bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal Design of Bubble Deck Concrete Slabs: Serviceability Limit State
Authors: Gajewski Tomasz , Staszak Natalia , Garbowski Tomasz
Published: July 2023

In engineering practice, one can often encounter issues related to optimization, where the goal is to minimize material consumption and minimize stresses or deflections of the structure. In most cases, these issues are addressed with finite element analysis software and simple optimization algorithms. However, in the case of optimization of certain structures, it is not so straightforward. An example of such constructions are bubble deck ceilings, where, in order to reduce the dead weight, air cavities are used, which are regularly arranged over the entire surface of the ceiling. In the case of these slabs, the flexural stiffness is not constant in all its cross-sections, which means that the use of structural finite elements (plate or shell) for static calculations is not possible, and therefore, the optimization process becomes more difficult. This paper presents a minimization procedure of the weight of bubble deck slabs using numerical homogenization and sequential quadratic programming with constraints. Homogenization allows for determining the effective stiffnesses of the floor, which in the next step are sequentially corrected by changing the geometrical parameters of the floor and voids in order to achieve the assumed deflection. The presented procedure allows for minimizing the use of material in a quick and effective way by automatically determining the optimal parameters describing the geometry of the bubble deck floor cross-section. For the optimal solution, the concrete weight of the bubble deck slab was reduced by about 23% in reference to the initial design, and the serviceability limit state was met.
Numerical and Experimental Analysis of Mechanical Properties in Hybrid Epoxy–Basalt Composites Partially Reinforced with Cellulosic Fillers
Authors: Chandan Vijay , Mishra Rajesh Kumar , Kolář Viktor , Jirků Petr , Müller Miroslav , Jamshaid Hafsa
Published: July 2023

The current work is focused on numerical and experimental studies of woven fabric composites modified by hybridisation with biological (cellulosic) filler materials. The mechanical performance of the composites is characterized under tensile, bending and impact loads and the effect of hybridisation is observed with respect to pure and nonhybrid composites. Numerical models are developed using computational tools to predict mechanical performance under tensile loading. The computational prediction results are compared and validated with relevant experimental results. This research is aimed at understanding the mechanical performance of basalt–epoxy composites partially reinforced with micro-/nano-sized bio-fillers from cellulose and intended for various application areas. Different weave structures, e.g., plain, twill, matt, etc., were investigated with respect to the mechanical properties of the hybrid composites. The effects of hybridizing with cellulose particles and different weave patterns of the basalt fabric are studied. In general, the use of high-strength fibres such as basalt along with cellulosic fillers representing up to 3% of the total weight improves the mechanical performance of the hybrid structures. The thermomechanical performance of the hybrid composites improved significantly by using basalt fabric as well as by addition of 3% weight of cellulosic fillers. Results reveal the advantages of hybridisation and the inclusion of natural cellulosic fillers in the hybrid composite structures. The material developed is suitable for high-end applications in components for construction that demand advanced mechanical and thermomechanical performance. Furthermore, the inclusion of biodegradable fillers fulfills the objectives of sustainable and ecological construction materials.
Influence of the Deposition Parameters on the Properties of TiO2 Thin Films on Spherical Substrates
Authors: Covei Maria , Bogatu Cristina , Gheorghita Silvioara , Duta Anca , Stroescu Hermine , Nicolescu Madalina , Calderon-Moreno Jose Maria , Atkinson Irina , Bratan Veronica , Gartner Mariuca
Published: July 2023

Wastewater treatment targeting reuse may limit water scarcity. Photocatalysis is an advanced oxidation process that may be employed in the removal of traces of organic pollutants, where the material choice is important. Titanium dioxide (TiO2) is a highly efficient photocatalyst with good aqueous stability. TiO2 powder has a high surface area, thus allowing good pollutant adsorption, but it is difficult to filter for reuse. Thin films have a significantly lower surface area but are easier to regenerate and reuse. In this paper, we report on obtaining sol-gel TiO2 thin films on spherical beads (2 mm diameter) with high surface area and easy recovery from wastewater. The complex influence of the substrate morphology (etched up to 48 h in concentrated H2SO4), of the sol dilution with ethanol (1:0 or 1:1), and the number of layers (1 or 2) on the structure, morphology, chemical composition, and photocatalytic performance of the TiO2 thin films is investigated. Etching the substrate for 2 h in H2SO4 leads to uniform, smooth surfaces on which crystalline, homogeneous TiO2 thin films are grown. Films deposited using an undiluted sol are stable in water, with some surface reorganization of the TiO2 aggregates occurring, while the films obtained using diluted sol are partially washed out. By increasing the film thickness through the deposition of a second layer, the roughness increases (from ~50 nm to ~100 nm), but this increase is not high enough to promote higher adsorption or overall photocatalytic efficiency in methylene blue photodegradation (both about 40% after 8 h of UV-Vis irradiation at 55 W/m2). The most promising thin film, deposited on spherical bead substrates (etched for 2 h in H2SO4) using the undiluted sol, with one layer, is highly crystalline, uniform, water-stable, and proves to have good photocatalytic activity.
Analysis of Shear Model for Steel-Fiber-Reinforced High-Strength Concrete Corbels with Welded-Anchorage Longitudinal Reinforcement
Authors: Li Shu-Shan , Peng Die , Wang Heng , Zhang Feng-Jian , Li Hong-Mei , Xie Yi-Jun , Chen Ai-Jiu , Xie Wei
Published: July 2023

According to the shear capacity test results of six steel-fiber-reinforced high-strength concrete (SFHSC) corbels with welded-anchorage longitudinal reinforcement under concentrated load, the effects of shear span ratio and steel fiber volume fraction on the failure mode, cracking load and ultimate load of corbel specimens were analyzed. On the basis of experimental research, the shear transfer mechanism of corbel structure was discussed. Then, a modified softened strut-and-tie model (MSSTM), composed of the diagonal and horizontal mechanisms, was proposed, for steel-fiber-reinforced high-strength concrete corbels. The contributions of concrete, steel fiber and horizontal stirrups to the shear bearing capacity of the corbels were clarified. A calculation method for the shear bearing capacity of steel-fiber-reinforced high-strength concrete corbels was established and was simplified on this basis. The calculation results of the model were compared with the test values and calculation results of the GB50010-2010 code, the ACI318-19 code, the EN 1992-1-1 code and the CSA A23.3-19 code. The results showed that the concrete corbel with small shear span ratio mainly has two typical failure modes: shear failure and diagonal compression failure. With the increase in shear span ratio, the shear capacity of corbels decreases. Steel fiber can improve the ductility of a reinforced concrete corbel, but has little effect on the failure mode of the diagonal section. The calculated values of the national codes were lower than the experimental values, and the results were conservative. The theoretical calculation values of the shear capacity calculation model of the corbels were close to the experimental results. In addition, the model has a clear mechanical concept considering the tensile properties of steel-fiber-reinforced high-strength concrete and the influence of horizontal stirrups, which can reasonably reflect the shear transfer mechanism of corbels.
Comparative Structural Analysis of GFRP, Reinforced Concrete, and Steel Frames under Seismic Loads
Authors: Mincigrucci Luca , Civera Marco , Lenticchia Erica , Ceravolo Rosario , Rosano Michele , Russo Salvatore
Published: July 2023

Fibre-reinforced polymer composites in general, and especially glass fibre-reinforced polymer (GFRP), have increasingly been used in recent decades in construction. The advantages of GFRP as an alternative construction material are its high strength-to-weight ratio, corrosive resistance, high durability, and ease of installation. The main purpose of this study is to evaluate the response of GFRP under dynamic conditions (more specifically, under seismic loads) and to compare the performance of this composite material with that of two traditional building materials: reinforced concrete and structural steel. To this aim, a finite element analysis is carried out on a two-dimensional frame modelled with steel, reinforced concrete (RC), or GFRP pultruded materials and subjected to a seismic input. The dynamic response of the structure is evaluated for the three building materials in terms of displacements, inter-storey drift, base shear, and stress. The results show a good performance of the GFRP frame, with stress distribution and displacements halfway between those of RC and steel. Most importantly, the GFRP frame outperforms the other materials in terms of reduced weight and, thus, base shear (−40% compared to steel and −88.5% compared to RC).
Phonon Anharmonicity and Spin–Phonon Coupling in CrI3
Authors: Tomarchio Luca , Mosesso Lorenzo , Macis Salvatore , Nguyen Loi T. , Grilli Antonio , Romani Martina , Cestelli Guidi Mariangela , Cava Robert J. , Lupi Stefano
Published: July 2023

We report on the far-infrared, temperature-dependent optical properties of a CrI3 transition metal halide single crystal, a van der Waals ferromagnet (FM) with a Curie temperature of 61 K. In addition to the expected phonon modes determined by the crystalline symmetry, the optical reflectance and transmittance spectra of CrI3 single crystals show many other excitations as a function of temperature as a consequence of the combination of a strong lattice anharmonicity and spin–phonon coupling. This complex vibrational spectrum highlights the presence of entangled interactions among the different degrees of freedom in CrI3.
Enhanced Energy Storage Performance and Efficiency in Bi0.5(Na0.8K0.2)0.5TiO3-Bi0.2Sr0.7TiO3 Relaxor Ferroelectric Ceramics via Domain Engineering
Authors: Pattipaka Srinivas , Choi Hyunsu , Lim Yeseul , Park Kwi-Il , Chung Kyeongwoon , Hwang Geon-Tae
Published: July 2023

Dielectric materials are highly desired for pulsed power capacitors due to their ultra-fast charge-discharge rate and excellent fatigue behavior. Nevertheless, the low energy storage density caused by the low breakdown strength has been the main challenge for practical applications. Herein, we report the electric energy storage properties of (1 − x) Bi0.5(Na0.8K0.2)0.5TiO3-xBi0.2Sr0.7TiO3 (BNKT-BST; x = 0.15–0.50) relaxor ferroelectric ceramics that are enhanced via a domain engineering method. A rhombohedral-tetragonal phase, the formation of highly dynamic PNRs, and a dense microstructure are confirmed from XRD, Raman vibrational spectra, and microscopic investigations. The relative dielectric permittivity (2664 at 1 kHz) and loss factor (0.058) were gradually improved with BST (x = 0.45). The incorporation of BST into BNKT can disturb the long-range ferroelectric order, lowering the dielectric maximum temperature Tm and inducing the formation of highly dynamic polar nano-regions. In addition, the Tm shifts toward a high temperature with frequency and a diffuse phase transition, indicating relaxor ferroelectric characteristics of BNKT-BST ceramics, which is confirmed by the modified Curie-Weiss law. The rhombohedral-tetragonal phase, fine grain size, and lowered Tm with relaxor properties synergistically contribute to a high Pmax and low Pr, improving the breakdown strength with BST and resulting in a high recoverable energy density Wrec of 0.81 J/cm3 and a high energy efficiency η of 86.95% at 90 kV/cm for x = 0.45.
Investigating the Distribution of Flatness Measurements in Battery Manufacturing through Empirical Investigation and Statistical Theory
Authors: Li Hangyu , Jin Sun
Published: July 2023

The battery is an important part of the new energy electric vehicle, and the control of the flatness of its side plate/bottom plate is the key to quality improvement in mass production. However, there are few pieces of research on the flatness distribution form at present, and the distribution form is often assumed to be a normal distribution, which leads to a significant deviation between the tolerance design and quality control of the flatness and the reality. This paper establishes a statistical model of flatness distribution, its theoretical distribution form is deduced as a normal range distribution, and then the experimental data of the flatness distribution are collected to verify this conclusion. Determining the flatness distribution form has practical effects on improving manufacturing quality and reducing costs in battery manufacturing.
Experimental Assessment of Hole Quality and Tool Condition in the Machining of an Aerospace Alloy
Authors: Aamir Muhammad , Sharif Aamer , Zahir Muhammad Zeeshan , Giasin Khaled , Tolouei-Rad Majid
Published: July 2023

This paper deals with an experimental investigation of hole quality in Al2024-T3, which is one of the aerospace alloys used in aircraft fuselage skin due to its high level of resistance to fatigue crack propagation. The experiments are conducted with 6 mm uncoated carbide and HSS drill bits using a CNC machine under dry conditions and different drilling parameters. The characteristics of the hole quality are investigated in terms of its perpendicularity, cylindricity, circularity and hole size. An ANOVA (analysis of variance) and Pareto charts are used to analyze the effects of the drilling parameters on the hole quality. The hole quality is also assessed using a digital microscope to observe the formation of hole burrs. Moreover, scanning electron microscopy is also used to investigate the inside-hole surface defects. Further investigations are carried out using optical microscopy to inspect the post-drilling tool condition at high drilling parameters. The results show that hole quality reduces as the feed rate and spindle speed increase. However, from the ANOVA results and Pareto charts, the influence of the feed rate on the hole quality is found to be insignificant. At the same time, the type of drill bit material shows the highest percentage of contribution affecting the hole quality, following the spindle speed. The HSS drill bit shows more adhesion and built-up edges than the uncoated carbide drill bit. There were more burrs formed at the hole edges when the holes were drilled with uncoated HSS drill bits. In the same way, the SEM analysis reveals more surface deformation and damage defects inside the hole walls of holes drilled using the uncoated HSS drill bit.
SOS Approach for Practical Stabilization of Tempered Fractional-Order Power System
Authors: Gassara Hamdi , Kharrat Dhouha , Ben Makhlouf Abdellatif , Mchiri Lassaad , Rhaima Mohamed
Published: July 2023

Fractional systems have been widely utilized in various fields, such as mathematics, physics and finance, providing a versatile framework for precise measurements and calculations involving partial quantities. This paper aims to develop a novel polynomial controller for a power system (PS) with fractional-order (FO) dynamics. It begins by studying the practical stability of a general class of tempered fractional-order (TFO) nonlinear systems, with broad applicability and potential for expanding its applications. Afterward, a polynomial controller is designed to guarantee the practical stability of the PS, encompassing the standard constant controller as a specific instance. The design conditions for this controller are resolved using the sum of squares (SOS) approach, a powerful technique for guaranteeing stability and control design. To showcase the practical value of the analytical findings, simulations of the PS are conducted utilizing SOSTOOLS.
Operational Matrix of New Shifted Wavelet Functions for Solving Optimal Control Problem
Authors: Abass Gufran , Shihab Suha
Published: July 2023

This paper is devoted to proposing an approximate numerical algorithm based on the use of the state parameterization technique in order to find the solution to the optimal control problem (OCP). An explicit formula for new shifted wavelet (NSW) functions is constructed. A new formula that expresses the first-order derivative of the NSW in terms of their original NSW is established. The development of our suggested numerical algorithms begins with the extraction of a new operational matrix of derivative from this derivative formula. The expansion’s convergence study is performed in detail, and some illustrative examples of OCP are displayed. The proposed algorithm is compared with the exact one and some other methods in the literature. This confirms the accuracy and the high efficiency of the presented algorithm.
Stochastic Comparisons of Lifetimes of Used Standby Systems
Authors: Kayid Mohamed , Alshehri Mashael A.
Published: July 2023

In this paper, we first establish upper stochastic bounds on the lifetime of a used cold standby system with arbitrary age, using the likelihood ratio order and the usual stochastic order. Then, stochastic comparisons are made between the lifetime of a used cold standby system with age t and the lifetime of a cold standby system consisting of used components with age t using the likelihood ratio order and the usual stochastic order. We use illustrative examples to explore the results presented.
Elucidating the Link: Chronic Obstructive Pulmonary Disease and the Complex Interplay of Gastroesophageal Reflux Disease and Reflux-Related Complications
Authors: Wang Xiaoliang , Wright Zachary , Wang Jiayan , Roy Stephen , Fass Ronnie , Song Gengqing
Published: July 2023

Background and Objective: Presenting chronic obstructive pulmonary disease (COPD) patients frequently report concurrent symptoms of gastroesophageal reflux disease (GERD). Few studies have shown a correlation between GERD and COPD. We aimed to examine the correlation between GERD and COPD as well as secondary related reflux complications, such as esophageal stricture, esophageal cancer, and Barrett’s esophagus. Methods: This population-based analysis included 7,159,694 patients. Patients diagnosed with GERD with and without COPD were compared to those without GERD. The enrollment of COPD included centrilobular and panlobular emphysema and chronic bronchitis. Risk factors of COPD or GERD were used for adjustment. Bivariate analyses were performed using the chi-squared test or Fisher exact test (2-tailed) for categorical variables as appropriate to assess the differences in the groups. Results: Our results showed that COPD patients had a significantly higher incidence of GERD compared to those without COPD (27.8% vs. 14.1%, p < 0.01). After adjustment of demographics and risk factors, COPD patients had a 1.407 times higher risk of developing non-erosive esophagitis (p < 0.01), 1.165 higher risk of erosive esophagitis (p < 0.01), 1.399 times higher risk of esophageal stricture (p < 0.01), 1.354 times higher risk of Barrett’s esophagus without dysplasia (p < 0.01), 1.327 times higher risk of Barrett’s esophagus with dysplasia, as well as 1.235 times higher risk of esophageal cancer than those without COPD. Conclusions: Based on the evidence from this study, there are sufficient data to provide convincing evidence of an association between COPD and GERD and its secondary reflux-related complications.
Hemophagocytic Lymphohistiocytosis Secondary to Hodgkin’s Lymphoma with Isolated Bone Marrow Involvement in a Newly Diagnosed HIV Patient
Authors: Lopez-Garcia Alberto , Solan Laura , Alvarez Beatriz , Caballero Juan Carlos , Cornago Javier , Pardo Laura , Diaz de la Pinta Francisco Javier , Cordoba Raul , Rodriguez-Pinilla Maria
Published: July 2023

Human immunodeficiency virus (HIV) infection is known to be associated with the development of Hodgkin’s lymphoma (HL). Exclusive extranodal bone marrow involvement is less common. Co-infection by other viruses, such as the Epstein–Barr virus (EBV), increases the incidence of a frequent complication denominated by hemophagocytic lymphohistocytosis (HLH). We present the case of a 50-year-old patient with the above clinical spectrum who develops several serious complications during treatment.
A Novel Notch-Related Gene Signature for Prognosis and Immune Response Prediction in Ovarian Cancer
Authors: Pi Yanan , Sun Fusheng , Zhang Zhaocong , Liu Xiaoli , Lou Ge
Published: July 2023

Background and Objectives: Notch is a fascinating signaling pathway. It is extensively involved in tumor growth, cancer stem cells, metastasis, and treatment resistance and plays important roles in metabolic regulation, tumor microenvironment, and tumor immunity. However, the role of Notch in ovarian cancer (OC) has yet to be fully understood. Therefore, this study systematically described the expression, mutation, and copy number variation of genes in the Notch signaling pathway in OC and evaluated the relationship between gene mutation and Overall Survival (OS) prognosis. Materials and Methods: Notch risk score (NTRS) was established by univariate Cox regression analysis combined with Lasso regression analysis, and the efficacy of NTRS in predicting prognosis and immunotherapy response in patients with OC was verified. We further assessed the correlations of NTRS with clinical features, immune infiltration level, immune checkpoint expression, and immune characteristics. Additionally, differential expression and functions of the fourteen signature genes were confirmed via vitro assays. Results: The results showed that Notch genes (NTGs) were markedly differentiated between tumor and normal tissues, which may help to explain the high heterogeneity in the biological characteristics and therapeutic outcomes of human OC. A Notch risk (NTR) prognostic model based on 11 key NTGs was successfully constructed. Tumors with high Notch risk scores (NTRS) were independently associated with shorter overall survival and poorer immunotherapy outcomes. We further assessed the correlations of NTRS with immune characteristics. The results showed that NTGs play a key role in regulating the tumor immune microenvironment. Additionally, we validated the baseline and induced expressions of 14 prognosis-related NTGs in our own OC samples. In vitro assays confirmed that the knockdown of NCOR2 and APH1B and overexpression of HEY2 and SKP2 could inhibit the proliferation, invasion, and migration of OC cells. Conclusions: These findings emphasize that Notch multilayer changes are associated with the prognosis of patients with OC and the characteristics of immune cell infiltration. Our predictive signature may predict the prognosis and immunotherapy response of OC patients in an independent manner. NCOR2, APH1B, HEY2, and SKP2 may more prominently represent important indicators to improve patient prognosis.
Critical Role of Molecular Packing in Lo Phase Membrane Solubilization
Authors: Puff Nicolas
Published: July 2023

Membrane solubilization induced by Triton X-100 (TX-100) was investigated. Different membrane compositions and phase states were studied along the detergent titration. Expected solubilization profiles were obtained but new information is provided. The fluorescence of nitrobenzoxadiazole (NBD)-labeled lipids indicates that the liquid-ordered (Lo)/liquid-disordered (Ld) phase coexistence is barely unaffected at sub-solubilizing detergent concentrations and highlights the vesicle-to-micelle transition. Moreover, the location of the NBD group in the bilayer emphasizes a detergent–membrane interaction in the case of the insoluble Lo phase membrane. It has also been shown that the molecular packing of the membrane loosens in the presence of TX-100, regardless of the solubilization profile. Motivated by studies on GPMVs, the solubilization of less ordered Lo phase membranes was considered in order to improve the effect of molecular packing on the extent of solubilization. Membranes composed of SM and Chol in an equimolar ratio doped with different amounts of PC were studied. The more ordered the Lo phase membrane is in the absence of detergent, the less likely it is to be solubilized. Furthermore, and in contrast to what is observed for membranes exhibiting an Lo/Ld phase coexistence, a very small decrease in the molecular packing of the Lo phase membrane radically modifies the extent of solubilization. These results have implications for the reliability of TX-100 insolubility as a method to detect ordered domains.
Study of the Effect of L-PBF Technique Temporal Evolution on Microstructure, Surface Texture, and Fatigue Performance of Ti gr. 23 Alloy
Authors: Lanzutti Alex , Magnan Michele , Vaglio Emanuele , Totis Giovanni , Sortino Marco , Fedrizzi Lorenzo
Published: July 2023

Titanium alloys are widely used in various technological fields due to their excellent performance. Since the early stages of the 3D printing concept, these alloys have been intensively used as materials for these processes. In this work, the evolution of the performance of the 3D printing process has been studied by analysing the microstructure and the mechanical properties, fatigue and tensile, of the Ti gr. 23 alloy produced by two different models of Concept Laser M2 Cusing machines (an old model and a more recent one). The process parameters recommended by the manufacturer were adopted for each machine. Both microstructural and surface texture characterisations were carried out to better correlate the differences with the production process technique. For the same purpose, tensile tests and microhardness profiles were obtained, while the dynamic mechanical properties were evaluated by means of fatigue tests aimed at determining the fatigue limit of the material using a staircase approach. The mechanical tests were carried out on specimens with three different orientations with respect to the building platform, using two different SLM techniques. The fatigue behaviour was then analysed by evaluating the fracture surfaces and, in particular, the crack nucleation sites. By comparing the calculated fatigue values with the results of local fatigue calculations, an estimate of the residual stresses near the crack nucleation site was obtained. The results showed that the specimens produced on a newer machine had lower roughness (about 10%), slightly higher ductility, and a higher fatigue limit (10–20 MPa) compared to the specimens produced with the same material but on older equipment.
Study on the Wear Resistance of Ni-Co-ZrO2 Composite Coatings with Different ZrO2 Nanoparticle Concentrations Prepared Using Electrodeposition on the Micro-Surface of Spindle Hook Teeth
Authors: Dong Tianxin , Wang Xingyu , Li Fei , Zhu Yifan , Fu Xiuqing
Published: July 2023

To improve the wear resistance of the surface of the cotton picker spindle, a Ni-Co-ZrO2 composite coating with different ZrO2 nanoparticle concentrations was prepared using electrodeposition technology on the micro surface of spindle hook teeth, and the morphologies of the surface and cross-section, element contents, grain sizes, microhardness and friction coefficients of the Ni-Co-ZrO2 composite coating were obtained; a simulated wear test was conducted based on the independently developed spindle hook tooth wear device, and the morphologies and elemental distributions of the composite coating before and after wear were obtained; the effects of different ZrO2 nanoparticle concentrations (0, 2, 4, 6, 8 g/L) on the morphology, element content, grain size, microhardness, friction coefficient and wear resistance of the coating were discussed. The test results indicated that compared with Ni-Co coatings, Ni-Co-ZrO2 composite coatings featured a more compact coating structure, a greater coating thickness, and a smaller grain size. The presence of ZrO2 nanoparticles led to further improvement of the coating’s microhardness, friction coefficient and wear resistance. When the mass concentration of ZrO2 nanoparticles reached 4 g/L, the microhardness of Ni-Co-ZrO2 composite coating reached the maximum value, 545.4 Hv0.1, and the friction coefficient decreased to 0.06. At the same time, in the simulated wear test, the composite coating with this concentration had the smallest wear area and the highest wear resistance.
Research on Robot Grasping Based on Deep Learning for Real-Life Scenarios
Authors: Hu Jie , Li Qin , Bai Qiang
Published: July 2023

The application of robots, especially robotic arms, has been primarily focused on the industrial sector due to their relatively low level of intelligence. However, the rapid development of deep learning has provided a powerful tool for conducting research on highly intelligent robots, thereby offering tremendous potential for the application of robotic arms in daily life scenarios. This paper investigates multi-object grasping in real-life scenarios. We first analyzed and improved the structural advantages and disadvantages of convolutional neural networks and residual networks from a theoretical perspective. We then constructed a hybrid grasping strategy prediction model, combining both networks for predicting multi-object grasping strategies. Finally, we deployed the trained model in the robot control system to validate its performance. The results demonstrate that both the model prediction accuracy and the success rate of robot grasping achieved by this study are leading in terms of performance.
Metallic and Non-Metallic Plasmonic Nanostructures for LSPR Sensors
Authors: Wu Judy Z. , Ghopry Samar Ali , Liu Bo , Shultz Andrew
Published: July 2023

Localized surface plasmonic resonance (LSPR) provides a unique scheme for light management and has been demonstrated across a large variety of metallic nanostructures. More recently, non-metallic nanostructures of two-dimensional atomic materials and heterostructures have emerged as a promising, low-cost alternative in order to generate strong LSPR. In this paper, a review of the recent progress made on non-metallic LSPR nanostructures will be provided in comparison with their metallic counterparts. A few applications in optoelectronics and sensors will be highlighted. In addition, the remaining challenges and future perspectives will be discussed.
Argon and Oxygen Gas Flow Rate Dependency of Sputtering-Based Indium-Gallium-Zinc Oxide Thin-Film Transistors
Authors: Han Youngmin , Lee Dong Hyun , Cho Eou-Sik , Kwon Sang Jik , Yoo Hocheon
Published: July 2023

Oxygen vacancies are a major factor that controls the electrical characteristics of the amorphous indium-gallium-zinc oxide transistor (a-IGZO TFT). Oxygen vacancies are affected by the composition ratio of the a-IGZO target and the injected oxygen flow rate. In this study, we fabricated three types of a-IGZO TFTs with different oxygen flow rates and then investigated changes in electrical characteristics. Atomic force microscopy (AFM) was performed to analyze the surface morphology of the a-IGZO films according to the oxygen gas rate. Furthermore, X-ray photoelectron spectroscopy (XPS) analysis was performed to confirm changes in oxygen vacancies of a-IGZO films. The optimized a-IGZO TFT has enhanced electrical characteristics such as carrier mobility (μ) of 12.3 cm2/V·s, on/off ratio of 1.25 × 1010 A/A, subthreshold swing (S.S.) of 3.7 V/dec, and turn-on voltage (Vto) of −3 V. As a result, the optimized a-IGZO TFT has improved electrical characteristics with oxygen vacancies having the highest conductivity.
Jump and Pull-in Instability of a MEMS Gyroscope Vibrating System
Authors: Zhu Yijun , Shang Huilin
Published: July 2023

Jump and pull-in instability are common nonlinear dynamic behaviors leading to the loss of the performance reliability and structural safety of electrostatic micro gyroscopes. To achieve a better understanding of these initial-sensitive phenomena, the dynamics of a micro gyroscope system considering the nonlinearities of the stiffness and electrostatic forces are explored from a global perspective. Static and dynamic analyses of the system are performed to estimate the threshold of the detecting voltage for static pull-in, and dynamic responses are analyzed in the driving and detecting modes for the case of primary resonance and 1:1 internal resonance. The results show that, when the driving voltage frequency is a bit higher than the natural frequency, a high amplitude of the driving AC voltage may induce the coexistence of bistable periodic responses due to saddle-node bifurcation of the periodic solution. Basins of attraction of bistable attractors provide evidence that disturbance of the initial conditions can trigger a jump between bistable attractors. Moreover, the Melnikov method is applied to discuss the condition for pull-in instability, which can be ascribed to heteroclinic bifurcation. The validity of the prediction is verified using the sequences of safe basins and unsafe zones for dynamic pull-in. It follows that pull-in instability can be caused and aggravated by the increase in the amplitude of the driving AC voltage.
Productivity of Concentration-Dependent Conversion of Substitutional Nitrogen Atoms into Nitrogen-Vacancy Quantum Emitters in Synthetic-Diamond by Ultrashort Laser Pulses
Authors: Kudryashov Sergey , Danilov Pavel , Kuzmin Evgeny , Smirnov Nikita , Gorevoy Alexey , Vins Victor , Pomazkin Daniil , Paholchuk Petr , Muratov Andrey , Kirichenko Alexey , Rodionov Nikolay , Vasil’ev Evgeny
Published: July 2023

Tightly focused 515-nm, 0.3-ps laser pulses modify in a laser filamentation regime the crystalline structure of an Ib-type high-pressure, high-temperature (HPHT) synthesized diamond in a thin-plate form. The modified microregions (micromarks) in the yellow and colorless crystal zones, possessing different concentrations of elementary substitutional nitrogen (N) impurity atoms (C-centers), exhibit their strongly diminished local IR absorption (upon correction to the thickness scaling factor). Simultaneously, local visible-range (400–550 nm) absorption coefficients were increased, and photoluminescence (PL) yield was strongly enhanced in the broad range of 450–800 nm. The strong yellow-red PL enhancement saturates with laser exposure, implying the complete conversion of C-centers into nitrogen-vacancy (NV0,−) ones due to the laser-induced generation of Frenkel “interstitial-vacancy” I–V carbon pairs. The other emerging blue-green (>470 nm) and green-yellow (>500 nm) PL bands were also simultaneously saturated versus the laser exposure. The observed IR/optical absorption and PL spectral changes enlighten the ultrashort pulse laser inscription of NV0−-based quantum-emitter centers in synthetic diamonds and enable the evaluation of the productivity of their inscription along with the corresponding I–V generation rates.
Editorial for the Special Issue on Flexible and Wearable Sensors
Authors: Gao Libo , Yang Zhuoqing
Published: July 2023

Flexible wearable sensors have garnered significant interest in the fields of human-computer interaction, materials science, and biomedicine [...]
Milk Transmission of Mammalian Retroviruses
Authors: Kemeter Laura M. , Birzer Alexandra , Heym Stefanie , Thoma-Kress Andrea K.
Published: July 2023

The transmission of viruses from one host to another typically occurs through horizontal or vertical pathways. The horizontal pathways include transmission amongst individuals, usually through bodily fluids or excretions, while vertical transmission transpires from mother to their offspring, either during pregnancy, childbirth, or breastfeeding. While there are more than 200 human pathogenic viruses to date, only a small number of them are known to be transmitted via breast milk, including cytomegalovirus (CMV), human immunodeficiency virus type 1 (HIV-1), and human T cell lymphotropic virus type 1 (HTLV-1), the latter two belonging to the family Retroviridae. Breast milk transmission is a common characteristic among mammalian retroviruses, but there is a lack of reports summarizing our knowledge regarding this route of transmission of mammalian retroviruses. Here, we provide an overview of the transmission of mammalian exogenous retroviruses with a focus on Orthoretrovirinae, and we highlight whether they have been described or suspected to be transmitted through breast milk, covering various species. We also elaborate on the production and composition of breast milk and discuss potential entry sites of exogenous mammalian retroviruses during oral transmission.
Carrier Flotation Using Coarse Pyrite for Improving the Recovery of Finely Ground Chalcopyrite: Development of Post-Process of Carrier Flotation to Separate Finely Ground Chalcopyrite Particles from Coarse Pyrite Particles
Authors: Bilal Muhammad , Park Ilhwan , Ito Mayumi , Hassan Fawad Ul , Aikawa Kosei , Jeon Sanghee , Hiroyoshi Naoki
Published: July 2023

Carrier flotation is a technique that can recover fine particles by using coarse carrier particles during the flotation process. In heterogeneous carrier flotation, coarse mineral particles of different minerals are used as carriers to recover fine mineral particles. By using Cu2+-treated pyrite particles as carriers, fine chalcopyrite particles recovery could be improved. However, a disadvantage of this heterogeneous carrier flotation is that it requires a post-flotation separation process to improve the grade of the final Cu concentrate. This study tested mechanical and chemical treatments to detach finely ground chalcopyrite (D50~3.5 µm) particles from Cu2+-treated coarse pyrite particles (−125 + 106 µm) after flotation. The results showed that the ultrasonic treatment was not effective to detach chalcopyrite fines from Cu2+-treated pyrite particles. However, acid treatment was effective to detach chalcopyrite fines from coarse pyrite particles. At pH 2, approximately 96% of chalcopyrite fines were detached from coarse Cu2+-treated pyrite particles. The acid treatment of flotation froth (mixture of chalcopyrite fines and Cu2+-treated pyrite particles) decomposed the collector KAX (potassium amyl xanthate) and dissolved the Cu precipitates adsorbed on the pyrite surface. This weakened the hydrophobic attraction force between the chalcopyrite fines and coarse pyrite particles, thus promoting the detachment of chalcopyrite fines from Cu2+-treated coarse pyrite particles.
Pilot Scale Testing of Lignite Adsorption Capability and the Benefits for the Recovery of Rare Earth Elements from Dilute Leach Solutions
Authors: Nawab Ahmad , Honaker Rick
Published: July 2023

Naturally occurring organic materials containing humic acids show a strong affinity towards rare earth elements (REE) and other critical elements. Leaching experiments on lignite coal waste produced from construction sand production revealed that the contained REEs were associated with the organic matter. Furthermore, adsorption studies revealed that the lignite waste was capable of extracting REEs from a model solution and increased the REE content of the lignite waste by more than 100%. As such, this study aimed to utilize the lignite waste to adsorb REEs from pregnant leach solutions and acid mine drainage sources having low REE concentrations and subsequently leach the lignite material to produce pregnant leach solutions containing relatively high amounts of REEs, which benefits the performance and economic viability of downstream separation and purification processes. An integrated flowsheet was developed based on this concept and tested at a pilot scale. The pregnant leachate solution (PLS) was generated from a heap leach pad containing 2000 tons of Baker seam coarse refuse. The pilot scale circuit was comprised of aluminum precipitation, adsorption using the waste lignite, and rare earth-critical metal (RE-CM) precipitation stages in succession. The results indicated that the aluminum precipitation stage removed over 88% and 99% of the Al and Fe, respectively. The adsorption stage increased the REE content associated with the waste lignite from 457 ppm to 1065 ppm on a whole mass basis. Furthermore, the heavy REE (HREE) content in the feedstock increased by approximately 250%, which raised the percentage of HREE in the REE distribution by 19 absolute percentage points. In addition to the REEs, concentrations of other critical elements such as Mn, Ni, and Zn also improved by 75%, 37%, and 250%, respectively. Bench-scale tests revealed that increasing the solids concentration in the waste lignite and PLS mix from 1% to 20% by weight enhanced the adsorption efficiency from 32.0% to 99.5%, respectively. As such, a new flowsheet was proposed which provides significantly higher REE concentrations in the PLS that can be fed directly to solvent extraction and/or oxalic acid precipitation and, thereby, enhancing process efficiency and economics.
Functionally Active Microheterogeneous Systems for Elastomer Fire- and Heat-Protective Materials
Authors: Kablov Victor F. , Novopoltseva Oksana M. , Kryukova Daria A. , Keibal Natalia A. , Burmistrov Vladimir , Kochetkov Vladimir G.
Published: July 2023

Elastomeric materials are utilized for the short-term protection of products and structures operating under extreme conditions in the aerospace, marine, and oil and gas industries. This research aims to study the influence of functionally active structures on the physical, mechanical, thermophysical, and fire- and heat-protective characteristics of elastomer compositions. The physical and mechanical properties of elastomer samples were determined using Shimazu AG-Xplus, while morphological research into microheterogeneous systems and coke structures was carried out on a scanning electronic microscope, Versa 3D. Differential thermal and thermogravimetric analyses of the samples were conducted on derivatograph Q-1500D. The presence of aluminosilicate microspheres, carbon microfibers, and a phosphor–nitrogen–organic modifier as part of the aforementioned structures contributes to the appearance of a synergetic effect, which results in an increase in the heat-protective properties of a material due to the enhancement in coke strength and intensification of material carbonization processes. The results indicate an 8–17% increase in the heating time of the unheated surface of a sample and a decrease in its linear burning speed by 6–17% compared to known analogues. In conclusion, microspheres compensate for the negative impact of microfibers on the density and thermal conductivity of a composition.
Formononetin Inhibits Mast Cell Degranulation to Ameliorate Compound 48/80-Induced Pseudoallergic Reactions
Authors: Zhou Zi-Wen , Zhu Xue-Yan , Li Shu-Ying , Lin Si-En , Zhu Yu-Han , Ji Kunmei , Chen Jia-Jie
Published: July 2023

Formononetin (FNT) is a plant-derived isoflavone natural product with anti-inflammatory, antioxidant, and anti-allergic properties. We showed previously that FNT inhibits immunoglobulin E (IgE)-dependent mast cell (MC) activation, but the effect of FNT on IgE-independent MC activation is yet unknown. Our aim was to investigate the effects and possible mechanisms of action of FNT on IgE-independent MC activation and pseudoallergic inflammation. We studied the effects of FNT on MC degranulation in vitro with a cell culture model using compound C48/80 to stimulate either mouse bone marrow-derived mast cells (BMMCs) or RBL-2H3 cells. We subsequently measured β-hexosaminase and histamine release, the expression of inflammatory factors, cell morphological changes, and changes in NF-κB signaling. We also studied the effects of FNT in several in vivo murine models of allergic reaction: C48/80-mediated passive cutaneous anaphylaxis (PCA), active systemic anaphylaxis (ASA), and 2,4-dinitrobenzene (DNCB)-induced atopic dermatitis (AD). The results showed that FNT inhibited IgE-independent degranulation of MCs, evaluated by a decrease in the release of β-hexosaminase and histamine and a decreased expression of inflammatory factors. Additionally, FNT reduced cytomorphological elongation and F-actin reorganization and attenuated NF-κB p65 phosphorylation and NF-κB-dependent promoter activity. Moreover, the administration of FNT alleviated pseudoallergic responses in vivo in mouse models of C48/80-stimulated PCA and ASA, and DNCB-induced AD. In conclusion, we suggest that FNT may be a novel anti-allergic drug with great potential to alleviate pseudoallergic responses via the inhibition of IgE-independent MC degranulation and NF-κB signaling.
In Silico Studies of Novel Vemurafenib Derivatives as BRAF Kinase Inhibitors
Authors: Żołek Teresa , Mazurek Adam , Grudzinski Ireneusz P.
Published: July 2023

BRAF inhibitors have improved the treatment of advanced or metastatic melanoma in patients that harbor a BRAFT1799A mutation. Because of new insights into the role of aberrant glycosylation in drug resistance, we designed and studied three novel vemurafenib derivatives possessing pentose-associated aliphatic ligands—methyl-, ethyl-, and isopropyl-ketopentose moieties—as potent BRAFV600E kinase inhibitors. The geometries of these derivatives were optimized using the density functional theory method. Molecular dynamic simulations were performed to find interactions between the ligands and BRAFV600E kinase. Virtual screening was performed to assess the fate of derivatives and their systemic toxicity, genotoxicity, and carcinogenicity. The computational mapping of the studied ligand–BRAFV600E complexes indicated that the central pyrrole and pyridine rings of derivatives were located within the hydrophobic ATP-binding site of the BRAFV600E protein kinase, while the pentose ring and alkyl chains were mainly included in hydrogen bonding interactions. The isopropyl-ketopentose derivative was found to bind the BRAFV600E oncoprotein with more favorable energy interaction than vemurafenib. ADME-TOX in silico studies showed that the derivatives possessed some desirable pharmacokinetic and toxicologic properties. The present results open a new avenue to study the carbohydrate derivatives of vemurafenib as potent BRAFV600E kinase inhibitors to treat melanoma.
A Comparative Evaluation of Antioxidant Activity of Extract and Essential Oil of Origanum onites L. In Vivo
Authors: Kubiliene Asta , Munius Edvinas , Songailaite Gabriele , Kokyte Indre , Baranauskaite Juste , Liekis Arunas , Sadauskiene Ilona
Published: July 2023

In the present study, the effects of Origanum onites L. extract and essential oil of O. onites L. on the antioxidant status of the liver and brain of mice were investigated. Due to certain disadvantages of essential oils, such as poor solubility, high volatility and sensitivity to UV light and heat, formulation of liposomes with Oregano essentials (OE) was optimized and used in this study. The results demonstrated that the best composition of the lipid carriers and OE were conducted in terms of the polydispersity index (PDI), mean particle size and encapsulation efficiency (EE). For further study the LE4 formulation was used, which contained Lipoid S100 at 45 mg, Lipoid S75 at 45 mg and 90 mg of EO. The administration of O. onites L. extract to mice for 21 days significantly decreased the glutathione (GSH) level in the livers and brains of the mice as well as the malondialdehyde (MDA) concentration in the livers. In the brains of the mice, MDA level significantly increased after this extract consumption. Whereas liposomes with OE significantly decreased GSH concentration in the mouse brain and MDA concentration in the mouse liver, there was an increased (p > 0.05) GSH level in the liver and MDA concentration in the brain of mice compared with the control group. It was found that both O. onites. ethanolic extract as well as liposomes with OE of this plant material affect the antioxidant status in the livers and brains of mice.