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Concept practical applications

The words basic concepts" in the title define what I mean by fundamental." This is the primary emphasis in this presentation. Practical applications of polymers are cited frequently—after all, it is these applications that make polymers such an important class of chemicals—but in overall content, the stress is on fundamental principles. Foundational" might be another way to describe this. I have not attempted to cover all aspects of polymer science, but the topics that have been discussed lay the foundstion—built on the bedrock of organic and physical chemistry—from which virtually all aspects of the subject are developed. There is an enormous literature in polymer science this book is intended to bridge the gap between the typical undergraduate background in polymers—which frequently amounts to little more than occasional relevant" examples in other courses—and the professional literature on the subject. [Pg.726]

The invention of the germanium transistor in 1947 [I, 2] marked the birth of modem microelectronics, a revolution that has profoundly influenced our current way of life. This early device was actually a bipolar transistor, a structure that is mainly used nowadays in amplifiers. However, logical circuits, and particularly microprocessors, preferentially use field-effect transistors (FETs), the concept of which was first proposed by Lilicnficld in 1930 [3], but was not used as a practical application until 1960 [4]. In a FET, the current flowing between two electrodes is controlled by the voltage applied to a third electrode. This operating mode recalls that of the vacuum triode, which was the building block of earlier radio and TV sets, and of the first electronic computers. [Pg.244]

Electrochemical promotion or NEMCA is the main concept discussed in this book whereby application of a small current (1-104 pA/cm2) or potential ( 2 V) to a catalyst, also serving as an electrode (electrocatalyst) in a solid electrolyte cell, enhances its catalytic performance. The phenomenology, origin and potential practical applications of electrochemical promotion, as well as its similarities and differences with classical promotion and metal-support interactions, is the main subject of this book. [Pg.10]

This simple concept has already found some practical applications The idea to use supported alkali-promoted noble metal catalysts for NO reduction,3,4 even under mildly oxidizing conditions,5 came as a direct consequence of electrochemical promotion studies utilizing both YSZ (Chapter 8) and p"-Al203 (Chapter 9), which showed clearly the electrophi-licity of the NO reduction reaction even in presence of coadsorbed O. This dictated the use of a judiciously chosen alkali promoter coverage to enhance both the rate and selectivity under realistic operating conditions on conventional supported catalysts. [Pg.516]

Some of the most important applications for conducting polymers which might show at least some commercial viability in the near future are listed in Table 3. The list is by no means complete, and is growing all the time. However, one should not expect fundamental progress in practical applications until basic research on conducting polymers moves beyond the stage of trial and error, and develops concepts to obtain quantitative information about molecular structures and properties, on the one hand, and the resultant material properties on the other hand. [Pg.35]

The use of Upid bilayers as a relevant model of biological membranes has provided important information on the structure and function of cell membranes. To utilize the function of cell membrane components for practical applications, a stabilization of Upid bilayers is imperative, because free-standing bilayer lipid membranes (BLMs) typically survive for minutes to hours and are very sensitive to vibration and mechanical shocks [156,157]. The following concept introduces S-layer proteins as supporting structures for BLMs (Fig. 15c) with largely retained physical features (e.g., thickness of the bilayer, fluidity). Electrophysical and spectroscopical studies have been performed to assess the appUcation potential of S-layer-supported lipid membranes. The S-layer protein used in aU studies on planar BLMs was isolated fromB. coagulans E38/vl. [Pg.369]

At all stages of the development of electrochemistry, an intimate connection existed between the development of theoretical concepts and the discovery of solutions for a practical application of electrochemical processes and phenomena. Theoretical investigations have been stimulated by the practical use of various electrochemical phenomena and processes, and the theoretical concepts that were developed have in turn contributed signihcantly to the development of applied electrochemistry. [Pg.321]

Significance of the Faraday s laws, e= F/N relationship between the Faraday, Avogadro s number and the charge on the electron Besides the practical applications so far described, Faraday s laws have an important significance in so far as theoretical interest goes. The laws have introduced the concept of atomic nature of electricity. [Pg.676]

The paper is structured to be read at three levels. The main thread of the text is a review of fundamentals and previous studies. Illustrations focusing on specific systems or more detailed elaboration of concepts are interspersed in the text. Many of these include new results they form a second level that can be read as independent subunits. Finally, the conclusions of each section, especially those with significance for practical applications, are summarized as heuristics]. [Pg.109]

Combined principles of thermodynamics are widely utilized in assessing the performances of heat storage systems. Thermoeconomics further combines the thermodynamic principles with engineering economics to estimate the cost of exergy, and optimize the cost under various constraints. Although, Valero et al. (1989) tried to unify the thermoeconomic theories, the concepts and procedures may vary, and create ambiguity in practical applications (Szargut, 1990 Tsataronis, 1993 Erlach et al., 1999 Sciubba, 2003). [Pg.134]

The early practical application of antioxidants was connected with the development of rubber production. The rubber is easily oxidized in air, and the first antioxidants were empirically found and used to stabilize it [1]. Empirical search for antioxidants was performed by Moureu and Dufresse [2] during the First World War. These researchers successfully solved the problem of acrolein stabilization by the addition of hydroquinone. They explained the retarding action of the antioxidant in the scope of peroxide conception of Bach and Engler (see Chapter 1). They proposed that the antioxidant rapidly reacts with the formed hypothetical moloxide and in such a way prevents the autoxidation of the substrate. [Pg.488]

Although simple in concept, the application of gene therapy to treat/cure genetic diseases has, thus far, made little impact in practice. The slow progress in this regard is likely due to a number of factors. These include ... [Pg.438]

Planning requirements for the specified value chain are elaborated in this chapter based on the value chain management framework established in chapter 2. Planning requirements are gathered from industry cases, research literature analysis and practice studies. A state of the art analysis of recent literature is conducted for these requirements in order to present recent concepts and applicable ideas and to specify research gaps. Requirements collection and coverage by state of the art literature is summarized at the end of the chapter also as input for the model development in the subsequent chapter. [Pg.105]

The book covers a gamut of related topics such as methods for determining atoms-in-molecuies, population analysis, electrostatic potential, molecular quantum similarity, aromaticity, and biological activity. It also discusses the role of reactivity concepts in industrial and other practical applications. Whether you are searching for new products or new research projects, this is the ultimate guide for understanding chemical reactivity. [Pg.593]

Re-design the Concept Organizer on page xxx so that it includes practical applications and explanations such as those you have investigated in this activity. [Pg.196]

Unfortunately, these aza-ethers showed limited solubility in the polar solvents that are typically preferred in nonaqueous electrolytes, and the electrochemical stability window of the LiCl-based electrolytes is not sufficient at the 4.0 V operation range required by the current state-of-the-art cathode materials. They were also found to be unstable with LiPFe. Hence, the significance of these aza-ether compounds in practical applications is rather limited, although their synthesis successfully proved that the concept of the anion receptor is achievable by means of substituting an appropriate core atom with strong electron-withdrawing moieties. [Pg.126]


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