Effect of an electric field on coalescence in gallium island films

It was found that the external longitudinal electric field stimulates coalescence in gallium island films with different particle sizes on a poorly conducting carbon substrate, which can be considered as a manifestation of the particle mutual-charging effect. - - - - - - - - - - - - - - - Установлено, что внешнее продольное электрическое поле стимулирует процесс коалесценции в островковых пленках галлия с различным размером частиц на слабопроводящей углеродной подложке, что может рассматриваться как проявление эффекта взаимного заряжения частиц

Size effects in wetting for highly dispersed systems

Wetting in systems with different dispersities of the solid and liquid phases and with different types of interfacial interaction was investigated. Studied were liq-uid metal-amorphous carbon and liquid metal-solid metal film-ionic crystal sys-tems in which the drop size and the thickness of film-substrates varied in the range 3x10^5–2x10^2 nm, respectively. It was found that for systems of the metal-amorphous carbon type a reduction in particle size and in thickness of carbon films brings about a size effect during wetting as a consequence of a decrease in the surface energy of the corresponding dispersed phase. For metal-metal-ionic crystal systems, a size effect during wetting is also observed but it is mainly caused by a changed nature of the interfacial interaction in the dispersed phases. Some parameters derived from the experimental data determine the dependence of the surface energy of small particles on their size

Size effects in wetting for highly dispersed systems

Wetting in systems with different dispersities of the solid and liquid phases and with different types of interfacial interaction was investigated. Studied were liq-uid metal-amorphous carbon and liquid metal-solid metal film-ionic crystal sys-tems in which the drop size and the thickness of film-substrates varied in the range 3x10^5–2x10^2 nm, respectively. It was found that for systems of the metal-amorphous carbon type a reduction in particle size and in thickness of carbon films brings about a size effect during wetting as a consequence of a decrease in the surface energy of the corresponding dispersed phase. For metal-metal-ionic crystal systems, a size effect during wetting is also observed but it is mainly caused by a changed nature of the interfacial interaction in the dispersed phases. Some parameters derived from the experimental data determine the dependence of the surface energy of small particles on their size

Light and Small-Angle X-Ray Diffraction from Opal-Like Structures: Transition from Two- to Three-Dimensional Regimes and Effects of Disorder

Conclusions To summarize, in this chapter diffraction of light and x-rays on opal-like structures is considered. New methodological approaches to collection, processing, and interpretation of experimental data are presented. In particular, a novel representation of the light diffraction data in the “incident angle–registration angle” (θ, Θ) coordinates is shown to be an effective tool of data analysis. This representation allows one to easily distinguish the reflections originating from 2D diffraction from the ones governed by 3D Bragg diffraction. In addition, structural disorder becomes apparent in the (θ, Θ) representation. It is also demonstrated that the immersion spectroscopy method can be used to selectively switch diffraction reflections. This phenomenon is caused by inhomogeneity of the a-SiO2 particles that form synthetic opals. Furthermore, it is demonstrated that microradian x-ray diffraction is a powerful technique that is able to reveal the dominating structure and the presence of disorder in opallike structures. Short acquisition times, modern 2D detectors, and progress in computing techniques make 3D reconstructions of reciprocal space routinely available. This method provides extremely valuable information on the real structure of mesoscopic materials that cannot be easily obtained by other analytical approaches. K13299

Methods of determination of wetting in highly dispersed systems

Procedures are described for studying the wetting of solid substrates by island vacuum condensates. The proposed methods are based on the application of optical and electron microscopy and may be used to find the angles of contact over a wide range of particle sizes (3-10^5 nm)

Methods of determination of wetting in highly dispersed systems

Procedures are described for studying the wetting of solid substrates by island vacuum condensates. The proposed methods are based on the application of optical and electron microscopy and may be used to find the angles of contact over a wide range of particle sizes (3-10^5 nm)

Modeling of Respiratory System Dysfunction Among Nuclear Workers: A Preliminary Study

Numerous studies have reported on cancers among Mayak Production Association (PA) nuclear workers. Other studies have reported on serious deterministic effects of large radiation doses for the same population. This study relates to deterministic effects (respiratory system dysfunction) in Mayak workers after relatively small chronic radiation doses (alpha plus gamma). Because cigarette smoke is a confounding factor, we also account for smoking effects. Here we present a new empirical mathematical model that was introduced for simultaneous assessment of radiation and cigarette-smoking-related damage to the respiratory system. The model incorporates absolute thresholds for smoking- and radiation-induced respiratory system dysfunction. As the alpha radiation dose to the lung increased from 0 to 4.36 Gy, respiratory function indices studied decreased, although remaining in the normal range. The data were consistent with the view that alpha radiation doses to the lung above a relatively small threshold (0.15 to 0.39 Gy) cause some respiratory system dysfunction. Respiratory function indices were not found to be influenced by total-body gamma radiation doses in the range 0–3.8 Gy when delivered at low rates over years. However, significant decreases in airway conductance were found to be associated with cigarette smoking. Whether the indicated cigarette smoking and alpha radiation associated dysfunction is debilitating is unclear

Ultrasmall-angle X-ray scattering analysis of photonic crystal structure

The results of an ultrasmall angle X ray scattering study of iron(III) oxide inverse opal thin films are presented. The photonic crystals examined are shown to have fcc structure with amount of stacking faults varying among the samples. The method used in this study makes it possible to easily distinguish between samples with predominantly twinned fcc structure and nearly perfect fcc stacking. The difference observed between samples fabricated under identical conditions is attributed to random layer stacking in the self assembled colloidal crystals used as templates for fabricating the inverse opals. The present method provides a versatile tool for analyzing photonic crystal structure in studies of inverse opals made of various materials, colloidal crystals, and three dimensional photonic crystals of other types

АНАЛИЗ СТРУКТУРЫ ФОТОННЫХ КРИСТАЛЛОВ МЕТОДОМ УЛЬТРАМАЛОУГЛОВОГО РЕНТГЕНОВСКОГО РАССЕЯНИЯ

Представлены результаты исследования структуры образцов пленочных инвертированных опалов на основе оксида железа ( III) методом ультрамалоуглового рентгеновского рассеяния. Показано, что исследованные фотонные кристаллы имели ГЦК-структуру с дефектами упаковки, причем количество последних может быть различным для разных образцов. Разработанный метод позволяет легко различить образцы с преимущественной двойникованной ГЦК-структурой и образцы с последовательностью слоев близкой к идеальной ГЦК-структуре. Наблюдаемые различия в структуре образцов, полученных в одинаковых условиях, связаны с вероятностным характером формирования слоев при самосборке коллоидных кристаллов, использовавшихся в качестве темплатов для синтеза инвертированных опалов. Описанный метод анализа структуры фотонных кристаллов является универсальным и может быть эффективно использован для исследования инвертированных опалов на основе различных материалов, коллоидных кристаллов, а также трехмерных фотонных кристаллов других типов