Ultraviolet–visible spectroscopy or ultraviolet–visible spectrophotometry refers to absorption spectroscopy or reflectance spectroscopy in part of the ultraviolet and the full, adjacent visible spectral regions. This means it uses light in the adjacent ranges; the absorption or reflectance in the visible range directly affects the perceived color of the chemicals involved. In this region of the electromagnetic spectrum and molecules undergo electronic transitions. Absorption spectroscopy is complementary to fluorescence spectroscopy, in that fluorescence deals with transitions from the excited state to the ground state, while absorption measures transitions from the ground state to the excited state. Molecules containing bonding and non-bonding electrons can absorb energy in the form of ultraviolet or visible light to excite these electrons to higher anti-bonding molecular orbitals; the more excited the electrons, the longer the wavelength of light it can absorb. There are four possible types of transitions, they can be ordered as follows:σ–σ* > n–σ* > π–π* > n–π*.
UV/Vis spectroscopy is used in analytical chemistry for the quantitative determination of different analytes, such as transition metal ions conjugated organic compounds, biological macromolecules. Spectroscopic analysis is carried out in solutions but solids and gases may be studied. Solutions of transition metal ions can be colored because d electrons within the metal atoms can be excited from one electronic state to another; the colour of metal ion solutions is affected by the presence of other species, such as certain anions or ligands. For instance, the colour of a dilute solution of copper sulfate is a light blue. Organic compounds those with a high degree of conjugation absorb light in the UV or visible regions of the electromagnetic spectrum; the solvents for these determinations are water for water-soluble compounds, or ethanol for organic-soluble compounds. Solvent polarity and pH can affect the absorption spectrum of an organic compound. Tyrosine, for example, increases in absorption maxima and molar extinction coefficient when pH increases from 6 to 13 or when solvent polarity decreases.
While charge transfer complexes give rise to colours, the colours are too intense to be used for quantitative measurement. The Beer–Lambert law states that the absorbance of a solution is directly proportional to the concentration of the absorbing species in the solution and the path length. Thus, for a fixed path length, UV/Vis spectroscopy can be used to determine the concentration of the absorber in a solution, it is necessary to know how the absorbance changes with concentration. This can be taken from references, or more determined from a calibration curve. A UV/Vis spectrophotometer may be used as a detector for HPLC; the presence of an analyte gives. For accurate results, the instrument's response to the analyte in the unknown should be compared with the response to a standard; the response for a particular concentration is known as the response factor. The wavelengths of absorption peaks can be correlated with the types of bonds in a given molecule and are valuable in determining the functional groups within a molecule.
The Woodward–Fieser rules, for instance, are a set of empirical observations used to predict λmax, the wavelength of the most intense UV/Vis absorption, for conjugated organic compounds such as dienes and ketones. The spectrum alone is not, however, a specific test for any given sample; the nature of the solvent, the pH of the solution, high electrolyte concentrations, the presence of interfering substances can influence the absorption spectrum. Experimental variations such as the slit width of the spectrophotometer will alter the spectrum. To apply UV/Vis spectroscopy to analysis, these variables must be controlled or accounted for in order to identify the substances present; the method is most used in a quantitative way to determine concentrations of an absorbing species in solution, using the Beer–Lambert law: A = log 10 = ε c L,where A is the measured absorbance, I 0 is the intensity of the incident light at a given wavelength, I is the transmitted intensity, L the path length through the sample, c the concentration of the absorbing species.
For each species and wavelength, ε is a constant known as the molar absorptivity or extinction coefficient. This constant is a fundamental molecular property in a given solvent, at a particular temperature and pressure, has units of 1 / M ∗ c m; the absorbance and extinction ε are sometimes defined in terms of the natural logarithm instead of the base-10 logarithm. The Beer–Lambert Law is useful for characterizing many compounds but does not hold as a universal relationship for the concentration and absorption of all s
Jacob Joseph Glatzer is an American violinist who resides in Portugal. He has performed as a soloist in North and South America, Asia and Australia, has released several acclaimed recordings. Glatzer specializes in the literature for solo violin, such as the unaccompanied works of Bach, Bartók, Locatelli, calls upon his strong academic background in world history and civilization in presenting frequent lecture-recitals of the solo violin literature. Glatzer was born in Dallas, the son of Fred and Miriam Glatzer, he began violin lessons at age five. Glatzer's primary teacher in Dallas was Henry Brahinsky. At 14, Glatzer performed a movement of the Violin Concerto No. 4 by Henri Vieuxtemps with the Dallas Symphony Orchestra conducted by Walter Hendl. In 1956, at age 17, he was the winner among all string players and runner-up for the Grand Prize at the Merriweather Post Competition in Washington, D. C. and performed a movement of the Brahms Violin Concerto with the National Symphony Orchestra under Howard Mitchell.
Glatzer's playing was praised by Washington music critics Day Thorpe and Paul Hume. Following his graduation from Forest Avenue High School of the Dallas Independent School District, Glatzer attended Yale University, where he studied violin with Joseph Fuchs while earning a bachelor's degree summa cum laude and Phi Beta Kappa in history. Glatzer, a Rhodes Scholar, subsequently earned an honours degree in history from Oxford University, he undertook further music study at the Musik Akademie in Basel, under Sándor Végh. In the 1960s, Glatzer performed as concertmaster of the Sándor Végh String Orchestra, he participated in the Prades Festival. Glatzer settled in Portugal, where he came to the attention of Maxim Jacobsen, an influential Russian violin pedagogue whose protégés included Benito Mussolini and Queen Elisabeth of Belgium. Jacobsen in his 80s, chose Glatzer as the young artist with whom he wished to share certain unpublished writings of the great 19th-century Italian virtuoso violinist Niccolò Paganini, which until had been kept among Mussolini's papers.
In these writings, Paganini described "secret" techniques for producing desired tone colors in his Caprices, Op. 1. Glatzer has since incorporated these techniques into his performances and describes many of them to listeners at recitals and on recordings. Glatzer has performed recitals in more than fifty countries and on every continent. Most of his recitals include visual components such as films and slides, as well as spoken discourse, he gives frequent presentations for schoolchildren. Jack Glatzer lives in Cascais,Portugal Glatzer has released several recordings, including the following: Locatelli: Caprices. Golden Crest RE-7077. Piano trios of Cowell. With the Manitoba Trio. UMSoM 111. February Suite. Music by S. C. Eckhardt-Gramatté and Robert Turner. With Delores Jerde Keahey, piano. Eckhardt-Gramatté Foundation EGF 200D. Jack Glatzer - Scattered Sparks of Sound. Music of Bloch, de Sousa, Bartók. Chatsworth FCM 1006. Released as 20th Century Violin Recital by Orient Vision. Cláudio Carneiro: Sonata and other works.
With Filipe de Sousa, piano. Strauss.. ISRC SP 4060 Niccolo Paganini: 24 Caprices for Solo Violin. Orient Vision CW 1002. Murray Adaskin: Sonatine Baroque for unaccompanied violin. On The Adaskin Collection. SOCAN MMI 05. Bach in the Cathedral. With Joseph Munzenrider, harpsichord. Jack Glatzer in Recital. Music of Bach, Elgar, Paganini. ABC Classic FM. Birth records of Dallas County, Texas. Communications. York University libraries newsletter. Undated, c. 1986. "Dal-Hi Salute Dated." The Dallas Morning News, 2 December 1963. "Dallas Violinist Wins Praise of Washington Music Critics" by Ruth Schumm. The Dallas Morning News, 26 May 1956. "Organ Guild Series to Open with Watkins." The Dallas Morning News, 16 November 1952. "Two Gain in Music Contest." The New York Times, 22 May 1956. Wilkinson, Anthony. Liner notes for Niccolo Paganini: 24 Caprices for Solo Violin. London: Orient Vision, 1998. Jack Glatzer official website
The 2009–10 daytime network television schedule for four of the five major English-language commercial broadcast networks in the United States covers the weekday daytime hours from September 2009 to August 2010. The schedule is followed by a list per network of returning series, any series canceled after the 2008–09 season. Affiliates fill time periods not occupied by network programs with syndicated programming. PBS – which offers daytime programming through a children's program block, PBS Kids – is not included, as its member television stations have local flexibility over most of their schedules and broadcast times for network shows may vary. Not included are stations affiliated with Fox or MyNetworkTV, as the former network and the latter programming service did not offer a daytime network schedule or network news, Ion Television, as its schedule was composed of paid programming and syndicated reruns at the time. New series are highlighted in bold. All times correspond to U. S. Eastern and Pacific Time scheduling.
Except where affiliates slot certain programs outside their network-dictated timeslots, subtract one hour for Central, Mountain and Hawaii-Aleutian times. Local schedules may differ, as affiliates have the option to delay network programs; such scheduling may be limited to preemptions caused by local or national breaking news or weather coverage and any major sports events scheduled to air in a weekday timeslot. Stations may air shows at other times at their preference. Notes: ABC, NBC and CBS offer their early morning newscasts via a looping feed to accommodate local scheduling in the westernmost contiguous time zones or for use a filler programming for stations that do not offer a local morning newscast. Many CBS affiliates returned the 3:00 p.m. ET timeslot to their affiliates starting September 21, although some stations continue to air Let's Make a Deal during the 3:00 p.m. hour to this day. In the two weeks preceding the October 5 debut of Let's Make a Deal, to fill a gap in the schedule caused by the discontinuance of Guiding Light, CBS aired repeats of The Price is Right in the timeslot.
As the World Turns—Canceled after 54 seasons on December 8, 2009. 2009–10 United States network television schedule 2009–10 United States network television schedule Curt Alliaume. "ABC Daytime Schedule". Curt Alliaume’s Utterly Irrelevant Web Site. Archived from the original on October 15, 2007. Curt Alliaume. "CBS Daytime Schedule". Curt Alliaume’s Utterly Irrelevant Web Site. Archived from the original on October 15, 2007. Curt Alliaume. "NBC Daytime Schedule". Curt Alliaume’s Utterly Irrelevant Web Site. Archived from the original on October 15, 2007