Plastic Ones Research Articles

Super engineering polyesters: synthesis and performance characteristics

The method of polycondensation allows to produce aromatic polyesters of various composition and structure. In this study, the structure and performance characteristics of the synthesized polymers have been investigated. It has been explained that the resulted aromatic polyesters have appropriate performance characteristics for using them as the base for producing prepregs and engineering polymeric materials with desired parameters in order to replace essential parts made of metals and metal alloys with the similar plastic ones in various industrial equipment.

Yielding capacity and adaptability of winter bread wheat breeding lines in environment of Ukrainian Forest-Steppe

Purpose. To estimate yielding capacity and adaptability of winter bread wheat promising lines bred at the V. M. Remeslo Myronivka Institute of Wheat in the final stage of breeding process for submission of the best lines to the State Qualifying Expertise. Methods. Field and mathematical-statistical. Results. During 2010–2014, 17 winter bread wheat promising lines of competitive testing in 18 environments (growing season conditions, preceding crop, sowing date) were evaluated by yielding capacity and adaptability parameters: plasticity, stability, general and specific adaptive ability, breeding value of genotype, compensation coefficient of genotype. According to the regression coefficient level, 3 groups of lines have been identified: weakly responding on changes in environment (bi < 1) – Erythrospermum 54866, Lutescens 36921; plastic ones (bi = 1) Lutescens 54630, Lutescens 35232; highly sensitive to changes in environment (bi > 1) – Lutescens 54739, Lutescens 36756, Lutescens 37090, Lutescens 54875. The maximum general adaptive ability was observed for the lines Lutescens 35354, Lutescens 54630, Lutescens 54739, Lutescens 54533, Erythrospermum 36802, Lutescens 36756, whereas the lines Lutescens 54533, Lutescens 320/02, Lutescens 36931, Erythrospermum 54866 were revealed to be the most stable in specific adaptive ability. The lines Lutescens 54533, Lutescens 54630, Lutescens 54739, Erythrospermum 36802, and Erythrospermum 54866 were characterized with the highest breeding value of genotype. Conclusions. Estimation by the integral index “breeding value of genotype” characterizing the balance between the yield level and stability gives more accurate information when testing high-yielding lines, and allows making the right choice that is confirmed with the adaptability rating of the genotype. Based on comprehensive assessment by yielding capacity and adaptivity parameters, the following lines as the future varieties were identified: Lutescens 54630 (Berehynia myronivska), Lutescens 54739 (Hospodynia myronivska), Lutesсens 36921 (Trudivnytsia myronivska), Erythrospermum 54866 (MIP Vyshyvanka), Erythrospermum 36802 (Hratsiia myronivska.

SUBSTANTIATION OF ENERGY EFFICIENT WATER SUPPLY IN CLOSED IRRIGATION SYSTEMS

Relevance of research. The research is aimed at improving the energy efficiency of automated water supply in irrigation systems. The purpose and objectives of research. The purpose of the research is to reduce the specific energy consumption for pumping water by pumping stations (PS) in closed irrigation systems (CIS). The task is to substantiate the efficiency of the method of automated control of water supply to the CIS when regulating the pressure at the outlet of the pumping station, which is set by the sum of hydraulic losses in the network from the pumping station to irrigation equipment (IE), static and free pressure at the dictating hydrant of CIS. The logical-mathematical model and technological conditions of energy-efficient water supply management "when it need" in CIS are given. The technical requirements for pumping units (PU) and auxiliary technological equipment of PS are presented in the application of automated water supply control with the use of frequency converters (FC).Research methods: experimental, mathematical modeling. Substantiation of the feasibility of introduction of automated electric drive with FC, as one of the measures of energy efficiency improvement, was carried out based on the results of energy audits of the PU and the CIS with the use of measuring equipment on the request of inter-district water management administration. The object of the energy audit is the CIS, which has been in operation since 1979. The PS is equipped with four PU with centrifugal section pumps 150-CVE-350-23/3 (D = 350 mm) and drive motors of the brand MAF315SK-4 with a rated power of 132 kW. During the period of operation the reconstruction and restoration of the CIS took place. “Dnepr” sprinkling machines have been replaced by modern low pressure SM and drip irrigation systems. With the replacement of irrigation equipment, asbestos-cement field pipelines with diameters D = 400 mm were replaced too with the plastic ones of D = 200 mm. The configuration, hydraulic characteristics of the CIS and modes of operation of the PU were changed. The efficiency of the pumps 150-CVE-350-23/3 decreased by 10-15% during the long-term operation of the PU. Research results. For energy efficient water supply management, it is proposed to: replace four worn pumps 150-CVE-350-23/3 with three pumps of domestic production ЦН400-105б; implement a system of automated water supply management at the CIS with the use of FC. Conclusions. The effectiveness of the application of a new method of water supply control in the CIS, which provides for automatic control of the pressure at the outlet of the PS, is given by the sum of hydraulic losses in the network from the PS to the IE, static and free pressure at the dictating inlet of the operating IE, using the proven FC. Introduction of automated electric drive with the FC on the PS-4 of the “Repin” CIS enables to reduce the daily power consumption from 12% to 25%.

On the mechanisms of production of large irreversible strains in materials with elastic, viscous and plastic properties

A thermodynamically and geometrically consistent mathematical model of large strains of materials with elastic, viscous and plastic properties is proposed. The viscous properties of a material are considered to provide a creep process and, therefore, the slow growth of irreversible strains during unloading and the stage preceding plastic flow. Under the fast growth of irreversible strains under the conditions of plastic flow, the viscous properties emerge as a mechanism that resists to this flow. Thus, the accumulation of irreversible strains initially occurs in the creep process, then under the plastic flow condition and finally because of material creep (during unloading). The change in the mechanism of irreversible strain growth occurs on elastoplastic boundaries moving in the deformed material. This change is only possible under the conditions of the continuity of irreversible strains and their rates. This continuity requires the coordination in the definitions of irreversible strain rates in the dependence on stresses, i.e. in laws of creep and plasticity. The change in the production mechanisms of irreversible strains means a different setting of the sources in differential equations of change (transfer equations) for these strains. Thus, irreversible strains are not divided into creep and plastic ones. The hypothesis of the independence of thermodynamic potentials (internal energy, free energy) from irreversible strains is applied with the aim of most visibility of the model relations. Under the condition of the acceptance of this hypothesis, an analogue of the Murnaghan formula is obtained, i.e. the stresses are completely determined by the level and distribution of the reversible strains as in the classical elastoplasticity theory. The main statements of the proposed model are illustrated by a boundary value problem solved in the framework of the model. This problem is about the deformation of an elastoviscoplastic material placed in the gap between two rigid cylindrical surfaces under the rotation of one of them and the material slipping in the neighbourhood of the internal surface.

Assessment of Varieties of Spring Barley of Selection of Omsk Agrarian Research Center for Adaptivity of Mass of 1000 Grains

Considering climatic factors and production demands, selection for increased productivity and adaptability to local climatic factors is currently relevant. To create new varieties of barley with the listed factors, a promising source material with improved adaptive qualities is required. One of the leading structural elements that determine the productivity of a variety is the mass of 1000 grains. Objective: to assess the adaptability of spring barley varieties from the selection of the Omsk Agrarian Scientific Center in terms of the mass of 1000 grains. The object of research was 11 varieties of spring barley breeding Omsk Agrarian Scientific Center. Based on this indicator, the following adaptability parameters were calculated: the indicator of the size of the grain size, the coefficient of variation, the coefficient and ecovalent of ecological plasticity, the relative stability of the trait and homeostaticity. The final assessment was carried out according to the sum of ranks obtained by each applied method, given that rank 1 is higher. The average weight of 1000 grains of barley varieties, breeding of the Omsk ANC, was 45.7 g in membranous and 40.9 g in huskless. According to the results of adaptability studies, stable varieties were identified that are poorly responsive to changes in cultivation conditions and better adapted to medium and low levels of agriculture: Omsky 95, Gift of Siberia and Omsk huskless 2 (the sum of ranks ranged from 22.0 to 29.0). Varieties Sibirsky Avant-garde, Sasha, Omsky 91, Omskyhuskless 1 and Omsky 90 (sum of ranks from 38.0 to 51.0) are classified as plastic ones – the change in grain size of these varieties is fully consistent with the change in growing conditions. Strong responsiveness to changing conditions was found in varieties Omsky 96, Omsky 100 and Omsky 99 (the sum of ranks varies from 59.0 to 63.0) – these varieties belong to the intensive group, which means less adaptability to adverse conditions.

“A journey as a flow”: A personal spatio-temporal projection of the world

Abstract. When regarding the changing world of today, both artists and cartographers attempt to map what they perceive and are increasingly compelled to go beyond static and unchangeable geometric plans which represent a constrained version of the dynamics of our lives. In so doing these skilled researchers are questioning the existing models of representation of reality, by placing a stronger accent on the way all connections are established at geopolitical, social and personal levels.Therefore, this project aims to draw attention to this, how living consciously in the contemporary world involves rethinking our self-projection in time. What follows are ideas for an art exhibition that depicts dynamic space-time and thematic aspects of individual lives, drawing from geographic and artistic representation, conveying as well the distinction between plastic spaces and behavioral ones (Forer, 1978). In moving forward, many models could be adapted to the changing individual status of the life traveler, represented in a 3D space-time exhibition room (Hagerstrand, 1970). Within the meta-space-time we have individual lifetime space-time paths traced by spherical structures, which themselves contain a more temporally specific daily path (Fig 1a). Being inside the flow of different events is more a case of switching between interchangeable references (or multiple spherical structures - Fig 1b) instead of using behavioral patterns to pigeon-hole the traveler in only one of a number of possible lifestyles, which is the static, invariant take. Therefore, many possible destinations and routes of each individual flow (Fig 1c) on today’s map are changeable too, leaving projected traces in space-time, because of differences in perception inside of the total flows within big urban metropolises.If we attempt to re-define a journey as a way to create all the spatial connections with others by including as well a specific way of being in time, we will realize that as a consequence of our real time or virtual behavior, each day becomes a new type of a journey inside of different flows. Our self-projections are multifaceted and directly related to the way we establish connections in the world, subject to disrupting forces, such as hurricanes (an alternative representation - Fig 1d).Another perspective on this is to regard the balloon or cloud as a result of environmental processes to visualize different flows that are happening and in which we are participating. It is more a result of the flows than a flow in itself. It can have different color because of the intensity of the process that are operating behind the flow (expressed through cartographic means, linking color to theme or emotion, Figure 2). Because it depends on how it appears, it can have different ways to be expressed: as a result of the connections of the city flows, a result of a daily exploration of space-time in a mental sense etc. But it appears because of the flows, which are interrupting the regular, grid-like patterns, just like emotions. Thus the ‘cloud’ has a double meaning as a psychological or mental symbol.A mental schema can also express how we move from one place into another: in Figure 3a we are staying at the same point inside of imaginary space-time, which moves in itself; in Figure 3b it is more about moving like a ping-pong pattern (moving and going back to the same place during one day, with the repetition and tedium that implies).Mental mapping in this context might consist as well of representing the physical path taken and one that comes from thoughts about clouds in the system of communication. As a result of connections and flows (Figure 4b), but not as a fixed result, a cloud can change its color, shape and can even disappear from the environment. It can be present as a potential resource, occurring within the perspective of a year, month or daily (Figure 4a) as a metaphor relating to everyday life. We define this self-projection in time as a result of these potential ever-evolving relationships and activities and we visualize them as a journey through the phenomenological qualities of the territory (e.g. Abbott, 2013). This is translated into the cartographic language of the planned 3D exhibition.

Object Properties Influence Visual Guidance of Motor Actions.

The dynamic nature of the real world poses challenges for predicting where best to allocate gaze during object interactions. The same object may require different visual guidance depending on its current or upcoming state. Here, we explore how object properties (the material and shape of objects) and object state (whether it is full of liquid, or to be set down in a crowded location) influence visual supervision while setting objects down, which is an element of object interaction that has been relatively neglected in the literature. In a liquid pouring task, we asked participants to move empty glasses to a filling station; to leave them empty, half fill, or completely fill them with water; and then move them again to a tray. During the first putdown (when the glasses were all empty), visual guidance was determined only by the type of glass being set down—with more unwieldy champagne flutes being more likely to be guided than other types of glasses. However, when the glasses were then filled, glass type no longer mattered, with the material and fill level predicting whether the glasses were set down with visual supervision: full, glass material containers were more likely to be guided than empty, plastic ones. The key finding from this research is that the visual system responds flexibly to dynamic changes in object properties, likely based on predictions of risk associated with setting-down the object unsupervised by vision. The factors that govern these mechanisms can vary within the same object as it changes state.

ОПРЕДЕЛЕНИЕ КЛАССА БЕТОНА ЖЕЛЕЗОБЕТОННЫХ БАЛОК ПО КОЭФФИЦИЕНТУ ЗАТУХАНИЯ КОЛЕБАНИЙ

The article considers the possibility of using the vibration-damping coefficient to determine the concrete class of reinforced concrete beams without prestressing reinforcement in the elastic stage of work. It is proposed to use this parameter as a characteristic that takes into account energy losses in an oscillatory system. It is likely that a change in the class of concrete will have a direct effect on the intensity of the damping of vibrations, since with an increase in the class of concrete the elastic properties of the structure begin to prevail over the plastic ones. Providing the same conditions of support and control of experimental designs, energy losses due to various physical and deforming properties of the products will be fully manifested, and the damping coefficient of vibrations will allow determining these properties with less errors and greater stability compared to ultrasonic or mechanical methods. A method has been developed for determining the class of concrete, based on the use of reference structures and constructing an analytical dependence of the damping coefficient of vibrations on the class of concrete. For the studied type and size of reinforced concrete structures, a smaller error in determining the class of concrete is obtained in comparison with known methods.

Normal Contact Model for Elastic and Plastic Mechanics of Rough Surfaces

An elastic and plastic mechanical model is proposed to characterize the normal contact of rough surfaces. The contact process is considered as three separated contact regimes, i.e., the fully elastic, mixed elastic–plastic and fully plastic ones. The Hertzian elastic contact solutions and the classical fully plastic contact model of Abbott and Firestone are used to model the contact behaviors of fully elastically deformed asperities and fully plastically deformed ones, respectively. For the mixed elastic–plastic regime, an improved Hermit interpolation method is applied to enforce the continuity and smoothness at the critical contact interference, and to decrease the interpolation waving effect by transforming the physical quantities of contact load into logarithmic coordinates. The contact model of rough surfaces is formulated by using the Greenwood and Williamson’s statistics analysis. Comparisons with the CEB, ZMC and KE models are then performed to examine the effects of plasticity index and mean separation. Agreeing well with the ZMC model, our results show that the total contact load of rough surfaces decreases with the increase in mean separation, and the difference between the prediction results of elastic models and the plastic ones also decreases, indicating that the contact behaviors mainly dominated by plastically deformed asperities have been changed to be controlled by elastically deformed ones. Larger plasticity index represents more plastically deformed asperities, inducing normal contact behaviors mainly dominated by plastic solutions.

Testing thermophysical and mechanical properties of cement-based composites with plastic and horse manure

Cement-based composites change their properties in dependence on added materials. Scientific papers display results on changes in various mechanical and thermophysical properties. In this paper, the effect of different amount of plastic in two shapes (granules and fibers) and horse manure on thermophysical and mechanical properties of cement-based composites are tested. To understand the structural changes 1-D process of water uptake and porosity measurements were done. The economic growth brings new possibilities for industry development but also increasing problem with waste disposal. Our tests were aimed at finding the optimal balance between plastic disposal in cement based materials and changes in some important properties. The best results of thermophysical properties were for plastic and natural fibers, where horse manure samples had even better mechanical properties than plastic ones.

Analysis of Slope Creep in the Example of a Landslide Slope in Koronowo near Bydgoszcz

Abstract This paper presents the results of a numerical simulation of a slope deformation process. The landslide slope “Grabina” in Koronowo near Bydgoszcz (Poland) serves as an example. A slope profile located in the central part of the slope, between the main scarp and the toe of the landslide, was selected. The average dip of the slope is about 10, and its length is approximately 55 m. Elasticity, plasticity and viscosity properties were taken into account in the model of the soil mass that composes the slope. The visco-elastic properties are described by the Burgers model (Mainardi and Spada 2011), and the plastic ones by the Coulomb-Mohr law. A numerical simulation was carried out by the computer code FLAC2D in the plane strain state with the assumption of the Lagrange routine. The model was discretized taking into account the results of inclinometric measurements, which proved that the slide movement was concentrated in a narrow loam zone of 0.5–1.0 m thickness. No tests of the viscosity parameters were performed, so they were determined by the back analysis and a trial and error method. The calculation results were verified by comparison with the displacement measured by the inclinometric method in three boreholes. The analysis performed demonstrated the possibility of approximating and forecasting landslide displacements by the combined Burgers and Coulomb-Mohr models.

The simultaneous moult of female hornbills is not triggered by the darkness of their nest cavity

A verbal model from 1937 proposed that the darkness of the nest cavity acts as a proximate trigger for the simultaneous moult observed in female hornbills. Although never tested, the plausibility of this hypothesis has allowed it to be cited frequently. We tested the role of darkness on the moult of Tockus hornbills by providing females with either opaque wooden nest boxes or translucent plastic ones. Most females underwent a simultaneous moult of their remiges and retrices following clutch completion, regardless of the amount of time they had spent in the nest. More importantly, the variation in the simultaneity of the flight feather moult was unrelated to box type. These results suggest that darkness does not act as a proximate cue for the simultaneous moult of female hornbills.

Materials on the move

At first, Michael Serpe and Keady Smyth weren’t thrilled to find Smyth’s lab bench littered with broken glass. Smyth, a University of Alberta senior, had been working in the lab the night before, coating glass slides with polymeric hydrogels as part of a project to create water-quality sensors. But when the professor and undergrad returned to lab the next day, they found that the slides had snapped spontaneously during the night. Their initial frustration soon turned to puzzlement; they weren’t sure how to stop it from happening again. Still, Serpe had ideas. He asked Smyth to redo the experiment—but this time swap out the glass slides for plastic ones. The next morning’s result confirmed Serpe’s suspicions. The samples were intact, but instead of being the flat sensor surfaces the pair was hoping for, the slides had rolled up into small scrolls. The hydrogel coating shrank extensively as it dried: On

Состояние вопроса производства и эксплуатации железнодорожных шпал из различных материалов

Sleepers are elements of the upper structure of the railway track. When choosing a material for the manufacture of sleepers, we are based on such basic factors as cost for the whole life cycle and performance characteristics. In connection with the depletion of wood stocks in the world and the short life of wooden sleepers, the process of using sleepers made of reinforced concrete, metal and plastic goes intensively. The service life of pine sleepers is no more than 12-15 years, reinforced concrete sleepers are about 30-50 years old, plastic ones are up to 40 years old, and metal ones are 50-60 years old. However, wooden sleepers differ in the least cost, they practically do not have restrictions on the laying areas, and in some cases have a clear advantage over other materials. Reinforced concrete, metal and plastic sleepers are more expensive than wooden ones, have a longer payback period and are recommended to be laid on roads with high freight intensity, where they can pay off as quickly as possible. It is possible to reduce the shortcomings of sleepers made of natural wood, using modified hardwood for their manufacture, which, by pressing, will be stronger than the sleepers made of natural wood, which, in its physical and mechanical properties, is not inferior to sleepers made of natural coniferous wood. However, a certain disadvantage of the modified wood is its ability to change size and shape with increasing humidity. Stabilization of sizes and forms of modified wood can be increased by impregnating it with the composition of antiseptic with stabilizer. The predicted service life of sleepers from modified wood can be significantly higher than that of wooden sleepers made of natural coniferous wood.

Experimental Research into Noise Emission of A Gear Micropump with Plastic Rotor

The previous researches show that it’s possible to replace several parts of gear pump to plastic ones. This substitution leads to cost and noise reduction of the pump. Therefore, the series of acoustic experiments on a test bench were carry-out. Sound pressure levels were recorded with microphone, located in a pipe made of a vacuum rubber. Conducted experiment shows that acoustic characteristics of the micropump depend on the different material of driven rotor. Experimental result indicates that the proposed measures for replacing metal rotor to plastic one reduce micropump noise on the studied modes. The maximum achieved acoustic efficiency on equivalent level is 11 dB.

Survival of Spoilage and Pathogenic Microorganisms on Cardboard and Plastic Packaging Materials.

The aim of this work was to study the interaction of corrugated and plastic materials with pathogenic and spoiling microorganisms frequently associated to fresh produce. The effect of the two packaging materials on the survival during the storage of microorganisms belonging to the species Escherichia coli, Listeria monocytogenes, Salmonella enteritidis, Saccharomyces cerevisiae, Lactobacillus plantarum, Pseudomonas fluorescens, and Aspergillus flavus was studied through traditional plate counting and scanning electron microscopy (SEM). The results obtained showed that cardboard materials, if correctly stored, reduced the potential of packaging to cross-contaminate food due to a faster viability loss by spoilage and pathogenic microorganisms compared to the plastic ones. In fact, the cell loads of the pathogenic species considered decreased over time independently on the inoculation level and packaging material used. However, the superficial viability losses were significantly faster in cardboard compared to plastic materials. The same behavior was observed for the spoilage microorganisms considered. The SEM microphotographs indicate that the reduction of superficial contamination on cardboard surfaces was due to the entrapping of the microbial cells within the fibers and the pores of this material. In addition, SEM data showed that the entrapped cells were subjected to more or less rapid lyses, depending on the species, due to the absence of water and nutrients, with the exception of molds. The latter spoilers were able to proliferate inside the cardboard fibers only when the absorption of water was not prevented during the storage. In conclusion, the findings of this work showed the reduction of cross-contamination potential of corrugated compared to plastic packaging materials used in fruit and vegetable sector. However, the findings outlined the importance of hygiene and low humidity during cardboard storage to prevent the mold growth on packaging.

Comparison of cellulose vs. plastic cigarette filter decomposition under distinct disposal environments

It is estimated that 4.5 trillion cigarette butts are discarded annually, making them numerically the most common type of litter on Earth. To accelerate their disappearance after disposal, a new type of cigarette filters made of cellulose, a readily biodegradable compound, has been introduced in the market. Yet, the advantage of these cellulose filters over the conventional plastic ones (cellulose acetate) for decomposition, remains unknown. Here, we compared the decomposition of cellulose and plastic cigarettes filters, either intact or smoked, on the soil surface or within a composting bin over a six-month field decomposition experiment. Within the compost, cellulose filters decomposed faster than plastic filters, but this advantage was strongly reduced when filters had been used for smoking. This indicates that the accumulation of tars and other chemicals during filter use can strongly affect its subsequent decomposition. Strikingly, on the soil surface, we observed no difference in mass loss between cellulose and plastic filters throughout the incubation. Using a first order kinetic model for mass loss of for used filters over the short period of our experiment, we estimated that conventional plastic filters take 7.5–14 years to disappear, in the compost and on the soil surface, respectively. In contrast, we estimated that cellulose filters take 2.3–13 years to disappear, in the compost and on the soil surface, respectively. Our data clearly showed that disposal environments and the use of cellulose filters must be considered when assessing their advantage over plastic filters. In light of our results, we advocate that the shift to cellulose filters should not exempt users from disposing their waste in appropriate collection systems.

Inkjet‐Printing: A New Fabrication Technology for Organic Transistors

AbstractInkjet‐printing is one of the most important fabrication techniques in the field of printed electronics. Its main advantages include the possibility of fabricating, at ambient conditions and by employing a digital layout, a large variety of electronic devices on different types of substrates, including flexible plastic ones. In this paper, the utilization of inkjet‐printing as an important fabrication tool for the realization of organic transistors and circuits/sensing systems based on such type of transistors is reviewed. The most important aspects of the fabrication process, including ink formulation, printing deposition, and postprinting treatment, are described in detail. The most significant examples of inkjet‐printed organic transistors of different types (field‐effect, electrolyte‐gated, and electrochemical) are presented and finally an overview of their applications as building blocks of more complex electronic circuits and systems for the detection and quantification of specific measurands is provided.

Влияние содержания древесного дисперсного наполнителя на долговечность композиционных материалов

Introduction. Usage of the biocomposites is a vital component of the environment protection policy. According to the classification of the petrochemical polymers, biopolymers can be divided into thermal and plastic heat-strengthening ones. The former can be modified for reheating, and the latter cannot - due to the calcium carbonate solidification. Thermal bioplastics are developed mainly for the packaging industry, and they can be used as a binder in the biocomposite materials. Materials and Methods. Sawdust wood fibers are selected as an additive to produce reinforced rubber plastics (polyester fiber) for this study. The work objective is to determine the optimum ratio of the sawdust volume and size. In the course of the experiments, various sawdust mixtures are tested through varying the combination of their size, volume and applied loads. Research Results. The obtained results show a growth of the composite material deformation when increasing the proportion of sawdust of any volumes studied under the pressure testing, as well as a decrease in strength and tensile strain when increasing the proportion of sawdust of medium and low volumes. The strength and elongation of the composite grows with increasing the sawdust fraction volume for more than 120 mm 3 . Stresses increase when the size of wood sawdust is 20 mm 3 and mixing ratio is 25%, therewith the material elasticity decreases. Discussion and Conclusions. In bending tests, the reduction in strength and increase in tension strain when mixing a sample with sawdust of 5 mm 3 , gain in strength and elongation at increasing their volume up to 25 mm 3 , and then the reduction of strength and tension strain at increasing their volume to 120 mm 3 are observed.

Visualization of Sweat Fingerprints on Various Surfaces Using a Conjugated Polyelectrolyte.

A conformation-variable conjugated polyelectrolyte responding to oppositely charged biomolecules was examined as an imaging agent for the detection of latent fingerprints (LFPs). Sulfonated poly(diphenylacetylene) (SPDPA) produces high-resolution fluorescence (FL) LFP images by simple wetting of the target objects with the polymer solution without any additional treatment. SPDPA readily interacts with LFP sweat components (especially amino acids) via electrostatic interactions, leading to significantly enhanced FL images in a "turn-on" mode. The FL emission enhancement was examined in a model reaction between SPDPA and an amino acid standard. Visualization with SPDPA is effective on various surfaces, including both rough (paper) and smooth (glass and plastic) ones. Moreover, SPDPA readily interacts with extremely thin sweat LFPs, especially on smooth glass surfaces.