Light controlled bending of a holographic transmission phase grating

We recorded a permanent phase transmission grating on a thin film made by using a recently developed holographic photomobile mixture. The recorded grating pitch falls in the visible range and can be optically manipulated by using an external coherent or incoherent low power light source. When the external light source illuminates the grating the entire structure bends and, as a consequence, the optical properties of the grating change. This peculiarity makes it possible to use the recorded periodic structure as an all-optically controlled free standing thin colour selector or light switch depending on the source used to illuminate the grating itself. Additionally, it could open up new possibilities for stretchable and reconfigurable holograms controlled by light as well as thin devices for optically reconfigurable dynamic communications and displays.

Influence of the Weld Joint Position on the Mechanical Stress Concentration in the Construction of the Alternative Skid Car System’s Skid Chassis

This paper deals with the optimization of the crossbars, parts of the existing frame of the experimental system of the Alternative SkidCar. This part plays a crucial role and is designed to enable and ensure reduced adhesion conditions between the vehicle and the road. To this end, its optimization targeted here is performed using both analytical calculations and simulations in MSC Adams software, wherein the loading forces and boundary conditions on the frame support wheels are obtained considering the static conditions, as well as the change of the direction of travel. The least favourable load observed was used, later on, as the input value for the strength analysis of the frame. The analysis was performed using the finite element method (FEM) in SolidWorks. Based on the linear and nonlinear analyses performed, the course of stress on the frame arms and critical points with the highest stress concentration were determined. Subsequently, according to the results obtained, a new design for the current frame was proposed and, thereby, warrants greater rigidity, stability and strength to the entire structure, while reducing its weight and maximizing the potential of the selected material. The benefit of the current contribution lies in the optimization of the current frame shape, in terms of the position of weld joints, the location of the reinforcements and the thickness of the material used.

GENERALIZED CRITERIA FOR LOADING CAPACITY OF INDUSTRIAL ROBOTS

The analysis of the correspondence of the set of functional indicators of industrial robots to the criteria of criteria similarity conditions is carried out. Using the methods of the theory of dimensions, criteria for the similarity of the functional properties of carrying capacity, speed-action and dynamism of industrial robots in terms of rotational and translational degrees of mobility have been determined. The necessary set of criteria has been created and a concept has been proposed for determining the generalized criterion complexes of the load capacity for modules, aggregates and the entire structure of the robot as a whole using the method of defragmentation and averaging the corresponding criteria by degrees of mobility. The proposed performance criterion makes it possible to compare the performance of a group of robots in terms of three kinematic indicators: speed, acceleration and the range of permissible displacements. For robots of light load capacity, the technical evolution of the considered criterion complexes is presented. It is noticed that with an increase in the reach of the robot, the criterion of load-carrying capacity for all robots decreases. The developed criteria make it possible to assess the speed action and loading capacity of a robot of any design and can be used to determine the technical level of robots and identify reserves for increasing it. Key words: degrees of mobility; manipulation system; homogeneous functions; dynamic parameters

Literature, Ontology, and Implex in Merleau-Ponty: Writing and Finding the Concrete Limit of Phenomena

This paper examines the ambiguous relationship between the literary uses of language in Merleau-Ponty’s own work and his ontology. It is argued that Merleau-Ponty’s critique of phenomenology—that is, his critique of an already critical philosophy—leads him to say that the limits of phenomena are inside the entire structure of the phenomena. They are, in other words, promiscuous or dehiscent and therefore are not limits that can themselves be given. Merleau-Ponty would say that such limits are silent or mute within meaning. This will have repercussions for the very method of phenomenology. It can no longer be a descriptive method, concerned with the givenness of the phenomena, but needs to be matrixed with an expressive method that shows up the impossibility of such a return. This expressive method has to do with what he calls the “implex”—the very bodily limit of the inside and the outside that cannot be thought as one or the other, or even their synthesis. In other words, Merleau-Ponty’s phenomenology invites us towards a concrete bodily limit that is, at the same time, a limit to philosophy. In effect, one cannot think of Merleau-Ponty’s ontology of the flesh apart from language, because this ontology, its very concrete crystallization, requires expression and not just description.

On the issue of the artistic integrity of Sergey Gorodetsky's cycle “Prison Songsˮ

This article is devoted to the characterisation of the main signs of integration, observed in “Prison Songsˮ by Sergey Gorodetsky, the presence of which testifies to the cyclical structure of the work. The work provides a detailed analysis of the core themes of the cycle, central motifs and images. The author points out that the leading role in the formation of the principle of textual construction of artistic unity is played by antithesis, through the use of which the development of the position of the lyrical hero is most clearly traced, which becomes identical with the position of the author himself. The article concludes that the poems that make up the structure of “Prison Songsˮ do reveal common artistic bonds that support the cyclical nature of the work, as well as maintain strong artistic ties with the entire structure of the collection “Unbound Freedomˮ. These include both a common title, a single lyrical hero, close to the very figure of the author, common motifs and images, and genre characteristics of individual poems of the cycle. In addition, conceptual meanings for understanding the work as a whole are born at their junctions rather than within individual poems, which makes it possible to get closer to comprehending the author's picture of the world, embodied by the poet in the text of the cycle.

Enhanced Efficiency and Reduced Side Lobe Level Convex Conformal Reflectarray

In this work, the design of a convex conformal reflectarray (CRA), suitable to be used for high gain on board antenna in mobile communication systems, is presented. The reflector is not planar, as in usual reflectarray configurations, but the re-radiating elements are printed on a surface conformed to a cylinder to mimic a curved surface, such as the fuselage of an airplane, on which the reflectarray could be mounted. To compensate for the loss in efficiency due to the curvature, an ad hoc feed is designed; the results obtained with the simulation of the entire structure and the measurements of its prototype prove the effectiveness of the design procedure and its capability in enhancing the CRA features, in comparison with similar but more conventional solutions.

The mesoscale order of nacreous pearls

A pearl’s distinguished beauty and toughness are attributable to the periodic stacking of aragonite tablets known as nacre. Nacre has naturally occurring mesoscale periodicity that remarkably arises in the absence of discrete translational symmetry. Gleaning the inspiring biomineral design of a pearl requires quantifying its structural coherence and understanding the stochastic processes that influence formation. By characterizing the entire structure of pearls (∼3 mm) in a cross-section at high resolution, we show that nacre has medium-range mesoscale periodicity. Self-correcting growth mechanisms actively remedy disorder and topological defects of the tablets and act as a countervailing process to long-range disorder. Nacre has a correlation length of roughly 16 tablets (∼5.5 µm) despite persistent fluctuations and topological defects. For longer distances (>25 tablets , ∼8.5 µm), the frequency spectrum of nacre tablets follows f−1.5 behavior, suggesting that growth is coupled to external stochastic processes—a universality found across disparate natural phenomena, which now includes pearls.

Long-read metagenomics of multiple displacement amplified DNA of low-biomass human gut phageomes by SACRA preprocessing chimeric reads

The human gut bacteriophage community (phageome) plays an important role in the host’s health and disease; however, the entire structure is poorly understood, partly owing to the generation of many incomplete genomes in conventional short-read metagenomics. Here, we show long-read metagenomics of amplified DNA of low-biomass phageomes with multiple displacement amplification (MDA), involving the development of a novel bioinformatics tool, SACRA, that efficiently preprocessed numerous chimeric reads generated through MDA. Using five samples, SACRA markedly reduced the average chimera ratio from 72% to 1.5% in PacBio reads with an average length of 1.8-kb. De novo assembly of chimera-less PacBio long reads reconstructed contigs of ≥ 5-kb with an average proportion of 27%, which was 1% in contigs from MiSeq short reads, thereby dramatically improving contig length and genome completeness. Comparison of PacBio and MiSeq contigs found MiSeq contig fragmentations frequently near local repeats and hypervariable regions in the phage genomes, and those caused by multiple homologous phage genomes coexisting in the community. We also developed a reference-independent method to assess the completeness of the linear phage genomes. Overall, we established a SACRA-coupled long-read metagenomics robust to highly diverse gut phageomes, identifying high-quality circular and linear phage genomes with adequate sequence quantity.

Auto-gyro Descent System for Earth’s Atmosphere

An atmospheric descent mechanism that utilizes no power would be an efficient way to perform a safe landing procedure for small sized payloads and selected large payloads. This research paper presents the safe landing concept of an auto gyro descent system in the atmosphere of Earth, from a height of less than 1 Kilometre taken from the surface of executing point, using a specialized lift producing blade even at very low free stream velocity. These blades are designed to be highly cambered with suitable parameters as described further in the paper. Most of the parts are designed using CAD software and are 3D printed after a thorough simulation and analysis tests done using COMSOL Multi-physics and Xflr 5 for respective solutions. The model also includes the aerodynamics of the entire structure along with a base casing of specified structural design for further inclusion of electronic components for suitable scientific experiments. This provides a future base line for any kind of atmospheric studies or tests at a reasonable price and can be reused.

Some Notes on a Formal Algebraic Structure of Cryptology

Cryptology, since its advent as an art, art of secret writing, has slowly evolved and changed, above all since the middle of the last century. It has gone on to obtain a more solid rank as an applied mathematical science. We want to propose some annotations in this regard in this paper. To do this, and after reviewing the broad spectrum of methods and systems throughout history, and from the traditional classification, we offer a reordering in a more compact and complete way by placing the cryptographic diversity from the algebraic binary relations. This foundation of cryptological operations from the principles of algebra is enriched by adding what we call pre-cryptological operations which we show as a necessary complement to the entire structure of cryptology. From this framework, we believe that it is improved the diversity of questions related to the meaning, the fundamentals, the statute itself, and the possibilities of cryptological science.