901 resultados para 690202 Coastal water transport
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A multiproxy record has been acquired from a piston core (SO139-74KL) taken offshore southern Sumatra, an area which is situated in the southwestern sector of the tropical Indo-Pacific Warm Pool. The high-resolution data sets (X-ray fluorescence, total organic carbon, and C37 alkenones) were used to track changes in paleoproductivity, freshwater budget, and sea surface temperature (SST) of the tropical climate system at orbital time scales over the past 300 ka. Our paleoclimatic data show that enhanced marine paleoproductivity was directly related to strengthening of coastal upwelling during periods of increased boreal summer insolation and associated SE monsoon strength with a precessional cyclicity. Changes in freshwater supply were primarily forced by precession-controlled changes in boreal NW winter monsoon rainfall enclosing an additional sea level component. SST variations of 2°-5°C occurred at eccentricity and precessional cyclicity. We suggest that the sea surface temperature variability off southern Sumatra is predominantly related to three major causes: (1) variations in upwelling intensity; (2) an elevated freshwater input into the southern Makassar Strait leading to reduced supply of warmer surface waters from the western Pacific and increased subsurface water transport via the Indonesian Throughflow into the Indian Ocean; and (3) long-term changes in the intensity or frequency of low-latitude climate phenomena, such as El Niño-Southern Oscillation.
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Cross-linked homopolymers and copolymers of 2-hydroxyethyl methacrylate, HEMA, and ethylene glycol methacrylate phosphate, MOEP, have been synthesized, and the diffusion of water into these systems has been investigated. Only polymers with 0-20 mot % MOEP exhibited ideal swelling behavior as extensive fracturing occurred in the systems with greater than 20 mot % MOEP as the polymers began to swell during water sorption. Gravimetric studies were used in conjunction with magnetic resonance imaging of the diffusion front to elucidate the diffusion mechanism for these systems. In the case of the cross-linked HEMA homopolymer gets, the water transport mechanism was determined to be concentration-independent Fickian diffusion. However, as the fraction of MOEP in the network increased, the transport mechanism became increasingly exponentially concentration-dependent but remained Fickian until the polymer consisted of 30 mot % MOEP where the water transport could no longer been described by Fickian diffusion.
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The control of cellular water flow is mediated by the aquaporin (AQP) family of membrane proteins. The family's structural features and the mechanism of selective water passage through the AQP pore are established, but there remains a gap in our knowledge of how water transport is regulated. Two broad possibilities exist. One is controlling the passage of water through the AQP pore, but this has only been observed as a phenomenon in some plant and microbial AQPs. An alternative is controlling the number of AQPs in the cell membrane. Here we describe a novel pathway in mammalian cells whereby a hypotonic stimulus directly induces intracellular calcium elevations, through transient receptor potential channels, that trigger AQP1 translocation. This translocation, which has a direct role in cell volume regulation, occurs within 30s and is dependent on calmodulin activation and phosphorylation of AQP1 at two threonine residues by protein kinase C. This direct mechanism provides a rationale for the changes in water transport that are required in response to constantly-changing local cellular water availability. Moreover, since calcium is a pluripotent and ubiquitous second messenger in biological systems, the discovery of its role in the regulation of AQP translocation has ramifications for diverse physiological and pathophysiological processes, as well as providing an explanation for the rapid regulation of water flow that is necessary for cell homeostasis.
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In this paper, absolute water permeability is estimated from capillary imbibition and pore structure for 15 sedimentary rock types. They present a wide range of petrographic characteristics that provide degrees of connectivity, porosities, pore size distributions, water absorption coefficients by capillarity and water permeabilities. A statistical analysis shows strong correlations among the petrophysical parameters of the studied rocks. Several fundamental properties are fitted into different linear and multiple expressions where water permeability is expressed as a generalized function of the properties. Some practical aspects of these correlations are highlighted in order to use capillary imbibition tests to estimate permeability. The permeability–porosity relation is discussed in the context of the influence of pore connectivity and wettability. As a consequence, we propose a generalized model for permeability that includes information about water fluid rate (water absorption coefficient by capillarity), water properties (density and viscosity), wetting (interfacial tension and contact angle) and pore structure (pore radius and porosity). Its application is examined in terms of the type of pores that contribute to water transport and wettability. The results indicate that the threshold pore radius, in which water percolates through rock, achieves the best description of the pore system. The proposed equation is compared against Carman–Kozeny's and Katz–Thompson's equations. The proposed equation achieves very accurate predictions of the water permeability in the range of 0.01 to 1000 mD.
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Recent studies have detected a dominant accumulation mode (~100 nm) in the Sea Spray Aerosol (SSA) number distribution. There is evidence to suggest that particles in this mode are composed primarily of organics. To investigate this hypothesis we conducted experiments on NaCl, artificial SSA and natural SSA particles with a Volatility-Hygroscopicity-Tandem-Differential-Mobility-Analyser (VH-TDMA). NaCl particles were atomiser generated and a bubble generator was constructed to produce artificial and natural SSA particles. Natural seawater samples for use in the bubble generator were collected from biologically active, terrestrially-affected coastal water in Moreton Bay, Australia. Differences in the VH-TDMA-measured volatility curves of artificial and natural SSA particles were used to investigate and quantify the organic fraction of natural SSA particles. Hygroscopic Growth Factor (HGF) data, also obtained by the VH-TDMA, were used to confirm the conclusions drawn from the volatility data. Both datasets indicated that the organic fraction of our natural SSA particles evaporated in the VH-TDMA over the temperature range 170–200°C. The organic volume fraction for 71–77 nm natural SSA particles was 8±6%. Organic volume fraction did not vary significantly with varying water residence time (40 secs to 24 hrs) in the bubble generator or SSA particle diameter in the range 38–173 nm. At room temperature we measured shape- and Kelvin-corrected HGF at 90% RH of 2.46±0.02 for NaCl, 2.35±0.02 for artifical SSA and 2.26±0.02 for natural SSA particles. Overall, these results suggest that the natural accumulation mode SSA particles produced in these experiments contained only a minor organic fraction, which had little effect on hygroscopic growth. Our measurement of 8±6% is an order of magnitude below two previous measurements of the organic fraction in SSA particles of comparable sizes. We stress that our results were obtained using coastal seawater and they can’t necessarily be applied on a regional or global ocean scale. Nevertheless, considering the order of magnitude discrepancy between this and previous studies, further research with independent measurement techniques and a variety of different seawaters is required to better quantify how much organic material is present in accumulation mode SSA.
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The Learning by Design Workshop Program 2010, a part of the Queensland Government Unlimited: Designing for the Asia Pacific Event Program, was a one-day professional development design thinking workshop run on October 9, 2011 at The Edge, State Library of Queensland for self-selected public and private secondary school teachers from the subject areas of Visual Art, Graphics and Industrial Technology and Design. Participants were drawn from a database of Brisbane and regional Queensland schools from the goDesign and Living City Workshop Programs. It aimed to generate leadership within schools for design-led education and creative thinking and give teachers a rare opportunity to work with professional designers to generate future strategies for design-based learning. Teachers were introduced to the concept of design thinking in education by international keynote speakers CJ Lim (Studio 8 Architects) and Jeb Brugmann (The Next Practice), national speaker Oliver Freeman (NevilleFreeman Agency) and three Queensland speakers, Alexander Loterztain, David Williams and Keith Holledge. Inspired by the Unlimited showcase exhibition Make Change: Design Thinking in Action and ‘Idea Starters’/teaching resources provided, teachers worked with a professional designer (from a discipline of architecture, interior design, industrial design, urban design, graphic design or landscape architecture) in ten random teams, to generate optimistic ideas for the Ideal City of tomorrow, each considering a theme – Food, Water, Transport, Ageing, Growth, Employment, Shelter, Health, Education and Energy. They then discussed how this process could be best activated and expanded on to build interest and knowledge in design thinking in the classroom. Assisted by illustrators, the teams prepared a visual presentation of their ideas and process from art materials provided. The workshop culminated in a video-taped interactive design charette to the larger group, which is intended to be utilised as a toolkit and praxis for teachers as part of the State Library of Queensland Design Minds Website Project.
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The Generation Workshop Program 2010, a part of the Queensland Government Unlimited: Designing for the Asia Pacific Event Program, consisted of two one-day intensive design thinking workshops run on October 7-8, 2011 at The Edge, State Library of Queensland, for 100 senior secondary students and 20 secondary teachers self-selected from the subject areas of Visual Art, Graphics and Industrial Technology and Design. Participants were drawn from a database of Brisbane and regional Queensland private and public schools from the goDesign and Living City Workshop Programs. The workshop aimed to facilitate awareness in young people of the role of design in society and the value of design thinking skills in solving complex problems facing the Asia Pacific Region, and to inspire the generation of strategies for our future cities. It also aimed to encourage the collaboration of professional designers with secondary schools to inspire post-secondary pathways and idea generation for education. Inspired by international and national speakers Bunker Roy (Barefoot College) and Hael Kobayashi (Associate Producer on "Happy Feet" film for Australia's Animal Logic), the Unlimited showcase exhibition Make Change: Design Thinking in Action and ‘Idea Starters’/teaching resources provided, students worked with a teacher in ten random teams, to generate optimistic strategies for the Ideal City of tomorrow, each considering a theme – Food, Water, Transport, Ageing, Growth, Employment, Shelter, Health, Education and Energy. Each team of 6 was led by a professional designer (from the discipline of architecture, interior design, industrial design, urban design, graphic design or landscape architecture) who was a catalyst for driving the student creative thinking process. Assisted by illustrators, the teams prepared a visual presentation of their idea from art materials provided. The workshop culminated in a video-taped interactive design chatter to the larger group, which will be utilised as a toolkit and praxis for teachers as part of the State Library of Queensland Design Minds Project. Photos of student design work were published on the Unlimited website.
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Modelling of food processing is complex because it involves sophisticated material and transport phenomena. Most of the agricultural products such fruits and vegetables are hygroscopic porous media containing free water, bound water, gas and solid matrix. Considering all phase in modelling is still not developed. In this article, a comprehensive porous media model for drying has been developed considering bound water, free water separately, as well as water vapour and air. Free water transport was considered as diffusion, pressure driven and evaporation. Bound water assumed to be converted to free water due to concentration difference and also can diffuse. Binary diffusion between water vapour and air was considered. Since, the model is fundamental physics based it can be applied to any drying applications and other food processing where heat and mass transfer takes place in porous media with significant evaporation and other phase change.
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The effects of reductions in cell wall lignin content, manifested by RNA interference suppression of coumaroyl 3'-hydroxylase, on plant growth, water transport, gas exchange, and photosynthesis were evaluated in hybrid poplar trees (Populus alba 3 grandidentata). The growth characteristics of the reduced lignin trees were significantly impaired, resulting in smaller stems and reduced root biomass when compared to wild-type trees, as well as altered leaf morphology and architecture. The severe inhibition of cell wall lignification produced trees with a collapsed xylem phenotype, resulting in compromised vascular integrity, and displayed reduced hydraulic conductivity and a greater susceptibility to wall failure and cavitation. In the reduced lignin trees, photosynthetic carbon assimilation and stomatal conductance were also greatly reduced, however, shoot xylem pressure potential and carbon isotope discrimination were higher and water-use efficiency was lower, inconsistent with water stress. Reductions in assimilation rate could not be ascribed to increased stomatal limitation. Starch and soluble sugars analysis of leaves revealed that photosynthate was accumulating to high levels, suggesting that the trees with substantially reduced cell wall lignin were not carbon limited and that reductions in sink strength were, instead, limiting photosynthesis.
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Due to ever increasing climate instability, the number of natural disasters affecting society and communities is expected to increase globally in the future, which will result in a growing number of casualties and damage to property and infrastructure. Such damage poses crucial challenges for recovery of interdependent critical infrastructures. Post-disaster reconstruction is a complex undertaking as it is not only closely linked to the well-being and essential functioning of society, but also requires a large financial commitment. Management of critical infrastructure during post-disaster recovery needs to be underpinned by a holistic recognition that the recovery of each individual infrastructure system (e.g. energy, water, transport and information and communication technology) can be affected by the interdependencies that exist between these different systems. A fundamental characteristic of these interdependencies is that failure of one critical infrastructure system can result in the failure of other interdependent infrastructures, leading to a cascade of failures, which can impede post-disaster recovery and delay the subsequent reconstruction process. Consequently, there is a critical need for developing a holistic strategy to assess the influence of infrastructure interdependencies, and for incorporating these interdependencies into a post-disaster recovery strategy. This paper discusses four key dimensions of interdependencies that need to be considered in a post-disaster reconstruction planning. Using key concepts and sub-concepts derived from the notion of interdependency, the paper examines how critical infrastructure interdependencies affect the recovery processes of damaged infrastructures.
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The accompanying collective research report is the result of the research project in 198690 between The Finnish Academy and the former Soviet Academy of Sciences. The project was organized around common field work in Finland and in the former Soviet Union and theoretical analyses of tree growth determining processes. Based on theoretical analyses, dynamic stand growth models were made and their parameters were determined utilizing the field results. Annual cycle affects the tree growth. Our theoretical approach was based on adaptation to local climate conditions from Lapland to South Russia. The initiation of growth was described as a simple low and high temperature accumulation driven model. Linking the theoretical model with long term temperature data allowed us to analyze what type of temperature response produced favorable outcome in different climates. Initiation of growth consumes the carbohydrate reserves in plants. We measured the dynamics of insoluble and soluble sugars in the very northern and Karelian conditions. Clear cyclical pattern was observed but the differences between locations were surprisingly small. Analysis of field measurements of CO2 exchange showed that irradiance is the dominating factor causing variation in photosynthetic rate in natural conditions during summer. The effect of other factors is so small that they can be omitted without any considerable loss of accuracy. A special experiment carried out in Hyytiälä showed that the needle living space, defined as the ratio between the shoot cylindric volume and needle surface area, correlates with the shoot photosynthesis. The penetration of irradiance into Scots pine canopy is a complicated phenomenon because of the movement of the sun on the sky and the complicated structure of branches and needles. A moderately simple but balanced forest radiation regime submodel was constructed. It consists of the tree crown and forest structure, the gap probability calculation and the consideration of spatial and temporal variation of radiation inside the forest. The common field excursions in different geographical regions resulted in a lot of experimental data of regularities of woody structures. The water transport seems to be a good common factor to analyse these properties of tree structure. There are evident regressions between cross-sectional areas measured at different locations along the water pathway from fine roots to needles. The observed regressions have clear geographical trends. For example, the same cross-sectional area can support three times higher needle mass in South Russia than in Lapland. Geographical trends can also be seen in shoot and needle structure. Analysis of data published by several Russian authors show, that one ton of needles transpire 42 ton of water a year. This annual amount of transpiration seems to be independent of geographical location, year and site conditions. The produced theoretical and experimental material is utilised in the development of stand growth model that describes the growth and development of Scots pine stands in Finland and the former Soviet Union. The core of the model is carbon and nutrient balances. This means that carbon obtained in photosynthesis is consumed for growth and maintenance and nutrients are taken according to the metabolic needs. The annual photosynthetic production by trees in the stand is determined as a function of irradiance and shading during the active period. The utilisation of the annual photosynthetic production to the growth of different components of trees is based on structural regularities. Since the fundamental metabolic processes are the same in all locations the same growth model structure can be applied in the large range of Scots pine. The annual photosynthetic production and structural regularities determining the allocation of resources have geographical features. The common field measurements enable the application of the model to the analysis of growth and development of stands growing on the five locations of experiments. The model enables the analysis of geographical differences in the growth of Scots pine. For example, the annual photosynthetic production of a 100-year-old stand at Voronez is 3.5 times higher than in Lapland. The share consumed to needle growth (30 %) and to growth of branches (5 %) seems to be the same in all locations. In contrast, the share of fine roots is decreasing when moving from north to south. It is 20 % in Lapland, 15 % in Hyytiälä Central Finland and Kentjärvi Karelia and 15 % in Voronez South Russia. The stem masses (115113 ton/ha) are rather similar in Hyytiälä, Kentjärvi and Voronez, but rather low (50 ton/ha) in Lapland. In Voronez the height of the trees reach 29 m being in Hyytiälä and Kentjärvi 22 m and in Lapland only 14 m. The present approach enables utilization of structural and functional knowledge, gained in places of intensive research, in the analysis of growth and development of any stand. This opens new possibilities for growth research and also for applications in forestry practice.
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Methyl isocyanate (MIC) interaction with the rabbit erythrocyte membrane increased the fluidity of the membrane and decreased the osmotic fragility of erythrocytes both in vitro and in vivo in rabbits intoxicated with MIC subcutaneously. MIC inhibited both acetylcholinesterase (AChE) and adenosine triphosphatase (ATPase) activities of erythrocytes dose-dependently in vitro, while in vivo a decreased trend in ATPase activity with unaltered AChE activity was observed. MIC also caused significant decrease in plasma sodium level with corresponding increase in potassium level in rabbits. The observed effects are due to MIC, per se, as the hydrolysis products of MIC, methylamine and N,Nprime-dimethylurea did not affect the erythrocyte fluidity and enzymes activities both in vitro and in vivo while they increased the osmotic fragility of erythrocytes in vivo in rabbits administered subcutaneously in equimolar concentration to MIC dosage. Inhibition of Na+-K+-dependent ATPase with altered permeability to cations and also probably water transport of plasma membrane due to MIC interaction are envisaged.
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Estimation of the water content of herring landings caused by pressure-vacuum double tank pumps and using of multi purpose transport containers About 80 % of herring that is landed in the fish processing company Euro-Baltic Fischverarbeitungs GmbH Mukran, on the Isle of Rügen at the Baltic coast is transported from the cutter into the processing plant by pumping. For this purpose 700 l-Euro-size polyethylene tubs (containers) are filled with herring by means of a pressure-vacuum pump-systems during the unloading of the cutter. To be able to pump the fish from the hold on board it is kept floating in water (transport water). At the end of the pumping/transporting process the fish ends in a dewatering box before reaching the tub, where the transport water is separated from the fish. Then, the not completely dewatered fish is slipped into the transport containers. The amount of transport water reaching the containers depends on the type of PV-equipment and on the amount of transport water in the fish holds of the different cutters. Methodologically the mixture of fish and water must be weighed together. For the experiments specially designed transport container were used which allow the measurement of the run-off of the water to be quantified and thus to measure the proportion of water remaining with the fish. Based on 30 experiments it could be shown that on average 6 % of remaining weight of the mixture is water. Furthermore, factors were detected which influence the variability of the proportion of water.
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The food of Ethmalosa fimbriata in the central part of the Ebrié lagoon, where the salinity is low, consists on limnic phytoplankton. In the region near Abidjan, which is more strongly influenced by coastal water, it consists of marine phyto- and zooplankton. The daily ration of a 12.5 cm fork-length fish is estimated to be between 2 and 3 % of its body weight.