Vertical distribution of benthic foraminifers in the Arctic Ocean

The vertical distribution of living (Rose Bengal stained) benthic foraminifers was determined in the upper 15 cm of sediment cores taken along transects extending from the continental shelf of Spitsbergen through the Eurasian Basin of the Arctic Ocean. Cores taken by a multiple corer were raised from 50 stations with water depths between 94 and 4427 m, from areas with moderate primary production values to areas that are among the least productive ones in the world. We believe, that in the Arctic Ocean the vertical distribution of living foraminifers is determined by the restricted availability of food. Live foraminiferal faunas are dominated by potentially infaunal species or epifaunal species. Species confined to the infaunal microhabitat are absent in Arctic sediments that we examined, and predominantly infaunal living species are nowhere dominant. In general, an infaunal mode of life is restricted to the seasonally ice-free areas and thus to areas with at least moderate primary production during the summer period. Under the permanent ice cover living species are usually restricted to the top centimeter of the sediment surface, even though some are able to dwell deeper in the sediment under ice-free conditions.

Britannia's pastorals.

Errata: p. [12] at beginning.

Thermal characterization of polyester-melamine coating matrices prepared under nonisothermal conditions

Thermal analysis methods (differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical thermal analysis) were used to characterize the nature of polyester-melamine coating matrices prepared under nonisothermal, high-temperature, rapid-cure conditions. The results were interpreted in terms of the formation of two interpenetrating networks with different glass-transition temperatures (a cocondensed polyester-melamine network and a self-condensed melamine-melamine network), a phenomenon not generally seen in chemically similar, isothermally cured matrices. The self-condensed network manifested at high melamine levels, but the relative concentrations of the two networks were critically dependent on the cure conditions. The optimal cure (defined in terms of the attainment of a peak metal temperature) was achieved at different oven temperatures and different oven dwell times, and so the actual energy absorbed varied over a wide range. Careful control of the energy absorption, by the selection of appropriate cure conditions, controlled the relative concentrations of the two networks and, therefore, the flexibility and hardness of the resultant coatings. (C) 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Cbem 41: 1603-1621, 2003.

Geometric phases of scattering states in a ring geometry: adiabatic pumping in mesoscopic devices

Geometric phases of scattering states in a ring geometry are studied on the basis of a variant of the adiabatic theorem. Three timescales, i.e., the adiabatic period, the system time and the dwell time, associated with adiabatic scattering in a ring geometry play a crucial role in determining geometric phases, in contrast to only two timescales, i.e., the adiabatic period and the dwell time, in an open system. We derive a formula connecting the gauge invariant geometric phases acquired by time-reversed scattering states and the circulating (pumping) current. A numerical calculation shows that the effect of the geometric phases is observable in a nanoscale electronic device.

COMUNICAÇÃO POPULAR-ALTERNATIVA DESENVOLVIDA POR JOVENS INDÍGENAS DAS ALDEIAS DO JAGUAPIRU E BORORÓ EM DOURADOS / MS

Trata-se de um estudo de caso em que analisamos a comunicação alternativa desenvolvida pela AJI (Ação dos Jovens Indígenas), em Dourados/MS, nas aldeias do Jaguapiru e Bororó. Os jovens, que produzem audiovisuais, fotografias, blog, fotolog e um jornal impresso, encontraram na comunicação uma alternativa ante à marginalidade com que os índios são tratados na cidade, e buscarem seus direitos à voz e ao espaço social, em suas próprias tribos, já que os jovens indígenas solteiros ocupam um não-lugar na Reserva, pois não pertencem à organização tradicional indígena, tampouco estão inseridos entre os brancos. A partir das características e limitações da comunicação alternativa no Jornal AJIndo, por meio de pesquisa bibliográfica, entrevistas semi-estruturadas e análise de conteúdo, buscamos verificar o impacto da utilização desta comunicação nas aldeias para os jovens que a produzem, levando em conta interferências nas formas tradicionais de hierarquia e comunicação entre os indígenas e a função social da comunicação alternativa para eles. Embora não seja o objetivo principal do AJIndo, destaca-se o desenvolvimento da auto-estima como resultado desse processo. Soma-se a esta função, a mobilização por transformação social e a formação crítico-educativa. Após o esforço de organização, os jovens começaram a se sentir pertencentes aos indígenas e a serem ouvidos pelos brancos, mesmo que acreditem ser por interesses políticos da comunidade como um todo.

Another angle on contact lens surface analysis

Purpose: Dynamic contact angle (DCA) methods have advantages over other contact angle methodologies, not least that they can provide more than single contact angle values. Here we illustrate the use of DCA analysis to provide “fingerprint” characterisation of contact lens surfaces, and the way that different materials change in the early stages of wear. Method: The DCA method involves attaching to a microbalance weighted strips cut from a lens. The strips are then cyclically inserted into and removed from an aqueous solution. Conventionally, readings of force taken from linear portions of the resultant dipping curves are translated into advancing (CAa) and receding contact (CAr) angles. Additionally, analysis of the force versus immersion profile provides a “fingerprint” characterisation of the state of the lens surface. Results: CAa and CAr values from DCA traces provide a useful means of differentiating gross differences in hydrophilicity and molecular mobility of surfaces under particular immersion and emersion conditions, such as dipping rate and dwell times. Typical values for etafilcon A (CAa:63.1; CAr:37) and balafilcon B (CAa:118.4; CAr:36.4) illustrate this. Surface modifications induced in lens manufacture are observed to produce not only changes in these value, which may be small, but also changes in the DCA “fingerprint” (slope, undulations, length of plateau). Interestingly, similar changes are induced in the first few hours of lens wear with some lens-patient combinations. Conclusions: Although single parameter contact angles are useful for material characterisation, information of potential clinical interest can be obtained from more detailed analysis of DCA traces.

Generalized methods and solvers for noise removal from piecewise constant signals. I. Background theory

Removing noise from piecewise constant (PWC) signals is a challenging signal processing problem arising in many practical contexts. For example, in exploration geosciences, noisy drill hole records need to be separated into stratigraphic zones, and in biophysics, jumps between molecular dwell states have to be extracted from noisy fluorescence microscopy signals. Many PWC denoising methods exist, including total variation regularization, mean shift clustering, stepwise jump placement, running medians, convex clustering shrinkage and bilateral filtering; conventional linear signal processing methods are fundamentally unsuited. This paper (part I, the first of two) shows that most of these methods are associated with a special case of a generalized functional, minimized to achieve PWC denoising. The minimizer can be obtained by diverse solver algorithms, including stepwise jump placement, convex programming, finite differences, iterated running medians, least angle regression, regularization path following and coordinate descent. In the second paper, part II, we introduce novel PWC denoising methods, and comparisons between these methods performed on synthetic and real signals, showing that the new understanding of the problem gained in part I leads to new methods that have a useful role to play.

Music as the Source of Information Influence and Soul Education

Unlike other works of art (painting, sculpture, etc.) a musical composition should be performed, it should sound to become accessible. Therefore, the role of the musical masterly performance is extremely important. But presently it has increased in importance when music through mass communication media i.e. radio, television, sound recording becomes in the full sense of the word the property of millions. Art in all its genres as a means of information helps to recreate a picture of one or other epoch as a whole. Moreover, art has a profound impact on education: it can be positive or negative, creative or destructive. Let us dwell on such aspect of music as means of information and the value of musical mastery activity for brining information to hearers of the alternating generations. Unlike other works of art (painting, sculpture etc.) a musical composition should be performed, it should sound to become intelligible. Therefore, the role of the musical masterly performance is extremely important. But presently it becomes particularly great in the XXI century when music becomes a true property of the masses due to mass media – radio, television, sound recording.

Grey Slate

GREY SLATE is a collection of poems that focuses on the natural world in order to explore the mysteries of life with the intent to create a meditation on what it means to be a human being interacting with this world. Inspired by John Keats’ theory of Negative Capability, GREY SLATE does not seek to explain, but to dwell in the mysteries it explores. The poems are tied together through similar images or ideas in order to mimic the way the mind works as it jumps from thought to thought. GREY SLATE also mixes different types of poems: from haiku to sonnet to paradelle, and from lyric to narrative to prose poem. GREY SLATE hopes to inspire readers to take a break from searching for truths and indulge in the beautiful mystery that is life with no need for answers.

Evaluation of degree of conversion and hardness of dental composites photo-activated with different light guide tips

Objective: The aim of this study was to evaluate the degree of conversion and hardness of different composite resins, photo-activated for 40 s with two different light guide tips, fiber optic and polymer. Methods: Five specimens were made for each group evaluated. The percentage of unreacted carbon double bonds (% C═C) was determined from the ratio of absorbance intensities of aliphatic C═C (peak at 1637 cm−1) against internal standard before and after curing of the specimen: aromatic C-C (peak at 1610 cm−1). The Vickers hardness measurements were performed in a universal testing machine. A 50 gf load was used and the indenter with a dwell time of 30 seconds. The degree of conversion and hardness mean values were analyzed separately by ANOVA and Tukey’s test, with a significance level set at 5%. Results: The mean values of degree of conversion for the polymer and fiber optic light guide tip were statistically different (P<.001). The hardness mean values were statistically different among the light guide tips (P<.001), but also there was difference between top and bottom surfaces (P<.001). Conclusions: The results showed that the resins photo-activated with the fiber optic light guide tip promoted higher values for degree of conversion and hardness.

The Experience of Dis-placed Communities: Mis-placed Educational Opportunities

Newfoundland and Labrador (NL) has a long history of out-migration and internal migration between communities in coastal areas within the province. Resettlement programs initiated by the NL government between 1954 and 1975 accounted for the internal migration of approximately 30,000 people from 300 communities. Modern-day encounters with these abandoned communities are relevant to understanding the loss of place and home, as significant numbers of students in NL today are affected by migration. This dissertation is a phenomenological study of the experiences of educators as they explored the remnants of an abandoned community. The participants of the study were six experienced public school educators with teaching experience at the primary, elementary, intermediate, and secondary levels. The study took place in eight abandoned communities located on the western shore of Placentia Bay, where mainly the remnants of Isle Valen, St. Leonard’s, St. Kyran’s, and Great Paradise were explored. Data collection consisted of two personal interviews and one group hermeneutic circle, with the aim to answer one fundamental question: What is the experience of educators exploring the remnants of an abandoned community? Data in this study are represented by lived experience descriptions, which were interpreted hermeneutically and guided by four phenomenological existentials: temporality, corporeality, spatiality, and relationality. The most prominent themes emerging from the educators’ anecdotes were determined to be attunement, tension, and intensity. The results of this study not only provide deeper insight into communities abandoned through resettlement; they also reveal the significance of place in our lives, place as heuristic teacher, the pedagogical power of place, the need for local, meaningful place-based experiences in a curriculum as lived, and their potential for furthering personal and educational insight no matter where in this world we live or dwell.

Synthesis and characterization of some carbon based nanostructures

The aim of present paper is to present the latest results on investigations of the carbon thin film deposited by Thermionic Vacuum Arc (TVA) method and laser pyrolysis. X-ray photoelectron spectroscopy (XPS) and X-ray generated Auger electron spectroscopy (XAES) were used to determine composition and sp2 to sp3 ratios in the outer layers of the film surfaces. The analyses were conducted in a Thermoelectron ESCALAB 250 electron spectrometer equipped with a hemispherical sector energy analyser. Monochromated Al K X-radiation was employed for the XPS examination, at source excitation energy of 15 KeV and emission current of 20 mA. Analyzer pass energy of 20 eV with step size of 0.1 eV and dwell time of 100 ms was used throughout. © 2010 SPIE.

Dionne Brand, Austin Clarke, and Tessa McWatt: Blackening Canada

This project analyzes contemporary black diasporic writing in Canada, arguing that Dionne Brand, Austin Clarke and Tessa McWatt evince a unique form of double-consciousness in their writings. Their work transforms African-American double-consciousness by locating it simultaneously within both the black diaspora and the practice of Canadian multiculturalism. The objective of this project is to offer a critical framework for situating these writers within the legacy of both Black Atlantic and Canadian cultural production. These writers do not aim to resolve their double-consciousness but rather dwell within that contradictory doubleness and hyphenation, forcing nation and diaspora to contend with one another in a discomfiting and unsettling dialogue. These authors employ the absences of the black diaspora to imagine new forms of black cultural production, multicultural citizenship and national identity. Their works produce a grammar of diasporic double-consciousness that locates the absented origins of diaspora within Canada. Brand’s depiction of temporality and Clarke’s tracing of movement explore the continuities between nation and diaspora while re-membering neglected aspects of the history of black Canada, such as the life and death of Albert Johnson. McWatt extends this blackening of nation by depicting coalitions between diasporic, indigenous, raced and sexed subjects. These authors transform hegemonic Canadian narratives of nation by dwelling in the hyphen, while their evocation of memory, absence, trauma, and desire gives blackness new meaning and legitimacy.

Modelling of water removal during a paper vacuum dewatering process using a Level-Set method

Water removal in paper manufacturing is an energy-intensive process. The dewatering process generally consists of four stages of which the first three stages include mechanical water removal through gravity filtration, vacuum dewatering and wet pressing. In the fourth stage, water is removed thermally, which is the most expensive stage in terms of energy use. In order to analyse water removal during a vacuum dewatering process, a numerical model was created by using a Level-Set method. Various different 2D structures of the paper model were created in MATLAB code with randomly positioned circular fibres with identical orientation. The model considers the influence of the forming fabric which supports the paper sheet during the dewatering process, by using volume forces to represent flow resistance in the momentum equation. The models were used to estimate the dry content of the porous structure for various dwell times. The relation between dry content and dwell time was compared to laboratory data for paper sheets with basis weights of 20 and 50 g/m2 exposed to vacuum levels between 20 kPa and 60 kPa. The comparison showed reasonable results for dewatering and air flow rates. The random positioning of the fibres influences the dewatering rate slightly. In order to achieve more accurate comparisons, the random orientation of the fibres needs to be considered, as well as the deformation and displacement of the fibres during the dewatering process.

Materiais à base de Sr(Ti,Nb)O3 para sensores lambda

Os sensores lambda resistivos possuem as vantagens de simplicidade e menor custo relativamente à utilização generalizada de sensores potenciométricos de oxigénio. Nesse sentido, os titanatos de estrôncio têm sido alvo de diversos estudos. Para a produção de uma relação inequívoca entre a condutividade destes materiais e a pressão parcial de oxigénio é necessária a adição de um dopante dador que suprime a condução eletrónica do tipo-p na região de pressões parciais de oxigénio próximas de ar. Contudo, a adição de um dopante dador produz respostas lentas destes materiais quando densos a variações da pressão parcial de oxigénio. Além da preparação usual dos pós por reação do estado sólido, foram preparadas diversas composições por mecanossíntese. Tal relaciona-se com o fato exaustivamente reportado de as amostras destes materiais, especialmente quando dopados com dadores, apresentarem comportamentos dependentes das condições de processamento. Teve ainda o intuito de avaliar a viabilidade da sua preparação por este método, e consequentemente verificar se este método de preparação, que presumivelmente produzirá pós com composição mais homogénea e mais reativos, permite alterar/manipular a resposta obtida por amostras com eles produzidas. Foram preparados diversos filmes, tipologia muito usada na produção de sensores resistivos, e amostras porosas com diversas composições à base de titanato de estrôncio produzidos com variadas condições de processamento. Foram realizadas diversas caracterizações sobre estes espécimes numa tentativa de melhor compreender as propriedades destes materiais e a dependência destas com parâmetros microestruturais como o tamanho de grão e a porosidade. Foi verificado que os exemplares de titanato de estrôncio não dopado, quer em filmes quer em amostras porosas, apresentam um comportamento elétrico semelhante ao apresentado por amostras densas deste material. Apurou-se ainda, que as suas características apresentam uma variação ténue com a alteração das condições de processamento. Já espécimes de titanato de estrôncio dopados com dador revelam uma forte dependência das suas propriedades com as condições de processamento utilizadas, nomeadamente, a temperatura de sinterização e o tempo de permanência a essa temperatura. Para o fabrico de sensores resistivos de oxigénio poderá ser preferível o recurso a amostras porosas pelo facto de mais facilmente se manipularem as suas características microestruturais e devido à exclusão dos problemas associados à interação entre o substrato de alumina e o filme. As composições não dopadas são as indicadas para esta função se a gama de pressões de oxigénio a avaliar for relativamente pouco extensa sendo aconselhadas as composições dopadas com dador se for pretendida uma medição da pressão parcial de oxigénio em zonas mais extensas correspondentes à queima com deficiência ou excesso de oxigénio. Mesmo em amostras de elevada porosidade poderá ocorrer resposta transiente do material dopado com dador.