Simple Method Research Articles

Simplified Modeling Method for Prefabricated Shear Walls Considering Sleeve Grouting Defects

The sleeve grouting connection is the most common form of vertical connection for prefabricated shear walls. However, during construction, this type of connection is prone to defects such as insufficient anchorage length of reinforcement, deviation of reinforcement, and insufficient amount of sleeve grouting, which significantly impact the integrity and seismic performance of the prefabricated shear wall structure. The finite element analysis of the prefabricated shear wall with sleeve grouting connection is still based on solid element modeling. This method has the disadvantages of complex models and low computational efficiency. In this paper, a simplified modeling method for prefabricated shear walls considering sleeve grouting defects was proposed to address this issue. Firstly, the equivalent constitutive relationship of the sleeve grouting defect connector was constructed based on the uniaxial tensile test of the existing sleeve grouting defect connector, and the T3D2 element was used to simulate the sleeve grouting connector. Then, the mechanical behavior of the horizontal joint between the shear wall and the foundation beam was simulated by the cohesive force model, and the prefabricated shear wall models with sleeve grouting defects were established. The accuracy of the simplified modeling method was verified by comparing the experimental results and numerical simulation results of the seismic performance of the prefabricated shear wall with sleeve grouting defects. The results showed that the hysteresis curve, skeleton curve, and failure mode of the numerical simulation were in good agreement with the test results. However, the stiffness of the concrete degenerated rapidly due to the apparent development of plastic-damaged concrete, which made the falling section of the hysteresis curve of the numerical simulation different from that of the test. The proposed simplified modeling method can be further applied to the performance study of prefabricated shear walls with sleeve grouting defects and can provide a reference for structural performance evaluation, design optimization, and construction quality control to a certain extent.

The Simplified Method of Head Stiffness Considering Semi-Rigid Behaviors of Deep Foundations in OWT Systems

The Simplified Method of Head Stiffness Considering Semi-Rigid Behaviors of Deep Foundations in OWT Systems

Fatigue life prediction of corroded hangers with parallel steel wire in a network arch bridge under vehicle-bridge interaction based on a novel noniterative simplified method

Fatigue damage is a main concern during the life-cycle maintenance of bridges with corroded hangers under vehicle-bridge interaction (VBI). In this study, a novel noniterative simplified method for VBI is proposed to analyze the responses of hangers in a network arch bridge, considering the effects of vehicle types, driving lanes, and road surface roughness. Furthermore, the fatigue life of corroded hangers is investigated, considering the actual traffic flow and uneven distribution of stress in the hanger’s cross-section. The results show that longitudinal and transverse bending moments of the hanger significantly affect the stress of steel wires in one hanger but have limited influence on stress amplitudes. The fatigue lives of steel wires are considerably reduced when subjected to both uniform and pitting corrosion. The fatigue life of steel wires is reduced under deteriorating road surface conditions. Moreover, as the fatigue life of steel wires in the hangers declines, the variations in fatigue life among individual steel wires within a single hanger gradually decrease. Consequently, this trend leads to a heightened likelihood of continuous wire breakage.

Axial partial compressive behavior of round-ended concrete-filled steel tubular columns

The paper conducted 19 partially and 5 fully loaded tests on round-ended concrete-filled steel tubular (CFST) columns. These tests revealed that the ultimate strengths of round-ended CFST columns under partial load declined as the cross-sectional aspect ratio or partial compression area ratio increased. However, the use of a top plate effectively enhanced their ultimate strengths. In addition, a finite element model (FEM) was utilized to generate 487 large-size models to explore the confinement effect, stress distribution, and parametric effects. Since there are no specific design standards available for round-ended CFST columns, the paper has evaluated the applicability of design methods provided in Eurocode 4, AISC 360–16, and Chinese code GB50396 which are intended for circular, square, or elliptical CFST columns for round-ended CFST columns under partial load. However, these existing design techniques showed inaccurate and dispersed resistance predictions for round-ended CFST columns. Therefore, an effective simplified method for forecasting the resistance predictions of round-ended CFST columns under the partial load has been proposed based on the testing results and FEM analysis.

Evaluation of a Simplified Direct SSI Method in the Dynamic Seismic Behavior of Traditional RC Minarets

Evaluation of a Simplified Direct SSI Method in the Dynamic Seismic Behavior of Traditional RC Minarets

A facile method to obtain colloidal dispersions of nickel hydroxide: Improving the processing of nickel oxide and facilitating its upscaling for perovskite-type solar devices

Nickel hydroxide has been successfully employed as a precursor to the widely used, inorganic hole transport material (HTM) nickel oxide (NiOx). However, manufacturing NiOx HTM layers from nickel hydroxide is more complicated than those involving organometallic precursors due to its poor solubility/dispersibility. We report here a substantial increase in nickel hydroxide dispersibility in organic solvents by complexing it with monoethanolamine. These improvements have enabled us to develop a simpler method for processing nickel hydroxide that resemble the known sol-gel method. The new metal complex remains dispersed for months and converts to nickel oxide at a temperature similar to that of nickel hydroxide (270–300 ºC). An extensive characterisation of NiOx films obtained from the deposited precursor has been carried out. Perovskites solar cells have also been built with these films as a proof of concept, showing promising results for the layers sintered at low (270 ºC) and high (500 ºC) temperatures. The pixel with highest efficiency for both sintering temperatures were 14.7 % and 16.7 %, respectively, which are close to or surpass the ones of the control samples (15.4 % and 15.7 %, respectively). The applied unpaired t-test statistical method showed that the mean efficiency values for our thick samples prepared at 270 °C are not statistically different from those of the control cells. Furthermore, the samples prepared at 500 °C presented a significant statistical difference with the control cells, showing higher average efficiencies (12.8 % and 13.3 % versus 11.4 % and 11.7 %, reverse and forward measurements, respectively). The simplicity of the manufacturing method developed, together with the use of non-toxic organic compounds for its preparation and the promising results observed in solar devices, makes it suitable for being upscaled.

Photomediated synthesis of stabilizer-free silver nanoprisms with a tunable plasmon wavelength for enhanced catalytic activity

Herein, we introduce a simplified photomediated method for fabricating silver nanoprisms (AgNPrs) with controllable surface plasmon resonance. The Ag nanoparticles (Ag seeds), Ag+, and citrate ions were used to control AgNPrs growth. Citrate ions served as a reducing agent and a stabilizer. The optimized [citrate]/[Ag+] ratio of 10 was sufficient to stabilize the final AgNPrs. Sodium borohydride (NaBH4) was used as a strong reducing agent to generate the initial Ag seed amount, then controlled by the [BH4−]/[Ag+] ratio. A ratio of 0.0005–0.005 ([BH4−]/[Ag+]) yielded a 545–702 nm plasmon band of AgNPrs. AgNPrs displayed an irregular plate shape in their morphological structure, featuring lateral dimensions spanning from 30.7 ± 4.3 to 51.0 ± 10.8 nm and a thickness ranging from 7.2 ± 0.8 to 10.7 ± 1.3 nm. The synthesized AgNPrs exhibited excellent stability in the dark at 4 °C without any additional polymeric stabilizer and presented negligible variations in their absorbance UV–visible spectra for at least 1 month. They demonstrated an enormous (111) facet potentially serving as an active catalytic site for reducing 4-nitrophenol to 4-aminophenol. With synthesized AgNPrs, the rate constant of the reduction reaction increased to 0.2440 min−1, which was 120 times greater than that without the catalyst or with spherical Ag nanoparticles. These AgNPrs can be reutilized for at least five catalytic cycles without losing their catalytic efficiency.

A simplified method for relapsing-remitting multiple sclerosis detection: Insights from resting EEG signals

Background and Objective:Multiple sclerosis (MS) is a neurodegenerative autoimmune disease affecting the central nervous system, leading to various neurological symptoms. Early detection is paramount to prevent enduring damage during MS episodes. Although magnetic resonance imaging (MRI) is a common diagnostic tool, this study aims to explore the feasibility of using electroencephalography (EEG) signals for MS detection, considering their accessibility and ease of application compared to MRI. Methods:The study involved the analysis of EEG signals during rest from 17 MS patients and 27 healthy volunteers to investigate MS-healthy patterns. Power spectral density features (PSD) were extracted from the 32-channel EEG signals. The study employed Linear Discriminant Analysis (LDA), Support Vector Machine (SVM), Classification and Regression Trees (CART), and k-Nearest Neighbor (kNN) classifiers to identify channels with the highest accuracy. Notably, the study achieved 100% accuracy in MS detection using the “Fp1” and “Pz” channels with the LDA classifier. A statistical analysis, utilizing the independent sample t-test, was conducted to explore whether PSD features of these channels differed significantly between healthy individuals and those with MS. Results:The results of the study demonstrate that effective detection of MS can be achieved using PSD features from only two channels of the EEG signal. Specifically, the “Fp1” and “Pz” channels exhibited 100% accuracy in MS detection with the LDA classifier. The statistical analysis further explored and confirmed the significant differences in PSD features between healthy individuals and MS patients. Conclusion:The study concludes that the proposed method, utilizing PSD features from specific EEG channels, offers a straightforward and efficient diagnostic approach for the effective detection of MS. The findings suggest the potential utility of EEG signals as a non-invasive and accessible alternative for MS detection, highlighting the importance of further research in this direction.

Effects of enhanced confinement on cyclic behavior of concrete bridge columns with partially unbonded seven-wire steel strands

The effects of enhanced confinement on the proposed bridge columns under lateral cyclic loading were investigated in this research by testing large-scale column specimens. The proposed column used nonprestressed partially unbonded seven-wire strands as elastic elements to increase the post-yield stiffness of the column to reduce the residual displacement under seismic loads. The enhanced confinement included rectilinear transverse reinforcement with an increased amount (specimen CSCR) and reduced spacing or innovative five-spiral reinforcement (specimen CSCS). Test results showed that all the specimens exhibited a positive post-yield stiffness ratio of 3.5–6.4 %. However, the enhanced confinement reduced the post-yield stiffness by 42–45 % but increased the lateral strength of the column, which is beneficial for controlling the residual displacement. The enhanced confinement did not affect the drift ratio when the positive post-yield stiffness ended (6 %) but significantly increased the deformation capacity by 15–31 % and the energy dissipation capacity by 37–63 % of the column. Even with a smaller amount of transverse reinforcement, the specimen with the innovative five-spiral reinforcement showed deformation and energy dissipation capacities better than the other specimens with conventional rectilinear transverse reinforcement. A pushover analysis model was developed and modified to better account for the effect of the enhanced confinement and the strand slip, and to consider the end point of positive post-yield stiffness. The comparison with the test result showed that the proposed pushover model well captured the envelope responses of the specimens. Finally, a simplified method was proposed for estimating the moment strength of the proposed column.

The thrust line in masonry arches: a new simplified algorithm

Masonry arches and vaults have been widely used in the past to construct horizontal structural elements using materials with low tensile strength. Initially, the design methods used were mostly based on empirical rules derived from the experience of builders. In more recent centuries, however, analytical theories and graphical methods have been developed to formalize the static behaviour of the masonry arch. Although computational methods for evaluating masonry arch structures have been widely developed in recent decades, graphical and analytical methods are still simple and clear tools for understanding the structural behaviour of these structures. Therefore, a simplified method for identifying the thrust line in masonry arches is presented in this paper. The proposed algorithm is then applied to several case studies, and the results obtained are compared with those derived from finite element models.

A New Method to Minimize the Standard Deviation and Root Mean Square of the Prediction Error of Single-Optimized IOL Power Formulas.

The purpose of this study was to develop a simplified method to approximate constants minimizing the standard deviation (SD) and the root mean square (RMS) of the prediction error in single-optimized intraocular lens (IOL) power calculation formulas. The study introduces analytical formulas to determine the optimal constant value for minimizing SD and RMS in single-optimized IOL power calculation formulas. These formulas were tested against various datasets containing biometric measurements from cataractous populations and included 10,330 eyes and 4 different IOL models. The study evaluated the effectiveness of the proposed method by comparing the outcomes with those obtained using traditional reference methods. In optimizing IOL constants, minor differences between reference and estimated A-constants were found, with the maximum deviation at -0.086 (SD, SRK/T, and Vivinex) and -0.003 (RMS, PEARL DGS, and Vivinex). The largest discrepancy for third-generation formulas was -0.027mm (SD, Haigis, and Vivinex) and 0.002mm (RMS, Hoffer Q, and PCB00/SN60WF). Maximum RMS differences were -0.021 and +0.021, both involving Hoffer Q. Post-minimization, the largest mean prediction error was 0.726 diopters (D; SD) and 0.043 D (RMS), with the highest SD and RMS after adjustments at 0.529 D and 0.875 D, respectively, indicating effective minimization strategies. The study simplifies the process of minimizing SD and RMS in single-optimized IOL power predictions, offering a valuable tool for clinicians. However, it also underscores the complexity of achieving balanced optimization and suggests the need for further research in this area. The study presents a novel, clinically practical approach for optimizing IOL power calculations.

Versatile simplistic correction of T-higrow sensors for improved soil moisture measurement accuracy

The use of soil moisture sensors for irrigation can help reduce water and energy consumption and risks of groundwater contamination, which are essential aspects for pursuing sustainable development goals. However, increased adoption of this technology is limited by calibration requirements, technical complexities, and sensor costs. In this work, a simplified method for reducing the measurement error of a recently released low-cost soil sensor (T-Higrow) is presented. The method only requires measurements of a dry sample from the target soil, which are inputted into a simple correction formula to reduce the measurement error at higher moisture levels. The requirements of the proposed method are simple enough for most labs or extension services. This method was compared to the commonly used linear, polynomial, and logarithmic regression models based on repeated bench-scale experiments within 0%–35% moisture range in silt and sandy loam soils and in silica sand. Uncorrected sensor readings correlated well with soil moisture (r: 0.94–0.98), but with significant overestimation (25%–60% error). The simplified correction method showed comparable error reduction to regression models across all soil types. All methods reduced error down to 2%–10% (0.02–0.1 cm3 cm−3) and maintained high correlations (r > 0.94), except for logarithmic regression which reduced correlation by around 3%. Variability amongst sensor measurements was generally low (Standard Deviation: 0.01–0.03) particularly at moisture ranges below 20%, this was also the case for sensor-to-sensor variability (Standard Deviation: 0.01–0.03). Sensor evaluation and calibration works are needed to increase the accessibility to this technology for improved water and energy conservation.

Experimental study on the flexural performance of FRP grid-reinforced ultra-high-performance concrete I-beams with different steel fiber contents

To adapt to harsh engineering environments, the use of structural components with fiber-reinforced polymer (FRP) grid-reinforced ultra-high-performance concrete (UHPC) is considered a new development trend. Twelve FRP grid-reinforced UHPC I-beams are fabricated to investigate the effects of the thicknesses of FRP grids (0 mm, 1 mm, 3 mm, and 5 mm) and the steel fiber contents of UHPC (0%, 1%, and 2%) on their flexural performance. Four-point bending tests are conducted to obtain the failure modes, load-deflection characteristics, and strain responses of each testing beam, and a simplified calculation method for cracking loading and flexural bearing capacity is proposed. The results reveal that the increase in FRP grid thickness, the ultimate load bearing capacity of FRP grid-reinforced UHPC structural beams increases and the ductility also can be enhanced. The presence of steel fiber effectively inhibits the cracking and increases the first cracking load of the beam during the test process, although its influence on the ultimate bearing capacity is limited. Besides, until to the cracking stage, there is no noticeable change in the tensile strain of the FRP grids as the applied load increases. It has been used to simplify theoretical calculations, which shows good agreement with the experimental results.

Polyetherimide nanocomposite with enhanced mechanical, thermal and dielectric properties by incorporating synergistically exfoliated‐chemical functionalization induced hexagonal boron nitride nanosheets

AbstractThe present study aims to improve the mechanical, thermal and dielectric properties of polyetherimide (PEI) nanocomposite via simplified method, involving the creation of a nanocomposite using PEI incorporated with exfoliated‐chemical functionalization induced hexagonal boron nitride nanosheets (BNNS). XRD, FTIR and Raman elucidated the chemical structure of functionalized BNNS and indicated the success preparation of functionalized BNNS. Functionalization effectively improved the compatibility of nanocomposites and contributed to the property improvements. Morphological analysis unveiled a compact and dense microstructure within the nanocomposites in correlation with functionalized BNNS. Broad band dielectric spectroscopy revealed excellent dielectric properties of produced PEI nanocomposite. DMA testing verified a noteworthy enhancement in both Tg and storage modulus upon incorporating of BNNS. In summary, this comprehensive investigation highlights the impact of functionalized BNNS on mechanical, thermal and dielectric properties of developed PEI dielectric nanocomposite and is expected to expand the application of PEI in the field of high‐temperature energy storage.Highlights Polyetherimide (PEI) was used as polymer matrix and boron nitride derivatives as dielectric fillers to prepare PEI dielectric nanocomposite. Due to the influences of dielectric properties by interface polarization effect and the local distribution of electric field of the fillers in PEI matrix, the dielectric constant, breakdown strength and energy storage density of PEI nanocomposites were obviously improved compared with pure PEI. The effects of interfacial interactions between PBNNS and PEI contributes to the uniform dispersion and comprehensive property improvements of PEI dielectric nanocomposites. This work presents a systematic investigation into the fabrication of PEI/BNNS nanocomposite using a one‐step solution blending method, inspiring the research and development of PEI in the energy storage applications areas in the future.

Microwave characterization of nanomaterials using planar slot resonator

Nanomaterial characterization using microwaves is needed in nanoscale semiconductor devices, microwave imaging, EM shielding, and wireless communication. Many nanomaterials are used as metallic or dielectric layers in these applications. In this paper, we report the characterization of nanomaterials using planar Microwave Slot Resonator (MSR) which was designed and studied using 3D EM simulation tool. The response of MSR is parameterized which offers a platform to calculate relative permittivity (ε r) and conductivity (σ) from measured high frequency response of nanomaterial loaded MSR. With simplified method, this microwave characterization offers accurate and faster results which be used in design, calculation and numerical analysis of nanomaterial based electronic/optoelectronic devices and sensor/shielding applications.

The structural and optical properties of PVA/CMC copolymer cured by UV irradiation for different times

Poly(vinyl alcohol) (PVA)/carboxymethylcellulose (CMC) blend films with equal amounts (0.25 g) of both polymers were prepared through a simple and low-cost comparative casting method. Then, the PVA/CMC blend films were exposed to ultraviolet (UV) radiation for varied time intervals (1, 12, 26, 32, 40 and 48 h). The UV-irradiation effect on the physical properties of as-prepared films, including the structure, morphology, composite and optical properties (transmittance, absorbance and band gap (E g)), was examined. Field-emission scanning electron microscopy images showed that UV irradiation had a strong effect on the shape of PVA/CMC blend films. The X-ray diffraction patterns showed various crystalline qualities in the microstructure of as-synthesized samples. The Fourier transform infrared spectra showed that the UV-irradiation time and CMC film had a positive impact on the blend polymer structure since covalent connections were formed between CMC and PVA. Furthermore, the analysis results of optical inspections showed that the absorbance of the PVA/CMC films improved with an increment in irradiation time from 1 to 40 h. Important tuning of the E g values of blend films was realized. It showed a slight increase from 4.64 to 4.84 eV with increasing irradiation time from 1 to 40 h. The E g value (3.21 eV), however, displayed an inverted behavior due to an increased irradiation time of 48 h. This reduction could be ascribed to the creation of defects inside the blend band gap. Finally, the physical property modification of PVA/CMC blend film using UV irradiation made it an amazing contender in the optoelectronic field.

Multiple stochastic and inverse stochastic resonances with transition phenomena in complex corporate financial systems.

This study examines the role of periodic information, the mechanism of influence, stochastic resonance, and its controllable analysis in complex corporate financial systems. A stochastic predator-prey complex corporate financial system model driven by periodic information is proposed. Additionally, we introduce signal power amplification to quantify the stochastic resonance phenomenon and develop a method for analyzing stochastic resonance in financial predator-prey dynamics within complex corporate financial systems. We optimize a simplified integral calculation method to enhance the proposed model's performance, which demonstrates superiority over benchmark models based on empirical evidence. Based on stochastic simulations and numerical calculations, we can observe multiple stochastic and multiple inverse stochastic resonances. Furthermore, variations in initial financial information, periodic information frequency, and corporate growth capacity induced stochastic resonance and inverse stochastic resonance. These variations also led to state transitions between the two resonance behaviors, indicating transition phenomena. These findings suggest the potential for regulating and controlling stochastic and inverse stochastic resonance in complex corporate finance, enabling controllable stochastic resonance behaviors.

Branching ratio in the photodissociation of (C6H5NH2)+-H2O–H218O

Molecular systems including clusters often manifest multiple photodissociation pathways upon absorption of photon energy enough to break down chemical bonds. This certainly raises fundamental questions to chemists: which pathway will be most favored and how can we predict it with precision? To address these issues, we had previously introduced a rather crude but highly simplified and straightforward calculation method, Rice-Ramsperger-Kassel-Marcus (RRKM) calculation method complemented by the concept of extreme loose transition state (eLTS). This approach has proven effective in estimating branching ratios in photodissociation of C6H4BrCl+. Here, we have extended this method to interpret results in IR photodissociation of (C6H5NH2)+-H2O–H218O for further evaluation and refinement of this method. We compared branching ratios derived from RRKM-eLTS with those obtained via phase-space theory (PST) to find that our calculation results through RRKM-eLTS were quite in line with the experimental data while those from PST calculation fluctuated significantly depending on the calculation levels and basis sets. This indicates that RRKM-eLTS model not only aligns well with experimental observations giving insights into the relevant rate constants but also intuitively explains these results. We, hereby, suggest that RRKM-eLTS model is a robust and user-friendly method for computing branching ratios, with possible applications to other molecular systems.

17‐1: Cylindrical Fiber‐based Oxide TFTs with a 2T1C Pixel Circuit for Wearable Textile Displays

This study introduces a simplified fabrication method for implementing a TFT array on a cylindrical fiber, using only four masks and a low‐temperature process below 120 ℃. To overcome the limitations of the one‐dimensional cylindrical fiber structure, the study emphasizes the design and implementation of a three‐dimensional backplane, utilizing the side or bottom surfaces of the fiber to address patterning and shadowing challenges. The proposed TFTs, part of the 2T1C pixel circuit within the fiber, exhibit electrical properties suitable for driving OLEDs.

Analysis of 2D and 3D Slope Stability Using the Bishop Simplified Method

Analysis of 2D and 3D Slope Stability Using the Bishop Simplified Method