Many Fields Of Engineering Research Articles

NEAT—NMR Spectroscopy for the Estimation of Activity Coefficients of Target Components in Poorly Specified Mixtures

Mixtures of which the composition is not fully known are important in many fields of engineering and science, for example, in biotechnology. Owing to the lack of information on the composition, suc...

Research and validation of design principles for PVDF wideband ultrasonic transducers based on an equivalent circuit model

With the increasing use of ultrasonic measurement technology in many fields, the demand for the wideband ultrasonic transducers is also growing. In order to design a wideband piezoelectric ultrasonic transducer, the design principles of wideband PVDF piezoelectric ultrasonic transducers are studied in this paper. A new equivalent circuit model of piezoelectric ultrasonic transducer is used here to simulate the piezoelectric ultrasonic transducer, which combines with the controlled source model and the lossy transmission line model. Based on this model, the relationships between physical structures and properties of PVDF transducers are studied both in simulation and experiment. It shows that the center frequency and many other property parameters of PVDF ultrasonic transducers are strongly related to the physical structures of it. Finally, a wideband PVDF piezoelectric ultrasonic transducer is produced with the center frequency of about 5.3 MHz ± 0.1 MHz and the bandwidth of more than 90%.

The History of Human Factors in Seating Comfort at SAE’s World Congress: 1999 to 2018

<div class="section abstract"><div class="htmlview paragraph">In many fields of technology, examinations of the past can provide insights into the future. This paper reviews the last 20 years of automotive seat comfort development and research as chronicled by SAE’s session titled “Human Factors in Seating Comfort”. Records suggest that “Human Factors in Seating Comfort” has existed as a separate session at SAE’s World Congress since 1999. In that time there have been 148 unique contributions (131 publications). The history is fascinating because it reflects interests of the time that are driven by technology trends, customer wants and needs, and new theories. The list of contributors, in terms of authors and their affiliations, is also telling. It shows shifts in business models and strategies around collaboration. The paper ends with a discussion of what can be learned from this historical review and the major issues to be addressed. One of the more significant contributions of this paper is the reference list. It contains all 131 of SAE’s “Human Factors in Seating Comfort” published papers in a single location. These references represent the foundation of automotive seating comfort, which should be considered core knowledge and should be familiar to those in the profession, both new and old.</div></div>

Numerical investigation of entropy generation in microporous channel with thermal radiation and buoyancy force

Microporous channels found to have extensive applications in many fields of engineering, particularly in thermal and petrochemical engineering. In particular, the microelectromechanical systems are useful to develop a large number of microscopic devices and systems such as micromixture, microheat exchangers, microchannel heat sinks, microfuel cells. The present work aims to scrutinize the combined effects of thermal radiation and buoyancy force on entropy generation in magneto-hydrodynamic Jeffrey fluid flow through a vertical microporous channel. The model equations of linear momentum and energy balance are developed and tackled numerically using fourth-order Runge–Kutta method. The results are exhibited pictorially and discussed quantitatively for active parameters which emerged in the mathematical formulation. Validation with previously published work is included, and the current results are in good agreement. It is found that the effects of viscous dissipation and suction/injection on entropy generation in microchannel are important and should not be ignored. Further, it is noticed that the fluid temperature retards with an increasing value of suction and the effect is reversed in the case of injection.

Investigation of Structure and Properties of Armos Para-Aramid Fibre in the Context of Potentials for its Subsequent Modification

For successful employment of technology in many fields, it is essential to have materials that possess high electrical conductivity. The electrical conductivity of polymeric materials depends on many factors, primarily on hygroscopicity, structure and chemical constitution, and presence of some substances on its surface. The investigation is conducted on the structure and properties of Armos para-aramid fibre in the context of potentials for subsequent modification for imparting electrical conductivity to it.

Enhanced uniform data sampling for constrained data‐driven modeling of antenna input characteristics

AbstractData‐driven surrogates are the most popular replacement models utilized in many fields of engineering and science, including design of microwave and antenna structures. The primary practical issue is a curse of dimensionality, which limits the number of independent parameters that can be accounted for in the modeling process. Recently, a performance‐driven modeling technique has been proposed where the constrained domain of the model is spanned by a set of reference designs optimized with respect to selected figures of interest. This approach allows for significant improvement of prediction power of the surrogates without the necessity of reducing the parameter ranges. Yet uniform allocation of the training data samples in the constrained domain remains a problem. Here, a novel design of experiments technique ensuring better sample uniformity is proposed. Our approach involves uniform sampling on the domain‐spanning manifold and linear transformation of the remaining sample vector components onto orthogonal directions with respect to the manifold. Two antenna examples are provided to demonstrate the advantages of the technique, including application case studies (antenna optimization).

Lamination of Nanofibre Layers for Clothing Applications

Nanofibre membranes and nanofibre products represent break-through technology in many fields of industry. They are used for air or liquid filtration, and their unique properties are suitable for many new health products or when manufacturing clothes etc. Their biggest advantage is their high porosity and fineness. On the other hand, the disadvantage of these membranes is the fact that it is not a homogenous material/foil, but a layer of fibres or rather several fibre layers (hereafter we will always use the term nanomembrane). This structure has a very negative impact on some of its properties i.e. strength, abrasion resistance, pressure resistance etc. This work introduces a 2-layer-laminate and 3-layer laminate where one of the layers is made of nanofibres with a view to their use in the manufacturing of clothes for sport and outdoor activities. The nanofibre membrane laminate must protect the wearer from weather conditions like rain and snow and, at the same time, enable transferring of liquid moisture from the wearer’s body to the outside environment. Using lamination, we can connect the fine nanofibre membrane to a resilient textile material (knitted, woven or non-woven). This stronger textile material protects the more fragile nanomembrane from the outside environment (abrasion, friction etc.) while not diminishing its good comfort properties, like being windproof, waterproof and having good steam-permeability. The result of this work is a laminate with a high level of steam permeability, with minimum air permeability and a water column higher than 5000 mm. The tests carried out proved that during repeated washing cycles no delamination occurred and hydrostatic resistance decreased by approximately 20%.

Sphericity measurement through a new minimum zone algorithm with error compensation of point coordinates

Sphericity is a relevant tolerance of form in many fields of engineering. Measuring sphericity is frequently accomplished through the fitting of the point coordinates obtained from coordinate measuring machines (CMMs) to a substitution sphere. This paper presents a new algorithm for sphericity of minimum zone tolerance. It faces its resolution through the flatness problem associated with the implicit formulation of the polar plane of the sphere. The polarity transformation allows the iterative resolution of the minimum zone sphericity through a simpler flatness problem. Its accuracy is compared with the least-squares solution and some well-known minimum zone algorithms from literature. Its performance reaches or surpasses them. Next, a new error compensation model of point coordinates for sphericity is developed. A model based on the regression of the error by each CMM axis is incorporated into the sphericity measurement model. The explained error propagated allows correcting the sphericity calculated by the CMM indication, but also facilitates the uncertainty estimation by the propagation of the unexplained residual error in the regression through the measurement model. The experimental verification by the Monte Carlo Method shows efficient results. The jointly proposed method of a new algorithm with error compensation and uncertainty estimation can effectively contribute to the improvement of sphericity measurement from point coordinates in precision and accuracy.

Design of Blockchain System for a Real Estate (a Revolution)

Blockchain the technology behind the highly successful Bitcoin has recently gained attention from researchers who want to use this new and disruptive technology in many fields, potentially redesigning businesses, politics, and society at large. Despite all the research in blockchain, no buyer-company-government buying and selling schema has been designed till date. This schema ensures no single point of failure, faster implementation of government schemes, e.g.- Pradhan Mantri Awas Yojna (PMAY), easy document recovery in case of disaster, and easier trade for everyone helps boost the economy etc. The prime objective of this paper is to fill in this gap and discuss the various key benefits of having a decentralized real estate ecosystem for buying and selling based on blockchain technology and the challenges are to replace the traditional real estate ecosystem and make this schema a standard for any buying or selling of property through the use of the platform of Real Chain providing the DLT (Distributed Ledger Technology) environment which will counter the corrupt middlemen and remove traditionally centralized institutions from the process of buying and selling.

A theoretical investigation on moving average filtering solution for fixed-path map matching of noisy position data

Precisely estimation of moving object locations from position sensors promises useful implications for many fields of engineering. The mapping of a moving object on a predefined path is an important process for object tracking and remote control applications. Owing to measurement noises of sensors and uncertainties, the measured object location may not precisely match to paths or roads in a map. This study presents a numerical method for a low computational-complexity solution of point to arc type mapping problems. This method has two main tasks: a noise reduction task by short-time moving average filtering of noisy two-dimensional position data, and a map matching task to estimate exact position of an object on a map. To evaluate performance of the investigated method, the algorithm is applied for bus route tracking simulations and results are discussed for several road scenarios and various levels of noise.

The amazing spectrum of light –LASER

“In right light at right time everything is extraordinary”- says Aaron Rose. This is very true with respect to lasers. Discovery of lasers from the spectrum of light has revolutionized the technology in many fields. The word “LASER” means Light Amplification by Stimulated Emission of Radiation. They offer many useful clinical applications for general dentists in the diagnosis and treatment of patients. There are many clinical, aesthetic, and psychological reasons to use lasers. Herein we present a brief overview of “THE AMAZING SPECTRUM OF LIGHT”

A theoretical investigation on moving average filtering solution for fixed-path map matching of noisy position data

Precisely estimation of moving object locations from position sensors promises useful implications for many fields of engineering. The mapping of a moving object on a predefined path is an important process for object tracking and remote control applications. Owing to measurement noises of sensors and uncertainties, the measured object location may not precisely match to paths or roads in a map. This study presents a numerical method for a low computational-complexity solution of point to arc type mapping problems. This method has two main tasks: a noise reduction task by short-time moving average filtering of noisy two-dimensional position data, and a map matching task to estimate exact position of an object on a map. To evaluate performance of the investigated method, the algorithm is applied for bus route tracking simulations and results are discussed for several road scenarios and various levels of noise.

K-Nets: Clustering through nearest neighbors networks

Importance of clustering is signified by its applications in many scientific fields and the uninterrupted presence of related algorithmic methods in the literature for more than half a century. The majority of these methods have complex operation and most of the times aim on a specific application field. Here we present K-Networks (K-Nets), a deterministic algorithm based on a network structure whose nodes represent data points and can intrinsically work within a single or multi-layer architecture. The number of interconnections of each node with the rest of the network indicates the clusteringresolution degree and can be the same or different in every layer. K-Nets automatically detects symmetric structures in data that can be utilized to recover clusters of different size, shape, or partitions composed of a specific number of clusters. We provide evidence that K-Nets performance compares favorably with other well established clustering algorithms in a wide range of fields, while it can be employed in cases when data dimensionality prohibits their application.

Numerical simulation of crack propagation in ceramic materials at high temperature

Ceramic Materials have been widely used in many fields of engineering, It is necessary to research the process of crack propagation of ceramic materials at high temperature by numerical simulation. The numerical model is applied to investigate the formation, extension and coalescence and crack propagation in ceramic materials at high temperature. A numerical model of ceramic materials is proposed to investigate thermally-induced damage and crack propagation at high temperature. The numerical simulations show that when the tensile stress exceeds its phase transition threshold, it produces tensile failure, in the specimen surface more and more the impact cracks are appear, the crack spacing’s are basically equal and parallel to each other, with the elapse of time, the main cracks continue to expand, small part of the cracks expansion are subjected to limited, there are the classifications of cracks. With the elapse of time, crack propagation speed gradually slows down, and eventually reaches a steady state. The numerical simulation demonstrates that the model proposed can visually replicate the thermal cracking propagation process of ceramic materials at high temperature. The result of our numerical simulation shows that thermal cracking propagation process in ceramic materials at high temperature is in good agreement with the real experimental thermal cracking result of crack propagation in ceramic materials at high temperature.

Numerical Simulation of Crack Propagation in Fiber Reinforced Polymer Concrete Composites in the high Temperatures

Fiber Reinforced Polymer Concrete composite materials have been widely used in many fields of engineering, it is necessary to research the crack propagation process of Fiber Reinforced Polymer Concrete composite material in the high temperature by Numerical Simulation. the numerical model is applied to investigate the formation, extension and coalescence and crack propagation in Fiber reinforced polymer reinforced concrete composites in the high temperature, the deformation and damage evolution are briefly described in the model, a numerical model of fiber reinforced polymers embedded in Concrete is proposed to investigate thermally-induced damage and crack propagation in the high temperature, the numerical Simulation show that the crack propagation behavior of the Fiber Reinforced Polymer Concrete composite material in the high temperature is developed at the interface between the Fiber Reinforced Polymer and Concrete, the numerical simulation demonstrates that the model proposed can visually replicate the thermal cracking propagation process of Concrete and the simulated cracking of Concrete is in good agreement with the experimental cracking result of Fiber Reinforced Polymer Concrete composite material in the high temperature.

Analysis of Computer IoT technology in Multiple Fields

In recent years, the level of informatization in China has developed rapidly, and the application of computer IoT technology has provided people with great convenience in daily life and work, and has certain positive significance for the promotion of China’s national economy. It has also been widely used in many fields. This paper mainly analyzes the application of computer Internet of Things technology in many fields.

Evolución y proceso de fabricación de imanes “NEO” aplicados a motores de vehículos eléctricos

Tras el desarrollo de los imanes Nd-Fe-B o “Neo”, éstos son ahora componentes esenciales en muchos campos de la tecnología debido a su capacidad para proporcionar un fuerte flujo magnético. Existen dos técnicas bien establecidas para la fabricación de imanes de tierras raras: a) el uso de la metalurgia de polvo para obtener cuerpos magnéticos de alto rendimiento, anisotrópicos, totalmente densos; y b) el proceso de hilado por fusión o HDDR (hidrogenación, decrepitación, desorción y recombinación) se usa ampliamente para producir polvos magnéticos para imanes aglomerados. En la industria de los imanes de Nd-Fe-B sinterizados, la producción total ha aumentado y su aplicación dominante es principalmente motores y en particular, su uso para automóviles híbridos es una de las aplicaciones más atractivas. También se han utilizado imanes aglomerados para motores pequeños, los estudios de nanocompuestos y de imanes Sm-Fe-N se han generalizado. Este artículo revisa el estado actual y las tendencias futuras en la investigación de imanes permanentes.

Weighted Network Estimation by the Use of Topological Graph Metrics

Topological metrics of graphs provide a natural way to describe the prominent features of various types of networks. Graph metrics describe the structure and interplay of graph edges and have found applications in many scientific fields. In this work, graph metrics are used in network estimation by developing optimisation methods that incorporate prior knowledge of a network's topology. The derivatives of graph metrics are used in gradient descent schemes for weighted undirected network denoising, network completion, and network decomposition. The successful performance of our methodology is shown in a number of toy examples and real-world datasets. Most notably, our work establishes a new link between graph theory, network science and optimisation.

Transmission efficiency analysis and optimization of magnetically coupled resonant wireless power transfer system with misalignments

Magnetically coupled resonant (MCR) wireless power transfer (WPT) is a promising technology, which has been widely used in many practical applications. In the practical application environment the misalignments between the transmitting coil and the receiving coil can not be avoided, and it will cause a rapid decline in transmission efficiency. So the misalignments have limited the applications of MCR-WPT technology in many fields. The mathematical formula of transmission efficiency with angular misalignment and lateral misalignment was deduced. And the effects of angular misalignment and lateral misalignment on the transmission efficiency were researched by simulation experiments. And the changing regularity of the transmission efficiency with the change of the angular misalignment and lateral misalignment was obtained. The results show that when there is an angular misalignment between the transmitting coil and the receiving coil, the transmission efficiency can be optimized by adjusting the lateral misalignment between the coils. And when there is a lateral misalignment between the coils, the transmission efficiency can be optimized by adjusting the angular misalignment between the coils. An experimental prototype of MCR-WPT system was built, and experiments had been carried out to evaluate the accuracy of the theoretical analysis. Therefore, the study in this paper lay a theoretical foundation for the analysis of WPT in the complex environment, and also provide a useful reference for the design of WPT system.

A Novel Inverse Analysis Method to Identify Concentration and Current Density Distributions on Electrode Surface

The measurement of polarization characteristics is important for products and processes such as corrosion inhibition, fuel cell, advanced electroplating and so on. When the current density increases during the polarization curve measurement, the concentration of reactive species distributes non-uniformly. In order to control the concentration on the surface of the electrode, rotating disc electrode (RDE) is sometimes applied. However, even the application of RDE, the non-uniformity of concentration distribution on the surface of the electrode is still remained. Accurate evaluation of concentration flux distribution on the surface of electrode is highly desired. Recently, application of numerical simulation methods such as boundary element method (BEM) or finite element method (FEM) to the electrochemistry problems has been studied intensively, and these methods have become powerful tools. With the progress of numerical simulation, “Inverse Problems” have received a lot of attention. Inverse Problem is a research area dealing with finding out unknown information from external or indirect observation through the model of the system. The background of inverse problems is the modeling and simulation of natural phenomena. When observations are taken of these phenomena, the observation data are used to infer knowledge about physical states. One of the most spectacular success in the field of inverse problems was the invention of an inversion algorithm for Computed Tomography. Not only the computed tomography in medical area, applications of inverse problems arise in many fields of engineering, too. In the fields of electrochemical engineering, there are many problems which can have a benefit from inverse analysis approach. Our research focuses on the techniques for monitoring the accurate current density distribution and concentration distribution on the surface of the electrode during the polarization characteristic measurement. We have developed a novel technique to identify current density and concentration distribution just on the electrode surface from the data of total current, bulk concentration and bulk flow rate. In order to measure total currents, we use electrochemical flow cell that can control bulk flow rate. In this inverse analysis, the concentration distribution on the electrode surface, i.e., boundary conditions of boundary value problem with advection diffusion equation are not fully given, but the total currents and bulk concentration are obtained by practical measurement to compensate for lack of unknown boundary conditions. The solution would be abnormally unstable due to the ill posedness. Hence, let us make use of the a-priori information that concentration and its flux proportional to the current density on the electrode must satisfy the polarization characteristics.we will approximate the polarization characteristics by a function of the concentration and its flux, e.g., piecewise bi-linear function with several number of parameters. Firstly, the velocity field of the flow cell is analyzed with finite volume method as shown at top-right in the figure. The velocity filed is described with Navier-Stokes equation. The figure represents the procedure of the whole inverse analysis. Assuming parameters of polarization characteristics, the direct analysis is performed and total currents is calculated. Minimizing the residual between the measured and the calculated total currents with nonlinear least square method, the parameters of polarization characteristics can be obtained. After obtaining the polarization characteristics, the concentration and the current density distribution on the electrode are easily calculated by the direct analysis. Our primary aim is to verify the applicability of the inverse analysis in the estimation of the polarization characteristics. In order to concentrate on the evaluation of process, we have created necessary measured data through a regular/direct numerical simulation instead of carrying out real experimental measurements. Such a procedure allows the present technique to be isolated from other factors such as unexpected measurement or simulation model error. Up on this, to accommodate an important aspect of experimental measurements, a small perturbation/error is added to the calculated results. These values are assumed as the measured data and used in the inverse analysis to determine the polarization characteristics. The final identified results by the proposed technique are in good agreement with the results computed by the numerical simulation. In order to demonstrate the effectiveness of this technique, the identification using real experimental data is also performed. Figure 1