Ease Of Deformation Research Articles

Interfacial toughening for high-efficiency perovskite solar modules

The distinctive benefits of perovskite solar cells, such as their lightweight nature, high flexibility, and ease of deformation, have garnered significant interest. These characteristics make them well-suited for use in portable electronic devices. Nevertheless, a large efficiency gap still exists between laboratory-based small cells and industrial-oriented large-scale modules. One of the primary reasons for the efficiency losses is the limited adhesion at the brittle interface between the perovskite layer and hole transport layer. Herein, potassium acetate is selected to tailor the interface of perovskite/hole transport layer. The presence of potassium acetate between the perovskite layer and hole transport layer has the potential to enhance the p-type perovskite interface. The strengthening of the interface contact could be verified by the utilization of KPFM and DFT calculations. As a result, the charge separation is accelerated associated with the substantial enhancement in Voc from 1.118 V to 1.139 V and the power conversion efficiency of the solar cell has been enhanced, resulting in an increase from 23.76% to 24.81%. Additionally, the perovskite solar module exhibits little loss, with an efficiency of 21.13% with an aperture area of 29.0 cm2.

Reviews on Flexible Force Sensors Based on Fiber Assemblies with Mass Production Efficiency

AbstractFlexible force sensors show great potential applications in smart wearable devices based on their softness and ease of deformation. Textiles are extremely compatible with the human body, where mechanical forces generated by human movements and physiological activities create rich application scenarios for flexible force sensors. Currently, the bottleneck in the development of flexible sensors depends on the breakthrough of mass production efficiency, which has been a research focus in recent years to accelerate the application of smart textiles in various fields. This work reviews the research progress of flexible force sensors based on fiber assemblies with mass production efficiency, which is discussed in four aspects: sensing mechanisms, structure design, preparation methods, and application. Finally, the challenges faced by mass production of flexible force sensors are analyzed and summarized, and a few inspirations for their future development direction are provided.

Surface roughness evolution and heterogeneous plastic deformation of austenitic stainless steel during micro deep drawing: Modeling and experiment

The present work involves the numerical simulation and experimental study on the surface roughness evolution and heterogeneous plastic deformation (strain localization and concomitant surface morphology evolution) in grain scale of micro deep drawn parts of austenitic stainless steel (ASS) 304 foils. A three-dimensional modeling framework was used to simulate the micro deep drawing (MDD) process. The simulation involved the development of a Voronoi-based polycrystalline geometry model (VPGM), a multi-stress-strain response model, and a crystal plasticity finite element methods (CPFEM) model. The results indicate that CPFEM model exhibits higher accuracy in the localized stress and strain, thickness distribution fluctuation and surface roughness evolution of the fabricated parts compared to multi-stress-strain response model. Therefore, the plastic deformation heterogeneity in MDD is in-depth discussed based on CPFEM model. The results show that the coarse-grained foils correspond to the intense strain localization, which is the main cause of surface roughening. Considering the average grain size is close to the thickness of ASS foils, mounding features on the rough surface may readily develop further into potentially fractured sites during deformation. On the other hand, crystal orientation influence plastic deformation by affecting the slip behavior of materials. The effect of crystal orientations including {011} 〈211〉 (Brass), {011} 〈100〉 (Goss), and {112} 〈110〉 components on deformation is discussed. The results indicate a strong correlation between the magnitude of the Schmid's factor and the ease of deformation. Additionally, variations in Schmid's factor across different directions result in differences in deformation accumulation, which affects the thickness distribution along the radial direction and the distribution of earrings and wrinkles along the circumferential direction of the fabricated micro parts.

Microstructural and Texture Evolution of Pearlite-Drawn Wires for Flexible Marine Pipelines: Investigating the Effect of Heat Treatments on Mechanical Properties

Flexible pipelines connect offshore platforms to subsea production systems due to their high flexibility, applicability, and recycling. Flexible armor layers in flexible pipelines are constructed using the parallel helical wrapping of several rectangular wires. The complex stress modes to which pipelines are subjected provide complex failure modes that are mostly unpredictable, requiring expensive pipeline integrity verification methods. This work investigates texture and microstructure evolution in pearlite-drawn wires due to different heat treatments. The material was subjected to annealing and isothermal heat treatments to obtain changes in its microstructure and texture. The changes were characterized using SEM, XRD, and EBSD techniques. Samples were subjected to tensile testing to evaluate their mechanical properties. This work revealed that annealing and isothermal treatments mainly modify the material microstructure, whereas annealing provides a material with grains with ease of deformation. In contrast, isothermal treatment provides grain growth with high internal energy and more deformation resistance. Annealing increases the intensity of all texture components, while isothermal treatment reduces intensity. These findings provide insights into the relationship between material properties and heat treatments, which can be used to optimize the design and performance of flexible pipelines, thereby reducing the need for expensive integrity verification methods.

Simulation of Li3HoCl6 Solid-state Lithium Batteries Based on COSMOL Multiphysics

The rapid development of portable smart devices and electric vehicles is placing greater demands on the energy density and safety of rechargeable secondary batteries. Lithium-ion batteries using the Solid State Electrolyte (SSE) are considered to be the most promising direction to achieve these goals. Among the latest electrolyte developments, chloride solid electrolytes have attracted much attention due to their physicochemical properties such as high ionic conductivity, ease of deformation and oxidative stability. In this paper, a one-dimensional model of a solid-state Li3HoCl6 battery is proposed based on COSMOL Multiphysics multi-physics field simulation software, and the charge-discharge curves and lithium-ion concentration variation curves at different discharge rates are obtained. The results show that the battery has a stable potential and relatively high-capacity density at low C rates (1.8C~14.4C). Therefore, it has application values at low currents and space for improvement at high currents.

Influence of Rib Structure and Elastic Yarn Type Variations on Textile Piezoresistive Strain Sensor Characteristics

Production parameters have been established to play a fundamental role in dictating the physical characteristics and sensing properties of knitted sensors. This research studied the influence of yarn type and rib fabric structure variation on the physical, tensile and conductive properties and sensitivity performance of knitted underwear strain sensors to be used for breathing mensuration. Four different structures in 1×1, 1×2, 1×3 and 2×2 mock ribs were knitted using covered elastic (CY) and bare strand elastic yarn (BS) combinations. These two parameters proffered unique physical, conductive and tensile characteristics to the samples. Wear and machine tests were conducted to ascertain the sensor’s piezoresistive responses. The machine test showed a higher piezoresistive response, with an average peak value (APV) from 1.70Ω to 0.24Ω, while those for the wear test recorded were around 0.0110Ω to 1.867Ω for all sample categories. However, sensors knitted with covered elastic yarns produced the best breathing test results (APV of 1.089Ω – 1.86Ω) compared to bare strand elastic yarns (APV 0.0027Ω - 0.0790Ω) when used in a wearable environment. Fabric structure variation had influences on both conductive and tensile characteristics; however, the effects on the piezoresistive response were negligible. The influences of the unique characteristics provided by these core parameters on sensor resistance values, piezoresistance, aging, ease of deformation and dimensional stability have also been discussed.

일시적 거주개념을 적용한 1인용 소형주택의 공간구축유형 및 특성

The purpose of this study was to analyze the types and characteristics of space construction in temporary small-sized housing for single-person household through the understanding and interpretation of the modern flexible lifestyle. A document research method and case studies were used to analyze and classified the spatial characteristics of temporary dwelling spaces since 2000. Findings of the study were as follows: In order to conform the concept of temporary dwelling for small-sized housing units of single-person households, the types and characteristics of space construction were divided into three aspects: (1) 'Transporting' by wheel, rotation and vehicles, (2) 'Transforming' by adapting, assembling disassembling, and folding unfolding, (3) 'Wearing Carrying' by inflatable and tented type. In conclusion, this study found two types of space construction in temporary small-sized housing. The first was 'formal aspect' which was focused on the simplicity of shape, ease of deformation and lightweight of materials. And the second was 'functional aspect' which was focused on the complex space composition, the rapidity of installation and dismantling, ease of movement and transportation. This study shows that the combination of two types of the temporality will be more ideal in temporary small-sized housing planning rather than relying on just one type.

Structure and reactivity of norbornene and syn-sesquinorbornene

The origin of the observed non-planarity of the syn-sesquinorbornene (syn-tetracyclo-[6.2.1.1 3,6.0 2,7]dodec-2(7)-ene) π system is discussed in terms of simple molecular orbital theory. Calculated out-of-plane bending energies for the double bonds in cyclohexene, bicyclo[2.2.2]oct-2-ene, bicyclo[2.1.1]hex-2-ene, bicyclo[3.2.1]oct-6-ene, and bicyclo(2.2.1]hept-2-ene closely parallel the published cycloaddition rate constants for these compounds, indicating that ease of deformation may be a rate determining factor. The “staggering effect” considered by Houk et al. is discussed and it is demonstrated that this effect is not equivalent with the norbornene “x” factor introduced by Huisgen et al.

Some studies of friction and lubrication using an instrumented tablet machine

Abstract Samples of crystalline aspirin, hexamine, and sodium chloride, and a granulation of hexamine were compressed on an instrumented tablet machine. Further samples of these materials, together with samples of sucrose and sucrose granulation, were lubricated with 2% magnesium stearate −100 mesh powder and compacted under similar conditions. The effect of magnesium stearate on die wall friction depends on the ease of deformation of the base particles. For the materials used there is a linear relationship of the form Fa = kd(Pm.A) and a linear relationship exists between Fe and Fd up to the point where Fe becomes constant. Granulations required larger ejection forces at a given pressure than the corresponding crystalline material, particularly when the materials were lubricated; constant values of Fe were associated with compaction pressures at which the density of the ejected tablets became maximal. Values of Fe for tablets of unlubricated sodium chloride and hexamine granulation depend on particle size; the size of other materials used caused no such effect. Lubrication eliminated this size effect.

THE EFFECT OF CONCENTRATION ON THE VISCOSITY OF STARCH PASTES AND OF LYOPHILIC SOLS

The critical concentration of a starch paste is the limiting concentration above which structural flow is apparent. The inverse of the critical concentration, termed the effective volume, is the minimum volume of solution per gram of starch below which structural flow is apparent. The critical concentrations and effective volumes have been measured for series of pastes of acid-modified corn and potato starches, and the effective volume has been shown to decrease with increasing degree of modification. The specific viscosities per unit concentration of these pastes, at concentrations below the critical, increases linearly with the effective volume, and the proportionality constants found are compared with those derived from the equations of Einstein and of Hatschek. The effects of phase-volume ratio and ease of deformation of the dispersed phase on the viscosity of a system are discussed, and previous relations applied to experimental data obtained in the present instance. Residual structure below the critical concentration is discussed. Above the critical concentration, the viscosity is dependent on the rate of shear, and the equation F = KPn expresses the experimental data well, where F is the flow, P is the pressure, K and n are constants. For two starches investigated, within the range of concentrations used n has been found to increase linearly with the concentration c, dn/dc being dependent on the elasticity or deformability of the granules.The form of lyophilic colloids in solution is discussed and agreement is expressed with the conception of Haller that the long-chain molecules, owing primarily to the free rotatability of the valence linkages, are irregularly bent and tangled in solution, as opposed to Staudinger's conception of straight rigid chains. These molecules occupy on the average a form approximating to the spherical, and solvation is due chiefly to immobilization. A dextrin in solution was found to have a [Formula: see text] ratio close to that of a pasted starch, and the forms of the two are probably similar. A lyophilic sol is considered heterogeneous and similar in many respects to an emulsion, with a very highly deformable discontinuous phase. The viscosity of such a system is due to phase-volume relations, modified by the ease of deformation of the dispersed phase, and the particular characteristics of these important sols admit of explanation on this basis.