Site-fidelity and spatial movements of western North Pacific gray whales on their summer range off Sakhalin, Russia

The Western North-Pacific (WNP) gray whale feeding grounds are off the northeastern coast of Sakhalin Island, Russia and is comprised of a nearshore and offshore component that can be distinguished by both depth and location. Spatial movements of gray whales within their foraging grounds were examined based on 13 years of opportunistic vessel and shore-based photo-identification surveys. Site fidelity was assessed by examining annual return and resighting rates. Lagged Identification Rates (LIR) analyses were conducted to estimate the residency and transitional movement patterns within the two components of their feeding grounds. In total 243 individuals were identified from 2002-2014, among these were 94 calves. The annual return rate over the period 2002-2014 was 72%, excluding 35 calves only seen one year. Approximately 20% of the individuals identified from 2002-2010 were seen every year after their initial sighting (including eight individuals that returned for 13 consecutive years). The majority (239) of the WNP whales were observed in the nearshore area while only half (122) were found in the deeper offshore area. Within a foraging season, there was a significantly higher probability of gray whales moving from the nearshore to the offshore area. No mother-calf pairs, calves or yearlings were observed in the offshore area, which was increasingly used by mature animals. The annual return rates, and population growth rates that are primarily a result of calf production with little evidence of immigration, suggest that this population is demographically self-contained and that both the nearshore and offshore Sakhalin feeding grounds are critically important areas for their summer annual foraging activities. The nearshore habitat is also important for mother-calf pairs, younger individuals, and recently weaned calves. Nearshore feeding could also be energetically less costly compared to foraging in the deeper offshore habitat and provide more protection from predators, such as killer whales

MONITORING COMPOSITION AND STRUCTURE OF MOCVD ZrO2-BASED MULTICOMPONENT FILMS BY INNOVATIVE MIXED METAL-ORGANIC PRECURSORS

Three volatile mixed-metal precursors [ZrL4Pb(hfa)2] (1), [ZrL4PbL2] (2), and [ZrL4La(dpm)3] (3) (L = 2-methoxy-2,6,6-trimethyl-3,5-heptanedionate; dpm = 2,2,6,6-tetramethyl-3,5-heptanedionate; hfa = 1,1,1,5,5,5-hexafluore-2,4-pentanedionate) are used to prepare ZrO2-based multicomponent films by metalorganic chemical vapor deposition (MOCVD). The deposition experiments are carried out in a hot-wall reactor at 600-750 °C on silicon substrates under 20 Torr in the presence of oxygen. According to X-ray powder diffraction, the main crystal phases in the films prepared from precursors 1 and 2 are solid solutions based on tetragonal and cubic ZrO2. Lead does not form separate crystal phases but is dissolved in the oxide form within the ZrO2 matrix, as is indicated by X-ray photoelectron spectroscopy data. La2Zr2O7 films are prepared from 3 using two ways of precursor supply: evaporation in argon and by direct liquid injection (DLI). It is shown that the composition and structure of obtained films are determined by the precursor composition. The results obtained for thermal behavior of precursors in condensed and gas phases are discussed

Emergency Electric Vehicle Power Bank

The thesis gives an overview to the electric vehicle (EV) market and an analysis of their impact on the environment and points out not only the advantages of electric cars, but also the disadvantages that the consumer is faced with. In terms of the environment, real explanations and examples are given that point to the benefits of EVs, as well as the dangers that lie behind battery manufacturing. This shows also the outlook for the market of batteries. The costs of the implementation of this project were economically justified so that the system would be useful for the fuel companies, battery makers and consumers. Then, the basic concept of an EV, the necessary components for its production and the control systems are explained. It also introduces the current situation on the EV market and shows existing technologies and modules to create a network that could help the owner of the EV car to get his or her car instantly charged. The last part is about calculations, modelling and simulating of the electrical vehicle system. It examines the methods of turning an ordinary fully electric vehicle into a truly mobile EV. The theoretical part of the thesis includes capacity and power consumption calculations as well as a selection and design of the components. As a result, possible solutions were designed

Calculation modeling of flexural reinforсed conсrete elements adjusted for crack propagation resistance of concrete

The calculation modeling of concrete structures is shown. Function model allows more exact (as compared with traditional design diagrams) mode determination of deformation characteristics of construction in all stages of process

Increase in efficiency of quality and hole-making in glass-reinforced titanium laminate by reducing drilling vibroactivity

The work objective is to study the impact of the drill design value and geometrics on the quality of the processed holes, the efficiency, and the machining dynamics of the high-strength polymer composite - fiberglass plastic reinforced by titanium foil. Packs of the reinforcing layers made from the titanium foil or carbon fiber tapes are often used in the highly-loaded polymer composite structures. Processing in several operations and the application of sharp-ground tools provide the required dimensional accuracy, the surface macro- and microgeometry of the hole, and allow avoiding the delamination. The process of drilling fiberglass laminates under different patterns of HSS drills sharpening is studied. The data obtained allow determining the optimum type of instrument and operation mode taking into account the dependence of the high-altitude roughness parameters, the nature and amount of delamination in the entry (exit point) of the drill. The vibroactivity of the drilling process and its relationship with the quality metrics are studied using the computer-aided torque-sensing system. Some proposals for improving the hole-making technology applying to the glass-fiber spars of the main and tail helicopter rotors are developed

On the Directivity of Acoustic Waves Generated by the Angle Beam Wedge Actuator in Thin-Walled Structures

The paper aims to develop improved acoustic-based structural health monitoring (SHM) and nondestructive evaluation (NDE) techniques, which provide the waves directivity emitted by the angle beam wedge actuators in thin-walled structures made of plastic materials and polymeric composites. Our investigation includes the dispersive analysis of the waves that can be excited in the studied plastic panel. Its results allowed to find two kinds of generated acoustic waves—anti-symmetric Lamb waves (A0) and shear horizontally polarized SH waves (SS0). The bounds of the chosen frequency range for the experimental and numerical studies were accepted as a compromise between the desire to obtain a high defect resolution by generating short waves, their adjustable directivity, and maximum propagation length. The finite element model for the transducer was built by using the results of an actuator structure experimental study. The frequency response functions for the actuator current and oscillation amplitude of the footprint surface demonstrated good agreement. The found eigenfrequencies of the actuator’s structure were used for the numerical and experimental study of the Lamb and SH wave generation and propagation in a thin-walled plastic panel. Our results convincingly demonstrated the satisfactory directivity of the actuated waves at their excitation on the frequencies that corresponded to the natural modes of the actuator oscillation. The authors assume that an efficient use of the proposed technique for other analyzed quasi-isotropic materials and applied actuators can be provided by preliminary research using a similar approach and methods presented in this article

ANN-Based Estimation of the Defect Severity in the Drilling of GFRP/Ti Multilayered Composite Structure

The main purpose of this study was to develop a model for predicting the quality of holes drilled in the root part of the spar of helicopter main rotor blades made of glass fiber-reinforced plastic (GFRP)-Ti multilayer polymer composite. As the main quality criterion, delaminations at the entry and exit of the drill from the hole were taken. In the experimental study, a conventional drill and two modified geometry drills, a double-point angle drill and a dagger drill, were used. Preliminary experiments showed the best hole quality when using modified drills, which allowed further detailed study only with both modified drills at different drilling speeds and feed rates. Its results in the form of training sets were used to build artificial neural networks (ANNs) to predict delamination at the entry and exit of the drilled holes. An analysis of the fitted response functions presented as 3D surface plots and contour plots led to the selection of the best tool, a double-point angle drill, which demonstrated the lowest achievable delamination both at the entry and at the exit of the holes approximately 1.5 times less (0.45/0.48 mm) compared to dagger drills (0.68/0.7 mm) and determined the ~5 times larger optimal area for the drilling speed and feed rate. The results obtained confirm the possibility of effective prediction of the quality and productivity of mechanically processed composites of complex reinforcement using ANN to quantify the quality criteria and search for the optimal modes of such technologies

DAMAGE PARAMETERS IDENTIFICATION IN ELASTIC ROD USING BOTH FINITE ELEMENT AND EXPERIMENTAL ANALYSIS OF FLEXURAL VIBRATION MODES

The results of finite-element analysis and experimental investigations of the cantilever elastic notched bar flexural modes are presented. The application of the kinking coordinate and tangent angle on the eigenform graphs under the transition through the damage point as a complex diagnostic property of the location and bar damage degree is offered

Protective Spinel Coating for Li1.17Ni0.17Mn0.50Co0.17O2 Cathode for Li-Ion Batteries through Single-Source Precursor Approach

The Li1.17Ni0.17Mn0.50Co0.17O2 Li-rich NMC positive electrode (cathode) for lithium-ion batteries has been coated with nanocrystals of the LiMn1.5Co0.5O4 high-voltage spinel cathode material. The coating was applied through a single-source precursor approach by a deposition of the molecular precursor LiMn1.5Co0.5(thd)5 (thd = 2,2,6,6-tetramethyl-3,5-heptanedionate) dissolved in diethyl ether, followed by thermal decomposition at 400 °C inair resulting in a chemically homogeneous cubic spinel. The structure and chemical composition of the coatings, deposited on the model SiO2 spheres and Li-rich NMC crystallites, were analyzed using powder X-ray diffraction, electron diffraction, high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and energy-dispersive X-ray (EDX) mapping. The coated material containing 12 wt.% of spinel demonstrates a significantly improved first cycle Coulombic efficiency of 92% with a high first cycle discharge capacity of 290 mAhg−1. The coating also improves the capacity and voltage retention monitored over 25 galvanostatic charge–discharge cycles, although a complete suppression of the capacity and voltage fade is not achieved