Triangular Pattern Research Articles

Highly Crystalized MAPbX3 Perovskite Triangular Nanowire Arrays for Optoelectronic Applications.

Here, a facile fabrication approach for the high-quality 1D perovskite triangular nanowire (TNW) array synthesis through space-confined effect is reported. A soft stamp containing 1D triangular linear array pattern is used to confine the MAPbX3 solution and to guide the growth of the nanowires along the prescribed direction with good crystallinity. The further constructed photodetectors based on the obtained MAPbI3 TNWs exhibit superior photoresponse properties with a responsivity of (125.2 ± 2.5) A W-1 and detectivity of (2.8 ± 0.8) × 1013 Jones at the wavelength of 650 nm. This excellent performance is attributed to the highly crystalline TNW with optical anisotropy and a small asymptotic height, which reduces the probability of the photon reflection and promotes the carrier transport. More interestingly, the increased surface area of the triangular device can present superior flexibility after a couple of thousands of bending cycles. Furthermore, by fabricating 7 × 7 photodetector arrays, the potential image sensor application is demonstrated. The perovskite nanowire fabrication approach is scalable and compatible with current semiconductor manufacturing, which indicates their great potential in broad applications.

Asymptotic analysis of the higher-order lump in the Davey-Stewartson I equation

In this paper, the long-time asymptotic dynamics of three types of the higher-order lump in the Davey-Stewartson I equation, namely the linear lump, triangular lump and quasi-diamond lump, are investigated. For large time, the linear lump splits into certain fundamental lumps arranged in a straight line, which are associated with root structures of the first component in used eigenvector. The triangular lump consists of certain fundamental lumps forming a triangular structure, which are described by the roots of a special Wronskian that is similar to Yablonskii-Vorob polynomial. The quasi-diamond lump comprises a diamond in the outer region and a triangular lump pattern in the inner region (if it exists), which are decided by the roots of a general Wronskain determinant. The minimum values of these lump hollows are dependent on time and approach zero when time goes to infinity. Our approximate lump patterns and true solutions show excellent agreement.

Flexural performance of 3D printed concrete structure with lattice infills

Large-scale 3D printed concrete structures with lattice infill will result in lightweight components with high mass-specific strength, and faster fabrication, compared to conventional casting methods. However, the effect of different infill patterns on mechanical performance is still not addressed clearly in many scientific publications. This study investigates the bending performance of 3D-printed concrete beams with four infill patterns such as lattice, triangular, lattice-triangular, and sinusoidal tested in vertical (layer deposition direction) and transverse (layer translation direction) loading directions. The load versus displacement curves and crack propagation patterns are investigated both via Finite Element (FE) simulations and experiments. The FE results corroborated by experiments indicated that the triangular patterns perform better than lattice-shaped infill counterparts particularly under the transverse loading direction exhibiting the highest flexural deformation resistance capacity. The findings of this study would be useful in latticing large-scale concrete structures for diverse applications.

Laboratory study on the spacing effect of vertical drains on the consolidation characteristics of clay

Sand drains are extensively utilized to fasten the consolidation rate, especially in soft clay deposits. However, due to the scarcity of sand, it should be substituted with some cost-effective material. In view of this, in the current investigation, along with sand, waste materials like rice husk ash, coir pith, fly ash, and quarry dust were used as drain materials. The consolidation test was performed using Kuttanad clay, filled in a mould of 15 cm diameter and 10 cm height, allowing single drainage. A triangular pattern of three drain system was used in the study. A parametric study on the effect of the spacing of the drain on consolidation characteristics was investigated by varying the spacing/diameter ratio (s/d ratio). It was observed that the consolidation rate is more for coir pith and quarry dust drains compared to rice husk ash and fly ash drain used in the study. The consolidation rate reduces with the increase in the spacing of the drain. For achieving a particular consolidation rate, the required drain spacing has to be known. Correlations were developed to predict the spacing between the drains for attaining a particular coefficient of consolidation.

Temporal origin of nestedness in interaction networks

Abstract Nestedness is a common property of communication, finance, trade, and ecological networks. In networks with high levels of nestedness, the link positions of low-degree nodes (those with few links) form nested subsets of the link positions of high-degree nodes (those with many links), leading to matrix representations with characteristic upper triangular or staircase patterns. Recent theoretical work has connected nestedness to the functionality of complex systems and has suggested that it is a structural by-product of the skewed degree distributions often seen in empirical data. However, mechanisms for generating nestedness remain poorly understood, limiting the connections that can be made between system processes and observed network structures. Here, we show that a simple probabilistic model based on phenology—the timing of copresences among interaction partners—can produce nested structures and correctly predict around two-thirds of interactions in two fish market networks and around one-third of interactions in 22 plant–pollinator networks. Notably, the links most readily explained by frequent actor copresences appear to form a backbone of nested interactions, with the remaining interactions attributable to opportunistic interactions or preferences for particular interaction partners that are not routinely available.

Poroelastic response of unsaturated soils to cyclic loads with arbitrary waveforms

AbstractWe develop an analytical solution to the problem of one‐dimensional consolidation of unsaturated soil subjected to cyclic loads with arbitrary waveforms. The solution predicts the excess pore water and pore air pressures and the accompanying vertical compression in a poroelastic, unsaturated soil material. Cyclic loading occurs in a variety of engineering applications and often generates higher excess pore fluid pressures and larger vertical compression than does a time‐invariant load. In the present study, the loading function is allowed to take on any arbitrary waveform represented by a Fourier trigonometric series. Analytical solution to the boundary‐value problem in one dimension is given in closed form describing the frequency‐independent and frequency‐dependent components of the poroelastic response. We verify the analytical solution through representative examples involving cyclic loads with square and triangular patterns. Apart from the shape of the forcing function, we also investigate the effects of initial water saturation, soil texture, and excitation frequency on the system response.

Clean energy storage device derived from biopolymers with moderate charge-discharge cycles: Structural and electrochemical properties

This work explores a green biopolymer (GBP) energy storage system to address the growing problem of microplastics that can harm our health. A GBP was made using solution casting with chitosan (CHN) and starch from potato (SPC) as the polymer hosts. Sodium thiocyanate (NaSCN) as Na+ cation provider and glycerol as an environmentally friendly plasticizer were mixed with CHN:SPC host polymers to prepare GBP electrolytes. The electrochemical impedance spectroscopy (EIS) results confirm the boost in DC conductivity. From the AC conductivity spectra, regions ascribing to EP and DC contributions are demonstrated. X-ray diffraction (XRD) and FTIR characterization provide evidence of salt dissociation and amorphous phase improvement. The determination of the ion fraction was achieved by means of TNM. The electrochemical stability of the conducting film was observed to be maintained up to 2.75 V. Cyclic voltammetry (CV), revealing no sign of charge transfer occurring through Faradaic processes at the interface between the electrode and electrolyte. The galvanostatic charge–discharge (GCD) plot displayed a triangular pattern, indicating a low voltage drop and a notable specific capacitance of 70 F/g. Moreover, the EDLC (electrical double-layer capacitor) exhibited an average power density of 1120 W/kg and an energy density of 9.11 Wh/kg.

Novel efficient and scalable design of full-adder in atomic silicon dangling bonds (ASDB) technology

Atomic Silicon Dangling Bonds (ASDB) is an advanced emerging nanotechnology to replace CMOS technology; because it allows the designing of circuits with very high-speed and low-density. However, one of the most critical challenges in implementing circuits in ASDB nanotechnology is output stability and possible defects, such as DB omission, DB misalignment, and DB extra deposition, which can be overcome using a suitable designing pattern. Therefore, developing stable and robust structures is considered as one of essential topics in ASDB. This paper first proposes two novel and stable computing circuits, including a three-input majority voter (MV3) and three-input XOR (XOR3); based on triangular and rhombus patterns, respectively. Then, an efficient ASDB full-adder is designed using the suggested MV3 and XOR3 gates. Finally, two and four-bit ripple carry adders are developed using proposed full-adder. Simulation results indicate that the suggested MV3 and XOR3 are superior to previous designs, by more than 80%, 48%, and 9.5%, averagely; in terms of occupied area, energy, and occurrence, respectively. Moreover, the proposed gates are investigated against possible defects, and the results show high stability.

Numerical simulation of oil shale in-situ exploration productivity comparison between steam injection and electrical heating

Oil shale is an important alternative resource to the conventional oil and gas because of its rich reserves. The in-situ heating exploitation is the most promising method to produce oil from the oil shale, mainly including electrical heating and steam injection heating. However, to the best of our knowledge, a comprehensive comparison between these two kinds of heating methods is still absent, thus the comparison is necessarily conducted to provide suggestions on how to select heating modes for the oil shale in-situ exploitation. On this basis, a systematic comparison is presented between in-situ steam heating and electrical heating, including physical and process parameters, and then sensitivity analysis and optimization on key parameters are carried out. Simulation results show that steam injection heating is superior to electrical heating in output, energy consumption and production cycle. The flow rate and temperature of the injected steam and the specific heat capacity of oil shale are sensitive to productivity. The production will be increased with larger injection flow rate and temperature. The thermal conductivity and porosity are less sensitive to the mining efficiency compared to the injection flow rate and temperature. At the same time, different well pattern structures also have an impact on productivity, and the hexagonal well pattern has better productivity benefits than the triangular and quadrilateral well patterns. In the simulation case of this paper, the most conducive parameters for exploitation were derived as injection flow rate 0.20 kg/s, injection temperature 650 °C, specific heat capacity 1.5 kJ/(kg⋅K), thermal conductivity 0.5 W/(m⋅K), porosity 0.05. These results are expected to provide theoretical suggestions for improving the productivity efficiency of oil shale in-situ exploitation.

Topological acoustic waveguide with high-precision internal-mode-induced multiband

In this paper, we propose a topological acoustic waveguide which can transmit high-precision and multiband sound energy with backscattering suppression and no energy loss. It is a kind of acoustic waveguide with spatial lattice uniformity without destroying lattice position. This acoustic structure is obtained by integrating two kinds of multi-stage resonators arranged in a triangular lattice pattern in the air environment. On one hand, the introduction of internal modes greatly improves the transmission accuracy of topological acoustic waveguide compared with the Bragg scattering alone under the same overall structure size. On the other hand, it greatly improves the utilization rate of the internal space of the structure and makes full use of the multi-modal in structure to construct more sound transmission bands. After introducing the rotational scattering mechanism, the numerical and experimental results show that up to seven high-precision acoustic transmission channels with backscattering suppression and no energy loss below 14 kHz are obtained along the sonic crystal interface with different topological states in this topological acoustic waveguide. This research paves the way for engineering applications of high-precision acoustic transmission, multi-band acoustic antennas, acoustic logic control, covert sound transmission and other multifunctional acoustic devices.

Penerapan Soil Preloading, PVD, dan PHD untuk Analisis Penurunan Konsolidasi Tanah

Soft clay has a low bearing capacity, high compressibility and low permeability. This condition causes soft clay soil to have a long settlement time. To overcome this soft soil condition, soil improvement methods are needed. One of the efforts is to use a combination of soil preloading methods, Prefabricated Vertical Drain (PVD), and Prefabricated Horizontal Drain (PHD) methods. Calculating soil settlement with soil improvement is carried out using the Asaoka method, which is a field observation method, and the theoretical method using the Terzaghi method. Based on the calculation results of field observations using the Asaoka method, the average degree of soil settlement is 93.5%. The calculation results of the Asaoka method are recalculated using a back calculation to produce a new parameter value, namely the horizontal consolidation (Ch) value, which is then compared with the Ch value in the previous plan. In the Terzaghi method, the average soil settlement value is 1.205 meters. The results of soil settlement value are used to analyze the height of the embankment based on the load ratio requirement in SNI 8460: 2017, where the load ratio on the ground is ≥ 1.3 times the planned load under service conditions. Based on the monitoring results, a load ratio value of 0.875 was obtained so that the SNI requirements carried out a re-planning of the landfill. Then, proceed with the design of PVD and PHD. The results obtained in planning use triangular PVD patterns with a distance between PVDs of 1 meter.

Ultra-broadband mid-infrared absorber based on hyperbolic α-MoO3

Owing to their broad operational bandwidth, broadband absorbers are extensively used in various applications, such as solar cells, microbolometers, and light modulators. To enhance energy harvesting, it is essential to achieve insensitivity to wide incident angles and polarization-independent absorption. α-MoO3 is a natural polar van der Waals crystal that hosts phonon polaritons in the mid-infrared spectral region. These polaritons can manipulate the infrared light at the nanoscale and break the diffraction limit, offering a great opportunity for the design of broadband absorbers. In this study, we propose a strategy based on an array of crossed the permittivity of α-MoO3 in [100] and [001] crystallographic axes to expand its broadband absorption. Triangular one-dimensional grating pattern is initially considered, which shows an ultra-broadband and wide-angle insensitive absorption within the range of 10.23–18.07 μm. Subsequently, square pyramidal two-dimensional arrays are investigated, which not only show ultra-broadband absorption and wide-angle insensitivity, but also exhibit polarization independence within the range of 10.46–18.32 μm. This remarkable broadband absorption is elucidated by the effective medium theory and the local power dissipation density. These results demonstrate an effective strategy for constructing ultra-broadband absorbers based on α-MoO3 for applications in solar thermal and photovoltaic systems.

Success Rate of Adrenal Venous Sampling and its Determining Factors: Experience of a Single Center in Malaysia

Primary hyperaldosteronism has been regarded as the commonest and potentially curable cause of secondary hypertension in up to 80% of cases if this condition is detected early. Laparoscopic adrenalectomy proved to be a promising curable method for primary hyperaldosteronism secondary to aldosterone producing adenoma (APA), while primary hyperaldosteronism secondary to bilateral adrenal hyperplasia (BAH) requires optimization of medical treatment. Adrenal venous sampling (AVS) has been recommended by the Endocrine Society's guideline in addressing the subtypes of primary hyperaldosteronism. Therefore, determining success rate of AVS in our centre is crucial in the management of primary hyperaldosteronism and to prevent redundant procedures. The objectives of this study were to evaluate the success rate of AVS in our centre and the associated factors that correlate with the success rate. A retrospective study in a single centre, all adult patients who were diagnosed with primary hyperaldosteronism and underwent AVS in our centre between 2014 until 2022 were included. Successful samples defined by a selectivity index (SI) of ≥ 2, that is, the ratio of adrenal vein cortisol level to the peripheral vein cortisol level, were evaluated. The baseline demographic characteristics of each patient, technical parameters of AVS, and anatomical parameters of right adrenal vein from the venographic images were evaluated and analysed to correlate with the outcome of AVS. A p-value of <0.05 was considered statistically significant. The overall success rate of AVS in our centre was 61.3%. The success rate significantly increased to 80.6% in the trained IR group, which represents a single IR who had completed specific training in adrenal venous sampling (AVS), compared to non-trained IR group which consisted of a total of 10 IRs without specific AVS training (p=0.046). The right AVS had lower success rate than the left AVS (64% vs 94.6%). The type of right adrenal vein pattern showed significant association with the outcome of AVS (p=0.014). There were 6 types of right adrenal vein patterns observed in our study; Type 1 - gland-like pattern with numerous branches, Type 2 - delta pattern, Type 3 - triangular pattern with central "blush", Type 4 - no discernible pattern and Type 5 - spidery or stellate pattern. The sixth pattern was the hepatic radicles blush with hepatic drainage, for which blood sampling were also collected due to its appearance was frequently indistinguishable from the Type 1 pattern. The results showed Type 2 pattern had the highest incidence (30.5%; 32/105 samples) and Type 5 had the highest success rate (100%; 11/11 samples), while the hepatic radicles blush pattern had the highest incidence in fail samples resulting in the highest failure rate (94.7%; 18/19 samples). The visualisation of the inferior emissary vein from the venographic images during right AVS had a significant association with the successful AVS (97.5% success rate; 39/40 samples; p=0.003). Contrariwise, blood sampling withdrawn from the right adrenal vein in the presence of hepatic drainage communication associated with the failure AVS (86.7% failure rate; 26/30 samples; p=0.001). The overall success rate of both AVS in our centre was 61.3%, and the success rate was higher in the trained IR group than the non-trained IR group. The visualisation of inferior emissary vein and the type of right adrenal vein patterns were the key determining factors with significant association to the successful right AVS. Conversely, blood sampling withdrawn from the hepatic radicles and hepatic drainage had significant association with the failure right AVS.

Modification Effect of Stone Column Dimensions and Configuration on Bearing Capacity Efficiency and Settlement in Soft Soils

In airport construction, one crucial aspect to consider is the condition of the underlying soil on the runway. Following soil investigations at X project, it was determined that the soil condition is primarily characterized by soft soil layers, with Standard Penetration Test (SPT) values ranging from 4 to 10. In response to this condition, soil reinforcement was carried out using the stone column method. The objective of this study was to compare the bearing capacity and settlement of stone columns under various dimensional variations (spacing of 1.5 m, 2.0 m, 2.2 m; diameters of 0.4 m, 0.5 m, 0.6 m) and configuration patterns (square and triangular). Bearing capacity calculations were done manually, and settlement calculations were performed both manually and with the assistance program. The results were presented in tables and graphs. Using the FHWA method for bearing capacity calculations, it was found that bearing capacity increases as the diameter is increased and the spacing is reduced. Conversely, bearing capacity decreases as the diameter is reduced and the spacing is increased. The ultimate bearing capacity value for the triangular pattern installation exceeded that of the square pattern. Regarding settlement calculations after manual stone column installation, it was observed that settlement decreases as the diameter increases and the spacing between columns decreases. Settlement increases under opposite conditions. Settlement calculations using the Plaxis program focused on diameter and spacing between stone columns. During the service life, the highest settlement occurred with the triangular pattern, while the square pattern exhibited the lowest settlement.

Patterns, evolution and determinants of child trafficking in Henan Province, China

ABSTRACT Child trafficking is a serious social problem in China that has led to numerous family tragedies and drawn considerable attention. Here, we used a new database to investigate child trafficking in Henan Province in central China from a geographical perspective to help researchers better understand and explain trafficking activity. We discovered that trafficking cases involved more male than female children and that the trafficking rate was the highest for younger age groups. Child trafficking presented an interannual variation of ‘rise and fall’ between 1949 and 2018. An increasing trend in trafficking cases was observed after 1981, peaking in 1991, followed by a rapid decline in trafficking cases in subsequent years. Trafficking occurs more frequently during the summer than in the winter. The geographic hotspots of trafficking have continuously expanded over time from central to southwestern to southeastern Henan Province, thus revealing a triangular trafficking pattern of decentralization. The spatial pattern of child trafficking is strongly influenced by transportation. We expect these findings to provide a valuable reference for local governments in their efforts to prevent and combat child trafficking.

Full‐scale tests of industrial steel storage pallet racks

Industrial steel storage pallet racks are framed structures typically made of cold‐formed steel profiles. The characteristics and the variability of the racking systems in terms of components and configurations make their behaviour quite complex to be predicted and the “design by testing” approach is commonly adopted. As part of an extensive research on the racks’ static and seismic behaviour carried out at the University of Trento, a total of eight full‐scale tests on four‐level two‐bay commercial pallet racks were performed, taking advantage of an innovative full‐scale testing set‐up. The experimental plan comprised of two preliminary tests in which racks with an initial out‐of‐plumb were vertically loaded up to their collapse and of six monotonic push‐over tests with three different levels of vertical loads and an inverse triangular pattern of horizontal forces in the down-aisle (longitudinal) direction. Tests’ results enabled investigation of the failure modes and evaluation of the racks’ behaviour factor q. The main features and findings of this experimental study are presented and discussed in the paper.

Improving mixing efficiency in laminar-flow static mixers with baffle inserts and vortex generators: A three-dimensional numerical investigation using corrugated tubes

Static mixers are vital for continuous processes, improving product quality, reducing costs, and enhancing efficiency. This study numerically investigates the mixing performance of various geometry configurations in static mixers. A corrugated tube with baffle inserts arranged in a triangular pattern is used. These studies are carried out using the CFD COMSOL Multiphysics 6.1 software with Reynolds numbers from 10 to 300, examining the impact of vortex generators on hydrodynamic behavior. The obtained outcomes reveal that the implementation of a corrugated tube induces a proficient recirculation flow within the divergence zone, thereby augmenting mixing efficiency by three times in comparison to a straight pipe as indicated by the mixing index. Introducing a baffle configuration composed of four triangular elements yields a heightened mixing index, albeit at the cost of an elevated pressure drop. An alteration of the angle of attack to 30° leads to a notable 22.6% enhancement in the mixing index while concurrently reducing pressure drop, in contrast to the condition where β equals 0°. These findings hold valuable implications for the optimization of static mixer designs, thereby elevating their utility within laminar flow applications. The resultant benefits encompass improved product quality, diminished operational costs, and heightened process efficiency.

Experimental study of effect of infill density on tensile and flexural strength of 3D printed parts

Additive manufacturing (AM) is an innovative procedure that can quickly create complex structures. By layering a material, a three-dimensional object is created using this technique. Every deposit of liquefied or partly liquefied material abides by the previous deposit. Fused deposition modelling’s (FDM) objective is to comprehend how varied interior structures influence the bending resistance of the printed samples and to investigate the impact of various infill patterns and percentages. The term “infill” describes the pattern of solid material used to fill a 3D-printed object's interior. It is utilized to give the printed part structural support and strength. Acrylonitrile butadiene styrene (ABS) material was chosen for this study as it offers a greater and superior finished plane along with dimensional stability. The infill pattern chosen for the flexural test study was the triangular pattern which includes different densities of infill percentages precisely, 25%, 50%, 75%, and 100%. A few specimens of ABS material having 100% infill density are put through a tensile test according to the ASTM D638. The ASTM D790 standard was used to make a model and test the flexural strength of the specimen. Line and triangle patterns provided the most ideal tensile and bending strength properties. This is likely because the deposited rasters are associated with the direction of loading. For line patterns with 100% infill, scanning electron microscopy (SEM) analysis showed a convincing connection between the microstructures and the rasters (porosity, voids, gap between beads and hole due to polymer pulled out). Furthermore, SEM analysis showed matrix failure and significant voids in a triangular pattern at infill densities of 25%, 50%, 75%, and 100%.

Experimental tensile strength analysis of ABS material through FDM technique

Additive manufacturing (AM) is a growing technique for generating intricate, challenging manufacturing things. Rapid prototyping for product development and design is typically done in industrial workplaces using fused deposition modelling, a layer-by-layer manufacturing technique. Using additive manufacturing technology, complex products may be easily produced. Patterns and percentages of infill have been researched. The majority study is established by findings from experiments using different single process parameters. Because infill patterns have an impact on manufacturing costs, material costs, and quality, they must be thoroughly studied. In this study, simulations of rectangular and triangular patterns with 25% were accomplished. During the analysis at 25% infill, it was found that the triangle pattern exhibits lower levels of stress compared to the rectangular pattern. For applications utilizing 25% infill, rectangular patterns demonstrate more favorable performance than triangular ones. This research work takes the overview of Finite Element Analysis (FEA) and Experimental Tensile Strength Analysis of Acrylonitrile Butadiene Styrene (ABS) Material through the Fused Deposition Modelling (FDM) Technique.

STUDY ON CHARACTERISTIC ANALYSIS OF ONYX-CARBON FIBER REINFORCED MATERIAL AT PT. MATAHARI MEGAH

Industry 4.0 focuses on automation with the help of technological and scientific developments in its application. Additive manufacturing is one of the pillars in Industry 4.0. 3D printing technology is part of additive manufacturing. One of the Indonesian companies that utilize 3D printing technology is PT Matahari Megah, the 3D-printing filament used to make a product in the company is Onyx-Carbon Fiber Reinforced. This material is used to make jaw grippers, soft jaws, threads, brackets, and jigs. However, the use of Onyx-Carbon Fiber Reinforced material is still not optimal, because there are no physical strength characteristics of the composite material. The method used in this research is to find a comparative study that starts by looking for literature studies that vary the parameters of the infill pattern and the percentage of density. In this study, the research data will be compared with the data from the literature study which will then be analyzed to find the most optimal parameters, based on the literature, the data obtained will be analyzed using the Taguchi method. From the data analysis, it is found that among the triangular, rectangular, and hexagonal infill patterns, the rectangular pattern is the most optimal. The optimal parameter configuration for the first data is by using rectangular infill pattern with 75% density percentage and for the second data by using rectangular infill pattern with 80% density percentage.