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Topic: Optical rotation

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Optical rotation - Wikipedia, the free encyclopedia The degree of rotation depends on the color of the light (the yellow sodium D line near 589 nm wavelength is commonly used), the optical path length, the specific rotation (a characteristic of the material), and the concentration of the material. The rotation of the orientation of linearly polarized light was observed in the early 1800's (Jean Baptiste Biot was one of the early investigators) before the nature of molecules was understood. The variation in rotation with the wavelength of the light is called ORD. www.wikipedia.org /wiki/Optical_rotation   (379 words)

optical rotation rotation of the plane of polarization in a beam of light as it passes through an optically active substance; may be clockwise or counterclockwise. crisp.cit.nih.gov /Thesaurus/00005822.htm   (24 words)

bk7 Arbitrarily, a rotation of the original “plane of polarization” to the right is termed a “positive” or “(+)” or “d” optical rotation. A rotation to the left is termed a “negative”, or (-), or “l” optical rotation. Thus, obtaining colorless crystals of an “optically active” substance (substance with an optical rotation), and the finding if the structure of the substance is in fact 3 or 4 is an arduous task. www.chem.unl.edu /cak/ch7.htm   (3078 words)

Self-aligning optical fiber directional coupler and fiber-ring optical rotation sensor using same - Patent 4755021 An optical fiber rotation sensor as set forth in claim 13 wherein said flat surfaces on said spliced ends of the optical fiber forming said sensing ring are aligned by engagement with common longitudinal surfaces of a substrate. The optical fiber of this invention is preferably made by forming a preform having the desired transverse cross-sectional configuration and drawing an optical fiber from the preform, with the drawing rate and temperature being controlled to produce a fiber with a cross-sectional configuration similar to that of the preform. An optical fiber as set forth in claim 1 wherein the fiber is drawn from a preform having a non-circular cross-section similar in shape to the cross-section of the outer surface of the fiber. www.freepatentsonline.com /4755021.html   (5056 words)

Optical Activity In a pair of optically active enantiomers, each enantiomer will rotate the plane of polarized light in equal and opposite directions; the enantiomers can therefore be referred to as (+) and (-) enantiomers, depending upon the direction of the observed rotation. A racemic mixture, in which there are equal concentrations of both enantiomers, will display no net optical rotation. The angle of rotation is measured in a device known as a polarimeter. www.chem.uic.edu /web1/OCOL-II/WIN/STEREO/31/OA.HTM   (406 words)

Polarization light splitting film, backlight system and liquid crystal display having particular diffusion layer under optical rotation selection layer - US Patent 6559911 As the optical rotation selection layer, a cholesteric liquid crystal polymer film (having the helical axis of the liquid crystal along a direction of the thickness and showing superior circular dichroism with respect to visible light) with a thickness of 15 µm was formed by photopolymerization with ultraviolet irradiation. The optical rotation selection layer of the present invention may have a single layered structure of a cholesteric liquid crystal layer or a multi-layer structure in which an optical rotation selection layer is coated on a base member (substrate). When the orientation of the optical rotation of the circularly polarized light matches the incident light, the circularly polarized light that has the same orientation as the optical rotation of the helical axis of the cholesteric liquid crystal is selectively reflected. www.patentstorm.us /patents/6559911.html   (9319 words)

Optical Activity Suppose that the observed rotation was -45.5 degrees of rotation. The observed rotation is dependent upon the path length of the light passing through the sample compartment and is also dependent upon the number of molecules of the isomer. As a result, the rotation of the plane polarized light by one configuration is not canceled out or negated by rotation of the light by the opposite configured molecule because it is not present. members.aol.com /logan20/optical.html   (893 words)

Optical Rotation by USP <781> Historically, polarimetry measures optical rotation by visually matching the intensity of split fields, using visible light from the sodium D-line at 589nm. The rotation is usually expressed as the "specific rotation," although some USP articles are expressed in terms of the "observed rotation." Specific rotation is calculated from the observed rotation based on the concentration, length of the measuring tube and water content of the material, and is generally measured in a specific solvent. Polarimetry, the measurement of the rotation of light by certain substances, has been used since the early nineteenth century. www.wcaslab.com /tech/optical_rotation.htm   (310 words)

Optical Sensor Using the Magnetic Optical Rotatory Effect of Glucose We have demonstrated a new approach to optical glucose sensing using the fact that magnetically induced optical rotation in glucose solutions is linearly proportional to glucose concentration at physiologic levels (the MORE phenomenon). The magnitude of rotation due to the MORE cell was proportional to the concentration of the glucose, the path length of the cell, and the magnitude of the B field in the cell. Cancellation of the conventional optical rotatory effect upon reflection from a dielectric mirror surface (the aqueous/lens interface is probably an example of such a surface). ieee.org /organizations/pubs/newsletters/leos/apr98/opticalsensor.htm   (1561 words)

Optical rotation of the second harmonic radiation from retinal in bacteriorhodopsin monomers in Langmuir-Blodgett film: evidence for nonplanar retinal structure -- Volkov et al. 73 (6): 3164 -- Biophysical Journal Optical rotation of the second harmonic radiation from retinal in bacteriorhodopsin monomers in Langmuir-Blodgett film: evidence for nonplanar retinal structure -- Volkov et al. Optical rotation of the second harmonic radiation from retinal in bacteriorhodopsin monomers in Langmuir-Blodgett film: evidence for nonplanar retinal structure We observed optical rotation of the plane of polarization of the second www.biophysj.org /cgi/content/abstract/73/6/3164   (277 words)

optical rotation on Encyclopedia.com Comparison of optical rotation and circular dichroism based chiral detectors. Device speeds image rotation -- Nonmechanical approach could rev preprocessing for optical, electronic imaging.(Information Technology Laboratory at the National Institute of Standards and Technology (NIST)) (Company... Nikon, Hitachi Maxell Announce Joint Venture to Produce Direct-OverWrite Optical Media. www.encyclopedia.com /html/X/X-opticalr.asp   (269 words)

optical rotation of an optical active substance is given in the field OR.FLG. 202.127.145.151 /siocl/cdbank/WebHelp/gmelin/gmehtml/cmdor.htm   (11 words)

Optical Rotation Continuous rotation of the pattern (and hence the trapped particles) is achieved by separating the frequencies the two interfering beams using what is known as the angular Doppler effect. The latter technique is capable of controllably rotating any object that can be optically trapped. This was achieved by using a Gaussian beam to sample the phase of the LG beam producing a spiral pattern that could be controllably rotated. www.st-andrews.ac.uk /~atomtrap/Research/Optical_Rotation.htm   (292 words)

Energy Citations Database (ECD) - Energy and Energy-Related Bibliographic Citations Magneto-optical rotation by transmission through or reflection from solids is examined by the classical free electron theory, with the view of taking such a measurement using fields in the megagauss range. In general the rotation is a markedly non-linear function of the magnetic field, and in some cases can change in sign as the field increases. For substances in which the intercollision time of the electron is small, measurements of the Kerr rotation (i.e., by reflection) will give the electron mobility as a function of the magnetic field, and thus will give important data which can be used in conjunction with kigh field magnetoresistance experiments. www.osti.gov /energycitations/product.biblio.jsp?osti_id=4155428   (185 words)

SparkNotes: Stereoisomers: Optical Activity If rotation occurs to the left (counter-clockwise), the optical rotation is assigned a--sign and the sample is levorotary. The number of degrees the sample is rotated is called the optical rotation of the sample. If rotation occurs to the right (clockwise), the optical rotation is given a + sign and the sample is considered dextrorotary. www.sparknotes.com /chemistry/organic3/stereoisomers/section1.html   (738 words)

Optical Rotation optical rotation and specific rotation are proportional to Optical Rotation is described by linear response property ++++++++++++++++++ Optical rotation ++++++++++++++++++ London G tensor for frequency 0.151878 au Bx By Bz Ex -0.5097663 1.5187140 0.1356463 Ey -1.9603457 0.4712682 -0.1916221 Ez -0.2108493 -0.5693790 0.0139671 Beta(London) : 0.053839 Optical rotation (London) : 138.345316 folk.uio.no /michalj/node38.html   (66 words)

[123.10] Extraction of Rotational Velocities from Optical Rotation Curves of Disk Galaxies Since rotation curves are typically rising in the outer regions of the disks, the optical histogram widths of HI-deficient galaxies are therefore systematically underestimated compared to the ones of HI-normal galaxies. We have used a large database of H-alpha optical rotation curves (ORCs), HI-line profiles, and I-band photometry designed for PV studies to investigate the errors and systematics associated with the velocity width measurement. Long-slit spectra of spiral galaxies are widely used to complement 21 cm HI observations, providing rotational velocity widths for the application of the Tully-Fisher (TF) relation. www.aas.org /publications/baas/v34n4/aas201/370.htm   (314 words)

Our work on optical rotation.html The goal is to improve our measurement of optical rotation in thallium from the current 1% level to a new level of about 0.3% uncertainty, which, if analyzed with foreseeable improvements in Tl atomic theory, will make a new test of the standard model. This measurement used the standard optical rotation method that had been the basis of our parity research for two decades. ``Optical rotation technique used for a high-precision measurement of parity nonconservation in atomic lead" D. Meekhof, P. Vetter, P. Majumder, S. Lamoreaux, and E. Fortson, Phys. www.phys.washington.edu /users/fortson/cronin/GroupOR.html   (301 words)

SYNTHESIS OF 1,2-DIBROMO-1,2-DIPHENYLETHANE AND OPTICAL ROTATION Part II Determine the optical rotations of the two enantiomers of carvones in tube A and B. Your instructor will show you how to use the polarimeter. Part II Determine the optical rotations of the two carvones. a = observed rotation in degrees, c = concentration in grams/mL (use density for pure liquid), l = length of sample tube in decimeters, l = wavelength of light (usually indicated as “D” for the sodium D line), t = temperature in degrees Celsius. science.csustan.edu /nhuy/chem3012/Experiments/transstilbene.htm   (697 words)

TITLE: By figuring out their optical rotations, I was able to identify glucose as a dextrorotatary substance and fructose as a levorotatary substance. This instrument is used to the show the optical rotation of a substance which can help identify a substance as a dextrorotatary or a levorotatary substance. The fact that an increase in volume or in concentration will increase the amount of rotation suggests that the amount of optical rotation is directly proportional to the number of sugar molecules encountered by the light. www.pilgrims.net /plymouth/schools/Science/scifair9/abstracts/physics/p6.htm   (268 words)

An analysis of 900 optical rotation curves: \\ Dark matter in a corner? The present analysis shows that the rotation velocity, V, at any radial displacement, R, in the optical disc of any given spiral galaxy satsifies the law V /R Of the original sample of 965 galaxies, the observations on 900 were considered by PS 1995 to be good enough for rotation curve studies, and the present analysis concerns itself with these 900 rotation curves. rotation curve data bases of spiral galaxies currently available is that provided by Persic and Salucci (PS) [1], which has been derived by them from unreduced rotation curve data of 965 southern sky spirals obtained by Mathewson, Ford and Buchhorn (MFB) [2]. www.ias.ac.in /pramana/v53/p1033/abs.htm   (193 words)

N to Q The ratio of the observed optical rotation of a sample consisting of a mixture of enantiomers to the optical rotation of one pure enantiomer. An enantiomer causing rotation in a clockwise direction (when viewed in the direction facing the oncoming light beam) under specified conditions is called dextrorotatory and its chemical name or formula is designated by the prefix (+)-; one causing rotation in the opposite sense is laevorotatory and designated by the prefix (-)-. A sample of material able to rotate the plane of polarisation of a beam of transmitted plane-polarised light is said to possess optical activity (or to be optically active). www.chem.qmul.ac.uk /iupac/stereo/NQ.html   (1532 words)

MSN Encarta - Search Results - optical rotation Search for books about your topic, "optical rotation" MSN Encarta - Search Results - optical rotation Rotation, in geometry, a transformation in which a figure is turned about a given point, known as the center of rotation. encarta.msn.com /optical+rotation.html   (145 words)

Atomic Contributions to the Optical Rotation Angle as a Quantitative Probe of Molecular Chirality -- Kondru et al. 282 (5397): 2247 -- Science We have introduced a method for calculating atomic and group contributions to the optical rotational angle of a chiral molecule. Atomic contributions to the molar rotation angle in 2-fluorohexane in the configurations 3a (~180° dihedral angle) and 3b (~60° dihedral angle). In the extended geometry, the rapid decay of CH group contributions to the rotation angle is marked (the first methylene unit contributes half as much as the CHF unit, and the second methylene contributes only 10% of the CHF unit; see Fig. www.sciencemag.org /cgi/content/full/282/5397/2247   (2106 words)

Optical Activity This experiment will be considering both effects: the amount of optical rotation and the amount of absorption on (initially) two particular transitions in thallium  (the E2  and M1  transitions at 1283 nm; please refer to Chapter 2 for more details). One can show that the angle of rotation that results is just proportional to the difference in the indices of refraction, as in (1.6). The net effect is a rotation of the plane of polarization. www.williams.edu /Physics/pmajumder/thesis/thesis-text/node9.html   (311 words)

APS - 2005 APS March Meeting PostDeadline - Event - Optical Rotation of Layered Liquid Crystalline Phases in the Absence of Helical Winding of Molecular Orientation In this model we derive an expression for the optical rotation using a linear expansion of the induced polarization. APS - 2005 APS March Meeting PostDeadline - Event - Optical Rotation of Layered Liquid Crystalline Phases in the Absence of Helical Winding of Molecular Orientation Abstract: B37.00004 : Optical Rotation of Layered Liquid Crystalline Phases in the Absence of Helical Winding of Molecular Orientation meetings.aps.org /Meeting/MAR05/Event/22022   (257 words)

Omicron Biochemicals, Inc. - Optical Rotation Optical rotation measurements are made at 589 nm using a Rudolph Research Analytical Autopol® III automatic polarimeter having a 100 mm pathlength sample cell requiring about 8 mL of sample. The jacketed glass cell is routinely thermostatted at 20.0°C by a circulating water bath, but can be set to other temperatures if needed. Instrument calibration is checked periodically against a NIST-traceable quartz control plate. www.omicronbio.com /obpol.html   (64 words)

Ab Initio Calculations of Optical Rotation in Chiral Molecules In this work, we consider the importance of basis set size and character as well as high-level electron correlation effects on coupled cluster optical rotation angles for rigid and confirmationally flexible species such as (P)-(+)-[4]triangulane, (R)-3-chloro-1-butene, and S-methyloxirane. We have recently developed a new series of programs for the computation of frequency-dependent optical rotation using coupled cluster linear-response theory. Ab Initio Calculations of Optical Rotation in Chiral Molecules acs.confex.com /acs/56serm/techprogram/P13801.HTM   (197 words)

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