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Feature extraction and emotional classification are significant roles in speech emotion recognition. It is hard to extract and select the optimal features, researchers can not be sure what the features should be. With deep learning approaches, features could be extracted by using hierarchical abstraction layers, but it requires high computational resources and a large number of data. In this article, we choose static, differential, and acceleration coefficients of log Mel-spectrogram as inputs for the deep learning model. To avoid performance degradation, we also add a skip connection with dilated convolution network integration. All representatives are fed into a self-attention mechanism with bidirectional recurrent neural networks to learn long term global features and exploit context for each time step. Finally, we investigate contrastive center loss with softmax loss as loss function to improve the accuracy of emotion recognition. For validating robustness and effectiveness, we tested the proposed method on the Emo-DB and ERC2019 datasets. Experimental results show that the performance of the proposed method is strongly comparable with the existing state-of-the-art methods on the Emo-DB and ERC2019 with 88% and 67%, respectively. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.

Nanoscale titanium nitride TiN is a metallic material that can effectively harvest sunlight over a broad spectral range and produce high local temperatures via the photothermal effect. Nanoscale indium oxide-hydroxide, In2 O3- x (OH)y , is a semiconducting material capable of photocatalyzing the hydrogenation of gaseous CO2 ; however, its wide electronic bandgap limits its absorption of photons to the ultraviolet region of the solar spectrum. Herein, the benefits of both nanomaterials in a ternary heterostructure: TiN@TiO2 @In2 O3- x (OH)y are combined. This heterostructured material synergistically couples the metallic TiN and semiconducting In2 O3- x (OH)y phases via an interfacial semiconducting TiO2 layer, allowing it to drive the light-assisted reverse water gas shift reaction at a conversion rate greatly surpassing that of its individual components or any binary combinations thereof.

We report on how to grow and control self-organized TiO2 nanotube arrays that show defined and regular gaps between individual nanotubes. For this we use electrochemical anodization of titanium in fluoride containing di-ethylene glycol (DEG) electrolytes, with variations in voltage and water content in the electrolyte. In these specific electrolytes, such nanotubes show a true spacing, i.e. nanotubes are spaced both at top and at bottom in regular intervals, this in contrast to classic nanotubes obtained in other organic electrolytes showing a close-packed organization. We identify critical parameters that define the “region of existence” i.e. under which condition tube spacing occurs as well as the intertube distance, to be the voltage and the water content. Using these findings allows to grow tubes where diameter and spacing can even be independently controlled. Keyword: Spaced TiO2 nanotubes, Anodization, TiO2 arrays

Noble metal dewetting on self-organized TiO2 nanotubes – nanoscopic design of photocatalysts towards green H2 generation., Formation and dispersion of metal nanoparticles on oxide surfaces in site-specific or even arrayed configuration are key in various technological processes such as catalysis, photonics, electrochemistry and for fabricating electrodes, sensors, memory devices, and magnetic, optical, and plasmonic platforms. A crucial aspect towards an efficient performance of many of these metal/metal oxide arrangements is a reliable fabrication approach. Since the early works on graphoepitaxy in the 70s, solid state dewetting of metal films on patterned surfaces has been much explored and regarded as a most effective tool to form defined arrays of ordered metal particles on a desired substrate. While templated dewetting has been studied in detail, particularly from a mechanistic perspective on lithographically patterned Si surfaces, the resulting outstanding potential of its applications on metal oxide semiconductors, such as titania, has received only limited attention. In this perspective we illustrate how dewetting and particularly templated dewetting can be used to fabricate highly efficient metal/TiO2 photocatalyst assemblies e.g. for green hydrogen evolution. A remarkable advantage is that the synthesis of such photocatalysts is completely based on self-ordering principles: anodic self-organized TiO2 nanotube arrays that self-align to a highest degree of hexagonal ordering are an ideal topographical substrate for a second self-ordering process, that is, templated-dewetting of sputter-deposited metal thin films. The controllable metal/semiconductor coupling delivers intriguing features and functionalities. We review concepts inherent to dewetting and particularly templated dewetting, and outline a series of effective tools that can be synergistically interlaced to reach fine control with nanoscopic precision over the resulting metal/TiO2 structures (in terms of e.g. high ordering, size distribution, site specific placement, alloy formation) to maximize their photocatalytic efficiency. These processes are easy to scale up and have a high throughput and great potential to be applied to fabricate not only (photo)catalytic materials but also a large palette of other functional nanostructured elements and devices.

Over the past ten years, self-aligned TiO2 nanotubes have attracted tremendous scientific and technological interest due to their anticipated impact on energy conversion, environment remediation and biocompatibility. In the present manuscript, we review fundamental principles that govern the self-organized initiation of anodic TiO2 nanotubes. We start with the fundamental question: Why is self-organization taking place? We illustrate the inherent key mechanistic aspects that lead to tube growth in various different morphologies, such as rippled-walled tubes, smooth tubes, stacks and bamboo-type tubes, and importantly the formation of double-walled TiO2 nanotubes versus single-walled tubes, and the drastic difference in their physical and chemical properties. We show how both double- and single-walled tube layers can be detached from the metallic substrate and exploited for the preparation of robust self-standing membranes. Finally, we show how by selecting the right growth approach to TiO2 nanotubes specific functional features can be significantly improved, e.g., an enhanced electron mobility, intrinsic doping, or crystallization into pure anatase at extremely high temperatures can be achieved. This in turn can be exploited in constructing high performance devices based on anodic TiO2 in a wide range of applications., Comment: from Nanoscale Horiz., 2016, Advance Article

In the present work we grow self-organized TiO2 nanotube arrays with a defined and controlled regular spacing between individual nanotubes. These defined intertube gaps allow one to build up hierarchical 1D-branched structures, conformally coated on the nanotube walls using a layer by layer nanoparticle TiO2 decoration of the individual tubes, i.e. having not only a high control over the TiO2 nanotube host structure but also on the harvesting layers. After optimizing the intertube spacing, we build host–guest arrays that show a drastically enhanced performance in photocatalytic H2 generation, compared to any arrangement of conventional TiO2 nanotubes or conventional TiO2 nanoparticle layers. We show this beneficial effect to be due to a combination of an increased large surface area (mainly provided by the nanoparticle layers) with a fast transport of the harvested charge within the passivated 1D nanotubes. We anticipate that this type of hierarchical structures based on TiO2 nanotubes with adjustable spacing will find even wider application, as they provide an unprecedented controllable combination of surface area and carrier transport.

This study develops a Multi-Objective Jellyfish Search (MOJS) algorithm to solve engineering problems optimally with multiple objectives. Levy flight, elite population, fixed-size archive, chaotic map, and the opposition-based jumping method are integrated into the MOJS to obtain the Pareto optimal solutions. These techniques are employed to define the motions of jellyfish in an ocean current or a swarm in multi-objective search spaces. The proposed algorithm is tested on 20 multi-objective mathematical benchmark problems, and compared with six well-known metaheuristic optimization algorithms (MOALO, MODA, MOEA/D, MOGWO, MOPSO, and NSGA-II). The results thus obtained indicate that the MOJS finds highly accurate approximations to Pareto-optimal fronts with a uniform distribution of solutions for the test functions. Three constrained structural problems (25-bar tower design, 160-bar tower design, and 942-bar tower design) of minimizing structural weight and maximum nodal deflection were solved using MOJS. The visual analytics demonstrates the merits of MOJS in solving real engineering problems with best Pareto-optimal fronts. Accordingly, the MOJS is an effective and efficient algorithm for solving multi-objective optimization problems.

Oxidation behaviour of surface nanocrystallized 321 austenitic stainless steel (SN–321ASS) and its conventional polycrystalline counterpart (CP–321ASS) in Ar + 20% O2 at 800 °C is comparatively investigated. Severe breakaway oxidation sets in for the CP–321ASS after 100 h, while the SN–321ASS shows a higher oxidation resistance. Surface nanocrystallization increases the diffusion and flux of Cr towards the oxidation front, and can consequently promote the kinetics of early oxidation and accelerate the formation of a thicker Cr-rich inner oxide layer, which aids in prohibiting the enhanced formation of Fe-rich oxides.

— Landfill leacheate is a type of wastewater which contains large amounts of nitrogen and phosphorus, therefore it needed to be treated before releasing to directly to the environment. The combination between struvite precipitation and nitrogen removal and poly-P bacteria into wastewater for landfill leachate treatment has been found to be a cost-effective practive, a viable technology in terms of environmental protection and sustainability, especially in the developing-countries. For optimum struvite crystallization from landfill leachate, the Mg:PO4 molar ratio as (1.2:1) was used, the pH of reaction was adjusted to 9 and the sample was stirred continously during 40 minutes. The supernatant sample was then added 1% nitrogen removal bacteria (Pseudomonas stutzeri D3b strain) and 1% poly-P bacteria (Kurthia sp. TGT1013L strain), 5 g glucose/L and aeration 12/24h during 3 days, ammonium concentration reduced significantly from 1076 mg/L to 1.5 mg/L and orthophosphate concentration decreased noticeably from 24.91 mg/L to 7.6 mg/L.

In the present work, we report the use of TiO2 nanotube (NT) layers with a regular intertube spacing that are decorated by Pt nanoparticles through the atomic layer deposition (ALD) of Pt. These Pt‐decorated spaced (SP) TiO2 NTs are subsequently explored for photocatalytic H2 evolution and are compared to classical close‐packed (CP) TiO2 NTs that are also decorated with various amounts of Pt by using ALD. On both tube types, by varying the number of ALD cycles, Pt nanoparticles of different sizes and areal densities are formed, uniformly decorating the inner and outer walls from tube top to tube bottom. The photocatalytic activity for H2 evolution strongly depends on the size and density of Pt nanoparticles, driven by the number of ALD cycles. We show that, for SP NTs, a much higher photocatalytic performance can be achieved with significantly smaller Pt nanoparticles (i.e. for fewer ALD cycles) compared to CP NTs.

Au and Pt do not form homogeneous bulk alloys as they are thermodynamically not miscible. However, we show that anodic TiO

In this study we investigate the performance of noble metal co-catalysts on anodic TiO2 nanotubes for the photocatalytic degradation of a model pollutant. We create the noble metal decoration (nanoparticles of Au, Pt and mixed AuPt) intrinsically and extrinsically. Intrinsic decoration is achieved using a noble metal containing titanium alloy for anodic tube growth. Extrinsic decoration is carried out by physical vapor deposition (PVD) of the same noble elements on pure titania tubes. We find the AuPt intrinsic decoration to provide a significant enhancement for the photocatalytic decomposition of the model pollutant acid orange 7 (AO7) due to a synergistic effect in the formed AuPt alloy. The AuPt alloy provides a photocatalytic activity that is higher than comparable extrinsic decoration or single element (Pt or Au) intrinsic decoration.

Regularly spaced TiO2 nanotubes were prepared by anodizing a titanium substrate in triethylene glycol electrolyte at elevated temperature. In comparison to conventional TiO2 nanotubes, spaced nanotubes possess an adjustable spacing between the individual nanotubes; this allows for controlled buildup of a hierarchical nanoparticle‐on‐nanotube structure. Here, we use this principle for layer‐by‐layer decoration of the tubes with TiO2 nanoparticles. The hierarchical structure after N doping and NH3 treatment at 450 °C shows a significant enhancement of visible‐light absorption, although it only carries a low doping concentration of nitrogen. For optimized N‐doped and particle‐decorated spaced TiO2 nanotubes, a considerable improvement in photocatalytic activity is obtained in comparison with conventional N‐doped TiO2 nanotubes or comparable N‐doped nanoparticle films. This is attributed to an enhanced visible‐light absorption through the N‐doped nanoparticle shell and a fast charge separation between the shell and the one‐dimensional nanotubular core.

In the present work we grow anodic self-organized Ta2O5 nanotube layers, which are converted by ammonolysis to Ta3 N5 nanotubes, and then are used as photoanodes for photoanalytic water splitting. We introduce a two-step anodization process that not only improves order (reduced growth defects) and overall light absorption in the nanotube layers, but also provides a significantly reduced interface charge resistance at the nitride/metal interface due to subnitride (TaNx ) formation. As a result, such nanotube anodes afford a 15-fold increase of the photocurrent compared with conventional nanotubular Ta3 N5 electrodes under AM 1.5 G simulated sunlight (100 mW cm(-2)) conditions.

Overlaid self-ordering processes: we form anodic self-organized TiO2 nanostumps and exploit them for self-ordering dewetting of Au-Ag sputtered films. This forms ordered particle configurations at tube top (crown position) or bottom (ground position). By dealloying we then form, from minimal amount of noble metal, porous Au nanoparticles that when in crown position allow for a drastically improved photocatalytic H2 production compared with nanoparticles produced by conventional dewetting processes.

We optimize the deposition of CH3NH3PbI3 perovskite into mesoporous electrodes consisting of anodic TiO2 nanotube layers. By a simple spin coating approach, complete filling of the tube scaffolds is obtained, that leads to interdigitated perovskite structures in conformal contact with the TiO2 tube counterparts. Such assemblies can be used as solid state solar cells in hole-transporting material-free configuration, i.e., the tube scaffold serves as electron collector and blocking layer, while the perovskite acts as visible light absorber and hole transporting material. We show that the complete filling of the tube scaffold with the perovskite is essential to improve the solar cell efficiency.

In the present work vertically aligned TiO2 nanorods were fabricated by anodization of Al/Ti dual layer structures. Anodization of Al leads to the formation of a porous alumina layer which is used as a template for the growth of TiO2 nanorods. We have studied the characteristics of these nanorods after annealing by high resolution TEM, showing a core–shell structure along the length of the nanorods formed from the expansion of the TiO2 nanorod into the alumina template during growth. Modification of the nanorods by spin coating of a solution of titanium isopropoxide (TIPO) in isopropanol yields enhanced photocatalytic activity up to 12 times due to the increase in surface area, light absorption volume, and the creation of a crystalline coating with an anatase-phase.

Ideally ordered anodic porous TiO2 was fabricated through the pretexturing of Ti by nanoimprinting using a metal mold with an ordered array of convexes. The shallow concaves prepared by nanoimprinting acted as initiation sites for hole development during the subsequent anodization and generated ideally hexagonally ordered porous or nanotubular TiO2. The hole interval of the ideally ordered TiO2 could be controlled by changing the pretexturing pattern. This process is a key step towards the preparation of various types of functional devices requiring ideally ordered defect-free hole or pore arrangements. Keywords: Porous TiO2, Anodization, Ti, Imprinting process, Nanotubes

The main goal of this paper is applying the cut-off projection for solving one-dimensional backward heat conduction problem in a two-slab system with a perfect contact. In a constructive manner, we commence by demonstrating the Fourier-based solution that contains the drastic growth due to the high-frequency nature of the Fourier series. Such instability leads to the need of studying the projection method where the cut-off approach is derived consistently. In the theoretical framework, the first two objectives are to construct the regularized problem and prove its stability for each noise level. Our second interest is estimating the error in $L^2$-norm. Another supplementary objective is computing the eigen-elements. All in all, this paper can be considered as a preliminary attempt to solve the heating/cooling of a two-slab composite system backward in time. Several numerical tests are provided to corroborate the qualitative analysis., 20 pages, 9 figures

We report on free-standing Ta

In the present work we report on the key factors dictating the photoelectrochemical (PEC) performance of suboxide titania (TiO

In this work, single crystalline α-Fe

In the present work we report on the key factors dictating the photo-electrochemical (PEC) performance of suboxide titania (TiOx) nanotubes. TiOx nanotubes were produced by a systematic variation of reduction heat treatments of TiO2 in Ar/H2. The properties of the TiOx tubes were investigated by electron paramagnetic resonance (EPR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), solid-state conductivity, reflectivity measurements, photocurrent spectroscopy, and photoelectrochemical hydrogen evolution. In line with earlier literature, these suboxide tubes show a drastically improved photoelectrochemical water splitting performance compared to non-reduced anatase TiO2 tubes. In this work we show that the key improvement in water splitting performance is due to the strongly improved conductivity of TiOx semimetalic tubes, reaching 13.5 KΩ/tube compared to 70 MΩ (for non-reduced anatase), and is not due to the enhanced visible light absorbance.

Separation and transfer of photogenerated charge carriers are key elements in designing photocatalysts. TiO2 in numerous geometries has been for many years the most studied photocatalyst. To overcome kinetic limitations and achieve swift charge transfer, TiO2 has been widely investigated with cocatalysts that are commonly randomly placed nanoparticles on a TiO2 surface. The poor control over cocatalyst placement in powder technology approaches can drastically hamper the photocatalytic efficiencies. Here in contrast it is shown that the site-selective placement of suitable charge-separation and charge-transfer cocatalysts on a defined TiO2 nanotube morphology can provide an enhancement of the photocatalytic reactivity. A TiO2–WO3–Au electron-transfer cascade photocatalyst is designed with nanoscale precision for H2 production on TiO2 nanotube arrays. Key aspects in the construction are the placement of the WO3/Au element at the nanotube top by site-selective deposition and self-ordered thermal dewetting of Au. In the ideal configuration, WO3 acts as a buffer layer for TiO2 conduction band electrons, allowing for their efficient transfer to the Au nanoparticles and then to a suitable environment for H2 generation, while TiO2 holes due to intrinsic upward band bending in the nanotube walls and short diffusion length undergo a facilitated transfer to the electrolyte where oxidation of hole-scavenger molecules takes place. These photocatalytic structures can achieve H2 generation rates significantly higher than any individual cocatalyst–TiO2 combination, including a classic noble metal–TiO2 configuration.

In the present work we introduce the formation of highly ordered single-walled TiO2 nanotubes based on anodizing nanoimprinted titanium substrates. In a first step, anodization on nanoimprinted substrates leads to the formation of highly ordered TiO2 nanotubes. These as-formed TiO2 nanotubes have a double-walled nature. After an optimized chemical treatment in piranha solution, the inner wall is removed and an array of single-walled TiO2 nanotubes is obtained that has a high degree of hexagonal ordering. These single walled arrangements show an enhanced photocatalytic activity for H2 evolution in comparison with classic self-ordered TiO2 nanotubes. Keywords: Nanoimprinting, Anodization, Single walled TiO2 nanotube, Photocatalysis

Among various semiconductors, TiO2 has become the most widely investigated material for photocatalysis because it is cheap, non-toxic and (photo-)electrochemically stable. TiO2 is commonly used in the form of nanoparticles, but most recently self-organized anodic TiO2 nanotube layers. Owing to their geometry and directional charge transport properties, these tubes have received considerable attention in view of fabricating highly efficient photocatalysts. However, under open-circuit conditions TiO2 is not effective in photoinducing H2 in the absence of a co-catalyst. The focus of this thesis is to understand how to improve the photocatalytic efficiency of TiO2 nanotubes by introducing a controlled metal deposition technique (Au, Ag and Pt) on a desired location of TiO2 nanotubes. By using a simple thermal dewetting process of a thin metal film (Au or Pt) or two metal films (Au/Ag and Au/W), we illustrate how to decorate TiO2 nanotubes in a highly controlled manner, with self-organized arrays of co-catalyst particles. Furthermore, different morphologies of TiO2 nanotubes are shown to have a strong impact on the resulting photocatalytic activity. First, we demonstrate a most effective way to tune the size and location of porous Au co-catalytic nanoparticles on TiO2 nanotubes. To do this, Au and Ag films are sequentially sputtered onto TiO2 nanotubes and a subsequent thermal dewetting treatment is carried out that leads to the formation of arrays of Au-Ag alloy particles. By changing the sputtering configuration, it is possible to precisely decorate the nanoparticles at either the top or bottom of nanotubes. Furthermore, a dealloying process is conducted by a selective dissolution of Ag that results in the generation of nanoporous Au particles with enhanced surface area. These structures, when compared to the conventional decoration technique, show a remarkably increased photocatalytic H2 production. Second, a photocatalyst composed of arrays of short aspect-ratio TiO2 nanotubes that possess a thin layer of WO3 and Au nanoparticles at their tops is introduced for photocatalytic H2 evolution. The synergistic advantages of this structure show significant photocatalytic enhancement. In the third section, a photocatalyst is constructed by a decoration of Pt nanoparticles suspended over the mouth of TiO2 nanotubes. To do this, a thin layer of nanofibrils formed on the top end of nanotubes acts as a substrate for Pt deposition. The final structures after thermal dewetting exhibit strongly improved photocatalytic efficiency. In the fourth part, the photocatalytic H2 evolution is further enhanced by using relatively small amounts of co-catalyst on TiO2 nanotubes by means of sputtering-dewetting. The obtained H2 evolution is similar to what classical photodeposition technique delivers though the amount of co-catalyst on dewetting sample is 100 times lower. In the last sections, different types of TiO2 tubular morphologies will be shown to have strong effects on the photogenerated H2 production. By exploiting self-induced organization on two size scales we are able to grow ordered tube layers that have a defined and controllable spacing between the individual tubes. The free intertube spacing allows the building of highly defined hierarchical structures on this nanotubular scaffold, for example, to increase the surface area. The structures can enhance the photocatalytic H2 evolution remarkably or the electrochemical capacitance, compared to hexagonally close-packed TiO2 nanotubes. Another strategy to improve the photocatalytic efficiency is to introduce single-walled TiO2 nanotubes with a “cleaner” tube wall through a selective dissolution of the inner walls of the highly ordered TiO2 nanotubes. Über die letzten Jahrzehnte hat sich TiO2 zum am weitaus meist erforschten Material für die Photokatalyse entwickelt, da es kostengünstig, nicht-toxisch und (photo-)elektrochemisch stabil ist. TiO2 wird gewöhnlich in der Form von Nanopartikeln verwendet; erst in jüngster Zeit ist es aber auch in Form von selbstorganisierten anodischen TiO2-Nanoröhren verfügbar. Aufgrund ihrer Geometrie und ihrer optischen und elektrochemischen Eigenschaften, haben diese Röhren beachtenswerte Aufmerksamkeit erregt, dies speziell in Hinblick auf die Produktion hocheffizienter Photokatalysatoren. TiO2 ist unter stromlosen Bedingungen nur bedingt in der Lage Wasserstoff ohne den Einsatz eines Co-Katalysators zu erzeugen. Diese Co-Katalysatoren sind gewöhnlich Edelmetalle wie Pt, Au oder Pd. Der Schwerpunkt dieser Dissertation liegt darauf zu untersuchen und zu verstehen, wie man die photokatalytische Effizienz von TiO2-Nanoröhren steigern kann, indem man eine kontrollierte lokale Metallabscheidung an einer gewünschten Stelle auf den TiO2-Nanoröhren erreichen kann. Hier zu wird ein einfacher thermischer Entnetzungsprozess eines dünnen Metallfilms (z.B. Au oder Pt), oder Kombinationen von Metallfilmen (Au/Ag und Au/W) verwendet, um TiO2-Nanoröhren kontrolliert mit selbstorganisierten Anordnungen von Co-Katalysatorpartikeln zu dekorieren. Außerdem wird gezeigt, dass unterschiedliche Morphologien der TiO2-Nanoröhren einen starken Einfluss auf die photokatalytische Aktivität haben. Im ersten Teil wird ein hocheffizientes Verfahren erarbeitet und beschrieben, mit dem sich die Größe und der Anlagerungsort von porösen Au co-katalytischen Nanopartikeln auf TiO2-Nanoröhren einstellen lassen. Dazu werden Au- und Ag-Filme nacheinander auf TiO2-Nanoröhren durch ein PVD Verfahren (gesputtert) aufgebracht; der darauffolgende thermische Entnetzungsschritt führt zu der Bildung von Bereichen, die aus Au-Ag Legierungspartikeln bestehen. Durch Änderung der Sputterparameter ist es möglich, die Nanopartikel präzise entweder am oberen, oder am unteren Ende der Nanoröhren aufzubringen. Durch einen Entlegierungsprozess, d.h. die selektive Auflösung von Ag lassen sich weiterhin nanoporöse Au-Partikel herstellen, die durch eine größerere Oberfläche zu einer weiteren Steigerung der photokatalytischen Effizienzführen. Generell führen diese durch Entnetzung hergestellten Strukturen im Vergleich zu konventionellen Dekorationstechniken zu einer signifikanten Steigerung der photokatalytischen H2-Produktion. Im zweiten Teil wird ein mehrlagiger Photokatalysator vorgestellt der aus TiO2-Nanoröhren und einer dünnen Schicht aus WO3- sowie einer Au-Nanopartikel Dekoration besteht. Die synergistischen Effekte dieser Struktur (Ladungstrennung und Reaktion) führen zu einer weiteren signifikanten Verbesserung der photokatalytischen Eigenschaften. Im dritten Abschnitt wird ein Photokatalysator durch Dekoration mit "schwebenden" Pt-Nanopartikeln hergestellt. Hierzu wird eine dünne Schicht aus Nanofibrillen auf die Öffnung der TiO2-Nanoröhren aufgebracht – diese Fibrillen, dienen als Substrat für die Pt-Ablagerung. Die nach der thermischen Entnetzung resultierenden Strukturen ergeben eine weitere, sehr stark verbesserte photokatalytische Effizienz. Im vierten Teil wird die photokatalytische H2-Bildung weiter verstärkt, indem kleine Mengen eines Co-Katalysators auf TiO2-Nanoröhren durch Sputter-Entnetzung verwendet werden. Die erreichte H2-Entwicklung ist vergleichbar mit der durch klassische Photoabscheidungstechniken erzielten Rate, obwohl die Menge des verwendeten Co-Katalysators auf den entnetzten Proben um den Faktor 100 geringer ist. In den letzten Abschnitten wird anhand unterschiedlicher Arten von TiO2-Morphologien gezeigt, dass diese einen starken Effekt auf die photogenerierte H2-Entwicklung hat. Indem man sich den selbstinduzierten Ordnungseffekt über zwei Größenordnungen zu Nutze macht, können geordnete Nanoröhren-Schichten gewachsen werden, die einen definierten und kontrollierbaren Abstand zwischen den einzelnen Röhren haben. Der freie Bereich zwischen den Röhren ermöglicht es hochgradig geordnete hierarchische Strukturen auf diesem Nanoröhren-Gerüst zu errichten, um so zum Beispiel die Oberfläche zu vergrößern. Diese Anordnung kann die photokatalytische H2-Entwicklung, oder die elektrochemische Speicherfähigkeit im Vergleich zu hexagonal dicht gepackten TiO2-Nanoröhren beträchtlich erhöhen. Ein weiterer Effekt um die photokatalytische Effizienz zu erhöhen, ist die Verwendung von einwandigen TiO2-Nanoröhren, die durch ihre Kontaminationsfreiheit einen wesentlich effizienteren Ladungstransport erlauben. Diese Befunde werden in den jeweiligen Kapiteln mit dem entsprechenden Stand der Kenntnisse konfrontiert und mechanistische Modellvorstellungen erarbeitet. Speziell werden die spezifischen Vorteile von Entnetzungstechniken zur Schaffung effizienter TiO2-Nanoröhren basierter Photokatalysatoren dargestellt und diskutiert.

The present review gives an overview of the highlights of more than 10 years of research on synthesis and applications of ordered oxide structures (nanotube layers, hexagonal pore arrangements) that are formed by self-organizing anodization of metals. In particular we address the questions after the critical factors that lead to the spectacular self-ordering during the growth of anodic oxides that finally yield morphologies such as highly ordered TiO2 nanotube arrays and similar structures. Why are tubes and pores formed—what are the key parameters controlling these processes? Keywords: TiO2 nanotube, Self-organization, Anodization, Key parameters

Text To Speech (TTS) using Hidden Markov Model (HMM) has become popular in recent years. However, because most of such systems were implemented on personal computers (PCs), it is difficult to offer these systems to real applications. In this paper, we present a hardware implementation of TTS based on DSP architecture, which is applicable for real applications. By optimizing hardware architecture, the quality of the DSP-based synthesized speech is nearly identical to that synthesized on PCs.

In the present work we introduce a technique to form a photocatalyst, based on Pt nanoparticles suspended over the mouth of TiO2 nanotubes. These structures are obtained by the decoration of the top end of highly ordered TiO2 nanotubes with a web of TiO2 nanofibrils, followed by sputter deposition of a minimum amount of Pt. A subsequent thermal dewetting step forms 3-6 nm-sized Pt nanoparticles along the nanofibrils. These structures, when compared to conventional Pt decoration techniques of TiO2 nanotubes, show a strongly enhanced photocatalytic H2 evolution efficiency.

Formation and dispersion of metal nanoparticles on oxide surfaces in site-specific or even arrayed configuration are key in various technological processes such as catalysis, photonics, electrochemistry and for fabricating electrodes, sensors, memory devices, and magnetic, optical, and plasmonic platforms. A crucial aspect towards an efficient performance of many of these metal/metal oxide arrangements is a reliable fabrication approach. Since the early works on graphoepitaxy in the 70s, solid state dewetting of metal films on patterned surfaces has been much explored and regarded as a most effective tool to form defined arrays of ordered metal particles on a desired substrate. While templated dewetting has been studied in detail, particularly from a mechanistic perspective on lithographically patterned Si surfaces, the resulting outstanding potential of its applications on metal oxide semiconductors, such as titania, has received only limited attention. In this perspective we illustrate how dewetting and particularly templated dewetting can be used to fabricate highly efficient metal/TiO2 photocatalyst assemblies e.g. for green hydrogen evolution. A remarkable advantage is that the synthesis of such photocatalysts is completely based on self-ordering principles: anodic self-organized TiO2 nanotube arrays that self-align to a highest degree of hexagonal ordering are an ideal topographical substrate for a second self-ordering process, that is, templated-dewetting of sputter-deposited metal thin films. The controllable metal/semiconductor coupling delivers intriguing features and functionalities. We review concepts inherent to dewetting and particularly templated dewetting, and outline a series of effective tools that can be synergistically interlaced to reach fine control with nanoscopic precision over the resulting metal/TiO2 structures (in terms of e.g. high ordering, size distribution, site specific placement, alloy formation) to maximize their photocatalytic efficiency. These processes are easy to scale up and have a high throughput and great potential to be applied to fabricate not only (photo)catalytic materials but also a large palette of other functional nanostructured elements and devices.

Object tracking is a common task in computer vision, an essential part of various vision-based applications. After several years of development, object tracking in video is still a challenging problem because of various visual properties of objects and surrounding environment. Particle filter is a well-known technique among common approaches, has been proven its effectiveness in dealing with difficulties in object tracking. In this research, we develop an particle filter-based object tracking method using color distributions as features. Moreover, recently embedded systems have become popular because of the rising demand of portable, low-power devices. Therefore, we also try to deploy the particle filter-based object tracker in an embedded system. Because particle filter is a high-complexity algorithm, we will utilize computing power of embedded systems by implementing a parallel version of the algorithm. The experimental results show that parallelization can increase performance of particle filter when deployed in embedded systems.