본 연구의 목적은 천연 소재를 이용한 자외선 차단 제품 개발의 기초 자료로 제공하는 것을 목적으로 하였다. 연구 방법은 피부미용 관련 자외선 차단제의 국내외 산업 현황과 천연 소재 연구 동향, 그리고 특허 현황을 조사하여 분석하였다. 연구 결과 자외선 차단제는 미국 시장이 전 세계의 약 21%를 차 지하는 가장 큰 시장이며 중국 시장이 급격하게 성장하고 있다. 기능성 화장품 주요 4종의 국내 생산실적 1위는 복합기능제품이며, 주름개선과 자외선 차단제, 미백의 순으로 나타났으며 세계시장 및 국내시장 모두 지속적으로 성장하고 있다. 최근 10년간 천연 자외선 차단 소재 연구동향을 조사하여 분석한 결과 황금, 홉, 감초, 핑거루트, 녹차, 야관문 추출물 등이 효능이 있으며 그 이외에도 광노화, 항산화, 항염, 항균, 미백, 주름개선 등의 효능도 있는 것으로 나타났다. 특허 등록 현황은 건수가 증가하는 추세이며 식물이나 해조류에서 성분을 확보하고 있었다. 본 연구의 결론은 향후 세계적 트렌드에 맞춰 안전하고 효능이 증명된 천연 자외선 차단 소재들을 개발해 간다면 다기능 천연 기능성 화장품 소재로 충분히 활용 가능할 것으로 전망된다.
현대사회는 반려동물을 기르는 가정이 증가하고 있다. 인간을 비롯한 반려동물도 일상 생활 속에서 피부질환의 위험에 놓여있고, 이에 따라 피부에 자극을 주지 않는 천연 세정 제품에도 큰 관심이 집중되고 있다. 천연제품이 대중화되어가고 있지만, 편리성과 즉효성을 장점으로 내세우는 일반 세제와 비누보다 천연제품의 이점을 보여주는 정확한 사례가 적다. 이를 알아보기 위해 기존에 사용되었던 세정제 제품을 직접 제작한 천연비누로 교체하였을 때의 피부변화를 실험하였다. 더 정확한 결과 값 측정을 위해 일제히 통제된 환 경에서 지정된 15마리의 실험견들을 선별하고, 유 수분 측정기와 관찰현미경을 이용해 연구를 진행하였고, 천연비누의 교체로 유분, 수분 함량은 증가하였고, 개선된 피부 상태를 확인했다.
The purpose of this study was to investigate the characteristics of macaroons prepared using natural color materials (Opuntia ficus-indica var. saboten (Re-N), mulberry leaf (Gr-N), pumpkin (Ye-N), and cocoa powder (Br-N)) and corresponding artificial food colorants (red (Re-A), yellow (Ye-A), green (Gr-A) and brown (Br-A)). The moisture content of macaroons prepared using natural color material was higher compared to the macaroons prepared using artificial food colorant. DPPH and ABTS radical scavenging activity was similar in both types of macaroons. Lightness and redness of Re-N, Gr-N, Ye-N, and Br-N macaroons were lower than Re-A, Gr-A, Ye-A and Br-A macaroons. Yellowness of Re-N was higher because of the browning reaction. The texture profile analysis revealed lower hardness when natural color powder was employed. In the sensory evaluation, overall acceptability was not significantly different between natural colored and artificial colored macaroons. As a result, macaroons with the natural color material were softer and showed higher antioxidative activity, however, organoleptic properties were not much different when compared with macaroons with artificial colors. Apparently, it is stated that more studies on the development of macaroons with more enhanced physical functionality and good taste using natural materials should be performed.
In this paper, the method of vibration analysis for calculating the natural frequency is presented. This method is a simple but exact method of calculating natural frequencies corresponding to the modes of vibration for the cantilevered composite materials conical beam. The influence of natural frequency of the cantilevered composite materials conical beam is presented. This method may be extended to stability analysis of complex structureal elements.
Theories of advanced composite structures are too difficult for such field engineers and some simple methods are necessary. In this paper, Simple method of vibration analysis is presented. This method presented in this paper is studied self-weight and other loads. The result of the 2~3 times iteration is good enough for field engineering purposes. In the case of cantilevered composite materials beams with different cross section, increase of mass near the support does not significantly affect the vibration characteristics. As a calculations of the simple method of vibration analysis for cantilevered composite materials beams with different cross section, it is noted that the result of the second cycle at the point of free end (actually 5L/6 span) is only 2.2% away from the ‘exact’ solution.
In order to prepare anode materials for high power lithium ion secondary batteries, carbon composites were fabricated with a mixture of petroleum pitch and coke (PC) and a mixture of petroleum pitch, coke, and natural graphite (PCNG). Although natural graphite has a good reversible capacity, it has disadvantages of a sharp decrease in capacity during high rate charging and potential plateaus. This may cause difficulties in perceiving the capacity variations as a function of electrical potential. The coke anodes have advantages without potential plateaus and a high rate capability, but they have a low reversible capacity. With PC anode composites, the petroleum pitch/cokes mixture at 1:4 with heat treatment at 1000 oC (PC14-1000C) showed relatively high electrochemical properties. With PC-NG anode composites, the proper graphite contents were determined at 10~30 wt.%. The composites with a given content of natural graphite and remaining content of various petroleum pitch/cokes mixtures at 1:4~4:1 mass ratios were heated at 800~1200 oC. By increasing the content of petroleum pitch, reversible capacity increased, but a high rate capability decreased. For a given composition of carbonaceous composite, the discharge rate capability improved but the reversible capacity decreased with an increase in heat treatment temperature. The carbonaceous composites fabricated with a mixture of 30 wt.% natural graphite and 70 wt.% petroleum pitch/cokes mixture at 1:4 mass ratio and heat treated at 1000 oC showed relatively high electrochemical properties, of which the reversible capacity, initial efficiency, discharge rate capability (retention of discharge capacity in 10 C/0.2 C), and charge capacity at 5 C were 330 mAh/g, 79 %, 80 %, and 60 mAh/g, respectively.
단감을 재배하는 농가에서 저장성을 향상 시킬 수 있는 값싸고 쉬운 방법을 개발하기 위해 본 연구를 수행 했다. 농가 관행 LDPE 포장재 내에 동봉할 수 있는 천연소재(대나무활성숯, 왕겨숯, 겔라이트)를 선발하여 상온과 저온환경에서 가용성 고형물 함량, 경도, 식미, 부패도, 연화도의 변화를 1주일 또는 2주일 간격으로 조사 하였다. 대나무활성숯을 동봉한 LDPE 포장 방법이 단순 LDPE 포장 방법 보다 저장성 및 품질을 을 좋게 유지하였다. 대나무활성숯을 동봉한 LDPE 포장 방법은 관행 농법 농가와 유기 농법 농가 모두에서 장기 저장 시 그리고 유통 중 온도변화 시 저장성을 향상 시킬수 있는 값싸고, 손쉬운 방법으로 활용할 수 있을 것으로 판단된다.
PURPOSES: This paper aims to give a guideline and the way to apply the advanced composite materials theory to the road structures with different cross sections to the practicing engineers. METHODS: To simple but exact method of calculating natural frequencies corresponding to the modes of vibration of road structures with different cross sections and arbitrary boundary conditions. The effect of the D22 stiffness on the natural frequency is rigorously investigated. RESULTS: Simple method of vibration analysis for calculating the natural frequency of the different cross sections is presented. CONCLUSIONS: Simple method of vibration analysis for calculating the natural frequency of the different cross sections is presented. This method is a simple but exact method of calculating natural frequencies of the road structures with different cross sections. This method is extended to be applied to two dimensional problems including composite laminated road structures.
PURPOSES: Current theories for composite structures are too difficult for design engineers for construction. The purpose of this paper is to demonstrate to the practicing engineers, how to apply the advanced composite materials theory to the road structures. METHODS: Some laminate orientations have decreasing values of D16, B16, D26 and B26 stiffnesses as the ply number increases. The plate aspect ratio considered is from 1 to 5. In order to study the effect of Mx on the equilibrium equations, two cases are considered. Mx term is considered or neglected. RESULTS: Most of the road structures have high aspect ratios, for such cases further simplification is possible by neglecting the effect of the longitudinal moment terms. CONCLUSIONS: Most of the road structures have plate aspect ratios higher than 2. It is concluded that, for all boundary conditions, neglecting the longitudinal moment(Mx) terms is acceptable if the aspect ratio (a/b) is equal to or higher than 2. This conclusion gives good guide line for design of the road structures.
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.
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.
This study was carried out to control the disease of wood-cultivated ginseng(panax ginseng) using natural materials. Four fungi spices such as Pythium ultimum, Alternaria alternata, Fusarium oxysporum and Rhizoctonia solani which caused disease of the wood-cultivated ginseng were investigated. The infection of these fungi causes symptom on roots, stems and leaves. The leaves became dry and die. The disease caused by Pythium ultimum can be prevented by using friendly environmental materials like Chamaecyparis obtuse essential oil and Wormstop. Alternaria alternata and Fusarium oxysporum might be prevented by using wormstop extracted from Neem tree(Azadirachta indica). No substance tested effectively prevents the growth of Rhizoctonia solani.
The first checklist of the North Korean insects was presented by Zhu (1969), and it included 34 species of Tortricidae. From the early 1970s to the late 1980s, the Hungarian Natural History Museum (HNHM) had conducted zoological expeditions to North Korea under cooperative scientific research agreements (Park & Lee, 1992). These expeditions added significant information to our knowledge of the fauna of North Korea, including a large numbers of Lepidoptera. Based on the entomological collection of Hungarian Natural History Museum, Budapest, we report three species of Tortricidae (Lepidoptera), Ancylis melanostigma Kuznetsov, Eucoenogenes japonica Kawabe, and Eucosma glebana (Snellen) for the first time from North Korea. Photos of adults and the genitalia of the newly recorded species are provided with brief comments on the distribution. Also taxonomic accounts for the species are given.