bluuebunny/crossref_metadata_2025 huggingface dataset:
A biomecânica e a produção do conhecimento em fisioterapia: levantamento baseado nos anais do congresso brasileiro de biomecânica
Authors: Costa Paula Hentschel Lobo da , Moreira Roberta de Fátima Carreira , Foltran Fabiana Almeida , Selistre Luiz Fernando Approbato , Santos Kleber Luis Silva , Castro Kelli Cristina de , Lima Natália Targas , Coletta Teresinha das Graças
Published: January 2013

O aumento gradual da participação da comunidade acadêmica da Fisioterapia nas edições do Congresso Brasileiro de Biomecânica (CBB) é notório. Os Anais do CBB passaram a ser importantes veículos para a divulgação científica em Fisioterapia no Brasil; porém, a caracterização dessa produção ainda não foi feita. O objetivo do presente estudo foi realizar um levantamento bibliográfico dos estudos em Fisioterapia publicados nas edições dos Anais do CBB, desde a primeira edição em 1992 (Anais do IV CBB) até a edição publicada em 2009 (Anais do XIII CBB), a fim de identificar quais especialidades da Fisioterapia têm aplicado o conhecimento em Biomecânica no contexto clínico e/ou científico, além de caracterizar o tipo de pesquisa que se tem desenvolvido. Seis revisores independentes levantaram os estudos pertencentes à área da Fisioterapia e coletaram informações de maneira padronizada através de questionários. Os resultados evidenciaram um grande crescimento da participação das diferentes áreas da Fisioterapia ao longo das dez edições do CBB. Embora os dados sejam positivos em relação à ampliação das pesquisas em Biomecânica, verificou-se uma carência da utilização dos recursos biomecânicos para avaliar efeitos de intervenções em pacientes. Dessa forma, recomenda-se que mais estudos sejam conduzidos em contextos clínicos e com acompanhamento longitudinal, de modo a ampliar a aplicação prática das ferramentas biomecânicas no campo da intervenção, bem como aperfeiçoar a avaliação em Fisioterapia.
Efeitos do uso de órteses na Doença de Charcot-Marie-Tooth: atualização da literatura
Authors: Pereira Rouse Barbosa , Orsini Marco , Ferreira Arthur de Sá , Silva Júlio Guilherme , Corrêa Clynton Lourenço , Freitas Marcos RG De , Coelho Valéria Marques , Goulart Mario Cézar , Kagohara Nelson , Souza Gabriela Guerra Leal , Menezes Sara Lúcia de
Published: January 2013

A Doença de Charcot-Marie-Tooth (DCMT) é a neuropatia periférica hereditária mais comum em seres humanos, apresentando incidência de 1:2.500 pessoas. A fraqueza distal crural na DCMT provoca inúmeras alterações na marcha, como, por exemplo, na velocidade, no comprimento, na largura e cadência dos passos. Vários recursos em reabilitação têm sido propostos para gerenciar os problemas de deambulação, dentre eles, destaca-se a utilização de órteses. O objetivo deste estudo é apresentar e discutir os resultados de estudos sobre os efeitos da utilização de órteses nos padrões de marcha na DCMT. Neste estudo foi utilizada atualização da literatura através das principais bases de dados nacionais/internacionais (SciELO, LILACS e MEDLINE), publicados entre os anos de 2006-2012. O tratamento da DCMT consiste em fisioterapia e utilização de equipamentos de assistência, visto que ainda não há fármacos ou terapia gênica capaz de atenuar os danos clínicos e funcionais. Tal associação busca maximizar a função e melhorar a qualidade de vida desses pacientes, na tentativa de evitar agravos adicionais relativos à incapacidade física. A partir de atualização de literatura é possível concluir que existe consenso sobre a utilização de órteses nos membros inferiores para promover a estabilização das articulações do tornozelo e um padrão de deambulação mais funcional, evitando sinergias inadequadas de movimento e atenuando o risco de quedas.
Description of Two New Species of Dryocosmus (Hymenoptera: Cynipidae: Cynipini) Inducing Galls on the Strictly Asian Subgenus Cyclobalanopsis of the Genus Quercus, with a Key to Species of Dryocosmus in East Asia
Authors: Ide Tatsuya , Wachi Nakatada , Abe Yoshihisa
Published: January 2013

ABSTBACT

Two new species of Dryocosmus (Hymenoptera: Cynipidae: Cynipini), D. sefuriensis Ide, Wachi et Abe, sp. nov. and D. sakureiensis Ide, Wachi et Abe, sp. nov., are described from Japan. A key to species of Dryocosmus in East Asia is given. Although the members of Dryocosmus have been known to induce galls on the subgenus Quercus of the genus Quercus and the genera Castanea, Castanopsis, Chrysolepis, and Lithocarpus of Fagaceae, this is the first record of this gall wasp genus from the strictly Asian subgenus Cyclobalanopsis of the genus Quercus. The discovery of two new species of Dryocosmus associated with Q. (C.) acuta suggests the exceptionally diverse host range of Dryocosmus and the species richness of Cynipini on this plant subgenus in Asia.
A Conspicuous Intoxication in Bombyx mori (Lepidoptera: Bombycidae) Caused by a Fungicide Containing Iminoctadine Triacetate
Authors: Arakawa T , Ito K , Kidokoro K , Kadono-Okuda K , Yukuhiro F , Noda H
Published: January 2013

ABSTBACT

We showed that an oral administration of a fungicide containing iminoctadine triacetate had a delayed effect on the development of Bombyx mori (L.) larvae. Larvae that ingested a diet with a moderate dose of formulated-iminoctadine triacetate throughout the third instar stage developed to the next (fourth) instar stage; thereafter they stopped growing. Those larvae died finally after prolonged fourth instar duration without molting to the next (fifth) instar stage. Dietary intake of the larvae showing the growth inhibition was significantly lower than that of the control group. Fourth instar larvae were reared with restricted amount of diet that was comparable to that of formulated-iminoctadine-treated specimens. These dietary restricted larvae grew at a slower pace and reached a lower maximum weight than controls; however, they developed to the next (fifth) instar stage. Nevertheless, the weight of which was smaller than the control group. These results suggested that reduced food intake did not cause the failure to molt to fifth instar. In the larvae affected by formulated-iminoctadine, “housekeeping genes” (18S ribosomal RNA, actin 3, elongation factor 2, and nsd-2) were expressed normally. From these results, it is assumed that the formulated-iminoctadine-treated larvae lost the capacity of high assimilatory performance and could not build up their body mass furthermore.
Invasive Stink Bug Wounds Trees, Liberates Sugars, and Facilitates Native Hymenoptera
Authors: Martinson Holly M , Raupp Michael J , Shrewsbury Paula M
Published: January 2013

ABSTBACT

Biological invasions often have devastating impacts on ecosystems and economies, while facilitative interactions between invasive and native species are often overlooked. Here, we demonstrate how the invasive brown marmorated stink bug, Halyomotpha halys (Stål) (Hemiptera: Pentatomidae), facilitates native Hymenoptera by opening a novel feeding niche. In the invaded mid-Atlantic region of the United States, several species of native ants and wasps feed on wound exudates from stink bug feeding sites; these exudates have high sugar concentrations and are rapidly used by indigenous Hymenoptera. Positive facilitative interactions between invasive and keystone native species such as ants may have far reaching impacts on invaded ecosystems.
The Diurnal Rhythmicity of Bactrocera cucurbitae (Diptera: Tephritidae) Attraction to Cuelure: Insights from an Interruptable Lure and Computer Vision
Authors: Manoukis Nicholas C , Jang Eric B
Published: January 2013

ABSTBACT

We introduce a novel method for quantifying the response of tephritid fruit flies to chemical attractants (lures) under seminatural conditions by using automated detection and quantification via computer vision and an interruptible lure apparatus. We use this method to obtain a high-resolution (0.1 Hz) dataset representing the response of colony-reared melon flies, Bactrocera cucurbitae Coquillett, to cuelure [1-(p-acetoxyphenyl)-butan-3-one] at three different times of the day: morning (0900–1000 hours), mid (1200–1300 hours), and afternoon (1500–1600 hours), or all three times combined. Results consistently show a high and sustained response to cuelure in the morning period, a high but quickly decreasing response during the middle of the day and a low response in the afternoon. We propose possible reasons for the difference in response between the morning and middle of the day periods that could be investigated in future studies. The approach used here also can be used to study other important questions on the biology of tephritid fruit flies and other insects of similar size, particularly those involving their response to chemical lures.
Energy indicators based on multi-source data and participation
Authors: Costa Silvia Dalla
Published: January 2013

The research presented is focused on new technologies and citizens’ participation in decision making with specific reference to their role in the construction of local knowledge to analyse energy performance of buildings. The first part describes the conceptual framework of the information system and the second part outlines the test phase, designed for validation and carried out in an Italian local administration. This stage was necessary to realise a three-dimensional geodatabase containing information derived from public archives, and gathered using energy monitoring and a survey conducted on a sample population. The collected data have been used to create a series of energy geo-indicators at urban and architectural scale, related to the main components that influence the energy performance – the system/envelope of building, context, and user. This was set up during the participatory activities with all the local stakeholders and then used to draw up a sustainable energy plan.
Data dimension: accessing urban data and making it accessible
Authors: Nabian Nashid , Offenhuber Dietmar , Vanky Anthony , Ratti Carlo
Published: January 2013

New technologies allow for new ways to sense the city. Thinking of urban data as substance, this paper criticises a certain approach in dealing with urban-related data analysis when it comes to identifying certain patterns and deriving narratives based on these patterns. In this approach, coined here as the ‘big data’ approach, having access to large-volume datasets is considered sufficient to study a phenomena and its very dynamics that the data refers to. In contrast to this, this paper examines ways in which data can be produced, modified and delivered; in any of these steps, there is an ongoing cost–benefit analysis, based on which a series of necessary decisions in terms of resolution and quality of data through the lens of filtering has to be made with the goal of accessing data and making it accessible most effectively. Projects from MIT SENSEable City Lab are used to better illustrate these ideas.
Selecting artificial intelligence urban models using waves of complexity
Authors: Wu Ning , Silva Elisabete A.
Published: January 2013

Urban land use change is a complex and dynamic process. It is therefore important to understand the complexity involved with system dynamics and choose appropriate modelling approaches. For this purpose, this paper firstly reviews how artificial intelligence (AI) approaches provide solutions to aid urban land dynamics modelling. The three dimensions that are considered pivotal for the understanding of urban dynamic processes – urban land dynamics, planning support and AI infrastructure – are defined. Once these three dimensions are clarified, it is possible to propose the different solution spaces provided by AI approaches using a graphic representation of a cube and its associated mathematical formulation. It is therefore possible to understand and define the best data model to represent the complexity of different phenomena in urban systems.
The classical and Hellenistic economy and the “Paleo-Balkan” hinterland a case study of the iron age “Hellenized settlements”
Authors: Vranic Ivan
Published: January 2013

Dozens of similar fortified settlements exhibiting a familiarity with some
Greek building techniques and traditions existed in some parts of the Balkans
during the Iron Age, especially from the fifth to third century BC. The
settlements are documented in a vast continental area stretching from
modern-day Albania, the FYR Macedonia and south central Serbia to Bulgaria.
Archaeological interpretations mostly accept that economic factors and trade
with late Classical and early Hellenistic Greece were instrumental in their
emergence, and the phenomenon is interpreted as Greek ?influence? and local
?imitation? of Mediterranean culture. Presenting the most influential
interpretations of the Classical and Hellenistic economy and some
perspectives in economic anthropology, this paper examines the traditional
(mostly formalistic) culture-historical understanding of the Balkan
?Hellenized settlements? of the mid-first millennium BC and Mediterranean
interrelations. It also looks at the construction and role of status identity
as a crucial social factor in shaping the Iron Age communities in the
hinterland, and defines possible trade and exchange activities as only one
aspect of the identity of a burgeoning elite.
The isles of great silence monastic life on Lake Scutari under the patronage of the Balsics
Authors: Tomic-Djuric Marka
Published: January 2013

At the time Zeta was ruled by the local lords of the Balsic family, in the
late fourteenth and the first half of the fifteenth century, the islets in
Lake Scutari (Skadarsko jezero) in Zeta were lively centres of monastic life.
The paper looks at the forms of monastic life as suggested by the spatial
organization and architecture of the monastic complexes founded by the
Balsics, and by the surviving written sources. The most important documentary
source is the correspondence between Jelena Balsic and her spiritual father,
Nikon, preserved in the manuscript known as Goricki zbornik (Gorica
Collection). The letters show that Lake Scutari was a centre of monasticism
touched by hesychast-inspired spirituality where both the eremitic and
coenobitic ways of life were practised.
Serbs in Romania relationship between ethnic and religious identity
Authors: Djuric-Milovanovic Aleksandra
Published: January 2013

The paper looks at the role of religion in the ethnic identity of the Serbs
in Romania, based on the fieldwork conducted in August 2010 among the Serbian
communities in the Danube Gorge (Rom. Clisura Dun?rii; loc. Ser. Banatska
klisura), western Romania. A historical perspective being necessary in
studying and understanding the complexities of identity structures, the paper
offers a brief historical overview of the Serbian community in Romania. Serbs
have been living in the Banat since medieval times, their oldest settlements
dating back to the fourteenth and fifteenth centuries. Today, they mostly
live in western Romania (Timi?, Arad, Cara?-Severin and Mehedin?i counties),
Timi?oara being their cultural, political and religious centre. Over the last
decades, the community has been numerically declining due to strong
assimilation processes and demographic trends, as evidenced by successive
census data (34,037 in 1977; 29,408 in 1992; 22,518 in 2002). The majority
belong to the Serbian Orthodox Church (Diocese of Timi?oara), but a number of
neo-Protestant churches have appeared in the last decades. The research
focuses on the role of the Orthodox religion among the Serbian minority in
Romania and the role of new religious communities in relation to national
identity. The role of the dominant Serbian Orthodox Church in preserving and
strengthening ethnic identity is looked at, but also influences of other
religious traditions which do not overlap with any particular ethnic group,
such as neo-Protestantism. With regard to the supranational nature of
neo-Protestantism, the aim of the study is to analyze the impact of these new
religions on assimilation processes among the Serbs in Romania and to examine
in what ways different religious communities influence either the
strengthening or the weakening of Serbian ethnic identity.
The Bulgarian-Yugoslav dispute over the Macedonian question as a reflection of the Soviet-Yugoslav controversy (1968-1980)
Authors: Sfetas Spyridon
Published: January 2013

During the Cold War, relations between Bulgaria and Yugoslavia were marred by
the Macedonian Question. Bulgaria challenged the historical roots of the
Macedonian nation, whereas Yugoslavia insisted that Bulgaria should recognize
the rights of the Macedonian minority within her borders. The Soviet Union
capitalized on its influence over Bulgaria to impair Yugoslavia?s
international position. Bulgaria launched an anti-Yugoslav campaign
questioning not only the Yugoslav approach to Socialism, but also the
Yugoslav solution of the Macedonian Question. This antipathy became evident
in 1968, in the wake of the events in Czechoslovakia. In the years 1978/9 the
developments in Indochina gave a new impetus to the old Bulgarian-Yugoslav
conflict.
Imagining the Serbs revisionism in the recent historiography of nineteenth-century Serbian history
Authors: Kovic Milos
Published: January 2013

The end of the Cold War has brought about a complete change of the political
and social context in the world. Consequently, history, as a scholarly
discipline, has also undergone a significant transformation. In this broader
context, with the destruction of Yugoslavia, the interpretations of the
Serbian nineteenth century have been experiencing a far-reaching revision. It
is necessary, therefore, to scrutinize the main topics of the debate on
nineteenth-century Serbian history in recent world historiography, as well as
to examine the main causes of this academic revision.
Design of a multimodal hearing system
Authors: Tessendorf Bernd , Debevc Matjaz , Derleth Peter , Feilner Manuela , Gravenhorst Franz , Roggen Daniel , Stiefmeier Thomas , Tröster Gerhard
Published: January 2013

Hearing instruments (HIs) have become context-aware devices that analyze the
acoustic environment in order to automatically adapt sound processing to the
user?s current hearing wish. However, in the same acoustic environment an HI
user can have different hearing wishes requiring different behaviors from the
hearing instrument. In these cases, the audio signal alone contains too
little contextual information to determine the user?s hearing wish.
Additional modalities to sound can provide the missing information to improve
the adaption. In this work, we review additional modalities to sound in HIs
and present a prototype of a newly developed wireless multimodal hearing
system. The platform takes into account additional sensor modalities such as
the user?s body movement and location. We characterize the system regarding
runtime, latency and reliability of the wireless connection, and point out
possibilities arising from the novel approach.
Biomechanical modeling of knee for specific patients with chronic anterior cruciate ligament injury
Authors: Filipovic Nenad , Isailovic Velibor , Nikolic Dalibor , Peulic Aleksandar , Mijailovic Nikola , Petrovic Suzana , Cukovic Sasa , Vulovic Radun , Matic Aleksandar , Zdravkovic Nebojsa , Devedzic Goran , Ristic Branko
Published: January 2013

In this study we modeled a patient specific 3D knee after anterior cruicate
ligament (ACL) reconstruction. The purpose of the ACL reconstruction is to
achieve stability in the entire range of motion of the knee and the
establishment of the normal gait pattern. We present a new reconstruction
technique that generates patient-specific 3D knee models from patient?s
magnetic resonant images (MRIs). The motion of the ACL reconstruction
patients is measured by OptiTrack system with six infrared cameras. Finite
element model of bones, cartilage and meniscus is used for determination
stress and strain distribution at different body postures during gait
analysis. It was observed that the maximum effective von Mises stress
distribution up to 8 MPa occurred during 30% of the gait cycle on the
meniscus. The biomechanical model of the knee joint during gait analysis can
provide insight into the underlying mechanisms of knee function after ACL
reconstruction.
Hydro-information system for drought monitoring
Authors: Gocic Milan , Trajkovic Slavisa
Published: January 2013

Drought is a natural hazard caused by the variability in climate, which
cannot be prevented. However, its effects can be reduced through management
systems incorporating drought monitoring. The main aim of this paper is the
presentation of information system for monitoring drought warning based on
the model with optimal set of hydro-meteorological parameters: minimal
number, availability of gauge data and spatial distribution of measuring
locations. Monitoring the relevant hydro-meteorological parameters and
creation of suitable forecast tools within a hydro-information system for
monitoring drought warning would serve as a platform for decision making in
drought effects reduction. Significance of this idea is in the substitution
of complex climatological models. It requires time and maintenance
investments with a practical method for estimation of drought duration and
intensity which will satisfy the users' needs and will not require
considerable economic investment.
The Neogene lakes on the Balkan land
Authors: Krstic Nadezda , Savic Ljubinko , Jovanovic Gordana
Published: January 2013

Palaeogeographic maps of the lacustrine Miocene and Pliocene have been
constructed according to all the known geological data. The Lakes of the
Balkan Land, depending on the tectonics, migrated due to causes from the deep
subsurface. There are several phases of the Miocene lakes: the lowermost
Miocene transiting from marine Oligocene, Lower, Middle, Upper Miocene
covering, in patches, the main part of the Land. The Pliocene lakes spread
mostly to the north of the Balkan Land and covered only its marginal parts.
Other lake-like sediments, in fact freshened parts of the Black Sea
Kuialnician (Upper Pliocene), stretched along the middle and southern
portions of the Balkan Peninsula (to the south of the Balkan Mt.).
Subsequently, the Balkan Peninsula was formed.
Temperature dependent tunability data and modeling in the paraelectric Ba0.7Sr0.3TiO3 solid solutions
Authors: Curecheriu Petronela , Mitoseriu Liliana , Ianculescu Adelina
Published: January 2013

The field dependence of the dielectric constant (dc-tunability) as a function of temperature in (Ba,Sr)TiO3 ceramics was investigated. Dense and homogeneous BaxSr1-xTiO3 ceramics prepared by Pechini method show low losses, high dielectric constant of ~4000 and typical ferroelectric properties at room temperature. The dc-tunability at various temperatures, including the Curie range, was obtained. A single polarization mechanism was used in the polar state of the ceramics to describe the tunability data. A good correlation between theory and experiment was found. In the paraelectric phase, a model of random uncorrelated non-interacting dipolar units in a double well potential was considered.
BaTiO3 thick films obtained by tape casting from powders prepared by the oxalate route
Authors: Ianculescu Adelina , Guillemet-Fritsch Sophie , Durand Bernard
Published: January 2013

BaTiO3 powders were prepared by co-precipitation via oxalate route. The size, morphology and particle size distribution of the oxalate powders have been optimized by the control of different synthesis parameters during the precipitation reaction (nature of salts, concentration of different solutions, aging time). The single phase BaTiO3 oxide particles were obtained after a thermal decomposition of the as-synthesized powders at 850?C for 4 hours under air atmosphere. Oxide powders with a suitable specific surface area were selected in order to obtain thick films by the tape casting technique. The microstructure and dielectric properties of the thick films varied obviously depending on the deposition-calcination-sintering cycle used. A double deposition-calcination cycle followed by sintering, as well as a two step deposition-calcination-sintering procedure was used in order to improve the compactness and therefore, the dielectric behaviour. A higher dielectric constant value (~ 750) and lower dielectric losses (~ 2 %) were achieved at room temperature and at 1 kHz frequency for the dense, double-deposited film obtained after two deposition-calcination-sintering cycles. For this film, a superior value of the dielectric constant (~ 1100), almost frequency independent in the frequency range of 100 Hz - 10 kHz was gained also at the ferroelectric-paraelectric phase transition temperature of 130?C. .
Dielectric investigations of BiFeO3 ceramics
Authors: Greicius Simonas , Banys Juras , Szafraniak-Wiza Izabela
Published: January 2013

In this paper we present the results from the investigation of the dielectric permittivity of BiFeO3 ceramics, prepared by mechanochemical synthesis method in a broad frequency and temperature range. The dielectric permittivity is mainly caused by high conductivity, which is suppressed in the frequencies above 1 MHz. The investigated ceramics showed conductivity activation energy E/k = 11280?12 K, and ?0 = 54161?800 S. The plots of M*revealed conductivity mechanism with ?0 = 1.12?10-13s, and E/k = 9245 K. .
Electrical and thermal properties of 10 mol% Gd3+ doped ceria electrolytes synthesized through citrate combustion technique
Authors: Mangalaraja Viswanathan , Ananthakumar Solaiappan , Paulraj Manidurai , Uma Kasimayan , López Marta , Camurri Porro , Avila Enrique
Published: January 2013

Nanocrystalline ceria electrolyte doped with 10 mol% gadolinia [Ce0.9Gd0.1O1.95] was synthesized by citric acid combustion technique involving mixtures of cerium nitrate oxidizer (O) and citric acid fuel (F) taken in the ratio of O/F=1. The as combusted precursors produced crystalline ceria particles upon calcination performed at 700?C for 2h. Ceria pellets were made and sintered at temperatures 1200, 1400 and 1500?C with a dwell time of 2, 4 and 6 h. The sintered microstructures, electrical and thermal conductivities and thermal diffusivity properties were evaluated in addition to the powder properties such as crystalline structure, surface area, particle size and morphology. Sintered ceria samples had 99% theoretical density at 1500?C/6h. The sintered microstructures exhibit dense ceria grains with sizes 500 nm to one micron. The electrical conductivity versus temperature showed conductivity in the order of 10-2 and 10-1 S?cm-1 at 500 and 700?C, respectively. The ceria sintered at 1500?C has the maximum thermal conductivity of ~2.79 W?m-1K-1 at room temperature. .
Infrared and THz spectroscopy of nanostructured dielectrics
Authors: Petzelt Jan
Published: January 2013

Results achieved using the infrared/THz spectroscopy of various inhomogeneous dielectrics in the Department of Dielectrics, Institute of Physics, Prague, during the last decade are briefly reviewed. The discussion concerns high-permittivity ceramics with inevitable low-permittivity dead layers along the grain boundaries, relaxor ferroelectrics with highly anisotropic polar nano-regions, classical matrix-type composites, core-shell composites, filled nanoporous glasses, polycrystalline and epitaxial thin films, heterostructures and superlattices on dielectric substrates. The analysis using models based on the effective medium approach is discussed. The importance of depolarizing field and of the percolation of components on the effective ac dielectric response and the excitations contributing to it are emphasized. .
Effect of compacting pressure, powder degassing and thermobaric treatment on densification and properties of nanocrystalline titanium nitride
Authors: Kapylou Andrei , Urbanovich Vladimir , Andrievski Rostislav , Kuznetsov Denis , Nohrin Aleksey , Klimczyk Piotr
Published: January 2013

The effects of compacting pressure, powder degassing and high pressure sintering temperature and time on the densification and properties of nanocrystalline titanium nitride have been investigated. For this reason, TiN powder with a mean particle size of 55 nm was pressed in the range of compacting pressure from 0.2 to 1.0 GPa and sintered under static pressure of 3.5 GPa in the temperature range of 900-1600?C for 45-120 s. Some of green bodies were degassed in vacuum before sintering. It was shown that samples compacted in the pressure range of 0.2-0.6 GPa have the highest density after the thermobaric treatment. The maximum density (about 97.3 %TD) was obtained with degassed samples. Microhardness and microstructure investigations have shown that recrystallization of the TiN nanopowder begins at the sintering temperatures of 1100-1200?C and sintering time less than one minute. The maximum microhardness obtained was 23.2?1.0 GPa and the maximum Young modulus was 370 GPa.
Microwave dielectric properties of BiFeO3 thin film prepared by aqueous chemical solution deposition method
Authors: Sobiestianskas Ricardas , Hardy An , Banys Jūras , D'haen Jan , van Bael
Published: January 2013

We report high frequency dielectric properties of multiferroic BiFeO3 (BFO) thin film deposited by means of aqueous chemical solution deposition on platinized silicon substrate. The structure analysis of the BFO performed by X-ray diffraction and energy dispersive analysis showed pure, single-phase quality of the thin films. The impedance measurements were performed by vector network analyzer in frequency range 100 MHz to 10 GHz at ambient temperature. The film leakage currents dominate dielectric losses at low frequencies. The dielectric constant of the film is around 40. An internal charged defects acting as energy traps for electrons dominate dielectric losses in the frequency region above 4 GHz. .
Master sintering curves of two different alumina powder compacts
Authors: Pouchly Vaclav , Maca Karel
Published: January 2013

Concept of Master Sintering Curve is a strong tool for optimizing sintering schedule. The sintering behaviour can be predicted, and sintering activation energy can be calculated with the help of few dilatometric measurements. In this paper an automatic procedure was used to calculate Master Sintering Curves of two different alumina compacts. The sintering activation energies were determined as 640 kJ/mol for alumina with particle size of 240 nm, respective 770 kJ/mol for alumina with particle size of 110 nm. The possibility to predict sintering behaviour with the help of Master Sintering Curve was verified. .
Synthesis of biomorphic Si-based ceramics
Authors: Egelja Adela , Devecerski Aleksandar , Gulicovski Jelena , Rosic Milena , Babic Biljana , Matovic Branko
Published: January 2013

Tilia wood was transformed by pyrolysis into carbon preform. This porous carbon preform was infiltrated with TEOS (Si(OC2H5)4), as a source of silica. In situ reaction between the silica and the carbon template occurred in the cellular wall at a hight temperature. Depending on the applied atmosphere, non-oxide (SiC) or oxide (SiO2) ceramics were obtained. Scanning electron microscopy (SEM), X-ray diffraction (XRD), infrared (IR) spectroscopy, mercury porosimetry and BET measurements were employed to characterize the phases and crystal structure of biomorphic ceramics. The experimental results showed that the biomorphic cellular morphology of the wood maintained in both the SiC and SiO2 ceramics, wich consisted of ?-SiC with trace of ?-SiC and SiO2, respectively. .
In vitro bioactivity of biphasic calcium phosphate silicate glass-ceramic in CaO-SiO2-P2O5 system
Authors: Radev Lachezar , Hristov Vladimir , Michailova Irena , Fernandes Helena , Salvado Miranda
Published: January 2013

The main purpose of the paper is the evaluation of the influence of chemical composition of the gel of the synthesized 15CaO?0.5P2O5-6SiO2 glass-ceramic on the structure, crystallization behaviour and in vitro bioactivity in static conditions for different periods of time - 3, 9 and 30 days in 1.5SBF. The obtained glass-ceramic was synthesized via polystep sol-gel technique. The structure of the prepared and the one thermally treated at 1200?C for 2 h powder was studied by XRD, 29Si MAS NMR, FTIR and SEM. .
Calcium phosphate bioceramics prepared from wet chemically precipitated powders
Authors: Salma Kristine , Berzina-Cimdina Liga , Borodajenko Natalija
Published: January 2013

In this work calcium phosphates were synthesized by modified wet chemical precipitation route. Contrary to the conventional chemical precipitation route calcium hydroxide was homogenized with planetary mill. Milling calcium oxide and water in planetary ball mill as a first step of synthesis provides a highly dispersed calcium hydroxide suspension. The aim of this work was to study the influence of main processing parameters of wet chemical precipitation synthesis product and to control the morphology, phase and functional group composition and, consequently, thermal stability and microstructure of calcium phosphate bioceramics after thermal treatment. The results showed that it is possible to obtain calcium phosphates with different and reproducible phase compositions after thermal processing (hydroxyapatite [HAp], ?-tricalcium phosphate [?-TCP] and HAp/?-TCP) by modified wet-chemical precipitation route. The ?-TCP phase content in sintered bioceramics samples is found to be highly dependent on the changes in technological parameters and it can be controlled with ending pH, synthesis temperature and thermal treatment. Pure, crystalline and highly thermally stable (up to 1300?C) HAp bioceramics with homogenous grainy microstructure, grain size up to 200-250 nm and high open porosity can be successfully obtained by powder synthesized at elevated synthesis temperature of 70?C and stabilizing ending pH at 9. .
Barium titanate thick films prepared by screen printing technique
Authors: Vijatovic Mirjana , Bobic Jelena , Stojanovic Biljana , Malic Barbara
Published: January 2013

The barium titanate (BaTiO3) thick films were prepared by screen printing technique using powders obtained by soft chemical route, modified Pechini process. Three different barium titanate powders were prepared: i) pure, ii) doped with lanthanum and iii) doped with antimony. Pastes for screen printing were prepared using previously obtained powders. The thick films were deposited onto Al2O3 substrates and fired at 850?C together with electrode material (silver/palladium) in the moving belt furnace in the air atmosphere. Measurements of thickness and roughness of barium titanate thick films were performed. The electrical properties of thick films such as dielectric constant, dielectric losses, Curie temperature, hysteresis loop were reported. The influence of different factors on electrical properties values was analyzed.
Beneficial effect of multi-wall carbon nanotubes on the graphitization of polyacrylonitrile (PAN) coating
Authors: Darányi Mária , Csesznok Tamás , Sarusi István , Kukovecz Ákos , Kónya Zoltán , Erdőhelyi András , Kiricsi Imre
Published: January 2013

Polyacrylonitrile (PAN) solutions were deposited on quartz plates by spin coating to yield 2-3 ?m thick PAN films. The films were decomposed at 1000?C in N2 atmosphere into electrically conducting carbonaceous coatings. When the precursor solution contained cobalt (0.2 g Co-acetate per 1 g PAN) and/or multi-wall carbon nanotubes (MWCNTs, 2 mg MWCNT per 1 g PAN) the specific electrical resistance of the product film dropped from the original 492 ??cm-1 value down to 46 ??cm-1. By excluding all other possibilities we came to the conclusion that the beneficial effect of carbon nanotubes is related to their catalytic action in the final graphitization of condensed nitrogen-containing rings into graphitic nanocrystallites.
Effect of cooling rate after hot pressing on electrical conductivity of Si3N4-ceramics with TiO2 and TiH2 additives
Authors: Cherniakova Iryna , Zdolnik Svitlana , Petrovsky Vitaly
Published: January 2013

It has been established that cooling rate after hot pressing has influence on microstructure, electrical conductivity and charge storage in Si3N4 ceramics with TiO2 and TiH2 additives, which can be used as substrates for the large capacity micro assemblies by Flip-Chip technology. It was shown that the critical cooling rate is 30?C/min for the Si3N4-TiO2 and 50?C/min for the Si3N4-TiH2 ceramics. Electrical conductivity is structurally sensitive property, strongly connected with evolution of Si3N4 microstructure. The best properties are typical for Si3N4 ceramics characterized by mono-trap state level with the activation energy of about 0.8 eV, obtained at the characteristic cooling rates. .
Low temperature sintered ZnTio3 dielectric ceramics with temperature coefficient of dielectric constant near zero
Authors: Chaouchi Ahcéne , Kennour Sadia , D'Astorg Sophie , Marinel Sylvain , Aliouat Mohamed
Published: January 2013

ZnTiO3 compound is an attractive dielectric ceramics owing to its interesting dielectric properties in high frequency range (?r = 19, QXf = 30,000GHz, ?? ? + 120 ppm/?C). The structure, microstructure and dielectric properties of sintered ZnTiO3, with a mixture of ZnO-B2O3 glass phase and CuO oxide as sintering aids, have been investigated. For all compounds, the sintering temperature becomes 850?C due to the glass addition. It is also shown that the addition of CuO oxide allows a control of the temperature coefficient of the permittivity (??). This parameter varies from positive to negative values with increasing the CuO content. The ZnTiO3 composition sintered at 850?C with 5 wt.% ZnO-B2O3 glass phase and 2.2 wt.% CuO addition exhibits attractive dielectric properties (?r = 23, tan ? < 10-3 and a temperature coefficient of the dielectric constant near zero, ?? = 3 ppm/?C) at 1 MHz. All these properties lead this system compatible for manufacturing Ag based electrodes multilayer dielectrics devices needed for LTCC application or other multilayer dielectric components. .
Numerical differentiation methods for the logarithmic derivative technique used in dielectric spectroscopy
Authors: Haspel Henrik , Kukovecz Ákos , Kónya Zoltán , Kiricsi Imre
Published: January 2013

In dielectric relaxation spectroscopy the conduction contribution often hampers the evaluation of dielectric spectra, especially in the low-frequency regime. In order to overcome this the logarithmic derivative technique could be used, where the calculation of the logarithmic derivative of the real part of the complex permittivity function is needed. Since broadband dielectric measurement provides discrete permittivity function, numerical differentiation has to be used. Applicability of the Savitzky-Golay convolution method in the derivative analysis is examined, and a detailed investigation of the influential parameters (frequency, spectrum resolution, peak shape) is presented on synthetic dielectric data.
Nanoferroelectric perovskite oxides with unusual morphology produced by different synthesis procedures
Authors: Bassano Alessio , Kalayani Vishwanath , Curecheriu Lavinia , Buscaglia Maria , Buscaglia Vincenzo , Mitoseriu Liliana , Nanni Paolo
Published: January 2013

We report in the present paper some original results of a joint research performed in the framework of the COST Action 539 ELENA. In search of higher miniaturisation of electroceramic devices a new outlook seems to arise from ceramics with unusual morphology that might present a new kind of circular or toroidal ferroelectric ordering of dipoles. Completely new perspectives in data storage can be expected if a close control of size confinement and dimensionality as well as of the chemical composition and the phase purity is reached. We succeeded in the fabrication of BaTiO3 hollow nanoparticles and nanowires, and Bi4Ti3O12 platelets. The use of soft chemistry and solid state methods allowed to produce coreshell powders and ferroelectric-ferromagnetic composites with completely new functional properties.
Perovskite type nanopowders and thin films obtained by chemical methods
Authors: Fruth Viktor , Popa Monica , Calderon-Moreno Jose , Tenea Ecaterina , Anastasescu Mihai , Osiceanu Petre , Anghel Elena , Predoana Luminita , Malic Barbara , Zaharescu Maria
Published: January 2013

The review presents the contribution of the authors, to the preparation of two types of perovskites, namely BiFeO3 and LaCoO3, by innovative methods. The studied perovskites were obtained as powders, films and sintered bodies. Their complex structural and morphological characterization is also presented. The obtained results have underlined the important influence of the method of preparation on the properties of the synthesized perovskites.
Dielectric investigations of La-doped barium titanate
Authors: Ramoska Tadas , Banys Juras , Sobiestianskas Ricardas , Vijatovic-Petrovic Mirjana , Bobic Jelena , Stojanovic Biljana
Published: January 2013

In the present paper results of the dielectric investigation of barium titanate (BaTiO3) doped with different concentrations of lanthanum are presented. Ceramic samples were prepared by the Pechini process. With increased doping the grain size of ceramics decreases from 2.5 ?m in pure samples down to 0.2 ?m in 0.5 mol% La - doped BaTiO3. Ceramics showed maximally enhanced dielectric permittivity around low-, room and high temperature phase transitions, which are the phase transitions of the pure BaTiO3. The Curie temperature, TC, is lowered by 30 K with increase of doping concentration to 0.5 mol% La. Dielectric spectra revealed three parts: low frequency part which is caused by conductivity process, middle frequency relaxational process part and high frequency relaxational/polar modes contribution.
Thickness dependent magnetic transitions in pristine MgO and ZnO sputtered thin films
Authors: Kapilashrami Mukes , Jun Xu , Rao K.V. , Belova Lyubov
Published: January 2013

We report a systematic study of the thickness dependency of room temperature ferromagnetism in pristine MgO (~100-500 nm) and ZnO (~100-1000 nm) thin films deposited by reactive magnetron sputtering technique under the respective identical controlled optimum oxygen ambience. As far as we know this is the first such report on ferromagnetic pure MgO thin films, a result which should be of significance in understanding the functional aspects of magnetic tunnelling characteristics in devices using MgO dielectrics. From the magnetic characterization we observe a distinct variation in the saturation magnetization (MS) with increasing film thickness. In the case of MgO thin films MS values vary in the range 0.04-1.58 emu/g (i.e. 0.0012-0.046 ?B/unit cell) with increasing film thickness showing the highest MS value for the 170 nm thick film. Above this thickness MS is found to decrease and eventually above 420 nm the films show a paramagnetic behaviour followed by the well known diamagnetic property for the bulk (>500 nm). It is obvious that since initially the MS values increase with thickness, there has to be a maximum before the films become diamagnetic at some finite thickness. We also note that the MS values observed for MgO are the highest (more than twice the value observed for ZnO) to be reported for such a defect induced ferromagnetism in a pristine oxide. The origin of ferromagnetic order in both the oxides appears to arise from the respective cat-ion vacancies. The discovery of film thickness dependent ferromagnetic order should be very useful in developing multifunctional devices based on the technologically important materials MgO and ZnO.
Development of porous ceramics by lycopodium using uniaxial pressing and sintering
Authors: Serzane Rita , Locs Janis , Berzina-Cimdina Liga , Sadretdinovs Romans
Published: January 2013

In this work microporous hydroxyapatite (HAp) ceramics were fabricated using lycopodium as a porosifier. The samples were produced by uniaxial pressing and then heating at high temperatures, 1100?C and 1200?C, to burn-out porogens and sintering. The obtained samples had porosity over the variable range of 12 to 45% with different pore size ranging from 0.2 to 25 ?m. Chemical and physical characterization was determined by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and bending strength measurements. The bending strength of the prepared samples was in the range of 1.97-21.81 MPa.
Structural determination of new solid solutions [Y2-xMx][Sn2-xMx]o7-3x/2 (M = Mg or Zn) by Rietveld method
Authors: Douma Mohamed , El Hossain , Trujillano Raquel , Rives Vicente
Published: January 2013

New [Y2-xMx][Sn2-xMx]O7-3x/2 (0 ?x? 0.30 for M = Mg and 0 ?x? 0.36 for M = Zn) solid solutions with the pyrochlore structure were synthesized via high-temperature solid-state reaction method. Powder X-ray diffraction (PXRD) patterns and Fourier transform infrared (FT-IR) spectra showed that these materials are new non-stoichiometric solid solutions with the pyrochlore type structure. The structural parameters for the solids obtained were successfully determined by Rietveld refinement based on the analysis of the PXRD diagrams. Lattice parameter (a) of these solid solutions decreases when x increases in both series. All samples obtained have the pyrochlore structure Fd-3m, no. 227 (origin at center -3m) with M2+ (M = Mg2+ or Zn2+) cations in Y3+ and Sn4+ sites, thus creating vacancies in the anionic sublattice.
Structural changes induced by argon ion irradiation in TiN thin films
Authors: Popovic Maja , Novakovic Mirjana , Rakocevic Zlatko , Bibic Natasa
Published: January 2013

In this work, the effects of 120 keV Ar+ ion implantation on the structural properties of TiN thin films were investigated. TiN layers were deposited by d.c. reactive sputtering on Si(100) wafers at room temperature or at 150?C. The thickness of TiN layers was ~240 nm. After deposition the samples were irradiated with 120 keV argon ions to the fluencies of 1?1015 and 1?1016 ions/cm2. Structural characterization was performed with Rutherford backscattering spectroscopy (RBS), cross-sectional transmission electron microscopy (XTEM), grazing angle X-ray diffraction (XRD) and atomic force microscopy (AFM). It was found that the argon ion irradiation induced the changes in the lattice constant, mean grain size, micro-strain and surface morphology of the TiN layers. The observed micro-structural changes are due to the formation of the high density damage region in the TiN thin film structure.
Ion-beam irradiation effects on reactively sputtered CrN layers
Authors: Novakovic Mirjana , Popovic Maja , Bibic Natasa
Published: January 2013

This paper presents a study of micro-structural changes induced in CrN layers by irradiation with 120 keV argon ions. The layers were deposited on (100) Si wafers, at different nitrogen partial pressures (2?10-4, 3.5?10-4 and 5?10-4 mbar), to a total thickness of 260-280 nm. During deposition the substrates were held at 150?C. After deposition the samples were irradiated with argon ions to the fluencies of 1?1015 and 1?1016 ions/cm2, under the vacuum of 7?10-6 mbar. Characterization of the samples structure and morphology were performed by X-ray diffraction (XRD) analysis and cross-sectional transmission electron microscopy (XTEM), and the concentration profiles were determined by Rutheford backscattering (RBS) spectrometry. It was found that the layer composition strongly depends on the nitrogen partial pressure during deposition. A pure stoichiometric CrN phase was achieved for the highest nitrogen partial pressure (5?10-4 mbar). Argon ions irradiation induces micro-structural changes in the CrN layers such as variation of the lattice constants, micro-strain and mean grain size.
Natural CaO-TiO2-SiO2 based ceramics
Authors: Pantic Jelena , Kahlenberg Volker , Poharc-Logar Vesna , Kremenovic Aleksandar
Published: January 2013

Lesnica river deposits consist of a large number of minerals of different grain sizes including sphene. Since it is very difficult to obtain pure monophase titanite by different synthetic routes (sol-gel, coprecipitation, combustion, spray pyrolysis and hydrothermal method), the aim of this work was to study the structure of the sphene from the Lesnica river deposits and possibility of using it as a natural precursor for CaO-TiO2-SiO2 based ceramics. The sphene from Lesnica was analyzed by different methods: tristimulus colorimetry, infrared spectroscopy, electron microprobe and X-ray single crystal diffraction. It was confirmed that Al, Fe, Mn and P are present in the sphene structure and proposed that corresponding structural formula could be: (Ca2+1.008 Mn2+0.002)1.010(Ti4+0.901 Fe3+0.033 Al3+0.060 P5+0.001)0.995 Si4+1.024 O2-5.