Since the 1970's, UNESCO and ICOMOS have adopted or emphasized on the principles of historic preservation. One of them is what to require a repair have not to be repaired beyond the limits of the features and techniques to have been born in those days of establishment. On the premise, this paper is to examine the materials and technique of lime plaster work in order for roof ridge, and for bond paste of stones and bricks in government constructions in the late of Joseon dynasty(17〜19c). The result of this examination will come up with a basic conformity in the case of repairing the building established in the late of Joseon dynasty. This paper is carried out for the proper repair and restoration of architectural cultural properties. Construction reports and other documents in those days are examined for the study. Following conclusions have been reached through the study. The components of old plaster mixtures which agglutinate stones each other were quicklime, perilla oil, and paper fiber. The components of old plaster mixtures which point joint of black bricks consisted of slaked lime, perilla oil, paper fiber, and cereal starch. These components were the same as coat surface of roof ridges. In the case of times, one of the following sand, white clay, sap of boiled elm bark was added to these components for the purpose of high efficiency. These materials and techniques which applied to plaster work of those buildings had developed in the process of making royal tombs. But these materials and techniques were quite different from the present.
The friction characteristics of automotive brake friction materials that contained different ceramic content were investigated. Several kinds of raw materials, such as resin-based binder, reinforcing fiber, friction restraint, abrasive, and filling materials were mixed, pressed, and heated in order to make the brake friction materials. The contents of SiC and BaSO4 changed from 5 vol% to 20 vol%, respectively. In addition to this, the content of Al2O3 adjusted from 1 vol% to 16 vol%. The surface morphology of the SiC containing sample appeared rough while more debris was observed when the contents of SiC increased. This implies that the SiC containing brake composite was not adequate for the automobile. However, the relatively smooth surface was observed in samples that contained the Al2O3. But the roughness was low with a content of 11 vol% Al2O3 compared to the other samples. This is consistent with the abrasive properties of the samples. In the case of BaSO4 containing samples, the smoothes surface was observed in the contents of 15 vol% BaSO4. Thus, it was concluded that the 11 vol% Al2O3 and 15 vol% BaSO4 containing composite would be the optimum content for the brake composite. Similar to the results of the surface morphology, the abrasion resistance consistently decreased when the content of SiC increased. On the contrary, the sample that contained 11 vol% Al2O3 and 15 vol% BaSO4 showed the highest abrasion resistance compared to the other samples.
The spot weldability of dissimilar metal joints between stainless steels (AISI316) and interstitial free (IF) steels were investigated. This study was aimed to determine the spot welding parameters for a dissimilar metal joint and to evaluate the dissimilar metal joint's weldability, including its welding nugget shape, tensileshear strength, hardness, and microstructure. The fracture surface was investigated by using a Scanning Electron Microscopy (SEM). The experimental results showed that the shape of nugget was asymmetric, in which the fusion zone of the STS316 sheet was larger due to the higher bulk-resistance. The microstructure of the fusion zone was fully martensite. In order to evaluate the microstructure further, dilution of stainless steels were calculated and imposed onto the Schaeffler diagram. The predicted microstructure from the Schaeffler diagram was martensite. In order to confirm the predicted microstructure, XRD measurements were carried out. The results showed that that initial weld nugget was composed of austenite and martensite.
[ Cf/C-Cu ]composites were fabricated by infiltrating molten Cu into different Cf/C preforms prepared by chemical vapor infiltration, resin impregnation and carbonization. The microstructure and properties of the composites were investigated. The results show that Cu in the composites filled the pores and showed network-like distribution. Compared with homemade J204 brush material and certain grade pantograph slider from abroad, the composites have higher flexural strength and better electrical conductivity. The friction and wear properties of the composites are better than that of J204, and closed to that of the abroad material.
참외 보온부직포 종류가 참외의 생육 및 수량에 미치는 영향을 검토하기 위하여 뚝심토좌호박 오복꿀 참외를 접목하여 정식 전부터 MD부직포, PE부직포 처리구와 대조구인 관행 12온스를 4월 25일까지 덮어서 재배하였다. 2009년 2월 6일 17시부터 익일 08시까지 야간 평균 온도의 일변화를 조사한 결과, 관행 12온스 부직포는 13.1℃였으나 MD솜 부직포 처리구는 14.7℃, PE솜 부직포 처리구는 13.3℃로 관행 12온스 부직포에 비하여 PE솜 부직포 처리구에서는 비슷하였으나 MD솜 부직포 처리구에서 1.6℃ 더 높았다. 정식 30일 후 참외의 초기 생육은 관행처리구에 비하여 MD솜 부직포 처리구에서 온도가 높아 활착이 빨라 초장이 길고 잎이 커 초기생육이 우수하였다. 참외 첫 수확은 관행 처리구에서는 정식 89일후에 수확하였으나 PE솜 부직포 처리구는 88일후, MD솜 부직포 처리구는 78일후 수확하였다. 따라서 첫 수확은 관행처리구에 비하여 MD솜 부직포 처리구에서 11일 단축되었다. 관행처리구에 비하여 MD솜 부직포 처리구에서 과중이 무겁고 당도가 높고 과피색도가 우수하고 상품과율이 높았다. 수량비율은 관행 및 PE솜 부직포 처리구에서 초기, 중기 및 후기가 4:3:3으로 비슷하였으나 MD솜 부직포 처리구에서는 초기, 중기 및 후기의 비율이 5:3:2로 특히 초기수량이 많았다. 10a당 총수량은 관행 처리구의 1,844kg에 비하여 PE솜 부직포 처리구는 큰 차이가 없었으나 MD솜 부직포 처리구에서는 9% 증가하였다.
The toxicity of Kaempferia galanga rhizome-derived methanol extract (RME), powder (RP) and steam distillate (RSD) to Meloidogyne incognita second-stage juveniles (J2) and eggs and their effects on Lycopersicon esculentum germination and growth were examined in vitro and in pot experiments. Results were compared with those of three nematicides. In contact+fumigant bioassays with J2, RME applied at 1, 0.5 and 0.25mg/g soil exhibited 92, 88, and 73% mortality, respectively. The lethality of RME was almost similar to that of carbofuran but lower than that of either fosthiazate or metam-sodium. RSD and RP were less active than RME. In vapor-phase mortality bioassayswith J2, the test materials were effective in closed container than in open one, indicating that mode of delivery was, in part, a result of vapor action. RME, RSD, and fosthiazate treatments resulted in 91, 100, and 95% inhibition of egg hatch at 250μg/ml and 82, 88, and 81% inhibition of egg hatch at 100μg/ml, respectively. In filter-paper bioassays with L. esculentum seed at 8.8μg/cm2, RME and RP did not cause germination inhibition, while RSD and fosthiazate treatments resulted in 84 and 13% germination inhibition. In pot tests, RME and RSD applied at 8mg/g soil reduced galling caused by M. incognita significantly and fosthiazate at 0.02mg/g soil reduced galling completely. Rhizome materials did not cause any adverse effect on growth of L. esculentum, while fosthiazate application caused significantly reduced root weight. K. galanga rhizome-derived materials, particularly methanol extract, merit further study as potential nematicides and hatching inhibitors for the control of M. incognita populations as fumigants with contact action.
This paper considers a six sigma project for reducing the cost copper of the cable materials in a electric wire company. The project follows a disciplined process of five macro phases: define, measure, analyze, improve, and control (DMAIC). A process map is used to identify process input variables. Three key process input variables are selected by using an input variables are selected by using an input variable evaluation table: large cable, plating, and a twisted pair. DOE is utilized for finding the optimal process conditions of the three key process input variables. The implementing result of this six sigma project is enable for reducing of the 2.8% copper materials.
In this study, the structural stability of stone pagoda in Korea is evaluated with regard to the contact characteristics between stone blocks and a method for restoring the static stability of the stone pagoda by increasing the friction coefficient between stone blocks are proposed. Existing steel insertions, which are used for a temporary retrofitting method, bring about not only decoloration on the surface due to its corrosion but also stress concentration in stone blocks which may end up fracturing blocks. In order to replace the stiff insertions such as iron with ductile materials, lead or tin, experirnental test is conducted for identifying the friction characteristics of stone blocks without/with various types of insertions and the results indicated that a ductile compound metal insertion brought about the increase of the friction coefficients when compared to the existing iron insertion.
We proposed the new nano-carbon ball (NCB) materials for eliminating the total volatile organic compounds(TVOCs) from the felt which is built in the car. The concentrations of acetaldehyde and formaldehyde of the original felts were varied upon the different production lots. Acetaldehyde in the felt can be eliminated to target level(0.2μg) after introducing 0.5 wt% of NCB into the felt. Detector tube method for analyzing formaldehyde gas was more accurate than HPLC method. Formaldehyde can be eliminated to target level (64 ppb) after introducing 0.5 wt% of NCB into the felt. We also found that TVOC can be reduced to target level (0.32μg) after introducing 2.0 wt% of NCB. Upon introducing small amounts of NCB into the felt, it was possible that the level of formaldehyde, acetaldehyde and TVOC formed from the felts can be reduced to the target level. We also suggest the effective analyzing method of TVOCs.
In order to investigate the effect of rapid solidification on the microstructure and the mechanical properties of Al-Zn-Mg system alloys, water atomization was carried out, since the water atomization beared the highest solidification rate among the atomization processes. The as atomized alloy powders consisted of fine grains less than 4 in diameter, and the second particles were not detected on XRD. The microstructure as solidified was maintained even after the spark plasma sintering at the heating rate of 50 K/min. On the other hand, lower rate of 20 K/min induced a formation of particles, resulting in strengthening of the matrix. The density was almost constant at the temperature above 698K. The sintering temperature above 698K had no effect on the strength of the sintered materials.
온실단지 내에서 발생되는 폐영농자재의 효율적인 관리방안을 제시하기 위한 목적으로 시설농업용 폐영농자재의 관리 실태를 조사하여 검토하였다. 조사 결과를 요약하면 다음과 같다.
현재 국내에서 발생되는 영농폐기물은 아직 생활쓰레기와 같이 취급되고 있었고, 일부 영농폐기물에 대한 자료는 별도로 관리되고 있었지만 공급량에 대한 정보가 전혀 없는 등 다소 신뢰도가 떨어지는 것을 알 수 있었다. 농촌지역에 보급되는 영농자재의 경우, 개인이 필요에 따라 수시로 구입하는 등 관리 및 조사가 용이하지는 않지만, 지역농협과 농업기술관리센터 등을 적극 활용하여 영농자재의 공급에서부터 수거, 재활용 및 처리단계까지 투명하게 관리할 수 있는 시스템의 도입이 절실히 필요한 것으로 나타났다. 그리고 영농자재도 재활용이 가능한 친환경 자재의 개발도 적극 도입하여야 할 것으로 판단되었다. 특히 공동 집하장의 경우, 재정지원으로 그칠 것이 아니라 재정지원은 물론 작목반, 마을 단위 또는 지자체별로 영농폐기물에 대한 인식을 지역 주민들을 대상으로 적극적으로 홍보 및 교육 등을 실시하여 지역주민이 그 지역의 환경지킴이 역할을 할 수 있도록 하여야 할 것으로 판단되었다.
Carbon blacks could be used as the filler for the electromagnetic interference (EMI) shielding. The poly vinyl alcohol (PVA) and polyvinylidene fluoride (PVDF) were used as the matrix for the carbon black fillers. Porous carbon blacks were prepared by CO2 activation. The activation was performed by treating the carbon blacks in CO2 to different degrees of burnoff. During the activation, the enlargement of pore diameters, and development of microporous and mesoporous structures were introduced in the carbon blacks, resulting in an increase of extremely large specific surface areas. The porosity of carbon blacks was an increasing function of the degree of burn-off. The surface area increased from 80 m2/g to 1142 m2/g and the total pore volume increased from 0.14073 cc·g-1 to 0.9343 cc·g-1. Also, the C=O functional group characterized by aldehydes, ketones, carboxylic acids and esters was enhanced during the activation process. The EMI shielding effectiveness (SE) of raw N330 carbon blacks filled with PVA was about 1 dB and those of the activated carbon blacks increased to the values between 6 and 9 dB. The EMI SE of raw N330 carbon blacks filled with PVDF was about 7 dB and the EMI SE increased to the range from 11 to 15 dB by the activation.
중국어 병음은 초급 단계의 중국어 교육에서 반드시 필요한 중요 도구로 그 중요성은 이미 중국어 교육학계에서 중요하게 인식되고 있으며 나날이 높은 관심과 중시를 받고 있다. 초급 중국어 교재에서는 어떻게 병음을 표기하느냐 하는 문제에 직면하게 된다. 본문에서는 초급 중국어 교재의 병음 표기와 단어를 기준으로 하여 띄어쓰기 하는 分詞連寫에 대하여 토론하고자 한다. 8권의 초급 중국어 교재의 병음 표기 상황을 대비 분석하고 이 교재들의 병음 표기와 《汉语拼音正词法基本规则》의 보편적인 차이와 개별적 차이 및 각 교재 내부의 불일치 현상에 대해서 연구하였다. 초급 중국어 교재의 편찬에서 병음 표기의 총체적인 원칙에 대해 3가지 의견을 제시하고, 또한 구체적인 分詞連寫에 대하여 6가지 의견을 제시하였다.
차선의 밝기를 나타내는 반사성능은 교통량, 도색 후 경과시간, 차선재료, 색상 등에 따라 지역별로 차이가 발생한다. 본 연구에서는 고속도로에서 조사된 차선 성능의 자료를 바탕으로 교통량과 차선의 공용수명을 독립변수로 하고 차선의 성능을 종속변수로 하는 회귀식을 산정하였다. 전국의 고속도로를 대상으로 모바일 차선반사 성능 차량을 사용하여 2005~2006년의 2년동안 3개월 간격으로 차선의 성능을 추적 조사하였다. 축적된 DB에는 차선의 성능뿐 아니라 차선의 재료, 색상, 기하구조, 교통량, 도색시기 등이 포함되어 있다. 본 연구에서 추적 조사된 차선성능을 기초로하여 다양한 환경에서의 차선재료의 성능을 비교 분석하여 여러 인자에 의한 차선성능 곡선을 도출하였다. 차선성능 곡선을 통해 지역별 교통량과 도색 이후의 시간의 경과에 따른 차선의 성능을 예측할 수 있었다. 선형함수, 로그함수, 지수함수, 음지수함수 등을 이용하여 차선의 성능을 나타내는 회귀식과 변동을 추정한 후, 결정계수가 가장 높고, 현장측정치와 가장 유사한 모형을 차선의 성능 예측모형으로 결정하였다. 현장조사 결과와의 검증결과, 차선성능 예측 모델은 90% 신뢰도에서 유의함을 볼 수 있었고, 특히 누적 교통량의 증가에 따라 현장 데이터와 높은 연관성을 보여주었다. 따라서 본 방법론에 의한 차선수명 예측 모델을 통해 차선의 공용수명과 잔존수명을 예측하여 도색시기를 결정할 수 있다.
이 연구에서는 과학탐구공동체 구성을 위한 잠재적인 학습 자료로서 자연사박물관의 전시물의 교육적 잠재성을 탐색해보고자 한다. 과학 탐구공동체는 과학적 지식의 습득과 과학 방법의 학습으로 연결되는 과학실습의 한 형태로 제안하였다. 공동체 학습은 주변에서 접하게 되는 과학-기술-사회적인 이슈들을 통해 이루어질 수 있다. 자연사 박물관 전시가 이러한 사회과학적인 이슈들을 포함하고 있다면 이는 자연사박물관의 과학탐구공동체로의 가능성에 대해 고려해 볼 수 있음을 전제로 하였다. 이런 맥락에서 본 연구는 자연사박물관 전시의 사회과학적 학습 자료 잠재성을 탐색하였다. 구체적으로 사회과학적 소재로서 적용 가능한 지진' 학습의 과학탐구공동체 구현을 위해, 첫째 미국 뉴욕시의 미국 자연사박물관과 워싱턴 D.C.의 스미소니언 미국국립자연사박물관의 지진 관련 전시물과 지구과학 교육과정과의 연관성을 분석하였다. 둘째, 두 박물관의 관계자와 인터뷰하여 이와 관련한 박물관의 교육적 의도와 노력을 알아보았다. 마지막으로 과학탐구공동체 구현을 위한 주제와 관련된 자연사 박물관 전시물의 특징을 탐색적으로 분석하였다. 이 연구에서 조사한 박물관의 전시는 교육과정과 관련하여 사회과학적 소재인 '지진'의 다양하고 실제적인 사례와 사건에 관한 풍부한 자료를 제공하고 있었다. 대상 박물관은 지역적 흥미와 사회과학적 이슈와의 연관성에 초점을 맞추어 박물관의 교육적 목적을 달성하고자 했음을 알았다. 지진이란 주제를 관람객에게 적절하도록 하기 위해 전시특성에 있어 원자료나 상호작용적 매체를 이용하여 살아있는 경험의 전달을 강조되고 있음을 알아내었다.
Porous carbon materials synthesized from various plant derived precursors i.e. seeds of [Castor (Ricinus communis), Soap nut (Sapindus sp.), Cashew-nut (Semecarpus anacardium), Jack fruit (Artocarpus heterophyllus), Safflower (Carthamus tinctorius), Ambadi (Crotolaria juncea), Neem (Azadirachta indica), Bitter Almond (Prunus amygdalus), Sesamum (Sisamum indicum), Date-palm (Phoenix dactylifera),Canola (Brassica napus), Sunflower (Helianthus annulus)] and fibrous materials from [Corn stem- (Zea mays), Rice straw (Oryza sativa), Bamboo (Bombax bambusa) and Coconut fibers (Cocos nucifera)] were screened to make supercapacitor in 5M KOH solution. Carbon material obtained from Jack fruit seeds (92.0 F/g), Rice straw (83.0 F/g), Soap nut seeds (54.0 F/g), Castor seeds (44.34 F/g) and Bamboo (40.0 F/g) gave high capacitance value as compared to others. The magnitude of capacitance value was found to be inversely proportional to the scan rate of measurement. It is suggested that carbon material should possess large surface area and small pore size to get better value of capacitor. Moreover, the structure of carbon materials should be such that majority of pores are in the plane parallel to the plane of electrode and surface is fluffy like cotton ball.