Free Shape Research Articles

Highly stretchable island‐structure metal oxide thin‐film transistor arrays using acrylic adhesive for deformable display applications

AbstractStretchable electronics are a promising technology for introducing new styles of display applications and for realizing displays that can be adapted to various free shapes, such as domes and spheres, to suit various viewing styles. To fabricate a stretchable display, it is necessary to form thin‐film transistors (TFTs) and light‐emitting devices on stretchable substrates. We demonstrate high‐performance stretchable metal oxide TFT islands on polyimide film using an acrylic adhesive structure. We developed mass transfer technology for metal oxide island TFTs on a polyimide film to be transferred on a stretchable substrate in a batch and a device structure with a passivation layer that stabilizes device characteristics when the substrate is stretched. The TFT showed stable switching characteristics with a mobility of 30 cm2/Vs without any fluctuation, even when the substrate was stretched from 0% to 50% and released to 0%.

Structural-Functional Changes in a Ti50Ni45Cu5 Alloy Caused by Training Procedures Based on Free-Recovery and Work-Generating Shape Memory Effect.

Active elements made of Ti50Ni45Cu5 shape memory alloy (SMA) were martensitic at room temperature (RT) after hot rolling with instant water quenching. These pristine specimens were subjected to two thermomechanical training procedures consisting of (i) free recovery shape memory effect (FR-SME) and (ii) work generating shape memory effect (WG-SME) under constant stress as well as dynamic bending and RT static tensile testing (TENS). The structural-functional changes, caused by the two training procedures as well as TENS were investigated by various experimental techniques, including differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), X-ray diffraction (XRD), and atomic force microscopy (AFM). Fragments cut from the active regions of trained specimens or from the elongated gauges of TENS specimens were analyzed by DSC, XRD, and AFM. The DSC thermograms revealed the shift in critical transformation temperatures and a diminution in specific absorbed enthalpy as an effect of training cycles. The DMA thermograms of pristine specimens emphasized a change of storage modulus variation during heating after the application of isothermal dynamical bending at RT. The XRD patterns and AMF micrographs disclosed the different evolution of martensite plate variants as an effect of FR-SME cycling and of being elongated upon convex surfaces or compressed upon concave surfaces of bent specimens. For illustrative reasons, the evolution of unit cell parameters of B19′ martensite, as a function of the number of cycles of FR-SME training, upon concave regions was discussed. AFM micrographs emphasized wider and shallower martensite plates on the convex region as compared to the concave one. With increasing the number of FR-SME training cycles, plates’ heights decreased by 84–87%. The results suggest that FR-SME training caused marked decreases in martensite plate dimensions, which engendered a decrease in specific absorbed enthalpy during martensite reversion.

The Shape of Human Red Blood Cells Suspended in Autologous Plasma and Serum.

(1) Background: In almost all studies of the shape of the human red blood cell (RBC), the suspending medium was a salt solution supplemented with albumin. However, the ratio of thickness across the dimple region to the thickness of the rim (THR) depends on the albumin concentration. Values of the THR in the literature range from 0.27 to 0.627 whereas in the present work it was 0.550 or 0.601 whether measured in plasma or serum. (2) Methods: 9911 RBCs of eight donors were suspended in autologous plasma or serum. Sedimented RBCs were observed under bright field illumination at 416 nm. From the profiles of gray value, the THR was determined. (3) Results: The THR displays a wide distribution within a single blood sample. A direct correlation of THR and spontaneous curvature of the membrane is likely. The variation of the mean THR between different donors is large. The aspect ratio of RBCs viewed face-on ranged on average from 1 to 1.48. In oval RBCs, the rim is thicker along the major axis than along the minor axis, an effect increasing with increasing aspect ratio. Remodeling of the membrane skeleton occurs in vivo with a characteristic time () on the order of 1 h. (4) Conclusions: Consideration of these data in models of RBC behavior might improve the agreement with observations. h suggests a more general type of reference configuration of the membrane skeleton than a stress free shape.

Seismic Performance Evaluation of Historical Case Study of Armenian Architecture Tekor Church

Masonry churches, which are one of the cultural heritages, show the historical background, cultural and religious characteristics of the cities and material properties. Churches in the earthquake zone, which are different from each other in terms of typology and have a special importance, are at risk. The aim of this study is to examine the earthquake behavior of a church sample in Turkey and to provide a guide for structures with similar typology. The building was modeled and subjected to dynamic loads using macro modeling technique. Free vibration mode shapes were determined by modal analysis, and it was determined that these modes were mainly in the form of translation of the upper part of the structure. In the time history analysis, the stress and deformation values were determined. It has been observed that the stresses take high values at the supports and top of the main columns and in the arches connecting these columns to the side walls. It was concluded that the deformations reached their maximum values at the apex of the triangular gable walls in the upper part of the building. The results obtained are consistent with the damage the church received in past earthquakes.

Some Studies on Verifying the Applicability of Free Vibration-based Modes Shapes Method to Rectangular Shaped Cracks in a Cantilever Beam

Cracks weaken structures. When the crack size increases in service, the structure becomes weaker than its earlier condition. Lastly, the structure may break down due to a small crack. Therefore, crack detection and classification is a fundamental issue. Many aspects of defects have already been addressed, but the application of non-destructive testing methods to structural materials has become more widespread. For a long time, vibration methods based on Natural Frequency and Mode Shapes have been used for possible cracks detection in the beams. The impact of arbitrary and random defect geometry on applying these methods has been overlooked. This study focuses on a mode shapes-based vibration analysis of a cracked cantilever beam to investigate this issue. The effects of crack geometries on mode shapes are examined theoretically and numerically using a new crack model (Rectangular shaped crack), which differs from the well-known V-shaped crack. A MATLAB code is written to obtain the natural frequencies and mode shapes for all cracked instances of beams. The mode shapes result of both the new (Rectangular), and V-shaped models are compared, and it is found that the results are less sensitive to the geometry change.

Dynamic and sound radiation characteristics of a non-uniformly heated isotropic plate

The influence of non-uniform heating on the anisotropic plate’s dynamic and acoustic response characteristics is investigated numerically. The effect of non-uniform heating on the plate is accounted in the form of pre-stress developed on the plate due to non-uniform heating of the plate. The influence of structural boundary conditions, nature of temperature variation, and level of temperature on vibration and acoustic response characteristics are investigated in detail. Thermal buckling strength and fundamental buckling mode are highly sensitive to the nature of temperature variation across the plate. Free vibration mode shapes of the plates with high aspect ratio and free edges are changing their pattern with an increase in temperature. The resonant amplitude of sound power radiated associated with a particular mode is dominated by vibration nodes and anti-nodes shifting relative to the excitation location. Further, an increase in sound power level with an increase in temperature is observed clearly in the lower octave frequency bands.

Zero-order-free complex beam shaping

The unwanted zero-order diffraction is still an issue in beam shaping using pixelated spatial light modulators. In this paper, we report a new approach for zero-order free beam shaping by designing an asymmetric triangle reflector and introducing a digital blazed grating and a digital lens to the phase hologram addressed onto the spatial light modulator. By adding the digital lens phase to the previously reported complex-amplitude coding algorithms, we realized the generation of complex beams without the burden of zero-order diffraction. We comparatively investigated the produced complex light fields using a modified complex-amplitude coding algorithm to validate the proposed method.

Methodology for Shape Optimization of Magnetic Designs: Magnetic Spring Characteristic Tailored to Application Needs

Topology and shape optimization are still rarely applied to problems in electromagnetic design due to the computational complexity and limited commercial tooling, even though components such as electrical motors, magnetic springs or magnetic bearings could benefit from it, either to improve performance (reducing torque ripple and losses through shaping harmonic content in back electromotive force) or reduce the use of rare-earth materials. Magnetic springs are a fatigue free alternative to mechanical springs, where shape optimization can be exploited to a great degree—allowing for advanced non-linear stiffness characteristic shaping. We present the optimization methodology relying on a combination of several approaches for characteristic shaping of magnetic springs through either a modular design approach based on: (i) Fourier order decomposition; (ii) breaking conventional design symmetry; or (iii) free shaping of magnets through deviation from a nominal design using problem formulations such as spline and polynomials for material boundary definitions. Each of the parametrizations is formulated into a multi-objective optimization problem with both performance and material cost, and solved using gradient free optimization techniques (direct search, genetic algorithm). The methodology is employed on several benchmark problems—both academic and application inspired magnetic spring torque characteristic requirements. The resulting designs fit well with the requirements, with a relatively low computational cost. As such, the methodology presented is a promising candidate for other design problems in 2D shape optimization in electrical motor research and development.

Content moderation as language policy

Commercial content moderation removes harassment, abuse, hate, or any material deemed harmful or offensive from user-generated content platforms. A platform’s content policy and related government regulations are forms of explicit language policy. This kind of policy dictates the classifications of harmful language and aims to change users’ language practices by force. However, the de facto language policy is the actual practice of language moderation by algorithms and humans. Algorithms and human moderators enforce which words (and thereby, content) can be shared, revealing the normative values of hateful, offensive, or free speech and shaping how users adapt and create new language practices. This paper will introduce the process and challenges of commercial content moderation, as well as Canada’s proposed Bill C-36 with its complementary regulatory framework, and briefly discuss the implications for language practices.

Analysis of universal joint using virtual simulation method

The guiding framework and directing section are the standouts amongst the most significant gadgets of a car. It is an extremely critical part to accomplish the steadiness and relentless development of the vehicle. Just like an insect in this part, a cross joint is formed made up of poles having some type of burdens on each pole. The poles due to the force which are applied to them tend to experience shear as well as torsion force. Movement transmission arrangement of vehicles comprises a few parts which some of the time experience disastrous disappointments. Forces combine to form a turning part and this tends to experience weakness due to variable torque. In this research paper, we have limited our investigation of just segment to understand its pressure and dislodging effect with regards to the last item. For virtual construction of the object framework, a solid works tool was utilized and for analysis purposes, ANSYS programming was utilized. Hereby using FEA methodologies we can understand as well as distinguish between different types of stresses. This can be further studied by assessing the impact on the heap, limit conditions, the geometry of the mass, and the nature of the yoke. The directing framework and guiding section are the standouts amongst the most significant gadgets of a vehicle. it is an exceptionally essential part to accomplish security and unfaltering development of the vehicle. Just like insects, it has poles which were due to cross formed at the middle of the road part having burdens on both of its pole which were joined at the middle like a cross joint which was used in cross joints. Due to forces applied on the cross joint poles, it experiences both shear as well as torsion force. Movement transmission arrangement of vehicles comprises a few segments which at times experience heartbreaking disappointments. We have optimized and analyzed the universal joint according to lattice and free size and shape methodology.

Finite element analysis of knee joint implant for varying bio material using ANSYS

In this research we want to carry out the finite element analysis of knee implant for a patient at static state and then compare it with materials used in commercially available knee implant and then comprehend its stress analysis results. In this research, we have used the STP file of the knee joint and this design was proposed taking general data of a human being. The 3D CAD model was designed by utilizing the CAD tool Catia which is one of the best in surface CAD modelling after that the model was meshed in ANSYS and finally a finite element analysis is performed for different materials of knee implant for the constant load of 500 N. The obtained results are compared with each other and the material with the least stress is suggested for usage in the knee joint. Well as torsion force. Movement transmission arrangement of vehicles comprises a few segments which at times experience heartbreaking disappointments. We have optimized and analyzed the universal joint according to lattice and free size and shape methodology.

Vibration optimization of laminated composites with curvilinear reinforcing fibers for shell structures

Tailored Fiber Placement (TFP) is an embroidery technique that enables it possible to design free fiber shapes on base material sheets. The TFP generally creates curved fibers on a flat surface. However, CFRP structures are often used as shell structures rather than as flat plates, and there is not enough research to design fiber shapes on curved surfaces. In this research, we applied our previous optimization method for curved fiber shapes to shell structures. Curved fiber shapes were created by the linear combination of radial basis functions (RBFs) to represent complex fiber shapes. The fiber shape on a curved surface was represented by projecting the fiber shape on a plane surface using a coordinate transformation technique. Using this method, we investigated optimum fiber shapes to improve the first natural frequency of shell structure composites. The results showed that the optimum fiber shape gave higher natural frequencies than the linear fiber orientation. Obtained optimum fiber shape resulted in higher natural frequencies than the linear fiber orientation.

Cadmium(II) and copper(II) complexes containing benzoate derivatives and 2-aminopyrimidine ligands: Synthesis, crystal structures and antibacterial activity

The new Cd(II) and Cu(II) complexes namely [Cd2(2-OHbza)4(apm)4] (1), [Cu2(2-OHbza)4(apm)]n•2(2-OHbza) (2) and [Cu2(2-CH3bza)4(apm)]n (3) (2-OHbza = 2-hydroxybenzoate, 2-CH3bza = 2-methylbenzoate and apm = 2-aminopyrimidine) were successfully prepared by using direct one pot synthesis method. All complexes were characterized by using CHN elemental analysis, FT-IR spectroscopy, powder X-ray diffraction and single crystal X-ray diffraction techniques. Compound 1 crystallized in monoclinic space group P21/c, while compound 2 and 3 crystallized in triclinic space group P-1. The dinuclear compound 1 consists of two seven-coordinated Cd(II) centers which are doubly bridged by 2-OHbza bridging ligands, while the rest two 2-OHbza and two apm are terminal ligand. The crystal structure of compound 1 is stabilized by the intermolecular hydrogen bonding and C-H•••π interaction and π•••π interactions. Compounds 2 and 3 present zigzag one-dimensional chainlike-structure which dimer Cu(II) units are linked by apm ligand. The crystal structure of these compounds is stabilized by π•••π and C-H•••π interactions. The photoluminescence properties of compound 1 has been studied comparing to those of 2-OHbza and apm ligands. The solid state PL emission spectrum of compound 1 shows similar intensity of free apm ligand and shape to free 2-OHbza ligand which present a single broad band centered at λem 525 nm (λex = 325 nm), but blue-shift. For solution PL experiment of compound 1 in various solvents, the results showed that compound 1 is selective PL quenching acetone. Electronic spectra for solid state and solution in different solvents of compounds 2 and 3 present the d-d absorption bands centered in the range of 701 – 794 nm. The highest red shifts of λmax are found for compounds 2 and 3 in DMSO. In addition, the antibacterial activity of all compounds are investigated for S.aureus and E.coil by agar diffusion method. The results show that compound 1 exhibits the activity against S.aureus better than E.coil.

Transfer learning of neural network based process models in Direct Metal Deposition

Direct Metal Deposition is an effective additive manufacturing technology to build parts from scratch, add complex features on existing raw parts or even repair highly specialized products. The combinations of high performance materials and free shape complexity achievable by such technology offers great advantages for industrial applications such as the aeronautic industry, where lightweight parts are crucial. However, the complexity of the process is difficult to control, resulting in more scrap and rework. To reduce these drawbacks, predictive models are developed to improve the process understanding and compute expected part properties before actual manufacturing, but the generation of such models is often time expensive and requires many experiments. The present work provides a machine learning based method to facilitate the model generation process and demonstrates the transferability to different production machines. Such a methodology is of relevance to support the effective and efficient modelling of different machine tools based on the same manufacturing processes.

Atomistic simulation of martensite microstructural evolution during temperature driven [formula omitted] transition in pure titanium

Titanium and its alloys undergo temperature-driven martensitic phase transformation leading to the development of complex microstructures at mesoscale. Optimizing the mechanical properties of these materials requires an understanding of the correlations between the processing parameters and the mechanisms involved in the microstructure formation and evolution. In this work, we study the temperature-induced phase transition from BCC to HCP in pure titanium by atomistic modeling and investigate the influence of local stress conditions on the final martensite morphology. We simulate the transition under different stress conditions and carry a detailed analysis of the microstructural evolution during transition using a deformation gradient map that characterizes the local lattice distortion. The analysis of final martensite morphologies shows how mechanical constraints influence the number of selected variants and the number/type of defects in the final microstructure. We give insight on the origin and structure of different interfaces experimentally observed, such as inter-variant boundaries and antiphase defects. In particular, we show how antiphase defects originate from the two-fold degeneracy shuffling displacement arriving during the transition and how the triple junction formation drives the texture evolution when local stresses prevent a free shape change of the matrix surrounding the growing martensite nuclei.

Investigation of Shape Transformations of Vesicles, Induced by Their Adhesion to Flat Substrates Characterized by Different Adhesion Strength.

The adhesion of lipid vesicles to a rigid flat surface is investigated. We examine the influence of the membrane spontaneous curvature, adhesion strength, and the reduced volume on the stability and shape transformations of adhered vesicles. The minimal strength of the adhesion necessary to stabilize the shapes of adhered vesicles belonging to different shape classes is determined. It is shown that the budding of an adhered vesicle may be induced by the change of the adhesion strength. The importance of the free vesicle shape for its susceptibility to adhesion is discussed.

Protein Folding Dynamics as Diffusion on a Free Energy Surface: Rate Equation Terms, Transition Paths, and Analysis of Single-Molecule Photon Trajectories.

The rates of protein (un)folding are often described as diffusion on the projection of a hyperdimensional energy landscape onto a few (ideally one) order parameters. Testing such an approximation by experiment requires resolving the reactive transition paths of individual molecules, which is now becoming feasible with advanced single-molecule spectroscopic techniques. This has also sparked the interest of theorists in better understanding reactive transition paths. Here we focus on these issues aiming to establish (i) practical guidelines for the mechanistic interpretation of transition path times (TPT) and (ii) methods to extract the free energy surface and protein dynamics from the maximum likelihood analysis of photon trajectories (MLA-PT). We represent the (un)folding rates as diffusion on a 1D free energy surface with the FRET efficiency as a reaction coordinate proxy. We then perform diffusive kinetic simulations on surfaces with two minima and a barrier, but with different shapes (curvatures, barrier height, and symmetry), coupled to stochastic simulations of photon emissions that reproduce current SM-FRET experiments. From the analysis of transition paths, we find that the TPT is inversely proportional to the barrier height (difference in free energy between minimum and barrier top) for any given surface shape, and that dividing the TPT into climb and descent segments provides key information about the barrier's symmetry. We also find that the original MLA-PT procedure used to determine the TPT from experiments underestimates its value, particularly for the cases with smaller barriers (e.g., fast folders), and we suggest a simple strategy to correct for this bias. Importantly, we also demonstrate that photon trajectories contain enough information to extract the 1D free energy surface's shape and dynamics (if TPT is >4-5-fold longer than the interphoton time) using the MLA-PT directly implemented with a diffusive free energy surface model. When dealing with real (unknown) experimental data, the comparison between the likelihoods of the free energy surface and discrete kinetic three-state models can be used to evaluate the statistical significance of the estimated free energy surface.

FROM PERSECUTIONS TO DOMINATION: SHAPING THE IDENTITIES OF EARLY CHRISTIANS. AN ARCHEOLOGICAL-HISTORICAL PERSPECTIVE IN THE NORTHERN ILLYRICUM

Archaeological testimonies of Early Christianity in the area of Northern Illyricum come from a relatively late period in regard to the edge of the Medi- terranean basin, in which Christianisation had already begun during the time of the apostles. With their edicts, issued in the first decades of the 4th century, two emperors, Galerius and Constantine I, who originated from these areas, set the foundation for free institutional shaping of the Christian community, which they recognised as a growing force in the Late Antique society. Man- ners in which the Christian community was shaped and reacted to the com- plex social-economic conditions during this forming period, can be seen from archaeological traces registered, most prominently, in larger urban centres of Northern Illyricum. The decline of the imperial and administrative power of the state, especially during the 5th and the 6th century, which led to a loss of territories and concessions under the pressure to allow barbarian tribes to settle on Roman soil, with the inclusion of barbarians in the top of the chain of command of the Roman army, led to a loss of control in managing complex relations, in which the Christian Church appeared as a mediator and a factor which brought together all members of the Roman society. This Church–state alliance enabled stability of sensitive zones of the Empire, and the intense policy of Christianisation and taking over certain administrative-governing jurisdic- tions only increased the power of the Church in Late Antiquity and led to its domination in the Roman society.

Fiber-Reinforced Polymers in Freeform Structures: A Review

This article is a survey discussing the application of fiber-reinforced polymer composites in freeform structures and their impact on the design and shape generation process. The analysis of case studies showed that the use of FRP composites not only helps to overcome some challenges in the construction of objects with complex geometry, but also creates brand new types of structures and design approaches. On the other hand, there is a problem—although FRP materials are frequently used in construction, the shapes of structures and design methods are often traditional and are simply copied from materials such as wood, concrete, and steel. FRP composites have been applied in civil engineering for several decades, since the 1960s, as building envelopes, façade skins, load-bearing structures, and internal and external reinforcement. The article aims to analyze this accumulated experience and to explore the role of FRP materials in the design of buildings with free, complex, fluid, and organic shapes. A new classification of freeform composite structures is proposed. They are classified in this article according to the methodology applied at the conceptual design stage: structures created by using a geometric approach, a form-finding (equilibrium) approach, or a biomimetic approach. Each approach is described in its own separate section, with a thorough literature and state-of-the-art review.

Multifunctional Ti3C2Tx MXene/Low-Density Polyethylene Soft Robots with Programmable Configuration for Amphibious Motions.

To diversify the motion modes of multifunctional soft robots capable of shape programming, we fabricate a biomimetic and programmable Ti3C2Tx MXene/low-density polyethylene (LDPE) bilayer actuator by spraying an aqueous dispersion of MXenes onto a plasma-activated LDPE film, followed by optimal thermal regulations. Because of the eminent light absorption and photothermal/electrothermal features of MXenes and the extremely mismatched thermal expansion coefficients between the two layers, the MXene/LDPE actuator can be sensitively driven by many stimuli of near-infrared light, electricity, and heat. The initial configuration of the bilayer actuator can be programmed by tuning the thermal regulation temperature, thereby assembling multiple actuation units to achieve biomimetic functions, such as artificial iris, mechanical arms, and flying birds. More importantly, in virtue of free shape cutting and programmable configuration, the MXene/LDPE bilayer actuator can perform untethered locomotion including crawling, rolling, and sailing. The soft robots can not only move on the ground in different forms but also sail on water along any designated routes and complete the surface cargo transportation driven by a near-infrared laser via the photothermal Marangoni effect. The shape-programmable methodology for the three amphibious motion modes lays foundations for wide applications of the MXene-based soft robots.