• Title/Summary/Keyword: Density Profile

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RETRIEVAL OF ELECTRON DENSITY PROFILE FOR KOMPSAT-5 GPS RADIO OCCULTATION DATA PROCESSING SYSTEM (아리랑위성 5호의 GPS 전파 엄폐 자료처리시스템 개발을 위한 전리층 전자밀도 산출)

  • Lee, Woo-Kyoung;Chun, Jong-Kyun;Cho, Sung-Ki;Park, Jong-Uk;Cho, Jung-Ho;Yoon, Jae-Cheol;Lee, Jin-Ho;Chun, Yong-Sik;Lee, Sang-Ryul
    • Journal of Astronomy and Space Sciences
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    • v.24 no.4
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    • pp.297-308
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    • 2007
  • The AOPOD (Atmosphere Occultation and Precision Orbit Determination) system, the secondary payload of KOMPSAT (KOrea Multi-Purpose SATellite)-5 scheduled to be launched in 2010, shall provide GPS radio occultation data. In this paper, we simulated the GPS radio occultation characteristic of KOMPSAT-5 and retrieved electron density profiles using KROPS (KASI Radio Occultation Processing Software). The electron density retrieved from CHAMP (CHAllenging Minisatellite Payload) GPS radio occultation data on June 20, 2004 was compared with IRI (International Reference Ionosphere) - 2001, PLP (Planar Langmuir Probe), and ionosonde measurements. When the result was compared with ionosonde measurements, the discrepancies were 5 km on the $F_2$ peak height ($hmF_2$) and $3{\times}10^{10}el/m^3$ on the electron density of the $F_2$ peak height ($NmF_2$). By comparing with the Laugmuir Probe measurements of CHAMP satellite (PLP), both agrees with $1.6{\times}10^{11}el/m^3$ at the height of 365.6 km.

A STUDY OF THE IONOSPHERIC ELECTRON MEASUREMENT ON THE MEDIUM-SIZED SCIENTIFIC ROCKET , KSR-II (중형과학로켓, KSR-II를 이용한 이온층 전자 밀도 및 온도 분포 측정에 관한 연구)

  • Lee, Jae-Jin;Kim, Jhoon;Lee, Soo-Jin;Min, Kyoung-Wook;Pyo, You-Surn;Cho, Gwang-Rae;Rhee, Hwang-Jae
    • Journal of Astronomy and Space Sciences
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    • v.15 no.2
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    • pp.401-415
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    • 1998
  • This paper reports the results obtained from the Langmuir probe (LP) and Electron Temperature Probe (ETP) experiments on the sounding rocket KSR-II (Korean Scientific Rocket - II) which was launched on Jun 11, 1998 at 10:00 KST from Tae-An peninsula (37$^{\circ}$ N, 126$^{\circ}$ E). The instruments successfully measured the electron density, electron temperature, and the floating potential at altitudes of 73km to 130km. While the electron temperature measurement is not easy in this region, since the temperature is very low and the contamination effect of the probe may give rise to a problem, we were able to obtain a reasonable electron temperature profile by employing two independent methods, the pulse modulated Langmuir Probe and Electron Temperature Probe. The preliminary results show that electron density increases sharply at about 90km, and forms a peak at 102km. The density profile is roughly consistent with IRI (International Reference Ionosphere)95-model or PIM (Parameterized Ionospheric Model) results except that the peak density appears at 110km in the model and model electron density is slightly lower than the observed one. Electron temperature obtained from ETP fluctuates between 200$^{\circ}$K and 700$^{\circ}$K, an effect presumably coming from the wakes developed by LP, and it tends to increase with the altitude, which is consistent with the LP results.

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Effects of Dietary Lycopene Supplementation on Plasma Lipid Profile, Lipid Peroxidation and Antioxidant Defense System in Feedlot Bamei Lamb

  • Jiang, Hongqin;Wang, Zhenzhen;Ma, Yong;Qu, Yanghua;Lu, Xiaonan;Luo, Hailing
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.7
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    • pp.958-965
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    • 2015
  • Lycopene, a red non-provitamin A carotenoid, mainly presenting in tomato and tomato byproducts, has the highest antioxidant activity among carotenoids because of its high number of conjugated double bonds. The objective of this study was to investigate the effect of lycopene supplementation in the diet on plasma lipid profile, lipid peroxidation and antioxidant defense system in feedlot lamb. Twenty-eight Bamei male lambs (90 days old) were divided into four groups and fed a basal diet (LP0, 40:60 roughage: concentrate) or the basal diet supplemented with 50, 100, and 200 mg/kg lycopene. After 120 days of feeding, all lambs were slaughtered and sampled. Dietary lycopene supplementation significantly reduced the levels of plasma total cholesterol (p<0.05, linearly), total triglycerides (TG, p<0.05) and low-density lipoprotein cholesterol (LDL-C, p<0.05), as well as atherogenic index (p<0.001), whereas no change was observed in high-density lipoprotein cholesterol (p>0.05). The levels of TG (p<0.001) and LDL-C (p<0.001) were decreased with the feeding time extension, and both showed a linear trend (p<0.01). Malondialdehyde level in plasma and liver decreased linearly with the increase of lycopene inclusion levels (p<0.01). Dietary lycopene intake linearly increased the plasma antioxidant vitamin E level (p<0.001), total antioxidant capacity (T-AOC, p<0.05), and activities of catalase (CAT, p<0.01), glutathione peroxidase (GSH-Px, p<0.05) and superoxide dismutase (SOD, p<0.05). The plasma T-AOC and activities of GSH-Px and SOD decreased with the extension of the feeding time. In liver, dietary lycopene inclusion showed similar antioxidant effects with respect to activities of CAT (p<0.05, linearly) and SOD (p<0.001, linearly). Therefore, it was concluded that lycopene supplementation improved the antioxidant status of the lamb and optimized the plasma lipid profile, the dosage of 200 mg lycopene/kg feed might be desirable for growing lambs to prevent environment stress and maintain normal physiological metabolism.

Significance of the Plasma Lipid Profile in Cases of Carcinoma of Cervix: A Tertiary Hospital Based Study

  • Raju, Kalyani;Punnayanapalya, Shruthi Suresh;Mariyappa, Narayanaswamy;Eshwarappa, Sumathi Mayagondanahalli;Anjaneya, Chandramouli;Kai, Lee Jun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.8
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    • pp.3779-3784
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    • 2014
  • Aims: To study alterations of plasma lipid profiles in carcinoma cervix and to assess significance comparedwith controls in different histological grades and stages. Materials and Methods: Totals of 99 histopathologically diagnosed cases and 35 controls from a tertiary hospital situated in the southern part of India which caters the rural and semi-urban populations were considered for the study. Fasting blood samples were taken to analyze total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C) and low density lipoproteins cholesterol (LDL-C), for comparison of cases, grouped according to histological grades and stages, and controls. One way ANOVA was used for multiple group comparisons and the Student's t test (unpaired) for group wise comparisons. For all tests a 'p' value of 0.05 or less was considered as significant. Results: Out of 99 cases, most (n-39) were seen in the 40-49 year age group followed by 60-69 years (n-22). Serum TG significantly differed between cases and controls but without any relation to differentiation grade. The lipid profile parameters in various grades of cervical cancer were not statistically significant. Statistically significant increase of TC and LDL-C values was observed with increase in stage of the disease. Conclusions: The study showed TG is elevated in cervical cancer, and that TC and LDL-C are proportional to the spread of cancer as it increases from stage I to stage IV. An in-depth study of molecular changes in lipid metabolism in cervical cancer patients, enzymes/genes responsible and alterations in LDL receptors is necessary to provide information to decide whether the lipid profile has any diagnostic/prognostic role in cervical cancer.

Dependency of the emission efficiency on doping profile of the red phosphorescent organic light-emitting diodes

  • Park, Won-Hyeok
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.224-224
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    • 2016
  • Many researchers have been tried to improve the performance of the phosphorescent organic light-emitting diode(PHOLED) by controlling of the dopant profile in the emission layer. In this work, as shown in Fig. 1 insert, a typical red PHOLED device which has the structure of ITO/NPB(50nm)/CBP(30nm)/TPBi(10nm)/Alq3(20nm)/LiF(0.8nm)/Al(100nm) is fabricated with a 5nm thick doping section in the emission layer. The doping section is formed by co-deposition of CBP and Ir(btp)2acac with a doping concentration of 8%, and it's location(x) is changed from HTL/EML interface to EML/HBL in 5nm steps. The current efficiency versus current density of the devices are shown in Fig. 1. By changing the location of doping section, as shown in Fig. 1 and 2, at x=5nm, the efficiency shows the maximum of 3.1 cd/A at 0.5 mA/cm2 and it is slightly decreased when the section is closed to HTL and slightly increased when the section is closed to HBL. If the doping section is closed to HTL(NPB) the excitons can be quenched easily to NPB's triplet state energy level(2.5eV) which is relatively lower than that of CBP(2.6eV). Because there is a hole accumulation at EML/HBL interface the efficiency can be increased slightly when the section is closed to HBL. Even the thickness of the doping section is only 5nm,. the maximum efficiency of 3.1 cd/A with x=5 is closed to that of the homogeneously doped device, 3.3 cd/A, because the diffusion length of the excitons is relatively long. As a result, we confirm that the current efficiency of the PHOLED can be improved by the doping profile optimization such as partially, not homogeneously, doped EML structure.

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Soil Profile Measurement of Carbon Contents using a Probe-type VIS-NIR Spectrophotometer (프로브형 가시광-근적외선 센서를 이용한 토양의 탄소량 측정)

  • Kweon, Gi-Young;Lund, Eric;Maxton, Chase;Drummond, Paul;Jensen, Kyle
    • Journal of Biosystems Engineering
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    • v.34 no.5
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    • pp.382-389
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    • 2009
  • An in-situ probe-based spectrophotometer has been developed. This system used two spectrometers to measure soil reflectance spectra from 450 nm to 2200 nm. It collects soil electrical conductivity (EC) and insertion force measurements in addition to the optical data. Six fields in Kansas were mapped with the VIS-NIR (visible-near infrared) probe module and sampled for calibration and validation. Results showed that VIS-NIR correlated well with carbon in all six fields, with RPD (the ratio of standard deviation to root mean square error of prediction) of 1.8 or better, RMSE of 0.14 to 0.22%, and $R^2$ of 0.69 to 0.89. From the investigation of carbon variability within the soil profile and by tillage practice, the 0-5 cm depth in a no-till field contained significantly higher levels of carbon than any other locations. Using the selected calibration model with the soil NIR probe data, a soil profile map of estimated carbon was produced, and it was found that estimated carbon values are highly correlated to the lab values. The array of sensors (VIS-NIR, electrical conductivity, insertion force) used in the probe allowed estimating bulk density, and three of the six fields were satisfactory. The VIS-NIR probe also showed the obtained spectra data were well correlated with nitrogen for all fields with RPD scores of 1.84 or better and coefficient of determination ($R^2$) of 0.7 or higher.

Flow of MHD Powell-Eyring nanofluid: Heat absorption and Cattaneo-Christov heat flux model

  • Sharif, Humaira;Khadimallah, Mohamed A.;Naeem, Muhammad Nawaz;Hussain, Muzamal;Hussain, Sajjad;Tounsi, Abdelouahed
    • Advances in nano research
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    • v.10 no.3
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    • pp.221-234
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    • 2021
  • During the previous few years, phenomenon of bioconvection along with the use of nanoparticles showed large number of applications in technological and industrial field. This paper analyzed the bioconvection phenomenon in magnetohydrodynamic boundary layer flow of a Powell-Eyring nanoliquid past a stretchable cylinder with Cattaneo-Christov heat flux. In addition, the impacts of chemical reaction and heat generation/absorption parameter are considered. By the use of appropriate transformation, the governing PDEs (nonlinear) have been transformed and formulated into nonlinear ODEs. The resulting nonlinear ODEs subjected to relevant boundary conditions are solved analytically through homotopy analysis method which is programmed in Mathematica software. Graphical and numerical results versus physical quantities like velocity, temperature, concentration and motile microorganism are investigated under the impact of physical parameters. It is noted that velocity profile enhances as the curvature parameter A and Eyring-Powell fluid parameter M increases but a decline manner for large values of buoyancy ratio parameter Nr and bio-convection Rayleigh number Rb. In the presence of Prandtl number Pr, Eyring-Powell fluid parameter M and heat absorption parameter ��, temperature profile decreases. Nano particle concentration profile increases for increasing values of magnetic parameter Ha and thermophoresis parameter Nt. The motile density profile has revealed a decrement pattern for higher values of bio-convection Lewis number Lb and bio-convection peclet number Pe. This study may find uses in bio-nano coolant systems, advance nanomechanical bio-convection energy conversion equipment's, etc.

Determining Vibration Qualification Level for the Equipment Loaded Inside a Tracked Vehicle (궤도차량 탑재장비의 진동 내구성 평가를 위한 시험수준 결정방법 연구)

  • Choi, Chang-Ha
    • Journal of Environmental Impact Assessment
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    • v.4 no.2
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    • pp.123-130
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    • 1995
  • The equipment composed of many complicated electronic stuffs undergoes diverse stresses caused by mechanical vibrations during its service. Thus, to ensure its proper operation in the field a simulated vibration test has to be carried out in the laboratory with the Vibration Qualification Level, the test specification, which can include the real environment. In this paper we intent to deal with method and procedure for determining the Vibration Qualification Level so as to estimate the vibration-endurance for the equipment precisely.

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A Study on the Optimal Var Planning Considering Uncertainties of Loads (부하의 불확실성을 고려한 최적 Var배분 앨고리즘에 관한 연구)

  • 송길영;이희영
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.41 no.4
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    • pp.346-354
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    • 1992
  • In the power-system, the active and reactive power levels of load bus randomly vary over days, months, and years which are stochastic in nature. This paper presents an algorithm for optimal Var planning considering the uncertainties of loads. The optimization problem is solved by a stochastic linear programming technique which can handle stochastic constraints to evaluate optimal Var requirement at load bus to maintain the voltage profile which results in probabilistic density function by stochastic Load Flow analysis within admissible range. The effectiveness of the proposed algorithm has been verified by the test on the IEEE-30 bus system.

Numerical simulation of diffusion in the stratified flow

  • Mizumoto N.;Kawamura T.
    • 한국전산유체공학회:학술대회논문집
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    • 2003.10a
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    • pp.255-256
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    • 2003
  • Simulations of atmospheric diffusion process under stable and unstable conditions were carried out using both numerical and experimental methods. Results from the previous study show that numerical simulation using 3-dimensional incompressible Navier-Stokes equation and density deviation are in good agreement with typical plume pattern. In this study, we use experimental data of temperature and wind profile obtained from a thermally stratified wind tunnel as initial conditions for numerical simulation and compare the results.

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