Experimental research

Hughes, D.E. Induction Balance and experimental Researches therewith. Phil. Mag. S5. Vol8, pp50... 

The results of an experimental research activity aimed at the system setup of the Stress Pattern Analysis by Measuring Thermal Emission used to measure the sum of the principal stresses of the free surface are presented. 

During many years in Scientific Research Institutes of Nuclear Physics and Introscopy at Tomsk Polytechnical University (TPU) researches into induction electron accelerators and their uses for non-destructive radiation quality control of materials and articles have been conducted. Control sensitivity and efficiency detection experimental researches have been conducted with the high-current stereo-betatron modifications [1], and KBC-25 M and BC-50 high-current betatrons [2,3] in range of 11 MeV and 25-50 MeV radiation energy. 

The resistance to nucleation is associated with the surface energy of forming small clusters. Once beyond a critical size, the growth proceeds with the considerable driving force due to the supersaturation or subcooling. It is the definition of this critical nucleus size that has consumed much theoretical and experimental research. We present a brief description of the classic nucleation theory along with some examples of crystal nucleation and growth studies. 

The fonnation of surface aggregates of surfactants and adsorbed micelles is a challenging area of experimental research. A relatively recent summary has been edited by Shanna [51]. The details of how surfactants pack when aggregated on surfaces, with respect to the atomic level and with respect to mesoscale stmcture (geometry, shape etc.), are less well understood than for micelles free in solution. Various models have been considered for surface surfactant aggregates, but most of these models have been adopted without finn experimental support. 

The scientific method, as mentioned, involves observation and experimentation (research) to discover or establish facts. These are followed by deduction or hypothesis, establishing theories or principles. This sequence, however, may be reversed. The noted twentieth-century philosopher Karl Popper, who also dealt with science, expressed the view that the scientist s work starts not with collection of data (observation) but with selection of a suitable problem (theory). In fact, both of these paths can be involved. vSignificant and sometimes accidental observations can be made without any preconceived idea of a problem or theory and vice versa. The scientist, however, must have a well-prepared, open mind to be able to recognize the significance of such observations and must be able to follow them through. Science always demands rigorous standards of procedure, reproducibility, and open discussion that set reason over irrational belief. 

M. Earaday, Experimental Researches in Electricity, Taylor and Erancis, London, 1838 Dover, New York, 1965, Vol. I, 1168. 

The birth of the field of carbon nanotubes is marked by the publication by lijima of the observation of multi-walled nanotubes with outer diameters as small as 55 A, and inner diameters as small as 23 A, and a nanotube consisting of only two coaxial cylinders [2]. This paper was important in making the connection between carbon fullerenes, which are quantum dots, with carbon nanotubes, which are quantum wires. FurtheiTnore this seminal paper [2] has stimulated extensive theoretical and experimental research for the past five years and has led to the creation of a rapidly developing research field. 

Studies on the electronic structure of carbon nanotube (CNT) is of much importance toward its efficient utilisation in electronic devices. It is well known that the early prediction of its peculiar electronic structure [1-3] right after the lijima s observation of multi-walled CNT (MWCNT) [4] seems to have actually triggered the subsequent and explosive series of experimental researches of CNT. In that prediction, alternative appearance of metallic and semiconductive nature in CNT depending on the combination of diameter and pitch or, more specifically, chiral vector of CNT expressed by two kinds of non-negative integers (a, b) as described later (see Fig. 1). 

This chapter is organized as follows. First, an overview of experimental research is presented. Experimental research has focused on identifying deflagration-enhancing mechanisms in vapor cloud explosions and on uncovering the conditions for a direct initiation of a vapor cloud detonation. 

At first glance, the science of vapor cloud explosions as reported in the literature seems rather confusing. In the past, ostensibly similar incidents produced extremely different blast effects. The reasons for these disparities were not understood at the time. Consequently, experimental research on vapor cloud explosions was directed toward learning the conditions and mechanisms by which slow, laminar, premixed combustion develops into a fast, explosive, and blast-generating process. Treating experimental research chronologically is, therefore, a far from systematic approach and would tend to confuse rather than clarify. 

Because the major causes of blast generation in vapor cloud explosions are reasonably well understood today, we can approach the overview of experimental research more systematically by treating and interpreting the experiments in groups of roughly similar arrangements. Furthermore, some attention is given to experimental research into the conditions necessary for direct initiation of a detonation of a vapor cloud and the conditions necessary to sustain such a detonation. 

Experimental research has shown that a vapor cloud explosion can be described as a process of combustion-driven expansion flow with the turbulent structure of the flow acting as a positive feedback mechanism. Combustion, turbulence, and gas dynamics in this complicated process are closely interrelated. Computational research has explored the theoretical relations among burning speed, flame speed, combustion rates, geometry, and gas dynamics in gas explosions. 

Experimental research during the last decade (Section 4.1) has shown clearly that deflagrative combustion generates blast only in those portions of a quiescent vapor cloud which are sufficiently obstructured and/or partially confined (Zeeuwen et al. 1983 Harrison and Eyre 1987 Harris and Wickens 1989 Van Wingerden 1989a). 

In the overview of experimental research, it was shown that explosive, blastgenerating combustion in gas explosions is caused by intense turbulence which enhances combustion rate. On one hand, turbulence may be generated during a gas explosion by an uncontrolled feedback mechanism. A turbulence-generative environment, in the form of partially confining or obstructing structures, must be present for this mechanism to be triggered. 

TABLE 6.3. Overview of Experimental Research on Fireball Generation... 

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