• Title/Summary/Keyword: Ar

Search Result 6,813, Processing Time 0.029 seconds

The Efficiency Assessment of the Iron Ore Brands Using DEA-AR Model in an Integrated Steel Mill (DEA-AR 모형을 이용한 일관제철소 철광석 브랜드별 효율성 평가)

  • Seong, Deokhyun;Byeon, Gwuiwon
    • Journal of Information Technology Services
    • /
    • v.12 no.4
    • /
    • pp.255-265
    • /
    • 2013
  • This paper proposes a DEA-AR model for the efficiency evaluation of the iron ore brands in an integrated steel mill. The input factor is defined as unit cost of each brand based on CIF and two output factors are chosen as Fe and Al which are the important ingredients of iron ore. The relative importance between two output factors is determined by several experts using AHP model. The efficiency of each brand is determined using DEA and DEA-AR models. The negative correlation between the DEA-AR efficiency and the unit cost (CIF) is shown as significant whereas no significant correlation exist between the efficiency and the output factors. Also, the Kruskal Wallis rank sum test shows that there exist efficiency differences among the iron ore types whereas no difference is shown among the countries. The result could be utilized in selecting good brands of iron ores based on the DEA-AR efficiency in an integrated steel mill.

Virtual Reality and Augmented Reality in Plastic Surgery: A Review

  • Kim, Youngjun;Kim, Hannah;Kim, Yong Oock
    • Archives of Plastic Surgery
    • /
    • v.44 no.3
    • /
    • pp.179-187
    • /
    • 2017
  • Recently, virtual reality (VR) and augmented reality (AR) have received increasing attention, with the development of VR/AR devices such as head-mounted displays, haptic devices, and AR glasses. Medicine is considered to be one of the most effective applications of VR/AR. In this article, we describe a systematic literature review conducted to investigate the state-of-the-art VR/AR technology relevant to plastic surgery. The 35 studies that were ultimately selected were categorized into 3 representative topics: VR/AR-based preoperative planning, navigation, and training. In addition, future trends of VR/AR technology associated with plastic surgery and related fields are discussed.

Etching Kinetics Of $SrBi_2Ta_2O_{9}$ Thin Film in $Cl_{2}$/$CF_{4}$/Ar gas Chemistry ($Cl_{2}$/$CF_{4}$/Ar gas chemistry에 의한 $SrBi_2Ta_2O_{9}$ 박막의 식각 특성)

  • 김동표;김창일;이원재;유병곤;김태형;장의구
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2001.07a
    • /
    • pp.62-65
    • /
    • 2001
  • $SrBi_2Ta_2O_{9}$ thin films were etched in inductively coupled $Cl_{2}$/$CF_{4}$/Ar plasma. The maximum etch rate was 1060 $\AA\textrm{m}$/min in $Cl_{2}$/$CF_{4}$/Ar (80). The chemical reactions on the etched surface were studied with x-ray photoelectron spectroscopy. The etching of SBT thin films in $Cl_{2}$/$CF_{4}$/Ar were etched by chemically assisted reactive ion etching. The small addition of $Cl_2$ into $CF_4$(20)/Ar(80) plasma will decrease the fluorine radicals and the increase Cl radical.

  • PDF

A Study on the GMA Welding Characteristics of Al5083-O Aluminum Alloy According to the Shield Gas Mixing Ratio and Heat Input (Al5083-O 알루미늄합금의 보호가스 혼합비율 및 입열량에 따른 GMA용접 특성에 관한 연구)

  • 정재강;양훈승;이동길
    • Journal of Welding and Joining
    • /
    • v.20 no.2
    • /
    • pp.65-70
    • /
    • 2002
  • This study was to evaluate GMA welding characteristics of the A15083-O aluminum alloy according to the shield gas mixing ratio and heat input change. The GMA welding of the base metal was carried out with flour different shield gas mixing ratios(Ar100%+He0%, Ar67%+He33%, Ar50%+He50%, and Ar33%+He67%). Regarding the if1uence on the bead shape of the shield gas mixing ratio and heat input, the bead width was greatest in Ar100%+He0% mixture. But the penetration depth and area were greatest in Ar33%+He67% mixture considering that the lower Ax gas ratio, the higher bead depth and area. Also, dilution was also best in the shield gas mixing ratio. The size and number of deflects were least in Ar33%+He67% mixture. Higher He gas ratio resulted in less deflects detected by the radiographic inspection.

The Ameliorative Effect of Adenophorae Radix on Atopic Dermatitis in vivo and in vitro

  • Jung, Ji-Wook;Kim, Su-Jin
    • Biomedical Science Letters
    • /
    • v.20 no.3
    • /
    • pp.117-123
    • /
    • 2014
  • Adenophorae Radix (AR) has been used as a traditional medicine for various diseases. However, the regulatory effects of AR in atopic dermatitis are not yet understood. This study attempted to determine the pharmacological effects of AR and its constituent on both compound 48/80 or histamine-induced scratching behaviors and 2, 4-dinitrochlrobenzene (DNCB)-induced atopic dermatitis in mice. The findings of this study demonstrated that AR reduced compound 48/80 or histamine-induced scratching behaviors in mice. Treatment of AR attenuated the AD symptoms such as eczematous, erythema and dryness and serum IgE and IL-6 levels in AD model. Additionally, AR inhibited the TNF-${\alpha}$-induced the Nuclear factor-${\kappa}B$ activation in HaCaT cells. Collectively, the findings of this study provide us with novel insights into the pharmacological actions of AR as a potential molecule for therapeutic agent against atopic dermatitis.

The Surface Damage of SBT Thin Film Etched in $Ar/CF_{4}/Cl_{2}$ Plasma ($Ar/CF_{4}/Cl_{2}$ 유도결합 플라즈마에 의한 SBT 박막의 표면 손상)

  • Kim, Dong-Pyo;Kim, Chang-Il;Lee, Cheol-In;Kim, Tae-Hyung;Lee, Won-Jae;Yu, Byung-Gon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2001.11b
    • /
    • pp.26-29
    • /
    • 2001
  • $SrBi_2Ta_2O_{9}$ thin films were etched at high-density $Cl_2/CF_4/Ar$ in inductively coupled plasma system. The etching of SBT thin films in $Cl_2/CF_4/Ar$ were chemically assisted reactive ion etching. The maximum etch rate was 1300 $\AA$/min at 900W in $Cl_2(20)/CF_4(20)/Ar(80)$. As rf power increase, radicals (F, Cl) and ion(Ar) increase. The influence of plasma induced damage during etching process was investigated in terms of the surface morphology and th phase of X-ray diffraction. The chemical residue was investigated with secondary ion mass sperometry.

  • PDF

Anti-reflection coating for Thermochromic Thin Films (써모크로믹 $\textrm{VO}_2$ 박막의 anti-reflection 코팅)

  • Park, Jun;Park, Eun-Seok;Lee, Moon-Hee
    • Korean Journal of Materials Research
    • /
    • v.7 no.1
    • /
    • pp.3-7
    • /
    • 1997
  • VO$_{2}$ 써모크로믹 원도우의 가시광 투과율을 높히기 위하여 내마모성이 우수한 SiO$_{2}$박막을 이용하여 AR(anti-rdflection)코팅을 하였다. 두가지 중요한 공정변수인 기판온도와 증착속도가 AR효과에 미치는 영향을 조사하였다. 그리고 SiO$_{2}$박막의 AR효과는 낮은 기판온도와 높은 증착속도에서 더 우수한 것으로 나타났으며, 이는 SiO$_{2}$AR 박막의 굴절율과 상관관계가 있는 것으로 나타났다. VO$_{2}$ 써모크로믹 유리 위에 SiO$_{2}$AR-코팅을 했을 때 약 30% 정도의 가시광 투과율의 향상이 있었다. 그리고 AR-코팅을 하지 않은 경우보다 더 뚜렷한 써모크로미즘을 나타냈다. 또한 천이온도는 7$0^{\circ}C$정도로 AR-코팅을 하지 않은 VO$_{2}$써모크로믹 유리의 경우와 같게 나타났다.

  • PDF

Etching Characteristics of Gold Thin films using Inductively Coupled Cl2/Ar Plasma (Cl2/Ar 유도 결합 플라즈마에 의한 gold 박막의 식각특성)

  • 장윤성;김동표;김창일;장의구;이수재
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.15 no.12
    • /
    • pp.1011-1015
    • /
    • 2002
  • In this study, Au thin films were etched with a Cl$_2$/Ar gas combination in an inductively coupled plasma. The highest etch rate of the Au thin film was 3500 A/min at a Cl$_2$/(Cl$_2$+Ar) gas mixing ratio of 0.2. The surface reaction of the etched Au thin films was investigated using x-ray photoelectron spectroscopy (XPS) analysis. There is Au-Cl bonding by chemical reaction between Cl and Au. During the etching of Au thin films in Cl$_2$/Ar plasma, Au-Cl bond is formed, and these products can be removed by the physical bombardment of Ar ions[l].

The First Study on Bacterial Flora and Biological Control Agent of Anoplus roboris (Sufr., Coleoptera)

  • Demirbag, Zihni;Sezen, Kazim;Demir, Ismail
    • Journal of Microbiology
    • /
    • v.40 no.2
    • /
    • pp.104-108
    • /
    • 2002
  • The hazelnut leaf holer (Anoplus roboris Sufr,, Coleoptera: Curculionidae) is a devastating pest of hazelnut and oak trees. It causes approximately 20-30% economic damage to hazelnut production per year in Turkey. In the present study, in order to fond a more effective and safe biological control agent against A. roboris, we investigated the bacterial flora of the hazelnut leave holer, and tested them for insecticidal effects on it. According to morphological, physiological and biochemical tests bacterial flora were identified as Bacillus circulans (Ar1), Bacillus polymyxa (Ar2), Enterobacter sp. (Ar3) and Bacillus sphaelicus (Ar4). Insecticidal effects of bacterial isolates were performed on adult A. roboris. The highest insecticidal effect determined was 67% by B. sphaericus within eight days. The insecticidal effects of the other isolates (Ar1, Ar2 and Ar3) were determined as 33%, 47% and 47% within the same period, respectively.

Effects of van der Waals Bonding on the Collisional Dissociation of a Highly Excited Chemical Bond

  • Yoo Hang Kim;Hyung Kyu Shin
    • Bulletin of the Korean Chemical Society
    • /
    • v.12 no.4
    • /
    • pp.397-403
    • /
    • 1991
  • Dissociation of a highly excited diatomic molecule in the Ar + Ar…$O_2$ and Ar + $O_2$ collisions is studied using trajectory dynamics procedures in the collision energy range of 0.050 to 1.0 eV. Between 0.050 and 0.2 eV, dissociation probabilities are very large for the complexed system compared to the uncomplexed system. This efficient dissociation of $O_2$ in Ar…$O_2$ is attributed to the ready flow of energy from the incident atom to the large-amplitude vibrational motion of the excited O2 via the van der Waals bond. Thermal-averaged dissociation probabilites of $O_2$ in Ar + Ar…$O_2$ near room temperature are nearly two orders of magnitude larger than those of $O_2$ in Ar + $O_2$.