Investigative experiments description

Historically, the problems studied and the approaches followed in scientific investigations are strongly constrained by the loading methods and diagnostics available to a particular investigator. Hence, the complete scientific description of shock-compressed matter often requires the interpretation of experiments from a number of independent directions that are often not consistent with each other and may contain significant ambiguities. 

This section covers radiation due to BLEVEs with accompanying fireballs. First, a brief description is given of experimental investigations of BLEVEs and their fireballs. Next, some fireball models, primarily for predicting fireball diameter and combustion duration, are presented. Most of these models evolved from experimental results. Finally, some radiation models, based on experiments and theory, are given. 

In summary, all the experiments expressly selected to check the theoretical description provided fairly clear evidence in favour of both the basic electronic model proposed for the BMPC photoisomerization (involving a TICT-like state) and the essential characteristics of the intramolecular S and S, potential surfaces as derived from CS INDO Cl calculations. Now, combining the results of the present investigation with those of previous studies [24,25] we are in a position to fix the following points about the mechanism and dynamics of BMPC excited-state relaxation l)photoexcitation (So-Si)of the stable (trans) form results in the formation of the 3-4 cis planar isomer, as well as recovery of the trans one, through a perpendicular CT-like S] minimum of intramolecular origin, 2) a small intramolecular barrier (1.-1.2 kcal mol ) is interposed between the secondary trans and the absolute perp minima, 3) the thermal back 3-4 cis trans isomerization requires travelling over a substantial intramolecular barrier (=18 kcal moM) at the perp conformation, 4) solvent polarity effects come into play primarily around the perp conformation, due to localization of the... 

Investigations have been performed to exemplify the DO surface removal rates from biofilms grown on different types of wastewater (Bjerre et al., 1998b). Such investigations may indicate if Equation (5.3) can be considered an appropriate description of the aerobic activity. The wastewater for these studies originates from an open sewer system, the Emscher river, Germany. The results of the experiments are outlined in Table 5.2, and further details are shown in Figures 5.6 and 5.7. 

With respect to the considerations above, research is split into three parts. The first is connected to the kinetic description of the release of ammonia from the biomass as function of temperature. This research employs infrared spectroscopy using a tunable diode laser. Here very small biomass particles are used that are heated up very rapidly in a small reactor, which ensures that transport effects are virtually excluded from the kinetic release effects. Since ammonia is released in very small quantities it is quite hard to detect. Therefore, we first measure CO release, which is easier. In the second part we investigate the propagation of a conversion front in biomass layers. Here we perform experiments and try to establish a modeling approach for the propagation by analytical and numerical approaches. In the third part the gas-phase conversion processes are described in terms of... 

Rossini s paper on the enthalpy of formation of water [99] is a masterpiece in terms of careful description of the experiment and presentation of data. It makes us wonder if the publication of all those details, which have been essential for updating the value of Af7/°(H20,1) over the years, would still be accepted by most modern journals. If the current tendency to eliminate from publications the reporting of primary results and basic experimental details had prevailed in the 1930s, Rossini s work on water would probably have had to be repeated by later investigators. 

Many areas of computational chemistry are gaining permanent place as dependable research techniques by providing reliable descriptions of structures and properties of chemical compounds. Due to improvements of hardware and accessibility of many commercial programs a theoretical study supplements experimental investigations and provides new accurate data when experiments are not available. Such... 

The next section, which is the most extensive, deals with the various kinds of spectroscopic experiments which have been done or can be done with lasers as external light sources, where external means that the probe under investigation is placed outside the laser resonator. Together with a brief description of the experiments and a summary of the results, there is a discussion of the main qualities of the laser which made these special investigations possible. 

Modern science is very different from the descriptions of early systems of thought. Early philosophers and theorists lacked the objective methodologies and rational investigative processes required for the controlled experiments that led to modern science. They were more concerned with seeking universal cures for sickness, transmutation of base metals into gold, and mysticism in general. Most, but not all, ancient philosophers depended more on the written words of experts than on their own observations and insights. 

Compounds 1,2,3,5,10,11,12,13,14 were dissolved in EPIP (diethyl ether, petroleum ether, isopropanol 5 5 2)whereas compounds 4,6,7,8,9,15 were dissolved in THF-DE (tetrahydrofurane, diethyl ether 1 1). These solvent mixtures can be frozen as glassy samples at 77 K. The absorption spectra were recorded on a standard spectrophotometer SF-10 or Beckman-5270. The measurements of fluorescence excitation and emission spectra were made with the aid of a spectrofluorometer SLM-4800 with automatic correction of spectral response. Fluorescence lifetimes were measured with the aid of a pulse fluorometer PRA-3000. Magnetic circular dichroism (MCD) measurements were carried out in a 8 kG magnetic field using a JASCO J-20 circular dichrometer. Triplet state formation was observed for investigated compounds at the experimental set up, whose detailed description can be found in our paper (27). The optical experiments were carried out with a porphyrin concentration of 4.10- - 4.10 mol.l". In NMR investigations (Bruker WM-360) we used higher concentrations ( 5.10" raol.l ) and dried solvents (CDCl, C 2 and toluene-d0). 

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