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        검색결과 38

        1.
        2025.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        10년 동안 경남 진주에서 수행된 야외 노출 시험은 실외 접지 환경(H4)에서 Alkaline Copper Quaternary(ACQ)로 방부 처리된 화이트 스프루스 (Picea glauca)의 사용 가능성을 보여주었으나, 10년이 경과하면서 일부 목재 시편에서 목재 부후균에 의한 가해가 관찰되었다. 부후 원인을 종합적으로 평가하기 위해 야외 노출 시험을 종료한 후 목재 시편들의 부후 상태를 조사하였으며 또한 목재 시편 내 방부제 유효 성분의 보유량 및 침윤도를 측정하였다. 스프루스 방부목의 약제 보유량은 국내 방부목 품질 기준(보유량: 5.2kg/m3 이상)을 충족하였으며, 변재 부위는 대부분 균일한 방부 처리를 보였다. 그러나 심재의 경우 자상 처리에도 불구하고 국내 방부목 품질 기준에서 규정하고 있는 최소 침윤 깊이인 8 mm를 충족하지 못하였다. 대부분의 목재 부후는 할렬의 발생에 의해 방부 처리되지 않은 심재의 미처리 부위가 노출됨에 의해 발생하였으며, 토양과 접한 지접부에서 할렬 발생이 다른 부위에 비해 상대적으로 많았는데, 이는 지상부나 지하부에 비해 수분의 이동이 용이하여 목재의 수축과 팽창 발생이 용이하기 때문인 것으로 판단된다. 이상의 결과로부터 H4에서 스프루스 방부목은 자상 처리를 하더라도 방부제가 깊이 침투되지 않는 심재의 특성 때문에 10년 이상의 사용 안전성을 요구하는 산업적인 용도로는 적합하지 않다고 할 수 있다.
        4,000원
        2.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Phosphorus is an essential and irreplaceable element for all living organisms and its resource is limited. Significant amount of used phosphorus is collected in sewage treatment plant as sludge. Sludge ash after incineration contains about 10% of phosphorus in dry mass basis, which is comparable to phosphate rocks, and it is an important source of phosphorus recovery. Acid and alkali were used to leach phosphorus from sludge ash and compared for their leaching kinetics and performance. Phosphorus leaching by NaOH was fast and 0.2 N and 2 N NaOH leached 49% and 56% of the total phosphorus in the sludge ash at the L/S ratio of 100. Phosphorus leaching by sulphuric acid and hydrochloric were very fast and most of the phosphorus was leached in 5 minutes. In case of sulphuric acid 95% of the total phosphorus in the sludge ash was leached by 0.2 N at the L/S ratio of 100 and 93% was leached by 1 N at the L/S ratio of 10. 1 N hydrochloric acid leached 99% of the total phosphorus at the L/S ratio of 10. The results showed acids were more effective than alkali for phosphorus leaching from sludge ash and hydrochloric acid leached more phosphorus than sulphuric acid.
        4,000원
        3.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Physicochemical and sensory properties of puffed rice snack containing various levels (0%, 50%, 100%) of alkali-cooked brown rice were examined. To prepare alkali-cooked rice, brown rice was cooked in boiling 2% Ca(OH)2solution for 5 min, steeped for 3 h, and dried at 50oC for 18 h. Alkali-cooked rice showed a higher degree ofexpansion than that of untreated rice after puffing. Although moisture content, enzyme susceptible starch (ESS), anddensity of puffed rice snack decreased with increasing amounts of the alkali-cooked rice replacement, calcium con-tent increased because of the absorption of calcium during alkaline processing. The puffed rice snack had a darkercolor as the level of replacement with alkali-cooked rice increased. A sensory test revealed that puffed rice snackreplaced with 50% of alkali-cooked rice had no significant differences in color and sensory attributes from those ofthe control. These results indicate that fortification of calcium could be achieved by partial replacement of alkali-cooked rice without any detrimental effects on the quality of puffed rice snack.
        3,000원
        4.
        2009.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Ti scaffolds with a three-dimensional porous structure were successfully fabricated using powder metallurgy and modified rapid prototyping (RP) process. The fabricated Ti scaffolds showed a highly porous structure with interconnected pores. The porosity and pore size of the scaffolds were in the range of 66~72% and 300~400 μm, respectively. The sintering of the fabricated scaffolds under the vacuum caused the Ti particles to bond to each other. The strength of the scaffolds depended on the layering patterns. The compressive strength of the scaffolds ranged from 15 MPa to 52 MPa according to the scaffolds' architecture. The alkali treatment of the fabricated scaffolds in an aqueous NaOH solution was shown to be effective in improving the bioactivity. The surface of the alkali-treated Ti scaffolds had a nano-sized fibre-like structure. The modified surface showed a good apatite forming ability. The apatite was formed on the surface of the alkali treated Ti scaffolds within 1 day. The thickness of the apatite increased when the soaking time in a simulated body fluid (SBF) solution increased. It is expected that the surface modification of Ti scaffolds by alkali treatment could be effective in forming apatites in vivo and can subsequently enhance bone formation.
        4,000원
        5.
        1999.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        침엽수와 활엽수 펄프내의 리그닌(lignin) 제거 효과를 개선하기 위해 호알칼리성 균류인 Cephalospotium sp. RYM-202의 xylanase를 표백 전처리하고 이에 의한 펄프의 표백 증진 효과를 조사하였다. 두 종류의 펄프 모두 50℃에서 효소반응을 수행하였을 때 펄프내 xylan의 가수분해가 가장 높게 나타났다. 펄프내 xylan의 가수분해를 위한 효소의 최적 pH는 8.0이었으며, pH 9.0에서도 최대활성의 90%
        4,000원
        6.
        1998.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        라면 제조에 있어서 알카리제의 첨가가 라면의 조직감과 관능적 특성에 미치는 영향을 검토하기 위하여 알카리제의 조성을 달리하여 소맥분에 대하여 0.5%를 사용하여 라면을 제조한 뒤 조리시험, 면의 조직 특성을 측정하고 관능검사를 평가하였다. 알카리제를 첨가하여 제조한 라면의 층밀림 압출력은 시료 A(potassium carbonate 64%, sodium carbonate 14%, sodium pyrophosphate 2% and sodium metaphosphate 20%)가 12.80(kgf)로 가장 높게 나타났으며, 표준 시료 E는 가장 작은 수치인 5.34(kgf)로 측정되었다. 경도도 시료 A가 18.57(kgf)로 가장 높게 나타났으며, 표준 시료 E는 11.23(kgf)으로 측정되었다. 시료 A로 제조한 라면의 무게 증가는 표준 시료 E보다 높게 나타났다. 반면에 부피 증가는 오히려 낮게 나타났으며 시료 A가 가장 낮은 수치를 보였다. 용출양의 차이는 모든 시료가 35~38%의 범위를 나타낸 반면 표준 시료 E는 70%로 나타나 시료 A보다 2배 정도 많게 증가하는 현상을 보였다. 요오드 정색도는 모든 시료가 2.10~2.20으로 유사하게 나타났다. 관능검사 결과는 시료 A와 B(potassium carbonate 31%, sodium carbonate 39%, sodium pyrophosphate 1%, sodium metaphosphate 15%, sodium polyphosphate 8%, sodium phosphate monobasic 4% and sodium phosphate basic 2%)가 각각 4.4, 4.2로 비교적 좋은 점수를 얻었으며, 그 다음이 시료 C(potassium carbonate 60%, sodium carbonate 33% and sodium pyrophosphate 7%)와 D(potasaum carnate 44%, sodium carbonate 27%, sodium metaphosphate 27% and sodium polyphosphate 2%)로 각각 3.8, 3.7을 얻었다. 반면 표준 시료 E는 2.8로 저조한 결과를 얻었다. 이 결과에서 알 수 있듯이 라면 제조시 알카리제의 조성 비율은 시료 A의 조성으로 하여 사용하면 라면의 품질 향상 효과가 크게 나타난다고 할 수 있겠다.
        4,000원
        8.
        1995.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Several kinds of coagulants such as aluminum sulfate, PAC, PASS are being used to treat drinking water resulting in residual aluminum ions in the water. Recently, it has been reported that high intake of aluminum ion may cause neurological dieseases such as Alzheimer's diesease and presenile dementia. Because of the possible adverse effect, WHO and EEC recommand to regulate residual aluminum. The autorities in Korea also has plan of regulating residual alunimum from 1995. But there is not enough information about the range of residual aluminum ion concentration when the aluminum sulfate, PAC or PASS has been used as a coagulant. Therefore the study has been conducted to find out the range of residual aluminum ion concentration after using aluminum sulfate, PAC, and PASS. Furthermore the effect of turbidity and alkalinity have been investigated. The experimental results are summarized as; 1. Most of the residual aluminum ion concentrations were within $10^{-6}$ and $10^{-5}mole/l$. Three coagulants have not showed any considerable difference in the residual aluminum concentration up to 50 NTU. However PAC has showed the least residual aluminum in high turbidity water over 100 NTU. 2. The low alkalinity water having 25mg/l as $CaCO_3$ has showed less residual aluminum than the water having 50mg/l alkalinity. However, the difference was not significcant. 3. Even the lowest residual aluminum concentration was over 0.05mg/l. Therefore the process to reduce residual aluminum would be necessary in water treatment plants.
        4,200원
        9.
        1995.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Conventional alkaline catalytic procedure, including sodium methoxide-methanol N, N, N', N'-tetramethyl guanidine-methanol, and acid-catalytic methods of BF3-methanol and HCI-methanol, have been applied for preparing methyl esters from the triacylglycerols of Trichosanthes kirilowiil seeds containing conjugated trienoic acids. The alkaline catalytic methods produce the methyl esters quantitatively without isomerization of the conjugated trienoic acids, but the acid-catalytic ones destroy almost the molecules of conjugated trienoic acids during transesterification of the triacylglycerols although the molar ratios of monoenoic and dienoic acids (non-conjugated) to saturated acids are in good agreement with those obtained from the alkaline methods.
        4,000원
        10.
        1994.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        본 연구는 Lithium Alumino Silicate 기본계에 핵형성제로 TiO2와 ZrO2를 사용하여 기본유리를 제조하고 열처리에 따른 β-quartz고용체의 미결정 형성과정을 분석하였다. 또한 β-quartz고용체의 형성에 따른 열적 특성과 광학적 특성을 비교하였다. 그 결과, 기본 유리의 열팽창 계수는 45~ 55 × 10-7 cm/˚C였으며, 결정화 시편의 열팽창 계수는 -8~ +8 × 10-7cm/˚C (25˚C ~ 525˚C)였다. 900˚C이하에서 열처리된 Glass Cermics의 결정은 β-quartz 고용체가 형성되었고, 결정의 크기가 0.21μ m를 초과하지 않았으며, 최고의 투광도는 80%이상을 나타냈다. RO성분을 MgO와 ZnO를 사용한 경우보다 MgO 단독으로 사용한 시편을 결정입자의 크기가 온도에 의존하지 않고 일정함을 나타냈으며, ZnO의경우는 입자의 크기가 최소값(0.18μ m)을 보이며 온도의존성이 크게 나타냈다.
        4,000원
        11.
        1989.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Coldwell alkaline complex adjacent to the north of Lake Superior in Ontario, Canada is an isolated plutonic body composed chiefly of syenite and gabbros and Archean metamorphic rocks intruded by above mentioned igneous rocks. A pegmatite swarm is developed in olivine gabbro, a member of the complex. Zonal distribution is found in most of pegmatites and is composed of three zones, that is, leucocratic fine-grained zone of anorthosite, melanocratic fine-grained zone of gabbronorite and pyroxenite and coarse-grained zone of gabbronorite. The mean grain size of the rock forming minerals in fine-grained zone is 0.27㎜ and that of coarse-grained zone 10.4㎜. An content of most plagioclases is in the range from An50 to An70 indicating that the pegmatite is mafic pegmatite. In a grain of plagioclase, An content decreases gradually from core to margin. Paragenetic sequence of main minerals in pegmatite is plagioclase, olivine, pyroxene, hornblende, biotite and opaque mineral from the earlier stage. Mineralogy in pegmatite is similar to that of the country rock, so it can be classified as simple and pure pegmatite. Fine-grained zone might be formed by rapid crystallization with high viscosity caused by rapid reduction in P_(H₂O) when coexisting vapor phase is suddenly released and raising the sotidus and liquidus temperatures abruptly. Coarse-grained zone is probably formed by high diffusion rate and low viscosity caused by depolymerization, formation of aqueous phase and decrease of solidus temperature. The rate of increase in viscosity caused by cooling of magma from the magmatic stage and high content of SiO₂ is ignorable compared with the rate of decrease in viscosity caused by concentration of water.
        4,500원
        13.
        1988.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to investigate the amino acid and fatty acid content in Thuja biotae water extract treated with alkaline, it was performed. There are 16 kinds of different amino acid and 20 kinds of different fatty acid in Thuja biotae water extract. An aspartic acid was contained 52% and proline was contained 10%, particulary, r-aminobutyric acid was analysed. Essential fatty acids; linoleic acid, linolenic acid and arachidonic acid were cotained a lot amount. There are 11 different unknown materials which were identified by GC-MS spectrum, such as N-[(4α,5α)-cholestan-4-yl]-acetamide; 22,26-Epithio-furost-5-en-3-ol; 2-Methyl-6-(4-methyl-3-cyclohexen-1-yl)-4-heptanone; 3,12,14-Tris(acetyloxy)-pregnane-15,20-dione;22-Methyl-26-thio-furost-5-en-3-ol; 7-Ethenyl-1,2,3,4,4a,4b,5,6,7,9,10,10a-dodecahydro-1,4a,7-trimethyl-1-phenanthrene carboxyaldehyde; Methoxyiminopro-panedioic acid; 13-Methyl-13-β-Methyl-13-vinyl-dodecaarp-7-en-3-3-ol; 22-Methyl-26-thio-furost-6-methyl-3-ol; 5α-Androstane-2,11-dione; 9-Methyl-heptadecanoic acid.
        4,000원
        14.
        1975.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The ammonium salt of N-Nitrosophenylhydroxiamine, namely Cupferron, is a well-known analytical reagent which precipitates a great number of metal ions in acid medium. Various structures of electrode reduction for N-Nitrosophenylhydroxiamine have been suggested in acid and alkaline media by many researchers, but not in neutral medium. So the mechanism of electrode reaction of Cupferron was investigated by both chronopotentiometric and polarographic methods. It was estimated that the reduction of Cupferron occurs in a three-step mechanism through which a chemical step is interposed between two charge transfer, the ECE (charge transfer-chemical reaction-charge transfer) mechanism, over a range of neutral and alkaline media. The chemical reaction of the process was assumed to be acid-base catalyzed from the fact that kapp (over all rate constant) of chemical reaction is pH dependent.
        6,100원
        15.
        2015.03 KCI 등재 서비스 종료(열람 제한)
        In this study, it was developed eco-friendly alkali-activated slag fiber reinforced concrete using ground granulated blast furnace slag, alkali activator (water glass, sodium hydroxides), and steel fiber. Eight reinforced concrete beam using alkali-activated slag concrete were constructed and tested under monotonic loading. The major variables were mixture ratio of alkali activator, mixed/without of steel fiber. Experimental programs were carried out to improve and evaluate the flexural performance of such test specimens, such as the load-displacement, the failure mode, the maximum load carrying capacity, and ductility capacity. All the specimens were modeled in scale-down size. The reinforced concrete beams using the eco-friendly alkali-activated slag fiber reinforced concrete was failed by the flexure or flexure-shear in general. In addition, the maximum strength increased with the adding the mol of sodium hydroxide, and the specimen reinforced the steel fiber showed the value of maximum strength which is increased by 15.8% through 25.9%. It is thought that eco-friendly alkali-activated slag fiber reinforced concrete can be used with construction material and product to replace normal concrete. If there is applied to structures such as precast concrete member and production of 2nd concrete product, it could be improved the productivity and reduction of construction duration etc.
        16.
        2014.11 서비스 종료(열람 제한)
        팜 오일 산업에서 fresh fruit bunch(이하 FFB)는 팜 오일을 만드는데 사용되며, 오일 생산 과정에서 부산물인 empty fruit bunch(이하 EFB)가 약 20 wt. %이상 배출된다고 보고되고 있다. 한편, 우리나라는 신・재생에너지 공급 의무화 제도에 따라 신・재생에너지원의 확보와 이에 대응할 수 있는 기술개발이 필요한 실정이다. 따라서, EFB를 바이오매스로써 활용한다면 신・재생에너지원 확보와 청정기술개발에 이바지 할 수 있을 것으로 기대된다. 그러나 EFB는 배출방식에 의해 회분 함량이 높고, 문헌에 따르면 이는 균질한 바이오오일을 생산하고 열화학공정에서의 효율을 증가시키기 위해 제거해야 한다고 제안한다. 또한, 바이오매스에 함유된 알칼리 금속은 바이오 오일의 품질에 악영향을 미친다고 보고된 바 있다. 따라서, 본 연구에서는 EFB를 일반 수돗물, 증류수와 질산용액(0.1 wt. %)을 이용하여 세척한 후, 공업분석과 ICP분석을 통해 회분과 알칼리금속의 제거효과를 정량화 하고자 하였다. 세척한 EFB는 24시간 건조 후에 공업분석으로부터 회분의 함량변화를 분석하였고, ICP 분석을 통해 EFB와 세척한 EFB들 간에 알칼리금속 함량도 비교・분석하였다. 비교 결과, 회분은 5.9 wt. %에서 1.53 wt. %로 감소하였고, 알칼리금속은 총 양의 80% 이상 제거되었다. 경제적 효율성을 고려하여 일반 수돗물(1일)과 질산용액(2일)으로 처리한 EFB를 실험에 이용하였다. 열분해실험 결과, 일반 수돗물로 세척한 EFB를 500℃ 조건에서 실험했을 때 가장 높은 수율(48 wt. %)을 얻을 수 있었다. 추가로, 바이오 오일의 특성변화를 확인하기 위해 GC-MS 분석, 원소분석, 디지털 현미경으로 균질성 분석을 수행하였다.
        18.
        2013.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        본 연구는 우라늄 변환시설 운전 중에 발생된 우라늄 함유 슬러지를 가열 처리하여 분말 형태로 저장 중인 우 라늄 함유 슬러지의 열분해 고체폐기물 (Thermal Decomposed Solid Waste of uranium-bearing sludge : TDSW)을 대상으로 TDSW의 용해, TDSW 질산 용해액의 알카리화에 의한 불순물 제거 및 탄산염 알카리화 용 액의 산성화에 의한 U 선택적 제거/회수 특성 등을 규명하였다. TDSW의 용해는 질산용해가 탄산염 산화용해 보다 효과적이었다. 1M 질산에서 TDSW의 약 30wt%가 고체 잔류물로 불용해되었고, TDSW 내 함유 U은 99% 이상이 용해되었다. TDSW의 질산 용해액의 알카리화는 탄산염에 의한 알카리화가 불순물 제거 측면에서 보 다 효과적이며, 탄산염 알카리화 (pH 약 9)에서 U과 공용해된 Ca, Al, Zn 및 Fe 등의 98±1%가 제거되었다. 그 리고 불순물이 거의 제거된 알카리화 용액 (0.5 M H2O2 첨가)의 산성화 (pH 약 3) 에서 U의 99% 이상을 회수 할 수 있어 TDSW로부터 U을 선택적으로 제거/회수할 수 있었다.
        20.
        2012.02 KCI 등재 서비스 종료(열람 제한)
        In this study, the alkiline water washing condition of mackerel(Scomber japonicus) dark meat was investigated to improve processing conditions of red muscle fish meat paste heating gel. Chemical alkaline water(CWM) and electrolytic alkiline water(EWM, pH 12) were used for washing the mackerel raw meat. Washed meats were minced with 2.5% salt and heated at 90℃/15 min to testing texture profile analysis. Moisture of CWM and EWM was increased with both washing times(p<0.05). Crude lipids and protiens were decreased with washing times. Lightness of chemical alkaline water washed mackerel heated paste gel(CWHPG) was higher than electrolytic alkaline water washed mackerel heated paste gel(EWHPG). Redness and yellowness were more decreased than control meats. Jelly strength of CWHPG and EWHPG was not increased more than 2 times wased meat and was increased with protein decrease. Texture profile analysis, max force1 of CWHPG and EWHPG was higher hardeness than the control meat except gel strains. From these results, it could be suggested that electric alkialine water washing is also effective in advance the red meat paste heating gel process of kamaboko industry.
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