5,665 research outputs found
Relative volatility of esters in ethyl alcohol-water-ester system.
The relative volatillities of five branch-chained esters with respect to ethyl alcohol in mixtures of ethyl alcohol and water containing small amounts of esters were determined experimentally. The results could be used in the design of distillation columns for ethyl alcohol purification.
For alcohol concentrations of more than 50 mol per cent, the increase of relative volatility of the esters was inversely proportional to the alcohol concentration. For dilute concentrations of less than 30 mol per cent the increase in volatility was very rapid, and the rates of increase were different for different esters. No simple quantitative correlation was established between the changes of relative volatility of ester and the concentration of ethyl alcohol
Reproductive biology of blue marlin (Makaira nigricans) in the western Pacific Ocean
The reproductive biology
of blue marlin (Makaira nigricans)
was assessed from 1001 fish (ranging
from 121 to 275 cm in eye-to-fork
length; EFL) caught by Taiwanese
offshore longliners in the western
Pacific Ocean from September 2000
to December 2001 and from 843 gonad
samples from these fish, The overall
sex ratio of the catch was approximately
1:1 dur ing the sampling
period, but blue marlin are sexually
dimorphic; females are larger than
males. Reproductive activity (assessed
by histology), a gonadosomatic index,
and the distribution of oocyte diameters,
indicated that spawning occurred
predominantly from May to September.
The estimated sizes-at-maturity
(EFL50) were 179.76 ±1.01 cm (mean
±standard error) for females and 130
±1 cm EFL for males. Blue marlin are
multiple spawners and oocytes develop
asynchronously. The proportion of
mature females with ovaries containing
postovulatory follicles (0.41) and
hydrated oocytes (0.34) indicated that
the blue marlin spawned once every
2–3 days on average. Batch fecundity
(BF) for 26 females with the
most advanced oocytes (≥1000 μm),
but without postovulatory follicles,
ranged from 2.11 to 13.50 million
eggs (6.94 ± 0.54 million eggs). The
relationships between batch fecundity
(BF, in millions of eggs) and
EFL and round weight (RW, kg) were
BF = 3.29 × 10 –12 EFL5.31 (r2 = 0.70)
and BF = 1.59 × 10–3 RW 1.73 (r2= 0.67),
respectively. The parameters estimated
in this study are key information
for stock assessments of blue
marlin in the western Pacific Ocean
and will contribute to the conservation
and sustainable yield o
Causality in Quantiles and Dynamic Stock Return-Volume Relations
This paper investigates the causal relations between stock return and volume based on quantile regressions. We first define Granger non-causality in all quantiles and propose testing non-causality by a sup-Wald test. Such a test is consistent against any deviation from non-causality in distribution, as opposed to the existing tests that check only noncausality in certain moment. This test is readily extended to test non-causality in different quantile ranges, and the testing results enable us to identify the quantile range for which causality is relevant. In the empirical studies of 3 major stock market indices, we find that, while the conventional test suggests no causality in mean, there are strong evidences that lagged volume Granger causes return in all but some middle quantiles. In particular, the causal effects have opposite signs at lower and upper quantiles and are stronger at more extreme quantiles. These relations form (symmetric) V shapes across quantiles. They also show that the dispersion of the return distribution increases with volume so that volume has a positive effect on return volatility. It is also shown that the quantile causal effects of lagged return on volume are mainly negative.Granger non-causality in quantiles, quantile causal effect, quantile regression, return-volume relation, sup-Wald test
Auto-adhesive transdermal drug delivery patches using beetle inspired micropillar structures
The patch described in this paper combines the principles of wet adhesion, which is a widely adopted biological adhesion system in nature, with transdermal drug delivery. A biologically inspired micropillar patch was fabricated that is self-adhesive, reusable, and can sustain a controlled drug release. We successfully preloaded the commercial non-steroidal anti-inflammatory generic drug unguents indomethacin, ketoprofen, diclofenac sodium and etofenamate into a polydimethylsiloxane elastomeric matrix and fabricated drug-containing micropillar patches. When examining the drug release kinetics and friction of the patches, we observed that these drug unguents can be released calculably and regularly for several days. Additionally, the drug unguents released from the patch to its attached surface are critical to increase the strength of the patch's adhesion, which is based on capillary attractive forces and is inspired by beetle feet. Here, we create a novel system combining biomimetics and drug delivery that can be modified for use across the biomedical and engineering spectra. Motivation: the objective of the present study was to characterize a micropillar PDMS patch that was inspired by a beetle's wet adhesion as a platform for conducting in vitro release studies. Commercially available non-steroid anti-inflammatory drugs (NSAIDs) were used as the model drugs for our delivery systems. An emphasis was put on quantitatively evaluating the drug release and friction manifestation of these patches
Multi-satellite altimetry and GOCE geoid based surface and subsurface currents in the Mediterranean Sea
Peer ReviewedPostprint (published version
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