bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of New Polymer Systems and Quantum Dots - Polymer Nanocomposites for Low-cost, Flexible OLED Display Applications
Authors: Zhao Lihua , Zhou Zhang-Lin , Guo Zengshan , Pei Jian , Mao Samuel
Published: September 2011

Recently, tremendous progress has been made toward application of organic (small molecule/polymer) light-emitting diodes (OLEDs) in full color flat panel displays and other devices. However, with current technologies, OLEDs are still struggling with high manufacturing costs which really limit the size of OLEDs panels and with life time, especially differential aging of colors. To be more cost-effective for fabricating OLEDs, we believe solution-processing would be an attractive path due to its simplicity and highly reduced equipment costs. This proceeding paper discusses our recent progress in development of new polymer systems that are highly solvent-resistant but maintaining their photophysical properties and hybrid quantum-dots (QDs)-polymer nanocomposites for their use in multicolor and multilayer OLEDs pixels through solution-processing. Our new polymer systems are named conductive semi-interpenetrating polymer networks (C-Semi-IPNs) served in different layers of OLEDs devices, containing an inert polymer network and conducting polymer(s) including hole transport and emissive materials. Since these do not require complicated chemical modification or introduction of reactive moieties to OLED materials, many state-of-the-arts emissive polymers can be utilized to achieve RGB and white OLEDs. The research findings on hybrid QDoligomer nanocomposite as a good analogue lead to the successful design and synthesis of QDpolymer nanocomposites which were used to build proof-of-the-concept devices showing a good promise in providing excellent color purity and stability as well as device robustness.
Electronic Excitation Induced Solid-State Amorphization in Ge-Sb-Te Alloy
Authors: Li Xian-Bin , Liu X.Q. , Liu Xin , Han Dong , Zhang Z. , Han X.D. , Zhang S. B.
Published: September 2011

On the basis of ab initio molecular dynamics modeling, we show that Ge-Sb-Te alloy under excitation can realize amorphization without going through a liquid phase. The electronic structure analysis further reveals that the excitation mainly involves the Ge s-like states near the valence band maximum. After the phase transition, the coordination number of Ge is reduced from six to four, while the change in the coordination number for Sb is noticeably less.
Influence of the pH on the Surface and Optical Properties of the Thin Film of Polyaniline / Polyethylene Terephthalate Composite. The AFM and Spectroscopies Studies
Authors: Paschoalin Rafaella T. , Steffens Clarice , Manzoli Alexandra , Hlophe Mhbuti R. , Herrmann Paulo S. P.
Published: September 2011

The effect of pH was investigated on the morphological and spectroscopic properties of PANI thin films on PET. PANI/PET strips were prepared by a pattern-printing technique and coated with a thin film of polyaniline in situ emeraldine oxidation state, doped with HCl (PANI-HCl), obtained by in situ polymerization. AFM, UV-VIS-NIR and FTIR/ATR spectroscopic results showed that pH has a great influence on the polymer layer morphology of the coating layers, while the intensity of vibrational bands decreases with rising pH, increase due to changes in the H-bonded structure in the polymer chain.
Conductive Polymer Bilayers – A Spectroelectrochemical Look at Their Doping Reactions
Authors: Gustafsson Henrik , Kvarnström Carita , Ivaska Ari
Published: September 2011

The doping behavior of bilayers of electropolymerized poly(3,4-ethylenedioxythiophene) doped with hexafluorophosphate and drop-cast poly(benzobisimidazobenzophenanthroline) was studied with cyclic voltammetry, and with in situ ultraviolet-visible and attenuated total reflectance Fourier transform infrared spectroscopy. The spectroelectrochemical characterization of the polymer bilayers provided us with fundamental information of the properties of the materials, information being essential in order to be able to use the conducting polymers in future real-life applications, e.g., as organic semiconducting components.
Development of Si Microliquid Processing using Piezo Actuator
Authors: Akazawa Muneki , Koyanagi Shunki , Higashi Seiichiro
Published: September 2011

The tip of a Si rod was melted by laser diode (LD) irradiation and we succeeded in dropping small Si droplets by vibration of the Si rod using a piezo actuator. We confirmed multiple small Si droplets under a condition of the resonance frequency of 5.8 kHz for the rod length of 6.0 mm. We observed ejection of droplets from a cone edge of molten Si and the minimum width of the solidified Si was ∼ 1 μ m in diameter. The solidified Si show high crystallinity with the Raman scattering TO phonon band of 515.6 cm-1.
Hierarchically Nanostructured Zeolites of Tunable Porosities with Aerogel Templating
Authors: Tao Yousheng , Endo Morinobu , Kaneko Katsumi
Published: September 2011

We present the synthesis of resorcinol-formaldehyde aerogels and carbon aerogels of different nanoporosities, emphasizing on the recent developments in fabrication pathways of lower cost. Recent results showed a simple way to the production of highly nanoporous carbon xerogels. While using an approach combined colloidal silica nanocasting and carbon dioxide supercritical drying, hydrophilicity-controlled carbon aerogels with high mesoporosity were synthesized. Then, we demonstrate the functions of these aerogels for template synthesis of hierarchically nanostructured zeolites having micropores and mesopores.
Optical characterization using ellipsometry of Si nanocrystal thin layers embedded in silicon oxide
Authors: Agocs E. , Petrik P. , Fried M. , Nassiopoulou A. G.
Published: September 2011

We have developed optical models for the characterization of grain size in nanocrystal thin films embedded in SiO2 and fabricated using low pressure chemical vapor deposition of Si from silane on a quartz substrate, followed by thermal oxidation. The as-grown nanocrystals thin film on quartz was composed of a two-dimensional array of Si nanocrystals (Si-NC) showing columnar structure in the z-direction and touching each other in the x-y plane. The nanocrystal size in the z-direction was equal to the Si nanocrystal film thickness, changing by the deposition time, while their x-y size was almost equal in all the samples, with small size dispersion. After high temperature thermal oxidation, a thin silicon oxide film was formed on top of the nanocrystals layer. The aim of this work was to measure the grain size and the nanocrystallinity of the Si nanocrystal thin films, a quantity related to the change of the dielectric function. We used a definition for the nanorcystallinity that is related to the effective medium analysis (EMA) of the material. The optical technique used for the investigations was spectroscopic ellipsometry. To measure the above sample properties the thickness and composition of several layers on a quartz substrate had to be determined by proper modeling of this complex system. We found that the nanocrystallinity (defined as the ratio of nc-Si/(c-Si+nc-Si) decreases systematically with increasing the Si-NC layer thickness. Using this approach we are sensitive to the lifetime broadening of electrons caused by the scattering on the grain boundaries, and not to the shift of the direct interband transition energies due to quantum confinement.
Tailoring of Boehmite-Derived Aluminosilicate Aerogel Structure and Properties: Influence of Ti Addition
Authors: Hurwitz Frances I. , Guo Haiquan , Sheets Erik J. , Miller Derek R. , Newlin Katy N.
Published: September 2011

Aluminosilicate aerogels offer potential for extremely low thermal conductivities at temperatures greater than 900°C, beyond where silica aerogels reach their upper temperature limits. Aerogels have been synthesized at various Al:Si ratios, including mullite compositions, using Boehmite (AlOOH) as the Al source, and tetraethoxy orthosilicate as the Si precursor. The Boehmite-derived aerogels are found to form by a self-assembly process of AlOOH crystallites, with Si-O groups on the surface of an alumina skeleton. Morphology, surface area and pore size varies with the crystallite size of the starting Boehmite powder, as well as with synthesis parameters.

Ternary systems, including Al-Si-Ti aerogels incorporating a soluble Ti precursor, are possible with careful control of pH. The addition of Ti influences sol viscosity, gelation time pore structure and pore size distribution, as well as phase formation on heat treatment.
Reliability of Oxide Thin Film Transistors under the Gate Bias Stress with 400 nm Wavelength Light Illumination
Authors: Lee Soo-Yeon , Kim Sun-Jae , Lee Yongwook , Lee Woo-Geun , Yoon Kap-Soo , Kwon Jang-Yeon , Han Min-Koo
Published: September 2011

We have investigated the reliability of the inverted-staggered etch stopper structure oxide-based TFTs under negative gate bias stress combined with 400 nm wavelength light illumination and the relationship between the carrier concentration at the channel and the extent of Vth shift. It was found that the photo-induced holes cause the severe Vth degradation at the beginning of stress and the hole trapping rate of a single hole is not altered with the increase of the hole concentration. In oxide-based TFTs, the hole concentration at the channel is the determinant factor of the reliability.
Thin-film Photodiode with an a-Si:H/nc-Si:H Absorption Bilayer
Authors: Vygranenko Y. , Vieira M. , Sazonov A.
Published: September 2011

We report on the fabrication and characterization of n+-n-i-δi-p thin-film photodiodes with an active region comprising a hydrogenated nanocrystalline silicon (nc-Si:H) n-layer and a hydrogenated amorphous silicon (a-Si:H) i-layer. The combination of wide- and narrow-gap absorption layers enables the spectral response extending from the near-ultraviolet (NUV) to the near-infrared (NIR) region. Moreover, in the low-bias range, when only the i-layer is depleted, the leakage current is significantly lower than that in the conventional nc-Si:H n+-n-p+ photodiode deposited under the same deposition conditions. Device with the 900nm/400nm thick n-i-layers exhibits a reverse dark current density of 3 nA/cm2 at −1V. In the high-bias range, when the depletion region expands within the n-layer, the magnitude of the leakage current depends on electronic properties of nc-Si:H. The density of shallow and deep states, and diffusion length of holes in the n-layer have been estimated from the capacitance-voltage characteristics and from the bias dependence of the long-wavelength response, respectively. To improve the quantum efficiency in the NIR-region, we have also implemented a Cr / ZnO:Al back reflector. The observed long-wavelength spectral response is about twice as high as that for a reference photodiode without ZnO:Al layer. Results demonstrate the feasibility of the photodiode for low-level light detection in the NUV-to-NIR spectral range.
Influence of Annealing in H2 Atmosphere on the Electrical Properties of Thin Film CdS
Authors: Maticiuc Natalia , Hiie Jaan , Potlog Tamara , Valdna Vello , Gavrilov Aleksei
Published: September 2011

Chemical bath-deposited (CBD) thin film CdS has been widely used as a buffer and n-type window layer in CdS/CIGS and CdS/CdTe thin film solar cells. Annealing of CBD CdS assigns to the layers required concentration and mobility of electrons, crystallinity, structural stability and perfect Ohmic front contact in TCO/CdS interface. But always annealing reduces band gap (Eg) of solution-deposited CdS and lowers current density of the CdS/CdTe PV device due to optical absorption within the CdS layer.

We have studied systematically dynamics of changes in CBD CdS/glass thin film structural, optical and electrical properties in annealing process in H2 ambient at normal pressure in pre-heated ceramic tubular furnace. Here we’ll present electrical, characterization results of annealed CBD CdS/glass thin films, 300 nm thick. The films were deposited with thiourea from ammoniacal 1 mM dilute solution of CdSO4 and 0.001 at. % of NH4Cl relative to Cd for Cl doping.

We found high concentration of electrons 1-4 E19 cm-3 in the layers annealed at 200–450 °C, while for 200 °C the long time of annealing over 60 min is needed, but for high temperature region 350–450 °C only for short 10 min annealing this concentration region of electrons was achieved. In the high temperature region rapid decrease of electron concentration and conductivity will go on with increasing annealing temperature and time. Mobility of electrons will decrease from 9 to 5 cm2/V·s in the annealing region 200–350 °C, which is probably connected with disordering of lattice. On the basis of acquired results we propose an hypothesis about substitutional incorporation of OH group on S site in CdS lattice in deposition process and that (OH)s complex defect acts as a donor defect like Cl and we believe that the both defects are responsible for changes of thin film CdS electrical, optical and structural properties in the annealing process. Thermal annealing in hydrogen atmosphere is a convenient and appropriate method for precise control of CdS thin film electrical properties, and also for creation of n/n+ CdS window layers in the substrate configuration of a solar cell.
Zinc Nitride Films by Reactive Sputtering of Zn in N2-Containing Atmosphere
Authors: Jiang Nanke , Georgiev Daniel G. , Jayatissa Ahalapitiya H. , Wen Ting
Published: September 2011

Fabrication, microstructure, chemical bonding and composition, and optical properties of zinc nitride films are investigated in this work. The films were deposited by reactive magnetron rf sputtering of zinc in N2-Ar ambient. Based on X-ray diffraction data, the as-deposited films are polycrystalline with cubic zinc nitride structure and (400) preferred orientation. Well defined Zn-N, N-N, as well as Zn-O and H-O bonding configurations are revealed by X-ray photoelectron spectroscopy data. The as-deposited films are found to be almost-stoichiometric and contain only a small fraction of oxygen. A direct band gap of 1.5 eV is obtained by using the photon energy dependence of the optical absorption of the films. This result is confirmed independently by spectroscopic ellipsometry.
Characterization of thermal interface resistance in thermoelectric generators
Authors: Koripella C. Ramesh , Bell Lon E. , Crane Doug , Wang Dazhi
Published: September 2011

Thermoelectric generators are actively being pursued to recover waste heat from the auto exhaust gas to improve vehicle fuel economy. Efficiency of a thermoelectric generator is defined as the ratio of electrical power output to the heat input. In a typical thermoelectric generator, a heat exchanger captures the heat from the medium (ex: hot exhaust gas heat) and this heat needs to be transferred to the hot end of the thermoelectric elements with minimum losses. It is important to understand and minimize these thermal losses to improve the efficiency of a thermoelectric generator. Accurate measurement of the thermal interface resistance parameters is also important because they are used in a comprehensive thermoelectric system model to predict the performance of the generator under actual use conditions. To understand the factors influencing the thermal interface resistance, and to determine the effective thermal interface resistance between the heat exchanger and the thermoelectric hot shunts in a prototype generator that is currently being developed for auto exhaust heat recovery application, we have designed and built a test setup to characterize the thermal interface resistance under high heat flux conditions. Measured temperature profiles in the test sample, heat input into the test device and its geometry are fed into a thermal model to extract the thermal conductance parameters. Factors affecting the thermal interface resistance and the influence of different interface materials were evaluated. Suitable solutions with minimum thermal loss were selected for building the prototype thermoelectric generator for waste heat recovery application and validating the system model.
Modification of iridium catalyst with rhenium oxide for the hydrogenolysis of glycerol to 1,3-propanediol
Authors: Amada Yasushi , Koso Shuichi , Nakagawa Yoshinao , Tomishige Keiichi
Published: September 2011

Rhenium-oxide-modified supported iridium nanoparticles on silica catalyzes direct hydrogenolysis of glycerol to 1,3-propanediol in an aqueous media. The selectivity to 1,3-propanediol at an initial stage reaches 67%. The yield of 1,3-propanediol reaches 38% at 81% conversion of glycerol. The characterization of catalyst shows that oxidized Re clusters are formed on Ir metal particles. The synergy between Ir metal and ReOx clusters enables the catalytic activity.
Graphene Role as Platinum Support for CO and Formic Acid Electrooxidation
Authors: Guo Shirui , Sarialtin Huseyin , Alia Shaun , Akin Hayri Engin , Yan Yushan , Ozkan Cengiz S. , Ozkan Mihrimah
Published: September 2011

The direct methanol fuel cell (DMFC) is a promising power source for electronic applications due to its high efficiency and compactness. To improve the efficiency, many support materials have been developed. We investigated uniform graphene nanoflake films as a support for catalytic Pt nanoparticles in direct carbon monooxide and formic acid electro-oxidation. Pt nanoparticles were deposited on the surface of graphene films with chemical reduction method. Chemical functionalization of graphene with ethylenediamine enables Pt nanoparticles mobilize on graphene uniformly. By simply changing the loading amount of Pt precursor, various particle sizes were achieved. The particle size of Pt plays prominent role in fuel cell test. The electrochemically active surface area of different sample are 6.3 (5 wt% Pt/G), 4.1 (20 wt% Pt/G), and 3.0 (50 wt% Pt/G) cm2mg-1 corresponding to the particle size 3±1nm, 10±2nm, 20±2nm respectively. The results obtained are ascribed to a uniform network made of 2-4 nm Pt monolayer nanopaticles on the surface of graphene flakes. Graphene will play significant role in developing next-generation advanced Pt based fuel cells and their relevant electrodes in the field of energy.
Um olhar sobre o corpo: o corpo ontem e hoje
Authors: Barbosa Maria Raquel , Matos Paula Mena , Costa Maria Emília
Published: September 2011

O entendimento dos sentidos construídos para o corpo na actualidade requer uma caminhada, ainda que breve, pela história, pela forma como o corpo foi pensado e sentido. Deste modo, neste ensaio em torno do tema do corpo, propomos pensar nalguns aspectos sociais e culturais, que contribuíram para a construção do corpo na nossa sociedade, a forma como ele tem sido e pode ser olhado e representado.
Amor e ciúme na contemporaneidade: reflexões psicossociológicas
Authors: Baroncelli Lauane
Published: September 2011

O presente artigo deriva-se da dissertação de Mestrado da autora que trata do ciúme nas relações amorosas contemporâneas. Partindo da perspectiva de que o ciúme na experiência amorosa é uma condição historicamente constituída, procuramos, neste estudo, investigar teoricamente as consequências que as práticas e princípios culturalmente estabelecidos na contemporaneidade têm sobre a experiência de ciúme dos indivíduos contemporâneos. Na busca desse objetivo, nosso estudo, a seguir, busca refletir sobre alguns impactos que o momento histórico atual tem produzido no domínio do amor, para, finalmente, discutir algumas maneiras de compreender o ciúme que se revela numa experiência amorosa que, nos dias de hoje, se vê marcada por intensa transitoriedade, flexibilidade e abertura.
Rappresentazioni sociali dell'invecchiamento tra psicologia sociale e letteratura
Authors: Contarello Alberta , Marini Ilaria , Nencini Alessio , Ricci Gaia
Published: September 2011

Scopo del presente lavoro è proporre l'analisi di testi letterari per lo studio delle rappresentazioni sociali dell'invecchiamento. Dopo un'introduzione al tema, con cenni ai recenti sviluppi in termini di invecchiamento positivo e all'utilità di un maggiore interscambio tra psicologia sociale e letteratura, vengono presentati i risultati di analisi quali-quantitative e qualitative di due recenti opere italiane. Sia l'analisi delle corrispondenze, sia una lettura più qualitativa dei testi, restituiscono indicazioni preziose rispetto all'intento di co-costruire un modo di Invecchiare Bene. Assonanze e divergenze rispetto alla letteratura psico-sociale sull'invecchiamento contribuiscono ad una lettura critica e generativa dell'ultimo 'dono del tempo'.
Espaço e subjetividade: estudo com ribeirinhos
Authors: Alves Andréia Duarte , Justo José Sterza
Published: September 2011

Nesta pesquisa, investigamos as transformações vividas por uma comunidade afetada pela construção de uma usina hidrelétrica no rio Paraná. Utilizando procedimentos da etnografia, realizamos várias visitas à comunidade, reassentada numa vila planejada e construída para substituir a antiga vila que foi submersa. Estabelecemos contatos com os moradores mais antigos e produzimos, com eles, diálogos entabulados em situações diversas, como em visitas às próprias casas e rodas de conversa ocorridas nas calçadas. Nas falas dos ribeirinhos, a mudança do espaço é sentida como algo negativo, em todos os planos da vida. Ressentem-se da perda do rio, da pesca farta, da caça realizada nas matas, das terras férteis cultivadas nas barrancas, da socialidade e de toda produção de subjetividade que mantinham naquele lugar marcado pela proximidade com o rio e suas águas.
Análise da transferência de calor em paredes compostas por diferentes materiais
Authors: Specht Luciano Pivoto , Borges Pedro Augusto Pereira , Rupp Ricardo Forgiarini , Varnier Rosane
Published: September 2011

O projeto de edificações energeticamente eficientes necessita de conhecimentos sobre a transferência de calor proveniente do ambiente externo, a fim de criar soluções que associem diferentes materiais e espessuras às condições desejadas de conforto térmico. O objetivo deste trabalho é avaliar diversos tipos e disposições de materiais em paredes de tijolos maciços, sob a ótica da térmica de edifícios. Para a realização dos experimentos, modelos em escala real foram confeccionados, instrumentados e acoplados a uma câmara térmica, desenvolvida especialmente para esse fim. O problema de transferência de calor foi modelado pela equação da energia, resolvida em Diferenças Finitas Centrais, utilizando-se o Método Implícito. As difusividades térmicas dos materiais foram calculadas resolvendo o Problema Inverso de transferência de calor. Também foi calculado o fluxo de calor e o custo total de cada alternativa, finalizando-se com a obtenção da relação termoeconômica para cada parede. Através da análise termoeconômica pode-se constatar que, apesar de o investimento inicial ser relativamente maior nas paredes mais espessas e/ou com isolamento térmico, estas apresentam um comportamento térmico muito superior às tradicionais. Notadamente, a parede com EPS na face exterior apresentou o melhor desempenho.
Métodos de aplicação da simulação computacional em edifícios naturalmente ventilados no clima quente e úmido
Authors: Trindade Sileno Cirne , Pedrini Aldomar , Duarte Raimundo Nonato Calazans
Published: September 2011

A ventilação natural é o principal recurso passivo para a obtenção do conforto térmico em climas quentes e úmidos, reduzindo também o consumo energético com condicionamento artificial. Entretanto, arquitetos fazem restrição a seu uso por não haver garantias de solução dos problemas de conforto térmico, quando comparada aos sistemas artificiais. Nesse sentido, decidiu-se investigar formas de prever o comportamento da ventilação natural em edifícios através de ferramentas de simulação computacional, visando apoiar a tomada de decisão no projeto de arquitetura. O objeto de estudo é o edifício pré-fabricado, do tipo galpão, considerado como típico na cidade de Natal, RN. Utilizaram-se um programa de dinâmica de fluidos computacional (CFD) e um de simulação térmica e energética de edificações. O artigo tem como foco a discussão dos procedimentos necessários para viabilizar as análises da ventilação, indicando como o método teve de ser adequado à complexidade de sucessivas abordagens, resultando em simplificações e incertezas de resultados. Para exemplificar a abordagem apresentam-se alguns resultados de simulações. Ao final, as limitações e potencialidades do método são discutidas com base nas características dos códigos de simulações utilizados, das condições de simulação e da representatividade dos modelos.
Conforto térmico propiciado por algumas espécies arbóreas: avaliação do raio de influência através de diferentes índices de conforto
Authors: Abreu Loyde Vieira , Labaki Lucila Chebel
Published: September 2011

As características termorreguladoras das árvores podem ser mais bem aproveitadas quando há um conhecimento sobre o conforto térmico proporcionado por um indivíduo arbóreo isolado em seu raio de influência. Vários índices de avaliação de conforto térmico têm sido utilizados, mas poucos são, de fato, adaptados à realidade brasileira. O objetivo deste trabalho é comparar os resultados de três índices de conforto térmico em ambientes externos, a Carta Bioclimática Tridimensional para clima Tropical de Altitude, o PET e o PMV, para a avaliação do comportamento de três diferentes espécies arbóreas no microclima urbano: ipê-amarelo, jambolão e mangueira. A pesquisa foi dividida em três etapas: (a) seleção dos locais de medição apropriados e os indivíduos arbóreos; (b) coleta dos parâmetros ambientais: radiação solar, temperatura do ar e de globo, velocidade do vento e umidade relativa do ar; e (c) comparação de índices por meio do parâmetro Unidade de Hora Confortável. Os resultados mostram que o conforto térmico propiciado pelas diferentes espécies ao longo do ano, independentemente dos índices utilizados na análise, dependem da arquitetura da copa. O ipê-amarelo é a espécie que proporciona melhor sensação de conforto térmico, enquanto as espécies perenes, como o jambolão e a mangueira, têm maior influência sobre a sensação térmica no entorno imediato no período de verão do que no inverno, com condições mais confortáveis encontradas à sombra da copa da árvore.
Desempenho acústico de paredes de blocos e tijolos cerâmico: uma comparação entre Brasil e Portugal
Authors: Ferreira Neto Maria de Fatima , Bertoli Stelamaris Rolla
Published: September 2011

Alguns questionamentos sobre a relação entre desempenho acústico e o conforto acústico percebido contribuíram para o início desta pesquisa, que estuda o desempenho e conforto acústicos de ambientes compostos por blocos e tijolos cerâmicos, respectivamente no Brasil e em Portugal. Os tijolos portugueses apresentam 11,0 cm e 15,0 cm de espessura, enquanto os blocos brasileiros 11,5 cm e 14,0 cm de espessura. A avaliação do comportamento acústico desses elementos consistiu de testes em laboratório e em campo. Os critérios de desempenho utilizados para a avaliação do desempenho acústico foram a norma ABNT NBR 15575, do Brasil, e o Decreto-lei nº 96/2008, de Portugal. A avaliação do conforto acústico consistiu na análise da participação de um júri, que indicou a percepção de sentenças emitidas por vozes feminina e masculina, em simulação de convivência entre vizinhos adjacentes. Os resultados do desempenho acústico dessas paredes estão aquém do recomendado pelos critérios locais para o uso como parede de geminação. A avaliação dos resultados com o júri corroborou essa conclusão. Quanto ao desempenho acústico, verifica-se que a indústria da construção civil destes dois países deve aprimorar-se para atender aos critérios da nova norma.
The Changing Face of Anemia Treatment
Authors: Lappin Terry
Published: September 2011

An overview of the manuscripts published in this supplemental issue of The Oncologist is provided.
Management of Anemia in Cancer Patients: Transfusions
Authors: Schrijvers Dirk
Published: September 2011

Anemia in cancer patients can be treated with transfusions, and 15% of patients with solid tumors are being treated by transfusions. Different cutoff values are used for transfusions, depending on clinical symptoms and patient characteristics, with a hemoglobin (Hb) level of <9 g/dL most commonly used. After the administration of one unit of red blood cells (RBC), the Hb rises with 1 g/dL, and the life span of transfused RBC is 100–110 days. Complications related to RBC transfusion are procedural problems, iron overload, viral and bacterial infections, and immune injury. RBC transfusions have been related to increased risk of the development of non-Hodgkin lymphoma and chronic lymphocytic leukemia, and are related to a worse treatment outcome in selected cancers. In addition, the cost of a transfusion for the patient and society is around 300–500 euros per unit transfused. RBC transfusions should be used carefully to correct anemia in patients with cancer.
Determinants and dynamics of banded vegetation pattern migration in arid climates
Authors: Deblauwe Vincent , Couteron Pierre , Bogaert Jan , Barbier Nicolas
Published: September 2011

Dense vegetation bands aligned to contour levels and alternating at regular intervals with relatively barren interbands have been reported at the margins of all tropical deserts. Since their discovery in the 1950s, it has been supposed that these vegetation bands migrate upslope, forming a space–time cyclic pattern. Evidence to date has been relatively sparse and indirect, and observations have remained conflicting. Unequivocal photographic evidence of upslope migration (a few decimeters per year) is provided here for three independent dryland areas exhibiting periodic banded pattern: (1) the U.S. northeastern Chihuahuan Desert, (2) the Somalian Haud, and (3) the Mediterranean steppes of eastern Morocco. Migration speeds, averaged through time and space using Fourier cross‐spectral analysis, are shown to be directly proportional to pattern scale (wavelength). A sequence of aerial photographs of the Chihuahuan Desert showed that migration was not continuous, but intermittent in response to fluctuating weather regimes. The rates at which bands expanded upslope and contracted downslope were better predicted by the change in annual rainfall than by its average level. However, the migration of banded patterns cannot be considered as systematic because in our observations of three other banded systems located in the Somalian Haud, central Australia, and western New South Wales, migration was undetectable at the available image resolution. In each of the six sites under study, the modal value of band orientation axes was verified to be approximately orthogonal to the steepest slope. Our results underscore the importance of taking both the spatial structure and the past climate sequence into account for understanding vegetation dynamics in arid to semiarid ecosystems. In addition, we show how Fourier spectral analysis applied to historical series of optical images can serve to quantify landscape dynamics at a decadal time scale.
Coupling microbiological testing and sanitary surveys in drinking water quality programs: results from Capiz Province, Philippines
Authors: Patrick J. Molly , Murcott Susan , Punsalan Jarvis
Published: September 2011

Developing countries often struggle to conduct laboratory-based water quality testing programs due to a lack of financial and technical resources. However, inexpensive, accurate, field-based tests are being developed which have the potential to overcome this barrier. This paper provides the results of an initiative by the Provincial Health Office in Capiz, Philippines, to conduct a first-ever, provincial, microbiological water quality test program. The effort was a collaboration with students from Massachusetts Institute of Technology, which aimed to identify sources most at risk, to test field-based analytical methods against standard methods, and to make recommendations for improving supplies in the short and long term. The microbiological, chlorine residual, and sanitary survey results are described in this paper. The results showed that there was an increasing trend in water quality from ‘unimproved’ to treated and/or piped supplies, but that many ‘improved’ point sources were contaminated. Less than 20% of the samples tested for chlorine residual were above the World Health Organization guideline. Sanitary surveys identified potential sources of contamination and were used to recommend priorities for remedial action. The implications of this work for other resource-limited areas are that microbiological testing and sanitary surveys are two essential components to assessing water safety and they should both be consistently applied in drinking water quality test programs.
Efficacy of a ceramic siphon household water filter for removal of pathogenic microorganisms: lifespan volume test
Authors: Kaufman Amanda R. , Casanova Lisa M. , Sobsey Mark D.
Published: September 2011

Treatment of drinking water at the point of use (POU) has demonstrated health benefits for people who have access only to microbially contaminated drinking water. In this work, the ceramic siphon POU water filter was evaluated for its ability to reduce indicator microorganisms in test waters. During batch challenge tests, the filter reduced Escherichia coli in filtered water by 7 log10 (99.999987%) and bacteriophage MS2 by 0.12 log10 (24.0%). Next, a novel continuous flow dosing system allowing sewage-amended feed water to constantly pass through the filters allowed for determination of changes in microbial reductions over time and total volume of water filtered. E. coli B, MS2 and fluorescent microspheres (as a surrogate for Cryptosporidium oocysts) were seeded into test water and dosed to filters at 10, 25 and 50% of the filter's volume lifespan. Microbial removal efficacy decreased as the volume of water filtered increased and test filters did not achieve their volume lifespan before physically failing. The ceramic siphon household water filter is effective in reducing E. coli and surrogates for Cryptosporidium in water, but filter modifications may be needed to achieve acceptable levels of virus removal and to reach the target 7,000 L volume lifespan of the filter.
Assessing and managing fluorosis risk in children and adults in rural Madhya Pradesh, India
Authors: Godfrey Sam , Labhasetwar Pawan , Chakma Tapas , Wate Satish , Swami Aditya , Bartram Jamie
Published: September 2011

This paper presents the application of quantitative chemical risk assessment for assessing and managing fluorosis in 19 schools and 6 villages in Madhya Pradesh, India. A longitudinal study was undertaken with a baseline survey in 2005 and an endline in 2007. Household surveys, water quality and food analysis were undertaken to measure the impact of an Integrated Fluorosis Mitigation programme that included water and nutritional interventions. The baseline survey indicated a maximum fluoride content of 7.8 mg/l in food and 3.7 mg/l in water, equating to a maximum fluoride uptake of 4.8 and 3.7 mg/l in food and water respectively. Mean (actual) daily intake of fluoride for all exposure routes was 0.4 mg/kg of combined adult and child body weight. Intake of fluoride through food was more than 40% of total intake. Calculated guideline values for age groups <18 years and >18 years were 1.7 and 1.9 mg/l respectively. Using WHO methodology, the Guideline Value would be 1.7 mg/l. Fluoride dilution was implemented to reduce the fluoride content to below this level. The endline survey indicated reduction in the prevalence of grade 1 fluorosis of 86%, of grade 2 of 77%, of grade 4 of 60% in all children examined.
Bertrand Competition in Markets with Network Effects and Switching Costs
Authors: Suleymanova Irina , Wey Christian
Published: September 2011

We analyze Bertrand duopoly competition in markets with network effects and consumer switching costs. Depending on the ratio of switching costs to network effects, our model generates four different market patterns: monopolization and market sharing, which can be either preserved or reversed. A critical mass effect where one firm becomes the monopolist for sure only occurs for intermediate values of the ratio, whereas for large switching costs market sharing is the unique equilibrium. For large network effects, both monopoly and market sharing equilibria exist. Our welfare analysis reveals a conflict between maximization of consumer surplus and social welfare when network effects are large. We also analyze firms’ incentives for compatibility and incentives to increase switching costs and examine how market outcomes are affected by market expansion and cost asymmetries. Finally, in a dynamic extension of our model, we show how competition depends on agents’ discount factors.
The Potential for Inflating Earnings through the Expected Rate of Return on Defined Benefit Pension Plan Assets
Authors: Adams Brian , Frank Mary Margaret , Perry Tod
Published: September 2011

SYNOPSIS

Using a sample of firms over the period of 1991 through 2005, we examine the opportunity that exists for firms to inflate earnings through the expected rate of return (ERR) assumption associated with defined benefit pension plans. The evidence suggests that, on average, the ERR is not overstated relative to several benchmarks, including contemporaneous actual returns, historical cumulative actual returns, and expected future returns based on asset allocation within the pension. We also find that actual changes in the ERR are infrequent and typically have less than a 1 percent impact on annual operating income. We also estimate that a 0.5 percent change (50 bps) in the ERR will result in a cumulative effect on operating income over a five-year period of approximately 0.5 percent or less for the majority of firms. When we examine firms with the highest ERRs or with the greatest opportunity to inflate earnings, again, we find that the ERR is not overstated relative to several benchmarks. Although we do not observe pervasive inflating of reported income through the ERR during our sample period, we do find that for some firms, small increases in ERR can have a material impact on reported earnings. Our results provide evidence related to the pervasiveness, materiality, and impact of overstated earnings through the ERR, which helps regulators assess the costs and benefits of eliminating this discretion in financial reporting.
Narrow operators on lattice-normed spaces
Authors: Pliev Marat
Published: September 2011

The aim of this article is to extend results of Maslyuchenko, Mykhaylyuk and Popov about narrow operators on vector lattices. We give a new definition of a narrow operator, where a vector lattice as the domain space of a narrow operator is replaced with a lattice-normed space. We prove that every GAM-compact (bo)-norm continuous linear operator from a Banach-Kantorovich space V to a Banach lattice Y is narrow. Then we show that, under some mild conditions, a continuous dominated operator is narrow if and only if its exact dominant is so.
Ionic liquids–an Overview
Authors: Jenkins Harry Donald Brooke
Published: September 2011

A virtually unprecedented exponential burst of activity resulted following the publication, in 1998, of an article by Michael Freeman (Freemantle, M. Chemical & Engineering News, 1998, March 30, 32), which speculated on the role and contribution that ionic liquids (ILs) might make in the future on the development of clean technology. Up until that time only a handful of researchers were routinely engaged in the study of ILs but frenzied activity followed that continues until the present day. Scientists from all disciplines related to Chemistry have now embarked on studies, including theoreticians who are immersed in the aim of improving the “designer role” so that they can tailor ILs to deliver specified properties. This article, whilst not in any sense attempting to be exhaustive, highlights the main features which characterise ILs, presenting these in a form readily assimilated by newcomers to this area of research. An extensive glossary is featured in this article as well as a chronological list which charts the major areas of development. What follows consists of a number of sections briefly describing the role of ILs as solvents, hypergolic fuels, their use in some electrochemical devices such as solar cells and lithium batteries and their use in polymerisation reactions, followed by a concise summary of some of the other roles that they are capable of playing. The role of empirical, volume-based thermodynamics procedures, as well as large scale computational studies on ILs is also highlighted. These developments which are described are remarkable in that they have been achieved in less than a decade and a half, although knowledge of these materials has existed for much longer.
Englacial seismic reflectivity: imaging crystal-orientation fabric in West Antarctica
Authors: Horgan Huw J. , Anandakrishnan Sridhar , Alley Richard B. , Burkett Peter G. , Peters Leo E.
Published: September 2011

Abrupt changes in crystal-orientation fabric (COF), and therefore viscosity, are observed near the base of the ice sheet throughout West Antarctica. We report on active-source seismic observations from WAIS Divide, mid-stream and downstream on Thwaites Glacier, and the onset region of Bindschadler Ice Stream. These data reveal a prevalence of englacial seismic reflectivity in the bottom quarter of the ice sheet. The observed seismic reflectivity is complex but largely bed-conformable, with long-spatial-wavelength features observed in the flow direction and short-wavelength features observed across flow. A correspondence of englacial structures with bed features is also observed. We determine the origin of the reflectivity to be abrupt changes in the COF of ice, based on the following: (1) observations of englacial reflectivity are consistent with current knowledge of COF within ice sheets, (2) englacial reflectivity caused by COF contrasts requires the simplest genesis, especially at ice divides, and (3) amplitude analysis shows that the observed englacial reflectivity can be explained by contrasts in seismic velocity due to COF changes. We note that the downstream increase in the quantity and complexity of observations indicates that direct observations of COF at ice divides likely underestimate the role that fabric plays in ice-sheet dynamics.
Microstructural evolution of fine-grained layers through the firn column at Summit, Greenland
Authors: Lomonaco R. , Albert M. , Baker I.
Published: September 2011

We present a microstructural characterization of fine-grained layers from the top 90 m of firn from Summit, Greenland, performed using a combination of scanning electron microscopy techniques including secondary electron imaging, energy-dispersive spectroscopy and electron backscattered patterns, and X-ray microcomputed tomography. The impurities in the firn, both soluble impurities and dust particles, were found largely in the grain interiors. Both c- and a-axis pole figures do not show strong evidence of a preferred orientation of the grains even at the bottom of the firn column. The firn structure became increasingly anisotropic with vertical alignment in the top 3 m, probably due to vapor transport associated with dry-snow metamorphism. The anisotropy decreases below this level until at ∼50 m the average firn structure is close to isotropic. In the near surface, the level of anisotropy is weaker than at Hercules Dome, Antarctica, confirming that differences in accumulation rates and temperatures leave enduring evidence in the structure of the firn. The fraction of closed-off pores is relatively low until ∼65 m; below that it rises through the end of our sampling at 90 m. Our microstructure measurements on the microscale are consistent with in situ firn-air sampling measurements on a decimeter scale, both indicating the existence of the lock-in zone starting near 69 m depth, and pore close-off at 81 m at this site.
Streaming flow of an Antarctic Peninsula palaeo-ice stream, both by basal sliding and deformation of substrate
Authors: Reinardy Benedict T.I. , Larter Robert D. , Hillenbrand Claus-Dieter , Murray Tavi , Hiemstra John F. , Booth Adam D.
Published: September 2011

Acoustic sub-bottom profiler surveys on the northeast Antarctic Peninsula shelf indicate that parts of the seabed are underlain by an acoustically transparent layer that is thin on the inner shelf and becomes thicker and more extensive towards the outer shelf. Sedimentological and geophysical data are combined to construct a bed model where streaming ice flow, by both deformation and basal sliding, took place within cross-shelf troughs. The model suggests only limited deformation contributed to fast flow on the inner shelf, i.e. in the onset zone of ice streaming, where the bed was predominantly underlain by a stiff till. Thus, fast ice flow in this area might have been by basal sliding, with deformation confined to discontinuous patches of soft till <40 cm thick. Towards the middle and outer shelf, extensive, thick sequences of soft till suggest a change in the dominant subglacial process towards widespread deformation. This downstream change from basal sliding to subglacial deformation is manifest in the transition from stiff-till dominance to soft-till dominance, while a downstream increase in ice flow velocity is evident from the complex geomorphic imprint on the inner shelf evolving to the more restricted set of bedforms on the outer shelf.
Snow/atmosphere coupled simulation at Dome C, Antarctica
Authors: Brun Eric , Six Delphine , Picard Ghislain , Vionnet Vincent , Arnaud Laurent , Bazile Eric , Boone Aaron , Bouchard Aurélie , Genthon Christophe , Guidard Vincent , Moigne Patrick Le , Rabier Florence , Seity Yann
Published: September 2011

Using a snow/atmosphere coupled model, the evolution of the surface and near-surface snow temperature is modeled at Dome C, Antarctica, during the period 20–30 January 2010. Firstly, the detailed multilayer snow model Crocus is run in stand-alone mode, with meteorological input forcing data provided by local meteorological observations. The snow model is able to simulate the evolution of surface temperature with good accuracy. It reproduces the observed downward propagation of the diurnal heatwave into the upper 50 cm of the snowpack reasonably well. Secondly, a fully coupled 3-D snow/atmosphere simulation is performed with the AROME regional meteorological model, for which the standard single-layer snow parameterization is replaced by Crocus. In spite of a poor simulation of clouds, the surface and near-surface snow temperatures are correctly simulated, showing neither significant bias nor drifts during the simulation period. The model reproduces particularly well the average decrease of the diurnal amplitude of air temperature from the surface to the top of the 45 m instrumented tower. This study highlights the potential of snow/atmosphere coupled models over the Antarctic plateau and the need to improve cloud microphysics and data assimilation over polar regions.
Crystallization of Mefenamic Acid from Dimethylformamide Microemulsions: Obtaining Thermodynamic Control through 3D Nanoconfinement
Authors: Nicholson Catherine E. , Cooper Sharon J.
Published: September 2011

Recently we showed how crystallization in microemulsions could lead directly to the most stable polymorph, thereby leapfrogging Ostwald’s rule of stages. Here we consider in more details the crystallization of mefenamic acid from dimethylformamide microemulsions. Crystallization of mefenamic acid from bulk DMF has previously been shown to produce only the metastable Form II irrespective of the supersaturation or temperature. In contrast, we show that stable Form I can be produced from DMF microemulsions provided the lowest supersaturations that can achieve crystallization are used; these correspond to initial supersaturations that are significantly higher than those commonly used in bulk solution crystallizations, owing to the large decrease in supersaturation that occurs when a nuclei grows in a 3D-nanoconfined droplet. Increasing the supersaturation above the minimum required for crystallization leads to increasing proportions of metastable Form II crystals. In compositions crystallizing a mixture of Form I and Form II crystals, the Form I crystals can nevertheless be obtained exclusively by slowly heating the microemulsions.