1,037 research outputs found
Meteorological utility of high resolution multi-spectral data
There are no author-identified significant results in this report
Performance of cylindrical converters with preferred-crystal-orientation emitters of chemically vapor deposited tungsten
Design and evaluation of cylindrical out-of-pile thermionic converter test vehicle to determine performance of tungsten emitters with preferred crystal orientatio
Entropy-scaling search of massive biological data
Many datasets exhibit a well-defined structure that can be exploited to
design faster search tools, but it is not always clear when such acceleration
is possible. Here, we introduce a framework for similarity search based on
characterizing a dataset's entropy and fractal dimension. We prove that
searching scales in time with metric entropy (number of covering hyperspheres),
if the fractal dimension of the dataset is low, and scales in space with the
sum of metric entropy and information-theoretic entropy (randomness of the
data). Using these ideas, we present accelerated versions of standard tools,
with no loss in specificity and little loss in sensitivity, for use in three
domains---high-throughput drug screening (Ammolite, 150x speedup), metagenomics
(MICA, 3.5x speedup of DIAMOND [3,700x BLASTX]), and protein structure search
(esFragBag, 10x speedup of FragBag). Our framework can be used to achieve
"compressive omics," and the general theory can be readily applied to data
science problems outside of biology.Comment: Including supplement: 41 pages, 6 figures, 4 tables, 1 bo
Self-excited Oscillations of Charge-Spin Accumulation Due to Single-electron Tunneling
We theoretically study electronic transport through a layer of quantum dots
connecting two metallic leads. By the inclusion of an inductor in series with
the junction, we show that steady electronic transport in such a system may be
unstable with respect to temporal oscillations caused by an interplay between
the Coulomb blockade of tunneling and spin accumulation in the dots. When this
instability occurs, a new stable regime is reached, where the average spin and
charge in the dots oscillate periodically in time. The frequency of these
oscillations is typically of the order of 1GHz for realistic values of the
junction parameters
Promising Developments in Bio-Based Products as Alternatives to Conventional Plastics to Enable Circular Economy in Ukraine
Transforming the plastic industry toward producing more sustainable alternatives than conventional plastics, as an essential enabler of the bio-based circular economy (CE), requires reinforcing initiatives to drive solutions from the lab to the market. In this regard, startups and ideation and innovation events can potentially play significant roles in consolidating efforts and investments by academia and industry to foster bio-based and biodegradable plastic-related developments. This study aimed to present the current trends and challenges of bioplastics and bio-based materials as sustainable alternatives for plastics. On this basis, having conducted a systematic literature review, the seminal research themes of the bio-based materials and bioplastics literature were unfolded and discussed. Then, the most recent developments of bio-based sustainable products in Ukraine, as alternatives to petroleum-based plastics, that have gained publicity through local startup programs and hackathons were presented. The findings shed light on the potential of the bio-based sector to facilitate the CE transition through (i) rendering innovative solutions most of which have been less noticed in academia before; (ii) enhancing academic debate and bridging the gap between developers, scholars, and practitioners within the plastic industry toward creating circularity across the supply chain; (iii) identifying the main challenges and future perspectives for further investigations in the future
The effect of paper waste and food waste on biohydrogen production at mesophilic temperatures in batch reactors
Bio-hydrogen production in an EGSB reactor under mesophilic, thermophilic and hyperthermophilic conditions
Mesophilic, thermophilic and hyperthermophilic bio-hydrogen production with an expanded
granular sludge blanket (EGSB) fed with glucose and arabinose, without methane production, was
demonstrated. Homoacetogenesis was observed on reactor when operated under mesophilic (37ºC)
conditions but not under thermophilic (55ºC) and hyper-thermophilic conditions (70ºC). It was
also found that under thermophilic and hyper-thermophilic conditions glucose is preferentially
consumed than arabinose.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/29823/2006, SFRH/BPD/24221/2005, POCI/ENR/57786/2004
Effect of arabinose concentration on dark fermentation hydrogen production using different mixed cultures
Dark fermentation hydrogen production from arabinose at concentrations ranging
between 0 and 100 g/L was examined in batch assays for three different mixed anaerobic
cultures, two suspended sludges (S1, S2) obtained from two different sludge digesters
and one granular sludge (G) obtained from a brewery wastewater treatment plant. After
elimination of the methanogenic activity by heat treatment, all mixed cultures produced
hydrogen, and optimal hydrogen rates and yields were generally observed for concentrations
between 10 and 40 g/L of substrate. Higher concentrations of arabinose up to 100 g/L
inhibited hydrogen production, although the effect was different from inoculum to inoculum.
It was evident that the granular biomass was less affected by increased initial arabinose
concentrations when calculating the rate of decrease in hydrogen yields versus
arabinose concentrations, compared against the two suspended sludges.
The largest amount of soluble microbial product produced for all three inocula was for
n-butyrate. Also, valeric acid production was observed in some samples.Fundação para a Ciência e a Tecnologia (FCT
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