Showing papers by "Polytechnic University of Valencia published in 1986"
TL;DR: The results indicate that the delay of the age of slaughter in order to obtain heavier carcasses and their cutting-up before marketing could be advisable.
27 citations
TL;DR: In this article, a study of short crack growth for a medium carbon steel in low cycle torsional fatigue has been carried out in order to measure crack length and derive growth laws.
Abstract: A study of short crack growth for a medium carbon steel in low cycle torsional fatigue has been carried out in order to measure crack length and derive growth laws. Comparison with a previous analysis of uniaxial tests in low cycle fatigue for the same material provides a tentative basis for formulating an equivalent stress approach to describe uniquely the propagation of short cracks under multiaxial stress.
20 citations
01 Oct 1986
TL;DR: In this paper, some modifications to the method of characteristics for the analysis of the gas exchange process in internal combustion engines are presented, mainly related to the calculation of the path lines and the Riemann characteristic lines at the grid points.
Abstract: Some modifications to the method of characteristics for the analysis of the gas exchange process in internal combustion engines are presented in this paper. The modifications are related to the calculation of the path lines and the Riemann characteristic lines at the grid points. Regarding the path lines, the algorithm for the generation and elimination of path lines has been improved, mainly for the cases in which the fluid motion passes from being null or going out of the pipe to going into the pipe. In those cases the algorithm proposed by Benson can cause some mistakes in the entropy level field of the duct. An alternative method is proposed: the duplication ofpath lines. The other modifcation proposed is related to assuming a linear interpolation for the pressure and the volume flowrate between the nearest grid points, rather than assuming a linear interpolation of the value of the Riemann characteristics. These modijcations substantially improve the results obtained in the calculation of the fluid f...
20 citations
TL;DR: In this article, the authors performed dynamic mechanical experiments on poly(diethylene glycol isophthalate) and poly(triethylene glycol terephthalate) networks and found that the intensity of the loss tangent associated with the rubber transition tends to decrease with increasing static deformation.
Abstract: Dynamic mechanical experiments were performed between −140 and 50°C on both poly(diethylene glycol isophthalate) and poly(triethylene glycol terephthalate) networks. Plots of loss tangent versus temperature show a well-defined α peak, associated with the transition from glasslike to rubberlike consistency, and two overlapping peaks (β1 and β2) in the glassy region. Dynamic deformations of small amplitude were superimposed on large static deformations. It was found that the position of the β1 and β2 peaks as well as their intensities are independent of the static elongation ratio. However, the intensity of the loss tangent associated with the glass–rubber transition tends to decrease with increasing static deformation. Moreover, the position of the maximum of the α peaks shifts to lower temperatures as the elongation ratio increases. This behavior suggests that for both networks the volume effects (shifting the α peaks to lower temperatures with increasing elongation ratio) overcome the entropic effects (shifting the α peaks to higher temperatures with decreasing entropy).
17 citations
TL;DR: An anamorphic correlator composed of two nonsymmetrical spectrum analyzers in cascade, each with different magnifications in the x and y -directions, is proposed in this article.
13 citations
TL;DR: Equational algebraic specifications are used for data whereas CCS-like expressions are used to specify the observable behaviour of the system, and the desired system behaviour is described as a composition of simple behaviour expressions.
2 citations
TL;DR: The unexpected formation of chroman-4-ones by refluxing 4-aryloxybut-2-yn-1-ols in diethylaniline has been studied, 4-hydroxymethyl-2H-chromene and chroman 4-carboxaldehyde derivatives being established as intennediates.
2 citations
TL;DR: In this article, a computer program for real-time computer control of a mill process in a cement plant is described, where the purpose is to blend and mill raw materials in adequate proportions so that slurry, the resulting product, has the required composition.
2 citations
TL;DR: This comment studies the problem of the stimulated recombination in an open system from a stochastic point of view, and obtains fluctuations of the number of photons and ions around its macroscopic values in the linear noise approximation.
Abstract: In this comment we study the problem of the stimulated recombination in an open system from a stochastic point of view. We set up the bivariate master equation for the number of photons and ions inside the system. Then we perform a systematic expansion, with the system volume as an expansion parameter, and we obtain the fluctuations of the number of photons and ions around its macroscopic values in the linear noise approximation; the stationary solution is also investigated.
2 citations
01 Jan 1986
TL;DR: In this paper, a model reference control is presented in order to overcome the difficulty of a measurement one because the slurry composition analysis is performed at elapsed times and a long time delay is involved.
Abstract: The blending process of raw materials in the cement industry must be controlled with strong performances in order to facilitate a correct kiln operation. The main problem is a measurement one because the slurry composition analysis is performed at elapsed times and a long time delay is involved. In order to overcome this difficulty, a model reference control is presented in this paper. The initial control structurre is a minimal variance controller with a reference varying according to the blended product already stored in the homogenization silo. The control action in computed and apllied every three minutes instead of at blend analysis sampling periods (30 minutes). A paralele model of the mill allows this control evaluation. The error between mill model output and actual mill output is evaluated at sampling periods. This error generates an additional corrective action on the control signal. In the inter-sampling periods the control is computed from model output. This control strategie is being applied to a 200 Tn/h. cement mill. The main results of this experience are reported on the paper. As expected, one of the main features of strategie is a smoothed control.
1 citations
TL;DR: In this paper, a non-linear controller for lift installations is proposed, and the main difficulties that arose during the evaluation of a prototype with a linear regulator are reported, showing the load influence and the nonlinearity of the motor.
TL;DR: A new philosophy has been introduced related to the fact that structure and sequence of events can be considered separately, and the new modelling technique and its use for analysis and system simulations is introduced.
TL;DR: The implementation of a fault-tolerant multiprocessor system where low-cost has been a important feature for its design and the outline of the distributed operating system and global strategies of the system for fault detection and recovery is presented.
01 Jan 1986
01 Jan 1986
TL;DR: In this article, a real-time sofware system based on the Modula-2 programming language is described, which consists of a number of program modules that provide for concurrent task scheduling and communication, timing and input-output functions.
Abstract: A real-time sofware system based on the Modula-2 programming language is described. The system consists of a number of program modules that provide for concurrent task scheduling and communication, timing and input-output functions. An application of this system to the development of a real-time control program for a pilot-scale chemical plant is presented, and its main features discussed.