Steel Mesh-Reinforced Cementitious Composites (SMRCC) (traditionally known as ferrocement) have been in existence for few decades, but have some limitations set on element thickness and number of reinforcing mesh layers and the resulting deflection ductility. Therefore, the author has made an attempt to explore whether deflection ductility will improve in mesh-reinforced cementitious composites (25 mm thick) if discontinuous fibres are added to slab elements. For this purpose, thin slab elements of dimensions 700 mm (length) × 200 mm (width) × 25 mm (thickness) were cast and subjected to four point bending tests. Based on the flexural tests conducted on SMRCC (Control Slab Elements, cast with Steel Mesh Volume of reinforcement, MVr = 0.78, 0.94, and 1.23%) and Hybrid Mesh-and-Fibre-Reinforced Cement Based Composite (HMFRCBC) (Test Slab Elements, combining MVr = 0.78, 0.94 and 1.23% and Polyolefin Fibre Volume fraction, PO-FVf = 0.5‒2.5% of volume of specimens, with 0.5% interval), load-deflection and the deflection ductility index were analyzed. From the flexural load-deflection curves it has been observed that HMFRCBC slabs demonstrate higher flexural load-carrying capacity and deflection ductility when compared to SMRCC slabs. This study shows that higher the polyolefin fibre volume fraction (PO-FVf) from 0.5 to 2.5% (with a 0.5% interval) in HMFRCBC slabs, the higher the flexural deflection ductility. The Deflection Ductility Index (DDI) of HMFRCBC (with 5 layers of mesh and PO-FVf = 2.5%) is 4.5 times that of SMRCC. This study recommends that HMFRCBC can be used as an innovative construction material due to its higher flexural ductility characteristics.

The explosive rise of wireless services necessitates a network connection with high bandwidth, high performance, low mistakes, and adequate channel capacity. Individual mobile users, as well as residential and business clusters are increasingly using the internet and multimedia services, resulting in massive increases in the internet traffic demand. Over the past decade, internet traffic has grown significantly faster than Moore’s law predicted. The current system is facing significant radio frequency spectrum congestion and is unable to successfully transmit growing amounts of (available) data to end users while keeping acceptable delay values in mind. Free space optics is a viable alternative to the current radio frequency technology. This technology has a few advantages, including fast data speeds, unrestricted bandwidth, and excellent security. Since free space optics is invisible to traffic type and data protocol, it may be quickly reliably and profitably integrated into an existing access network. Despite the undeniable benefits of free space optics technology under excellent channel conditions and its wide range of applications, its broad use is hampered by its low link dependability, especially over long distances, caused by atmospheric turbulence-induced decay and weather sensitivity. The best plausible solution is to establish a secondary channel link in the GHz frequency range that works in tandem with the primary free space optics link. A hybrid system that combines free space optics and millimeter wave technologies in this research is presented. The combined system offers a definitive backhaul maintenance, by drastically improving the link range and service availability.

The use of foreign bases in derivation and compounding has led to the creation of a very young, but rapidly expanding, fourth sub-lexicon of Contemporary Korean – hybrids. Their growing number enhances the degree of hybridization within the Korean lexical subsystem. Hybrids, however, can also be coined be means of borrowed affixes. It is on these that this article will use to illustrate the growing influence the formation of the global communicative community exerts on Contemporary Korean. It will also address the reasons for borrowing these bound morphemes. Although Korean linguists generally deny the existence of foreign affixes in Korean, this article, based on an analysis of neologisms coined after 2000, will identify -reo, -ijeum, -iseuteu and anti- corresponding to English -er, -ism, -ist and anti-, respectively. Hybrid derivatives with foreign affixes may be treated as marginal, due to their relatively small morphological productivity, in comparison to other well-researched coinages. Nonetheless their existence and the growing popularity of Konglish might be perceived as the beginning of further and even more prominent changes to the Korean language, which in a long-term perspective may also influence the perception of the world by Korean speakers, since the national language not only stores the cultural and material values of the community but also a changing view of the world.

This article presents a hybrid control system for a group of mobile robots. The components of this system are the supervisory controller(s), employing a discrete, event-driven model of concurrent robot processes, and robot motion controllers, employing a continuous time model with event-switched modes. The missions of the robots are specified by a sequence of to-be visited points, and the developed methodology ensures in a formal way their correct accomplishment.

We discuss recent progress in hybrid atomistic-continuum methods with particular emphasis on developments in boundary condition imposition in molecular simulations, an essential ingredient of hybrid methods. Both Dirichlet (state variable) and flux boundary conditions are discussed. We also briefly review various coupling approaches and discuss the effects of compressibility and molecular fluctuations on the choice of coupling method. Common elements between hybrid methods and related multiscale simulation approaches are also briefly discussed.

The subject of this paper is the study of the specificity of the transformation of the urban public spaces of the Western world and the problem of the multi form nature of this phenomenon. The Author uses such concepts as that of the "hybrid" and of "hybridization" borrowed from the field of natural sciences and explains the reasons for their introduction within this specific scope of research in a broad manner.

The requirements for environmentally friendly refrigerants promote application of CO2and water as working fluids. However there are two problems related to that, namely high temperature limit for CO2in condenser due to the low critical temperature, and low temperature limit for water being the result of high triple point temperature. This can be avoided by application of the hybrid adsorption-compression system, where water is the working fluid in the adsorption high temperature cycle used to cool down the CO2compression cycle condenser. The adsorption process is powered with a low temperature renewable heat source as solar collectors or other waste heat source. The refrigeration system integrating adsorption and compression system has been designed and constructed in the Laboratory of Thermodynamics and Thermal Machine Measurements of Cracow University of Technology. The heat source for adsorption system consists of 16 tube tulbular collectors. The CO2compression low temperature cycle is based on two parallel compressors with frequency inverter. Energy efficiency and TEWI of this hybrid system is quite promising in comparison with the compression only systems.

This paper deals with a three-phase power system with hybrid transformer (HT) installed between two AC sources. The main aim of this paper is analyze the basic properties of HT with active load and ability to bidirectional energy flow. The HT contains two main units – a conventional transformer with electromagnetic coupling and PWM AC line chopper connected with secondary windings with electric coupling. The HT is located between the distribution system and a Local Balancing Area (LBA) with low power local energy sources. After describing the HT circuit and three-phase, twosources power system, the mathematical and circuit models of the AC source with HT are presented. These models are verified by means of the simulation and experimental test results obtained for a three-phase HT of about 3 kVA rated power.

Lately, there has been increased interest in hybrid excitation electrical machines. Hybrid excitation is a construction that combines permanent magnet excitation with wound field excitation. Within the general classification, these machines can be classified as modified synchronous machines or inductor machines. These machines may be applied as motors and generators. The complexity of electromagnetic phenomena which occur as a result of coupling of magnetic fluxes of separate excitation systems with perpendicular magnetic axis is a motivation to formulate various mathematical models of these machines. The presented paper discusses the construction of a unipolar hybrid excitation synchronous machine. The magnetic equivalent circuit model including nonlinear magnetization curves is presented. Based on this model, it is possible to determine the multi-parameter relationships between the induced voltage and magnetomotive force in the excitation winding. Particular attention has been paid to the analysis of the impact of additional stator and rotor yokes on above relationship. Induced voltage determines the remaining operating parameters of the machine, both in the motor and generator mode of operation. The analysis of chosen correlations results in an identification of the effective control range of electromotive force of the machine.

Searching for new refrigerants is one of the most significant scientific problems in refrigeration. There are ecological refrigerants commonly known: H2O and CO2. H2O and CO2 known as natural refrigerants, but they have problems:a high freezing point of H2O and a low triple point of CO2. These problems can be solved by the application of a hybrid sorption-compression refrigeration cycle. The cycle combines the application possibility of H2O in the high temperature sorption stage and the low temperature application of CO2 in the compression stage. This solution gives significant energy savings in comparison with the two-stage compressor cycle and with the one-stage transcritical CO2 cycle. Besides, the sorption cycle may be powered by low temperature waste heat or renewable heat. This is an original idea of the authors. In the paper an analysis of the possible extension of this solution for high capacity industrial refrigeration is presented. The estimated energy savings as well as TEWI (Total Equivalent Warming Impact) index for ecological gains are calculated.

The paper discusses the results of investigations of material, tribological and anti-corrosion properties of hybrid coatings of the Cr/CrN type, consisting of chromium and chromium nitride, formed on the surface of alloy tool steel by the Arc-PVD method. Investigations of the morphology and microstructure of hybrid coatings, as well as of their phase composition were carried out. The studies on mechanical properties included tests on hardness and Young’s modulus using the nanoindentation method. Tests on adhesion were conducted using the scratch-test method. Tribological properties of the obtained coatings were evaluated by the pin-on-disc method. Resistance to corrosion was determined by electrochemical methods. It was shown that hybrid coatings of the Cr/CrN type are characterized by good adhesion to the substrate and very good tribological properties, as well as by very good resistance to corrosion in a solution containing chlorine ions.

This study investigates the use of steel fibers and hybrid composite with a total fibers content of 2% on the high strength flowing concrete and determines the density, compressive strength, static modulus of elasticity, flexural strength and toughness indices for the mixes. The results show that the inclusion of more than 0.5% of palm fibers in hybrid fibers mixes reduces the compressive strength. The hybrid fibers can be considered as a promising concept and the replacement of a portion of steel fibers with palm fibers can significantly reduce the density, enhance the flexural strength and toughness. The results also indicates that the use of hybrid fibers (1.5 steel fibers + 0.5% palm fibers) in specimens increases significantly the toughness indices and thus the use of hybrid fibers combinations in reinforced concrete would enhance their flexural toughness & rigidity and enhance their overall performances.

Pollution continues to experience a rapid increase so cities in the world have required the use of renewable energy. One of the keys that can prevent climate change with a sustainable system is renewable energy. Renewable energy production, especially for hybrid systems from biomass and wind, is the objective of the analysis in this work. The potential of feedstock for different biofuels such as bio-diesel, bio-ethanol, bio-methane, bio-hydrogen, and biomass is also discussed in this paper. The sustainability of the energy system for the long term is the main focus of work in this investigation. The configuration of the hybrid system between biomass energy and wind energy as well as some problems from various design factors are also presented. Based on the findings, this alternative energy utilization through biomass-based hybrids can save costs and improve environmental conditions, especially for the electrification of off-grid rural areas. This paper will provide important information to policymakers, academics, and investors, especially in carrying out the development and factors related to the utilization of wind-biomass-based hybrid energy systems.

In recent years, metal halide perovskites have gained significant attention due to their unique optical and electronic properties of semiconductor materials, which make them ideal for use in sustainable and energy-efficient devices. These devices include solar cells, lasers, and light-emitting diodes. Therefore, this review aims initially to provide an overview of the most important characteristics of metal halide perovskites, including their engineering development in various types, such as those based on lead or lead-free materials, like tin or germanium. Additionally, perovskites made from purely inorganic compounds like caesium bromide, chloride, or iodide, as well as hybrids mixed with organic compounds like formamidinium and methylammonium halides will be discussed. The goal is to improve their stability and efficiency. Secondly, some of the studies have proposed technologies combining electronic and mechanical characteristics of flexibility or rigidity as required, promoting their synthesis with different materials such as polymers (poly methyl methacrylate, polyvinylidene fluoride), biopolymers (starch, cyclodextrin, polylactic acid, and polylysines), among others. Finally, the subject of this work is to establish the main purpose of the research carried out so far, which is to develop simpler and more scalable processes at industrial level to achieve greater efficiency and duration in storage, exposure to visible light, critical environments, humid or high temperatures.

Nowadays, aluminum-based composites have been produced by pure alumina (Al2O3) or pure graphene nanoplatelets (GNPs) in aluminum matrix because of the high compressive strength of alumina and the solid lubricant properties of graphene. However, there are no studies on the influence of both alumina and graphene reinforced aluminum composites. In this study, Al-Al2O3 and Al-Al2O3-GNPs composites were reinforced with pure alumina (between 0 and 30 wt.%), pure graphene (0, 0.1, 0.3, 0.5 wt.%), and their hybrid forms (Al2O3-GNPs) by the powder metallurgy method. This method involved ultrasonic dispensing, mixing, filtering, drying, pressing, and sintering processes. From the test results, the micro Vickers hardness of pure aluminum (28.2±1 HV) improved to 51.5±0.8 HV (Al-30Al2O3) and 63.1±1 HV (Al-30Al2O3-0.1GNPs). Similarly, the ultimate compressive strength (UCS) enhanced from 92.4±4 MPa (pure aluminum) to 165±4.5 MPa (Al-30Al2O3) and 188±5 MPa (Al-30Al2O3-0.1GNPs), respectively. In conclusion, the Vickers hardness and ultimate compressive strength of aluminum hybrid composites improved up to 0.1 wt.% graphene content. After 0.1 wt.% graphene content, these mechanical properties decreased because of the clumping of graphene nanoparticles.

This study analyses the performances of various path controlling strategies for a 3-degrees of freedom wrist exoskeleton, by comparing key indicators, such as rise time, steady-state error, and implementation difficulty. A model was built to describe both system’s kinematics and dynamics, as well as 3 different controllers (PID, PD¸, and a hybrid force/position controller) that were designed to allow each joint to perform smooth motions within anatomic ranges. The corresponding simulation was run and assessed via Matlab (version 2020a). In addition to the performance comparison, remarkable characteristics could be identified among controllers. PD¸ showed higher response speed than the other controllers (about 4 times), and PID was reinforced as the technique with the easiest implementation due to the smallest matrices. The study also allowed to greater potential of the hybrid controller to interact with its environment, i.e., the robotic device.

To improve the user’s localization estimation in indoor and outdoor environment a novel radiolocalization system using deep learning dedicated to work both in indoor and outdoor environment is proposed. It is based on the radio signatures using radio signals of opportunity from LTE an WiFi networks. The measurements of channel state estimators from LTE network and from WiFi network are taken by using the developed application. The user’s position is calculated with a trained neural network system’s models. Additionally the influence of various number of measurements from LTE and WiFi networks in the input vector on the positioning accuracy was examined. From the results it can be seen that using hybrid deep learning algorithm with a radio signatures method can result in localization error 24.3 m and 1.9 m lower comparing respectively to the GPS system and standalone deep learning algorithm with a radio signatures method in indoor environment. What is more, the combination of LTE and WiFi signals measurement in an input vector results in better indoor and outdoor as well as floor classification accuracy and less positioning error comparing to the input vector consisting measurements from only LTE network or from only WiFi network.

In order to enhance bioactive properties of titanium 99.2 used in implantology and various biomedical applications, numerous methods to form tight oxide coatings are being investigated. Some of these interesting techniques for generating TiO2 coatings include: electrochemical methods with anodizing, electric discharge treatment, plasma methods (PVD) and diffusive methods (i.e. oxidation in a fluidized bed). Each method aims to create a thin homogenous oxide coating characterized with thermal stability and repassivation ability in the presence of body fluid environment. However, new methods are still sought for increasing the biocompatibility of the substrate following a change in the intensity of depositing on the oxide coating compounds with high biocompatibility with body tissues, including hydroxyapatite, which constitutes the basis for subsequent osseointegration processes. The article presents investigation of HAp formation on titanium substrate surface after hybrid oxidation process. Hybrid surface treatments combine methods of fluidized bed atmospheric diffusive treatment FADT with the PVD surface treatment realized with different parameters (FADT – 640°C / 8h and PVD – magnetron sputtering with TiO2 target). In order to investigate the effects of hybrid oxidation and the formation of HAp molecules, SEM-EDS, SEM-EBSD, STEM-EDS, RS, nanoindentation and Kokubo bioactivity tests (c-SBF2) were carried out. The hybrid method of titanium oxidation, proposed by the Author, presents a new outlook on the modification and development of the properties of oxide coatings in the area of biomedical applications. Combining the ways of Ti Grade 2 oxidation in the hybrid method highly improves the formation of hydroxyapatite compounds and shows the potential of applying such a technique in implantology, where the intensive growth of bone tissues is crucial.

The intercalation into interlayer spaces of montmorillonite (MMT), obtained from natural calcium bentonite, was investigated. Modification of MMT was performed by the poly(acrylic acid-co-maleic acid) sodium salt (co-MA/AA). Efficiency of modification of MMT by sodium salt co-MA/AA was assessed by the infrared spectroscopic methods (FTIR), X-ray diffraction method (XRD) and spectrophotometry UV-Vis. It was found, that MMT can be relatively simply modified with omitting the preliminary organofilisation – by introducing hydrogel chains of maleic acid-acrylic acid copolymer in a form of sodium salt into interlayer galleries. A successful intercalation by sodium salt of the above mentioned copolymer was confirmed by the powder X-ray diffraction (shifting the reflex(001) originated from the montmorillonite phase indicating an increase of interlayer distances) as well as by the infrared spectroscopy (occurring of vibrations characteristic for the introduced organic macromolecules). The performed modification causes an increase of the ion exchange ability which allows to assume that the developed hybrid composite: MMT-/maleic acid-acrylic acid copolymer (MMT-co- MA/AA) can find the application as a binding material in the moulding sands technology. In addition, modified montmorillonites indicate an increased ability for ion exchanges at higher temperatures (TG-DTG, UV-Vis). MMT modified by sodium salt of maleic acid-acrylic acid copolymer indicates a significant shifting of the loss of the ion exchange ability in the direction of the higher temperature range (500–700°C).

The concept of a hybrid scheme with connection of SIDH and ECDH is nowadays very popular. In hardware implementations it is convenient to use a classical key exchange algorithm, which is based on the same finite field as SIDH. Most frequently used hybrid scheme is SIDH-ECDH. On the other hand, using the same field as in SIDH, one can construct schemes over Fpn, like Diffie-Hellman or XTR scheme, whose security is based on the discrete logarithm problem. In this paper, idea of such schemes will be presented. The security of schemes, which are based on the discrete logarithm problem over fields Fp; Fp2 ; Fp4 ; Fp6 and Fp8 , for primes p used in SIDH, will be analyzed. At the end, the propositions of practical applications of these schemes will be presented.

In this study, the electrospray deposition (ESD) method was used to deposit carbon nanotubes (CNT) onto the surfaces of carbon fibers (CF) in order to produce hybrid carbon fiber-carbon nanotubes (CF-CNT) which is rarely reported in the past. Extreme high-resolution field emission scanning electron microscopy (XHR-FESEM), high-resolution transmission electron microscopy (HRTEM) and x-ray photoelectron spectroscopy (XPS) were used to analyse the hybrid carbon fiber-carbon nanotube (CF-CNT). The results demonstrated that CNT was successfully and homogenously distributed on the CF surface. Hybrid CF-CNT was then prepared and compared with CF without CNT deposition in terms of their tensile properties. Statistically, the tensile strength and the tensile modulus of the hybrid CF-CNT were increased by up to 3% and 25%, respectively, as compared to the CF without CNT deposition. The results indicated that the ESD method did not cause any reduction of tensile properties of hybrid CF-CNT. Based on this finding, it can be prominently identified some new and significant information of interest to researchers and industrialists working on CF based products.

The paper presents a model of a car with special attention given to the drive system. Two possible drive systems were considered: with standard differential and independent drive of each wheel by means of an electric motor. In both cases, flexibilities of live axle shafts have been taken into consideration. A 3D model of the car was assumed. The model consists of a system of rigid bodies connected one with another by means of elastic-damping elements. The phases of static and kinetic friction were considered in the steering and drive systems. The method of homogenous transformations was used in the mathematical description. The results of computer simulations are presented.

The paper shows the hybrid method of stress and strain distributions analysis. In the method, the results of displacement measurement were used as boundary conditions in the numerical analysis of the tested objects. The numerical analysis was performed with the use of the finite element method (FEM), whereas measurements of displacement were made by laser grating interferometry technique (moire interferometry). Examples of tests presented in the paper show good efficiency of the method in the analysis of stress and strain distribution in the areas of their heterogeneous distribution. Mutual completion of laser grating interferometry and finite element method makes it possible to exclude their disadvantages creating broader' possibilities for research impossible to achieve in separate use.

Recently, there has been research on high frequency dissipative mufflers. However, research on shape optimization of hybrid mufflers that reduce broadband noise within a constrained space is sparse. In this paper, a hybrid muffler composed of a dissipative muffler and a reactive muffler within a constrained space is assessed. Using the eigenvalues and eigenfunctions, a coupling wave equation for the perforated dissipative chamber is simplified into a four-pole matrix form. To efficiently find the optimal shape within a constrained space, a four-pole matrix system used to evaluate the acoustical performance of the sound transmission loss (STL) is evaluated using a genetic algorithm (GA).

A numerical case for eliminating a broadband venting noise is also introduced. To verify the reliability of a GA optimization, optimal noise abatements for two pure tones (500 Hz and 800 Hz) are exemplified. Before the GA operation can be carried out, the accuracy of the mathematical models has been checked using experimental data. Results indicate that the maximal STL is precisely located at the desired target tone. The optimal result of case studies for eliminating broadband noise also reveals that the overall sound power level (SWL) of the hybrid muffler can be reduced from 138.9 dB(A) to 84.5 dB(A), which is superior to other mufflers (a one-chamber dissipative and a one-chamber reactive muffler). Consequently, a successful approach used for the optimal design of the hybrid mufflers within a constrained space has been demonstrated.