Search results for "Mechanical engineering"

Comprensión de textos expositivos académicos en e-book Reader y en papel: influencia del conocimiento previo de dominio y la aptitud verbal

2018

espanolResumen: En un estudio del que participaron 102 estudiantes universitarios, se comparo la comprension en la lectura de textos expositivos academicos impresos versus en formato de e-book Reader. Se examinaron los efectos del soporte, del conocimiento especifico de dominio previo del lector y la aptitud verbal. Asimismo se indagaron las actitudes de los estudiantes hacia los soportes textuales antes y despues de la experiencia. Los resultados sugieren que el e-book Reader beneficiaria a los lectores competentes, y/o que podria promover mayor actividad metacognitiva en los procesos de comprension. Asimismo, las opiniones hacia el e-book Reader cambiaron despues de la experiencia, aunque…

Earth Construction: The Mechanical Properties of Adobe with the Addition of Laponite

2015

The contribution describes testing of compression strength, flexural strength and abrasion resistance of adobe made up of soil, water and sand (AS), soil, water, sand and straw (ASP), soil, water, sand and laponite nanoparticles (ASN). Embodied energy in materials presents an increasingly high percentage of the energy spent in the whole life cycle of a building. The same applies for carbon dioxide (CO2). Therefore, the development of new sustainable construction materi- als with lower embodied energy and lower CO2 emissions is needed. The use in construction of the brick made from soil, water and sand or straw, called adobe, boasts a millenary tradition and in recent years there has been re…

Automatic Segmentation and Enhancement of Pavement Cracks Based on 3D Pavement Images

2019

Pavement cracking is a significant symptom of pavement deterioration and deficiency. Conventional manual inspections of road condition are gradually replaced by novel automated inspection systems. As a result, a great amount of pavement surface information is digitized by these systems with a high resolution. With pavement surface data, pavement cracks can be detected using crack detection algorithms. In this paper, a fully automated algorithm for segmenting and enhancing pavement crack is proposed, which consists of four major procedures. First, a preprocessing procedure is employed to remove spurious noise and rectify the original 3D pavement data. Second, crack saliency maps are segmente…

Analysis and optimization against buckling of beams interacting with elastic foundation

2017

We consider an infinite continuous elastic beam that interacts with linearly elastic foundation and is under compression. The problem of the beam buckling is formulated and analyzed. Then the optimization of beam against buckling is investigated. As a design variable (control function) we take the parameters of cross-section distribution of the beam from the set of periodic functions and transform the original problem of optimization of infinite beam to the corresponding problem defined at the finite interval. All investigations are on the whole founded on the analytical variational approaches and the optimal solutions are studied as a function of problems parameters. peerReviewed

Vibrations of a continuous web on elastic supports

2017

We consider an infinite, homogenous linearly elastic beam resting on a system of linearly elastic supports, as an idealized model for a paper web in the middle of a cylinder-based dryer section. We obtain closed-form analytical expressions for the eigenfrequencies and the eigenmodes. The frequencies increase as the support rigidity is increased. Each frequency is bounded from above by the solution with absolutely rigid supports, and from below by the solution in the limit of vanishing support rigidity. Thus in a real system, the natural frequencies will be lower than predicted by commonly used models with rigid supports. peerReviewed

Discussion: “Chaotic Motion of an Elastic-Plastic Beam” (Poddar, B., Moon, F. C., and Mukherjee, S., 1988, ASME J. Appl. Mech., 55, pp. 185–189)

1988

Discussion on caotic motion of a pinned beam subjected to pulse loading

Active Electric Control of Emissions from Swirling Combustion

2007

New approach to characterisation of electric alloys under rotating magnetic flux density

1996

The computation of electrical machines using the characterisation of electric alloys proposed by several authors gives performances not verified by experiments on actual machines. By means of finite-element-method software, the authors show that the electromagnetic context where electrical alloys are built into rotating electrical machines is completely different from the actual characterisation system. A new testing device is proposed to take into account the phenomena highlighted.

Analysis of magnetohydrodynamic generator driven by thermoacoustic engine for deep Space applications

2020

This paper discusses the results of theoretical and experimental investigation of magnetohydrodynamic generator with liquid metal working body. This electric machine is used to convert mechanical energy, supplied by thermoacoustic engine, to an AC form of electrical energy. The purpose of this technology is an electricity production in deep Space, potentially suitable for long term missions far away from Sun.

A Gasless Reservoir Solution for Electro-Hydraulic Compact Drives with Two Prime Movers

2020

Abstract Due to an increased focus on improving the energy efficiency and compactness of hydraulic linear actuators, the electro-hydraulic compact drive (ECD) has received increased attention lately. In this study the ECD consists of variable-speed electric motors and fixed-displacement pumps, which are directly connected to the cylinder, thus controlling the linear motion in a throttleless manner. Furthermore, ECDs are self-contained systems, i.e. based on a fully enclosed oil circuit, in order to avoid external contamination and air to enter the system and to increase system compactness. Conventionally a low-pressure gas-loaded accumulator is used as an oil reservoir to compensate for the…