• Title/Summary/Keyword: solid elements

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Chemical Components and Anti-oxidant Activities of Black Currant (블랙 커런트의 화학성분 및 항산화 활성)

  • Jeong, Chang-Ho;Jang, Chi-Weon;Lee, Koo-Yul;Kim, Il-Hun;Shim, Ki-Hwan
    • Food Science and Preservation
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    • v.19 no.2
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    • pp.263-270
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    • 2012
  • The chemical components and anti-oxidant activities of black currant were investigated. The pH, soluble solid and total acidity values were 3.36, 15.11 $^{\circ}Brix$, and 1.65%, respectively. The Hunter L, a, and b values were 18.20, 5.13, and 1.08, respectively. The proximate compositions were as follows; moisture, 77.64%; nitrogen free extract, 17.41%; crude fiber, 3.08%; crude protein, 1.28%; crude ash, 0.31%; and crude lipid, 0.28%, respectively. The mineral elements were K (177.36 mg/100 g), P (54.74 mg/100 g), and Ca (26.45 mg/100 g). The free sugar components were glucose (7.71%) and fructose (5.88%). The amino acid contents of the black currant were very rich in glutamic acid (105.73 mg/100 g) and deficient in cystine (5.29 mg/100 g). The ascorbic acid and total phenolic contents were 112.19 mg/100 g and 34.48 mg GAE/g, respectively. The ABTS and DPPH radical scavenging activity levels were 99.48% and 89.03% at the 10 and 1.25 mg/mL concentrations. The reducing power and FRAP of the black currant were dose-dependent. Thus, black currant can be an effective source of functional food substances, i.e., natural anti-oxidants.

Technical Trends of Hydrogen Production (수소생산 기술동향)

  • Ryi, Shin-Kun;Han, Jae-Yun;Kim, Chang-Hyun;Lim, Hankwon;Jung, Ho-Young
    • Clean Technology
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    • v.23 no.2
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    • pp.121-132
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    • 2017
  • The increase of greenhouse gases and the concern of global warming instigate the development and spread of renewable energy and hydrogen is considered one of the clean energy sources. Hydrogen is one of the most elements in the earth and exist in the form of fossil fuel, biomass and water. In order to use hydrogen for a clean energy source, the hydrogen production method should be eco-friendly and economic as well. There are two different hydrogen production methods: conventional thermal method using fossil fuel and renewable method using biomass and water. Steam reforming, autothermal reforming, partial oxidation, and gasification (using solid fuel) have been considered for hydrogen production from fossil fuel. When using fossil fuel, carbon dioxide should be separated from hydrogen and captured to be accepted as a clean energy. The amount of hydrogen from biomass is insignificant. In order to occupy noticeable portion in hydrogen industries, biomass conversion, especially, biological method should be sufficiently improved in a process efficiency and a microorganism cultivation. Electrolysis is a mature technology and hydrogen from water is considered the most eco-friendly method in terms of clean energy when the electric power is from renewable sources such as photovoltaic cell, solar heat, and wind power etc.

Effect of Drying Methods on the Quality in Lycii Fructus (구기자(枸杞子)의 건조방법(乾燥方法)이 품질(品質)에 미치는 영향(影響))

  • Cho, Im-Shik;No, Jae-Goan;Park, Jong-Sang;Li, Run-Huai
    • Korean Journal of Medicinal Crop Science
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    • v.4 no.4
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    • pp.283-287
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    • 1996
  • As a part of studies on the quality control for drying methods in Lycii Fructus. Dried Lycii Fructus were obtained from several treatments to examine the control of the extracts and its physical properties, and also to analyze the inorganic elements and proximate compositions. The results were summerized as follows; the changes of solid matter contents dried at $50^{\circ}C\;for\;4\;hrs\;and\;60^{\circ}C$ for 28 hrs were highest. The changes of Hunter values were 66 in lightness, 5.0 in redness and 51.3 in yellowness, respectively in treatment No. 1. And also the viscosity of treatment No. 1. was some high compared to the other treatment. The desirable drying temperature were at $50^{\circ}C$ for 2hrs in initial and at $60^{\circ}C$ for 24hrs in final temperature and it was the best conditions as a quality, economics and chemical compositions of Lycii Fructus.

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Evaluation of Seismic Performance of Prefabricated Bridge Piers with a Circular Solid Section (중실원형단면 조립식 교각의 내진 성능 평가)

  • Kim, Hyun-Ho;Shim, Chang-Su;Chung, Chul-Hun;Kim, Cheol-Hwan
    • Journal of the Earthquake Engineering Society of Korea
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    • v.11 no.3 s.55
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    • pp.23-31
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    • 2007
  • Fast bridge construction has been increasingly needed according to the changed construction environment. This paper deals with quasi-static tests on precast piers for bridge substructures. One of the most crucial aspect of the design of precast prestressed concrete bridge piers is the seismic performance. Seven precast pier elements were fabricated. The amount of prestressing bars, the prestressing force, and the location and number of the joint between segments were the main test parameters. Test results showed that the introduced axial prestress made the restoration of the deformation under small lateral displacement and minor damage. However, there was no effect of the prestress when the plastic hinge region was damaged severely due to large lateral displacement. Judging from the observed damage, the design of the joints in precast piers should be done for the first joint between the foundation and the pier segment. The amount of the necessary prestressing steel may be designed to satisfy the P-M diagram according to the service loads, not by having the same steel ratio as normal RC bridge piers. In order to satisfy the current required displacement ductility, it is necessary to have the same amount of the transverse reinforcements as RC piers. As the steel ratio increases, the energy absorption capacity increases. The number of joints showed a little influence on the energy absorption capacity.

A Study of Mechanical Properties With Variation of Heattreatments on HSLA Cast Steels Microalloyed With Nb, Ti, and V (Nb, Ti 및 V를 첨가한 HSLA 주강의 열처리 변화에 따른 기계적 특성 연구)

  • Park, Jae-Hyeon;Kim, In-Bae
    • Korean Journal of Materials Research
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    • v.10 no.11
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    • pp.760-769
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    • 2000
  • Mechanical properties of HSLA cast steels alloyed with 0.15% Nb, Ti or V were tested as variations of austenizing temperatures and tempering times. The test results are as follows. The hardness of HSLA cast steels austenized for 2hrs at 115$0^{\circ}C$ was shown the highest value regardless of alloying elements and then decreased as the temperature decreased below 110$0^{\circ}C$. The hardness of HSLA cast steels with 0.15% Ti austenized for 2 hrs at $1150^{\circ}C$ was higher than that of any other HSLA cast steels, and chich was mainly attributed to the relatively high amount of bainite, and solid solution hardening. Charpy impact energy of HSLA cast steels was comparable to the C-Mn cast steel except HSLA cast steels with 0.15% Ti austenized at 115$0^{\circ}C$. The hardness of HSLA cast steels austenized for 2 hrs at $1150^{\circ}C$ increased at a ten-minute tempering, and after that, the hardness kept almost sililar level except HSLA cast steels with 0.15% V.

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A Comparative Study on Power Tool Manufacturers' Products Spec. and Design Development Features - By the Case Study on BOSCH, BLACK&DECKER and KEYANG Electrics- (전동공구 회사의 제품사양별 디자인개발특성 비교연구 -보슈(BOSCH), 블랙앤데커(BLACK&DECKER), 계양전기 사례를 중심으로 -)

  • 채승진
    • Archives of design research
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    • v.17 no.1
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    • pp.383-392
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    • 2004
  • The power tools is the product using working power generated by electric motor. Many companies are manufacturing numerous devices. Main features of tools are included various assembled products, small, light and solid and durable enough to match several standards. Fundamental requirements for the product is excellent performance and convenience for use. The quality of them depends on the equipped motor'(s) capability, accuracy of gear and endurance against worn-out. By adapting the state-of-the-art parts, they could be used in the place from home to heavy industry broadly. They can be classified electronic drills, grinders, saws and sanders families for the household appliances. For industrial tools, bore drill, grinder, polisher, and driver drill are classified as special and high priced group. This study presents the strategy of power tool development of BOSCH, BLACK&DECKER and KEYANG. Their products were analyzed in terms of product line and product mix concept. Then they are examined by design elements, such as color, shape and material for housing. As an analysis method, the image scale parameter and criteria were applied to each company's product.

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A study on the electrodeposition of uranium using a liquid cadmium cathode at 440℃ and 500℃ (440℃와 500℃에서 액체카드뮴음극을 이용한 우라늄 전착에 관한 연구)

  • Yoon, Jong-Ho;Kim, Si-Hyung;Kim, Gha-Young;Kim, Tack-Jin;Ahn, Do-Hee;Paek, Seungwoo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.11 no.3
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    • pp.199-206
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    • 2013
  • Electrowinning process in pyroprocessing recovers U (uranium) and TRU (Trans Uranium) elements simultaneously from spent fuels using a liquid cadmium cathode (LCC). When the solubility limit of U deposits over 2.35wt% in Cd, U dendrites were formed on the LCC surface during the electrodeposition at $500^{\circ}C$. Due to the high surface area of dendritic U, the deposits were not submerged into the liquid cadmium pool but grow out of the LCC crucible. Since the U dendrites act as a solid cathode, it prevents the co-deposition of U and TRUs. In this study, the electrodeposition of U onto a LCC was carried out at 440 and $500^{\circ}C$ to compare the morphology and component of U deposits. The U deposits at $440^{\circ}C$ have a specific shape and were stacked regularly at the center of the LCC pool, while the U dendrites (i.e., ${\alpha}$-phase) at $500^{\circ}C$ were grow out of the LCC crucible. Through the microscopic observation and XRD analysis, the electrodeposits at $440^{\circ}C$, which have a round shape, were identified as an intermetallic compound such as $UCd_{11}$. It can be concluded that the LCC electrowinning operation at $440^{\circ}C$ achieves the co-recovery of U and TRU without the formation of U dendrites.

Surface state Electrons as a 2-dimensional Electron System

  • Hasegawa, Yukio
    • Proceedings of the Korean Vacuum Society Conference
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    • 2000.02a
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    • pp.156-156
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    • 2000
  • Recently, the surface electronic states have attracted much attention since their standing wave patterns created around steps, defects, and adsorbates on noble metal surfaces such as Au(111), Ag(110), and Cu(111) were observed by scanning tunneling microscopy (STM). As a typical example, a striking circular pattern of "Quantum corral" observed by Crommie, Lutz, and Eigler, covers a number of text books of quantum mechanics, demonstrating a wavy nature of electrons. After the discoveries, similar standing waves patterns have been observed on other metal and demiconductor surfaces and even on a side polane of nano-tubes. With an expectation that the surface states could be utilized as one of ideal cases for studying two dimensionakl (sD) electronic system, various properties, such as mean free path / life time of the electronic states, have been characterized based on an analysis of standing wave patterns, . for the 2D electron system, electron density is one of the most importnat parameters which determines the properties on it. One advantage of conventional 2D electron system, such as the ones realized at AlGaAs/GaAs and SiO2/Si interfaces, is their controllability of the electrondensity. It can be changed and controlled by a factor of orders through an application of voltage on the gate electrode. On the other hand, changing the leectron density of the surface-state 2D electron system is not simple. On ewqy to change the electron density of the surface-state 2D electron system is not simple. One way to change the electron density is to deposit other elements on the system. it has been known that Pd(111) surface has unoccupied surface states whose energy level is just above Fermi level. Recently, we found that by depositing Pd on Cu(111) surface, occupied surface states of Cu(111) is lifted up, crossing at Fermi level around 2ML, and approaches to the intrinsic Pd surface states with a increase in thickness. Electron density occupied in the states is thus gradually reduced by Pd deposition. Park et al. also observed a change in Fermi wave number of the surface states of Cu(111) by deposition of Xe layer on it, which suggests another possible way of changing electron density. In this talk, after a brief review of recent progress in a study of standing weaves by STM, I will discuss about how the electron density can be changed and controlled and feasibility of using the surface states for a study of 2D electron system. One of the most important advantage of the surface-state 2D electron system is that one can directly and easily access to the system with a high spatial resolution by STM/AFM.y STM/AFM.

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Effect of Screw Configurations and Process Parameters on Characteristics of Wheat Bran Extrudates (스크류 조합과 공정변수 조절에 따른 밀기울 압출물의 특성)

  • Kim, Chong-Tai;Hwang, Jae-Kwan;Cho, Sung-Ja;Kim, Chul-Jin;Kim, Hae-Sung
    • Korean Journal of Food Science and Technology
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    • v.28 no.1
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    • pp.169-178
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    • 1996
  • Target parameters such as water solubility index (WSI), intrinsic viscosity (IV), water holding capacity (WHC), oil holding capacity (OHC), soluble dietary fiber (SDF) and microstructure were investigated on three different screw configurations during twin-screw extrusion of wheat bran. WSI of raw wheat bran (RWB) was 13.7%, while that of extrudates ranged $16.3{\sim}23.2%$ when extruded using screw configurations with 5 reverse screw elements (RSE). It was found that the moisture content of RWB greatly affected WSI of extrudates. IV of wheat bran extrudates increased from 10.6 ml/g of RWB to $37.86{\sim}44.37\;ml/g$ of extrudates extruded using 3, 4 and 5 RSE, whose trend was highly related to the moisture content of RWB and the extrusion pressure. Multiplication of IV and soluble solid (SS) content exhibited good correlation $(R^2=0.85)$ with specific mechanical energy (SME). The results suggested that SS and molecular size are an important factor governed by the SME in solubilization of wheat bran. WHC increased with increasing feed rate and moisture content, while OHC decreased. SDF increased from 2.68% of RWB to $4.32{\sim}6.48%$ of extruded wheat bran, indicating the significant breakdown of cell wall components. Microstructure of the extrudates showed the distinct patterns of degradation and solubilization of cell wall structure, depending on the moisture content of RWB.

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The Change of Korean Men's Pants Design from 1962 to 1998 - Based on the Content Analysis of Magazine Advertisements and Pictorials -

  • Kwon, Hae-Sook
    • Journal of Fashion Business
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    • v.10 no.6
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    • pp.52-62
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    • 2006
  • The purpose of this study is to investigate the changes of modern Korean men's pants design from 1962 to 1998 by reviewing fashion magazine advertisements and pictorials. For theoretical study, the characteristics and the importance of apparel advertisements and the changes of modern Korean men's fashion trend were reviewed. For sample selection, first, 932 pictorials of men';s wear designs from Joongang Magazine, Shin Dong-A, Bokjangwolbo, Meot, Men's Life, WWD, and SFAA's photograph album, published from 1962 to 1998 were selected and then excluded some samples that could not clearly identify the pants design. Content analysis method was used to analyze the content of magazines and pictorials. The final samples are classified into pattern, color, length, silhouette, and existence or non-existence of turn-up. Frequency and $x^2$-test were conducted using a SAS statistics package to analyse the data. The results were as follows. ; (1) Solid pattern was the most prevailed throughout the last four decades and followed by stripe, check, the others, abstract, dot and floral. There is no significant difference in the type of men's pants pattern between each decade. (2) It showed a significant difference in colors of men's pants between decades. The colors in men's wear are divided into nine categories and the order of occurrence are as follows; multi-color is the most frequently shown and followed by brown, gray, blue, black, green, pink, yellow, and red. More various colors appeared over the period, however, multi color was the most popular in all decades but in the 60s. (3) Full length of pants style occupied more than 96% throughout all four decades. Due to the popularity of sports wear in men's fashion during the 90s, the shorts style appeared not only in sports wear and casual wear but also in suit style. (4) There is a significant difference in silhouette of men's pants between decades. The silhouette of men's pants were divided into four types and their order of occurrence are as follows; basic, baggy, fitted, and loose silhouette. Basic silhouette was the most prevailed throughout the whole four decades. (5) A significant difference was shown in the existence or non-existence of turn-up of men's pants between decades. Non-existence of turn-up of men's pants was the most prevailed throughout the whole four decades.