High voltage impulse (HVI) has been gained attention as an alternative technique that could control the CaCO3 scale problems encountered in water main, pipe, cooling tower and heat exchanger vessels. The aim of this study was to investigate the effect of electric field (E) and contact time (t) of HVI on reduction of Ca2+ concentration at two different temperatures of 25℃ and 60℃. A kinetic model on the effect of E and t was investigated too. As the E and t increased, the Ca2+ concentration decreased more than that of the control (= no HVI). The Ca2+ concentration decreased up to 81% at 15 kV/cm at 60℃, which was nearly 2 times greater than the control. With these experimental data-set of reduction of Ca2+ concentration under different E and t, the kinetic model was developed. The relationship between E and t required to reduce the concentration of Ca2+ by 30% was modeled at each temperature. The empirical model equations were; E0.83· t = 60.3 at 25℃ and E0.08· t = 1.1 at 60℃. These equations state the products of En and t is always constant, which means that the required contact time can be reduced in accordance with the increment of E and vice versa.

전기장에 의해 생성 된 진공 분극은 양자장에서 가상 전자-양전자 쌍의 재배열을 만든다. 그러나 정지 전하가 다른 장소로 이동할 때, 정지 전하에 의해 생성된 전기장은 사라질 것이다. 이때, 정지 전하에 의해 분극화된 가상 전자-양전자 쌍들은 같이 소멸된다. 가상 전자-양전자의 소멸 과정에서 가상 광자가 생성되는데, 이때 만들어지는 가상 광자들은 양자 전기 역학에서 자기력을 매개하는 광자가 된다. 이로 인하여, 전하의 이동은 자기장을 발생시키고, 전기장의 변화가 자기장을 생성하게 하는 원인이 된다.

The processing properties of spent hen and broiler chicken were investigated before and after treatment to improve texture characteristics. Each treatment consisted steaming (S) with 85℃ for 20 min, Pulsed Electric Field (PEF) with 1.5 KV/cm for 4 sec, and Super Heated Steam (SH) with an oven temp. of 300℃, a steam temp. of 350℃ for 8 min. The yield of spent hen and broiler were 66.85% and 63.80% respectively in the control, but decreased in every treatment was lowest at 61.05% in the PEF treatment (p<0.05). In the color test, L value decreased, but the a and b values increased regardless of the species of spent hen or broiler. In the test of heating loss, the S treatment of spent hen had the highest result of 45.25% but lowest of 30.66% in the SH treatment of the broiler. When it was compared with various treatments, SH after PEF treatment showed the better result in terms of heating loss than the PEF or SH treatment respectively. In the test of texture, the broiler showed the lowest hardness of 5.57 kg in the SH (p<0.05). Otherwise, the spent hen resulted in 14.08 kg of hardness in steaming after PEF, but it improved significantly to 10.73 kg in SH after PEF. In the test of 9 scored sensory evaluation of overall palatability, 7.8 point was the best score with SH treatment in the broiler. The best score in spent hen was 6.3 point which was SH after PEF treatment. With this experiment, SH after PEF was the condition in the treatments to have the better texture of spent hen.

Broccoli, one of Brassica vegetables, has been known to possess various health beneficial activities including anti-inflammation, anti-oxidation and anti-cancer etc. Various metabolites were indicated as active compounds in broccoli. Glucosinolates such as glucoraphanin, glucobrassicin, glucoerucin and isothiocyanates, i.e. sulforaphane, which is produced through the enzymatic action of myrosinase are getting focus as their bioactivities. In this study, we treated broccoli with pulsed electric field (PEF) processing and the metabolite profiles were investigated based on the metabolomics analysis. PEF process was applied to stem and floret of broccolis with three different levels; 500, 1000, 1500 pulses with 2 kV/cm, then metabolites were extracted with 70% methanol. Metabolomic analysis was carried out with mass spectrometry through multivariate statistical analysis based on the OPLS-DA model. Significant changes of metabolite profiles were observed by PEF treatment and specific metabolites were affected as dose dependent manner. Content of major glucosinolates compounds such as glucoerucin, glucoiberin, glucoraphanin, glucobrassicin, 4-hydroxy glucobrassicin, and 4-methoxy glucobrassicin were significantly reduced, while sulforaphane was distinctively increased in PEF treated broccolis. The results implied that myrosinase released from vacuole by PEF processing transformed glucosinolate into isothiocyanate, which would be useful findings for enhancing bioactivity of broccoli by simple PEF treatment.

As basic research to develop HEV and EV agricultural field machinery, the present study analyzes the technical trend of electric agricultural field machinery through product analysis, paper analysis, and patent analysis concerning HEV and EV in the automobile, construction machinery, and agricultural machinery sectors. For product analysis, the homepages of companies in these sectors were consulted to analyze the number of products of each company. For paper analysis, key words related to HEV and EV were selected, a search formula was drawn up, and articles search sites were consulted. And for patent analysis too, key words were selected and then a search formula was drawn up to examine published patent applications or registered patent applications, and trends were analyzed by structure, country, and year. The number of HEV and EV products were 17 in the automobile area, 8 in construction machinery, and 4 in agricultural machinery. Notably, in the agricultural machinery area, all HEV and EV products were from advanced companies overseas. In terms of papers, papers published in the past 5 years were searched and 33,195 papers were from the automobile area, 3,806 were from construction machinery, and 2,687, the fewest papers, were from the agricultural machinery area. A search of patents in the electric drive technology area in Korea, USA, and Japan, and Europe showed 1,927 valid patents, with 1,120 in Japan, 497 in USA, 193 in Korea, and 117 in Europe. Analysis of the trend of research on electric agricultural field machinery by product, paper, and patent shows the development of HEV and EV technology in Korea is insufficient compared to USA, Japan, and Europe, which means rapid technological development is needed.

Pulsed electronic field(PEF) 처리에 의한 우유 단백질과 물리화학적 특성의 변화를 확인하기 위하여 원유, 탈지유, HTST, LTLT, UHT 우유를 PEF 처리하였다. 시료 중의 단백질을 SDS-PAGE로 확인하였을 때, PEF 처리에 의한 우유 단백질의 변성은 관찰할 수 없었다. Differential scanning calorimetry(DSC)로 우유 단백질의 열변성 정점 온도(Td)를 분석한 결과, 탈지유를 65oC에서 PEF 처리하였을 때 Td가 87.66oC에서 97.18oC로 증가하여 PEF 처리가 우유 단백질의 변성에 영향을 미치는 것을 확인하였다. PEF 처리에 의한 alkaline phosphatase, protease, lactoperoxidase의 잔존효소활성을 측정한 결과, 원유와 탈지유에서 alkalinephosphatase는 PEF 처리에 의해 효소활성이 감소하였다. 또한 protease와 lactoperoxidase의 활성은 PEF 처리에 의해 영향을 받지 않았다. 65oC에서 PEF 처리한 원유는 처리하지 않은 원유보다 높은 갈색도를 나타내었으나, 기타 우유는 PEF에 의한 유의적인 차이가 없었다. 우유를 PEF 처리하였을 경우 산도의 변화는 관찰되지 않았고 pH의 경우에도 PEF 처리 여부에 따라 유의적인 차이는 있었으나 크게 변화하지는 않았다.

PURPOSES : This study aims to investigate the snow-melt effects of an underground electric heater's snow-melt system via a field performance test, for evaluating the suitability of the system for use on a concrete pavement. The study also investigates the effectiveness of dynamic measures for clearing snow after snowfall events. METHODS : In order to check the field applicability, in November 2010, specimens were prepared from materials used for constructing concrete pavements, and underground electric heating meshes (HOT-mesh) were buried at depths of 50 mm and 100 mm at the site of the Incheon International Airport Construction Research Institute. Further, an automatic heating control system, including a motion sensor and pavement-temperature-controlled sensor, were installed at the site; the former sensor was intended for determining snow-melt effects of the heating control system for different snowfall intensities. Pavement snow-melt effects on snowy days from December 2010 to January 2011 were examined by managing the electric heating meshes and the heating control system. In addition, data on pavement temperature changes resulting from the use of the heating meshes and heating control system and on the dependence of the correlation between the outdoor air temperature and the time taken for the required temperature rise on the depth of the heating meshes were collected and analyzed. RESULTS : The effects of the heating control system's preheat temperature and the hot meshes buried at depths of 50 mm and 100 mm on the melting of snow for snowfalls of different intensities have been verified. From the study of the time taken for the specimen's surface temperature to increase from the preheat temperature (0℃) to the reference temperature (5~8℃) for different snowfall intensities, the correlation between the burial depth and outdoor air temperature has been determined to be as follows: Time=15.10+1.141Depth-6.465Temp CONCLUSIONS : The following measures are suggested. For the effective use of the electric heating mesh, it should be located under a slab it may be put to practical use by positioning it under a slab. From the management aspect, the heating control system should be adjusted according to weather conditions, that is, the snowfall intensity.

The alignments of polystyrene particles of 1μm and 5μm sizes in an aqueous colloidal system were observed by varying the electric field strength, the frequency and the water flow. Spherical mono-dispersed polystyrene particles dispersed in pure water were put into a perfusion chamber; an AC electric field was applied to the Au/Cr electrodes with a 4 mm gap on the glass substrate. The mixture of the 1μm and 5μm sized polystyrene particles at 0.5 vol% concentrations for each size was set in the dielectrophoresis conditions of 1 kHz and 150 V/cm. Large particles of 5μm size were aligned to form chains as the result of the dielectrophoresis force interaction. On the contrary, small particles of 1μm size did not form chains because the dielectrophoresis force was not sufficiently large. When the electric field increased to 250 V/cm, small particles were able to form chains. After the chains were formed from both large and small particles, they began to coalescence as time passed. Owing to the electroosmotic flow of water, wave patterns along the perpendicular direction of the applied electric field appeared at the conditions of 200 Hz and 50 V/cm, when the dielectrophoresis force was small. This wave pattern also appeared for small particles at 1 kHz and 150 V/cm conditions due to the flow of solvent when water was forced to circulate.