Titanium fluorescence

X-Ray Methods. A camera with a curved quartz crystal monochromator served to identify the crystal type of the sulfide under study and to verify that it belonged to a single-phase system. To reduce the effect of the titanium fluorescence excited by the copper radiation used, an aluminum filter 0.03 mm. thick was... 

Wavelength dispersive x-ray fluorescence spectrometric (xrf) methods using the titanium line at 0.2570 nm may be employed for the determination of significant levels of titanium only by carefiil matrix-matching. However, xrf methods can also be used for semiquantitative determination of titanium in a variety of products, eg, plastics. Xrf is also widely used for the determination of minor components, such as those present in the surface coating, in titanium dioxide pigments. 

Fischer A, Cremer C, StelzerEHK (1995) Fluorescence of coumarins and xanthenes after two-photon absorption with a pulsed titanium-sapphire laser. Appl Opt 34 1989-2003... 

The introduction and diversification of genetically encoded fluorescent proteins (FPs) [1] and the expansion of available biological fluorophores have propelled biomedical fluorescent imaging forward into new era of development [2], Particular excitement surrounds the advances in microscopy, for example, inexpensive time-correlated single photon counting (TCSPC) cards for desktop computers that do away with the need for expensive and complex racks of equipment and compact infrared femtosecond pulse length semiconductor lasers, like the Mai Tai, mode locked titanium sapphire laser from Spectra physics, or the similar Chameleon manufactured by Coherent, Inc., that enable multiphoton excitation. 

Two-photon fluorescence microscopy has also been used with good effect in the near-IR. For example, Ferguson et al.r24> at the University of Strathclyde have used 270 fsec pulses from a titanium sapphire (Ti sapphire) laser at 790 nm to observe visible fluorescence from dyes in zebra fish larvae and erythrocytes. The high depth and lateral definition afforded by the two-photon process and confocal microscopy are useful here. Also, the use of near-IR excitation minimizes photobleaching. 

In the other study. X-ray fluorescence spectroscopy was used to analyze trace element concentrations by observing dusts on 37 ram diameter cellulose acetate filters (20). Twenty-three elutriator and twenty-three area samples from 10 different bales of cotton were analyzed. The average fraction of total dust accounted for by the elements analyzed was 14.4% amd 7.6% for vertical elutriator and area samples, respectively. Although the variation in absolute quantity of atn element was high, the relative abundance of an element was consistent for measurements within a bale. Averaged over all the samples analyzed, calcium was the most abundant element detected (3.6%), followed by silicon (2.9%), potassium (2.7%), iron (1.1%), aluminum (1.1%), sulfur (1.0%), chlorine (0.8%) and phosphorous (0.6%). Other elements detected in smaller aunounts included titanium, manganese, nickel, copper, zinc, bromine, rubidium, strontium, barium, mercury amd lead. 

Titanium dioxide suspended in an aqueous solution and irradiated with UV light X = 365 nm) converted benzene to carbon dioxide at a significant rate (Matthews, 1986). Irradiation of benzene in an aqueous solution yields mucondialdehyde. Photolysis of benzene vapor at 1849-2000 A yields ethylene, hydrogen, methane, ethane, toluene, and a polymer resembling cuprene. Other photolysis products reported under different conditions include fulvene, acetylene, substituted trienes (Howard, 1990), phenol, 2-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol, 2,6-dinitro-phenol, nitrobenzene, formic acid, and peroxyacetyl nitrate (Calvert and Pitts, 1966). Under atmospheric conditions, the gas-phase reaction with OH radicals and nitrogen oxides resulted in the formation of phenol and nitrobenzene (Atkinson, 1990). Schwarz and Wasik (1976) reported a fluorescence quantum yield of 5.3 x 10" for benzene in water. 

Electrons from the heated tungsten filament are accelerated to the annular anode. Depending on the anticathode material a characteristic fluorescence radiation is emitted, passes through a thin Aluminum window and induces photoelectrons on the surface of the analytical sample. These photoelectrons are deflected in the spherical electrostatic analyzer, double focussed to eliminate stray electrons and finally counted by the electron multiplier. The whole system works under a vacuum of 10-s to 10 7 torr or even 10 10 torr, if surface properties have to be studied. This vacuum is generated by a Titanium... 

The nanocrystalline solids are metal oxides, especially titanium dioxide [54-58], Various dyes are used. Transition metal complexes such as (65) and (66) have broad absorption bands and allow the harvesting of a large fraction of sunlight [54,58], Fluorescent dyes are also used, such as Eosin-Y (67) [57], Dye-sensitized nanocrystalline solar cells are now giving efficiencies in excess of 10% [54,58], compared to just 1 % ten years ago [3],... 

Figure 8.9 Time-resolved fluorescent lifetime analysis of Cy3 attached to double-stranded DNA (Iqbal et al., 2008b). Fluorescent decay curve for Cy3 attached to a 16 bp DNA duplex, showing the experimental data and the instrument response function (IRF), and the fit to three exponential functions (line). The decay curve was generated using time-correlated single-photon counting, after excitation by 200 fs pulses from a titanium sapphire laser at 4.7 MHz.

As a first application of narrow exotic-atom transitions to the energy calibration of fluorescence X-rays, preliminary results for scandium and titanium are presented. 

Several of these extracts have been analyzed for iron and titanium via the X-ray fluorescence technique. The results for West Virginia (Ireland Mine) hvAb coal, one which has been found to deposit titanium on fixed bed catalysts, are presented in Table HL... 

A critical component of the cell is the X-ray-transparent window that allows the X-ray beam to impinge on the sample and the transmitted or fluorescent X-rays to be detected. Typical window materials that have been used are polyimide (Kapton ), beryllium, quartz, diamond, polyester (Mylar ), and titanium. Table 3 shows estimates of the thicknesses of window materials for various X-ray energies from 5 to 25 keV, determined on the basis of the assumption that 25% of the X-rays are absorbed by the window material. 

Modification of the polymer or the presence of additives can effect the light resistance of a fiber. This is extremely important for textile conservation since fibers being produced currently by the man-made fiber industry may perform differently from those produced in earlier years. For example, a company bulletin, published first in 1960, reported that the resistance to chemical decomposition by fluorescent light or by sunlight of many of the nylons they manufactured had been improved (20). Titanium dioxide, which is used as a delustrant during the manufacture of fibers, can decrease their light resistance (13,15,18, 21, 22, 23). Dyes (18, 24, 25) and finishes (25, 26) are other important factors. 

The presence of light-scattering mineral pigments such as titanium dioxide or iron oxides will quench the flourescent effect. Similarly, excessive concentration of the fluorescent acts to prevent reemission of light and is a waste of money. 

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