• Journal of Magnetics
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• v.3 no.3
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• pp.74-77
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• 1998

A method to analyze the anisotropy constants of a two sublattice system with uniaxial anisotropy has been investigated by extending the Sucksmith and Thompson's method to higher order anisotropy terms. Using the method, a set of anisotropy constants for Pr-sublattice of $Pr_2Fe_{14}B at 4.2K has been obtained as K_{1Pr}=5210 J/kg, K_{2Pr}=-7200 J/kg, K_{3Pr}=-770 J/kg, K_{4Pr}=4940 J/kg and K_{SPr}=700 J/kg for N_{PrFe}=2.2 T/Am^2kg^{-1}.$ The magnetization calculated by an energy minimum method by using the sublattice anisotropy constants well reproduced the experimental results and satisfied the simulation assumptions.

• Korean Chemical Engineering Research
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• v.44 no.5
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• pp.498-504
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• 2006

The etch rates of photoresist (PR) and the etch selectivity of $SiO_2$ to PR in a high density $CHF_3$ plasma were investigated at different ion-incident angles and bias voltages. A Faraday cage was employed for the accurate control of ion-incident angles. The ion energy was controlled by changing bias voltages. The etch rate of $SiO_2$ continuously decreased with ion-incident angles but the etch rate of PR remained constant up to the middle angle region and decreased afterwards. The etch rates of $SiO_2$ normalized to those at $0^{\circ}$ incident angle changed with the ion-incident angle following a cosine(${\theta}$) curve. On the other hand, the normalized etch rates of the PR changed showing a drastic over-cosine shape in the middle angle region. The etch selectivity of $SiO_2$ to PR decreased with an increase in the ion-incident angle because the etch yields of PR were enhanced by physical sputtering in the middle angle region compared to the case of $SiO_2$ etching. The etch selectivity of $SiO_2$ to PR decreased with an increase in the bias voltage at nearly all ion-incident angles.

• Journal of Venture Innovation
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• v.3 no.2
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• pp.129-145
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• 2020

The purpose of this study was to examine the effects of the job characteristics of the PR practitioner on flourishing and to identify the mediating effect of the meaning of work and job engagement. This study used a survey of 353 PR practitioners from PR firms and the hypothesis was verified by gathering the data of the job characteristics, the meaning of work, the job engagement and the flourishing by conducting hierarchical regression analysis and SPSS Process Macro bootstrapping analysis. The results showed that the job characteristics of the PR practitioner were found to influence the flourishing with the double-mediation effect, the meaning of the work and job engagement. The more PR practitioners regard their work affects their surroundings, the higher the degree of autonomy is, and the more they get feedbacks they engaged more, as they valued their job more thereby experience flourish more. Moreover, when PR practitioners valued their job more, they more engaged in their work and experience flourish. The meaning of work revealed to be the important factor to affect flourish regardless of the job characteristics and the job engagement so that gained the results that PR firms' effort to elevate the meaning of work of PR practitioners has is important. The study findings suggest that PR practitioners' flourishing is manageable in the organization by paying attention to oneself in the aspect of the organization, not leaving in individual areas. Limitaions and implications for future studies were discussed.

• Journal of Acupuncture Research
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• v.22 no.6
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• pp.61-74
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• 2005

Objectives : The aim of this study was to investigate the effect of Asthma-depression and Immunoregulation with PR-HAS(Herbal-acupuncture with Platycodi Radix infusion solution) injection at Joksamni(St36) on ovalbumin-induced asthma in mice. Methods : C57BL/6 mice were sensitized and challenged with OVA(ovalbumin) for 12 weeks(once a week). The experimental group(OVA-PR-HA) wase treated with concentrations(1%) of PR-HAS at Joksamni(St36) for the later 8 weeks(3times/week). The second experimental group(OVA-Needle prick) was treated with Needle-Prick at Joksamni(St36) for the later 8 weeks(3times/week). Results : 1. The weight and total cells in the mice lung treated with PR-HA decreased significantly compared with that of control group. 2. Total leukocytes and eosinophils in BALF of the mice group treated with PR-HA decreased remarkably compared with those of control group. 3. The sticking of collagen on histological analysis of lung sections, the mice group treated with PR-HA decreased significantly compared with those of control group. 4. The concentrations of IL-4, IL-5, IgE in BALF, and IL-4, IL-5, IL-13 in serum of the mice group treated with PR-HA decreased significantly compared with those of control group. 5. The number of $Gr-1^+/CD11b^+\;and\;CD11b^+$ cells in the lungs of the mice group treated with PR-HA decreased significantly compared with that of control group. 6. The numbers of $CCR3^+\;cells,\;CD4^+\;cells\;and\;CD8^+\;cells$ in the lungs, and $CD3e^+/CD69^+$ in the lungs of the mice group treated with PR-HA decreased significantly compared with those of control group. 7. The mRNA expression of ${\beta}-actin,\;TNF-{\alpha}$, IL-4, IL-5,IL-13 in the mice group treated with PR-HA with RT-PCR decreased significantly compared with those of control group. Conclusion : The concentrations of IL-4, IL-5, IgE in BALF, and IL-4, IL-5, IL-13 in serum of the mice group treated with PR-HA decreased significantly compared with those of control group. The number of $Gr-1^+/CD11b^+\;and\;CD11b^+$ cells in the lungs of the mice group treated with PR-HA decreased significantly compared with that of control group. The numbers of $CCR3^+\;cells,\;CD4^+\;cells\;and\;CD8^+\;cells$ in the lungs, and $CD3e^+/CD69^+$ in the lungs of the mice group treated with PR-HA decreased significantly compared with those of control group. The mRNA expression of ${\beta}-actin,\;TNF-{\alpha}$, IL-4, IL-5, IL-13 in the mice group treated with PR-HA with RT-PCR decreased significantly compared with those of control group. These result suggests that Platycodi Radix Herbal-acupuncture at Joksamni(St36) in C57BL/6mice may be an effictive part to OVA-induced asthma in C57BL/6 mice.

• Journal of the Korean Ceramic Society
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• v.35 no.7
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• pp.757-763
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• 1998

The effect of {{{{ {Ga }^{3+ } }} addition on the photoluminescence and cathodoluminescence of {{{{ {SrTiO}_{3 } }}:{{{{ { Pr}^{3+ } }} was stu-died by performing the excitation emission and decay time measurements. Addition of {{{{ {Ga }^{3+ } }} in {{{{ {SrTiO}_{3 } }}:{{{{ { Pr}^{3+ } }} resulted in a considerable enhancement of {{{{ { Pr}^{3+ } }} emission intensity. From the analysis of the experimental results the following mechanism is proposed. Excitation in the {{{{ {SrTiO}_{3 } }} host lattice leads to the formation of electrons in the conduction band and holes in the valence band. The electrons in the conduction band re-combine radiatively with the holes trapped at {{{{ { Ga}^{3+ } }} and the energy is transferred to {{{{ { Pr}^{3+ } }} ion which give its own characteristic red emission.

• Progress in Superconductivity
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• v.13 no.3
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• pp.158-162
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• 2012

$Y(Pr)Ba_2Cu_4O_8$ system is one of the most studied high temperature superconductors. Substitution of Pr for Y in this system suppresses $T_c$ and superconductivity finally disappears at a high Pr doping. There are competing theories for the suppression of $T_c$ but systematic experimental results are very rare. In order to find the change in Fermi surface topology which can affect the superconductivity, we have performed angle-resolved photoemission studies on single crystal samples of $YBa_2Cu_4O_8$ and $PrBa_2Cu_4O_8$. While the Fermi surface of $YBa_2Cu_4O_8$ shows a similar topology to those of other cuprates, we observe only 1D like band structures in $PrBa_2Cu_4O_8$. We find no significant differences in the chain band for both samples.

• Geomechanics and Engineering
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• v.32 no.4
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• pp.361-373
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• 2023

This study aimed to investigate the engineering properties and mechanical behaviors of polymer-fibers treated sand. Para rubber (PR), natural fiber (NF), and geosynthetic fiber (GF) were used to reinforce poorly graded sand. A series of unconfined compressive and splitting tensile strength tests were performed to analyze the engineering behaviors and strength enhancement mechanism. The experiment results indicated that the PR-fibers mixture could firmly enhance the strength properties of sand. The stress-strain characteristics and failure patterns have been changed due to the increase of PR and fibers content. The presence of PR and fibers strengthened the sand and enhanced the stiffness and ductility behavior of the mixture. The stiffness of reinforced sand reaches an optimum state when both NF and GF are 0.5%, while the optimum PR contents are 20% and 22.5% for the mixture with NF and GF, respectively. An addition of PR and fiber into sand contributed to increasing interlocking zone and bonding of PR-sand interfacial.

• The Korea Journal of Herbology
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• v.32 no.1
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• pp.33-40
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• 2017

Objectives : The objective of this study is to evaluate antioxidant activity of water extracts from steamed Polygonati Rhizoma(PR). Methods : The alcohol steamed PR from Jinju-si, Gyeongsangnam-do and Samcheok-si Gangwon-do are treated for the research into the antioxidant activity of the water extract. The sample was divided into 4 groups that PR without steaming process, PR with once, second and third steaming process. The antioxidant activities of polyphenol, flavonoid, DPPH, SOD, hydroxyl radical and nitrite scavenging activity. Results : The total content of polyphenol was the grow rapidly when the number of steaming adds up. For the third time, both the steamed PR from Jinju-si and the one from Samcheok-si in the water extract indicate the highest content levels measured $50.59\;mg/m{\ell}$ and $37.33\;mg/m{\ell}$ respectively. The more the number of steaming increases, the more rising the content of flavonoid. The steamed PR from Jinju-si and Samcheok-si in the third time are measured $30.03\;mg/m{\ell}$ and $54.9\;mg/m{\ell}$ respectively. DPPH radical scavenging activity of the steamed PR rises high rather than the non-steamed one when the number of steaming increases. As increase steaming time, SOD like activity and hydroxyl radical scavenging ability were increasing too. The steamed PR from Jinju-si in the third time is measured as the highest level 22.4%, 71.90% respectively. As increase steaming time, nitrite scavenging ability was the number was decreased. Conclusions : These results suggest that water extracts from steamed PR, exhibited higher antioxidant activities can be potentially used as proper natural antioxidants.

• Journal of the Semiconductor & Display Technology
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• v.21 no.2
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• pp.15-18
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• 2022

The ultraviolet-C emitting praseodymium doped yttrium phosphate (YPO₄:Pr³⁺) powder was synthesized by conventional solid-state reaction. The electroluminescence device was fabricated by simple screen-printing method using the synthesized YPO₄:Pr³⁺ powder, especially, polyvinylidene fluoride as an insulating layer was applied on the printed YPO₄:Pr³⁺ powder for stable performance of the electroluminescence. The electroluminescence properties were investigated under alternating current power system of 400 Hz. The device starts to emit at 350 V, which showed the ultraviolet-C emission peaking at the 233, 245, 264, 273 nm attributed to electronic transition of the Pr³⁺ ions. The electroluminescence intensity was increased as increasing the operating voltage and the device revealed stable performance up to 600 V due to the polyvinylidene fluoride serve as a protective layer.

• Journal of Nutrition and Health
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• v.48 no.2
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• pp.133-139
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• 2015

Purpose: There is a fair amount of evidence indicating that increased risk of obesity and insulin resistance is associated with postmenopausal state, but can be modulated by diet and exercise. In this study, we explored whether a Pueraria lobata root-based supplement containing Rehmannia glutinosa (PR) and/or aerobic treadmill exercise can modify the metabolic changes associated with estrogen deficiency. Methods: Seventy rats were randomly assigned to the following groups for 8 weeks (n=10 per group): SHAM, sham-operated; PR0, ovariectomized (OVX) control; PR200, OVX with PR200 mg/kg B.W; PR400, OVX with PR400 mg/kg B.W; EPR0, OVX with exercise; EPR200, OVX with exercise and PR200 mg/kg B.W; EPR400, OVX with exercise and PR400 mg/kg B.W. Results: OVX induced significant increases in body weight, food intake, fat mass, LDL-cholesterol, and fasting blood glucose, confirming induction of menopausal symptoms. PR supplementation or exercise significantly suppressed the above mentioned changes through different regulatory elements in adipose tissue: PR supplement upregulated adiponectin gene expression and aerobic exercise upregulated adiponectin and insulin receptor gene expression and a combination of PR supplement and aerobic exercise showed an additive effect on adiponectin gene expression. Conclusion: Taken together, the results of this study suggest that PR supplement has a potential to provide health benefits in OVX rats through leptin and adiponectin secretion. In addition, the data suggest that combination of exercise and PR would have additive effects on metabolic dysfunction associated with estrogen deficiency.