Specific Laboratory Experiments

Preparation of Experiment-Specific Laboratory Chemical Safety Summaries from Material Safety Data Sheets for Undergraduate Chemistry Courses... 

OSHA mandated Material Safety Data Sheets (MSDSs) contain important safety information that should be incorporated into undergraduate chemistry instruction. Ho>vever, these documents are not well designed for the academic teaching laboratory. Additionally, there is little or no coverage of MSDSs in chemistry laboratory manuals or textbooks. One approach to the incorporation of this topic this is the introduction of a student exercise that involves the preparation of an experiment-specific laboratory chemical safety summary (LCSS) based on the LCSSs presented in the latest edition of Prudent Practices in the Laboratory (1). These one-page student-prepared summaries use information obtained from MSDSs, but are modified to the actual quantities, concentrations, and procedures used in the experiment. This approach provides beginning chemistry students with appropriate education about MSDSs. 

Plant designers are well supplied with corrosion data by materials manufacturers. These data are based on both experience and laboratory studies, but the information is usually based on specific parameters such as concentration of chemical or temperature. Edeleanu has emphasised this problem... 

The preparation and execution should follow a validation protocol, in which the scope of the method and its validation criteria should first be defined (46). The scope of the analytical method should be clearly understood since this will govern the validation characteristics that need to be evaluated. For example, if the method is to be used for qualitative trace residue analysis, there is no need to examine and validate its linearity over the full dynamic range of the equipment. The scope of the method should also include the different types of equipment and the locations where the method will be run. In this way, experiments can be limited to what is really necessary. For example, if the method is intended for use in one specific laboratory, there is no need to include other laboratories and different equipment in the validation experiments. 

Temperature Dependence. Early experiments with laboratory stills and a variable-speed steam compressor had shown that heat transfer and yield increased with temperature. The No. 5 compressor has a fixed speed and, since the specific volume of the steam decreases as temperature increases, the compressor was evidently starved for steam and operated in the unstable region when run at evaporator temperatures above 125° F. However, a trend toward increasing performance persisted,... 

The scope of the method should include the different types of equipment and the locations where the method will be run. For example, if the method is to be run on one specific instrument in one specific laboratory, there is no need to use instruments from other vendors or to include other laboratories in the validation experiments. In this way the experiments can be limited to what is really necessary. 

For mechanistic studies, ambient pressure experiments on emulsions and foams often offer significant experimental advantages over high-pressure experiments. However, high-pressure measurements are also needed since the phase behavior, physical properties of the fluids, and dispersion flow may all depend on pressure. Experiments under laboratory conditions that closely match reservoir conditions are particularly important in the design of projects for specific fields. Chapter 19, by Lee and Heller, describes steady-state flow experiments on CO2 systems at pressures typical of those used in miscible flooding. The following chapter, by Patton and Holbrook,... 

Huff, J., Cirvello, J., Haseman, J., and Bucher, J. (1991). Chemicals associated with site-specific neoplasia in 1394 long-term carcinogenesis experiments in laboratory rodents. Environ Health Perspect 93, 247-270. 

The scattering expressions in Sections 3.2 and 3.3 have been written in general tensoi notation and hence are independent of any specific laboratory coordinate system used for a scattering experiment. It is, however, convenient for many applications to use... 

The idea of a rapid reaction is so much conditioned by experience and laboratory equipment as to be hard to define nowadays. When the first rapid reactions in biochemistry were studied by Hartridge and Roughton more than 60 years ago, a rapid reaction was simply one too fast to follow using a stopwatch to time removal of samples from a reaction vessel. A modem equivalent might define rapid as beyond the reach of the apparatus expected to be part of the equipment of an average biochemical laboratory, and translate into a half-time less than 5-10 sec. The choice of methods to discuss is even more difficult because little equipment has achieved off-the-shelf status, and groups of workers have assembled unique systems tailored to specific applications. The present material therefore represents an arbitrary selection, influenced by personal bias. 

The elucidation of the scalar coupling network by the correlation experiments is, apart from small molecules, not sufficient for the unambiguous, sequential and stereo-specific assignment. The complementary information of spatially adjacent protons is obtained via cross-relaxation experiments, the laboratory-frame nuclear Overhauser enhancement spectroscopy (NOESY) and the rotating-frame nuclear Overhauser effect spectroscopy (ROESY). These experiments provide also the distance restraints for the structure determination and help to recognize exchange processes. 

Specific Laboratory Experiments Of What Value Is This Experiment ... 

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