Arrangement Of Sheets Research Articles

Binder free self-standing high performance supercapacitive electrode based on graphene/titanium carbide composite aerogel

The flexible and light weight supercapacitors as a power source for flexible electronics have attracted extensive attention recently. Herein, we present the fabrication of a flexible aerogel composed of reduced graphene oxide (rGO) and delaminated titanium carbide (Ti3C2) sheets as a high performance, binder free, flexible and self-standing electrode for supercapacitor application. Micron sized two dimensional (2D) delaminated Ti3C2 sheets were synthesized from Ti3AlC2 and were successfully accommodated inside a three-dimensional (3D) microporous network of rGO, prepared via room temperature interfacial gelation route and successive reduction of GO at Zn surface. The vacuum dried composite aerogel with a quasi-parallel arrangement of the 2D sheets showed high areal capacitance of 171.4 mF cm−2 at 1 mA/cm2 current density, which was ~4.7 times higher than that of the only rGO aerogel electrode. The high areal capacitance was accompanied by excellent cycle stability of only 4.3 ∗ 10−3% capacitance loss per cycle over 1500 cycles at 3 mA/cm2 current density. The impressive electrochemical performance of the rGO/Ti3C2 composite aerogel was also realized in a solid state symmetric supercapacitor using PVA/H3PO4 gel polymer electrolyte with high areal energy density of 2.1 μWh/cm2 accompanied by excellent cycle stability.

Structured illumination for two-dimensional laser induced fluorescence imaging to eliminate stray light interference

<sec>Laser sheet imaging, also called planar laser imaging, is one of the most versatile optical imaging techniques and has been frequently used in several different areas. However, when applied to the limited operating space and strong light scattering media, the light originating from indirect reflections, multiple scattering and surrounding backgrounds can produce error especially in intensity-ratio based measurements.</sec><sec>This work is motivated by these challenges, with the overall aim of making laser sheet imaging technique applicable for the study of eliminating the stray light interference. Therefore a novel two-dimensional imaging technique named structured laser illumination planar imaging (SLIPI) is developed based on planar laser imaging but uses a sophisticated illumination scheme i.e. spatial intensity modulation, to differentiate between the intensity contribution arising from useful signals and that from stray light. By recording and dealing with images, the SLIPI method can suppress the diffuse light and retain the useful signals.</sec><sec>In this paper, we first use the MATLAB software to simulate the phase-shift SLIPI method, and the results show that the stray light interference can be eliminated completely. Furthermore, the phase-shift SLIPI is combined with the liquid solution (Rhodamine B solution) laser induced fluorescence (LIF) approach to imagine the concentration distribution. By recording three images, between which this encoding is changed noticeably only for the useful LIF signals, the phase-shift SLIPI method is evidenced to be able to remove the diffuse light contribution, thus improving and enhancing the visualization quality. The instantaneous SLIPI images of rapidly moving samples, a key feature to study dynamic liquid solution diffusion behavior, are also acquired. The lock-in amplifier SLIPI technique is then experimentally studied under Rhodamine B diffused solution, and the phase-shift SLIPI method can remove the unwanted background interferences and achieve the significant improvements in terms of pronounced concentration distribution within the Rhodamine B solution.</sec><sec>The SLIPI technique is relatively inexpensive: the cost does not exceed the cost of an ordinary laser sheet arrangement noticeably, and it can combine with several other linear imaging techniques, such as Rayleigh scattering, particle image velocimetry and laser-induced phosphorescence. </sec>

Efficient peptide based gelators for aromatic organic solvents and vegetable oils: application in phase selective gelation and dye entrapment

The examples of organogel in vegetable oil are limited and the illustration of single amphiphile showing organogel in a lot of vegetable oils are rare. Hence, invention of a new type of amphiphile capable to gelate different vegetable oils are demanding and challenging aspect to us. In this article, we have synthesized two peptide based low molecular weight organic gelators, [11-(2-tert-Butoxycarbonylamino-3-methyl-butyrylamino)-undecanoylamino]-acetic acid (TBMBUA) and [11-(2-tert-Butoxycarbonylamino-3-methyl-pentanoylamino)-undecanoylamino]-acetic acid (TBMPUA) and have demonstrated their excellent gelation ability towards a number of aromatic organic solvents and different edible vegetable oils. FT-IR and temperature dependence 1H-NMR spectroscopy studies confirmed that hydrogen bonding interaction among the amide linkages plays significant role for formation of gel in organic solvents. XRD and FT-IR measurements suggested anti-parallel beta sheet arrangement between the peptide chains in the self-assembled state. The study revealed that the synthesized amphiphile TBMBUA is a good phase selective gelator of aromatic organic solvents in water-solvent mixture and both the gelators are able to entrap toxic dyes from aqueous dye solution. Hence the gelators can be successfully utilized to remove the toxic aromatic organic solvents and toxic dyes present in waste water which is one of the serious problems in recent years.

A DFT study of structural, electronic and optical properties of heteroatom doped monolayer graphene

In this paper we present a theoretical work on the influence of doped and co-doped Al, Al-S, Al-N and Al-P heteroatoms in the mono layer graphene surface. The Density functional study reveals that, Al, P and S co-doping significantly modifies the neighborhood bonding arrangement of the graphene sheet. The Natural population analysis revels that Al, P and S co-doping makes the graphene surface as electron rich system. From the molecular orbital analysis it is found that HOMO-LUMO energy gap decreases by starting from the pristine graphene in following manner Al doping >Al-S co-doping>Al-N co-doping >Al-P co-doping. On the other hand, the time dependent density functional theory (TD-DFT) calculation shows that the maximum absorbing wavelength of Al-P and Al-N co-doped graphene systems shifted towards the lower wavelength range with respect to Al doped graphene.

An exploration of O-H⋯O and C-H⋯π inter-actions in a long-chain-ester-substituted phenyl-phenol: methyl 10-[4-(4-hydroxyphenyl)phenoxy]decanoate.

An understanding of the driving forces resulting in crystallization vs organogel formation is essential to the development of modern soft materials. In the mol-ecular structure of the title compound, methyl 10-[4-(4-hydroxyphenyl)phen-oxy]decanoate (MBO10Me), C23H30O4, the aromatic rings of the biphenyl group are canted by 6.6 (2)° and the long-chain ester group has an extended conformation. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, forming chains along [10[Formula: see text]]. The chains are linked by C-H⋯O hydrogen bonds, forming layers parallel to the ac plane. The layers are linked by C-H⋯π inter-actions, forming a three-dimensional supra-molecular structure. The extended structure exhibits a lamellar sheet arrangement of mol-ecules stacking along the b-axis direction. Each mol-ecule has six nearest neighbors and the seven-mol-ecule bundles stack to form a columnar superstructure. Inter-action energies within the bundles are dominated by dispersion forces, whereas inter-columnar inter-actions have a greater electrostatic component.

Multi-response optimization on single-point incremental forming of hyperbolic shape Al-1050/Cu bimetal using response surface methodology

In present work, experimental and numerical investigations were carried out on single-point incremental forming of explosive bonded clad sheets. The sheets were produced by explosion welding from 1050 aluminum alloy and C10100 copper alloy sheets. A generatrix of hyperbolic curve was utilized as profile of final shapes formed by SPIF process. During some investigations, the interaction and main effect of the process parameters viz. tool diameter, step down, rotational speed, and sheet arrangement were evaluated on the fracture depth and wall thickness at fracture using ANOVA method. For experimentation, a customized design table was built with three quantify and one qualify factors in two levels. The design table totally provides four input factors and two responses in 12 runs. The responses are fracture depth and wall thickness. A multi-response optimization was conducted to find optimum values for input parameters using response surface methodology (RSM) and the confirmatory experiment revealed the reliability of RSM in this regard. Moreover, predictive models were presented in confidence interval of 95% to formulate the relationship between the responses and the input factors using RSM approach. Additionally, a finite element analysis was carried out on the SPIF based on optimal input parameters to depict reaction force changing, thickness variation, and stress distribution.

Magnetic field induced orderly arrangement of Fe3O4/GO composite particles for preparation of Fe3O4/GO/PVDF membrane

Magnetic Fe3O4/graphene oxide (GO) composite particles with excellent properties of magnetic susceptibility and hydrophilicity were synthesized by a facile one-step chemical coprecipitation method. Then the prepared magnetic Fe3O4/graphene oxide (MGO) particles were introduced to polyvinylidene fluoride (PVDF) casting solution to fabricated PVDF/MGO hybrid membrane under the magnetic field. The directional migration and ordered arrangement of MGO sheets in magnetic field were investigated. The preparation of multilayer composite membrane was in the form of functional layer and support substrate in series, in which the functional layer with MGO orderly embedded into the membrane surface was prepared via magnetic field induced MGO sheets to the membrane surface during the phase inversion process. There was obvious effects of this novel structure on the pure water flux, hydrophilicity and antifouling properties of the membranes. The PVDF/MGO membranes showed high pure water flux (484Lm−2h−1) and high flux recovery ratio (up to 83.0%).

Oriented Arrangement: The Origin of Versatility for Porous Graphene Materials.

Macroscopic porous graphene materials composed of graphene sheets have demonstrated their advantageous aspects in diverse application areas. It is essential to maximize their excellent performances by rationally controlling the sheet arrangement and pore structure. Bulk porous graphene materials with oriented pore structure and arrangement of graphene sheets are prepared by marrying electrolyte-assisted self-assembly and shear-force-induced alignment of graphene oxide sheets, and the super elasticity and anisotropic mechanical, electrical, and thermal properties induced by this unique structure are systematically investigated. Its application in pressure sensing exhibits ultrahigh sensitivity of 313.23 kPa-1 for detecting ultralow pressure variation below 0.5 kPa, and it shows high retention rate for continuously intercepting dye molecules with a high flux of ≈18.7 L m-2 h-1 bar-1 and a dynamic removal rate of 510 mg m-2 h-1 .

Insights on molecular structure and micro-properties of alkali-activated slag materials: A reactive molecular dynamics study

The material design of the alkali activated slag (AAS) contributes to the development of the sustainable “Green Building Materials” for the recycle of industrial waste and energy reservation of cement materials production. A computational simulation technique based on reactive molecular dynamics proposed a new view of molecular structure for the main hydrate, C-A-S-H gel, in AAS. In this paper, structure, dynamics and mechanical properties of C-A-S-H gel have been investigated. The proposed C-A-S-H model exhibits heterogeneity layered features with ordered and stable atomistic arrangement in the calcium sheets and disordered chemical connections in the interlayer region. Structurally, Al atoms bridge the neighboring oxygen atoms in the defective silicate chains, contributing to the polymerization of the C-A-S-H gel. The increase of Al or Si can significantly enhance the mean silicate chain length of the structure, and the introduction of Al atoms in the interlayer region can improve the mechanical properties of the C-A-S-H gel. Therefore, the mean chain length can be taken as important parameter to guide the high performance AAS materials design.

Sporicidal efficacy of thermal-sprayed copper alloy coating.

Approximately 200 000 Canadians acquire healthcare-associated bacterial infections each year and several-fold more acquire food-borne bacterial illnesses. Bacterial spores are particularly problematic because they can survive on surfaces for several months. Owing to its sporicidal activity, copper alloy sheet metal is sometimes used in hospital settings, but its widespread use is limited by cost and incompatibility with complex furniture and instrument designs and topographies. A potential alternative is the use of thermal spray technology to coat surfaces with copper alloys. We compared the sporicidal activity of thermally sprayed copper alloy on stainless steel with that of copper alloy sheet metal against Bacillus subtilis spores. Spores remained intact for at least 1 week on uncoated stainless steel, whereas spore fragmentation was initiated within 2 h of exposure to either copper surface. Less than 15% of spores were viable 2 h after exposure to either copper surface, as compared with stainless steel. By day 7, only degraded spores and petal-like nanoflowers were present on the copper surfaces. Nanoflowers, which are laminar arrangements of thin crystal sheets composed of carbon - copper phosphate, appeared to be derived from the degraded spores. Altogether, these results indicate that a thermal-sprayed copper alloy coating on stainless steel provides sporicidal activity similar to that afforded by copper alloy sheet metal.

A better UV light and TiO 2 -PET sheet arrangement for enhancing photocatalytic decomposition of volatile organic compounds

Abstract Although the relative arrangement of a UV light source and immobilized TiO 2 is estimated to strongly affect the photocatalytic decomposition of volatile organic compounds (VOCs), no studies have been published regarding this matter. In the present study, reactor performances were compared between parallel arrangements, where UV lamps are placed in parallel to flat TiO 2 -PET sheets, and circular arrangements, where each glass tube has a UV lamp and a cylindrical TiO 2 -PET sheet closely attached to the inside surface of the tube. In the decomposition of isopropanol, acetone was released into air and decomposed after being readsorbed onto TiO 2 . In the decomposition of toluene, benzaldehyde remained on the surface and inhibited the decomposition. Parallel arrangement generated an area of low UV intensity on TiO 2 -PET sheets, leaving unconverted intermediates on the sheets. Circular arrangement made it possible to irradiate the whole surface of a TiO 2 -PET sheet with high intensity UV light and provided higher rates of VOC decomposition such that intermediates could be decomposed efficiently. To completely decompose VOCs including the intermediates, TiO 2 must be irradiated with strong UV light above a certain threshold that depends on the kind of VOC. The use of the circular arrangement is recommended for the VOC decomposition.

The effect of atomic arrangement on photoabsorption of freestanding double-layer honeycomb sheets of zinc selenide

State-of-the-art computation shows that the atomic arrangements of double-layer ZnSe sheets play a significant role in photoabsorption.

A Method for Truck Underbody Aerodynamic Investigation

Copyright © 2016 SAE International. The underbody of a truck is responsible for an appreciable portion of the vehicle’s aerodynamic drag, and thus its fuel consumption. A better understanding of the underbody aerodynamics could lead to designs that are more environmentally friendly. Unfortunately there are difficulties with correctly replicating the ground condition and rotating wheels when using the classical approach of a wind-tunnel for aerodynamic investigation. This in turn leads to computational modelling problems. A lack of experimental data for Computational Fluid Dynamics (CFD) validation means that the flow field in this area has seldom been investigated. There is thus very little information available for the optimisation and design of underbody aerodynamic devices. This paper investigates the use of a water-towing tank, which allows the establishment of the correct near-ground flow while permitting good optical access. Using a 1/10 scale model, Reynolds Numbers of around 0.7 million are achieved. A novel double light-sheet planar PIV setup is used to measure the flow field. This arrangement of two coplanar horizontal laser sheets provides data in regions that would typically be zones of no information with a single laser sheet arrangement. Two high-speed cameras are used, and their images are stitched together to give a large field of view at high resolution. It is found that this new experimental arrangement allows detailed quantitative flow data to be collected throughout the vehicle underbody. These results may then be used to provide a basis for the optimisation of underbody components.

Dislocation Nucleation in Nickel-Graphene Nanocomposites Under Mode I Loading

Graphene has superior mechanical properties, and previous studies have shown that it can be used as a fiber laminate in metal-graphene nanocomposites. Our research outlines the advantages and disadvantages of different Ni-graphene nanocomposite laminates. Using molecular dynamics, Ni-graphene nanocomposites are studied under mode I loading normal to the graphene laminate plane. The stress intensity factor (\(K_{\text{I}}\)) is predicted for the nanocomposite at varying distances between a simulated crack and the graphene sheet(s) in the Ni-matrix. We find that \(K_{\text{I}}\) of the Ni-matrix is reduced with the addition of graphene sheet. However, for a single graphene sheet in the Ni-matrix, \(K_{\text{I}}\) increases with increased spacing between the crack and the graphene sheet. This is due to the change in the crack-generated stress field in the region between the Ni-matrix containing the crack and the graphene sheet, which leads to the lower stress values at which dislocation nucleation occurs compared to single-crystal Ni. For multiple layers of graphene sheets in the Ni-matrix, we find that failure occurs exclusively by delamination at a lower stress than the one-layer case. This research concludes that fabricated Ni-graphene nanocomposites can be tuned for optimal fracture strength by the structural arrangement of graphene sheets within the Ni-matrix.

Hard carbon derived from cellulose as anode for sodium ion batteries: Dependence of electrochemical properties on structure

Cellulose, the most abundant organic polymer on Earth, is a sustainable source of carbon to use as a negative electrode for sodium ion batteries. Here, hard carbons (HC) prepared by cellulose pyrolysis were investigated with varying pyrolysis temperature from 700°C to 1600°C. Characterisation methods such as Small Angle X-ray Scattering (SAXS) measurements and N2 adsorption were performed to analyse porosity differences between the samples. The graphene sheet arrangements were observed by transmission electron microscopy (TEM): an ordering of the graphene sheets is observed at temperatures above 1150°C and small crystalline domains appear over 1400°C. As the graphene sheets start to align, the BET surface area decreases and the micropore size increases. To correlate hard carbon structures and electrochemical performances, different tests in Na//HC cells with 1M NaPF6 ethylene carbonate/dimethyl carbonate (EC/DMC) were performed. Samples pyrolysed from 1300°C to 1600°C showed a 300mAh/g reversible capacity at C/10 rate (where C=372mA/g) with an excellent stability in cycling and a very good initial Coulombic efficiency of up to 84%. Furthermore, hard carbons showed an excellent rate capability where sodium extraction rate varies from C/10 to 5C. At 5C more than 80% of reversible capacity remains stable for hard carbons synthesized from 1000°C to 1600°C.

Seismic retrofit of short RC coupling beams using CFRP composites

To improve the deformation and energy dissipation capacities of conventionally reinforced coupling beams with low shear span to beam depth ratios, a new method for seismic retrofitting coupling beams using carbon-fibre-reinforced polymer (CFRP) composites is proposed and studied. Experiments are conducted to test four large-scale coupling beams with identical geometries and reinforcement layouts but with different retrofitting schemes. The effects of the arrangement of CFRP sheets and CFRP anchors on the seismic behaviour in terms of strength, stiffness, ductility, energy dissipation capacity and failure modes are evaluated. The study indicates the proposed retrofitting technique is well suited to improving the seismic behaviour of low-slenderness coupling beams in moderate seismic zones. The use of CFRP U-wraps can significantly improve the deformation and cumulative energy dissipation capacities of coupling beams while the beam stiffness can remain nearly constant. By using diagonal CFRP sheets, the strength, stiffness and energy dissipation capacity of coupling beams can be increased. The delamination of CFRP U-wraps can be delayed by using CFRP anchors, but sufficient insertion depth of the anchors is required to avoid their pull-out failure.

Bone marrow amyloid spherulites in a case of AL amyloidosis

Parallel arrangement of β-pleated sheets by amyloidogenic proteins is a well known phenomenon. Rarely, amyloid fibrils undergo radial orientation to form globular structures called spherulites. These amyloid spherulites show Maltese cross pattern under polarized microscopy. The clinical significance of amyloid spherulites is undetermined. Amyloidogenic proteins like insulin and β-lactoglobulin form spherulites in vitro. The senile plaques of Alzheimer's disease rarely form in vivo spherulites. Amyloid spherulites have been described in the liver and small intestine. For the first time, we document amyloid spherulite formation in the bone marrow biopsy of an AL amyloidosis patient.

Enhanced electrical and mechanical properties of rubber/graphene film through layer-by-layer electrostatic assembly

Despite a large amount of work have been carried out to prepare polymer/graphene hybrid nanocomposites, preparing rubber composites filled with graphene oxide via layer-by-layer (LBL) electrostatic self-assembly has not yet been reported. In this work, free-standing conductive multilayer film of (PEI/XNBR/PEI/GO)30 (30 is referred to the number of deposition cycles) was fabricated on glass substrate through alternative LBL self-assembly with graphene oxide (GO), carboxylic acrylonitrile butadiene rubber (XNBR) latex, and polyethyleneimine (PEI). During the self-assembly process, negatively charged carboxyl groups on XNBR latex and GO sheets can be electrostatically bound by positively charged amino groups from PEI molecules. After thermal treatment, XNBR latex particles in each layer are gradually mixed together and became a continuous rubber film layer, and partial ionic bonds among XNBR latex, PEI and GO sheets are changed into covalent amide bonds. The formation of the multilayer XNBR/graphene film with ordered arrangement of GO sheets and XNBR latex layers was demonstrated by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The obtained XNBR/graphene film exhibited a significant improvement in mechanical properties, namely, 192% increase of the tensile strength and 215% increase of the elastic modulus. Besides, electrical conductivity of the prepared multilayer film reached 8.2E-03 S cm−1 after thermal reduced reaction. Hopefully, this prepared multilayer film may be potentially used as an elastomeric conductive material.

Impact of H2S Impurity on Carbon Dioxide Hydrate Formation Kinetics in Fixed Bed Arrangements

In the present work, a combination of silica sand and metallic sheets as a fixed bed media was used for carbon dioxide hydrate formation studies. Two metallic sheets, aluminum and brass, were incorporated into the fixed bed of silica sand to enhance heat transfer properties of the bed. The results obtained from this arrangement of metal sheets were compared with those obtained with a pure silica sand system. Both brass and aluminum systems were found to be good candidates to enhance gas hydrate formation kinetics compared to simply a sand system. Production of fuel gas from coal often contains a toxic gas, hydrogen sulfide (H2S). For the first time, the effect of H2S on the formation kinetics of CO2 + H2 + H2S hydrates has been studied. It was observed that the presence of H2S does not affect the hydrate formation kinetics and total gas uptake in the presence of H2S is either as good as CO2 + H2 hydrate or better. However, H2S impurity in the fuel gas mixture shows a corrosive effect on silica sand media.

Effect of incorporation of black phosphorus into PEDOT:PSS on conductivity and electron–phonon coupling

The effect of incorporation of few-layer black phosphorus (BP) into poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) on conductivity is investigated. BP is a two-dimensional material with high carrier mobility. It is shown that the carrier mobility (μ) increases significantly while the carrier density does not change substantially at 300K. μ in PEDOT:PSS samples with or without BP addition exhibits a strong temperature dependence, which demonstrates the dominance of tunneling (hopping) at low (high) temperatures. The high conductivity of PEDOT:PSS samples with the addition of BP is attributed to the arrangement of the high hole-mobility BP sheets that induces the modification of the electron-phonon coupling.