Historical introduction

The development of transition-metal-based, low-pressure ethylene polymerization technology resulted in the introduction of new process methods used for the commercial manufacture of polyethylene. Two of these low-pressure processes were the slurry polymerization process and the gas-phase process, both of which produce granular polyethylene particles in which the polyethylene is removed directly from the process as solid particles, which is referred to as particle-form technology. 

Therefore, suitable supports for second generation Ziegler-Natta catalyst systems must meet similar requirements in order to perform satisfactorily. 

The particle size of the finished catalyst precursor should range from about 1-250 [im (a preferred range of 10-100 tm). Spherical catalyst precursor particles are preferred but not necessary. Catalyst particles should provide granular polymer particles of 500-2000 p,m in diameter. Polymer particles of this size are optimal for the operation of the slurry and gas-phase polymerization processes. 

The log-linear model (LLM) is closely related to correspondence factor analysis (CFA). Both methods pursue the same objective, i.e. the analysis of the association (or correspondence) between the rows and columns of a contingency table. In CFA this can be obtained by means of double-closure of the data in LLM this is achieved by means of double-centring of the logarithmic data. 

According to Andersen [12] early applications of LLM are attributed to the Danish sociologist Rasch in 1963 and to Andersen himself. Later on, the approach has been described under many different names, such as spectral map analysis [13,14] in studies of drug specificity, as logarithmic analysis in the French statistical literature [15] and as the saturated RC association model [16]. The term log-bilinear model has been used by Escoufier and Junca [ 17]. In Chapter 31 on the analysis of measurement tables we have described the method under the name of log double-centred principal components analysis. 

Here we develop the method specifically from the point of view of contingency tables and within the context of weighted metrics. We will show that LLM differs only from CFA in the type of preprocessing that is applied to the contingency table. The results of both approaches are often similar when there are no extreme contrasts in the data. 

Preprocessing of the contingency table involves the taking of (natural) logarithms yy = og(Xij) with i = 1. n and j = 1. p followed by double centring  

From this point on, the analysis is identical to that of CFA. Briefly, this involves a generalized singular vector decomposition (SVD) of Z using the metrics W and Wp, such that  

The implications of the foregoing concept have profoundly influenced modern trends in polymer research. If polymers owe their differences from other compounds to the extent and arrangement of their primary valence structures, the problem of understanding them is twofold. It is necessary in the first place to provide appropriate means, both experimental and theoretical, for elucidating their macromolecular structures a nd for subjecting them to quantitative characterization. Secondly, suitable relationships must be established to express the de- 

Quantum theory was developed primarily to find an explanation for the stability of atomic matter, specifically the planetary model of the hydrogen atom. In the Schrodinger formulation the correct equation was obtained by recognizing the wave-like properties of an electron. The first derivation by Schrodinger [30] was done by analogy with the relationship that was known to exist between wave optics and geometrical optics in the limit where the index of refraction, n does not change appreciably over distances of order A. This condition leads to the eikonal equation (T3.15) 

To satisfy the conditions of wave mechanics the relationships are written in the form 

The operator representation for linear momentum and energy is derived from the derivatives 

The contours along which Hamilton s principal function S remains constant describe moving surfaces in Euclidean space. The gradient VS at each point of a moving surface is orthogonal to the surface, and the particle trajectories associated with S are given by the solutions to 

It follows that a family of trajectories may be obtained by constructing the normals to S, each one distinguished by its starting point x0. This description of particle motion is equivalent to the classic Huygens construction of elementary waves and their envelopes, with mechanical action taking the role of the phase in wave formalism. 

The history of cellulosic precursors is interesting because of its association with the early forms of carbon fiber used for electric lamp filaments. 

It was Dr. Robert Hooke [163,164], of Hooke s Law fame, who first recorded, in 1664, a possible technique for producing a man-made fiber that could be a substitute for natural silk but, unfortunately, he became too involved with his other inventions and architectural design, helping to rebuild the city of London after the Great Fire, to be able to undertake the requisite trials. 

In 1846, Schoenbein invented guncotton, a cellulose tetranitrate which, when dissolved in a 1 7 mixture of ethanol and diethylether, produced collodion, a thick viscous solution. The first patent to produce rayon in England was taken out by George Audemars [165] in 1855, who used collodion made from mulberry bark, and by dipping a needle into the viscous 

At about the same time as Edison was undertaking his work in the USA, Sir Joseph Swan in England had invented an electric lamp and in 1883, produced a precursor material for his carbon fiber lamp filaments by extruding a solution of nitrocellulose dissolved in acetic acid through a small hole into a bath of ethanol and collecting the drawn coagulated fiber, which he later denitrated with a solution of ammonium sulfide, to regenerate the initial cellulose. 

In 1899, Cross and Steam formed a laboratory-cum-pilot plant at Kew, London to make carbon fiber electric lamp filaments and artificial silk fibers. The national patent rights were gradually sold off and, in 1904, Courtaulds purchased the British rights, setting up a factory in Coventry, which was in production by 1905, becoming so successful that by 1909, 

Ecliptic Apparent orbit of the sun, the plane of the earth s orbit. 

Epicyclic frequency Rate at which an orbiting body sees radial and angular oscillations in nearly comoving orbits due to variations in eccentricities of the orbits. 

Mean anomaly Mean rate of motion of a body in an ellipse, relative to the center of the osculating circle. 

Osculating circular orbit Literally, the kissing orbit the circular reference orbit that precisely matches an inscribed ellipse along the major axis 

Perigee, perihelion Distance of closest approach to the central body, the earth or sun in this instance, respectively, in a conic section. The opposite of apogee or aphelion. 

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Domb C 1996 The Critical Point. A Historical Introduction to the Modern Theory of Critical Phenomena (London Taylor and Francis)... 

This handbook deals mainly with the practice of cathodic protection, but the discussion includes fundamentals and related fields as far as these are necessary for a complete review of the subject. We thought it appropriate to include a historical introduction in order to explain the technological development of corrosion protection. The second chapter explains the theoretical basis of metal corrosion and corrosion protection. We have deliberately given practical examples of combinations of various materials and media in order to exemplify the numerous fields of application of electrochemical protection. 

In the following sections and before we describe the synthesis of zaragozic acid A, we give a brief historical introduction to the dihydroxylation reaction, then describe the development of the Sharpless AD and some of its recent applications. 

The preceding quotation serves admirably as a brief historical introduction to x-ray diffraction. This field of research has proved enormously fruitful in yielding information about crystal structure, and in providing a means of obtaining monochromatic x-rays and of measuring their wavelength. The determination of crystal structure, though important to analytical chemistry, is outside the scope of this book.31... 

Historical Introduction and Perchlorates in General History. The early history of perchlorates and the perchlorate mdustryhas been thoroughly discussed (Refs 12 14, p 2), so it will be only briefly reviewed here. Early exptl work on chlorates and perchlorates was closely tied to the discovery and identification of Cl. Several workers, notably Priestly, Lavoisier, and Scheele reported the isolation of volat liqs and gases which probably were oxides or oxyacids of Cl, but they failed to identify and characterize the compds isolated. Scheele, for example, treated muriatic ac (HCl) with Mn dioxide and obtained a volat liq which he called muriatic ac derived of its phlogiston (Ref 14, p3). The first perchlorate definitely identified was the K salt which was prepd by Stadion in 1816 by the thermal decompn of K chlorate (Ref 2). From this he prepd a hydrate of perchloric ac by heating the K salt with sulfuric ac (Ref 3). Pure (anhyd) perchloric ac was first prepd by Roscoe in 1862 by distn of the hydrated ac (Ref 4)... 

In the historical introduction to this book (Sec. 1.1) it was mentioned that the discoverer of diazo compounds, Peter Griess, realized quite early (1864 a) that these species could react with alkali hydroxides. Thirty years later Schraube and Schmidt (1894) found that the primary product from the addition of a hydroxide ion to a diazo compound can isomerize to form a secondary product. In this section we will discuss the equilibria of the first acid-base process of aromatic diazonium ions. In the following section additional acid-base reactions will be treated in connection with the isomerism of addition products of hydroxide ions to diazonium ions. 

Andreae, Johann Valentin.Christianopolis an ideal state of the seventeenth century translated with historical introduction by F.E. Held. Translated by Felix Emil Held. New York OUP, 1916. 287p. 

Eastman Kodak Co. Historical introduction to the study of chemistry / Eastman Kodak Co., Teaching Films Division made in cooperation with the Film Committee of the Chemistry Teacher s Club of New York. Eastman Kodak Co., Teaching Films Division, 1937 ... 

An influential textbook in physical organic chemistry by Lapworth s student, William Waters, appeared in 1935 with an introduction by Lowry giving an account of recent developments as Lapworth saw them. 132 But, as Robinson knew, the history of a theory and the history of a discipline in large measure is created by historical introductions and the systems of citations in the most-cited articles and books in a field. 

Historical introductions to chemistry courses and citations in journal articles provided ample opportunity for scientists to trace family lines to suit the discipline-building task at hand and to set up a record for later historians. Ostwald made sure to settle his name into a progeny of physical chemists in his history of electrochemistry. Later, Ingold minimized the historical role of contemporary rivals by spare citations to work well known at the time. 

Lowry, T.M. (1936). Historical Introduction to Chemistry. Macmillan, London. Morgan, N. (1983). William Dobinson Halliburton, FRS, (1860-1931) Pioneer of British biochemistry Notes and records of the Royal Society 38, 129-145. Needham, J. (1970). The Chemistry of Life. Cambridge UP. 

D. Bremner, Historical introduction to sonochemistry. Advances in Sonochemistry,... 

One of the earliest references to USP s commitment to international harmonization may be found in the historical introduction to the 3rd revision [1] of the U.S. Pharmacopeia (1851) The new Dublin and London Pharmacopoeias were compared with our own, with a view of introducing uniformity wherever more important considerations did not seem to forbid the requisite modifications.. .. Note that uniformity for its own sake was not the sine qua non. 

A historical introduction into the uses of solar energy was attempted followed by a description of the various types of collectors including flat-plate, compound parabolic, evacuated tube, parabolic trough, Fresnel lens, parabolic dish and heliostat field collectors (Kalogirou, 2004a, 2004b). Solar thermal electricity systems utilize... 

CONTENTS Introduction to Series An Editor s Foreword, Albert Padwa. Introduction, Timothy J. Mason. Historical Introduction to Sonochemistry, D. Bremner. The Nature of Sonochemical Reactions and Sonoluminescence, M.A. Mar-guli. Influence of Ultrasound on Reactions with Metals, 6. Pugin and A.T. Turner. Ultrasonically Promoted Carbonyl Addition Reactions, J.L. Luche. Effect of Ultrasonically Induced Cavitation on Corrosion, W.J. Tomlinson. The Effects ... 

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