bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating Residual Stresses in Metal-Plastic Composites Stiffening Ribs Formed Using the Single Point Incremental Forming Method
Authors: Kubit Andrzej , Al-Sabur Raheem , Gradzik Andrzej , Ochał Kamil , Slota Ján , Korzeniowski Marcin
Published: November 2022

Low weight and high strength are significant factors in the current decade’s spread of composite sandwich materials. Previous studies have proven that forming stiffening ribs in these materials through the Single Point Incremental Forming (SPIF) process is possible and gives encouraging results. On the other hand, knowledge of residual stress (RS) values that form during the manufacturing process is essential, as they may affect the structural integrity of manufactured elements, whether in compression or tension. The investigation of the RS in the composite materials formed by the SPIF process using the XRD method was very limited in the previous studies, so this research aims to apply the X-ray diffraction (XRD) method to determine RS on the part of the LITECOR® sandwich material formed using SPIF. LITECOR® consists of a plastic core between two layers of steel. In this study, three types of LITECOR® were used with differing plastic core thicknesses of 0.8, 1.25, and 1.6 mm, while the steel layers’ thickness remained the same at 0.3 mm. The axial and traverse RSs were measured in five positions on both sides of the formed part. It was found that the achieved RSs varied from tensile to compressive along the formed regions. It was found that the residual stress values in both directions were inversely proportional to the thickness of the plastic core. It was noted that the highest RS values were in the unformed base metal, after which the RS was reduced on both sides of the SPIF-formed region, followed by a rise in the RS at the concave of the SPIF-formed region. The maximum measured RS for X-axes was 1041 MPa, whereas, for Y-axes, it was 1260 MPa, both of which were recorded on the back side at a thickness of t = 0.8 mm.
Patient with Aberrant Internal Carotid Artery in the Middle Ear Presenting with Rare Symptoms of Mixed Hearing Loss and Postauricular Pain: A Case Report
Authors: Chen Bo-Nien
Published: November 2022

Aberrant internal carotid artery in the middle ear (aICA) is a rare congenital malformation in which the internal carotid artery passes through the tympanic cavity without being separated by bone. A pulsatile vascular mass can be observed in the tympanic cavity of patients with aICA. The diagnosis of aICA may be challenging because improper surgery or treatment can lead to iatrogenic injury, including massive hemorrhage. The aim of this case report was to describe a 39-year-old woman with aICA presenting with mixed hearing loss and postauricular pain. We provided detailed clinical images of the patient to illustrate how aICA can be diagnosed. Because this patient’s aICA had no risk of bleeding, close observation, pharmacological therapy, and regular follow-up were applied. The patient’s postauricular pain was significantly improved after treatment with oxcarbazepine. At the time of this manuscript’s preparation, the patient had been monitored for 10 years and had stable mixed hearing loss with no other complications. Based on the management of this patient, oxcarbazepine can improve aICA-associated postauricular pain, and conservative treatment should be prioritized in cases of aICA without a risk of bleeding. Further studies in a large cohort are required to confirm our findings and recommendations.
Automated Detection of Surgical Implants on Plain Knee Radiographs Using a Deep Learning Algorithm
Authors: Kim Back , Lee Do Weon , Lee Sanggyu , Ko Sunho , Jo Changwung , Park Jaeseok , Choi Byung Sun , Krych Aaron John , Pareek Ayoosh , Han Hyuk-Soo , Ro Du Hyun
Published: November 2022

Background and Objectives: The number of patients who undergo multiple operations on a knee is increasing. The objective of this study was to develop a deep learning algorithm that could detect 17 different surgical implants on plain knee radiographs. Materials and Methods: An internal dataset consisted of 5206 plain knee antero-posterior X-rays from a single, tertiary institute for model development. An external set contained 238 X-rays from another tertiary institute. A total of 17 different types of implants including total knee arthroplasty, unicompartmental knee arthroplasty, plate, and screw were labeled. The internal dataset was approximately split into a train set, a validation set, and an internal test set at a ratio of 7:1:2. You Only look Once (YOLO) was selected as the detection network. Model performances with the validation set, internal test set, and external test set were compared. Results: Total accuracy, total sensitivity, total specificity value of the validation set, internal test set, and external test set were (0.978, 0.768, 0.999), (0.953, 0.810, 0.990), and (0.956, 0.493, 0.975), respectively. Means ± standard deviations (SDs) of diagonal components of confusion matrix for these three subsets were 0.858 ± 0.242, 0.852 ± 0.182, and 0.576 ± 0.312, respectively. True positive rate of total knee arthroplasty, the most dominant class of the dataset, was higher than 0.99 with internal subsets and 0.96 with an external test set. Conclusion: Implant identification on plain knee radiographs could be automated using a deep learning technique. The detection algorithm dealt with overlapping cases while maintaining high accuracy on total knee arthroplasty. This could be applied in future research that analyzes X-ray images with deep learning, which would help prompt decision-making in clinics.
Studying Different Operating Conditions on Reverse Osmosis Performance in the Treatment of Wastewater Containing Nickel (II) Ions
Authors: Shigidi Ihab , Harharah Ramzi H. , Abdalla Ghassan M. T. , Elkhaleefa Abubakar , Alsaiari Norah S. , Harharah Hamed N. , Amari Abdelfattah , Hassan Mohamed G.
Published: November 2022

The reverse osmosis performance in removing nickel ions from artificial wastewater was experimentally and mathematically assessed. The impact of temperature, pressure, feed concentration, and feed flow rate on the permeate flux and Ni (II) rejection % were studied. Experiments were conducted using a SEPA CF042 Membrane Test Skid—TFC BW30XFR with applied pressures of 10, 20, 30, and 40 bar and feed concentrations of 25, 50, 100, and 150 ppm with varying operating temperatures of 25, 35, and 45 °C, while the feed flow rate was changed between 2, 3.2, and 4.4 L/min. The permeate flux and the Ni (II) removal % were directly proportional to the feed temperature and operating pressure, but inversely proportional to the feed concentration, where the permeate flux increased by 49% when the temperature was raised from 25 to 45 °C, while the Ni (II) removal % slightly increased by 4%. In addition, the permeate flux increased by 188% and the Ni (II) removal % increased to 95.19% when the pressure was raised from 10 to 40 bar. The feed flow rate, on the other hand, had a negligible influence on the permeate flux and Ni (II) removal %. The temperature correction factor (TCF) was determined to be directly proportional to the feed temperature, but inversely proportional to the operating pressure; nevertheless, the TCF was unaffected either by the feed flow rate or the feed concentration. Based on the experimental data, mathematical models were generated for both the permeate flux and nickel removal %. The results showed that both models matched the experimental data well.
Tin Removal from Tin-Bearing Iron Concentrate with a Roasting in an Atmosphere of SO2 and CO
Authors: Li Lei , Xu Zhipeng , Wang Shiding
Published: November 2022

The tin could be volatilized and removed effectively from the tin-bearing iron concentrate while roasted in an atmosphere of SO2 and CO. The reduction of SO2 by CO occurred in preference to the SnO2 and Fe3O4, and the generated S2 could sulfurize the SnO2 to an evaporable SnS, which resulted in the tin volatilization. However, the Fe3O4 could be sulfurized simultaneously, and a phase of iron sulfide was formed, retaining in the roasted iron concentrate. It decreased the quality of the iron concentrate. In addition, the formation of Sn-Fe alloy was accelerated as the roasting temperature exceeded 1100 °C, which decreased the Sn removal ratio. An appropriate SO2 partial pressure and roasting temperature should be controlled. Under the condition of the roasting temperature of 1050 °C, SO2 partial pressure of 0.003, CO partial pressure of 0.85, and residence time of 60 min, the tin content in the roasted iron concentrate was decreased to 0.032 wt.% and the sulfur residual content was only 0.062 wt.%, which meets the standard of iron concentrate for BF ironmaking.
Effects of Vacancy Defects on Electrical and Optical Properties of ZnO/WSe2 Heterostructure: First-Principles Study
Authors: Yong Xi , Wang Ao , Deng Lichuan , Zhou Xiaolong , Li Jintao
Published: November 2022

In this work, based on the first principles calculation of density functional theory (DFT), we studied the band structure changes of monolayer ZnO and ZnO/WSe2 before and after vacancy generation, and systematically studied the vacancy formation energy, band structure, density of states, electronic density difference and optical properties of ZnO/WSe2 heterostructure before and after vacancy generation. The results show that the band structures of ZnO, WSe2, and ZnO/WSe2 heterostructure are changed after the formation of Zn, O, W, and Se vacancies. The bandgap of the ZnO/WSe2 heterostructure can be effectively controlled, the transition from direct to indirect bandgap semiconductor will occur, and the heterostructure will show metallic properties. The optical properties of heterostructure have also changed significantly, and the absorption capacity of heterostructure to infrared light has been greatly increased with red shift and blue shift respectively. The generation of vacancy changes the electrical and optical properties of ZnO/WSe2 heterostructure, which provides a feasible strategy for adjusting the photoelectric properties of two-dimensional optoelectronic nano devices and has good potential and broad application prospects.
Effects of Simulated PWHT on the Microstructure and Mechanical Properties of 2.25Cr1Mo0.25V Steel for a Hydrogenation Reactor
Authors: Li Yanmei , Cui Yonghao , Zhang Jimou , Song Minghui , Xu Chen
Published: November 2022

The effect of post-welding heat treatment (PWHT) on the microstructure and mechanical properties of large-thickness 2.25Cr1Mo0.25V steel was investigated through simulated post-welding heat treatment (SPWHT). The results showed that an increase in the SPWHT time decreased the toughness, hardness, and strength of the steel. After Min.SPWHT, the high-temperature tensile strength decreased more significantly, and the damage of Min.SPWHT to the high-temperature tensile strength reached approximately 80% of the Max.SPWHT. The microstructure of the tested steel before and after SPWHT consisted of granular bainite and lath bainite. After SPWHT, intergranular carbides were precipitated as coarsened carbides, carbide clusters, and chains of carbides; alloy element segregation occurred, and the segregation of Mo was the most serious, followed by Cr, and V. The precipitation behavior of the carbides and the increase in the effective grain size caused by the widening of the bainite–ferrite lath worked together and resulted in the decline of the impact toughness; the reduction in the solid solution and precipitation strengthening effects were the main factors in the strength reduction of the tested steel. In the high-temperature tensile tests, defects first appeared around the coarse carbides and carbide clusters. Controlling the size of the intergranular large-size carbides and the degree of cluster precipitation in the NT state structure may be a means of obtaining higher strength of the base metal subjected to PWHT.
Structural Optimization, Fabrication, and Corrosion Behaviors of Biodegradable Mg-Nd-Zn-Zr Alloy Hemostatic Clip
Authors: Mao Lin , Zheng Xin , Tian Yongji , Shi Yiling , Zhang Xiaochen , Song Chengli
Published: November 2022

In this study, the process of ligating blood vessels via biodegradable Mg alloy hemostatic clips with toothless, transverse teeth, and embedded teeth was simulated through finite element analysis (FEA). The results showed that the transverse tooth clip caused the minimum stress (0.81489 MPa) to blood vessels. Furthermore, the effects of clips with transverse teeth of different parameters, including lower tooth length, tooth height, and tooth pitch, on clamped blood vessels were studied. The numerical simulation results showed that the three optimal parameters for clips with transverse teeth were 0.2, 0.1, and 0.1 mm, respectively. Then, the optimally designed clip based on the Mg–Nd–Zn–Zr alloy was manufactured and evaluated using immersion tests. Results from the corrosion behavior study showed that closed clips (0.118 ± 0.041 mg·cm−2·day−1) corroded slightly faster than open clips (0.094 ± 0.041 mg·cm−2·day−1). Moreover, micromorphological observations showed that no cracks appeared on the closed clips, indicating that the Mg alloy had excellent performance and avoided stress corrosion cracking (SCC). Thus, the new type of Mg alloy clip kept good blood vessel closure during FEA and exhibited no corrosion cracking during the degradation process, making it a promising candidate for applications with biodegradable hemostatic clips.
Impact Abrasive Wear of Cr/W-DLC/DLC Multilayer Films at Various Temperatures
Authors: Zhong Wen , Wang Haoyu , Ma Lei , Zhang Changhua
Published: November 2022

Diamond-like carbon (DLC) films are widely used in key parts of nuclear reactors as a protective coating. A study on the abrasive wear property of Cr/W-DLC/DLC multilayer films was performed at various temperatures. Results show that the mechanism of impact wear under no sand condition is mainly plastic deformation. The multilayer film still has excellent impact wear resistance and favorable adhesion with 308L stainless steel substrate at elevated temperatures under no sand conditions. Sand particles destroy the surface of the multilayer film due to the effect of cutting and ploughing, leading to a nine-fold increase in the wear area. The impact wear mechanism changes into abrasive wear with sand addition. Oxidation wear exists on 308L stainless steel substrate material due to the removal of the multilayer film at high temperatures. More energy is absorbed for plastic deformation and material removal under sand conditions, resulting in lower rebound velocity and peak contact force than under no sand conditions. The temperature leads to the softening of the substrate; thus, the specimens become more prone to plastic deformation and material removal.
Application of Optimizing Slab Corner Shapes to Reduce Edge Seam Defect on Heavy Plates
Authors: Wang Minglin , Zhang Hui , Zhao Wenbo , Liu Heping , Wang Xuebing
Published: November 2022

The edge seam defect is a common defect in hot rolling heavy plates. It can be improved by optimizing the corner shapes of slabs. Based on a numerical analysis of the effects of the slab corner shape on the temperature distribution after the slab’s exit from the heating furnace, three rolling methods are proposed for controlling the two-chamfered slab corner shape. The stress and deformation of the corner of the slab during the two-chamfered rolling process are investigated using a numerical simulation. The results show that a two-chamfered shape slab has the smallest temperature drop during the cooling process, and the slab corner can maintain higher temperature and uniformity, which is beneficial for controlling the deformation during the rolling process. Among the three kinds of two-chamfered rolling methods, frontal rolling using a two-roller has the smallest rolling force and rolling resistance to the casting machine, followed by horizontal rolling and then vertical rolling, which has the largest. The favorable slab corner in a two-chamfered shape can be obtained by frontal rolling using a two-roller. Industrial trials confirm that an edge seam defect rate of less than 5% in heavy plates can be achieved under the condition of a large broadside ratio.
Experimental Investigation and Numerical Simulation of the Fluidity of A356 Aluminum Alloy
Authors: Bang Hyeon-Sik , Kwon Hyeok-In , Chung Sung-Bean , Kim Dae-Up , Kim Min-Su
Published: November 2022

The fluidity of A356 aluminum alloy was experimentally determined at the melt temperatures and vacuum degrees by a series of suction fluidity tests. In order to achieve different cooling rates during the test, quartz tubes, as well as stainless steel tubes, were employed as the fluidity channels. As the melt temperature increased from 650 to 730 °C, fluidity lengths either linearly increased from 26 to 36 cm or parabolically increased from 13 to 29 cm when quartz tubes or stainless steel tubes were employed, respectively. As the vacuum degree of the fluidity test increased from 0.005 to 0.03 MPa, fluidity increased from 25 to 43 cm in quartz tubes while the smaller increase in fluidity from 20 to 31 cm was observed in stainless steel tubes. Shorter fluidity lengths in stainless steel tubes than those in quartz tubes under the same fluidity measurement condition were due to faster solidification speed confirmed by microstructural analysis. In order to predict the fluidity of the A356 alloy obtained from the suction fluidity tests, a mathematical model was developed based on heat and mass transfer equations coupled with thermodynamic calculations by ChemApp software. The simulation results show good agreement with the fluidity length obtained in the present study. From a series of model calculations, the effects of casting parameters on the fluidity of the A356 melt were discussed.
Research Progress of Magnetic Field Regulated Mechanical Property of Solid Metal Materials
Authors: Hu Yujun , Zhao Hongjin , Yu Xuede , Li Junwei , Zhang Bing , Li Taotao
Published: November 2022

During the material preparation process, the magnetic field can act with high intensity energy on the material without contact and affect its microstructure and properties. This non-contact processing method, which can change the microstructure and properties of material without affecting the shape and size of products, has become an important technical means to develop new materials and optimize the properties of materials. It has been widely used in scientific research and industrial production. In recent years, the magnetic field assisted processing of difficult-to-deform materials or improving the performance of complex and precision parts has been rapidly and widely concerned by scholars at home and abroad. This paper reviews the research progress of magnetic field regulating the microstructure, and properties of solid metal materials. The effects of magnetic field-assisted heat treatment, magnetic field assisted stretching, and magnetic field independent treatment on the microstructure and properties of solid metal materials are introduced. The mechanism of the magnetic field effect on the properties of metal materials is summarized, and future research on the magnetic field effect on solid metal has been prospected.
Macrosegregation Evolution in Eutectic Al-Si Alloy under the Influence of a Rotational Magnetic Field
Authors: Al-Omari Kassab , Roósz András , Rónaföldi Arnold , Svéda Mária , Veres Zsolt
Published: November 2022

Using magnetic stirring during solidification provides a good opportunity to control the microstructure of alloys, thus controlling their physical properties. However, magnetic stirring is often accompanied by a change in local concentrations, and new structures form which could harm the physical properties. This research paper investigated the effect of forced melt flow by a rotating magnetic field (RMF) on the macrostructure of an Al-Si eutectic alloy. To serve this purpose, Al-12.6 wt% Si alloy samples were solidified in a vertical Bridgman-type furnace equipped with a rotating magnetic inductor to induce the flow in the melt. The diameter and length of the sample are 8 mm and 120 mm, respectively. The solidification parameters are a temperature gradient (G) of 6 K/m, and the solid/liquid front velocity (v) of 0.1 mm/s. These samples were divided into parts during the solidification process, where some of these parts are solidified under the effect of RMF stirring while others are solidified without stirring. The structure obtained after solidification showed a distinct impact of stirring by RMF; new phases have been solidified which were not originally present in the structure before stirring. Besides the eutectic structure, the new phases are the primary aluminum and the primary silicon. The Si concentration and the volume fraction of each phase were measured using Energy-Dispersive Spectroscope (EDS)and new image processing techniques. The experimental results reveal that applying the RMF during the solidification has a distinct effect on the macrostructure of Al-Si eutectic alloys. Indeed, the RMF provokes macro-segregation, reduces the amount of eutectic structure, and changes the sample’s Si concentration distribution.
Normal Thermostability of p.Ser113Leu and p.Arg631Cys Variants of Mitochondrial Carnitine Palmitoyltransferase II (CPT II) in Human Muscle Homogenate
Authors: Joshi Pushpa Raj , Gräfin zu Stolberg-Stolberg Maria , Scholle Leila Motlagh , Meinhardt Beate , Pegoraro Elena , Zierz Stephan
Published: November 2022

Previous fibroblast and recombinant enzyme studies showed a markedly thermolabile p.Ser113Leu variant compared to the wild-type (WT) in muscle carnitine palmitoyltransferase II (CPT II) deficiency. Additionally, it has been shown that cardiolipin (CLP) stimulated or inhibited the p.Ser113Leu recombinant variant depending on the pre-incubation temperatures. In this study, the thermolabilities of mitochondrial enzyme CPT II in muscle homogenates of patients with the p.Ser113Leu (n = 3) and p.Arg631Cys (n = 2) variants were identified to be similar to that of WT. Pre-incubation with CLP on ice stimulated the WT enzyme more than both variants. However, CLP stimulated the variants and WT at 46 °C to about 6–18-fold. The present data indicate that the thermostability of CPT II variant in muscle homogenate is similar to that of WT. This is in contrast to the increased thermolability of enzymes derived from fibroblast and that of recombinant enzymes. Hence, it can be speculated that the disruption of the compartmentation in muscle homogenate mediates a protective effect on the thermolability of the native variant. However, the exact mechanism remains unclear. However, the activating effect of CLP on CPT II in muscle homogenate seems to align with those on recombinant enzymes.
Fabrication of LuAG:Ce3+ Ceramic Phosphors Prepared with Nanophosphors Synthesized by a Sol-Gel-Combustion Method
Authors: Kwon Seok Bin , Choi Seung Hee , Yoo Jung Hyeon , Lee Seon Yeong , Kim Bo Young , Jeong Ho Jung , Kim Wan Ho , Kim Jae Pil , Kang Bong Kyun , Yoon Dae Ho , Song Young Hyun
Published: November 2022

The aim of this study was to investigate properties of ceramic phosphors fabricated using nano Lu3Al5O12:Ce3+ phosphors produced with a sol-gel-combustion method. These nano Lu3Al5O12:Ce3+ phosphors had a size of about 200 nm, leading to high density when fabricated as a ceramic phosphor. We manufactured ceramic phosphors through vacuum sintering. Alumina powder was added to improve properties. We mounted the manufactured ceramic phosphor in a high-power laser beam projector and drove it to determine its optical performance. Ceramic phosphor manufactured according to our route will have a significant impact on the laser-driven lighting industry.
Effect of Polyvinylpolypyrrolidone Surfactant on Characteristics of Iron-Oxide Nanoparticles Synthesized by Using Recycled Waste Permanent Magnets
Authors: Hong Sung-Jei , Jo Ajin , Hong Sang Hyeok , Kim Byeong Jun , Kim Young Sung , Yang Suwon , Lee Jae-Yong
Published: November 2022

In this study, iron oxide nanoparticles (FeOx NPs) were synthesized by using Fe solution recycled from NdFeB permanent magnet scrap. Furthermore, the effect of polyvinylpolypyrrolidone (PVP) as a surfactant on the characteristics of the FeOx NPs was investigated. Firstly, Fe solution was prepared by using 10% H2SO4 solution and Na2SO4 salt. In addition, three reducing agent solutions were prepared by dissolving PVP in 0.5 M NH4OH solution in distilled (D.I.) water with concentrations of 0 wt%, 1 wt%, and 2 wt%, respectively. Each reducing agent solution was added dropwise into the Fe solution to precipitate three precursors of FeOx NPs, and they were heat-treated at 400 °C to prepare three FeOx NPs samples, P0, P1, and P2. In X-ray diffractometer (XRD) analysis, diffraction peaks of P0 sample are consistent with the Fe3O4 with (311) preferred orientation. The XRD peak shifted from Fe3O4 to Fe2O3 structure as PVP concentration increased, and the crystal structure of P2 sample was transformed to Fe2O3 with (104) preferred orientation. Brunauer, Emmett, and Teller (BET) specific surface area increased in proportional to PVP concentration. HRTEM observation also supported the tendency; the particle size of the P0 sample was less than 40 nm, and particle size decreased as PVP concentration increased, leading to the particle size of the P2 sample being less than 20 nm in width. In addition, particle morphology started to be transformed from particle to rod shape as PVP concentration increased and, in the P2 sample, all the morphology of particles was transformed to a rod shape. Magnetic properties analysis revealed that the P0 sample exhibited the highest value of magnetic moment, 65.6 emu/g, and the magnetic moment was lowered in the P1 sample, and the P2 sample exhibited the lowest value of magnetic moment, 2.4 emu/g.
Temperature-to-Digital Converters’ Evolution, Trends and Techniques across the Last Two Decades: A Review
Authors: Aprile Antonio , Bonizzoni Edoardo , Malcovati Piero
Published: November 2022

This paper presents an extensive review of the main highlights in the Temperature-to-Digital Converters (TDCs) field, which has gained importance and research interest throughout the last two decades. The key techniques and approaches that have led to the evolution of this kind of systems are presented and compared; their peculiarities are identified in order to highlight the pros and cons of the different design methods, and the main trade-offs are extracted from this analysis. Finally, the trends that have emerged from the performance evaluation of the large amount of published works in this field are identified with the purpose of providing a directional view of the past, present and future features of these devices.
A Miniaturized Device Coupled with Digital Image Correlation for Mechanical Testing
Authors: Cruz Daniel J. , Xavier Jose , Amaral Rui L. , Santos Abel D.
Published: November 2022

Miniaturized mechanical testing based on small sample testing technology is a powerful technique to characterize the mechanical properties of different materials, and it is being used in different application fields. However, the small size of the specimens poses several challenges because the results are highly sensitive to measurement accuracy and the corresponding mechanical properties can change substantially due to the so-called specimen size effect. In this work, a novel testing device based on miniaturized specimens is presented. The equipment is designed to test materials in tensile and compressive loadings, but it is also capable of performing reverse-loading tests. Buckling of the specimen is an inherent phenomenon in compression loadings, especially for thin materials. Therefore, specimen geometry is properly studied and optimized to mitigate this effect. To evaluate the deformation of the specimen, the digital image correlation (DIC) technique is used to capture the full-field strain in the central gauge section of the sample. A sensitivity analysis of the DIC setting parameters was performed for this application. To evaluate the performance of the developed system, experimental results of monotonic tests and tests with reverse loadings (tension-compression) are presented, considering two high-strength steels (DP500 and DP780).
Electromagnetic Actuation for a Micro/Nano Robot in a Three-Dimensional Environment
Authors: Abdelaziz Mostafa , Habib Maki
Published: November 2022

Micro/nanorobots have several potential biomedical applications, such as drug delivery, minimal invasiveness, and moving within narrow and complex areas. To achieve these desirable applications, precise path tracking and controlling magnetic micro/nanorobots within blood vessels is a crucial but challenging point. In this paper, a three-dimensional electromagnetic actuation system composed of three pairs of Helmholtz coils and three pairs of Maxwell coils is proposed. A closed-loop control algorithm is proposed to enhance trajectory tracking of a micro/nanorobot. Different simulation experiments were carried out using Simulink to verify the performance of the proposed algorithm. Different trajectories were tested in tracking two-dimensional and three-dimensional reference trajectories. The results showed that by using the developed algorithm and electromagnetic actuation system, a micro/nanorobot can follow the desired trajectory within a maximum error of 13 μm.
An Optimization Design Method of Rigid-Flexible Soft Fingers Based on Dielectric Elastomer Actuators
Authors: Ouyang Fuhao , Guan Yuanlin , Yu Chunyu , Yang Xixin , Cheng Qi , Chen Jiawei , Zhao Juan , Zhang Qinghai , Guo Yang
Published: November 2022

The soft gripper has received extensive attention, due to its good adaptability and flexibility. The dielectric elastomer (DE) actuator as a flexible electroactive polymer that provides a new approach for soft grippers. However, they have the disadvantage of having a poor rigidity. Therefore, the optimization design method of a rigid-flexible soft finger is presented to improve the rigidity of the soft finger. We analyzed the interaction of the rigid and soft materials, using the finite element method (FEM), and researched the influence of the parameters (compression of the spring and pre-stretching ratio of the DE) on the bending angle. The optimal parameters were obtained using the FEM. We experimentally verified the accuracy of the proposed method. The maximum bending angle is 19.66°. Compared with the theoretical result, the maximum error is 3.84%. Simultaneously, the soft gripper with three fingers can grasp various objects and the maximum grasping quality is 11.21 g.
The Rheological Properties and Strength Characteristics of Cemented Paste Backfill with Air-Entraining Agent
Authors: Yang Baogui , Wang Xiaolong , Yin Peng , Gu Chengjin , Yin Xindong , Yang Faguang , Li Tao
Published: November 2022

Clogging pipelines is one of the most common and urgent problems in paste backfill mining. The aim of the present study was to solve the problem of pipe blockage in paste backfill mining. In this paper, paste mixed with coal gangue, fly ash, cement, and additives is used to investigate the influence of three air-entraining agents (AEAs) (including sodium dodecyl sulfate (SDS), triterpene saponin (SJ), and sodium abietate (SA)) on the flow characteristics and strength characteristics of the paste. A series of relevant tests was conducted on the paste, such as air content experiments, slump and expansion experiments, viscosity and yield stress tests, and the uniaxial compressive strength (UCS) test. The results show that the air content of the paste increases with increasing AEA content, but the increase is limited and reaches a maximum at 0.9 AEA. The slump of the paste increased by up to 10–13 mm, and expansion increased by up to 66–130 mm compared to the paste without AEA. The viscosity of the paste decreased by up to 0.13–0.20 Pa·s, and the yield stress decreased by 81.47%–93.7% of the original. The strength of the paste was also reduced, and after 28 days of curing, the strength was reduced by up to 1–1.2 MPa. Taking into account the strength requirement of 3 MPa for the paste from the Linxi mine, it was considered that the dosage of 0.9 B was a good choice, as it could better change the flowability of the paste and reduce the pipeline transportation resistance and transportation energy consumption. At the same time, the strength was also acceptable. The study in this paper can provide a reference for performance studies of pastes mixed with coal gangue, fly ash, cement, and additives as materials.
Magma Evolution and Constraints on the Graphite Mineralization Hosted by the Huangyangshan Alkaline Granite Suite in the East Junggar of Xinjiang Province: Evidence from In Situ Analyses of Silicate Minerals
Authors: Sun Xinhao , Ren Yunsheng , Li Jingmou , Huang Mengjia , Sun Zhenjun , Li Zuowu
Published: November 2022

The Huangyangshan super-large graphite deposit, located in the East Junggar area of the Xinjiang Province, is hosted in and has closely temporal, spatial, and genetic relationships with the Huangyangshan alkaline granites. There are such silicate minerals as amphibole, biotite, pyroxene, and plagioclase occurring in the graphite-bearing granites. The integration of the electron microprobe analysis (EMPA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) enabled us to reveal the physicochemical conditions and evolution process, as well as the relationship of alkaline magmatism with graphite mineralization. The results show that the amphiboles generally have low Al and high Ti, K, Si, and Fe contents, as well as similar rare-earth elements (REEs) patterns and trace element distribution patterns to granites with significantly negative Eu anomalies. In the analyzed samples, primary biotite belongs to Fe-biotite and has characteristics of high Si and Fe and low Al and Mg contents. In the graphite orbicules, the pyroxene phenocrysts develop multiple zonal structures and are characterized by high Si and low Ca and Fe contents. The dominant plagioclase phenocrysts in the graphite orbicules are oligoclase and andesine, with normal and occasionally oscillatory zoning. The calculated crystallization temperature of the pyroxene, amphibole, and primary biotite in graphite orbicules are 840–1012 °C, 681–761 °C, and 658–720 °C, respectively, corresponding with their crystallization order. The pressure and depth calculation results of the amphibole, representing those of the magmatism, are 157–220 Mpa and 5.95–8.32 km, respectively. Both amphibole and biotite crystallized in a reducing environment with extremely low oxygen fugacity. The elemental compositions of these silicates indicate that the Huangyangshan pluton experienced significant mixing of mafic mantle-derived magma and felsic crust-derived magma. The cores of graphite orbicules were formed in a relatively earlier magmatic stage, while the granites and their dioritic enclaves were formed in a later magmatic stage. During magmatism, the mixing of mantle-derived basic magma had an important influence on the evolution and differentiation of the melts. According to the coexisting sulfides with graphite and compositional difference of amphibole and biotite in the granites and graphite ores, the graphite mineralization might be triggered by a magma mixing process.
Metallogenesis of Porphyry Copper Deposit Indicated by In Situ Zircon U-Pb-Hf-O and Apatite Sr Isotopes
Authors: Zhang Hong , An Fang , Ling Mingxing , Feng Xiaolin , Sun Weidong
Published: November 2022

The origin of the Dexing porphyry Cu deposit is hotly debated. Zircon and apatite are important accessory minerals that record key information of mineralization processes. SHRIMP zircon U-Pb analyses of granodiorite porphyries yield ages of 168.9 ± 1.2 Ma, 168.0 ± 1.0 Ma, and 172.8 ± 1.3 Ma, whereas zircons in the volcanic rocks of the Shuangqiaoshan Group have Neoproterozoic ages of 830 ± 7 Ma, 829 ± 8 Ma, and 899 ± 12 Ma. The porphyry displays zircon in situ δ18O of mantle values (5.5 ± 0.2‰), low apatite 87Sr/86Sr ratios (0.7058 ± 0.0005), and high εHf values (5.1 ± 1.5), which are consistent with mantle-derived magmatic rocks. Apatite from the porphyries has relatively high total rare earth elements (REEs) and negative Eu anomalies, with relatively high Cl and As contents. These features are distinctly different from apatite in the Shuangqiaoshan Group, which shows lower total REE, Cl, and As contents but higher F content and positive Eu anomalies. Zircon in porphyries yields a relative high oxygen fugacity of ∆FMQ + 1.5 based on zircon Ce4+/Ce3+. Apatite in porphyries also shows high oxygen fugacity based on its SO3 and Mn compositions, reaching ∆FMQ + 2, which is different from that of the lower continental crust in general, but similar to subduction-related magmas. In contrast, the oxygen fugacity of the Shuangqiaoshan Group is much lower, suggesting a different origin for its wall rock. Therefore, the Dexing porphyries were not derived from the lower crust but derived from partial melting of the subducting Paleo-Pacific plate.
Minerochemical and Microtextural Study of the Ungrouped Iron Meteorite Oglat Sidi Ali, Eastern Highlands, Morocco, and Geomorphological Characterization of Its Strewnfield
Authors: Nachit Hassane , Ibhi Abderrahmane , En-nasiry Mohamed , Moggi Cecchi Vanni , Pratesi Giovanni , Herd Christopher D. K. , Senesi Giorgio S.
Published: November 2022

Fragments of a new iron meteorite were found in and collected from Oglat Sidi Ali, Maatarka region, Morocco, during a series of expeditions in the years 2013–2017. The physical characteristics of recovered fragments feature typical attributes of individual samples of a unique meteorite strewnfield that originated from an iron meteorite shower via the fragmentation of a single body that broke up in the lower atmosphere. The total recovered mass of the Oglat Sidi Ali meteorite fragments was estimated to amount to more than 800 kg spread across a NE–SW oriented, 20 km-long and 5 km-wide strewnfield. Geochemical and mineralogical data achieved on Oglat Sidi Ali fragments, as well as the analysis of its microstructures obtained using electron backscattered diffraction (EBSD), suggested it should be classified as an ungrouped iron meteorite. A comparison of this meteorite with other ungrouped iron meteorites, such as NWA 859 and NWA 11010, purchased between 2001 and 2016 in various cities of Northeast Morocco show apparently similar mineralogy, geochemistry and textural features, suggesting a common origin from a single extraterrestrial body.
Correlation between Compressive Strength and Heat of Hydration of Cement Mortars with Siliceous Fly Ash
Authors: Kuryłowicz-Cudowska Aleksandra
Published: November 2022

This paper presents the results of calorimetric and strength tests of mortars with ordinary Portland cement and two substitution rates (10 and 20%) of cement by siliceous fly ash. The prepared samples were cured under isothermal conditions at four different temperatures: 23, 33, 43 and 53 °C. Heat of hydration was measured using an isothermal calorimeter dedicated to monitor the hydration process of cementitious composites such as paste, mortar and concrete. Thermal data were recorded continuously for 7 days, while compression tests were performed at 6 h and 1, 2, 5, 7 and 14 days of hardening. The studies proved that the amount of heat released correlates with the early-age strength of 50 mm mortar cubes. In the case of samples cured at 23 and 53 °C, a linear relationship between the heat of hydration and compressive strength was observed. The high value of the coefficient of determination (R2) allows one to estimate the mortar compressive strength after 7 and 14 days based on hydration heat tests conducted at standard temperature (23 °C), regardless of the percentage of siliceous fly ash. The increased curing temperatures do not guarantee a high correlation between compressive strength and the amount of heat released.
Setting Boundaries for Statistical Mechanics
Authors: Eisenberg Bob
Published: November 2022

Statistical mechanics has grown without bounds in space. Statistical mechanics of noninteracting point particles in an unbounded perfect gas is widely used to describe liquids like concentrated salt solutions of life and electrochemical technology, including batteries. Liquids are filled with interacting molecules. A perfect gas is a poor model of a liquid. Statistical mechanics without spatial bounds is impossible as well as imperfect, if molecules interact as charged particles, as nearly all atoms do. The behavior of charged particles is not defined until boundary structures and values are defined because charges are governed by Maxwell’s partial differential equations. Partial differential equations require boundary structures and conditions. Boundary conditions cannot be defined uniquely ‘at infinity’ because the limiting process that defines ‘infinity’ includes such a wide variety of structures and behaviors, from elongated ellipses to circles, from light waves that never decay, to dipolar fields that decay steeply, to Coulomb fields that hardly decay at all. Boundaries and boundary conditions needed to describe matter are not prominent in classical statistical mechanics. Statistical mechanics of bounded systems is described in the EnVarA system of variational mechanics developed by Chun Liu, more than anyone else. EnVarA treatment does not yet include Maxwell equations.
Encapsulation of Vitamin C by Glycerol-Derived Dendrimers, Their Interaction with Biomimetic Models of Stratum corneum and Their Cytotoxicity
Authors: Bacha Katia , Chemotti Catherine , Monboisse Jean-Claude , Robert Anthony , Furlan Aurélien , Smeralda Willy , Damblon Christian , Estager Julien , Brassart-Pasco Sylvie , Mbakidi Jean-Pierre , Pršić Jelena , Bouquillon Sandrine , Deleu Magali
Published: November 2022

Vitamin C is one of the most sensitive cosmetic active ingredients. To avoid its degradation, its encapsulation into biobased carriers such as dendrimers is one alternative of interest. In this work, we wanted to evaluate the potential of two biobased glycerodendrimer families (GlyceroDendrimers-Poly(AmidoAmine) (GD-PAMAMs) or GlyceroDendrimers-Poly(Propylene Imine) (GD-PPIs)) as a vitamin C carrier for topical application. The higher encapsulation capacity of GD-PAMAM-3 compared to commercial PAMAM-3 and different GD-PPIs, and its absence of cytotoxicity towards dermal cells, make it a good candidate. Investigation of its mechanism of action was done by using two kinds of biomimetic models of stratum corneum (SC), lipid monolayers and liposomes. GD-PAMAM-3 and VitC@GD-PAMAM-3 (GD-PAMAM-3 with encapsulated vitamin C) can both interact with the lipid representatives of the SC lipid matrix, whichever pH is considered. However, only pH 5.0 is suggested to be favorable to release vitamin C into the SC matrix. Their binding to SC-biomimetic liposomes revealed only a slight effect on membrane permeability in accordance with the absence of cytotoxicity but an increase in membrane rigidity, suggesting a reinforcement of the SC barrier property. Globally, our results suggest that the dendrimer GD-PAMAM-3 could be an efficient carrier for cosmetic applications.
Design, Synthesis and Biological Assessment of Rhodanine-Linked Benzenesulfonamide Derivatives as Selective and Potent Human Carbonic Anhydrase Inhibitors
Authors: Swain Baijayantimala , Khan Abrar , Singh Priti , Marde Vaibhav S. , Angeli Andrea , Chinchilli Krishna Kartheek , Yaddanapudi Venkata Madhavi , Carradori Simone , Supuran Claudiu T. , Arifuddin Mohammed
Published: November 2022

A novel series of twenty-five rhodamine-linked benzenesulfonamide derivatives (7a–u and 9a–d) were synthesized and screened for their inhibitory action against four physiologically relevant human (h) carbonic anhydrase (CA) isoforms, namely hCA I, hCA II, hCA IX, and hCA XII. All the synthesized molecules showed good to excellent inhibition against all the tested isoforms in the nanomolar range due to the presence of the sulfonamide as a zinc binding group. The target compounds were developed from indol-3-ylchalcone-linked benzenesulfonamide where the indol-3-ylchalcone moiety was replaced with rhodanine-linked aldehydes or isatins to improve the inhibition. Interestingly, the molecules were slightly more selective towards hCA IX and XII compared to hCA I and II. The most potent and efficient ones against hCA I were 7h (KI 22.4 nM) and 9d (KI 35.8 nM) compared to the standard drug AAZ (KI 250.0 nM), whereas in case of hCA II inhibition, the derivatives containing the isatin nucleus as a tail were preferred. Collectively, all compounds were endowed with better inhibition against hCA IX compared to AAZ (KI 25.8 nM) as well as strong potency against hCA XII. Finally, these newly synthesized molecules could be taken as potential leads for the development of isoform selective hCA IX and XII inhibitors.
In Vitro Screening for Anti-Acetylcholinesterase and Antioxidant Activities of Hottonia palustris L. Extracts and Their Unusual Flavonoids
Authors: Strawa Jakub W. , Jakimiuk Katarzyna , Kita Zuzanna , Tomczyk Michał
Published: November 2022

Hottonia palustris L. is from the genus Hottonia (Primulaceae), and the understanding of its phytochemical and pharmacological properties is limited. In this study, the use of chromatographic techniques led to the isolation of a further eleven compounds, including three new flavonoids: 2′,5-dihydroxyflavone 2′-O-β-glucopyranoside, 5,6-dihydroxyflavone 6-O-(6”-O-glucopyranosyl)-β-glucopyranoside (hottonioside A), and 4′,5,7-trihydroxyflavone 7-O-(2”-O-β-glucuronide)-β-glucopyranoside. Their structures were determined using extensive 1D and 2D NMR data and mass spectrometry (HRMS). The qualitative assessment of the chemical composition of the investigated extracts and fractions was performed using the LC-HRMS technique. Furthermore, the antioxidant potential of extracts, fractions, and compounds and their ability to inhibit acetylcholinesterase were also evaluated. Thus, we may conclude that the observed biological effects are the result of the presence of many biologically active compounds, of which dibenzoylmethane is the most active. Therefore, H. palustris is a source of substances with desirable properties in the prevention and treatment of neurodegenerative diseases.
Salidroside Alleviates Renal Fibrosis in SAMP8 Mice by Inhibiting Ferroptosis
Authors: Yang Sixia , Pei Tingting , Wang Linshuang , Zeng Yi , Li Wenxu , Yan Shihua , Xiao Wei , Cheng Weidong
Published: November 2022

Renal fibrosis progression is closely associated with aging, which ultimately leads to renal dysfunction. Salidroside (SAL) is considered to have broad anti-aging effects. However, the roles and mechanisms of SAL in aging-related renal fibrosis remain unclear. The study aimed to evaluate the protective effects and mechanisms of SAL in SAMP8 mice. SAMP8 mice were administered with SAL and Ferrostatin-1 (Fer-1) for 12 weeks. Renal function, renal fibrosis, and ferroptosis in renal tissue were detected. The results showed that elevated blood urea nitrogen (BUN) and serum creatinine (SCr) levels significantly decreased, serum albumin (ALB) levels increased, and mesangial hyperplasia significantly reduced in the SAL group. SAL significantly reduced transforming growth factor-β (TGF-β) and α-smooth muscle actin (α-sma) levels in SAMP8 mice. SAL treatment significantly decreased lipid peroxidation in the kidneys, and regulated iron transport-related proteins and ferroptosis-related proteins. These results suggested that SAL delays renal aging and inhibits aging-related glomerular fibrosis by inhibiting ferroptosis in SAMP8 mice.