Search results for "Polar"

Director orientation in chevron surface-stabilized ferroelectric liquid crystal cells. Verification of orientational binding at the chevron interface…

1990

Abstract We present results of theoretical modelling and experimental study of director distributions and the associated optical properties of chevron surface stabilized ferroelectric liquid crystal (SSFLC) cells. Chevron cells are modelled as being two stacked FLC slabs, described by distinct orientation distributions of the director [ncirc]-polarization P([ncirc] – P) couple. In each slab the [ncirc] – P distribution is governed by bulk Frank elastic and electric field-induced torques and by surface torques at the FLC-solid interface and at the chevron interface, where the two distributions are coupled. The optical properties of such structures are calculated numerically and the results t…

Surface induced smectic order in ionic liquids - an X-ray reflectivity study of [C(22)C(1)im](+)[NTf2](-)

2017

Physical chemistry, chemical physics 19(39), 26651 - 26661 (2017). doi:10.1039/C7CP04852A

Magneto-optical linear dichroism in threshold photoemission electron microscopy of polycrystalline Fe films.

2000

Magnetic linear dichroism in threshold photoemission has been exploited to obtain magnetic contrast in a photoemission electron microscope using a mercury arc lamp. The dichroism at threshold can be described similar to the magneto-optical Kerr effect in the region of visible light. The asymmetry of electron intensity observed for a 100 nm polycrystalline Fe film on silicon is A=(0.37+/-0.05)%. The asymmetry occurs for the geometry of the transverse Kerr effect. For unpolarized light the asymmetry was about half the value observed for linearly polarized light. Threshold photoemission microscopy has a large potential for high resolution magnetic domain imaging with fast data acquisition.

Thermotropic polyesters with mesogenic groups based on substituted hydroquinone units and highly flexible siloxan spacer in the main chain

1984

New thermotropic Polyesters having mesogenic groups based on substituted hydroquinone units and highly flexible oligosiloxan spacer in the main chain, are synthesized and characterized. The mesophase formed at low temperature are studied by differential scanning calorimetry (DSC) and polarized light microscopy. The liquid crystalline behaviour of these polyesters, particulary their transition temperatures and the mesophase width could be explained on the basis of their structural features.

Morphological patterns of circumpulpal dentin affected by radiation-related caries

2020

Background The aim of this work was to evaluate the microscopic characteristics through polarized light microscopy, scanning electron microscopy and the mineral content of circumpulpal dentin of irradiated (IT) and non-irradiated teeth (NIT), with deep caries that reached the root canal. Material and methods A total of 25 IT were analyzed macroscopically, and radiographed. 5 NIT were used as controls. Two 100-μm-thick sections, per specimen, were evaluated in a polarized light microscopy and a scanning electron microscope. Demographics and clinical data were collected. Results The results did not demonstrate distinct morphology of the IT compared with NIT. Mineral content values by weight p…

Phase Conjugation in BaTiO/sub 3/ Using Orthogonally Polarized Light Waves

2005

DC polarographic reduction of chloroguanide hydrochloride.

1984

Chloroguanide hydrochloride, an antimalarial drug, shows one well-defined DC polarographic wave in Britton-Robinson buffered media. In the pH range 3–9 the observed reduction wave is related to the reduction of the two azomethine centers on the monoprotonated biguanide group (BH+). The effects of pH and other experimental variables on the limiting current and half-wave potentials as well as the reduction mechanism are discussed.

Simultaneous determination of 4-nitroanisole, 4-nitrophenol, and 4-nitrocatechol by phase-sensitive ac polarography.

1977

Abstract Phase‐sensitive ac polarography was applied to the simultaneous quantitative determination of 4‐nitroanisole, 4‐nitrophenol and 4‐nitrocatechol in alkaline solutions. Certain experimental precautions are necessary to determine each compound in the presence of the other two. Thus, 4‐nitrocatechol is determined indirectly by forming a yellow ratio chelate with cupric ions, whereas 4‐nitroanisole is determined directly by the reduction waves of the nitro group. For the determination of 4‐nitrophenol, the interference by the simultaneously present 4‐nitrocatechol must be eliminated by masking it by the addition of magnesium ions. The method described permits a qualitative and quantitat…

Electrochemical and spectroscopic investigations of selected N -heteroalkylaminomethylenebisphosphonic acids with Pb(II) ions

2016

Abstract The coordination properties of aminomethylenebisphosphonic acids towards various metal ions have been exploited during the last decade. These compounds are good chelators for biologically important metal ions, such as Cu(II), Fe(II), Zn(II), Ca(II), and Mg(II), as well as a toxic ion (i.e., Cd(II)). In this study, the interactions of five aminomethylenebisphosphonates with N-substituted heteroalkyl moieties (L1, L2 and L3) and their N-pyridyl (L4) and N-benzylpiperazine (L5) derivatives with Pb(II) ions were investigated. A wide range of analytical methods were employed, including potentiometry, pulse polarography (DPP), nuclear magnetic resonance (NMR) spectroscopy and electrospra…

Calculation of voltammetric peaks by the transformed Heyrovsky-Ilkovi? equation

1990

Calculating real polarographic or voltammetric peaks is rather difficult. A new possibility to compute such peaks is the use of the transformed Heyrovsky-Ilkovic equation. The calculation allows to simulate polarograms or voltammograms by computer. Furthermore, it is possible to smooth voltammetric peaks without loss of peak height or separation of overlapping peaks.