bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECTS OF COOLING RATE AND POURING TEMPERATURE ON MICROSTRUCTURE AND FRACTURE TOUGHNESS OF THE INDUCTION MELTED Nb-16Si-22Ti-2Hf-2Cr-2Al ALLOY
Authors: JIA LINA , GE JINGRU , SHA JIANGBO , ZHANG HU
Published: August 2010

The effects of cooling rate and pouring temperature on microstructure and fracture toughness of the induction melted Nb -16 Si -22 Ti -2 Hf -2 Cr -2 Al alloy were extensively investigated. The results revealed that with the decrease of cooling rates, the Nbss exhibits the dendrite-like morphology, the primary Nb 5 Si 3 blocks form and the mean sizes of Nb 5 Si 3, Nbss and eutectic colonies increase; with the increase of the pouring temperature, the microstructure shows columnar structure and the particles of Nb 5 Si 3 or Nbss become long and thin. Pouring temperature and cooling rate had little influence on the volume fractions of Nbss and Nb 5 Si 3 and their compositions. The Nb 3 Si phase eliminated in the case of high pouring temperature and slow cooling rate. Fracture toughness of the alloy prepared by induction melting is on the order of 13.7 to 15.3 MPa·m1/2. Similar fracture toughness value of each slab may be ascribes to the same volume fraction of the Nbss .
CHARACTERISTICS OF DLC FILMS INCORPORATED HMDS BY RF PECVD
Authors: KIM TAE GYU , OH JEONG SEOK , YOON HAN KI , KIM HYE SUNG
Published: August 2010

Silicon incorporated diamond-like carbon films up to 6.2 at. % (DLC- Si ) were deposited onto a high speed steel samples by using a radio frequency plasma-enhanced chemical vapor deposition method. The influence of silicon doping on chemical composition, bonding structure, hardness, and adhesion of DLC films was investigated. Hexamethyldisilane ( HMDS ) gas was used as a silicon source with Ar carrier gas ranging from 0 to 15 sccm. Also, the mixtures of methane ( CH 4) and Ar gases were used as precursor gases. The addition of silicon into the DLC film was found to lead an increase of bonding ratio ( sp 3/ sp 2), hardness and critical adhesion
WETTING BEHAVIOR OF GRAPHITE BY Ti-78Cu AND Ti-50Cu ALLOYS
Authors: MAO YANGWU , LI SHUJIE , PAN YANG
Published: August 2010

The wetting behavior of Ti -78 Cu and Ti -50 Cu alloys on graphite has been investigated by the sessile drop method in high vacuum. The contact angle of Ti - Cu alloys on graphite is influenced by the wetting temperature. The wetting of Ti -78 Cu and Ti -50 Cu alloys on graphite is chemical wetting. The microstructure and composition of the interfacial zone of the wetting samples were analyzed by SEM, EDX and XRD. Microstructure and phase analysis reveals that inter-diffusions and interfacial reactions take place in the wetting process. The reaction products include TiC and the intermetallic compounds composed of Ti and Cu . The inter-diffusions and interfacial reactions contribute to the interfacial bonding.
EFFECT OF POWDER STRUCTURE ON MICROSTRUCTURE OF THE OXIDE SCALES FORMED ON COLD-SPRAYED NiCrAlY COATINGS
Authors: ZHANG QIANG , LI CHANG-JIU , YANG GUAN-JUN , LI CHENG-XIN
Published: August 2010

Commercially available, gas-atomized NiCrAlY powder was milled in Ar atmosphere to prepare nanostructured powder. The NiCrAlY coatings in the conventional microstructure and the nanostructure were subsequently deposited by cold spraying using the as-atomized powder and milled powder. The influence of the powder structure on the microstructure of cold-sprayed coating was investigated. It was found that dense NiCrAlY coatings can be cold-sprayed using two powders. Isothermal oxidation was performed at 1000°C in air for up to 500 hours. The results showed that the growth rate of the oxide on the nanostructured NiCrAlY coating was almost comparable to that of the conventional NiCrAlY coating. A uniform Al 2 O 3 layer was formed on the surface of the nanostructured coating surface. Moreover, a dual-subscale oxide was formed on conventional coating composing of an inner Al 2 O 3 oxide and an external mixed oxide.
ANALYSIS OF PNEUMATIC FINE PARTICLE PEENING PROCESS BY USING A HIGH-SPEED-CAMERA
Authors: ITO TATSUYA , KIKUCHI SHOICHI , HIROTA YO , SASAGO ATSUSHI , KOMOTORI JUN
Published: August 2010

In this study, the peening behavior of shot particles in a fine particle peening (FPP) process such as velocity and impact angles were analyzed by using a high-speed-camera. Results showed that the velocity of shot particles depended on a peening pressure; the higher the peening pressure, the higher the particle velocity. The particle velocity measured in this study was approximately 120 m/s; this was much higher than that of the conventional shot peening (SP) process. This was because the air resistance of shot particles in the FPP process was higher than that of shot particles in the SP process. In order to discuss the surface modification effect of the FPP process, commercial-grade pure iron treated by the FPP process was characterized by micro-Vickers hardness tester and scanning electron microscope (SEM). Thickness of hardened layer treated with higher peening pressure was much higher than that of the lower pressure treated one. The unique microstructure with stratification patterns, which was harder than that of the other part, was observed near the specimen surface. The reason for the microstructural changes by the FPP treatment was discussed based on the kinetic energy of shot particles.
STUDY ON THE ATOMIC OXYGEN EROSION RESISTANCE OF POLY-Γ-AMINOPROPYLSILOXANE/METHYLPHENYLSILICONEHYBRID FILMS
Authors: ZHAO WEI , LIU HUICONG , LI WEIPING , ZHU LIQUN
Published: August 2010

To improve the atomic oxygen (AO) erosion resistance of the polyimide (PI) maretials, cage-shaped poly-γ-aminopropylsiloxane (NPOSS) was synthesized from γ-aminopropyltriethoxysilane through the control of hydrolytic condensation conditions. Poly-γ-aminopropylsiloxane/methylphenylsilicone (NPOSS/MPS) hybrid films were prepared on PI samples. The physics and chemistry properties of the hybrid films surface was analyzed after exposure to AO flux in a ground AO simulated facility. The results showed that: NPOSS gathered to the spherical shapes and uniformly distributed in films, SiO 2 layer formed on the films surface after explorer and prevented the further AO erosion, mass loss and erosion rate of samples was dramatically decreased, AO erosion resistance had been increased and it could be further enhanced with the increase of NPOSS content.
THE EFFECT OF a-SiN:H AND a-Si:H SURFACE ROUGHNESS OF TFT BY PE/RACVD
Authors: KIM JIN-EUI , RYU SANG-HYUK , CHOI SIE-YOUNG
Published: August 2010

This paper describes the influence of surface roughness on the mobility of a - SiN : H and a - Si : H . For the a - SiN : H deposited by PECVD, the roughness was 0.832 nm. The a - SiN : H layer composed of (PECVD 150 nm + RACVD 100 nm) had better characteristic of roughness than the a - SiN : H layer (PECVD 250 nm) by 47%. The roughness of the a - Si : H (PECVD 200 nm) deposited on the a - SiN : H layer was 0.803 nm. And the roughness of a - Si : H (RACVD 100 nm + PECVD 100 nm) deposited the a - SiN : H layer is better than the a - Si : H (PECVD 200 nm) by 27%. After depositing the layer of a - SiN : H and a - Si : H at the best condition obtained by the experiments the mobility was measured. The a - Si : H is deposited by the PECVD, the obtained mobility was 0.218 cm 2/V ·sec. The a - Si : H was deposited by the PE/RACVD, the obtained mobility was 0.248 cm 2/V ·sec. The mobility is enhanced by 10% by depositing the a - Si : H layer using the PE/RACVD method.
SURFACE FATIGUE CRACK GROWTH BEHAVIOR FROM SMALL NOTCH IN WASPALOY
Authors: SUH CHANG-MIN , KIM SEON-GAB
Published: August 2010

We investigated the surface fatigue crack behaviors including initial surface crack appearances depend on three artificial notch lengths applied with the axle load level of the maximum load, 1,103 MPa and minimum load 55.3 MPa at the stress ratio of 0.05. This load level is the F100 engine's maximum operation condition of Waspaloy. The initial cracking site in depth is started from multi-origin. The effectiveness of crack growth rate by ductile striation space measurement on the fractured surface is confirmed by the working load and the stress intensity factor range. The surface cracks of Waspaloy at room temperature in air follow the ΔK vs da/dN and db/dN relation, even though the crack length initiated early in notch size 1 mm and initiated very late in notch size 4 mm. And the ΔK vs da/dN and db/dN relation have similar slope at 3 kinds of notches.
EFFECTS OF MICROSTRUCTURE ON TENSILE STRENGTH OF ELECTROFORMED COPPER
Authors: LIAO QIANG , ZHU LI QUN , LIU HUI CONG , LI WEI PING
Published: August 2010

The electroformed copper with various microstructures are fabricated under conditions of non-agitation and ultrasonic agitation according to the demand of the electroforming micro components. The microstructure of the electroformed copper layer was observed by optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The preferred orientations of the layer were characterized by X-ray diffraction (XRD). The tensile strength was evaluated with a tensile tester. It was found that the copper layer preferentially grow along the (220) plane during the electroforming process, and the ultrasound-assisted technique led to a highly preferred orientation. The effects of ultrasonic vibration increased the chance of nucleation and controlled the excessive growth of copper grains during electroforming process. The microstructure of copper electroformed under condition of ultrasonic agitation is made up of regular columnar crystals, and its tensile strength increased by 40% in comparison with that of under condition of stationary state.
MICROSTRUCTURE AND TRIBOBOGICAL PERFORMANCE OF TI1-XALXN FILMS FABRICATED BY REACTIVE MAGNETRON SPUTTERING
Authors: ZHANG YE , LI CHANG SHENG , LI XUE CHAO
Published: August 2010

Ti - Al - N Films with large scale chemical composition were fabricated on stainless steels by changing the relative substrate positions to targets using double-targeted reactive magnetron sputtering technique in one same process. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the composition and microstructure of films. Tribological performance of films was test at room temperature in air without any lubricant. Chemical composition of films altered with substrate positions from Ti 0.82 A 10.18 N to Ti 0.12 Al 0.88 N . XRD results indicated that before heat treatment sputtered films were amorphous, but different phases such as TiN , AlN and TiAlN were formed in films with different composition after heat treatment of 700° C × 1 h . Friction and wear tests indicated that films with x = 0.57, 0.65 hold the best tribological performance of Ti - Al - N films system because of the formation of hard phase TiAlN and different wear mechanism.
THE INVESTIGATION OF THE ELASTIC-PLASTIC BEHAVIOR USING THE PROPERTY GRADIENT OF THE INTERFACIAL REGION IN FIBER REINFORCED MMC
Authors: KANG J. W. , KWON O. H. , YUN Y. S.
Published: August 2010

In this study, the interfacial perpendicular crack behavior and stress state of the unidirectional fiber reinforced Metal Matrix Composites (MMCs) are investigated by using FEA under the transverse loading. The fiber assumed as isotropic linear elastic SiC and the matrix is assumed as isotropic elastic-plastic Ti . The fiber/matrix interface is modeled as multi thin layer with different linear material properties. The behavior of perpendicular crack to the interface according to the change of the interface characteristics and thickness are evaluated.
EFFECTS OF Dy ON THE MICROSTRUCTURE AND SPALLATION FAILURE OF THE ALUMINA SCALES GROWN ON NiAl
Authors: GUO HONGBO , WANG XIAOYAN , GONG SHENGKAI
Published: August 2010

NiAl has attracted increasing attentions because of its promising potential as protective coating materials for high temperature oxidation resistance. In this paper, Dysprosium ( Dy ) doped NiAl alloys were produced by arc melting. Cyclic oxidation of the alloys was carried out at 1200°C. The effects of Dy as a reactive element on the microstructure and failure of alumina scales on NiAl were investigated. For the melted alloy, Dy was mainly precipitated along the grain boundary and some within the grains in the form of DyNi 2 Al 3 phase. Compared to Al 2 O 3 scale formed on the undoped NiAl alloy, the microstructure of the scale was greatly changed and the ridge-like Al 2 O 3 scale became less distinct on Dy -doped NiAl . The equi-axed alumina scale grew on NiAl , whereas the columnar alumina developed on Dy doped NiAl . The Dy dopant prevented the oxide scale from rumpling and the formation of cavities beneath the oxide scale. Due to this, the oxide scale adhesion was significantly improved. For Dy -doped NiAl , the scale failure mostly occurred surrounding the oxide protrusions where were rich in Dy .
INTERDIFFUSION STUDY IN THE Nb-Si BINARY SYSTEM
Authors: YANG JUNYING , WEI HAIXIA , ZHOU CHUNGEN
Published: August 2010

Diffusion experiments on Nb / Si couples were conducted at 1050°C, 1150°C, 1250°C for annealing for 8h, 10h and 15h. Two intermediate phases, NbSi 2 and Nb 5 Si 3, were found to develop and grow as parallel layers in the Nb / Si couples, according to the parabolic rate law. The diffusion properties of the different phases were evaluated in terms of alternative theories, which were demonstrated to be equivalent algebraically but complementary because they are expressed in terms of different experimental variables.
THE EFFECT OF TITANIA SOL IN PHOSPHATE ELECTROLYTE ON MICROARC OXIDATION COATINGS ON ALUMINUM ALLOY
Authors: TANG MING QI , LI WEI PING , LIU HUI CONG , ZHU LI QUN
Published: August 2010

Black and gray microarc oxidation coatings have been obtained on 2A70 Aluminum alloy in phosphate electrolyte with and without titania sol, respectively. The growth process of the microarc oxidation coating in the electrolyte with titania sol was investigated. The coating was characterized by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray. The coating thickness was measured by eddy current thickness meter. The results show that the titania sol increase the growth rate of microarc oxidation coating. In both cases the composition of coatings contain Al and O , and are mainly composed of γ- Al 2 O 3 and AlPO 4. Compared with the gray coating, large amount of Ti is found on the surface of black coating. The titania sol added in the electrolyte results in Ti in the coating, in the form of TiO and Al 2 TiO 5.
PHOTOCATALYTIC ACTIVITY OF NITROGEN AND FLUORINE CO-DOPED TITANIUM DIOXIDE PREPARED USING OF VARIOUS PH SOLUTIONS
Authors: KATOH MASAHIRO , IMAYAMA AKIHIRO , MORI NARISUKE , HORIKAWA TOSHIHIDE , TOMIDA TAHEI
Published: August 2010

Introducing different atoms into TiO 2 crystal lattice is a famous method to improve photocatalytic activity of TiO 2 under visible-light irradiation. In this paper, Nitrogen ( N ) and fluorine ( F ) co -doped TiO 2 powders were prepared by mixing TiCl 3 solutions with ammonium fluoride ( NH 4 F ). In preparation, we used NH 3- H 2 O solution for adjustment of pH values (pH 2, 7, and 9) of mixed solution. X-ray diffraction (XRD) indicated N , F - TiO 2 powders prepared at pH7 and pH9 contained only anatase phase, but the powders prepared at pH2 contained both anatase and rutile phase. The result of XRD also indicated N , F - TiO 2 powders prepared at pH7 had the smallest crystallite size. We measured photocatalytic activity of prepared N , F - TiO 2 powders by the decomposition of methylene blue. N , F - TiO 2 powder prepared at pH7 and pH9 showed same high photocatalytic activity under ultraviolet light irradiation (peak wave length = 352 nm). Furthermore, under green light LED irradiation (wave length = 525 nm), a sample prepared at pH7 decomposed methylene blue more quickly than any other samples. As the result, N , F - TiO 2 prepared at pH7 had the best catalytic activity under both UV-light and visible light in the all of N , F - TiO 2 prepared and reference TiO 2 photocatalyst (ST-01 produced by Ishihara Co. Ltd).
CATALYTIC CONVERSION OF ETHYLENE TO PROPYLENE OVER MCM-41
Authors: KATO YUHKI , NISHIOKA YUKINORI , WADA TAKAHIRO , NAKAGAWA KEIZO , SOTOWA KEN-ICHIRO , SUGIYAMA SHIGERU
Published: August 2010

The conversion of ethylene to propylene on MCM-41 and that doped with Ni , the latter of which was prepared using various procedures, is described. Undoped MCM-41 showed no activity for the conversion of ethylene to propylene. The catalytic activity for the conversion of ethylene to propylene on Ni -doped MCM-41 was strongly dependent on the preparation procedure of the catalyst and the reaction conditions. It was found that template ion-exchange procedure using organic base was suitable for the preparation of Ni -doped MCM-41, while the catalysts thus prepared was suffered from carbon deposition during the conversion of ethylene. However the introduction of water into the reactant gas and the slower introduction of the reactant gas into the catalysts resulted in the enhancement of the catalytic activity and stability.
RAMAN SCATTERING OF HEXAPOD-LIKE PBS NANOMATERIALS
Authors: YIN PENGGANG , ZHANG RUI , ZHANG YAHUI , GUO LIN
Published: August 2010

A hexapod-like lead sulphide (PbS) nanostructure with six symmetric arms were investigated by Raman spectrum. The first order longitudinal optical phonons (1–LO) and second order longitudinal optical phonons (2–LO) vibration modes locate at 205 cm-1 and 456 cm-1, respectively. The transverse optical ( TO ) mode and combination modes (LO+TO and TO+TA) exist in the low frequency area. In air circumstance, the surface of PbS nanomaterials can be easily damaged by laser with power ~1.2 mW. The vacuum circumstance can avoid from photodegradation efficiently. Therefore, both irradiation by enough power laser and oxygen condition are necessary conditions for the photodegradation of PbS nanomaterials.
CLASSIFICATION-ORIENTED LOCALLY LINEAR EMBEDDING
Authors: HSIEH PI-FUEI , YANG MING-HUA , GU YI-JAY , LIANG YU-CHENG
Published: August 2010

The locally linear embedding (LLE) algorithm is hypothetically able to find a lower dimensional space than a linear method for preserving a data manifold originally embedded in a high dimensional space. However, uneven sampling over the manifold in real-world data ultimately causes LLE to suffer from the disconnected-neighborhood problem. Consequently, the final dimensionality required for the data manifold is multiplied by the number of disjoint groups in the complete data representation. In addition, LLE as an unsupervised method is unable to suppress between-class connections. This means that samples from different classes are mixed during reconstruction. This study presents CLLE, a classification-oriented LLE method that uses class label information from training samples to guide unsupervised LLE. The criterion for neighbor selection is redesigned using class-conditional likelihood as well as Euclidean distance. This algorithm largely eliminates fractured classes and lowers the incidence of connections between classes. Also, a reconnection technique is proposed as a supporting method for ensuring a fully connected neighborhood graph, so that CLLE is able to extract the fewest features. Experiments with simulated and real data show that CLLE exceeds the performance of linear methods. Comparable classification performance can be achieved by CLLE using fewer features. In comparison with LLE, CLLE demonstrates a higher aptitude for and flexibility towards classification.
A NONLINEAR TRANSFORM BASED THREE-DIMENSIONAL SHAPE RECOVERY FROM IMAGE FOCUS
Authors: KHAN ASIFULLAH , MAHMOOD MUHAMMAD TARIQ , CHOI TAE-SUN
Published: August 2010

The use of intelligent and sophisticated approaches in the domain of computer vision and pattern recognition is consistently increasing. This paper introduces a novel machine learning based approach for Shape From Focus (SFF), where the in-focus pixels are selected from a sequence of images. In contrast to computing focus values directly in spatial or transform domain, the proposed method first nonlinearly transforms the input space into feature space and then computes the focus value by transforming the data into eigenspace. First, the nonlinear transformation is performed by using kernel function and then Principal Component Analysis (PCA) is applied. This idea is also supported by the fact that out-of-focus is analogous to blurring and is a nonlinear phenomenon. An initial depth map is computed by maximizing the focus measure. To further refine the 3D shape, bilateral filter is applied. The proposed method is experimented using synthetic and real image sequences. The results demonstrate the effectiveness and the robustness of the new method.
STOCHASTIC OFFLINE PROGRAMMING
Authors: MALITSKY YURI , SELLMANN MEINOLF
Published: August 2010

We propose a framework which we call stochastic off-line programming (SOP). The idea is to embed the development of combinatorial algorithms in an off-line learning environment which helps the developer choose heuristic advisors that guide the search for satisfying or optimal solutions. In particular, we consider the case where the developer has several heuristic advisors available. Rather than selecting a single heuristic, we propose that one of the heuristics is chosen randomly whenever the heuristic guidance is sought. The task of the SOP is to learn favorable instance-specific distributions of the heuristic advisors in order to boost the average-case performance of the resulting combinatorial algorithm. Applying this methodology to a typical optimization problem, we show that substantial improvements can in fact be achieved when we perform learning in an instances specific manner.
SEARCH-BASED TESTING OF MULTI-AGENT MANUFACTURING SYSTEMS FOR DEADLOCKS BASED ON MODELS
Authors: MANI NARIMAN , GAROUSI VAHID , FAR BEHROUZ H.
Published: August 2010

Multi-Agent Systems (MAS) have been extensively used in the automation of manufacturing systems. However, similar to other distributed systems, autonomous agents' interaction in the Automated Manufacturing Systems (AMS) can potentially lead to runtime behavioral failures including deadlocks. Deadlocks can cause major financial consequences by negatively affecting the production cost and time. Although the deadlock monitoring techniques can prevent the harmful effects of deadlocks at runtime, but the testing techniques are able to detect design faults during the system design and development stages that can potentially lead to deadlock at runtime. In this paper, we propose a search based testing technique for deadlock detection in multi-agent manufacturing system based on the MAS design models. MAS design artifacts, constructed using Multi-agent Software Engineering (MaSE) methodology, are used for extracting test requirements for deadlock detection. As the case study, the proposed technique is applied to a multi-agent manufacturing system for verifying its effectiveness. A MAS simulator has been developed to simulate multi-agent manufacturing system behavior under test and the proposed testing technique has been implemented in a test requirement generator tool which creates test requirements based on the given design models.
LEARNING FOR DYNAMIC SUBSUMPTION
Authors: HAMADI YOUSSEF , JABBOUR SAÏD , SAÏS LAKHDAR
Published: August 2010

This paper presents an original dynamic subsumption technique for Boolean CNF formulae. It exploits simple and sufficient conditions to detect, during conflict analysis, clauses from the formula that can be reduced by subsumption. During the learnt clause derivation, and at each step of the associated resolution process, checks for backward subsumption between the current resolvent and clauses from the original formula are efficiently performed. The resulting method allows the dynamic removal of literals from the original clauses. Experimental results show that the integration of our dynamic subsumption technique within the state-of-the-art SAT solvers Minisat and Rsat particularly benefits to crafted problems.
APPROXIMATING GREEN'S FUNCTIONS ON ℙ1 POSITIVE CHARACTERISTIC
Authors: PARK DAESHIK
Published: August 2010

Fix a finite K-symmetric set [Formula: see text] and a K-symmetric probability vector [Formula: see text]. Let 𝔇v be a finite union of balls [Formula: see text] for some ah ∈ Kv and some [Formula: see text], where the balls 𝔅(ah, rh) are disjoint from 𝔛. Put 𝔈v := 𝔇v ∩ ℙ1(Kv). Then there exists a positive integer Nv such that for each sufficiently large integer N divisible by Nv, there are a number Rv, with [Formula: see text], and an [Formula: see text]-function fv(z) ∈ Kv(z) of degree N whose zeros form a "well-distributed" sequence in 𝔈v such that [Formula: see text] is a disjoint union of balls centered at the zeros of fv(z) and for all z ∉ 𝔇v, [Formula: see text]
TURING PATTERNS IN GENERAL REACTION-DIFFUSION SYSTEMS OF BRUSSELATOR TYPE
Authors: GHERGU MARIUS , RĂDULESCU VICENŢIU
Published: August 2010

We study the reaction-diffusion system [Formula: see text] Here Ω is a smooth and bounded domain in ℝN (N ≥ 1), a, b, d1, d2 > 0 and f ∈ C1[0, ∞) is a non-decreasing function. The case f(u) = u2 corresponds to the standard Brusselator model for autocatalytic oscillating chemical reactions. Our analysis points out the crucial role played by the nonlinearity f in the existence of Turing patterns. More precisely, we show that if f has a sublinear growth then no Turing patterns occur, while if f has a superlinear growth then existence of such patterns is strongly related to the inter-dependence between the parameters a, b and the diffusion coefficients d1, d2.
PROBING BELL'S INEQUALITY WITH CLASSICAL SYSTEMS
Authors: FERRY D. K.
Published: August 2010

From the early days of quantum mechanics, there has been a discussion on the concept of reality, exemplified by the EPR paradox. To many, the idea of the paradox and the possibility of local hidden variables was dismissed by the Bell inequality. Yet, there remains considerable evidence that this inequality can be violated even by classical systems, so that experiments showing quantum behavior and the violation of the inequality must be questioned. Here, we demonstrate that classical optical polarization experiments can be shown to violate the Bell inequality. Hence, such experiments cannot be used to distinguish between classical and quantum theories.
IMPROVING EXTRACTION OF IMPULSE RESPONSE FUNCTIONS USING STATIONARY WAVELET SHRINKAGE IN TERAHERTZ REFLECTION IMAGING
Authors: CHEN YANG , SUN YIWEN , PICKWELL-MACPHERSON EMMA
Published: August 2010

In terahertz imaging, deconvolution is often performed to extract the impulse response function of the sample of interest. The inverse filtering process amplifies the noise and in this paper we investigate how we can suppress the noise without over-smoothing and losing useful information. We propose a robust deconvolution process utilizing stationary wavelet shrinkage theory which shows significant improvement over other popular methods such as double Gaussian filtering. We demonstrate the success of our approach on experimental data of water and isopropanol.
ON COMPARING TWO STRUCTURED RNA MULTIPLE ALIGNMENTS
Authors: PATEL VANDANABEN , WANG JASON T. L. , SETIA SHEFALI , VERMA ANURAG , WARDEN CHARLES D. , ZHANG KAIZHONG
Published: August 2010

We present a method, called BlockMatch, for aligning two blocks, where a block is an RNA multiple sequence alignment with the consensus secondary structure of the alignment in Stockholm format. The method employs a quadratic-time dynamic programming algorithm for aligning columns and column pairs of the multiple alignments in the blocks. Unlike many other tools that can perform pairwise alignment of either single sequences or structures only, BlockMatch takes into account the characteristics of all the sequences in the blocks along with their consensus structures during the alignment process, thus being able to achieve a high-quality alignment result. We apply BlockMatch to phylogeny reconstruction on a set of 5S rRNA sequences taken from fifteen bacteria species. Experimental results showed that the phylogenetic tree generated by our method is more accurate than the tree constructed based on the widely used ClustalW tool. The BlockMatch algorithm is implemented into a web server, accessible at . A jar file of the program is also available for download from the web server.
TOWARD ANALYZING THE IMPACT OF ADVERTISEMENT BILLBOARDS ON SOCCER TELECAST VIEWERS
Authors: DAS SUPRIO , SURAL SHAMIK , MAJUMDAR ARUN K.
Published: August 2010

Important soccer tournaments like the World Cup and the European Cup are broadcast to billions of people across the world. Therefore, advertising through billboards surrounding the playing arena in a soccer match is very attractive for promoting the brand image of a company. Analysis of strength and weakness of such an advertisement is helpful for the sponsors since a lot of money is spent on it and due to its potential impact on a large number of viewers at the same time. In this paper, we present a two-stage fuzzy system for analyzing the visual impact of advertisement billboards in soccer telecasts. In the first stage, visual impact of each shot is evaluated. Two parameters, namely, size and duration, of the billboards are considered in the fuzzy rules. After the shot level analysis, results are combined in the second stage to derive an overall visual impact. In both the stages, parameters of the fuzzy set membership functions are tuned using the Particle Swarm Optimization algorithm. The results have been compared against a user survey.
IGNORANCE-BASED FUZZY CLUSTERING ALGORITHM
Authors: JURIO ARANZAZU , PAGOLA MIGUEL , BUSTINCE HUMBERTO
Published: August 2010

In this work an ignorance-based fuzzy clustering algorithm is presented. The algorithm is based on the entropy-based clustering algorithm proposed by Yao et al.[14]In our proposal, we calculate the total ignorance instead of using the entropy at each data point to select the cluster centers. The experimental results show that the ignorance-based clustering improves the data classification made by the EFC in image segmentation.
FIXATION OF CARBON NANOTUBE WITHIN MESOPOROUS TITANIA PARTICLES
Authors: KIM SUNG SOO , KIM JIN HOE , YOON JEONG AH , JIN MINGSHI , PARK JUNG-NAM , SHON JEONG KUK , LEE YOON YUN , BOO JIN-HYO , KIM JI MAN
Published: August 2010

Carbon nanotube (CNT) and mesoporous TiO 2 composite (CNT/meso- TiO 2) was synthesized by a nanocasting method using CNT-implanted mesoporous silica material as the template. The CNT was successfully incorporated within a mesoporous TiO 2 particle, and the CNT/meso- TiO 2 composite obtained exhibits a high surface area and well-established mesoporosity. Moreover, the composite material exhibits much lower electric resistance than those of mesoporous TiO 2 only and physical mixture of CNT and mesoporous TiO 2, which probably due to the large interface area and strong junction between the implanted CNT and TiO 2 framework in the composite.
THE EFFECT OF ANNEALING ATMOSPHERES ON STRUCTURAL, ELECTRICAL AND OPTICAL PROPERTIES OF THE ATO FILMS PREPARED BY RF MAGNETRON SPUTTERING
Authors: LEE SUNG UK , HONG BYUNGYOU , BOO JIN-HYO
Published: August 2010

Antimony-doped tin oxide ( SnO 2: Sb , ATO) films were deposited on 7059 corning glass substrate by radio frequency magnetron sputtering method using a commercial ceramic target with a mixture of SnO 2 and Sb (6 wt.%) for application to transparent electrodes. The ATO film was deposited at working pressure of 5 mTorr and RF power of 175 W without substrate heating. The thickness of the deposited ATO films was about 150 nm using a surface profiler (alpha-step). The films were annealed at temperatures ranging from 300 to 600°C in step of 100°C using RTA equipment in vacuum and oxygen atmosphere, respectively. We investigated the effects of the post-annealing atmospheres on structural, electrical and optical properties of the ATO films. The results show that the increase of the annealing temperature improved the crystallinity of the ATO films, increased the grain size and improved electrical and optical properties, regardless of annealing atmospheres. The resistivity of the ATO films decreased significantly with higher annealing temperatures in vacuum and oxygen atmosphere. In the visible range from 400 to 800 nm, the optical transmittance of the ATO films increased over 90% at higher annealing temperature.
Frequency Metrology with Optical Lattice Clocks
Authors: Hong Feng-Lei , Katori Hidetoshi
Published: August 2010

The precision measurement of time and frequency is of great interest for a wide range of applications, including fundamental science and technologies that support broadband communication networks and the navigation with global positioning systems (GPSs). The development of optical frequency measurement based on frequency combs has revolutionized the field of frequency metrology, especially research on optical frequency standards. The proposal and realization of the optical lattice clock have further stimulated studies in the field of optical frequency metrology. Optical carrier transfer using optical fibers has been used to disseminate optical frequencies or compare two optical clocks without degrading their stability and accuracy. In this paper, we review the state-of-the-art development of optical frequency combs, standards, and transfer techniques with emphasis on optical lattice clocks. We address recent results achieved at the University of Tokyo and the National Metrology Institute of Japan in respect of frequency metrology with Sr and Yb optical lattice clocks.
Properties of InGaN Films Grown by Reactive Sputtering
Authors: Guo Qixin , Kusunoki Yuta , Ding Yaliu , Tanaka Tooru , Nishio Mitsuhiro
Published: August 2010

InGaN films were grown on (0001) sapphire substrates by reactive sputtering in nitrogen plasma, using a GaAs wafer and a pure indium target. It was found that In, Ga, As, and N atoms adsorb on the substrate and react with each other to form an InGaNAs film at a low substrate temperature. With increasing the substrate temperature to 550 °C, the arsenic atoms in the grown layer are completely desorbed, forming the InGaN film. X-ray diffraction analysis showed that the lattice constant for the c-axis obtained from the (0002) diffraction peak of the InGaN films decreases linearly with an increase in Ga composition, obeying Vegard's law. Optical analysis revealed that the InGaN films have a direct band gap structure as InN and GaN and the band gap energy of the InGaN films can be tailored by varying the area ratio of the GaAs wafer to the indium target.
Contribution of Carbon to Growth of Boron-Containing Cluster in Heavily Boron-Doped Silicon
Authors: Itokawa Hiroshi , Ohta Akio , Ikeda Mitsuhisa , Mizushima Ichiro , Miyazaki Seiichi
Published: August 2010

It is well known that substitutional carbon (C) atoms can capture excess self-interstitial silicon (Si) atoms and suppress the diffusion of ion-implanted interstitial-type dopants, such as boron (B), in Si. In the case of B concentrations as high as ∼1×1021 cm-3, the B activation ratio in Si decreases with C incorporation. Thus, many studies on stable B-containing clusters and/or precipitates in heavily doped Si with a C additive have thus far been conducted. However, the impact of the C incorporation on the activation and clustering of B atoms in Si is yet to be researched. In this work, the chemical bonding features of B and C atoms in heavily B-doped Si with different C contents after high-temperature annealing were characterized systematically by high-resolution X-ray photoelectron spectroscopy (XPS). It was found that the C incorporation enhances B-clustering at B concentrations higher than ∼1×1021 cm-3 after 1050 °C spike annealing. In addition, the formation of C–B bonds with accompanying B-clustering was confirmed by photoemission measurement using a hard X-ray. As a result, the intrinsic B-diffusion was observed to be markedly suppressed by the C incorporation under thermodynamic equilibrium annealing at 1000 °C.
Photovoltaic and Spectral Properties of Conjugated Polymer Poly(3-octylthiophene) Doped with Various Acceptor Materials
Authors: Lee Tsung-Hsien , Chen Wei-Hsin , Su Mu-Ting , Lai Tzay-Shing , Lee Wei
Published: August 2010

We propose a novel approach for enhancement of efficiency of polymer-based photovoltaic devices by means of a low-molar-mass liquid crystal as a dopent. The active layers of the photovoltaic cells are primarily fabricated from the conjugated polymer poly(3-octylthiophene) as well as various acceptor substances including single-wall carbon nanotubes, buckminsterfullerene and the nematic liquid crystal E7 for comparison. The current–voltage characteristics are measured in dark and under green light illumination at wavelength of 514.5 nm. The power conversion efficiency for the active layer doped with E7 is the best among all cells in the simplest monolayer cell structure. Owing to the superior miscibility and orientational order of the nematic liquid crystal, E7 molecules may have promoted a composite film with fewer defects and locally helped the macromolecules align more orderly and consequently improved the charge-carrier transport, leading to the higher photocurrent and power conversion efficiency.
Real-Time Monitoring of Millimeter-Tall Vertically Aligned Single-Walled Carbon Nanotube Growth on Combinatorial Catalyst Library
Authors: Hasegawa Kei , Noda Suguru
Published: August 2010

The rapid growth dynamics of millimeter-tall, vertically aligned single-walled carbon nanotubes (VA-SWCNTs) was studied using a simple real-time monitoring method. By using combinatorial catalyst libraries, VA-SWCNT growth curves under various catalyst conditions were obtained in a single chemical vapor deposition (CVD) run. VA-SWCNTs grew at constant or gradually decreasing rates for several minutes and then abruptly ceased growth. This unusual behavior of the growth occurred under wide ranges of catalyst and CVD conditions.
Enhancement and Stabilization of Pulsed Streamer Discharge in Water by Adding Carbon Nanotubes
Authors: Imasaka Kiminobu , Sun Wei , Tomita Hironari , Kato Yuki , Khaled Usama , Suehiro Junya
Published: August 2010

Effects of adding single-walled carbon nanotubes (SWCNTs) on pulsed streamer discharge characteristics in water were investigated. Adding a small amount of SWCNTs to deionized water generated stable streamer discharge. The number of streamer onset positions on a high-voltage wire electrode and the length of the streamer channels dramatically increased, in which the particles are larger than SWCNTs. The emission of the streamers became intense, and their propagation velocity increased rapidly in the SWCNT suspension. The SWCNTs' effects on the streamer discharge are discussed on the basis of a numerical calculation of the electric field around an SWCNT and a graphite powder particle. The electric field strength at the tip of a vertically standing SWCNT was strongly enhanced. The results suggested that adding SWCNTs to water could enhance and stabilize streamer discharge onset and its propagation.
Accumulation and Decay Characteristics of Exoelectron Sources at MgO Protective Layer Surface in Alternating-Current Plasma Display Panels
Authors: Yoshino Kyohei , Nagatomi Takaharu , Morita Yukihiro , Oue Toshiyasu , Kosugi Naoki , Nishitani Mikihiko , Kitagawa Masatoshi , Takai Yoshizo
Published: August 2010

The accumulation and decay characteristics of exoelectron sources at a MgO protective layer surface in alternating-current plasma display panels (AC-PDPs) were investigated. The positively charged MgO surface provides a larger number of exoelectrons than the negatively charged surface, indicating that electrons trapped in shallow carrier traps coexist with trapped holes, and exoelectrons are emitted through Auger and/or photoionization processes after their recombination. The exoelectron sources are accumulated by sustain discharges and always decay. The half-life of the decay of the exoelectron sources is relatively long, of the order of a few tens of ms, confirming that the exoelectron emission property at the address discharge in a certain television (TV) field is strongly affected by sustain firings in the previous two TV fields or more. The effects of such a long-term decay of the exoelectron sources should be taken into consideration when designing the driving waveforms of AC-PDPs.
Etching Magnetic Tunnel Junction with Metal Etchers
Authors: Kinoshita Keizo , Utsumi Hiroaki , Suemitsu Katsumi , Hada Hiromitsu , Sugibayashi Tadahiko
Published: August 2010

Etch performances of inductory-coupled plasma (ICP) metal etchers with several gas systems are examined under constant ion energy condition to evaluate extendibility to the 300 mm wafer magnetic tunnel junction (MTJ) etch process. The ICP-Ar sputter etch affects little on magnetic properties, and shows about the same magnetoresistive (MR) ratio with conventional Ar ion milling. Major issue is the electrical short by redeposition. The etch uniformity over the wafer and precise etch end-point detection are important. The Cl2 addition to the ICP-Ar etch plasma shows serious pattern deformation and degradation of loop offset (H
off). Methanol (Me-OH) etch shows slightly lower MR-ratio due to material degradation. However, better H
off is observed probably due to the ion protection effect by thin carbon layer over the etched surface. Dilution of Me-OH with Ar improves MR ratio. Ar/Me-OH and ICP-Ar etch processes would be the candidate for 300 mm process at present.
Analysis of Plasma Wall Reactions Using Virtual Optical Emission Spectrometry Signal during Dielectric Etching
Authors: Kuboi Nobuyuki , Fukasawa Masanaga , Kawashima Atsushi , Oshima Keiji , Nagahata Kazunori , Tatsumi Tetsuya
Published: August 2010

We confirmed that the SiN etch rate uniformity depends on not only the spatial distribution of the H radical density which is strongly affected by loss rates on chamber walls but also time-dependence of the loss rates. We developed a numerical simulation method for plasma–wall reactions to predict both the spatial distribution of the H radical density and the optical emission intensity observed from the view port during dielectric etching. In comparing experimental optical emission spectrometer (OES) data with virtual OES (our simulation), loss probabilities of the H radical on the Si, SiO2, and C–F polymer surfaces were estimated to be 0.5, 0.06, and 0.1, respectively. We successfully predicted SiN etch rates under various wall conditions by considering the spatial distribution and time-dependence of the loss probabilities.
Epitaxial Orientation of β-FeSi2 on 3C-SiC/Si(111)
Authors: Akiyama Kensuke , Kaneko Satoru , Kadowaki Teiko , Hirabayashi Yasuo
Published: August 2010

(100)-oriented β-FeSi2 films were expitaxially grown on a SiC (3C-SiC)-buffered Si(111) substrate by cosputtering iron and silicon. The full width at half maximum (FWHM) of the rocking curve of the β-FeSi2 800 diffraction peaks was 0.37° for the films deposited at 750 °C, which is the same as that for epitaxial β-FeSi2 films on the Si(111) substrate. These epitaxial films had a triple-domain structure. The photoluminescence spectrum from β-FeSi2 was observed at 10 K, and roughly had four luminescence bands.
Effect of N2 Gas Flow Ratio in Plasma-Enhanced Chemical Vapor Deposition with SiH4–NH3–N2–He Gas Mixture on Stress Relaxation of Silicon Nitride
Authors: Murata Tatsunori , Miyagawa Yoshihiro , Matsuura Masazumi , Asai Koyu , Miyatake Hiroshi
Published: August 2010

The effects of N2 gas flow ratios in silicon nitride deposition with SiH4–NH3–N2–He gas mixtures at a temperature of 275 °C on stress relaxation have been investigated. We have demonstrated that film stress can be controlled in the range from -692 MPa (compression) to 170 MPa (tension) by increasing N2 gas flow ratio. From the evaluation of the composition ratio of N/Si, film density, and bonding structure, the relationships between film stress and these properties are investigated. The amount of nitrogen incorporated into the film as N–H bonds increased with increasing N2 flow ratio, resulting in a higher composition ratio of N/Si. At a higher N2 gas flow ratio, excess N2 gas in the plasma may disturb the ion bombardment of ionized species on the film surface, resulting in a decrease in the film density. The higher N2 gas flow ratio leads to the generation of a Si–N bonding structure with a larger bond angle at the nitrogen atom site due to bond-strain relaxation, leading to a higher frequency of Si–N stretching vibration. Therefore, a nitrogen-richer SiN film with many N–H bonds and a lower film density exhibits bonding structures with a lower bond strain, leading to the relief of film stress.
Oxygen Gas Barrier Properties of Hydrogenated Amorphous Carbon Thin Films Deposited with a Pulse-Biased Inductively Coupled Plasma Chemical Vapor Deposition Method
Authors: Baek Sang-min , Shirafuji Tatsuru , Cho Sung-pyo , Saito Nagahiro , Takai Osamu
Published: August 2010

Hydrogenated amorphous carbon (a-C:H) films have been deposited on poly(ethylene terephthalate) (PET) films with an pulse-biased inductively coupled plasma chemical vapor deposition method using CH4 and C2H2 gases. We have investigated the effects of the pulse-bias frequency on the oxygen transmission rate (OTR) of the a-C:H-coated PET sample, and discussed relationship between the OTR characteristics and the structure of the films based on the results of Raman and infrared absorption spectroscopy. In case of CH4 plasmas, the OTR of the sample has been reduced down to 1.12 cm3/(m2·day·atm) by increasing the bias-frequency to 2 kHz, and the structure of the a-C:H films has been modified from polymer-like to tetrahedral one. In case of C2H2 plasmas, the OTR of the samples has been 1.18 cm3/(m2·day·atm) with the lower bias frequency of 0.5 kHz, and has not shown strong dependence on the pulse-bias frequency. This has been explained by the fact that the films prepared with C2H2 plasma can be modified to tetrahedral structures by applying the bias with the lower frequency.
Synthesis of Carbon Nanoflakes by Radio-Frequency Sputtering and Their Field Emission Characteristics
Authors: Shih Wen-Ching , Jeng Jian-Min , Tsou Chi-Wei , Lo Jyi-Tsong , Chen Huang-Chin , Lin I-Nan
Published: August 2010

The growth, structure and field emission properties of the two-dimensional carbon nanoflakes (CNFs) produced by radio-frequency (RF) sputtering without any catalyst or special substrate treatment have been investigated. The effects of deposition parameters (such as deposition time, sputtering gas composition, substrate temperature and RF power) on the structure and properties of the CNFs were also studied. Possible growth mechanism of the CNFs has been discussed with time evolution of surface microstructure. These films contain nanosized diamonds and allotropic phases (i-carbons and graphites) embedded in amorphous carbon films. The electron field emission (EFE) process can be turned on at E
0=2.8 V/µm, achieving an EFE current density of J
e = 1 mA/cm2 at a 5 V/µm applied field. The low turn-on field of 2.8 V/µm for electron field emission suggests that the CNFs could be used as a potential edge emitter.
Color Stability and High Efficiency of White Phosphorescent Organic Light-Emitting Diodes with Suitable Position of Phosphorescent Red Emitter
Authors: Park Jung Sun , Seo Ji Hoon , Koo Ja Ryong , Seo Bo Min , Lee Kum Hee , Park Jeong Keun , Yoon Seung Soo , Kim Young Kwan
Published: August 2010

We have demonstrated high-efficiency phosphorescent white organic light-emitting diodes (PHWOLEDs) using iridium(III) bis[(4,6-difluorophenyl)-pyridinato-N,C
2] picolinate and iridium(III) bis[1-phenyl(quinolinato-N,C
2')]acetylacetonate doped in N,N '-dicarbazolyl-3,5-benzene as a single-host system. As the position of the doped red emitter changed from near the anode to the cathode, the PHWOLED exhibited reduced exciton loss and greater color stability. The optimized PHWOLED exhibited a peak external quantum efficiency of 13.49%, a power efficiency of 20.59 lm/W, a current efficiency of 26.20 cd/A, and Commission Internationale de l'Eclairage coordinates of (0.37, 0.35). The red emitter near the cathode includes efficient triplet energy confinement in the emitting layers.