5,760 research outputs found
Evaluation of River Health and Water Quantity at the Anseong River, Changwon City, Korea
The paper aims to analyse the degree of river naturality according to the river morphology and the flora at raparian regions on the Anseong River during four seasons. Number of flexion was one at upper and low regions. That of middle region was absent. Bed materials were boulders and gravel in upper region and sand, silt, and clay in middle and low regions. Material of river shore at low channel width was the state of nature without protecting materials at upper region, but that was concreted impervious. Those of middle and upper regions were many artificial levees. The flora on the Anseong River was a total of 61 taxa, including 25 families, 54 species, and 7 varieties. The oxygen demand parameters COD, and BOD were within unacceptable levels at middle and low regions. Many cement blocks were creating instead river grasslands by the Direct stream Rivers Project and wide road construction. This artificial action reduced the waters natural filtration action
Surface temperatures and temperature gradient features of the US Gulf Coast waters
Satellite thermal infrared data on the Gulf of Mexico show that a seasonal cycle exists in the horizontal surface temperature structure. In the fall, the surface temperatures of both coastal and deep waters are nearly uniform. With the onset of winter, atmospheric cold fronts, which are accompanied by dry, low temperature air and strong winds, draw heat from the sea. A band of cooler water forming on the inner shelf expands, until a thermal front develops seaward along the shelf break between the cold shelf waters and the warmer deep waters of the Gulf. Digital analysis of the satellite data was carried out in an interactive mode using a minicomputer and software. A time series of temperature profiles illustrates the temporal and spatial changes in the sea-surface temperature field
Clustering of nicotinic acetylcholine receptors: from the neuromuscular junction to interneuronal synapses
Fast and accurate synaptic transmission requires high-density accumulation of neurotransmitter receptors in the postsynaptic membrane. During development of the neuromuscular junction, clustering of acetylcholine receptors (AChR) is one of the first signs of postsynaptic specialization and is induced by nerve-released agrin. Recent studies have revealed that different mechanisms regulate assembly vs stabilization of AChR clusters and of the postsynaptic apparatus. MuSK, a receptor tyrosine kinase and component of the agrin receptor, and rapsyn, an AChR-associated anchoring protein, play crucial roles in the postsynaptic assembly. Once formed, AChR clusters and the postsynaptic membrane are stabilized by components of the dystrophin/utrophin glycoprotein complex, some of which also direct aspects of synaptic maturation such as formation of postjunctional folds. Nicotinic receptors are also expressed across the peripheral and central nervous system (PNS/CNS). These receptors are localized not only at the pre- but also at the postsynaptic sites where they carry out major synaptic transmission. In neurons, they are found as clusters at synaptic or extrasynaptic sites, suggesting that different mechanisms might underlie this specific localization of nicotinic receptors. This review summarizes the current knowledge about formation and stabilization of the postsynaptic apparatus at the neuromuscular junction and extends this to explore the synaptic structures of interneuronal cholinergic synapse
Pressure Relief Sizing of Reactive System using DIERS Simplified Methods and Dynamic Simulation Method
PresentationIncidents involving uncontrolled chemical reactions continue to result in fatality, injury and economic loss. These incidents are often the result of inadequate pressure relief system designs due to a limited knowledge of the chemical reactivity hazard. A safe process design requires knowledge of the chemical reactivity of desired as well as undesired chemical reactions due to upset conditions. Simplified, cost effective methods to relief system sizing are presented by The Design Institute of Emergency Relief Systems (DIERS). They require multiple experiments and sizing is only valid for the system composition and thermal inertia represented by the small scale experiments. Results are often conservative, especially for gassy systems. Detailed, dynamic computer simulation is highly accurate and can be used for iterative design and multiple scenario evaluation. In this study, an accelerating rate calorimeter (ARC®) and a low thermal inertia calorimeter (automatic pressure tracking adiabatic calorimeter – APTACTM) were used to collect chemical reactivity data for the dicumyl peroxide and toluene system. Results of the pressure relief system sizing using the two methodologies are presented and compared
Classical-to-quantum convolutional neural network transfer learning
Machine learning using quantum convolutional neural networks (QCNNs) has
demonstrated success in both quantum and classical data classification. In
previous studies, QCNNs attained a higher classification accuracy than their
classical counterparts under the same training conditions in the few-parameter
regime. However, the general performance of large-scale quantum models is
difficult to examine because of the limited size of quantum circuits, which can
be reliably implemented in the near future. We propose transfer learning as an
effective strategy for utilizing small QCNNs in the noisy intermediate-scale
quantum era to the full extent. In the classical-to-quantum transfer learning
framework, a QCNN can solve complex classification problems without requiring a
large-scale quantum circuit by utilizing a pre-trained classical convolutional
neural network (CNN). We perform numerical simulations of QCNN models with
various sets of quantum convolution and pooling operations for MNIST data
classification under transfer learning, in which a classical CNN is trained
with Fashion-MNIST data. The results show that transfer learning from classical
to quantum CNN performs considerably better than purely classical transfer
learning models under similar training conditions.Comment: 16 pages, 7 figure
River Morphology and Riparian Vegetation at the Tributary of Seongdong, Korea
The purpose of this study is to investigate river morphology, riparian vegetation, and water quality on the tributary of Seongdong River in Korea during four seasons. There were not significant differences for river structure according to the river morphology and river naturality according to the environment of river at three regions (upper, middle and low areas). The portion of BOD and COD in the river increased exponentially along the upper-down gradient. The surveyed region was a total of 57 taxa, including 23 families, 50pecies, and 7varieties. Naturalized plants were 18species
Logarithmic concavity of Schur and related polynomials
We show that normalized Schur polynomials are strongly log-concave. As a consequence, we obtain Okounkov's log-concavity conjecture for Littlewood-Richardson coefficients in the special case of Kostka numbers
Electronic density of states derived from thermodynamic critical field curves for underdoped La-Sr-Cu-O
Thermodynamic critical field curves have been measured for
over the full range of carrier concentrations
where superconductivity occurs in order to determine changes in the normal
state density of states with carrier concentration. There is a substantial
window in the plane where the measurements are possible because the
samples are both thermodynamically reversible and the temperature is low enough
that vortex fluctuations are not important. In this window, the data fit
Hao-Clem rather well, so this model is used to determine and
for each temperature and carrier concentration. Using N(0) and the ratio of the
energy gap to transition temperature, , as fitting
parameters, the curves give over the
whole range of . Values of N(0) remain rather constant in the optimum-doped
and overdoped regime, but drops quickly toward zero in the underdoped regime.
Vortex fluctuations in superconducting La-Sr-Cu-O
Vortex fluctuations in the system have been
studied as a function of magnetic field, temperature and carrier concentration
in order to determine the dimensionality of the fluctuations. For a
sample, there is a unique crossing-temperature on the magnetization vs.
temperature plots for all magnetic fields up to 7 T, and the data scale very
well with 2D fluctuation theory. At lower x-values where is much
smaller, there are two well defined crossing points, one at low fields
(typically less than 1 T) and another at high fields (typically 3-7 T). A fit
of the data to fluctuation theory shows that the low field crossing data scale
as 2D fluctuations and the high field crossing data scale as 3D fluctuations.
It would appear that as the magnetic field approaches , there is a 2D
to 3D cross-over where the low field 2D pancake vortex structure transforms
into a 3D vortex structure
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Dosimetric comparison study between intensity modulated radiation therapy and three-dimensional conformal proton therapy for pelvic bone marrow sparing in the treatment of cervical cancer.
The objective was to compare intensity-modulated radiation therapy (IMRT) with 3D conformal proton therapy (3DCPT) in the treatment of cervical cancer. In particular, each technique's ability to spare pelvic bone marrow (PBM) was of primary interest in this study. A total of six cervical cancer patients (3 postoperative and 3 intact) were planned and analyzed. All plans had uniform 1.0 cm CTV-PTV margin and satisfied the 95% PTV with 100% isodose (prescription dose = 45 Gy) coverage. Dose-volume histograms (DVH) were analyzed for comparison. The overall PTV and PBM volumes were 1035.9 ± 192.2 cc and 1151.4 ± 198.3 cc, respectively. In terms of PTV dose conformity index (DCI) and dose homogeneity index (DHI), 3DCPT was slightly superior to IMRT with 1.00 ± 0.001, 1.01 ± 0.02, and 1.10 ± 0.02, 1.13 ± 0.01, respectively. In addition, 3DCPT demonstrated superiority in reducing lower doses (i.e., V30 or less) to PBM, small bowel and bladder. Particularly in PBM, average V10 and V20 reductions of 10.8% and 7.4% (p = 0.001 and 0.04), respectively, were observed. However, in the higher dose range, IMRT provided better sparing (> V30). For example, in small bowel and PBM, average reductions in V45 of 4.9% and 10.0% (p = 0.048 and 0.008), respectively, were observed. Due to its physical characteristics such as low entrance dose, spread-out Bragg peak and finite particle range of protons, 3DCPT illustrated superior target coverage uniformity and sparing of the lower doses in PBM and other organs. Further studies are, however, needed to fully exploit the benefits of protons for general use in cervical cancer
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