• Title/Summary/Keyword: Mass changes

Search Result 2,182, Processing Time 0.082 seconds

Reduction of High Explosives (HMX, RDX, and TNT) Using Micro- and Nano- Size Zero Valent Iron: Comparison of Kinetic Constants and Intermediates Behavior (마이크로와 나노 철을 이용한 고성능 화약물질(HMX, RDX 및 TNT)의 환원처리: 중간산물의 거동과 도역학 상수의 비교)

  • Bae, Bum-Han
    • Journal of Soil and Groundwater Environment
    • /
    • v.11 no.6
    • /
    • pp.83-91
    • /
    • 2006
  • Reduction kinetics and the behaviour of intermediate of three high explosives (HMX, RDX, and TNT) were studies in batch reactors using nano- or micro- size zero valent iron(nZVI or mZVI) as reducing agent. The kinetic constants normalized by the mass of iron ($k_M$) or by the surface area ($k_{SA}$) were measured and compared along with the changes in the concentrations of intermediates. Results showed that $k_M$ and $k_{SA}$ values were not suitable to fully explain the behaviour of mother compounds and reduced intermediates in the batch reactor. The concentrations of initial explosives degradation products, such as nitroso-RDXs, nitroso-HMXs, and hydroxylamino-TNTs, were higher in mZVI treated reactor than in nZVI treated reactor, whereas more reduced polar intermediates such as TAT were accumulated in the nZVI reactor. Therefore, a new parameter, which accounted for the intermediates reduction, needs to be developed.

Anti-Melanogenic Potentials of Nanoparticles from Calli of Resveratrol-Enriched Rice against UVB-Induced Hyperpigmentation in Guinea Pig Skin

  • Lee, Taek Hwan;Kang, Ji Hee;Seo, Jae Ok;Baek, So-Hyeon;Moh, Sang Hyun;Chae, Jae Kyoung;Park, Yong Un;Ko, Young Tag;Kim, Sun Yeou
    • Biomolecules & Therapeutics
    • /
    • v.24 no.1
    • /
    • pp.85-93
    • /
    • 2016
  • We already reported that genetically engineered resveratrol-enriched rice (RR) showed to down-regulate skin melanogenesis. To be developed to increase the bioactivity of RR using calli from plants, RR was adopted for mass production using plant tissue culture technologies. In addition, high-pressure homogenization (HPH) was used to increase the biocompatibility and penetration of the calli from RR into the skin. We aimed to develop anti-melanogenic agents incorporating calli of RR (cRR) and nanoparticles by high-pressure homogenization, examining the synergistic effects on the inhibition of UVB-induced hyperpigmentation. Depigmentation was observed following topical application of micro-cRR, nano-calli of normal rice (cNR), and nano-cRR to ultraviolet B (UVB)-stimulated hyperpigmented guinea pig dorsal skin. Colorimetric analysis, tyrosinase immunostaining, and Fontana-Masson staining for UVB-promoted melanin were performed. Nano-cRR inhibited changes in the melanin color index caused by UVB-promoted hyperpigmentation, and demonstrated stronger anti-melanogenic potential than micro-cRR. In epidermal skin, nano-cRR repressed UVB-promoted melanin granules, thereby suppressing hyperpigmentation. The UVB-enhanced, highly expressed tyrosinase in the basal layer of the epidermis was inhibited by nano-cRR more prominently than by micro-cRR and nano-cNR. The anti-melanogenic potency of nano-cRR also depended on pH and particle size. Nano-cRR shows promising potential to regulate skin pigmentation following UVB exposure.

Studies on the Blistering Resistance(I) - The influence of pigment ratio on blistering resistance - (블리스터링에 관한 연구(제1보) - 안료의 배합비가 블리스터링에 미치는 영향 -)

  • Lim, Won-Seok;Ha, Young-Baeck;Kim, Chang-Keun;Lee, Yong-Kyu
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.39 no.2 s.120
    • /
    • pp.25-30
    • /
    • 2007
  • Recently the use of web offset printing has been increasing, which can provide high print speed, mass production, and high print quality. However, high speed web offset printing has frequently undergone a blistering problem when the printed paper passes through hot air dryers. Blistering occurs in the middle of the base paper or in the coating layer. This paper focused on the blistering occurring in the base paper. In order to elucidate the effect of pigment ratio on blistering, 6 types of coating color were prepared with varying GCC/clay ratios and printability and blistering were investigated focusing on structure changes in the coating layer. When the clay content in the coating layer was increased, surface roughness and surface strength were decreased and paper gloss was increased. In addition, it was found that the coating layer structure with high clay content, which contains lots of discontinuous pores, hindered water vapors to penetrate out and, as a result, blistering occurred.

A Study on Lithium Leaching from the Fly Ash of Taean Electric Power Plant (태안화력발전소 비산재로부터 리튬용출연구)

  • Kim, Kang-Joo;Lee, Eun-Gyu;Lee, Jae-Cheol;Hwang, Soo-Yeon;Kim, Chang-Hyeon
    • Journal of the Mineralogical Society of Korea
    • /
    • v.25 no.2
    • /
    • pp.117-122
    • /
    • 2012
  • The leaching of Li from fly ashes was studied. The fly ash produced from the Taean electric power plant of the Korea Western Power Co., Ltd. was used for this study. The Li leaching was observed according to the changes in solid:solution ratio, solution types (seawater or deionized water), and the $CO_2$ condition in the atmosphere. The results showed that the Li concentrations in the solution increased continuously as the solid:solution ratio increased. The Li leaching per unit mass of fly ash was greater when the deionized water was used for the experiment and when the $CO_2$ dissolution is limited during the reaction because the precipitation of $CaCO_3$ is suppressed under those conditions. At high solid:solution ratio, $Mg^{2+}$, the ion preventing the Li extraction from seawater by adsorption, was effectively removed from the seawater.

Suggestion of Regression Equations for Estimating RMR Factor Rating by Geological Condition (지질 조건을 고려한 RMR 인자값 추정을 위한 선형회귀식 제안)

  • Kim, Kwang-Yeom;Yim, Sung-Bin;Kim, Sung-Kwon;Kim, Chang-Yong;Seo, Yong-Seok
    • The Journal of Engineering Geology
    • /
    • v.17 no.4
    • /
    • pp.555-566
    • /
    • 2007
  • In general, RMR classification system is used for the support design of a tunnel. Face mapping during excavation and RMR-based rock classifications are conducted in order to provide information for complementary changes to preliminary survey plans and for continuous geological estimations in direction of tunnel route. Although they are ever so important, there are not enough time for survey in general and sometimes even face mapping is not available. Linear regression analysis for the estimation of mediating RQD and condition of discontinuities, which require longer time and more detailed observation in RMR, was performed and optimum regression equations are suggest as the result. The geological data collected from tunnels were analyzed in accordance with three rock types as sedimentary rock, phyllite and granite to see geological effects, generally not been considered in previous researches. Parameters for the regression analysis were set another RMR factor.

A Study on Versatile Chair Design Reflecting Users' Behavior

  • Kim, Gwang-Hee;Choi, Kyung-Ran;Sung, Yun-Jung
    • Journal of the Korea Furniture Society
    • /
    • v.22 no.3
    • /
    • pp.151-159
    • /
    • 2011
  • This study is to suggest versatile chair designs that are organically shaped to take individual orientation. This study intends to provide design method to ensure the face of the chair that contacts the body of its user is transformed flexibly to support the body. The movement of human body is not just a behavior but the ways and tools that reflexively express against external stimuli that are sensed and identified by the person. The versatile chair whose users' sitting position is fixed is made by covering the lump form with a piece of cloth ensuring that the content is firmly fixed and by placing the beads-woven wood fabric according to the shape. And then, it is covered with the external cover. The proposed versatile chair designs assume specific forms as follows: First, it is a versatile chair whose user's sitting position can fix. The organically-shaped form that can accept varying postures is made as a mass, which changes into different shapes when human body touches the form so that users can lie down or sit. Due to such transformation, body posture is determined and individual differences in shape changing are all acceptable. Second, it is a versatile chair that reflects the user's position in a fixed chair, where a cloth-wrapper feature is applied to the form a sifit wrapped postures so that a variety of body postures can be accepted. Finally, a versatile chair that reflects the user's position by changing the shape of is covered with forms so that it will be transformed and used in accordance with situations and chair shapes and reflect multiple shapes including round or square ones.

  • PDF

The Perception of Librarians and Multicultural Users on the Multicultural Library Services of Public Libraries in Seoul (사서와 다문화인 이용자의 서울시 공공도서관 다문화 서비스에 관한 인식 연구)

  • Kim, Young-Me;Cho, In-Sook
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.45 no.1
    • /
    • pp.103-124
    • /
    • 2011
  • The 21st century society is becoming globalized rapidly due to mass immigration and South Korea has become a multicultural nation since 2007 with over one million foreigners living here. Due to these social environmental changes, there was a need to provide multicultural programs and services in public libraries. In order to develop multicultural library services, we need to look into what librarians and users of public libraries know of the existing services. We assumed that comparing the two groups, librarians and users, and establishing a fit model would be the most effective way to provide information. According to the survey, there were differences in understanding between the two groups. By providing services that help fill in the gap, public libraries could be closer to multicultural families, and help them become integrated into Korean society. We have presented a multicultural service model based on the results of the survey.

Changes of Volatile Components in Extracts of Bovine Bone Using an Electronic Nose and Fourier Transform-Near Infrared Spectrometer (전자코와 푸리에 변환 근적외선 분광기를 사용한 사골 추출물의 향기 성분 변화 분석)

  • Jang, Nak-Hoon;Cho, Yon Soo;Park, Su Won;Dong, Hyemin;Han, Hyun Jung;Noh, Bong-Soo
    • Korean Journal of Food Science and Technology
    • /
    • v.46 no.6
    • /
    • pp.734-738
    • /
    • 2014
  • This study was conducted to investigate whether four hot-water extraction steps could effectively remove off-flavor from bovine bone extracts and produce compounds with pleasant aroma. Experiments were performed using a mass spectrometry-electronic nose and Fourier transform-near infrared spectrometer (FT-NIR). Off-flavor compounds were removed by washing and extraction with hot water. Steaming treatment produced compounds with a better aroma, such as 4-methylthiazole. In addition, a change in flavor compounds was observed in treated samples.

Relationship between Fashion Design Form and Art Plastique - Focused on Pop Art in 1960's - (의상디자인의 형태와 조형예술자의 관계 -1960년대의 팝아트를 중심으로-)

  • 이인성
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.21 no.8
    • /
    • pp.1427-1438
    • /
    • 1997
  • The art plastique is the part from which designers draw their inspirations to create fashion design. Many designers look for their inspirations from Art Plastique. Since the early 20th century, lots of designers led by Paul Poiret drew their inspirations from Art and co-works with artists. The direct involvement of those artists helped to position Fashion to be an art. Also, these co-works brought the mass media's attention and commercial profit. The most prevalent relationship between the fashion design and art plastique is the reproduction of art such as the 1960s 'Pop Art printed on T-shirts, which can be seen easily todays. After World War ll, art was popularized in a new society where young generation played a major role. Pop Art having image of the freedom and the rejection of tradition was considered as the major trend of 1960s. This study considers reflection of anti-traditionalism, anti-elitism and popularity as the kitsch of Pop. That is the attraction which youth culture looked for from Pop Art and the reason that 60's avast-garde cloth could position itself into the masses. Therefore, this study examines the influence of the kitsch of Pop and the expression of parody upon the major changes in 1960s fashion from which are the mini-look and women's trousers wearing. This study examines Andra Courreges who led 1960s Mini look and Yves Saint Laurent who introduced Pop dress, Smoking look and transparent blouse to find the way which makes it possible for avant garde fashion to have a close relationship with the public and to position itself to be a art.

  • PDF

Spermiogenesis in the Korean Greater Horseshoe Bat, Rhinolophus ferrumequinum korai (한국산 관박쥐 (Rhinolophus ferrumequinum korai)에 있어서의 정자변태)

  • Lee, Jung-Hun;Choi, Byung-Jin;Son, Sung-Won
    • Applied Microscopy
    • /
    • v.22 no.2
    • /
    • pp.97-117
    • /
    • 1992
  • In order to study process of spermiogenesis of the Korean greater horseshoe bat, Rhinolophus ferrumequinum korai, the cycle of seminiferous epithelium was examined by the light and electron microscope and the following results were obtained based on the epithelial cell differentiation. 1. Spermiogenesis occurred from early July to mid-Octber, and spermatogenic activity was vigorous from mid-August to late September. Spermatocytes including spermatogonia were found to be degenerated in only July. It is deduced that the degeneration serves as the mechanism to regulate effective use of energy to prepare for mating and hibernating periods, and regulation of breeding cycle. 2. Spermiogenesis of the Korean greater horseshoe bat was divided according to differentiation of the cell structure, into Golgi, cap, acrosome, maturation and spermiation phases; Golgi, cap and spermiation phases were further divided into two steps of early and late phase respectively, and acrosome phase into three steps of early, mid and late phases, and maturation phase has only one step. Hence, the spermiogenesis consists of ten phases. The first research was done in this article on the changes of chromatin with nucleus, the time of appearance and disappearance of chromatin granules, in case of Korean greater horseshoe bat (Rhinolophus ferrumequinum korai). Chromatin granule began to be condensed in late Golgi and the condensation proceeded to form an irregular mass of a electron-dense chromatin in a form of circular cylinder in the center of nucleus at the phase of maturation. Finally, the chromatin condensation proceeded and perfect nucleus of sperm with homogeneous density was formed when the sperm was separated from Sertoli cell. Therefore, appearance and disappearance of chromatin granules occurred in the period of time between late Golgi and maturation phase, The tail of sperm began to develop in early cap phase, Numerous lipid droplets were obseved in the cytoplasm of spermatids during the maturation phase, which seemed to be used as energy source necessary to make mature sperm during spermiogenesis.

  • PDF