Earticle

This research was conducted for dewatered sludge cake of industrial wastewater treatment, i.e., as the object of inorganic sludge discharged especially in iron & steel manufacturing shop which used Air drying system to reduce water content. That drying system's single-type cyclone separator was confirmed to have significantly lower separation efficiency on the conditions 20μm and below of particular size through computational fluid dynamics(CFD) analysis. However, we found out the primarily advanced value of separation efficiency on dual-type directly connected. Regarding separation efficiency on size of 10μm, the efficiency of a single-type was presented at 51.91%. On the other side, the efficiency of the dual-type was 97.88%. This advanced effect of the dual cyclone separator was checked at a demo facility of air drying equipment designed by 340m3/min of airflow on site.

본 연구에서는 배터리 파쇄 공정 산물에 대해 영상 인식 기반 분석 기법을 적용하여, 복합 폐기물의 재활용 효율 향상을 도모하고자 하였다. YOLOv8을 기반으로 재질 인식을 위한 학습 모델을 구축하였으며, Canny edge 기반 윤곽선 검출 및 기준선 보정 기법을 통해 입자의 면적을 정량화하였다. 약 7,000개의 이미지를 학습 데이터로 활용하였으며, 데이터 증강 및 보정 알고리즘을 이용하여 mAP 0.971의높은 객체 인식 정확도를 달성하였다. 입자 면적 정보를 기반으로 단위 면적당 질량(g/mm2)을 통해 입자별 질량을 추정하였으며, 이를 통해 영상 기반 회수율 및 순도를 계산하였다. 예측값은 실험을 통해 얻은 실측값과 비교되었으며, 회수율은 모든 재질에서 95% 이상, 순도는 약 90% 수준의 정합률을 보여 영상 기반 분석의 신뢰성을 입증하였다. 영상인식 기반의 재질 인식 및 입자 특성 분석을 통한 선별 회수율 및 순도 계산에 대한 신뢰도를 확보하였다. 연구는 영상 기반 분석이 기존 장비 대비 신속하고 효율적임을 보여주며, 향후 실시간 품질모니터링 및 공정 최적화 시스템으로의 확장 가능성을 제시한다.

In this study, an image recognition-based analysis method was applied to by-products generated from the battery crushing process, aiming to improve the recycling efficiency of complex waste streams. A deep learning model for material classification was developed based on YOLOv8, and particle areas were quantified using Canny edge-based contour detection along with baseline calibration techniques. Approximately 7,000 images were utilized for training, and data augmentation and correction algorithms enabled the model to achieve a high object detection accuracy with an mAP of 0.971. Based on the quantified particle area and the calibrated mass per unit area (g/mm2), the mass of each particle was estimated. These values were used to calculate recovery and grade, and the predicted results were compared with experimentally measured data. Recovery exceeded 95% across all material types, and the correspondence rate for grade reached approximately 90%, confirming the reliability of the image-based analysis. The study demonstrates that material classification and particle property analysis based on image processing enable accurate evaluation of separation recovery and product grade. In addition, the method shows potential for rapid and efficient assessment compared to conventional equipment and can be further expanded into real-time quality monitoring and process optimization systems.

This study aims to optimize the SDC (Spinning Dust Collector) system in amphibious assault vehicle engines through numerical analysis of dust and moisture particle separation efficiency using CFD-DPM. Focusing on an axial cyclone structure, the research evaluates separation efficiency across various particle sizes and flow conditions. The results demonstrate that vortices generated by cyclone blades play a critical role in influencing particle trajectories and improving separation performance. Additionally, the study highlights the significant impact of engine flow conditions and housing design, emphasizing that their careful optimization enhances the system's efficiency in separating dust and water. These findings offer valuable insights into optimizing inlet and outlet flow paths and cyclone housing design, providing a solid foundation for advancing SDC system performance in high-efficiency engines.

This study aimed to enhance the grade and yield of titanium oxide through magnetic separation of titanium ore from the Taebaek Myeon-San Layer titanium deposit, which contains non-magnetic rutile. The magnetizing roasting characteristics of the ore and the magnetic separation properties of the roasted product were investigated. The titanium ore in the Myeon-San Layer deposit is a sedimentary rock in which the target mineral, rutile (TiO2), is intergrown with hematite (Fe2O3) and gangue minerals, including quartz (SiO2) and clay minerals. Consequently, there are limitations to improving the grade and yield of titanium oxide using conventional beneficiation methods. When graphite, a reducing agent, was added to the titanium ore at levels of 10-30 % and the mixture was roasted at temperatures between 900 and 1,100 °C, the rutile reacts with hematite in the 925 to 975 °C range, transforming them into titanomagnetite (a solid solution of Fe2TiO3 and Fe3O4), a weakly magnetic mineral, and ilmenite (FeTiO3), a paramagnetic mineral. The excess hematite was reduced to magnetite (Fe3O4), a ferromagnetic mineral. However, at temperatures above 1,000 °C, these minerals were reduced again to rutile and metallic iron (Fe). Magnetic separation during synthesis indicated that rutile was not recovered because it is nonmagnetic. Nevertheless, magnetite was recovered at over 90 % using a magnetic field of 0.1 T, titanomagnetite at 1.0 T, and ilmenite at 1.2 T, confirming that titanomagnetite and ilmenite, as roasted products, exhibit high magnetic sensitivity. During magnetic separation at 0.8 T for products roasted at 900-1,050 °C, titanomagnetite and ilmenite, which are titanium-bearing minerals, were recovered as magnetic concentrates. Therefore, when titanium ore from the Myeon-San Layer deposit is mixed with a reducing agent, roasted, and separated by magnetic separation, the non-magnetic rutile reacts with hematite to form titanomagnetite and ilmenite with high magnetic sensitivity. This demonstrates that the yield of titanium oxide can be increased.

에어 롤러 선별기는 고속 롤러 회전으로 생성된 회전 유체 흐름을 통해 물질의 비중에 따라 이물질을 선별하는 장비이며, 본 연구에서미선별 폐플라스틱의 물질 재활용률 향상을 위해 도입하였다. 본 연구에서는 미선별 원물 폐플라스틱 파쇄물을 에어 롤러 선별기를 사용하여 선별을 진행하였으며, 선별기의 기계적 요인(롤러 높이, 롤러 간격, 롤러 회전속도)과 운전 조건(열풍 온도, 피드 투입량)에 따라 이물질 비율 및 목적 물질의 품위에 미치는 영향을 평가하여 최적 조건을 도출하였다. 각 조건에 따른 선별 경향성 분석을 통해 롤러 높이 0 mm, 롤러 간격 15 mm, 롤러 회전속도 1,800 rpm, 열풍 온도 90 ℃, 피드 투입량 800 kg/h 조건에서 이물질 비율 0.5%, 목적 물질 품위97.7%로 선별할 수 있는 최적 조건을 설정하였다. 해당 연구를 통해 에어 롤러 선별기가 적용된 선별 공정 최적화를 통해 미선별 폐플라스틱의 선별 효율 개선 가능성을 확인하였다.

The air roller separator classifies impurities based on their specific gravity by utilizing a rotating fluid flow generated through high-speed roller rotation. This study introduces an advanced separation system designed to improve the recycling rate of unsorted plastic waste. The effects of key mechanical parameters (roller height, roller gap, and roller rotation speed) and operational parameters (temperature and feed rate) on impurity rates and target material grades were evaluated to determine optimal parameters. The optimal mechanical parameters were identified as a roller height of 0 mm, a roller gap of 15 mm, and a roller rotation speed of 1800 rpm. Additionally, the optimal operational parameters were determined to be a temperature of 90 °C and a feed rate of 800 kg/h. Under these optimized conditions, the impurity rate was reduced to approximately 0.5%, while the target material grade reached approximately 97.7%. These findings demonstrate the potential for enhanced separation efficiency through the optimization of air roller separator parameters.

플라이애시의 부유선별 과정에서 교반속도와 공기주입량과 같은 기계적 요소 변화에 따른 영향을 알아보고자 본 연구를 실시하였다. 본 연구에서는 미연탄소 함량이 약 3.4 ~ 3.7% 수준인 화력발전소 플라이애시를 사용하였다. 대표적인 부유선별의 선별 요소인 pH, 교반속도, 포수제 첨가량, 기포제 첨가량 변화에 따른 영향을 살펴보았을 때, Safflower oil을 포수제로 사용하여 첨가량을800 g/ton, pH 7, 교반속도 1,200 rpm, 기포제 첨가량이 400 g/ton였을 때, 미연탄소 회수율과 미연탄소 함량이 각각 63%, 34%로나타났다. 이 때 부상물 SEM/EDS 분석을 통해 알아본 결과, 구형의 플라이애시 미립자가 미연탄소 내에 고용되거나, 광액 내에 가라앉지 못하고 기포와 함께 부유함으로써 미연탄소의 함량을 낮추는 것으로 나타났다. 교반속도와 공기주입량과 같은 기계적 요소를 변화시킨 실험에서는 공기주입량 8L/min, 교반 속도 900 rpm에서 미연탄소 회수율 74%, 미연탄소 함량 67%인 것으로 나타났다. 이는 낮은 교반속도와 추가 공기주입으로 인하여 광액 내 와류의 강도가 낮아져, 미립의 플라이애시 입자가 미연탄소와 함께부유되는 현상을 방지됨으로써, 미연탄소 회수율과 미연탄소 함량이 향상된 것으로 나타났다. 또한, 교반속도와 공기주입량을 각각800 rpm, 6 L/min으로 설정하였을 때 미연탄소 회수율과 미연탄소 탄소함량이 각각 80%, 70%로 향상되어 가장 우수한 것으로 나타났다.

This study aimed to investigate the effects of mechanical factors such as agitation speed and air rate in fly ash flotation. Specifically, we used thermal power plant fly ash with unburned carbon content of 3.4 to 3.7%. The effect of pH, agitation speed, collector dosage, and frother dosage - the key factors of froth flotation - showed unburned carbon recovery and unburned carbon content of 63% and 34%, respectively, when the dosage of safflower oil used as collector was 800 g/ton, pH was 7, agitation speed was 1,200 rpm, and frother dosage was 400 g/ton. The SEM/EDS analysis of fly ash in that case indicated that the spherical fly ash particles lowered the unburned carbon content as they floated with the air bubbles without being dissolved in the unburned carbon or settled in the ore solution. The other experiment of changing the mechanical factors such as agitation speed and air rate resulted in unburned carbon recovery and unburned carbon content of 74% and 67%, respectively, at air rate of 8 L/min and agitation speed of 900 rpm. The recovery and unburned carbon content increased as the low agitation speed and additional air injection decreased the strength of the eddy current in the ore solution and consequently prevented the floating of fine fly ash particles with unburned carbon. In addition, the recovery rate and unburned carbon increased further to 80% and 70%, respectively, showing the best performance when the agitation speed and air rate were lowered to 800 rpm and 6 L/min, respectively.

본 연구에서는 주로 결정질 산화물(fraction 4)과 잔류상(fraction 5) 형태로 존재하는 비소 오염 토양에 대해 효과적인 정화 방법을 설계하기 위해 물리적 선별과 토양세척공법에 대한 효율성을 평가하였다. 자력 선별을 적용한 결과, fraction 5 형태의 비소가 효과적으로 제거되었으며, 자력의 세기가 높을수록 좋은 효과를 보였다. 부유 선별에서는 P.E.X 포수제가 P.A.X 포수제 보다 높은 제거효율을 보였으나, 투입되는 포수제의 양에서는 효율 차이가 크지 않았다. 토양세척에서는 옥살산과 디씨오나이트를 혼합한 세척액이 가장 효과적이었으며, fraction 5에서 높은 효율을 보인 아스코빅산을 추가한 단계적 세척을 통해 최대 61.4%의 비소 제거율을 달성할 수 있었다. 이러한 연구결과는 향후 fraction 4와 5 형태로 존재하는 비소 오염 토양에서 최적의 정화공법을 설계하기 위한기초자료로 활용될 수 있을 것으로 판단된다.

In this study, the efficiency of physical screening and soil washing methods was evaluated to assess the effective remediation of arsenic (As)-contaminated soils, which mainly exist in the form of crystalline oxides (fraction 4) and the residual phase (fraction 5). The results showed that magnetic separation effectively removed the As in fraction 5, and the stronger the magnetic force, the better the effect. In the flotation separation method, the potassium ethyl xanthate (PEX) collectors showed a higher removal efficiency than the potassium amyl xanthate (PAX) collectors, with the amount used exerting a minimal impact. In soil washing, a mixture of oxalic acid and dithionite was the most effective, and As removal rates of up to 61.4% were achieved by cascade washing with the addition of ascorbic acid, which was highly efficient in removing fraction 5. These results provide a foundation for designing optimal remediation processes for As-contaminated soils, especially those dominated by fractions 4 and 5.

본 연구는 효율성을 분석하기 위한 경영 분석 및 경제성 분석의 주요한 분석 방법인 Super DEA(Data Envelopment Analyais) 기법을 이용하여 국내 제약사들의 의약분업 이전과 의약분업 후 10년 후의 매출액 대비 광고비 지출의 효율성을 측정 하였으며, 측정 결과를 통한 효율적 광고비운영 방안을 제시 하였다. 분석 대상 제약사(DMU)는 매출 및 광고비 상위사들로 1999년은 33개사, 2010년은 37개사로, 광고비는 한국광고데이타(KADD)의 자료를, 매출액은 각 사에서 공시한 재무제표를 활용하였다. 분석을 위한 변수의 선정은 선행연구에 근거하였으며, 투입 광고비의 경우, 1999년은 TV, 라디오, 신문, 잡지로, 2010년 광고비는 공중파TV, 케이블TV, 라디오, 신문, 잡지로 선정하였고, 산출 변수는 매출액을 이용하였다. 연구 결과, 1999년에 비해 2010년의 국내 제약사의 광고비 효율성은 전반적으로 큰 폭으로 하락한 것으로 파악되었다. 또한, 2010년 분석 결과를 기초로 향후 광고비를 늘림으로서 규모의 경제를 통한 매출에 긍정적인 영향을 기대할 수 있는 제약사는 22개, 현재 광고비 수준을 축소함으로서 효율성 제고를 꾀 할 수 있는 제약사는 9개, 현재의 광고비 수준이 적정한 것으로 평가된 6개 제약사를 제시하여, 이들 제약사의 향후 광고비 운영 방향에 대한 가이드라인을 제시하였다.

This study has been measured the advertising expense efficiency to sales of the separation of prescribing and dispensing before and 10 years later and presented the efficient advertising expense management plan based on the results of the measurements. The analyzed pharmaceutical companies were 33 companies in 1999 and 37 companies in 2010 and all of them were advertising spending most companies. And the advertising expense of Korea Advertising Data(KADD) and the sales data based on published financial statements were used for measurements. The variables for measurements were chosen based on previous studies, and the input variables are advertising expense of TV, Radio, Newspaper and Magazine in 1999, and of TV, CATV, Newspaper and Magazine in 2010. The sales data were used for output variables. The results of this study showed that the overall advertising efficiency in 2010 compared to 2009 declined significantly. And those showed that 22 pharmaceutical companies can expect positive impact on sales in increasing of advertising expense through economy scale in the future, 9 pharmaceutical companies can make advertising expense efficiency through decreasing of the present advertising expense and 6 pharmaceutical companies was considered a reasonable level of current advertising expense. It might be very useful and significant that the results of this study preset the guideline for advertising expense management plan of those pharmaceutical companies in the future.

Purpose: Using a laboratory indented cylinder separator, broken rice separation experiments were conducted and the characteristics of the separation process were studied to provide information for developing a prototype indented cylinder broken rice separator. Methods: Rice (Ilmi variety) milled in a local RPC was used for the experiment. Rice kernels were classified into four groups according to their length l; whole kernels (I > 3.75 mm), semi-whole kernels (2.5 < I < 3.75 mm), broken kernels (1.75 < I < 2.5 mm), and foreign matters (I < 1.75 mm). A laboratory grain cleaner, Labofix '90 (Schmidt AG, Germany) was used for the experiments. Experiments were designed as a $4{\times}4$ factorial arrangement in randomized blocks with three replications. Cylinder rotational speeds (17, 34, 51, 68 rpm) and trough angles (15, 37.5, 60, $82.5^{\circ}$) were the two factors and feed rates (25, 50 kg/h), indent shapes (Us, $S_1$ type), and indent sizes (2.5, 3.75 mm) were treated as the blocks. Two 125 g samples and one 125 g sample were taken at the cylinder outlet and from the trough, respectively. The whole, semi-whole, and broken kernel weight ratio of the samples and feed was determined by a rice sizing device. From these weight ratios, purities, degrees of extraction and coefficient of separation efficiency were calculated. Results: Trough angle, cylinder speed, and their interaction on the coefficient of separation efficiency were statistically significant. Cylinder speed of 17, 34, and 51 rpm made the most effective separation when the trough angle was $15^{\circ}$ or $37.5^{\circ}$, $60^{\circ}$, and $82.5^{\circ}$, respectively. Maximum values of coefficient of separation efficiency were in the range of 60 to 70% except when the indent size was 2.5 mm and were recorded for the combinations of low cylinder speed (17 rpm) with medium trough angle ($37.5^{\circ}$ or $60^{\circ}$). Indent shape did not appear to make any noticeable difference in separation efficiency. Conclusions: Due to the interaction effect, the trough angle needs to be increased appropriately when an increase in cylinder speed is made if a rapid drop of effectiveness of separation should be avoided. In commercial applications, $S_1$ type indents are preferred because of their better manufacturability and easier maintenance. For successful separation of broken kernels, the indent size should be set slightly bigger than the actual sizes of broken kernels: an indent size of 3.0 mm for separating broken kernels shorter than 2.5 mm.

High gradient magnetic separation (HGMS) is the most commonly used magnetic cell separation technique in biomedical science. However, parameters determining target cell capture efficiencies in HGMS are still not well understood. This limitation leads to loss of information and resources. The present study develops a bead-capture theory to predict capture efficiencies in HGMS. The theory is tested with CD3- and CD14-positive cells in combination with paramagnetic beads of different sizes and a generic immunomagnetic separation system. Data depict a linear relationship between normalized capture efficiency and the bead concentration. In addition, it is shown that key biological functions of target cells are not affected for all bead sizes and concentrations used. In summary, linear bead-capture theory predicts capture efficiency ($E_t$) in a highly significant manner.

As it is known, uranium enrichment is carried out on industrial scale by means of multistage separation facilities, i.e., separation cascades in which gas centrifuges (GCs) are connected in series and parallel. Design and construction of these facilities require significant investment. So, the problem of calculation and optimization of cascade working parameters is still relevant today. At the same time, in many cases, the minimum unit cost of a product is related to the cascade having the smallest possible number of separation elements/GCs. Also, in theoretical studies, it is often acceptable to apply as an efficiency criterion the minimum total flow to supply cascade stages instead of the abovementioned minimum unit cost or the number of separation elements. In this article, cascades with working parameter of a single GC changing from stage to stage are optimized by two of the abovementioned performance criteria and are compared. The results obtained allow us to make a conclusion about their differences.

In electrostatic separation process for recycling of Automobile Shredder Residue (ASR), its separation efficiency is decreased by the influence of conductive matters attached onto the fine glass particles. Hence induction electrostatic separation testwork has been carried out using non-magnetic products obtained through pre-treatment (such as sieving, washing, pyrolysis and oxidation) to remove impurities. From test result, the sieving and water washing are superior to pyrolysis and oxidation for removing the conductive matters. In the electrostatic separation for recovering non-ferrous, a grade of 78 % and recovery of 82 % could be successfully achieved under conditions of 30 kV electrode potential, 45 % relative humidity and 8 cm splitter position.

건설폐기물에서 발생하는 순환골재의 분류 과정에서 발생하는 이물질을 순환골재 출하 전에 회수하기 위하여 회전분리망 흡착 선별기를 설계 및 제작하였다. 제작된 선별기의 성능을 평가하기 위하여, 순환골재에서 자체적으로 회수한 이물질 종류에 따라, 아크릴을 사용하여 규격화된 이물질 샘플을 제작하고, 선별기에서 작동하는 흡입팬의 제어주파수 및 분리망의 흡입구 위치에 따른 선별효율과 순환골재의 오분류율을 평가하여 적절한 운전점을 평가하였다. 순환골재 및 이물질을 입자로 가정한 유동해석을 통해 예측된 선별기의 운전점에서의 분류효율을 평가하였다. 성능 시험 결과 컨베이어 밸트와 흡입구의 거리가 0.2m일 때 95%의 선별효율을 보이는 것으로 나타났으나, 순환골재의 오분류율이 2% 이상으로 선별효율과 2% 이하의 오분류율을 만족하는 운전점은 흡입구 거리 0.254m에서 제어주파수 58Hz으로 나타났다. 유동해석 결과 이물질 선별기에서 순환골재의 오분류는 나타나지 않았다. 기존 순환골재 생산공정에서 이물질 저감을 위해 설치식으로 운용이 가능한 회전분리망을 이용한 풍력 선별시스템을 구축하였다.

Aggregate waste separator with rotating separating net was designed for applying classification process of construction waste. In order to evaluate the performance of the aggregate waste separator, according to the type of waste, standardized waste samples are prepared using acrylic. The appropriate operating point was evaluated by the classification efficiency and misclassification rate of recycled aggregate according to the control frequency of the blower operating and inlet position of the separating net. The classification efficiency at the operating point of the aggregate waste separator was evaluated through flow analysis assuming recycled aggregate and waste sample as particles. As a result of the performance test, when the distance. between the conveyor belt and the inlet was 0.2m, the classification efficiency was 95%, but the misclassification rate of recycled aggregate was 2% or more, which satisfies the classification efficiency and the misclassification rate of less than 2%. The operating point was shown at a control frequency of 58Hz at a suction distance of 0.254m. As a resu lt of flow analysis, there was no misclassification of recycled aggregate. In order to redu ce constru ction waste in the existing recycled aggregate production process, adsorption system using a rotating separating net that can be operated as an installation type was built.

To develop an ash separator for the solid fuel chemical looping combustion system, effects of operating variables such as solid injection nozzle velocity, diameter of solid injection nozzle, gap between solid injection line and vent line, vent line inside diameter, and solid intake height on solid separation rate and solid separation efficiency were measured and discussed using heavy and coarse particle and light and fine particles mixture as bed material in an acrylic fluidized bed apparatus. The solid separation rate increased as the solid injection nozzle velocity and the diameter of solid injection nozzle increased. However, the solid separation rate decreased as the gap between solid injection line and vent line, the vent line inside diameter, and the solid intake height increased. The solid separation efficiency was in inverse proportion to the solid separation rate. In this study, we could get high solid separation rate up to 2.39 kg/hr with 91.6% of solid separation efficiency.

콩은 높은 단백질 함량과 다양한 기능적 특성으로 인해 식품 및 사료 산업에 필수적인 작물이다. 그러나 농촌 인구의 고령화와 저렴한 수입 콩으로 인해 국내 콩 생산량은 꾸준히 감소하고 있다. 이러한 문제를 해결하기 위해서는 농업 기계 기술의 발전이 필수적이며, 특히 콩수확기의 선별 메커니즘을 개선하는 것이 중요하다. 따라서 본 연구는 CFD-DEM 결합 시뮬레이션을 사용하여 콩수확기의 선별장치 내의 유동 역학과 입자 움직임을 분석하여 선별 효율성을 향상시키는 것을 목표로 했다. 경남농업기술원에서 재배한 진풍 콩(Glycine max (L.) Merrill) 품종을 실험에 사용하였다. 선별장치는 콩, 콩대, 줄기를 분리하여 콩알만 수집하도록 설계되었다. 실험 중에는 콩 줄기를 균일하게 투입하여 분리율과 수집률을 측정하였다. 또한 유동 분석을 위해 표준 k-ε 난류 모델을 사용하였으며, CFD-DEM 결합 방법을 사용하여 선별 장치 내의 내부 유동과 입자 움직임을 시뮬레이션하였다. 추가로 CFD 분석 결과를 DEM 시뮬레이션에 활용하여 Ganser 항력 모델을 적용하여 콩과 콩대의 분리 특성을 분석하였다. 마지막으로 CFD-DEM 결합 시뮬레이션을 통해 콩수확기의 선별 장치 성능을 평가하고 최적의 팬 회전속도를 결정하였다. 실험에서 팬 회전속도는 각각 900 rpm, 1,000 rpm, 1,100 rpm, 1,200 rpm으로 설정하였다. 실제 선별장치에서 측정한 풍구 회전 시의 공기 유속과 시뮬레이션 에서 팬 회전으로 발생한 공기 유속 간의 RMSE 값은 0.64 m/s에서 1.12 m/s로 나타났다. 풍구 회전수에 대한 콩의 수집률을 시뮬레이션 결과 풍구 회전수가 증가할수록 수집률이 감소했으며, 900 rpm일 때 최대 94.08%의 수집률을 보였다. 콩대와 콩줄기 분리율의 경우 900 rpm과 1,000 rpm에서 55%~60%로 낮은 효율을 보였다. 1,100 rpm에서 86.38%, 1,200 rpm일 때 86.14%의 분리율이 측정되었다. 콩 수집률과 콩대 분리율 모두에서 최적의 성능을 발휘하려면, 풍구 회전수는 1,100 rpm이 적절한 것으로 보인다.

Soybeans are an essential crop in the food and feed industries due to their high protein content and various functional properties. However, domestic soybean production has been steadily declining due to an aging farming population and the availability of cheaper imported soybeans. To address this issue, advancements in agricultural machinery technology are crucial, particularly in improving the sorting mechanism of soybean harvesters. This study aimed to enhance sorting efficiency by analyzing the flow dynamics and particle movement within the soybean harvester's sorting device using CFD-DEM coupled simulations. The Jinpung soybean (Glycine max (L.) Merrill) variety cultivated at the Gyeongnam Agricultural Research and Extension Services was used in the experiment. The sorting device was designed to separate soybeans, pods, and stalks, collecting only the soybean kernels. During the experiment, soybean stems were uniformly fed to measure the separation rate and collection efficiency. A standard k-ε turbulence model was employed for flow analysis, and the CFD-DEM coupling method was used to simulate the internal flow and particle movement within the sorting device. Additionally, CFD analysis results were utilized in DEM simulations, applying the Ganser drag model to analyze the separation characteristics of soybeans and pods. Finally, the study evaluated the performance of the soybean harvester's sorting device and determined the optimal fan speed using CFD-DEM coupled simulations. The fan speeds were set to 900 rpm, 1,000 rpm, 1,100 rpm, and 1,200 rpm, respectively. The RMSE range between measured and simulated airflow speeds in the sorting device was found to be 0.64 m/s to 1.12 m/s. Simulation results showed that the collection rate decreased with increasing fan speed, with a maximum collection rate of 94.08% at 900 rpm. The separation rate of soybean pods and stalks was low at 55%~60% for 900 rpm and 1,000 rpm, while it was higher at 86.38% for 1,100 rpm and 86.14% for 1,200 rpm. Overall, the optimal fan speed for achieving the best performance in both soybean collection and pod separation was determined to be 1,100 rpm

As environmental pollution has been serious, there is increasing stricter standards for automotive emissions. NOx and HC emissions regulation will be enforced when EURO-V emission standards go into effect. To meet those standards, we are developing oil separator for module gasoline in EURO-V. In order to improve the fuel economy and the emissions, blow-by gas and oil-particles are separated effectively in cylinder head cover by this module. To measure the oil separation efficiency of oil separator, we have the test bench for oil separation which could generates blow-by gas with oil mist. Thus, in this research, the development of the CCV system with cyclones ensures that it is better efficiency, economy, reliability than other types of oil separation.

The aim of this study is to provide fundamental informations that make it possible to use a cool stream simultaneously. We changed the pressure of compressed air that flows into a tube, the inner diameter of orifice that a cold stream exits, and the mass flow rate ratio. And in each case, we measured the temperature of a cold stream and the efficiency. From the study, following conclusive remarks can be made. As inlet pressure increases temperature distribution to increase. But, efficiency not to change. As a number of nozzle increases efficiency enlarge.

권력분립원리는 주로 ‘권력의 분할’과 ‘분할된 권력 사이의 견제와 균형’으로 이해되어 왔으나, 현대에는 ‘분할된 권력 사이의 분업과 협동’ 및 ‘국가작용의 효율성’의 의미가 재조명되고 있다. 후자의 의미에서 위헌법률심판은 법률을 합헌적으로 변화시키기 위한 국회와 헌법재판소 사이의 분업과 협동의 과정으로서 의미를 지니게 된다. 이러한 과정은 변이와 선택, 피드백을 기본 원리로 하는 변화의 일반이론으로 설명할 수 있는데, 이에 따르면 위헌법률심판은 법률을 합헌 상태로 변화시키기 위한 헌법재판소로부터 국회로의 피드백 장치에 해당된다. 이와 같은 피드백 기능이 효과적으로 이루어질수록 법률은 보다 효율적으로 합헌적으로 변화하게 된다. 이를 실질적으로 담보하는 제도적 장치로 「헌법재판소법」 및 「헌법재판소 심판규칙」상 헌법재판소 결정의 통보 제도와 「국회법」상 헌법재판소 위헌결정에 대한 위원회의 심사 제도가 있다. 이 두 제도는 특히 헌법불합치 결정의 경우 선고에 이은 단순한 후속 절차에 불과한 것이 아니라 법률 변화의 효율성을 제고하기 위해 필수불가결한 제도적 장치이다. 또한 한정위헌결정도 법률에 대한 위헌결정인 이상 법원이 아니라 국회에 대한 피드백임을 분명히 하기 위해 양적 일부위헌결정의 형태로 주문을 선고할 필요가 있고, 그러한 주문이 불가능할 경우에는 자제하는 것이 제도의 본질에 부합한다.

The classic understanding of the principle of separation of powers is ‘checks and balances between divided powers’. However, ‘cooperation among divided powers’ and ‘efficiency of state operation’ has drawn new attention in modern understanding. In the latter sense, judicial review of parliamentary statutes means division of labor and cooperation between the legislature and judiciary. This can be explained by the general theory of change, which explains change of everything by three components: mutation, selection, and feedback. According to this, Constitutional Court’s review on statutes serves as a feedback mechanism to the National Assembly. The more effective this feedback functions, the more efficiently the law will be changed constitutionally. As an institutional device that practically guarantees this feedback function, the Constitutional Court Act and Constitutional Court Judgment Rules provide the notification of decisions of the Constitutional Court, and the National Assembly Act provides the Committee of National Assembly’s deliberation of the Constitutional Court’s unconstitutionality decisions. These two systemic devices are not merely follow-up procedures of the pronouncement of judgement, but are indispensable feedback mechanism enhancing the effectiveness of legal changes. The ‘Conditionally Unconstitutional’ decisions should be rephrased as quantitative partial unconstitutional decisions to clarify the direction of feedback to the National Assembly. If the rephrasing is impossible, the Constitutional Court should avoid the conditionally unconstitutional decision.

본 연구는 가축분뇨 혐기성소화에서 발생된 바이오가스 이용 활성화를 위하여 효율적인 가스성상별분리 및 정제 방법을 모색코자 수행하였다. 바이오가스의 분리 및 정제를 위하여 폴리술폰 고분자 소재를 상분리법을 이용하여 중공사막을 제조하였고, 중공사막이 충진된 맴브레인 모듈을 제작하여 바이오가스 분리 및 정제를 실시하였다. 이러한 특징을 가진 중공사막을 사용하여 멤브레인 모듈을 제작하였으며, 제작된 멤브레인 모듈을 사용하여 혐기성소화조에서 발생하는 바이오가스를 분리 및 정제하였다. 바이오가스의 분리 및 정제를 위해서 멤브레인 모듈에 공급한 바이오가스는 실록산 0.1 ppm 이하, H2S3 ppm 이하, Dewpoint –20℃ 이하로 제어하여 공급하였다. 멤브레인 모듈의 운전압력은 4∼7 ㎏f/㎠,온도의 범위는 15∼45℃이였다. 가축분뇨에서 발생하는 바이오가스를 분리 및 정제한 결과, CH494.2%, CO2 92.0%로 분리 및 정제되었으며, 회수율은 CH4 102.1%, CO2 83.5%가 회수되었다. 따라서 본 연구에서 제작한 멤브레인 모듈을 사용한 바이오가스의 분리 및 정제 실험을 통해서 분리전 바이오 가스의 성분(CH4 68%, CO2 28%, O2 0.6%, H2S 1 ppm 이하, Balance 2.7%)에 대해서 CH494.2%, CO2 92.0%의 고농도 분리 및 정제가 가능한 것을 알 수 있었다