• 한국축산식품학회지
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• 제25권1호
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• pp.1-6
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• 2005

본 연구는 돼지 도축 규모 및 계절별로 도축단계에 따른 미생물 오염도와 변화를 조사하기 위하여 수행하였다. 도축 5단계 즉, 내장적출 전, 내장적출 후, 최종세척 전, 최종세척 후 그리고 냉장실에서 돼지 도체 복부 표면에 대한 미생물 오염도를 조사하기 위하여 가로 세로 10×10 cm의 면적에 대하여 swab 방법으로 시료를 채취하였다. 그 결과 가을철 시료의 경우 소규모 도축장의 일반세균수는 모든 도축공정에서 10⁴∼10/sup 5/ CFU/㎠로서 10²∼10³ CFU/㎠의 균수를 보인 대규모 도축장에 비하여 높은 경향을 보였고, 냉장실 시료의 경우 대규모 도축장에 있어서 일반세균수가 10² CFU/㎠ 수준으로 10⁴ CFU/㎠ 수준값을 보여준 소규모 도축장과 일반세균수의 값에 있어서 큰 차이를 보였다. 겨울철 시료와 봄시료에 있어서도 가을 시료와 마찬가지로 대규모 도축장은 모든 도축공정에서 중소규모 도축장에 비하여 적은 미생물수준을 보였으나, 봄 시료의 경우 최종세척 전(10⁴ CFU/㎠)과 냉장실(10³ CFU/㎠)의 미생물수에 있어서는 도축장 규모에 따른 차이를 보여주지 않았다. 최종 세척 공정의 시료 채취 부위에 따른 세척 효과를 보기 위한 실험에서 둔부 및 복부 부위에서는 세척 효과를 보였지만, 턱 부위에서는 오히려 세척 후 미생물 수가 최종세척 전 단계보다 증가하는 경향을 보였다.

• 자원리싸이클링
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• 제29권6호
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• pp.104-113
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• 2020

기포크기는 컬럼부선에서 기포체류시간, 기포표면적플럭스(Sb) 및 운송율(Cr)에 영향을 미치는 중요 변수로 인식되고 있다. 본 논문은 부선컬럼에서 기포크기의 측정방법, 가동변수들의 관계 그리고 가스분산특성을 논한다. 기포크기는 고속카메라와 이미지 분석 시스템을 이용하여 가동변수들(가스속도, 세척수속도, 기포제농도)의 조건에 따라 부선컬럼에서 직접적으로 측정되었다. 각 측정과 산정된 기포크기 값들을 비교한 관계식이 ±15~20의 오차범위 내에서 도출되었고 평균 기포크기(Sauter mean diameter)는 0.718mm로 확인되었다. 본 시스템으로부터 기포크기 및 분포를 조절할 수 있는 경험식이 가동조건들(Jg: 0.65~1.3cm/s, JW: 0.13~0.52cm/s, frother concentration: 60~200ppm) 하에서 개발되었다. 기포제농도의 증가는 표면장면과 기포크기를 감소시킨다. 임계병합농도는 표면장력이 가장 낮은 49.24mN/m일 때인 기포제농도 200ppm이라고 판단된다. 공기속도의 감소, 기포제농도 및 세척수속도의 증가에 따라 기포크기가 감소하는 경향을 보였다. 가스홀드업은 가스속도와 비례관계에 있으며 고정된 가스속도 조건에서 기포제농도 및 세척수속도와 비례관계였다.

• 한국전산유체공학회지
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• 제18권3호
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• pp.8-13
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• 2013

Drag reduction of a running vehicle is very important issue for the energy savings and emission reduction of its power train. Especially for a solar powered electric vehicle, the drag reduction and weight lightening are two serious problems to be solved to extend its driving distance under the given energy condition. In this study, the ground effect of an airfoil shaped road vehicle was studied for an optimum body design of an ultra-light solar powered electric vehicle. Clark-Y airfoil type was adopted to the body shape of the model vehicle to reduce aerodynamic drag. From the study, it was found that the drag of the model vehicle was reduced as the height(h) between ground and the lower surface of the model vehicle was decreased. It is due to the reduction of the down-wash decreasing the induced drag of the vehicle. The lift was also decreased as the height decreased. It is due to the turbulent boundary layer developed beneath the vehicle body. The drag is classified into two types; the form and friction drag. The fraction of form drag to friction one is 76 to 24 on the model vehicle. As the height(h) of the model vehicle from the ground surface increases the form drag also increases but the friction drag is in reverse.

• 보존과학회지
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• 제33권2호
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• pp.97-106
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• 2017

본 연구는 출토직물의 세척을 위한 천연계면활성제 선정을 위하여 그 특성과 세척성을 알아보는데 목적이 있다. 이를 위해 대조군으로 합성계면활성제인 SDS (Sodium dodecyl sulfate)와 천연계면활성제 중 LES (Disodium laurethsulfosuccinate), apple wash (Sodium cocoyl apple amino acids), tea saponin (Saponin), cornacopa (Decyl glucoside), coco betain (Cocamidopropyl betaine) 등 5종을 선별하여 계면활성제의 FT-IR (Fourier transform infrared spectroscopy) 분석으로 구조를 확인하고, pH와 표면장력 측정으로 특성을 파악하였다. 인공오염포 4종과 출토직물편에 대한 세척성 실험을 수행하였다. 그 결과 인공오염포에 대해서는 apple wash, tea saponin, cornacopa가 세척성에 있어서 SDS만큼 좋은 것으로 나타났으며 출토직물편에 대해서는 tea ssponin과 coco betain의 세척성이 좋은 것으로 나타났다. 따라서 세제의 안전성과 세척성을 감안할 때 천연계면활성제 중 tea saponin이 출토복식 세척을 위한 천연계면활성제로써 적합한 것으로 사료되었다.

• 한국농공학회지
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• 제12권4호
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• pp.2078-2083
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• 1970

The purpose of this study is to give the data neccesary for improving the planning of drainage structures, specially inverted siphons, in irrigation channels. With the samples of 15 drainage inlets, one drainage flume, 16 drainage inverted siphons and 6 drainage culverts in the 3 lines of irrigation channel under Chong-Won Irrigation Association, author abtained the following results. 1. It is presumed that design drainage discharge should be determined with some additional reserves, on the basis of the maximum rainfall intensity in local area and the size of drainage area on the topographical map, avoiding the way of eye measure. 2. Location of drainage inlet should be kept away from the place where topography can make lots of wash load, but when unavoidably allowing the inflow into irrigation channel, wash load outlet with even the purpose of drainage, or drainage flume in stead of drainage inlet should be taken account of. 3. It is presumed that drainage flume may be the structure which can perform its function from a structural point of view as far as topography permits. 4. Drainage inverted siphon should be avoided at any place as much as possible; a) In case that location of the siphon would be permitted only at paddy field, drainage area hauing the amount of discharge which requires more than 90cm in diameter could only be allowed. b) In this case, crest elevation of the tank of both inlet and outlet, at least, should not be lower than the surface level of paddy field. c) As far as topography and stratum permit, ratio of depth of outlet tank to head drop should be decreased as much as possible so that discharging efficiency of wash load could increase. d) In case of avoiding the setting of the siphon, irrigation aqueduct, irrigation inverted siphon, or drainage flume should be recommended in accordance with topography. 5. Discharging capability of wash load by drainage culvert appeared to depend hardly upon the diameter of the culvert, but greatly upon the location, specially near village, for there stones and dirts dumped may considerably be piled up. So, a counter plan for that is required.

• 대한치과보철학회지
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• 제43권5호
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• pp.622-632
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• 2005

Statement of problem: Silicone Index Tooth Tray impression system which does not use gingicord has a shortcoming. It takes time to remove internal wall of Silicone Index Tooth Tray for space of wash impression material. Purpose: This study was to evaluate whether providing certain space to impression body can prevent from doing complicated laboratory work. Material and methods: After mounting metal dies with shoulder and chamfer margins arbiturarily, SITT was produced using $Blu-mousse^(R)$. In one experimental group, wash impression was taken using $Fit-tester^(R)$ without removing interior surface of SITT and in the other group, wash impression was taken using $Fit-tester^(R)$ providing 0.5mm space in the SITT and then compared the differences in two groups. Results: 1. There was no significant difference between a group which did not allow space and a group which granted equal 0.5mm space. 2. There was no significant difference between gingival diameter, occlusal diameter of metal die that has shoulder margin and gingival diameter, occlusal diameter of metal die that has chamfer margin. 3. There was no significant difference between a group which did not take pick-up impression and a group which took pick-up impression through relining method using SITT 4. There was no significant difference between a group that poured immediately after taking primary impression and a group that poured after removing poured stone die. Conclusions: When taking an impression of an abutment using SITT impression system, it is considered to obtain clinically identical results between a group that did not grant a 0.5mm space within SITT for wash impression and a group which invest a space. Furthermore, it is considered possible to produce an individual die through secondary pouring.

• 한국축산식품학회지
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• 제24권3호
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• pp.232-237
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• 2004

본 연구는 도축장 규모 및 계절별로 도축 공정 단계에 따른 미생물학적 오염도와 변화 추이를 조사하기 위하여 수행되었다. 도축 5단계 즉, 박피 후, 내장 적출 후, 최종 세척 전, 최종 세척 후 그리고 냉장실에서 소 도체 흥부 표면에 대한 미생물학적 분석을 위하여 가로세로 10${\times}$10 cm의 면적에 대하여 swab 방법으로 시료를 채취하였다. 그 결과 겨울철 시료에 있어 대규모 도축장은 박피, 내장 적출 및 최종 세척 전까지의 도축단계에서는 $10^{0}$∼$10^2$CFU/ $\textrm{cm}^2$ 수준의 일반세균이 검출되어 $10^{0}$∼$10^3$ 수준을 보인 중소규모 도축장에 비하여 1∼2 log값이 적은 미생물이 검출되었으나, 최종세척 후($10^2$CFU/$\textrm{cm}^2$)와 냉장실($10^1$CFU/$\textrm{cm}^2$)의 미생물 검출값에 있어서는 도축장 규모에 따른 차이를 보여주지 않았다. 겨울철 시료는 봄철 시료에 비하여 도축장 규모에 차이 없이 일반세균이 1 log 값 정도 적게 검출되었다. 최종세척 공정의 시료채취 부위에 따른 세척 효과를 보기 위한 실험에서 둔부 부위에서는 세척 효과를 보여주었지만, 옆구리와 흉부 부위에서는 오히려 세척 후 미생물 수가 최종 세척 전 단계보다 증가하는 경향을 보여주었다.

• 한국염색가공학회지
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• 제13권3호
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• pp.165-171
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• 2001

In this study, UV/vis. spectra of color solution extracted from onion shell and dyeing properties of polyamide fibers such as wool, silk, and nylon were investigated. Also, the effect of mordanting on wash fastness and light fastness was Investigated. The amount of colors extracted was increased with extracting temperature and time. The wavelength of maximum absorption of onion shell extract corresponds to flavonol peak and quercetin peak. Also, spectra of color solution were shifted to longer wavelength at higher pH values. It appeared that the optimum condition of the dyeing of wool, nylon, and silk fabrics with onion shell extract was $60^\circ{C}$ , 30min, and pH 4.0 of dyed bath. Surface colors of the dyed fabrics were different according to the used mordants: Al and Cr mordanted fabrics were dyed in yellowish colors, Cu mordanted fabric in greenish color, Sn mordanted fabric in orange color, and Fe mordanted fabric in khaki color. The mordanting was effective at improving wash fastness and light fastness.

• 한국응용과학기술학회지
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• 제37권4호
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• pp.723-732
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• 2020

RHDS 촉매는 코크와 황 화합물 그리고 금속인 바나듐이 표면에 침적되어 비활성화가 된다. 이러한 오염물을 제거하기 위해서 먼저 폐 RHDS 촉매에 묻어있는 중질유분의 세정, 코크와 황 화합물을 고온 배소 처리한 후, 과량으로 침적되어 있는 바나듐의 침출량을 조절하기 위하여 0.5, 1 wt% 옥살산 수용액을 이용하여 초음파 교반기에서 50 ℃, 10 sec 동안 교반하여 NOx 저감을 위한 SCR 촉매로의 적용 가능성을 확인하고자 하였다. 재생처리 한 RHDS 촉매의 성분은 XRF 를 사용하여 분석하였고, 상압 고정층 연속 흐름 반응기 상에서 NOx 저감 성능을 측정하였다. 옥살산 수용액 0.5 wt%, 10 sec 동안 초음파 침출한 촉매가 가장 안정적인 NOx 저감 성능을 보였으며, 375 ℃ 이상의 고온에서는 상용 촉매와 동등 수준의 NOx 저감 성능을 확인할 수 있었으나 저온영역 200 ℃에서 250 ℃까지는 상용 촉매보다 낮은 NOx 저감 성능을 보였다. 따라서 폐 RHDS 촉매를 재생처리 한 후 분말로 메탈 코로게이트 지지체에 워시코팅한 촉매는 상용 SCR 촉매로서 이용 가능함을 확인하였다.

• 한국의류학회지
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• 제25권1호
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• pp.173-182
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• 2001

The physical properties and biodegradability of cellulose fabrics, such as cotton and rayon, are expected to vary with textile care. In this study cotton and rayon fabrics were washed repeatedly with detergents, bleaches, or softeners. The changes of physical properties were investigated by measuring retention of breaking strength, shrinkage, handle, and the fiber surface was observed by SEM. The biodegradability of fabrics was also estimated by soil burial test. The results were as follows. Cotton fabrics laundered repeatedly by detergents and bleaches lost virtually no strength. The breaking strength of the rayon fabrics decreased by about 17%∼25% after repeated launderings. Shrinkage in weft direction was much larger than that in warp direction. Bending rigidities of both fabrics decreased remarkably within 10 wash cycles. Shear rigidity in cotton fabrics increased continuously with repeated washing cycles, however, that in rayon fabrics did not show any change as washing went on. Friction coefficient increased in both fabrics after 10 wash cycles, and this is thought to be attributed to the wrinkle, interlocking of hairs, surface damage resulted from repeated washings. In cotton fabrics made of staple yarns, short hairs on the yarn surface entangled together with repeated launderings. This resulted in the continuous increase in % shrinkage, shear rigidity, friction coefficient. Rayon fabrics made of filament yarns, however, did not show this phenomenon. Softener treated fabrics showed the lowest values in bending rigidity, shear rigidity and friction coefficient because the cationic surfactants adsorbed on the fiber surface behaved like lubricants. The biodegradability of fabrics was noticeably affected by the composition of washing solutions. The fabrics washed with detergents and bleaches were decomposed faster than those washed with the others were and the cotton fabrics washed with detergents and softeners hardly degraded. The fabrics soiled with milk were decomposed almost completely and those soiled with Palmitic acid did not degrade greatly.