Influence of Contamination with Silicone Release Agent on the Ellipsometric Parameters of CFRP Surface in the Sub-THz Range

2021 ◽  
Author(s):  
Ivan Kolenov ◽  
Alexey Galuza ◽  
Alla Belyaeva ◽  
Sergey Mizrakhy ◽  
Pavel Nesterov ◽  
...  
Keyword(s):  
Release Agent ◽  
Thz Range

Gum arabic helps prepare better lacey polymer films for specimen support in electron microscopy

1993 ◽  
Vol 51 ◽  
pp. 240-241
Author(s):  
Shailesh R. Sheth ◽  
Jayesh R. Bellare
Keyword(s):  
Electron Microscopy ◽  
Polymer Films ◽  
Gum Arabic ◽  
Complete Removal ◽  
Ammonium Bromide ◽  
Release Agent ◽  
Astigmatism Correction ◽  
Long Time ◽  
Micro Holes ◽  
Cetyl Trimethyl Ammonium

Specimen support and astigmatism correction in Electron Microscopy are at least two areas in which lacey polymer films find extensive applications. Although their preparation has been studied for a very long time, present techniques still suffer from incomplete release of the film from its substrate and presence of a large number of pseudo holes in the film. Our method ensures complete removal of the entire lacey film from the substrate and fewer pseudo holes by pre-treating the substrate with Gum Arabic, which acts as a film release agent.The method is based on the classical condensation technique for preparing lacey films which is essentially deposition of minute water or ice droplets on the substrate and laying the polymer film over it, so that micro holes are formed corresponding to the droplets. A microscope glass slide (the substrate) is immersed in 2.0% (w/v) aq. CTAB (cetyl trimethyl ammonium bromide)-0.22% (w/v) aq.

Formulation and Evaluation of Atenolol and Indapamide SR Matrix Tablets for Treatment of Hypertension

2014 ◽  
Vol 7 (2) ◽  
pp. 2450-2458
Author(s):  
Sarika Pundir ◽  
Ashutosh Badola
Keyword(s):  
Kinetic Studies ◽  
Film Coating ◽  
Matrix Tablets ◽  
Wet Granulation ◽  
Simultaneous Estimation ◽  
Matrix Tablet ◽  
Release Agent ◽  
Disintegration Time ◽  
Weight Variation

In the present study we have formulated (F1 to F6) matrix tablets of atenolol and indapamide for the management of hypertension. As in simultaneous estimation of these drugs it was found that a confined release can be formulated. In the formulation of SR matrix tablet by using different concentration of delayed release agent DCP and pregelatinized starch as disintegrant we prepared tablets by wet granulation method. For sustained release action HPMC polymers were used for film coating. Preformulation studies were performed prior to compression. The compressed SR matrix tablets were evaluated for weight variation, hardness, friability, drug content, disintegration time and in vitro drug release using USP dissolution apparatus type 2 (paddle). It was found that the optimized formulation showed 49.33%, 48.90%, 48.52%, 47.65%, 46.84% and 46.51% release for atenolol in 12 hours respectively. However, indapamide released 49.62%, 49.39%, 48.72%, 48.27%, 47.59% and 47.36% at the end of 12 hr. The IR spectrum study revealed that there is no disturbance in the principal peaks of pure drugs atenolol and indapamide. This confirms the integrity of pure drugs and no incompatibility of them with excipients. The stability studies were carried out for the optimized batch for one months and it showed satisfactory results. The kinetic studies of the formulations revealed that diffusion is the predominant mechanism of drug and release follows Zero-order, Super case II transport.

scholarly journals Broadband spectroscopy of astrophysical ice analogues

2019 ◽  
Vol 629 ◽  
pp. A112 ◽  
Author(s):  
B. M. Giuliano ◽  
A. A. Gavdush ◽  
B. Müller ◽  
K. I. Zaytsev ◽  
T. Grassi ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Time Domain ◽  
Complex Refractive Index ◽  
Far Infrared ◽  
Infrared Region ◽  
Thz Radiation ◽  
The Real ◽  
Thz Range ◽  
The Time Domain

Context. Reliable, directly measured optical properties of astrophysical ice analogues in the infrared and terahertz (THz) range are missing from the literature. These parameters are of great importance to model the dust continuum radiative transfer in dense and cold regions, where thick ice mantles are present, and are necessary for the interpretation of future observations planned in the far-infrared region. Aims. Coherent THz radiation allows for direct measurement of the complex dielectric function (refractive index) of astrophysically relevant ice species in the THz range. Methods. We recorded the time-domain waveforms and the frequency-domain spectra of reference samples of CO ice, deposited at a temperature of 28.5 K and annealed to 33 K at different thicknesses. We developed a new algorithm to reconstruct the real and imaginary parts of the refractive index from the time-domain THz data. Results. The complex refractive index in the wavelength range 1 mm–150 μm (0.3–2.0 THz) was determined for the studied ice samples, and this index was compared with available data found in the literature. Conclusions. The developed algorithm of reconstructing the real and imaginary parts of the refractive index from the time-domain THz data enables us, for the first time, to determine the optical properties of astrophysical ice analogues without using the Kramers–Kronig relations. The obtained data provide a benchmark to interpret the observational data from current ground-based facilities as well as future space telescope missions, and we used these data to estimate the opacities of the dust grains in presence of CO ice mantles.

Graphene-based dual-band tunable perfect absorber in THz range

2021 ◽  
Vol 68 (2) ◽  
pp. 93-99
Author(s):  
Zhaoyang Liu ◽  
Jian Li ◽  
Lingjuan He ◽  
Tianbao Yu
Keyword(s):  
Dual Band ◽  
Perfect Absorber ◽  
Thz Range

scholarly journals Improvement of an InfraRed Pyroelectric Detector Performances in THz Range Using the Terajet Effect

2021 ◽  
Vol 11 (15) ◽  
pp. 7011
Author(s):  
Oleg V. Minin ◽  
Jaime Calvo-Gallego ◽  
Yahya M. Meziani ◽  
Igor V. Minin
Keyword(s):  
Internal Structure ◽  
Diffraction Limit ◽  
Noise Equivalent Power ◽  
Pyroelectric Detector ◽  
Optical Window ◽  
Ir Sensors ◽  
Thz Detection ◽  
Thz Range ◽  
Thz Applications

An infrared (IR) pyroelectric detector was investigated for terahertz (THz) detection using the principle of the terajet effect, which focuses the beam beyond the diffraction limit. The terahertz beam was coupled to the detector’s optical window through a two-wavelength-dimension dielectric cubic particle-lens based on the terajet effect. We experimentally demonstrate an enhancement of about 6 dB in the sensitivity under excitation of 0.2 THz without degradation of the noise equivalent power value. The results show that the proposed method could be applied to increase the sensitivity of various commercial IR sensors for THz applications that do not require modification of the internal structure, and it may apply also to acoustics and plasmonic detectors.

Hydrophobicizing mould release agent for press moulding

2007 ◽  
Vol 59 (5) ◽  
pp. 236-241
Author(s):  
F.T. Seyidov ◽  
Y. Mansoori ◽  
J. Taghi Nezhad
Keyword(s):  
Release Agent
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