bluuebunny/crossref_metadata_2025 huggingface dataset:
Corrosion and Micro-Abrasion Properties of an AISI 316L Austenitic Stainless Steel after Low-Temperature Plasma Nitriding
Authors: Landek Darko , Kurtela Marin , Stojanović Ivan , Jačan Jurica , Jakovljević Suzana
Published: October 2023

The paper investigates the effects of DC plasma nitriding on surface roughness, hardness, microstructure, micro-abrasion, and corrosion resistance of AISI 316L Austenitic Stainless (AS) steel. The nitriding has been conducted for durations ranging from 4 to 24 h at a temperature of 430 °C in a commercial vacuum furnace, Rübig PN90/70. Micro-abrasion resistance has been tested using the calotest device with a measurement diameter of craters produced on the sample surface after 10 to 60 s of wear. Corrosion resistance has been tested using the Electroimpedance Spectroscopy (EIS) method in a 3.5% NaCl water solution. The surface roughness parameters and hardness of the samples increased with longer nitriding times, attributed to the saturation of austenite and the formation of iron and chromium nitrides. Nitriding for longer than 8 h resulted in the formation of a thicker compound layer that is hard and brittle, leading to reduced wear resistance compared with shorter nitriding times. EIS measurements revealed that nitrided samples had lower corrosion resistance compared with the untreated sample. The corrosion stability was not significantly affected by nitriding time. Different nitriding times have a great influence on resistance to pitting corrosion. This study provides valuable insights into the effects of plasma nitriding on the properties of AS steel, highlighting the importance of optimizing nitriding parameters for specific applications.
The Microstructure and Mechanical Properties of High Entropy Alloy CoCrFeNiMn Matrix with Cr3C2 Reinforcement and Ag, BaF2/CaF2 Solid Lubrication
Authors: Guo Zhiming , Li Jingdan , Ren Xiaoyan
Published: October 2023

A series of CoCrFeNiMn high-entropy alloy matrix self-lubricating composites were prepared by spark plasma sintering. The composites are composed of an FCC phase, Cr7C3, Ag, and eutectic fluoride BaF2/CaF2 phases. The microstructure of the composites is uniform. The additional phases distribute along the boundary of equiaxed grains of the FCC phase. The compressive yield strength and fracture toughness decrease with the increase of eutectic fluoride BaF2/CaF2. The composites are susceptible to brittle cleavage fracture.
Improved Wear Resistance of Nitro-Chromized Carbon Steel Using an Additional Carburizing
Authors: Hong Yue , Huang Shuqi , Deng Bin , Yu Yingmei , He Chupeng , Xu Wei , Fan Touwen
Published: October 2023

The controversial wear resistance limits the application of the nitro-chromizing process, which is a potential advanced chromizing strategy with a low chromizing temperature and thick strengthening layer. In this study, additional carburizing was proposed to optimize the nitro-chromizing process and the associated wear resistance. Samples of carbon steel were used to evaluate the optimized nitro-chromizing, normal nitro-chromizing, and other relevant processes. Comparative analyses were conducted through XRD composition analysis, microstructure observations, and mechanical property tests.The results confirm that the normal nitro-chromized sample has poor wear resistance due to severe abrasive wear, while the wear rate of the optimized nitro-chromized sample is only about 1/15 of that of the normal nitro-chromized sample. Both the above two samples have similar main phase compositions of Cr2N and Cr7C3. However, the optimized nitro-chromized sample exhibits a lower friction coefficient and better adhesion strength than the normal nitro-chromized sample. The additional carburizing induces the formation of massive fine graphite sheets deposited on porous nitriding structures, which can be in charge of the low friction coefficient and good adhesion strength.
Subregion Based Prediction of Residual States in Friction Stir Welding of Dissimilar Metals
Authors: Zhang Zhao , Wang Binbin , Liu Yali , Liu Fuhan , Zhang Xinyu
Published: October 2023

Mechanical property changes in friction stir welding can directly affect the rebalance of the stress field in friction stir welding. This means that it reveals a high relevance with the residual states of friction stir welding. Here, we propose a subregion model in which the mechanical property changes are considered to predict the residual states in friction stir welding of dissimilar metals. Results indicate that the accuracy of the predicted distortion can be greatly increased when the different mechanical properties are considered in friction stir welding of 2024-T3 and 6061-T6. The final mechanical property is determined by the mixture of the materials at retreating and advancing sides. The final mechanical property in the stirring zone can be increased to 171 MPa for yield strength and 194 MPa for tensile strength when the strength of the advancing side material is higher. The shrinkage of material in the stirring zone during the cooling stage is the key reason for the formation of the tensile residual stress and the V-shape distortion on the cross-section in the as-weld state.
Printing with tonalli: Reproducing Featherwork from Precolonial Mexico Using Structural Colorants
Authors: Trujillo-Vazquez Abigail , Abedini Fereshteh , Pranovich Alina , Parraman Carinna , Klein Susanne
Published: October 2023

Two of the most significant cases of extant 16th-century featherwork from Mexico are the so-called Moctezuma’s headdress and the Ahuizotl shield. While the feathers used in these artworks exhibit lightfast colors, their assembly comprises mainly organic materials, which makes them extremely fragile. Printed media, including books, catalogs, educational materials, and fine copies, offer an accessible means for audiences to document and disseminate visual aspects of delicate cultural artifacts without risking their integrity. Nevertheless, the singular brightness and iridescent colors of feathers are difficult to communicate to the viewer in printed reproductions when traditional pigments are used. This research explores the use of effect pigments (multilayered reflective structures) and improved halftoning techniques for additive printing, with the objective of enhancing the reproduction of featherwork by capturing its changing color and improving texture representation via a screen printing process. The reproduced images of featherwork exhibit significant perceptual resemblances to the originals, primarily owing to the shared presence of structural coloration. We applied structure-aware halftoning to better represent the textural qualities of feathers without compromising the performance of effect pigments in the screen printing method. Our prints show angle-dependent color, although their gamut is reduced. The novelty of this work lies in the refinement of techniques for printing full-color images by additive printing, which can enhance the 2D representation of the appearance of culturally significant artifacts.
Obtaining Boron Carbide and Nitride Matrix Nanocomposites for Neutron-Shielding and Therapy Applications
Authors: Chkhartishvili Levan , Makatsaria Shio , Gogolidze Nika , Tsagareishvili Otar , Batsikadze Tamaz , Mirzayev Matlab , Kekutia Shalva , Mikelashvili Vladimer , Markhulia Jano , Minashvili Tamaz , Davitadze Ketevan , Barbakadze Natia , Dgebuadze Tamar , Kochiashvili Ketevan , Tsiskarishvili Rusudan , Chedia Roin
Published: October 2023

The very high capture cross-section of (epi)thermal neutrons by the boron isotope 10B makes elemental boron and its compounds and composites prospective for serving as materials intensively interacting with neutron irradiation. In their nanostructured form, boron-rich materials reveal properties that improve their radiation-performance characteristics. In this regard, new technologies have been proposed for the synthesis of nanocomposites with matrices of boron carbide B4C and hexagonal boron nitride h-BN. For the first time, boron carbide-tungsten and hexagonal boron nitride–(iron,magnetite) composites were obtained, respectively, in the form of layered/sandwich structures of components B4C and W and h-BN nanopowders coated/intercalated with magnetic nanoclusters of iron Fe or magnetite Fe3O4. Studying of their chemical/phase composition, structure/morphology, and some other properties leads to the conclusion that the developed B4C–W and h-BN–(Fe,Fe3O4) composites would be useful for solving important problems of boron-based neutron shielding and BNCT (Boron Neutron Capture Therapy), such as attenuating the gamma-radiation accompanying the absorption of neutrons by 10B nuclei and targeted delivery of 10B nuclei, as BNCT therapeutic agents, to tumor tissues using control by an external magnetic field, respectively.
Vortex Dynamics and Pinning in CaKFe4As4 Single Crystals from DC Magnetization Relaxation and AC Susceptibility
Authors: Ionescu Alina M. , Ivan Ion , Miclea Corneliu F. , Crisan Daniel N. , Galluzzi Armando , Polichetti Massimiliano , Crisan Adrian
Published: October 2023

Among various “families” of iron-based superconductors, the quite recently discovered AeAFe4As4 (where Ae is an alkali-earth metal and A is an alkali metal) has high critical current density, a very high upper critical field, and a low anisotropy, and has recently received much interest for the possibility of high magnetic field applications at the liquid hydrogen temperature. We have performed DC magnetization relaxation and frequency-dependent AC susceptibility measurements on high-quality single crystals of CaKFe4As4 with the aim of determining the pinning potential U*. The temperature dependence of U* displays a clear crossover between elastic creep and plastic creep. At temperatures around 27–28 K, U* has a very high value, up to 1200 K, resulting in an infinitesimally small probability of thermally activated flux jumps. From the dependence of the normalized pinning potential on irreversible magnetization, we have determined the creep exponents in the two creep regimes, which are in complete agreement with theoretical models. The estimation of the pinning potential from multifrequency AC susceptibility measurements was possible only near the critical temperature due to equipment limitations, and the resulting value is very close to the one that resulted from the magnetization relaxation data. Magnetic hysteresis loops revealed a second magnetization peak and very high values of the critical current density.
Optimization of Wire EDM Process Parameters for Machining Hybrid Composites Using Grey Relational Analysis
Authors: Jebarose Juliyana Sunder , Udaya Prakash Jayavelu , Rubi Charles Sarala , Salunkhe Sachin , Gawade Sharad Ramdas , Abouel Nasr Emad S. , Kamrani Ali K.
Published: October 2023

The materials used in engineering have seen a significant transformation in the contemporary world. Numerous composites are employed to overcome these problems because conventional materials are unable to meet the needs of current applications. For quite some time, professional engineers and researchers have been captivated by the problem of choosing the best machining parameters for new composite materials. Wire electrical discharge machining is a popular unconventional machining process that is often used for making complex shapes. Numerous process parameters influence the WEDM process. Thus, to achieve affordable and high-quality machining, the right set of process parameters must be provided. Finding the wire cut EDM optimized settings for the fabricated LM5/ZrO2/Gr composite is the main aim of this research. The chosen input parameters are the wire feed, pulse on and pulse off times, the gap voltage, and the reinforcing percentage. In this study, LM5/ZrO2/Gr composites were made from stir casting with 6-weight percent ZrO2 as the reinforcement and varying graphite percentages of 2, 3, and 4 wt%. Then they were machined in WEDM using L27 OA to seek the best parameters for machining by adjusting the input parameters. The findings were analysed by means of grey relation analysis (GRA) to achieve the supreme material removal rate (MRR), lowest surface roughness (SR), and a smaller kerf width (Kw) simultaneously. GRA determines the impact of the machining variables on the standard characteristics and tests the impact of the machining parameters. Confirmation experiments were performed finally to acquire the best findings. The experimental findings and GRA show that the ideal process conditions for achieving the highest grey relational grade (GRG) are 6% ZrO2 with 2% graphite reinforcement, a wire feed of 6 m/min, a pulse off time (Toff) of 40 µs, a pulse on time (Ton) of 110 µs, and a gap voltage (GV) of 20 V. The gap voltage (22.87%) has the greatest impact on the GRG according to analysis of variance (ANOVA), subsequent to the interaction between the pulse on time and the gap voltage (16.73%), pulse on time (15.28%), and pulse off time (14.42%). The predicted value of the GRG is 0.679; however, the experimental GRG value is 0.672. The values are well-aligned between the expected and the experimental results. The error is only 3.29%, which is really little. Finally, mathematical models were created for each response.
Heterogeneity in La Distribution in Highly La-Doped SrTiO3 Crystals
Authors: Pilch Michał Marek , Rodenbücher Christian , Krok Franciszek , Szot Kristof
Published: October 2023

Our paper is focused on the investigation of the dopant distribution in lanthanum-doped strontium titanate (LSTO) single crystals with a 5 wt.% doping level of La. Using X-ray diffraction analysis and pycnometric density measurement, we have found a discrepancy between the theoretical density and the experimentally determined value. The origin of this behavior could be either the creation of the voids in the matrix or the intergrowth of secondary phases with La surplus in the crystal. Transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and selected area diffraction (SAD) microscopic investigation have confirmed the second hypothesis, namely, that in different regions of LSTO, the local concentration of La shows a substantial variation on the micro- and nanoscopic scale. In order to study the influence of the La dopants on the electronic structure and, therefore, on the electrical conductivity, we have used the local conductivity atomic force microscopy (LCAFM) method as a local electrical probe to map the in-plane electrical conductivity of the La-doped crystal’s surface. The LCAFM conductivity maps reveal heterogeneous conductivity (here in the form of the bands with higher conductivity than the surroundings), related to band-like inhomogeneities of the La distribution. Using LCAFM measurements with atomic resolution obtained between the conducting and nonconducting regions, we analyzed the spreading (spatial expansion) of doping on the undoped or low-doped part of the STO crystal. The found limitation of the doping effect of La on the dielectric part of the STO crystal to 4–5 lattice constants was in good correlation with ab initio studies from the literature.
The Ultrasound-Assisted Preparation of Crystal Seeds for the Hydrolysis of TiOSO4 to H2TiO3
Authors: Lu Ruifang , Li Feifan , Li Xianglan , Dong Lichun
Published: October 2023

The hydrolysis of an industrial titanyl sulfate (TiOSO4) solution to metatitanic acid (H2TiO3) is the crucial step in the production of titanium dioxide (TiO2) using the sulfuric acid process, and the extra-adding seeded route is generally adopted in industry, in which the quality of the crystal seeds plays a critical role. In this study, the optimal process conditions for preparing the crystal seeds via the NaOH neutralization method were first investigated. Then, the ultrasound-assisted preparation of crystal seeds was studied to explore the effect of the ultrasonic time and intensity on the particle size and particle size distribution of crystal seeds. The results demonstrated that ultrasonic assistance is helpful in obtaining crystal seeds with smaller particle sizes and more uniform particle size distribution, and the quality of the hydrolysis product of H2TiO3, i.e., the particle size and its distribution, is strictly correlated with those of the crystal seeds. Under the optimal process conditions for preparing the hydrolytic seeds, the average particle of the hydrolytic seeds prepared without ultrasonic assistance is 25.50 nm. In contrast, the introduction of ultrasonic assistance in the preservation stage could significantly decrease the particle size and narrow the particle size distribution of the hydrolytic seeds. When the ultrasonic time is 4 min and the ultrasonic intensity is 40 W, the average particle of the hydrolytic seeds is decreased to 23.48 nm. Therefore, the quality of the crystal seeds, as well as that of H2TiO3 products, could be significantly improved by introducing ultrasonic assistance with a suitable intensity at a suitable time in the preparation process of crystal seeds via the NaOH neutralization method.
Colorectal Cancer in Individuals with Cirrhosis: A Population-Based Study Assessing Practice Patterns, Outcomes, and Predictors of Survival
Authors: Patel Sunil , Brennan Kelly , Zhang Lisa , Djerboua Maya , Nanji Sulaiman , Merchant Shaila , Flemming Jennifer
Published: October 2023

Those with cirrhosis who develop colorectal cancer (CRC) are an understudied group who may tolerate treatments poorly and are at risk of worse outcomes. This is a retrospective cohort study of 842 individuals from Ontario, Canada, with a pre-existing diagnosis of cirrhosis who underwent surgery for CRC between 2009 and 2017. Practice patterns, overall survival, and short-term morbidity and mortality were assessed. The most common cirrhosis etiology was non-alcoholic fatty liver disease (NAFLD) (52%) and alcohol-associated liver disease (29%). The model for end-stage liver disease score (MELD-Na) was available in 42% (median score of 9, IQR7-11). Preoperative radiation was used in 62% of Stage II/III rectal cancer patients, while postoperative chemotherapy was used in 42% of Stage III colon cancer patients and 38% of Stage II/III rectal cancer patients. Ninety-day mortality following surgery was 12%. Five-year overall survival was 53% (by Stages I–IV, 66%, 55%, 50%, and 11%, respectively). Those with alcohol-associated cirrhosis (HR 1.8, 95% CI 1.5–2.2) had lower survival than those with NAFLD. Those with a MELD-Na of 10+ did worse than those with a lower MELD-Na score (HR 1.9, 95% CI 1.4–2.6). This study reports poor survival in those with cirrhosis who undergo treatment for CRC. Caution should be taken when considering aggressive treatment.
Optimal Age at First Calving in Pasture-Based Dairy Systems
Authors: Vargas-Leitón Bernardo , Romero-Zúñiga Juan José , Castillo-Badilla Gloriana , Saborío-Montero Alejandro
Published: October 2023

The age at first calving (AFC) is one of the most used indicators to evaluate the efficiency of rearing systems in dairy herds. The objective of the present study was to evaluate the association between AFC and different parameters of productive and reproductive efficiency in dairy cows of Holstein and Jersey breeds and their crosses, reared under pasture-based conditions. A retrospective longitudinal study was carried out with information on the performance of 77,311 cows with birth and culling dates between 1990 and 2016 from 654 specialized dairy herds located in mid and high-altitude regions of Costa Rica. Cows were classified into five classes according to their age in months at first calving (≤24, 25–27, 28–30, 31–33, ≥34). A generalized linear mixed model was used to assess the effect of AFC and breed factors on milk production (first lactation, lifetime total, and per day of life), open period (first calving and lifetime total), and herd life. The mean AFC was 29.5, 29.1, and 28.0 months for Holstein, Holstein × Jersey, and Jersey, respectively. The AFC was significantly associated (p < 0.01) with all the variables evaluated. Cows with AFC ≤ 24 presented a higher (p < 0.01) milk production (total lifetime and per day of life), as well as a longer herd life, compared to cows in classes of AFC > 28 m. The reduction in AFC contributes to a significant increase in the production and reproduction efficiency of pasture-based dairy herds. This effect was consistent across the three breed groups.
The Significance of FilmArray Blood Culture Identification Panel (FA-BCID) for Managing Patients with Positive Blood Cultures
Authors: Widyasari Kristin , Lee Seungjun , Cho Oh-Hyun , Hong Sun-In , Ryu Byung-Han , Kim Sunjoo
Published: October 2023

We analyzed the accuracy and time efficiency of the FilmArray blood culture identification (FA-BCID) panel in identifying the pathogens in positive blood cultures. Two-hundred and seventy-two individuals were randomly assigned as the control (n = 212) and FA-BCID (n = 60) groups participating in this study. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used to assess the control group. Meanwhile, the FA-BCID group was evaluated using both FA-BCID and MALDI-TOF, and the results were compared. The identification results from 73% (44/60) of the blood samples demonstrated agreement between FA-BCID and MALDI-TOF. The FA-BCID panel detected mecA genes in seven Staphylococcus species; six cases were confirmed using antimicrobial susceptibility testing. In addition, KPC genes were detected in one Escherichia coli and one Klebsiella pneumoniae, although only the latter corresponded with the result from antimicrobial susceptibility testing. The turnaround time (TAT) for identification through FA-BCID was shorter, with a median of 3.6 [2.4–4.6] hours (p < 0.05). No significant differences in the clinical and microbial outcomes following the ASP were observed between FA-BCID and MALDI-TOF. These results suggest that the FA-BCID panel provides an identification result that is as reliable as that provided by the routine identification procedure but with shorter TAT; thus, the FA-BCID method is considered an effective and beneficial method for therapeutic decision making and the improvement of the ASP for patients with bloodstream infection.
Progressive Lower Extremity Paralysis Caused by Intrathecal MTX-Induced Myelopathy Mimicking Guillain–Barre Syndrome: A Case Report
Authors: Lee Eun Chae , Lee Dong Gyu
Published: October 2023

Methotrexate (MTX) is commonly used in intrathecal chemotherapy for patients with acute lymphocytic leukemia (ALL) to prevent central nervous system (CNS) involvement. However, the use of MTX-based chemotherapy can lead to rare yet severe complications, such as MTX-induced myelopathy. Here, we report the case of MTX-induced myelopathy initially misdiagnosed as Guillain–Barre syndrome, leading to a delay in diagnosis and treatment. We present a case of a 39-year-old male with a history of B-cell acute lymphoblastic leukemia (B-ALL) who experienced bilateral foot paresthesia and progressive lower extremity weakness after intrathecal methotrexate (MTX) treatment. Initially, the patient was suspected as having Guillain–Barre syndrome (GBS) due to similar clinical features and nerve conduction studies. The patient received intravenous immunoglobulin (IVIG) treatment, but his condition worsened. T2-weighted images of the thoracic spinal cord revealed high signal intensity in both lateral and posterior columns, typically associated with subacute combined degeneration. However, elevated vitamin B12 levels ruled out SCD in this case. Based on the aforementioned findings, intrathecal methotrexate-induced myelopathy was diagnosed. This case highlights the diagnostic challenge posed by the similarity in clinical presentation between MTX-induced myelopathy and GBS. Differentiating between these conditions is critical for appropriate management. Prompt recognition and treatment with folate metabolism compounds may mitigate neurological sequelae.
Colorectal Endoscopic Submucosal Dissection: Performance of a Novel Hybrid-Technology Knife in an Animal Trial
Authors: Jacques Jérémie , Neuhaus Horst , Enderle Markus D. , Biber Ulrich , Linzenbold Walter , Schenk Martin , Khalaf Kareem , Repici Alessandro
Published: October 2023

Endoscopic submucosal dissection (ESD) was developed for the removal of benign and early malignant lesions in the gastrointestinal tract. We aimed to evaluate the performance and safety of a novel high-pressure waterjet-assisted ESD knife in colorectal applications. Six female German Landrace pigs with an average weight of 62 kg (range 60–65 kg) were used in this prospective, randomized, and controlled study. Twenty-four ESDs were performed by three endoscopists: Twelve each with the new Erbe HYBRIDknife® flex T-Type (HK-T) and the Olympus DualKnife® J (DK-J), including six rectal and six colonic ESDs per instrument. The order of performance was randomized regarding anatomic position and instrument. As the primary endpoint, ESD knife performance characteristics were combined and rated on a 5-point Likert scale, with 5 Likert points (LP) representing the best response (5 = very good). The HK-T was rated significantly better than the DK-J (4.7 LP versus 4.4 LP, p = 0.0295), mainly because of HK-T injection ability (5 LP versus 3 LP, p < 0.0001) and hemostasis (5 LP versus 4 LP, p = 0.0452). There was no difference in procedure time (HK-T: 35 min versus DK-J: 34 min, p = 0.8005), resection diameter (3.1 cm versus 2.8 cm, p = 0.3492), injection volume (41 mL versus 46 mL, p = 0.5633), and complication rates. HK-T is as effective as DK-J in colorectal ESD in terms of dissection quality but has better injection and hemostatic properties. The impact of these technical advantages on the ESD treatment of patients with large superficial colorectal lesions remains to be clinically verified.
Quantum Phase Transitions in a Generalized Dicke Model
Authors: Liu Wen , Duan Liwei
Published: October 2023

We investigate a generalized Dicke model by introducing two interacting spin ensembles coupled with a single-mode bosonic field. Apart from the normal to superradiant phase transition induced by the strong spin–boson coupling, interactions between the two spin ensembles enrich the phase diagram by introducing ferromagnetic, antiferromagnetic and paramagnetic phases. The mean-field approach reveals a phase diagram comprising three phases: paramagnetic–normal phase, ferromagnetic–superradiant phase, and antiferromagnetic–normal phase. Ferromagnetic spin–spin interaction can significantly reduce the required spin–boson coupling strength to observe the superradiant phase, where the macroscopic excitation of the bosonic field occurs. Conversely, antiferromagnetic spin–spin interaction can strongly suppress the superradiant phase. To examine higher-order quantum effects beyond the mean-field contribution, we utilize the Holstein–Primakoff transformation, which converts the generalized Dicke model into three coupled harmonic oscillators in the thermodynamic limit. Near the critical point, we observe the close of the energy gap between the ground and the first excited states, the divergence of entanglement entropy and quantum fluctuation in certain quadrature. These observations further confirm the quantum phase transition and offer additional insights into critical behaviors.
A Fluid Perspective of Relativistic Quantum Mechanics
Authors: Yahalom Asher
Published: October 2023

In previous papers, it has been shown how Schrödinger’s equation which includes an electromagnetic field interaction can be deduced from a fluid dynamical Lagrangian of a charged potential flow that interacts with an electromagnetic field. The quantum behaviour is derived from Fisher information terms added to the classical Lagrangian, showing that a quantum mechanical system is driven by information and not only electromagnetic fields. This program was applied to Pauli’s equations by removing the restriction of potential flow and using the Clebsch formalism. Although the analysis was quite successful, there were terms that did not admit interpretation, a number of which can be easily traced to the relativistic Dirac theory. Here, this analysis is repeated for a relativistic flow, pointing to a new approach for deriving relativistic quantum mechanics.
A Novel Intelligent Fault Diagnosis Method for Self-Priming Centrifugal Pumps
Authors: Zhang Bo , Wang Zhenya , Yao Ligang , Luo Biaolin
Published: October 2023

The real-time diagnostic monitoring of self-priming centrifugal pumps is essential to ensure their safe operation. Nevertheless, owing to the intricate structure and complex operational conditions inherent in such pumps, existing fault diagnosis methods encounter challenges in effectively extracting crucial fault feature information and accurately identifying fault types. Consequently, this paper introduces an intelligent fault diagnosis method tailored for self-priming centrifugal pumps. The approach amalgamates refined time-shift multiscale fluctuation dispersion entropy, cosine pairwise-constrained supervised manifold mapping, and adaptive chaotic Aquila optimization support vector machine techniques. To begin with, refined time-shift multiscale fluctuation dispersion entropy is employed to extract fault-related features, adeptly mitigating concerns related to entropy domain deviations and instability. Subsequently, the application of cosine pairwise-constrained supervised manifold mapping serves to reduce the dimensionality of the extracted fault features, thereby bolstering the efficiency and precision of the ensuing identification process. Ultimately, the utilization of an adaptive chaotic Aquila optimization support vector machine facilitates intelligent fault classification, leading to enhanced accuracy in fault identification. The experimental findings unequivocally affirm the efficacy of the proposed method in accurately discerning among various fault types in self-priming centrifugal pumps, achieving an exceptional recognition rate of 100%. Moreover, it is noteworthy that the average correct recognition rate achieved by the proposed method surpasses that of five existing intelligent fault diagnosis techniques by a significant margin, registering a notable increase of 15.97%.
Perception of Sports Science Students in Higher Education on Basic Digital Competences: Spanish Case
Authors: García-Tascón Marta , Meroño Lourdes , Maciá-Andreu María-José , Abenza-Cano Lucía , Gallardo Ana-María
Published: October 2023

In order to improve the teaching–learning process at the university level, it is essential to consolidate students’ digital competences (DCs) during their initial training. This development is analysed in the area of sports management as part of the physical activity and sports science (CAFyD) bachelor’s degree. Students (n = 236) from private (n = 120) and public (n = 116) universities participated by completing the COBADI questionnaire (registered trademark: 2970648®), structured into three dimensions: (I) Competences in knowledge and use of ICTs in social communication and collaborative learning; (II) competences in the use of ICT for information search and processing; and (III) virtual and social communication tools of the university. Likert scale responses ranged from 1 to 4 points. The results show significant differences in terms of the type of university. In terms of gender, females have a better digital perception, with a significant difference (… I know how to use programs…). This pioneering research is of relevance for higher education professors in the field of sports, as it helps to detect areas where students lack DCs and engages them in the enhancement of their learning.
The Concentrator for Single-Phase Inverters with Three-Phase Output Using Magnetically Coupled Reactors
Authors: Muc Adam , Kasprowicz Andrzej , Mysiak Piotr
Published: October 2023

This paper presents a passive concentrator for single-phase inverters with a three-phase output, which uses magnetically coupled reactors. Due to the development of renewable energy systems, the proposed systems may enable the easier integration of converters in the form of inverters with the power system. Two variants of cooperation of the concentrator with single-phase voltage inverters were considered. The first variant proposed a system topology in which three single-phase full-bridge inverters were connected to the concentrator, while the other variant proposed six half-bridge inverters. A control system of the inverters that does not use PWM was developed. A common star point was created for the supply voltages in the form of a capacitive divider covering all the inverters. An analysis of the concentrator system was presented, taking into account the cooperation with inverters. The overall power of the TDSλ system was defined and the relationship for its determination was given. Simulation studies were described, presenting the obtained voltage and current waveforms. The impact of changing the supply voltage of the inverters on the operation of the concentrator and the shape of the output voltages was assessed. The proposed systems allow you to connect 3 or 6 single-phase inverters. The use of magnetically coupled reactors enables the use of a magnetic system of lower power and size. The described concentrators enable the generation of multi-level three-phase output voltage with a low THD content.
Soil Microbial Community and Their Relationship with Soil Properties across Various Landscapes in the Mu Us Desert
Authors: Wang Lihua , Li Xuewu
Published: October 2023

Soil microorganisms play crucial roles in maintaining material circulation and energy flow in desert ecosystems. However, the structure and function of soil microorganisms in different forestlands are currently unclear, restricting the use of sand-fixing plants and the understanding of forest ecosystem functions. In this study, Artemisia ordosica, Caragana korshinskii, and Salix psammophila, three types of sand-fixing forests widely distributed in the Mu Us Sandy Land, were used to explore the effects of sand-fixing forests on soil physicochemical properties, soil enzyme activity, soil microbial biomass, microbial community structure, and inter-microbial species relationships. Soils of forestlands showed higher soil organic carbon (SOC), total phosphorus (TP), and total nitrogen (TN) contents than bare sandy land. The SOC in bare sandy soil was only 0.84 g kg−1, while it remained 1.55–3.46 g kg−1 in forestland soils. The TN in bare sandy land soil was 0.07 g kg−1, which was significantly lower than that in forestland soils (0.35–0.51 g kg−1). The TP in bare sandy soil was 0.18 g kg−1, significantly lower than that in forestland soils (0.46–0.69 g kg−1). Afforestation of bare sandy land improved soil microbial carbon and nitrogen contents and increased microbial enzyme activities of acid phosphatase and N-acetyl-β-D-glucosaminidase. Significant differences were observed between the three forestlands and bare sandy land in terms of soil microorganisms and community composition. With the establishment of a sand-fixing forest, the alpha diversity of soil bacteria significantly improved, whereas that of soil fungi remained stable. The bacterial community comprised 33 phyla, 106 classes, 273 orders, 453 families, and 842 genera. While five fungal phyla were detected by OTUs at a similarity of 97%, bacterial and fungal community structures were affected by the organic carbon content, sand particle content, soil pH, total nitrogen, and total phosphorus contents of soils. This study is helpful for vegetation construction and protection on sandy lands from the perspective of plant-microbe interactions.
Nocturnal Water Use Partitioning and Its Environmental and Stomatal Control Mechanism in Caragana korshinskii Kom in a Semi-Arid Region of Northern China
Authors: Li Wei , Zhang Yu , Wang Nan , Liang Chen , Xie Baoni , Qin Zhanfei , Yuan Ying , Cao Jiansheng
Published: October 2023

As an important aspect of plant water consumption, nocturnal water use (En) behavior provides reliable information on the effect of plantation carbon and water budgets at stand and regional scales. Therefore, quantifying En and its environmental and stomatal controlling mechanisms is urgent to establish adaptation strategies for plantation management in semiarid regions. With the help of the sap flow technique, our study investigated the seasonal variations in canopy transpiration and canopy conductance in a Caragana korshinskii Kom plantation. Environmental variables were measured concurrently during the growing seasons of 2020 and 2021. The results indicated that the average En values were 0.10 mm d−1 and 0.09 mm d−1, which accounted for 14% and 13% of daily water use, respectively, over two years. The proportions of nocturnal transpiration (Tn) to En were approximately 49.76% and 54.44%, while stem refilling (Re) accounted for 50.24% and 45.56% of En in 2020 and 2021, respectively, indicating that C. korshinskii was able to draw on stored stem water to support transpiration. En was predominantly affected by nocturnal canopy conductance (Gc–n), air temperature (Ta–n) and wind speed (u2-n). In contrast, Gc–n and Ta–n explained the highest variation in Tn and nocturnal vapor pressure (VPDn), and u2-n explained the highest variation in Re. Total effects of the five environmental and stomatal variables explained 50%, 36% and 32% of En, Tn and Re variation, respectively. These findings could enable a better understanding of nocturnal water use dynamics and their allocation patterns in C. korshinskii plantations on the Bashang Plateau. Moreover, our results reveal the water use strategies of artificial shrubs and highlight the importance of incorporating nocturnal water use processes into large-scale ecohydrological models in semiarid regions.
Analysis of Genetic Diversity and Construction of a Core Collection of Ginkgo biloba Germplasm Using EST-SSR Markers
Authors: Yao Zhi , Feng Zhi , Wu Chunwen , Tang Longping , Wu Xiuzhong , Chen Dahua , Wang Qiye , Fan Kaifang , Wang Yiqiang , Li Meng
Published: October 2023

Understanding genetic diversity and population structure is essential for the conservation and utilization of germplasm. Ginkgo biloba L. is a medicinal, edible and ornamental tree species. Detailed knowledge of genetic variability and diversity in different Ginkgo germplasm resources is still scarce. In this study, a total of 173,160 Expressed Sequence Tag Simple Sequences Repeat (EST-SSR) loci were derived from 43,073 Unigenes of the Ginkgo genome. A total of 43,731 pairs of specific primers were designed for the EST-SSR loci, with sequence lengths >20 bp, and 100 of the SSR primers were randomly selected. Among these, 20 EST-SSR markers were verified and used to assess the genetic diversity of 101 Ginkgo individuals collected from different regions. The average values for Shannon’s diversity index (I, 0.993), expected heterozygosity (0.566) and Nei’s genetic diversity index (H, 0.563) indicate a high level of genetic diversity of Ginkgo populations. Based on the EST-SSR markers, a core collection of Ginkgo germplasm comprising 27 genetic resources was constructed. The retention rates of the number of resources, the number of alleles, the number of effective alleles, the I index, the H index and the percentage of polymorphic loci of the constructed core collection are 26.73%, 95.29%, 103.43%, 102.25%, 102.91% and 100.00%, respectively. The molecular markers developed in this study are an effective tool for Ginkgo genetic diversity analysis and will facilitate the future breeding of this species.
FireViT: An Adaptive Lightweight Backbone Network for Fire Detection
Authors: Shen Pengfei , Sun Ning , Hu Kai , Ye Xiaoling , Wang Pingping , Xia Qingfeng , Wei Chen
Published: October 2023

Fire incidents pose a significant threat to human life and property security. Accurate fire detection plays a crucial role in promptly responding to fire outbreaks and ensuring the smooth execution of subsequent firefighting efforts. Fixed-size convolutions struggle to capture the irregular variations in smoke and flames that occur during fire incidents. In this paper, we introduce FireViT, an adaptive lightweight backbone network that combines a convolutional neural network (CNN) and transformer for fire detection. The FireViT we propose is an improved backbone network based on MobileViT. We name the lightweight module that combines deformable convolution with a transformer as th DeformViT block and compare multiple builds of this module. We introduce deformable convolution in order to better adapt to the irregularly varying smoke and flame in fire scenarios. In addition, we introduce an improved adaptive GELU activation function, AdaptGELU, to further enhance the performance of the network model. FireViT is compared with mainstream lightweight backbone networks in fire detection experiments on our self-made labeled fire natural light dataset and fire infrared dataset, and the experimental results show the advantages of FireViT as a backbone network for fire detection. On the fire natural light dataset, FireViT outperforms the PP-LCNet lightweight network backbone for fire target detection, with a 1.85% increase in mean Average Precision (mAP) and a 0.9 M reduction in the number of parameters. Additionally, compared to the lightweight network backbone MobileViT-XS, which similarly combines a CNN and transformer, FireViT achieves a 1.2% higher mAP while reducing the Giga-Floating Point Operations (GFLOPs) by 1.3. FireViT additionally demonstrates strong detection performance on the fire infrared dataset.
Impact of Simulated Acid Rain on Soil Base Cations Dissolution between Eucalyptus Pure Plantations and Eucalyptus–Castanopsis fissa Mixed Plantations
Authors: Wu Tong , Ullah Saif , Zhong Lianxiang , Xu Yuanyuan , Wei Guoyu , Yang Mei
Published: October 2023

The soils of Eucalyptus pure plantations and Eucalyptus–Castanopsis fissa mixed plantations were studied using soil column leaching experiments with acid solutions to mimic the effects of acid rain on the soils. This helped researchers learn more about how soil base ions react to acid deposition and their ability to protect the soil from excessive acidity under pure and mixed-species plantations. The results showed that acid rain leaching increased the leaching loss, desorption, and desorption rate of soil base ions while decreasing the soil pH value, adsorption, and adsorption rate of soil base ions. The soil pH value and the leaching loss ranges of K+, Na+, and Mg2+ were all greater in the pure plantations than in the mixed plantations, while the leaching range of Ca2+ was greater in the mixed plantation than in the pure plantations. In the two types of plantations, the adsorption rates of Ca2+ and Na+ in the mixed plantations were higher than in the pure plantations, while K+ and Mg2+ showed higher adsorption rates in the pure plantations than in the mixed plantations. Therefore, soil pH and base ions were greatly affected by the pH value of acid rain. Compared with the pure plantations, the establishment of Eucalyptus–Castanopsis fissa mixed plantations can slow soil acidification and leaching of K+, Na+, and Mg2+ and contribute to the adsorption of Ca2+ and Na+, which is beneficial for the soil nutrient fixation of Eucalyptus plantations. The mixed plantations were found to increase the exchange reaction between H+ and base ions, thereby improving the acid buffer performance of the soil. This, in turn, helped to mitigate the decline in soil fertility. Therefore, establishment of Eucalyptus–Castanopsis fissa mixed-species plantations can slow down the impact of acid rain on soil acidification in artificial plantation land to a certain extent and play an important role in optimizing the plantation structure of Eucalyptus stands and maintaining their productivity.
Who Prefers Legal Wood: Consumers with Utilitarian or Hedonic Shopping Values?
Authors: Larasatie Pipiet , Handrito Radityo Putro , Fitriastuti Triana , Sari Dhina Mustika
Published: October 2023

Although certification is perceived to be beneficial for enhancing forest sustainability and open access to green markets, certification practices in Indonesia face controversy, particularly in its wood-based industry. We aim to approach this issue from the end-user perspective. Drawing on the theories of value-belief-norm and planned behavior, we examine the psychological aspects of consumers toward legal wood consumption. A survey of 515 consumers showed that individuals with hedonic values tended to have a high perception of green values toward legal wood. Also, when consumers’ hedonic values dominated over their utilitarian consumption, their perception of green values toward legal wood tends to be higher. Based on these results, wood marketers could benefit from directing their communication efforts toward emphasizing the hedonic worth of the product, as opposed to its utilitarian values. It is imperative for distributors and promoters of wood products to carefully deliberate on strategies to effectively elicit the hedonic shopping values that are inherently linked to the utilization of such green products. An illustration can be represented by the case of IKEA in Indonesia. Consumers are probably attracted to IKEA’s neuromarketing strategy, such as their attractive display and labyrinth effect, without realizing that IKEA also applies green marketing and supports green products.
Managing Access to Confidential Documents: A Case Study of an Email Security Tool
Authors: Al Qahtani Elham , Javed Yousra , Tabassum Sarah , Sahoo Lipsarani , Shehab Mohamed
Published: October 2023

User adoption and usage of end-to-end encryption tools is an ongoing research topic. A subset of such tools allows users to encrypt confidential emails, as well as manage their access control using features such as the expiration time, disabling forwarding, persistent protection, and watermarking. Previous studies have suggested that protective attitudes and behaviors could improve the adoption of new security technologies. Therefore, we conducted a user study on 19 participants to understand their perceptions of an email security tool and how they use it to manage access control to confidential information such as medical, tax, and employee information if sent via email. Our results showed that the participants’ first impression upon receiving an end-to-end encrypted email was that it looked suspicious, especially when received from an unknown person. After the participants were informed about the importance of the investigated tool, they were comfortable sharing medical, tax, and employee information via this tool. Regarding access control management of the three types of confidential information, the expiration time and disabling forwarding were most useful for the participants in preventing unauthorized and continued access. While the participants did not understand how the persistent protection feature worked, many still chose to use it, assuming it provided some extra layer of protection to confidential information and prevented unauthorized access. Watermarking was the least useful feature for the participants, as many were unsure of its usage. Our participants were concerned about data leaks from recipients’ devices if they set a longer expiration date, such as a year. We provide the practical implications of our findings.