927 resultados para timber storage
Resumo:
Reagent pre-storage in a microfluidic chip can enhance operator convenience, simplify the system design, reduce the cost of storage and shipment, and avoid the risk of cross-contamination. Although dry reagents have long been used in lateral flow immunoassays, they have rarely been used for nucleic acid-based point-of-care (POC) assays due to the lack of reliable techniques to dehydrate and store fragile molecules involved in the reaction. In this study, we describe a simple and efficient method for prolonged on-chip storage of PCR reagents. The method is based on gelification of all reagents required for PCR as a ready-to-use product. The approach was successfully implemented in a lab-on-a-foil system, and the gelification process was automated for mass production. Integration of reagents on-chip by gelification greatly facilitated the development of easy-to-use lab-on-a-chip (LOC) devices for fast and cost-effective POC analysis.
Resumo:
In this study, we describe a simple and efficient method for on-chip storage of reagents for point-of-care (POC) diagnostics. The method is based on gelification of all reagents required for on-chip PCR-based diagnostics as a ready-to-use product. The result reported here is a key step towards the development of a ready and easy to use fully integrated Lab-on-a-chip (LOC) system for fast, cost-effective and efficient POC diagnostics analysis.
Resumo:
Abstract
Nano-sized(nO-Co3O4, 387nm)andmicron-sized(mO-Co3O4, 6.65 mm) Co3O4 octahedraenclosedby
{111}facetshavebeenbothsynthesizedthroughawetchemicalmethodfollowedbythermal
treatment,andservedasanodematerialoflithium ionbatteries(LIBs).Electrochemicalresults
demonstratethatthenO-Co3O4 showsexcellentlongcyclabilityandratecapability.ThenO-Co3O4
candeliverastablechargecapacityashighas955.5mAhg1 upto200cycleswithoutnoticeable
capacityfadingatacharge/dischargecurrentdensityof0.1Ag1 (ca. 0.11C).Theexcellent
electrochemicalperformanceisascribedtothenano-sizeandthe{111}facetsthatenclosethe
octahedra. WhilethemO-Co3O4 could onlymaintain288.5mAhg1 after 200cycles,illustratingvery
poorcyclingperformance,whichisascribedtothelargeparticlesizethatmaycausehugevolume
changeduringrepeatedcharging/discharging process.TheresultsrevealthattheCo3O4 nano-
octahedrawouldbeapromisinganodematerialforthenext-generationofLIBs.
Resumo:
The genetic variation existing in a set of barley (Hordeum vulgare L.) landrace samples recently collected in Morocco was estimated. Two kinds of genetic markers, seed storage proteins (hordeins) and random amplified polymorphic DNA (RAPD), were used. Only six out of 31 landraces were subjected to RAPD analysis. Both kinds of markers, RAPD and storage proteins, yielded similar results, showing that the level of variation observed in Moroccan barley was high: all landraces showed variability; 808 different storage protein patterns (multilocus associations) were observed among 1897 individuals (2.32 seeds per association, on average) with an average of 43 multilocus associations per accession. In general, genetic variation within accessions was higher than between accessions. The 100 polymorphic RAPD bands generated by 21 effective primers were able to generate enough patterns to differentiate between uniform cultivars and even between individuals in variable accessions. One of the aims of this work was to compare the effectiveness of RAPD versus storage protein techniques in assessing the variability of genetic resource collections. On average hordeins were more polymorphic than RAPDs: they showed more alternatives per band on gels and a higher percentage of polymorphic bands, although RAPDs supply a higher number of bands. Although RAPD is an easy and standard technique, storage protein analysis is technically easier, cheaper and needs less sophisticated equipment. Thus, when resources are a limiting factor and considering the cost of consumables and work time, seed storage proteins must be the technique of choice for a first estimation of genetic variation in plant genetic resource collections.
Resumo:
In this work, we demonstrate a very high-energy density and high-temperature stability capacitor based on SrTiO3-substituted BiFeO3 thin films. An energy density of 18.6 J/cm3 at 972 kV/cm is reported. The temperature coefficient of capacitance (TCC) was below 11% from room temperature up to 200°C. These results are of practical importance, because it puts forward a promising novel and environmentally friendly, lead-free material, for high-temperature applications in power electronics up to 200°C. Applications include capacitors for low carbon vehicles, renewable energy technologies, integrated circuits, and for the high-temperature aerospace sector. © 2013 Crown copyright
Resumo:
We address the propagation of a single photon pulse with two polarization components, i.e., a polarization qubit, in an inhomogeneously broadened "phaseonium" \Lambda-type three-level medium. We combine some of the non-trivial propagation effects characteristic for this kind of coherently prepared systems and the controlled reversible inhomogeneous broadening technique to propose several quantum information processing applications, such as a protocol for polarization qubit filtering and sieving as well as a tunable polarization beam splitter. Moreover, we show that, by imposing a spatial variation of the atomic coherence phase, an effcient quantum memory for the incident polarization qubit can be also implemented in \Lambda-type three-level systems.
Resumo:
It has often been assumed that the islands of Orkney were essentially treeless throughout much of the Holocene, with any ‘scrub’ woodland having been destroyed by Neolithic farming communities by around 3500 cal. BC. This apparently open, hyper-oceanic environment would presumably have provided quite marginal conditions for human settlement, yet Neolithic communities flourished and the islands contain some of the most spectacular remains of this period in north-west Europe. The study of new Orcadian pollen sequences, in conjunction with the synthesis of existing data, indicates that the timing of woodland decline was not synchronous across the archipelago, beginning in the Mesolithic, and that in some areas woodland persisted into the Bronze Age. There is also evidence to suggest that woodland communities in Orkney were more diverse, and therefore that a wider range of resources was available to Neolithic people, than has previously been assumed. Recent archaeological investigations have revealed evidence for timber buildings at early Neolithic settlement sites, suggesting that the predominance of stone architecture in Neolithic Orkney may not have been due to a lack of timber as has been supposed. Rather than simply reflecting adaptation to resource constraints, the reasons behind the shift from timber to stone construction are more complex and encompass social, cultural and environmental factors.
Resumo:
Renewable energy generation is expected to continue to increase globally due to renewable energy targets and obligations to reduce greenhouse gas emissions. Some renewable energy sources are variable power sources, for example wind, wave and solar. Energy storage technologies can manage the issues associated with variable renewable generation and align non-dispatchable renewable energy generation with load demands. Energy storage technologies can play different roles in each of the step of the electric power supply chain. Moreover, large scale energy storage systems can act as renewable energy integrators by smoothing the variability. Compressed air energy storage is one such technology. This paper examines the impacts of a compressed air energy storage facility in a pool based wholesale electricity market in a power system with a large renewable energy portfolio.
Resumo:
Although pumped hydro storage is seen as a strategic key asset by grid operators, financing it is complicated in new liberalised markets. It could be argued that the optimum generation portfolio is now determined by the economic viability of generators based on a short to medium term return on investment. This has meant that capital intensive projects such as pumped hydro storage are less attractive for wholesale electricity companies because the payback periods are too long. In tandem a significant amount of wind power has entered the generation mix, which has resulted in operating and planning integration issues due to wind's inherent uncertain, varying spatial and temporal nature. These integration issues can be overcome using fast acting gas peaking plant or energy storage. Most analysis of wind power integration using storage to date has used stochastic optimisation for power system balancing or arbitrage modelling to examine techno-economic viability. In this research a deterministic dynamic programming long term generation expansion model is employed to optimise the generation mix, total system costs and total carbon dioxide emissions, and unlike other studies calculates reserve to firm wind power. The key finding of this study is that the incentive to build capital-intensive pumped hydro storage to firm wind power is limited unless exogenous market costs come very strongly into play. Furthermore it was demonstrated that reserve increases with increasing wind power showing the importance of ancillary services in future power systems. © 2014 Elsevier Ltd. All rights reserved.