Population structure, recruitment and distribution patterns of Patella depressa Pennant, 1777 on the central Portuguese coast

Using in situ individual measurements at two levels of the shore during a one-year period, recruitment peaks of Patella depressa Pennant, 1777, possibly related to breeding periods, were identified during autumn-winter. Recruits were associated with lower levels on the shore, and juveniles mainly inhabited Mytilus galloprovincialis Lamarck, 1819 patches. Niche partitioning, intraspecific competition, and desiccation stress are discussed as decisive factors in the different size-class distributions found. A mark-recapture growth study was made at two substrata within study sites, one substratum with irregular depressions mainly composed of Chthamalus spp., and a second regular substratum comprising mostly bare rock. Our results indicated lower growth increments in the irregular substratum zone, probably due to space availability and limited foraging activity.Utilizando mediciones individuales in situ a dos niveles de la orilla durante un año, se han identificado en otoño-invierno los picos de reclutamiento de Patella depressa Pennant, 1777 relacionados, posiblemente, con los periodos de reproducción. Los reclutamientos se asocian con bajos niveles en la orilla y juveniles ocupando principalmente pequeñas extensiones junto a Mytillus galloprovincialis Lamarck, 1819. Se discute la influencia del reparto de nichos, la competencia intraespecífica y el estrés por desecación como factores decisivos en las distribución de las distintas clases de tallas encontradas. Se ha hecho un estudio de marcado y recaptura en dos sustratos comparando uno con otro: un primer sustrato con depresiones irregulares compuesto principalmente por Chthamalus spp. y un segundo, regular, compuesto fundamentalmente por rocas desnudas. Nuestros resultados indicaron incrementos bajos de crecimiento en la zona de sustrato irregular, probablemente debido a la limitada disponibilidad de espacio y a la actividad de forraje.Instituto Español de Oceanografí

A Full Automatic Device for Sampling Small Solution Volumes in Photometric Titration Procedure Based on Multicommuted Flow System

In this work, an automatic device to deliver titrant solution into a titration chamber with the ability to determine the dispensed volume of solution, with good precision independent of both elapsed time and flow rate, is proposed. A glass tube maintained at the vertical position was employed as a container for the titrant solution. Electronic devices were coupled to the glass tube in order to control its filling with titrant solution, as well as the stepwise solution delivering into the titration chamber. The detection of the titration end point was performed employing a photometer designed using a green LED (λ=545 nm) and a phototransistor. The titration flow system comprised three-way solenoid valves, which were assembled to allow that the steps comprising the solution container loading and the titration run were carried out automatically. The device for the solution volume determination was designed employing an infrared LED (λ=930 nm) and a photodiode. When solution volume delivered from proposed device was within the range of 5 to 105 μl, a linear relationship (R = 0.999) between the delivered volumes and the generated potential difference was achieved. The usefulness of the proposed device was proved performing photometric titration of hydrochloric acid solution with a standardized sodium hydroxide solution and using phenolphthalein as an external indicator. The achieved results presented relative standard deviation of 1.5%

Automatic flow system for simultaneous determination of iron and chromium in steel alloys employing photometers based on LEDs as radiation source

A multicommutated flow system for simultaneous determination of iron and chromium in steel alloys by photometry is described. The flow network consisted of an automatic injector and four solenoid valves assembled to form two independent analytical pathways, each one comprising reaction coils and a flow cell. The light source (LED) and detector (photodiode) were attached to the flow cells to form a compact unit. The flow system was microcomputer controlled by Quick BASIC 4.5 software, which carried out all steps of the analytical procedure. The feasibility of the system was proved by the determination of iron and chromium in steel alloys and its accuracy was accessed by comparing results with those obtained by plasma atomic emission spectrometry (ICP-AES). No significant difference at the 95% confidence level was observed. Other profitable features such as low reagent consumption (0.33 mg 1,10-phenantroline and 0.03 mg 1,5-diphenylcarbazide per determination); relative standard deviations (n = 5) of 0.4% for iron and 1.2% for chromium; and an analytical throughput of 160 determinations per h were also achieved

Sistem Tataniaga Kentang di Kecamatan Hatu-Builiko, Kabupaten Ainaro, Timor Leste

Marketing system in important part in agribusiness system with forming connectivity of agriculture produck from farmers to the final consumer. The marketing system wil influence product purchasing including divides of benefit. Use of descriptive method Analysis in this research is aims to clarify how are the potato producing in Hatu-Builiko Sub-District delivery to the market consume. The purpose of the research to determine how far the channel marketing involve, hows the marketing function applied to the condition of the market and which marketing channel mostly efficient trough margin marketing and farmer share. The sample of location and sample of farmer were selected by purposive sampling method; and the sample of trades was selected trough snowbowling sampling method. The number of farmers was selected 20 peoples and the number of trades was selected fourteen peoples.the technical coleteing data was by observation and direct interview. The research conducted in Hatu-Builiko Sub District at Ainaro District of Timor Leste. The result, there were three channel of marketing applied, mostly the three marketing channel function were selling potatoin Ainaro District market. Market structure was conducted as monophony for the farmers, monopoly for the trade collector and free competition for the retailer and wholesalers. The market behavior was elaborate in good way between farmers and trade collector and either between trade collector and retailer and also trade collector and wholesalers. The payment procedure was cash based. The most efficient marketing channel wascontributing the best value as the result of margin marketing and farmer share which is was third marketing channel

Reproduction of Patella depressa Pennant, 1777 on the central Portuguese coast

The reproductive cycle and the sex ratio of the limpet Patella depressa Pennant, 1777 were studied on two rocky shores of the central coast of the Portugal, over a period of one year. The gonads were examined and their stage of development was assessed. The gonads of P. depressa were found to develop mainly from September/October to December, and between February and April. The spawning peaks occurred in January and between May and August. From June to August the gonads seem to go into a resting phase. In P. depressa the sex proportions seem to be approximately equal, suggesting the absence of sex reversal in these limpets. High wind speed under optimum conditions of air temperatures appears to induce spawning in this species.Estudiamos el ciclo reproductor y la proporción de sexos de la lapa Patella depressa Pennant, 1777 en dos litorales rocosos de la costa central de Portugal. Examinamos las gónadas y valoramos su fase de desarrollo. Encontramos gónadas de P. depressa desarrollándose principalmente desde septiembre/octubre hasta diciembre y entre febrero y abril. Los picos de puesta aparecieron en enero y entre mayo y agosto. Las gónadas parecen permanecer en una fase de reposo desde junio hasta agosto. En P. depressa la proporción de sexos parece ser aproximadamente uno, lo que sugiere la ausencia de inversión sexual en estas lapas. Bajo condiciones óptimas de temperatura del aire, la alta velocidad del viento parece inducir la puesta en esta especie.Instituto Español de Oceanografí

New designsns of solar collectors for heterogeneous TiO2 photocatalytic processes

Solar hardware design for photocatalytic processes includes aspects of optics, geometry and reactor materials. Compound parabolic collectors (CPCs) have widely been used to promote heterogeneous and homogeneous photocatalytic reactions. In this work, different reflective surface (RS) materials (anodized aluminum with [MS] and without [R85] protective coating, soiled aluminum [R85s] and stainless steel [SS]) and geometries (flat [F], single piece-double parabola [SP] and two pieces-double parabola [DP]) were tested aiming the degradation of a recalcitrant organic compound, gatifloxacin (GAT), by using a heterogeneous TiO2 photocatalytic system. Firstly, the photonic flux entering the system was measured by 2-nitrobenzaldehyde actinometry, considering the different RSs. After that, the catalyst (TiO2-P25) was immobilized in the surface of a static mixer and axially inserted in the tubular borosilicate photoreactor. Finally, the efficiency of the heterogeneous photocatalytic system was evaluated for GAT removal from aqueous solution using the best photoreactor configuration.info:eu-repo/semantics/publishedVersio

Automatic flow analysis procedure for the determination of bromide in L-alanine by chemiluminescence detection

An automatic flow analysis procedure for bromide determination in L-alanine aminoacid employing detection by chemiluminescence is described. The procedure was based on the bromide oxidation by chloramine-T followed by reaction with luminol. Spiking sample with standard solution gave recoveries values ranging from 94 to 106 %. Profitable features such as linear response ranging from 0.01 to 1.000 mg L-1 bromide (R = 0.999); detection limit of 8.9 µg L-1 Br-; relative standard deviation of 3.0% (n = 10); sampling throughput of 18 determination per hour; and reagent consumption 0.07 mg luminol and 0.4 mg chloramine-T per determination were achieved

Dinâmica da atrazina no solo do Cerrado: influência da matéria orgânica na sorção e mineralização.

A atrazina, um herbicida seletivo recomendado para o controle de plantas daninhas principalmente na cultura do milho, é um dos mais utilizados no Brasil. Devido ao seu uso expressivo, tem sido frequentemente detectada em concentrações acima do limite máximo permitido em amostras de água e solo. Assim, objetivando avaliar o potencial contaminante deste herbicida, este trabalho visa estudar as diferentes interações da atrazina com o solo natural oriundo de uma região de monocultura de milho localizada no município de Rio Paranaíba (MG). O estudo proposto constou da avaliação da degradação da atrazina em solos com diferentes históricos de aplicação do herbicida e da avaliação da sorção da atrazina e de seus principais metabólitos no solo com e sem aplicação de matéria orgânica e correção de pH. Foram realizados ensaios de caracterização geotécnica, análises químicas e difração de raios-X. Para a avaliação do comportamento deste herbicida no solo, foram realizados ensaios de fluxo, utilizando ensaios de coluna em laboratório e coleta de amostras em diferentes profundidades no campo. Com os resultados obtidos foi possível verificar o processo de degradação da atrazina em diferentes condições físicas e químicas do solo condicionado principalmente ao histórico da sua aplicação no campo

A caracterização e proveniência geológica das lajes de antas da região de Lisboa

As antas são sepulcros megalíticos que representam uma das evidências mais conspícuas das populações dos 4º e primeira metade do 3º milénios a.n.e., tanto pela sua monumentalidade, como pelo investimento socioeconómico que terá representado a sua construção para aquelas comunidades neolíticas peninsulares, nomeadamente do Centro-Sul de Portugal. Estas construções foram erigidas no âmbito do fenómeno funerário designado por Megalitismo, um complexo conjunto de práticas mágico-religiosas relacionadas com a morte e não estritamente com um tipo de arquitectura. Apesar das antas serem estudadas pelos seus conteúdos e tipologias, a abordagem interdisciplinar de caracterização e proveniência geológica dos megálitos utilizados nas suas construções, não tem recebido a devida atenção da investigação.Da necessidade de sistematizar e promover um aporte significativo de informações com a finalidade de caracterizar do ponto de vista geológico as proveniências dos materiais construtivos dos monumentos funerários de cronologia neolítica, apresentam-se os resultados preliminares obtidos para alguns dos monumentos em análise na região de Lisboa, no âmbito do projecto de investigação “MEGAGEO: Movendo megálitos no Neolítico - A proveniência geológica dos esteios de antas do Centro-Sul de Portugal”. A caracterização das lajes destes monumentos recorreu a técnicas de análise petrográfica, mineralógica, química e isotópica, de suporte às observações macroscópicas dos elementos construtivos e dos afloramentos geológicos na sua sua vizinhança. As observações macroscópicas dos litótipos que constituem aqueles elementos,quando comparados com os afloramentos,permitiram numa primeira fase estabelecer similaridades entre ambos. Esta abordagem reveste-se, aliás, de fundamental importância para a definição de potenciais zonas de extracção na utilização dos recursos naturais disponíveis