economic, Social, and Environmental Assessment
Authors: Hansson Julia , Klugman Sofia , Lönnqvist Tomas , Elginoz Nilay , Granacher Julia , Hasselberg Pavinee , Hedman Fredrik , Efraimsson Nora , Johnsson Sofie , Poulikidou Sofia , Safarian Sahar , Tjus Kåre
Published: December 2023

A techno-economic assessment and environmental and social sustainability assessments of novel Fischer–Tropsch (FT) biodiesel production from the wet and dry gasification of biomass-based residue streams (bark and black liquor from pulp production) for transport applications are presented. A typical French kraft pulp mill serves as the reference case and large-scale biofuel-production-process integration is explored. Relatively low greenhouse gas emission levels can be obtained for the FT biodiesel (total span: 16–83 g CO2eq/MJ in the assessed EU countries). Actual process configuration and low-carbon electricity are critical for overall performance. The site-specific social assessment indicates an overall positive social effect for local community, value chain actors, and society. Important social aspects include (i) job creation potential, (ii) economic development through job creation and new business opportunities, and (iii) health and safety for workers. For social risks, the country of implementation is important. Heat and electricity use are the key contributors to social impacts. The estimated production cost for biobased crude oil is about 13 €/GJ, and it is 14 €/GJ (0.47 €/L or 50 €/MWh) for the FT biodiesel. However, there are uncertainties, i.e., due to the low technology readiness level of the gasification technologies, especially wet gasification. However, the studied concept may provide substantial GHG reduction compared to fossil diesel at a relatively low cost.
The European Market for Guarantees of Origin for Green Electricity: A Scenario-Based Evaluation of Trading under Uncertainty
Authors: Wimmers Alexander , Madlener Reinhard
Published: December 2023

Guarantees of Origin (GOs) were introduced in order to enhance transparency about the origin of green electricity produced in Europe, and to deliberately empower end-consumers to participate in the sustainable energy transition. The separation of electricity and the GO trade has resulted in a prosperous GO market that, however, has been characterized by non-transparency and opportunistic behavior. Historic price development has been opaque and can therefore not be used to forecast future GO prices. This paper, firstly, provides a thorough overview of the European GO market and an analysis of the historic price development; secondly, it proposes a model, the first of its kind, for determining future price developments of European GOs for different renewable energy technologies in different countries up to 2040. For household consumers, GO price determination is based on willingness-to-pay estimates from the literature, whereas for non-household consumers, the model introduces a novel approach to determine the willingness to pay for green electricity. Four different scenarios are considered (Status Quo, Sustainable Development, Full Harmonization, and Ideal Development) and annual GO data are used. The findings indicate that GO prices can be expected to increase on average in the next years, with prices ranging from 1.77 to 3.36 EUR/MWh in 2040. Sensitivity analysis shows that ‘WTP percentages’ have the highest influence on GO prices. It can be concluded that future GO prices will remain challenging to predict, even with the support of sophisticated models, due to the expected supply and demand-driven market growth affecting the market equilibrium prices for different GOs in different countries.
Effect of an Amphoteric Surfactant Concentration on Absorbance, Contact Angle, Surfactant, and Thermal Conductivity of CNT Nanofluids
Authors: Baek Seungyeop , Lee Seunghyeon , Sung Yonmo , Shin Dongmin , Kim Junhyo , Jeong Hyomin
Published: December 2023

In this work, the effects of carbon nanotubes and an amphoteric surfactant, namely lauryl betaine, on the absorbance, contact angle, surface tension, and thermal conductivity of DW were experimentally investigated. The concentration of the carbon nanotubes was 0.5 wt% and that of lauryl betaine was 100, 500, and 1000 ppm in distilled water. From the absorbance measurement results, the addition of lauryl betaine could increase the absorbance in the wavelength range of UV and visible rays (200~1000 nm). In addition, the higher the surfactant concentration, the higher the dispersibility. The contact angle of the distilled water showed a monotonic decreasing trend with an increase in the surfactant blending ratio, while there were no significant changes in that of the carbon nanotube nanofluid. Analogous behaviors were observed in the surface tension measurements. The surface tension of the distilled water dramatically decreased with an increase in the surfactant blending ratio. The highest decrement was 46.05% at the surfactant concentration of 1000 ppm. In contrast, there were no significant changes in the case of the carbon nanotube nanofluid. Adding 0.5 wt% of the carbon nanotubes to distilled water could substantially enhance the thermal conductivity up to approximately 3%. The degradation effect of the amphoteric surfactant on the thermal conductivity of the fluids was observed in both distilled water and nanofluids.
Construction and Electrothermal Performance Evaluation of a Solar-Powered Emergency Shelter
Authors: Lv Tiangang , Liu Bing , Liu Rujie , Zhu Li , Huo Yujiao , Ji Mingda
Published: December 2023

Power outages and poor thermal conditions are common in emergency shelters. In light of this, a novel design for a solar-powered emergency shelter (SPES) with flexible photovoltaics is proposed and investigated in this paper. Firstly, the space and structure of SPES are designed based on ergonomic and easy open-and-close requirements. Then, considering the finishing strength of the building and the convenience and economy of the processing design, the construction of solid models using a 1:2 equal scale, and three double-top SPES were developed, in which internal roofs are canvas, polyethylene(PE), and polyvinyl chloride(PVC). Finally, measurements and ANSYS-Fluent simulations are employed for testing the dynamic fluctuation of the electrothermal performance of SPES. It is found that the maximum differences between the inner roof interior side temperature (IRIST) and the outdoor ambient environment temperature (OAET) for Sref, Dsc, Dpe, and Dpvc are 33.3 °C, 32.9 °C, 28.1 °C, and 25.9 °C, respectively, in winter conditions in China cold zone. The optimized design parameters of SPES in Poso City, Indonesia, characterized by equatorial humid climatic conditions, recommended that the air interlayer be 0.2 meters thick and the exhaust air volume be 0.3 m3/s. Mechanical ventilation coupled with evaporative conditioners can further reduce indoor temperatures effectively. This research offers a novel solution to the problems of indoor thermal environments and power outages for post-disaster resettlement.
An Energy-Feed Type Split-Capacitor Three-Phase Four-Wire Power Electronic Load Compatible with Various Load Demands
Authors: Sun Shiyi , Huang Qingjun , Luo Bingyang , Lu Jianghua , Luo Jiapeng , Ma Zexu , Zhu Guorong
Published: December 2023

Energy-feed power electronic loads can precisely control the phase and magnitude of the power supply output current, achieving the emulation of loads. Moreover, they can feed energy back to the grid for energy regeneration, demonstrating significant research value. This article proposes an energy-fed power electronic load topology and control method that can realize the static and dynamic simulation of linear and non-linear loads and take into account the simulation needs of single-phase, three-phase three-wire, and three-phase four-wire loads. The main circuit uses a two-stage back-to-back AC/DC/AC structure: the front side is a three-phase four-wire split capacitor PWM rectifier bridge, which is used to simulate loads under various operating conditions; the back side is a three-phase three-wire PWM inverter bridge, which realizes the energy feeding back to the grid and reduces the waste of energy; and the intermediate side uses a split capacitor to equalize the voltage and achieve voltage stabilization. The topology is analyzed under the simulation demands of three-phase balanced, three-phase unbalanced, single-phase and non-linear loads. Finally, a MATLAB(R2022a)/Simulink simulation platform is built for a power electronic load with a rated capacity of 200 kVA. The simulation results verify the effectiveness, feasibility, and advancement of the power electronic load proposed in this article.
Childhood Mediterranean Diet Adherence Is Associated with Lower Prevalence of Childhood Obesity, Specific Sociodemographic, and Lifestyle Factors: A Cross-Sectional Study in Pre-School Children
Authors: Pavlidou Eleni , Papadopoulou Sousana K. , Alexatou Olga , Voulgaridou Gavriela , Mentzelou Maria , Biskanaki Fani , Psara Evmorfia , Tsourouflis Gerasimos , Lefantzis Nikos , Dimoliani Sophia , Apostolou Thomas , Sampani Anastasia , Chatziprodromidou Ioanna P. , Angelakou Exakousti-Petroula , Giaginis Constantinos
Published: December 2023

Background: The Mediterranean diet (MD) has been related with a decreased probability of overweight/obesity as well as central obesity at all stages of the human life, decreasing the risk of diverse disease states and improving quality of life. Over the last few years, the prevalence of childhood overweight/obesity and especially abdominal obesity has highly increased worldwide, being associated with a higher likelihood of overweight/obesity as well as central obesity at the next stages of the life during adulthood. The purpose of the present study was to explore the relationship of MD compliance with sociodemographic, anthropometry and lifestyle features in pre-school children aged 2–5 years old. Methods: This is a cross-sectional study, which includes 5188 pre-school children from diverse regions of Greece. Relevant questionnaires were applied to evaluate the sociodemographic features of the enrolled children. Anthropometric parameters were measured by relevant techniques. Qualified questionnaires were utilized for assessing several lifestyle factors such as physical activity, quality of life, breastfeeding practices, MD adherence, as well as the prevalence of childhood asthma and diabetes mellitus type I. Results: Of the enrolled children, 41.7% showed low MD compliance and 36.4% of them indicated moderated compliance, while only 21.9% of them showed a high MD adherence. Overweight/obesity was noted in 24.2% of the assigned children, while abdominal obesity was noticed in 18.2% of them. Higher MD compliance was related with an elevated prevalence of sex (boys, p = 0.0005), Greek nationality (p = 0.0088), rural type of residence (p = 0.0099), childhood overweight/obesity (p < 0.0001) and abdominal obesity (p < 0.0001), lower childbirth weight (p < 0.0001), increased physical activity (p = 0.0041), improved quality of life (p = 0.0008), exclusive breastfeeding (p < 0.0001), childhood asthma (p = 0.0001) and diabetes mellitus type 1 (p = 0.0002). Conclusions: A higher MD adherence is associated with specific sociodemographic, better anthropometric, and beneficial lifestyle factors in pre-school children. However, MD compliance remains low or moderate in the vast majority of children aged 2–5 years old. Thus, future public strategies and policies should be performed to inform parents of the potential beneficial effects of MD against obesity and related chronic diseases at the next stage of their children’s lives.
Cloning, Characterization, and Expression Pattern Analysis of the BBM Gene in Tree Peony (Paeonia ostii)
Authors: Zhang Xue , Zhang Wenbo , Chang Yanting , Ma Yanjun , Deng Yayun , Zhang Na , Bai Yiwei , Jiang Zehui , Hu Tao
Published: December 2023

BABY BOOM (BBM) is one of the members of the plant-specific APETALA2/ethylene-responsive factor (AP2/ERF) transcription factor superfamily. It acts as a key regulator of plant cell pluripotency, playing a significant role in promoting somatic embryogenesis. In this study, a BBM gene named PoBBM was screened, cloned, and identified from the third-generation full-length transcriptome data of Paeonia ostii. Its open reading frame was 2136 bp, encoding 711 amino acids. Sequence feature analysis revealed that it possessed two AP2 conserved domains and eight motifs, including bbm-1. The phylogenetic tree indicated that PoBBM clusters with AtBBM in the euANT group of the Arabidopsis AP2 family, which is most closely related to grape VvBBM and may have the same ancestry as grape. Subcellular localization demonstrated that the PoBBM protein was localized in the nucleus. Semi-quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to assess the PoBBM transcript levels during ten developmental stages of somatic embryos and in five tissue types of peonies. The results indicate that PoBBM was highly expressed in the early stages of peony somatic embryo development. The expression on 0–15 d was the highest and decreased gradually with somatic embryogenesis. The gene is almost not expressed after 40 d since somatic embryo formation. PoBBM was expressed in roots, stems, leaves, seeds, and calli, with the highest levels in seeds, followed by leaves and calli. The PoBBM protein displayed transcriptional self-activation activity, which may facilitate further research on its relationships with other proteins. The above results provide a key gene PoBBM for somatic embryogenesis in peonies, which is significant for advancing the establishment of a stable and efficient regeneration and genetic transformation system for peonies.
Enhancing Fire Monitoring Method over Peatlands and Non-Peatlands in Indonesia Using Visible Infrared Imaging Radiometer Suite Data
Authors: Indradjad Andy , Dimyati Muhammad , Vetrita Yenni , Adiningsih Erna Sri , Rokhmatuloh Rokhmatuloh
Published: December 2023

Indonesia needs a daily monitoring system due to its frequent fires and, more importantly, to assist stakeholders in the field in taking action to mitigate disasters. Our method simplified the number of hotspots for field-based purposes and was verified by comparing the point-based (point-HS) VIIRS (Visible Infrared Imaging Radiometer Suite) 375m-derived temperature anomalies (hotspots) and clustered-based hotspots (cluster-HS, our suggested method). Using Euclidean clustering, we calculated the distance between hotspot points and applied specific criteria to reduce the number of hotspots while aligning them closely with fire incidents. We evaluated accuracy at different fire sizes, burned areas, peatlands, and distances from the reported burn center. We found that the accuracy increases at 1.5 km from the center of the fire for both point- and cluster-HS at 52% and 53%, respectively. For areas larger than 14 ha, both types of hotspots yielded superior results of 83%. Cluster-HS performs better on peatlands than non-peatlands (62% vs. 57%). Without diminishing the precision of the hotspot observation, this study indicates that our method is reliable for assisting field stakeholders in the field in taking actions. Therefore, this product could be implemented into Indonesia’s daily hotspot monitoring.
Expected Climate Change in the High Arctic—Good or Bad for Arctic Charr?
Authors: Svenning Martin A. , Bjørvik Eigil T. , Godiksen Jane A. , Hammar Johan , Kohler Jack , Borgstrøm Reidar , Yoccoz Nigel G.
Published: December 2023

Lakes in the High Arctic are characterized by their low water temperature, long-term ice cover, low levels of nutrients, and low biodiversity. These conditions mean that minor climatic changes may be of great importance to Arctic freshwater organisms, including fish, by influencing vital life history parameters such as individual growth rates. In this study, Arctic charr sampled from two Svalbard lakes (78–79° N) over the period 1960–2008 provided back-calculated length-at-age information extending over six decades, covering both warm and cold spells. The estimated annual growth in young-of-the-year (YOY) Arctic charr correlated positively with an increasing air temperature in summer. This increase is likely due to the higher water temperature during the ice-free period, and also to some extent, due to the winter air temperature; this is probably due to thinner ice being formed in mild winters and the subsequent earlier ice break-up. However, years with higher snow accumulation correlated with slower growth rates, which may be due to delayed ice break-up and thus a shorter summer growing season. More than 30% of the growth in YOY charr could be explained specifically by air temperature and snow accumulation in the two Arctic charr populations. This indicated that juvenile Svalbard Arctic charr may experience increased growth rates in a future warmer climate, although future increases in precipitation may contradict the positive effects of higher temperatures to some extent. In the longer term, a warmer climate may lead to the complete loss of many glaciers in western Svalbard; therefore, rivers may dry out, thus hindering migration between salt water and fresh water for migratory fish. In the worst-case scenario, the highly valuable and attractive anadromous Arctic charr populations could eventually disappear from the Svalbard lake systems.
Reproductive Conditioning of the Peruvian Scallop Argopecten purpuratus in Different Environments
Authors: Crisóstomo Rafael Octavio , Pepe-Victoriano Renzo , Méndez-Ancca Sheda , Zambrano-Cabanillas Abel Walter , Marín-Machuca Olegario , Perez Hernan Mauricio , Yana-Mamani Víctor , Ruiz-Choque Mario
Published: December 2023

Obtaining viable Argopecten purpuratus seeds faces challenges, especiallyci the unpredictability of the marine environment and high production costs in hatcheries. However, improving the method of "Broodstock Conditioning In Hatcheries" is key to ensure permanent seed supplies by minimizing the dependence on marine conditions and by maximizing economic viability in hatcheries. In an effort to overcome these barriers, broodstock were conditioned into two different environments: (a) Natural Environment: Natural marine conditions located in Bahía Inglesa, Atacama Region, Chile. (b) Hatchery: Laboratory conditions to achieve gonadal maturation, spawning induction, fertilization and larval development. The purpose of this research was to evaluate how the type of reproductive conditioning affects the reproductive potential and nutritional quality of the progeny. Both methods were successful at inducing the necessary maturity for reproduction, obtaining viable gametes and larvae. On the other hand, it was observed that in the natural environment, the oocytes and D larvae reached a greater size and nutritional value, being the most significant differences with (p < 0.05): the size of the D larvae reached figures of 95.8 ± 3.1 μm and 91.2 ± 2.7 μm in the environment and hatchery, respectively; the lipid content in dry mass was 25.2 ± 3.1 mg g−1 and 13.5 ± 1.9 mg g−1 for the natural environment and hatchery, respectively. Although quality indicators in hatcheries were slightly lower compared to the natural environment, the possibility of conditioning A. purpuratus broodstock independently of environmental variability highlights the importance of further optimizing broodstock conditioning aspects in hatcheries that would allow more predictable and sustainable production.
Cavitation Strength, Acoustic Nonlinearity, and Gas Bubble Distribution in Water
Authors: Bulanov Alexey V. , Sosedko Ekaterina V. , Bulanov Vladimir A. , Korskov Igor V.
Published: December 2023

The acoustic properties of real liquids are largely related to the phase inclusions contained in them, of which gas bubbles are the most common. The aim of the work was to find the relationship between the nonlinear acoustic parameter and the cavitation strength of the liquid with the distribution of bubbles in the liquid, which has so far been poorly studied. The theoretical studies of the parameter of acoustic nonlinearity and the cavitation strength of a liquid with bubbles were carried out within the framework of the homogeneous approximation of a micro-homogeneous liquid; the relationship of these parameters with the bubble distribution function was established, and the typical values of these parameters for different concentrations of bubbles were calculated. Experimental measurements of the parameter of acoustic nonlinearity and the cavitation strength in the upper layer of seawater were carried out; these measurements were consistent with the theoretical estimates. A connection was established between the thresholds of acoustic and optical cavitation—the optical breakdown of a liquid by laser radiation. The results obtained can find practical application in the measurement of the cavitation strength of seawater at great depths in the sea, and the use of an optoacoustic method associated with the use of optical cavitation is proposed.
Proposal for Use of the Fractional Derivative of Radial Functions in Interpolation Problems
Authors: Torres-Hernandez Anthony , Brambila-Paz Fernando , Ramirez-Melendez Rafael
Published: December 2023

This paper presents the construction of a family of radial functions aimed at emulating the behavior of the radial basis function known as thin plate spline (TPS). Additionally, a method is proposed for applying fractional derivatives, both partially and fully, to these functions for use in interpolation problems. Furthermore, a technique is employed to precondition the matrices generated in the presented problems through QR decomposition. Similarly, a method is introduced to define two different types of abelian groups for any fractional operator defined in the interval [0,1), among which the Riemann–Liouville fractional integral, Riemann–Liouville fractional derivative, and Caputo fractional derivative are worth mentioning. Finally, a form of radial interpolant is suggested for application in solving fractional differential equations using the asymmetric collocation method, and examples of its implementation in differential operators utilizing the aforementioned fractional operators are shown.