Planar Construction Research Articles

Enhancing light trapping for improved efficiency of perovskite solar cells: design and analysis

Abstract A hybrid organic-inorganic perovskite solar cells (PSCs) is explored for its potential to achieve high-efficiency and cost-effective solar energy conversion, especially through improved light management. In this paper, COMSOL Multiphysics is utilized to explore PSCs with light trapping nanostructures which will enhance the optical and electrical properties. A nanometer-scale concave structure is proposed in this paper to direct and capture light. This configuration is compared to a planar structure to see how it affect PSCs optoelectronic performance. Electrical simulations showed that concave nanostructured PSCs increase carrier generation and collect more carriers. The short-circuit current rose from 3.91 mA for the planar structure to 4.95 mA for the concave structure. Power conversion efficiency for concave PSCs increased 11% compared to the planar construction after choosing optimal height of concave structure. Thus, the performance investigation by combined optical and electrical analysis of nanostructures shows that it has the ability to build high-efficiency PSCs with light-trapping approach.

Facile Electrolytic (111)‐Textured Copper Foil for Dendrite‐Free Zinc Metal Batteries

AbstractAqueous Zn metal batteries are emerging as a promising candidate for the next‐generation largescale energy storage system due to their high safety, low lost, and eco‐friendliness. Nevertheless, their practical application is restricted by the uncontrollable Zn dendrite growth and the limited utilization of the Zn metal anode. Herein, a room temperature electrodeposition strategy based on an optimized rate relationship between the diffusion and consumption of Cu2+ to prepare a (111)‐textured Cu current collector for the construction of the dendrite‐free Zn metal anode with high reversibility is developed. Attributed to the high lattice match between the (002) facet of Zn with the (111) facet of Cu, the deposition of Zn along its [001] orientation is achieved on the (111)‐textured Cu. The (002) facets horizontally aligned with the current collector endow Zn with the dendrite‐free planar construction and superior corrosion resistance, resulting in a high reversibility with a long life‐span over 2186 cycles. Impressively, the resultant Zn anodes can stabilize the operation of pouch cells with an extremely demanding negative‐to‐positive capacity ratio of 2. This work provides a new avenue for the development of the current collectors for the low‐cost sustainable energy storage.

High thermally conductive polyimide film designed with heterostructural Cring-C3N4 filler and multilayer strategy

With the emerging of advanced flexible electronic, the PI film with excellent thermally conductive, flexible, lightweight, electrically insulating qualities is in high demand as a potential substrate and encapsulation material. Conventional thermally conductive fillers such as ceramic, metal and carbon material with high hardness, high density or electrical conductivity are unsuitable to prepare the advanced PI film. Furthermore, the confined loading of thermally conductive filler in PI matrix limited by its film-forming property is another obstacle to optimizing the thermal conductivity of PI film. In this work, the development of novel filler (carbon nitride in-plane grafted by two-dimensional carbon material, Cring-C3N4) with intrinsic thermal conductivity and a design of three-layer structure for the introduction of high filler loading have dramatically improved the thermal conductivity of PI film. Benefitting by the planar heterostructure construction of g-C3N4 and Cring, the existence of Cring increases the phonon transfer rate in g-C3N4, and the presence of g-C3N4 prevents the electron movement in the facet of Cring-C3N4 endowing its excellent electrical insulation property. The design of three-layer structure in which the first and third layers served as mechanical support layers with a fixed filler content (20 wt%). The second layer has the higher filler content to enhance the quantity of thermally conductive filler in PI film. Resultantly, the maximum out-of-plane thermal conductivity of the PI/Cring-C3N4 composite film is 1.35 Wm−1K−1, which is 10 times higher than the pure PI film. In addition, the PI/Cring-C3N4 composite film exhibit excellent photothermal conversion ability in which the saturation temperature of PI/Cring-C3N4 can reach 283.6 °C under 0.75 W/cm2 laser radiation being 6 times higher than that of the corresponding PI film. After the incorporation of Cring-C3N4, the PI composite film still has excellent thermal stability, low CTE, electrical insulation and mechanical properties. This work provides a novel idea for the preparation of advanced high thermal conductivity PI film.

Numerical Solution of Natural Frequencies and Mode Shapes

Every construction has a set of their natural frequencies (resonant frequencies) and mode shapes that depend on its material, structure, and boundary conditions. A mode shape is a deflection pattern. It is related to a particular natural frequency and represents the relative displacement of all parts of a construction for that particular mode. This paper deals with numerical solutions of natural frequencies and mode shapes. The method of stiffness constants and bisection method is used. The procedure can be used for any planar bar construction. First, the mode shapes of the simple beam are solved, where the solution is compared with the results obtained using known relationships. The article further describes the solution of the parabolic arc.

Enantioselective construction of planar, axially and central chiral ferrocenyl phosphines via a Pd-catalyzed domino reaction and diastereoselective phosphination

A family of both axially and planar chiral ferrocenes was prepared through a Pd-catalyzed domino reaction.

The demultiplexing and broadband focusing on a gold nanoarray of in-plane propagating surface plasmons

An analytical approach is presented to comprehensively describe a meticulously designed gold nanoarray situated on a silicon waveguide(length (L) and width(W) are 12 µm and 3 µm). The incorporation of a glass substrate with an L and W of 12 µm is proposed as a means to achieve broadband focusing. At the same time, a demultiplexing element utilizing surface plasmon polariton (SPP) waves is introduced, employing a novel phase modulation method that uses in-plane diffraction processes. The analytical calculations are focused on the sublattice arrays, which are currently under investigation to enhance the performance of demultiplexers and confocal SPP beams. The suggested method exhibits various functionalities that make it a promising approach. Its planar construction ensures a streamlined and integrated design, and the absence of SPP coupling processes adds to its practicality for implementation in photonic integrations. By leveraging the unique properties of the gold nanoarray on the silicon waveguide, combined with the glass substrate for broadband focusing and the novel phase modulation method for demultiplexing SPP waves, this approach holds great potential for advancing the field of photonics.

Regulating the band gaps of seven stacking patterns of bilayer hexagonal boron nitrides by doping carbon atoms in opposite sites

The band gaps of seven stacking patterns of bilayer hexagonal boron nitrides(h-BNs) are regulated by changing the doping positions of carbon atoms using density functional theory calculations. The calculation results dwell on that the AA1 stacking pattern h-BN has the largest band gap among seven stacking patterns of h-BNs. The influences of five different doping positions of carbon atoms to the band gap of AA1 stacking pattern bilayer h-BN are investigated and the results shows that the opposite doping model has the largest band gap decline among five doping configurations under the same doping content. As for the other four doping models, the calculation results illustrate that the adjacent doping model is the most stable configuration, the remote doping configuration makes the planar construction of bilayer h-BN destroyed and the two cases of alternate doping configurations present metal properties. Therefore, the opposite doping model is the most valuable doping configuration. Bilayer h-BN transformed from insulating state to semiconductor state and the optical absorption coefficient of it shows that the absorption peak shifts to longer wavelength range after doping carbon atoms into opposite sites. Density of states and electron densities results indicate that the main reason of band gap decline is the charge transfer among atoms. This research should be helpful for designing band gaps of h-BN bilayers in nano- electronics applications.

Nutritionally enhanced fibrous scaffolds by rolling droplet-interfacial polyelectrolyte complexation (RD-IPC)

The challenge of producing protein in a more sustainable manner than what is currently afforded by meat from livestock has led to the advent of cell-based or cultured meat. One method of obtaining whole-cuts of meat would be to culture the relevant cells on fibrous scaffolds to obtain meat-like textures. In the present work, a novel process of rolling droplet interfacial polyelectrolyte complexation (RD-IPC) is used to make aligned fibrous constructs that can be incorporated with nutritional components. Fiber is drawn by a falling droplet consisting of two oppositely charged polyelectrolytes that are continuously delivered by means of a syringe pump. The fibers are collected individually as they form and accumulate on a rotating collecting device to form planar constructs. Scaffolds incorporating gelatin, soybean flour, potato starch and garlic could be made by dispersing the respective powders into the polyelectrolyte solutions. Following the formation of the constructs, a heating step was found to improve their mechanical properties, in particular the potato starch-incorporated constructs, which exhibited higher tensile moduli due to a gelatinization process. Scaffolds imbued with gelatin and RGD moieties supported the adhesion, alignment, and differentiation of mouse myoblasts, while scaffolds incorporating gelatin alone sufficed for the differentiation of preadipocytes. RD-IPC provides for a scalable, continuous process that allows the incorporation of nutritional components into scaffolds possessing good mechanical and cell-adhesive properties. These fibrous scaffolds are constructed using edible polyelectrolyte components and aqueous solutions at relatively mild process conditions, underlining their promise for the nutritional enhancement of cultured meat.

Π‐Skeleton Tailoring of Olefin‐Linked Covalent Organic Frameworks Achieving Low Exciton Binding Energy for Photo‐Enhanced Uranium Extraction from Seawater

AbstractAdsorption‐photocatalysis technology based on covalent organic frameworks (COFs) offers an alternative method for advancing the field of uranium extraction from seawater. When determining the photocatalytic activity of COFs, the binding energy of excitons (Eb) functions is the decisive factor. Nevertheless, the majority of reported COFs have a large Eb, which seriously restricts their application in the field of photocatalysis. Using a practical π‐skeleton engineering strategy, the current study synthesizes three donor‐acceptor olefin‐linked COFs containing amidoxime units in an effort to minimize Eb. Theoretical and experimental results reveal that the construction of planar and continuous π‐electron delocalization channels can significantly reduce Eb and promote the separation of electron‐hole pairs, thereby enhancing the photocatalytic activities. Moreover, the Eb of the TTh‐COF‐AO with a planar π‐skeleton donor is significantly reduced, and exhibits a substantially smaller Eb (38.4 meV). Under visible light irradiation, a high photo‐enhanced uranium extraction capacity of 10.24 mg g−1 is achieved from natural seawater without the addition of sacrificial reagents, which is superior to the majority of olefin‐linked COFs that have been reported to date. This study, therefore, paves the way for the development of tailored, efficient COFs photocatalysts for the extraction of uranium from seawater.

Single-Step Construction of Planar and Central Chirality in Metallocenes by Rhodium-Catalyzed Desymmetric Cyclization

Single-Step Construction of Planar and Central Chirality in Metallocenes by Rhodium-Catalyzed Desymmetric Cyclization

Tunable Acoustic Properties in Reconfigurable Kerf Structures

Freeform structures are appealing in architecture owing to their ability to combine pleasing aesthetics and functionality. Regarding architectural functionality, freeform structures have the potential to meet desired acoustic requirements in indoor architecture through the proper design of materials and geometries. Kerfing is one of the practical methods to generate reconfigurable freeform structures from rigid planar construction materials. This study aims to explore tunable room acoustic characteristics through the use of kerf structures. In this study, we investigate acoustic responses of kerf structures made out of a medium density fiber board having a hexagon spiral kerf pattern with varying cut densities. Experiments are conducted to measure the acoustic properties (e.g., absorption coefficient) of the kerf unit cells with different cut densities. We then design kerf patterns using the parametric design method and explore the flexibility of kerf structures with different kerf cut densities. We model the kerf structures of varying kerf cut density and shape reconfigurations and use a ray-tracing simulation to study their impacts on the acoustic performance, i.e., reverberation times, of a small office space. Overall, this study leverages the unique attributes of kerf structures such as different cut densities and shape reconfigurations to tune the room acoustics in addition to their usage in indoor architectures due to their pleasing aesthetics.

Localized Spoof Surface Plasmon Skyrmions Excited by Guided Waves

AbstractRecently, skyrmions are constructed in the system of localized spoof surface plasmons (LSSPs), showing topological robustness and near‐equidistant multi‐resonant response. Guided wave excitation of the LSSP skyrmions plays an elementary role in large‐scale planar integration and construction of complex networks. However, it is not investigated. In this study, the LSSP skyrmions are excited by guided waves supported by two kinds of widely used transmission lines, microstrip line and coplanar waveguide. Space‐coiling meta‐structures with different shapes that support LSSP skyrmions are etched on the ground planes as defected ground structures (DGSs). All structures including resonator, transmission line, input and output ports are in one plane. The structures are fabricated on printed circuit boards (PCBs) and the near‐equidistant multi‐resonant spectra of the LSSP skyrmions are measured. Moreover, to reduce the material loss, the structure is made on MgB2 superconducting film, and the quality factor (Q‐factor) is increased by seven times compared to the corresponding mode on PCB. This study paves the way for the massive planar integration of the LSSP skyrmions and the construction of complex networks with the LSSP skyrmions, and provides an idea for developing metasurfaces with low material loss in the microwave and terahertz bands.

Boron clusters sheets with algebraic properties

Boron clusters are small, three-dimensional structures made of boron atoms. These come in a wide range of shapes and sizes, from basic planar constructions to complex polyhedral patterns. Boron clusters are fascinating from both a fundamental and practical perspective because of their unique electrical, optical, and chemical properties. More focus has lately been placed on boron cluster sheets, which are two-dimensional structures made of boron clusters. Quantitative structure-activity relationship (QSAR) studies implement M-polynomials, a type of molecular descriptor, to describe the topology of molecules. These are based on the notion of graph theory, which provides a theoretical framework for quantitatively studying molecular graphs. In this article, we discussed some novel topological descriptors-based M-polynomials and found algebraic formulations for the boron cluster or borophene sheets. We discussed first Zagreb, second Zagreb and Randić M-polynomials, based on the different differential and integral operators.

Application of BIM to Rebar Modeling of a Variable Section Column

A planar construction drawing is usually used to guide the construction of reinforced concrete structures in the construction industry. Due to a lack of effective technical methods, the accuracy of rebar engineering lofting is insufficient. The rejection rate of rebar is high, which results in high processing costs. Under the background of intelligent construction and BIM technology, the prefabricated factory adopts an automatic production mode to concentrate on steel bar processing, which improves production quality and processing efficiency and reduces production costs. Based on Revit secondary development, using the C# programming language, combined with the Revit API development interface, an automatic 3D modeling plugin for a reinforced concrete variable cross-section column is developed. The BIM model of steel bars is quickly generated, and the engineering quantity of steel bars is automatically calculated, which saves time for the designer to build the BIM model. It is conducive to the automatic assembly and intelligent construction of reinforced concrete engineering, which promotes the information and intelligent development of reinforced concrete structure construction.

The swarm within the labyrinth: planar construction by a robot swarm

The swarm within the labyrinth: planar construction by a robot swarm

An Adhesive Bioink toward Biofabrication under Wet Conditions.

Three-dimensional (3D) bioprinting is driving significant innovations in biomedicine over recent years. Under certain scenarios such as in intraoperative bioprinting, the bioinks used should exhibit not only cyto/biocompatibility but also adhesiveness in wet conditions. Herein, an adhesive bioink composed of gelatin methacryloyl, gelatin, methacrylated hyaluronic acid, and skin secretion of Andrias davidianus is designed. The bioink exhibits favorable cohesion to allow faithful extrusion bioprinting in wet conditions, while simultaneously showing good adhesion to a variety of surfaces of different chemical properties, possibly achieved through the diverse bonds presented in the bioink formulation. As such, this bioink is able to fabricate sophisticated planar and volumetric constructs using extrusion bioprinting, where the dexterity is further enhanced using ergonomic handheld bioprinters to realize in situ bioprinting. In vitro experiments reveal that cells maintain high viability; further in vivo studies demonstrate good integration and immediate injury sealing. The characteristics of the bioink indicate its potential widespread utility in extrusion bioprinting and will likely broaden the applications of bioprinting toward situations such as in situ dressing and minimally invasive tissue regeneration.

Metal Anodes with Ultrahigh Reversibility Enabled by the Closest Packing Crystallography for Sustainable Batteries.

The ever-growing annual electricity generated from sustainable and intermittent energy such as wind and solar power requires the cost effective and reliable electrochemical energy storage. Rechargeable batteries based on multivalent metal anodes such as Zn, Al and Fe, taking advantages of large-scale production and affordable cost, have been emerged as promising candidates. However, the uncontrollable dendrite-like metal deposition on regular substrate caused by disordered metal crystallization usually leads to premature failure of batteries and even safety concern when the dendrite bridges the electrodes. Here we report that a series of metal anodes (Zn, Co, Al, Ni, Fe) with multiple crystal structures (hcp, fcc, bcc) can achieve dendrite-free and epitaxial deposition on single-crystal Cu(111) substrates enabled by the closest packing crystallography. Moreover, the closest packed facets are aligned horizontally with the substrates, resulting in compact planar construction and excellent chemical stability even at an unprecedented current density of 1 A cm-2 . The full cells under a practical anode-to-cathode capacity ratio of 2.3 show cycling life span over 800 cycles with Coulombic efficiency of >99.9%. The universal approach of regulating metal electrodeposition in this work is expected to boost the development of emerging sustainable energy storage/conversion devices. This article is protected by copyright. All rights reserved.

A two-stage μCAT-MPD thruster: toward millinewton thrust

We discuss our efforts aimed at simultaneous improvement of the levels of thrust, thrust-to-power ratio (TPR) and efficiency of the two-stage micro-cathode arc thruster with magneto-plasma-dynamical second stage (μCAT-MPD). Such efforts include planar construction of the first stage (μCAT) with tightly-pressed ring anode and central disc cathode, enhanced hardness and durability of the inter-electrode dielectric gap provided by deposited boron-copper thin film, refractory (Mo) second-stage electrode, higher and stabilized second-stage voltage, and improved thermal isolation of the permanent magnet from the discharge area. Aforementioned features allowed achieve the average thrust of milli-newton range – up to 1.7 ± 0.3 mN, together with high TPR of 37 μN/W and efficiency of 50%, remaining low mass (~ 100 g) and low consuming power (~ 50 W) of the thruster.

Emerging Nonplanar van der Waals Nanoarchitectures from 2D Allotropes for Optoelectronics

AbstractThe unique atomic thickness and mechanical flexibility of 2D van der Waals (vdW) materials endow them with spatial designability and constructability. It is easy to break the inherent planar construction through various spatial manipulations, thus creating vdW nanoarchitectures with nonplanar topologies. The basic properties before evolution are retained and tunable by architecture‐related feature sizes, and other newly generated properties are inspiring as they are beyond the reach of 2D allotropes, bringing great competitiveness for their encouraging applications in optoelectronics. Here, these representative nonplanar vdW nanoarchitectures (i.e., nanoscrolls, nanotubes, spiral nanopyramids, spiral nanowires, nanoshells, etc.) are summarized and their structural evolution processes are elucidated. Their fascinating nascent properties based on their distinctive structural features, focusing on generally enhanced light–matter interactions and device physics, are further introduced. Finally, their opportunities and challenges for in‐depth experimental exploration are prospected. It is a brand‐new idea to modify the properties of 2D vdW materials from micro‐ and nanostructural design and evolution, offering a solid platform for twistronics, valleytronics, and integrated nanophotonics.

Out-of-Plane Tensile Properties of Cross Laminated Timber (CLT)

A systematic investigation is still lacking for tension out-of-plane in cross laminated timber (CLT), as a planar timber construction product. The objectives of the present study are the determination of the tensile properties of CLT made of Norway spruce, the identification of essential product-specific influencing parameters and a comparative analysis with glulam. For this purpose, seven test series were defined, which allowed the determination of the tensile properties on board segments and thereof produced glulam and CLT specimens by varying the number of layers, layer orientation and number of elements within a layer. The orthogonal laminated structure of CLT led to between 50% and 70% higher tensile properties out-of-plane, which is explained by the different stress distribution compared to glulam; the regulation of 30% higher properties than for glulam is suggested. In addition, the lognormal distribution turned out to be a more representative distribution model for characterizing the tensile strength out-of-plane than the Weibull distribution. This was also confirmed with regard to the investigated serial and parallel system effects, in which a clearly more homogeneous behavior was found in CLT compared to glulam, which in turn can be attributed again to the different stress distributions.