• Nuclear Engineering and Technology
• /
• v.49 no.5
• /
• pp.996-1005
• /
• 2017

In this paper, nuclear data for cross sections of the $^{64}Zn(n,2n)^{63}Zn$, $^{64}Zn(n,3n)^{62}Zn$, $^{64}Zn(n,p)^{64}Cu$, $^{66}Zn(n,2n)^{65}Zn$, $^{66}Zn(n,p)^{66}Cu$, $^{67}Zn(n,p)^{67}Cu$, $^{68}Zn(n,p)^{68}Cu$, and $^{68}Zn(n,{\alpha})^{65}Ni$ reactions were studied for neutron energies up to 40 MeV. In the nuclear model calculations, TALYS 1.6, ALICE/ASH, and EMPIRE 3.2 codes were used. Furthermore, the nuclear data for the (n,2n) and (n,p) reaction channels were also calculated using various cross-section systematics at energies around 14-15 MeV. The code calculations were analyzed and obtained using the different level densities in the exciton model and the geometry-dependent hybrid model. The results obtained from the excitation function calculations are discussed and compared with literature experimental data, ENDF/B-VII.1, and the TENDL-2015 evaluated data.

• Nuclear Engineering and Technology
• /
• v.53 no.10
• /
• pp.3151-3157
• /
• 2021

Copper is an important structural material in various nuclear energy applications, therefore the correct knowledge of copper cross sections is crucial. The presented paper deals with a validation of different copper transport libraries by means of activation of selected samples. An intense ²⁵²Cf(sf) source with a reference neutron spectrum was used as a neutron source. After irradiation, the samples were measured using a high purity germanium detector and the dosimeter reaction rates were inferred. These experimental data were compared with MCNP6 calculations using CENDL-3.1, JENDL-4.0, ENDF/B-VII.1, ENDF/B-VIII.0, JEFF-3.2 and JEFF-3.3 evaluated Cu transport libraries. The experiment specifically focuses on ⁵⁸Ni(n,p)⁵⁸Co, ⁹³Nb(n,2n)^92mNb, ¹⁹⁷Au(n,g)¹⁹⁸Au and ⁵⁵Mn(n,g)⁵⁶Mn dosimetry reactions. Evaluated activation cross sections of these dosimetric reactions were taken from the IRDFF-II library. The best library performance depends on the energy region of interest.

• Nuclear Engineering and Technology
• /
• v.51 no.1
• /
• pp.170-175
• /
• 2019

Displacement cross-sections for an advanced assessment of radiation damage rates were obtained for a number of materials using the arc-dpa model at neutron incident energies from $10^{-5}eV$ to 10 GeV. Evaluated data files, CEM03 and ECIS codes, and an approximate approach were applied for the calculation of recoil energy distributions in neutron induced reactions. Three sets of displacement cross-sections based on the use of low-energy data from JEFF-3.3, ENDF/B-VIII.0, and JENDL-4.0u were prepared. Files contain also cross-sections calculated using the standard NRT model. Special efforts were made to estimate the uncertainty of obtained displacement cross-sections.

• Bulletin of the Korean Chemical Society
• /
• v.24 no.11
• /
• pp.1632-1636
• /
• 2003

Palladium-catalyzed cross-coupling reactions of neopentyloxysulfonylphenyl bromides with arylboronic acids provided a variety of neopentyl biphenylsulfonates in good yields. 2-Bromo- and 4-bromobenzenesulfonates underwent the coupling reaction more rapidly than 3-bromobenzenesulfonate, while chlorobenzenesulfonate did not produce the coupling product under the standard reaction conditions.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.1
• /
• pp.137-140
• /
• 2011

The aminolysis reactions of phenyl N-benzyl thiocarbamate with benzylamines in acetonitrile at $50.0^{\circ}C$ are investigated. The reactions are first order in both the amine and the substrate. Under amine excess, pseudo-first coefficient ($k_{obs}$) are obtained, plot of $k_{obs}$ vs free amine concentration are linear. The signs of ${\rho}_{XZ}$ (< 0) are consistent with concerted mechanism. Moreover, the variations of $\rho_X$ and $\rho_Z$ with respect to the sustituent in the substrate and large ${\rho}_{XZ}$ value indicate that the reactions proceed concerted mechanism. The normal kinetic isotope effects ($k_H/k_D$ = 1.3 ~ 1.5) involving deuterated benzylamine nucleophiles suggest a hydrogen-bonded, four-centered-type transition state. The activation parameters, ${\Delta}H^\ddagger$ and ${\Delta}S^\ddagger$, are consistent with this transition state structure.

• Bulletin of the Korean Chemical Society
• /
• v.11 no.5
• /
• pp.435-438
• /
• 1990

Primary and secondary ${\alpha}$-deuterium kinetic isotope effects are determined with deuterated aniline nucleophiles in the nucleophilic substitution reactions of benzyl benzenesulfonates and 1-phenylethyl benzenesulfonates in acetonitrile at 30.0^{\circ}C. The $k_H/k_D$ values support our previous conclusions regarding the transition state structures proposed for the two reactions based on the cross-interaction constants ${\rho}_{ij}$; the former is a typical $S_N2$ reaction whereas in the latter the four-center transition state may be involved.

• Journal of the Korean Chemical Society
• /
• v.47 no.3
• /
• pp.191-198
• /
• 2003

The pairwise energy model (PEM) assumes that the cross section for the reaction cross section for the reaction A+BC$\{leftrightarrow}$B+C, where B and C are isotopes of hydrogen, depends on only the pairwise relative energy Es between A and B. Until now, the PEM has been used to interpret theoretically the isotope effect for the reactions such as $O(^3P)+HD,\;Ar^++(H_2,\;D_2,and\;HD)$. In this paper we carry out extensive quasiclassical trajectory calculations for the three possible reactions $Cl+H_2$ and HD and show that the PEM works very well at high energy. In particular we are able to accurately predict the intramolecular isotope effect at high energy for the reaction of Cl+HD using only the cross section data for $Cl+H_2$. To understand that the PEM works so well at high energy, the internal energy distributions for the products are examined. The distributions for three reactions are different at a fixed relative collision energy E but are approximately same at a fixed pairwise energy Es. This suggests that the PEM works very well at high energy. We believe the conclusions reached here will apply to other A+BC systems.

• Tuberculosis and Respiratory Diseases
• /
• v.66 no.6
• /
• pp.457-462
• /
• 2009

While receiving appropriate treatment, patients with tuberculosis occasionally have unusual, paradoxical reactions, with transient worsening of lesions or the development of new lesions. This report is a case of tuberculosis brain abscess and tuberculosis peritonitis with intra-abdominal abscess that developed during appropriate anti-tuberculosis chemotherapy. A 45-year-old male patient had been diagnosed as with all-drug susceptible pulmonary tuberculosis with pleurisy. Subsequently, the patient underwent standard treatment with anti-tuberculosis therapy; the pulmonary lesions improved. Three months after initial treatment, the patient developed brain abscesses and peritonitis. With the addition of corticosteroid treatment, the patient's neurologic symptoms were relieved. Exploratory laparotomy with surgical drainage was performed and a diagnosis of tuberculosis peritonitis was confirmed on biopsy. Anti-tuberculosis therapy was continued for 19 months, the patient improved eventually without further complications, although the therapeutic regimen had not been altered. In this case, the paradoxical response to treatment may have been involved in the pathogenesis of disease.

• The Journal of Korean Medicine
• /
• v.28 no.2 s.70
• /
• pp.66-79
• /
• 2007

Objectives : To explore the type and frequency of short term reactions, de Qi associated with acupuncture treatment and to determine the incidence of adverse events following acupuncture in Korea. Subjects and methods : This study is a retrospective and cross-sectional survey of patient reports. 1095 subjects, 585 of out-patients of the Oriental Medicine of Stroke & Neurological Disorders Center, East-West NEO Medical Center of Kyunghee University and 510 of out-patients of the Department of Cardiovascular & Neurologic Diseases (Stoke Center), Hospital of Oriental Medicine, Kyunghee Medical Center, from June through November of 2006, who had acupuncture, gave informed consent and completed one survey form. On this form, patients were asked to report short term acupuncture reactions, de Qi, patient satisfaction measurement (using VAS), and adverse events relating to acupuncture treatment. The acupuncturists of this study are Korean Medicine Doctors (KMD) who had worked as practitioners for 3-30 years or more. Results : The average age of the 1095 subjects was 58 years old. Positive short term acupuncture reactions after treatment were reported by 878 (80.2%), negative short term acupuncture reactions by 75 (6.8%) and no reactions were reported by 142 (13.0%). The most common positive short term acupuncture reactions were feeling 'relaxed', 472 (43.1%), followed by feeling 'less pain' 90 (8.2%), 'energized' 16 ( 1.5%), 'tingling' 16 (1.5%), 'heat feeling or Cold feeling' 10 (0.9%), and others 274 (25.0%), respectively. Negative short term acupuncture reactions were feeling 'pain' 37 (3.4%), tiredness 24 (2.2%), dizziness 9 (0.8%), and others 5 (0.2%), respectively. Traditionally described needling sensations of de Qi refer to a patient's response to distention, pulling, soreness, heaviness, numbness. 39.7% of subjects reported de Qi during needling, experiencing 'distention' 333 (30.4%), 'soreness' 52 (4.7%), 'pulling' 22 (2.0%), 'heaviness' 18 (1.6%), and 'numbness' 10 (0.9%) respectively. Positive short term acupuncture reactions and de Qi rate were the highest in the less than 40 years group (83/96 86.5%, 50/96 52.1%). No acupuncture reactions were highly seen in the over 70 years old group (31/187, 16.6%). Patient satisfaction level using VAS was a comparatively high $72.9{\pm}19.9$. Adverse events were only bleeding in 92 (8.4%) of the total subjects. High sensitive acupoints were 95 points as GV26 (54 times), LI4 (54 times), ST36 (53 times), GB20 (37 times), HT8(34 times), LV3 (29 times), SI3 (29 times), and LI11 (27 times) in order. Main impressions were stroke patients 430 (16.9%), headache 185 (16.9%), hypertension 97 (8.9%), and dizziness 85 (7.8%). Conclusions : Although 8 different Korean Medicine Doctors participated in this research, we obtained similar results from each. There were no significantly different results between the two hospitals. Short term acupuncture reactions and de Qi were most related to age. Except for bleeding there were no adverse events relating to acupuncture treatment in this study. We consider acupuncture treatment as very safe depending on practitioners. Positive short term acupuncture reactions after treatment were 12 times higher than negative short term acupuncture reactions. Subjects were comparatively satisfied with acupuncture treatment.

• Journal of the Korean Applied Science and Technology
• /
• v.32 no.4
• /
• pp.718-723
• /
• 2015

For the fabrication of the Si negative electrode in Li-ion batteries (LIBs) containing the cross-linking polymer binder, in this work, the urethane acrylate (UA) oligomer was synthesized via a simple synthetic process. The cross-linked poly(urethane acrylate) (CPUA)/carbone black (CB)/Si composite (CPUA/CB/Si composite) was fabricated through reactions between their reactive vinyl segments in the UA oligomer. Interestingly, the CPUA/CB/Si composite showed better cycle performance than the poly(vinylidene fluoride) (PVdF)/CB/Si composite (PVdF/CB/Si composite) and the polyurethane (PU)/CB/Si composite (PU/CB/Si composite). The CPUA/CB/Si composite had the best lithiation of about $2586mAh\;g^{-1}$. The UA oligomer showed a good compatibility with the electrode materials and current collector after and before a curing process.