PURPOSES: This study aims to evaluate the effects of vehicle dynamic behaviors on ride quality. METHODS: Simulation and field test were conducted to analyze the behavior of a driving vehicle. The simulation program CarSIM was applied and an INS (Inertial Navigation System) was used for field experiments. A small simulator was developed to simulate vehicle behavior such as roll, pitch, and bounce. The panels evaluated the ride quality in five stages from “very satisfied”to “very dissatisfied.”Experiments were conducted on a total of 144 cases of vehicle behavior combinations. RESULTS: In both simulation and field tests, pitch is the largest and yaw the smallest. Especially in the field test, the amount of yaw is very low, about 7% of pitch and 18% of roll. The sensitive and extensive analysis conducted related ride quality with changing the frequency and amplitude. It was found that the most sensitive frequency range is 8 Hz across all amplitudes. Moreover, the combination of the roll and bounce was most sensitive to the ride quality at the low-frequency range. CONCLUSIONS: This result show that the vertical vehicle behavior (bounce) as well as the rotational behavior (roll and pitch) are highly correlated with ride quality. Therefore, it is expected that a more reasonable roughness index can be developed through a combination of vertical and rotational vehicle behavior.

The small-scale sewage treatement system with A2/O process was applied to evaluate applicability for Mongolian sewage, It was designed to have 10 m3/d flowrate and installed in Ulaanbaatar, Mongolia. During over 6month operation BOD, COD, TN, TP removal efficiency were measured and operation condition was optimized. In addition, MLSS concentration its internal circulation rate and DO were adjusted properly. BOD, COD showed average 88 perecent of removal and TN and TP achieved 81 percent and 88 percent removal efficency, respectively. Maxium influent concentration of BOD, COD, TN and TP was 214 mg/L, 300 mg/L, 24.3 mg/L and 5 mg/L respectively, which were decreased to 4.1 mg/L, 5.6 mg/L, 1.3 mg/L and 0.15 mg/L by the test system. This study show possibility tham small-scale sewage treatment system could be a useful system for scattered sewage wastewater treatment.

Scale formation is inevitable problem when seawater is treated by vacuum membrane distillation. The reason is the high concentration of calcium ion(Ca2+), sulfate ion(SO4 2-) and bicarbonate ion(HCO3 -). These ions form calcium sulfate(CaSO4) and calcium carbonate(CaCO3) on the membrane. The scale formed on membrane has to be removed, because the flux can be severely reduced and membrane wetting can be incurred. This study was carried out to investigate scale formation and effectiveness of acid cleaning in vacuum membrane distillation for SWRO brine treatment. It was found that permeate flux gradually declined until volume concentration factor(VCF) reached around 1.55 and membrane wetting started over VCF over 1.6 in the formation of precipitates containing CaSO4 during VMD operation. In contrast, when calcium carbonate formed on membrane, permeate flux was gradually reduced until VCF 3.0. The precipitates containing both CaSO4 and CaCO3 were formed on the membrane surface and in the membrane pore.

Mill scale, an iron waste, was used to separate magnetite particles for the adsorption of phosphate from aqueous solution. Mill scale has a layered structure composed of wustite (FeO), magnetite (Fe3O4), and hematite (Fe2O3). Because magnetite shows the highest magnetic property among these iron oxides, it can be easily separated from the crushed mill scale particles. Several techniques were employed to characterize the separated particles. Mill scale-derived magnetite particles exhibited a strong uptake affinity to phosphate in a wide pH range of 3-7, with the maximum adsorptive removal of 100%, at the dosage of 1 g/L, pH 3-5. Langmuir isotherm model well described the equilibrium data, exhibiting maximum adsorption capacities for phosphate up to 4.95 and 8.79 mg/g at 298 and 308 K, respectively. From continuous operation of the packed-bed column reactor operated with different EBCT (empty bed contact time) and adsorbent particle size, the breakthrough of phosphate started after 8-22 days of operation. After regeneration of the column reactor with 0.1N NaOH solution, 95-98% of adsorbed phosphate could be detached from the column reactor.

A typical snowfall pattern occurs over the east coastal region of the Korean Peninsula, known as the Yeongdong region. The precipitation over the Yeongdong region is influenced by the cold and dry northeasterly wind which advects over warm and moist sea surface of the East Sea of Korea. This study reveals the influence of large-scale factors, affecting local to remote areas, on the mesoscale snowfall system over the Yeongdong region. The National Centers for Environmental Prediction-Department of Energy reanalysis dataset, Extended Reconstructed sea surface temperature, and observed snowfall data are analyzed to reveal the relationship between February snowfall and large-scale factors from 1981 to 2014. The Yeongdong snowfall is associated with the sea level pressure patterns over the Gaema Plateau and North Pacific near the Bering Sea, which is remotely associated to the sea surface temperature (SST) variability over the North Pacific. It is presented that the relationship between the Yeongdong snowfall and large-scale factors is strengthened after 1999 when the central north Pacific has warm anomalous SST. These enhanced relationships explain the atmospheric patterns of recent strong snowfall years (2010, 2011, and 2014). It is suggested that the newly defined index in this study based on related SST variability can be used for a seasonal predictor of the Yeongdong snowfall with 2-month leading.

Recently, measures for reducing noise and vibration of a railroad station are actively being developed to enhance its property value and comfort level of passengers. In this paper, the applicability of the recently developed vibration mitigation method utilizing a platform TMD (Tuned Mass Damper) by installing a spring-damper system beneath the platform is experimentally verified using a bench scale structure. The two-story bench scale structure is built to simulate a real railroad station, and vibration reduction effect is verified by comparing acceleration before and after applying the platform TMD at the 2nd floor of the structure. The design parameters of the platform TMD system is determined based on vibration analysis result and the MTMD (Multiple TMD) theory recently developed to enhance the effectiveness of the platform TMD method. The vibration is excited to the bench-scale structure using a vibrator. The performance test result for a spring-damper system is also presented. The result of the experiment reveals that the platform TMD method can reduce the vibration of the bench-scale structure by greater than 5dB(V).

반 건조 소화 하수슬러지와 폐플라스틱을 혼합하여 파일롯 규모(85.3kg/hr)의 연속식 저온 (510℃~530℃) 열분해 실험을 하였다. 실험결과 열분해가스 발생량은 투입물 건량의 최대 68.3%, 발열 량은 40.9 MJ/Nm3 이었으며, 연속식 열분해에 따른 외기 유입율이 19.6%이었다. 오일은 투입물 건량 의 4.2%가 발생하였고, 저위발열량은 32.5 MJ/kg 이었으며 시설부식 등을 일으킬 수 있는 황과 염소의 함량이 각각 0.2% 이상이었다. 투입물 건량의 27.5%가 발생한 탄화물의 저위 발열량은 10.2 MJ/kg 이 었고, 용출시험 결과 지정폐기물에 해당하지 않았다. 열분해가스의 연소 배가스는 일산화탄소, 황산화물, 시안화수소 등의 배출농도가 특히 높았고, 다이옥신 (PCDDs/DFs)은 0.034 ng-TEQ/Sm3 로서 법적 기 준치 이내였다. 건조 배가스 응축으로 발생한 폐수는 수질오염물질 47개 항목 중 총질소, n-H 추출물질, 시안 등의 고농도 항목이 많아 전처리 후 하수처리장 등에서의 병합처리 방식을 고려할 필요가 있었다.

In this study, a direct contact membrane module was manufactured to be used in a pilot scale membrane distillation process to treat 3 m3/day of the digestate produced from anaerobic digestion of livestock manure. In order to investigate the performance of the membrane module, permeate flux was measured with and without spacer inside the module under various condition of temperature difference and cross flow velocity (CFV) through the membrane surfaces. Flux recovery rate after chemical cleaning was also investigated by applying three different cleaning methods. Additionally, thermal energy consumption was theoretically simulated based on actual pilot plant operation conditions. As results, we observed flux of the module with spacer was almost similar to the theoretically predicted value because the installation of spacer reduced the channeling effect inside the module. Under the same operating condition, the permeate flux also increased with increasing temperature difference and CFV. As a result of chemical in-line cleaning using NaOCl and citric acid for the fouled membranes, the recovery rate was 83.7% compared to the initial flux when NaOCl was used alone, and 87% recovery rate was observed when only citric acid was used. However, in the case of using only citric acid, the permeate flux was decreased at a rapid rate. It seemed that a cleaning by NaOCl was more effective to recover the flux of membrane contaminated by the organic matter as compared to a cleaning by citric acid. The total heat energy consumption increased with increasing CFV and temperature difference across the membrane. Thus, further studies should be intensively conducted to obtain a high permeate flux while keeping the energy consumption to a minimum for a practical application of membrane distillation process to treat wastewater.

단감원에서 식나무깍지벌레의 발생을 최소화하고자 시기별 발생특성과 우수 방제약제를 선발하였다. 가지에서 월동한 약충이나 암컷 깍지 는 9월 중순경에 교미 후, 월동에 들어가며 다음 해 봄철에 기온상승과 더불어 포란과 산란의 과정을 거쳐, 5월 중하순까지 산란을 마친 후 죽었 다. 수컷은 대부분 9월 말까지 우화하여 암컷과 교미하고 죽었으나 낙엽에서 월동하는 개체의 경우 모두 사멸하였다. 식나무깍지벌레의 산란 특 성은 매년 기상상황에 따라 차이가 있었고, 4월 중순부터 5월 중·하순까지 산란하고, 5월 초․ 중순에 산란 최성기를 보였다. 산란 량은 160개 정 도로 추정되며, 산란 최성기로부터 약 1주일 경과 후 부화 최성기를 보였다. 여름철에는 7월 초․ 중순에 시작하여 8월 중․ 하순까지 산란하고, 7월 말과 8월 초에 산란 최성기에 도달하며, 암컷 한 마리당 산란수는 봄철보다도 다소 적은 130개 정도이고, 난 기간은 약 4일로 추정되었다. 가는 가지에서 월동한 성충이 산란한 알로부터 부화한 1세대 약충은 가지와 잎에서 각각 10%, 90% 정도의 비율로 관찰되었다. 가는 가지에서 대부분 암컷 깍지로 발육하고 2009년 7월 27일 2세대 약충 발생 최성기에 도달한 다음 8월 중 ․ 하순경부터 월동처로 정하고 살아간다. 암컷과 수컷 깍지 는 8월 이전까지 잎에서 거의 비슷한 비율로 발육하다가, 2009년 8월 12일 이후 잎에서 수컷의 약충 발생 최성기를 시작으로 8월 27일 수컷 깍지 벌레 발생 최성기, 9월 14일 전후로 수컷 성충의 발생에 이르기까지 일관된 발생관계를 관계를 보여주었다. 8월 12일 잎에서 관찰되는 약충 중 75% 정도는 발육하여 수컷으로 우화하여 교미하고 죽는 것으로 나타났다. Buprofezine+dinotefurn (20+15) WP로 6월 9일과 16일 2회 방제 하고 7주 후에 생사충을 판정한 결과 방제가가 90.6%로 나타났다.

In changes of social environment, change of the use of land due to the change of residence type, industry and urban structure is an influential factor to safety vulnerable social group. From PTSD from disaster experience point of view, experience of disaster, damage from disaster, witness of disaster make people experience anxiety and confusion, increase the anxiety toward disaster and lead to difficulty in daily lives. As for the result of analyzing anxiety factors regarding disaster damage potential composed of 20 items of safety manager, damage potential of sink hole which recently rapidly increased was the highest, and followed by anxiety from safety damage potential of family, anxiety from phone call damage. Likewise, if the anxiety toward disaster damage potential is digitized, it contributes to setting safety management planning for disaster prevention as it visualizes the risk.