bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-Healing Properties of Asphalt Concrete with Calcium Alginate Capsules Containing Different Healing Agents
Authors: Wang Huoming , Yuan Miao , Wu Jie , Wan Pei , Liu Quantao
Published: August 2022

Calcium alginate capsules encapsulating rejuvenator are a promising self-healing technology for asphalt pavement, but the effects of different healing agents on the self-healing performance of asphalt concrete has not been considered. In view of this, this paper aimed at exploring the effects of calcium alginate capsules containing different healing agents on the self-healing properties of asphalt concrete. Three types of capsules with sunflower oil, waste cooking oil and commercial rejuvenator were fabricated via the orifice-coagulation bath method and the interior structure, mechanical strength, thermal stability and oil content of the prepared capsules were characterized. The healing levels of asphalt mixtures with different capsules under different loading cycles and stress levels were evaluated. Furthermore, the saturates, aromatics, resins and asphaltenes (SARA) fractions and rheological property of extracted asphalt binder within test beams with different capsules after different loading conditions were assessed. The results indicated that all the three types of capsules meet the mechanical and thermal requirement of mixing and compaction of asphalt mixtures. The healing levels of test beams containing vegetable oil capsules were higher than that of waste cooking oil capsules and industrial rejuvenator capsules. The strength recovery ratio and fracture energy recovery ratio of test beams with vegetable oil capsules reached 82.8% and 96.6%, respectively, after 20,000 cycles of compressive loading at 1.4 MPa. The fracture energy recovery ratio of the waste cooking oil capsules also reached as high as 90%, indicating that waste cooking oil can be used as the healing agent of calcium alginate capsules to improve the self-healing property of asphalt mixture. This work provides a significant guide for the selection of healing agent for self-healing capsules in the future.
Study of Structural and Strength Changes in Lithium-Containing Ceramics—Potential Blanket Materials for Nuclear Power, Subjected to High-Dose Proton Irradiation
Authors: Berguzinov Askhat , Kozlovskiy Artem L. , Khametova Ainagul A. , Shlimas Dmitriy I.
Published: August 2022

The paper considers the hydrogenation processes in Li2TiO3 ceramics under irradiation with protons with an energy of 500 keV and fluences of 1 × 1010–5 × 1017 ion/cm2. The choice of the type of irradiation, as well as the irradiation fluences, is based on the possibilities of modeling hydrogenation processes and studying the kinetics of structural changes caused by the accumulation of radiation damage. The choice of Li2TiO3 ceramics as objects of research is due to their prospects for using as blanket materials of thermonuclear reactors for the tritium production and accumulation. It was found that the formation of point defects and their subsequent evolution associated with the formation of complex compounds and the filling of pores, followed by the formation of gas-filled bubbles, the presence of which leads to a decrease in crack resistance and resistance to destruction of the near-surface layer. Based on the data on structural changes and evolution of the crystal lattice parameters, its swelling, a description of the destruction processes associated with hydrogenation in Li2TiO3 ceramics was proposed. Also, during the studies, it was found that at irradiation fluences above 1 × 1017 ion/cm2, the appearance of impurity inclusions characteristic of the TiO2 phase was observed, the presence of which indicates the crystal lattice destruction processes because of accumulation of radiation damage and deformations caused by them. Critical doses are established at which there is a sharp deterioration in strength and crack resistance, reflecting the resistance of ceramics to mechanical external influences.
Use of Zeolites in the Capture and Storage of Thermal Energy by Water Desorption—Adsorption Cycles
Authors: de Gennaro Bruno , Cappi Angelo , de Gennaro Maurizio , Bianco Nicola , Langella Alessio , Cappelletti Piergiulio , Marocco Antonello , Aprea Paolo , Pansini Michele
Published: August 2022

In this work, four zeolite-bearing materials (three naturally occurring and one of synthetic origin) were considered for thermal energy capture and storage. Such materials can store thermal energy as heat of desorption of the water present therein, heat that is given back when water vapor is allowed to be re-adsorbed by zeolites. This study was carried out by determining the loss of water after different activation thermal treatments, the water adsorption kinetics and isotherm after an activation step of the zeolites, the intergranular and intragranular porosity, and the thermal conductivity of the zeolite-bearing materials. Moreover, the thermal stability of the framework of the zeolites of the four materials tested was investigated over a large number of thermal cycles. The results indicate that zeolite 13X was the most suitable material for thermal energy storage and suggest its use in the capture and storage of thermal energy that derives from thermal energy waste.
Analysis of the Effect of Component Ratio Imbalances on Selected Mechanical Properties of Seasoned, Medium Viscosity Bone Cements
Authors: Szabelski Jakub , Karpiński Robert , Krakowski Przemysław , Jojczuk Mariusz , Jonak Józef , Nogalski Adam
Published: August 2022

The paper presents the results of experimental strength tests of specimens made of two commercially available bone cements subjected to compression, that is a typical variant of load of this material during use in the human body, after it has been used for implantation of prostheses or supplementation of bone defects. One of the factors analysed in detail was the duration of cement seasoning in Ringer’s solution that simulates the aggressive environment of the human body and material degradation caused by it. The study also focused on the parameters of quantitative deviation from the recommended proportions of liquid (MMA monomer, accelerator and stabiliser) and powder (PMMA prepolymer and initiator) components, i.e., unintentional inaccuracy of component proportioning at the stage of cement mass preparation. Statistical analysis has shown the influence of these factors on the decrease in compressive strength of the cements studied, which may be of significant importance in operational practice.
Analysis of E-Scooter Vibrations Risks for Riding Comfort Based on Real Measurements
Authors: Cano-Moreno Juan David , Cabanellas Becerra José María , Arenas Reina José Manuel , Islán Marcos Manuel Enrique
Published: August 2022

Means of transport should be able to fulfil their main function safely and comfortably for travellers and drivers. The effects of vibrations on ride comfort are in the frequency range of 0.5 to 80 Hz and can be analysed using the UNE-2631 standard. This type of analysis has been conducted for several means of transport (bicycles, motorcycles, cars, trucks, etc.), but the literature on e-scooter comfort is very scarce. Existing research describes methodologies, simulation models, and a few measurements related to e-scooter comfort. This paper presents, for the first time, a comfort analysis using an Arduino-based data acquisition system at a sampling frequency of 200 Hz (higher than that in previous studies). Acceleration and speed measurements were obtained by sensorising an e-scooter with inflated wheels without any additional damping systems, which is one of the commonly used e-scooter types. In this study, the comfort for two different speeds (20 and 28 km/h), two types of pavements (pavers and asphalt), and two drivers with different weights was investigated. The results indicate the lowest comfort values for higher velocities and paver pavement. Furthermore, the comfort values were extremely low for all scenarios. In addition, the results demonstrate the necessity of using a sampling rate of at least 80 Hz for this e-scooter model.
Asteroids and Their Mathematical Methods
Authors: Jiang Yu , Ni Yanshuo , Baoyin Hexi , Li Junfeng , Liu Yongjie
Published: August 2022

In this paper, the basic classification of asteroids and the history and current situation of asteroid exploration are introduced. Furthermore, some recent research progress on the orbital dynamics of asteroids, including models of the gravitational potential field, the dynamics near asteroids, hopping motion on the surface, and bifurcations under varying external parameters, is reviewed. In the meanwhile, the future research development such as the configuration and evolution of binary or triple asteroid systems and near-Earth asteroid defense is briefly discussed.
The Kinematics of a Bipod R2RR Coupling between Two Non-Coplanar Shafts
Authors: Alaci Stelian , Doroftei Ioan , Ciornei Florina-Carmen , Romanu Ionut-Cristian , Doroftei Ioan Alexandru
Published: August 2022

The paper presents a new solution for motion transmission between two shafts with non-intersecting axes. The structural considerations fundament the existence in the structure of the mechanism of three revolute pairs and a bipod contact. Compared to classical solutions, where linkages with cylindrical pairs are used, our solution proposes a kinematical chain also containing higher pairs. Due to the presence of a higher pair, the transmission is much simpler, the number of elements decreases, and as a consequence, the kinematical study is straightforward. Regardless, the classical analysis of linkages cannot be applied because of the presence of the higher pair. For the proposed spatial coupling, the transmission ratio is expressed as a function of constructive parameters. The positional analysis of the mechanism cannot be performed using the Hartenberg–Denavit method due to the presence of a bipod contact, and instead, the geometrical conditions of existence for the bipod contact are applied. The Hartenberg–Denavit method requires the replacement of the bipodic coupling with a kinematic linkage with cylindrical (revolute and prismatic) pairs, resulting in complicated analytical calculus. To avoid this aspect, the geometrical conditions required by the bipod coupling were expressed in vector form, and thus, the calculus is significantly reduced. The kinematical solution for the proposed transmission can be obtained in two ways: first, by considering the equivalent transmission containing only cylindrical pairs and applying the classical analysis methods; second, by directly expressing the condition of definition for the higher pairs (bipodic pair) in vector form. The last method arrives at a simpler solution for which analytical relations for the positional parameters are obtained, with one exception where numerical calculus is needed (but the precision of this parameter is controlled). The analytical kinematics results show two possibilities of building the actual mechanism with the same constructive parameters. The rotation motions from the revolute pairs, internal and driven, and the motions from the bipod joint were obtained through numerical methods since the equations are very intricate and cannot be solved analytically. The excellent agreement validates the theoretical solutions obtained and the possibility of applying such mechanisms in technical applications. The constructive solution exemplified here is simple and robust.
Integral Representation and Asymptotic Expansion for Hypergeometric Coherent States
Authors: Pereskokov Alexander
Published: August 2022

An integral representation is found for hypergeometric coherent states. It contains a generalized hypergeometric function. An asymptotic expansion of hypergeometric coherent states near z=1 is constructed. This expansion is used to find asymptotic eigenfunctions of the Hamiltonian of the hydrogen atom in a magnetic field near the lower boundaries of spectral clusters.
Event-Triggered Non-PDC Filter Design of Fuzzy Markovian Jump Systems under Mismatch Phenomena
Authors: Nguyen Khanh Hieu , Kim Sung Hyun
Published: August 2022

This paper focuses on dealing with the problem of co-designing a fuzzy-basis-dependent event generator and an asynchronous filter of fuzzy Markovian jump systems via event-triggered non-parallel distribution compensation (non-PDC) scheme. The introduction of the event-triggered non-PDC scheme can reduce the number of real-time filter gain design operations with a large computational load. Furthermore, to perform an effective relaxation process, several kinds of time-varying parameters in filter design conditions are simultaneously relaxed by utilizing two zero equalities of transition probabilities and mismatch errors. In addition, to improve the considered performance, the event generation function is established based on fuzzy-basis-dependent event weighting matrices.
A Methodology for Obtaining the Different Convergence Orders of Numerical Method under Weaker Conditions
Authors: Argyros Ioannis K. , Regmi Samundra , Shakhno Stepan , Yarmola Halyna
Published: August 2022

A process for solving an algebraic equation was presented by Newton in 1669 and later by Raphson in 1690. This technique is called Newton’s method or Newton–Raphson method and is even today a popular technique for solving nonlinear equations in abstract spaces. The objective of this article is to update developments in the convergence of this method. In particular, it is shown that the Kantorovich theory for solving nonlinear equations using Newton’s method can be replaced by a finer one with no additional and even weaker conditions. Moreover, the convergence order two is proven under these conditions. Furthermore, the new ratio of convergence is at least as small. The same methodology can be used to extend the applicability of other numerical methods. Numerical experiments complement this study.
Novel Labdane Diterpenes-Based Synthetic Derivatives: Identification of a Bifunctional Vasodilator That Inhibits CaV1.2 and Stimulates KCa1.1 Channels
Authors: Carullo Gabriele , Saponara Simona , Ahmed Amer , Gorelli Beatrice , Mazzotta Sarah , Trezza Alfonso , Gianibbi Beatrice , Campiani Giuseppe , Fusi Fabio , Aiello Francesca
Published: August 2022

Sesquiterpenes such as leucodin and the labdane-type diterpene manool are natural compounds endowed with remarkably in vitro vasorelaxant and in vivo hypotensive activities. Given their structural similarity with the sesquiterpene lactone (+)-sclareolide, this molecule was selected as a scaffold to develop novel vasoactive agents. Functional, electrophysiology, and molecular dynamics studies were performed. The opening of the five-member lactone ring in the (+)-sclareolide provided a series of labdane-based small molecules, promoting a significant in vitro vasorelaxant effect. Electrophysiology data identified 7 as a CaV1.2 channel blocker and a KCa1.1 channel stimulator. These activities were also confirmed in the intact vascular tissue. The significant antagonism caused by the CaV1.2 channel agonist Bay K 8644 suggested that 7 might interact with the dihydropyridine binding site. Docking and molecular dynamic simulations provided the molecular basis of the CaV1.2 channel blockade and KCa1.1 channel stimulation produced by 7. Finally, 7 reduced coronary perfusion pressure and heart rate, while prolonging conduction and refractoriness of the atrioventricular node, likely because of its Ca2+ antagonism. Taken together, these data indicate that the labdane scaffold represents a valuable starting point for the development of new vasorelaxant agents endowed with negative chronotropic properties and targeting key pathways involved in the pathophysiology of hypertension and ischemic cardiomyopathy.
Evaluation of the Growth-Inhibitory Spectrum of Three Types of Cyanoacrylate Nanoparticles on Gram-Positive and Gram-Negative Bacteria
Authors: Sarian Fean Davisunjaya , Ando Kazuki , Tsurumi Shota , Miyashita Ryohei , Ute Koichi , Ohama Takeshi
Published: August 2022

The development of novel effective antibacterial agents is crucial due to increasing antibiotic resistance in various bacteria. Poly (alkyl cyanoacrylate) nanoparticles (PACA-NPs) are promising novel antibacterial agents as they have shown antibacterial activity against several Gram-positive and Gram-negative bacteria. However, the antibacterial mechanism remains unclear. Here, we compared the antibacterial efficacy of ethyl cyanoacrylate nanoparticles (ECA-NPs), isobutyl cyanoacrylate NPs (iBCA-NPs), and ethoxyethyl cyanoacrylate NPs (EECA-NPs) using five Gram-positive and five Gram-negative bacteria. Among these resin nanoparticles, ECA-NPs showed the highest growth inhibitory effect against all the examined bacterial species, and this effect was higher against Gram-positive bacteria than Gram-negative. While iBCA-NP could inhibit the cell growth only in two Gram-positive bacteria, i.e., Bacillus subtilis and Staphylococcus aureus, it had negligible inhibitory effect against all five Gram-negative bacteria examined. Irrespective of the differences in growth inhibition induced by these three NPs, N-acetyl-L-cysteine (NAC), a well-known reactive oxygen species (ROS) scavenger, efficiently restored growth in all the bacterial strains to that similar to untreated cells. This strongly suggests that the exposure to NPs generates ROS, which mainly induces cell growth inhibition irrespective of the difference in bacterial species and cyanoacrylate NPs used.
Modeling of Tensile Test Results for Low Alloy Steels by Linear Regression and Genetic Programming Taking into Account the Non-Metallic Inclusions
Authors: Kovačič Miha , Župerl Uroš
Published: August 2022

Štore Steel Ltd. is one of the biggest flat spring steel producers in Europe. The main motive for this study was to study the influences of non-metallic inclusions on mechanical properties obtained by tensile testing. From January 2016 to December 2021, all available tensile strength data (472 cases–472 test pieces) of 17 low alloy steel grades, which were ordered and used by the final user in rolled condition, were gathered. Based on the geometry of rolled bars, selected chemical composition, and average size of worst fields non-metallic inclusions (sulfur, silicate, aluminium and globular oxides), determined based on ASTM E45, several models for tensile strength, yield strength, percentage elongation, and percentage reduction area were obtained using linear regression and genetic programming. Based on modeling results in the period from January 2022 to April 2022, five successively cast batches of 30MnVS6 were produced with a statistically significant reduction of content of silicon (t-test, p < 0.05). The content of silicate type of inclusions, yield, and tensile strength also changed statistically significantly (t-test, p < 0.05). The average yield and tensile strength increased from 458.5 MPa to 525.4 MPa and from 672.7 MPa to 754.0 MPa, respectively. It is necessary to emphasize that there were no statistically significant changes in other monitored parameters.
Targeting Ferroptosis in Colorectal Cancer
Authors: Liang Xiaojie , You Zhihuan , Chen Xinhao , Li Jun
Published: August 2022

Ferroptosis is a unique way of regulating cell death (RCD), which is quite different from other programmed cell deaths such as autophagy. It presents iron overload, accumulation of reactive oxygen species (ROS), and lipid peroxidation. A ferroptotic cell usually has an intact cell structure as well as shrinking mitochondria with decreased or vanishing cristae, concentrated membrane density, and ruptured outer membrane. Recently, increasing investigations have discovered that tumor cells have a much greater iron demand than the normal ones, making them more sensitive to ferroptosis. In other words, ferroptosis may inhibit the progress of the tumor, which can be used in the therapy of tumor patients, especially for those with chemotherapy resistance. Therefore, ferroptosis has become one hot spot in the field of tumor research in recent years. Colorectal cancer (CRC) is one common type of gastrointestinal malignancy. The incidence of CRC appears to have an upward trend year by year since the enhancement of living standards. Although surgery and chemoradiotherapy have largely improved the prognosis of patients with CRC, some patients still appear to have severe adverse reactions and drug resistance. Moreover, much research has verified that ferroptosis has a necessary association with the occurrence and progression of gastrointestinal tumors. In this review, we provide a comprehensive evaluation of the main mechanisms of iron metabolism, lipid metabolism, and amino acid metabolism involved in the occurrence of ferroptosis, as well as the research progress of ferroptosis in CRC.
Simvastatin Loaded Dissolvable Microneedle Patches with Improved Pharmacokinetic Performance
Authors: Zulcaif  , Zafar Nadiah , Mahmood Asif , Sarfraz Rai Muhammad , Elaissari Abdelhamid
Published: August 2022

Microneedle patches (MNPs) are one of the emerging approaches for drug delivery involving minimal invasion and improved skin penetration of macro- and micro-entities. Herein, we report dissolvable microneedle patches (dMNPs) as a novel tool for better systemic delivery of Simvastatin in the management of hypocholesteremia. Thiolated chitosan (TC), polyvinyl pyrolidone (PVP) and polyvinyl alcohol (PVA) were employed in the development of dMNPs. Developed patches were characterized through SEM, FTIR, DSC, TGA, PXRD, dissolution testing, tensile strength, elongation (%), skin irritation studies, moisture content and pharmacokinetic evaluation. dMNP F26 exhibited excellent tensile strength (9.85 MPa), penetration potential (~700 µm), moisture content (5.95%), elongation (35.54%) and Simvastatin release of 77.92%. Pharmacokinetic properties were also improved, i.e., Cmax 1.97 µg/mL, tmax 9 h, MRT 19.9 h and AUC 46.24 µg·h/mL as compared to Simvastatin solution displaying Cmax 2.55 µg/mL, tmax 3 h, MRT 5.91 h and AUC 14.20 µg·h/mL thus confirming higher and improved bioavailability. Kinetic modelling revealed zero order as the best fit model based on regression coefficient. Histopathological findings proved the biocompatibility of the developed dMNPs.
BPSK Circuit Based on SDC Memristor
Authors: Gao Ran , Shen Yiran
Published: August 2022

Digital communication based on memristors is a new field. The main principle is to construct a modulation and demodulation circuit by using the resistance variation characteristics of the memristor. Based on the establishment of the Knowm memristor simulation model, firstly, the modulation circuit is designed by using the polarity and symmetry of the memristor and combined with the commercial current feedback amplifier AD844. It is proved that the modulated signal based on the memristor is a strong function of phase, and the demodulation circuit is designed accordingly. All simulation circuits are based on the actual commercial physical device model. The analytical expression of the output signal of the modulation and demodulation circuit is deduced theoretically, and the communication performance of the whole system is simulated by LTSpice. At the same time, the influence of the parasitic capacitance of the memristor on the circuit performance is also considered. After the simulation verification, the hardware circuit experiment of the modulation and demodulation circuit is carried out. The waveforms of the modulated signal and the demodulated signal are measured by an oscilloscope. The experimental results are completely consistent with the simulation and theoretical results.
On-Demand Metallization System Using Micro-Plasma Bubbles
Authors: Yamashita Yu , Sakuma Shinya , Yamanishi Yoko
Published: August 2022

3D wiring technology is required for the integration of micro–nano devices on various 3D surfaces. However, current wiring technologies cannot be adapted to a variety of materials and surfaces. Here, we propose a new metal deposition method using only a micro-plasma bubble injector and a metal ion solution. Micro-plasma bubbles were generated on demand using pulses, and the localized reaction field enables metal deposition independent of the substrate. Three different modes of micro-plasma bubble generation were created depending on the power supply conditions and mode suitable for metal deposition. Furthermore, using a mode in which one bubble was generated for all pulses among the three modes, copper deposition on dry/wet materials, such as chicken tissue and glass substrates, was achieved. In addition, metal deposition of copper, nickel, chromium, cobalt, and zinc was achieved by simply changing the metal ion solution. Finally, patterning on glass and epoxy resin was performed. Notably, the proposed metal deposition method is conductivity independent. The proposed method is a starting point for 3D wiring of wet materials, which is difficult with existing technologies. Our complete system makes it possible to directly attach sensors and actuators to living organisms and robots, for example, and contribute to soft robotics and biomimetics.
Oil Displacement in Calcite-Coated Microfluidic Chips via Waterflooding at Elevated Temperatures and Long Times
Authors: Le-Anh Duy , Rao Ashit , Stetten Amy , Ayirala Subhash , Alotaibi Mohammed , Duits Michel , Gardeniers Han , AlYousef Ali , Mugele Frieder
Published: August 2022

In microfluidic studies of improved oil recovery, mostly pore networks with uniform depth and surface chemistry are used. To better mimic the multiple porosity length scales and surface heterogeneity of carbonate reservoirs, we coated a 2.5D glass microchannel with calcite particles. After aging with formation water and crude oil (CRO), high-salinity Water (HSW) was flooded at varying temperatures and durations. Time-resolved microscopy revealed the CRO displacements. Precise quantification of residual oil presented some challenges due to calcite-induced optical heterogeneity and brine–oil coexistence at (sub)micron length scales. Both issues were addressed using pixel-wise intensity calibration. During waterflooding, most of the ultimately produced oil gets liberated within the first pore volume (similar to glass micromodels). Increasing temperature from 22 °C to 60 °C and 90 °C produced some more oil. Waterflooding initiated directly at 90 °C produced significantly more oil than at 22 °C. Continuing HSW exposure at 90 °C for 8 days does not release additional oil; although, a spectacular growth of aqueous droplets is observed. The effect of calcite particles on CRO retention is weak on flat surfaces, where the coverage is ~20%. The calcite-rich pore edges retain significantly more oil suggesting that, in our micromodel wall roughness is a stronger determinant for oil retention than surface chemistry.
Design and Fabrication of High-Frequency Piezoelectric Micromachined Ultrasonic Transducer Based on an AlN Thin Film
Authors: Zang Junbin , Fan Zheng , Li Penglu , Duan Xiaoya , Wu Chunsheng , Cui Danfeng , Xue Chenyang
Published: August 2022

A piezoelectric micromachined ultrasonic transducer (PMUT) is a microelectromechanical system (MEMS) device that can transmit and receive ultrasonic waves. Given its advantages of high-frequency ultrasound with good directionality and high resolution, PMUT can be used in application scenarios with low power supply, such as fingerprint recognition, nondestructive testing, and medical diagnosis. Here, a PMUT based on an aluminum nitride thin-film material is designed and fabricated. First, the eigenfrequencies of the PMUT are studied with multiphysics coupling simulation software, and the relationship between eigenfrequencies and vibration layer parameters is determined. The transmission performance of the PMUT is obtained via simulation. The PMUT device is fabricated in accordance with the designed simple MEMS processing process. The topography of the PMUT vibration layer is determined via scanning electron microscopy, and the resonant frequency of the PMUT device is 7.43 MHz. The electromechanical coupling coefficient is 2.21% via an LCR tester.
Gold Recovery from Sulfide Concentrates Produced by Environmental Desulfurization of Mine Tailings
Authors: Allard Olivier , Lopez Mathieu , Demers Isabelle , Coudert Lucie
Published: August 2022

Environmental desulfurization is gaining attention as an efficient approach to manage sulfidic mine tailings by separating sulfide minerals from tailings. While extensive research has been done to reuse desulfurized tailings in mine site reclamation, the responsible management or potential of valorization of desulfurization concentrates did not receive as much attention. The objective of this study was to evaluate the potential to recover Au from desulfurization concentrates originating from active gold mine sites. Desulfurization concentrates were produced by froth flotation of tailings and characterized. Cyanidation tests and gravity separation experiments were performed on the concentrates. Desulfurization concentrates, mostly composed of fine particles, contained high amounts of S (between 23.0 and 34.5% S) and variable contents of Au (between 0.7 and 1.9 g/t). Mineralogical characterization by SEM showed that 99% of Au-bearing particles were locked, mainly in pyrite (94%). Cyanidation allowed the recovery of 13 to 78% of Au, depending on the desulfurization concentrate. Low Au-bearing particles liberation, and possibly the presence of Cu, were identified as parameters negatively affecting the Au recovery. Gravity separation was poorly efficient (<50%) in recovering Au, which is quite consistent with physical (small particle size) and mineralogical characterizations. A desulfurization concentrate reprocessing flowsheet is proposed.
Reducing Negative Effects of Oxidation on Flotation of Complex Cu–Zn Sulfide Ores
Authors: Özçelik Seda , Ekmekçi Zafir
Published: August 2022

Surface oxidation of the sulfide minerals negatively affects the flotation performance, i.e., the selectivity and even the recoveries at heavy oxidation conditions. Oxidation may take place during the formation of the ore, during mining and stockpiling, and during the flotation process. Stockpiling of large amounts of ore is a common practice in mine sites for blending the process–plant feed. However, a long stockpiling time may cause severe surface oxidation of the complex sulfide ores, particularly the complex Cu–Zn sulfide ores containing secondary copper minerals, which resulted in loss of Cu–Zn selectivity and copper recovery. A complex Cu–Zn sulfide ore was used to investigate effects of stockpile time on flotation performance and to determine the most efficient mitigation method to restore the flotation performance. Batch-scale flotation tests were performed on a heavily oxidized sample using sulfidization, high intensity conditioning, and their combination. The results showed that sulfidization desliming and stage addition of depressants during flotation was the most effective method for producing a copper concentrate from oxidized ores.
Simply Prepared Magnesium Vanadium Oxides as Cathode Materials for Rechargeable Aqueous Magnesium Ion Batteries
Authors: Vasić Milica M. , Milović Miloš , Bajuk-Bogdanović Danica , Petrović Tamara , Vujković Milica J.
Published: August 2022

Vanadium-oxide-based materials exist with various vanadium oxidation states having rich chemistry and ability to form layered structures. These properties make them suitable for different applications, including energy conversion and storage. Magnesium vanadium oxide materials obtained using simple preparation route were studied as potential cathodes for rechargeable aqueous magnesium ion batteries. Structural characterization of the synthesized materials was performed using XRD and vibrational spectroscopy techniques (FTIR and Raman spectroscopy). Electrochemical behavior of the materials, observed by cyclic voltammetry, was further explained by BVS calculations. Sluggish Mg2+ ion kinetics in MgV2O6 was shown as a result of poor electronic and ionic wiring. Complex redox behavior of the studied materials is dependent on phase composition and metal ion inserted/deinserted into/from the material. Among the studied magnesium vanadium oxides, the multiphase oxide systems exhibited better Mg2+ insertion/deinsertion performances than the single-phase ones. Carbon addition was found to be an effective dual strategy for enhancing the charge storage behavior of MgV2O6.
Inspection of the Defect State Using the Mobility Spectrum Analysis Method
Authors: Ahn Il-Ho , Kim Deuk Young , Yang Woochul
Published: August 2022

Mobility spectrum analysis (MSA) is a method that enables the carrier density (and mobility) separation of the majority and minority carriers in multicarrier semiconductors, respectively. In this paper, we use the p-GaAs layer in order to demonstrate that the MSA can perform unique facilities for the defect analysis by using its resolvable features for the carriers. Using two proven methods, we reveal that the defect state can be anticipated at the characteristic temperature Tdeep, in which the ratio (RNn/Nh) that is associated with the density of the minority carrier Nn, to the density of the majority carrier Nh, exceeds 50%. (1) Using a p-GaAs Schottky diode in a reverse bias regime, the position of the deep level transient spectroscopy (DLTS) peak is shown directly as the defect signal. (2) Furthermore, by examining the current–voltage–temperature (I–V–T) characteristics in the forward bias regime, this peak position has been indirectly revealed as the generation–recombination center. The DLTS signals are dominant around the Tdeep, according to the window rate, and it has been shown that the peak variation range is consistent with the temperature range of the temperature-dependent generation–recombination peak. The Tdeep is also consistent with the temperature-dependent thermionic emission peak position. By having only RNn/Nh through the MSA, it is possible to intuitively determine the existence and the peak position of the DLTS signal, and the majority carrier’s density enables a more accurate extraction of the deep trap density in the DLTS analysis.
SnS Nanoflakes/Graphene Hybrid: Towards Broadband Spectral Response and Fast Photoresponse
Authors: Li Xiangyang , Ruan Shuangchen , Zhu Haiou
Published: August 2022

High responsivity has been recently achieved in a graphene-based hybrid photogating mechanism photodetector using two-dimensional (2D) semiconductor nanosheets or quantum dots (QDs) sensitizers. However, there is a major challenge of obtaining photodetectors of fast photoresponse time and broad spectral photoresponse at room temperature due to the high trap density generated at the interface of nanostructure/graphene or the large band gap of QDs. The van der Waals interfacial coupling in small bandgap 2D/graphene heterostructures has enabled broadband photodetection. However, most of the photocarriers in the hybrid structure originate from the photoconductive effect, and it is still a challenge to achieve fast photodetection. Here, we directly grow SnS nanoflakes on graphene by the physical vapor deposition (PVD) method, which can avoid contamination between SnS absorbing layer and graphene and also ensures the high quality and low trap density of SnS. The results demonstrate the extended broad-spectrum photoresponse of the photodetector over a wide spectral range from 375 nm to 1550 nm. The broadband photodetecting mechanisms based on a photogating effect induced by the transferring of photo-induced carrier and photo-hot carrier are discussed in detail. More interestingly, the device also exhibits a large photoresponsivity of 41.3 AW−1 and a fast response time of around 19 ms at 1550 nm. This study reveals strategies for broadband response and sensitive photodetectors with SnS nanoflakes/graphene.
Experimental and Theoretical Investigation of the Thermophysical Properties of Cobalt Oxide (Co3O4) in Distilled Water (DW), Ethylene Glycol (EG), and DW–EG Mixture Nanofluids
Authors: Alsboul Monther , Ghazali Mohd Sabri Mohd , Gomaa Mohamed R. , Albani Aliashim
Published: August 2022

Solid particles scattered in a base fluid for a standard no larger than 100 nm, constituting a nanofluid, can be used to improve thermophysical characteristics compared to the base fluid. In this study, theoretical and experimental investigations were carried out to estimate the density, viscosity, and effective thermal conductivity of Co3O4 in distilled water (DW), ethylene glycol (EG), and DW–EG mixture nanofluids. Co3O4 nanoparticles with diameters of 50 nm were dispersed in different base fluids (i.e., EG, DW, 60EG:40DW, 40EG:60DW, 20EG:80DW) with varying concentrations of 0.025–0.4 vol.%. Thermal conductivity was estimated by the hot-wire technique, and viscosity was determined using a viscometer apparatus. According to the measurements, the viscosity of Co3O4 nanofluids decreased with increasing temperature, and increased with increasing volume fraction. The results revealed that the thermal conductivity of Co3O4 nanofluids increased with increasing temperature and volume concentrations. Moreover, the measurements found that the maximum thermal conductivity of 10.8% and the maximum viscosity of 10.3% prevailed at 60 °C in the volume fraction of 0.4%. The obtained viscosity and thermal conductivity results of the present experiments on Co3O4 nanofluids were compared with previous results. The results showed good agreement with theoretically proposed models to predict nanofluids’ viscosity and thermal conductivity. Thus, the thermal conductivity results of Co3O4 nanofluids are promising with respect to the use of nanofluids in solar thermal applications.
The Joule Heating Effect of a Foldable and Cuttable Sheet Made of SWCNT/ANF Composite
Authors: Koo Min Ye , Lee Gyo Woo
Published: August 2022

A foldable and cuttable sheet heater was fabricated using single-walled carbon nanotubes (SWCNTs) and aramid nanofibers (ANFs). SWCNTs are particularly well suited for Joule heating based on their high thermal stability, electrical properties, high current density, and aspect ratio. When the SWCNT/ANF composite reaches a high temperature during Joule heating, ANFs will endure this temperature due to their impressive thermal stability, derived from aramid fibers. With the aim of achieving a synergistic effect between the SWCNTs and ANFs, 0–100 wt% SWCNT/ANF composite sheets were fabricated by tip-type sonication and vacuum filtration. After assessing the thermal stability and electrical properties of the composite sheets, the Joule heating effect was analyzed. TGA showed that our sheet had high thermal stability in an air condition up to around 500 °C. The electrical conductivity of the composite sheet was improved as the amount of SWCNT added rose to 790.0 and 747.5 S/cm in the 75 and 100_SWCNTs/ANF, respectively. The maximum heating temperature, up to 280 °C, reached by Joule heating was measured as a function of SWCNT content and input voltage, and the relationship among SWCNT content, input voltage, heating temperature, and electric power was described. Mechanical properties were also measured in a temperature range similar to the heating temperature of 300 °C reached by Joule heating. Ultimately, we obtained a foldable and cuttable composite sheet with a stretchable structure, capable of being molded into a variety of shapes. This energy-efficient material can potentially be employed in any device in which a heater is required to deliver high temperatures.
Application of Organic Amine Modified Natural Zeolite in Filling Natural Rubber
Authors: Chen Xiaolong , Zhang Taozhong , Sun Pengliang , Yu Fujia , Li Bin , Dun Linan
Published: August 2022

In this paper, the method of filling natural rubber with zeolite as filler was mainly studied in the following two aspects: firstly, experiments selected organic amine surface modifier to modify natural zeolite and used infrared spectroscopy to analyze the interaction between the modifier and zeolite, and secondly, studying the application of modified zeolite in natural rubber and using scanning electron microscopy to analyze the mechanism of action between zeolite and natural rubber. The test results show that octadecylamine in the modifier had the relatively best effect. Under the best conditions, the activation index of the modified product could reach 95% and above, and the contact angle could reach about 100°. When the filling amount was 30 phr, the octadecylamine modification had the most obvious effect on the performance of zeolite/natural rubber and the composite rubber had better mechanical properties. The corresponding tensile strength, tear strength, elongation at break and Shore hardness were 22.59 MPa, 28.52 MPa, 782.1% and 41, respectively, which were 45.74%, 19.28%, 7.95% and 7.89% higher than those of unmodified zeolite/natural rubber. As the first study of organic amine modified zeolite as a filler for filling natural rubber, this work provides a new way to improve the added value of natural zeolite.
Ultra−Wide Range Vibration Frequency Detection Sensors Based on Elastic Steel Triboelectric Nanogenerators for Intelligent Machinery Monitoring
Authors: Huang Xili , Zhang Cheng , Pang Hongchen , Zhao Zhiqiang , Zhang Qianxi , Li Xiaoning , Wang Xianzhang , Lin Fang , Li Bo , Pan Xinxiang
Published: August 2022

Vibration measurement and analysis play an important role in diagnosing mechanical faults, but existing vibration sensors are limited by issues such as dependence on external power sources and high costs. To overcome these challenges, the use of triboelectric nanogenerator (TENG)−based vibration sensors has recently attracted attention. These vibration sensors measure a small range of vibration frequencies and are not suitable for measuring high-frequency vibrations. Herein, a self-powered vibration sensor based on an elastic steel triboelectric nanogenerator (ES−TENG) is proposed. By optimizing the elastic steel sheet structure and combining time-frequency transformation and filtering processing methods, the measurement of medium- and high-frequency vibrations is achieved. These results demonstrate that the ES−TENG can perform vibration measurements in the range of 2–10,000 Hz, with a small average error (~0.42%) between the measured frequency and external vibration frequency values. Therefore, the ES−TENG can be used as a self-powered, highly-accurate vibration sensor for intelligent machinery monitoring.
Anti-Colorectal Cancer Effects of Inonotus hispidus (Bull.: Fr.) P. Karst. Spore Powder through Regulation of Gut Microbiota-Mediated JAK/STAT Signaling
Authors: Yang Hongxin , Li Siyu , Qu Yidi , Li Lanzhou , Li Yu , Wang Di
Published: August 2022

Inonotus hispidus (Bull.: Fr.) P. Karst. spore powder (IHS) contains polyphenols and triterpenoids with pharmacological effects. Here, we analyzed its composition, and we investigated the effects of IHS on colorectal cancer (CRC) in B6/JGpt-Apcem1Cin(min)/Gpt (ApcMin/+) mice and its potential mechanisms by analyzing gut microbiota and serum metabolomics. The enzyme-linked immunosorbent assays and Western blotting were used to confirm the changes in the cytokine and protein levels associated with IHS administration. The IHS affected the abundance of gut microbiota and the level of L-arginine (L-Arg). Furthermore, the IHS influenced T cells in ApcMin/+ mice by increasing the interleukin (IL)-2 and decreasing the IL-5, -6, and -10 levels, thus suppressing tumor development. Overall, IHS showed anti-CRC properties in ApcMin/+ mice by affecting the gut microbiota and serum metabolites, which in turn affected the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling, and regulated the abundance of CD8+ T cells. These results provide experimental support for the potential future treatment of CRC with IHS.
Luteolin-7-O-Glucuronide Improves Depression-like and Stress Coping Behaviors in Sleep Deprivation Stress Model by Activation of the BDNF Signaling
Authors: Ryu Dajung , Jee Hye-Jin , Kim Sang-Yoon , Hwang Seung-Hwan , Pil Gam-Bang , Jung Yi-Sook
Published: August 2022

Stress exposure is a major risk factor for mental disorders such as depression. Because of the limitations of classical antidepressants such as side effects, low efficacy, and difficulty in long-term use, new natural medicines and bioactive molecules from plants with greater safety and efficacy have recently attracted attention. Luteolin-7-O-glucuronide (L7Gn), a bioactive molecule present in Perilla frutescens, is known to alleviate severe inflammatory responses and oxidative stress in macrophages. However, its antistress and antidepressant effects have not been elucidated. The present study aims to explore the antidepressant the effect of L7Gn on stress-induced behaviors and the underlying mechanism in a mouse sleep deprivation (SD) model. L7Gn treatment improved depression-like and stress coping behaviors induced by SD stress, as confirmed by the tail suspension test and forced swimming test. Furthermore, L7Gn treatment reduced the blood corticosterone and hippocampal proinflammatory cytokine levels which were increased by SD stress, and L7Gn also increased the mRNA and protein levels of hippocampal brain-derived neurotrophic factor (BDNF) which were reduced by SD stress. Additionally, treatment with L7Gn resulted in increases in the phosphorylation of tropomyosin-related kinase B (TrkB), extracellular signal-regulated kinase (ERK), and cAMP response element-binding protein (CREB), which are downstream molecules of BDNF signaling. These findings suggest that L7Gn have therapeutic potential for SD-induced stress, via activating the BDNF signaling.
Impaired Height Growth Associated with Vitamin D Deficiency in Young Children from the Japan Environment and Children’s Study
Authors: Kuraoka Shohei , Oda Masako , Mitsubuchi Hiroshi , Nakamura Kimitoshi , Katoh Takahiko ,   Japan Environment and Children’s Study (JECS) Group
Published: August 2022

Vitamin D is essential for calcium absorption and bone homeostasis. Although short-stature children were reported to have low vitamin D concentrations, there is no clear evidence of a link between vitamin D and height growth in young children not limited to those with short stature. We collected height and weight data at 2 and 4 years of age, serum vitamin D concentrations at 4 years, and questionnaire results on sun exposure from the Japan Environment and Children’s Study (JECS). We then analyzed the relationship between vitamin D deficiency and height growth. We also analyzed the correlation between serum vitamin D concentration and sun exposure. Overall, 3624 participants from JECS were analyzed. We identified cases of subclinical vitamin D deficiency and insufficiency. We further found that definitive vitamin D deficiency (<10 ng/mL) impaired height growth by 0.6 cm per year even in young children not limited to those with short stature. Furthermore, we clarified that children with vitamin D deficiency had reduced outdoor activity, especially during winter. In children with either short or normal stature, definitive vitamin D deficiency was associated with height growth decline, and reduction in outdoor activity, especially during winter, was a risk factor for vitamin D deficiency.