• Title/Summary/Keyword: Bio-film

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Effect of Row Covers on the Growth and Yield of Broccoli During Spring Culture (막덮기 재배가 봄재배시 녹색꽃양배추의 생육 및 수량에 미치는 영향)

  • 이정수;이재욱;성기철
    • Journal of Bio-Environment Control
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    • v.11 no.4
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    • pp.175-180
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    • 2002
  • This study was conducted to examine the effect of row covering materials on the growth and yield of broccoli for early production in the open meld. Materials for plastic tunnel were row-covering (ventilating non-woven fabric), perforated film (2.3% pore space) and P.E. film. The types of row covers were tunnel and covering period was one months after transplanting. The row cover and perforated film increased daily air and soil temperature by 3~4$^{\circ}C$ and 2~3$^{\circ}C$, respectively as compared to no covering. Also, relative humidities in those treatments were higher than those in P.E. and no covering. The row covering and perforated film enhanced plant growth. Broccoli grew best and abnormal head appeared the least with row covering treatment. Days taken for head formation, however, did not differ between treatments but the weight of curd was over 400 g in the treatment of row covering and perforated film covering. Marketable yield doubled under row covering as compared to no covering. The first harvest time was earlier by two weeks in row-covering. The results of this experiment indicated that covering row-cover film in spring cultivation was effective fer not only yield increase but also quality evaluation in early production of broccoli.

Effect of centrifugation on the structure and properties of silk sericin

  • Park, Chun Jin;Um, In Chul
    • International Journal of Industrial Entomology and Biomaterials
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    • v.33 no.2
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    • pp.144-148
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    • 2016
  • Recently, silk sericin has been studied extensively for biomedical and cosmetic applications because of its unique properties, including UV resistance and wound healing ability. For use in applications, sericin is fabricated in various forms including films and gels. However, the mechanical properties of sericin are too weak. In this basic study on improving the mechanical properties of sericin, a silk sericin aqueous solution was separated into two layers by centrifugation. The solution viscosity, molecular conformation, and mechanical properties of each separation layer of the sericin were examined. Sericin from the lower layer had a higher solution viscosity and film mechanical properties (strength and strain) than that from the upper layer, implying that sericin from the lower layer had a higher molecular weight than that from the upper layer. The molecular conformation of the sericin films varied depending on the casting solvent. In aqueous solution, the sericin film from the lower layer showed a ${\beta}$-sheet conformation, whereas that from the upper layer displayed a random coil conformation. All the sericin films showed a highly ${\beta}$-sheet-crystallized state when cast in formic acid, regardless of the separation layer.

A Study on the Typhoon Disaster of Greenhouse (시설원예용 플라스틱 하우스의 태풍피해에 관한 연구)

  • 윤용철;서원명;윤충섭
    • Journal of Bio-Environment Control
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    • v.4 no.2
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    • pp.167-174
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    • 1995
  • This study was carried out to find a way of improving the windproof capability of greenhouse foundations. Generally, greenhouses are often collapsed due to the strong winds, because they are very light weight structures. In such a critical situations, the foundations are very often subjected to uplift and vibration at the same time. This paper describes both the wind disaster of greenhouses by the typhoon FAEY and the uplift resistance of greenhouse foundations. Followings are the results obtained from this study ; Judging from the view point of year round cultural aspects, it is recommended that some measures be taken for the preventions of greenhouse film ruptures because greenhouse structural damages are found to be directly associated with the local rupture of cover film. In the case of surveyed area, movable pipe-houses or pipe-houses of 1-2W type were found to be completely destroyed when the maximum instantaneous wind velocity was over 30m/sec or so. In the case of movable pipe-houses, the uplift resistance of greenhouse was expected to increase with the increase of pipe diameter and/or the embedment pipe length. But at present situations there is a limitation in raising the uplift resistance of movable pipe-house, because pipe diameters as well as pipe lengths customarily selected by farmers are quite a much limited.

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Hydrophobicity and Nanotribological Properties of Silicon Channels coated by Diamond-like Carbon Films

  • Pham, Duc Cuong;Na, Kyung-Hwan;Pham, Van Hung;Yoon, Eui-Sung
    • KSTLE International Journal
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    • v.10 no.1_2
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    • pp.1-5
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    • 2009
  • This paper reports an investigation on nanotribological properties of silicon nanochannels coated by a diamond-like carbon (DLC) film. The nanochannels were fabricated on Si (100) wafers by using photolithography and reactive ion etching (RIE) techniques. The channeled surfaces (Si channels) were then further modified by coating thin DLC film. Water contact angle of the modified and unmodified Si surfaces was examined by an anglemeter using the sessile-drop method. Nanotribological properties, namely friction and adhesion forces, of the Si channels coated with DLC (DLC-coated Si channels) were investigated in comparison with those of the flat Si, DLC-coated flat Si (flat DLC), and Si channels, using an atomic force microscope (AFM). Results showed that the DLC-coated Si channels greatly increased hydrophobicity of silicon surfaces. The DLC coating and Si channels themselves individually reduced adhesion and friction forces of the flat Si. Further, the DLC-coated Si channels exhibited the lowest values of these forces, owing to the combined effect of reduced contact area through the channeling and low surface energy of the DLC. This combined modification could prove a promising method for tribological applications at small scales.

Prevalence of Human Papillomavirus in Women from Saudi Arabia

  • Turki, Rola;Sait, Khalid;Anfinan, Nisreen;Sohrab, Sayed Sartaj;Abuzenadah, Adel Mohammed
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.5
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    • pp.3177-3181
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    • 2013
  • Background: Human papillomavirus (HPV) infection is the main causes of cervical cancer in women worldwide. The goal of the present study was to determine the prevalence and distribution of HPV genotypes in women from Saudi Arabia. Recently, several HPV detection methods have been developed, each with different sensitivities and specificities. Methods: In this study, total forty cervical samples were subjected to polymerase chain reaction and hybridization to BioFilmChip microarray assessment. Results: Human papillomavirus (HPV) infections were found in 43% of the specimens. The most prevalent genotypes were HPV 16 (30%) HPV 18 (8.0%) followed by type HPV 45, occurring at 5.0%. Conclusion: Our finding showed the HPV infection and prevalence is increasing at alarming rate in women of Saudi Arabia. There was no low risk infection detected in the tested samples. The BioFilmChip microarray detection system is highly accurate and suitable for detection of single and multiple infections, allowing rapid detection with less time-consumption and easier performance as compared with other methods.

Sur face Modification of Ultra High Molecular Weight Polyethylene Films by UV/ozone Ir radiation

  • Yun, Deuk-Won;Jang, Jin-Ho
    • Textile Coloration and Finishing
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    • v.23 no.2
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    • pp.76-82
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    • 2011
  • Ultra High molecular weight polyethylene(UHMWPE) films were photooxidized by UV/ozone irradiation. Reflectance of the irradiated films decreased in the low wavelength regions of visible light, indicating destructive interference of visible light due to roughened surface. The UV treatment developed the nano-scale roughness on the UHMWPE films surface, which increased by two-fold from 82.6 to 156.6nm in terms of peak-valley roughness. The UV irradiation caused the oxygen content of the UHMWPE film surface to increase. Water contact angle decreased from $83.2^{\circ}$ to $72.9^{\circ}$ and surface energy increased from 37.8 to 42.6mJ/$m^2$ with increasing UV energy. The surface energy change was attributed to significant contribution of polar component rather than nonpolar component indicating surface photooxidation of UHMWPE films. The increased dyeability to cationic dyes may be due to the photochemically introduced anionic and dipolar dyeing sites on the film surfaces.

Carbon Monoxide Sensor Based on a B2HDDT-doped PEDOT:PSS Layer

  • Memarzadeh, R.;Noh, Hui-Bog;Javadpour, S.;Panahi, F.;Feizpour, A.;Shim, Yoon-Bo
    • Bulletin of the Korean Chemical Society
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    • v.34 no.8
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    • pp.2291-2296
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    • 2013
  • An efficient carbon monoxide (CO) sensor was developed based on poly(3,4-ethylenedioxy)thiophenepoly(styrenesulfonate) (PEDOT:PSS) modified with a new pyrimidine-fused heterocyclic compound, bis(2-hydroxyphenyl)dihydropyrido[2,3-d:6,5-d]dipyrimidine-tetraone (B2HDDT). B2HDDT remains stable in the polymer matrix through interactions with functional groups of the polymer. It created prominent sites that captured CO gas, and the experimental parameters, including the amount of doped B2HDDT in the PEDOT:PSS film, were optimized. The sensor probe was also examined to verify its reliability for detecting CO in the presence of atmospheric gases in a discriminating manner. NMR, AFM, and FT-IR spectra were obtained to evaluate the structure and morphology of the B2HDDT-doped PEDOT:PSS (PEDOT:PSS/B2HDDT) film. The content of 35 vol % B2HDDT (7.0 mM) in PEDOT:PSS provided the largest response factor (${\Delta}R/R_o$) for the CO gas. The sensor response was reproducible, with a relative standard deviation < 5% (n = 5). The detection limit was determined to be $0.44{\pm}0.05$ vol %.

Effect of biofibers addition on the structure and properties of soy protein composite films

  • Ye Eun Kim;Su Jin Kim;Yong-Il Chung;Chae Hwa, Kim;Tae Hee Kim;In Chul Um
    • International Journal of Industrial Entomology and Biomaterials
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    • v.48 no.1
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    • pp.25-32
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    • 2024
  • Soy protein isolate (SPI) has garnered researchers' attention due to its abundance, costeffectiveness, excellent biocompatibility, hemo-compatibility, and biodegradability. However, SPI faces limitations in application due to poor processability and weak mechanical strength. Substantial efforts have been made to address these challenges. In this preliminary study, glycerol and biofibers were added to SPI to improve the mechanical properties and film forming, and glyoxal was employed to crosslink SPI molecules. The microstructure and mechanical properties of the resulting SPI/composite films were evaluated. A 15% addition of glycerol proved sufficient for good film formation. Among the biofibers, short SF microfibers were the most effective in enhancing breaking strength, while TEMPO-oxidized CNF (cellulose nanofiber) excelled among CNFs. Crosslinking with glyoxal significantly enhanced the mechanical properties, with the type of biofiber minimally affecting the mechanical properties of the crosslinked SPI composite films.

A Method for Absolute Determination of the Surface Areal Density of Functional Groups in Organic Thin Films

  • Min, Hyegeun;Son, Jin Gyeong;Kim, Jeong Won;Yu, Hyunung;Lee, Tae Geol;Moon, Dae Won
    • Bulletin of the Korean Chemical Society
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    • v.35 no.3
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    • pp.793-797
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    • 2014
  • To develop a methodology for absolute determination of the surface areal density of functional groups on organic and bio thin films, medium energy ion scattering (MEIS) spectroscopy was utilized to provide references for calibration of X-ray photoelectron spectroscopy (XPS) or Fourier transformation-infrared (FT-IR) intensities. By using the MEIS, XPS, and FT-IR techniques, we were able to analyze the organic thin film of a Ru dye compound ($C_{58}H_{86}O_8N_8S_2Ru$), which consists of one Ru atom and various stoichiometric functional groups. From the MEIS analysis, the absolute surface areal density of Ru atoms (or Ru dye molecules) was determined. The surface areal densities of stoichiometric functional groups in the Ru dye compound were used as references for the calibration of XPS and FT-IR intensities for each functional group. The complementary use of MEIS, XPS, and FT-IR to determine the absolute surface areal density of functional groups on organic and bio thin films will be useful for more reliable development of applications based on organic thin films in areas such as flexible displays, solar cells, organic sensors, biomaterials, and biochips.

Development of Temperature Control Technology of Root Zone using Evaporative Cooling Methods in the Strawberry Hydroponics (증발 냉각방식을 이용한 딸기 수경재배의 배지 온도조절 기술 개발)

  • Kim, Ki-Dong;Ha, Yu-Shin;Lee, Ki-Myung;Park, Dae-Heum;Kwon, Soon-Gu;Park, Jong-Min;Chung, Sung-Won
    • Journal of Bio-Environment Control
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    • v.19 no.4
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    • pp.183-188
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    • 2010
  • It is necessary to develop an efficient and affordable cooling technology and apply the practical system to rural farmhouse, control to adequate growth environment by adjusting temperature of root zone. A study on managing medium temperature of the hydroponics for strawberry cultivation was conducted and feasible evaporative cooling system for the media cooling were as follows: Characteristics of temperature drop were investigated for the evaporative cooling devices using microporous film duct, felt mulching on media surface, and water permeable sheet in culture tank. The evaporative device with water permeable sheet in culture tank was the most efficient and economic on media cooling system.