5,472 research outputs found
Impact of Physical Stress on Salivary Buffering Capacity
Background: Saliva has many properties and the buffering capacity is important for the neutralization of oral fluids. It is unclear whether stressful conditions directly affect salivary buffering capacity, and we investigated the impact of physical stress on salivary buffering capacity. Methods: Twelve participants were subjected to the physical stress of jogging and running. The salivary buffering capacity and flow rate of the participants were measured before and after exposure to stressful conditions. Salivary α-amylase activity was measured as a quantitative index of stress. Results: No change in buffering capacity was detected among each time point during the whole course under physically stressful conditions. Next, we examined the change in buffering capacity after jogging compared to baseline. Six participants showed an increase in buffering capacity (Group A), while the other six participants showed a decrease or no change (Group B) after jogging. Group B showed a decrease in flow rate and increases in α-amylase activity and protein level after jogging, whereas Group A showed no changes in these properties. Conclusions: The results suggest that salivary buffering capacity changes following exposure to physically stressful conditions, and that the changes are dependent on the stress susceptibility of individuals
Correlation between Infrared Colors and Intensity Ratios of SiO Maser Lines
We present the results of SiO millimeter-line observations of a sample of
known SiO maser sources covering a wide dust-temperature range. A cold part of
the sample was selected from the SiO maser sources found in our recent SiO
maser survey of cold dusty objects. The aim of the present research is to
investigate the causes of the correlation between infrared colors and SiO maser
intensity ratios among different transition lines. In particular, the
correlation between infrared colors and SiO maser intensity ratio among the
J=1-0 v=1, 2, and 3 lines are mainly concerned in this paper. We observed in
total 75 SiO maser sources with the Nobeyama 45m telescope quasi-simultaneously
in the SiO J=1-0 v=0, 1, 2, 3, 4 and J=2-1 v=1, 2 lines. We also observed the
sample in the 29SiO J=1-0 v=0 and J=2-1 v=0, and 30SiO J=1-0 v=0 lines, and the
H2O 6(1,6)-5(2,3) line. As reported in previous papers, we confirmed that the
intensity ratios of the SiO J=1-0 v=2 to v=1 lines clearly correlate with
infrared colors. In addition, we found possible correlation between infrared
colors and the intensity ratios of the SiO J=1-0 v=3 to v=1&2 lines. Two
overlap lines of H2O (i.e., 11(6,6) nu_2=1 -> 12(7,5) nu_2=0 and 5(0,5) nu_2=2
-> 6(3,4) nu_2=1) might explain these correlation if these overlap lines become
stronger with increase of infrared colors, although the phenomena also might be
explained by more fundamental ways if we take into account the variation of
opacity from object to object.Comment: 49 pages, 7 figures, 3 tables, accepted for publication in ApJ. Full
resolution version available at
http://www.asiaa.sinica.edu.tw/~junichi/paper
Irreducible Modules of Finite Dimensional Quantum Algebras of type A at Roots of Unity
Specializing properly the parameters contained in the maximal cyclic
representation of the non-restricted A-type quantum algebra at roots of unity,
we find the unique primitive vector in it. We show that the submodule generated
by the primitive vector can be identified with an irreducble highest weight
module of the finite dimensional A-type quantum algebra which is defined as the
subalgebra of the restricted quantum algebra at roots of unity.Comment: LaTeX(2e), 17 page
Identification of Very Red Counterparts of SiO Maser and OH/IR Objects in the GLIMPSE Survey
Using the 3.6/4.5/5.8/8.0 micron images with 1.2 arcsec pixel resolution from
the Spitzer/GLIMPSE survey, we investigated 23 masing and 18 very red objects
that were not identified in the 2MASS survey. Counterparts for all selected
objects were found in the GLIMPSE images. Color indices in these IR bands
suggest the presence of a high-extinction layer of more than a few tenths of a
solar mass in front of the central star. Furthermore, radio observations in the
SiO and H2O maser lines found characteristic maser-line spectra of the embedded
objects, e.g., the SiO J=1-0 line intensity in the v=2 state stronger than that
of the v=1 state, or very widespread H2O maser emission spectra. This indicates
that these objects are actually enshrouded by very thick circumstellar matter,
some of which cannot be ascribed to the AGB wind of the central star.
Individually interesting objects are discussed, including two newly found water
fountains and an SiO source with nebulosity.Comment: High resolution figures available at
ftp://ftp.nro.nao.ac.jp/nroreport/no653.pdf.gz. ApJ No. 655 no.1 issue in
pres
A novel fast gas chromatography method for higher time resolution measurements of speciated monoterpenes in air
Biogenic emissions supply the largest fraction of non-methane volatile
organic compounds (VOC) from the biosphere to the atmospheric boundary
layer, and typically comprise a complex mixture of reactive terpenes. Due to
this chemical complexity, achieving comprehensive measurements of biogenic
VOC (BVOC) in air within a satisfactory time resolution is analytically
challenging. To address this, we have developed a novel, fully automated
Fast Gas Chromatography (Fast-GC) based technique to provide higher time
resolution monitoring of monoterpenes (and selected other C<sub>9</sub>-C<sub>15</sub>
terpenes) during plant emission studies and in ambient air. To our
knowledge, this is the first study to apply a Fast-GC based separation
technique to achieve quantification of terpenes in ambient air. Three
chromatography methods have been developed for atmospheric terpene analysis
under different sampling scenarios. Each method facilitates chromatographic
separation of selected BVOC within a significantly reduced analysis time
compared to conventional GC methods, whilst maintaining the ability to
quantify individual monoterpene structural isomers. Using this approach, the
C<sub>9</sub>-C<sub>15</sub> BVOC composition of single plant emissions may be
characterised within a 14.5 min analysis time. Moreover, in-situ
quantification of 12 monoterpenes in unpolluted ambient air may be achieved
within an 11.7 min chromatographic separation time (increasing to 19.7 min
when simultaneous quantification of multiple oxygenated C<sub>9</sub>-C<sub>10</sub>
terpenoids is required, and/or when concentrations of anthropogenic VOC are
significant). These analysis times potentially allow for a twofold to fivefold
increase in measurement frequency compared to conventional GC methods. Here we outline the technical
details and analytical capability of this chromatographic approach, and
present the first in-situ Fast-GC observations of 6 monoterpenes and the
oxygenated BVOC (OBVOC) linalool in ambient air. During this field
deployment within a suburban forest ~30 km west of central
Tokyo, Japan, the Fast-GC limit of detection with respect to monoterpenes
was 4–5 ppt, and the agreement between Fast-GC and PTR-MS derived total
monoterpene mixing ratios was consistent with previous GC/PTR-MS
comparisons. The measurement uncertainties associated with the Fast-GC
quantification of monoterpenes are ≤ 12%, while larger uncertainties
(up to ~25%) are associated with the OBVOC and
sesquiterpene measurements
CALCULATION OF PRESSURE DROP IN NARROW ROTATING ANNULAR CLEARANCES
This paper presents a review of correlations used for pressure drop calculation in narrow annular clearances with rotation of inner cylinder. Based on these review, a new general correlation is proposed to calculate pressure drop through such clearances. Results are compared with experimental data for different flow regimes: laminar, laminar with Taylor vortex, smooth and rough turbulent, with good agreement. The main objective is to develop a simple and general correlation that could be used for backflow calculation in twin-screw multiphase pumps. In this kind of pump, the volumetric efficiency is defined mainly by the backflow rate which occurs in the annular clearance between screw and casing. Usually, the backflow is calculated ignoring the influence of shaft rotation over pressure drop and does not consider the several possible flow regimes. Depending on operational conditions, this simplification can lead to significant errors
SUBSEA MULTIPHASE PUMPING SYSTEM X GAS LIFT: AN EXERGO-ECONOMIC COMPARISON
This paper presents a methodology for an exergetic comparison between two artificial lift
systems: a gas lift and a twin-screw multiphase pump system, and a standalone offshore
platform. A software (Hysys.Process v2.1) was used to simulate an offshore platform with
the artificial lift methods and calculate all properties (including exergy) of the material
and energy streams. The twin-screw multiphase pump behavior was simulated with a
thermodynamic model developed recently (NAKASHIMA (2000) and NAKASHIMA,
OLIVEIRA and CAETANO (2002)). The operational conditions of the PETROBRAS 7-
MRL-72D-RJS well operating with cited systems were predicted by an internal study
conducted in PETROBRAS (BARUZZI et al. (2001a) and partially published in BARUZZI
et al. (2001b)). The comparisons cover the range of 2000 to 2020, the same range adopted
in the study. Results show that in general the production costs are lower when the multiphase
pump is used. The main advantages of this method over the gas lift is the absence of
material (gas) recycle and a better energy management
Quantum R-matrix and Intertwiners for the Kashiwara Algebra
We study the algebra presented by Kashiwara and introduce
intertwiners similar to -vertex operators. We show that a matrix determined
by 2-point functions of the intertwiners coincides with a quantum R-matrix (up
to a diagonal matrix) and give the commutation relations of the intertwiners.
We also introduce an analogue of the universal R-matrix for the Kashiwara
algebra.Comment: 21 page
In-situ micro-FTIR Study of Thermal Changes of Organics in Tagish Lake Meteorite: Behavior of Aliphatic Oxygenated Functions and Effects of Minerals
Systematic in-situ FTIR heating experiments of Tagish Lake meteorite grains have been performed in order to study thermal stability of chondritic organics. Some aliphatic model organic substances have also been used to elucidate effects of hydrous phyllosilicate minerals on the thermal stability of organics. The experimental results indicated that organic matter in the Tagish Lake meteorite might contain oxygenated aliphatic hydrocarbons which are thermally stable carbonyls such as ester and/or C=O in ring compounds. The presence of hydrous phyllosilicate minerals has a pronounced effect on the increase of the thermal stability of aliphatic and oxygenated functions. These oxygenated aliphatic organics in Tagish Lake can be formed during the aqueous alteration in the parent body and the formation temperature condition might be less than 200 C, based especially on the thermal stability of C-O components. The hydrous phyllosilicates might provide sites for organic globule formation and protected some organic decompositio
Separation of colour degree of freedom from dynamics in a soliton cellular automaton
We present an algorithm to reduce the coloured box-ball system, a one
dimensional integrable cellular automaton described by motions of several
colour (kind) of balls, into a simpler monochrome system. This algorithm
extracts the colour degree of freedom of the automaton as a word which turns
out to be a conserved quantity of this dynamical system. It is based on the
theory of crystal basis and in particular on the tensor products of sl_n
crystals of symmetric and anti-symmetric tensor representations.Comment: 19 page
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