In order to ensure the high carbon conversion in a short residence time in a coal slurry entrained gasifier, the objectiveof this study lies in to investigate the effect of important variables to influence on the complex reacting flow and therebyto clarify the physical feature occurring inside the gasifier using a comprehensive gasifier computer program. To this end,the gasification process of a 1.0ton/day gasifier is numerically modeled using the code of Fluent and systematicallyinvestigated with the change of major design and operation parameters. Special emphasis is given on the effect of theparticle size distribution on the gasification process, since it is associated with various length and time scales via multi-phase and with complex reacting flows. Three different particle sizes are tested for a given coal mass flow rate, the firstis 70µm mean diameter with Rosin-Rammler distribution based on the actual measurement. But in the other two casestwo uniform mean particle diameters are employed, that is, very fine 1µm and 70µm with mean diameter itself. Thecalculation results of these three cases show quite different flow pattern, temperature and reacting flows probably causedby the different particle trajectory as well as reaction rate. However, the results obtained can be explained in a consistentmanner with particle size. Especially, it is noted that the presence of coal particle, the diameter of which is larger thanthat of mean diameter of Rosin-Rammler distribution, shows a significantly retarded gasification reaction in a gasifier,even if its mass fraction is less than 50%.

The amount of contaminated dredged materials are increasing every year in Korea. Secondary contamination would be expected, if contaminated marine clayey slurry remains without treatment. Therefore, the appropriate remedial treatments are required in order to prevent secondary contamination. Electrokinetic method is especially suitable for low permeability dredged clayey soils because pore fluid can be easily transported by electric field. Hydrogen ions created by electrolysis enhance the remedial processes by desorbing heavy metal contaminants from slurry soil surfaces. This study investigated variation of electrical current and voltage gradient during the treatment, and ICP analysis as well as pH measurements were carried out to measure zinc concentration during and after the treatment.

The optimum annealing conditions of corn starch slurry were studied for RS4 type resistant starch production by phosphorylated cross-linking. When a corn starch slurry was cross-linked by using phosphate salts (STMP/STPP mixture) in the presence of 0.9%, 1.2% and 1.5% NaOH/st.ds, a high concentration of NaOH resulted in a rapid increase of the RS contents at the early reaction stage. However, similar RS contents were obtained after 12 h of cross-linking regardless of NaOH concentrations. The annealing treatment was conducted under various conditions such as pH between 2-10, temperature 40-60℃, time 0-14 h followed by phosphorylated cross-linking. The lower slurry pH was for the annealing treatment, the higher RS contents were obtained after cross-linking. When the slurry annealed for various period of time and temperature, a maximal amount of RS was formed after 2 h of annealing at 50℃ of annealing temperature of the starch slurry (pH 2.0). Therefore, an optimal annealing conditions at pH 2.0 and 50℃ for 2 h were proposed under the cross-linking conditions of sodium sulfate 10%/st.ds, NaOH1.2%/st.ds and 12 h of the reaction time. The RS contents were linearly increased with the increase of phosphate salt addition. The RS4 prepared under the optimal conditions contained RS 72.3% and its phosphorus content was 0.36%/st.ds, which was below the limit (0.4%/st.ds) of modified starch by Korea Food Additives Code.

최근 지구 온난화와 더불어 급격한 기후 변화 등으로 여름철 주간 냉방 수요가 급격히 증가하고 있다. 이에 따른 전력 수요량 또한 증가하고 있다. 이런 이유로 세계적으로 에너지 이용 효율 향상에 대한 관심이 높아지고 있고, 최근 국내 및 국외의 축냉시스템을 이용한 주간 전력 피크값을 최소화 하는 연구개발과 실제 적용 사례가 늘어나고 있다. 빙축열시스템의 경우 그 경제적 효과가 높아 그 관심이 높아지고 있는 추세이다. 축냉시스템은 주간 냉방에 사용하는 냉열을 야간에 만들어 탱크에 저장해 두었다가 그것을 낮에 이용함으로써, 갑작스런 부하 증가에 적절히 대응할 수 있는 등 여러 가지 장점을 갖고 있다. 본 실험에서는 슬러리아이스 생성을 위해 냉각표면에서 생성된 슬러리아이스를 분리시키기 위해 유체보다 밀도가 낮은 역전유동 물질을 삽입하여 역전 유동층을 형성하였으며, 역전유동층의 유동에 의해 관군으로 구성되어 있는 냉각튜브 표면에 빙부착이 심화되기 전에 얼음 입자를 분리시켜 수 내지 수십 미크론 단위의 슬러리아이스를 생성하도록 하였다.

Repeated additions of untreated slurry to soil affected ecology and caused high levels of heavy metal in soil and ground water. The objective of this study was to evaluate heavy metal from hanwoo slurry with ferrous sulfate (FeSO4·7H2O), aluminum sulfate [Al2(SO4)3·14H2O, alum] and aluminum chloride (AlCl3·6H2O) as a way to improve environmental management in hanwoo industry. The treatment rates, which were incorporated totally within the hanwoo slurry, were 1.0 g and 1.5 g of ferrous sulfate, alum and aluminum chloride/25 g of hanwoo slurry. The various rates of chemical additives significantly increased dry matter (9.98~13.94%) and decreased pH (3.48~6.52) compared with the controls. The use of chemical additives decreased Fe (11~29%), Al (7~12%), Zn (13~36%), and Cu (4~32%) contents, except for Fe in hanwoo slurry with ferrous sulfate and Al in hanwoo slurry with alum and aluminum chloride. In addition, the reduction in heavy metal should be associated with reduction in pH. In conclusion, the results of this study suggest that alum and aluminum chloride additives at rate of 1.5 g were cost-effective management practice that significantly reduces heavy metal from hanwoo slurry, while it may be improved environmental management.

파우더 파운데이션은 사용이 간편하고 수정화장이 용이하여 고객들이 많이 사용하고 있으며, 파우더 파운데이션을 만드는 방법은 건식방식, 소성방식, 그리고 습식방법으로 크게 분류할 수가 있다. 이중 습식방법은 이미 잘 알려진 바와 같이 back injection 방법과 front injection 방법이 있으며, 본 논문에서는 front injection 방법을 사용해 실험을 진행하였다. 실험결과 용매의 종류에 따른 경도 변화를 살펴보면 휘발성 실리콘이나 탄화수소계 휘발성 물질을 이용할 때 보다 정제수를 이용할 때 경도가 높게 나타났으며, 사용감 측면에서는 물보다는 탄화수소계 휘발성 물질과 휘발성 실리콘 등을 사용했을 때, 고객 선호도가 높게 나타났다. 또한 코팅물질 변화에 따른 경도 변화로는 아미노산계 코팅물질을 사용하였을 대 경도가 상승하는 효과를 나타냈으며, 실리콘 코팅 물질을 사용했을 때 경도 상승효과가 미비한 것으로 나타났다. 이러한 결과를 토대로 각 대상 고객에 맞는 처방을 개발하고자 할 때 사용감과 경도의 상관관계를 알고, 처방설계에 이용한다면 고객이 원하는 사용감에 한발 더 접근할 수 있으리라 생각된다.

고순도 니켈 금속염으로부터 미세하고 입도가 균일한 니켈 분말 직접 제조 연구를 수행하였다. 구형의 형상을 갖는 미세한 니켈 분말을 제조하기 위하여 입도제어가 가능한 슬러리환원법을 사용하였다. 제조된 니켈 분말에 화학성분, 입도, X선회절, 주사전자현미경 분석을 실시하여 니켈 분말의 특성을 조사하였다. 환원제로 하이드라진(hydrazine)을 사용하고, 4.5 M NaOH에서 90분 반응시켜 약 100~200 nm의 입도를 가진 분산도가 양호한 구형의 니켈 분말을 제조할 수 있었다.

아이스슬러리의 생성을 위하여 냉각평판에 작동수를 분사하는 실험을 수행하여 그에 대한 영향에 대하여 영향을 평가하였다. 실험에 사용된 에틸렌글리콜 수용액은 10~20wt%의 수용액을 사용하였다. 실험장치는 슬러리아이스 저장탱크, 브라인 탱크, 브라인 순환장치, 유량계 및 온도기록계로 구성되어 있다. 실험조건은 평균유속 1.0~2.0m/s, 냉각온도 -17~-10℃의 조건 하에 실험을 수행하였다.

The objectives of this study were to evaluate the effects of chemical additives on total phosphorus (TP), soluble reactive phosphorus (SRP), and total volatile fatty acids (total VFAs) in hanwoo slurry. The treatments in this study were ferrous sulfate, alum, and aluminum chloride, and applied at the rate of 0, 0.5, and 1.0 g/25 g of hanwoo slurry. All of the chemical treatments significantly lowered TP (11 to 53% of the untreated control), SRP (41 to 99.9% of the untreated control), and total VFAs (22 to 48.5% of the untreated control) by reducing hanwoo slurry pH (3.42 to 6.86). Among these chemical amendments, addition of 0.5 g ferrous sulfate, alum, and aluminum chloride to hanwoo slurry were the best results evaluated on farms with respect to reducing negative environmental impacts. In conclusion, the results of this study indicate that the use of chemical amendments should be considered in the development of best management practices (BMPs) for the hanwoo industries.

To determine changes in nitrogen contents and optimal rates as N fertilizer, we investigated nitrogen characteristics in the slurry in the respond to the application of 0, 0.5, and 1 g of ferrous sulfate or alum /25g of dairy slurry. Additions of ferrous sulfate or alum increase total nitrogen, inorganic nitrogen, available nitrogen, and predicted available nitrogen contents in dairy slurry, resulting in reduction in pH. The best results were found in the treatment with 0.5 g of ferrous sulfate or alum /25 g of dairy slurry. In conclusion, the use of ferrous sulfate or alum as on-farm amendment to dairy slurry should be represented an alternative to improve N in dairy slurry.

It was compared the reduction effect of contaminants and odor according to DO change and EM (effective microorganisms) addition in maturation process of piggery slurry. The maturation processes were divided into three cases as follows: R-1 was operated at 2.5 mg/ℓ of DO without the addition of EM, R-2 was operated at 7.5 mg/ℓ of DO without the addition of EM and R-3 was operated at 2.5 mg/ℓ of DO with the addition of EM. The addition of EM was more effective than the increase of DO for the reduction of CODcr, NH3-N and T-N in the maturation of piggery slurry. In addition, the reducing effect of odor intensity appeared high even in the short-term maturation period in case of adding EM and one could not even smell the stimulating odor of piggery slurry.

The changes of contaminants and odor corresponding to anaerobic maturation process of piggery slurry were investigated by applying the additives, such as different kinds of complex microorganism products and deodorants containing microorganism activating agents. The pHs during 20-day anaerobic maturation were operated stably without great change regardless of the additives, although they were rather lower in the case that the additives were contained than the case that they were not contained. The effects of removing CODcr, NH3-N, T-N, and T-S in case that the additives were not contained, were not so great during the 20-day operation and so it would be difficult to remove the organic materials and nitrogen ingredients simply with anaerobic maturation process. However, in case of anaerobic maturation process that the additives were contained, their average removal rates were improved with the values of 49%, 63.5%, 48.5%, and 30.7% for above each of items, even if the 20-day of short-term maturation period was applied. Especially, odor intensity with the additives was lowered continuously during the operation period and it had more than two times of lowering effect compared to that without those.

약용작물(藥用作物)중 재배 면적이 많고 소득성(所得性)이 높은 다년생(多年生)의 초본성 작물인 황기의 1~2년생근(年生根) 재배시 헤어리베치 녹비와 액상분뇨 시용이 황기의 생육특주(生育特注) 및 생산성(生産性)과 토양(土壤) 특성에 미치는 영향을 검토한 시험결과를 요약하면 아래와 같다. 1. 지상부 생육 중 경장(莖長)과 분지수(分枝數)는 헤어리베치 녹비, 액상분뇨 시용구에서 생장량이 컸으며, 생육이 늦게까지 지속되었다. 근장(根長), 근경(根徑), 지근수(支根數) 모두 헤어리베치 녹비와 액상분뇨 시용구에서 증가하는 경향이었으며 건물비율(乾物比率) 재배 1년차 보다 재배 2년차에 증가하였다. 2. 재배 2년차의 건근수양(乾根收量)은 녹비를 피복한 무비구, 화학비료, 액상분뇨 시용구에서 각각 196, 240, 255kg/10a으로서 녹비를 피복하지 않는 무비구, 화학비료, 액상분뇨 시용구에서는 각각 115, 225, 232 kg/10a 보다 증수되었다. 황기 재배시 헤어리베치 녹비 피복은 질소공급에 의한 수량증가와 잡초억제 효과를 나타내었다. 3.뿌리의 질소함양(窒素含量)은 재배 1년차에 1.33~2.56%, 재배 2년차에 1.9~2.95%으로 재배 년차가 높을수록 증가(增加)되었다. 질소함량을 조단백질 함량으로 환산하면 재배 2년차에 20~23%로서 콩 단백질 함량의 45~65% 수준이었다. 4. 시험 후 토양의 총 질소함량은 녹비 액상분뇨 시용구에서 유의성 있게 증가하였으나 토양 내 염류집적(鹽類集積)은 되지 않았다.

An agricultural land application of swine slurry is one of the best management practices in Jeju island whose ground water must be protected. So as to study the effect of appling swine slurry on ground water or aquifer, incubation-leaching technique was used by assuming the incubating period of 1, 2, 4, 8, 16, or 32 days, and application rate of 3200.0㎎T-N/ℓ, 820.0㎎T-P/ℓ, and 1887.0㎎K+/ℓin swine slurry. The leachates were collected from the soil columns(PVC 30cmL×5.5cmD) packed 15cm in depth with Gangjeong soil series by washing with 100mL distilled water. The leached components were measured by using Ion chromatography for Cl-, NO3-N, F-, Br-, Na+, K+, Ca2+, and Mg2+, atomic absorption spectrophotometry for Fe and Mn, and UV-Vis spectrophotometry for T-N and T-P. Application of swine slurry in naked soil could influence on the ground water or aquifer by increasing nitrate-nitrogen in leachate with time, or leaching the cations present in soils in accompany with anions because of H+ produced in nitrification. Therefore, careful consideration should be taken about what amount, when, where, and how for protecting ground water system.

In the present paper, batch and semi-continuous settling characteristics of a binary calcium carbonatewater system were investigated. Using experimental data of batch settling characteristics, a graphical analysis for a semi-continuous thickening column was developed and compared with experimental results on the basis of Kynch theory, only where the feed velocity line was within the limits of Kynch theorem Ⅲ. The analysis showed good agreement with experiments. Quite erroneous results, however, was observed for the analysis of a sludge region on the underloaded operation, which was considered due to the deviation from the limits of theory.