Search Results

You are looking at 1 - 5 of 5 items for

  • Author or Editor: Kyung-Sook Kim x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

We measured neutron total cross-sections of natural niobium in the neutron energy region from 0.05 to 300 eV by using the time-of-flight method at the Pohang Neutron Facility, which consists of an electron linear accelerator, a water-cooled tantalum target with a water moderator, and a 12-m long time-of-flight path. A 6Li–ZnS(Ag) scintillator with a diameter of 12.5 cm and a thickness of 1.6 cm was used as a neutron detector, and a high purity natural niobium metallic disc with a diameter of 8.0 cm and a thickness of 15.0 mm thickness was used for the neutron transmission measurement. Notch filters composed of Co, In, Cd were used to estimate the background level and to calculate the length of neutron flight path. In order to reduce the gamma-ray background from bremsstrahlung and from neutron capture, we used a neutron-gamma separation system based on their different pulse shapes. The present measurement was compared with the existing experimental and the evaluated data. The resonance parameters of 93Nb isotope were obtained from the transmission by using the SAMMY code and were compared with other previous results.

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors:
Nguyen Do
,
Pham Khue
,
Kim Thanh
,
Tran Nam
,
Md. Rahman
,
Kyung-Sook Kim
,
Manwoo Lee
,
Guinyun Kim
,
Hee-Seock Lee
,
Moo-Hyun Cho
,
In Ko
, and
Won Namkung

Abstract  

We measured the isomeric yield ratios for the 44m,gSc isomeric pairs produced from different reaction channels 45Sc(γ,n)44m,gSc and natTi(γ,xnp)44m,gSc by using the activation method and γ-ray spectroscopic methods at 50-, 60-, and 70-MeV bremsstrahlung energies. The high-purity natural Sc and Ti foils in disc shape were irradiated with uncollimated bremsstrahlung beams generated from an electron linear accelerator at Pohang Accelerator Laboratory. The induced activities in the irradiated foils were measured by the high-resolution γ-ray spectrometric system which consists of a high-purity Germanium detector and a multichannel analyzer. In order to improve the accuracy of the experimental results the necessary corrections were made in the γ-ray activity measurements and data analysis. The measured isomeric yield ratios for the 45Sc(γ,n)44m,gSc reaction are 0.20 ± 0.02, 0.21 ± 0.02, and 0.21 ± 0.02 and those for the natTi(γ,xnp)44m,gSc reaction are 0.063 ± 0.012, 0.079 ± 0.014, and 0.124 ± 0.022 at 50-, 60-, and 70-MeV bremsstrahlung energies, respectively. The obtained results are compared with the corresponding values found in the literature. We observed that the isomeric yield ratios for the 45Sc(γ,n)44m,gSc reaction increase rapidly with the increasing bremsstrahlung energies from the reaction threshold up to giant resonance region, and then those are almost constant in the energy range from about 30 to 2.5 GeV. The isomeric yield ratios for the natTi(γ,xnp)44m,gSc reaction increase with increasing bremsstrahlung energies in a wide range of bremsstrahlung energies from 50 to 2.5 GeV.

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors:
Van Nguyen
,
Duc Pham
,
Tien Kim
,
Md. Rahman
,
Kyung-Sook Kim
,
Guinyun Kim
,
Hee-Seock Lee
,
Moo-Hyun Cho
,
In Ko
,
Won Namkung
, and
Tae-Ik Ro

Abstract  

The isomeric yield ratios for the natFe(γ,xn1p)52m,gMn reactions have been measured by the activation and the γ-ray spectroscopic methods at 50-, 60-, 70-MeV, and 2.5-GeV bremsstrahlung energies. The high purity natural iron foils in disc shape were irradiated with uncollimated bremsstrahlung beams of the Pohang Accelerator Laboratory. The induced activities in the irradiated foils were measured by the high-resolution γ-ray spectrometry with a calibrated high-purity Germanium (HPGe) detector. In order to improve the accuracy of the experimental results the necessary corrections were made in the gamma activity measurements and data analysis. The obtained isomeric yield ratios for the natFe(γ,xn1p)52m,gMn reactions at 50-, 60-, 70-MeV, and 2.5-GeV bremsstrahlung energies are 0.27 ± 0.03, 0.33 ± 0.04, 0.34 ± 0.04, and 1.25 ± 0.15, respectively. The present results at 50-, 60-MeV, and 2.5-GeV bremsstrahlung energies are the first measurements. We found that the isomeric yield ratio of the natFe(γ,xn1p)52m,gMn reaction depends on the incident bremsstrahlung energy and the mass difference between the product and the target nucleus when we compared the present results with other experimental data at different energies.

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors:
Md. Rahman
,
Kyung-Sook Kim
,
Manwoo Lee
,
Guinyun Kim
,
Youngdo Oh
,
Hee-Seock Lee
,
Moo-Hyun Cho
,
In Ko
,
Won Namkung
,
Van Nguyen
,
Duc Pham
,
Tien Kim
, and
Tae-Ik Ro

Abstract  

We measured isomeric-yield ratios for the 197Au(γ,n)196m,gAu reactions with bremsstrahlung energies of 50-, 60-, 70- MeV, and 2.5-GeV at the two different electron linac of the Pohang accelerator laboratory by using the activation method. The photons were produced when a pulsed electron beam hit a thin tungsten target. The well-known photoactivation method was used and hence the induced activities in the irradiated foils were measured with the high-resolution γ-ray spectrometric system consisting of lithium drifted high-purity Germanium detector and a multichannel analyzer. The measured isomeric-yield ratios for the 197Au(γ,n)196m,gAu reactions were (4.95 ± 0.51) × 10−4, (5.72 ± 0.72) × 10−4, (6.03 ± 0.50) × 10−4, and (9.27 ± 0.83) × 10−4 for 50-, 60-, 70-MeV, and 2.5-GeV bremsstrahlung energies, respectively. The present results measured with the bremsstrahlung energy higher than 60-MeV are the first measurement.

Restricted access
Acta Veterinaria Hungarica
Authors:
Sung Jae Kim
,
Van Giap Nguyen
,
Cheong Ung Kim
,
Bong Kyun Park
,
Thi-My Le Huynh
,
Sook Shin
,
Woo Kyung Jung
,
Yong Ho Park
, and
Hee Chun Chung

Abstract

Porcine epidemic diarrhoea virus (PEDV) is one of the major pathogens causing acute enteritis, which is characterised by vomiting and watery diarrhoea and commonly leads to high rates of mortality and morbidity in suckling piglets. Chitosan has been regarded as a promising natural disinfectant. In this study, the disinfectant effect and mammalian-cell toxicity of chitosan were evaluated against PEDV using Vero cells. A 0.01% solution of chitosan was determined to be an effective disinfectant. In addition, no evidence of toxicity was observed during the cell toxicity test; on the contrary, chitosan promoted cell proliferation. In conclusion, chitosan is a promising candidate for an effective and safe disinfectant against PEDV as well as other coronaviruses.

Open access