5,214 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
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
Efficient Coil Design by Electromagnetic Topology Optimization for Electromagnetic Sharp Edge Forming of DP980 Steel Sheet
This paper proposes a design method of the tool coil by topology optimization for the
electromagnetic sharp edge forming process. Topology optimization is an approach that
optimizes material configuration in a given domain to meet the design requirements. The
design problem for the tool coil is defined as enhancing efficiency of the forming process
and optimization problem is set to be maximization of the Lorentz force induced on the tool
coil. A new topology optimization formulation based on the numerical methods for
electromagnetism using FEM and BEM is developed for maximization of the Lorentz force.
Optimum design of the tool coil is obtained by the topology optimization using the element
density approach. The optimized result is compared with other coils which have different
configurations to show the effectiveness of the proposed method. The idea of applying
topology optimization to the design of the tool coil is successful and this formulation deals
effectively for the optimization problems
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
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.
Complements of hypersurfaces, variation maps and minimal models of arrangements
We prove the minimality of the CW-complex structure for complements of
hyperplane arrangements in by using the theory of Lefschetz
pencils and results on the variation maps within a pencil of hyperplanes. This
also provides a method to compute the Betti numbers of complements of
arrangements via global polar invariants
Classical generalized constant coupling model for geometrically frustrated antiferromagnets
A generalized constant coupling approximation for classical geometrically
frustrated antiferromagnets is presented. Starting from a frustrated unit we
introduce the interactions with the surrounding units in terms of an internal
effective field which is fixed by a self consistency condition. Results for the
magnetic susceptibility and specific heat are compared with Monte Carlo data
for the classical Heisenberg model for the pyrochlore and kagome lattices. The
predictions for the susceptibility are found to be essentially exact, and the
corresponding predictions for the specific heat are found to be in very good
agreement with the Monte Carlo results.Comment: 4 pages, 3 figures, 2 columns. Discussion about the zero T value of
the pyrochlore specific heat correcte
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Knockdown of Ant2 Reduces Adipocyte Hypoxia And Improves Insulin Resistance in Obesity.
Decreased adipose tissue oxygen tension and increased HIF-1α expression can trigger adipose tissue inflammation and dysfunction in obesity. Our current understanding of obesity-associated decreased adipose tissue oxygen tension is mainly focused on changes in oxygen supply and angiogenesis. Here, we demonstrate that increased adipocyte O2 demand, mediated by ANT2 activity, is the dominant cause of adipocyte hypoxia. Deletion of adipocyte Ant2 improves obesity-induced intracellular adipocyte hypoxia by decreasing obesity-induced adipocyte oxygen demand, without effects on mitochondrial number or mass, or oligomycin-sensitive respiration. This led to decreased adipose tissue HIF-1α expression and inflammation with improved glucose tolerance and insulin resistance in both a preventative or therapeutic setting. Our results suggest that ANT2 may be a target for the development of insulin sensitizing drugs and that ANT2 inhibition might have clinical utility
Therapeutic embolization of the dural arteriovenous malformation involving the jugular bulb.
Pulsatile tinnitus is a rarely occurring symptom of vascular origin. Most frequently, the symptoms are due to an arteriovenous malformation, to a tumor of the jugular glomus or to a local arterial stenosis. A 39-yr-old Korean male suffering from pulsatile tinnitus of the left ear was diagnosed to have dural arteriovenous malformation of the jugular bulb. Magnetic resonance imaging and angiography revealed a high-velocity vascular lesion encroaching the internal jugular vein and sigmoid sinuses. Digital subtraction angiography demonstrated a dural arteriovenous malformation involving the jugular bulb. The arterial supply was from the neuromeningeal branch of the left ascending pharyngeal artery and inferior tympanic artery. Stenosis of the left jugular vein caused retrograde venous drainage through the contralateral transverse sinus. Superselective embolization of these feeding arteries was successfully performed using 25% mixture of N-butylcyanoacrylate and lipiodol. In postembolization period, his complaints of pulsatile tinnitus and buzzing noise behind his left ear disappeared
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