8,573 research outputs found
Coarsening Dynamics of Granular Heaplets in Tapped Granular Layers
A semi-continuum model is introduced to study the dynamics of the formation
of granular heaplets in tapped granular layers. By taking into account the
energy dissipation of collisions and screening effects due to avalanches, this
model is able to reproduce qualitatively the pattern of these heaplets. Our
simulations show that the granular heaplets are characterised by an effective
surface tension which depends on the magnitude of the tapping intensity. Also,
we observe that there is a coarsening effect in that the average size of the
heaplets, V grows as the number of taps k increases. The growth law at
intermediate times can be fitted by a scaling function V ~ k^z but the range of
validity of the power law is limited by size effects. The growth exponent z
appears to diverge as the tapping intensity is increased.Comment: 4 pages, 4 figure
How to do quantile normalization correctly for gene expression data analyses.
Quantile normalization is an important normalization technique commonly used in high-dimensional data analysis. However, it is susceptible to class-effect proportion effects (the proportion of class-correlated variables in a dataset) and batch effects (the presence of potentially confounding technical variation) when applied blindly on whole data sets, resulting in higher false-positive and false-negative rates. We evaluate five strategies for performing quantile normalization, and demonstrate that good performance in terms of batch-effect correction and statistical feature selection can be readily achieved by first splitting data by sample class-labels before performing quantile normalization independently on each split ("Class-specific"). Via simulations with both real and simulated batch effects, we demonstrate that the "Class-specific" strategy (and others relying on similar principles) readily outperform whole-data quantile normalization, and is robust-preserving useful signals even during the combined analysis of separately-normalized datasets. Quantile normalization is a commonly used procedure. But when carelessly applied on whole datasets without first considering class-effect proportion and batch effects, can result in poor performance. If quantile normalization must be used, then we recommend using the "Class-specific" strategy
Anisotropic Superconducting Properties of Optimally Doped BaFe(AsP) under Pressure
Magnetic measurements on optimally doped single crystals of
BaFe(AsP) () with magnetic fields applied
along different crystallographic axes were performed under pressure, enabling
the pressure evolution of coherence lengths and the anisotropy factor to be
followed. Despite a decrease in the superconducting critical temperature, our
studies reveal that the superconducting properties become more anisotropic
under pressure. With appropriate scaling, we directly compare these properties
with the values obtained for BaFe(AsP) as a function of
phosphorus content.Comment: 5 pages, 3 figure
Bioaccessibility of Carotenoids and Tocopherols in Marine Microalgae, Nannochloropsis sp. and Chaetoceros sp.
Microalgae can produce various natural products such as pigments, enzymes, unique
fatty acids and vitamin that benefit humans. The objective of the study is to study the
bioaccessibility of carotenoids (β-carotene and lycopene) and vitamin E (α- and β-
tocopherol) of Nannochloropsis oculata and Chaetoceros calcitrans. Analyses were carried
out for both the powdered forms of N. oculata and C. calcitrans, and the dried extract
forms of N. oculata and C. calcitrans. In vitro digestion method together with RP-HPLC
was used to determine the bioaccessibility of carotenoids and vitamin E for both forms
of microalgae. Powdered form of N. oculata had the highest bioaccessibility of β-carotene
(28.0 ± 0.6 g kg-1), followed by dried extract N. oculata (21.5 ± 1.1 g kg-1), dried extract C.
calcitrans (16.9 ± 0.1 g kg-1), and powdered C. calcitrans (15.6 ± 0.1 g kg-1). For lycopene,
dried extract of N. oculata had the highest bioaccessibility of lycopene (42.6 ± 1.1 g kg-
1), followed by dried extract C. calcitrans (41.9 ± 0.6 g kg-1), powdered C. calcitrans (39.7
± 0.1 g kg-1) and powdered N. oculata (32.6 ± 0.7 g kg-1). Dried extract C. calcitrans had the
highest bioaccessibility of α-tocopherol (72.1 ± 1.2 g kg-1). However, β-tocopherol was
not detected in both dried extract and powdered form of C. calcitrans. In conclusion, all
samples in their dried extract forms were found to have significantly higher
bioaccessibilities than their powdered forms. This may be due to the disruption of the
food matrix contributing to a higher bioaccessibility of nutrients shown by the dried
extract form
Health status of older adults with Type 2 diabetes mellitus after aerobic or resistance training: A randomised trial
10.1186/1477-7525-9-59Health and Quality of Life Outcomes9
Influence of Channel Layer Thickness on the Electrical Performances of Inkjet-Printed In-Ga-Zn Oxide Thin-Film Transistors
Cataloged from PDF version of article.Inkjet-printed In-Ga-Zn oxide (IGZO) thin-film transistors (TFTs) with bottom-gate bottom-contact device architecture are studied in this paper. The impact of the IGZO film thickness on the performance of TFTs is investigated. The threshold voltage, field-effect mobility, on and off drain current, and subthreshold swing are strongly affected by the thickness of the IGZO film. With the increase in film thickness, the threshold voltage shifted from positive to negative, which is related to the depletion layer formed by the oxygen absorbed on the surface. The field-effect mobility is affected by the film surface roughness, which is thickness dependent. Our results show that there is an optimum IGZO thickness, which ensures the best TFT electrical performance. The best result is from a 55-nm-thick IGZO TFT, which showed a field-effect mobility in the saturation region of 1.41 cm(2)/V . s, a threshold voltage of 1 V, a drain current on/off ratio of approximately 4.3 x 10(7), a subthreshold swing of 384 mV/dec, and an off-current level lower than 1 pA
Insights into the enzymatic synthesis of alcoholic flavor esters with molecular docking analysis
\ua9 2024The enzymatic synthesis is essential for the flavor esters in the food and fragrance industries. This paper introduces a novel preparation method for lipase microarrays (CALB@PMHOS-TEOS) with loadings up to 229 \ub1 1.4 mg/g. Using surfactant-free hydrophobic silica-hybridized mesoporous materials and Candida antarctica lipase, this resulted in the effective synthesis of flavor esters. Using CALB@PMHOS-TEOS a Pickering emulsion system was formed at the oil-water interface for the sustainable synthesis of flavor esters. This resulted in a 93.5 \ub1 0.5 % conversion of hexanoic acid within 2 h at an optimal temperature of 35 \ub0C, which is the highest level recorded in the literature to date. Furthermore, the conversion of hexanoic acid was maintained at 63.9 \ub1 1.2 % after 9 cycles of CALB@PMHOS-TEOS reuse. The application of the enzyme to the synthesis in a variety of flavor esters achieved a new benchmark in the existing literature. A molecular docking model was evaluated to understand the molecular mechanism underpinning the immobilized lipase. This work introduces a novel method for the eco-friendly and efficient synthesis of flavor esters for applications across various fields including food and cosmetics
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