Research purpose

Free-living bacteria are, however, used as the source of the enzyme nitrogenase, responsible for N2 fixation (1,4,26,80), for research purposes because these ate easier to culture. The enzyme is virtually identical to that from the agriculturally important thizobia. These free-living N2-fixets can be simply classified into aerobes, anaerobes, facultative anaerobes, photosynthetic bacteria, and cyanobacteria. 

A number of pool, also called swimming pool, reactors have been built at educational institutions and research laboratories. The core in these reactors is located at the bottom of a large pool of water, 6 m deep, suspended from a bridge. The water serves as moderator, coolant, and shield. An example is the Lord nuclear reactor at the University of Michigan, started in 1957. The core is composed of fuel elements, each having 18 aluminum-clad plates of 20% enriched uranium. It operates at 2 MW, giving a thermal flux of 3 x 10 (cm -s). The reactor operates almost continuously, using a variety of beam tubes, for research purposes. 

Because of the time and expense involved, biological assays are used primarily for research purposes. The first chemical method for assaying L-ascorbic acid was the titration with 2,6-dichlorophenolindophenol solution (76). This method is not appHcable in the presence of a variety of interfering substances, eg, reduced metal ions, sulfites, tannins, or colored dyes. This 2,6-dichlorophenolindophenol method and other chemical and physiochemical methods are based on the reducing character of L-ascorbic acid (77). Colorimetric reactions with metal ions as weU as other redox systems, eg, potassium hexacyanoferrate(III), methylene blue, chloramine, etc, have been used for the assay, but they are unspecific because of interferences from a large number of reducing substances contained in foods and natural products (78). These methods have been used extensively in fish research (79). A specific photometric method for the assay of vitamin C in biological samples is based on the oxidation of ascorbic acid to dehydroascorbic acid with 2,4-dinitrophenylhydrazine (80). In the microfluorometric method, ascorbic acid is oxidized to dehydroascorbic acid in the presence of charcoal. The oxidized form is reacted with o-phenylenediamine to produce a fluorescent compound that is detected with an excitation maximum of ca 350 nm and an emission maximum of ca 430 nm (81). 

The study of the combustion of sprays of Hquid fuels can be divided into two primary areas for research purposes single-droplet combustion mechanisms and the interaction between different droplets in the spray during combustion with regard to droplet size and distribution in space (91—94). The wide variety of atomization methods used and the interaction of various physical parameters have made it difficult to give general expressions for the prediction of droplet size and distribution in sprays. The main fuel parameters affecting the quaHty of a spray are surface tension, viscosity, and density, with fuel viscosity being by far the most influential parameter (95). 

The American Association of Cereal Chemists has made avaUable a certified food grade wheat bran as a reference standard for research purposes. This bran is a blend of soft white wheat (87.3%) and club white wheat (12.7%). 

Other routes have also been devised which are sometimes useful for research purposes and include ... 

Personal monitoring devices (sometimes referred to as "dosimeters") are carried or worn by individuals and are used to measure that individual s exposure to particular chemical(s). Devices that include a pump are called "active" monitors devices that do not include a pump are called "passive" monitors. Such devices are currently used for research purposes. It is possible that sometime in the future they may also be helpful in lAQ investigations in public and commercial buildings. 

The recommended value of the face velocity has Ireen the subject of much debate and variation over the years. The recommended values have also varied widely with use. For example, CIBSE recommends values as low as 0.2 and 0.25 m s for fume cupboards for teaching and research purposes, respectively, and as high as 2.0 m for radioactive work dependii on grade. Middleton quotes the optimum range for the face velocity of laboratory fume cupboards to lie between... 

The nonporous spherical gels for PCHdC are often specially prepared for research purposes. However, nonporous polystyrene/divinylbenzene beads. Solid Bead, can be obtained in various particle sizes from Jordi Associates, Inc. (Bellingham, MA). Columns packed with these gels can be used for HdC of the polymers that are currently analyzed using polystyrene/divinylbenzene SEC columns. Fumed silica nanospheres are offered by Cabot (Tuscola, IL) (17), and nonporous silica (NPS) microspheres are offered by Micra Scientific, Inc. (Northbrook, IL). These nonporous silica gels may also be used for HdC. 

Apart from g Pu, which is a nuclear fuel and explosive, the transuranium elements have in the past been produced mainly for research purposes. A number of specialized applications, however, have led to more widespread uses. I Pu (produced by neutron bombardment of I Np to form 93 Np which decays by jS-emission to 94Pu) is a compact heat source (0.56 Wg as it decays by a-emission) which, in conjunction with PbTe thermoelectric elements, for instance, provides a stable and totally reliable source of electricity with no moving parts. It has been... 

To remove water, commercial ionic liquids used for fundamental research purposes should be dried at 60 °C in vacuo overnight. The water content should be checked prior to use. This can be done qualitatively by infrared spectroscopy or cyclovoltametric measurements, or quantitatively by Karl-Fischer titration. If the ionic liquids cannot be dried to zero water content for any reason, the water content should always be mentioned in all descriptions and documentation of the experiments to allow proper interpretation of the results obtained. 

Control laboratories in the canned food industry are usually divorced from the research organization to a lesser degree than is the case in the chemical and allied industries. For this reason, a closer relationship exists between the problems of the control laboratory and the research laboratory. Although from a research standpoint this condition is often considered undesirable, it has considerable merit in the case of the canned food industry, in which production may be seasonal and often of rather short duration. The collection of control data in many instances may also serve for research purposes—for example, in the case of soil analyses, which may be correlated with agricultural research designed to improve crop yields. Because the variables which affect the quality of canned foods must usually be investigated rather extensively, and often over a period of more than one year, the application of statistical methods to data collected for control purposes can conceivably make a substantial contribution to a research program. 

What is needed for operations research purposes is an extension of the theory of network flow to stochastic flow in edges that, in turn, have capacities, lengths, etc. that assume values stochastically. 

GHB has been used both for legitimate clinical and chnical research purposes and for a range of iUicit purposes. It was marketed legally in the United States until 1990, when the U.S. Food and Drug Administration (FDA) banned its sale to consumers. Except for the one indication described later in this section, GHB is a Schedule I controlled substance without other FDA-approved indications. The FDA has also declared y-butyrolactone (GBL) as a List I chemical and 1,4-butanediol (1,4-BD) as a Class I health hazard, practically designating these GHB precursors, which are also industrial solvents, as illicit and unapproved new drugs (National Institute on Drug Abuse 2000). 

Having a speed range from 2 to 100 km/h, although the maximum speed is usually not necessary for abrasion, except perhaps for research purposes... 

Diagnosis and procedure codes may reflect reimbursement strategies instead of clinically accurate diagnoses Limited information on important covariates Sparse outcomes data Lack of representativeness Lack of structure for research purposes... 

The distinction between software as a product and software as a service seems more relevant to research. As Prince [22] suggests, the fact that software is sold and used as a prepackaged item means that strict liability obtains. Should there be a defect in the software, the manufacturer is held liable. Flowever, and especially with research, software is often written with a specific purpose in mind. As such, the programmer is providing a service rather than a product. In the case of software written specifically for a certain research purpose, the liability may not fall exclusively on the software provider. In those situations, it behooves the researcher to be very clear in knowing and stating his or her purposes to the programmer. 

Several analytical methods are available to quantify chlorophylls and choice depends on the information needed. For quality control in industries and legislation attendance, simple and cost-effective methods represent widely used problem-solving approaches. For research purposes, more sensitive and precise methods are necessary to identify chlorophylls and derivatives simultaneously and individually. 

For the high accuracy needed in the quantitative measmement of the species, quality assurance of the analytical procedures is of prime importance. This can only be achieved by using representative RMs, certified for the relevant species. Up to now the number of existing certified reference materials is very limited. This section will give a survey of the main species that are presently determined routinely or for research purposes. 

The last of the lanthanides, this metal is also the hardest and the densest of them. It is a component of cerium mischmetal. Lutetium has some applications in optoelectronics. Shows great similarities to ytterbium. Its discoverer, Georges Urbain, carried out 15 000 fractional crystallizations to isolate pure lutetium (record ). The element has special catalytic properties (oil industry). 176Lu is generated artificially and is a good beta emitter (research purposes). 177Lu has a half-life of six days and is used in nuclear medicine. 

Besides alkylphosphates, OP metabolism gives rise to the production of other metabolites that can be used as exposure markers (Table 4). Unchanged OP compounds in blood or urine can also be measured to confirm exposure (Table 4), but this method is of limited use for routine biological monitoring of occupational exposure, as OP compounds are rapidly excreted in urine. Moreover, most OP pesticides are unstable, and, with a few exceptions, they are not detectable in biological specimens after a few hours. So far, the measurement of unchanged compounds in biological fluids has been performed primarily for research purposes and has limited practical applicability. 

With animal viruses, the initial host may be a whole animal which is susceptible to the virus, but for research purposes it is desirable to have a more convenient host. Many animal viruses can be cultivated in tissue or cell cultures, and the use of such cultures has enormously facilitated research on animal viruses. 

Some cell cultures prepared in this way will grow indefinitely, and can be established as permanent cell lines. Such cell cultures are most convenient for virus research because continuously available cell material can be available for research purposes. In other cases,... 

Several excellent reviews have appeared recently covering emerging therapies in CF, including CFTR modulators [45-47] and a collection of CFTR modulators are available through the CFF Consortium for research purposes [48]. Multiple structural classes that potentiate CFTR have been identified by screening compound libraries, natural products, and approved drugs. A subset is described below, which has proved amenable to lead optimization. 

Random" measurements made at no charge for willing participants selected randomly by mailing service computers. They are used for research purposes described below, and to study methods for making data from the 12 measurements useful. 

Continuous culture systems have been widely used to culture microorganisms for industrial and research purposes (Kubitschek 1970 Tempest 1970 Veldkamp 1976 Rhee 1980). In recent years, these culture techniques have found their way into the bioassay methods of ecotoxicology and allelopathy (Rhee 1980). The early development of a continuous culture system can be traced back to the work of Novik and Szilard (1950 a,b) who developed the first chemostat. In a continuous culture system, nutrients are supplied to the cell culture at a constant rate and to maintain a constant volume, an equal volume of cell culture is removed. This allows the cell population to reach a steady state, where the growth rate and the total number of cells/ml of culture remains constant. Two kind of continuous culture systems can be distinguished turbidostat and chemostat. ... 

If a recombinant protein is developed and expressed for research purposes, the most labor- and cost-intensive part of the project normally lies with the upstream tasks, i.e. cloning, expression vector design, sequencing, transformation and selection. Once a suitable expresser strain or plant line is available, it is often sufficient to visualize expression of the recombinant protein, verify its activity, study its biological... 

The choice of solid carriers spans a wide spectrum (Table 1) from materials most suitable for research purposes (sintered glass beads, laterite stone deposited on a gramophone disk) to industrial materials (pumice, activated carbon, etc.). Key properties that affect the performance of the carrier are porosity (from impervious to controlled-size pores), composition (from ceramics to activated carbon), and hydrophilic behavior. It is difficult to perform a direct comparison of different carriers. Colonization and biofilm growth depend strongly on the nature of bacteria and on their intrinsic propensity to adhere on hydrophilic vs. hydrophobic surfaces. 

Although the United States began investigating carbamates as warfare agents in the late 1950s, there is no information to indicate that these agents have ever been used other than for research purposes. 

Many of these properties would obviously limit applicability of non-continuous cell lines in the industrial-scale production of recombinant proteins. However, such cell types are routinely cultured for research purposes, toxicity testing, etc. 

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