Simple Method For Construction Research Articles

Impedimetric identification of heteroMOFs modified porous nickel foam self-supports as robust electrodes for CA 19-9 pancreatic tumor marker in human serum

An impedance-based electrochemical immunosensor for direct and binder-free target recognition of carbohydrate antigen (CA 19-9) tumor biomarker for the early diagnosis of pancreatic cancer was reported. This study uses an in situ solvothermal process to develop a simple method for the one-pot construction of Ni-Fe heteroMOFs (HFNMOFs,) self-supported on conductive nickel foam (NicFm). Utilizing HFNMOFs@NicFm developed in this study, the electrochemical performance of the biosensor was studied for the first time. The as-prepared mixed MOFs decorated NicFm electrodes displayed potential electrochemical outputs. They demonstrated the potential for developing binder-free non-enzymatic immunosensors with wide linear limits, high selectivity, stability, and excellent sensitivity. The bifunctional MOFs exhibit improved electrochemical conductivity owing to the highly exposed metal sites and hierarchical porosity. The changes in the charge transfer resistance present a linear response against increasing target concentrations. The immunosensor developed in this study exhibited its detection limit of 2.56 U/mL. Further, the bioelectrodes produced were validated against real human spiked serum with good results of percentage recovery, indicating the immunosensor is well-suitable to be tested in real-time analysis.

Design procedure and seismic performance assessment of structures equipped with bar-fuse dampers

The application of metallic yielding dampers (MYDs) to enhance the seismic performance of a structure has been a focus of attention in recent years. One recently introduced MYD is the bar-fuse damper (BFD). Its advantages include ease of installation, simple construction method, cost effectiveness (including replacement and repair costs) and shorter required repair time after strong seismic events. However, the most important benefits of the BFD are its high energy dissipation capacity, which can improve collapse safety and enhance the seismic performance of a structure. Despites its benefits, BFDs have been less studied than other types of MYDs. The present research provides a simple and efficient method for designing structures equipped with BFDs. Moreover, the mechanical characteristics of differently shaped BFDs made with different types of steel has been investigated using finite element analysis. Finally, the seismic performance of three model structures was evaluated using nonlinear time-history analysis. The results indicate that structures equipped with BFDs experience less inter-story drift and are less likely to undergo severe damage compared to similar bare moment-frame buildings.

Aptamer‐Based Antibiotic Electrochemical Detection Platform Using Portable Plastic Gold Electrode and Multichannel Chip

Comprehensive SummaryThe development of accurate, rapid and practical electrochemical sensing technology for antibiotic detection has an important application prospect in many fields such as food safety, environmental monitoring, medical and health care. In this research, kanamycin specific DNA aptamer and its partially complementary short chain were self‐assembled onto the surface of an integrated portable plastic gold electrode (PGE) by Au—S bond, and a simple kanamycin electrochemical biosensor interface was constructed. At the same time, the epoxy resin channel layer was designed, and the auxiliary instrument was set up independently in the laboratory, which could help to measure and analyze eight groups of samples automatically in turn. The quantitative analysis results showed that in 20 min, the sensor had a good linear relationship between the peak current change of square wave voltammetry and the negative logarithm of kanamycin concentration when kanamycin concentration was in the range of 1—1000 μmol/L, and the detection limit could reach 0.40 μmol/L. In addition, the discrimination could be achieved within 5 min in the real‐time analysis mode. The sensor had a simple construction method, good selectivity and stability, and could be used for rapid or real‐time detection of kanamycin residues in actual water samples, which provided a new direction for the practical detection of kanamycin in environmental water samples.

A Simple Construction Method of Multi-stable Switched Multi-scroll/Multi-wing Chaotic System and Circuit Design

A Simple Construction Method of Multi-stable Switched Multi-scroll/Multi-wing Chaotic System and Circuit Design

Wearable electrochemical sensor based on bimetallic MOF coated CNT/PDMS film electrode via a dual-stamping method for real-time sweat glucose analysis

Non-invasive wearable sweat glucose sensors are expected to be highly desirable for personalized diabetes management. Therefore, developing facile, convenient, and scalable manufacturing method of such wearable sensors is urgently needed. Herein, we report a simple and low-cost stamping-vacuum filtration dry transfer (SVFDT) method for construction of a wearable sweat glucose electrochemical sensor. In this patch, a three-electrode array template was made by using a polyvinyl chloride (PVC) stamp, followed by the preparation of multiwalled carbon nanotubes (MWCNTs)/polydimethylsiloxane (PDMS) (MP) film electrode using the vacuum-filtration dry transfer method. In addition, for further enhancing the conductivity of the electrode, another similar stamp with a raised surface dipping carbon nanotubes (CNTs) conductive coating was stamped on the surface of the MP electrode to obtain CNTs/MWCNTs/PDMS (CMP) electrode. CMP electrode was modified with the enzyme-like Ni-Co metal-organic framework (MOF) material which showed good electro-catalytic activity and achieved high sensitivity for glucose detection with a low detection limit of 6.78 μM and a wide linear range of 20 μM - 1.1 mM. More importantly, the Ni-Co MOF modified CMP (NCMP) electrode also displayed high stability under stretching and bending conditions. Finally, the sweat absorbent cloth was combined with the NCMP film electrode to form a wearable flexible electrochemical sensor patch, which could adhere to the skin to enrich sweat and realize real-time detection of sweat glucose with high accuracy. This SVFDT method can also be applied to the fabrication of other electronic devices.

Investigation of In Situ Thermal Properties and Early-Age Pavement Behavior in the Design and Performance Evaluation of Roller Compacted Concrete Pavement in Louisiana, U.S

The proven durability and high load-carrying capacity of roller compacted concrete pavement (RCCP), combined with its simple and cost-effective construction method and high placement speed, has created a great deal of interest from many states and local transportation agencies in the U.S. Roller compacted concrete (RCC) mixture uses less cement content and less water compared with conventional concrete mixtures, which reduces the total shrinkage strain and RCC set temperature during the hardening stage, resulting in a reduction of early-age deformation and stress developments in the RCCP. Currently, research on the early-age behavior and other thermal properties of RCCP has not been well documented. Therefore, investigations of early-age behavior and thermal properties such as coefficient of thermal expansion, ultimate shrinkage, and built-in curling are needed to understand the true behaviors of RCCP under real climatic conditions. On the other hand, the currently available RCC thickness design procedures, for example, Street-Pave and Pavement Designer, are in general short of flexibility in consideration of the combined effect of wheel and environmental loading on RCCP performance. The primary objective of this work is to investigate the early-age behavior of RCCP and to evaluate the effect of thermal properties on the design and performance of RCCP constructed in Louisiana.

NPS COMPOSITE BEAMS AND COLUMNS USED FOR THE ODENSE UNIVERSITY HOSPITAL

AbstractThis document presents the case study of the Odense University Hospital, built with the NPS steel‐concrete composite frame. This is one of the most challenging projects currently in Europe: 250,000 square meters to be built in just over three years. The client has taken up the challenge of respecting timeframe and budget by focusing on offsite construction and digitalization of processes. Time constrains, safety and sustainability are the three main drivers of the project. Among these, the strict delivery time represents the main critical aspect. The expected turnkey delivery in 2022 assumed the choice of an extremely simple and fast construction method. Further advantages of using steel‐concrete composite structures with reference to the Odense University Hospital Case are explained.

Observer Design for n + m Linear Hyperbolic ODE-PDE-ODE Systems

In this letter, an observer design is presented for a system of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$n + m$ </tex-math></inline-formula> hetero-directional transport partial differential equations (PDEs) coupled on both boundaries of the domain to ordinary differential equations (ODEs). This class of systems can represent, for instance, actuator and load dynamics at the boundaries of a hyperbolic system. The results in this letter provide a constructive way to reconstruct the state of the ODEs and the PDEs using only available measurements on one of the two ODEs. This observer design completes existing full-state feedback designs for this class of systems and enables, together with previous results, the construction of output-feedback stabilizers. As a complementary result, this letter includes a simple (constructive) method to obtain a stable left-inverse of a specific transfer matrix required in the observer design, which can also be applied (after a transposition) to the computation of the analogous stable right-inverses required for the control design.

"Blockchain-Like" MIL-101(Cr)/Carbon Black Electrodes for Unprecedented Defluorination by Capacitive Deionization.

Metal-organic frameworks (MOF) have attracted extensive attention due to their ultra-high specific surface area and tunable structure, the mechanism of direct utilization for capacitive deionization (CDI) defluorination remains undefined. Here, MIL-101(Cr) with ultra-high specific surface area, high water stability, and open metal sites (OMSs) is prepared by a hydrothermal method for defluorination of CDI. Carbon black is used as a "chain" to connect F-stored in the holes of MIL-101(Cr) (Cr-MOF)as "blocks" to enhance the conductivity and ion storage capacity of MIL-101(Cr)/carbon black electrodes (Cr-MOF electrodes). This simple construction method avoids the process complexity of in situ synthesis and performs better. These easily constructed "blockchain-like" Cr-MOF electrodes exhibit excellent defluorination capacity (39.84 mgNaF gelectrodes -1 ), low energy consumption (1.2kWh kgNaF -1 ), and good stability. The coupling of the electrochemical redox reaction of Cr3+ /Cr4+ with confined water is investigated using in situ and ex situ analysis methods combined with density functional theory (DFT), resulting in an unprecedented defluorination mechanism for Cr-MOF electrodes. This study opens up new ideas for the application of MOF in CDI, clarifies the removal mechanism of MOF, and lays a foundation for further promoting the application of raw materials with poor conductivity in the field of CDI.

Ce3+-induced Fluorescence Amplification of Copper Nanoclusters Based on Aggregation-induced Emission for Specific Sensing 2,6-pyridine Dicarboxylic Acid.

A straightforward, cost-effective and biocompatible reduction approach was applied to fabricate soluble but non-luminous glutathione-stabilized copper nanocluster (GSH-CuNCs). Surprisingly, as high as 1 × 103 times fluorescence enhancement was acquired when Ce3+ was injected at an extremely low concentration of only 18µM. Ce3+ outperformed other rare-earth metal ions in terms of inducing fluorescence amplification of the non-luminous GSH-CuNCs. Furthermore, Ce3+ was employed as inducer for aggregation-induce emission (AIE) effect as well as reactant to coordinate with target of 2,6-pyridine dicarboxylic acid (DPA) due to the stronger coordination ability between Ce3+ and DPA than that of Ce3+ and GSH. As a result, the Ce3+/GSH-CuNCs ensemble was developed as a novel sensor to detect DPA in the "on-off" mode. When DPA was introduced into the sensor, Ce3+ failed to interact with GSH and detached from the surface of GSH-CuNCs, leading to fluorescence quenching. In addition, static quenching process and internal filtration effect (IFE) between Ce3+/GSH-CuNCs and DPA were also responsible for fluorescence quenching effect. A good linear relationship was obtained from 0.3µM to 18µM, with a limit of detection (LOD) of 0.19µM. The as-proposed probe displayed high specificity to DPA and provided a simple, fast rapid and cheap method for construction this type of ensemble sensors to detect other targets.

Impact of compact and novel 1-Bit coding based metamaterial design for microwave absorption applications

This work investigates compact 1-bit coding metamaterial for microwave absorption applications. The coding metamaterial act as a technologically advanced development that has been investigated widely in many application fields. The 1-bit coding metamaterial is composed of couples of unit cells, with 0 and π phase responses, which are known as ‘0′ and ‘1′ coding particles, respectively. By coding ‘0′ and ‘1′ elements with controlled sequences, the electromagnetic (EM) waves can be manipulated and realize different functionalities. Therefore, it has a high possibility to be applied for the microwave absorption application to optimize the outcomes by adopting a simple coding sequence construction method. All the simulation analyses were performed by utilizing well-known Computer Simulation Technology (CST) software. Firstly, the unit cells of coding metamaterial design were analyzed by the phase response properties to identify the materials with 0 and 180° responses. Meanwhile, the phase response properties of the proposed design were validated by simulating in High-Frequency Simulation Software (HFSS). Once, the ‘0′ and ‘1′ elements are selected, the proposed elements were used to perform parametric studies such as, various coding sequences with a diverse number of lattices on absorption applications and as well the radar cross-section (RCS) properties. The monostatic and bistatic scattering patterns RCS of the proposed coding metamaterial based on the number of lattices were examined as well. Initially, the 4 lattices successfully manifest three absorption peak points with the highest values of 90.1 %. However, this result was optimized by slightly increasing the number of lattices. Thus, the 8 lattices coding metamaterial design exhibit the highest absorption value, for instance, 99.4 %. Meanwhile, the 12 lattices design successfully manifests 9 absorption peak points in the range between 15 and 22.35 GHz. Moreover, for the validation purpose, the absorption values of Coding Sequences 3 of 8 lattices coding metamaterial were performed by adopting HFSS software. In a nutshell, the miniaturization concept is possible and relatively produces optimized absorption values by utilizing smaller unit cell designs in the coding metamaterial concept.

A general Monte Carlo method for multivariate goodness–of–fit testing applied to elliptical families

A general and relatively simple method for construction of multivariate goodness–of–fit tests is introduced. The proposed test is applied to elliptical distributions. The method is based on a characterization of probability distributions via their characteristic function. The consistency and other limit properties of the new test statistics are studied. Also in a simulation study the proposed tests are compared with earlier as well as more recent competitors.

Fractional-order multiwing switchable chaotic system with a wide range of parameters

This paper presents a novel fractional-order multiwing switchable Liu chaotic system by introducing a state equation. Multiwing switching can be realized by switching the new equation coefficient symbols with symbolic functions. The new fractional-order multiwing switchable Liu chaotic system has various switching branches, a simple construction method, and an outstanding performance effect. On this basis, by modifying the nonlinear term of the equation, a new fractional-order chaotic system with variable powers of the nonlinear term and a wide range of value parameters is constructed. The dynamic characteristics of the new system are studied through theoretical numerical simulation, such as phase diagrams, equilibrium points, the multiwing generation mechanism, Lyapunov exponent spectra and Poincare cross-section. The Poincare cross-section diagrams are used to compare and analyze the power change of the nonlinear term and the wide range of parameter values in the new system. Furthermore, the method of constructing the fractional-order multiwing switchable system is applied to the fractional-order Lorenz, Chen, and Lü systems. Finally, a Multisim chaotic circuit of the fractional-order multiwing Liu system is designed. The simulation results demonstrate that the construction method of the fractional-order multiwing switchable chaotic system is feasible and offers good generality.

Poly(N-methyl pyrrole) decorated rGO nanocomposite: A novel ultrasensitive and selective carbon monoxide sensor

An ultrasensitive and selective carbon monoxide (CO) sensor based on poly(N-methyl pyrrole)/reduced graphene oxide (P(NMP)/rGO) nanocomposites working at room temperature (RT) has been presented. A unique three-step approach has been introduced to ensure the preparation of a highly conductive and water-soluble rGO. P(NMP)/rGO nanocomposite was materialized through the inexpensive and straightforward self-assembled micellar soft-template polymerization route in the presence of rGO. The P(NMP)/rGO based sensor demonstrates outstanding response upon exposure to a broad concentration of CO ranging from 10 ppm to 275 ppm. The experimental results revealed that incorporation of rGO with P(NMP) nanosphere improved the sensor response (231.5 % to 75 ppm), leading to fast response and recovery characteristics (40 s / 36 s) and excellent selectivity at RT. The lowest detection limit of P(NMP)/rGO nanocomposite-based sensor for CO is calculated to be 1.042 ppm. Based on the outcomes of this investigation, it is believed that the proposed sensor, with its inexpensive and simple construction method, along with its remarkable performance towards CO, might be a wonderful option for real-time detection of CO.

Optical Characterization and Prediction with Neural Network Modeling of Various Stoichiometries of Perovskite Materials Using a Hyperregression Method.

Quaternary perovskite solar cells are being extensively studied, with the goal of increasing solar cell efficiency and securing stability by changing the ratios of methylammonium, formamidinium, I3, and Br3. However, when the stoichiometric ratio is changed, the photoelectric properties reflect those of different materials, making it difficult to study the physical properties of the quaternary perovskite. In this study, the optical properties of perovskite materials with various stoichiometric ratios were measured using ellipsometry, and the results were analyzed using an optical simulation model. Because it is difficult to analyze the spectral pattern according to composition using the existing method of statistical regression analysis, an artificial neural network (ANN) structure was constructed to enable the hyperregression analysis of n-dimensional variables. Finally, by inputting the stoichiometric ratios used in the fabrication and the wavelength range to the trained artificial intelligence model, it was confirmed that the optical properties were similar to those measured with an ellipsometer. The refractive index and extinction coefficient extracted through the ellipsometry analysis show a tendency consistent with the color change of the specimen, and have a similar shape to that reported in the literature. When the optical properties of the unmodified perovskite are predicted using the verified artificial intelligence model, a very complex change in pattern is observed, which is impossible to analyze with a general regression method. It can be seen that this change in optical properties is well maintained, even during rapid variations in the pattern according to the change in composition. In conclusion, hyperregression analysis with n-dimensional variables can be performed for the spectral patterns of thin-film materials using a simple big data construction method.

Constructing MnO2 alpha/amorphous heterophase junction by mechanochemically induced phase transformation for formaldehyde oxidation

Construction of heterophase junction has emerged as an effective approach for boosting the catalytic performance of diverse photoelectrocatalysts and electrocatalysts. But its potential in remediation of formaldehyde (HCHO) pollution was scarcely investigated. Herein, we report the fabrication, catalytic properties, and mechanistic study of α/A-MnO2 heterophase junction catalyst for HCHO oxidation. Our study found that mechanically milling δ-MnO2 could readily induce an δ to α phase transformation via an intermediate amorphous phase, thus providing a simple method for construction of MnO2 heterophase junction. The α/A-MnO2 catalyst prepared under the optimal condition exhibited an exceptionally high area specific reaction rate of 0.21 μmol m−2 min−1 at 80 °C and excellent stability towards HCHO oxidation, outperforming most reported MnO2-based catalysts. Based on the in situ diffused reflectance infrared Fourier transform spectroscopy and on-line gas chromatography analyses, a possible mechanism was put forward to describe the synergistic catalysis effect between α-MnO2 and amorphous MnO2.

Constructing Continuous Functions

Summary This paper introduces a simple geometric construction method for graphs of continuous functions. Graphs of a nowhere differentiable continuous function, a Lipschitz function that is not differentiable on a perfect set, and a continuous function whose level sets are countable are constructed using this method. We argue that introducing students to this method early on in Real Analysis fosters proper geometric intuition about continuity and provides for simple geometric proofs of non-differentiability properties.

2 × 2 Textile Rectenna Array with Electromagnetically Coupled Microstrip Patch Antennas in the 2.4 GHz WiFi Band

The development of e-textiles is fostering research in wireless energy transmission. This paper presents a purely textile 2.4 GHz WiFi band 2 × 2 rectenna array for RF energy harvesting. It utilizes the electromagnetically coupled microstrip patch antenna topology and a simple and precise construction method that provides a good performance repeatability to create multilayer microstrip textile patch antennas. The rectifier is implemented with Schottky diodes and it takes the voltage doubling configuration. An average DC power of 1,1 mW was measured for 14 μW/cm2 of RF input power density, while the end-to-end average power conversion efficiency (PCE) measured was 31%. The characterization of the end-to-end PCE was evaluated considering the physical size of the prototype to make the comparison with other designs easier. Measurements in a real WiFi scenario were also performed, demonstrating its feasibility for feeding e-textiles.

Mode superposition methods based on hysteretic damping assumption used in seismic calculation of hybrid structures

To make it mathematically easy to solve, various practical time history analysis methods are all based on the viscous damping assumption to establish the dynamic equations of the system. From the viscous damping assumption, the conclusion that the damping force or its energy dissipation of the system is proportional to the frequency of the system can be deduced, which is not consistent with the experimental results. When the classical mode superposition method based on the viscous damping assumption is used to calculate the dynamic response of a hybrid structure under an earthquake, how to calculate the modal damping ratio or how to determine a number of significant frequencies of the response to calculate the damping matrix has always been an urgent problem to be resolved in the engineering community. Since the hysteretic damping assumption is consistent with the experimental results, the mode superposition method based on the hysteretic damping assumption is explored in this paper to solve the above problems. The mode superposition method based on the hysteretic damping assumption can avoid the modal damping ratio trouble of the classical mode superposition method based on the viscous damping assumption, and its damping matrix has advantages of simple construction method and small construction workload and clear physical meaning. In this paper, the complex mode superposition method and the real mode superposition method based on the hysteretic damping assumption are studied, the calculation results and calculation efficiency of the two methods are analyzed and compared, and the conclusion is drawn that the real mode superposition method is better than the complex mode superposition method.

Laboratory Investigation on the Interface Bonding between Portland Cement Concrete Pavement and Asphalt Overlay

The interface bonding between Portland cement concrete (PCC) pavement and hot-mix asphalt (HMA) overlay plays an important role in the performance of the composite pavement. This research conducted a series of comprehensive laboratory studies to investigate the influence factors of the interface bonding strength using a self-designed direct shear test apparatus that can simultaneously apply normal stress and shear stress on a specimen. Four kinds of commonly used tack coat materials were systematically tested and compared under various combinations of normal stress and temperature. Then, coupling effects of the normal stress and temperature on the interface bonding between PCC and HMA were analyzed. The test results show that temperature has a significant impact on the adhesion of the tack coat. Emulsified asphalt was considered the optimal tack coat material because of its simple construction method. In addition, it was found that a damaged interface could still provide considerable bonding strength. Normal stress generated by traffic loads was beneficial to the interface bonding strength, especially at lower temperatures. The temperature had a significant effect on interface bonding and played a leading role in the failure mode of interface bonding.