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Electron spin resonance (ESR) and diffuse reflectance spectroscopy (DRS) were applied to study the origin of the strongly enhanced photographic sensitivity of red-sensitized (dye RS) AgCl systems upon addition of a Ultraviolet- (UV-) absorbing supersensitizer (SS). Both techniques were used to identify the radicals formed in this system upon spectral (red) as well as intrinsic (UV) excitation. Upon coadsorption of SS on the AgCl/RS system, the intensity of the photoinduced ESR signal is strongly increased. The ESR signals detected in systems with and without SS are very similar in line shape, line width, and g value, suggesting the formation of RS radicals. This was confirmed by the observation of a pair of absorption bands in the DRS spectrum, demonstrating that the radicals are formed on the RS molecules for all systems and ruling out supersensitization by hole trapping on the SS molecules for these systems. The effect of the supersensitizer is shown to be an overall increase in electron transfer efficiency from the dye molecules RS to the AgCl crystals. Indirect evidence is presented for the partitioning model, in which the electron transfer is facilitated by a rise of the lowest unoccupied molecular orbital level of the dye molecules, resulting from a reduction of the effective size of the RS aggregates. [ABSTRACT FROM AUTHOR]

Presents information on a study which investigated the relation between fluorescence decays and composition of the emulsions of several spectrally sensitized photographic emulsions. Experimental details; Results and discussion; Conclusions.

The review discusses the possibility of obtaining highly effective relief-phase structures on silver halide photographic emulsions and dichromated gelatin layers by irradiating initially recorded holographic structures with short-wave UV radiation. [ABSTRACT FROM AUTHOR]

Neoglaziovia variegata is a Bromeliaceae plant species widely found in Brazil with several pharmacological properties, including photoprotective activity. Although herbal-based active ingredients have been applied in cosmetic products, especially for skin treatment, its application in sunscreen formulations remains unexplored. The aim of this work is to evaluate the photoprotective effect of cosmetic formulations containing hydroalcoholic extract of N. variegata (Nv-HA). Initially, the phenolic and flavonoid total content of Nv-HA were determined. The photoprotective activity of Nv-HA was subsequently assessed using a spectrophotometric method. Nv-HA was incorporated in O/W emulsions in the presence or absence of synthetic filters and their photoprotective efficacy was evaluated by spectrophotometric SPF determination. Finally, the stability study of the formulations was performed through the freezing/defrosting method. Nv-HA showed significant phenolic and flavonoids content (61.66 ± 5.14 mg GAE/g and 90.27 ± 5.03 mg CE/g, resp.). Nv-HA showed SPF values of 5.43 ± 0.07 and 11.73 ± 0.04 for the concentrations of 0.5 and 1.0% (v/v), respectively. It was verified that Nv-HA potentiated the photoprotective effect of formulations containing only synthetic filters. Furthermore, the formulations have remained stable at the end of the preliminary stability study. According to the results, it was concluded that Nv-HA can be used as a chemical filter in cosmetic formulations. [ABSTRACT FROM AUTHOR]

One of the most interesting techniques for the production of holographic optical elements is silver halide sensitised gelatin (SHSG). It combines the high sensitivity of photographic emulsions with the well-known low scattering and high diffraction efficiencies corresponding to dichromated gelatin. In this work we made a comparative study on SHSG holograms recorded on three different red sensitive emulsions: Agfa 8E75 HD, Slavich PFG-01 and BB-640 . The influence of the degree of hardening of the gelatin and the size and concentration of silver halide grains in the SHSG proccess is studied. And we will show that real high diffraction efficiencies can be obtained when using BB-640 and Slavich PFG-01 plates for recording phase transmission holograms (as high as 93% for PFG-01 and 90% for BB-640, allowing for reflections). Our investigations reveal that PFG-01 and BB-640 emulsions are not only a substitution to Agfa material, but may offer better results at a moment in which Agfa has stopped its production of holographic material.Una de las técnicas más interesantes para la obtención de elementos ópticos holográficos es la gelatina sensibilizada de haluro de plata (GSHP). Esta técnica combina la alta sensibilidad de las emulsiones fotográficas con los conocidos altos rendimientos en difracción y bajos niveles de scattering correspondientes a la gelatina dicromatada. En este trabajo se ha hecho un estudio comparativo sobre hologramas en gelatina sensibilizada de haluro de plata registrados en tres emulsiones diferentes sensibles al rojo: Agfa 8E75 HD, Slavich PFG-01 y BB-640. En dicho estudio se ha analizado la influencia del grado de endurecido de la gelatina y la concentración y el tamaño de los granos de haluro de plata en el procesado GHSP. Se obtuvieron rendimientos en difracción realmente altos cuando se utilizaron las placas BB-640 y Slavich PFG-01 para el registro de hologramas de fase por transmisión (tan altos como el 93% para las PFG-01 y el 90% para las BB-640, después de haber corregido los resultados teniendo en cuenta las reflexiones en las distintas superficies de separación de la placa). Nuestras investigaciones indican que las emulsiones BB-640 y Slavich PFG-01 pueden cubrir el vacío dejado por las placas Agfa 8E75 HD, e incluso pueden ofrecer mejores resultados en un momento en el cual Agfa ha dejado de fabricar material para aplicaciones en Holografía.

We have developed a new multicolor holographic polymer film. Our holographic polymer film contains 3-[(2,4,6-trichloro)azo]-9H-carbazole-9-ethanol (A-1) and poly(methyl methacrylate). The holographic polymer film can be recorded with a holographic image without applying an external electric field. The diffraction efficiency was 57% at A-1 with a 20 wt% of dope ratio. The writable holographic image writing for the holographic polymer film step used the silver halide photographic emulsion master plate 532-nm laser beam under the nonelectric field. After the copy hologram is formed, our holographic polymer film can be displayed in red and green holographic images. Even though our holographic polymer film is rewritten over 200 times, the diffraction efficiency does not fall. As the holographic polymer film is manufactured using roll-to-roll techniques, although still in a laboratory scale in this study, it has a strong possibility of being manufactured in larger sizes with lower cost. [ABSTRACT FROM AUTHOR]

In 1913 J. Herweg first (June 30) and M. de Broglie slightly later (November 17) claimed the discovery of a series of spots and lines closely following the main absorption edges of heavy metals, which they interpreted as the proof of the existence of X-ray spectra analogous to light spectra. In the following year they documented their discoveries via photographic plates. However, they were both discredited: Herweg by G.E.M. Jauncey, who showed that his spectra, taken on Pt and W, did not obey Moseley's rule; de Broglie by W.H. Bragg, M. Siegbahn and E. Wagner, who showed that his lines were in fact the fluorescence lines of the Ag and Br constituents of the photographic emulsion. Consequently, W. Stenström's description (sent to publisher on July 2, 1918) of certain photographically recorded and graphically rendered modulations near the M -series edges of heavy metals may possibly be the first published evidence of true X-ray absorption spectra. Indeed, they were interpreted as such by W. Kossel (1920) in his seminal theoretical paper. Otherwise, H. Fricke's table, although printed in 1920, which exhibits the photographic plate of sulphur absorption dated October 1, 1918, and its graphical rendering by a photometric method, is the first unequivocally dated evidence of recorded modulations at a XAS K -edge. [ABSTRACT FROM AUTHOR]

The article discusses research which examines the effects of physicochemical colorants on polymeric composites printing toners cyan, magenta and yellow. Topics discussed include increased industrial applications of digital electrophotographic printing, synthesis of printing toners by the emulsion aggregation method and evaluation of the influence of solid-state parameters and physicochemical properties of the pigments on printing toner.

Purpose: The purpose of this study is the correction of the lateral scanner artifact, i.e., the effect that, on a large homogeneously exposed EBT3 film, a flatbed scanner measures different optical densities at different positions along the x axis, the axis parallel to the elongated light source. At constant dose, the measured optical densitiy profiles along this axis have a parabolic shape with significant dose dependent curvature. Therefore, the effect is shortly called the parabola effect. The objective of the algorithm developed in this study is to correct for the parabola effect. Any optical density measured at given position x is transformed into the equivalent optical density c at the apex of the parabola and then converted into the corresponding dose via the calibration of c versus dose. Methods: For the present study EBT3 films and an Epson 10000XL scanner including transparency unit were used for the analysis of the parabola effect. The films were irradiated with 6 MV photons from an Elekta Synergy accelerator in a RW3 slab phantom. In order to quantify the effect, ten film pieces with doses graded from 0 to 20.9 Gy were sequentially scanned at eight positions along the x axis and at six positions along the z axis (the movement direction of the light source) both for the portrait and landscape film orientations. In order to test the effectiveness of the new correction algorithm, the dose profiles of an open square field and an IMRT plan were measured by EBT3 films and compared with ionization chamber and ionization chamber array measurement. Results: The parabola effect has been numerically studied over the whole measuring field of the Epson 10000XL scanner for doses up to 20.9 Gy and for both film orientations. The presented algorithm transforms any optical density at position x into the equivalent optical density that would be measured at the same dose at the apex of the parabola. This correction method has been validated up to doses of 5.2 Gy all over the scanner bed with 2D dose distributions of an open square photon field and an IMRT distribution. Conclusions: The algorithm presented in this study quantifies and corrects the parabola effect of EBT3 films scanned in commonly used commercial flatbed scanners at doses up to 5.2 Gy. It is easy to implement, and no additional work steps are necessary in daily routine film dosimetry. [ABSTRACT FROM AUTHOR]

Abstract: Several models have been proposed for scaling in situ cosmogenic nuclide production rates from the relatively few sites where they have been measured to other sites of interest. Two main types of models are recognized: (1) those based on data from nuclear disintegrations in photographic emulsions combined with various neutron detectors, and (2) those based largely on neutron monitor data. However, stubborn discrepancies between these model types have led to frequent confusion when calculating surface exposure ages from production rates derived from the models. To help resolve these discrepancies and identify the sources of potential biases in each model, we have developed a new scaling model based on analytical approximations to modeled fluxes of the main atmospheric cosmic-ray particles responsible for in situ cosmogenic nuclide production. Both the analytical formulations and the Monte Carlo model fluxes on which they are based agree well with measured atmospheric fluxes of neutrons, protons, and muons, indicating they can serve as a robust estimate of the atmospheric cosmic-ray flux based on first principles. We are also using updated records for quantifying temporal and spatial variability in geomagnetic and solar modulation effects on the fluxes. A key advantage of this new model (herein termed LSD) over previous Monte Carlo models of cosmogenic nuclide production is that it allows for faster estimation of scaling factors based on time-varying geomagnetic and solar inputs. Comparing scaling predictions derived from the LSD model with those of previously published models suggest potential sources of bias in the latter can be largely attributed to two factors: different energy responses of the secondary neutron detectors used in developing the models, and different geomagnetic parameterizations. Given that the LSD model generates flux spectra for each cosmic-ray particle of interest, it is also relatively straightforward to generate nuclide-specific scaling factors based on recently updated neutron and proton excitation functions (probability of nuclide production in a given nuclear reaction as a function of energy) for commonly measured in situ cosmogenic nuclides. Such scaling factors reflect the influence of the energy distribution of the flux folded with the relevant excitation functions. Resulting scaling factors indicate 3He shows the strongest positive deviation from the flux-based scaling, while 14C exhibits a negative deviation. These results are consistent with a recent Monte Carlo-based study using a different cosmic-ray physics code package but the same excitation functions. [Copyright &y& Elsevier]

Abstract: The main goal of the AEgIS experiment at CERN is to test the weak equivalence principle for antimatter. We will measure the Earth's gravitational acceleration with antihydrogen atoms being launched in a horizontal vacuum tube and traversing a moiré deflectometer. We intend to use a position sensitive device made of nuclear emulsions (combined with a time-of-flight detector such as silicon ) to measure precisely their annihilation points at the end of the tube. The goal is to determine with a 1% relative accuracy. In 2012 we tested emulsion films in vacuum and at room temperature with low energy antiprotons from the CERN antiproton decelerator. First results on the expected performance for AEgIS are presented. [Copyright &y& Elsevier]

A biography of Indian physicist Mambillikalathil Govind Kumar Menon is presented. He was born on August 28, 1928 in Mangalore, India and studied science and medicine at the Punjab University, the Jaswant College and the Agra University in Indian states of Punjab, Rajasthan and Uttar Pradesh respectively. He started a project on photographic emulsion and cosmic rays and nurtured Tata Institute of Fundamental Research in Mumbai, India.

We have presented an investigation on the ring- and jet-like azimuthal angle substructures in the emission of secondary charged hadrons coming from S-Ag/Br interactions at 200 A GeV/c. Nuclear photographic emulsion technique has been employed to collect the experimental data. The presence of such substructures, their average behaviour, their size, and their position of occurrence have been examined. The experimental results have also been compared with the results simulated by Monte-Carlo method. The analysis strongly indicates the presence of ring- and jet-like structures in the experimental distributions of particles beyond statistical noise. The experimental results are in good agreement with I M Dremin idea, that the phenomenon is similar to the emission of Cherenkov electromagnetic radiation. [ABSTRACT FROM AUTHOR]

Abstract: This work is devoted to the analysis of possibilities of nuclear emulsions for Dark Matter search, particles of which can produce slow recoil-nuclei. Tracks of such recoil-nuclei in developed nuclear emulsion consist from several emulsion grains. The analysis was carried out with Monte-Carlo calculations made on the basis of the Track Theory and the various factors influencing Dark Matter particles registration efficiency were investigated. Problems, which should be solved for optimal utilization of nuclear emulsions in Dark Matter search, were formulated."Body [Copyright &y& Elsevier]

This paper presents the projectile fragments emerged from non-central events of 3.7A GeV 28Si collisions in nuclear emulsion. The charges of these fragments were carefully measured and compared with those obtained from 3.7A GeV 28Si. The distributions of those charges were given and fitted by the Gaussian shapes. The topology of 28Si fragmentation is given. The dependence of fragmentation process on incident beam energy is studied. The presence of α-cluster inside silicon beam is investigated [ABSTRACT FROM AUTHOR]