Line Selection

In order to achieve single-line oscillation in laser media that exhibit gain for several transitions, wavelength-selecting elements inside or outside the laser resonator can be used. If the different lines are widely separated in the spectrum, the selective reflectivity of the dielectric mirrors may already be sufficient to select a single transition. 

The line at A = 3.39 umoratA = 0.633 nm can be selected using special mirrors. The different lines around 1.15 Lim cannot be separated solely via the spectral reflectivity of the mirrors other measures are required, as outlined below. 

If some of the simultaneously oscillating laser transitions share a common upper or lower level, such as the lines 1, 2, and 3 in Fig. 5.29c and Fig. 5.31a, gain competition diminishes the output of each line. In this case, it is advantageous to use intracavity line selection in order to suppress all but one of the competing transitions. Sometimes, however, the laser may oscillate on cascade transitions (Fig. 5.31b). In such a case, the laser transition 1 2 increases the population of level 2 and therefore enhances the gain for the transition 2 3 [327]. Obviously, 

For lasers with a broad continuous spectral gain profile, the preselecting elements inside the laser resonator restrict laser oscillation to a spectral interval, which is a fraction of the gain profile. 

Some examples illustrate the situation (see also Sect. 5.7)  

Some examples, besides those given in Sect.5.7, illustrate the situation  

HeNe Laser. The HeNe laser is probably the most thoroughly investigated gas laser [5.38]. From the level scheme (Fig.5.31) which uses the Paschen notation [5.39], we see that two transitions around A = 3.39 /xm and the visi- 

This laser transition populates the 3p4 level, and produces gain for another line at A = 2.3951 pm. This last line only oscillates together with the 3.3913-/xm one, which acts as pumping source. This is an example of cascade transitions in laser media [5.36], as depicted in Fig.5.30b. 

HeNe Laser The HeNe laser is probably the most thoroughly investigated gas laser [5.39]. From the level scheme (Fig. 5.30), which uses the Paschen notation [5.40], we see that two transitions around X = 3.39 p.m and the visible transitions at X = 0.6328 p.m share a common upper level. Suppression of the 3.39 p.m lines therefore enhances the output power at 0.6328 xm. The 1.15 p.m and the 0.6328 p.m lines, on the other hand, share a common lower level and also compete for gain, since both laser transitions increase the lower-level population and therefore decrease the inversion. If the 3.3903-p.m transition is suppressed, e.g., by placing an absorbing CH4 cell inside the resonator, the population of the upper 3. 2 level increases, and a new line at A. = 3.3913 p.m reaches the threshold. 

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Steam pre.s.sure. Ejector selection should be based upon the minimum pressure in the supply line selected to serve the unit. 

Equation (24.3) defines the active power as independent of p.f. However, depending upon the p.f. of the load, this will adjust the load angle S. The larger the angle of transmission, the higher will be the power transfer. Figure 24.19 illustrates the power transfer characteristics of a 250 km line selected from Table 24.5. 

Figure 13.11 Column-switcliing RPLC trace of a surface water sample spiked with eight chlorophenoxyacid herbicides at the 0.5 p-g 1 level 1, 2,4-dichlorophenoxyacetic acid 2, 4-chloro-2-methylphenoxyacetic acid 3, 2-(2,4-diclilorophenoxy) propanoic acid 4, 2-(4-cliloro-2-methylphenoxy) propanoic acid 5, 2,4,5-trichlorophenoxyacetic acid 6, 4-(2,4-dichlorophenoxy) butanoic acid 7, 4-(4-chloro-2-methylphenoxy) butanoic acid 8, 2-(2,4,5-tiichlorophenoxy) propionic acid. Reprinted from Analytica Chimica Acta, 283, J. V. Sancho-Llopis et al., Rapid method for the determination of eight chlorophenoxy acid residues in environmental water samples using off-line solid-phase extraction and on-line selective precolumn switcliing , pp. 287-296, copyright 1993, with permission from Elsevier Science.

J. V. Sancho-Elopis, E. Hernandez-Hernandez, E. A. Hogendoorn and P. van Zoonen, Rapid method for the determination of eight clilor ophenoxy acid residues in envhon-mental water samples using off-line solid-phase excaction and on-line selective precolumn switching . Anal. Chim. Acta 283 287-296(1993). 

E. Referring to Figure 9-21B or 21C, read up from the abscissa to the pressure drop line selected, and read across to the ordinate (note differences) ... 

In the internal standard method the intensity of the unknown line is measured relative to that of an internal standard line. The internal line may be a weak line of the main constituent. Alternatively, it may be a strong line of an element known not to be present in the sample and furnished by adding a fixed small amount of a compound of the element in question to the sample. The ratios of the intensities of these lines — the unknown line and the internal standard line — will be unaffected by the exposure and development conditions. This method will provide lines of suitable wavelength and intensity by variations of the added element and the amount added, due regard being paid to the relative volatility of the selected internal standard element. It is important to use as internal standard pairs only those lines of which the relative intensities are insensitive to variations in excitation conditions. The line selected as standard should have a wavelength close to that of the unknown and should, if possible, have roughly the same intensity. 

Table 4. Salt resistance of plants regenerated from cell lines selected for tolerance of salt iir vitro...

Fig. 1. Change of R22 conversion and selectivity for TFE with TOS (solid line R22 conversion dot line selectivity for TFE).

The PCR technique is very useful during all stages of the research and development of biotech crops. PCR analysis is used for gene discovery, event selection, screening, transformant identification, line selection and plant breeding. Quantitative real-time PCR is used to determine the number of transgene copies inserted in experimental... 

Explain the general intention of the vessel and its lines Select a line... 

The development of isofemale lines selected for different developmental routes is affected by temperature, but the magnitude of the effect differs... 

Fig. 5.4. The sensitivity of four isofemale lines of S. ratti in response to temperature. ED248 Heterogonic ( ) and ED132 Homogonic (a) are two lines selected for heterogonic and homogonic development, respectively, from an ancestral line (ED132). ED5 Heterogonic ( ) and ED5 Homogonic ( ), as for Fig. 5.3. Error bars are 95% confidence intervals.

A number of attempts have been made to select on nematode immune-related traits. Lines of Heligmosomoides polygyrus have been selected in hosts with different histories of previous exposure (naive, once previously exposed, or multiply previously exposed). This resulted in parasite lines that differed in fitness when tested in semi-immune animals, with the lines selected in the hosts with greatest previous exposure surviving best and... 

Figure 4 Structure of UCS1025A 46 with COSY-defined spin systems (bold lines), selected NOSEY (dashed arrows), and HMBC (solid arrows) correlations.

Fig. 31 Trajectories of seven crystallizing chains (thick lines) selected at random from 640 chains during crystallization at 330 K a at 0.128 ns, b at 6.4 ns, c at 12.8 ns, and d at 19.2 ns. Also shown are the growing crystalline domains (thin parallel lines). Pictures are all side view along the x-axis...

Likelihood of developing dependence to nicotine will involve specific functional changes in the brain. Examining the detailed genetic basis for these functional changes is difficult in humans, so animal models are needed. Three approaches have been taken to examining genetic influences of the effects of nicotine in rodents namely inbred lines, selectively bred lines and knockout mice. 

Chemical abundances are inferred from the EW of the lines. Selected lines and atomic data are from our previous paper [5], from [4] and. Stellar parameters were first inferred from Geneva photometry and Hipparcos parallaxes. Then temperatures, microturbulence velocities, gravities and metallicities were iteratively changed in order to i) obey the excitation equilibrium of the Fe I lines ii) require that Fe I and Fe II abundances agree within 0.1-0.15 dex and iii) require that Fe I lines with different equivalent widths (EW) give the same iron abundance. 

Raman spectroscopy is primarily useful as a diagnostic, inasmuch as the vibrational Raman spectrum is directly related to molecular structure and bonding. The major development since 1965 in spontaneous, c.w. Raman spectroscopy has been the observation and exploitation by chemists of the resonance Raman effect. This advance, pioneered in chemical applications by Long and Loehr (15a) and by Spiro and Strekas (15b), overcomes the inherently feeble nature of normal (nonresonant) Raman scattering and allows observation of Raman spectra of dilute chemical systems. Because the observation of the resonance effect requires selection of a laser wavelength at or near an electronic transition of the sample, developments in resonance Raman spectroscopy have closely paralleled the increasing availability of widely tunable and line-selectable lasers. 

Rickard DJ, Hofbauer LC, Bonde SK, Gori F, Spelsberg TC, Riggs BL (1998) Bone morphogenetic protein-6 production in human osteoblastic cell lines. Selective regulation by estrogen. J Clin Invest 101 413-422... 

Levy, L. M., Warr, D., and Attwell, D. (1998) Stoichiometry of the glial glutamate transporter GLT-1 expressed inducibly in a Chinese hamster ovary cell line selected for low endogenous Na+-dependent glutamate uptake. J. Neurosci. 18,9620-9628. 

Segal, I., Kloner, A., and Brenner, I. B. (1994). Multielement analysis of archaeological bronze objects using inductively coupled plasma-atomic emission spectrometry -aspects of sample preparation and spectral-line selection. Journal of Analytical Atomic Spectrometry 9 737-744. 

Mirski, S.E., Gerlach, J.H. and Cole, S.P. (1987) Multidrug resistance in a human small cell lung cancer cell line selected in adriamycin. Cancer Research, 47, 2594-2598. 

The ELISA is a versatile method that can be used throughout the biopharmaceutical product development process, from small-scale research to cell-line selection, to monitoring fermentation and downstream processing, and to product release testing. The use of the microtiter plates allows for high sample throughput and various degrees of automation. ELISAs satisfy the biopharmaceutical production requirements for specific, accurate, precise, and reproducible assays. 

The representative example of this type of laser is the CO2 laser. Laser oscillation is achieved on many rotational lines within two vibrational transitions of the molecule. Without any line selection, the system oscillates at only around 10.6 /u.m. This transition is found to give a continuous wave (cw) output power of several kilowatts with an efficiency of around 30 %, which is quite exceptional for a gas laser. 

Vaysse L, Burgelin I, Merlio JP, et al. Improved transfection using epithelial cell line-selected ligands and fusogenic peptides. Biochim Biophys Acta 2000 1475(3) 369-376. 

Allen, J. D., Biinkhuis, R. F., Wijnholds, J., and Schinkel, A. H. (1999) The mouse Bcrpl/ Mxr/Abcp gene amplification and overexpression in cell lines selected for resistance to topo-tecan, mitoxantrone, or doxorubicin. Cancer Res. 59, 4237-4241. 

Previous experience in arc and spark emission spectroscopy has revealed numerous spectral overlap problems. Wavelength tables exist that tabulate spectral emission lines and relative intensities for the purpose of facilitating wavelength selection. Although the spectral interference information available from arc and spark spectroscopy is extremely useful, the information is not sufficient to avoid all ICP spectral interferences. ICP spectra differ from arc and spark emission spectra because the line intensities are not directly comparable. As of yet, there is no atlas of ICP emission line intensity data, that would facilitate line selection based upon element concentrations, intensity ratios and spectral band pass. This is indeed unfortunate because the ICP instrumentation is now capable of precise and easily duplicated intensity measurements. 

Courage C, Bradder SM, Jones T, Schultze-Mosgau MH, Gescher A (1997) Characterisation of novel human lung carcinoma cell lines selected for resistance to anti-neoplastic analogues of staurosporine. Int J Cancer 73 763-768... 

In this part we deal with the major chemical and physical factors affecting insect cell growth, baculovirus replication and product expression. The issues addressed are cell line selection for product expression, baculovirus-cell interactions and impact of differences in metabolic requirements of infected and non-infected cells in overall productivity. 

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