Ellipsometry of thin films of biological objects under conditions of total internal reflection

An analysis of the ellipsometric parameters of the reflected light from the prism test material air system is carried out when circularly polarized light is incident on it under the conditions of the onset of the phenomenon of total internal reflection. At the onset of total internal reflection, the ellipsometry parameter shows high variability with the angle of incidence, in contrast to the parameter r0. It is shown that TIR occurs when the angle of incidence is not equal to the critical angle of the adjacent media for two different materials, these angles differ from each other. In the case of a film, the TIR phenomenon occurs at an angle equal to the critical angle at the prism-air interface and does not depend on the film material. The results obtained show the high efficiency of using the ellipsometric method together with circularly polarized incident radiation for diagnostics of thin films made of biological material.

Thermophysical Parameters of a Semi-Finished Watermelon Product as an Object of Dehumidification

Introduction. Pectin-based protective coatings can produce a perfect biodegradable edible film. Secondary watermelon raw materials are a promising resource for this type of food coating as it contains 13.4% of pectin components, of which 8.1% is protopectin. The present research objective was to find the density and thermophysical characteristics of the pectin extract in order to optimize the drying process. Study objects and methods. The research featured a pectin extract from watermelon rind. Its thermophysical properties were defined according to the thermocouple inertia method. The calorimetric method was used to change the aggregation state, while the pycnometric method was applied to calculate the density. The method of criterion equations helped to define the heat transfer coefficient. Results and discussion. The average density of the final film material was 652 kg/m3 and that of the liquid semi-finished product was 1,028 kg/m3. The research also revealed the dependence of physical density and humidity W, heat capacity, thermal diffusivity, and thermal conductivity. For different W, averaged were 3393, 3225, 3137, and 3113, respectively. The study also provided the criterion dependence for determining the heat transfer coefficient and modified α on the speed of the air coolant for artificial convection at conventional coolant temperature (≈ 100°C) in contact with the food product surface (≈ 80°C). Conclusion. The article introduces the thermophysical characteristics and physical density of watermelon gel for various humidity and thermal agent parameters, as well as a modified criterion dependence for determining the heat transfer coefficient. The research results can be used to design dehydration operations, other thermophysical processes, and their equipment.

Transient, Sub-Continuum, Heat Conduction in Irregular Geometries

Phonon transfer in irregular shapes is important for assessing the influence of shape effect on thermal transport characteristics of low-scale films. It becomes critical for evaluating the contribution of the scattering phonons to the phonon intensity distribution inside the film. Hence, the sub-continuum ballistic-diffusive model is incorporated to formulate the phonon transport in an irregular geometry of low-size film adopting the transient, frequency-independent, equation of phonon radiative transfer. The discrete ordinate method is used in the numerical discretization of the governing transport equation. It is demonstrated that the geometric feature of the film influences the phonon intensity distribution within the film material. The transport characteristics obtained from the Fourier and the ballistic-diffusive models are markedly different in their spatial and temporal behavior. This is true when the device sizes are of the same order of magnitude as the mean-free path of the heat carriers.

Review of the Monograph “Advertising as an Integral Part of a Film” by Yuliia Shevchuk

The topic of Yu. S. Shevchuk's monograph "Advertising as an integral part of the film"involves the interdisciplinary nature of the study. Its disclosure required the scientist to have a thorough knowledge of film material, the ability to analyze the visual and audiovisual series of cinema in combination with the use of categorical apparatus and methodology of social communication research.

Różewicz vs. Różewicz, czyli o noweli „Piwo” Tadeusza Różewicza i jej ekranizacji w reżyserii Stanisława Różewicza

The author of this article makes a comparative interpretation of Tadeusz Różewicz’s novella Piwo [Beer] and its film adaptation directed by Stanisław Różewicz. Among other things, the researcher asks the question: to what extent do the differences between the film material and the text material – in this particular case – stem from the specificity of the film language and its autonomy in relation to literature? He believes that this can be explained by the fact that the action of the film takes place only in the station’s waiting room; the movement between the inn and the station, undoubtedly justified in the case of the original text, would be for the viewer something illegible and disturbing to the sequence of events. The multilevel linguistic code forcing symbolic readings, so important in Różewicz’s prose, seems, however, not to be translatable (at least not in its entirety) into the language of the image, which enforces a number of other artistic solutions. It seems that the film work here speaks the language of symbols on a different level.

Dispersion of watermelon rinds as secondary raw materials in technologies of pectin-containing extracts and film structures

The development of protective coatings based on pectin substances that serve as natural structure-forming agents developed from a secondary resource base is focused on removing a complex problem in the production of finished products by deep processing of basic raw materials and developing an original film material. At the same time, the technical result of obtaining pectin-containing film structures is their ability to protect food products from microbiological spoilage, natural losses during storage and the preservation of quality and safety indicators. An important preparatory procedure that determines the efficiency and intensity of extraction processes can be attributed to the operation of dispersing the feedstock, since it directly affects the size of the contact surface area of the phases involved in mass transfer. However, it is clear that the greater the degree of grinding, the higher the efficiency of the process, but an excessive increase can lead to additional unjustified energy costs and, as a result, to an increase in the cost of the finished products sold. In this regard, the purpose of the research is to analyze existing technologies for producing pectin-containing extracts, in which watermelon rinds can be used as secondary resources and to intensify the extraction process by conducting a rational preparatory procedure for grinding the raw materials. The object of the research are watermelon rinds as non-recyclable waste from processing watermelon raw materials. According to the obtained graphs, and taking into account the high rates of gelatinization of the obtained pectin extracts, it is possible to recommend a complex treatment of watermelon rinds, including, in addition to the operations of preliminary preparation of raw materials, ultrasonic exposure and acid hydrolysis, and it is desirable to use food acids, for example, acetic or citric, instead of aggressive sulfuric and hydrochloric acids. As a result of the study of the dispersed composition, it has been concluded that the average equivalent particle size of the dispersed raw materials does not exceed the recommended limits, that is, the result obtained can be considered acceptable.

Structure and Tribo-Mechanical Properties of MoSx:N:Mo Thin Films Synthesized by Reactive dcMS/HiPIMS

Modifying MoS2 thin films by additional elements shows great potential in order to adjust the property profile and to meet the increasing requirements regarding high wear resistance and low friction properties of industrial components. Within that context, MoSx:N:Mo thin films were deposited by a reactive hybrid dcMS/HiPIMS process. By systematically increasing the Mo target cathode power, an investigation of the structural and the mechanical properties was conducted to understand the evolution of the tribological behavior. A low Mo target cathode power of 1 kW is related to the formation of the preferential (002) MoS2 basal-plane and thus a low friction with µ = 0.2. With an increasing amount of Mo, the film loses its solid lubricant MoS2 properties and a nitride constitution of the thin film is developing due to the formation of crystalline Mo and MoN phases. Related to this transformation, the hardness and elastic modulus are increased, but the adhesion and the tribological properties are impaired. The film loses its plasticity and the generated film material is directly removed from the contact area during the sliding contact.

Ultra Narrow Dual-Band Perfect Absorber Based on a Dielectric−Dielectric−Metal Three-Layer Film Material

This paper proposes a perfect metamaterial absorber based on a dielectric−dielectric−metal structure, which realizes ultra-narrowband dual-band absorption in the near-infrared band. The maximum Q factor is 484. The physical mechanism that causes resonance is hybrid coupling between magnetic polaritons resonance and plasmon resonance. At the same time, the research results show that the intensity of magnetic polaritons resonance is much greater than the intensity of the plasmon resonance. By changing the structural parameters and the incident angle of the light source, it is proven that the absorber is tunable, and the working angle tolerance is 15°. In addition, the sensitivity and figure of merit when used as a refractive index sensor are also analyzed. This design provides a new idea for the design of high-Q optical devices, which can be applied to photon detection, spectral sensing, and other high-Q multispectral fields.

PMMA – C60 composite: thermal decomposition experiments in mass spectrometer and quantum chemical modeling

Mass-spectrometric thermal decomposition experiments with submicron films of neat polymethylmethacrylate (PMMA), and PMMA-fullerene composite (PMMA-C60) after UV irradiation are discussed. The experiment registers thermal desorption mass spectra (TDMS), that is the monomer desorption rate versus time upon gradual heating the PMMA films in a given heating regime. The spectra provide information on the amount of the monomer desorbed at different decomposition stages upon heating the given amount of film material as well as on the spectral shape changes. It is shown that both amount of monomer and the TDMS spectral shape are sensitive to the presence of fullerene and UV irradiation. The experimental results are discussed in terms of quantum chemical models of binding. The DFT/B3LYP-D3/def2/J RIJCOSX level of theory was used. The MMA-C60 structures which can yield different amounts of monomer have been compared.

Tunable Three-Dimensional Vibrational Structures for Concurrent Determination of Thin Film Modulus and Density

The real-time characterization of thin film properties can provide insights into the behavior of film material during process such as phase-transition, hydration and chemical reaction. The shift of reasonant frequency in structural vibration serves as the basis of an effective approach to determine film properties, but encounters the difficulty that multiple to-be-determined quantites (e.g. film modulus and density) are often related to the resonant frequency simultaneously and therefore cannot be determined by a structure with fixed shape and vibration mode. Determinsitic mechanical buckling provides an effective route for the vibrational structure to rapidly switch between designed shapes and vibration modes. Here, we adopt a ribbon structure in the flat state and buckled state to yield two distinct vibration modes. Theoretical models of the natural frequencies are established for first-order out-of-plane modes of the ribbon with patterned thin films in these two states, respectively. The model suggests that with optimized film pattern the sensitivity of the natural frequencies to the film modulus and density can be partially decoupled. The results lead to a simple and effective method based on tunable vibration to characterize the thin film modulus and density at small scale.