Earticle

In the automotive information display device industry, products with high reliability and wide temperature conditions are required, and interest in products that do not cause lighting defects even under extremely low temperature conditions is increasing. In this experiment, we produced an LED backlight unit for car navigation in a cryogenic environment. And to make this backlight unit, we used 12 side-emitting white LEDs with 3[W] high power LEDs. This backlight unit emits up to 18,000[nits] at a power consumption of 36[W] and has a startup voltage time of less than 1[ms] at -50° ambient temperature.

In 2010, a new variety for sawdust cultivation,was produced by monokaryotic-monokaryotic crossing between Sanjo 701ho and FMRI0995. The optimum temperature for Sanjo 708ho mycelial growth was 25oC; mycelial growth on potato dextrose agar was 51.6 mm over 7 days. The fruiting pattern was sporadic, and the optimal temperature range for fruiting was 5~20oC. Regarding fruiting body characteristics, the pileus was 65.8 mm in size, 16.1 mm in thickness, and hemispherical in shape. The stipe was 42.6 mm in and 19.6 mm in thickness. Mproductivity was good during thelow-temperature period from autumn to spring, with an average productivity of 310.7 g/bag.

Cars using diesel have always had problems with reducing exhaust fumes, and have been studied steadily in this regard. There were studies on the remanufacturing effect of DOC catalyst deactivated by diesel vehicle smoke reduction device, analysis of vehicle fire accident cases caused by damage to diesel vehicle smoke reduction device, and related studies on the remanufacturing effect of diesel vehicle smoke reduction device DPF. This study also developed a burner system in a smoke reduction device suitable for exhaust engines to completely burn smoke generated by institutions using diesel engines in low-temperature exhaust gases. Following the development of the existing high-performance heater, burner structure capable of maintaining ignition state in exhaust flow, pulsation generated by diesel engines, and exhaust flow control unit, the actual configuration, function and effect of the device, development contents, basic data and abnormalities of the vehicle, and comparison with other developed products.

Cars using diesel have always had problems with reducing exhaust fumes, and have been studied steadily in this regard. There were studies on the remanufacturing effect of DOC catalyst deactivated by diesel vehicle smoke reduction device, analysis of vehicle fire accident cases caused by damage to diesel vehicle smoke reduction device, and related studies on the remanufacturing effect of diesel vehicle smoke reduction device DPF. This study is also to develop an exhaust flow control unit suitable for an exhaust engine to completely burn smoke generated by an engine using a diesel engine in a low temperature exhaust gas. The main systems to be developed are high-performance heaters, burner structures that can maintain ignition in exhaust flows, and exhaust flow control units that reduce exhaust gas backflow effects caused by diesel engines.

Cars using diesel have always had problems with reducing exhaust fumes, and have been studied steadily in this regard. There were studies on the remanufacturing effect of DOC catalyst deactivated by diesel vehicle smoke reduction device, analysis of vehicle fire accident cases caused by damage to diesel vehicle smoke reduction device, and related studies on the remanufacturing effect of diesel vehicle smoke reduction device DPF. This study also developed an optimized system for complete combustion of smoke generated by institutions using diesel engines in low-temperature exhaust gases. The main systems to be developed are high-performance heaters, burner structures that can maintain ignition in exhaust flows, and exhaust flow control units that reduce exhaust gas backflow effects caused by diesel engines.

Cars using diesel have always had problems with reducing exhaust fumes, and have been studied steadily in this regard. There were studies on the remanufacturing effect of DOC catalyst deactivated by diesel vehicle smoke reduction device, analysis of vehicle fire accident cases caused by damage to diesel vehicle smoke reduction device, and related studies on the remanufacturing effect of diesel vehicle smoke reduction device DPF. This study also developed a burner system in a smoke reduction device suitable for exhaust engines to completely burn smoke generated by institutions using diesel engines in low-temperature exhaust gases. The main systems to be developed are high-performance heaters, burner structures that can maintain ignition in exhaust flows, and exhaust flow control units that reduce exhaust gas backflow effects caused by diesel engines.

Cars using diesel have always had problems with reducing exhaust fumes, and have been studied steadily in this regard. There were studies on the remanufacturing effect of DOC catalyst deactivated by diesel vehicle smoke reduction device, analysis of vehicle fire accident cases caused by damage to diesel vehicle smoke reduction device, and related studies on the remanufacturing effect of diesel vehicle smoke reduction device DPF. This study is also to develop a burner structure in a smoke reduction device suitable for an exhaust engine to completely burn smoke generated by an engine using a diesel engine in a low-temperature exhaust gas. The main systems to be developed are high-performance heaters, burner structures that can maintain ignition in exhaust flows, and exhaust flow control units that reduce exhaust gas backflow effects caused by diesel engines.

This study was carried out to investigate the effects of dietary energy levels on growth performance, blood parameter, and intestinal morphology of Pekin ducks in low temperature. A total of 500, 21-d-old Pekin ducks (initial BW = 1,089 ± 5.21 g) were evenly assigned to five dietary treatments (2,950, 3,000, 3,050, 3,100, or 3,150 kcal AME/kg, calculated on an as-is basis) with four replicates (pens) for each treatment (25 ducks per pen). During the experiment, hens were provided with feed and water ad libitum. Overall, increasing dietary energy levels corresponded to an increase of final body weight and body weight gain (linear, p < 0.01). Feed intake decreased (linear, p < 0.01) and feed conversion ratio increased (linear, p < 0.01) with increasing levels of energy. There were no significant differences (p < 0.05) in the level of leukocytes between groups. However, heterophils decreased (quadratic, p < 0.05) and lymphocytes increased (linear, p < 0.01) as inclusion of dietary energy levels increased. The H/L ratio increased (linear, p < 0.01) with increasing dietary energy levels while serum corticosterone levels decreased at overall experimental periods. Triglycerides increased (linear and quadratic, p < 0.05) with increasing dietary energy levels. There were no significant changes in villus height or crypt depth of the jejunum at overall experimental. In conclusion, increasing concentrations of dietary energy levels up to 2,950?3,150 kcal/kg in diet. Additionally, 3,150 kcal/kg dietary energy had been revealed more beneficial and could be practiced as protective management for the Pekin ducks reared under low ambient temperature (8°C to 10°C).

The study aimed to investigate the effect of low-frequency oscillations on the cow udder, milk parameters, and animal welfare during the automated milking process. The study’s objective was to investigate the impact of low-frequency oscillations on the udder and teats’ blood circulation by creating a mathematical model of mammary glands, using milkers and vibrators to analyze the theoretical dynamics of oscillations. The mechanical vibration device developed and tested in the study was mounted on a DeLaval automatic milking machine, which excited the udder with low-frequency oscillations, allowing the analysis of input parameters (temperature, oscillation amplitude) and using feedback data, changing the device parameters such as vibration frequency and duration. The experimental study was performed using an artificial cow’s udder model with and without milk and a DeLaval milking machine, exciting the model with low-frequency harmonic oscillations (frequency range 15?60 Hz, vibration amplitude 2?5 mm). The investigation in vitro applying low-frequency of the vibration system’s first-order frequencies in lateral (X) direction showed the low-frequency values of 23.5?26.5 Hz (effective frequency of the simulation analysis was 25.0 Hz). The tested values of the first-order frequency of the vibration system in the vertical (Y) direction were 37.5?41.5 Hz (effective frequency of the simulation analysis was 41.0 Hz), with higher amplitude and lower vibration damping. During in vivo experiments, while milking, the vibrator was inducing mechanical milking-similar vibrations in the udder. The vibrations were spreading to the entire udder and caused physiotherapeutic effects such as activated physiological processes and increased udder base temperature by 0.57℃ (p < 0.001), thus increasing blood flow in the udder. Used low-frequency vibrations did not significantly affect milk yield, milk composition, milk quality indicators, and animal welfare. The investigation results showed that applying low-frequency vibration on a cow udder during automatic milking is a non-invasive, efficient method to stimulate blood circulation in the udder and improve teat and udder health without changing milk quality and production. Further studies will be carried out in the following research phase on clinical and subclinical mastitis cows.

One of the recent proposals with nuclear magnetic resonance (NMR) is a multi-bore NMR which consists of array of magnets which could present possibilities to quickly cope with pandemic virus by multiple inspection of virus samples. Low temperature superconductor (LTS) can be a candidate for mass production of the magnet due to its low price in fabrication as well as operation by applying the helium zero boil-off technology. However, training feature of LTS magnet still hinders the low cost operation due to multiple boil-offs during premature quenches. Thus in this paper, LTS magnet with low mechanical stress is designed targeting the “training-free” LTS magnet for mass production of magnet array for multi-bore NMR. A thorough process of an LTS magnet design is conducted, including the analyses as the followings: electromagnetics, mechanical stress, cryogenics, stability, and protection. The magnet specification was set to 4.7 T in a winding bore of 85 mm, corresponding to the MR frequency of 200 MHz. The stress level is tolerable with respect to the wire yield strength and epoxy crack where mechanical disturbance is less than the minimum quench energy.

황화수소(H2S)는 고농도의 유기물이 모여있는 혐기성 환경에서 발생하며 대표적으로 퇴적토에서 발생한다. 이는 호수 내 어류의 집단 폐사나 악취 등의 주요 원인 중 하나이다. 현재 H2S는 주로 활성탄과 금속산화물을 통해 처리한다. 본 연구에서는 황화수소와의 반응성이 우수한 구리(Cu)와 철(Fe)를 TiO2 기반에 합성 방법 중 하나인 함침법을 활용하여 Cu-Fe/TiO2를 제작하였으며 H2S 흡착효율 평가 및 표면분석을 진행하였다. 위 흡착제는 Fe(NO3)3⦁9H2O 2 g, Cu(NO3)2⦁3H2O 2 g를 TiO2 5 g에 2시간을 교반한 후 80 °C에 48시간 동안 건조를 진행한 시료를 소성로를 사용하여 400 °C에 2시간 소성하여 제조하였다. H2S 흡착효율은 10 ppm H2S를 1.0 L/min의 유속으로 주입하여 제거된 H2S 양을 계산하여 평가하였다. 또한, 각 금속의 함침 여부를 확인하기 위해 SEM분석, 표면적 변화를 확인하기 위해 BET분석, 금속의 결정구조를 확인하기 위해 XRD 분석을 진행하였다. 실험 결과, Cu-Fe/TiO2의 H2S 제거량은 일반 TiO2 대비 약 240 배 향상되었으며, SEM과 XRD분석을 통해 Cu와 Fe가 성공적으로 함침되었음을 확인하였다..

본 연구에서는 Lab 규모의 생물반응장치를 제작하여 운전조건 변화(온도, 저해물질(Cl), 활성화된 질산화균 투입 등)가 질 산화에 미치는 영향을 파악하여 저온 조건에서 질산화효율을 향상시킬 수 있는 방안을 찾고자 하였다. NO2 −-N+NO3 −-N 농 도 실험에서 20oC의 경우 염소를 투입하여 질산화균을 사멸한 후 활성화된 질산화균을 투입하면, 정상수준까지 회복하는 데 약 4일 정도 소요되었다. 10oC의 경우, 활성화된 질산화균을 투입하여 이전 상태로 회복 되는 데는 약 7일 정도 소요되어 20oC 에 비하여 약 3일이 더 소요되었다. 비질산화속도 실험에서는 10oC 운전조건에서 활성화된 질산화균 투입 후 1일경과시 비 질산화속도는 0029 mgN/gSS/hr에서 6일 경과시 0.767 mgN/gSS/hr까지 증가하였다. 선형 모형식과 지수함수 모형식에 의한 8일 경과후의 비질산화속도는 각각 0.840, 3.625 mgN/gSS/hr로 예측되어 정상수준인 2.592 mgN/gSS/hr을 상회하는 것으로 예상되었다. 본 연구를 통하여 저온 운전시 활성화된 질산화균을 주입하면 질산화효율을 향상시키는데 많은 효과가 있음을 확인하였다. 향후 연구에서 현장별 운전특성을 고려한 ANB 투입량의 결정, 효율적인 ANB reactor의 설계 등에 대한 추가적 인 연구가 진행된다면 동절기 질산화효율 향상에 많은 기여를 할 수 있을 것이다.

In this study, we have developed a lab scale bioreactor to identify the characteristics of nitrification reaction according to operation condition (temperature, inhibitor (as Cl), activated nitrifying bacteria (ANB). etc) to improve nitrification efficiency at low temperature. Recovery rate of nitrification took about 4 days to reach the normal level by injected ANB after inhibition shock of CI injection at 20oC, when measured the concentration of NO2 −-N+NO3 −-N in the effluent. In the case of 10oC, recovery of nitrification rate took about 4 days to reach the level of half to the normal level and 7 days for complete recovery which took 3 days more than those at 20oC. At 10oC considering the winter season, the specific nitrification rate(SNR) of the from 1 day to 6 days after injected ANB according to its operation condition increased from 0.029 to 0.767 mgN/gSS/hr. The simulated SNR for the 8th day after the injected ANB at 10oC was 0.840, 3.625 mgN/gSS/hr, respectively as linear function and exponential function, expecting to exceed level of 2.592 mgN/gSS/hr at normal condition. It was confirmed that injection of ANB during low temperature operation has many effects for improving nitrification efficiency through this study. In future studies, if further studies are carried out the determination of ANB injection and the design of efficient ANB reactor considering the changes of operating characteristics by site, it will contribute to the improvement of nitrification efficiency in winter season.

This study was carried to investigate the suitable conditions of Pleurotus eryngii through precooling for the more long-term freshness. The time to be same temperatures between P. eryngii and storage room through precooling at 0℃ and 4℃ were showed 2 hours and 5.5 hours, respectively. P. eryngii was cooled within 6 hours and 18 hours at 0℃ and 4℃ with two type, forced air cooling and pressure cooling. After precooling, P. eryngii was packed 400±10g with anti-fog film, and then stored at 4±1℃. In all treatment of precooling, the weight loss was peaked at 25 days and hardness of P. eryngii were decreased at 10 days during storage. There were no significant freshness differences between precooling type and conditions. It was found that the optimum stored period of P. eryngii at 4℃ after precooling was estimated to be 30~35days. Consequently, it is necessary to elucidate efficient and economic precooling conditions.

We studied the distribution of the current density and its magnetic-field dependence in GdBCO coated conductors with AC bias currents using low temperature scanning Hall probe microscopy. We selectively measured magnetic field profiles from AC signal obtained by Lock-in technique and calculated current distributions by inversion calculation. In order to confirm the AC measurement results, we applied DC current corresponding to RMS value of AC current and compared distribution of AC and DC transport current. We carried out the same measurements at various external DC magnetic fields, and investigated field dependence of AC current distribution. We notice that the AC current distribution unaffected by external magnetic fields and preserved their own path on the contrary to DC current.

In this study we attempted to analyze the change of protein and mycelial activity during low temperature storage progressed. At first, esterase and peroxidase isozymes were detected at third and fourth subculture in Pleurotus ostreatus and peroxidase isozymes in Pleurotus eryngii were detected at first and second subculture but esterase isozymes showed almost same band patterns subculture advanced. The decolorization ratio of media color including indicator were decreased according to subculture advanced in P. ostreatus and P. eryngii. However there were not significantly difference of mycelial growth, fruit body yield, esterase isozyme band pattern and laccase activity of P. eryngii according to storage periods at low temperature. Therefore, it was possible to store sawdust spawn of P. eryngii at 4℃ for 120days.

In this study we attempted to analyze the change of protein and mycelial activity during low temperature storage progressed. At first, esterase and peroxidase isozymes were detected at third and fourth subculture in Pleurotus ostreatus and peroxidase isozymes in Pleurotus eryngii were detected at first and second subculture but esterase isozymes showed almost same band patterns subculture advanced. The decolorization ratio of media color including indicator were decreased according to subculture advanced in P. ostreatus and P. eryngii. However there were not significantly difference of mycelial growth, fruit body yield, esterase isozyme band pattern and laccase activity of P. eryngii according to storage periods at low temperature. Therefore, it was possible to store sawdust spawn of P. eryngii at 4℃ for 120days.