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Examples of the Design of Measurement Systems
Published in Robert B. Northrop, Introduction to Instrumentation and Measurements, 2018
A polarimeter is an instrument used to measure the angle of rotation of LPL when it is passed through an optically active material. (Polarimeters are introduced in Section 6.7.2.) There are many types of polarimeters, and there are a number of optically active substances found in living systems; probably the most important is the sugar, d-glucose-glucose, dissolved in water. Clear biological liquids such as urine, extracellular fluid, saliva, and the aqueous humor of the eyes contain dissolved d-glucose whose molar concentration is an increasing function of the blood glucose concentration (Northrop 2002). d-glucose-glucose concentration is also an important parameter in the fermentation industry and also in biotechnology applications where genetically engineered cells are grown in bioreactors.
Other Techniques
Published in C. R. Kitchin, Astrophysical Techniques, 2020
A polarimeter is an instrument that measures the state of polarisation, or some aspect of the state of polarisation, of a beam of radiation. Ideally, the values of all four Stokes’ parameters should be determinable, together with their variations with time, space and wavelength. In practice, this is rarely possible, at least for astronomical sources, when only the degree of linear polarisation and its direction are found most of the time. Astronomical optical polarimeters now normally use CCDs, photomultipliers (PMTs) or avalanche photodiodes as their detectors but photographic plates have been used in the past.
Polarimetry
Published in Toru Yoshizawa, Handbook of Optical Metrology, 2015
A dictionary definition of polarimetry is “the art or process of measuring the polarization of light” [1]. A more scientific definition is that polarimetry is the science of measuring the polarization state of a light beam and the diattenuating, retarding, and depolarizing properties of materials [2]. Similarly, a polarimeter is an optical instrument for determining the polarization state of a light beam, or the polarization-altering properties of a sample [2].
Effect of chiral monomer containing D(+)-camphoric acid on the optical properties and phase behaviours of side-chain cholesteric liquid crystal polymers
Published in Liquid Crystals, 2021
Ya-Ru Ma, Xue-Song Zhang, Xuan Xie, Yue-Jiao Huang, Xiao-Zhi He, Yue-Hua Cong, Bao-Yan Zhang, Ying-Gang Jia
Fourier transform infrared spectroscopy (FT-IR) was conducted by a PerkinElmer Spectrum One FT-IR spectrometer (PerkinElmer Instruments, USA). 1H NMR spectra (400 MHz) were recorded on a Bruker AV 400 spectrometer in 5-mm o.d. sample tubes. Specific rotation was performed with Autopol IV (Rudolph, USA) polarimeter. All optical activity measurements of PPL series were performed in chloroform with a Na lamp (λ = 589 nm). Differential scanning calorimetry (DSC) was carried out on a Netzsch DSC 204 (Netzsch, Germany) with a flow of dry nitrogen cooling system under the scanning rates of 10°C min−1. A Leica DMRX (Leica, Germany) polarising optical microscope (POM) equipped with a Linkam THMSE-600 (Linkam, UK) hot stage was used to test liquid-crystal properties. XRD measurements were performed with a nickel-filtered Cu-Kα radiation (λ = 0.1542 nm) with a DLAX-3A Rigaku (Rigaku, Japan) powder diffractometer. Thermogravimetric analysis (TGA) measurement is performed by a NETZSCH TGA 209 C thermogravimetric analyser.
The effect of partially fluorinated chain length on the mesomorphic properties of chiral 2’,3’-difluoroterphenylates
Published in Liquid Crystals, 2020
Jakub Herman, Albert Aptacy, Ewelina Dmochowska, Paweł Perkowski, Przemysław Kula
The purity of synthesised compounds and the synthesis monitoring were performed by thin-layer chromatography, Shimadzu GCMS-QP2010S gas chromatograph equipped with quadrupole mass analyser (MS) and high-performance liquid chromatography (HPLC), HPLC-PDA-MS (APCI-ESI dual source) Shimadzu LCMS 2010 EV equipped with a polychromatic UV–VIS detector. The optical purity was determined by HPLC analysis using Lux® 5 μm Cellulose-1 column (hexane–i-PrOH 90:10, 1 mL/min). The optical rotation was performed by Bellingham & Stanley Polarimeter, model D with range 0–360, with sodium lamp. Proton 1H nuclear magnetic resonance spectra in CDCl3 were collected using Bruker, model Avance III spectrometer (Karlsruhe, Germany). Chemical shifts (δ) are reported in ppm relative to the residual solvent peak.
NaClO2-mediated preparation of pyridine-2-sulfonyl chlorides and synthesis of chiral sulfonamides
Published in Journal of Sulfur Chemistry, 2020
Dong Xu, Shiyi Yang, Aijun Gao, Zhanhui Yang
All the chemicals and solvents were used directly as received. TLC analyses were performed on Yantai Chemical Co., Ltd. silica gel GF254 plates with petroleum ether (PE) and ethyl acetate (EA), and the plates were visualized with UV light. Products were purified with column chromatography using Qingdao Ocean Chemical Co., Ltd. silica gel (200-300 mesh) with PE and EA as eluents. Melting points were obtained on a Yanaco MP-500 melting point apparatus and are uncorrected. The specific rotation analysis was measured by Anton Paar MCP200 Polarimeter. IR spectra were taken on a Bruker FT-IR spectrometer on KBr pellets. 1H and 13C spectra were recorded on a Bruker 400 MHz spectrometer as CDCl3 solution with TMS as an internal standard. HRMS data were obtained with an Agilent LC/MS TOF mass spectrometer.