bluuebunny/crossref_metadata_2025 huggingface dataset:
An Improved Failure Mode and Effect Analysis of Floating Offshore Wind Turbines
Authors: Li He , Teixeira A. P. , Guedes Soares C.
Published: November 2022

This paper proposes an improved failure mode and effect analysis method for a comprehensive failure analysis that provides a holistic perspective of actions on the potential failures of floating offshore wind turbines. A new way of constructing risk priority numbers was developed by considering the background knowledge of the specialists involved in the failure analysis. The failure analysis was conducted based on an extensive dataset from multiple specialists that covers five floating offshore wind turbine systems, 15 main components, 42 failure modes, and 104 failure causes. Consequently, 21 recommendations are suggested for designers and operators to prevent and mitigate the risk of unexpected failures of floating offshore wind turbines. Furthermore, a comparison analysis was conducted to illustrate the similarities and differences between the proposed failure mode and effect analysis and the conventional method.
Engineering, Ecological and Social Monitoring of the Largest Underwater Sculpture in the World at John Brewer Reef, Australia
Authors: Smith Adam , Songcuan Al Jayson , Cook Nathan , Brown Rachelle , Cook Kailash , Richardson Reuben
Published: November 2022

The largest underwater sculpture in the world, the ‘Coral Greenhouse’ by artist Jason deCaires Taylor, was commissioned by the Museum of Underwater Art and installed at John Brewer Reef, Australia, in December 2019. The planning process required certified engineering design drawings associated with design life, durability and suitability of materials, and baseline ecological surveys. Following approval, the operational phase required annual monitoring of substrate, ecology, social values, and marine debris. We geo-referenced three permanent transects and designed a before/after rapid monitoring assessment of substrate, fish, and invertebrates. Substrate surveys indicated 11% concrete and 89% sand. Fish surveys indicated significant increases of diversity and abundance, with 12 species and 65 individuals recorded in 2018 compared to 46 species and 365 individuals recorded in 2022. Macroinvertebrate species maintained no significant trends in abundance, species richness, and diversity with respect to time between 2018 and 2022. We monitored coral restoration and natural recruitment at the site, measuring aesthetics, survivorship of planted corals, and coral recruitment. Of 131 corals transplanted in March 2020, survivorship was 100% at 1 month, 92% at 6 months, and 91.6% at 12 months. Hard and soft corals were recruited to the structure at a density of 8.35 hard corals/m2 and 10.9 soft corals/m2 over 26 months.
Numerical Study on Hydrodynamics of Submerged Permeable Breakwater under Impacts of Focused Wave Groups Using a Nonhydrostatic Wave Model
Authors: Qu K. , Huang J. X. , Guo L. , Li X. H.
Published: November 2022

Extreme waves, called rogue waves or freak waves, usually occur unexpectedly and with very large wave heights. In recent years, extreme waves were reported not only in deep ocean waters but also in shallow waters, which threaten the safety and intactness of the coastal regions. To prevent the coastal infrastructures and communities from the devastating power of extreme surges and waves, many coastal defense structures were built along the coastline, i.e., submerged permeable breakwaters. However, the number of studies on the hydrodynamic characteristics of a submerged permeable breakwater under the impact of extreme waves is relatively few. In addition, wave focusing has been widely used to generate extreme waves in the past few decades. Hence, as a necessary supplement to the previous research work, the hydrodynamic performance of a submerged permeable breakwater under the impacts of focused wave groups was numerically studied by using a nonhydrostatic numerical wave model (NHWAVE). The influences of several main factors, such as the incident significant wave height, water depth, wave peak period, porosity of the breakwater (n), and the side slope angle of the breakwater, were considered. It is expected that the results of this study will further strengthen the research on the hydrodynamic characteristics of a submerged permeable breakwater under extreme wave conditions.
Precision Medicine in Radiomics and Radiogenomics
Authors: Monti Serena
Published: November 2022

Precision medicine is an innovative and emerging approach to treatment that accounts for individual variability in genetic and environmental factors to identify and utilize the specific biomedical profile of a patient’s disease [...]
An Overview of Frontier Technologies for Land Tenure: How to Avoid the Hype and Focus on What Matters
Authors: Hull Simon , Liversage Harold , Rizzo Maria Paola , Evtimov Vladimir
Published: November 2022

Secure land and natural resource rights are key ingredients for rural transformation, social inclusion, and the realization of the Sustainable Development Goals. In many cases, these rights are not formally recorded, and statutory land administration systems are inaccessible to rural communities. The rapid development of geospatial technologies and systems, combined with participatory methods for social empowerment, have contributed significantly to addressing these challenges and in developing fit-for-purpose land administration/land recordation systems that promote land tenure security, but with the plethora of options currently available, it is challenging to know which technologies are appropriate for what circumstances and purposes. This paper reports on the findings from a joint FAO/IFAD project that addresses this problem. Thirteen one-hour interviews were conducted with knowledgeable experts to showcase which technologies are being used for what purposes and by whom, the associated benefits and challenges, and what the future may hold. We conclude that technologies are best used in partnership with communities and as integrated solutions, that successful implementations must incorporate maintenance plans, and that the real challenge is not the technology–it is the social, legal, and political context. These findings are useful for governments, NGOs, academia, donors, and others involved in land-related projects aimed at benefitting small-scale farmers.
Simulating Soil-Plant-Climate Interactions and Greenhouse Gas Exchange in Boreal Grasslands Using the DNDC Model
Authors: Forster Daniel , Deng Jia , Harrison Matthew Tom , Shurpali Narasinha
Published: November 2022

With global warming, arable land in boreal regions is tending to expand into high latitude regions in the northern hemisphere. This entails certain risks; such that inappropriate management could result in previously stable carbon sinks becoming sources. Agroecological models are an important tool for assessing the sustainability of long-term management, yet applications of such models in boreal zones are scarce. We collated eddy-covariance, soil climate and biomass data to evaluate the simulation of GHG emissions from grassland in eastern Finland using the process-based model DNDC. We simulated gross primary production (GPP), net ecosystem exchange (NEE) and ecosystem respiration (Reco) with fair performance. Soil climate, soil temperature and soil moisture at 5 cm were excellent, and soil moisture at 20 cm was good. However, the model overestimated NEE and Reco following crop termination and tillage events. These results indicate that DNDC can satisfactorily simulate GHG fluxes in a boreal grassland setting, but further work is needed, particularly in simulated second biomass cuts, the (>20 cm) soil layers and model response to management transitions between crop types, cultivation, and land use change.
Intonation Patterns Used in Non-Neutral Statements by Czech Learners of Italian and Spanish: A Cross-Linguistic Comparison
Authors: Pešková Andrea
Published: November 2022

The objective of the study is to contribute to our understanding of the acquisition of second language intonation by comparing L2 Italian and L2 Spanish as produced by L1 Czech learners. Framed within the L2 Intonation Learning theory, the study sheds light on which tonal events tend to be successfully learnt and why. The study examines different types of non-neutral statements (narrow focus, statements of the obvious, what-exclamatives), obtained by means of a Discourse Completion Task. The findings show that the two groups diverge significantly in producing the nuclear pitch accents L+H* (L2 Spanish) and (L+)H*+L (L2 Italian), which is indicative of a target-like realization in each language. However, the learners struggle with the acquisition of the target boundary tones HL% and L!H% in L2 Spanish and prenuclear pitch accents in both Romance varieties. It is speculated that this is due not only to difficulties in acquiring semantic or systemic dimensions, but also to perceptual salience and frequency effects. In addition, the study explores individual differences and reveals no significant effects of the time spent in an L2-speaking country, the age of learning and the amount of active use of a foreign language on accuracy in L2 production.
Crystal Structures of Half-Sandwich Ru(II) Complexes, [(η6-p-Cymene)(3-chloro-6-(1H-pyrazol-1-yl)pyridazine)Ru(X)]BF4, (X = Cl, Br, I)
Authors: Mambanda Allen , Ongoma Peter , Gichumbi Joel , Omondi Reinner O. , Hunter Leigh A. , Kanyora Amos K.
Published: November 2022

Herein, we report the synthesis and single-crystal X-ray structures of three (η6-p-cymene)Ru(II) tetrafluoroborate salts, viz., [(η6-p-cymene)(3-chloro-6-(1H-pyrazol-1-yl)pyridazine)Ru(X)]BF4, (X = Cl, Br, I), Ru1-3. They were prepared by the reactions of [(η6-p-cymene)Ru(μ-X)(X)]2, (X = Cl, Br, I) with two-mole equivalents of 3-chloro-6-(1H-pyrazol-1-yl)pyridazine, under inert conditions at ambient temperatures, and subsequently precipitated by the addition of excess BF4− ions. Orange crystalline precipitates were obtained in good yields, from which the respective single crystals for X-ray diffraction analysis were recrystallized by slow evaporation from their methanolic/diethyl ether solutions. The Ru(II) complexes were characterized by various spectroscopic techniques and chemical methods, which included FTIR, 1H/13C NMR, UV-visible absorption, mass spectrometry, and elemental analysis. The molecular structures were solved by single-crystal X-ray crystal diffraction analysis. The complexes crystallized in the monoclinic crystal system in the P21/c (Ru1-2) and P21/n (Ru3) space groups. Density Functionals Theoretical (DFT) calculations were performed in methanol to gain an understanding of the electronic and structural properties of the complexes. Trends in the data metrics were established, and selected data were compared with the diffraction data. The electrophilicity indices of Ru1-3 follow the order Ru3 > Ru2 > Ru1, and the trend is in line with their anticipated order of reactivity towards nucleophiles.
Sol-Gel Derived Silica-Titania Waveguide Films for Applications in Evanescent Wave Sensors—Comprehensive Study
Authors: Karasiński Paweł , Zięba Magdalena , Gondek Ewa , Nizioł Jacek , Gorantla Sandeep , Rola Krzysztof , Bachmatiuk Alicja , Tyszkiewicz Cuma
Published: November 2022

Composite silica-titania waveguide films of refractive index ca. 1.8 are fabricated on glass substrates using a sol-gel method and dip-coating technique. Tetraethyl orthosilicate and tetraethyl orthotitanate with molar ratio 1:1 are precursors. Fabricated waveguides are annealed at 500 °C for 60 min. Their optical properties are studied using ellipsometry and UV-Vis spectrophotometry. Optical losses are determined using the streak method. The material structure and chemical composition, of the silica-titania films are analyzed using transmission electron microscopy (TEM) and electron dispersive spectroscopy (EDS), respectively. The surface morphology was investigated using atomic force microscopy (AFM) and scanning electron microscopy (SEM) methods. The results presented in this work show that the waveguide films are amorphous, and their parameters are stable for over a 13 years. The optical losses depend on their thickness and light polarization. Their lowest values are less than 0.06 dB cm−1. The paper presents the results of theoretical analysis of scattering losses on nanocrystals and pores in the bulk and interfaces of the waveguide film. These results combined with experimental data clearly indicate that light scattering at the interface to a glass substrate is the main source of optical losses. Presented waveguide films are suitable for application in evanescent wave sensors.
Magnetic and Magnetocaloric Properties of Nano- and Polycrystalline Manganites La(0.7−x)EuxBa0.3MnO3
Authors: Atanasov Roman , Bortnic Rares , Hirian Razvan , Covaci Eniko , Frentiu Tiberiu , Popa Florin , Deac Iosif Grigore
Published: November 2022

Here, we report synthesis and investigations of bulk and nano-sized La(0.7−x)EuxBa0.3MnO3 (x ≤ 0.4) compounds. The study presents a comparison between the structural and magnetic properties of the nano- and polycrystalline manganites La(0.7−x)EuxBa0.3MnO3, which are potential magnetocaloric materials to be used in domestic magnetic refrigeration close to room temperature. The parent compound, La0.7Ba0.3MnO3, has Curie temperature TC = 340 K. The magnetocaloric effect is at its maximum around TC. To reduce this temperature below 300 K, we partially replaced the La ions with Eu ions. A solid-state reaction was used to prepare bulk polycrystalline materials, and a sol-gel method was used for the nanoparticles. X-ray diffraction was used for the structural characterization of the compounds. Transmission electron spectroscopy (TEM) evidenced nanoparticle sizes in the range of 40–80 nm. Iodometry and inductively coupled plasma optical emission spectrometry (ICP-OES) was used to investigate the oxygen content of the studied compounds. Critical exponents were calculated for all samples, with bulk samples being governed by tricritical mean field model and nanocrystalline samples governed by the 3D Heisenberg model. The bulk sample with x = 0.05 shows room temperature phase transition TC = 297 K, which decreases with increasing x for the other samples. All nano-sized compounds show lower TC values compared to the same bulk samples. The magnetocaloric effect in bulk samples revealed a greater magnetic entropy change in a relatively narrow temperature range, while nanoparticles show lower values, but in a temperature range several times larger. The relative cooling power for bulk and nano-sized samples exhibit approximately equal values for the same substitution level, and this fact can substantially contribute to applications in magnetic refrigeration near room temperature. By combining the magnetic properties of the nano- and polycrystalline manganites, better magnetocaloric materials can be obtained.
Characteristics of Radio Frequency Dielectric Barrier Discharge Using Argon Doped with Nitrogen at Atmospheric Pressure
Authors: Li Sen , Sun Jiazhen , Sun Rui , Pan Jie , Wang Lin , Chen Chen , Chen Qiang , Liu Zhongwei
Published: November 2022

In order to study the characteristics of radio frequency dielectric barrier discharge (RF-DBD) using argon doped with nitrogen at atmospheric pressure, electrical and optical diagnoses of the discharge with different nitrogen ratios from 1% to 100% were carried out, and the self-organizing form of the filamentous plasma was studied through a transparent water electrode. At the same time, an ICCD camera was used to study the spatiotemporal evolution filamentous discharge during one cycle. Different from discharge using pure argon, using argon doped with nitrogen made the discharge change from glow discharge to filamentous discharge when the voltage increased to a certain value, and a higher nitrogen ratio made the filaments thicker and more sparsely arranged. Under different input power and nitrogen content conditions, several forms of glow discharge, hexagonal/irregularly arranged filamentous discharge and local filamentous discharge were obtained, all of which have potential applications to reduce the high cost of using inert gases.
Discrete Element Modelling of Cold Crushing Tests Considering Various Interface Property Distributions in Ordinary Refractory Ceramics
Authors: Du Weiliang , Jin Shengli
Published: November 2022

The microstructures and local properties of ordinary refractory ceramic materials are heterogeneous and play a role in the fracture behavior of ordinary refractory ceramic materials. It is important to consider them in numerical modeling. Herein, the discrete element (DE) method was applied to determine the influences of heterogeneity of ordinary refractory ceramic materials by applying statistically distributed interface properties (uniform, Weibull), as opposed to constant interface properties, among the elements. Uniaxial cold crushing tests were performed as a case study. A reasonable loading strain rate for receiving quasi-static loading conditions and computation efficiency was evaluated. The loading wall displacement was recorded to present the stress–strain curves of cold crushing tests. Furthermore, the effects of the interface property distributions on the load/displacement curve, fracture energy, cold crushing strength, and fracture events were investigated. The results reveal that the DE method is a promising method for visualizing and quantifying the post–peak fracture process and crack events in ordinary refractory ceramics. Different interface property distributions contribute to significant variances in the load/displacement curve shape and fracture pattern. The heterogeneity of ordinary refractory ceramics can be further determined by comparing the experimental curves and fracture propagation along with an inverse identification approach.
Hydrothermal Synthesis of Zinc Oxide Nanoparticles Using Different Chemical Reaction Stimulation Methods and Their Influence on Process Kinetics
Authors: Strachowski Tomasz , Baran Magdalena , Małek Marcin , Kosturek Robert , Grzanka Ewa , Mizeracki Jan , Romanowska Agata , Marynowicz Stefan
Published: November 2022

The aim of this work was to study the effect of the applied chemical reaction stimulation method on the morphology and structural properties of zinc oxide nanoparticles (ZnONPs). Various methods of chemical reaction induction were applied, including microwave, high potential, conventional resistance heater and autoclave-based methods. A novel, high potential-based ZnONPs synthesis method is herein proposed. Structural properties–phase purity, grain size–were examined with XRD methods, the specific surface area was determined using BET techniques and the morphology was examined using SEM. Based on the results, the microwave and autoclave syntheses allowed us to obtain the desired phase within a short period of time. The impulse-induced method is a promising alternative since it offers a non-equilibrium course of the synthesis process in an highly energy-efficient manner.
Energy Transfer from Pr3+ to Gd3+ and Upconversion Photoluminescence Properties of Y7O6F9:Pr3+, Gd3+
Authors: Sun Yang , Wang Yangbo , Hu Chengchao , Zhou Xufeng , Hao Jigong , Li Wei , Li Huaiyong
Published: November 2022

Upconversion materials have numerous potential applications in light energy utilization due to their unique optical properties. The use of visible light excitation to obtain ultraviolet emission is a promising technology with broad application prospects, while relevant research is absent. A series of Pr3+, Gd3+ doped Y7O6F9 phosphors were synthesized by traditional solid–state reaction. X-ray diffraction, scanning electronic microscopy, steady-state photoluminescence spectra, a decay dynamic, and upconversion emission spectra of the samples were studied. Under the excitation of 238 nm, the energy transfer from Pr3+ to Gd3+ was realized and a strong ultraviolet B emission due to the 6P7/2→8S7/2 transition of the Gd3+ ions was achieved. Under the excitation of a 450 nm blue laser, Pr3+ absorbed two blue photons to realize the upconversion process and then transferred the energy to Gd3+ to obtain the ultraviolet B emission.
X-ray Diffuse Scattering from Ca3NbGa3Si2O14 Single Crystal under External Electric Field Application
Authors: Irzhak Dmitrii , Roshchupkin Dmitry
Published: November 2022

X-ray diffuse scattering from the Ca3NbGa3Si2O14 (CNGS) crystal was measured with a triple axis X-ray diffractometer under the conditions of an external electric field. It is found that the nature of the intensity distribution of the asymmetrical part of diffuse scattering depends on the value of the applied electric field. This phenomenon is apparently associated with different piezoelectric characteristics of defect regions and the rest of the single crystal.
Effect of Preheating Temperature on Thermal–Mechanical Properties of Dry Vibrating MgO-Based Material Lining in the Tundish
Authors: Deng Xiaodong , Li Jianli , Xie Xiao
Published: November 2022

For the collapse of the working layer of dry vibrating material during preheating, the four-strand tundish of a steel plant was taken as a prototype for numerical simulation. The software ANSYS was used to calculate the temperature field and stress and strain field on the working layer under three preheating stages through the indirect coupling method. The results show that during the preheating process, the temperature field distribution on the hot surface of the working layer gradually develops toward uniformity with the increase in preheating temperature. However, the temperature gradient between the cold and hot surfaces increases subsequently, and the highest temperature between the cold and hot surfaces reaches 145.31 °C in the big fire stage. The stress on the top of the working layer is much larger than in other areas, and the maximum tensile stress on the top reaches 39.06 MPa in the third stage of preheating. Therefore, the damage to the working layer starts from the top of the tundish. In addition, the strain of the area near the sidewall burner nozzle in the casting area is much larger than that in the middle burner area with the increase in preheating temperature. Thus, the working layer near the sidewall burner nozzle is more prone to damage and collapse compared with the middle burner nozzle.
Fault Feature Enhanced Extraction and Fault Diagnosis Method of Vibrating Screen Bearings
Authors: Cheng Xiaohan , Yang Hui , Yuan Long , Lu Yuxin , Cao Congjie , Wu Guangqiang
Published: November 2022

For mechanical equipment, bearings have a high incidence area of faults. A problem for bearings is that their fault characteristics include a vibrating screen exciter which is weak and thus easily covered in strong background noise, hence making the noise difficult to remove. In this paper, a noise reduction method based on singular value decomposition, improved by singular value’s unilateral ascent method (SSVD), and a fault feature enhancement method, i.e., variational mode decomposition, improved by revised whale algorithm optimization (RWOA-VMD), are proposed. These two methods are used in vibration signal processing with early faults of bearings having a vibrating screen and they have achieved significant application results. This paper also aims to construct a multi-modal feature matrix composed of energy entropy, singular value entropy, and power spectrum entropy, and then the early fault diagnosis of bearings of a vibrating screen exciter bearing is realized by using the proposed support vector machine, improved by the aquila optimizer algorithm (AO-SVM).
Synthesis and Characterization of Bioactive Magnetic Nanoparticles from the Perspective of Hyperthermia Applications
Authors: Moacă Elena-Alina , Socoliuc Vlad , Stoian Dana , Watz Claudia , Flondor Daniela , Păcurariu Cornelia , Ianoș Robert , Rus Cristiana Iulia , Barbu-Tudoran Lucian , Semenescu Alexandra , Sarău Cristian , Chevereșan Adelina , Dehelean Cristina Adriana
Published: November 2022

Magnetic iron oxide nanoparticles were obtained for the first time via the green chemistry approach, starting from two aqueous extracts of wormwood (Artemisia absinthium L.), both leaf and stems. In order to obtain magnetic nanoparticles suitable for medical purposes, more precisely with hyperthermia inducing features, a synthesis reaction was conducted, both at room temperature (25 °C) and at 80 °C, and with two formulations of the precipitation agent. Both the quality and stability of the synthesized magnetic iron oxide nanoparticles were physiochemically characterized: phase composition (X-ray powder diffraction (XRD)), thermal behavior (thermogravimetry (TG) and differential scanning calorimetry (DSC)), electron microscopy (scanning (SEM) and transmission (TEM)), and magnetic properties (DC and HF-AC). The magnetic investigation of the as-obtained magnetic iron oxide nanoparticles revealed that the synthesis at 80 °C using a mixture of NaOH and NH3(aq) increases their diameter and implicitly enhances their specific absorption rate (SAR), a mandatory parameter for practical applications in hyperthermia.
Analysis of the Level of Adoption of Business Continuity Practices by Brazilian Industries: An Exploratory Study Using Fuzzy TOPSIS
Authors: Bobel Vitor Amado de Oliveira , Sigahi Tiago F. A. C. , Rampasso Izabela Simon , Moraes Gustavo Hermínio Salati Marcondes de , Ávila Lucas Veiga , Leal Filho Walter , Anholon Rosley
Published: November 2022

The COVID-19 outbreak caused several negative effects in industries of all sizes and in all parts of the world, leading academic and practitioners to ask whether organizations could have been better prepared to face disruptive situations. This paper aims to analyze business continuity practices performed by Brazilian industries. A survey was conducted with academics who work in the field of organizational resilience and business continuity and are familiar with the reality of Brazilian companies in the industrial sector. The participants assessed 16 practices (P) proposed by the ISO 22301:2020, considering two categories: large industries (LI) and small and medium-sized industries (SMI). Data analysis was performed using Hierarchical Cluster Analysis, frequency analysis, Fuzzy TOPSIS and sensitivity analysis. For LIs, P4 (leaders conduct periodic critical analyses of practices) was considered the practice with the best application rate, while for SMIs, P2 (understand stakeholders’ needs and expectations, and use information in business continuity management) was chosen. In all scenarios tested for LIs and SMIs, P8 (well-structured systematic processes to analyze the impact of abnormal situations on their business and the potential risks of a disruption) and P16 (periodic audits of their business continuity management activities to identify opportunities for improvement, and information record) are in the bottom quartile. When compared to LIs in the Brazilian context, SMIs exhibit more profound deficiencies in terms of applying business continuity practices. The findings of this study can be of great value to assist managers in improving organizational resilience. Organizations should be better prepared to face future disruptive events, whether biological, social, technological, or economic.
Fuzzy Based Convolutional Noise Clustering Classifier to Handle the Noise and Heterogeneity in Image Classification
Authors: Suman Shilpa , Kumar Dheeraj , Kumar Anil
Published: November 2022

Conventional Noise Clustering (NC) algorithms do not consider any spatial information in the image. In this study, three algorithms have been presented, Noise Local Information c-means (NLICM) and Adaptive Noise Local Information c-Means (ADNLICM), which use NC as the base classifier, and Noise Clustering with constraints (NC_S), which incorporates spatial information into the objective function of the NC classifier. These algorithms enhance the performance of classification by minimizing the effect of noise and outliers. The algorithms were tested on two study areas, Haridwar (Uttarakhand) and Banasthali (Rajasthan) in India. All three algorithms were examined using different parameters (distance measures, fuzziness factor, and δ). An analysis determined that the ADNLICM algorithm with Bray–Curtis distance measures, fuzziness factor m = 1.1, and δ = 106, outperformed the other algorithm and achieved 91.53% overall accuracy. The optimized algorithm returned the lowest variance and RMSE for both study areas, demonstrating that the optimized algorithm works for different satellite images. The optimized technique can be used to categorize images with noisy pixels and heterogeneity for various applications, such as mapping, change detection, area estimation, feature recognition, and classification.
Pairwise Constraints Multidimensional Scaling for Discriminative Feature Learning
Authors: Zhang Linghao , Pang Bo , Tang Haitao , Wang Hongjun , Li Chongshou , Luo Zhipeng
Published: November 2022

As an important data analysis method in the field of machine learning and data mining, feature learning has a wide range of applications in various industries. The traditional multidimensional scaling (MDS) maintains the topology of data points in the low-dimensional embeddings obtained during feature learning, but ignores the discriminative nature between classes of low-dimensional embedded data. Thus, the discriminative multidimensional scaling based on pairwise constraints for feature learning (pcDMDS) model is proposed in this paper. The model enhances the discriminativeness from two aspects. The first aspect is to increase the compactness of the new data representation in the same cluster through fuzzy k-means. The second aspect is to obtain more extended pairwise constraint information between samples. In the whole feature learning process, the model considers both the topology of samples in the original space and the cluster structure in the new space. It also incorporates the extended pairwise constraint information in the samples, which further improves the model’s ability to obtain discriminative features. Finally, the experimental results on twelve datasets show that pcDMDS performs 10.31% and 8.31% higher than PMDS model in terms of accuracy and purity.
Closed-Loop Solvability of Stochastic Linear-Quadratic Optimal Control Problems with Poisson Jumps
Authors: Li Zixuan , Shi Jingtao
Published: November 2022

The stochastic linear–quadratic optimal control problem with Poisson jumps is addressed in this paper. The coefficients in the state equation and the weighting matrices in the cost functional are all deterministic but are allowed to be indefinite. The notion of closed-loop strategies is introduced, and the sufficient and necessary conditions for the closed-loop solvability are given. The optimal closed-loop strategy is characterized by a Riccati integral–differential equation and a backward stochastic differential equation with Poisson jumps. A simple example is given to demonstrate the effectiveness of the main result.
Thermal and Phase Change Process in a Locally Curved Open Channel Equipped with PCM-PB and Heater during Nanofluid Convection under Magnetic Field
Authors: Aich Walid , Selimefendigil Fatih , Alqahtani Talal , Algarni Salem , Alshehery Sultan , Kolsi Lioua
Published: November 2022

Thermal performance and phase-change dynamics in a channel having a cavity equipped with a heater and phase-change material (PCM)-packed bed (PB) region are analyzed during nanoliquid convection under an inclined magnetic field. Curvature of the upper wall above the PCM zone is also considered by using the finite element method. Impacts of curvature of the upper wall (between 0.01H and 0.6H, H-channel height), strength of magnetic field (MGF) (Hartmann number between 0 and 40), height (between 0.1H and 0.4H) and number (between 5 and 17) of heaters on the thermal performance and phase-change dynamics are studied. In the interior and wall near regions of the PCM-PB, the curvature effects become opposite, while phase completion time (tF) rises by about 42% at the highest radius of the curvature. Imposing MGF and increasing its strength has positive impacts on the phase change and thermal performance. There is a reduction in tF by about 45.2% and 41.8% when MGF is imposed at Ha = 40 for pure fluids and nanofluids. When thermal performance for all different cases is compared, using MGF+nanofluid+PCM provides the most favorable case. When the reference case (only pure fluid without MGF and PCM) is used, including nanoparticles results in an improvement of 33.7%m while it is further increased to 71.1% when PCM-PB is also installed. The most favorable case by using MGF, nanofluid and PCM-PB results in thermal performance improvement of about 373.9% as compared to the reference configuration.
Estimation of the Total Heat Exchange Factor for the Reheating Furnace Based on the First-Optimize-Then-Discretize Approach and an Improved Hybrid Conjugate Gradient Algorithm
Authors: Yang Zhi , Luo Xiaochuan , Liu Pengbo , Qiao Jinwei , Liu Ming
Published: November 2022

The total heat exchange factor is one of the most important thermal physical parameters in the heat transfer model for a reheating furnace machine. In this paper, a novel general strategy, which is combined with the first-optimize-then-discretize (FOTD) approach and an improved hybrid conjugate gradient (IHCG) algorithm, is proposed to identify the total heat exchange factor by solving a nonlinear inverse heat conduction problem (IHCP). Firstly, a nonlinear IHCP with the Dirichlet-type boundary condition Tm(t)=T(0,t) is built to determine the unknown total heat exchange factor w(t). Secondly, the analysis of the Fréchet gradient of the cost functional is given and the gradient is proved as Lipschitz continuous by the FOTD approach. Thirdly, based on the gradient information by FOTD, a new IHCG algorithm, whose global convergence is proved by us, is proposed for fast solving of the optimization problem. Finally, simulation experiments are given to verify the effectiveness of the proposed strategy. Compared with the first-discretize-then-optimize (FDTO) approach, the FOTD approach can reduce running time and iteration number. Compared with other CG algorithms, the proposed IHCG algorithm has better convergence performance. The experimental data by the thermocouples experiments from a reheating furnace are also given to identify the total heat exchange factor.
A Multi-Population Mean-Field Game Approach for Large-Scale Agents Cooperative Attack-Defense Evolution in High-Dimensional Environments
Authors: Wang Guofang , Li Ziming , Yao Wang , Xia Sikai
Published: November 2022

As one of the important issues of multi-agent collaboration, the large-scale agents’ cooperative attack–defense evolution requires a large number of agents to make stress-effective strategies to achieve their goals in complex environments. Multi-agent attack and defense in high-dimensional environments (3D obstacle scenarios) present the challenge of being able to accurately control high-dimensional state quantities. Moreover, the large scale makes the dynamic interactions in the attack and defense problems increase dramatically, which, using traditional optimal control techniques, can cause a dimensional explosion. How to model and solve the cooperative attack–defense evolution problem of large-scale agents in high-dimensional environments have become a challenge. We jointly considered energy consumption, inter-group attack and defense, intra-group collision avoidance, and obstacle avoidance in their cost functions. Meanwhile, the high-dimensional state dynamics were used to describe the motion of agents under environmental interference. Then, we formulated the cooperative attack–defense evolution of large-scale agents in high-dimensional environments as a multi-population high-dimensional stochastic mean-field game (MPHD-MFG), which significantly reduced the communication frequency and computational complexity. We tractably solved the MPHD-MFG with a generative-adversarial-network (GAN)-based method using the MFGs’ underlying variational primal–dual structure. Based on our approach, we carried out an integrative experiment in which we analytically showed the fast convergence of our cooperative attack–defense evolution algorithm by the convergence of the Hamilton–Jacobi–Bellman equation’s residual errors. The experiment also showed that a large number of drones can avoid obstacles and smoothly evolve their attack and defense behaviors while minimizing their energy consumption. In addition, the comparison with the baseline methods showed that our approach is advanced.
Quality Parameters of PE–Pomace Based Membranes
Authors: Betlej Izabela , Salerno-Kochan Renata , Borysiuk Piotr , Boruszewski Piotr , Monder Sławomir , Krajewski Krzysztof , Andres Bogusław , Krochmal-Marczak Barbara , Pisulewska Elżbieta , Danecki Leszek , Pochwała Stanisław
Published: November 2022

This paper presents the results of research on selected mechanical and physical properties of polyethylene membranes containing 50% of the plant fraction obtained as waste from an edible oil press. The produced biomembranes were characterized by low tensile strength (2.02–4.28 MPa). The addition of plant material will not adversely affect the barrier properties such as water vapor permeability or the contact angle. Additionally, there was a discoloration of the characteristics affecting the shrinkage of the membrane. The presence of the plant component clearly lowered the shrinkage of the material. This research is important and provides valuable knowledge on the possibilities of using plant waste and the direction of the potential application of the materials produced with their use.
Correlating the Macrostructural Variations of an Ion Gel with Its Carbon Dioxide Sorption Capacity
Authors: Nguyen Tung , Bavarian Mona , Nejati Siamak
Published: November 2022

We report on a direct correlation between the macroscale structural variations and the gas sorption capacities of an ion gel. Here, we chose 1-ethyl-3-methylimidazolium bis(trifluoromethyl sulfonyl)imide ([Emim][TF2N]) and poly(vinylidene fluoride)-co-hexafluoropropylene (PVDF-HFP) as the ionic liquid and host polymer, respectively. The CO2 sorption in the thin films of the IL-polymer was measured using the gravimetric method. The results of our experiment showed that the trend in CO2 uptake of these mixtures was nonlinearly correlated with the content of IL. Here, we highlight that the variations in the molecular structure of the polymers were the main reason behind the observed trend. The presented data suggested the possibility of using the composition of mixtures containing IL and polymers to realize a synergistic gain for gas sorption in these mixtures.
The Association of Peptide Hormones with Glycemia, Dyslipidemia, and Obesity in Lebanese Individuals
Authors: Abou-Samra Murielle , Venema Koen , Ayoub Moubareck Carole , Karavetian Mirey
Published: November 2022

Peptide-hormones, including pancreatic peptide-YY(PYY), glucagon-like peptide-1 (GLP-1), cholecystokinin (CCK), insulin, and leptin function as satiety signals, while ghrelin promotes hunger. These hormones are also involved in glucose homeostasis and body-weight regulation. The aim of this cross-sectional analysis was to examine the association of these peptide-hormones with obesity-markers, insulin-resistance, and dyslipidemia (total-cholesterol (TC), low-density-lipoprotein-cholesterol (LDL-C), high-density-lipoprotein-cholesterol (HDL-C), triglyceride (TG)). Sixteen-obese (OB) adults and 21 normal-weight (NW) age-and gender-matched counterparts were recruited. OB-participants showed significantly higher levels of leptin, insulin, Homeostatic-Model Assessment of Insulin Resistance (HOMA-IR), and TG. NW participants had significantly higher levels of ghrelin. GLP-1 was positively correlated with insulin, HOMA-IR, and obesity-markers except percent body fat. Leptin was positively correlated with all markers (except glucose and dyslipidemia). PYY was positively correlated with BMI, insulin and HOMA-IR. Ghrelin was inversely correlated with all of the markers except glucose, TC, and LDL-C. In the regression analysis model, leptin was positively associated with obesity markers and insulin resistance. Our results indicate a significant difference in peptide hormones among OB and NW Lebanese individuals. Since there is controversial evidence regarding body-weight and peptide-hormones in the literature, this study highlights a step forward towards finding ethnic based strategies to treat obesity and its consequences.
A New Concept of Associations between Gut Microbiota, Immunity and Central Nervous System for the Innovative Treatment of Neurodegenerative Disorders
Authors: Yoshikawa Sayuri , Taniguchi Kurumi , Sawamura Haruka , Ikeda Yuka , Tsuji Ai , Matsuda Satoru
Published: November 2022

Nerve cell death accounts for various neurodegenerative disorders, in which altered immunity to the integrated central nervous system (CNS) might have destructive consequences. This undesirable immune response often affects the progressive neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, schizophrenia and/or amyotrophic lateral sclerosis (ALS). It has been shown that commensal gut microbiota could influence the brain and/or several machineries of immune function. In other words, neurodegenerative disorders may be connected to the gut–brain–immune correlational system. The engrams in the brain could retain the information of a certain inflammation in the body which might be involved in the pathogenesis of neurodegenerative disorders. Tactics involving the use of probiotics and/or fecal microbiota transplantation (FMT) are now evolving as the most promising and/or valuable for the modification of the gut–brain–immune axis. More deliberation of this concept and the roles of gut microbiota would lead to the development of stupendous treatments for the prevention of, and/or therapeutics for, various intractable diseases including several neurodegenerative disorders.
Altered Liver Metabolism, Mitochondrial Function, Oxidative Status, and Inflammatory Response in Intrauterine Growth Restriction Piglets with Different Growth Patterns before Weaning
Authors: Wang Jun , Zhu Pengwei , Zheng Xiaoyu , Ma Ziwei , Cui Chang , Wu Caichi , Zeng Xiangfang , Guan Wutai , Chen Fang
Published: November 2022

Frequent occurrence of intrauterine growth restriction (IUGR) causes huge economic losses in the pig industry. Accelerated catch-up growth (CUG) in the early stage of life could restore multiple adverse outcomes of IUGR offspring; however, there is little knowledge about this beneficial phenomenon. We previously found that nutrient absorption related to intestinal function was globally promoted in CUG-IUGR piglets before weaning, which might be the dominant reason for CUG, but what this alteration could lead to in subsequent liver metabolism is still unknown. Firstly, a Normal, CUG, and non-catch-up growth (NCUG) piglet model before weaning was established by dividing eighty litters of newborn piglets into normal birth weight (NBW) and IUGR groups according to birth weight, and those piglets with IUGR but above-average weanling body weight were considered CUG, and the piglets with IUGR still below average body weight were considered NCUG at weaning day (d 26). Liver samples were collected and then systematically compared in glycolipid metabolism, mitochondrial function, antioxidant status, and inflammatory status among these three different growth models. Enhanced hepatic uptake of fatty acids, diminished de novo synthesis of fatty acids, and increased oxidation of fatty acids were observed in CUG livers compared to Normal and NCUG. In contrast, the NCUG liver showed enhanced glucose uptake and gluconeogenesis compared to Normal and CUG. We also observed deteriorating hepatic vacuolation in NCUG piglets, while increasing hepatic lipid deposition in CUG piglets. Besides, the expression of genes related to mitochondrial energy metabolism and biogenesis was reduced in CUG piglets and the phosphorylation level of AMPK was significantly higher compared to Normal (p < 0.05). Moreover, NCUG liver showed decreased T-AOC (p < 0.01) and GSH-PX (p < 0.05), increased MDA concentrations (p < 0.01), upregulated phosphorylation levels of ERK and NF-κB (p < 0.05), and elevated pro-inflammatory factors IL-1β, IL-6 and TNF-α (p < 0.05) compared to Normal. Furthermore, correlation analysis revealed a significant positive correlation between glucose metabolism and inflammatory factors, while a negative correlation between mitochondrial function-related genes and fatty acid transport. NGUG piglets showed simultaneous enhancement of glucose uptake and gluconeogenesis, as well as reduced antioxidant capacity and increased inflammatory status, whereas CUG comes at the expense of impaired hepatic mitochondrial function and pathological fat accumulation.
Influence of Filler Materials on Wettability and Mechanical Properties of Basalt/E-Glass Woven Fabric–Reinforced Composites for Microfluidics
Authors: Atmakuri Ayyappa , Kolli Lalitnarayan , Palevicius Arvydas , Urbaite Sigita , Janusas Giedrius
Published: November 2022

This paper presents the development of novel hybrid composites in the presence of filler particles and manufactured using a proposed new fabrication technique. The hybrid composites were fabricated using a basalt and E-glass woven fabric–reinforced epoxy resin matrix combined with graphite powder nanoparticles. Six sets of samples were fabricated using the vacuum-assisted free lamination compression molding technique. After the fabrication, wettability, mechanical properties (tensile, flexural and impact properties) and moisture properties were evaluated. Surface morphology and chemical composition of the composite samples were examined using a scanning electron microscope (SEM) and spectroscopy. The obtained results showed that the use of filler materials in hybrid composites improves the properties of hybrid composites. Basalt/E-glass hybrid composites with 10% graphite material exhibited superior mechanical properties over the other composites, with high-quality, improved adhesion and surface morphology. Thus, novel composites with the combination of exceptional properties may be integrated in the design of flexible electronics and microfluidics devices as a structural layer of the system. High flexibility and good surface tension of the designed composites makes them attractive for using the thermal imprint technique for microfluidics channel design.