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Drawing as a notation is a method for architecture which investigates the notation and mark making of classical music as an input and explores how these notations can inform unexpected architectural outcomes through a translation process of the notations. The purpose of this study is to look into drawing as a notation as a method and a tool and to discover new architectural formations. By interpreting and translating the marks, new suggestions for architecture can be found which express the formal language of music. I am interested in the dynamics of music - the repetition, the movement, and the rhythm - and what music can do for architecture. This is not a solution to anything or doesn’t try to solve anything, but rather a search or a struggle to find opportunities with the help of notation making in early stages of an architecture project and to propose what architecture can be.

Drawing as a notation is a method for architecture which investigates the notation and mark making of classical music as an input and explores how these notations can inform unexpected architectural outcomes through a translation process of the notations. The purpose of this study is to look into drawing as a notation as a method and a tool and to discover new architectural formations. By interpreting and translating the marks, new suggestions for architecture can be found which express the formal language of music. I am interested in the dynamics of music - the repetition, the movement, and the rhythm - and what music can do for architecture. This is not a solution to anything or doesn’t try to solve anything, but rather a search or a struggle to find opportunities with the help of notation making in early stages of an architecture project and to propose what architecture can be.

The focus of this thesis is on the phenomenon of the informal settlement and its informal economy. The location of the graduation project called Tarlabası is an informal settlement in the middle of the city centre of Istanbul. The neighbourhood has been a shelter for the poor, refugees and minorities for generations. The district functions as its own hidden and self-regulating world. This has created an informal economy that is inextricably linked to the rest of Istanbul, such as the waste/recycling industry. It cannot exist without the informal branch of waste pickers, who are responsible for 80% of recycling in Turkey. The unique district of Tarlabası is seen as bad and criminal by the authoritarian neoliberal city planners. Therefore, the neighbourhood has already been hit by gentrification processes, ignoring the unique characteristics and social roots of this neighbourhood. Urban renewal or gentrification or however you want to name it, is seen as a necessary tool to erase certain parts of social and physical identities created in the last 50 years via programs of demolition and resettlement. Residents are evicted or given unfair compensation to leave their homes or workplaces. As a result, the gentrification processes result in a displacement of the poor, driving them away from the city centre and their informal work. In 2009, at least one million residents in Istanbul were under threat of forced eviction due to the Urban Transformation Project. The unique characteristics, such as creativity, flexibility, intrinsic value and self-regulation are ignored by the top-down view of modernization, leading to generic neighbourhoods without economic flexibility and with social segregation, but also resulting in a further decline of informal settlements. This thesis aims to take a critical look at the current neoliberalist modernization processes of urban areas around the world through the case of Istanbul. Urban informality is receiving more and mor, Borders and Territories, Architecture, Urbanism and Building Sciences | Borders and Territories

Strain hardening cementitious composites (SHCC) can be used to reduce the amount of reinforcement needed to control crack widths. SHCC has a strain hardening behaviour with dense micro-cracking, which makes it more ductile compared to conventional concrete. Conventional concrete can be used in the non-critical locations. An interface is formed in between the two concrete layers. The interface is the weakest link in the system, governing the structural performance. Therefore, the interface is of interest in ongoing research. The lattice model allows to investigate the effect of the fundamental parameters, the interface tensile strength and interface stiffness, on the structural behaviour in different bond tests between normal strength concrete and SHCC. Direct tension, direct shear and the notched-beam test were used to investigate the effect of the individual interface properties on the global behaviour. In all bond tests a smooth and profiled interface were simulated to investigate the effect of applying a roughness to the interface. In the small-scale tests activation of adjacent materials was found to occur at increased interface tensile strength and decreased interface stiffness. For a smooth interface a decrease in interface stiffness resulted in a scatter of failed elements over the interface in the direct tension test, increasing the ductility. Initially, a linear relation is obtained between the interface tensile strength and load capacity for the direct tension and direct shear test. With higher interface tensile strength cracking of the adjacent materials increased the load capacity, but the adjacent materials started to become governing. The application of a profile in the interface increased the capacity even further and resulted in an increased softening. For a profiled interface the effect of changing interface properties was limited in most cases compared to the effect on a smooth interface. This was due to the activation of the adjacent material, Civil Engineering | Structural Engineering | Concrete Structures

This chapter works on designing an efficient channel estimator for hybrid mmWave massive multiple-input multiple-output (mMIMO) systems. The proposed doubly-sparse approach relies on a judiciously designed training pattern to decouple the convoluted channel. By doing so, it becomes convenient to exploit the under-investigated channel sparsity in the delay domain together with the well-known beamspace sparsity. Furthermore, dedicated probing strategies are accordingly developed to ensure compatibility with the hybrid structure while utilizing double sparsity. Compared with existing alternatives, the proposed mmWave channel estimator works exceptionally in doubly-selective (frequency-time) channels and can hugely reduce the training overhead, storage demand, and computational complexity thanks to the exploitation of double (delay-beamspace) sparsity. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

The bonding of Carbon Fibre Reinforced ThermoPlastic composites (CFRTP) and steel is of great interest nowadays. Nevertheless, the difference in machinability between dissimilar materials requires a specific machining process. Abrasive water jet machining is a flexible and environmentally friendly technology that can machine dissimilar materials at the same time with good results. However, due to the characteristics of the process and materials, geometrical defects such as taper angle can be caused by the loss of kinetic energy. In this research, the study of the final geometry in abrasive waterjet machining of a hybrid CFRTP/Steel structure. A new methodology for the evaluation of taper angle with high accuracy has been developed through image processing. In addition, the surface quality in terms of Ra and Rz has been assessed. A potential-type trend between taper and hydraulic pressure has been established for both materials. Minimum taper values between 1.5° and 5° have been obtained for both materials and stacking configurations with a combination of a hydraulic pressure of 420 MPa, an abrasive mass flow of 225 g/min and a traverse speed of 50 mm/min. © 2021 The Author(s)

There is an increasing interest in large-dimensional timber structural elements within the construction sector in order to fulfil the combined demand of sustainability, open spaces and architectural flexibility. Current timber technology allows for efficient production of long-size beams, but many problems are related to their overall high costs due to difficulties in transportation, manufacturing on site and handling during the mounting phase. Hence, the aim of this work is to propose and study an innovative timber-steel hybrid structural element composed of shorter pieces of beams connected and reinforced by means of a system consisting of steel shear keys and steel rods. The small timber elements and steel devices can be prefabricated with low costs and easily assembled into large elements at the construction sites. The proposed system can also be used for retrofitting of existing timber members when it is necessary to increase their strength, stiffness and ductility. The structural behavior of the proposed system was therefore studied both as a connection and as a retrofitting technique, which were analyzed via two types of hybrid beams, one with a splice at mid-span and one without, separately. A simple glulam beam with the same geometrical characteristics of the two hybrid structures was also investigated for the comparison of the structural behavior. The analytical results show that the hybrid beams with and without splice have both obtained significant increasement in the stiffness, strength and ductility. The numerical analyses are limited in the elastic stage due to the elastic mechanical properties assigned to the structural components. The numerical results show good agreement with the analytical ones for each type of beam in terms of the stiffness in the elastic stage. Finally, the influence of the parameters such as the distance between shear keys, slip modulus of shear keys and diameter of rod, on the structural behavior of hybrid beams is discussed i, QC 20220216

Strain Hardening Cementitious Composite (SHCC) is a new type of concrete that is able to control the crack-width in concrete structures. The application of this material in the tension zone of hybrid concrete structures is thus of interest in practice. The interfacial behavior for these hybrid structures is something that is of importance for the composite action. Therefore, a study is performed to investigate the behavior of the interface in hybrid SHCC-concrete beams. This is done by performing an experimental study on beams with a joint at midspan. Several parameters such as the interface roughness, coupling reinforcement cover, curing method and protruding reinforcement have been investigated. The hybrid SHCC-concrete beams are tested in a four-point bending configuration to obtain a constant-bending moment region along the interface. The crack propagation along the interface and through the SHCC/concrete has been evaluated with the use of Digital Image Correlation (DIC). Furthermore, also a numerical analysis has been performed using DIANA FEA based. The numerical analysis was used to help to determine the experimental campaign. Furthermore, also several experimental samples have been modelled to study the behavior of the beam in more detail and to make recommendations for future modelling of the interface. Based on the experimental results, the influence of the interface roughness resulted in an increased bond at the interface. This is both seen in an increased bearing capacity and a reduction of the interface and joint opening at equal loads. The profiled interface and holed interface resulted in an increased capacity due to the mechanical interlocking at the interface. The bearing capacity of these samples increased by 78.4% and 54.7% respectively compared to the reference sample (13.9 kN). In case of the profiled sample, no delamination of the interface occurred as the sample failed due to a horizontal crack at the level of the coupling reinforcement. This, Civil Engineering | Structural Engineering

In this work, we reported the fabrication of hybrid structures by growing the multi-walled carbon nanotubes (MWCNT) on porous silicon (PS) as a template. Aligned multi-walled carbon nanotubes have been successfully synthesized on PS by ultrasonic spray pyrolysis (USP) using a solution of Toluene/Ferrocene as the precursor, while electrochemical anodization method was used to fabricate the PS layers. Au contact was deposited as a metallic contact on the MWCNT layer in order to measure the electrical properties and to analyze the electrical effect of the incorporation of MWCNT on PS. The structural and morphological characteristics of the hybrid structures were investigated by using Field Emission Scanning Electron Microscope (FE-SEM) showing that MWCNT formed a thin film on the PS surface in the form of an aligned array and perpendicular fiber-like structures to the porous surface. High-Resolution Transmission Electron Microscopy (HRTEM) images confirmed the diameter of the CNT between 10 and 30 nm and typically consisted of 10–20 concentric shells of carbon sheets. Raman Microscopy showed three characteristic bands and a high graphitization extent, even it was possible to observe that the carbon structures passivated the PS layer. Consequently, the photoluminescence (PL) spectrum of PS layers significantly was modified by MWCNT. Finally, electrical measurements provided a practical approach to describe how the materials behave under specific conditions that can be used for different applications in electronics or optoelectronics such as diodes or photodetectors. Significant differences were found under darkness, and illumination conditions of current-voltage (I–V) curves implied their possible application in optoelectronics. Moreover, symmetrical rectifying and Ohmic behavior was observed, which rarely has been reported in the literature, even it was possible to fit a transport mechanism, and the capacitance-voltage (C–V) curves presented an un-exponential behavior

In this work, we reported the fabrication of hybrid structures by growing the multi-walled carbon nanotubes (MWCNT) on porous silicon (PS) as a template. Aligned multi-walled carbon nanotubes have been successfully synthesized on PS by ultrasonic spray pyrolysis (USP) using a solution of Toluene/Ferrocene as the precursor, while electrochemical anodization method was used to fabricate the PS layers. Au contact was deposited as a metallic contact on the MWCNT layer in order to measure the electrical properties and to analyze the electrical effect of the incorporation of MWCNT on PS. The structural and morphological characteristics of the hybrid structures were investigated by using Field Emission Scanning Electron Microscope (FE-SEM) showing that MWCNT formed a thin film on the PS surface in the form of an aligned array and perpendicular fiber-like structures to the porous surface. High-Resolution Transmission Electron Microscopy (HRTEM) images confirmed the diameter of the CNT between 10 and 30 nm and typically consisted of 10–20 concentric shells of carbon sheets. Raman Microscopy showed three characteristic bands and a high graphitization extent, even it was possible to observe that the carbon structures passivated the PS layer. Consequently, the photoluminescence (PL) spectrum of PS layers significantly was modified by MWCNT. Finally, electrical measurements provided a practical approach to describe how the materials behave under specific conditions that can be used for different applications in electronics or optoelectronics such as diodes or photodetectors. Significant differences were found under darkness, and illumination conditions of current-voltage (I–V) curves implied their possible application in optoelectronics. Moreover, symmetrical rectifying and Ohmic behavior was observed, which rarely has been reported in the literature, even it was possible to fit a transport mechanism, and the capacitance-voltage (C–V) curves presented an un-exponential behavior

Strain Hardening Cementitious Composite (SHCC) is a new type of concrete that is able to control the crack-width in concrete structures. The application of this material in the tension zone of hybrid concrete structures is thus of interest in practice. The interfacial behavior for these hybrid structures is something that is of importance for the composite action. Therefore, a study is performed to investigate the behavior of the interface in hybrid SHCC-concrete beams. This is done by performing an experimental study on beams with a joint at midspan. Several parameters such as the interface roughness, coupling reinforcement cover, curing method and protruding reinforcement have been investigated. The hybrid SHCC-concrete beams are tested in a four-point bending configuration to obtain a constant-bending moment region along the interface. The crack propagation along the interface and through the SHCC/concrete has been evaluated with the use of Digital Image Correlation (DIC). Furthermore, also a numerical analysis has been performed using DIANA FEA based. The numerical analysis was used to help to determine the experimental campaign. Furthermore, also several experimental samples have been modelled to study the behavior of the beam in more detail and to make recommendations for future modelling of the interface. Based on the experimental results, the influence of the interface roughness resulted in an increased bond at the interface. This is both seen in an increased bearing capacity and a reduction of the interface and joint opening at equal loads. The profiled interface and holed interface resulted in an increased capacity due to the mechanical interlocking at the interface. The bearing capacity of these samples increased by 78.4% and 54.7% respectively compared to the reference sample (13.9 kN). In case of the profiled sample, no delamination of the interface occurred as the sample failed due to a horizontal crack at the level of the coupling reinforcement. This, Civil Engineering | Structural Engineering

This paper develops efficient channel estimation techniques for millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO) systems under practical hardware limitations, including an arbitrary array geometry and a hybrid hardware structure. Taking on an angle-based approach, this work adopts a generalized array manifold separation approach via Jacobi-Anger approximation, which transforms a non-ideal, non-uniform array manifold into a virtual array domain with a desired uniform geometric structure to facilitate super-resolution angle estimation and channel acquisition. Accordingly, structure-based optimization techniques are developed to effectively estimate both the channel covariance and the instantaneous channel state information (CSI) within a short sensing time. The different time-varying scales of channel path angles versus path gains are capitalized to design a two-step CSI estimation scheme that can quickly sense fading channels. Theoretical results are provided on the fundamental limits of the proposed technique in terms of sample efficiency. For computational efficiency, a fast iterative algorithm is developed via the alternating direction method of multipliers. Other related issues such as spurious-peak cancellation in non-uniform linear arrays and extensions to higher-dimensional cases are also discussed. Simulations testify the effectiveness of the proposed approaches in hybrid mmWave massive MIMO systems with arbitrary arrays., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Circuits and Systems

This paper develops efficient channel estimation techniques for millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO) systems under practical hardware limitations, including an arbitrary array geometry and a hybrid hardware structure. Taking on an angle-based approach, this work adopts a generalized array manifold separation approach via Jacobi-Anger approximation, which transforms a non-ideal, non-uniform array manifold into a virtual array domain with a desired uniform geometric structure to facilitate super-resolution angle estimation and channel acquisition. Accordingly, structure-based optimization techniques are developed to effectively estimate both the channel covariance and the instantaneous channel state information (CSI) within a short sensing time. The different time-varying scales of channel path angles versus path gains are capitalized to design a two-step CSI estimation scheme that can quickly sense fading channels. Theoretical results are provided on the fundamental limits of the proposed technique in terms of sample efficiency. For computational efficiency, a fast iterative algorithm is developed via the alternating direction method of multipliers. Other related issues such as spurious-peak cancellation in non-uniform linear arrays and extensions to higher-dimensional cases are also discussed. Simulations testify the effectiveness of the proposed approaches in hybrid mmWave massive MIMO systems with arbitrary arrays., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Signal Processing Systems

Hybrid metal-polymer structures are an alternative solution to reduce weight and fuel consumption in the transportation industry in order to minimize the emission of noxious gases in regard to the greenhouse effect. Friction Riveting is a relatively new technique for joining metal-polymer hybrid structures. The process relies on the generation of frictional heat between the components causing the plastic deformation of the metallic rivet and its anchoring in the polymer component. This study evaluated the technical feasibility of friction-riveted AA 6056 T6 and PA6 joints, and the influence of the rotational speed (RS) on the maximum process temperature and on the mechanical performance of the joints. The maximum temperature reached increased with the rotational speed, from 291 ± 6 °C at 10000 rev/min to 375 ± 5 °C at 15000 rev/min. The use of greater rotational speeds induced the plastic deformation of the tip of the metallic rivet during the frictional phase. This led to mechanically stronger joints due to the larger anchoring of the metallic rivet within the polymeric plate. The AA 6056 T6-PA6 joints had good tensile strength, achieving 85% of the metallic rivet’s tensile strength. Therefore, the feasibility of friction-riveted AA 6056 T6-PA6 joints was proven. Furthermore, it was shown that the rotational speed influences directly the rivet anchoring and thus the tensile strength of the joints.

This paper presents an efficient approach for exciting a dielectric resonator antenna (DRA) in the terahertz frequencies by means of a graphene plasmonic dipole. Design and analysis are performed in two steps. First, the propagation properties of hybrid plasmonic one-dimensional and two-dimensional structures are obtained by using transfer matrix theory and the finite-element method. The coupling amount between the plasmonic graphene mode and the dielectric wave mode is explored based on different parameters. These results, together with DRA and plasmonic antenna theory, are then used to design a DRA antenna that supports the TEy 112 mode at 2.4 THz and achieves a gain (IEEE) of up to 7 dBi and a radiation efficiency of up 70%. This gain is 6.5 dB higher than that of the graphene dipole alone and achieved with a moderate area overhead, demonstrating the value of the proposed structure., Peer Reviewed, Postprint (published version)

Пояснювальна записка до дипломної роботи «Кремнієвий фотовольтаїчний перетворювач сонячної енергії на основі фталоціаніну кобальту», 63 сторінки, 34 ілюстрації, 4 таблиці, 43 посилання Об’єкт дослідження – органічно-неорганічна гібридна структура на мікропрофільованому кремнії з органічним шаром фталоціаніну кобальту. Мета роботи: обрати технологію виготовлення та провести процес отримання гібридної структури фталоціанін кобальту – мікропрофільований кремній n-типу, дослідити час впливу осадження органічного шару на вольт-амперні характеристики та морфологію поверхні гібриду,який використано для створення перетворювача сонячної енергії. Методи дослідження: оптична мікроскопія, скануюча електронна мікроскопія, фотовольтаїчна характеристика при енергетичній освітлюваності 0,03 Сонця. Анотація. Розглянуто різні види органічних сонячних елементів. Обрано та досліджено лабораторний зразок органічно-неорганічного гібриду, який отримано осадженням фталоціаніну кобальту наn мікропрофілбований кремній при кімнатній температурі з хімічної ванни. Отримані результати подані у вигляді світлових та темнових вольт-амперних характеристик. Знайдено тенденцію появи органічного шару у вигляді сітки, що з’єднує верхівки пірамідок підкладинки. В результаті виявлено, що оптимальний час утворення органічного шару є 60-80 хвилин витримки у хімічній ванні. ККД отриманих гібридів сягає 3,0 % при 0,03 сонця., Different types of organic solar cells are considered. Laboratory sample of organic-inorganic hybrid was choosed and studied. The hynrid was obtained by deposition of cobalt phtalocianine on microprofiled n-type silicon at room temperature from chemical bath. The results presented in the form of dark and light current-voltage characteristics. The tendency of the grid creation which connects the tops of pyramids substrate. As the result the best time of the organic layer formation was determined. It is 60-80 minutes of exposure to the chemical bath. Energy conversion efficiency of created hybrid was about 3 % at 0.03 sun.

The combination of two or more materials into a hybrid structural system is becoming increasingly important in the construction industry. The present study focusses on the design of a hybrid beam consisting of a rectangular hollow pultruded glass fiber reinforced polymer (GFRP) composite filled with concrete. The static flexural performance of the hybrid beam showed it has potential to be used as a structural element. However, the dynamic performance of the hybrid beam has yet to be assessed. If it is to be used as a railway sleeper or bridge girder, it could be subjected to low-velocity impact loading. The aim of this study therefore is to investigate the impact behaviour of the hybrid GFRP-concrete beam under low-velocity impact.This research comprised multiple experimental and numerical studies on the impact response of the hybrid GFRP-concrete beam subjected to low-velocity impact loading. The impact behaviour study of pultruded GFRP composites indicated that the impact energy level was the main factors that affected the response of the composite. The energy was absorbed mainly through the elastic-plastic deformation and failure mechanisms, such as matrix cracking and delamination. A numerical model was developed to analyse the development and propagation of the stress. The numerical investigation of the hybrid beam to static loading was conducted to validate the material models of the structural elements. The numerical results were highly consistent with the experimental data. Finally, the impact behaviour of the hybrid GFRP-concrete beam to the low-velocity impacts was analysed using experimentation and numerical simulations. The results indicated that the impact response could be divided into two stages, inertial resistance stage and dynamic bending resistance stage. In the former stage, the impact load was resisted completely by the inertial force. The majority of the impact energy was absorbed in the second stage. Multiple failure modes were presented in th

Research abstract:The world steel demand and production are constantly growing parallelly to the world economic growth. Even though steel is fully recyclable, there is still a vast amount of virgin production which put tremendous pressure on the natural scarcity of natural resources. Steel recycling only mitigates the impacts since it alone requires a significant amount of energy (including re-manufacturing process) and it produces more greenhouse gases into the atmosphere. Therefore, assumptions suggest that the market of reclaimed material will play a progressively more important role in the future. This research paper presents the limitations which currently make the reuse scenario very unlikely to occur excluding industrial uses which is a relatively narrow sector. Through this, it will investigate the relevance of onsitu frame structural reconfiguration as a potential alternative for demolishing steel frame buildings Project abstract: tbu, Architecture, Urbanism and Building Sciences

This paper presents an efficient approach for exciting a dielectric resonator antenna (DRA) in the terahertz frequencies by means of a graphene plasmonic dipole. Design and analysis are performed in two steps. First, the propagation properties of hybrid plasmonic one-dimensional and two-dimensional structures are obtained by using transfer matrix theory and the finite-element method. The coupling amount between the plasmonic graphene mode and the dielectric wave mode is explored based on different parameters. These results, together with DRA and plasmonic antenna theory, are then used to design a DRA antenna that supports the TEy 112 mode at 2.4 THz and achieves a gain (IEEE) of up to 7 dBi and a radiation efficiency of up 70%. This gain is 6.5 dB higher than that of the graphene dipole alone and achieved with a moderate area overhead, demonstrating the value of the proposed structure., Peer Reviewed, Postprint (published version)

Research abstract:The world steel demand and production are constantly growing parallelly to the world economic growth. Even though steel is fully recyclable, there is still a vast amount of virgin production which put tremendous pressure on the natural scarcity of natural resources. Steel recycling only mitigates the impacts since it alone requires a significant amount of energy (including re-manufacturing process) and it produces more greenhouse gases into the atmosphere. Therefore, assumptions suggest that the market of reclaimed material will play a progressively more important role in the future. This research paper presents the limitations which currently make the reuse scenario very unlikely to occur excluding industrial uses which is a relatively narrow sector. Through this, it will investigate the relevance of onsitu frame structural reconfiguration as a potential alternative for demolishing steel frame buildings Project abstract: tbu, Architecture, Urbanism and Building Sciences

A novel mesoporous nanosheet networked hybrid comprising Co3O4 and Co-3(PO4)(2) is successfully synthesized using a facile and scalable method through calcinating the carbon, cobalt hydroxy carbonate, and cobalt phosphate composite precursor. Electron transfer from Co3O4 to Co-3(PO4)(2), together with the special networked structure and the porous nature of the nanosheets enable the Co-3(PO4)(2)-Co3O4 hybrid to have a high oxygen evolution reaction (OER) activity and outstanding stability in alkaline electrolyte, e.g., an overpotential of 270 mV at current density of 10 mA cm(-2), and a Tafel slope of 39 mV dec(-1), which are superior to most non-noble metal-based OER electrocatalysts reported thus far and as well the commercial RuO2 electrocatalyst. Furthermore, Co-3(PO4)(2)-Co3O4 hybrid is demonstrated to be used as an efficient cocatalyst to enhance the photoelectrochemical OER performance of BiVO4 photoanode. A significantly increased photocurrent density of 3.0 mA cm(-2) at 1.23 V (vs reversible hydrogen electrode, RHE), and a potential reduction of 530 mV with respect to that of bare BiVO4 at the photocurrent density of 0.5 mA cm(-2) are achieved. The electron transfer-induced enhancement of OER by a hybrid structure may pave the new routes for the design and synthesis of low-cost catalysts for electrochemical and photoelectrochemical oxygen evolution.

This study identifies for the first time, the hybrid structure of the white layer in high carbon steel and describes its formation mechanism and properties. The so-called ‘white layer’ in steel forms during high strain rate deformation and appears featureless under optical microscopy. While many researchers have investigated the formation of the white layer, there has been no definitive study, nor is there sufficient evidence to fully explain the formation, structure and properties of the layer. In this study, the formation, morphology and mechanical properties of the white layer was determined following impact testing, using a combination of optical and SE- microscopy, HR-EBSD, TKD and TEM as well as nano-indentation hardness measurements and FE modelling. The phase transformation and recrystallization within and near the white layer was also investigated. The microstructure of the steel in the white layer consisted of nano-sized grains of martensite. A very thin layer of austenite with nano sized grains was identified within the white layer by HR-EBSD techniques, the presence of which is attributed to a thermally-induced reverse phase transformation. Overall, the combination of phase transformations, strain hardening and grain refinement led to a hybrid structure and an increase in hardness of the white layer.

A novel mesoporous nanosheet networked hybrid comprising Co3O4 and Co-3(PO4)(2) is successfully synthesized using a facile and scalable method through calcinating the carbon, cobalt hydroxy carbonate, and cobalt phosphate composite precursor. Electron transfer from Co3O4 to Co-3(PO4)(2), together with the special networked structure and the porous nature of the nanosheets enable the Co-3(PO4)(2)-Co3O4 hybrid to have a high oxygen evolution reaction (OER) activity and outstanding stability in alkaline electrolyte, e.g., an overpotential of 270 mV at current density of 10 mA cm(-2), and a Tafel slope of 39 mV dec(-1), which are superior to most non-noble metal-based OER electrocatalysts reported thus far and as well the commercial RuO2 electrocatalyst. Furthermore, Co-3(PO4)(2)-Co3O4 hybrid is demonstrated to be used as an efficient cocatalyst to enhance the photoelectrochemical OER performance of BiVO4 photoanode. A significantly increased photocurrent density of 3.0 mA cm(-2) at 1.23 V (vs reversible hydrogen electrode, RHE), and a potential reduction of 530 mV with respect to that of bare BiVO4 at the photocurrent density of 0.5 mA cm(-2) are achieved. The electron transfer-induced enhancement of OER by a hybrid structure may pave the new routes for the design and synthesis of low-cost catalysts for electrochemical and photoelectrochemical oxygen evolution.

A novel mesoporous nanosheet networked hybrid comprising Co3O4 and Co-3(PO4)(2) is successfully synthesized using a facile and scalable method through calcinating the carbon, cobalt hydroxy carbonate, and cobalt phosphate composite precursor. Electron transfer from Co3O4 to Co-3(PO4)(2), together with the special networked structure and the porous nature of the nanosheets enable the Co-3(PO4)(2)-Co3O4 hybrid to have a high oxygen evolution reaction (OER) activity and outstanding stability in alkaline electrolyte, e.g., an overpotential of 270 mV at current density of 10 mA cm(-2), and a Tafel slope of 39 mV dec(-1), which are superior to most non-noble metal-based OER electrocatalysts reported thus far and as well the commercial RuO2 electrocatalyst. Furthermore, Co-3(PO4)(2)-Co3O4 hybrid is demonstrated to be used as an efficient cocatalyst to enhance the photoelectrochemical OER performance of BiVO4 photoanode. A significantly increased photocurrent density of 3.0 mA cm(-2) at 1.23 V (vs reversible hydrogen electrode, RHE), and a potential reduction of 530 mV with respect to that of bare BiVO4 at the photocurrent density of 0.5 mA cm(-2) are achieved. The electron transfer-induced enhancement of OER by a hybrid structure may pave the new routes for the design and synthesis of low-cost catalysts for electrochemical and photoelectrochemical oxygen evolution.

A new process, sheathed powder compaction (SPC), was proposed to fabricate hybrid metallic composite samples at room temperature. The process involves densification of fine powder in an annulus sheath under combined moderate pressure and shear. Hybrid samples of copper annular with aluminum powder were produced to demonstrate the merits of the process. The fabricated samples were characterized and explored using electron microscopy, micro hardness, micro shear punch tests and density ratio measurements. Comparing “shear punch response” of the samples in the Al region with those of commercially pure aluminum and Al 5005-H34 samples showed an excellent shearing strength in the region. The electron backscatter diffraction analyses and scanning electron microscopy observations suggested that the substantially enhanced strength was facilitated by a significant SPC induced grain refinement. Moreover, the annular sheath (copper) also showed significant grain refinement due to the process. These demonstrated promising potentials of the SPC to manufacture hybrid metals with concurrent grain refinement at room temperature under moderate processing conditions.

Graphene is a unique material for the implementation of terahertz antennas due to extraordinary properties of the resulting devices, such as tunability and compactness. Existing graphene antennas are based on pure plasmonic structures, which are compact but show moderate to high losses. To achieve higher efficiency with low cost, one can apply the theory behind dielectric resonator antennas widely used in millimeter-wave systems. This paper presents the concept of hybridization of surface plasmon and dielectric wave modes. Radiation efficiency, reconfigurability, and miniaturization of antennas built upon this principle are qualitatively discussed and compared with those of pure plasmonic antennas. To this end, a quantitative study of pure and hybrid plas-monic one-dimensional guided-wave structures is performed. The results show that hybrid structures can be employed to design terahertz antennas with high radiation efficiency and gain, moderate miniaturization, and tunability, while terahertz antennas based on pure plasmonic structures can provide high miniaturization and tunability yet with low radiation efficiency and gain., Peer Reviewed, Postprint (published version)

This paper presents a study of two different hybrid composite-aluminum concepts applied to a winglike structure which is exposed to mechanical and thermal load. The aim of the study is to determine the most suitable hybrid concept to later on be used in structural fatigue and static testing. In both concepts, the mass is optimized with respect to two different sets of requirements, one of which is currently in use in the fighter aircraft industry and one which is a modified version of the current requirement set. The issues considered in the study are mass, thermal behavior, buckling, bolted joints, failure criteria and fatigue damage, and they are examined in the frame of both requirement sets. The results clearly indicate the order of criticality between the different criteria in the different parts of each concept. Also, the comparison of two requirement sets gives an idea of the degree of influence of the modified criteria on the hybrid concepts and their mass. Based on the mass and the structural behavior in a thermal-mechanical loading one of the hybrid concepts is chosen for further studies and testing.

This paper presents a study of two different hybrid composite-aluminum concepts applied to a winglike structure which is exposed to mechanical and thermal load. The aim of the study is to determine the most suitable hybrid concept to later on be used in structural fatigue and static testing. In both concepts, the mass is optimized with respect to two different sets of requirements, one of which is currently in use in the fighter aircraft industry and one which is a modified version of the current requirement set. The issues considered in the study are mass, thermal behavior, buckling, bolted joints, failure criteria and fatigue damage, and they are examined in the frame of both requirement sets. The results clearly indicate the order of criticality between the different criteria in the different parts of each concept. Also, the comparison of two requirement sets gives an idea of the degree of influence of the modified criteria on the hybrid concepts and their mass. Based on the mass and the structural behavior in a thermal-mechanical loading one of the hybrid concepts is chosen for further studies and testing.

Optical properties of hybrid structures based on zinc oxide nanocrystals (NCs) and Gallium Nitride quantum well (QW) has been studied. The ZnO NCs thin films on the top of GaN QW structures were fabricated using spin coating. The surface morphology was characterized by scanning electron microscopy (SEM). We have performed temperature dependence time-resolved photoluminescence (TRPL) measurements of the bare AlGaN/GaN QW structures and hybrids, containing ZnO NCs. It was found that at some temperatures the QW PL decay has shorter decay time in the presence of ZnO NCs thin film compared to the bare QW. The effect was stronger for the samples with thinner cap layers. The results are discussed in terms of three models such as exciton nonradiative energy transfer (NRET), tunneling effect, and piezoelectric field influence on the QW exciton energy.

Optical properties of hybrid structures based on zinc oxide nanocrystals (NCs) and Gallium Nitride quantum well (QW) has been studied. The ZnO NCs thin films on the top of GaN QW structures were fabricated using spin coating. The surface morphology was characterized by scanning electron microscopy (SEM). We have performed temperature dependence time-resolved photoluminescence (TRPL) measurements of the bare AlGaN/GaN QW structures and hybrids, containing ZnO NCs. It was found that at some temperatures the QW PL decay has shorter decay time in the presence of ZnO NCs thin film compared to the bare QW. The effect was stronger for the samples with thinner cap layers. The results are discussed in terms of three models such as exciton nonradiative energy transfer (NRET), tunneling effect, and piezoelectric field influence on the QW exciton energy.

Paper presents stress calculation in the stationary temperature domain for a hybrid structure with standard epoxy-carbon fiber composite and metallic part, showing different thermal behavior. The thermal stress analysis is based on the finite element method. A sample problem involving such a composite plate and metallic part of structure or mould at two different temperature levels, corresponding to curing process (co-curing) and operating temperatures, respectively, is calculated and discussed. The specific properties of composite are emphasized particularly for thermal coefficients, especially if the shear coefficient is different than zero, causing completely different behavior compared to isotropic materials.

p. 2458-2464, Arch structure has been one of the most popular architectural sculptures due to its graceful sculpts and rational bearing mechanism. In order to deal with he thrust at the arch foot and the out-plane stability of arch structure which could result in the failure of the whole structure, a practical arch bridge, which failed work after accomplishment, was taken as example to develop the research. Through analysis of the origin structure by finite element program Midas under dead and live load, the reason for the failure of the present arch structure was pointed out. Considering the concept of `hybrid¿, three hybrid structures with arch as a composition were advanced to reinforce the initial structure. Two of them are arch-truss hybrid structure with different dimension, and another one is cable-supported arch hybrid structure. The present reinforced structures were analyzed and their reinforced effects were attained respectively. Through comparison of the bearing characteristic of each structure, a relatively most suitable structure was proposed to be used in this project, which could make as full as possible use of the hybrid structure.

První část práce s názvem „Hybridní lepené spoje kovových a kompozitních materiálů“ obsahuje popis povrchových úprav adherendů. Rovněž je uveden aktuální ucelený přehled lepidel používaných pro spojování kompozitních a kovových adherendů. Druhá část práce je zaměřena na zkoušky smykové pevnosti hybridních spojů. Byl zkoumán vliv tloušťky adherendu, délky přeplátování a vliv přípravy povrchu na smykovou pevnost spoje. Naměřené závislosti jsou ověřeny FE analýzami s dostatečnou přesností. Poznatky a závěry uvedené v práci je možné využít pro optimální návrh hybridního spoje duralu a kompozitu., The first part of the diploma thesis with name „Hybrid adhesive bonded joints of metals and composite materials“ comprise surface pretreatment review. There is also mentioned current review of adhesives for composite and aluminium adherends. The second part of the thesis is dedicated to lap hybrid joint shear strength tests. The effects of adherend thickness, overlap lenght and surface pretreatment on shear strength were investigated. Measured parameters of hybrid joints are proved with a FE analysis with enough accuracy. Conclusions could be used for optimum design of hybrid joint with aluminium and composite adherends.

První část práce s názvem „Hybridní lepené spoje kovových a kompozitních materiálů“ obsahuje popis povrchových úprav adherendů. Rovněž je uveden aktuální ucelený přehled lepidel používaných pro spojování kompozitních a kovových adherendů. Druhá část práce je zaměřena na zkoušky smykové pevnosti hybridních spojů. Byl zkoumán vliv tloušťky adherendu, délky přeplátování a vliv přípravy povrchu na smykovou pevnost spoje. Naměřené závislosti jsou ověřeny FE analýzami s dostatečnou přesností. Poznatky a závěry uvedené v práci je možné využít pro optimální návrh hybridního spoje duralu a kompozitu., The first part of the diploma thesis with name „Hybrid adhesive bonded joints of metals and composite materials“ comprise surface pretreatment review. There is also mentioned current review of adhesives for composite and aluminium adherends. The second part of the thesis is dedicated to lap hybrid joint shear strength tests. The effects of adherend thickness, overlap lenght and surface pretreatment on shear strength were investigated. Measured parameters of hybrid joints are proved with a FE analysis with enough accuracy. Conclusions could be used for optimum design of hybrid joint with aluminium and composite adherends.

První část práce s názvem „Hybridní lepené spoje kovových a kompozitních materiálů“ obsahuje popis povrchových úprav adherendů. Rovněž je uveden aktuální ucelený přehled lepidel používaných pro spojování kompozitních a kovových adherendů. Druhá část práce je zaměřena na zkoušky smykové pevnosti hybridních spojů. Byl zkoumán vliv tloušťky adherendu, délky přeplátování a vliv přípravy povrchu na smykovou pevnost spoje. Naměřené závislosti jsou ověřeny FE analýzami s dostatečnou přesností. Poznatky a závěry uvedené v práci je možné využít pro optimální návrh hybridního spoje duralu a kompozitu., The first part of the diploma thesis with name „Hybrid adhesive bonded joints of metals and composite materials“ comprise surface pretreatment review. There is also mentioned current review of adhesives for composite and aluminium adherends. The second part of the thesis is dedicated to lap hybrid joint shear strength tests. The effects of adherend thickness, overlap lenght and surface pretreatment on shear strength were investigated. Measured parameters of hybrid joints are proved with a FE analysis with enough accuracy. Conclusions could be used for optimum design of hybrid joint with aluminium and composite adherends.

První část práce s názvem „Hybridní lepené spoje kovových a kompozitních materiálů“ obsahuje popis povrchových úprav adherendů. Rovněž je uveden aktuální ucelený přehled lepidel používaných pro spojování kompozitních a kovových adherendů. Druhá část práce je zaměřena na zkoušky smykové pevnosti hybridních spojů. Byl zkoumán vliv tloušťky adherendu, délky přeplátování a vliv přípravy povrchu na smykovou pevnost spoje. Naměřené závislosti jsou ověřeny FE analýzami s dostatečnou přesností. Poznatky a závěry uvedené v práci je možné využít pro optimální návrh hybridního spoje duralu a kompozitu., The first part of the diploma thesis with name „Hybrid adhesive bonded joints of metals and composite materials“ comprise surface pretreatment review. There is also mentioned current review of adhesives for composite and aluminium adherends. The second part of the thesis is dedicated to lap hybrid joint shear strength tests. The effects of adherend thickness, overlap lenght and surface pretreatment on shear strength were investigated. Measured parameters of hybrid joints are proved with a FE analysis with enough accuracy. Conclusions could be used for optimum design of hybrid joint with aluminium and composite adherends.

První část práce s názvem „Hybridní lepené spoje kovových a kompozitních materiálů“ obsahuje popis povrchových úprav adherendů. Rovněž je uveden aktuální ucelený přehled lepidel používaných pro spojování kompozitních a kovových adherendů. Druhá část práce je zaměřena na zkoušky smykové pevnosti hybridních spojů. Byl zkoumán vliv tloušťky adherendu, délky přeplátování a vliv přípravy povrchu na smykovou pevnost spoje. Naměřené závislosti jsou ověřeny FE analýzami s dostatečnou přesností. Poznatky a závěry uvedené v práci je možné využít pro optimální návrh hybridního spoje duralu a kompozitu., The first part of the diploma thesis with name „Hybrid adhesive bonded joints of metals and composite materials“ comprise surface pretreatment review. There is also mentioned current review of adhesives for composite and aluminium adherends. The second part of the thesis is dedicated to lap hybrid joint shear strength tests. The effects of adherend thickness, overlap lenght and surface pretreatment on shear strength were investigated. Measured parameters of hybrid joints are proved with a FE analysis with enough accuracy. Conclusions could be used for optimum design of hybrid joint with aluminium and composite adherends.

První část práce s názvem „Hybridní lepené spoje kovových a kompozitních materiálů“ obsahuje popis povrchových úprav adherendů. Rovněž je uveden aktuální ucelený přehled lepidel používaných pro spojování kompozitních a kovových adherendů. Druhá část práce je zaměřena na zkoušky smykové pevnosti hybridních spojů. Byl zkoumán vliv tloušťky adherendu, délky přeplátování a vliv přípravy povrchu na smykovou pevnost spoje. Naměřené závislosti jsou ověřeny FE analýzami s dostatečnou přesností. Poznatky a závěry uvedené v práci je možné využít pro optimální návrh hybridního spoje duralu a kompozitu., The first part of the diploma thesis with name „Hybrid adhesive bonded joints of metals and composite materials“ comprise surface pretreatment review. There is also mentioned current review of adhesives for composite and aluminium adherends. The second part of the thesis is dedicated to lap hybrid joint shear strength tests. The effects of adherend thickness, overlap lenght and surface pretreatment on shear strength were investigated. Measured parameters of hybrid joints are proved with a FE analysis with enough accuracy. Conclusions could be used for optimum design of hybrid joint with aluminium and composite adherends.

První část práce s názvem „Hybridní lepené spoje kovových a kompozitních materiálů“ obsahuje popis povrchových úprav adherendů. Rovněž je uveden aktuální ucelený přehled lepidel používaných pro spojování kompozitních a kovových adherendů. Druhá část práce je zaměřena na zkoušky smykové pevnosti hybridních spojů. Byl zkoumán vliv tloušťky adherendu, délky přeplátování a vliv přípravy povrchu na smykovou pevnost spoje. Naměřené závislosti jsou ověřeny FE analýzami s dostatečnou přesností. Poznatky a závěry uvedené v práci je možné využít pro optimální návrh hybridního spoje duralu a kompozitu., The first part of the diploma thesis with name „Hybrid adhesive bonded joints of metals and composite materials“ comprise surface pretreatment review. There is also mentioned current review of adhesives for composite and aluminium adherends. The second part of the thesis is dedicated to lap hybrid joint shear strength tests. The effects of adherend thickness, overlap lenght and surface pretreatment on shear strength were investigated. Measured parameters of hybrid joints are proved with a FE analysis with enough accuracy. Conclusions could be used for optimum design of hybrid joint with aluminium and composite adherends.

První část práce s názvem „Hybridní lepené spoje kovových a kompozitních materiálů“ obsahuje popis povrchových úprav adherendů. Rovněž je uveden aktuální ucelený přehled lepidel používaných pro spojování kompozitních a kovových adherendů. Druhá část práce je zaměřena na zkoušky smykové pevnosti hybridních spojů. Byl zkoumán vliv tloušťky adherendu, délky přeplátování a vliv přípravy povrchu na smykovou pevnost spoje. Naměřené závislosti jsou ověřeny FE analýzami s dostatečnou přesností. Poznatky a závěry uvedené v práci je možné využít pro optimální návrh hybridního spoje duralu a kompozitu., The first part of the diploma thesis with name „Hybrid adhesive bonded joints of metals and composite materials“ comprise surface pretreatment review. There is also mentioned current review of adhesives for composite and aluminium adherends. The second part of the thesis is dedicated to lap hybrid joint shear strength tests. The effects of adherend thickness, overlap lenght and surface pretreatment on shear strength were investigated. Measured parameters of hybrid joints are proved with a FE analysis with enough accuracy. Conclusions could be used for optimum design of hybrid joint with aluminium and composite adherends.

Der Fokus der vorliegenden Arbeit liegt auf endlosfaser- und langfaserverstärkten thermoplastischen Materialien. Hierfür wurde das „multilayered hybrid (MLH)“ Konzept entwickelt und auf zwei Halbzeuge, den MLH-Roving und die MLHMat angewendet. Der MLH-Roving ist ein Roving (bestehend aus Endlosfasern), der durch thermoplastische Folien in mehrere Schichten geteilt wird. Der MLH-Roving wird durch eine neuartige Spreizmethode mit anschließender thermischen Fixierung und abschließender mehrfacher Faltung hergestellt. Dadurch können verschiedene Faser-Matrix-Konfigurationen realisiert werden. Die MLH-Mat ist ein glasmattenverstärktes thermoplastisches Material, das für hohe Fasergehalte bis 45 vol. % und verschiedene Matrixpolymere, z.B. Polypropylen (PP) und Polyamide 6 (PA6) geeignet ist. Sie zeichnet sich durch eine hohe Homogenität in der Flächendichte und in der Faserrichtung aus. Durch dynamische Crashversuche mit auf MLH-Roving und MLH-Mat basierenden Probekörpern wurden das Crashverhalten und die Performance untersucht. Die Ergebnisse der Crashkörper basierend auf langfaserverstärktem Material (MLH-Mat) und endlosfaserverstärktem Material (MLH-Roving) waren vergleichbar. Die PA6-Typen zeigten eine bessere Crashperformance als PP-Typen. The present work deals with continuous fiber- and long fiber reinforced thermoplastic materials. The concept of multilayered hybrid (MLH) structure was developed and applied to the so-called MLH-roving and MLH-mat. The MLH-roving is a continuous fiber roving separated evenly into several sublayers by thermoplastic films, through the sequential processes of spreading with a newly derived equation, thermal fixing, and folding. It was aimed to satisfy the variety of material configuration as well as the variety in intermediate product. The MLH-mat is a glass mat reinforced thermoplastic (GMT)-like material that is suitable for high fiber contents up to 45 vol. % and various matrix polymers, e.g. polypropylene (PP), polyamide 6 (PA6).