Active clays, Diatomite, bentonite and zeolite were used as porous materials for fabricating hygroscopic gypsum boards. Pohang active clay and Cheolwon diatomite showed excellent characteristics of moisture adsorption and desorption. These characteristics were caused by higher surface area and pore volume of porous materials. Moisture adsorption content of gypsum board with 10% active clay(P1) was 62.0 g/m2, and moisture desorption content was 50.2 g/m2. Moisture adsorption content of gypsum board with 10% diatomite(P) was 59.5 g/m2, and moisture desorption content was 49.0 g/m2. Moisture adsorption contents of gypsum boards with porous materials were higher than that moisture desorption contents of gypsum board without porous materials. Correlation coefficient between surface area and moisture adsorption content of gypsum boards was 0.98. Also, correlation coefficient between surface area and moisture desorption content of gypsum boards was 0.97. Moisture adsorption and desorption contents were influenced by surface area and pore volume of the gypsum boards, and surface area had a larger effect on moisture adsorption and desorption.

The toxicity of Kaempferia galanga rhizome materials and constituents against Meloidogyne incognita second‐stage juveniles (J2) and eggs were examined. The active principles of K. galanga rhizome were identified as the phenylpropanoids ethyl (E)‐cinnamate (EC, 1) and ethyl (E)‐p‐methoxycinnamate (EMC, 2) by spectroscopic analysis. Results were compared with those of carbofuran, fosthiazate, and metam‐sodium. In direct‐contact mortality bioassay, EC (LC50, 0.037 mg/ml) was the most toxic constituent, followed by EMC (0.041 mg/ml). EC was more effective than carbofuran (LC50, 0.092 mg/ml) but less active than fosthiazate (0.002 mg/ml). EC, egg hatch was inhibited 100, 93, and 87% at 125, 62.5, and 31.25 μg/ml, respectively. EMC caused 100, 81, and 75% inhibition of egg hatch at 125, 62.5, and 31.25 μg/ml, respectively. The inhibition of two phenylpropanoids were similar or more inhibition to that of either carbofuran or metam‐sodium but was lower than that of fosthiazate. In contact + fumigant mortality bioassay, EC and EMC treatments resulted in 86 and c 73% mortality at 0.5 and 0.125 mg/g soil, respectively. The lethality of these phenylpropanoids was almost similar to that of either carbofuran or metam‐sodium but was lower than that of fosthiazate. In vapor‐phase mortality bioassay, EC and EMC were more effective in closed container than open containers, indicating that the mode of delivery of these compounds was, in part, a result of vapor action. K. galanga rhizome‐derived materials, merit further study as potential nematicides and hatching inhibitors for the control of M. incognita populations.

Recently, metal molding has become essential not only for automobile parts, but also mass production, and has greatly influenced production costs as well as the quality of products. Its surface has been treated by carburizing, nitriding and induction hardening, but these existing treatments cause considerable deformation and increase the expense of postprocessing after treatment; furthermore, these treatments cannot be easily applied to parts that requiring the hardening of only a certain section. This is because the treatment cannot heat the material homogeneously, nor can it heat all of it. Laser surface treatment was developed to overcome these disadvantages, and, when the laser beam is irradiated on the surface and laser speed is appropriate, the laser focal position is rapidly heated and the thermal energy of surface penetrates the material after irradiation, finally imbuing it with a new mechanical characteristic by the process of self-quenching. This research estimates the material characteristic after efficient and functional surface treatment using HPDL, which is more efficient than the existing CW Nd:YAG laser heat source. To estimate this, microstructural changes and hardness characteristics of three parts (the surface treatment part, heat affect zone, and parental material) are observed with the change of laser beam speed and surface temperature. Moreover, the depth of the hardened area is observed with the change of the laser beam speed and temperature.

In this study, the silica-based hybrid material with high barrier property was prepared by incorporating ethylene-vinyl alcohol (EVOH) copolymer, which has been utilized as packaging materials due to its superior gas permeation resistance, during sol-gel process. In preparation of this EVOH/SiO2 hybrid coating materials, the (3-glycidoxy-propyl)-trimethoxysilane (GPTMS) as a silane coupling agent was employed to promote interfacial adhesion between organic and inorganic phases. As confirmed from FT-IR analysis, the physical interaction between two phases was improved due to the increased hydrogen bonding, resulting in homogeneous microstructure with dispersion of nano-sized silica particles. However, depending on the range of content of added silane coupling agent (GPTMS), micro-phase separated microstructure in the hybrid could be observed due to insufficient interfacial attraction or possibility of polymerization reaction of epoxide ring in GPTMS. The oxygen barrier property of the mono-layer coated BOPP (biaxially oriented polypropylene) film was examined for the hybrids containing various GPTMS contents. Consequently, it is revealed that GPTMS should be used in an optimum level of content to produce the high barrier EVOH/SiO2 hybrid material with an improved optical transparency and homogeneous phase morphology.

본 연구에서는 고도정수처리를 위하여 모듈 내부와 관형 세라믹 정밀여과막 외부 사이의 공간에 입상 활성탄(GAC)을 충전한 혼성 모듈을 사용하였다. 정수 원수 중의 자연산 유기물(NOM)과 미세 무기 입자를 대체하기 위해, 휴믹산(humic acid)과 카올린(kaolin) 모사용액을 대상으로 하였다. 혼성공정에서 막오염을 최소화하고 투과선속(J)을 향상시키기 위하여 10분 주기로 10초 동안 질소 역세척을 시행하였다. 그 결과, 휴믹산의 농도가 10 mg/L부터 2 mg/L로 단계적으로 변화시킴에 따라 막오염에 의한 저항(Rf)이 감소하고 J가 증가하여 2 mg/L에서 가장 높은 총여과부피(VT)를 얻을 수 있었다. 한편, 탁도 및 UV254 흡광도의 처리효율은 각각 99.36% 및 97.19% 이상으로 우수하였으나, 휴믹산의 농도 10 mg/L에서 활성탄 주입 없이 정밀여과 단독으로 UV254 흡광도의 처리효율은 90.84%로 다소 감소하였다.

느타리버섯의 배지에 철, 고춧가루, 은행잎을 첨가하였을 때 버섯의 생육과 생리활성을 분석한 결과는 다음과 같다. 수량은 춘추 품종에 철 34.9g을 첨가하였을 때 144g으로 가장 높았고, 나머지 품종간에는 차이가 없었으며, 34.9g 및 174.5g 처리시 17.4g 처리에 비해 수량이 높은 경향이었다. 자실체와 배지에 포함된 무기물의 함량은 종류별로 차이가 있었으며, 배지중 철의 함량이 증가하여도 자실체내의 철의 함량은 0.31∼0.43mg/kg으로 거의 일정하게 유지되었다. 배지에 포함된 고춧가루의 함량이 많아질수록 자실체에 포함된 캡사이신의 함량도 많아졌으며, 수한품종에서 6mg/100g으로 가장 많이 전이되었다. 철이나 고추를 첨가한 배지에서 재배한 버섯에서 페놀성 화합물의 함량이 높게 나타났으며, 항산화력과 총 페놀성 화합물 함량, 환원력과 총페놀성 화합물 함량, 금속이온 제거능과 페놀성 화합물의 함량 간에는 서로 영향을 미치지 않는 경향이었다. Macrophage 활성화능은 수한 품종이 다른 품종에 비해 높은 경향이었다.

본 연구에서는 콘크리트포장의 단면보수용 복합재료 8개(초속경시멘트계열 : RCC 3종, 폴리머시멘트계열 : PCC 2종, 폴리머계열 : PC 3종)에 대해 역학적인 특성 및 내구성 실험을 수행하였다. 역학적 특성으로서 응결시간, 압축강도, 휨강도, 탄성계수, 경화수축에 대해 실험하였고, 내구성으로서 동탄성계수 및 동결융해 후 부착강도, 흡수율, 내화학성, 자외선 노출 실험을 수행하였다. 탄성계수는 RCC〉PCC〉PC계열의 순으로 나타나서 폴리머가 사용되면서 연성의 특성을 보였다. 초기 재령에서의 폴리머 콘크리트의 경화수축이 상대적으로 큰 것으로 관찰되었지만 재령 28일에서는 다소 안정된 결과를 보였다. 상대동탄성계수, 흡수율, 10% CaCl2와 10% Na2SO4의 화학용액을 사용한 내화학성 실험결과 PC계열, PCC계열, RCC계열 순으로 저항성이 우수한 것으로 나타났다. 200~300회 동결융해 이후의 부착강도 실험결과 PC-2를 제외하고는 모두 1.3MPa 이상을 확보하였고, PC 및 PCC 제품의 부착강도가 RCC 제품보다 전체적인 면에서 우수한 것으로 나타났다. 또한 시편을 500시간동안 자외선 노출시험 결과 모든 패치재료 시편에서 균열 및 표면 결함 등이 발견되지 않아 PC 및 PCC 제품의 자외선에 대한 내구성이 확보됨을 확인하였다.

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.