Composites - Science topic

This study aims to investigate the fexural behavior of reinforced concrete (RC) beams strengthened using aluminum hon�eycomb sandwich panels (AHSPs) with three diferent thicknesses (6, 10, and 15 mm) and CFRP U-Jackets with diferent cross-section confgurations (i.e. support and middle sections). The experimental performance of RC beams was evaluat...

https://www.mdpi.com/journal/materials/special_issues/2KR2MDX81Z

The heat transfer process of the sweeping jet and film composite cooling (SJF) structure of the turbine blade leading edge is complex. The current work divides the overall cooling effectiveness of the SJF into the impingement heat transfer effectiveness, the convection heat transfer effectiveness inside the film holes, and the external film cooling...

This study concerns the importance of curing kinetic models for the prediction accuracy of the thermal overshoot in the curing process of thick polymeric composite plates. An adaptive activation energy (AAE) method was proposed to determine an accurate curing kinetic model with adaptive activation energy (CK-AAE). Then the temperature field model o...

In the paper, using several approaches, the authors expand the composite function $\ln(1+e^x)$ into power series around $x=0$, whose coefficients are expressed in terms of the Dirichlet eta function $\eta(1-n)$ and the Stirling number of the second kind $S(n,k)$.

This work studies the natural powers of prime numbers as the building blocks of a Euclidian vector semispace. Some vectors generate the composite natural numbers by defining an appropriate geometrical norm. One also studies the structure of extended Mersenne numbers within this geometric point of view. Further geometric applications and extensions...

The internal pressure and temperature of type IV on-board hydrogen storage cylinders constantly change during the hydrogen fast-filling process. In this work, a 2D axisymmetric computational fluid dynamics (CFD) model is established to study the temperature rise of hydrogen storage cylinders during the fast-filling process. The hydrogen filling rat...

https://authors.elsevier.com/a/1gnUS6gayqggUj

The composite length-biased exponential-Pareto (CLBEP) distribution is a new composite distribution that is introduced in this article. This model’s probability density function, moments, and quantiles, among other statistical characteristics, are determined mathematically. The parameters’ maximum-likelihood estimation and stochastic ordering are d...

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The effect of rare-earth Ce on the evolution behaviour of inclusions in heavy rail steel was studied. The addition of Ce can significantly reduce the number and size of class A, B, D, and Ds inclusions in the heavy rail steel smelting process. According to the statistical analysis of the size of inclusions in steel, the number and size of A and B i...

This article presents the microstructure, hardness, fracture toughness coefficient KIC and phase composition of submicron WC-4Co carbides. The carbides were sintered using the innovative U-FAST (Upgraded Field Assisted Sintering Technology) method, from mixtures of WC-Co powders with an average WC grain size of 0.4 µm and 0.8 µm. The obtained sinte...

The gauge-invariant two-point function of the Higgs field at the same spacetime point can make a natural gauge-invariant order parameter for spontaneous gauge symmetry breaking. However, this composite operator is ultraviolet divergent and is not well-defined. We propose using a gradient flow to cure the divergence from putting the fields at the sa...

In this paper, we focus on optimizing the optimization problems with the objective function formed as a sum of three terms: one is smooth, and the other two are simple convex functions with known structures. This problem is challenging to solve, as the last two functions are both non-smooth and non-separable. Existing algorithms have high computati...

https://www.mdpi.com/journal/fibers/special_issues/YH53370C2H

Carbon-fiber-reinforced plastics (CFRPs) are of increasing popularity in a wide range of applications, and microwave curing promises significant reduction in processing times. However, for the design of an efficient microwave curing system, the composites’ effective material parameters must be known. This work presents a measurement system using a...

In this paper, we introduce the restricted minimum density power divergence Gaussian estimator (MDPDGE) and study its main asymptotic properties. In addition, we examine it robustness through its influence function analysis. Restricted estimators are required in many practical situations, such as testing composite null hypotheses, and we provide in...

Composite materials, regarding their lightweight, can be considered a suitable option for the next generation of piezoelectric energy harvesters, which are used for supporting low-power applications. Also, due to the broader selection range and different stacking sequences, one of the advantages of these materials is that they can provide better st...

A reformulated Mathematical framework for Density matrix description of N=2 Matrix Shell system is presented. In this presentation, we consider the Basic pathway structure of the Composite Pathways and the criterion of " Inter - Pathway synchronicity " between the Basic Pathways as the determining condition for the accessibility of the Configurati...

Работа посвящена картографированию и анализу сезонной динамики опустынивания (открытых песков и котловин выдувания) Кизлярских пастбищ, расположенных в северной части Республики Дагестан. Использованы ежемесячные композитные изображения спутника Sentinel 2 второго уровня обработки с отфильтрованной облачностью и радиометрической нормализацией за пе...

Mob : (00213) 0665177790 Préface Le présent support de cours, intitulé « Matériaux Composites», est destiné aux étudiants suivant une formation en Sciences et Technologie. Les étudiants de la filière Génie Mécanique et plus précisément ceux de la spécialité Construction Mécanique peuvent trouver dans ce manuscrit des informations de base intéressan...

We propose a unified approach to the investigation of the processes of dynamic interaction of thin elastic inhomogeneities with an elastic medium. It is based on the methods of the theory of singular perturbations in constructing mathematical models of contact of the components of elastic systems with subsequent application of the null-field method...

Modern composite materials, thanks to their excellent properties, are widely used [...]

This ‘opinion’ article has been undertaken to provide a plausible answer to the question of why nanocomposites that are reinforced by acicular nanoparticles such as carbon nanotubes (CNTs) do not exhibit the anticipated physical properties—particularly, why the glass transition temperature in some compositions exhibits huge decreases, contrary to e...

We present a method to calculate the $x$--space expressions of massless or massive operator matrix elements in QCD and QED containing local composite operator insertions, depending on the discrete Mellin index $N$, directly, without computing the Mellin--space expressions in explicit form analytically. Here $N$ belongs either to the even or odd pos...

In the present mini-review are discussed the findings reported in the last five years on the ion-conducting composites of polymers and molecules of nematic liquid crystals (NLCs), as well as their applications at present and in the future. Nowadays, free-standing and flexible thin films of such organic composite electrolytes synthesized from plasti...

In this paper we use a contour integral method to derive a bilateral generating function in the form of a double series involving Chebyshev polynomials expressed in terms of the incomplete gamma function. Generating functions for the Chebyshev polynomial are also derived and summarized. Special cases are evaluated in terms of composite forms of bot...

This work synthesized a novel chitosan-loaded MgAl-LDH (LDH = layered double hyroxide) nanocomposite, which was physicochemically characterized, and its performance in As(V) removal and antimicrobial activity was evaluated. Chitosan-loaded MgAl-LDH nanocomposite (CsC@MgAl-LDH) was prepared using cross-linked natural chitosan from shrimp waste and m...

We employ a general Monte Carlo method to test composite hypotheses of goodness-of-fit for several popular multivariate models that can accommodate both asymmetry and heavy tails. Specifically, we consider weighted L2-type tests based on a discrepancy measure involving the distance between empirical characteristic functions and thus avoid the need...

The classical Coriolis force finds its quantum analogue in the difference $\Sigma(t)=H(t)-G(t)$ where the ``true'', observable Hamiltonian $H(t)$ represents the instantaneous energy. The other, ``false'' Hamiltonian $G(t)$ generates the time-evolution of wave functions. Whenever $\Sigma(t)\neq 0$, quantum mechanics acquires an interaction-picture f...

In this paper, we focus on optimizing the optimization problems with the objective function formed as a sum of three terms: one is smooth, and the other two are simple convex functions with known structures. This problem is challenging to solve, as the last two functions are both non-smooth and non-separable. Existing algorithms have high computati...

This paper proposes a new montmorillonite-type multiple network composite gel for the prevention of coal spontaneous combustion. The first network is formed by the cross-linking of polyvinyl alcohol (PVA) and boric acid under alkaline conditions. The second network is formed as a result of intermolecular hydrogen-bonding interactions between polyac...

The numerical simulation was used to examine the impacts of pit precipitation and the presence or absence of waterproof curtain on the CFG pile composite foundation near to the under-construction pit, and the following primary results were reached. For starters, the precipitation will force the CFG pile composite foundation to slope towards the ent...

The fitness of a genotype is defined as its lifetime reproductive success, with fitness itself being a composite trait likely dependent on many underlying phenotypes. Measuring fitness is important for understanding how alteration of different cellular components affects a cell’s ability to reproduce. Here, we describe an improved approach, impleme...

We examine US County-level observational data on Cancer Mortality and it's "Top Ten" potential causes from Federal or State sources for the two individual years (2012 and 2016) that we have made publicly available. We find that these two Cancer Mortality rates for individual years have remarkably little in common, and we propose using a simple comp...

Composite foundation

The punching behaviour of a slab-column connection with a spatial steel drop panel composed of a steel drop plate, batten plates and a confined steel plate were experimentally investigated in this study. The experimental variables were the size of steel drop plate, the length of batten plate and whether the steel drop plates have slits. Five specim...

In this paper, we study the convergence of the nonsymmetric interior penalty Galerkin (NIPG) method on a Bakhvalov-type mesh for the first time. For this purpose, a new composite interpolation is designed, which solves the inherent difficulty of analysis on Bakhvalov-type meshes. More specifically, Gauss Radau interpolation and Gauss Lobatto interp...

Zusammenfassung Dieser Beitrag stellt einen elektrodynamischen Wandler vor, der im Vergleich zu konventionellen E‑Maschinen wettbewerbsfähige Betriebseigenschaften aufweist, beliebig skalierbar und kostengünstig herzustellen ist. Der Wandler ist geeignet, in vielfältigen Anwendungen als effizienter und effektiver Generator oder Motor eingesetzt zu...

We study the problem of binary composite channel discrimination in the asymmetric setting, where the hypotheses are given by fairly arbitrary sets of channels, and samples do not have to be identically distributed. In the case of quantum channels we prove: (i) a characterization of the Stein exponent for parallel channel discrimination strategies a...

We propose a DIDE-FPP composite algorithm to improve the spatial location accuracy of tunnel fires based on the distributed individuals differential evolution (DIDE) algorithm and the four-point positioning (FPP) method. Using the DIDE algorithm to solve the multimodal optimization problems in tunnel fire location can locate more peaks and improve...

Trimodal grain structure was effective to balance the strength-ductility trade-off in ultrafine-grained metals, but the relationship between microstructures and mechanical performance is unclear. Here the dimension of coarse grain (CG) domains was elaborately tuned in the trimodal CNT/2024Al composites, and an excellent strength-ductility combinati...

In this study, the formation and evolution mechanism of residual stress in the process of solution heat treatment of a 316L/Q235B composite plate and the influence law of different factors on residual stress were analyzed by combining experiments and simulation. The results showed that the bending stress caused by interlayer thermal stress was the...

Based on the heuristic packing algorithm, this paper proposes a 3D packing algorithm that can run efficiently to improve the efficiency of palletizing and packing. The design of the algorithm starts from three parts: block construction, remaining space processing, and optimal block search. Firstly, the goods are packed to meet the constraints of th...