2,614 research outputs found
Development of real-time investigation technique for nonpoint pollution source distribution using programming interface
Currently both central and local governments that are aware of the importance of conserving rivers, are making continuous efforts to solve the problem of non-point pollution sources (NPS) flowing into rivers. This study established a reactive web service app with a mobile application, to accommodate the need for systematic and scientific investigation and management of NPS. The developed investigation and management techniques incorporate all the PC-based administrative features, thereby improving development efficiency. A prototype of mobile GIS platform for a survey, inspection, and input was proposed, in which data related to pollution source locations and attributes can be effectively collected, stored, updated, and adjusted. To demonstrate, we conducted a quantitative analysis of river pollution source using GPS and GIS to show further details of the framework, which provides geographic information required to develop management technique of NPS flowing into rivers and related parameters in the form of a map. Furthermore, based on the interpolated maps and various environmental factors, the prediction of NPS as well as other parameters can be done. The research will not only improve the efficiency of investigation and management of NPS but also contribute to establishing a management policy, which covers quick decision-making and reaction to inflow accidents
Investigation of the physicochemical features and mixing of East/Japan Sea Intermediate Water: An isopycnic analysis approach
We present spatial distributions of the mixing ratio and properties of the East/Japan Sea Intermediate Water (ESIW) at its core density layer (σθ = 27.2–27.3) based on high-quality hydrographic data observed in the East/Japan Sea (EJS) during summer 1999. ESIW is defined as a source water type showing minimum salinity and maximum dissolved oxygen concentration. ESIW plays an important role in supplying dissolved oxygen and transporting anthropogenic carbon into the intermediate/deep layers in EJS. Studying the ESIW formation and distribution processes may provide insights on EJS\u27s shallow- to mid-depth thermohaline circulation and recent ocean changes. Here, we combine the previously estimated mixing ratio of ESIW, based on Optimum Multi-Parameter (OMP) analysis, and its physicochemical properties, such as pressure, dissolved oxygen, and phosphate, interpolated onto several isopycnic surfaces (σθ = 27.20, 27.25, and 27.30). The physicochemical properties of ESIW show steep north-south gradients across the subpolar front at 40–41°N. Higher dissolved oxygen concentrations (≥335 μmol kg–1) of ESIW are found in the western Japan Basin particularly off the Primorye coast, indicating a potential source region. The spatial and depth distributions of apparent oxygen utilization (AOU) on the ESIW isopycnic surfaces indicate that the subduction of ESIW occurs at 131–133°E (Ulleung Basin) across the subpolar front to the south. The density layer of ESIW shoals near the Korean coast in the Ulleung Basin, implying a potential link to coastal upwelling. The relative age of ESIW at its core layer is estimated from the oxygen utilization rate and AOU. The correlation between the pCFC12 and relative ages, and AOU estimated at 90% surface water oxygen saturation condition suggests a decadal-scale ventilation of ESIW (≤24 years). Younger waters at the ESIW coexist with the high-salinity intermediate water at the same density layer in the eastern Japan Basin. Our analysis suggests that ESIW is sensitive to climate forcing and an important shallow- to mid-depth thermohaline circulation component of EJS
Refraction traveltime tomography using damped monochromatic wavefield
For complicated earth models, wave-equation–based
refraction-traveltime tomography is more accurate than
ray-based tomography but requires more computational
effort. Most of the computational effort in traveltime
tomography comes from computing traveltimes
and their Fr´echet derivatives, which for ray-based
methods can be computed directly. However, in most
wave-equation traveltime-tomography algorithms, the
steepest descent direction of the objective function
is computed by the backprojection algorithm, without
computing a Fr ´echet derivative directly.
We propose a new wave-based refraction-traveltime–
tomography procedure that computes Fr´echet derivatives
directly and efficiently. Our method involves solving
a damped-wave equation using a frequency-domain,
finite-element modeling algorithm at a single frequency
and invoking the reciprocity theorem. A damping factor,
which is commonly used to suppress wraparound
effects in frequency-domain modeling, plays the role
of suppressing multievent wavefields. By limiting the
wavefield to a single first arrival, we are able to extract
the first-arrival traveltime from the phase term
without applying a time window. Computing the partial
derivative of the damped wave-equation solution
using the reciprocity theorem enables us to compute
the Fr ´echet derivative of amplitude, as well as that of
traveltime, with respect to subsurface parameters. Using
the Marmousi-2 model, we demonstrate numerically
that refraction traveltime tomography with large-offset
data can be used to provide the smooth initial velocity
model necessary for prestack depth migration.This work was financially supported by the National Laboratory
Project of the Ministry of Science and Technology
and the Brain Korea 21 project of the Ministry of Education.
We are also grateful to Prof. K. J. Marfurt of the University
of Houston and Dr. M. Schoenberger for editing our
manuscript
Characteristics and Trends of Strawberry Cultivars throughout the Cultivation Season in a Greenhouse
Each strawberry (Fragaria × ananassa) cultivar has its own growth and yield characteristics. However, the characteristics of many cultivars have not been determined at a consistent time and place, making direct comparative analysis difficult. The objective of this study was to identify characteristics and trends of five Korean strawberry cultivars in the same environment during an entire season. Therefore, environmental factors such as daily average air temperature, daily average relative humidity, daily average solar radiation, daily soil temperature, daily soil water content, daily soil electrical conductivity (EC), plant growth characteristics such as the number of leaves, plant height, leaf length, leaf width, and crown diameter, and productivity characteristics such as flowering and fruiting were measured to investigate the possible correlations of the data over one season. The vegetative growth of “Seolhyang” and “Keumsil” was greater than that of “Jukhyang” and “Maehyang”. The yield of “Arihyang” was greater than that of all other cultivars. “Arihyang” also presented the greatest weight per number of fruits. Among environmental factors, higher variability in air temperature and soil water content was correlated to lower total fresh weight in the following week at different degrees for each cultivar. Among the cultivars, the time to the first flowering was delayed by about seven days when the number of leaves increased by one and was reduced by one day per 1 cm increase in plant height. The total fresh weight was enhanced up to 271 g per experimental unit, while the average number of leaves increased by one. The results indicate that the data can be used by those who need information regarding the characteristics of the strawberry cultivars through direct comparative analysis
Harvesting electrical energy using plasmon-enhanced light pressure in a platinum cut cone
We have designed a method of harvesting electrical energy using plasmon-enhanced light pressure. A device was fabricated as a cut cone structure that optimizes light collection so that the weak incident light pressure can be sufficiently enhanced inside the cut cone to generate electrical energy. An increase in the device's current output is a strong indication that the pressure of incident light has been enhanced by the surface plasmons on a platinum layer inside the cut cone. The electrical energy harvested in a few minutes by irradiating pulsed laser light on a single micro device was possible to illuminate a blue LED
Toxicological Study on MUNOPHIL, Water Extract of Panax ginseng and Hericium erinaceum in Rats
AbstractObjectiveAs data on the safety profile of Panax ginseng and Hericium erinaceum is lacking, the safety of these two compounds was examined in a series of toxicological studies.Materials and MethodsMUNOPHIL, the water extract mixture of Panax ginseng and Hericium erinaceum was tested in an oral subchronic 28-day toxicity study in rats at doses of 1250, 2500 and 5000 mg/kg/day.ResultsIn repeated dose toxicity studies, no mortality was observed when varying doses of the extracts were administered once daily for a period of 28 days. There were no significant differences in body weight, absolute and relative organ weights between controls and treated rats of both sexes. Hematological analysis showed no differences in most parameters examined. In the biochemistry parameter analysis, no significant change occurred. Pathologically, neither gross abnormalities nor his-topathological changes were observed. Therefore, MUNOPHIL appears to be safe and non-toxic in these studies and a no-observed adverse effect level in rats was established at 5000 mg/kg/day.ConclusionThe data could provide satisfactory preclinical evidence of safety to launch clinical trials on standardized formulation of plant extracts
Predictive Scale for Amyloid PET Positivity Based on Clinical and MRI Variables in Patients with Amnestic Mild Cognitive Impairment
The presence of amyloid-β (Aβ) deposition is considered important in patients with amnestic mild cognitive impairment (aMCI), since they can progress to Alzheimer's disease dementia. Amyloid positron emission tomography (PET) has been used for detecting Aβ deposition, but its high cost is a significant barrier for clinical usage. Therefore, we aimed to develop a new predictive scale for amyloid PET positivity using easily accessible tools. Overall, 161 aMCI patients were recruited from six memory clinics and underwent neuropsychological tests, brain magnetic resonance imaging (MRI), apolipoprotein E (APOE) genotype testing, and amyloid PET. Among the potential predictors, verbal and visual memory tests, medial temporal lobe atrophy, APOE genotype, and age showed significant differences between the Aβ-positive and Aβ-negative groups and were combined to make a model for predicting amyloid PET positivity with the area under the curve (AUC) of 0.856. Based on the best model, we developed the new predictive scale comprising integers, which had an optimal cutoff score ≥ 3. The new predictive scale was validated in another cohort of 98 participants and showed a good performance with AUC of 0.835. This new predictive scale with accessible variables may be useful for predicting Aβ positivity in aMCI patients in clinical practice
Epitheliotropic cutaneous lymphoma (mycosis fungoides) in a dog
A seven-year-old castrated male Yorkshire terrier dog was presented for a recurrent skin disease. Erythematous skin during the first visit progressed from multiple plaques to patch lesions and exudative erosion in the oral mucosa membrane. Biopsy samples were taken from erythematous skin and were diagnosed with epitheliotropic T cell cutaneous lymphoma by histopathology and immunochemical stain. In serum chemistry, the dog had a hypercalcemia (15.7 mg/dl) and mild increased alkaline phosphatase (417 U/l). Immunohistochemistry was performed to detect parathyroid hormone-related peptide (PTH-rP) in epitheliotropic cutaneous lymphoma tissues but the neoplastic cells were not labeled with anti-PTH-rP antibodies. The patient was treated with prednisolone and isotretinoin. However, the dog died unexpectedly
Effect of Mechanical Deformation on in Vitro Calcification of Segmented Polyurethane
To investigate why calcification is accelerated by mechanical flexure,
in vitro calcification of segmented polyurethane (SPU) under static elongation and
dynamic mechanical flexure was performed. After the calcification period, the amount
of calcium deposition was increased by elongation, but the amount of calcium
deposition per unit area of the elongated surface was relatively smaller as compared
to that of the severe flexing area. Although the surface calcium concentration of the
elongated SPU was relatively smaller than the flexed area, there was the increase of
surface area by the elongation. The total amount of deposited calcium on the elongated
SPU was increased as it is reduced to the original surface area. Therefore, the
results reveal that certain changes of surface properties by the Mechanical deformation
accelerate the calcium deposition onto the surface and the enlargement of
surface area by the mechanical deformation results in the heavy calcification of the
severe flexing area in the SPU
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