Vapour layer formation by electrical discharges through electrically conducting liquids-modelling and experiment

Experimental and finite element modelling methods are used to study the formation of vapour layers in electrical discharges through saline solutions. The experiments utilize shadowgraphic and photometric methods to observe the time dependence of thin vapour layers and plasma formation around electrodes driven by moderate voltage (<500 V) pulses, applied to an electrode immersed in a conducting saline solution. Finite element multiphysics software, coupling thermal and electrical effects, is employed to model the vapour layer formation. All relevant electrical and thermal properties of the saline are incorporated into the model, but hydrodynamic and surface tension effects are ignored. Experimental shadowgraph and modelling images are compared, as are current histories, and the agreement is very good. The comparison of experiment and modelling gives insight into both vapour layer production and subsequent plasma production. We show that, for example, superheating of the saline above its normal vaporization temperature may be playing a significant role in vapour formation. We also show that electric fields of approaching 10(7) V m(-1) can be achieved in the vapour layer.

Production and Characterization of Composite Material Useful as a Protective Barrier in Electronic Applications

This work describes the production and characterization of a selective membrane useful for electronic devices. The membrane was a composite made by a thin film of plasma-polymerized HFE (methyl nonafluoro(iso)butyl ether) immersed in plasma-polymerized HMDS (hexamethyldisilazane) film, a third phase being 5 µm starch particles included in this matrix. The film was deposited on silicon substrates and its physical, chemical and adsorption characteristics were determined. Infrared and x-ray photoelectron spectroscopy analyses showed fluorine and carboxyl groups on the bulk and the surface, respectively. SEM results indicate the film is conformal even if starch is present. Optical microscopy analysis showed good resistance toward acid and base solutions. Quartz crystal microbalance indicated adsorption of polar organic compounds on ppm range. This thin film is environment-friendly and can be used as a protective layer or in electronic devices due to adsorption of volatile organic compounds.

Estimating mortality in laying hens as the environmental temperature increases

Layer mortality due to heat stress is an important economic loss for the producer. The aim of this study was to determine the mortality pattern of layers reared in the region of Bastos, SP, Brazil, according to external environment and bird age. Data mining technique were used based on monthly mortality records of hens in production, 135 poultry houses, from January 2004 to August 2008. The external environment was characterized according maximum and minimum temperatures, obtained monthly at the meteorological station CATI in the city of Tupa, SP, Brazil. Mortality was classified as normal (<= 1.2%) or high (> 1.2%), considering the mortality limits mentioned in literature. Data mining technique produced a decision tree with nine levels and 23 leaves, with 62.6% of overall accuracy. The hit rate for the High class was 64.1% and 59.9% for Normal class. The decision tree allowed finding a pattern in the mortality data, generating a model for estimating mortality based on the thermal environment and bird age.

Avaliação do ciclo de vida de um pavimento flutuante de cortiça

A consciencialização ambiental vem assumindo um papel preponderante na construção civil. Nesse sentido, o desenvolvimento de materiais sustentáveis e ecológicos é essencial para a satisfação de fabricantes e consumidores, respeitando diversos requisitos: níveis reduzidos de poluição e toxicidade, durabilidade dos materiais, possibilidade de reutilização e/ou reciclagem, a proveniência das matérias-primas e a possibilidade de contaminação do ar no interior dos edifícios. As declarações ambientais de produto (DAP) permitem informar o consumidor do desempenho ambiental dos materiais dos produtos. Assim, ao longo de todo o processo de fabrico são registados os consumos de recursos e emissões ambientais e, através da metodologia de avaliação de ciclo de vida, é quantificada a contribuição resultante para impactes ambientais. Esta dissertação visa analisar os possíveis impactes ambientais no decurso do processo de produção de um pavimento flutuante de cortiça, constituído por cortiça, High Density Fibreboard (HDF) e acabamento de superfície, denominado Artcomfort Floating NPC e elaborar de um relatório de suporte, que servirá de base para a DAP do pavimento Artcomfort Floating NPC do sistema do Institut Bauen und Umwelt (IBU). Esta dissertação inclui um relatório de fundo, para a avaliação do ciclo de vida do pavimento flutuante Artcomfort Floating NPC da empresa Amorim Revestimentos, que servirá de base para a elaboração da declaração ambiental de produto (DAP) do mesmo. Para tal, recorreu-se ao software SimaPro para análise dos impactes ambientais das várias fases do processo de fabrico do pavimento em estudo, sendo as fases consideradas, a produção da camada base de cortiça aglomerada, camada backing de cortiça aglomerada, montagem da sanduiche, placa pintada, placa acabada e corte e embalagem. A fase que tem maior contribuição para os impactes ambientais do processo de fabrico do produto, em todas as categorias de impacte analisadas, com exceção da depleção dos recursos abióticos sem combustíveis fósseis, foi a fase de montagem da sanduiche.

Estimating mortality in laying hens as the environmental temperature increases

Layer mortality due to heat stress is an important economic loss for the producer. The aim of this study was to determine the mortality pattern of layers reared in the region of Bastos, SP, Brazil, according to external environment and bird age. Data mining technique were used based on monthly mortality records of hens in production, 135 poultry houses, from January 2004 to August 2008. The external environment was characterized according maximum and minimum temperatures, obtained monthly at the meteorological station CATI in the city of Tupa, SP, Brazil. Mortality was classified as normal (<= 1.2%) or high (> 1.2%), considering the mortality limits mentioned in literature. Data mining technique produced a decision tree with nine levels and 23 leaves, with 62.6% of overall accuracy. The hit rate for the High class was 64.1% and 59.9% for Normal class. The decision tree allowed finding a pattern in the mortality data, generating a model for estimating mortality based on the thermal environment and bird age.

Surface pigments,algal biomass profiles,and potential production of the euphotic layer:Relationships reinvestigated in view of remote-sensing applications

Maps of surface chlorophyllous pigment (Chl a + Pheo a) are currently produced from ocean color sensors. Transforming such maps into maps of primary production can be reliably done only by using light-production models in conjuction with additional information about the column-integrated pigment content and its vertical distribution. As a preliminary effort in this direction. $\ticksim 4,000$ vertical profiles pigment (Chl a + Pheo a) determined only in oceanic Case 1 waters have been statistically analyzed. They were scaled according to dimensionless depths (actual depth divided by the depth of the euphotic layer, $Z_e$) and expressed as dimensionless concentrations (actual concentration divided by the mean concentration within the euphotic layer). The depth $Z_e$ generally unknown, was computed with a previously develop bio-optical model. Highly sifnificant relationships were found allowing $\langle C \rangle_tot$, the pigment content of the euphotic layer, to be inferred from the surface concentration, $\bar C_pd$, observed within the layer of one penetration depth. According to their $\bar C_pd$ values (ranging from $0.01 to > 10 mg m^-3$), we categorized the profiles into seven trophic situations and computed a mean vertical profile for each. Between a quasi-uniform profile in eutrophic waters and a profile with a strong deep maximum in oligotrophic waters, the shape evolves rather regularly. The wellmixed cold waters, essentially in the Antarctic zone, have been separately examined. On average, their profiles are featureless, without deep maxima, whatever their trophic state. Averaged values their profiles are featureless, without deep maxima, whatever their trophic state. Averaged values their profiles are featureless, without deep maxima, whatever their trophic state. Averaged values of $ρ$, the ratio of Chl a tp (Chl a + Pheo a), have also been obtained for each trophic category. The energy stored by photosynthesizing algae, once normalized with respect to the integrated chlorophyll biomass $\langle C \rangle _tot $ is proportional to the available photosythetic energy at the surface via a parameter $ψ∗$ which is the cross-section for photosynthesis per unit of areal chlorophyll. By tanking advantage of the relative stability of $ψ∗.$ we can compute primary production from ocean color data acquired from space. For such a computation, inputs are the irradiance field at the ocean surface, the "surface" pigment from which $\langle C \rangle _tot$ can be derived, the mean $ρ value pertinent to the trophic situation as depicted by the $\bar C_pd or $\langle C \rangle _tot$ values, and the cross-section $ψ∗$. Instead of a contant $ψ∗.$ value, the mean profiles can be used; they allow the climatological field of the $ψ∗.$ parameter to be adjusted through the parallel use of a spectral light-production model.

Impact of Laptev Sea flaw polynyas on the atmospheric boundary layer and ice production using idealized mesoscale simulations

The interaction between polynyas and the atmospheric boundary layer is examined in the Laptev Sea using the regional, non-hydrostatic Consortium for Small-scale Modelling (COSMO) atmosphere model. A thermodynamic sea-ice model is used to consider the response of sea-ice surface temperature to idealized atmospheric forcing. The idealized regimes represent atmospheric conditions that are typical for the Laptev Sea region. Cold wintertime conditions are investigated with sea-ice–ocean temperature differences of up to 40 K. The Laptev Sea flaw polynyas strongly modify the atmospheric boundary layer. Convectively mixed layers reach heights of up to 1200 m above the polynyas with temperature anomalies of more than 5 K. Horizontal transport of heat expands to areas more than 500 km downstream of the polynyas. Strong wind regimes lead to a more shallow mixed layer with strong near-surface modifications, while weaker wind regimes show a deeper, well-mixed convective boundary layer. Shallow mesoscale circulations occur in the vicinity of ice-free and thin-ice covered polynyas. They are forced by large turbulent and radiative heat fluxes from the surface of up to 789 W m−2, strong low-level thermally induced convergence and cold air flow from the orographic structure of the Taimyr Peninsula in the western Laptev Sea region. Based on the surface energy balance we derive potential sea-ice production rates between 8 and 25 cm d−1. These production rates are mainly determined by whether the polynyas are ice-free or covered by thin ice and by the wind strength.

Production and applications of multi-layer 3D fabrics

In this paper, 3D textile structures, their types and applications have been discussed. Woven structures especially multi-layer woven structures are discussed in detail. A simple and quick method to produce 3D textile woven preforms on conventional looms is also given at the end of this paper. 3D textile fabrics give composite structures weight reduction with improved mechanical properties in comparison to traditionally used materials.

Concentration and production of bacteria and bacterial destruction in the photic layer of the Sodruzhestvo Sea area, Southern Ocean

Bacterioplankton in the photic layer of the Sodruzhestvo Sea area and adjoining waters consists in summer primarily of cocci, with fractions smaller than 2 ?m predominating. The average abundance and biomass of microorganisms are 427 thousand cells/ml and 438 mg C/m**2, with ranges of 150-1770 thousand cells/ml and 221-1146 mg C/m**2. The average daily production and bacterial destruction increase from 49 and 104 mg C/m**2 at the beginning of the growth period to 85 and 180 mg C/m**2 in the middle of the period and remain at this level till the end. Despite low rate of increase (daily P/B coefficient averages 0.12), because of its high abundance bacterioplankton in Antarctic waters plays a major role in destruction of organic matter, accounting for 60-85% of energy consumed by heterotrophs.

Primary production within the euphotic layer of the Norwegian Sea in July 1997: measurements by different methods

Results of primary production measurements obtained by different methods are presented. These methods are radiocarbon and oxygen modifications of the flask method, as well as fluorometric procedure with a PrimProd submersible probing fluorometer (produced at the Biological Department, Moscow State University). The research was carried out during a complex expedition aboard R/V Akademik Boris Petrov to the Norwegian Sea in July, 1977. Distributions of primary production values measured by different methods were correlated with other oceanographic data. Then a comparison of obtained values by the above-mentioned methods was performed.