• 제목/요약/키워드: double exposure

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신축 주택의 톨루엔 발생량 모델을 이용한 건강위해성 평가 (Risk Assessment by Toluene Source Emission Model in Indoor Environments of New Houses)

  • 김영희;양원호;손부순
    • 한국환경보건학회지
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    • 제32권5호
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    • pp.398-403
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    • 2006
  • Indoor air quality can be affected by indoor sources, ventilation, decay and outdoor levels. Understanding the effectiveness of indoor air quality control depends on knowledge of the characteristics of air pollutants in indoor air, especially their quantities and persistence, and the relevance of indoor sources to these factors. Toluene within new and established houses has been determined and factors significant to its presence have been identified. A total of 30 selected houses in Seoul, Asan and Daegu areas that were constructed within 4 years and over 4 years of construction were measured the concentration of toluene from July to September in 2004. Toluene emission decay of double-exponential model exhibited good fit of $Y=276.37e^{-1.21x}(R^{2}=0.34,\;P=0.06)$ for 2 years and then $Y=51.54e^{-0.11x}(R^{2}=0.40,\;P=0.0)$ from 23 years in new houses. In case of living in new houses, noncarcinogenic health effects of exposure to toluene was 1.38 of hazard quotient (HQ) comparing to toluene reference dose of 0.13 mg/kg-day.

초고진공 전자공명 플라즈마를 이용한 SiC buffer layer 형성에 관한 연구 (A Study on SiC Buffer Layer Prepared by Ultra High Vacuum Electron Cyclotron Resonance CVD)

  • 전우곤;표재확;황기웅
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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    • pp.326-328
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    • 1995
  • SiC buffer layers were grown on Si(100) substrates by ultra-high-vacuum electron cryclotron resonance plasma (UHV ECR plasma) from $CH_4/H_2$ mixture at 700$^{\circ}C$. The electron densities and temperature were measured by single probe. The axial plasma potentials measured by emissive probe had the double layer structure at positive substrate bias. Piranha cleaning was carried out as ex-situ wet cleaning. Clean and smooth silicon surface were prepared by in-situ hydrogen plasma cleaning at 540$^{\circ}C$. A short exposure to hydrogen plasma transforms the Si surface from 1$\times$1 to 2$\times$1 reconstruction. It was monitored by reflection high energy electron diffraction (RHEED). The defect densities were analysed by the dilute Schimmel etching. The results showed that the substrate bias is important factor in hydrogen plasma cleaning. The low base pressure ($5\times10^{-10}$ torr) restrains the $SiO_2$ growth on silicon surface. The grown layers showed different characteristics at various substrate bias. RHEED and K-ray Photoelectron spectroscopy study showed that grown layer was SiC.

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상악골 확장이 안면골에 미치는 영향에 관한 Laser Holography연구 (LASER HOLOGRAPHIC STUDY ON THE EFFECT OF FACIAL SKELETON TO MAXILLARY EXPANSION)

  • 박준상;양원식
    • 대한치과교정학회지
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    • 제16권2호
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    • pp.43-51
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    • 1986
  • The highly accurate laser holographic interferemotry method was used to determine in what way low-magnitude forces during maxillary expansion are transmitted to the entire maxillary complex and its surrounding structures. The experiments were carried out on a dryed human skull which had a perfectly preserved, normally aligned maxillary dental arch and intact alveolar process. The skull was fixed within a constructed metal frame which ensured maximal stability of the object. The optical equipment and the object were mounted on antivibration table. Interferograms were taken on the lateral and frontal sides of the maxillary complex, using the 10mW He-Ne laser and the double-exposure method. Analysis of the fringe pattern on the recorded object surface was performed by graphically determining the deformation curves related to the bony surface in selected horizontal and vertical planes. On the basis of this study, the following conclusions can be drawn: 1. The density of the interference fringes was gradually increased with the degree of expansion force. 2. Mechanical reactions on the maxillary complex, circummaxillary sutures, and surrounding bones were clearly visible, even with the lowest loading degree. 3. The amount of bone displacement was greater in application of the force after $90^{\circ}$ turn than in initial application of the same force. 4. The direction of interference fringes on the bony surface was similar at all loading degrees.

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Post modern-Feminism의 문화 현상과 패션 (The Cultural Phenomena of the Post modern-Feminism and Contemporary Fashion)

  • 손미희
    • 복식
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    • 제46권
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    • pp.49-66
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    • 1999
  • The bisexuality deconstructivity and diversity that are great characteristics on the comtemporary fashion are showed in the fashion collections. The purpose of this paper is to investigate and analyze the influence of these characteristics made by the post modern-feminism fashion through the cultural pattern analysis. The post modern-feminism was analyzed by dividing the cultural pattern into 1) the deconstructivity of androcentrism -This characteristic was presented in the costume design that breaks the basic from of the line color and quality of the material showing in men's clothes. 2) By rejecting main current fashion -Subculture style appeared in main current fashion the boundary of main and anti-main current fashion was vagued and the phenomena that the identity of subgroup was weakened were showed. 3) In the coexistence of double-sided value -This characteristic was presented in the cross-dressing fashion that cut away women's slender part and men's rough part. 4) In the open-minded thought of gender -This tendency was reached an extreme from excessive exposure to design which gives the sexual stimulus. This paper is expected to be helpful to understand the contemporary fashion by treating the cultural category associated with post-modern feminism in relation to contemporary fashion and to establish the direction of 21 century fashion.

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A Proposal of Dietary Supplement from Choto-san, a Kampo Medicine

  • Watanabe, Hiroshi
    • Biomolecules & Therapeutics
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    • 제12권3호
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    • pp.138-144
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    • 2004
  • Therapeutic effect of a Kampo medicine, Choto-san, in patients with vascular dementia was demonstrated by a double-blind and placebo-controlled clinical trial. To clarify the therapeutic efficacy of Choto-san, anti-ischemic effect in mice, hypotensive effect in spontaneously hypertensive rats (SHR), anti-oxidative effects in vitro, and N-methyl-D-aspartate (NMDA) receptor-blocking activity using Xenopus oocytes were studied. (1) Pretreatment with Choto-san (0.75-6.O g/kg, P.O.) or a component herb Chotoko (Uncaria genus: 75 - 600 mg/kg, P.O.) prevented ischemia-induced impairment of spatial learning behaviour in mice. Indole alkaloids- and phenolic fractions extracted from Chotoko also improved significantly the learning deficit. (2) Subchronic administration of Choto-san (0.5 g/kg, p.o.) caused a significant hypotensive effects in SHR. (3) Choto-san, Chotoko, and the phenolic constituent, (-) epicatechin, significantly protected the NG108-15 cell injury induced by $H_20_2$ exposure in vitro and also inhibited lipid peroxidation in the brain homogenate. (4) Indole alkaloids, rhynchophylline and isorhynchophylline (1-100 uM), reversibly reduced NMDA-induced current in the receptor-expressed Xenopus oocytes. These results suggest that anti-vascular dementia effects of Choto-san are mainly due to the effect of Chotoko. From these results, it is possible to make a novel dietary supplement through several extraction steps from Chotoko.

개방 코성형술에서 톱을 이용한 외절골술 (Lateral Osteotomy with Sawing Technique in Open Rhinoplasty)

  • 김연환;이학승;;김정태
    • Archives of Plastic Surgery
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    • 제37권4호
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    • pp.499-530
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    • 2010
  • Purpose: Lateral osteotomy is an essential step in the correction of nasal bony asymmetry. Direct visualization allows accurate repositioning of the nasal bones compared to blind techniques, which require precision and manual dexterity. We propose direct visualization procedures in open corrective rhinoplasty. Methods: The technique was used on 16 patients. All patients underwent open rhinoplasty with a columellar incision. The marginal incisions were extended on either side to allow access to the piriform aperture. A double hook was used to caudally retract the lower lateral cartilages and the fibrous connections between the upper and lower lateral cartilages were released until the piriform aperture was visualized. Through the incision, lateral osteotomy was performed using a reciprocating saw at that time with direct visualization. Additional procedures including augmentation rhinoplasty, hump resection, septoplasty and tip plasty were performed simultaneously. Results: This method provided excellent exposure to the lateral nasal bones and allowed the lateral osteotomy to be carried out precisely using the reciprocating saw. Conclusion: This extended open rhinoplasty method is suitable for most individuals, allowing a wide surgical field.

Environmental Exposure of Sperm Sex-Chromosomes: A Gender Selection Technique

  • Oyeyipo, Ibukun P.;van der Linde, Michelle;du Plessis, Stefan S.
    • Toxicological Research
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    • 제33권4호
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    • pp.315-323
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    • 2017
  • Preconceptual sex selection is still a highly debatable process whereby X- and Y-chromosome-bearing spermatozoa are isolated prior to fertilization of the oocyte. Although various separation techniques are available, none can guarantee 100% accuracy. The aim of this study was to separate X- and Y-chromosome-bearing spermatozoa using methods based on the viability difference between the X- and Y-chromosome-bearing spermatozoa. A total of 18 experimental semen samples were used, written consent was obtained from all donors and results were analysed in a blinded fashion. Spermatozoa were exposed to different pH values (5.5, 6.5, 7.5, 8.5, and 9.5), increased temperatures ($37^{\circ}C$, $41^{\circ}C$, and $45^{\circ}C$) and ROS level ($50{\mu}M$, $750{\mu}M$, and $1,000{\mu}M$). The live and dead cell separation was done through a modified swim-up technique. Changes in the sex-chromosome ratio of samples were established by double-label fluorescent in situ hybridization (FISH) before and after processing. The results indicated successful enrichment of X-chromosome-bearing spermatozoa upon incubation in acidic media, increased temperatures, and elevated $H_2O_2$. This study demonstrated the potential role for exploring the physiological differences between X-and Y-chromosome-bearing spermatozoa in the development of preconceptual gender selection.

Crystal Structure of an Acetylene Sorption Complex of Dehydrated Fully Mn(II)-Exchanged Zeolite X

  • 배명남;김양
    • Bulletin of the Korean Chemical Society
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    • 제19권10호
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    • pp.1095-1099
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    • 1998
  • The crystal structure of an acetylene sorption complex of dehydrated fully Mn(Ⅱ)-exchanged zeolite X, Mn46Si100Al92O384·30C2H2 (a=24.705(3) Å) has been determined by single-crystal X-ray diffraction techniques. The structure was solved and refined in the cubic space group Fd3 at 21(l) ℃. The complex was prepared by dehydration at 380 ℃ and 2 x 10-6 Torr for 2 days, followed by exposure to 300 Torr of acetylene gas for 2 h at 24 ℃. The structure was refined to the final error indices, R1=0.060 and R2=0.054 with 383 reflections for which I > 3σ(Ⅰ). In the structure, Mn2+ ions are located at two different crystallographic sites; sixteen Mn2+ ions at site I are located at the centers of the double six rings and thirty Mn2+ ions are found at site Ⅱ in the supercage, respectively. Each of these latter Mn2+ ions is recessed ca. 0.385(2) Å into the supercage from its three-oxygen plane. Thirty acetylene molecules are sorbed per unit cell. Each Mn2+ ion at site Ⅱ lies on a threefold axis in the supercage of the unit cell, close to three equivalent trigonally arranged zeolite framework oxygen atoms (Mn(Ⅱ)-O=2.135(9) Å) and symmetrically to both carbon atoms of a C2H2 molecules. At these latter distances, the Mn(Ⅱ)-C interactions are weak (Mn(Ⅱ)-C=2.70(5) Å), probably resulting from electrostatic attractions between the divalent cations and the polarizable π-electron density of the acetylene molecules.

DNA Damage Triggers the Activation of Immune Response to Viral Pathogens via Salicylic Acid in Plants

  • Hwi-Won Jeong;Tae Ho Ryu;Hyo-Jeong Lee;Kook-Hyung Kim;Rae-Dong Jeong
    • The Plant Pathology Journal
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    • 제39권5호
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    • pp.449-465
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    • 2023
  • Plants are challenged by various pathogens throughout their lives, such as bacteria, viruses, fungi, and insects; consequently, they have evolved several defense mechanisms. In addition, plants have developed localized and systematic immune responses due to biotic and abiotic stress exposure. Animals are known to activate DNA damage responses (DDRs) and DNA damage sensor immune signals in response to stress, and the process is well studied in animal systems. However, the links between stress perception and immune response through DDRs remain largely unknown in plants. To determine whether DDRs induce plant resistance to pathogens, Arabidopsis plants were treated with bleomycin, a DNA damage-inducing agent, and the replication levels of viral pathogens and growth of bacterial pathogens were determined. We observed that DDR-mediated resistance was specifically activated against viral pathogens, including turnip crinkle virus (TCV). DDR increased the expression level of pathogenesis-related (PR) genes and the total salicylic acid (SA) content and promoted mitogen-activated protein kinase signaling cascades, including the WRKY signaling pathway in Arabidopsis. Transcriptome analysis further revealed that defense-and SA-related genes were upregulated by DDR. The atm-2atr-2 double mutants were susceptible to TCV, indicating that the main DDR signaling pathway sensors play an important role in plant immune responses. In conclusion, DDRs activated basal immune responses to viral pathogens.

Public Identity, Paratext, and the Aesthetics of Intransparency: Charlotte Smith's Beachy Head

  • Jon, Bumsoo
    • 영어영문학
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    • 제58권6호
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    • pp.1167-1191
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    • 2012
  • For Romantic women writers the paratext itself is essentially a masculine literary space affiliated with established writing practices; however, this paper suggests that Charlotte Turner Smith's mode of discourse in her use of notes and their relation to the text proper are never fixed in her contemplative blank-verse long poem, Beachy Head (1807). Even though the display of learning in the paratext partly supports the woman writer's claim to authority, this paper argues that Smith's endnotes also indicate her way of challenging the double bind for women writers, summoning masculine authority on the margins of her book while simultaneously interrogating essentialist thinking and instructions about one's identity in a culture and on the printed page. The poem shows how the fringes of the book can be effectively transformed from a masculine site of authority to an increasingly feminized site of interchange as Smith writes with an awareness of patriarchal, imperial abuses of power in that area of the book. There is a persistent transgression of cultural/textual boundaries occurring in Beachy Head, which explores the very scene and languages of imperial encounter. Accordingly, if Wordsworth's theory of composition suggests a subjective and abstract poetic experience-an experience without mediation-in which its medium's purpose seems to be to disappear from the reader's consciousness, an examination of the alternative discourse of self-exposure in Smith's poem reveals the essentially fluid nature of media-consciousness in the Romantic era, which remains little acknowledged in received accounts of Romantic literary culture.