bluuebunny/crossref_metadata_2025_split huggingface dataset:
Constructal Optimization of Paths for Heat Transfer
Authors: Bejan A 
Published: November 2023

Abstract
This article is a review of recent work in which heat transfer enhancement, or thermal resistance minimization is achieved by optimizing the internal architecture of a heat-generating volume. When the cooling is provided by a stream that flows through the volume, it is possible to optimize the spacings between the internal features that are being cooled. When the cooling function is served by a point-size heat sink, a fixed amount of high conductivity material can be distributed through the volume to minimize its overall thermal resistance. The discovery is that any volume element can have its shape (or size) optimized such that its flow resistance is minimal. The given volume is covered in successive steps of optimization and construction. The visible portion of the optimized volume-to-point flow path that emerges is a tree network that is completely deterministic. This solution has a definite time direction: from small to large, hence the name “constructal”. Small size and slow and shapeless flow (diffusion) come first, and larger sizes and organized flows (streams) come later.
Prediction of Turbulent Heat Transfer 1n Single-Phase Industrial Flows
Authors: Launder B E 
Published: November 2023

Abstract
The paper surveys recent developments at UMIST in the computational modelling of heat transfer in single-phase turbulent flows. Particular attention is given to models capable of wide geometric applicability because only such approaches find utility in industrial applications. Attention is mainly given to non-linear eddy-viscosity models and second-moment closure with applications drawn principally from turbomachinery applications.
Continuous Cellular Automata for Heat Conduction
Authors: Berezovski A 
Published: November 2023

Abstract
A generalization of cellular automata is presented to simulate heat conduction in continua. The essential feature of the method is a description of the interaction between the elements of a continuum in terms of the Gibbsian phase space instead of the space of physical variables. The behaviour of the material satisfies the equations of state or constitutive equations. The method provides a tool for the direct simulation of a process rather than for the solution of partial differential equations. One- and two-dimensional examples of the method are discussed.
Random Walk Trajectory Model of Interphase Heat Exchange in Turbulent Two-Phase Flow
Authors: Brenerman M H , Kessel A R 
Published: November 2023

Abstract
The universally accepted continuous mixture (CM) models are valid for describing two-phase flows (TPF) when the inhomogeneities have a characteristic size which is much less than the scale of the problem. There is a great interest in creating alternative models. Here a combined EulerianLagrangian mathematical model of heat transfer in TPF with large-scale inhomogeneities is presented. It treats the kinetics of the carrying phase as a random process and that of the dispersed phase as a random walk (Lagrangian approach on a macro scale). The interaction between the particles and the carrying phase is chosen in a classical form (Eulerian approach on a micro scale). Differential equations are replaced by a random walk simulation scheme. This approach incorporates some phenomenological details of TPF and is simple for numerical simulation.
Solving Systems of Ordinary Differential Equations
Authors: Heggs P J , Walton C 
Published: November 2023

Abstract
If a process is described by a system of ordinary differential equations, which is also a boundary value problem (BVP), a clearer physical understanding is obtained from the solution of the BVP problem, rather than treating the system as an initial value problem (IVP). As an example, the thermal analysis of a 1:2 pass exchanger has been considered. In such an exchanger, the thermal performance may be described by 3 simultaneous ordinary differential equations containing three dependent variables. It is shown that the solution of these equations as an initial value problem results in the Logarithmic Mean Temperature Difference (LMTD) approach. In contrast the boundary value problem leads to the Effectiveness - Number of Transfer Units (c-NTu) method and the solution itself generates three dimensionless parameters, each of which has a clear physical significance.
Precedence Ordering Techniques
Authors: Heggs P J , Walton C 
Published: November 2023

Abstract
Engineers frequently encounter systems of non-linear equations. Precedence ordering is a technique which not only minimizes the number of steps in their solution, but can also reveal whether an explicit solution exists. As an example, the technique is applied to the rating calculation for the performance evaluation of a heat exchanger. It is often stated that the use of the logarithmic mean temperature difference methodology in the rating calculation requires an iterative procedure. By applying a precedence ordering technique, it is shown that this is untrue, and that it is possible to obtain an explicit solution for the new duty.
New Approach to Modelling Structures of Randomly Intersecting Pores. Application to Char Gasification
Authors: Kantorovich I I , Bar-Ziv E 
Published: November 2023

Abstract
A general approach to the analytical treatment of arbitrary complex random porous structures has been developed. The idea of the method is that all information on the porous system can be obtained from a consideration of the intersections of infinite imaginary objects with the elements of the porous structure. The combination of features that must be imposed on the system (set of probabilities, shape of interpore contact region, combination of shapes of pores and/or solid elements, conditions of intersections, etc.) determines a specific model of the porous structure. A model of the porous structure based on cylindrical pores (grains) truncated at the inersections is developed. Variations of the internal surface area of char during gasification have been studied. A comparison of the model results with experimental data on char reactivity has not revealed a correlation between the surface area and reactivity.
Heat Transfer of High Temperature Fouling in Combustion Chambers
Authors: Mulholland A J , Gomatam J 
Published: November 2023

Abstract
In the current economic and political climate it is vital to develop energy saving methodologies as well as protecting the environment. According to recent studies conducted by the European Union, heat exchangers, due to their ubiquity in industry, represent the largest potential area for energy saving. Their efficiency is significantly affected by the build-up of insulating deposits, known as fouling, on their surfaces. We present an image analysis of industrial deposits which confirms their fractal morphology; we exploit these properties to derive an equation governing the fouling resistance which has an explicit dependency on the Sierpinski fractal dimension of the deposit geometry. Using computer simulated deposits, which include the auto-retardation effect of compaction but with no deposit removal, we show that the fouling resistance can not only reach an asymptotic value over time as the mass increases, but in fact can decrease. This is due to the increased connectivity of the constituent particles and reduced insulation as the density increases.
Modelling of Heat Transfer Processes 1n Naturally Fractured Oil Formations
Authors: ustrov V N , Plochoi S 
Published: November 2023

Abstract
It is well-known that many naturally fractured oil and gas beds display a non-linear behaviour during their development (1). Therefore, the application of a standard linear approach (2) for such formations is limited. A non-linear dependence of the effective bed parameters upon the stress state system is suggested within the framework of the model [3]. Consequently the effective porosity and permeability coefficients can decrease significantly when the reservoir pressure falls. Investigations of some classic and new filtration problems confirm the usefulness of the approach. Here two non-isothermal filtration processes are considered. The first is the injection of a hot fluid into a fractured formation. Such a process is used to increase the recovery rate of oil. The second process is that of non-isothermal gas filtration.
Confidence Intervals for Transient Estimation of Thermal Properties - Theory
Authors: Osman A M , Al-Najem N M , Beck J V 
Published: November 2023

Abstract
The present paper develops an efficient method for the construction of confidence intervals of thermal properties estimates when correlated random errors are present in temperature measurements. A first-order autoregressive model is used to model autocorrelated measurement errors. An efficient method for numerical evaluation of the covariance matrix of the estimated parameters is described. The approximate Bonferroni method is used to provide simultaneous 95% confidence intervals. A test case for simultaneous estimation of thermal conductivity and volumetric specific heat, and the associated 95% confidence intervals is presented. The paper concludes with a preliminary Monte Carlo study to validate the developed method for the estimation of confidence intervals.
Numerical Modelling of Concentration Fluctuations in Turbulent Reactive Plumes in the Atmospheric Boundary Layer
Authors: Silue M , Mokhtarzadeh-Dehgham M R 
Published: November 2023

Abstract
A major source of atmospheric pollution is the exhaust gases released from the combustion of fossil fuels in the power generation and other industries. The nitrogen oxides in the effluent are of major concern as they react with atmospheric oxidants to produce nitrogen dioxide which has harmful environmental effects. As a gas it adversely effects health and vegetation at low concentrations (of order 200 parts per billion by volume). It also undergoes reactions leading to fine particles and aerosols which are readily taken up in cloud and rain water and contribute to the acidification of rainfall.
Modelling Crystallization in Chocolate Moulding
Authors: Tewkesbury H , Stapley A G F , Fryer P J 
Published: November 2023

Abstract
Classical models for phase change in materials cannot be applied to chocolate as a sharp solidification front cannot be identified. This makes a front tracking or moving mesh system inappropriate. Chocolate can, instead, be classified as a continuous solidification process [1] for treatment by finite-element analysis. The numerical modelling of chocolate solidification is not simple as the rate at which chocolate is cooled during the production process affects the rate of crystallization and thus the generation of latent heat.
Minimizing Heat Loss into Creeping Flow Past a Cylinder
Authors: Turfus C 
Published: November 2023

Abstract
The heat loss from a cylinder translating uniformly at low speed in an unbounded region of viscous fluid is considered. If the obstacle’s boundary is given by a conformal outer-radius-preserving mapping of a circle, a global maximum is achieved when the circle is mapped onto a line segment aligned parallel to the direction of motion. If the cylinder boundary is constrained to be an ellipse, a minimum occurs with a line segment aligned perpendicular to the direction of motion, although this is not a minimum in the space of general perturbations. The heat loss from star-shaped cylinders is independent of the angle of their orientation.
Analytical Investigation into the Effect of Thermal Capacity on the Phase Delay Angle used to Determine Local Heat Transfer Coefficients
Authors: Turnbull W O , Oosthuizen P H 
Published: November 2023

Abstract
A proposed one-dimensional model for transient heat conduction within a thermally thin surface layer bonded to an adiabatic substrate is expanded to include the effects of back conduction. The adiabatic model suggests that it may be possible to measure local heat transfer coefficients from the phase delay that develops between a sinusoidally imposed surface heat flux and the local surface temperature. The results from the expanded model indicate that the back conduction and substrate thermal capacity cannot be ignored, even when using materials of very low thermal resistivity. However, the previously indicated phase delay angle is still apparent, albeit significantly modified by the effects of the substrate thermal capacity.
Process research and development: the modern approach
Authors: Cabri Walter , Fabio Romano Di 
Published: November 2023

Abstract
The evolution of chemistry during the last 20 years has been impressive; there are practically no limits on what can be synthesized in a laboratory. Nowadays, medicinal chemists have available an incredible portfolio of reactions and analytical apparatus to design new drugs to meet society’s needs. The most important and spectacular characteristics of the drugs discovered since the 1980s are the complexity and sophistication of their architecture. However, over the last five years, the drug discovery process has changed dramatically, making use of different technologies such as high-throughput screening and combinato rial chemistry. This approach, based on solid phase chemistry, results in simple structures, generally heterocycles, that are flat with a poor chemical diversity. The first decade of the third millennium will tell us if this type of approach, based on numbers of new molecules and not on diversity and complexity, will allow us to discover new successful drugs.
Losartan
Authors: Cabri Walter , Fabio Romano Di 
Published: November 2023

Abstract
This chapter describes the evolution of the synthesis of the cardiovascular drug losartan potassium 1. This molecule, now largely in use as an antihypertensive agent, was the first approved drug of its class. The claims of the patents filed by DuPont/Merck’s researchers over the years determined the synthetic approaches that other companies developed to produce losartan 1 analogues. From a chemical and industrial point of view, the most interesting topic of this chapter is palladium(O)-catalysed synthesis of biphenyls such as in the Suzuki- and Negishi-type reactions.
Concerning Biot-Savart’S Law
Authors: Chemin Jean-Yves , Gallagher Isabelle , Iftimie Dragos 
Published: November 2023

Abstract
It is very easy to describe in terms of the curl whether a divergence-free vector field belongs to spaces of the LP type or not. Proposition 3.1.1 Let a and b be two real numbers such that There exists a constant C such that, for every antisymmetric matrix Ω with coefficients in La, there exists a unique divergence-free vector field belonging to the space La + Lb, having Ω as curl and satisfying As the space s is dense in La, we may assume that the coefficients of the matrix Ω belong to s. Biot-savart’s law (1.8) says that
Analyticity and Gevrey Regularity
Authors: Chemin Jean-Yves , Gallagher Isabelle , Iftimie Dragos 
Published: November 2023

Abstract
The aim of this chapter is to describe some properties concerning high order regularities in the Euler equation. The two principal theorems we will prove here concern the regularity in time of the flow of a solution of the Euler system (E). They are: Theorem 8.1.1 Let r be a real number, strictly greater than 1.
Samuel’s Checkersplaqer and Other Models as Cgp’s
Authors: Holland John H 
Published: November 2023

Abstract
In chapters 3 and 4 we closely examined two modeling projects that increased our understanding of learning and self-organization: Samuel’s checkersplayer and models of Hebb’s theory of the central nervous system. Both studies took place at IBM at the dawn of the computer age, but they teach lessons that are surprisingly current. We have only recently advanced beyond what was learned at that time, and many current studies fail to take those lessons about learning and self-organization into account. In part, such failures occur because the field moved in other directions for a long time. But the lessons also seemed largely tied to the specific efforts, checkers and Hebb’s theory. Their general applicability was questioned.
The coarse extreme: life on sandy beaches
Authors: Little Colin 
Published: November 2023

Abstract
Sand and shingle shores are high-energy environments. Waves pound the shores, stirring up and eroding particles, making settled life difficult for plants and animals. The particles are, in any case, non-cohesive, so unless they are held together by the actions of organisms, the sediment is unstable. There are often few signs of life to be seen on the surface, where the particles are most likely to be disturbed: most fauna is infauna.
A fine option: life on mudflats and seagrass beds
Authors: Little Colin 
Published: November 2023

Abstract
There is no strict demarcation in particle size between sand beaches and mudflats. Despite the powerful sorting capacity of currents derived from waves and tides, both invariably have a wide range of particle sizes. In estuaries especially, sediment may even have alternating layers of mud and sand laid down by successive current regimes. Nevertheless, the differences between a clean sandy beach facing the open ocean (where particles larger than 63 µm predominate) and a sheltered mudflat (where many particles are less than 63 µm) are enormous.
Life at the bottom: sublittoral sediments and community structure
Authors: Little Colin 
Published: November 2023

Abstract
Below the level of low tide, species common in the intertidal zone are replaced by others. In part, the changes are related to increasing depth, so there are species characteristic depth zones. In some cases the reasons for this sublittoral zonation are fairly easily understood-for instance algae and seagrasses do not penetrate to great depths because they need light for photosynthesis. But in general, we know little of why species are distributed in this way, and there have been no rigorous tests to examine why intertidal species are not found in the sublittoral.
Experimental determination of structure factor phases in biocrystallography
Authors: Fourme Roger , Shepard William , Schiltz Marc , Ramin Michel , Kahn Richard 
Published: November 2023

Abstract
X-ray crystallography plays a central role in the elucidation of three dimensional structures of biological macromolecules as it can reach, in favourable conditions, atomic or near-atomic resolution. The sample is a single crystal that diffracts X-ray radiation. In optical microscopy, the recombination of scattered rays (which is expressed mathematically as a Fourier synthesis) is performed by the lens system of the microscope; in the case of crystallography, the synthesis is performed by computation. Unfortunately, measurements allow us to derive quantities proportional to the amplitudes of diffracted rays, but the phases are lost. This difficulty, known as the phase problem, is familiar to all crystallographers. In the case of macromolecular crystals, special procedures have been designed to get estimates of lacking phases. The present chapter is devoted to this question.
Local structure of metalloproteins at atomic resolution by XAFS
Authors: Hasnain S S 
Published: November 2023

Abstract
Soon after the first X-ray experiment using X-rays from a synchrotron for muscle diffraction (Rosenbaum et al. 1971), the Kronig and Kossel structures of the physics text books were transformed into a ubiquitous technique called XAFS (X-ray absorption fine structure) (Sayers et al. 1971; Kincaid and Eisenberger 1975), which found immediate applications in biology, chemistry, geology and materials science [see, e.g. Goulon et al. (1997)]. The growth of the subject has been very rapid and can be judged by the size of the proceedings for first international XAFS conference (140 pp.) held in March 1981 at Daresbury (Garner and Hasnain 1981) and the tenth conference in August 1998 in Chicago (nearly 900 pp. of the Journal of Synchrotron Radiation (1999), 6, Part 3). Worldwide, the number of XAFS instruments continues to increase, some 25% of all SR instruments are either devoted or partially used for doing XAFS.
Separating the wheat from the chaff
Authors: Freeman Ray 
Published: November 2023

Abstract
A high resolution NMR spectrum contains two kinds of information-signals that will help us solve the chemical problem in hand, and the remaining signals that are of no real interest. In many cases the latter are more numerous or more intense and may mask the former. So we must find some specific property that allows us to discriminate between them. It may be based on differences of chemical shift, spin-spin coupling, relaxation times, the number or topology of coupled spins, or on symmetry properties. Some of these techniques are so important that they are in everyday use, others are more specific and perhaps less well-known.
Inter-group aggression and territoriality in Tar chimpanzees
Authors: Boesch Christophe , Boesch-Achermann Hedwige 
Published: November 2023

Abstract
Forest scenes, questions of neighbourhood: In the early days of the project we had difficulty in estimating the size of the territory of the study community. We happened to be following for a certain distance a noisy group of chimpanzees that vocalized and drummed at regular intervals, in what we considered the northern range of their territory. After about two hours of moving northwards, we started to wonder how far they were going and tried to get into visual contact without scaring them by approaching too quickly. In striking contrast to the behaviour we had so far achieved in the habituation process, they immediately ran away at full speed before we could even get a faint glimpse of them. This was quite unlike what we expected. We expected them to be curious and, if they decided to leave, they would do so quietly and slowly. It became obvious that we had been following two communities, first the one under study and then a totally non-habituated neighbour community. What is it that attracts two communities? Do they have violent interactions or do they peacefully intermingle? 27 June 1985: We were with a large party in the northern part of the territory. The chimpanzees quietly socialized after having fed for some time on the abundant fruit of Chrysophyllum trees. Macho had been trying for some time to lead the oestrus female Loukoum away from the other males, without much success. Suddenly, at 14.55, as he had just made another attempt to lead her away, he found himself, without any kind of warning, facing several stranger chimpanzees who rushed towards him. With a tremendous scream of fear, Macho ran towards the other males to be reassured by Brutus and Schubert, the alpha and beta males. They stared for a few seconds in the direction of the strangers, then the three of them followed by four other adult males charged with typical waa-barks against the strangers. Possibly surprised by the violence of this immediate reaction, the strangers fled and were pursued for many hundred metres before the two parties apparently settled down to exchange signals by drumming and calls.
Divergence along genetic lines of least resistance
Authors: Schluter Dolph 
Published: November 2023

Abstract
The idea that genetic variation in a population is limited, that traits covary genetically, and that the results of natural selection are consequently biased, is older than the ecological theory of adaptive radiation (Maynard Smith et al., 1985). Simpson (1953) mentioned the idea (see the above quote) but made no attempts to determine whether in any adaptive radiation ‘the realized path of evolution [was] more likely, in strictly genetic terms, than the paths not taken’ (Futuyma et al., 1995). A conceptual framework for addressing the question had not yet been developed and the ecological theory did not incorporate one. Yet, incorporating such a framework would benefit the study of adaptive radiation for at least one very practical reason: if genetics favours certain paths of evolution over others, then the direction and rate of phenotypic divergence is partly predictable. In this chapter I evaluate the success of recent attempts to predict divergence in adaptive radiation from genetic measurements of populations.