Width Of Sheets Research Articles

A new tunnel drainage system using double-adhesive spray-applied membrane: key parameters and applicable scope

To address water leakage in tunnels with high water pressure, a new waterproof drainage system was proposed. The system uses a spray-applied material with double-adhesive properties as a waterproof layer, significantly reducing leakages, and incorporates a unique bottom drainage system to reduce water pressure. In order to check the effectiveness of the new drainage system and to analyze the effects of various structural measures on pressure reduction, a numerical seepage analysis was carried out under the conditions of a water head of 160 m and a surrounding rock permeability of 1 × 10−6 m/s. The results show that the maximum water pressure on the secondary lining is 0.6 MPa, which is about 60% reduction compared to a fully enclosed waterproof system and shows a significant pressure reduction. The spacing of the circumferential drainage pipe and the width of the drainage sheet significantly affect the drainage performance, while the arrangement of the drainage system and the size of the bottom drainage pipe have minimal impact. With full consideration of pressure reduction, cost efficiency and construction feasibility, it is recommended to use the following drainage scheme for iterative calculations during the design stage: “1” shaped arrangement, blind pipe diameter of 10 cm, width of drainage sheets of 0.8 m, and drainage spacing of 6 m. By combining the experimentally determined hydrostatic peel-off strength of 1.4 MPa for spray-applied membrane, the applicable scope of the new drainage system was acquired. The research results can provide valuable insights into the application of spray-applied waterproofing membrane in drainage tunnels with high water pressure.

Independent Control of the Width and Length of Semiconducting 2D Nanorectangles via Accelerated Living Crystallization-Driven Self-Assembly.

Self-assembly of conjugated polymers offers a powerful method to prepare semiconducting two-dimensional (2D) nanosheets for optoelectronic applications. However, due to the typical biaxial growth behavior of the polymer self-assembly, independent control of the width and length of 2D sheets has been challenging. Herein, we present a greatly accelerated crystallization-driven self-assembly (CDSA) system of polyacetylene-based conjugated polymer to produce 2D semiconducting nanorectangles with precisely controllable dimensions. In detail, rectangular 2D seeds with tunable widths of 0.2-1.3 μm were produced by changing the cosolvent% and grown in the length direction by uniaxial living CDSA up to 11.8 μm. The growth rate was effectively enhanced by tuning the cosolvent%, seed concentration, and temperature, achieving up to 27-fold increase. Additionally, systematic kinetic investigation yielded empirical rate equations, elucidating the relationship between growth rate constant, cosolvent%, seed concentration, and seed width. Finally, the living CDSA allowed us to prepare penta-block comicelles with tunable width, length, and height.

Effects of CFRP sheets on the flexural behavior of high-strength concrete beam

Abstract The aim of this study is to evaluate numerically the effects of carbon fiber-reinforced polymer (CFRP) sheets strengthening on the flexural performance of high-strength concrete (HSC) beam using ABAQUS 3D finite element (FE) modeling software. The developed FE models were verified against the experimental results found in literature. The FE models can accurately estimate the performance of CFRP-strengthened high-strength reinforced concrete (RC) beams. Subsequent parametric analysis was performed to assess the performance of CFRP-strengthened concrete beams considering various parameters including compressive strength of concrete, CFRP width, thickness, length, number of CFRP layers, and CFRP strengthening schemes. Based on the results of FE analysis. It was demonstrated that using HSC significantly enhances the performance of CFRP-strengthened RC beams. It was also confirmed that width, thickness, and layer number of CFRP sheets improve the flexural behavior of CFRP-strengthened HSC beams by increasing the ultimate loads and strain-hardening behavior of the specimens. The strengthening schemes contribute to delaying or inhabiting the debonding especially when the CFRP sheets are added along the bottom of the beams. It was demonstrated that using CFRP sheets U-wrapping contributes to the prevention or delay of debonding and increases the capability of resisting the stress imposed on the concrete. Therefore, installing the CFRP sheets at the bottom face of beam below the tensile reinforcement enhances the performance of CFRP-strengthened HSC beams.

Current Spreading in Thin Foils or Flat Current Sheets

To consider the evolution of current distribution in inhomogeneous thin conductive layers or foils, we apply an integrodifferential equation, which reduces the three-dimensional problem for the magnetic field to a two-dimensional problem, and, for the current distribution across the width of inhomogeneous conductive sheets or foils, this equation reduces the two-dimensional problem for the magnetic field to a one-dimensional problem. For homogeneous conductive layers with constant conductivity, the spatial scale of current distribution, initially concentrated in a limited area, increases proportionally to time at a rate of u = c2/4πσΔ, where σ is the conductivity of the layer material and Δ is its thickness. As an application to the problems of current transfer through electroexplosive opening switches, a current distribution across the width of a foil is considered for a periodic serpentine-type system of flat foils. It is shown that initially a current distribution corresponding to the perfect conductivity of foils is established in this system. Then, in a time on the order of s/u (2s is the width of a foil), the current distribution in the foil relaxes to a uniform distribution. Estimates show that if the foils are used as opening switches, then currents through the foils during the current transfer to the load are expected to have time to get uniformly distributed across their width; therefore, corrections for the nonuniformity of the current distribution in the switches should be small.

Investigating the positive effects of wrap-around resting on the qualities of semi-dried noodles through the quantitative analysis of gluten network.

In this study, the dough sheet wrap-around was employed to assist the resting process of the semi-dried noodles comparatively with dough crumbs resting and common dough sheet resting. The gluten network quantitative analysis was carried out to investigate the positive impacts of dough sheet wrap-around resting in semi-dried noodles production. The results showed that the dough sheet wrap-around resting improved the color, surface smoothness, cooking qualities, and eating qualities of semi-dried noodles. Dough sheet wrap-around resting for 30 min significantly (p < 0.05) increased the surface smoothness and chewiness by 47.08% and 44.35%, respectively. Furthermore, increased extensibility in the transverse direction of dough sheets generated superior processing properties. The average protein length and width of dough sheets experienced a considerable (p < 0.05) reduction. In contrast, the branching rate was markedly (p < 0.05) augmented, which meant the distribution of gluten network was more uniform and denser. The total protein length and the number of protein network lines both significantly (p < 0.05) increased. The number of transverse protein network lines increased by 28.70%, which was much higher than that (5.77%) of the longitudinal direction. Conclusively, at the optimal dough sheet wrap-around time of 30 min, the higher-quality semi-dried noodles were produced by enhancing the gluten network.

STUDIES OF INTERIOR SLAB-COLUMN CONNECTIONS STRENGTHENED WITH HEMP FIBER REINFORCED POLYMER SHEETS

With increasing environmental concerns, using natural materials in concrete, such as bio-based fibers, is now becoming popular. Recently, hemp fibers have been utilized in the production of composite materials that have the possibility to replace synthetic fibers. The main objective of the research reported in this paper was to investigate the feasibility of using externally bonded hemp fiber-reinforced polymer (HFRP) fabric sheets as an alternative to synthetic carbon fiber-reinforced polymer (CFRP) sheets for punching shear strengthening of reinforced concrete two-way slabs. The experimental program consisted of testing small-scale, interior slab-column connections, under monotonically increased load until failure. The main test parameters included the slab thickness, type of strengthening material (HFRP or CFRP sheets), the width of HFRP sheets, number of sheets layers, and the location of the HFRP sheets relative to the column face. Test results showed that HFRP strengthening sheets enhanced the structural behavior of slab-column connections.

STUDIES OF INTERIOR SLAB-COLUMN CONNECTIONS STRENGTHENED WITH HEMP FIBER REINFORCED POLYMER SHEETS

With increasing environmental concerns, using natural materials in concrete, such as bio-based fibers, is now becoming popular. Recently, hemp fibers have been utilized in the production of composite materials that have the possibility to replace synthetic fibers. The main objective of the research reported in this paper was to investigate the feasibility of using externally bonded hemp fiber-reinforced polymer (HFRP) fabric sheets as an alternative to synthetic carbon fiber-reinforced polymer (CFRP) sheets for punching shear strengthening of reinforced concrete two-way slabs. The experimental program consisted of testing small-scale, interior slab-column connections, under monotonically increased load until failure. The main test parameters included the slab thickness, type of strengthening material (HFRP or CFRP sheets), the width of HFRP sheets, number of sheets layers, and the location of the HFRP sheets relative to the column face. Test results showed that HFRP strengthening sheets enhanced the structural behavior of slab-column connections.

Current Spreading Across the Width of Thin Foils (in Snake-Like Systems) or Plane Current Sheets

Current Spreading Across the Width of Thin Foils (in Snake-Like Systems) or Plane Current Sheets

Finite element modeling of flexural behavior of reinforced concrete beams externally strengthened with CFRP sheets

In this research, the finite element method is used to develop a numerical model to analyse the effect of the external strengthening of reinforced concrete beams by using carbon Fiber Reinforced Polymer (CFRP) sheets. A finite element model has been developed to investigate the behavior of RC beams strengthened with CFRP sheets by testing nineteen externally simple R.C. beams, tested under a four-point load setup until failure. Various CFRP systems were used to strengthen the specimens. The numerical results using the (ANSYS workbench v.19.1) were calibrated and validated with the experimental results. The research results indicate a significant improvement in the structural behavior of the specimens strengthened using CFRP sheet systems. Then the validated model investigated the effect of the width of CFRP sheets, no of layers, and CFRP size on the behavior of strengthened R.C. beams. Results of this numerical investigation show the effectiveness of increase CFRP width to improve the flexural capacity of R.C. beams. An increase in the flexural capacity up to 100 % compared to the control beam.

Flexural Behaviours of CFRP Sheets Reinforced Steel-Concrete Composite Beams

The finite element simulation was performed for 8 carbon fiber reinforced plastic (CFRP) sheets reinforced steel-concrete composite beams via ABAQUS software, in an effort to further investigate their mechanical properties. Next, the influences of shear connection degree and elasticity modulus, width and constitutive relation of CFRP sheets on the mechanical properties of steel-concrete composite beams were studied. Subsequently, their load-dependent change laws of midspan deflection were reported in detail. The simulation results show that the reinforcement effect on the negative moment region of each composite beam is improved with the increase in the elasticity modulus, width of CFRP sheets and the shear connection degree.

Density functional study on hybrid graphene/h-BN 2D sheets

The structural and Electronic properties of two/three/four atomic Graphene/h-BN/BN molecules doped hybrid GR/h-BN 2D sheets are investigated without and with vacancies. The first principle density functional theory is considered for the analysis. Weaker atomic bonds are found in hybrid 2D-sheets with two vacancies, partially ionic and covalent bonds are found between boron and nitrogen atoms. The band-gap of the pristine BN sheets reduce from 4.56 eV to 3.99 eV with two vacancies, it reduces relative to increase the width of atomic sheets; and further with increasing the number of vacancies. Hybrid 2D-sheets have semiconducting nature due to p-orbitals of C atoms, a hybrid four atomic sheet with a single vacancy has a smaller band-gap 0.825 eV, and remaining hybrids have around 1.0 eV. With the application of the electric field, the shifting in the bottom of the density of states in the pristine GR-sheets is occurred, which is higher with a four atomic graphene sheet with a vacancy, it causes to enhance its electronic properties, and pristine insulating BN sheets without and with vacancy are transformed into semiconductors. The energy band-gap of hybrid sheets gradually reduces and becoming zero at 6 V/Å, i.e. hybrid semiconductors are transformed into conductors which can be applicable in the electronic devices. • Weaker atomic bonds are found in hybrid GR/h-BN 2D-sheets. • Pristine-ZGR 2D-sheets are conductors and hybrid 2D-sheets are semiconductors. • BN14-4U–1V has smaller band-gap 0.825 eV, and remaining hybrids have around 1.0 eV. • In the presence of the electric field: - There is shifting in the bottom of density of states in all pristine GR-sheets. - Pristine insulating 2D-BN-sheets are transformed into semiconductors. - Semiconducting hybrids are transformed into conductors. • The functions of 2D-hybrid semiconducting sheets can be employed in various electronic sensing devices.

Effects of concrete heterogeneity on FRP-concrete bond behaviour: Experimental and mesoscale numerical studies

Extensive experimental and numerical studies have been conducted to understand the bond behaviour of FRP-concrete interfaces with the assumption of homogenous materials. This study is aimed at a better understanding of the effects of concrete heterogeneity on the FRP-concrete bond behaviour, by a combination of experiments and mesoscale numerical modelling. FRP-concrete and FRP-mortar bonded joints were tested using a four-point bending setup. The crack initiation and propagation process with interfacial debonding until failure was accurately captured by the digital image correlation (DIC) technique. The results show that the presence of coarse aggregates in the FRP-concrete joints leads to 19% higher bond strength, but much higher variations in the bond strength and the strain distribution across the width of FRP sheets, than the FRP-mortar joints. Monte Carlo simulations of mesoscale finite element models with random distribution of polygonal aggregates were then carried out for the FRP-concrete bond tests. It is found that the distribution of coarse aggregates significantly affects the overall force–deflection responses as well as the simulated fracture processes and final failure modes that are highly comparable with the DIC observations.

Influence of EDM generator programs on shape and surface roughness of Ni-Ti sheets

In the last decades caloric cooling technologies received an increasing scientific and industrial interest as promising alternatives to conventional vapor compression technology. Theoretically, efficiency of caloric technologies is more than 40% higher than for the conventional vapor compression cycle. Particularly interesting is elastocaloric cooling, which is an emerging technology, occurring due to the uniaxial mechanical loading of active regenerators. These are made of shape memory alloys, such as Ni-Ti. The regenerators must have a high fatigue resistance to withstand multiple loading cycles and simultaneously possess excellent elastocaloric properties. Therefore, it is crucial to establish a manufacturing process that allows fabricating thin regenerator elements with profound surface quality and as little impact on their functionality as possible. Considering the challenges of conventional machining technologies due to the specific characteristics of Ni-Ti, electrical discharge machining (EDM) demonstrates a high potential to meet the requirements for micro-shaping surfaces for elastocaloric applications. This paper presents fundamental analyses of the influence of EDM generator programs on the resulting removal depth, removal width and surface roughness of Ni-Ti sheets. Based on the perspective application in elastocaloric applications, adequate EDM programs are selected with regard to the targeted precision, surface roughness and minimal surface roughness.

On the theoretical and molecular dynamic methods for natural frequencies of multilayer graphene nanosheets incorporating nonlocality and interlayer shear effects

In this paper, a multiplate nonlocal shear model and molecular dynamic simulations are presented to investigate the effects of interlayer shear and nonlocality on the natural frequencies of multilayer graphene sheets (MLGSs). From one aspect in the optimal design of such structures, the interaction between graphene layers, which can significantly vary the static and dynamic behavior due to lack of solidity of layers stack, should be considered. On the other hand, it is requied that the nonlocality phenomenon which has an effective role in the mechanical analysis of nanostructures is taken into account. To this aim, the equation of motion along with corresponding boundary conditions is derived by using the Kirchhoff plate model and nonlocal continuum theory to capture these effects. For a case study, the free vibration problem of simply supported MLGSs is studied by presenting the closed-form Navier’s solution of natural frequencies and carrying out Molecular dynamics (MD) simulations to estimate the value of nonlocal parameter. Finally, the influences of interlayer shear modulus, number of layers, foundation stiffness, and nonlocal parameter on the natural frequencies of such MLGSs are examined in detail. Findings show that natural frequencies including nonlocality effect become smaller than ones of the classical continuum theory and also have good agreements with MD simulations. Moreover, it is seen that the sensitivity of natural frequency to the nonlocal parameter becomes more significant when the number of layers or interlayer shear modulus increases as well as the aspect ratio or width of sheets decreases.

CVN impact energy and fracture characteristics correlations with different oxide nanoparticles improving submerged arc welds

The main aim of this research is to correlate the toughness improvement with fracture features of tested Charpy V-Notch impact specimens obtained from submerged arc welds enriched by different oxide nanoparticles (TiO2, SiO2, Al2O3 and Mn2O3). Through Scanning Electron Microscopy (SEM) fractography, fracture features were determined, which are the shear fracture percent, the loading angle, as well as the diameter of dimples and the width of cleavage sheets at ductile and brittle fracture regions, respectively. It was observed an increase of the Charpy V-Notch impact energy with the decrease of loading angle and the average diameter of dimples, as well as with the increase of its shear fractures percents. Moreover, it was correlated the increase of Acicular Ferrite surface density with the decrease of width of cleavage sheets. Thus, the toughness of the submerged arc welds can be improved by adding TiO2, SiO2, Al2O3 or Mn2O3 nanoparticles.

Determination of the Structure of Current Sheets and Detection of Sheet Disruption Based on Measurements by External Magnetic Probes

A simple macroscopic method for detection of current sheet disruptions and determination of the width of metastable sheets is proposed based on the measurements of magnetic fields at the external surface of the vacuum chamber. This contactless diagnostic method does not affect the plasma processes in the current sheet and allows one to increase the signal-to-noise ratio. Such changes will allow us to relatively quickly determine the conditions of current sheet development under which sheet disruptions are most probable.

Self-Association of Purified Reconstituted ER Luminal Spacer Climp63.

Membranes of the endoplasmic reticulum (ER) are shaped into cisternal sheets and cylindrical tubules. How ER sheets are generated and maintained is not clear. ER membrane protein Climp63 is enriched in sheets and routinely used as a marker of this structure. The luminal domain (LD) of Climp63 is predicted to be highly helical, and it may form bridges between parallel membranes, regulating the abundance and width of ER sheets. Here, we purified the LD and full-length (FL) Climp63 to analyze their homotypic interactions. The N-terminal tagged LD formed low-order oligomers in solution, but was extremely aggregation-prone when the GST tag was removed. Purified FL Climp63 formed detectable but moderate interactions with both the FL protein and the LD. When Climp63 was reconstituted into proteoliposomes with its LD facing out, the homotypic interactions were retained and could be competed by soluble LD, though vesicle clustering was not observed. These results demonstrate a direct self-association of Climp63, supporting its role as an ER luminal spacer.

Calumenin-1 Interacts with Climp63 to Cooperatively Determine the Luminal Width and Distribution of Endoplasmic Reticulum Sheets.

SummaryThe ER is composed of distinct structures like tubules, matrices, and sheets, all of which are important for its various functions. However, how these distinct ER structures, especially the perinuclear ER sheets, are formed remains unclear. We report here that the ER membrane protein Climp63 and the ER luminal protein calumenin-1 (Calu1) collaboratively maintain ER sheet morphology. We show that the luminal length of Climp63 is positively correlated with the luminal width of ER sheets. Moreover, the lumen-only mutant of Climp63 dominant-negatively narrows the lumen of ER sheets, demonstrating that Climp63 acts as an ER luminal bridge. We also reveal that Calu1 specifically interacts with Climp63 and antagonizes Climp63 in terms of both ER sheet distribution and luminal width. Together, our data provide insight into how the structure of ER sheets is maintained and regulated.

A new correlation between soot sheet width and soot volume fraction in turbulent non-premixed jet flames

Abstract Measurements of soot volume fraction (SVF) using planar Laser-Induced Incandescence (LII) were performed in a set of attached turbulent non-premixed jet flames, burning the same mixture of C2H4/H2/N2. A novel post processing technique was used to identify and characterize the average width (Ws) and volume fraction of the soot sheets and correlate it with key flame features and parameters. The axial distributions of both Ws and SVF, within those sheets, in all flames are shown to grow with flame length up to the region where soot oxidation becomes significant, with only a secondary dependence on the inflow conditions. Probability density functions (pdfs) of Ws are seen to exhibit far less variation than those of SVF, also indicating the soot structure morphology insensitivity to inflow conditions. The effects of fuel exit strain (U/D) and bulk exit Reynolds number (ReD) on soot sheets are also assessed for three flames, of which two share the same U/D and two share the same ReD. The variation in U/D at constant ReD is seen to only affect SVF within the sheets, while a variation in ReD, at constant U/D is shown to have negligible effect on both Ws and SVF, in agreement with previous findings by the authors. Finally, a strong power-law correlation is deduced from joint statistics for Ws and SVF through all flame locations and for all the flames investigated.

Dependence between the width of strip overlap and the strength of joints of one-layer bitumen sheets

This paper focuses on the examination of mutual dependence of overlap width of bituminous sheets and the strength characteristics of their mechanically fastened joints. Bituminous sheets with two different widths of overlap and different degree of modification were selected as samples for experimental measurements. They are supposed to be used as single-layer mechanically fastened waterproofing membranes. The aforementioned dependence has not been explicitly documented yet. The aim of this paper is to confirm or to refute a hypothesis that a relationship exists between a different width of overlap of bituminous sheets and the strength of their joints. The formulation of the results was based on the statistical evaluation of laboratory measurement data.