Triangular Column Research Articles

Refractive Laser Beam Measuring Diffusion Coefficient of Concentrated Battery Electrolytes

A thorough understanding of electrolyte transport properties is crucial in the development of alternative battery technology. As a key parameter, the diffusion coefficient offers important insights into the behavior of electrolytes, especially for fast charge of high-energy batteries. Existing methods of measurement are often limited by redox species or offer questionable accuracy due to side reactions and/or disruption of the diffusion profile. A highly sensitive optical method was developed using a refractive laser beam through triangular diffusion column to measure the diffusion coefficient of concentrated battery electrolytes. The method based on Snell’s law can be applied to all liquid phase electrolytes since the refractive index is concentration dependent for all liquid electrolytes. This universal method relies on the deflection of a refractive laser beam passing through an electrolyte of a minor concentration gradient in a triangular diffusion column (Figure 1). A polarized HeNe laser was arranged to pass the beam through a right-angled triangular quartz precision cell, slightly rotated to the normal. The exact position of the refracted beam was located by a silicon photodiode-based position detector. Deflection calibration curves made simple conversion of beam position to concentration, and during the diffusion of two layered solutions, data points were collected every minute to produce a concentration profile descriptive of the 48-hour diffusion. Diffusion coefficients were calculated using a model based on OSM theory, accounting for multi-component concentrated systems in a restricted diffusion column.1 The measured diffusion coefficients are between 4.12x10-10 m2/s for 0.15 mol/kg ZnSO4 and 0.681x10-10 m2/s for 2.5 mol/kg ZnSO4 at 22.4 °C. The profile of concentration-dependent diffusion coefficients follows a non-linear inverse relationship described by the function D=4.943(1+m)-1.564 (Figure 2).Several other physicochemical properties of the same electrolytes were studied to correlate to the concentration-dependent diffusion coefficients, including refractive index, viscosity, conductivity, and microstructure analysis based on vibrational spectroscopy (Infrared and Raman). High concentration electrolytes with more ion pairs show increased viscosity which ultimately leads to smaller diffusion coefficients. A QCM-I instrument standard flow cell were used to determine the viscosity of ZnSO4 electrolyte and the concentration-dependent viscosity was fitted to the function η=1.06-0.476m+2.13m2-1.01m3+0.204m4. Interionic interactions also led to reduced conductivity at concentrations beyond 1.5mol/kg, despite the increased charge density of concentrated solutions. FT-IR spectrums allowed analyzation of increased charge density, which increased intensity of the O-H stretching peak in concentrated electrolytes, despite the decrease in the ratio of water. Competition between charge density and viscosity continues to challenge the efficiency of concentrated electrolytes.Lastly, we demonstrate the prototype in situ triangular cell to characterize the electrolyte in working batteries. The cell responds to short, low-voltage pulses with beam deflection and relaxation, and offers an opportunity as a novel in situ spectroscopic tool to characterize the battery electrolyte. Acknowledgments This work is supported by a grant from NSF (CBET-2243098).

Crushing performance evaluation of gradient Sierpinski triangular fractal column

Thin-Walled Structures with excellent mechanical properties are the key to the protective system of the vehicle. This paper proposes a novel Sierpinski triangular fractal column with graded thickness (STFC-GT) to improve the crushing stability and energy absorption of Thin-Walled Structures. The crashworthiness of the STFC-GT is investigated through the experimental test and numerical simulation under axial crushing load. The results show that the Sierpinski triangular fractal column contributes to the energy absorption, and the graded thickness design can decrease the initial peak force. Specifically, the energy absorption of STFC-GT improves by 144.22 % from 0th to 2nd. And the initial peak force of 2nd STFC-GT is 55.32 % lower than that of 2nd STFC with uniform thickness. In addition, a theoretical relationship between the parameter configurations and the mean crushing force of STFC-GT are developed using the simplified super folding element theory (SSFE). The maximum error is less than 7.89 % between the theoretical and numerical results. Finally, the influence of gradient types on crushing performance is investigated to determine the optimal gradient configuration and maximize the mechanical performance of the STFC. The research result provides reliable guidance for the design of a new vehicle safety protection device.

Refractive Laser Beam Measuring Diffusion Coefficient of Concentrated Battery Electrolytes

A thorough understanding of electrolyte transport properties is crucial in the development of alternative battery technology. As a key parameter, the diffusion coefficient offers important insights into the behavior of electrolytes, especially for fast charge of high-energy batteries. Existing methods of measurement are often limited by redox species or offer questionable accuracy due to side reactions and/or disruption of the diffusion profile. This work provides a novel optical method for measuring diffusion coefficients of liquid-phase concentrated battery electrolytes without electrochemical reactions. The method relies on the deflection of a refractive laser beam passing through an electrolyte of a minor concentration gradient in a triangular diffusion column. The diffusion coefficient, D, for a range of zinc sulfate electrolytes was successfully extracted by correlating the position of the laser beam to its concentration. Several other physicochemical properties of the same electrolytes are studied to correlate to the concentration-dependent diffusion coefficients, including viscosity, conductivity, and microstructure analysis based on vibrational spectroscopy (Infrared and Raman). Also included is the future application of the triangular column for in situ electrochemical measurements.

Finely tuned water structure and transport in functionalized carbon nanotube membranes during desalination.

Molecular dynamics simulations were performed to tune the transport of water molecules in nanostructured membrane in a desalination process. Four armchair-type (7,7), (8,8), (9,9) and (10,10) carbon nanotubes (CNTs) with pore diameters around 1 nm were chosen, their interior surfaces were modified with -OH, -CH3 and -F groups. Simulation results show that water transport in nanochannel depends on confined water structures which could be regulated by precisely controlled channel diameter and chemical functionalization. Increasing CNT diameter changes water structures from single-file-like to be square and hexagonal-like, then into a disordered pattern, resulting in a concave-shaped trend of water permeance. The -OH functional groups promote structural ordering of water molecules in (7,7) CNT, but disrupt water structures in (8,8) and (9,9) CNTs, and reduce the order degree of water molecules in (10,10) CNT, moreover, exert an attraction to enhance surface friction inside channel. The -CH3 groups induce more strictly single-file movement of water molecules in (7,7) CNT, turning water structures in (8,8) and (9,9) CNTs into two and triangular column arrangements, improving water transport, however, causing again square-like water structure in (10,10) CNT. Fluorinations of CNT make water structure more disordered in (7,7), (9,9) and (10,10) CNTs, while enhance the square water structure in (8,8) CNT with a lower water permeance. Through changing channel diameter and functionalization, the low tetrahedral order corresponds to a more single-file-like water structure, associated with rapid water diffusion and high permeability; an increase in tetrahedrality results in more ice-like water structures, lower water diffusion coefficients, and permeability. The results of this study demonstrate that water transport could be finely regulated via a functionalized CNT membrane.

Shaking table test on irregular and complex connected structure

Affected by the external environment, it is easy to cause complex and irregular problems in the building structure, bringing new safety hazards to the seismic resistance of the structure. Based on the background of the east building of the railway station with cross ground crack, the seismic performance of irregular and complex connected structures under different seismic intensities was analysed.The research results indicate that under the action of a 7-degree seismic fortification, the structure is basically in an elastic state, with a stiffness degradation of 12.9%, meeting the performance requirements of being undamaged during small earthquakes; Under seismic fortification, the structure is mainly characterized by cracking at the bottom beam end, with a small crack width and a stiffness degradation of 41.7%, meeting the requirements for moderate earthquake repairability; Under the rare earthquake of 8degree , plastic hinges begin to form at the beam and column ends of the structure and gradually develop, with stiffness degradation reaching 81.9%. All seismic responses of the structure comply with the limit requirements of the code (GB 50011-2010); Under the rare earthquake of 8 degree , there is a serious torsion phenomenon in the small triangle area, which leads to the disharmony of forces on the inner and outer beams and columns. In earthquakes, it is easy to cause structural collapse due to the first failure of the outer columns. Suggesting to increasethe stiffness of the small triangular column to solve the above problem. Under extremely rare earthquakes, the plastic hinge mechanism of the structure has developed completely, with stiffness degradation approaching 90% and no collapse phenomenon, indicating that complex connected structures have excellent seismic performance.

Study on Enhanced Heat Transfer of the Convex Columns in the Cooling Channel of Motorized Spindle Based on Field Synergy

The cooling performance of motorized spindles plays an important role in accuracy in high-speed machining. Aiming at improving the cooling performance of traditional motorized spindles, convex columns were built in the cooling channel. Based on field synergy, the effects of quadrilateral, circular and triangular convex columns on the heat transfer performance of the cooling channel were analyzed numerically. We also compared the pressure drop between the inlet and outlet under the same conditions. The results show that the cooling channels with triangular convex columns provide the best cooling effect with the smallest increase in area compared to quadrilateral convex columns and circular convex columns. The pressure drop in the cooling channels with a circular convex column is minimized. By optimizing the spacing of the convex column, the best effect was found at a spacing of 7 mm. By optimizing the angle of the top angle of the triangular column, it is found that the enhanced heat transfer effect is best at 120° when the heat transfer area is the same. In addition, when considering the addition of convex columns, it is important to ensure sufficient pressure drop to achieve a good cooling effect.

A block Cholesky‐LU‐based QR factorization for rectangular matrices

AbstractThe Householder method provides a stable algorithm to compute the full QR factorization of a general matrix. The standard version of the algorithm uses a sequence of orthogonal reflections to transform the matrix into upper triangular form column by column. In order to exploit (level 3 BLAS or structured matrix) computational advantages for block‐partitioned algorithms, we develop a block algorithm for the QR factorization. It is based on a well‐known block version of the Householder method which recursively divides a matrix columnwise into two smaller matrices. However, instead of continuing the recursion down to single matrix columns, we introduce a novel way to compute the QR factors in implicit Householder representation for a larger block of several matrix columns, that is, we start the recursion at a block level instead of a single column. Numerical experiments illustrate to what extent the novel approach trades some of the stability of Householder's method for the computational efficiency of block methods.

Characterization of energy absorption for side hierarchical structures under axial and oblique loading conditions

This paper develops triangular, quadrangular and hexagonal side hierarchical structures to promote the energy absorption of thin-walled protective devices. The axial crush testing exhibits that side hierarchical structures can form stable folding deformation. The energy absorption of side hierarchical structures under oblique loads is further investigated by the numerical simulation, and the energy absorption of 7th order triangular hierarchical structure is 112% higher than that of the non-hierarchical triangular column under axial impact. The hierarchical factor and loading angle have great influence on the crushing response of side hierarchical structures, and the critical hierarchical order is observed for different side hierarchical structures. Furthermore, 4th order side hierarchical structures are believed with excellent comprehensive crashworthiness based on the technique for order preference by similarity to ideal solution (TOPSIS). Lastly, the wall thickness parameter of 4th order side hierarchical structures is further investigated to reveal the influence of material distribution on the crashworthiness, and results show that the energy absorption of 4th order hexagonal side hierarchical structure can much easier suffer the influence of wall thickness than that of the other two side hierarchical structures.

Three new species of Liparis s.l. (Orchidaceae: Malaxideae) from Southwest China based on morphological characters and phylogenetic evidence

Liparis aureolabella and L. mengziensis, two new species from the karst region of southwestern China, and L. bingzhongluoensis, a new species from montane region in Yunnan, are described and illustrated. L. aureolabella is easily distinguished from its relatives by having abaxially purple leave with purple reticulate veins prominent adaxially, a lip auriculate at base, and falcate-lanceolate pollinia. Liparis mengziensis is closely related to L. petiolata and L. auriculata, but differs from them by having an ovate to broadly ovate leaf, purple lip and apex connate along the margins. Liparis bingzhongluoensis is similar to Liparis nanlingensis, but the new species is characterized by having a lip with two transparent ridges on its disc, longitudinally concave basal callus and triangular column wings. Phylogenetic analyses based on nuclear ribosomal ITS and plastid matK sequences showed that L. aureolabella and L. mengziensis are nested with L. petiolata or L. auriculata in a monophyletic clade. L. bingzhongluoensis is sister to a clade formed by L. nanlingensis, L. tsii, L. sasakii and L. krameri. Moreover, morphological comparisons strongly support that the three species as separated species newly to science.

Analytical investigation on light gauge steel fluted columns

Cold formed steel is one of the structural materials which are vastly growing product and being used as various structural elements. It has major advantages in time effectiveness and the ability to shape it into the necessary shape even in room temperature. In this study the behaviour of the Steel column having flutes of different shapes when filled with concrete will be analytically investigated by analysing 8 column models using Finite Element Analysis software. Here Cold formed steel is to be used as the hollow section that confines the concrete. The Finite Element Analysis software that will use for the analysis is ABAQUS 14. All the specimens will be loaded with an eccentrically load and the results will be studied further. By providing the flutes along the longitudinal length of the column increases the moment of inertia and the stiffness of the column. The parameters of the column that will be varied for the analysis are the D/t ratios, Shapes of flutes and the thickness of the steel column. High Strength concrete of grade M50 will be used here in this analytical study. The thickness of the steel column used is 1 mm and 1.2 mm. The shapes of the flutes varied is rectangular flute and triangular flute. The maximum stress induced was in the column with 1 mm thickness with triangular flutes. And the maximum load was carried by the Triangular fluted column with 1.2 mm thickness.

The Effect of Strontium Doping on LaFeO3 Thin Films Deposited by the PLD Method

The aim of the presented investigations was to deposit the thin films La1−xSrxFeO3 (x = 0, 0.1, 0.2) on (100) Si substrate by using the Pulsed Laser Deposition (PLD) method. Structure was exanimated by using XRD, SEM, AFM, TEM and XPS methods. The catalytic properties were analyzed in 4 ppm acetone atmosphere. The doping of Sr thin films La1−xSrxFeO3 (x = 0, 0.1, 0.2) resulted in a decrease in the size of the crystallites, the volume of the elemental cell and change in the grain morphology. In the LaFeO3 and La0.9Sr0.1FeO3, clusters around which small grains grow are visible in the structure, while in the layer La0.8Sr0.2FeO3, the visible grains are elongated. The TEM analysis has shown that the obtained thin films had a thickness in the range 150–170 nm with triangular or flat column ends. The experiment performed in the presence of gases allowed us to conclude that the surfaces (101/020) in the triangle-shaped columns and the plane (121/200) faces in flat columns were exposed to gases. The best properties in the presence of CH3COCH3 gas were noted for LaFeO3 thin film with triangle columns ending with orientation (101/020).

Prediction Capability of Cartesian Cut-Cell Method with a Wall-Stress Model Applied to High Reynolds Number Flows

The Cartesian cut-cell method is one of the most promising methods for computational fluid dynamics due to its sharp interface treatment. However, the Cartesian cut-cell method and other Cartesian mesh solvers have difficulty with concentrating grid to boundary layers. The wall-modelling of shear stress is one of the most effective methods to reduce computational grids in boundary layers. This study investigated the applicability of a wall-stress model to the Cartesian cut-cell method. In the numerical simulations of the flow around a triangular column, Cartesian cut-cell simulation with the wall-stress model adequately predicted the drag coefficient. In the numerical simulations of the flow around a 30P30N high-lift airfoil configuration, the Cartesian cut-cell simulation with the wall-stress model adequately predicts the lift coefficient. The intermittent vortex structure of the outer layer of the turbulent boundary layer was observed on the suction side of the main element and the flap. The Cartesian cut-cell method with a wall-stress model is useful for predicting high Reynolds number flows at R e ∼ 10 6 .

Comparative analysis of bearing characteristics between triangular columns and variable-section columns

Fengnan 500KV substation fully united framework was taken as the engineering background for analyzing the effect of load on the bearing characteristics of triangular frame columns and variable-section steel columns under different working conditions. Through ANSYS simulation, the bearing characteristics of the two structures under the same working conditions were obtained. The possibility of replacing the original triangular frame column with a variable-section frame column in a 500kV fully united substation frame was analyzed.

Three-dimensional piezoelectric MEMS actuator by using sputtering deposition of Pb(Zr,Ti)O3 on microstructure sidewalls

For the realization of piezoelectric microelectromechanical systems (MEMS) with multiple degrees-of-freedom, lead zirconate titanate thin films were deposited and micropatterned on the sidewalls of a pre-etched substrate with a feature depth of several hundred micrometers. The piezoelectric test structures, consisting of concave geometries and cantilevers with vertical and sloped sidewalls were successfully fabricated onto a 4 inch full sized wafer. Characterization of the fundamental properties of the lead zirconate titanate thin films indicated values comparable to those deposited on flat substrates. Actuation tests demonstrated that the triangular column cantilevers can be driven both in-plane and out-of-plane. The deposition of lead zironate titanate thin films onto a vertical sidewall created bimorph cantilevers composed of piezo/non-piezo/piezo structures in the horizontal direction. The use of microfabrication techniques to deposit lead zironate titanate thin films on pre-etched substrates gives MEMS actuators with multiple degrees-of-freedom and batch process compatibility.

Cobalt‐Doping‐Induced Synthesis of Ceria Nanodisks and Their Significantly Enhanced Catalytic Activity

High-quality cobalt-doped ceria nanostructures with triangular column, triangular slab, and disklike shapes are synthesized by tuning the doping amount of cobalt nitrate in a facile hydrothermal reaction. The cobalt-doped ceria nanodisks display significantly enhanced catalytic activity in CO oxidation due to exposed highly active crystal planes and the presence of numerous surface defects.

Studies on the performance of different coiled column configurations for compact type-I countercurrent chromatography

Three types of novel coiled column configurations, i.e. a triangular coiled column and elliptical coiled columns I and II, were designed for type-I countercurrent chromatography and their performances were evaluated with two solvent systems each with suitable test samples. Three dinitrophenyl (DNP) amino acids (DNP-DL-glu, DNP-β-ala and DNP-L-ala) were separated with a moderately hydrophobic two-phase solvent system composed of hexane-ethyl acetate-metanol-0.1 M hydrochloric acid (1:1:1:1, v/v), while two dipeptides (tryptophyl-tyrosine and valyl-tyrosine) were separated with a polar solvent system composed of 1-butanol-acetic acid-water (4.75:0.25:5, v/v). The overall results indicated that the performance of compact type-I countercurrent chromatography was improved by elliptical coiled column I which was mounted with its maximum coil diameter perpendicular to the surface of the column holder. Hydrodynamic effects involved in these separations were discussed.

Triangular Helical Column for Centrifugal Countercurrent Chromatography

Effective column space and stationary phase retention have been improved by changing the configuration of the helical column originally used for toroidal coil countercurrent chromatography. The use of an equilateral triangular core for the helix column doubles effective column space and retains the stationary phase over 40% of the total column capacity without increasing the column pressure. The present results suggest that the stationary phase retention and the peak resolution will be further improved using new column designs fabricated by a new technology called “laser sintering for rapid prototyping.”

Fabrication of high fill factor optical film using two-layer photoresists

A new process to fabricate gapless triangular micro-lens array (GTMA) optical film is realized in this study. Two-layer photoresists are used to define a triangular column array template. The upper and lower layer photoresists are AZ 4620 and AZ 9260, respectively. The two-layer photoresists form a higher aspect ratio than the individual photoresist does. This process includes a two-layer ultraviolet (UV) lithography, photoresist reflow process, Ni–Co electroplating and the hot embossing technique. After a triangular column array of two layers of photoresist is defined by UV lithography, the reflow technique is applied to melt the triangular column array into the shape of a triangular micro-lens array. With this reflowed triangular micro-lens array, Ni–Co alloy is electroplated and covered uniformly on the triangular micro-lens array to form the GTMA mould. After this electroplating process, a mould of GTMA is obtained, which serves as the primary mould. Next, with the passivation technique applied on this primary mould's surface, a secondary mould is obtained by applying the electroplating process again. This secondary mould serves as a master for the subsequent hot embossing process to replicate the GTMA pattern onto a polymethyl methacrylate (PMMA) sheet. The Ni–Co mould with a hardness over 650 Hardness of Vicker (Hv) is obtained. The stiffness and hardness of the mould play important roles in the GTMA hot embossing process. In addition, this PMMA-based GTMA film used as optical film offers a 100% fill factor and high optical coupling efficiency to improve the luminance. The optical measurement shows that this optical film with GTMA pattern increases 18.39% of luminance for a backlight module (BLM) of a liquid crystal display (LCD).

Fluid impact on a solid boundary

Abstract The hydrodynamic impact due to a column of liquid hitting on a solid wall is analysed. The problem is solved using the complex velocity potential together with the boundary element method, based on the assumption that the fluid is inviscid and incompressible and the flow is irrotational. A stretched coordinate system is used, which is defined through the ratio of the normal Cartesian system to an appropriately chosen length scale varying with time. Numerical simulations are made for incoming liquid columns of various shapes. The results from the triangular column are compared with those obtained from a similarity solution and excellent agreement is found. It is shown that for a symmetrical liquid column with a shape defined by f(x)=a1−αxα, with 0 0, the flow field and pressure distribution in the fluid after impact depend only on the parameter Ut/a: they do not depend separately on the speed U of the liquid column, the time t or the coefficient a.

Fabrication of gapless triangular micro-lens array

This study presents a new process to fabricate gapless triangular micro-lens array (GTMA) optical film. The process includes ultraviolet (UV) lithography, photoresist reflow process, Ni–Co electroplating and hot embossing technique. After photoresist triangular column array is defined by UV lithography, reflow technique is applied to melt photoresist triangular column array into the shape of triangular micro-lens array. With this reflowed triangular micro-lens array, metal Ni–Co is deposited and covered uniformly on the triangular micro-lens array using electroplating process. The growth rate of Ni–Co is controlled at 0.4–0.6 μm/min at electroplating current density of 1 A/dm 2 (ampere square decimetre, ASD). After this electroplating process, a mold of GTMA is obtained, which is served as the primary mold. Next, with passivation technique applied on this primary mold's surface, a secondary mold is obtained by applying the electroplating process again. This secondary mold is served as master for the subsequent hot embossing process to replicate the GTMA pattern onto polymeric material of polymethyl methacrylate (PMMA) sheet. The Ni–Co mold with hardness over hardness of vicker (Hv) 650 is obtained. The stiffness and hardness of the mold play important roles in GTMA hot embossing process. In addition, this PMMA-based GTMA film used as optical film offers a 100% fill factor and high optical coupling efficiency to improve luminance. The optical measurement shows that this optical film with GTMA pattern increases 15.1% of luminance for backlight module (BLM) of liquid crystal display (LCD).