• Title/Summary/Keyword: Mass varying

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A Study of Pop-art Fashion, from the 1960's to the Present (2000년대 패션에 나타난 팝아트의 특성 연구)

  • Choi, Soo-Ah;Kim, Min-Ja
    • Journal of the Korean Society of Costume
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    • v.58 no.8
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    • pp.137-157
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    • 2008
  • The purpose of this study is to acquire clear understanding of classic Pop art, and furthermore, how it evolved within the art and fashion industries in relations until present days. Throughout the studies, it was inevitable to find that there needs to be additional traits to Richard Hamilton's famous quote regarding the definition; "Pop Art is: Popular, transient, expendable, low cost, mass produced, young, witty, sexy, gimmicky, glamorous, big business." Distinctively, though Pop art is continually evolving, sustaining, costly, authentic, and, adaptable for all ages. Pop art's varying influence continued, and Neo-pop, Japanese Neo-pop, les Nouveaux pop, Post-pop art appeared with progression. These transformed Pop arts share similar contexts with the Classic Pop art; and yet, it is inevitably more narrative, and has diversity in sources and expressions. If the Classic Pop art's been mostly flourished in the United States, new Pop arts are well established in various countries with individualities. Indeed, Pop art influenced the fashion world with attempted young and sexy looks with pastiche characters. In the 1960's, "Mods", "Teddy Boys", and "Hippie" styles became popular, and fashion trend started trickling up. Various usages of fabrics and uncommon materials were popularized due to the advanced technology and Pop art. Recently: 1) classic Pop art's been directly applied to fashion, 2) it's been reflected in more various motives and techniques 3) Neo-pop artists and designers wire involved with collaborative efforts. Undoubtedly, Pop art still remains popular for those who seek for fun; and so-called "Kidult" and "Peter-Pan syndrome" are closely correlated to the fundamentals of Pop art.

Comparison of Condenser Characteristics using R134a and R22 under the Same Inlet Temperature Condition (동일한 유입온도조건에서 R134a와 R22 적용 응축기의 특성비교)

  • Kang, Shin-Hyung;Byun, Ju-Suk;Kim, Chang-Duk
    • Journal of Energy Engineering
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    • v.15 no.3 s.47
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    • pp.166-173
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    • 2006
  • R134a is considered as an alternative refrigerant to R22 for air conditioners. An experimental investigation was made to study the characteristics of the heat transfer and pressure drop for R134a flowing in a fin-and-tube heat exchanger used for commercial air-conditioning units. Experiments were carried out under the conditions of inlet refrigerant temperature of $60^{\circ}C$ and refrigerant mass fluxes of $150,\;200,\;and\;250\;kg/m^{2}s$. The inlet air has dry bulb temperature or $35^{\circ}C$, relative humidity of 40% and air velocity varying from 0.68 to 1.6 m/s. Experiments show that air velocity decreased by 5.9% is needed for R134a than that of R22 while pressure drop for R134a was $18.1{\sim}20.4%$ higher than that of R22 for the degree of subcooling $5^{\circ}C$. The results are useful in designing more compact and effective condensers for various refrigeration and air conditioning systems using refrigerant R134a.

Analysis of fatty acid methyl ester in bio-liquid by hollow fiber-liquid phase microextraction

  • Choi, Minseon;Lee, Soyoung;Bae, Sunyoung
    • Analytical Science and Technology
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    • v.30 no.4
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    • pp.174-181
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    • 2017
  • Bio-liquid is a liquid by-product of the hydrothermal carbonization (HTC) reaction, converting wet biomass into solid hydrochar, bio-liquid, and bio-gas. Since bio-liquid contains various compounds, it requires efficient sampling method to extract the target compounds from bio-liquid. In this research, fatty acid methyl ester (FAME) in bio-liquid was extracted based on hollow fiber supported liquid phase microextraction (HF-LPME) and determined by Gas Chromatography-Flame Ionization Detector (GC-FID) and Gas Chromatography/Mass Spectrometry (GC/MS). The well-known major components of biodiesel, including methyl myristate, palmitate, methyl palmitoleate, methyl stearate, methyl oleate, and methyl linoleate had been selected as standard materials for FAME analysis using HF-LPME. Physicochemical properties of bio-liquid was measured that the acidity was 3.30 (${\pm}0.01$) and the moisture content was 100.84 (${\pm}3.02$)%. The optimization of HF-LPME method had been investigated by varying the experimental parameters such as extraction solvent, extraction time, stirring speed, and the length of HF at the fixed concentration of NaCl salt. As a result, optimal conditions of HF-LPME for FAMEs were; n-octanol for extraction solvent, 30 min for extraction time, 1200 rpm for stirring speed, 20 mm for the HF length, and 0.5 w/v% for the concentration of NaCl. Validation of HF-LPME was performed with limit of detection (LOD), limit of quantitation (LOQ), dynamic range, reproducibility, and recovery. The results obtained from this study indicated that HF-LPME was suitable for the preconcentration method and the quantitative analysis to characterize FAMEs in bio-liquid generated from food waste via HTC reaction.

Heat Transfer Characteristics of Fin-Tube Heat Exchanger Coated with FAPO Zeolite Adsorbent at Different Operating Conditions (FAPO 제올라이트 흡착제 코팅을 통한 핀-관 열교환기 운전조건별 열전달 성능특성)

  • Jeong, Chul-Ki;Kim, Yong-Chan;Bae, Kyung-Jin;Cha, Dong-An;Kwon, Oh-Kyung
    • Journal of Power System Engineering
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    • v.21 no.3
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    • pp.93-101
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    • 2017
  • In conventional adsorption chamber, adsorbent is embedded in between heat exchanger fins by wire mesh. This method impedes heat and mass transfer efficiency. So in this study, to improve the heat transfer performance of heat exchanger, a fin-tube exchanger was coated with FAPO (Ferroaluminophosphate) zeolite adsorbent. The fin-tube heat exchanger has a fin pitch of 1.8 mm with a variation of adsorbent coating thickness of about 0.1 mm, 0.15 mm and 0.2 mm. By varying cooling water temperature and chilled water temperature respecively, heat transfer rate and overall heat transfer coefficient were investigated. As a result, the heat transfer rate and overall heat transfer coefficient increase with decreasing cooling water temperature and increasing chilled water temperature. Under the basic conditions, the heat transfer rate of heat exchanger with 0.2 mm coating thickness is 11% and 43% higher than that of 0.1 mm and 0.15 mm, respectively. The overall heat transfer coefficient is $189.1W/m^2{\cdot}^{\circ}C$, it is two times lager than that of 0.1 mm.

Micropropagation of Aronia (Aronia melaocarpa Elliot, black chokeberry) and its 5 varieties (아로니아(Aronia melanocarpa Elliot) 5개 품종의 기내번식)

  • Kwak, Myoung-Chul;Choi, Chung-Ho;Choi, Yong-Eui;Moon, Heung-Kyu
    • Journal of Plant Biotechnology
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    • v.42 no.4
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    • pp.380-387
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    • 2015
  • Aronia (Aronia melanocarpa, Black chokeberry) is an important cash crop in domestic agriculture. We investigated the effects of plant growth regulators on shoot proliferation and rooting using in vitro tissue culture. The most effective shoot multiplication was observed on WPM (woody plant medium) supplemented with 1.0 mg/L zeatin ($8.3{\pm}1.0$ shoots/explant), while the highest rooting rate was obtained from half-strength WPM with 3.0 mg/L IBA (8.8 roots/explant). The rooted plantlets all survived in the artificial soil mixture (with a mixture of peat moss : perlite : vermiculite, 1:1:1, v/v/v) and grew up relatively uniform, ranging from 14 to 16 leaves, 8 to 10 cm in stem height, and 2.3 to 2.8 mm in stem diameter. While experimenting with 5 different varieties of Aronia, we found out that each variety had different characteristics of shoot proliferation and rooting. The total numbers of proliferated shoots per variety is as follows: $17.4{\pm}0.8$ for Nero, 14 to 15 for Purple and Mackenzie, and 10 for both Viking and Odamamachiko. Rooting rates were also various depending on the variety: 88% of Odamamachiko, 80% of Viking and Purple, and 76% of Nero and 60% of Mackenzie shoots rooted. The survival rate of the rooted plantlets was from 92% to 100%, varying by type. Further growth appeared to be better in auxin-treated plantlets, compared to untreated ones. Our results showed the possibility of establishing an effective in vitro micropropagation system for Aronia melanocarpa.

Effect of biocide addition on plantlet growth and contamination occurrence during the in vitro culture of blueberry

  • Huh, Yoon Sun;Lee, Joung Kwan;Kim, Ik Jei;Kang, Bo Goo;Lee, Ki Yeol
    • Journal of Plant Biotechnology
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    • v.42 no.2
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    • pp.111-116
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    • 2015
  • Interest and great demand for blueberry (Vaccinium corymbosum) have increased, as V. corymbosum is now one of the most economically important crops in Korea. It is expected that blueberry production and the area planted for cultivation will increase consistently in the years ahead because of high profitability and the consumer's demand for healthy ingredients. Effective mass production of blueberry is urgently needed for commercial cultivation establishment, but a main limitation is lack of a propagation system that produces a disease-free plant material for commercial plantation. A large amount of research has focused entirely on developing tissue culture techniques for blueberry propagation. However, controlling fungal and bacterial contamination of woody plant material is extremely difficult. Our study was conducted to investigate the effect of biocide addition during the in vitro culture of blueberry on plantlet growth and contamination occurrence. Four biocides, including Plant Preservative Mixture ($PPM^{TM}$), vancomycin, nystatin and penicillin G, were used in varying concentrations during the in vitro propagation of blueberry. When nystatin was added into the medium at low concentrations, the overall growth of blueberry plantlets was retarded. Addition of vancomycin and penicillin G in high concentrations decreased contamination but induced plantlet mortality. On the other hand, when 1ml/L $PPM^{TM}$ was added, the growth characteristics of blueberry plantlets did not significantly differ from non-treatment (control), and the contamination occurrence rate was very low. From these results, we found that the addition of the appropriate biocide could provide an effective method to reduce contamination in the culture process, thereby raising in vitro production efficiency.

SnO2 Semiconducting Nanowires Network and Its NO2 Gas Sensor Application (SnO2 반도체 나노선 네트웍 구조를 이용한 NO2 가스센서 소자 구현)

  • Kim, Jeong-Yeon;Kim, Byeong-Guk;Choi, Si-Hyuk;Park, Jae-Gwan;Park, Jae-Hwan
    • Korean Journal of Materials Research
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    • v.20 no.4
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    • pp.223-227
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    • 2010
  • Recently, one-dimensional semiconducting nanomaterials have attracted considerable interest for their potential as building blocks for fabricating various nanodevices. Among these semiconducting nanomaterials,, $SnO_2$ nanostructures including nanowires, nanorods, nanobelts, and nanotubes were successfully synthesized and their electrochemical properties were evaluated. Although $SnO_2$ nanowires and nanobelts exhibit fascinating gas sensing characteristics, there are still significant difficulties in using them for device applications. The crucial problem is the alignment of the nanowires. Each nanowire should be attached on each die using arduous e-beam or photolithography, which is quite an undesirable process in terms of mass production in the current semiconductor industry. In this study, a simple process for making sensitive $SnO_2$ nanowire-based gas sensors by using a standard semiconducting fabrication process was studied. The nanowires were aligned in-situ during nanowire synthesis by thermal CVD process and a nanowire network structure between the electrodes was obtained. The $SnO_2$ nanowire network was floated upon the Si substrate by separating an Au catalyst between the electrodes. As the electric current is transported along the networks of the nanowires, not along the surface layer on the substrate, the gas sensitivities could be maximized in this networked and floated structure. By varying the nanowire density and the distance between the electrodes, several types of nanowire network were fabricated. The $NO_2$ gas sensitivity was 30~200 when the $NO_2$ concentration was 5~20ppm. The response time was ca. 30~110 sec.

Numerical Study of Distribution Characteristics of Pulverized Coal According to Operation Condition in PM Burners (저공해 버너에서의 운전조건에 따른 미분탄 분배특성에 관한 수치 해석 연구)

  • Yoon, Sung-Hwan;Park, Jeong;Kwon, Oh-Boong;Park, Ho-Young;Seo, Sang-Il
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.5
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    • pp.491-501
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    • 2011
  • We performed numerical simulation using a DPM (discrete phase model) to identify the optimal operation ranges in two representative PM burners widely used in domestic 500-MW pulverized coal-fired power plants. Recently there has been an increased utilization of low-cost coals such as sub-bituminous coal. We investigate the effects of coal blends on the distribution ratio of coal to air by varying the mass flow rates of pulverized coal and primary air and the particle size. We present and discuss optimal conditions for the distribution ratio of coal to air in PM burners.

Filter- and Denuder-Based Organic Carbon Correction for Positive Sampling Artifacts

  • Hwang, InJo;Na, Kwangsam
    • Asian Journal of Atmospheric Environment
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    • v.11 no.2
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    • pp.107-113
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    • 2017
  • This study describes (1) the impact of positive sampling artifacts caused by not only a filter-based sampling, but also a denuder-based sampling in the determination of particle-phase organic carbon (POC), (2) the effect of sample flow rate on positive artifacts, and (3) an optimum flow rate that provides a minimized negative sampling artifact for the denuder-based sampling method. To achieve the goals of this study, four different sampling media combinations were employed: (1) Quartz filter-alone (Q-alone), (2) quartz filter behind quartz-fiber filter (QBQ), (3) quartz filter and quartz filter behind Teflon filter (Q-QBT), and (4) quartz filter behind carbon-based denuder (Denuder-Q). The measurement of ambient POC was carried out in an urban area. In addition, to determine gas-phase OC (GOC) removal efficiency of the denuder, a Teflon filter and a quartz filter were deployed upstream and downstream of the denuder, respectively with varying sample flow rates: 5, 10, 20, and 30 LPM. It was found that Q-alone sampling configuration showed a higher POC than QBQ, Q-QBT, and Denuder-Q by 12%, 28%, and 23%, respectively at a sample flow rate of 20 LPM due to no correction for positive artifact caused by adsorption of GOC onto the filter. A lower quantity of GOC was collected from the backup quartz filter on QBQ than that from Q-QBT. This was because GOC was not in equilibrium with that adsorbed on the front quartz filter of QBQ during the sampling period. It is observed that the loss of particle number and mass across the denuder increases with decreasing sample flow rate. The contribution o f positive arti facts to POC decreased with increasing sample flow rate, showing 29%, 25%, and 22% for 10, 20, and 30 LPM, respectively. The 20 LPM turns out to be the optimum sample flow rate for both filter and denuder-based POC sampling.

Cyclosporin A Binding Protein Type-19 kDa Peptidyl-Prolyl Cis/Trans Isomerase from Euglena gracilis

  • SONG HYUK-HWAN;PARK SUNG-YONG;LEE CHAN
    • Journal of Microbiology and Biotechnology
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    • v.15 no.5
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    • pp.1047-1053
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    • 2005
  • Cyclosporin A binding protein type-19 kDa peptidyl-prolyl cis/trans isomerase (PPIases, EC 5.2.1.8) of Euglena gracilis was purified and some of its biochemical characters were elucidated. Purification of the PPIase was achieved by employing a series of steps involving ammonium sulfate precipitation, Superdex G-75 gel filtration chromatography, Mono­Q anion and Mono-S cation exchange chromatographies, and Superdex S-200 gel filtration chromatography on FPLC. Purified PPIase had a specific activity of 8,250 units/mg, showing a 27-fold increase compared with that of cell-free extract of Euglena gracilis. The enzyme consisted of a single polypeptide chain with a molecular mass of 19 kDa. It showed high substrate specificity to succinyl-Ala-Ala-Pro-Phe-p-nitroanilide, and $k_{car}/K_{m}$, for this substrate was found to be $61.19{\times}10^5/sec$. The isomer distributions were investigated at an equilibrium of seven different peptide substrates, varying Xaa in Suc-Ala-Xaa-Pro-Phe-p-nitroanilide in dimethylsulfoxide. The cis/trans equilibrium constants were estimated to be from 0.14 (Ile) to 0.63 (Gly), which correspond to $12.00\%\;to\;38.52\%$ of the cis population, respectively, under experimental condition. The enzyme was highly sensitive to the immunosuppressive ligand cyclosporin A, but not to other immunosuppressants such as FK506 and rapamycin. Thus, it appears to belong to the class of cyclophilin.