The Clausius inequality corrected for heat transfer involving radiation

The objective of this paper is to prove that the Clausius inequality must be re-stated to have general applicability for heat transfer involving radiative fluxes. The integrand (đQ/T) of the Clausius expression applies to heat conduction and convection, but does not hold for most radiative transfer scenarios, with the exception of reversible infinitesimal net blackbody radiation transfer. In other cases involving radiative transfer, the equality holds for a cycle even though irreversible heat addition by radiative transfer occurs. This is without the erroneous presumption of entropy destruction anywhere in the cycle. Thus, the Clausius inequality indicates reversibility for a cycle that includes an irreversible process. Further, in some radiative cases the quantity đQ/T, where T is the boundary temperature, is not the entropy transfer at the system boundary, and in fact, primarily represents entropy production within the system. It is also clear that in another case considered, the quantity đQ/T had no physical meaning whatsoever. Consequently, the Clausius expression has been re-stated so that it is applicable to cycles with processes involving any form of heat transfer. A new integrand (đQ_cc/T + đS_Net,Rad) is presented, allowing the Clausius inequality to generally apply to all heat transfer scenarios. The work in this paper emphasizes the need to re-state other fundamental equations allowing applicability to all heat transfer processes, and draws attention to the unique character of radiative entropy calculations.     

Coupling of free surface and groundwater flows

In this paper we present some preliminary results about the coupling of shallow water equations for free surface flows and Darcy equation for groundwater flows. A suitable set of interface conditions is discussed: the Beavers and Joseph formula for the bottom stress is used. An iterative algorithm to solve the coupled problem is proposed and some numerical results are presented.     

石油企业办社会的“悖理行为”辨疑

企业办社会虽与市场经济的客观要求相悖，但石油企业大量办社会的事实仍揭示了所具备的理性面。认为国家作为不受所有者监督的代理者对石油企业的要求，石油企业的行业特性以及在传统体制下长期运作所成的定热是石油企业办社会的主要原因。     

Law,liability and expert systems

This paper examines some of the possible legal implications of the production, marketing and use of expert systems. The relevance of a legally useful definition of expert systems, comprising systems designed for use both by laymen and professionals, is related to the distinctions inherent in the legal doctrine underlying provision of goods and provision of services. The liability of the sellers and users of, and contributors to, expert systems are examined in terms of professional malpractice as well as product liability. A recurring theme indicates that legislators may be inclined to restrict possibilities of liability suits in order to avoid disincentives to the creation of expert systems.     

工程招投标中的违法现象及对策

在分析工程招投标中的违法现象及产生原因的基础上，提出相应对策和减少违法投标的措施。     

A new ‘Tailor-made’ methodology for the mechanical behaviour analysis of rubber-like materials: II. Application to the hyperelastic behaviour characterization of a carbon-black filled natural rubber vulcanizate

The purpose of this paper is the modelling of the mechanical behaviour of an elastomeric material, through detailed experimental and numerical procedures, specific to large strains. The experimental technique is based on in-plane kinematics measurements using a speckle extensometer, from which the whole two-dimensional field of in-plane displacements is obtained by a digital image processing [Polymer (2002)]. This part of the work concerns the identification of the constitutive equation for a carbon black natural rubber (NR) vulcanizate. We start by quoting some theoretical considerations relative to rubber elasticity and stress-softening effect, which is the counterpart of the filler reinforcement. Then, we describe the experimental procedure and present data for both non-preconditioned and preconditioned samples. Next, the identification of the constitutive law parameters using a minimization algorithm is driven. Finally, we present the validation of the constitutive model, by its implementation into the finite element code SYSTUS and the numerical simulation of the response of a double edge notched tensile (DENT) specimen.     

Efficient and accurate approach for powder compaction problems

 In this paper, a new approach for powder cold compaction simulations is presented. A density-dependent plastic model within the framework of finite strain multiplicative hyperelastoplasticity is used to describe the highly nonlinear material behaviour; the Coulomb dry friction model is used to capture friction effects at die-powder contact; and an Arbitrary Lagrangian–Eulerian (ALE) formulation is used to avoid the (usual) excessive distortion of Lagrangian meshes caused by large mass fluxes. Several representative examples, involving structured and unstructured meshes are simulated. The results obtained agree with the experimental data and other numerical results reported in the literature. It is shown that, contrary to other Lagrangian and adaptive h-remeshing approaches recently reported for this type of problems, the present approach verifies the mass conservation principle with very low relative errors (less than 1% in all ALE examples and exactly in the pure Lagrangian examples). Moreover, thanks to the use of an ALE formulation and in contrast with other simulations, the presented density distributions do not present spurious oscillations. Received: 20 March 2002 / Accepted: 15 October 2002 The partial financial support of the Ministerio de Ciencia y Tecnología (grant number DPI 2001-2204) is gratefully acknowledged.     

SIMILARITY LAW OF FLUCTUATING PRESSURE WITHIN HYDRAULIC JUMP AREA

Through a series of model tests of five scales for 2-D free hydraulic jump, the da-ta of fluctuating pressure acting on the floor level within the hydraulic jump were obtained. Dur-ing the experiments, Froude number varied from 2.94 to 8.61, and Reynolds number rangedfrom 2×10~4 to 6×10~5. Experiment results indicate that the amplitude scale of fluctuating pres-sure is the length scale of model, i. e. P'=L, which agrees with gravity similarity law: Thefrequency scale of the fluctuating pressure is a unity i. e., f=1, which does not satisfy thegravity similarity law.     

Diffusion Coefficient of a Binary Liquid System

A generalized diffusion coefficient correlation for a binary system of liquids has been developed to represent the data for a wide range of temperatures. Detailed analysis shows that the proposed correlation fits the experimental measurements of diffusivity with the corresponding calculated values with an acceptable percentage error.     

Non-Steady Equilibrium during Pro-Eutectoid Ferrite Formation in Fe-0.2C Alloy

Ｔｈｅｐｒｅｃｉｐｉｔａｔｉｏｎｏｆｐｒｏ ｅｕｔｅｃｔｏｉｄｆｅｒｒｉｔｅｆｒｏｍａｕｓｔｅｎｉｔｅｉｓｃｏｎｔｒｏｌｌｅｄｂｙｄｉｆｆｕｓｉｏｎｉｎＦｅ Ｃａｌｌｏｙｓ .Ｗｉｔｈｔｈｅａｓｓｕｍｐｔｉｏｎｔｈａｔｔｈｅｍｉｇｒａｔｉｎｇｉｎｔｅｒｆａｃｅｉｓａｌｗａｙｓｉｎｌｏｃａｌｅｑｕｉｌｉｂｒｉｕｍ ,ｅａｒｌｙｉｎ 194 9,ＺｅｎｅｒＣ[1] ｅｘｐｌａｉｎｅｄｔｈｅｄｉｆｆｕｓｉｏｎａｌｇｒｏｗｔｈｏｆｐｒｏ ｅｕｔｅｃ ｔｏｉｄｆｅｒｒｉｔｅｂｙｕｓｉｎｇｔｈｅＦｉｃｋ’ｓｌａｗ .Ｓｉｎｃｅ…