bluuebunny/crossref_metadata_2025 huggingface dataset:
Strength Prediction of Ball-Milling-Modified Phosphorus Building Gypsum Based on NSGM (1,4) Model
Authors: Zhang Yi , Tao Zhong , Wu Lei , Zhang Zhiqi , Zhao Zhiman
Published: November 2022

Phosphogypsum is an industrial byproduct from the wet preparation of phosphoric acid. Phosphorus building gypsum can be obtained from phosphogypsum after high-thermal dehydration. This study aimed to analyze the influence of ball milling with different parameters on the strength of phosphorus building gypsum. In this paper, the absolute dry flexural strength and the absolute dry compressive strength of phosphorus building gypsum were compared under different mass ratios of material to ball, ball-milling speed, and ball-milling time, and the NSGM (1,4) model was applied to model and predict the strength of phosphorus building gypsum modified by ball milling. According to the research results, under the same mass ratio of material to ball and ball-milling speed, the absolute dry flexural strength and absolute dry compressive strength of phosphorus building gypsum firstly increased and then decreased with the increase in milling time. The NSGM (1,4) model established in this paper could effectively simulate and predict the absolute dry flexural strength and the absolute dry compressive strength of the ball-milling-modified phosphorus building gypsum; the average relative simulation errors were 12.38% and 13.77%, and the average relative prediction errors were 6.30% and 12.47%.
Effect of the Granularity of Cubic Boron Nitride Vitrified Grinding Wheels on the Planar Technical Blades Sharpening Process
Authors: Zieliński Bartosz , Nadolny Krzysztof , Zawadka Wojciech , Chaciński Tomasz , Stachurski Wojciech , Batalha Gilmar Ferreira
Published: November 2022

The most widely used method for shaping technical blades is grinding with abrasive tools made of cubic boron nitride (cBN) grains and vitrified bond. The goal of this work was to determine the effect of grinding wheel grain size (cBN grain number according to FEPA standards: B126, B181 and B251), kinematics (grinding with the circumference, face and conical surface of the wheel) and feed rate (vf = 100; 150; 200 mm/min) on the effects of the grinding process evaluated by the cutting force of the blade after machining F, blade surface texture parameters (Sa, St, Smvr, Str, Sdq, Sdr and Sbi) as well as blade surface morphology. An analysis of output quantities showed that grinding wheels made of B181 cBN grains are most favorable for shaping planar technical blades of X39Cr13 steel in the grinding process.
Eu3+ and Tb3+ @ PSQ: Dual Luminescent Polyhedral Oligomeric Polysilsesquioxanes
Authors: Marchesi Stefano , Miletto Ivana , Bisio Chiara , Gianotti Enrica , Marchese Leonardo , Carniato Fabio
Published: November 2022

The synthesis and characterization of novel luminescent amorphous POSS-based polysilsesquioxanes (PSQs) with Tb3+ and Eu3+ ions directly integrated in the polysilsesquioxane matrix is presented. Two different Tb3+/Eu3+ molar ratios were applied, with the aim of disclosing the relationships between the nature and loading of the ions and the luminescence properties. Particular attention was given to the investigation of site geometry and hydration state of the metal centers in the inorganic framework, and of the effect of the Tb3+ → Eu3+ energy transfer on the overall optical properties of the co-doped materials. The obtained materials were characterized by high photostability and colors of the emitted light ranging from orange to deep red, as a function of both the Tb3+/Eu3+ molar ratio and the chosen excitation wavelength. A good energy transfer was observed, with higher efficiency displayed when donor/sensitizer concentration was lower than the acceptor/activator concentration. The easiness of preparation and the possibility to finely tune the photoluminescence properties make these materials valid candidates for several applications, including bioimaging, sensors, ratiometric luminescence-based thermometers, and optical components in inorganic or hybrid light-emitting devices.
L-Ascorbic Acid as an Efficient Green Corrosion Inhibitor of Steel Rebars in Chloride Contaminated Cement Mortar
Authors: Argiz Cristina , Arroyo Celia , Bravo Astrid , Moragues Amparo , Andrade Carmen , Bolzoni Fabio
Published: November 2022

Corrosion of reinforcement is a major problem regarding concrete durability. In new structures the corrosion onset can be delayed if additional protection methods are provided as is the case for the addition of corrosion inhibitors in the concrete mix. The main goal of this paper is the evaluation of the effect of the ascorbic acid (AA) as a green steel corrosion inhibitor in cement mortars contaminated by chlorides. Concentration levels of ascorbic acid, ranging from 0.5 to 10−3 mol/L, were added to the mixing water. Electrochemical methods, including corrosion potential (Ecorr), linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS), were employed to assess the corrosion rate of the steel embedded in the mortars. The corrosion inhibiting performance of ascorbic acid was compared with that of sodium nitrite. The interaction of the ascorbic acid with the hydrated cement matrix was also evaluated with differential thermal and thermogravimetric analysis (DTA/TG) and pH measurements. The results indicated that, depending on the ascorbic acid concentration, it can be an activator of the corrosion process or an effective corrosion inhibitor in a similar manner to sodium nitrite. A corrosion rate decrease was achieved with concentrations below 10−2 mol/L and the optimum content was 10−3 mol/L. Within this concentration range, the AA does not modify the hydration performance of the cement matrix.
Carburization Kinetics of Zircalloy-4 and Its Implication for Small Modular Reactor Performance
Authors: Kardoulaki Erofili , Abdul-Jabbar Najeb , Byler Darrin , Hassan Md Mehadi , Mann Shane , Coons Tim , White Josh
Published: November 2022

Carburization of cladding materials has long been a concern for the nuclear industry and has led to the restricted use of high-thermal conductivity fuels such as uranium carbides. With the rise of small modular reactors (SMRs) that frequently implement a graphite core-block, carburization of reactor components is once more in the foreground as a potential failure mechanism. To ensure commercial viability for SMRs, neutron-friendly cladding materials such as Zr-based alloys are required. In this work, the carburization kinetics of Zircaloy-4 (Zry-4), for the temperature range 1073–1673 K (covering typical operating temperatures and off-normal scenarios) are established. The following Arrhenius relationship for the parabolic constant describing ZrC growth is derived: Kp (in μm2/s) = 609.35 exp(−1.505 × 105/RT)). Overall, the ZrC growth is sluggish below 1473 K which is within the operational temperature range of SMRs. In all cases the ZrC that forms from solid state reaction is hypo-stoichiometric, as confirmed through XRD. The hardness and elastic modulus of carburized Zry-4 are also examined and it is shown that despite the formation of a ZrC layer, C ingress in the Zry-4 bulk does not impact the mechanical response after carburization at 1073 K and 1473 K for 96 h.
Mechanically Stable Magnetic Metallic Materials for Biomedical Applications
Authors: Mehmood Shahid , Ali Zahid , Khan Shah Rukh , Aman Salma , Elnaggar Ashraf Y. , Ibrahim Mohamed M. , Zubar Tatiana I. , Tishkevich Daria I. , Trukhanov Sergei V. , Trukhanov Alex V.
Published: November 2022

The structural, electrical, and magneto-elastic properties of lanthanide base nitride (Ln = Dy-Lu) anti-perovskites were investigated using density functional theory (DFT). The reported structural outcomes are consistent with the experiment and decrease from Dy to Lu due to the decrease ofatomic radii of Ln atoms. According to the electronic band profile, the metallic characteristics of these compounds are due to the crossing over of Ln-f states at the Fermi level and are also supported by electrical resistivity. The resistivity of these compounds at room temperature demonstrates that they are good conductors. Their mechanical stability, anisotropic, load-bearing, and malleable nature are demonstrated by their elastic properties. Due to their metallic and load-bearing nature, in addition to their ductility, these materials are suitable as active biomaterials, especially when significant acting loads are anticipated, such as those experienced by such heavily loaded implants as hip and knee endo-prostheses, plates, screws, nails, dental implants, etc. In thesecases, appropriate bending fatigue strength is required in structural materials for skeletal reconstruction. Magnetic properties show that all compounds are G-type anti-ferromagnetic, with the Neel temperatures ranging from 24 to 48 K, except Lu3Nin, which is non-magnetic. Due to their anti-ferromagnetic structure, magnetic probes cannot read data contained in anti-ferromagnetic moments, therefore, data will be unchanged by disrupted magnetic field. As a result, these compounds can be the best candidates for magnetic cloaking devices.
Parametric Investigation into the Shear Strength of Adhesively Bonded Single-Lap Joints
Authors: Chen Quanlong , Du Bing , Zhang Xiaodong , Zhong Hai , Ning Conggang , Bai Huimin , Li Qian , Pan Ruqing , Zhou Baocheng , Hu Hanjie
Published: November 2022

In this paper, the shear strength of adhesively bonded single-lap joints were experimentally and numerically investigated. Based on the validated simulation, the effects of lap length, adhesive layer thickness, adhesive layer shape, adhesive layer overflow length, and laminate lay-up on the shear strength of adhesively bonded single-lap joints were studied. The load-displacement curves and shear strength under different parameters were compared. It was shown that the shear strength of single-lap joints gradually decreases with the increase of lap length and adhesive layer thickness, which were 53.83% and 16.15%, respectively. Considering the potential condition in fabrication, the adhesive layer shape and adhesive layer overflow length were also investigated. The adhesive with normal and triangle shape owned the comparable shear strength, which was higher than the arc one. The shear strength increased by 19.37% from 18.43 MPa to 22.00 MPa with increasing the adhesive layer overflow length to 50% of lap length. It was beneficial for shear strength to increase the adhesive layer overflow length to 50% of lap length. Among the selected four lay-ups, [0]16s had the highest shear strength, which was nearly 3 times greater than the one of [90]16s. In the real process preparation, increasing the number of 0° layers, selecting the appropriate lap length and thickness of the adhesive layer, and controlling the shape and length of the adhesive layer overflow are of great help to improve the tensile shear strength of the single-lap glue joint.
Preparation and Characterization of Novel 5Mg(OH)2·MgSO4·7H2O Whiskers
Authors: Ning Xinkuang , Wu Chengyou , Chen Hongdu
Published: November 2022

Herein, novel monodisperse basic magnesium sulfate whiskers (5Mg(OH)2·MgSO4·7H2O) were prepared under low-temperature and atmospheric-pressure conditions, using the admixture sodium citrate. X-ray diffraction, Raman spectroscopy, scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, selected area electron diffraction, thermogravimetric analysis, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy were used to characterize the structure and morphology of the whisker products. The analysis results showed that the product was composed of high-purity basic magnesium sulfate whiskers. The lengths and diameters of the whiskers were 10–20 μm and 0.1–0.2 μm, respectively, and their aspect ratios were higher than 30. The formation mechanism of 5Mg(OH)2·MgSO4·7H2O involved direct assembly from the precursors without the formation of magnesium hydroxide for redissolution. High-purity MgO whiskers with smooth surfaces were prepared using the as-prepared whisker products via thermal decomposition. Thus, the findings of this study can provide technical support for the cost-effective industrial-scale preparation of basic magnesium-sulfate whiskers and associated whisker products.
Microstructures and Mechanical Properties of an AlCoCrNiFe HEA/WC Reinforcing Particle Composite Coating Prepared by Laser Cladding
Authors: Huang Jiang , Zhu Zhikai , Li Kaiyue , Shi Wenqing , Zhao Yang , He Minyi
Published: November 2022

In this study, an AlCoCrFeNi HEA coating with a 10% mass fraction of WC particles was fabricated on the surface of 316L stainless steel by laser cladding technology. WC powders were formed by the partial or total dissolution of the initial WC particles with different sizes in the AlCoCrFeNi HEA coating. Micron WC particles were dispersed in the coating homogeneously, and millimeter WC particles were deposited on the bottom of coating because of their high density. The addition of the WC powers prompted Columnar dendritic and cellular grains, observed in the bottom and top regions of the coating, respectively. Additionally, this led to a higher micro-hardness and better corrosion resistance than that of the pure HEA coating.
Efficient Preparation of High-Purity Fucoxanthinol by SpyTag-Tailored Active Cholesterol Esterase Aggregates
Authors: Jin Wenhui , Yang Ting , Chen Hui , Fang Hua , Chen Weizhu , Xie Quanling , Liu Qian , Zhang Yiping , Hong Zhuan , Zhang Guangya
Published: November 2022

A novel approach to producing high-purity fucoxanthinol (FXOH) was exploited as a sustainable method to maximize fucoxanthin (FX) utilization. Through fusing the genes of cholesterol esterase and SpyTag and then expressing them in Escherichia coli, the fusion chimera was self-assembled into insoluble active aggregates by SpyTag, which could be regarded as carrier-free immobilization. The immobilization yield of the active cholesterol esterase aggregates could reach 60%. They have expressed good activity retention at 92.48% and 60.13% after 3 and 12 cycles, respectively, which is an exciting finding. The conversion ratio of FX to FXOH is 95.02%, which is remarkably higher than those realized via the conventional chemical reduction method (55.86%) and the enzymatic hydrolysis method by free cholesterol esterases (84.51%). The purity of FXOH obtained by this method is as high as 98%, which is much higher than those obtained by other methods. Thus, a promising method for simultaneously purifying and immobilizing active cholesterol esterase aggregates is demonstrated in this study by SpyTag tailoring. In addition, this study provides an eco-friendly method for producing high-purity FXOH from FX in a highly efficient manner.
Anti-Inflammatory Polyketide Derivatives from the Sponge-Derived Fungus Pestalotiopsis sp. SWMU-WZ04-2
Authors: Jiang Peng , Luo Jinfeng , Jiang Yao , Zhang Liping , Jiang Liyuan , Teng Baorui , Niu Hong , Zhang Dan , Lei Hui
Published: November 2022

Five undescribed polyketide derivatives, pestaloketides A–E (1–5), along with eleven known analogues (6–16), were isolated from the sponge-derived fungus Pestalotiopsis sp. Their structures, including absolute configurations, were elucidated by analyses of NMR spectroscopic HRESIMS data and electronic circular dichroism (ECD) calculations. Compounds 5, 6, 9, and 14 exhibited weak cytotoxicities against four human cancer cell lines, with IC50 values ranging from 22.1 to 100 μM. Pestaloketide A (1) is an unusual polyketide, featuring a rare 5/10/5-fused ring system. Pestaloketides A (1) and B (2) exhibited moderately inhibited LPS-induced NO production activity, with IC50 values of 23.6 and 14.5 μM, respectively, without cytotoxicity observed. Preliminary bioactivity evaluations and molecular docking analysis indicated that pestaloketides A (1) and B (2) had the potential to be developed into anti-inflammatory activity drug leads.
HYSTEROSCOPIC MYOMECTOMY
Authors: Lasmar Ricardo Bassil , Lasmar Bernardo Portugal , Moawad Nash S.
Published: November 2022

Leiomyomas are the most common pelvic tumors. Submucosal fibroids are a common cause of abnormal bleeding and infertility. Hysteroscopic myomectomy is the definitive management of symptomatic submucosal fibroids, with high efficacy and safety. Several techniques have been introduced over time and will be covered in depth in this manuscript. Advances in optics, fluid management, electrosurgery, smaller diameter scopes, and tissue removal systems, along with improved training have contributed to improving the safety and efficiency of hysteroscopic myomectomy.
Increased Risk of Common Orthopedic Surgeries for Patients with Rheumatic Diseases in Taiwan
Authors: Hsieh Min-Chih , Koo Malcolm , Hsu Chia-Wen , Lu Ming-Chi
Published: November 2022

Background and Objectives: Rheumatic diseases, including rheumatoid arthritis, ankylosing spondylitis, psoriasis, and systemic lupus erythematosus (SLE), are characterized by chronic arthritis or spondyloarthritis, which can lead to joint and spine destruction. Our previous studies showed that the risk of common orthopedic surgeries, including total knee replacement (TKR), total hip replacement (THR), or spine surgery, was increased in patients with rheumatoid arthritis, ankylosing spondylitis, psoriasis, and SLE. The aim of this review was to summarize the risk of TKR, THR, cervical spine, and lumbar spine surgery on the basis of studies conducted using data from Taiwan’s National Health Insurance Research Database (NHIRD). Materials and Methods: The risk of TKR, THR, cervical spine surgery, and lumbar spine surgery in patients with rheumatoid arthritis, ankylosing spondylitis, psoriasis, and SLE was summarized from the results of our previous studies and unpublished findings based on NHIRD data. Results: Patients with rheumatoid arthritis and psoriasis and men with ankylosing spondylitis showed an increased risk of TKR. Patients with rheumatoid arthritis, ankylosing spondylitis, and women with SLE showed an increased risk of receiving THR. Only patients with ankylosing spondylitis had an increased risk of cervical spine surgery, and patients with rheumatoid arthritis or ankylosing spondylitis showed an increased risk of lumbar spine surgery. Although the risk of THR, TKR, or spine surgery in these patients has declined in the era of biologics use, direct evidence for the effects of biologics agents is not yet available. Conclusions: There was an increased risk of common orthopedic surgery in patients with rheumatoid arthritis, ankylosing spondylitis, psoriasis, and SLE. Clinicians should be vigilant to reduce the increased risk of TKR and THR in young and middle-aged patients with rheumatoid arthritis, THR in young patients with ankylosing spondylitis, and young female patients with SLE, as well as cervical spine surgery in young patients with ankylosing spondylitis.
Innovative Use of Biodex Balance System to Improve Dynamic Stabilization and Function of Upper Quarter in Recreational Weightlifters: A Randomized Controlled Trial
Authors: Abdelraouf Osama R. , Abdel-aziem Amr A. , Ghally Shahesta A. , Osama Lamis A. , Dawood Reem S. , Yehia Amr M. , Eed Emad M. , EI-Gendy Amira M. , Radwan Rafik E.
Published: November 2022

Background and Objectives: Following an injury, upper-body strength and proprioception training is typically suggested. To our understanding, no prior research has looked into the impact of balance training on upper-body strength and stability. So, this study investigated the effects of Biodex balance training on enhancing the dynamic stability, strength, and function of the upper quarter (UQ) in recreational weightlifters. Materials and Methods: Fifty male weightlifters were randomly assigned into two groups. The experimental group received an upper-extremity Biodex balance training program three times/week for eight weeks, while the control group underwent a regular weightlifting training routine. Pre- and post-test scores of the upper-quarter dynamic stability, strength, and function were measured for both groups using the shoulder active repositioning accuracy test, two-minute push-up test, and the upper-quarter Y-balance test (UQ-YBT) and one-arm hop test, respectively. Results: Post-test values were significantly greater for the normalized UQ-YBT test than pre-test values in both groups (p < 0.05). Post-test values of the experimental group were significantly greater than the control group (p < 0.05). Regarding the shoulder active repositioning accuracy test and the time of the one-arm hop test, post-test values were significantly lower than pre-test values for both groups (p < 0.05), and post-test values of the experimental group were significantly lower than those of the control group (p < 0.05). The post-test value of the two-minute push-up test of each group was significantly higher than the pre-test value (p < 0.05), without any significant difference between both groups (p > 0.05). Conclusions: Adding upper-body Biodex balance training to a regular weightlifting training routine was effective in enhancing the upper quarter′s dynamic stability and function.
Polystyrene Sulfonate Particles as Building Blocks for Nanofiltration Membranes
Authors: Jahn Philipp , Zelner Michael , Freger Viatcheslav , Ulbricht Mathias
Published: November 2022

Today the standard treatment for wastewater is secondary treatment. This procedure cannot remove salinity or some organic micropollutants from water. In the future, a tertiary cleaning step may be required. An attractive solution is membrane processes, especially nanofiltration (NF). However, currently available NF membranes strongly reject multivalent ions, mainly due to the dielectric effect. In this work, we present a new method for preparing NF membranes, which contain negatively and positively charged domains, obtained by the combination of two polyelectrolytes with opposite charge. The negatively charged polyelectrolyte is provided in the form of particles (polystyrene sulfonate (PSSA), d ~300 nm). As a positively charged polyelectrolyte, polyethyleneimine (PEI) is used. Both buildings blocks and glycerol diglycidyl ether as crosslinker for PEI are applied to an UF membrane support in a simple one-step coating process. The membrane charge (zeta potential) and salt rejection can be adjusted using the particle concentration in the coating solution/dispersion that determine the selective layer composition. The approach reported here leads to NF membranes with a selectivity that may be controlled by a different mechanism compared to state-of-the-art membranes.
Effect of the Surface Oxide Layer on Shape Memory Effect and Superelasticity of [011]-Oriented Ti-50.1Ni Single Crystals
Authors: Chumlyakov Yuriy I. , Kireeva Irina V. , Saraeva Anastasia A. , Pobedennaya Zinaida V. , Vyrodova Anna V.
Published: November 2022

Effect of the surface oxide layer on the shape memory effect (SME) and superelasticity (SE) after marforming (deformation in the martensitic state, followed by annealing at 713 K for 0.5 h in an inert helium gas and in dry air) was investigated on Ti-50.1Ni (at.%) single crystals, oriented along [011]-direction, under compression. Quenched [011]-oriented crystals of the Ti-50.1Ni alloy experience a one-stage B2-B19′ martensitic transformation (MT) without SE under compression. Marforming leads to a two-stage B2-R-B19′ MT and creates conditions for SE. A thin TiO2 oxide layer of 170 nm thick was formed on the sample surface upon annealing at 713 K for 0.5 h in dry air. In [011]-oriented crystals without and with an oxide layer, maximum of the SE value reached 4%, and the SME was 2.4 and 2.6%, respectively. Appearance of an oxide layer upon annealing in dry air: (i) reduces the stresses of B2-phase by 50 MPa from Md to 473 K; (ii) decreases Θ = dσ/dε from 6.5 GPa in crystals without an oxide layer to 2.0 GPa with an oxide layer and (iii) does not affect the SME and SE values.
Analysis of Operational Characteristics of AlGaN/GaN High-Electron-Mobility Transistor with Various Slant-Gate-Based Structures: A Simulation Study
Authors: Lee Jun-Ho , Choi Jun-Hyeok , Kang Woo-Seok , Kim Dohyung , Min Byoung-Gue , Kang Dong Min , Choi Jung Han , Kim Hyun-Seok
Published: November 2022

This study investigates the operational characteristics of AlGaN/GaN high-electron-mobility transistors (HEMTs) by applying a slant-gate structure and drain-side extended field-plate (FP) for improved breakdown voltage. Prior to the analysis of slant-gate-based HEMT, simulation parameters were extracted from the measured data of fabricated basic T-gate HEMTs to secure the reliability of the results. We suggest three different types of slant-gate structures that connect the basic T-gate electrode boundary to the 1st and 2nd SiN passivation layers obliquely. To consider both the breakdown voltage and frequency characteristics, the DC and RF characteristics of various slant-gate structures including the self-heating effect were analyzed by TCAD simulation. We then applied a drain-side extended FP to further increase the breakdown voltage. The maximum breakdown voltage was achieved at the FP length of 0.4 μm. Finally, we conclude that the slant-gate structures can improve breakdown voltage by up to 66% without compromising the frequency characteristics of the HEMT. When the drain-side FP is applied to a slant-gate structure, the breakdown voltage is further improved by up to 108%, but the frequency characteristics deteriorate. Therefore, AlGaN/GaN HEMTs with an optimized slant-gate-based structure can ultimately be a promising candidate for high-power and high-frequency applications.
Raman Spectroscopy and Spectral Signatures of AlScN/Al2O3
Authors: Solonenko Dmytro , Žukauskaitė Agnė , Pilz Julian , Moridi Mohssen , Risquez Sarah
Published: November 2022

III-V solid solutions are sensitive to growth conditions due to their stochastic nature. The highly crystalline thin films require a profound understanding of the material properties and reliable means of their determination. In this work, we have investigated the Raman spectral fingerprint of Al1−xScxN thin films with Sc concentrations x = 0, 0.14, 0.17, 0.23, 0.32, and 0.41, grown on Al2O3(0001) substrates. The spectra show softening and broadening of the modes related to the dominant wurtzite phase with increasing Sc content, in agreement with the corresponding XRD results. We investigated the primary scattering mechanism responsible for the immense modes’ linewidths by comparing the average grain sizes to the phonon correlation length, indicating that alloying augments the point defect density. The low-frequency Raman bands were attributed to the confined spherical acoustic modes in the co-forming ScN nanoparticles. Temperature-dependent Raman measurements enabled the temperature coefficient of the E2(high) mode to be determined for all Sc concentrations for the precise temperature monitoring in AlScN-based devices.
New Solutions of Fractional Jeffrey Fluid with Ternary Nanoparticles Approach
Authors: Asjad Muhammad Imran , Riaz Ayesha , Alnahdi Abeer S. , Eldin Sayed M.
Published: November 2022

The existing work deals with the Jeffrey fluid having an unsteady flow, which is moving along a vertical plate. A fractional model with ternary, hybrid, and nanoparticles is obtained. Using suitable dimensionless parameters, the equations for energy, momentum, and Fourier’s law were converted into non-dimensional equations. In order to obtain a fractional model, a fractional operator known as the Prabhakar operator is used. To find a generalized solution for temperature as well as a velocity field, the Laplace transform is used. With the help of graphs, the impact of various parameters on velocity as well as temperature distribution is obtained. As a result, it is noted that ternary nanoparticles approach can be used to increase the temperature than the results obtained in the recent existing literature. The obtained solutions are also useful in the sense of choosing base fluids (water, kerosene and engine oil) for nanoparticles to achieved the desired results. Further, by finding the specific value of fractional parameters, the thermal and boundary layers can be controlled for different times. Such a fractional approach is very helpful in handling the experimental data by using theoretical information. Moreover, the rate of heat transfer for ternary nanoparticles is greater in comparison to hybrid and mono nanoparticles. For large values of fractional parameters, the rate of heat transfer decreases while skin friction increases. Finally, the present results are the improvement of the results that have already been published recently in the existing literature. Fractional calculus enables us to control the boundary layers as well as rate of heat transfer and skin friction for finding suitable values of fractional parameters. This approach can be very helpful in electronic devices and industrial heat management system.
Design of Wideband Decoupling Antenna Pairs for 5G Portable Devices at N77/N78/N79 Bands
Authors: Du Kaiwen , Wang Yongshun , Zhang Lijun , Hu Yao
Published: November 2022

We proposed an antenna pair that is applicable for mobile terminals: a type of coupling feed planar antenna that has a size of 28×6 mm2, a wide band, coupling suppression and compact size. Different from the conventional antenna design, the process of band expansion comes from a dual-band antenna pair and is based on characteristic modes theory (CMA). By observing characteristic current distributions, the optimization emphasis is placed on current sensitive parts in antenna structures, which is an effective method to create or modify resonant points for exciting band potential. Meanwhile, the multiple defective ground structure (DGS) is introduced for isolation enhancement. The −10 dB bandwidth of 3.23–5.24 GHz can be realized, and the isolation of two antenna pairs with only 2 mm spacing is lower (−17.34 dB). The eight-port MIMO system constructed by four proposed antenna pairs has been fabricated. The simulated and measured results of MIMO indicate that its −10 dB operating bandwidth can work at N77/N78/N79/WLAN 5 GHz bands. Moreover, a lower ECC of less than 0.04 and a high efficiency of more than 60% can be obtained, which confirms that it is capable of excellent data transmission as a terminal MIMO antenna system.
Influence of Marangoni Effect on Heat and Mass Transfer during Evaporation of Sessile Microdroplets
Authors: Liu Haiting , Deng Jiewen
Published: November 2022

Evaporative cooling is an important method for controlling the temperature of micro devices, and heat and mass transfer from the microdroplets in the evaporation process directly affect the cooling performance. In order to study the droplet heat and mass transfer law in the droplet evaporation process, this paper builds a coupled thermal mass model of droplet evaporation and tests the accuracy of the numerical model through theoretical results. In order to study the influence of the Marangoni effect on the droplet evaporation process and the effects of different initial droplet radius and ambient temperature on the temperature and flow, fields within the droplet are compared. From this result, it can be seen that the droplet volume is 20 μL, and the maximum flow velocity in the droplet is 0.34 mm/s, without taking into account the Marangoni effect. When the Marangoni effect is taken into account, the maximum flow velocity increases by almost 100 times. The Marangoni effect can cause the convection in the droplet to change direction, and the formation of the Marangoni flow may affect the temperature distribution within the droplet, thereby increasing the evaporation efficiency by 2.5%. The evaporation process will increase the velocity of the air close to the surface of the liquid, but the increase in air velocity close to the liquid surface is not sufficient to reinforce evaporation. There is a non-linear relationship between increasing ambient temperature and increasing evaporation efficiency. For every 5 °C increase in ambient temperature, the maximum increase in the rate of evaporation is approximately 22.7%.
Broadband Frequency Selective Rasorber Based on Spoof Surface Plasmon Polaritons
Authors: Bai Jin , Yang Qingzhen , Liang Yichao , Gao Xiang
Published: November 2022

A broadband frequency selective rasorber (FSR) based on spoofsurface plasmon polaritons (SSPP) is proposed. The FSR is composed of a multi-layer structure comprising frequency selective surface (FSS)-polyresin (PR)-indium tin oxide (ITO)-PR-FSS and placed vertically on a metal base plate. A periodic square cavity structure is formed. The transmission characteristics of the FSR are studied by full-wave simulation and equivalent circuit method. The simulation results demonstrate that under normal incidence, the absorption rate of the structure remains 95% in the 5–30 GHz band, and the absorption rate is also 80% in the 3.5–5 GHz band. As the incident angle of the electromagnetic wave increases to 40°, the absorption rate in the 15–20 GHz band decreases to 70% in the transverse electric (TE) mode, and the absorption rate in the transverse magnetic (TM) mode is almost the same as that of vertical incidence. The transmission response of the structure is measured in an anechoic chamber. The measurement results agree well with the simulation results, proving the reliability of the design and fabrication. The structure is less sensitive to the incident angle of magnetic waves and has a better broadband absorbing ability.
Paleoproterozoic Layered Intrusions of the Monchegorsk Ore District: Geochemistry and U–Pb, Sm–Nd, Re–Os Isotope Analysis
Authors: Smol’kin Valery F. , Mokrushin Artem V.
Published: November 2022

The paper concerns the geochemical analysis of rocks from the ore-bearing layered intrusions that belong to two age groups of the Monchepluton and the Imandra–Umbarechka Complex (2.50 and 2.44 Ga) and the largest gabbro-anorthosite of the Main Ridge Complex (2.51–2.45 Ga). The intrusion of these complexes happened at different depths when the endogenous and geodynamic settings changed at the beginning of the Paleoproterozoic Era. Five megacycles are distinguished in a generalized cross-section of the two-chamber Monchepluton. The megacycles differ in rock composition, rock geochemical features, and mineralization types, i.e., the chromite, sulfide Cu–Ni–PGE and low-sulfide PGE types. The abrupt changes in isotope indicators (εNd, 87Sr/86Sr) mark their boundaries. At a depth of 2037–2383 m, the M-1 borehole intersects a standalone intrusive body that is essentially a magma feeder channel. The intrusive body’s geochemical characteristics and U–Pb isotope age correlate to the Monchepluton rocks. The gabbro-anorthosite massifs united in the Main Ridge Complex were intruded in the following order: the Monchetundra, Chunatundra, Volchetundra, and Losevo–Medvezhye tundras. The largest Monchetundra massif was formed as a result of multiple intrusions of mafic magmatic melt from the deep reservoirs. The melts intruded in two stages, i.e., 2.51–2.49 Ga and 2.48–2.47 Ga, and their composition changed gradually. The gabbro-pegmatites and coeval harrisite dykes are more recent ones (2.46–2.45 Ga). The summarized results of the U–Pb, Sm–Nd, and Re–Os systems research allowed us to establish genetic relations between the studied geological objects. We proposed a model where there was an uplift of a mantle plume to the lower crust area at the age of 2.5 Ga, the deep mantle reservoirs were formed, and a large-scale interaction happened between the parental magma and granulite–eclogite complex rocks. Local contamination and assimilation processes took place during the uplifting of magmas in areas where the magmatic feeding system contacted the host amphibolite–gneiss Archean complexes.
Development of a Low-Cost Device for Monitoring Ventilation Parameters (Temperature, Humidity and Pressure) in Underground Environments to Increase Operational Safety Using IoT
Authors: Santos Rita de Cassia Pedrosa , da Silva José Margarida , Junior Walter Albergaria , Pinto Claudio Lúcio , Oliveira Michel Melo , Mazzinghy Douglas Batista
Published: November 2022

The important role of ventilation in underground mines is to ensure safety and adequate environmental conditions in all accessible areas of a mine. This research aims to develop low-cost solutions for monitoring ventilation parameters in underground mines using the Internet of Things (IoT). A comparison between standard measuring equipment and a new low-cost wearable monitoring device prototype was performed, and the variables measured in an underground mine were pressure, temperature, and relative humidity. The results in all surveys indicate that the wearable monitoring device prototype can properly be used for continuous monitoring of the underground environment. The standard measurement devices for underground mines should continuously be used by mining companies as requested by local legislation. The low-cost wearable monitoring device developed should be viewed as a redundant measurement device for operators’ safety. The constant innovations in technology can support mining operators in anticipating problems, improving productivity, ensuring safety, and meeting standards at low investments.
The Effect of Mining Activities on the Paleokarstic Features, Recent Karstic Features, and Karst Water of the Bakony Region (Hungary)
Authors: Veress Márton
Published: November 2022

This study describes the direct and indirect effects of mining on the karst of the Bakony Region. For this, the results of geological and mining research of the last century, the results of hydrological research of fifty years, as well as the investigations of several decades on the karst of the mountain region are used. Direct effects include the exploitation of filling materials (limonite, kaolinite, manganese ore, and bauxite) from paleokarst features, dolomite rubble, activities exploring or destroying cavities, and the pollution of cavity systems with mining waste (dirt). An indirect effect is karst water extraction. Mining activities (coal and quarrying) resulting in the development of pseudokarstic features are also mentioned here. It can be stated that the effects on the karst and karst features may be permanent and even renewing, but the original state may also have returned or can be expected in the near future. Damages may be local or regional. A regional effect is the decrease in karst water level, which has the most significant effect on the environment, but it has already reached its original state by now.
A Review of The Application of Spectroscopy to Flavonoids from Medicine and Food Homology Materials
Authors: Zou Lin , Li Huijun , Ding Xuejie , Liu Zifan , He Dongqiong , Kowah Jamal A. H. , Wang Lisheng , Yuan Mingqing , Liu Xu
Published: November 2022

Medicinal and food homology materials are a group of drugs in herbal medicine that have nutritional value and can be used as functional food, with great potential for development and application. Flavonoids are one of the major groups of components in pharmaceutical and food materials that have been found to possess a variety of biological activities and pharmacological effects. More and more analytical techniques are being used in the study of flavonoid components of medicinal and food homology materials. Compared to traditional analytical methods, spectroscopic analysis has the advantages of being rapid, economical and free of chemical waste. It is therefore widely used for the identification and analysis of herbal components. This paper reviews the application of spectroscopic techniques in the study of flavonoid components in medicinal and food homology materials, including structure determination, content determination, quality identification, interaction studies, and the corresponding chemometrics. This review may provide some reference and assistance for future studies on the flavonoid composition of other medicinal and food homology materials.
Antibacterial and Antiproliferative Activities of Azadirachta indica Leaf Extract and Its Effect on Oil-in-Water Food Emulsion Stability
Authors: Ouerfelli Manel , Metón Isidoro , Codina-Torrella Idoia , Almajano María Pilar
Published: November 2022

The present study aims to identify and quantify the phenolic compounds of Azadirachta indica leaf extract using HPLC-MS and to evaluate the antioxidant, antibacterial (against different Gram-positive and negative bacteria) and in vitro anti-proliferative activities of this extract (against breast, human liver and cervix adenocarcinoma-derived cells). The application of this extract as a natural antioxidant for food preservation was also tested on oil-in-water food emulsions for the first time in the present work in order to determine the use of Azadirachta indica leaves as a natural additive to preserve the food against lipid oxidation and rancidity. The results obtained revealed that 50%-aqueous ethanol leaf extract showed the best extraction yield (25.14%), which was characterized by a high content in phenolic compounds and strong antioxidant activity. Moreover, this leaf extract inhibited the growth of the bacterial strains tested (Staphylococcus aureus, Escherichia coli, Salmonella paratyphi and Micrococcus luteus) and showed better anti-proliferative activity against breast and cervix adenocarcinoma-derived cells than human liver cancer cells after 48 h of treatment. Additionally, Azadirachta indica leaf extract showed almost similar effects as gallic acid solutions (0.25% and 0.5%) in preserving the oxidation of oil-in-water food emulsions and prevented the formation of secondary oxidation products (malondialdehyde) as well. The results obtained suggested that extracts of Azadirachta indica leaves are a potential source of antioxidant and antibacterial compounds and pointed to the potential of these natural extracts as therapeutic agents.
Assessment of Performance of Photocatalytic Nanostructured Materials with Varied Morphology Based on Reaction Conditions
Authors: Ganguli Ashok Kumar , Kunde Gajanan B. , Raza Waseem , Kumar Sandeep , Yadav Priyanka
Published: November 2022

Synthesis of nanomaterials with specific morphology is an essential aspect for the optimisation of its properties and applications. The application of nanomaterials is being discussed in a wide range of areas, one of which is directly relevant to the environment through photocatalysis. To produce an effective photocatalyst for environmental applications, morphology plays an important role as it affects the surface area, interfaces, crystal facets and active sites, which ultimately affects efficiency. The method of synthesis and synthesis temperature can be the basic considerations for the evaluation of a particular nanomaterial. In this study, we have considered the aspects of morphology with a basic understanding and analyzed them in terms of nanomaterial efficacy in photocatalysis. Different morphologies of specific nanomaterials such as titanium dioxide, zinc oxide, silver phosphate, cadmium sulphide and zinc titanate have been discussed to come to reasonable conclusions. Morphologies such as nanorods, nanoflower, nanospindles, nanosheets, nanospheres and nanoparticles were compared within and outside the domain of given nanomaterials. The different synthesis strategies adopted for a specific morphology have been compared with the photocatalytic performance. It has been observed that nanomaterials with similar band gaps show different performances, which can be linked with the reaction conditions and their nanomorphology as well. Materials with similar morphological structures show different photocatalytic performances. TiO2 nanorods appear to have the best features of efficient photocatalyst, while the nanoflowers show very low efficiency. For CdS, the nanoflower is the best morphology for photocatalysis. It appears that high surface area is the key apart from the morphology, which controls the efficiency. The overall understanding by analyzing all the available information has enumerated a path to select an effective photocatalyst amongst the several nanomaterials available. Such an analysis and comparison is unique and has provided a handle to select the effective morphology of nanomaterials for photocatalytic applications.
Transformation of Residual Açai Fruit (Euterpe oleracea) Seeds into Porous Adsorbent for Efficient Removal of 2,4-Dichlorophenoxyacetic Acid Herbicide from Waters
Authors: Ramirez Rolando , Schnorr Carlos Eduardo , Georgin Jordana , Netto Matias Schadeck , Franco Dison S. P. , Carissimi Elvis , Wolff Delmira , Silva Luis F. O. , Dotto Guilherme Luiz
Published: November 2022

Brazil’s production and consumption of açai pulp (Euterpe oleracea) occur on a large scale. Most of the fruit is formed by the pit, which generates countless tons of residual biomass. A new purpose for this biomass, making its consumption highly sustainable, was presented in this study, where activated carbon (AC) was produced with zinc chloride for later use as an adsorbent. AC carbon formed by carbon and with a yield of 28 % was satisfactorily used as an adsorbent in removing the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). Removal efficiency was due to the highly porous surface (Vp = 0.467 cm3 g−1; Dp = 1.126 nm) and good surface área (SBET = 920.56 m2 g−1). The equilibrium data fit the Sips heterogeneous and homogeneous surface model better. It was observed that the increase in temperature favored adsorption, reaching a maximum experimental capacity of 218 mg g−1 at 328 K. The thermodynamic behavior indicated a spontaneous, favorable, and endothermic behavior. The magnitude of the enthalpy of adsorption was in agreement with the physical adsorption. Regardless of the herbicide concentration, the adsorbent displayed fast kinetics, reaching equilibrium within 120 min. The linear driving force (LDF) model provided a strong statistical match to the kinetic curves. AC with zinc chloride (ZnCl2), created from leftover açai biomass, is a potential alternative as an adsorbent for treating effluents containing 2,4-D.
Regulation of the Gut Microbiota and Inflammation by β-Caryophyllene Extracted from Cloves in a Dextran Sulfate Sodium-Induced Colitis Mouse Model
Authors: Yeom Ji Eun , Kim Sung-Kyu , Park So-Young
Published: November 2022

Ulcerative colitis is an inflammatory bowel disease characterized by symptoms such as abdominal pain, diarrhea, bleeding, and weight loss. Ulcerative colitis is typically treated with anti-inflammatory drugs; however, these drugs are associated with various side effects, limiting their use. β-Caryophyllene (BCP), a natural compound derived from cloves, has antioxidant, antibacterial, and anti-inflammatory activities. In this study, we aimed to investigate the effects of BCP on colitis in a dextran sulfate sodium (DSS)-induced colitis mouse model. BCP was administered for seven days, followed by 2.5% DSS for additional seven days to induce colitis. Changes in stool weight, recovery of gut motility, colon length, colon histology, myeloperoxidase activity, inflammatory cytokines (TNF-α, IL-1β, IL-6, IgA, and IgG), and the gut microbiota were observed. Administration of BCP increased stool weight, restored gut motility, and considerably increased colon length compared to those in the untreated colitis mouse model. In addition, the amount of mucin and myeloperoxidase activity in the colon increased, whereas the concentrations of IL-1β, IL-6, and TNF-α decreased following the administration of BCP. Furthermore, BCP reduced the abundance of Proteobacteria which can cause intestinal immune imbalance. These results suggest that BCP has a potential to be developed as a preventive agent for colitis.