Noise gratings for single- and double-beam exposures in silver halide emulsions

1990 ◽  
Vol 7 (11) ◽  
pp. 2107 ◽  
Author(s):  
L. Solymar ◽  
G. D. G. Riddy
Keyword(s):  
Author(s):  
C. Goessens ◽  
D. Schryvers ◽  
J. Van Landuyt ◽  
A. Verbeeck ◽  
R. De Keyzer

Silver halide grains (AgX, X=Cl,Br,I) are commonly recognized as important entities in photographic applications. Depending on the preparation specifications one can grow cubic, octahedral, tabular a.o. morphologies, each with its own physical and chemical characteristics. In the present study crystallographic defects introduced by the mixing of 5-20% iodide in a growing AgBr tabular grain are investigated. X-ray diffractometry reveals the existence of a homogeneous Ag(Br1-xIx) region, expected to be formed around the AgBr kernel. In fig. 1 a two-beam BF image, taken at T≈100 K to diminish radiation damage, of a triangular tabular grain is presented, clearly showing defect contrast fringes along four of the six directions; the remaining two sides show similar contrast under relevant diffraction conditions. The width of the central defect free region corresponds with the pure AgBr kernel grown before the mixing with I. The thickness of a given grain lies between 0.15 and 0.3 μm: as indicated in fig. 2 triangular (resp. hexagonal) grains exhibit an uneven (resp. even) number of twin interfaces (i.e., between + and - twin variants) parallel with the (111) surfaces. The thickness of the grains and the existence of the twin variants was confirmed from CTEM images of perpendicular cuts.


2019 ◽  
pp. 105-110
Author(s):  
Mikhail Yongon Lee ◽  
Sergei V. Fedorov

The article describes the structure and the operation principle of the spectrophotometer developed on the basis of a compact rapid monochromator with one input port and two output ports and a radiometric unit where upwelling radiation radiance and sea surface irradiance channels are located. A new approach to measurements of spectral characteristics of upwelling radiation of sea based on combination of advantages of a double beam photometer with a photomultiplier and a directreading photometer with a highstability silicon photodiode for its absolute adjustment in energy units is implemented.


1998 ◽  
Vol 536 ◽  
Author(s):  
H. Porteanu ◽  
A. Glozman ◽  
E. Lifshitz ◽  
A. Eychmüller ◽  
H. Weller

AbstractCdS/HgS/CdS nanoparticles consist of a CdS core, epitaxially covered by one or two monolayers of HgS and additional cladding layers of CdS. The present paper describes our efforts to identify the influence of CdS/HgS/CdS interfaces on the localization of the photogenerated carriers deduced from the magneto-optical properties of the materials. These were investigated by the utilization of optically detected magnetic resonance (ODMR) and double-beam photoluminescence spectroscopy. A photoluminescence (PL) spectrum of the studied material, consists of a dominant exciton located at the HgS layer, and additional non-excitonic band, presumably corresponding to the recombination of trapped carriers at the interface. The latter band can be attenuated using an additional red excitation. The ODMR measurements show the existence of two kinds of electron-hole recombination. These electron-hole pairs maybe trapped either at a twin packing of a CdS/HgS interface, or at an edge dislocation of an epitaxial HgS or a CdS cladding layer.


Author(s):  
Manmeet Kaur ◽  
Suman Prajapati ◽  
Samneek Cholia ◽  
Jaskeet Singh Mann ◽  
Gurpreet Singh

Background: In the recent years, the green synthesis of nanoparticles has taken a lead role over the conventional chemical and physical approach due to its non-toxic, cost effective parameters and has found its place in various applications. Objectives: The major objectives of this study was to synthesise and characterize the copper nanoparticles using the rose extract at different set of conditions and analyse these nanoparticles as a source of dye degradation agent under sunlight conditions. Methods: Present study was conducted with the aim to synthesis the copper nanoparticle using the rose petal extract. The components present the in the extract act as the reduction and stabilization agents for the synthesis of CuNPs. The synthesized nanoparticles were characterized by using UV-VIS, FTIR, XRD and SEM analysis. Photocatalytic degradation of two dyes (Malachite Green and Carbol fuchsin) was analysed using double beam spectroscopic analysis Results: UV-Vis analysis indicated the presence of a peak at around 630 nm. The FT-IR analysis indicated the involvement of various biomolecules during the synthesis of nanoparticles. The structure and the conformation was elucidated using XRD and SEM showed the agglomerated form of the synthesized nanoparticles with the size range of about 60-90 nm. The synthesised copper nanoparticles was used for degradation of malachite green and carbol fuchsin dye using photocatalytic under sunlight irradiation. UV-Vis spectral analysis indicated that synthesised copper nanoparticle act more effective in degradation of malachite green (around 95%) whereas carbol fuchsin showed a maximum degradation by 52% therefore suggesting that CuNPs act as an efficient photo catalyst in dye degradation. Conclusion: The results obtained from this study indicates that rose extract has the potential of synthesis of copper nanoparticles which is non-toxic and convenient approach as compared to physical and chemical synthesis. These nanoparticles can be effectively employed as dye decolourization agents to treat industrial effluent and prevent the environmental pollution.


Author(s):  
SACHIN A. YANJANE ◽  
SHRISHAIL M. GHURGHURE ◽  
VINOD K. MATOLE

Objective: A new, simple, economical, precise, sensitive, linear, accurate, rapid UV spectrophotometric method has been developed for the estimation of Oseltamivir Phosphate in pure form and pharmaceutical formulation. Methods: This UV method was developed using Methanol as a solvent. In the present method, the wavelength selected for analysis was 218 nm. UV-Visible double beam spectrophotometer (Systronic 2201) was used to carry out spectral analysis. The ICH guidelines were used to validate the method. Results: The method was validated for linearity, range, accuracy, precision, robustness, LOD and LOQ. Linearity was found in the range of 10-50µg/ml. Accuracy was performed by using a recovery study. The amount of drug recovered was found to be in the range of 99.01-100.1%. The % RSD value was found to be less than 2. Conclusion: The developed UV spectrophotometric method was found to be simple, economic, sensitive, easy, accurate, linear, specific and highly sensitive and can be used for routine estimation of Oseltamivir Phosphate.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Heinz Mustroph

Abstract Oxonol dyes are classified as anionic polymethine dyes, which cover a wide variety of structural types. The name of the class originates from the oxygen atoms which terminate each end of the polymethine chains that form the backbone of their structure. In technically useful dyes, these oxygen atoms tend to be substituents of heterocycles. The main technical application of water soluble oxonol dyes was in silver halide photography as filter dyes and antihalation dyes. Lipophilic oxonol dyes are used in bio-analysis and medical diagnostics to stain cells, bacteria or liposomes for example. Their main bioanalytical usage is in the determination of membrane potentials in eukaryotic cells and prokaryotic bacteria.


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