bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermodynamic Modelling of the Uranium-Carbon-Oxygen System in the Frame of the Uranium Oxide and Carbon Interaction in the TRISO Fuel Particle of High Temperature Reactor
Authors: Dumas Jean Christophe , Piron Jean Paul , Chatain Sylvie , Guéneau Christine
Published: March 2009

A thermodynamic approach is necessary in order to predict and understand
physico-chemical phenomena occurring in nuclear materials under irradiation, involving large
chemical systems with a lot of elements including both initial nuclides and fission products
(FP). In the frame of thermo-chemical studies of the High Temperature Reactors fuel, a first
step is to assess the (U-O-C) system in order to understand the interaction between the UO2
kernel and the pyrocarbon layers constituting such a fuel particle. Our model for irradiated
oxide fuel, based on Lindemer’s analysis, has been improved by introducing the (U-O-C)
model developed by C. Guéneau & al into the SAGE code. Chemical compositions and
related carbon oxides pressures of irradiated TRISO fuel particles have been calculated with
the data published by Minato & al. We discuss our results by comparison with their thermochemical
calculations and with their experimental observations. This approach can be used to
predict the behaviour of complex nuclear materials, especially for the different kind of fuel
materials considered in the frame of Gas Fast Reactors.
Radiation Damage Effects in Insulators for Fusion Reactors: Microstructure Evolution in MgO-Al2O3 System Oxide Crystals
Authors: Yasuda Kazuhiro , Matsumura Syo
Published: March 2009

Characteristic features of radiation damage in insulators for fusion reactors are that those
materials are exposed to synergistic radiation damage of elastic displacements and electric excitation
with the presence of an electric field. This paper describes the nucleation-and-growth of
radiation-induced defects and their stability in oxide ceramics, such as magnesium-aluminate spinel
(MgAl2O4) and alpha-alumina (α-Al2O3). Microstructure evolution in these oxides is shown through
transmission electron microscopy for the formation process of dislocation loops under synergistic
irradiation with displacements and ionizing radiation, the stability of dislocation loops, and the
nucleation-and-growth process of loops with an applied electric field.
Single Phase Ceramic Wasteforms for Plutonium Disposition
Authors: Hyatt N.C. , Stennett M.C. , Maddrell Ewan R. , Lee William Edward
Published: March 2009

Four single phase ceramic formulations were investigated as potential wasteforms for
plutonium disposition, using Ce as a Pu surrogate: pyrochlore, Gd2(Zr1-2xCexHfx)O7; zirconolite,
(Ca1-x/2Gdx/2)(Zr1-5x/2CexHfxGdx/2)Ti2O7; britholite, (Ca2+xY8-2xCex)Si6O26; and kosnarite,
Na(Zr2-xCex)P3O12. The single phase solid solution limits for each formulation were established and
the processing parameters required to produce high quality ceramic specimens were optimised.
This was achieved within the constraints of a generic processing route suitable for fabrication of
Pu bearing samples. Whereas the pyrochlore, zirconolite and britholite formulations show
considerable promise as single phase ceramic wasteforms, the kosnarite formulation was found to
be unsuitable.
Studies in Mesoporous Silicates: Impedance Measurements on SBA-15 Loaded with Sulfonated-Polystyrene and Nafion with SBA-15 Filler
Authors: Stockton Jon D. , Lomax Joseph F. , Edmondson Charles A. , Fontanella John J. , Wintersgill Mary C.
Published: March 2009

An organic-inorganic composite was formed by cross-linking polystyrene (PS) into a
SBA-15-type mesoporous silica (SBA/PS). The SBA-15/PS reacted with sulfuric acid according to
published methods to sulfonate the benzene rings of the styrene (SBA-15/PS/SO3). These two latter
solids were investigated by TGA/MS to determine stability and decomposition mechanisms.
Complex impedance measurements at 10-105 Hz were taken on (SBA-15/PS/SO3) and Nafion cast
films loaded with SBA-15 at a level of 1-10%, and similar films with SBA-15/PS/SO3 in hopes that
the mesoporous solids might impart desirable properties on the Nafion.
Novel Approches in Oxidative Catalysis for Diesel Particulate Abatement
Authors: Fino Debora , Russo Nunzio , Cauda Emanuele , Mescia Davide , Solaro Simone , Saracco Guido , Specchia Vito
Published: March 2009

Next 2008 European legislation on diesel engines will impose the use of specific traps,
placed in the car exhaust line, so as to meet very stringent particulate emission limits (0.005 g/km).
This paper provides a survey of the advancement status of R&D in the field of diesel particulate
traps. Special emphasis is given to the combined use of traps and catalysts for regeneration purposes
via catalytic combustion of the collected soot in the traps. Issues like trap materials selection,
catalyst development, catalytic vs. non-catalytic trap performance are addressed. Specific highlights
of the research in catalytic materials developed at Politecnico di Torino in the framework of EU
projects will also be provided. In order to enhance the soot-catalyst contact conditions, several
kinds of catalysts have been developed: oxygen spillover oxide, mobile catalysts based on alkali
vanadates, spinels for the combined removal of particulate and NOx, precious metals enabling the
NO oxidation to NO2 followed by reaction of this latter with particulate, heavy metal oxides, alkalimetal
substituted perovskites capable of delivering oxygen species. An overview of these different
approaches to soot oxidation will be provided pointing the way towards possible synergetic effects
in multi-component catalysts.
Oxygen Radicals Occlusion/Release Behavior of Nanoporous Aluminosilicate, Ca12Al14-XSiXO33+0.5X (0≦X≦4)
Authors: Nagashima Makoto , Hirabayashi Daisuke , Suzuki Kenzi
Published: March 2009

Oxygen radicals occlusion / release behavior of nanoporous aluminosilicate,
Ca12Al14-XSiXO33+0.5X (0≦X≦4), synthesized under different condition was examined by the
temperature programmed reduction (TPR) in an atmosphere of hydrogen in the temperature range
of 200-1000°C and temperature programmed oxidation (TPO) measurement at 800°C. From the
TPR results of Ca12Al14O33 (X=0) and Ca12Al10Si4O35 (X=4), it was found that there were three
oxygen release peaks, denoted as α, β and γ, on each sample and the peaks appeared in the
temperature range 300-420°C, 420-600°C, and 600-750°C, respectively. The oxygen contents of α
and γ of samples were almost the same. However, the oxygen content of β in the sample with x = 4
was much larger, almost double, compared to that in x = 0. From the TPR, TPO results and
catalytic performance, it was concluded that the oxygen content of β peak strongly influenced the
catalytic activity of the nanoporous aluminosilicate in the propylene combustion.
Characterization and Applications of Calcium Ferrites Based Materials Containing Active Oxygen Species
Authors: Hirabayashi Daisuke , Yoshikawa Takeshi , Kawamoto Yoshiki , Mochizuki Kazuhiro , Suzuki Kenzi
Published: March 2009

Characterization and application of calcium ferrites based solid solutions containing active
oxygen species for catalysts in propylene total and methane partial oxidation has been studied. The
calcium ferrite based solutions containing brownmillerite phases showed a structural transition based
on the migration of oxide ions at high temperature. The calcium ferrite solution provided two types of
active oxygen species due to the existence of the brownmillerite phase. These oxygen species
individually played important roles in the propylene and methane oxidation mechanisms.
Environmental Aspects on the Use of Bayer's Process Bauxite Residue in the Production of Ceramics
Authors: Pontikes Y. , Vangelatos I. , Boufounos Dimitri , Fafoutis Dimitris , Angelopoulus G.N.
Published: March 2009

Bauxite Residue (BR) is the main waste generated during the alumina-producing Bayer
process. With the aim to utilize BR in the production of traditional ceramics, the potential impact
such a use might have on the leaching behaviour and radioactivity levels of the final products was
investigated. Leaching behaviour of Cr, Ni and V on calcined BR was studied according to the
maximal availability test, NEN 7341. Firing atmosphere, firing temperature and soaking time were
the investigated parameters. Results demonstrate that the soluble fraction of Cr is higher for
oxidizing atmosphere whereas the soluble fraction of V and Ni increases for inert and reducing
atmosphere, respectively. For assessing radioactivity, the activity concentrations of 226Ra, 40K, and
232Th were determined by means of gamma ray spectroscopy. For an excess gamma dose less than
1mSv/a, the maximum quantity of BR that can be introduced replacing the raw materials ranges
from 14wt.% up to 100wt.%, depending on the type of product and the extent of use in the
dwelling.
Structured Catalysts for Environmental and Energetical Applications
Authors: Forzatti Pio , Arosio Fabrizio , Cristiani Cinzia
Published: March 2009

The paper presents an overview of the present status and the perspectives for use of
structured catalysts in the power generation, transport and environmental sectors. In particular
catalytic combustion of natural gas for the production of energy in gas turbines, abatement of NOx
from mobile and stationary sources under lean and stoichiometric conditions, removal of VOC from
industrial effluents and soot combustion in the exhaust gases of vehicles are discussed.
Development of Platy Alumina and its Application
Authors: Sano Saburo , Fukuda Takeshi , Shibasaki Yasuo
Published: March 2009

It has been required to change the industrial production processes to low waste emission ones from a
view point of environmental issue. In the production of aluminum building materials, large amount
of sludge is emitted as industrial waste. If we can change the waste to valuable products, we can
respond to the request. Synthesis technology of kaolinitic particles from various starting raw
materials had been established at National Industrial Research Institute of Nagoya (NIRIN, present:
AIST Chubu). Hydro-thermal treatment is applied to the technology and obtained particles show
various shapes such as plate, shell and so on. Collaborative research work between NIRIN and YKK
corporation to develop high performance alumina powder form aluminum sludge, a by-product from
surface treatment process in the manufacturing of aluminum building materials, had been done by
using the fruits from the research project on kaolinite synthesis at NIRIN. As the result, high
performance platy alumina powder was developed by using hydro-thermal synthesis technology.
A Study of Porous Slag with Plasma Arc Melting
Authors: Lian Shuang Shii , Chang Chih Kang , Tzeng Chin Ching
Published: March 2009

The slag from steel plants or incinerators was tried to be recycled and be reused as foam
materials through plasma arc melting. The study was intended to investigate the making of foam slag
with laboratory plasma melting facilities. The investigated materials consisted of different mixtures
of Al2O3、SiO2 、FetO、CaO and Na2O, with the fluxes that were necessary to examine the
capability of pore-formation in the solidified ingots. It has been found that the foam slag could be
obtained with the proper compositions and conditions of arc heating. The dimensions and
distributions of pores were studied and correlated with the temperatures and compositions of slag.
The results showed that the sizes of pores inside the solidified ingots were in the range of 1~5 mm,
and the thickness of slag was around 20 mm. As to the distributions of the pores in the ingots of slag,
further improvement would be needed in the future.
Particle Distribution Design in a Self-Flow Alumina Refractory Castable without Cement
Authors: Silva Abílio P. , Segadães Ana M. , Devezas Tessaleno C.
Published: March 2009

A self-flow refractory castable (SFRC) without cement requires a matrix of fine particles
and a broad size distribution of coarse particles (aggregate). The matrix ensures the rheological
behaviour and performs the binding role of the absent refractory cement. The presence of the
aggregate coarse particles hinders the flowability index (FI), but improves the castable mechanical
strength and reduces firing shrinkage.
A new methodology of SFRC particle distribution design was developed, using response surface
statistical modelling and commercial alumina powders (reactive and tabular). First, the composition
of the fine matrix was optimised, seeking minimum water content and maximum IF. To this matrix,
various aggregate distributions, combining six tabular alumina size fractions and with different
Andreasen distribution modulus, q, between 0.18 to 0.28, were added, to identify the composition
with maximum FI.
The results obtained show that a minimum specific surface area (SSA) of 2.22m2/g is necessary
to reach the self-flow turning point, after which the largest FI requires the maximisation of the
aggregate maximum paste thickness (MPT), corresponding to a distribution with q=0.22. The
optimised castable composition presents high mechanical strength (>60MPa) and low shrinkage.
The Influence of Starting Mass Grain Size Distribution on Magnesia-Spinel Products Microstructure
Authors: Szczerba Jacek , Pędzich Zbigniew
Published: March 2009

The paper presents the results of investigations on the influence of the starting mass grain
size distribution on microstructure of sintered magnesia-spinel products. The model investigation
was conducted using magnesia clinkers and fused spinel. The grain size distribution of starting
mixes were selected according to Dinger and Funk's theoretical curves with different values of n
coefficient. The results clearly indicate that the best properties were achieved when n value changed
in the range of 0.22 - 0.30 and forming pressure was contained in the range of 160 - 200 MPa.
Synthesis of Undoped ZnO Nanoparticles by Spray Pyrolysis
Authors: Rossignol C. , Verelst M. , Dexpert-Ghys J. , Rul S.
Published: March 2009

During the past few years, a pilot-scale spray pyrolysis set-up able to produce large
quantities of submicronic powders (1kg/day) has been assembled in our laboratory. During
the process, droplets of a precursor solution are dried and decomposed to the required
compound.
The presence of an additional soluble flux in the precursor solution permits to obtain
agglomerate - free nanoparticles after washing the product. Therefore, pure zinc oxide
nanoparticles have been successfully synthesized by adding lithium or sodium nitrates to the
initial zinc nitrate solution. The nanoparticles have been characterized by X-ray diffraction,
field-emission scanning electron microscopy, laser scattering size analyzer. The influence of
the precursor solution composition and of the operating parameters on the morphology and
the average size of ZnO nanoparticles is discussed.
Nanoscale Ferroelectrics
Authors: Rüdiger Andreas , Waser Rainer
Published: March 2009

Ferroelectrics are among the most advanced materials for non-volatile storage
applications. Their two thermodynamically equivalent groundstates of spontaneous polarization can
be toggled between by an external electric field. We present recent progress in the fabrication,
registration, manipulation and characterization of nanoscale ferroelectrics. Chemical solution
deposition is adapted to a pre-registration process by e-beam lithography to fabricate registered
ferroelectric nanostructures below 100 nm width. A post-processing by chemical mechanical
polishing either for embedded or free grains modifies the aspect ratio thus controlling the coercive
field distribution of nanoferroelectrics. We also discuss some very recent findings of the complex
interaction of field and piezoelectric tensor in a real piezoresponse force microscope. This method
requires a comprehensive treatment of all contributions to tell apart extrinsic from intrinsic effects.
Influence of Fibre Diameter on the Microstructure and the Piezoelectric Properties of PZT-Fibres
Authors: Heiber Juliane , Clemens Frank J. , Graule Thomas , Hülsenberg Dagmar
Published: March 2009

Lead zirconate titanate (PZT) fibres with diameters between 70 and 300 μm have been
extruded and sintered at 1200°C in a PbO-enriched atmosphere. Subsequently, the influence of fibre
diameter on the microstructure (porosity and grain size) was investigated. The measurements
revealed that with decreasing fibre diameter, the porosity decreases whereas the grain size
increases. The influence of these microstructural differences on the piezoelectric properties was
evaluated using a novel characterisation procedure for single PZT fibres. Fibres with an as-extruded
diameter of 100 μm developed an average maximum strain of 3800 ppm at an applied electrical
field of 3 kV/mm and exhibited the best performance for all fibres processed with the chosen
sintering parameters.
Characterization of Indium Oxide Nanoparticles Prepared by Soft Chemistry Route
Authors: Souza E.C.C. , Muccillo E.N.S.
Published: March 2009

Indium oxide, a wide band gap transparent conductor, is of great interest for many
device applications due to its unusual combination of high transparency in the visible region
and high electrical conductivity. Several methods, comprising all three phases, namely, the
solid phase, the solution phase, as well as the vapor phase, have been used for the preparation
of In2O3 powders and thin films. In this work, indium oxide nanoparticles were synthesized
by homogeneous precipitation using hexamethylenetetramine as ligand and indium nitrate or
indium chloride as precursor materials. Thermogravimetry and differential thermal analysis
results evidenced the relatively low temperature for crystallization of indium oxide. Spherical
clusters consisting of about 8 nm of diameter indium oxide nanoparticles were obtained after
thermal decomposition at 400 °C for 2 h, as revealed by X-ray diffraction experiments and
nitrogen adsorption measurements. Transmission electron microscopy observations confirm
the single-crystalline nature of the prepared nanoparticles. This material exhibits
photoluminescence emission at room temperature with peak onset at 315 nm as a
consequence of the small size of the particles.
Analysis of the Magnetic Anisotropy in Ba Ferrite Particles
Authors: Bottoni Giancarlo
Published: March 2009

The magnetic anisotropy of Co/Ti-doped Ba ferrite particles for application in recording
media is studied. A method which deduces the anisotropy from the measurement of the reduced
perpendicular magnetization and allows to find also the distribution of anisotropy fields is
employed. The effect of the doping ions content, of the alignment degree of the particles and of the
variation of the temperature on the anisotropy is analysed and discussed, taking account of the
contemporary presence of magnetocrystalline and shape anisotropy, with different easy
magnetization axes, in the Ba ferrite particles.
Hybrid Ordered Hole-Random Hole Optical Fibers
Authors: Pickrell Gary R. , Smirnova Evgenya S. , De Haven Stanton L. , Rogowski Robert S.
Published: March 2009

Photonic band gap (PBG) fibers have generated significant interest over
the last decade due to the unique set of properties these fibers exhibit. In general,
these fibers have been made by drawing a series of glass tubes (which are stacked in
an ordered array) into a fiber. These fibers consist of an ordered arrangement of holes
or tubes in a glass matrix. In this invited paper we describe a novel type of fiber,
called HORHOFs (hybrid ordered random hole optical fibers). In these fibers, the
refractive index of the ordered-hole region is controlled by incorporation of very
small tubes of glass produced in-situ during the fiber drawing process. The result is a
region of controllable glass density inside the “ordered hole”. This allows tailoring of
the refractive index of the hole region and of the matrix glass around the holes.
Description of the process to produce these new types of fibers, micrographs of some
of the fibers produced, some potential applications, and the results of some computer
modeling to predict the properties of these fibers, are presented.
Study of Pseudoboehmite Synthesis by Sol-Gel Process
Authors: Munhoz Jr. Antônio Hortêncio , de Miranda Leila Figueiredo , Uehara G.N.
Published: March 2009

A pseudoboehmite was obtained by sol-gel synthesis using aluminum nitrate
as precursor. It was used a 2n full factorial design for studying the effect of the
temperature of synthesis, the concentration of ammonium hydroxide, and the radiation
dose in the product of sol-gel synthesis. The product of the synthesis was analyzed by
scanning electron microscopy, x-ray diffraction of the product (after firing the
pseudoboehmite at different temperatures), and it was also analyzed the temperature of
endothermic and exothermic transformations using the thermo gravimetric analysis
(TG) and differential scanning calorimetry (DSC). The X-ray diffraction data show that
α-alumina was obtained at 1100o C.
Ceramic Pigments with Perovskite Structure
Authors: Stobierska Ewa , Lis Jerzy , Bućko Mirosław M. , Gubernat Agnieszka
Published: March 2009

The results of preliminary investigation on preparation of perovskite pigments by solid
state reaction are presented. The effects of different raw materials used as component carriers on
formation of colored pigments were examined. Pigment composition, optimum chromophore
addition, type of mineralizer and the conditions of synthesis were determined experimentally as
well as the resulting color, phase composition and morphology of powders. The wet method of
preparation of starting mixtures was also analyzed.
The Crystallisation of B-Phase Glass-Ceramics
Authors: Falk L.K.L. , Menke Yvonne , Hampshire Stuart
Published: March 2009

Five-component B-phase may be readily formed through the nucleation and
crystallisation heat treatment of nitrogen-rich parent glasses with composition (e/o)
35R:45Si:20Al:83O:17N. This paper is focussed on the B-phase structure where R stands for
ytterbium, erbium or yttrium. Fine probe EDX analysis in the TEM has shown that the lenticular
B-phase crystals take up a substantial range of composition and that the element R is always
clearly anti-correlated with silicon. A larger R3+ cation radius moves the B-phase composition
range to lower R contents, and as a consequence of the anti-correlation with silicon, the silicon
solid solution range goes to higher values. The EDX results lend support to a B-phase structure
consisting of two-dimensional network of randomly linked (Si,Al)(O,N)4 tetrahedra between
layers of R3+ cations. It is suggested that, in addition to the random substitution of silicon by
aluminium in the (Si,Al)(O,N)4 tetrahedra, a locally increased density in the bi-dimensional
network of randomly oriented tetrahedra is associated with an increased density of vacancies in
the R3+ cation lattice.
Rheology of Nanometric Powders
Authors: Akinc Mufit , Li Chuan Ping
Published: March 2009

Use of environmentally friendly processing additives for nanometric
powders has tremendous technological implications. In this study, the rheology of
aqueous nanometric alumina powdersuspensions and variation of viscosity with
solids content and with fructose concentration were studied by rheometry. The
mechanism of dramatic viscosity reduction by fructose addition is studied by
differential scanning calorimetry (DSC) and thermogravimetry (TGA). The
interparticle forces between the particles were investigated by colloidal probe-atomic
force microscopy (CP-AFM). DSC indicates that the significant fraction of water is
bound on the surface hence does not contribute to flow of the particles. It also
indicates that the fructose displaces water from the particle surface and reducing the
interparticle forces. The interactions between the nanometric alumina particles in
water can be explained by the DLVO theory. The interaction forces (amplitude and
range) between nanometric alumina particles decrease with increasing fructose
concentration.
Colloidal Processing of Powder for Membrane Applications
Authors: Levänen R.E.
Published: March 2009

Consolidation of colloidal particles onto porous ceramic substrate is the critical issue in
the ceramic membrane preparation. The membrane functional properties are determined mainly by
the powder properties, but also by the colloidal condition of the slip. This presentation concentrates
on the colloidal processing of submicron alumina for the membrane preparation and for the
membrane layer formation based on the capillary colloidal filtration.
The solid content of the slip and the degree of deflocculation are the primary factors for the control
of the membrane layer growth and pore properties. Electrostatic and electrosteric dispersion lead
into different degree of deflocculation and different surface charge, which further resulted on
differences in membrane layer growth behavior. Additives, such as polyelectrolytes, electrolytes,
binders have also effect on the colloidal condition of the slip, but also have effect on the properties
of the liquid phase of the slip. Changes in viscosity and surface tension of liquid phase have also
significant effect on the membrane layer growth behavior.
High Energy Ball-Milling of Tin Titanate Zirconate for Use in Microwave Applications
Authors: Arantes V.L. , Souza Dulcina P.F.
Published: March 2009

Tin titanate zirconate (ZTS) is widely known for its good
dielectric properties at high frequencies and has been widely
employed as a dielectric resonator. ZTS does not sinter easily by solid
state difusion and it is necessary to introduce sintering aids capable of
increasing diffusion coefficients and/or leading to liquid phase
sintering. Consequently, the dielectric properties in microwave
frequencies can be reduced. This work focused on the utilization of
high energy ball-milling as a method of reducing initial particle size
and further improving sintering of ZTS.The powders obtained were
characterized by X-ray diffraction as a function of milling time, as
well as by a light scattering particle size analyzer.
Characterization of Particle Alignment in Pre-Sintered Alumina Body Using Birefringence Imaging Microscopy
Authors: Wei George C.
Published: March 2009

The packing structure in green alumina bodies has been studied using thin sections of
prefired bodies impregnated with refractive-index liquid examined with an automatic, polarizedlight
microscope equipped with liquid-crystal adjustable quarter-wave plate and analyzer, and
circularly polarized light. The combined intrinsic birefringence (caused by the anisotropy of the
hexagonal symmetry of the alumina particles) and form birefringence (due to packing of the
slightly elongated particles oriented in the green structure), can be quantified on a small scale.
Birefringence values and slow-vibration directions are mapped for the anisotropic fine particles
and agglomerates circumferentially or radially aligned in the structure. For some pre-sintered
bodies, the interference pattern shows three radial dark brushes with relatively low birefringence,
coming from the spider in the extruder. Slow-axis distribution shows random particle orientation
in the spider region. The birefringence pattern often indicates a relatively high degree of
circumferential alignment in the surface area where frictional force is present during forming. A
uniform distribution of the birefringence represents a consistent green structure. The improved
procedure for characterization of prefired body provides considerable insight to the optical
crystallography of powder/particle arrangement in pre-sintered ceramic body and the relationship
of the particle alignment with respect to flow and forming.
Model Constrained Sintering Experiments: Bi-Layers and Cylinder-Filled Rings
Authors: Garino Terry J. , Argüello Jose G.
Published: March 2009

When structures that consist of powders of two or more materials, such as low
temperature co-fired ceramic packages or a planar solid oxide fuel cells, are sintered, the mismatch
in the sintering shrinkage rates between the different materials produces stress, since the faster
shrinking materials are constrained by those that shrink at a slower rate. These stresses can lead to
the formation of defects such as cracks or shape distortion. Results of recent model experiments to
study the constrained sintering in multi-material systems will be discussed for two model
geometries. The first geometry is a simple bi-layer consisting of single layers of two different
materials bonded together. Results of in situ observation of sintering bi-layers will be presented and
discussed in relation to the properties of the individual layers such as their free sintering rates,
uniaxial viscosities and viscous Poisson’s ratio. The second geometry studied was that of a ring of
one material filled with a cylinder of a second, slower shrinking material. In this case, the results of
several variations of this geometry including filling the ring either fully or partly with a rigid, nonshrinking
cylinder or with rigid, non-cylindrical shapes will be presented and discussed.
Influence of Pressure and Heating Rate on the Mechanical Properties of Mesophase Based Sintered Parts
Authors: Rottmair Christian , Bauer J. , Gruhl Michael , Volek Andreas , Singer Robert F.
Published: March 2009

This work focuses on the influence of different sintering parameters on the mechanical
properties of pressed and sintered mesophase based parts. In a first approach we analyzed the
influence of the heating rate on the sintering process and in subsequent experiments we applied
inert gas pressure up to 1000 bar.
Development of an Efficient of Microwave Sintering Process
Authors: Yasuoka Masaki , Shirai Takashi , Nisimura Yutsuki , Nagaoka Takaaki , Watari Koji
Published: March 2009

The drying and sintering processes require large quantities of energy. If this energy could
be used more efficiently, less would be consumed. In this research, the effect of the microwave on the
manufacturing process of ceramics where heat was needed was examined. We obtained the following
results when oxide ceramics were dried and sintered by microwave technique: In drying process, slip
cast bodies were dried rapidly by microwave drying and compared with those dried by conventional
drying techniques. In sintering process, power consumption and efficiency were lower with the
time-control method than with the power-control method. The power-control method gave more
precise temperature control under our experimental conditions.
Processing and Applications of "Oxide Nanoskin"
Authors: Hozumi Atsushi
Published: March 2009

A novel photochemical approach is presented to fabricate a silicon oxide (SiOx) layer, which we
have named an “oxide nanoskin” (ONS), whose thickness is defined in the molecular-order of 1~3
nm. Through the chemisorption of a vapor phase organosilane and subsequent photooxidation
using 172 nm vacuum ultraviolet (UV) light, an extremely flat SiOx layer without cracks or
aggregates was formed on various polymer substrates. Owing to this ONS coating, the charge
density and surface acidity of the polymer substrates became almost equal to those of a native
oxide-covered Si (SiOx/Si) substrate. In addition, there was marked improvement in the durability
of the hydrophilicity and in the micro-wear resistance of the polymer surfaces. Moreover,
organosilane self-assembled monolayer (SAM) chemistry currently available for the treatment of
inorganic glass and Si substrates could be similarly utilized. Well-ordered SAMs with a wide
variety of terminal-end groups (e.g., trifluorocarbon or amino groups) could be fabricated even on
inert polymer substrates, in a manner similar to their fabrication on SiOx/Si substrates. Furthermore,
we demonstrated the site-selective deposition of metal oxide and metal films on polymer substrates
using photolithographically micropatterned SAMs as microtemplates. Well-shaped microstructures
were achieved only on the polymer substrates with the ONS layer. On the substrates without the
ONS layer, pattern resolution degraded significantly and growth rate decreased, since both
depended greatly on the SAM density and quality. Our ONS was very useful not only in forming
highly ordered SAMs on the polymer substrates, but also in obtaining excellent pattern resolution,
sufficient growth rate, and adhesion of the target materials.
Nanofibres of Ceramic Compounds by Electrospinning
Authors: Nuansing W. , Maensiri S.
Published: March 2009

This paper reports on the fabrication of nanofibres of ceramic compounds using
electrospinning technique. In a typical process, ceramic nanofibres are fabricated by electrospinning
a precursor mixture of appropriated metal sources, polymer and solvent, followed by calcination
treatment of the electrospun composite nanofibres. In this work, the electrospinning set up as well as
experimental procedure are described in detail. The fabrication of thermoelectric oxide NaCo2O4,
ferroelectric Ba1-xSrxTiO3 and semiconductor TiO2 nanofibres with diameter of ~20-200 nm are
demonstrated. The characterization of the fabricated nanofibres using TG-DTA, X-ray diffraction,
Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and
transmission electron microscopy is also investigated.
Adsorption of Biomolecules on Ceramic Particles and the Impact on Biomedical Applications
Authors: Gauckler Ludwig J. , Rezwan Kurosch
Published: March 2009

Protein adsorption onto metal oxide surfaces is an essential aspect of the cascade of
biological reactions taking place at all interfaces between implanted materials and the
biological environment. The types and amounts of adsorbed proteins mediate subsequent
adhesion, proliferation and differentiation of cells. Protein adsorption to surfaces of metal
oxides and their kinetics are important in the formation and growth of seashells, one of the
toughest natural ceramics, in modern bio-analytical devices as well as in bone and teeth
implant technology. This paper describes results obtained in a feasibility study of how to use
metal-oxide particles to obtain biosensors with a high turnover. The most important features
of proteins are outlined describing them as purpose-built "polymers" from amino acids with
specific conformations. Some key aspects of Metaloxide (MeO) surfaces in water and the
influence of electrostatic and hydrophobic interaction on protein adsorption are reported.
Results concerning the interaction between different proteins and MeO surfaces in water are
discussed in detail. Examples of purely electrostatic interactions of proteins with MeO
surfaces as well as the influence of hydrophobic interaction are elucidated. An outlook of the
implications of the new insights on natural and synthetic materials will be given concerning
bio-compatibility, bio-mineralization and self assembly of materials.
Ways of Controlling Structure and Properties of Sol-Gel-Derived Hybrid Micro- and Nanocomposite Materials
Authors: Shilova Olga A.
Published: March 2009

Technically useful hybrid micro- and nanocomposite materials might be prepared by solgel
processing. Inorganic dopants (acids, metal salts) and organic modifiers (polyols, polyionens) as
well as fillers (metal oxides, detonation diamond) were involved into the tetraethoxysilane (TEOS)-
derived sols to modify sol-gel system properties. Influence of the above mentioned additives on
parameters xerogels and films prepared (covering capacity, surface morphology, phase
compositions, fractal parameters, and some others physicochemical properties) has been shown.
Simultaneous use of dopants, organic modifiers and fillers has allowed preparing new hybrid
nanocomposite materials. for microelectronics, electrical and power engineering.
Synthesis of Structure Controlled Magnetostrictive Materials by Use of Microgravity and Magnetic Fields
Authors: Okutani Takeshi , Nagai Hideaki , Mamiya M. , Castillo Martin
Published: March 2009

Tb-2Fe and Sm-2Fe molten alloys with a 1:2 molar ratio were unidirectionally solidified
separately in microgravity and normal gravity in concurrence with a magnetic flux (0-0.12T). The
Tb-2Fe molten alloy was solidified unidirectionally in microgravity with a 0.1T magnetic flux and
the solidification product, TbFe2, had dominant [111] crystallographic alignment and the
microstructure was lamellar with an average lamellar thickness of 30μm oriented along the
solidification direction. The single phase SmFe2 was synthesized by unidirectional solidification
in microgravity with a magnetic flux of 0T, and the microstructure was lamellar. The average
SmFe2 lamella thickness was 30μm and each lamella possessed a <111> crystallographic alignment
along the direction of cooling. The unidirectional solidification of Sm-2Fe molten alloys in
normal gravity or in microgravity with a magnetic field resulted in Sm2Fe17 and Fe crystalline
phases. The magnetostriction of TbFe2 solidified unidirectionally in microgravity with a 0.1T
magnetic flux was 4,500ppm with an external 1.6T static magnetic flux. In TbFe2 solidified in
normal gravity, the maximum magnetostriction remained at 2,000ppm with an external 1.6T static
magnetic flux. The magnetostriction of single phase SmFe2 solidified unidirectionally in
microgravity with a magnetic flux of 0T was -3,200ppm with an external 0.09T static magnetic
flux.
Comparison of Conventional and High Velocity Compaction of Alumina Powders
Authors: Souriou D. , Goeuriot P. , Bonnefoy O. , Thomas G. , Drapier S. , Bourdin Stephane , Lazzarotto Ludovic
Published: March 2009

Ceramic compacts can be usually prepared by uniaxial pressing in a die made of stainless steel, but
the pressure applied is limited and density gradients occur in many cases. Recently a new forming
method in powder metallurgy, the High Velocity Compaction (HVC) has been applied to ceramic
powders. This method is similar to conventional pressing but consists in making an ram falling
down at a very high speed to the upper punch. The kinetic energy is converted into a strike that
produces a high pressure in a really short time. By controlling the kinetic energy, it is possible to
apply a desired pressure that can be extremely high (up to 1 GPa) without any damage for the tool.
The aim of the study is to compare the process conditions and the properties of green compacts
elaborated by the two methods (conventional and HVC) for a similar forming pressure: forming
pressure, green density (homogeneity), pore size distribution of the tablets, and then the sintering
behavior, the shrinkage, the final density and microstructure of the ceramic material are studied.
Densification of Nano-Sized Alumina Powders under Radial Magnetic Pulsed Compaction
Authors: Paranin S. , Ivanov Victor , Nikonov Alexey , Spirin A. , Khrustov Vladimir , Ivin S. , Kaygorodov Anton Sergeevich , Korolev P.
Published: March 2009

An influence of aggregation degree of alumina nanopowder and of radial magnetic pulsed
compaction conditions on the powder densification and on the density distribution inside compacts
has been investigated experimentally. The usage of radial magnetic pulsed compaction allows to
compact alumina nanopowders up to high densities at low degree of aggregation. The compacts
homogeneity is attained by appropriate compaction pulse duration and by the usage of powder
packing prior to compaction until the condition with high local sound speed is achieved.
Studies by In Situ and Real-Time Synchrotron Imaging of Interface Dynamics and Defect Formation in Solidification Processing
Authors: Billia Bernard , Nguyen-Thi Henri , Reinhart Guillaume , Mangelinck-Noël Nathalie , Gastaldi J. , Schenk Thomas , Hartwig J. , Baruchel J. , Cristiglio V. , Grushko B. , Klein Holger
Published: March 2009

The solid microstructure built in the solid governs the properties of materials elaborated
from the melt. In order to clarify the dynamical mechanisms controlling solidification processing,
we use in situ and real-time synchrotron X-ray radiography at ESRF (European Synchrotron
Radiation Facility) to analyze microstructure formation in thin aluminum alloys solidified in the
Bridgman facility installed at the ID19 beamline. During directional solidification of Al - 3.5 wt%
Ni alloys, global mechanical constraints induced by the shape are found to act on the solid
microstructure. In particular, radiography videos of dendritic growth show disorientations of
sidebranches induced by mechanical stresses. In the solidification of AlPdMn quasicrystals, live
imaging reveals that facetted growth proceeds by the lateral motion of ledges at the solid-melt
interface. When the solidification rate is increased, the kinetic undercooling becomes sufficient for
grain nucleation and growth in the liquid. These grains develop specific features that can be
attributed to grain competition and concomitant poisoning of growth caused by the rejection of
aluminum in the melt.
Finite Element Modeling of Space Charge Phenomena on the Nanoscale
Authors: Franceschetti Donald R.
Published: March 2009

The NernstPlanckPoisson
(NPP) system of equations provides a continuum
model for the behavior of interfacial charge in solid ionic conductors. Despite the obvious
limitations in using such models to describe systems a few atomic diameters in extent, the
success of the PoissonBoltzmann
equation in modeling the electrostatic interactions of
individual molecules with their ionic atmospheres suggests that continuum solutions have
some value as a first approximation in describing charge distributions in nanoparticles and
thin layers.
Except for static charge distributions onedimensional
geometries, solution of the NPP
equations requires numerical approximation. Here we examine the applicability of the finite
element method to the study of space charge phenomena in selected 1 and 2dimensional
geometries, comparison to exactly soluble onedimensional
cases to gauge the validity of the
results.
Atom Probe Tomography: Studying Reactions on Top of the Tip
Authors: Schmitz Guido , Ene Constantin , Lang Ch. , Vovk Vitaliy
Published: March 2009

Down-scaling is a major principle of modern technology. As a consequence, the
stability of many technical devices is controlled by solid state reactions that proceed on the range of
a few nanometres only. On such a short length scale even basic aspects of reaction physics as
fundamental as e.g. the Ficks laws of diffusion, need to be reconsidered.
Only very few dedicated techniques are suitable to study atomic transport and reactions with
sufficient accuracy. Among them, the atom probe tomography is exceptional, as it allows the
detection and localization of individual atoms with an accuracy of a lattice constant. An almost
complete reconstruction of the 3D atomic arrangement of different atomic species gets possible.
This article provides an overview on recent atom probe studies of reactive diffusion. After an
introduction into the principles of the analysis method, physical mechanisms of solid state reactions
are discussed in view of recent experiments at metallic thin film interfaces. How does nucleation of
an interfacial product take place In which way do grain boundaries influence the reaction As a
technical example, the stability of Cu/NiFe GMR sensor layers is discussed.
Study on Microstructure and Magnetic Properties of TM-Mg (TM: Fe, Co) Alloys Synthesized by Mechanical Alloying
Authors: Chiba Masafumi , Hotta Hideki , Sotoma Atsushi , Kuji Toshiro
Published: March 2009

Magnesium alloys are extremely attractive candidates for hydrogen storage applications
since they can potentially absorb hydrogen between 3 and 8 wt.%. The purpose of this work is to
understand the microstructural and the magnetic properties for 3d-transition metal and magnesium
alloys with the difficult to alloy by the conventional method due to the positive value of mixing
enthalpy. We successfully formed alloys of iron or cobalt, and magnesium powders with a wide
range of compositions by mechanical alloying and characterized synthesized alloys with an X-ray
diffractometer, a TEM, an SEM-EPMA and a vibration sample magnetometer. The obtained Fe-Mg
alloys containing less than 25 at.% Mg were single phase bcc with expanded lattice parameter. The
average powder particle size changes with Mg composition. The magnetization of the samples
showed a linear dilution with content of Mg. The opposite variations in lattice parameter and the
coercive force with Mg content were observed. On the other hand, we observed markedly
broadened XRD lines from Co-Mg alloy compounds. The microstructure of these powders implies
that the alloy could be partially amorphized or changed into a nanostructure as expected from
microscopy and an XRD results.
Power Generation Using Oxide Thermoelectric Modules
Authors: Funahashi Ryoji , Urata Saori , Mihara Toshiyuki , Nabeshima Naoki , Iwasaki Kanako
Published: March 2009

Different versions of thermoelectric unicouples composed of p-type Ca3Co4O9
(Co-349) and n-type LaNiO3 (Ni-113) or CaMnO3 (Mn-113) bulk materials were
prepared. In the unicouples p- and n-type legs were connected with Ag electrodes
using Ag paste including various oxide powders with various ratios. For the
Co-349/Ni-113 unicouples, maximum output power (Pmax) reaches 177mW at a hot
side temperature (TH) of 1073K and a temperature differential (ΔT) between TH and
cold side temperature of 500K at 6wt% of Co-349 powder. On the other hand, the
lowest internal resistance (RI) is observed in a Co-349/Mn-113 unicouple prepared
using Ag paste including 3wt% of Mn-113 powder. Thermoelectric modules
consisting of 8 pairs of oxide legs were fabricated using the same method with the
unicouples. The open circuit voltage (VO) and Pmax increase with increasing TH and
reach 0.392 V and 0.314 W, and 0.911 V and 0.233 W at a TH of 1273 K in air for the
Co-349/Ni-113 and Co-349/Mn-113 modules, respectively.
Molecular Simulation of Ion-Transport inside Chitosan Membranes
Authors: López-Chàvez Ernesto , Solorza-Guzmàn Misael , de Landa Castillo-Alvarado Fray
Published: March 2009

We have presented general ideas to develop a theoretical methodology, based
on Molecular simulation and Einstein equation aimed to describe the mechanism and
behavior of chitosan-membrane ion conductivity and to obtain its magnitude for
different ionic species. Atomistic molecular modelling has been utilized to construct an
ionic-conducting polymer electrolyte system consisting of poly(chitosan), H O 2
molecules, and + H O 3 , − OH , 2−
4 SO ions, inside of the simulation cell. The COMPASS
force field was used. The simulation allows describing the mechanism of ionic
conductivity along the polymer matrix. The theoretical results obtained are compared
with previously-reported experimental data for chitosan membranes. The present
methodology can be considered as a first step towards understanding these complex
problems of technological interest.
Hydrogen Diffusion Mechanisms and Hydrogen-Dopant Interactions in Diamond
Authors: Chevallier Jacques , Jomard François , Saguy Cecile , Kalish R. , Deneuville A.
Published: March 2009

Electronic grade diamond is usually grown by Microwave Plasma assisted CVD from
a hydrogen rich CH4/H2 mixture, hence hydrogen is likely to be incorporated during growth. It
may thus affect the properties of the material. In this work, we present the state of the art on the
understanding of the diffusion properties of hydrogen and of the hydrogen-dopant interactions in
diamond. First, we show the existence of strong interactions between H and boron dopants in
diamond. The formation of H-acceptor pairs results in the passivation of the acceptors. Further,
we show that an excess of hydrogen in selected boron-doped diamond epitaxial layers can result
in the creation of H and boron-containing donors with a ionization energy of 0.36 eV (about half
the ionization energy of phosphorus). At 300 K, the n-type conductivity of hydrogenated borondoped
diamond is several orders of magnitude higher than the conductivity of phosphorus-doped
diamond. The formation process of these new donors is discussed.