• Title/Summary/Keyword: $E_b/N_t$

Search Result 466, Processing Time 0.036 seconds

Effect of thermal annealing on low-energy C-ion irradiated MgB2 thin films

  • Jung, Soon-Gil;Son, Seung-Ku;Pham, Duong;Lim, W.C.;Song, J.;Kang, W.N.;Park, T.
    • Progress in Superconductivity and Cryogenics
    • /
    • v.21 no.3
    • /
    • pp.13-17
    • /
    • 2019
  • We investigate the effect of thermal annealing on $MgB_2$ thin films with thicknesses of 400 and 800 nm, irradiated by 350 keV C-ions with a dose of $1{\times}10^{15}atoms/cm^2$. Irradiation by low-energy C-ions produces atomic lattice displacement in $MgB_2$ thin films, improving magnetic field performance of critical current density ($J_c$) while reducing the superconducting transition temperature ($T_c$). Interestingly, the lattice displacement and the $T_c$ are gradually restored to the original values with increasing thermal annealing temperature. In addition, the magnetic field dependence of $J_c$ also returns to that of the pristine state together with the restoration of $T_c$. Because $J_c$(H) is sensitive to the type and density of the disorder, i.e. vortex pinning, the recovery of $J_c$(H) in irradiated $MgB_2$ thin films by thermal annealing indicates that low-energy C-ion irradiation on $MgB_2$ thin films primarily causes lattice displacement. These results provide new insights into the application of low-energy irradiation in strategically engineering critical properties of superconductors.

THE EVOLUTION OF LYMAN$\alpha$ FOREST CLOUDS AT z > 2

  • KIM T.-S.;Hu E. M.;COWIE L. L.;SONGAILA A.
    • Journal of The Korean Astronomical Society
    • /
    • v.29 no.spc1
    • /
    • pp.39-40
    • /
    • 1996
  • Using the Keck 10 m telescope data with the HIRES spectrograph, we analyzed the evolution of Lyman$\alpha$ forest clouds at z > 2 down to the HI column density $10^{12.8}cm^{-2}$. The number density per unit column density does not change with redshifts at lower HI cloumn density ($N_{HI} < 10^{14}cm^{-2}$), while the forest clouds at higher column density disappear rapidly. The cutoff b value, the thermal temperature indicator, increases as redshift decreases. The correlation strength seems to be stronger as redshift decreases.

  • PDF

The Historical Study of Headache in Chinese Ming Dynasty (명대의가(明代醫家)들의 두통(頭痛)에 대한 인식변화에 관한 연구)

  • Chun, Duk-Bong;Maeng, Woong-Jae;Kim, Nam-Il
    • The Journal of Korean Medical History
    • /
    • v.24 no.1
    • /
    • pp.43-56
    • /
    • 2011
  • Everyone once in a life experience headaches as symptoms are very common. According to a study in a country of more than a week and as many as those who have experienced a headache amounts to 69.4%. In addition, the high reported prevalence of migraine in 30s for 80% of all migraine sufferers daily life interfere with work or was affected. In Western medicine, the cause of headaches is traction or deformation of pain induced tissue like scalp, subcutaneous tissue, muscle, fascia, extracranial arteriovenous, nerves, periosteum. But it turns out there are not cause why pain induced tissue is being tracted or deformated. Therefore, most of the western-therapy is mainly conducted with regimen for a temporary symptom reduction. Therefore, I examined how it has been developed in Chinese Ming Dynasty, the perception of headache, change in disease stage and an etiological cause. Oriental medicine in the treatment of headache is a more fundamental way to have an excellent treatment. The recognition of head in "素問($s{\grave{u}}$ $w{\grave{e}}n$)" and "靈樞($l{\acute{i}}ng$ $sh{\bar{u}}$)" began to appear in 'Soul-神($sh{\acute{e}}n$) dwelling place' and 'where to gather all the Yang-'諸陽之會($zh{\bar{u}}$ $y{\acute{a}}ng$ $zh{\bar{i}}$ $hu{\grave{i}}$)'. Also, head was recognized as '六腑($li{\grave{u}}f{\check{u}}$) 淸陽之氣($q{\bar{i}}ng$ $y{\acute{a}}ng$ $zh{\bar{i}}$ $q{\grave{i}}$) and 五臟($w{\check{u}}$ $z{\grave{a}}ng$) 精血($j{\bar{i}}ng$ $xu{\grave{e}}$) gathering place'. More specific structures such as the brain is considered a sea of marrow(髓海-$su{\check{i}}$ $h{\check{a}}i$) in "內經($n{\grave{e}}i$ $j{\bar{i}}ng$)" and came to recognized place where a stroke occurs. Accompanying development of the recognition about head, there had been changed about the perception of headache and the recognition of the cause and mechanism of headache. And the recognition of headache began to be completed in Ming Dynasty through Jin, Yuan Dynasty. Chinese Ming Dynasty, specially 樓英($l{\acute{o}}u$ $y{\bar{i}}ng$), in "醫學綱目($y{\bar{i}}xu{\acute{e}}$ $g{\bar{a}}ngm{\grave{u}}$)", first enumerated prescription in detail by separating postpartum headache. and proposed treatment of headache especially due to postpartum sepsis(敗血-$b{\grave{a}}i$ $xu{\grave{e}}$). 許浚($x{\check{u}}$ $j{\grave{u}}n$) accepted a variety of views without impartial opinion in explaining one kind of headache in "東醫寶鑑($d{\bar{o}}ng-y{\bar{i}}$ $b{\check{a}}oji{\grave{a}}n)$" 張景岳($zh{\bar{a}}ng$ $j{\check{i}}ng$ $yu{\grave{e}}$), in "景岳全書($j{\check{i}}ng$ $yu{\grave{e}}$ $qu{\acute{a}}nsh{\bar{u}}$)", established his own unique classification system-新舊表裏($x{\bar{i}}nji{\grave{u}}$ $bi{\check{a}}ol{\check{i}}$)-, and offered a clear way even in treatment. Acupuncture treatment of headache in the choice of meridian has been developed as a single acupuncture point. Using the classification of headache to come for future generation as a way of locating acupoints were developed. Chinese Ming Dynasty, there are special treatments like 導引按蹻法($d{\check{a}}o$ y ${\check{i}}n$ ${\grave{a}}n$ $ji{\check{a}}o$ $f{\check{a}}$), 搐鼻法($ch{\grave{u}}$ $b{\acute{i}}$ $f{\check{a}})$, 吐法($t{\check{u}}$ $f{\check{a}}$), 外貼法($w{\grave{a}}i$ $ti{\bar{e}}$ $f{\check{a}}$), 熨法($y{\grave{u}}n$ $f{\check{a}}$), 點眼法($di{\check{a}}n$ $y{\check{a}}n$ $f{\check{a}}$), 熏蒸法($x{\bar{u}}nzh{\bar{e}}ng$ $f{\check{a}}$), 香氣療法($xi{\bar{a}}ngq{\grave{i}}$ $li{\acute{a}}of{\check{a}}$). Most of this therapy in the treatment of headache, it is not used here, but if you use a good fit for today's environment can make a difference.

Comparative Transcriptome Analysis of Caryophyllene-Treated Helicobacter pylori

  • Woo, Hyun Jun;Yang, Ji Yeong;Kwon, Hye Jin;Kim, Hyun Woo;Kim, Sa-Hyun;Kim, Jong-Bae
    • Microbiology and Biotechnology Letters
    • /
    • v.49 no.3
    • /
    • pp.440-448
    • /
    • 2021
  • Helicobacter pylori (H. pylori) establishes long-term infections associated with severe gastric diseases such as peptic ulceration and gastric cancer. Exposure to an antibacterial agent can help regulate the expression levels of its pathogenic genes. In this study, we analyzed the transcriptional changes in H. pylori genes induced by β-caryophyllene. We used next-generation sequencing (NGS) to analyze RNA expression changes, and reverse transcription-polymerase chain reaction (RT-PCR) was performed as required to verify the results. The NGS results showed that 30 out of 1,632 genes were expressed differentially by β-caryophyllene treatment. Eleven genes associated with DNA replication, virulence factors, and T4SS components were significantly downregulated. RT-PCR confirmed that treatment reduced the expression levels of 11 genes. RT-PCR showed the reduced expression of 11 genes (dnaE, dnaN, holB, gyrA, cagA, vacA, secA, flgE, virB2, virB4, and virB8) following β-caryophyllene treatment. These results suggest that β-caryophyllene can modulate various H. pylori pathogenic determinants and be a potential therapeutic agent for H. pylori infection.

A study on the phase transition characteristics of the $Ba(La_{1/2} Nb_{1/2})O_3-Pb(Zr, Ti)O_3$ ceramics ($Ba(La_{1/2} Nb_{1/2})O_3-Pb(Zr, Ti)O_3$ 세라믹의 상전이 특성에 관한 연구)

  • 류기원;배선기;박인길;이영희
    • Electrical & Electronic Materials
    • /
    • v.8 no.2
    • /
    • pp.190-195
    • /
    • 1995
  • Temperature dependences of the dielectric constant K(T), remanent polarization $P_{r}$, (T), effective birefringence overbar .DELTA.n(T), transmitted light intensity and quadratic electro optic coefficient R(T) of the two-stage sintered xBa(L $a_{1}$2/N $b_{1}$2/) $O_{3}$-(1-x)Pb(Z $r_{y}$ $Ti_{1-y}$) $O_{3}$(x=0.085, 0.09, 0.40.leq.y.leq.0.70) ceramics were investigated. Increasing the PbZr $O_{3}$ contents, the crystal structure of a specimen was changed from a tetragonal phase to a rhombohedral and cubic phase, and the phase transition was showed a diffuse phase transition(DPT) characteristics. In the compositions which located on the PE-FE phase boundary, the discrepancy was observed between the Curie temperature and temperature which a microscopic polarization and effective birefringence were disappeared.red.d.

  • PDF

Photocurrent study on the splitting of the valence band and growth of $ZnIn_{2}Se_{4}$ single crystal thin film by hot wall epitaxy (Hot wall epitaxy(HWE)법에 의한 $ZnIn_{2}Se_{4}$ 단결정 박막 성장과 가전자대 갈라짐에 대한 광전류 연구)

  • Hong, Kwang-Joon
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.18 no.5
    • /
    • pp.217-224
    • /
    • 2008
  • A stoichiometric mixture of evaporating materials for $ZnIn_2Se_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $ZnIn_2Se_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $630^{\circ}C$ and $400^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $ZnIn_2Se_4$ single crystal thin films measured from Hall effect by van der Pauw method are $9.41\times10^{16}cm^{-3}$ and $292cm^2/v{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $ZnIn_2Se_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=1.8622eV-(5.23\times10^{-4}eV/K)T^2/(T+775.5K)$. The crystal field and the spin-orbit splitting energies for the valence band of the $ZnIn_2Se_4$ have been estimated to be 182.7 meV and 42.6 meV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $ZnIn_2Se_4/GaAs$ epilayer. The three photo current peaks observed at 10 K are ascribed to the $A_{1}-$, $B_{1}-exciton$ for n = 1 and $C_{27}-exciton$ peaks for n = 27.

Theoretical Study on the Hydrogen-Bonding Effect of H2On-H2Om (n=1-4, m=1-4) Dimers (H2On-H2Om (n=1-4, m=1-4) 이중합체의 수소결합에 따른 구조적 특성 및 결합에너지에 관한 이론 연구)

  • Song, Hui-Seong;Seo, Hyun-Il;Shin, Chang-Ho;Kim, Seung-Joon
    • Journal of the Korean Chemical Society
    • /
    • v.59 no.2
    • /
    • pp.117-124
    • /
    • 2015
  • The DFT and ab initio calculations have been performed to elucidate hydrogen interaction of hydrogen polyoxide dimers, $H_2O_n-H_2O_m$ (n=1-4, m=1-4). The optimized geometries, harmonic vibrational frequencies, and binding energies are predicted at various levels of theory. The harmonic vibrational frequencies of the molecules considered in this study show all real numbers implying true minima. The higher-order correlation effect were discussed to compare MP2 result with CCSD(T) single point energy. The binding energies were corrected for the zero-point vibrational energy (ZPVE) and basis set superposition errors (BSSE). The largest binding energy predicted at the CCSD(T)/cc-pVTZ level of theory is 8.18 kcal/mol for $H_2O_4-H_2O_3$ and the binding energy of water dimer is predicted to be 3.00 kcal/mol.

Research on prescription candidates for Parkinson's disease in 『Dongeuibogam』 (『동의보감(東醫寶鑑)』에 수록된 파킨슨병 치료 처방(處方) 후보군 선별 연구)

  • Hwang, Min-Seob;Park, Hye-Jin;Kim, Si-Won;Baek, Jin-Ung
    • Herbal Formula Science
    • /
    • v.26 no.1
    • /
    • pp.65-80
    • /
    • 2018
  • Objectives : This study aims to sort out prescription candidates for four major symptoms of Parkinson's disease from Korean traditional medical publication, "Dongeuibogam". Methods : Medical terms related to four major symptoms of Parkinson's disease were primarily selected from "Dongeuibogam". Prescriptions that include at least one or more medical terms which are selected above were classified by the four major symptoms of Parkinson's disease, and finally analyzed to sort the most effective candidates. Results & Conclusions : 1. There are 18 medical terms in efficacy ($ch{\grave{i}}$ $z{\grave{o}}ng$, $j{\bar{u}}$ $lu{\acute{a}}n$, $j{\bar{i}}ng$${\check{u}}$ $ju{\check{a}}n$($ju{\check{a}}n$, $qu{\acute{a}}n$) $lu{\acute{a}}n$, $j{\bar{i}}ng$${\check{u}}$ $lu{\acute{a}}n$($lu{\acute{a}}n$) $t{\grave{o}}ng$, $j{\bar{i}}n$ $lu{\acute{a}}n$, $j{\bar{i}}n$ $t{\grave{i}}$, $sh{\check{o}}u$ $zh{\grave{e}}n$, $y{\acute{a}}ng$ $sh{\check{o}}u$, $lu{\acute{a}}n$ $j{\acute{i}}$, $lu{\acute{a}}n$ $b{\grave{i}}$, $r{\grave{o}}u$ $r{\acute{u}}n$, $zh{\grave{a}}n$ $di{\grave{a}}o$, $zh{\grave{a}}n$ $y{\acute{a}}o$, $zh{\grave{i}}$ $z{\acute{u}}$, $ch{\grave{e}}$ $t{\grave{o}}ng$, $ch{\bar{o}u}$ $ch{\grave{e}}$, $f{\bar{e}}ng$ $ch{\grave{u}}$, $ch{\grave{u}}$ $nu{\grave{o}}$) related to tremor, one of four major symptoms of Parkinson's disease. 2. There are 9 medical terms in efficacy ($qi{\acute{a}}ng$ $j{\acute{i}}$, $qi{\acute{a}}ng$ $zh{\acute{i}}$, $qi{\acute{a}}ng$ $t{\grave{o}}ng$, $j{\bar{u}}$ $j{\acute{i}}$, $j{\bar{i}}n$ $j{\acute{i}}$, $sh{\bar{e}}n$ $qi{\acute{a}}ng$, $lu{\acute{a}}n$ $j{\acute{i}}$, $y{\bar{a}}o$ $j{\acute{i}}$ $qi{\acute{a}}ng$, $xi{\grave{a}}ng$ $qi{\acute{a}}ng$) related to rigidity, one of four major symptoms of Parkinson's disease. 3. 38 prescription candidates (jiaweishouxingyuan, jiaweilonghusan, gehuajiexingtang, qiangfutang, qianghuoxuduantang, dawugongsan, duhuojishengtang, mahuangzuojingtang, fangfengbaizhumulitang, fangfengtongshengsan, baizhutang, buxinwan, fulingtang, binsusan, xieqingwan, sanbitang, shengdiqinliantang, shujinbaoansan, xingxiangsan, xiaotanfulingwan, shengjunwan, shenmizuojingtang, wuyaoshunqisan, yuzhenwan, wenjingyiyuantang, yiziqingjinsan, ziyinningshentang, shaoyaogancaotang, dingtongsan, zhushazhijiasan, cangzusan, chuanxiongfulingtang, tiedanyuan, choubaowan, duomingsan, xuanhusuosan, xuefengtang, huoluodan) were selected for tremor, one of the four major symptoms of Parkinson's disease. 4. 21 prescription candidates (qianghuoshengshitang, guizhiqianghuotang, guizhifuzitang, jiuweiqianghuotang(qianghuochonghetang), xiongzhixiangsusan, daqianghuotang, mahuangguizhitang, muguajian, fuzilizhongtang, shenzhusan, lianqiaobaidusan, yuzhensan, niuhuangjinhudan, renshenbaidusan, shaoyaogancaotang, jiuzhumuguazhou, cangzusan, shenxiangtianmatang, xiangjiaosan, xuefengtang, huishousan) were selected for rigidity, one of the four major symptoms of Parkinson's disease. 5. The results in this study ought to be verified by subsequent studies and clinical trials.

Morphological Characteristics of Weed Seed Fibers (잡초 종자섬유의 형태적 특징 비교)

  • Yoon, A Ra;Lee, Min Woo;Kim, Seul Ki;Kim, Jin-Seog
    • Weed & Turfgrass Science
    • /
    • v.3 no.3
    • /
    • pp.196-205
    • /
    • 2014
  • In this study, to obtain basic data for searching potential resources as new natural fibers, we investigated morphological and classificatory characteristics of 21 weed seed fibers. According to classification keys in this study, the collected weed seed fibers could be classified into total 13 types, showing their diversity. Seven species among them belonged to BOT3 type. Two species belonged to B2N0 and DOS3 type, respectively. Many of weed seed fibers had not branched. However, three species had various branched fibers at one main fibers on the seed. Three species had various branched fibers at several main fibers on the seed. Eight species had a smooth fiber surface but 13 species had a weakly or significantly developed-corniculum on the fiber surface. In the fiber cell shape, fiber cells of eight weed species were composed of one long cell without septum. But others had a fiber cell shape composed of a bunch of several long cells. Based on the easiness of harvesting, productivity of fibers, and morphological characteristics of seed fiber, it seemed that five seed fibers (TYPLA, METJA, HEMLY, IMPCK, and EREHI) should be additionally investigated if they are practically applicable as renewable resources for new natural fibers.