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        검색결과 1,794

        681.
        2012.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        For heat exchanger applications, 2-ply clad materials were fabricated by rolling of aluminum (Al) and mild steel sheets. Effects of annealing temperature on interface properties, especially on inter-layer formation and softening of strain hardened mild-steel, for Al/mild steel clad materials, were investigated. To obtain optimum annealing conditions for the Al/mild steel clad materials, annealing temperature was varied from room temperature to 600˚C. At the annealing temperature about 450˚C, an inter-layer was formed in an island-shape at the interface of the Al/mild steel clad materials; this island expanded along the interface at higher temperature. By analyzing the X-ray diffraction (XRD) peaks and the energy dispersive X-ray spectroscopy (EDX) results, it was determined that the exact chemical stoichiometry for the inter-layer was that of Fe2Al5. In some samples, an X-layer was formed between the Al and the inter-layer of Fe2Al5 at high annealing temperature of around 550˚C. The existence of an X-layer enhanced the growth of the inter-layer, which resulted in the delamination of the Al/mild-steel clad materials. Hardness tests were also performed to examine the influence of the annealing temperature on the cold deformability, which is a very important property for the deep drawing process of clad materials. The hardness value of mild steel gradually decreased with increasing annealing temperature. Especially, the value of hardness sharply decreased in the temperature range between 525˚C and 550˚C. From these results, we can conclude that the optimum annealing temperature is around 550˚C under condition of there being no X-layer creation.
        4,000원
        683.
        2012.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to develop children-friendly education materials based on food replicas for the dietary education of lower grade elementary students. Through a literature review on current dietary problems and dietary education for children, five education themes were chosen: balanced diet, seasonal food, traditional food, noodle culture, and making instant noodles. A total of 304 key food items for food replicas were selected based on the themes: six basic food groups (113 items), balanced meals (37 items), dietary habits (74 items), spring foods (13 items), summer foods (17 items), autumn foods (16 items), winter foods (11 items), Korean traditional foods (52 items), Korean native noodles (18 items), noodles from foreign countries (19 items), and making instant noodles (46 items). Next, a food replica database was developed consisting of name of the food, picture, size, ingredient, recipe, reference, and attached code. Powerpoint slides and teaching plans for all education themes were developed utilizing the food replicas in order to raise interest and understanding of serving size and intake amount. This research provides a basis for the development of food replicas as effective dietary education materials for elementary students and their use in extra-curricular activities, after school programs, community health centers, or food companies.
        4,200원
        684.
        2012.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        탄소 한외여과막 및 광촉매 혼성 수처리를 위해 관형 여과막 외부와 원통형 막 모듈 내부 사이 공간에 광촉매를 충전하였다. 광촉매는 PP (polypropylene) 구에 이산화티타늄 분말을 플라즈마 화학증착 공정으로 코팅한 것이다. 휴믹산과 카올린 모사용액을 대상으로 막오염을 최소화하기 위해 10분 주기로 10초 동안 물 역세척을 시행하였다. 기존 결과와 동일하게 휴믹산을 10 mg/L부터 2 mg/L로 변화시킴에 따라, 막오염에 의한 저항(Rf)이 감소하여 2 mg/L에서 최대 총여과부피 (VT)를 얻었다. 탁도와 휴믹산의 처리효율은 각각 98.9%와 88.7% 이상이었다. UF 및 UF + TiO2, UF + TiO2 + UV 공정의 처리 분율 결과, 광촉매 흡착과 광산화에 의해 탁도는 거의 처리되지 않았으나, 광촉매 흡착 및 광산화에 의한 휴믹산 처리 분율은 각각 2.5%, 12.3%이었다. 기존 결과와 비교하면, 분리막의 재질과 기공의 크기에 따라 광촉매 흡착과 광산화에 의한 휴믹산의 처리 분율이 다르게 나타났다. 공정이 단순화될수록 180분 운전 후 막오염 저항(Rf,180)은 증가하였고, 최종 투과선속(J180)은 소폭 감소하였다.
        4,000원
        685.
        2012.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The purpose of thi s study is to deve lop teaching materials for underachievers In e lementary Engli sh ed ucati on. Accord ing to Seoul metropolitan office of education (20 I I), the rate of underachievement has increased sharpl y when students go from primalY to secondary school. Therefore, it is necessalY to systematically teach underachi evers when they are in elementalY school. In order to develop teachi.ng materi als, a meta-analysis of the previous studies was cond ucted in the areas of underachi evers' characteri st ics and reasons, teaching ways, learning strategies and teaching contents. Moreover, a questionnaire survey for analyzing teachers' needs on teaching mate rials was conducted to elementalY school teachers. These resu lts were used as a fo undation to design the teaching materials. The major research findings are as follows: First, the developed teaching materials are expected to he lp teachers to teach underac hievers with practica l mater ia ls in the Engli sh e lementary classroom. Second, the suggested directions for developing teaching materials can gu ide teachers to develop the ir own teac hing materi als for underachi evers. Third, the integrated results of meta-ana lysis of the previous studies on teach ing underachievers help teachers to understand underac hievers better and thus construct effective teach ing strategies, teaching methods, and teaching contents.
        7,000원
        686.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to determine an authenticity of food ingredient, we used DNA barcode method by universal primers. For identification of animal food ingredients, LCO1490/HCO2198 and VF2/FISH R2 designed for amplifying cytochrome c oxidase subunit1 (CO1) region and L14724/H15915 for cytochrome b (cyt b) region on mitochondrial DNA were used. Livestock (cow, pig, goat, sheep, a horse and deer) was amplified by LCO1490/HCO 2198, VF2/FISH R2 and L14724/H15915 primers. Poultry (chicken, duck, turkey and ostrich) was amplified by LCO1490/HCO 2198 and VF2/FISH R2 primers. But, Fishes (walleye pollack, herring, codfish, blue codfish, trout, tuna and rockfish) were only amplified by VF2/FISH R2 primers. For plant food ingredients, 3 types of primers (trnH/ psbA, rpoB 1F/4R and rbcL 1F/724R) have been used an intergenic spacer, a RNA polymerase beta subunit and a ribulose bisphosphate carboxylase region on plastid, respectively. Garlic, onion, radish, green tea and spinach were amplified by trnH/psbA, rpoB 1F/4R and rbcL 1F/724R. The PCR product sizes were same by rpoB 1F/4R and rbcL 1F/724R but, the PCR product size using trnH/psbA primer was different with others for plants each. We established PCR condition and universal primer selection for 17 item's raw materials for foods and determine base sequences aim to PCR products in this study. This study can apply to determine an authenticity of foods through making an comparison between databases and base sequences in gene bank. Therefore, DNA barcode method using universal primers can be a useful for species identification techniques not only raw materials but also processed foods that are difficult to analyze by chemical analysis.
        4,000원
        687.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        유기농업에 자주 이용되는 축분퇴비와 작물잔사를 이용하여 질소무기화율을 추정하기 위한 항온실험을 수행하였다. 순무기화량은 유기자재 처리시 토양중 무기화된 질소(NH4-N + NO3-N)에서유기자재를 처리하지 않은 토양의 무기화된 질소량을 빼서 계산하였다. 담수 조건(논토양조건)에서 용출법을 이용하여 25oC에서 0, 1, 2, 3, 4, 6, 8, 16, 21주차에 무기화량을 조사하였다. 담수조건의 토양에 유기자재를 혼합한 후 지속적으로 물로 무기화된 질소를 용출하고 용출된 무기질소의 합을 이용한 무기화량을 추정하였다. 투입된 자재는 옥수수잔사, 알팔파, 수단그라스, 수수, 들깨잔사, 볏짚, 배추, 별꽃, 네마장황, 퇴비I, 퇴비II, 퇴비III, 유박, 토마토잔사, 수박잔사, 피마자박, 요소 이었고, 수행된 결과를 요약하면 다음과 같다. 1. 알팔파는 가장 높은 질소용출량을 나타내었다. 2. 자재 투입으로 토양 중 질산태 질소는 축적되지 않았다. 3. 침출수 중 암모니아태 질소의 누적량은 대부분의 유기자재에서 탄질비가 낮을수록 높은 무기화량을 보였다. 4. 볏짚과 퇴비I과 II를 제외한 대부분의 유기자재는 인산의 무기화를 증가시키지는 못하였다.
        3,000원
        688.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cosmetics using natural materials which was purchased in retail stores, distributed in Gyeonggi province(32 samples) and online through internet(24 samples) were analyzed by pesticide residues and target preservatives for assessing the safety of it. Natural or organic certifications was identified in 22 samples among 56 samples and most of them were Ecocert. Pesticide residues was detected in 3 samples among 56 samples and each compound and concentration was permethrin(0.6 mg/kg), tricyclazole(11.7 mg/kg) and malathion(0.05 mg/kg). All of it was purchased through internet. Target preservatives was detected in 13 samples among 56 samples and one of them was over the maximum allowed concentration and the rest of them were within the maximum allowed concentration of the respective preservatives. The compound which was over the maximum allowed concentration was benzoic acid and compounds which were within the maximum allowed concentration were sorbic acid, benzoic acid and methylparaben. They were all identified substances in products and the number of detected preservatives in retail stores were higher than online samples purchased through internet. As a result of this study, The method of analyzing pesticide residues and limit in cosmetics using natural materials should be set up as soon as possible and the monitoring about preservatives in cosmetics using natural materials should be conducted on continuously.
        4,000원
        689.
        2012.09 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        According to a recent government study, development and distribution of functional building materials are increasing in Korea.
        In this study, we evaluated reduction performance of formaldehyde and toluene by sorptive building materials using small-scale chamber(20L) test method for 7 days.
        According to the results of this study, 18 building materials showed that the effects of formaldehyde reduction among the 23 building materials. And the number of the building materials with respect to its ability to reduce the concentration of toluene was relatively small.
        The mean sorption rate and total amount of sorption for formaldehyde were 36.8% and 1,525.4㎍/㎡, respectively. The sorption rate and total amount of sorption for formaldehyde were in the range 1.5∼78.4% and 87.5∼3,086.0㎍/㎡, respectively.
        And the mean sorption rate and total amount of sorption for toluene were 11.6% and 1,054.4㎍/㎡, respectively. The sorption rate and total amount of sorption of toluene were in the range 0.1∼62.4% and 29.6∼6,764.0㎍/㎡, respectively.
        In most cases, the performance of the building materials with respect to its ability to reduce the concentration of pollutants has steadily decreased within 7 days.
        4,200원
        690.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed to investigate the pesticide residue of commercial medicinal plants used for food materials in the Seoul area. Multi class pesticide multiresidue methods in Korea Food Code was used to analyze 100 pesticides. Analyzed samples were 261 cases(domestic 201, imported 60), detection rate was 19.2%(domestic 20.9%, imports 13.3%). 17 pesticides were detected in fruit(chinese matrimony vine, jujube, rubus coreanus, japanese cornlian cherry, schizandra, tangerine peel), and root(cnidium, licorice, astragalus). Pesticide over Maximum Residue Limits were detected in jujube, cnidium. Frequently detected pesticides were cypermethrin, chlorpyrifos, cyhalothrin, fenvalerate, bifenthrin. More than 50% of the sample were detected two or more pesticides at the same time. Because of the variety and increase of pesticide detection in medicinal roots and fruits, continued monitoring and safety management is required.
        4,000원
        692.
        2012.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In order to improve osseointegration of dental implants with bone we studied an implant with holes inside its body to deliver bioactive materials based on a proposed patent. Bioactive materials can be selectively applied through holes to a patient according to diagnosis and the integration progress. After the bioactive material is applied, bone can grow into the holes to increase implant bonding and also enhance surface integration. In order to improve the concept and study the effect of bioactive material injection on implant integration, design optimization and integration research were undertaken utilizing the finite element method. A 2-dimensional simulation study showed that when bone grew into the holes after the bioactive material was injected, stress vertically distributed in the upper part of the implant was relieved and mild stress appeared at the opening of the injection holes. This confirmed the effect of the bioactive material and the contribution of the injection holes, but the maximum stress increased ten-fold at the opening. In order to reduce the maximum stress, the size, location, and the number of holes were varied and the effects were studied. When bioactive materials formed an interface layer between the implant and the mandible and four holes were filled with cortical and cancellous bones all the stress concentrated opposite to the loading side without holes disappeared. The stresses at the four outlets of the holes was mildly elevated but the maximum stress value was ten-fold greater compared to the case without the bioactive material.
        4,000원
        693.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Graphene is the thinnest known materials in the universe and the strongest ever measured. Graphene has emerged as an exotic material of the 21st century and received world-wide attention due to its exceptional charge transport, thermal, optical, mechanical, and adsorptive properties. Recently, graphene and its derivatives are considered promising candidates as adsorbent for H2 storage, CO2 capture, etc. and as the sensors for detecting individual gas molecule. The main purpose of this review is to comprehensive the synthesis method of graphene and to brief the adsorption behaviors of graphene and its derivatives.
        4,800원
        694.
        2012.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Hydroxyapatite (HA) is well known as a biocompatible and bioactive material. HA has been practically applied as bone graft materials in a range of medical and dental fields. In this study, two types of dense hydroxyapatite ceramics were prepared from natural bones and synthetic materials. The biocompatibility of HA ceramics for supporting osteoblast cell growth and cytotoxicity using an in vitro MG-63 cell line model were respectively evaluated. Artificial hydroxyapatite shows relative density of 93% with 1-2 μm after sintering, but a hydroxyapatite compact derived from bovine bone has low sintered density of 85% with a small content of MgO. Irrespective of the starting raw materials, both types of sintered hydroxyapatite displayed similar biocompatibility in the tests. FE-SEM observations showed that most MG-63 cells had a stellar shape and formed an intercellular matrix containing fibers on sintered HA. The cells were well attached and grown over the HA surface, indicating that there was no toxicity.
        4,000원
        695.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, effective gene extraction methods were compared to identify raw materials of processed meat products through molecular biological methods. Species specific primers were used to identify ingredients of processed foods and, as a sample, 13 kinds of processed meat products including beef, pork and chicken. According to the type of sample, 13 kinds of samples were classified into liquid type, source type and powder type. The samples were pre-treated (centrifugation) and (or) performed Whole Gene Amplification (WGA) kit for amplification of the extracted DNA. As a result, it was possible to identify the raw material of products through the centrifugation of sample 1 ml for liquid type of processed meat products. For source type of products after gene extraction, it was required to perform WGA for the identification of ingredients. For powder type products did not required any further pre-treatment and WGA. In this study, it was an opportunity to confirm the possibility of identification of raw material from the gene extraction of processed meat products and this method could be used to examine the authenticity of raw material of products.
        4,000원
        696.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
         ,  , An outbreak of Ricania sp. occurred in the Kurye, Jeonnam area in 2011. This outbreak damaged many kinds of fruit trees such as Cornus, Persimmon and Chestnut. This experiment was conducted to survey the occurrence ecology of Ricania sp. such as host plants, oviposition characters, morphological characters and life cycle, as well as to select environmental friendly control agents. Ricaina sp. host plants included 51 species such as 32 xylophytes, and 19 herbaceous plants. Ricaina sp. preferred Cornus officinalis, Diospyros kaki, Castanea crenata, Eucommia ulmoides, Styrax japonicus for oviposition. Adults laid eggs on new inner twigs with 28.8 eggs per egg-ass. Egg size was 1.24 mm(length), 0.55 mm(width) in an oval shape. Nymphs molted four times. Every nymph stage had an × shape of yellow or white beeswax around the anus. Overwintered eggs of Ricania sp. hatched from the mid May to early June. Nymphal periods were from mid May to mid August and adults appeared from mid July but spawning began in mid August. Ricania sp. damaged new twigs by oviposition and retarded growth by sucking nutrients and producing a sooty mold. Sophora and natural plant extracts were effective environmentally friendly agricultural materials used to control the nymph and adult Ricania sp. Mortality was 〉80%.
        4,000원
        697.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        친환경 유기농자재를 이용하여 잿빛곰팡이병균의 포자 발아, 균사생장 억제효과를 기내에서 조사하였다. 그 결과 잿빛곰팡이병의 균사생장 억제 효과는 Bacillus subtilis를 주성분으로 하는 제제가 100%의 억제효과를 보였으며, 그 외의 제제는 20% 이하의 범위에서 억제효과를 나타내었다. 포자발아 억제효과는 유기황 수화제 2종('BTB', '황스타')이 각각 97.7%, 92.3%으로 나타났다. 균사생장 억제와 포자 발아억제에 모두 효과를 보이는 제제는 없었다. 따라서 잿빛곰팡이병 방제를 위해서는 포자발아 억제를 위한 방제와 균사생장억제를 위한 제제를 각각 처리하여야 할 것으로 사료되었다. 아울러 사물 기생성을 가진 잿빛곰팡이병의 방제를 위해서는 잔재물에서 생장을 막는 것이 중요하며 이를 위해 예방을 전제로 한 방제의 경우 유기황을 주성분으로 하는 제제가 적용 가능할 것으로 생각된다.
        4,000원
        698.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        친환경 유기농자재를 이용하여 고추 탄저병균의 포자 발아, 균사생장 억제효과를 기내에서 조사하였다. 그 결과 균사생장 억제효과 기내검정. 탄저병의 균사생장 억제 효과는 Bacillus subtilis를 주성분으로 하는 제제가 100%의 억제효과를 보였으며, 그 외의 제제는 20~40%의 범위에서 억제효과를 나타내었다. 포자발아억제효과는 유황 수화제 2종('BTB', '황스타')이 각각 100%, 95.1%, '고려역'(95.0%), '보르스타'(99.0%), '지하부대 KM'(96.1%) 순으로 나타났다. 균사생장 억제와 포자 발아억제, 부착기 형성억제 결과를 고려하여 고추 탄저병 방제에 적용 가능한 친환경 방제제는 Bacillus subtilis, Panibacillus polymyxa 혼용제('고려역')가 가장 효과적인 것으로 판단되었으며, 예방을 전제로 한 방제의 경우 유황 수화제, 보르도액을 주성분으로 하는 제제가 적용 가능할 것으로 생각된다. 본 연구에서 선택된 제제는 고추 포장에서 탄저병 방제효과가 최종적으로 인정되면 차후 고추 탄저병 방제에 이용될 것으로 사료된다.
        4,000원
        699.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 탄소 : 질소(탄질)비가 다른 유기자재를 시용하였을 때 시기별 양분의 동태와 유기재배 수수*수단그라스의 비료이용율에 미치는 영향을 조사하였다. 처리구는 질소함량 210kg/ha 수준으로 축분퇴비, 알팔파, 유박, 화학비료를 포함하였다. 유박과 알팔파는 가장 낮은 탄질비를 나타내었고 축분퇴비는 33.7 : 1의 가장 높은 탄질비를 보였다. 축분퇴비는 시용량이 가장 많았고 이에 따라 토양내 양분농도를 증가시켰다. 탄질비가 낮은 유박과 알팔파는 축분퇴비에 비해서 질소의 무기화율을 촉진시켰다. 질소이용효율은 화학비료구에 비해서 알팔파와 유박이 약 60% 전후를 나타내었고, 축분퇴비는 20% 이하의 효율이 관찰되었다. 인산의 이용효율은 알팔파가 가장 높았고 축분퇴비가 가장 낮았다. 이에 따라 탄질비를 고려한 유기자재를 선택해서 밭토양에 시비를 해야 할 것으로 판단되었다.
        4,000원
        700.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Since 2011, proficiency test for the air dilution olfactory method started in Korea for the evaluation of the authorized odor inspection agencies’ analysis skill. For this purpose, sulfur compounds of PTMs (proficiency test materials) were made and investigated for the application to the proficiency test as a complex malodor sample. Time stability and homogeneity between samples were analysed for the PTM which was made with 10 ppm of DMS and 10 ppm of DMDS. As the results, the stability of sample concentration with GC analysis was shown around 6%RSD through the time of 6~48 hr. In addition, dilution number during the same test period appeared almost stable, less than 6%RSD in air dilution olfactory method. The reproducibility results of four laboratories showed very similar results except one lab which was caused by the elder panel characteristics.
        4,000원