• Title/Summary/Keyword: retardation film

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Effect of Soy Protein Film Packaging on the Qualities and the Microbial Growth of Beef during Storage (대두 단백 필름 포장 방법에 따른 저장 중 쇠고기의 품질 및 미생물 변화)

  • Lee Myoungsuk;Park Sangkyu;Bae Dongho;Ha Sangdo;Song Kyung Bin
    • Food Science and Preservation
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    • v.11 no.4
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    • pp.565-568
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    • 2004
  • To investigate the effect of soy protein film packaging on the quality of beef, the rate of weight loss, pH, 2-thiobarbituric acid reactive substance (TBARS), and microbial (total bacterial count) Salmonella spp., E. coli changes were determined during storage. Beef samples were packaged with soy protein film containing rosemary extract and then stored at $4^{\circ}C$. Soy protein film was effective on prevention of weight loss, compared with the control, regardless of addition of rosemary extract. Change in pH of soy protein films containing the rosemary extract (RPF) was less during storage, compared with the control. Packaging of beef products with RPF inhibited lipid oxidation by $86\%$ at day 8 of storage, compared to the control. RPF packaging also affected the microbial growth, resulting in retardation of total bacteria by more than 1 log cycle. These results indicate that storage of beef packaged with RPF should be appropriate in terms of quality as well as shelf-life.

Electro-Optic Characteristics of the Fringe-Field driven Reflective Hybrid Aligned Nematic Liquid Crystal Display (Fringe-Field 구동형 반사형 Hybrid Aligned Nematic 액정 디스플레이의 전기-광학 특성)

  • Jung, T.B.;Park, C.H.;Son, J.S.;Rhee, J.M.;Lee, S.H.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07b
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    • pp.972-975
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    • 2003
  • We have performed computer simulation to obtain electro-optic characteristics of reflective hybrid aligned nematic liquid crystal displays driven by fringe field. The results show that the optimal retardation value of the cell is $0.289{\mu}m$, which allows for the cell to have a practical cell gap of larger than $3{\mu}m$ when manufacturing. A reflectance of the dark state is only 0.114% for an incident light 550nm. At this condition, the light efficiency of white state reaches 92.7%. Further, we have studied a new reflective display with polarizer, optical compensation with half plate, LC plus reflector. The display with optimized cell parameters shows low wavelength dispersion and the contrast ratio greater than 5 over exists about $120^{\circ}$ in vertical direction and $160^{\circ}$ in horizontal direction.

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Effects of environmental parameters on chloride-induced stress corrosion cracking behavior of austenitic stainless steel welds for dry storage canister application

  • Seunghyun Kim;Gidong Kim;Chan Kyu Kim;Sang-Woo Song
    • Nuclear Engineering and Technology
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    • v.56 no.1
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    • pp.317-327
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    • 2024
  • This study investigated the chloride-induced stress corrosion cracking (CISCC) behavior expected to occur in welds of austenitic stainless steel, which are considered candidate materials for dry storage containers for spent nuclear fuel. The behavior was studied by varying temperature, relative humidity (RH), and chloride concentration. 304L-ER308L welded plates were processed into U-bend specimens and exposed to a cyclic corrosion chamber for 12 weeks. The CISCC behavior was then analyzed using electron microscopy. A previous study by the authors confirmed that CISCC occurred in ER308L at 60 ℃, 30% RH, and 0.6 M NaCl via selective corrosion of δ-ferrite. When the temperature was lowered from 60 ℃ to 50 ℃, CISCC still occurred. However, when the humidity was reduced to 20% RH, CISCC did not happen. This can be attributed to the retardation of the deliquescence of NaCl at lower humidity, which was insufficient to promote CISCC. Furthermore, increased chloride concentration to 1.0 M resulted in the absence of CISCC and widespread surface corrosion with severe pitting corrosion because of the increase in thin film thickness.

The Alignment of Liquid Crystals on the Film Surfaces of Soluble Aromatic Polyimides Bearing t-Butylphenyl and Trimethylsilylphenyl Side Groups

  • Hahm, Suk-Gyu;Jin, Kyeong-Sik;Park, Sam-Dae;Ree, Moon-Hor;Kim, Hyung-Sun;Kwon, Soon-Ki;Kim, Yun-Hi
    • Macromolecular Research
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    • v.17 no.12
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    • pp.976-986
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    • 2009
  • With the study goal of firstly elucidating the anisotropic interactions between oriented polymer chain segments and liquid crystal (LC) molecules, and secondly of determining the contributions of the chemical components of the polymer segments to the film surface topography, LC alignment, pretilt, and anchoring energy, we synthesized three dianhydrides, 1,4-bis(4'-t-butylphenyl)pyromellitic dianhydride (BBPD), 1,4-bis(4'-trimethylsilylphenyl)pyromellitic dianhydride(BTPD), and 2,2'-bis(4"-tert-butylphenyl)-4,4',5,5'-biphenyltetracarboxylic dianhydride (BBBPAn), and a series of their organosoluble polyirnides, BBPD-ODA, BBPD-MDA, BBPD-FDA, BTPD-FDA, and BBBPAn-FDA, which contain the diamines 4,4'-oxydianiline (ODA), 4,4'-methylenediamine (MDA), and 4,4'-(hexafluoroisopropylidene)dianiline (FDA). All the polyimides were determined to be positive birefringent polymers, regardless of the chemical components. Although all the rubbed polyimide films exhibited microgrooves which were created by rubbing process, the film surface topography varied depending on the polyimides. In all the rubbed films, the polymer chains were unidirectionally oriented along the rubbing direction. However, the degree of in-plane birefringence in the rubbed film varied depending on the polyimides. The rubbing-aligned polymer chains in the polyimide films effectively induced the alignment of nematic LCs along their orientation directors by anisotropic interactions between the preferentially oriented polymer chain segments and the LCs. The azimuthal and polar anchoring energies of the LCs ranged from $0.45{\times}10^{-4}\;-\;1.37{\times}10^{-4}\;J/m^2$ and from $0.86{\times}10^{-5}\;-\;4.26{\times}10^{-5}\;J/m^2$, respectively, depending on the polyimides. The pretilt angles of the LCs were in the range $0.10-0.62^{\circ}$. In summary, the soluble aromatic polyimides reported here are promising LC alignment layer candidates for the production of advanced LC display devices.

Transport behavior of a surfactant tracer(CPC) with Langmuir type adsorption isotherm on NAPL-water interface in a homogeneous porous medium (NAPL-물 계면에서 Langmuir형 흡착특성을 보이는 계면추적자(CPC)의 다공성 균질매질내 유동특성)

  • 김헌기;문희수;이상훈
    • Journal of Soil and Groundwater Environment
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    • v.6 no.2
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    • pp.3-13
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    • 2001
  • It has been known that nonlinear characteristics of sorption affect the transport behavior of water soluble pollutants in soils. However detailed experimental studies have not been performed to verify the effect of non-linearity of adsorption isotherm on transport of chemicals in porous media. In this research, the distortion of breakthrough curves of a cationic surfactant (cetylpyridinium chloride, CPC) in a engineered stainless steel column packed with glass beads were investigated. Glass beads with about 110 $\mu\textrm{m}$diameter coated with a thin n-decane film were used as the media providing the sorption surface for CPC. The CPC adsorption isotherm on the surface of n-decane from aqueous solution was a typical Langmuir type. The breakthrough curve of CPC using step Input showed a late breakthrough on the front side and early breakthrough on the back side accordance to the shape of the isotherm. The retardation factor of CPC was found to be a strong function of the input concentration, which also a manifestation of the non-linearity of the isotherm. The retardation factors for the CPC with step input agreed with those of pulse input that the maximum concentrations are controlled to be the same as the step input concentrations. This results support the validity of the unproven field practices of using hydrogeotracers with non-linear adsorption isotherms to determine the hydrogeological parameters, e.g., NAPL saturation, air-water or NAPL-water interfacial areas.

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Growth and Yield of Peanuts Affected by Weeding Time and Periods in Bare Soil and Under the P. E. film Mulch (노지(露地) 및 P. E. film 피복하(被覆下)에서 제초시기(除草時期)와 기간(期間)이 땅콩의 생육(生育) 및 수량(收量)에 미치는 영향(影響))

  • Kang, K.H.;Lee, S.S.;Lee, K.H.;Hwang, H.B.;Lee, S.B.;Ye, B.D.
    • Korean Journal of Weed Science
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    • v.7 no.1
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    • pp.52-57
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    • 1987
  • To know the effects of weeding periods (weeding from 12 days, 28 days and 42 days after seeding to harvest, and weeding from seeding to 14 days, 28 days and 42 days after seeding) and growing conditions such as transparent polyethylene film mulch (P.E. mulch) and bare soil on growth and yield of peanuts, "Yeongho-Tangkong" was planted on May 10, 1984. Under P.E. mulch, the number of weeds was higher, but the weed dry weight was lower than in bare soil by the middle of July. Sixty days after seedings, the length of main stems in weedy check plots was longer, but shoot dry weight was lower compared to weed free plot. In the correlation coefficients between weed dry weight and the shoot dry weight of peanut on July 14, the growth retardation of peanuts due to weeds was showed earlier under P.E. mulch than in bare soil. Shoot dry weight, shelling ratio, number of seeds per pod, 100 pod weight, and seed yield were higher under P.E, mulch compared to bare soil. But weed dry weight, length of branches, number of pod bearing branches, number of pods per square meters, and pod yield were similar between P.E. mulch and bare soil. Shoot dry weight of peanuts, length of branches, number of pod bearing branches, number of pods per square meters, pod yield, 100 pod weight, 100 seed weight, and seed yield in weed free plots from 28 days after seeding to harvest (28 DAS-Harvest) were higher compared to weed free plots from 42 DAS-Harvest. However, in the weed free plot from seeding to 42 days after seeding seed yield was lower than that of the continuous weeding plot due to lower number of pod bearing branches and number of pods per square meters. When weed was not controlled at the later growth stages of peanuts, reduction in seed yield due to weeds was greater in bare soil than that under P.E. mulch.

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Alignments of Reactive Mesogen Using Rubbed Glass Substrates (러빙한 유리 기판을 이용한 반응성 액정 배향)

  • Lee, Mongryong;Bae, Jin Woo;Kim, Anna;Yun, Hyeong Seuk;Song, Kigook
    • Polymer(Korea)
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    • v.39 no.1
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    • pp.174-179
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    • 2015
  • Alignments of photo-reactive mesogen were induced using bare glass substrates without a polymer alignment layer. It was found by using polarized FTIR spectroscopy, polarized microscopy, and birefringence measurement experiments that the reactive mesogen could be aligned along the rubbing direction although the glass substrate without an alignment layer was used. The induction mechanism of the rubbed bare glass is ascribed to that polymers from rubbing clothes are coated on the glass substrate along the rubbing direction and lead the alignment of liquid crystals through intermolecular interactions.

Efficiency of Retarding Reflection Crack in Reinforced-and-Modified Asphalt Pavement Overlay (개질재.보강재를 이용한 덧씌우기 아스팔트 포장의 반사균열 지연 효과)

  • Kim, Kwang-Woo;Doh, Young-Soo;Lim, Sung-Bin;Rhee, Suk-Keun;Eum, Joo-Yong
    • International Journal of Highway Engineering
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    • v.1 no.1
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    • pp.85-96
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    • 1999
  • This study was performed to evaluate performance of polymer-modified asphalt mixtures and specially designed reinforcement techniques against reflection cracking of the asphalt pavement overlay. Selected polymers were used for asphalt modification and polyester fiber, a polypropylene film (vinyl) and a grid were used for mixture reinforcement. Using the asphalt mixture with optimum asphalt content, a slab was made and cut into two pieces of specimen. A layer of grid or vinyl was placed at the bottom of specimen to strengthen the pavement layer against crack. A repeated loading was applied to the asphalt mixture specimen which is Placed on a cement concrete with a pseudo-crack. Crack propagation under repeated loading was monitored and effectiveness of the devised crack retarding techniques was evaluated. From the test results. a significant retardation of mode I crack progress was monitored from some of the modified and reinforced asphalt mixtures.

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Spectroscopic Analyses of Rose Bengal Sensitized and NaI Supersensitized Photocurrent (Rose Bengal 감응 및 NaI 초감응 광전류의 분광학적 분석)

  • Yoon Kil-Joong;Min Hyun-Jin;Kim Kang-Jin
    • Journal of the Korean Chemical Society
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    • v.36 no.1
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    • pp.107-112
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    • 1992
  • Electron injection from excited rose bengal into the conduction band of a thin film of $SnO_2$ semiconductor in acetonitrile was investigated in an electrochemical cell, ITO/$SnO_2$/rose bengal, NaI or $I_2$, $NaClO_4$/Pt. It was observed that NaI enhanced the supersensitized photocurrent, followed by the slow reduction, whereas $I_2$ yielded a fast decaying photocurrent. Spectroscopic analyses of the dye solution containing NaI revealed that electron is transferred to the $SnO_2$ electrode from the reduced rose bengal and iodide is responsible for the reduction of the dye in triplet state. However $I_2$ appears to possess neither the reducing ability of the oxidized dye nor the retardation of the dehalogenation of RB.

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Practical Application of Fine Particle Cement for Shotcrete in Cold Weather (동절기 Shotcrete 시공을 위한 미립자 시멘트의 활용)

  • Kim, Kyoung-Min;Hwang, In-Sung;Kim, Sung-Soo;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.997-1000
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    • 2008
  • Strength development of concrete subjected to cold weather is generally delayed due to its low temperature. In case of soil nailing method, it is necessary to apply the shotcrete. However, the shotcrete placement under low temperature experiences retardation of strength development due to delayed hydration reaction. Therefore, in this paper, the use of fine particle cement which is produced through particle classification in cement manufacturing process, is discussed to enhance the strength development of the shotcrete under low temperature. According to the results, the concrete containing 100% of fine particle cement had excellent strength development even at $-9^{\circ}C$ of temperature and at 5days, it reached design strength with PE film curing. It is thought that more than 70% of fine particle cement can secure required strength of the shotcrete even at low temperature condition.

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