bluuebunny/crossref_metadata_2025 huggingface dataset:
Networks, Group Identity and Poverty
Authors: Truyts Tom
Published: January 2012

Résumé Dans les dernières décennies, l’analyse économique des réseaux et groupes sociaux s’est rapidement développée. Cet article traite de quelques mécanismes par lesquels les réseaux et groupes sociaux affectent la pauvreté et les inégalités sociales et économiques. Les réseaux sociaux et les groupes peuvent à la fois maintenir les gens dans la pauvreté ou être des outils pour l’émancipation des pauvres. Une politique efficace pour réduire la pauvreté devrait tenir compte de ces mécanismes, ou même les employer pour le plus grand bien.
Inégalité et pauvreté chez les personnes âgées : une projection à long terme
Authors: Dekkers Gijs , Desmet Raphaël
Published: January 2012

Résumé Cette contribution fournit une évaluation à long terme de l’adéquation du premier pilier de pension en Belgique. Suite à la participation accrue des femmes au marché du travail et à la revalorisation de certains minima sociaux, le taux de risque de pauvreté des pensionnés devrait décroître fortement dans les prochaines décennies. Une analyse plus approfondie concernant l’impact de revalorisations récentes de minima sociaux met en lumière le rôle crucial de la revalorisation de la Grapa sur l’amélioration des indicateurs d’adéquation des pensions. À l’inverse, cette analyse n’escompte aucun effet positif sur ces mêmes indicateurs suite à la revalorisation du droit minimum par année de carrière.
Des critères d'application de la théorie des facilités essentielles dans le cadre de la politique de concurrence européenne
Authors: Marty Frédéric , Pillot Julien
Published: January 2012

Résumé La notion de facilité essentielle recouvre l’ensemble des installations (matérielles ou non), détenues par une entreprise dominante, qui s’avèrent non aisément reproductibles et dont l’accès est indispensable aux tiers pour exercer leur activité sur le marché. Initialement utilisée en matière d’accès aux infrastructures de réseaux, les autorités de la concurrence européennes l’ont peu à peu étendue aux droits de propriété intellectuelle (DPI) au travers des décisions Magill (1995), IMS (2004) et surtout Microsoft (2007). Ce recours, dans le dernier cas cité, a suscité une polémique entre les autorités de la concurrence européennes et américaines tenant aux risques de décisions infondées et à leurs conséquences potentielles sur les incitations à innover et à investir des firmes. Il s’agira dans le cadre de cet article de s’attacher aux critères d’activation de la théorie des facilités essentielles. Ceci nous conduira à nous interroger sur la nature des concepts juridiques caractérisés par un fort degré d’ambiguïté et de plasticité. Ces derniers peuvent à la fois être vecteurs d’insécurité juridique (manque de lisibilité de la règle et manque de prévisibilité quant aux résultats de son application) mais aussi être porteurs de potentialité d’action stratégique ou de marges de discrétion pour les acteurs de la réglementation.
Pleuronectes platessa, a ghost fish in the Mediterranean Sea?
Authors: Lleonart Jordi , Farrugio Henri
Published: January 2012

European plaice Pleuronectes platessa often appears in ichthyological check lists for the Mediterranean Sea, as well as in regional field guides and even in some official national landings statistics. However we have not found a single ichthyologist or fisheries biologist who has actually observed this fish in the Mediterranean. The ichthyologic sources available, from classical antiquity to recent times, were checked in order to follow the track of the citations (i.e. true field observations or citations of former authors), and to try to detect misidentifications, if any. Few of these citations appear to be reliable and misidentifications with flounder Platichthys flesus are frequent. Recent scientific trawl surveys have not reported any observations of plaice. The statistics provided by France to the FAO with positive catches of P. platessa appear to be misidentifications of P. flesus. Plaice may have been present in some areas of the Mediterranean in the past, as a result of climatic changes related to the ice age. However, the species seems to be absent now. We propose that this species should be removed from the ichthyofauna records of the Mediterranean.
Experimental Evaluation of Grinding Mechanism in Micro Depth of Cut
Authors: Yamada Takazo , Yuge Hiroki , Lee Hwa Soo , Miura Kohichi
Published: January 2012

In order to make clear the grinding mechanism in micro depth of cut, micro grinding test with a diamond indenter having defined geometrical shape is carried out. As the experimental results, it is clarified that the ratio of two force components and the swell-out residual ratio in micro grinding have different tendencies from ordinary grinding area. Based on these results, it can be estimated that the grinding mechanism in micro grinding differs from the ordinary grinding mechanism.
Bearing Surfaces with Sapphire for Total Hip-Joint Replacement
Authors: Rozenberg Oleg A. , Turmanidze Raul , Sokhan Sergei V. , Voznyy Vyacheslav V.
Published: January 2012

In the article are shown the results of tests on friction and wear behavior of friction couples sapphire against sapphire or tetragonal dioxide of zirconium. Tribological characteristics of tetragonal dioxide of zirconium (Y,Ce,Hf)-TZP in pair with a counter body from sapphire are essentially better than characteristics of the couple sapphire/sapphire (friction force lower 1,3 times, linear wear 1,5 times).
A Model of Forming the Surface Layer of Ceramic Parts Based on Silicon Nitride in the Grinding Process
Authors: Kuzin V
Published: January 2012

The results of the study of the influence of the grinding regimes and the characteristics of the diamond tool on the strength and the surface layer of the ceramic parts based on silicon nitride are presented in this article. The revealed regularities of the surface layer and defect formation have been used to develop a model of the forming of the surface layer of the ceramic parts. The proposed model will increase operational resource resistance of the ceramic parts by 10–25%.
Pulsed Processes when Cutting Heat-Resistant Alloys
Authors: Kozlov Arkadiy , Deryabin M.
Published: January 2012

In this paper, the pulsed processes of machining by cutting heat-resistant alloys are consid-ered. It is proved that such processes can exclude unwanted loss of the steadiness of elastoplastic deformations in the chip formation zone. As a result the accuracy of machining, the quality of ma-chined surface and the resistance to wear of the cutting tool increase. Finally, some methods of in-tensification of pulsed processes when cutting difficult to machine materials have been suggested.
An Investigation on Improved Theoretical Modelling for Surface Generation in Nanometric Cutting
Authors: Sawangsri Worapong , Cheng K.
Published: January 2012

In this paper, the existing models micro/nanometric cutting mechanics and physics are critically reviewed including ductile mode cutting models, cutting forces models and surface generation models. A comparison study is carried out each aspect of the three groups of models being considered. The combination and formulation of these models into one integrated model is to be performed in order to accrue benefits arising from the advantages of each model. This paper concludes with further discussion on the concepts for the improved modelling and possible development of new models.
Theory and Practice of Technology for Machining Non-Rigid Smooth Shafts
Authors: Maximov Yury
Published: January 2012

In modern machine-building the problem of creating highly-efficient technological mechanical machining processes, taking into account the energy and resources-saving and ecological requirements is one of the paramount importance. Throughout the whole period of machine-building technology development there were great difficulties owing to the problems of machining parts with low rigidity and high demands on quality. At creating the technological processes of similar parts’ machining, as at creating any technological process, it is necessary to provide realization of the principle of combining technical, economic and organization assignments. But unlike usual technological processes, in this case it is much more difficult to meet all these requirements.
Reactive Atom Plasma for Rapid Figure Correction of Optical Surfaces
Authors: Castelli Marco , Jourdain Renaud , Morantz Paul , Shore Paul
Published: January 2012

Nanometre-scale figuring technique at atmospheric pressure for large optical surfaces is a high profile research topic which attracts numerous competing state-of-the-art technologies. In this context, a dry chemical process, called Reactive Atom Plasma (RAP), was developed as a prospectively ideal alternative to CNC polishing or Ion Beam Figuring. The RAP process combines high material removal rates, nanometre level repeatability and absence of subsurface damage. A RAP figuring facility with metre-scale processing capability, Helios 1200, was then established in the Precision Engineering Centre at Cranfield University. The work presented in this paper is carried out using Helios 1200 and demonstrates the rapid figuring capability of the RAP process. First experimental tests of figure correction are performed on fused silica substrates over 100 mm diameter areas. A 500 nm deep spherical hollow shape is etched onto the central region of 200x200 mm polished surfaces. The test is carried out twice for reproducibility purposes. After two iterative steps, a residual figure error of ~16 nm rms is achieved. Subsequently, the process is scaled up to 140 mm diameter areas and two tests are carried out. First, the developed algorithm for 500 nm deep spherical hollow test is confirmed. Residual deviation over processed area is ~18 nm rms after three iterations. Finally, a surface characterised by random topography (79 nm rms initial figure error) is smoothed down to ~ 16 nm rms within three iteration steps. All results presented in this paper are achieved by means of an in-house developed tool-path algorithm. This can be described as a staggered meander-type tool motion path specifically designed to reduce heat transfer and consequently temperature gradient on the surface. Contiguously, classical de-convolution methods are adapted to non-linear etching rates for the derivation of the surface scanning speed maps. The figuring procedure is carried out iteratively. It is noteworthy that iteration steps never exceed ~7 minutes mean processing time.
Optimizing Heat Transfer Rate in an Internally Cooled Cutting Tool: FE- Based Design Analysis and Experimental Study
Authors: Che Ghani Saiful , Cheng Kai , Sun Xi Zhi , Bateman Richard
Published: January 2012

The machining process produces high local temperatures in the tool-chip and tool-workpiece contact areas, normally lead to negative influence on the machine performance. This paper presents a study on optimizing the internal micro channel structure of a tungsten carbide (WC) cutting tool in order to enhance heat transfer rate when applied with internal cooling fluid. Inspired by water jet impingement theory, the efficiency and heat transfer rate of single phase micro channel mainly depends on the fluid velocity as well as temperature difference between the cooling fluid and hot surface. In this study three variables, i.e. the space between channel and internal wall of the insert, channel diameter and fluid temperature, have been tested with design of experiments (DoE) to study the significance of the factors and interactions between them on cutting temperature. A 3-D finite element (FE) model has been developed to observe the effects of these factors on heat transfer rate. The simulation results show the most dominant factor to affect the cutting temperature is the temperature of the cooling fluid followed by the space between channel and tool insert internal wall.
Error Size of the Helix (screw) Groove by Grinding
Authors: Jandečka Karel
Published: January 2012

This paper presents further results in addressing this issue and builds upon the results obtained within the project GACR No. 101/07/0751 (research was supported by Czech Grant Agency), and the findings and information obtained from grant project GACR No. 101/05/2562. The problems are oriented to the production and sharpening of rotary tools, especially because all the know-how is owned by foreign companies. The main chapter is devoted to "Solution of the dependance of undercutting of the helical grooves on the grinding wheel diameter, its thickness and depth of the cut" at zero thickness of the grinding wheel. This method is an original analytical method for calculating the undercutting and is a part of the theoretical studies of the grinding helix slot. Then follows a passage, which defines the actual width of the spiral groove profiles at various grinding wheels. The present article summarizes only part of a broad range of problems in the area.
Simulation Study of Cutting Forces, Stresses and Temperature during Nanometric Cutting of Single Crystal Silicon
Authors: Goel Saurav , Luo Xi Chun , Reuben R.L. , Bin Rashid Waleed , Sun Ji Ning
Published: January 2012

Wear of diamond tool has always been a limiting factor in ductile regime machining of large size silicon components. In order to understand the tool wear phenomena, it is non-trivial to know the process outputs especially cutting forces, stresses and temperature during nanometric turning. In this paper, a realistic potential energy function has been deployed through molecular dynamic (MD) simulation, to simulate the process outputs of single diamond turning operation against single crystal silicon. The simulation result suggests that wear mechanism of diamond tool is fundamentally governed by these process parameters and thus critical.
Monitoring of Vibrations in the Technology of AWJ
Authors: Krenický Tibor , Rimár Miroslav
Published: January 2012

Vibrations of cutting head act as co-factor causing striation of machined work-piece surface, deteriorating its surface quality. In this paper, measurement and evaluation of vibrations generated during the AWJ machining is performed using specialized diagnostic systems. In conclusion, means to minimize influence of cutting-head vibrations on the machined work-piece surface quality are discussed.
Analysis of Micro-Pin Manufacturing Using Inverse Slab Electrical Discharge Milling (ISEDM) Process
Authors: Gil Ruben , Sánchez J.A. , Ortega N. , Plaza S. , Izquierdo B. , Pombo I.
Published: January 2012

Abstract. This paper analyses the technological capabilities of a novel rotary (EDM) electrical discharge machining process for the manufacturing of high aspect ratio cylindrical micro-components. The process is called Inverse Electrical Discharge Grinding (ISEDM). An experimental analysis has been carried out on high speed steel (tool steel Vanadis 23), using a conventional EDM machine and graphite electrode. The effect of pulse off-time, work piece final diameter and machining length on material removal rate, electrode wear ratio, radial accuracy and surface roughness has been quantified. From the study, optimum strategies that involve the use of different EDM regimes for achieving the optimum requirements can be defined. Micro-pins of 0.3 mm diameter with aspect ratio as high as 100:1 have been successfully manufactured.
The Investigation of Thrust Force of Printed Circuit Board Drilling
Authors: Zheng Li Juan , Wang Cheng Yong , Qu Yun Peng , Yang Li Peng , Song Yue Xian
Published: January 2012

This work is focused on the investigation of the influence of the materials of PCB, feed rate, spindle speed and tool wear on thrust force when drilling PCB using 0.3 mm diameter cemented tungsten carbide drills. The results indicate that thrust force increases with feed rate and drill wear, but decreases with spindle speed firstly and then increases with it within the cutting range tested. Thrust force caused by the copper foil is much larger than that caused by the epoxy glass fiber cloth when feed rate is low. However, the difference between them decreases as feed rate increases. The thickness of nail head increases with thrust force. The accuracy of hole location increases with thrust force firstly but decreases afterward. The influence of thrust force on hole wall roughness is not obvious.
New Laser Machine Tools for Processing Carbon Fibre Reinforced Plastic (CFRP)
Authors: French Paul W , Wolynski Alexander , Naeem Mo , Sharp Martin C
Published: January 2012

The interest in laser material processing of Carbon Fibre Reinforced Plastic (CFRP) over the past few years has increased, especially in the aerospace industry. A number of different laser groups around the world are investigating different laser sources for the express reason of developing a laser material processing centre for machining CFRP for the aerospace and automotive industry. This paper reports on the work of two such groups, in the UK and Germany, who are using fibre laser technology and a diode pumped solid state laser system. The initial results from the two studies are reported and show that these two very different laser systems offer processing capability with respect to machining CFRP.
Advanced Fiber Laser Perforation Technology for Thermoplastic Pre-Preg Material
Authors: Kutin A.A , Turkin M.V.
Published: January 2012

A study concerning the application of fiber laser to perforate thermoplastic pre-pregs is presented. An IPG fiber laser was used to drill arrays of holes in PEKK carbon-fiber composite pre-preg material. Perforated holes were of the order of 100μm. The effects of laser perforation process parameters including the number of pulses on the geometry of the resultant holes and the thermal damage to the matrix and fibres have been investigated. Dimensional analysis and experimental results have been used to construct the laser perforation process model. Keywords: Laser perforation; Fibre laser; Process modelling; Polymer matrix composites.
Laser Assisted Micro Grinding of High Strength Materials
Authors: Chang Wen Long , Luo Xi Chun , Zhao Qi Ling , Sun Ji Ning , Zhao Yi
Published: January 2012

This paper aims to develop a laser assisted grinding process capable of manufacturing micro features in high strength materials. A diode laser with wavelength 808 nm was set on a precision grinding machine. Micro grooves were fabricated on high strength materials including silicon nitride and aluminium oxide by using the laser assisted grinding process, i.e. laser pre-heat workpiece flowed by micro grinding. The experimental results showed that the laser assisted grinding process resulted in deeper grooves due to thermal expansion of workpiece materials caused by laser heating. However, the machined surface roughness was more consistently better than that obtained using solo grinding process and applying coolant. No subsurface damage was observed in the SEM images of cross sections of the machined workpieces when laser assisted grinding process was used.
Tool Coatings with the Effect of Adaptation to Cutting Conditions
Authors: Migranov Mars , Migranov Regina
Published: January 2012

The objective of the present work is to study tribological properties of multilayered wear resistant coatings on the cutting tools. Two types of coatings (TiAl)N were studied: normal monolayer coating and improved coating. The tests were conducted with cooling, and without it. During high speed machining an intensive tribo-oxidation of tool surface occurs. Formation of aluminum oxide films on the surface of cutting tool significantly changes the heat flow and heat dissipation into the chip. Conditions of the chips formation (chip thickness ratio and the shear plane angle) and the coefficient of friction on the rake face of the cutting tool have been measured during the cutting process. The results demonstrated significant improvement of tribological parameters for the cutting tools with filtered coatings.
The Influence of Machining Condition Forming Multilayer Coatings for Cutting Tools
Authors: Tabakov V.P.
Published: January 2012

The study has shown a correlation between the machining conditions and peculiarities of damage occurring to wear-resistant coatings in the process of cutting. The study has made it possible to formulate requirements for wear-resistant coatings and the principle of forming multilayer coatings depending on machining conditions. The article presents study results illustrating the efficiency of cutting tools with multilayer coatings.
High Speed Turning of Ti-6Al-4V Alloy with Straight Cemented Carbide and PVD Coated Carbide Tools
Authors: Li You Sheng , Deng J. X. , Ebbrell Steve , Morgan Michael N. , Ren X.J.
Published: January 2012

This work comparatively studied the performances of straight cemented carbide tools and PVD coated carbide tools in high speed dry turning of Ti-6Al-4V alloy. Systematic machining tests have been performed and the tool life data were analysed using multiple linear regression method to establish extended Taylor tool life models. The wear mechanisms for both tools have been investigated in detail through SEM observation and X-ray energy dispersive microanalysis (EDS).
Analysis of New Designs of Rotors with Variable Geometry Parameters and Results of their Tests
Authors: Turmanidze Raul , Mosashvili Teimuraz
Published: January 2012

In this paper the dynamics of updating designs of rotors with variable parameters developed during last fifteen years at the Georgian Technical University are presented. All the positive and negative appearances of each design have been analyzed and advantages of the last design based on the principles of ropes and hydro-system have been validated.
Crystal Growth Suppression by N-Doping into Chalcogenide for Application to Next-Generation Phase Change Memory
Authors: Yin You , Hosaka Sumio
Published: January 2012

In this work, we investigate the effect of the N-doping on microstructure and electrical properties of chalcogenide Ge2Sb2Te5(GST) films for application to multilevel-storage phase change memory (PCM). Crystal size can be markedly reduced from 16 nm to 5 nm by N-doping into GST. The crystal growth suppression is believed to be controlled by distributed fine nitride particles. The resistivity of N-GST as a function of annealing temperature exhibits a gradual change due to the crystal growth suppression. The characteristics imply that N-GST is suitable for application to multilevel-storage PCM as the next-generation nonvolatile memory.
Influence of Phase-Change Materials and Additional Layer on Performance of Lateral Phase-Change Memories
Authors: Yin You , Hosaka Sumio
Published: January 2012

Performance of lateral phase change memories (LPCMs) is investigated by both electrical characterization and finite element analysis. Ge2Sb2Te5 lateral PCMs (GST-LPCMs) exhibit a low reset current but a bad endurance. By replacing GST with Sb2Te3 (ST) and adding a TiN layer between ST and electrodes, the ST-TiN-LPCMs are demonstrated to have a much improved endurance. Finite element analysis of the LPCMs with electric-thermal structural interaction shows that thermal confinement makes GST-LPCMs low-power consumptive but that high level stress makes them readily broken. In contrast, ST-TiN-LPCMs experience low level stress during operation but high power consumption is required.
Guide Pattern Functionalization for Regularly Arranged PS-PDMS Self-Assembled Nanodot Pattern by Brush Treatment
Authors: Akahane Takashi , Huda Miftakhul , Tamura Takuro , Yin You , Hosaka Sumio
Published: January 2012

We have studied functionalization of guide pattern with brush treatment. Especially, the effect of brush treatment on ordering of nanodots formed on the guide pattern was investigated. We used polydimethylsiloxane (PDMS) as brush modification to form self-assembled nanodots on the guide pattern using polystyrene (PS) - PDMS as block copolymer. The brush treatment using toluene solvent made guide patterns of the electron beam (EB) drawn resist behave like PDMS guide patterns and good ordering of the nanodots has been achieved. It was demonstrated that the brush treatment enabled the PDMS nanodots to be regularly located in the desired positions defined by the EB drawn guide patterns.
Formation of 12-nm Nanodot Pattern by Block Copolymer Self-Assembly Technique
Authors: Huda Miftakhul , Tamura Takuro , Yin You , Hosaka Sumio
Published: January 2012

In this work, we studied the fabrication of 12-nm-size nanodot pattern by self-assembly technique using high-etching-selectivity poly (styrene)-poly (dimethyl-siloxane) (PS-PDMS) block copolymers. The necessary etching duration for removing the very thin top PDMS layer is unexpectedly longer when the used molecular weight of PS-PDMS is 13.5-4.0 kg/mol (17.5 kg/mol total molecular weight) than that of 30.0-7.5 kg/mol (37.5 kg/mol total molecular weight). From this experimental result, it was clear that PS-PDMS with lower molecular weight forms thicker PDMS layer on the air/polymer interface of PS-PDMS film after microphase separation process. The 22-nm pitch of nanodot pattern by self-assembly holds the promise for the low-cost and high-throughput fabrication of 1.3 Tbit/inch2storage device. Nanodot size of 12 nm also further enhances the quantum-dot effect in quantum-dot solar cell.
Estimation of Nanometer-Sized EB Patterning Using Energy Deposition Distribution in Monte Carlo Simulation
Authors: Zhang Hui , Tamura Takuro , Yin You , Hosaka Sumio
Published: January 2012

We have studied on theoretical electron energy deposition in thin resist layer on Si substrate for electron beam lithography. We made Monte Carlo simulation to calculate the energy distribution and to consider formation of nanometer sized pattern regarding electron energy, resist thickness and resist type. The energy distribution in 100 nm-thick resist on Si substrate were calculated for small pattern. The calculations show that 4 nm-wide pattern will be formed when resist thickness is less than 30 nm. Furthermore, a negative resist is more suitable than positive resist by the estimation of a shape of the energy distribution.
Calculation of Compton Profiles for Rare Gases Using the DV-Xα Method
Authors: Kobayashi Kohjiro , Sakurai Hiroshi
Published: January 2012

Compton profiles related to the electron momentum distribution are calculated using the DV-Xα method for a series of rare gases from He to Rn. To verify the criteria of the DV-Xα-derived Compton profiles, our results are compared with those obtained from the Hartree-Fock method. The trend of Compton profiles obtained from the DV-Xα method is discussed.
Optically Controlled Light Propagation in Dye-Doped Nematic Liquid Crystals with Homogeneous Alignment
Authors: Sasaki Tomoyuki , Miura Kenta , Ono Hiroshi , Hanaizumi Osamu
Published: January 2012

Light propagation in an optical waveguide fabricated by employing a dye-doped liquid crystal (DDLC) was observed. The propagation of a light signal in the waveguide was varied by irradiation with a control light whose wavelength was in the absorption band of the DDLC. By considering the photothermal effect of the DDLC, which enables the change of the refractive index due to temperature variation based on the absorption of light, we qualitatively explained the observed light propagation and demonstrated manipulation of the propagation.
Simulator for Application of Shear Wave Velocity Measurement System to Arbitrary Tissue Elasticity Distribution
Authors: Miwa Takashi , Yamakoshi Yoshiki
Published: January 2012

Local shear wave velocity measurements are effective to obtain tissue elasticity map. We have proposed novel wave number spectrum based shear wave velocity measurement system. However, the accuracy and resolution of this technique should be optimized and sophisticated in future clinical application for breast cancer diagnosis. We propose a simulator of RF signal in shear wave velocity measurement system which can consider arbitrary shear wave propagation. We demonstrate the usefulness of this simulator by experimental result. Moreover, accuracy and resolution of small object is discussed for breast cancer application.
Calculation of Compton Profiles Using the DV-Xα Method for 14 Electron Diatomic Molecules
Authors: Kobayashi Kohjiro , Sakurai Hiroshi
Published: January 2012

Isotropic and directional Compton profiles are calculated for 14 electron diatomic molecules, N2, CO, and BF, using the DV-Xα method. In order to investigate the effect of chemical bonding for Compton profiles, parallel and perpendicular directional Compton profiles to the molecules are calculated and compared with the results from Hartree-Fock and configuration interaction methods. The DV-Xα method could describe the more detailed character of covalent bonding than that of ionic bonding.
A Design Method for Two-Degree-of-Freedom Modified Smith Predictors for Multiple-Input/Multiple-Output Time-Delay Plants
Authors: Mai Nghia Thi , Yamada Kou , Ando Yoshinori , Murakami Iwanori , Hoshikawa Tatsuya
Published: January 2012

The modified Smith predictor is well known as an effective time-delay compensator fora plant with large time-delays, and several papers on the modified Smith predictor have been published.Recently, the parameterization of all stabilizing modified Smith predictors for time-delay plantswas obtained by Yamada et al. But, their method cannot specify the input-output characteristic andthe feedback characteristic separately. From the practical point of view, it is desirable that the inputoutputcharacteristic and the feedback characteristic are specified separately. In this paper, we proposethe parameterization of all stabilizing two-degree-of-freedom modified Smith predictors for multipleinput/multiple-output time-delay plants.
A Design Method for Two-Degree-of-Freedom Multi-Period Repetitive Control Systems with the Specified Frequency Characteristic
Authors: Chen Zhong Xiang , Yamada Kou , Nakazawa Nobuaki , Murakami Iwanori , Ando Yoshinori , Sakanushi Tatsuya , Hagiwara Takaaki , Nguyen Nhan Luong Thanh , Yamamoto Shun
Published: January 2012

Multi-period repetitive controllers improve the disturbance attenuation characteristic of themodified repetitive control system that follows the periodic reference input with small steady stateerror. Recently, the parameterization of all stabilizing multi-period repetitive controllers was studied.However, when the parameterization of all stabilizing multi-period repetitive controllers is used, theinput-output characteristic and the feedback characteristic cannot be specified separately. From thepractical point of view, it is desirable to specify the input-output characteristic and the feedback characteristicseparately. In addition, the parameterization is useful to design stabilizing controllers. Fromthis view-point, the parameterization of all stabilizing two-degree-of-freedom multi-period repetitivecontrollers those can specify the input-output characteristic and the disturbance attenuation characteristicseparately was solved by Yamada et al. However, when we design a stabilizing two-degree-offreedommulti-period repetitive controllers using the parameterization proposed by Yamada et al, thefrequency characteristic of the control system cannot be settled so easily. From the practical point ofview, the frequency characteristic of the control systems are required to be easily settled. This problemcan be solved by obtaining the parameterization of all stabilizing two-degree-of-freedom multi-periodrepetitive controllers with the specified frequency characteristic. In this paper, we propose the parameterizationof all stabilizing two-degree-of-freedom multi-period repetitive controllers with thespecified frequency characteristic.
A Dicode Signaling Scheme for Capacitively Coupled Interface
Authors: Yuminaka Yasushi , Kawano Kyohei
Published: January 2012

In this paper, we present a bandwidth-efficient partial-response signaling scheme for capacitivelycoupled chip-to-chip data transmission to increase data rate. Partial-response coding is knownas a technique that allows high-speed transmission while using a limited frequency bandwidth, by allowingcontrolled intersymbol interference (ISI). Analysis and circuit simulation results are presentedto show the impact of duobinary (1+D) and dicode (1-D) partial-response signaling for capacitivelycoupled interface.
Inhibition of Protein Aggregation: SAXS Study on the Role of the αC Region of Fibrinogen in the Fibrin Polymerization
Authors: Kubota Kenji , Wakamatsu Kaori , Nameki Nobukazu , Toyama Yoshiharu
Published: January 2012

Fibrin polymerization proceeds in a stepwise manner. In the first step, fibrinogen-to-fibrin conversion is triggered by the enzymatic fibrinopeptide release and protofibril formation/growth proceeds. In the following second step, lateral aggregation of the protofibrils occurs resulting in the network formation. Switchover from the first step to the second one can regulate the resultant network structure, and the lateral aggregation is considered to be induced by the interaction between the αC regions of two adjacent protofibrils. In order to clarify the characteristics of this interaction, we examined the cross-sectional diameter DCin addition to the hydrodynamic diameter (Stoke diameter) of fibrinogen molecule in various solution conditions. Cross-sectional diameter of intact fibrinogen was 4.7 nm in agreement with the molecular structure. On the other hand, fragment-X, in which the αC regions are deleted, had smaller DCof 4.2 nm. This means that the αC regions snuggle up to the molecular backbone, which is consistent with the model that the termini of the αC regions are tethered to the central E-region in the intact fibrinogen. On the other hand, fibrinogen at pH 3 had a cross-sectional diameter of 4.0 nm, which is further smaller than that of fragment-X. This is accounted for by the scheme that the αC regions are released from the central region, because side chains of Asp and Glu residues have neutral charge at pH 3. With the increase of ionic strength up to 150 mM at pH 3, fibrinogen molecules become to aggregate resulting in huge aggregated particles. Our results suggest that the released αC regions can interact attractively with each other through the hydrophobic interaction, which supports the proposed scheme of fibrin polymerization.
Solvent-Free Synthesis of Functional Siloxanes Bearing 4-Trifluoromethylphenyl Group
Authors: Egawa Yasunobu , Unno Masafumi
Published: January 2012

Recently we have been investigating solvent-free synthesis of siloxanes. Using no solvent gives less load to environment, and decreases cost in chemical industry. On the other hand, acidic or basic condition may not be applied to siloxanes bearing functional substituents. Therefore, the development of synthetic methods in neutral condition is desired. In this paper, we report the solvent-free thermal condensation of siloxane from silanol bearing vinyl group and strong electron-withdrawing 4-trifluoromethylphenyl group. Furthermore, we examined thermal properties of obtained vinyl-substituted silanol by TG-DTA measurement. With these results, we could determine the temperature of thermal condensation. We also elucidated the reaction pathway by tracing the reaction with GC-MS. Finally, we propose the possible reaction pathway from silanediol to cyclotrisiloxane (D3) and cyclotetrasilxane (D4).
Adsorption and Sensitizing Properties of Azobenzenes Having Different Numbers of Silyl-Anchor Groups in Dye-Sensitized Solar Cells
Authors: Kakiage Kenji , Yamamura Masaki , Kyomen Toru , Unno Masafumi , Hanaya Minoru
Published: January 2012

The effects of the silyl-anchor group number on the adsorption and the sensitizing properties were examined in sensitizing dyes for dye-sensitized solar cells by using 4-alkoxysilyl and 2,4-dialkoxysilyl azobenzenes. The TiO2electrode with the 2,4-disilyl dye exhibited higher durability to water and better photovoltaic performance than that with the 4-monosilyl dye, although the amount of 2,4-disilyl dye molecules adsorbed on the TiO2electrode was slightly smaller than in the case of 4-monosilyl dye.
PAN Based Carbon Nanofibers as an Active ORR Catalyst
Authors: Abdelkareem Mohammad Ali , Takino Daiki , Ishikawa Takayuki , Tsujiguchi Takuya , Nakagawa Nobuyoshi
Published: January 2012

Polyacrylonitrile (PAN) based carbon nanofibers were prepared by electrospinning and their activity for oxygen reduction reaction (ORR) in acidic media was investigated. Field emission electron microscope (FE-SEM), transition electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV) were carried out to investigate the surface morphology, composition, and catalytic activity. Thin carbon nanofibers of a 150 nm diameter were successfully produced by electrospinning using 8 wt% PAN in dimethylformamide, 15 cm pin to plate distance, and applying voltage of 18 kV at different carbonization temperatures of 700, 900, 1000, 1100, and 1200 °C. The ORR activity of the prepared carbon nanofibers was evaluated. The PAN based carbon nanofibers showed a considerable ORR activity and this activity was increased by increasing the carbonization temperature. The high ORR onset potentials over 700 mV vs. RHE (milli-volt versus reversible hydrogen electrode) were obtained at temperatures over 1000 °C. The activity of PAN based carbon nanofibers increased with increasing carbonization temperature from 700 to 1100 °C, this would be related to the increasing in the electrical conductivity at low carbonization temperatures, and the high Pyridine N content at the high carbonization temperatures.
Analytical Characteristic of Chromatography Device Using Dielectrophoresis Phenomenon
Authors: Hakoda Masaru , Otaki Takashi
Published: January 2012

This paper reports the separation of cells using a dielectrophoretic (DEP) chromatography device. The device consists of a micro channel and an array of interdigitated microelectrodes on a glass substrate. The sample cells were fed pulse-wise into the carrier flow using a micro-injector. The cells in the sample received a non-uniform electric field made with an electrode array. The direction of DEP motion is towards the higher field when the cell is more polarizable than the medium (positive DEP), while the direction is towards the lower field when the cell is less polarizable than the medium (negative DEP). Therefore, the cell separation depends on the size and dielectric characteristic. The effects of carrier flow rate, frequency, applied voltage, and sweep frequency on the retention time of the sample in the device were examined. In this study, mouse-hybridoma 3-2H3 cells and yeast cells were used as the sample cell. The analytical characteristic of the DEP chromatography device was evaluated according to the difference of retention time by the electric field. As a result, the separation in the cells in the negative DEP using the DEP chromatography was found to be effective. In addition, the effect of the sweep frequency on the difference in the retention time of the mouse hybridoma 3-2H3 cells and the yeast cells was very large. Consequently, the effectiveness of the DEP chromatography device was proven.
Pico-Newton Controlled Step-in Mode NC-AFM Using a Quadrature Frequency Demodulator and a Slim Probe in Air for CD-AFM
Authors: Hosaka Sumio , Takizawa Takayuki , Terauchi Daisuke , Yin You , Sone Hayato
Published: January 2012

We have studied a step-in mode non-contact atomic force microscopy (NC-AFM) for precise measurement of fine and steep structure with nanometer resolution in air. When a high aspect structure is measured using step-in mode AFM with the sharpened and slim probe, it is required that AFM control has to be performed at a force of <1 nN in pico-Newton range to suppress the bending and slipping of the probe on slop. Using a home-made step-in mode NC-AFM using a quadrature frequency demodulator for resonant frequency shift of the cantilever, the NC-AFM demonstrated that Si steep structure was faithfully observed at about 2 pN in air.
Reliability Based Design Optimization for Selective Excitation of the Vibration Modes of a Cantilever Spring
Authors: El-Hami Khalil , El Hami Abdelkhalak
Published: January 2012

This paper is devoted to procedures for the reliability-based optimization methods of engineering structures combining measurement and sensitivity technique, for the purpose of the better sensitivity in force-gradient detection. In the experiment part of this study, the mica muscovite cantilever beam clamped-free is used. The excitation of a cantilever beam with several small sheets of piezoelectric polymer adequately glued to it selects one high-frequency vibration mode of the cantilever. The proposed strategy is design into a framework that allows the solution of optimization problems involving a several number of design parameters that characterizes the systems, including dimensional tolerance, material properties, boundary conditions, loads, and model predictions, considered to be uncertainties or variables. The proposed methodology directly supports quality engineering aspects enabling to specify the manufacturing tolerances normally required to achieve desired product reliability. Within this context, the robust design obtained is optimal over the range of variable conditions because it considers uncertainties during the optimization process. The large number of exact evaluations of problem, combined with the typically high dimensions of FE models of industrial structures, makes reliability-based optimization procedures very costly, sometimes unfeasible. Those difficulties motivate the study reported in this paper, in which a strategy is proposed consisting in the use of reliability-based optimization strategy combined with measurement and sensitivity technique specially adapted to the structures of industrial interested.
Delamination-Crater Interaction in Damage of Glass/Epoxy Composite Plates Subjected to Impact Fatigue
Authors: Mouhoubi Said , Azouaoui Krimo
Published: January 2012

The use of composite materials is increasing although their behavior under impact fatigue loading remains rather unknown. This study is to assess the evolution of damage, especially delamination and crater, in a composite Glass/Epoxy woven fabric, using repeated impact tests at low energy levels (<10J). Both types of damage that arise and grow within the material cannot be independent from each other. Our objective in this work is to establish the interaction between two damages (delamination and crater) on laminate damage, and understand the contribution of each of them in the different phases through which passes the composite before perforation. To do this, impact fatigue tests are carried out on composite plates and measures of the crater size (diameter and depth) and the size of the delaminated area (diagonals from a diamond shape) are collected for different numbers of impacts and impact energies. A question worth asking; can we foster one of these damages over the other? especially when we are interesting to the “structure applications”, where one "prefers" perforation to delamination (while completing correctly the function's intended to the structure), or “shielding applications”, where one "prefers" the delamination to perforation. Although the range of impact velocities is not the same, it is still interesting to consider the synergy between these two damages at low impact velocities, always in the case of “structure applications” and “shielding applications”.
Structural and Mechanical Characterization of Stainless Steel Joints Realized by CMT Process
Authors: Roşu Radu Alexandru , Pascu Doru Romulus , Drăgoi Sorin
Published: January 2012

CMT weld brazing process (Cold Metal Transfer) knows a higher applicability in various industries (aeronautic, automobile) due its advantages compared with other welding processes. The paper presents the experimental results obtained on sheets joints using austenitic stainless steel mark 304 of 1 mm thick in butt and overlap variants using CuSi3 filler alloy of 1.2 mm diameter. The macroscopic analysis shows that were not presented welding defects and the microscopic examination did not showed welding defects such as microcracks. After the mechanical tests it was observed that al the tested specimens the fracture occurred in the base metal except the sample 1 where the fracture occurred in the welding zones. The bending test showed that all the samples were bent to 180° without cracks which assure good mechanical resistance to deformation. ΔHV1 estimator values ​​determined in the characteristic areas of the joints shows that at sample 2 there are structural hardening tendencies in the zones BM1-WELD and BM2-WELD with values ​​of 36% respectively 28.5% attesting moderate structural hardening (ΔHV1<50%), the brittle-type fracture risk in these areas is considered low.
3D Adaptive Remeshing Procedure and its Application to Large Deformation Problems
Authors: Zhang Jie , Cherouat Abel , Borouchaki Houman
Published: January 2012

Metal orthogonal cutting and blanking are two important forming processes which include material removing. During finite element analyzing, the nonlinear problems of boundary, material and geometry must be considered to obtain the accurate calculating results. In this paper, we present an advanced adaptive remeshing procedure which has the capacities to simulate material removing processes in three dimensions. The sizes of finite elements are well adapted to local conditions which have the high distributions of physical fields using priori and posteriori error estimates. Based on constraint Delaunay Kernel, the unit mesh strategy is proposed to improve the mesh quality. By optimizing of both mesh edges and mesh elements, the mesh shape qualities are strictly controlled as the regular tetrahedrons. In this paper, Johnson-cook model is considered to simulate the elastic-visco-plastical material behaviors. The damage initiation is also judged by Johnson-cook criterion. The finite elements which reach the criterion will be killed and the material removing processes finished step by step. The proposed adaptive remeshing scheme is well present using the simulation of metal orthogonal cutting, milling and blanking processes.
Effects of the Unified Viscoplastic Formulation and Temperature Terms on the Thermomechanical Behavior of Soldering Materials
Authors: Msolli S. , Dalverny Olivier , Alexis Joël , Karama Moussa
Published: January 2012

Solder materials are critical packaging compounds and due to usually weakest melting temperature among packaging constitutive materials, thus, they are frequently subjected to a multitude of physical phenomena: creep, fatigue and combined hardening effects. The complexity and interaction of such factors must be considered in suitable way in the mechanical behavior modeling using the appropriate material behavior laws. The choice of the mechanical model depends on several factors such as the complexity of constitutive equations to be integrated, the availability and suitability of implementation in the FE codes, the number of parameters to be identified, the capability of the model to represent the most common physical features of the material… Following these observations and in order to deal with these critical remarks, comparisons between the most common unified viscoplastic models should be done in the local and finite element levels for the decision upon the most efficient model. That is the aim of this paper with application to a tin based solder token as the test material.