In the Laboratory

Dimeihylamine, C2H7N, (CH3)2NH. Colourless, inflammable liquid with an ammoniacal odour, mp -96" C, b.p. 7°C. Occurs naturally in herring brine. Prepared in the laboratory by treating nitrosodimetbyl-aniline with a hot solution of sodium hydroxide. Dimethylamine is largely used in the manufacture of other chemicals. These include the solvents dimethylacetamide and dimethyl-formamide, the rocket propellant unsym-metrical dimethylhydrazine, surface-active agents, herbicides, fungicides and rubber accelerators. 

The rate of radioactive transformations cannot be altered by changing the conditions which are available in the laboratory. The process is a spontaneous one. 

Asphaltenes are obtained in the laboratory by precipitation in normal heptane. Refer to the separation flow diagram in Figure 1.2. They comprise an accumulation of condensed polynuclear aromatic layers linked by saturated chains. A folding of the construction shows the aromatic layers to be in piles, whose cohesion is attributed to -it electrons from double bonds of the benzene ring. These are shiny black solids whose molecular weight can vary from 1000 to 100,000. 

Along the same lines, a distillation can be simulated by gas phase chromatography. As in a refinery, distillation in the laboratory is very often the first step to be carried out, because it gives the yields in different cuts gasoline, kerosene, etc., and makes further characterization of the cuts possible. 

As seen in Chapter 2, mixtures of hydrocarbons and petroleum fractions are analyzed in the laboratory using precise standards published by ASTM (American Society for Testing and Materials) and incorporated for the most part into international (ISO), European (EN) and national (NF) collections. We wiil recall below the methods utilizing a classification by boiling point ... 

The flash point is measured in the laboratory following procedures that depend on the sample being tested. 

In the distillation units for producing petroleum cuts, the curves are determined in the laboratory from samples taken at regular intervals. 

Measuring the gross heating value (mass) is done in the laboratory using the ASTM D 240 procedure by combustion of the fuel sample under an oxygen atmosphere, in a bomb calorimeter surrounded by water. The thermal effects are calculated from the rise in temperature of the surrounding medium and the thermal characteristics of the apparatus. 

The experimental conditions used to determine the CFPP do not exactly reflect those observed in vehicles the differences are due to the spaces in the filter mesh which are much larger in the laboratory filter, the back-pressure and the cooling rate. Also, research is continuing on procedures that are more representative of the actual behavior of diesel fuel in a vehicle and which correlate better with the temperature said to be operability , the threshold value for the Incident. In 1993, the CEN looked at two new methods, one called SFPP proposed by Exxon Chemicals (David et al., 1993), the other called AGELFI and recommended by Agip, Elf and Fina (Hamon et al., 1993). 

Typical analysis in the laboratory consists of sample validation, a compositional analysis of the individual and reoombined samples, measurement of oil and gas density and viscosity over a range of temperatures, and determination of the basic PVT parameters Bo, Roand B. ... 

Upon arrival in the laboratory the core will be sectioned (one third two thirds) along its... 

The main cost factor ot coring is usually the rig time spent on the total operation and the follow up investigations in the laboratory. Core analysis is complex and may involve different laboratories. It may therefore take months before final results are available. As a result of the relatively high costs and a long lead time of core evaluations the technique is only used in selected intervals in a number of wells drilled. 

The above experiment was conducted for a single fluid only. In hydrocarbon reservoirs there is always connate water present, and commonly two fluids are competing for the same pore space (e.g. water and oil in water drive). The permeability of one of the fluids is then described by its relative permeability (k ), which is a function of the saturation of the fluid. Relative permeabilities are measured in the laboratory on reservoir rock samples using reservoir fluids. The following diagram shows an example of a relative permeability curve for oil and water. For example, at a given water saturation (SJ, the permeability... 

The experiments were performed by U. Ewert and B. Redmer in the laboratory VIII.31 Radiation Techniques, Federal Institute of Material Research and Testing (BAM), Berlin, Geimany. 

Exposure of samples of film types selected by BAM with the same emulsion number in each case and out of the same package respectively in the laboratories of the project partners. 

Measuring of the parameters of the film system of these samples in BAM and in the laboratories of the partners. 

The water quality (air content) and the water flow influenced the measurements using one channel. Therefore the four channel system was first tested in the laboratory with a stationary tube. The best results were obtained using tap water and a well controlled flow in a water-filled chamber. A great difference in the concentration of air in the different grades of water was obvious, and the tap water was superior to soft water during these measurements. 

In compliance with the requirements stated in the System of accreditation to the practical experience and qualification the technical manager in NDT must have at least level 2 on each of NDT methods used in the laboratory seeking accreditation, where not more than 3 NDT methods are in practice, and level 3 on the basic method used in the laboratory where there are more than 3 methods. Moreover all specialists must be certified in relevant NDT method and industrial sector. 

While, in principle, a tricritical point is one where three phases simultaneously coalesce into one, that is not what would be observed in the laboratory if the temperature of a closed system is increased along a path that passes exactly tlirough a tricritical point. Although such a difficult experiment is yet to be perfomied, it is clear from theory (Kaufman and Griffiths 1982, Pegg et al 1990) and from experiments in the vicinity of tricritical points that below the tricritical temperature only two phases coexist and that the volume of one slirinks precipitously to zero at T. ... 

Figure A3.5.2. The Ar photofragment energy spectmm for the dissociation of fiions at 752.5 mn. The upper scale gives the kinetic energy release in the centre-of-mass reference frame, both parallel and antiparallel to the ion beam velocity vector in the laboratory.

Progress in the theoretical description of reaction rates in solution of course correlates strongly with that in other theoretical disciplines, in particular those which have profited most from the enonnous advances in computing power such as quantum chemistry and equilibrium as well as non-equilibrium statistical mechanics of liquid solutions where Monte Carlo and molecular dynamics simulations in many cases have taken on the traditional role of experunents, as they allow the detailed investigation of the influence of intra- and intemiolecular potential parameters on the microscopic dynamics not accessible to measurements in the laboratory. No attempt, however, will be made here to address these areas in more than a cursory way, and the interested reader is referred to the corresponding chapters of the encyclopedia. 

Figure Bl.3.6. The configuration of tire unit polarization vectors e, C2, and in the laboratory Cartesian basis as found in the ASTERISK teclurique.

Thaddeus P, MoCarthy M C, Travers M, Gottlieb C and Chen W 1998 New oarbon ohains in the laboratory and in interstellar spaoe Faraday See. Discuss. 109 121 -36... 

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