Smooth Cross Section Research Articles

A comparison of the mechanical properties of 3D-printed, milled, and conventional denture base resin materials.

This study investigated the mechanical properties of three denture base resin materials produced by three-dimensional (3D) printing (Group P), computer-aided design/computer-aided manufacturing milling (Group M), and conventional (Group C) methods. Three-point flexural tests were performed before and after thermocycling treatment to evaluate the mechanical properties. Additionally, nanoindentation and dynamic mechanical analysis (DMA) were used to analyze the behavior of the materials. After flexural strength tests, scanning electron microscopy (SEM) was performed to evaluate the fracture cross-section. The results consistently showed that Group P exhibited significantly higher flexural strength and modulus regardless of thermocycling than Groups C and M (p<0.05), along with a higher storage modulus in DMA and greater resistance and resilience to nanoindentation deformation. SEM analysis showed that Group C had a relatively smooth cross-section, whereas Groups M and P had torn cross-sections. This study suggests that the 3D-printed material has suitable mechanical properties for hard dental prosthesis applications.

Neutron resonance cross sections evaluation based on the phase shift deep neural network

Neutron resonance cross sections are essential in many nuclear science and application fields. Evaluated nuclear libraries usually derive neutron resonance parameters using R-matrix theory. However, determining these parameters and reconstructing the pointwise cross sections required for transport calculations is a time-consuming process. This paper presents a new method for fitting neutron resonance cross sections by using a phase shift deep neural network (PhaseDNN). The network presents resonance cross sections based on its network parameters. This approach allows for the quick calculation of cross section values from the given network parameters. Additionally, PhaseDNN can fit network parameters to experimental data to obtain a smooth resonance cross section curve. Therefore, it has the potential to be an alternative to R-matrix theory.

Process optimization of broad ion beam milling for preparation of coating cross-sections

The application of Argon ion based broad ion beam milling in the preparation of coating cross-sections is systematically evaluated in this work. In order to reduce and eliminate defects and artefacts from the prepared sectional surface, the substrate side of the sample is found to be best facing the ion beams, and the milling time needs to be optimized to be not too long to introduce scratching of the obtained surface, while not too short to result in particle deposition. Further, the energy of the ion beams is found to have great effect on the etch rate of the sample, thus having a large impact on the process time and quality depending on the materials nature of the samples. It is found that by introducing a second low-energy polishing step after the high-energy milling step, the quality of the cross-section is greatly improved with the measured surface roughness down to the nanometer scale. The capability of broad ion beam milling method to provide smooth cross-sections for the subsequent microscopic investigations by e.g. scanning electron microscopy or atomic force microscopy is important to reveal morphological information of the coating systems with high level of details without distortions due to sample preparation.

Operando Nanomechanical Mapping of Silicon Thin Film Electrode during the First Lithiation and Delithiation Investigated By Bimodal Atomic Force Microscopy

Si is emerging as one of the most prospective anode materials for all-solid-state Li-ion batteries due to its extremely high theoretical capacity density of 4200 mAh g-1 and relatively negative potential for lithiation/delithiation. Towards its widespread use, controlling severe volume expansion/contraction during lithiation/delithiation is a challenge because it may cause cracking, fracture, and pulverization that negatively influence the cycle performance and rate capability of the cells [1]. Such mechanical event is induced by the change in the lattice structure due to the formation of LixSi and successive increasing/decreasing of Li content x in LixSi [2].Bimodal atomic force microscopy (AFM) offers quantitative mapping of nanoscale mechanical property, simultaneously with surface topography imaging [3]. Our group previously applied this technique to the cross-section of a composite electrode consist of active materials, binders, conductive additives, and deposited electrolyte solution and successfully demonstrated nanomechanical mapping [4]. Here, we develop an operando bimodal AFM system to track Young’s modulus changes of electrode materials in an all-solid-state battery configuration during the lithiation and delithiation reactions in real-time.A cell in a Cu/Si/LLZT/In/Li configuration was fabricated as follows; a 3 µm-thick Si thin-film and a 100 nm-thick Cu layer were sputter-deposited on one side of Li6.6La3Zr1.6Ta0.4O12 (LLZT) solid electrolyte, an In layer was sputter-deposited on the other side of LLZT, the Cu/Si/LLZT/In sample was milled with an Ar-ion beam to yield a flat and smooth cross-section suitable for AFM analysis, and then a 50 µm-thick Li metal foil was combined with the pre-coated In thin layer. Operando nanomechanical mapping was performed by mounting the cross-section-exposed cell in the custom-made sample holder coupled with a potentiostat for bias applications, in an Ar-filled glove box to prevent any atmospheric influences.Electrochemical lithiation and delithiation were carried out within a potential window of 0.01-1.20 V vs. Li/Li+. Electrochemical characterization indicated that the capacities of the Si electrode for the first lithiation and delithiation are 3300 and 1833 mAh g-1, respectively. These capacities are equal to the formation of Li3.46Si after the first lithiation of the pristine Si and Li1.54Si after the successive delithiation from Li3.46Si. Throughout the lithiation, the averaged Young’s modulus of Si electrode decreased due to the formation of LixSi and increase in the Li content x in LixSi. In the initial stage of lithiation, it drastically decreased because LixSi was formed by the lithiation of pristine Si. Then, it moderately decreased with increasing Li content x in LixSi. Unfortunately, the Young’s modulus maps were only recorded until the formation of Li1.54Si because the successive delithiation was not completed possibly due to the phase transformation of crystalline LixSi to amorphous LixSi [5], which may cause a significant mechanical strain inside the thin film. The measured Young’s modulus values were consistent with those obtained by first principle calculation [6]. Further details are given at the presentation.

Effects of superfine grinding sweet potato leaf powders on physicochemical and structure properties of sweet potato starch noodles.

Sweet potato leaves (SPLs) containing abundant functional components are consumed primarily as fresh vegetables worldwide. This study investigated the physical properties of superfine grinding SPLs powder, and their effects on cooking, texture, and sensory properties, micro- and molecular structures of starch noodles were also explored. The results showed that the bulk and tapped density (from 0.34 to 0.28 g/mL3 and from 0.69 to 0.61 g/mL3), repose and slid angle (from 42.15 to 30.96° and from 48.67 to 22.00°), water-holding capacity and swelling capacity (from 8.66 to 4.94 g/g and from 10.03 to 7.77 mL/g) of SPLs powders were decreased with milling time increased. The cooking loss, swelling index, texture, and sensory properties of SPLs sweet potato starch noodles (SPLSNs) were improved as the particle size of SPLs decreased. XRD and FT-IR showed that SPLSNs contained less complete crystallites (from 28.85% to 14.19%) and lower proportion of crystalline region (R 1047/1017 from 0.96 to 0.81, R 1017/994 from 0.41 to 0.43). SEM revealed that SPLSNs exhibited fewer ordered arrays and smooth cross sections. Our findings provide a foundation for utilizing SPLs and developing functional starch noodles.

Preparation and Characterization of Soybean Protein Adhesives Modified with an Environmental-Friendly Tannin-Based Resin.

Soybean protein-based adhesives are limited in their application due to their poor wet bonding strength and poor water resistance. Herein, we prepared a novel, environmentally friendly soybean protein-based adhesive by adding tannin-based resin (TR) to improve the performance of water resistance and wet bonding strength. The active sites of TR reacted with the soybean protein and its functional groups and formed strong cross-linked network structures, which improved the cross-link density of the adhesives and then improved the water resistance. The residual rate increased to 81.06% when 20 wt%TR was added, and the water resistance bonding strength reached 1.07 MPa, which fully met the Chinese national requirements for plywood (Class II, ≥0.7 MPa). SEM observations were performed on the fracture surfaces of all modified SPI adhesives after curing. The modified adhesive has a denser and smooth cross-section. Based on the TG and DTG plots, the thermal stability performance of the TR-modified SPI adhesive was improved when TR was added. The total weight loss of the adhesive decreased from 65.13% to 58.87%. This study provides a method for preparing low-cost and high-performance, environmentally friendly adhesives.

On the structure group of an infinite dimensional JB-algebra

We extend several results for the structure group of a real Jordan algebra V, to the setting of infinite dimensional JB-algebras. We prove that the structure group Str(V), the cone preserving group G(Ω) and the automorphism group Aut(V) of the algebra V are embedded Banach-Lie groups of GL(V), and that each of the inclusions Aut(V)⊂G(Ω)⊂Str(V) are of embedded Banach-Lie subgroups. We give a full description of the components of Str(V) via cones, isotopes and central projections. We apply these results to V=B(H)sa the special JB-algebra of self-adjoint operators on an infinite dimensional complex Hilbert space, describing the groups Str(V),G(Ω),Aut(V), their Banach-Lie algebras and their connected components. We show that the action of the unitary group of H on Aut(V) has smooth local cross sections, thus Aut(V) is a smooth principal bundle over the unitary group, with structure group S1.

Evaluation of light-element reactions in the resolved resonance region

Light-element reactions at low energies in the resolved resonance region are important for a range of applications in basic and applied sciences including nuclear reactors, nonproliferation, cultural heritage, forensics and environmental control, rare event investigations and nuclear astrophysics. In this paper, we report on an effort to evaluate charged-particle cross sections in the resolved resonance region and produce evaluated nuclear data files for further processing and inclusion in evaluated data libraries. We discuss the open issues in R-matrix calculations as we extend to higher energies, such as dealing with the rapidly growing number of open channels and merging with the regime of smooth cross sections described by the statistical model, and present attempts to address these issues in neutron-induced reactions relevant to nuclear reactor applications.

An analytical method for the solution of earthquake-induced hydrodynamic forces and wave forces on multiple vertical cylinders with arbitrary smooth sections

Analytical methods are developed to investigate the interaction of water with multiple cylinders with arbitrary smooth cross-sections subjected to horizontal ground motion and incident linear waves. Based on the boundary conditions of the seafloor and the water surface, the three-dimensional Laplace equation was transformed into the two-dimensional (2D) Helmholtz equation. Based on the condition that the coefficient function of the cylinder surface can be expanded into a Fourier series, radiation theory and diffraction theory are extended to solve earthquake-induced hydrodynamic forces and wave forces on multiple cylinders. The proposed analytical solution consists of the high-order scattered wave pressures due to diffracted waves. The present method was verified using two double cylinder arrays with elliptical and round-ended cross-sections. Finally, this method was extended to multiple scattering analysis for the interaction of water under earthquake and wave loads.

Basic exploration and research on magnetoelectric synergistic rheological finishing

Both the magnetorheological effect and the electrorheological effect can effectively constrain and clamp abrasives for polishing processing. This paper proposes a magneto-electric synergy rheological finishing (MERF) method. Based on a magnetoelectric composite field simulation, magnetoelectric synergistic rheological finishing equipment is built. A polishing slurry with both electrorheological and magnetorheological effects is prepared for processing a 2-inch single-crystal silicon wafer. Comb-type electrodes and cylindrical flat-bottomed magnetic poles are used to construct magnetoelectric composite fields. Under the action of a magnetoelectric composite field, a hemispherical polishing pad with abrasives distributed in strips can be obtained. By conducting a test, a smooth and gentle arc cross section of the removed contour can be obtained. The removal rate of MERF was 4.04 mg/h, which was between those of electrorheological finishing (ERF) and magnetorheological finishing (MRF). The surface roughness Ra reached 1.80 nm, and the depth and width of the machining traces were the largest. Magnetoelectric synergistic rheological finishing equipment can realize processing under electric fields, magnetic fields, and magnetoelectric composite fields. The MERF method can effectively enhance the semifixed binding force and distributional uniformity of the abrasive and achieve a more efficient and uniform planarization process.

Photoionization of negatively charged NV centers in diamond: Theory and ab initio calculations

We present ab-initio calculations of photoionization thresholds and cross sections of the negatively charged nitrogen-vacancy (NV) center in diamond from the ground $^{3}\!A_2$ and the excited $^{3}\!E$ states. We show that after the ionization from the $^{3}\!E$ level the NV center transitions into the metastable $^{4}\!A_2$ electronic state of the neutral defect. We reveal how spin polarization of $\mathrm{NV}^{-}$ gives rise to spin polarization of the $^{4}\!A_2$ state, providing an explanation of electron spin resonance experiments. We obtain smooth photoionization cross sections by employing dense $k$-point meshes for the Brillouin zone integration together with the band unfolding technique to rectify the distortions of the band structure induced by artificial periodicity of the supercell approach. Our calculations provide a comprehensive picture of photoionization mechanisms of $\mathrm{NV}^{-}$. They will be useful in interpreting and designing experiments on charge-state dynamics at NV centers. In particular, we offer a consistent explanation of recent results of spin-to-charge conversion of NV centers.

Canonical Identification at Infinity for Ricci-Flat Manifolds

We give a natural way to identify between two scales, potentially arbitrarily far apart, in a non-compact Ricci-flat manifold with Euclidean volume growth when a tangent cone at infinity has smooth cross section. The identification map is given as the gradient flow of a solution to an elliptic equation.

Long-term storage and temperature induced quality changes of industrial-scale wet starch noodles

Wet starch noodle (moisture content: 51.38 ± 1.29%) as a retrograded starch-gel product was produced on an industrial scale and investigated to learn the role of long-term storage and storage temperature in its water characteristics, physicochemical properties, sensorial properties and structure changes. During twelve weeks' storage, moisture content, hardness, water absorption index, brightness, and overall acceptability of wet starch noodles dwindled with increasing storage time, accompanied by the increased cooking loss and water mobility transformation from “freezable” to “un-freezable”. In particular, storage temperature was found to have significant correlations with moisture loss, textural performance and appearance color of wet starch noodles during long-term storage. Although refrigeration temperature increased the color stability of wet starch noodles, it would weaken the internal linkage strength and increase cooking loss and broken noodles. Comparatively, wet starch noodles stored at 25 °C exhibited more ordered arrays and smooth cross-section evidenced by SEM, as well as favorable sensorial properties after twelve weeks’ storage. These findings provide beneficial insights into storage stability of wet starch noodles and its correlation with storage temperature, thus giving guiding information for manufacturers and suppliers in selecting of appropriate storage conditions for this industrial-scale product.

Microstructures and properties of (TiCrZrVAl)N high entropy ceramics films by multi-arc ion plating

High entropy ceramics (HECs) films (TiCrZrVAl)N were deposited on Inconel 718 alloys by multi-arc ion plating (MAIP) equipment at different nitrogen flow ratios RnN2/(N2+ Ar). The effects of Rn (0%, 20%, 50%, 80%, 90%) on the evolution of microstructure, mechanical properties, and tribological properties of films were systematically studied. The films deposited at low Rn exhibited an amorphous structure and smooth cross-section, whereas the films at Rn of 50% and higher showed a face-centered-cubic (FCC) NaCl-type structure with loose columnar cross-section. With the increase of Rn, the content of the N element increased, the Cr element decreased, and other elements (Ti, Zr, V, Al) nearly remained stable. The films' hardness and elastic modulus increased gradually and reached the maximum value of 31.08 ± 1.81 GPa and 387.66 ± 12.49 GPa, respectively, when Rn was 80%. The films deposited at Rn of 20% invalided easily in tribology tests, whereas the films prepared under Rn exceeded 20% presented outstanding wear resistance and obtained the minimum wear rate of 7.4×10-16 m3/(N·m) when Rn is 80%.

Preparation and evaluation of a novel intelligent starch‐based film with both color indication and antibacterial function

The study has developed an intelligent starch-based film to monitor pH changes and inhibit undesired microbial growth in foods. The anthocyanin (ANT) and rosemary essential oil (REO) were used to achieve simultaneous colorimetric indication and antimicrobial activity. The study found that both the ANT and the REO can improve the mechanical properties with a relatively smooth cross-section surface. Meanwhile, the water vapor permeability (WVP) increased and the oxygen permeability (OP) decreased significantly. Additionally, there was a distinguishable change of colors as the film was immersed in solutions of pH value ranging from 1.0 to 14.0. Moreover, the developed film showed excellent antimicrobial activity for two typical undesired microorganisms in foods, Bacillus subtilis and Aspergillus niger. The results indicated that the developed film have great potential to use as a diagnostic tool for the detection of food spoilage. Novelty Impact Statement This work developed a novel intelligent film that is capable of monitoring pH changes. The results showed that there was a distinguishable change of colors as the film was immersed in solutions with different pH. Moreover, the developed film also showed excellent antimicrobial activity for two typical undesired microorganisms.

Biberiye ve defne uçucu yağları ile zenginleştirilmiş hamsi atık protein filmlerin karakterizasyonu ve antioksidan kapasitesi

In this study, characterization and antioxidant capacity of anchovy by-product protein (ABP) films with 0.5, 1.0 and 1.5% rosemary (REO) and laurel essential oils (LEO) were investigated. The films with REO and LEO showed higher elongation at break and water vapor permeability (WVP), but lower elastic modulus, transparency, and tensile strength. L* and b* values decreased as a function of essential oil (EO) amount and films became darker and slightly yellowish. The solubility of films with REO and LEO decreased by 10.00-16.05% and 13.84-18.20%, respectively. Intermolecular interaction and molecular organization in the polymer matrix were changed by EO incorporation. Films with EOs showed a nonhomogeneous surface and comparatively smooth cross-section structure providing easy permeation. The antioxidant properties of films were enriched by addition EO and the highest antioxidant capacity was determined in 1.5% LEO film. As a result, although ABP films enriched with EOs have a high WVP, they can be used as packaging material for food products that are susceptible to lipid oxidation.

Testing of fast dissolution of ibuprofen from its electrospun hydrophilic polymer nanocomposites

The dissolution of poorly water-soluble drug poses a big challenge to the researchers in drug discovery. Electrospun nanofibers have been broadly demonstrated as good candidates for resolving this issue. However, the testing methods are often indiscriminate with the drug sustained release profiles. In this study, a new coaxial solid core spinneret was developed to carry out the preparation of ibuprofen (IBU)-loaded polyvinylpyrrolidone (PVP) nanofibers. These nanofibers have an average diameter of 740 ± 130 nm with linear morphology, smooth surface and smooth cross-section without any solid phase separation, as verified by SEM images. XRD and DSC results suggested that IBU presented in the fibers in an amorphous state thanks to their fine compatibility, as disclosed by FTIR spectra. Four different methods (a polarized microscope, an artificial tongue, a contact angle meter, and the in vitro dissolution tests) are exploited to assess the fast dissolution properties of the fibers. Their results concurred the fine functional performances of electrospun nanofibers on improving the dissolution rate of IBU from different standpoints, with 100.3 ± 4.2% of the loaded IBU freed into the dissolution media within the first minute. They are synergistic effects of hydrophilic polymer, large surface and porosity of electrospun nanofiber mats, and amorphous state of the drug.

Numerical Investigation of 2D Turbulent Flow past a Circular Cylinder at Lower Subcritical Reynolds Number

The main objective of the present study is to evaluate the applicability of the standard k-ε turbulence model in engineering practice in the subcritical flow regimes. Also, examine the influence of Reynolds number variation on the flow characteristics are considered. The numerically simulation of the flow characteristics over a smooth uniform cross section circular cylinder with a diameter of 50 mm and 400mm span, placed horizontally perpendicular to the main flow direction at four different Reynolds numbers (Re) based on the cylinder diameter (D) and the undisturbed free-stream velocity in the range Re=(0.5,0.7,0.85 and 1.0) ×105 were performed. The simulated results of the flow properties such as flow stream velocity components, pressure distribution contours, pressure coefficient (Cp) and drag coefficient(CD) around the circular cylinder were consider. The numerical analysis obtain by CFD using ANSYS FLUNET (19.1) with K-ε turbulence model, for solving the 2D (ANSE) governing equation for tested model were consider. The present simulation results validation is obtained by comparing the converged results with published numerical and experimental data.

Surface effects in superconductors with corners

We review some recent results on the phenomenon of surface superconductivity in the framework of Ginzburg-Landau theory for extreme type-II materials. In particular, we focus on the response of the superconductor to a strong longitudinal magnetic field in the regime where superconductivity survives only along the boundary of the wire. We derive the energy and density asymptotics for samples with smooth cross section, up to curvature-dependent terms. Furthermore, we discuss the corrections in presence of corners at the boundary of the sample.

Diffraction of flexural-gravity waves by a vertical cylinder of non-circular cross section

The linear three-dimensional problem of flexural-gravity wave (hydro-elastic wave) diffraction by a vertical cylinder of an arbitrary smooth cross section is studied using an asymptotic approach combined with the vertical mode method for water of finite depth. The surface of the water is covered by an infinite, continuous elastic ice plate. The rigid cylinder extends from the sea bottom to the ice surface. The ice plate is frozen to the cylinder. The ice deflection is described by the equation of a thin elastic plate of constant thickness with clamped edge conditions at the cylinder. The flow under the ice is described by the linear theory of potential flows. The coupled problem of wave diffraction is solved in two steps. First, the problem is solved without evanescent waves similar to the problem of water waves diffracted by a vertical cylinder. This solution does not satisfy the edge conditions. Second, a radiation problem with a prescribed motion of the ice plate edge is solved by the vertical mode method. The sum of these two solutions solve the original problem. Both solutions are obtained by an asymptotic method with a small parameter quantifying a small deviation of the cylinder cross section from a circular one. Third-order asymptotic solutions are obtained by solving a set of two-dimensional boundary problems for Helmholtz equations in the exterior of a circle. Strains along the edge, where the ice plate is frozen to the cylinder, are investigated for nearly square and elliptic cross sections of the vertical cylinders depending on the characteristics of ice and incident wave. The strains are shown to be highest in the places of high curvatures of the cross sections. The derived asymptotic formulae can be used in design of vertical columns in ice. They directly relate the strains in ice plate to the shape of the column.