• 공업화학
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• 제9권5호
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• pp.758-762
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• 1998

유화중합을 이용하여 중량 평균입자크기가 $0.3{\mu}m{\sim}1.5{\mu}m$인 중공 라텍스 입자를 제조함에 있어 평균입자크기와 고형분 함량에 영향을 미치는 반응 인자를 조사하였다. 실험결과 유화제 (SDS)의 농도가 증가함에 따라 친수성 코어 폴리머의 크기가 작아졌으며, 친유성 스티렌 단량체 (styrene monomer)와 개시제 (SPS)의 첨가량이 증가함에 따라 중공입자의 크기가 커졌다. 한편, 친수성 아크릴산의 첨가속도가 증가함에 따라 중공입자의 크기가 작아졌다. 또한, 스틸렌 단량체의 첨가량이 증가함에 따라 에멀젼 폴리머의 고형분 함량이 선형적으로 증가하였다.

• 유기물자원화
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• 제10권4호
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• pp.86-95
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• 2002

도시쓰레기의 혐기성 소화는 에너지원 및 온난화 가스 저감 문제 등에 의해 최근에 사회적 관심사가 되고 있다. 도시쓰레기는 고형분 함량이 높고 질소성분이 낮으며 셀루로스와 헤미셀루로스가 주성분으로 되어 있다. 도시쓰레기의 메탄 전화율은 대개 50%이며 $0.2m^2/kg$ VS에 해당한다. 고형물 농도가 높을수록 긴 수리학적 체류시간이 필요하며 주입물에 접종슬러지를 혼합하여야 한다. 도시쓰레기의 혐기성 소화 시 C/N비는 25가 상한이고 NH3-N의 적정농도는 700mg/L로 알려져 있다. pH조절을 위하여 흔히 석회와 탄산나트륨이 사용되고있는데 탄산나트륨을 3,500mg/L이상 첨가하면 나트륨 독성이 나타난다. 고온성 혐기 소화조는 운용과 관리가 어려우나 병원성 미생물 억제에 효과적인 것으로 알려져 있다. 도시쓰레기의 혐기성 소화공정의 최적화를 이룩하려면 소화공정에 관여하는 미생물의 작동기전에 대한 이해가 필요하다.

• 동아시아식생활학회지
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• 제23권2호
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• pp.218-226
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• 2013

This study examined the optimal mixture ratio of rice gruel supplemented with puffed rice by mixture design. The quality characteristics of rice gruel samples were examined according to mixture ratios at eleven experimental points. The high soluble solid content and viscosity of gruel samples were significantly dependent on rice (short grain) content instead of glutinous rice. The viscosity ranged from $2,891{\sim}9,153\;cP{\cdot}s$ and soluble solid content ranged from $8.23{\sim}10.13^{\circ}Brix$ at the eleven experimental points. The mixture with the highest solid content and viscosity, 12% rice gruel sample was $10.10{\sim}10.13^{\circ}Brix$ and $9,150{\sim}9,153\;cP{\cdot}s$. The L color of sample decreased with decreasing rice content, while "a" (redness) and "b" (yellowness) values slightly increased. In the sensory evaluation, samples with higher amount of puffed rice and glutinous rice scored higher for brown color, flavor and sweetness than high-content rice samples. The response surface and trace plot results showed that increasing of puffed rice increased the brown color, sweet taste and sticky aftertaste. From the results of the F-test, viscosity, "a" (redness) and "b" (yellowness) values fit a quadratic model with significant probabilities within 0.05%. The optimum predicted formulations of rice gruel containing puffed rice were 1.69% of puffed rice, 0.47% of glutinous rice and 9.84% of rice, respectively.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.315-316
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• 2001

In this study various nutritional and environmental parameters such as, initial moisture content, pH. inoculum size, air rate, sample size and nutrient supplement that influence pigment production were evaluated in solid-state cultures. optimum initial moisture content and pH were determined to be 50% and 6.0, respectively. The supplement of the substrate with different carbon, nitrogen, and mineral source reveals a more inhibitive effect as the substrate concentration increase. optimum aeration rate was determined to be 2vvm in flask culture. The maximum amount of red pigment, 3500 OD/g dried fermented rice, was obtained in optimum conditions which is obtained in solid flask culture.

• 펄프종이기술
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• 제48권2호
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• pp.99-105
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• 2016

The increase of wet web solid content after wet press and dry compressive strength were observed in lab study by judicious application of wood flour and starch for the old corrugated container (OCC). Pearl starch was better than cationic starch in strength development, but cationic starch was better for drainage. Application of vacuum on the mixed solution of wood flour and starch helped strength development further without loss of other properties. The effect of wood flour addition on wet web solid content improved as the wet pressing pressure increased. The use of wood flour and starch mixture improved wet web solid contents further.

• 한국추진공학회지
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• 제6권1호
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• pp.30-38
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• 2002

복합재 연소관에 기계적 물성을 향상시킨 추진제를 충전한 모타와 복합재 연소관에 기존의 내탄도 성능을 어느 정도 유지하며 연소속도의 조절로 추진제의 둔감화를 시도한 추진제를 충전한 로켓모타에 대하여 탄환충격시험을 실시하여 그 반응을 비교·분석하였다.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.75-76
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• 2006

New PM route via bulk mechanical alloying is developed to fabricate the solid solution semi-conductive materials with $Mg_2Si_{1-x}Ge_x$ and $Mg_2Si_{1-y}Sn_y$ for 0 < x, y < 1 and to investigate their thermoelectric materials. Since $Mg_2Si$ is n-type and both $Mg_2Ge$ and $Mg_2Sn$ are p-type, pn-transition takes place at the specified range of germanium content, x, and tin content, y. Through optimization of chemical composition, solid-solution type thermoelectric semi-conductive materials are designed both for n-and p-type materials.

• 기술사
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• 제19권1호
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• pp.25-32
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• 1986

The number of visiters to Bukhan Mt. national park, generation quantity of solid waste and collection system were researched to consider a counterplan for the pollution control of the national park and study for developing the effective treatment of solid waste was tried through the proximate analysis of each component containing. Results obtained in this study were summerized as follows; The great part of visitors go on an excursion to the Bukhan Mt. national park during July and August and also, the solid waste was generated nearly a half of the total amount at the same period. The major collection facilities in the national park were waste basket and incineration box. But the incineration box was too large in volume and very far in distance, and its collection period was irregular, so it was cause to the congestion of solid waste and bad smell and dirty. Therefore, to complete collection of solid waste, we must set up the waste basket which able to find within 40～50m from the origination place of solid waste and induce the visitors to throw the solid waste. It was obtained as moisture content: 48.5 wt%, volatile solid: 28.4wt％, fixed solid: 23.1 wt％, lower heating value: 1,320kca1/kg from experimental analysis of solid waste. According to this analysis, the incineration operation is possible, but the generation quantity of solid waste was too small to construct incineration plant for heat recovery. It was found that it is suitable for the aerobic composting by mixing with the night soil which generate in the national park after the recovery of resources such as metals, glasses and plastics.

• Journal of Microbiology and Biotechnology
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• 제20권3호
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• pp.525-531
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• 2010

This work was aimed at utilizing rice bran as a substrate for $\beta$-carotene production by Rhodotorula glutinis DM 28 under optimized conditions of solid-state fermentation. The biomass and $\beta$-carotene content of Rhodotorula glutinis DM 28 grown on rice bran as a sole substrate under solid-state fermentation were 54 g/kg rice bran and 1.65 mg/kg rice bran, respectively. Its biomass and $\beta$-carotene content, however, could be improved by 60% and 30%, respectively, using the Central Composite Design for the optimization of its cultivation conditions. The optimized conditions obtained were a pH of 5, a moisture content of 70% (w/w), and a carbon-to-nitrogen ratio of 4. Under these conditions, rice bran containing R. glutinis DM 28 had nutritional values of $\beta$-carotene, protein, and fat higher than those of rice bran alone. Yeast-grown rice bran could be suitable, therefore, to use as a $\beta$-carotene-enriched supplement in animal feeds.

• 신재생에너지
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• 제16권2호
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• pp.47-53
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• 2020

The amount of food waste and its water content depends on both the season and region. In particular, the water content typically varies between 73.8 wt.% and 83.3 wt.%, depending on the proportion of vegetables. Current food waste drying technologies are capable of reducing the water content to less than 10 wt.%, while increasing the heating value. Ongoing studies aim to utilize dried food waste as fuel. Food waste can be used to produce solid refuse fuel (SRF) by mixing it with various solid fuels or other types of waste. The analysis of specimens is very important when considering the direct combustion of food waste or its co-firing with solid fuels. In this study, the weight reduction of specimens after burning them in a small combustor, and compared with the results of thermogravimetric analysis (TGA). The concentration of various chemicals was also measured to define the characteristics of waste generation. Performed proximate analysis, elemental analysis, TGA, combustion experiment, the heating value, and derivative thermogravimetry (DTG).