During indoor air conditioning, cold condensate is generated. But until recently, this condensate has not been recycled. This experiment and research is on the technology of the condensed water recycling in air conditioning. This study demonstrates the effect of condensate recycling, contributes to energy saving and water use reduction. For this purpose, the test equipment was installed to measure the temperature of the condensate generated in the fan-coil unit, and the performance of the high-pressure pump to be applied to the cooling pipe was examined. As a result, the water quality and energy saving effect.

Corrosion inhibitors including calcium hydroxide have been used to prevent corrosion in the pipes for tap water supply. The corrosion index (i.e., Langelier Index) differs by area and water quality. The corrosion indices of the areas studied differed by more than 2.0. The ‘homogenized’ calcium hydroxide was added to the treated water at the K water treatment plant, in order to increase the value of the corrosion index and the concentration of calcium. As the result, the concentration of calcium was increased while the turbidity and pH changed little. The corrosion rate of the tap water with the 'homogenized' calcium hydroxide could be slowed down pretty much. The results suggested that the technology of 'homogenization' of calcium hydroxide can applied to tap water and desalinated water to prevent corrosion in water pipes even in corrosive pipes.

The effects of chitosan upon the experimentally induced differentiation of MDPC-23 cells, derived from mouse dental papilla cells, were investigated by RT-PCR, observations of cell morphology and Alizaline red-S staining. Chitosan was found to significantly increase and accelerate the expression of ALP mRNA but decrease the ColI transcript levels, as compared with the control, in a time-dependent manner during the differentiation of MDPC-23 cells. Chitosan also significantly downregulated ON mRNA expression and accelerated mineralization in differentiating MDPC-23 cells. These results suggest that chitosan facilitates odontoblast differentiation and mineralization and may have potential clinical applications as a dentin regeneration material.

1993년 6월부터 1994년 5월까지 진양호에 대한 육수 학적 조사가 월간 조사로 실시되었다. 표층의 투명도, 엽록소 a, 총질소, 총인농도 및 일차생산력은 조사기간 각각 0.8~3.5 m, 0.9~13.6 mgChl/m3, 0.78~2.32 mgN/l, 11~56 mgP/m3, 270~2,160 mgCm-2 day-1로 이들의 하계 평균농도로 산정한 진양호의 영양상태는 부영양호에 해당된다. 진양호의 투명도에는 엽록소 a 보다 부유물질 (SS)로 나타나 무기성부유물질(NVSS)이 투명도에 크게 영향을 미치는 것으로 보인다. 총인 농도는 하계에 높게 나타났고 질소농도보다 상대적으로 큰 계절변동을 보였다. 연간 TN/TP 원자비는 61~334으로 국내 대형인공호 중 대체로 낮은 수준에 해당된다. 식물플랑크톤군집은 하계에는 남조류인 Microcystis ichthyoblabe, M. aeruginosa과 녹조류인 Chlorella sp.와 Cosmarium sp.가 우점하였으며 추계와 동계에는 규조류인 A. granulata, A. granulata var. angustissima A. distans가 우점하였다. 동물플랑크톤은 요각류 유생이 연중 우점하였고 8월과 10월에는 요각류 유생 이외에 지각류인 Bosminopsis deitersi, Bosmina longirostris가 각각 우점하였다. 조사 기간 진양호 퇴적물의 조사정점별 유기탄소 및 인, 질소의 평균 함량은 각각 0.4~9.4 mgC/g, 0.14~0.62 mgP/g, 0.59~1.23 mgN/g으로 동기간 조사된 체류시간이 긴 호수들보다 크게 낮았다. 진양호의 연간 평균 C/N 비는 2.6~9.2로 oligohumic한 상태이다. 진양호의 연간 수면 적당 인부하량은 6.4 gPm-2 yr-1로 부영양화 임계부하량 (4.1 gPm-1 yr-1)을 초과하고 있다. 진양호의 유역으로부 터의 유기물 유입량은 3,429 tonC/yr이며 식물플랑크톤 의 일차생산에 의한 자체생성유기물량은 4,632 tonC/yr 으로 전체 유기물부하량중 자체생성 유기물 비율이 높았으나 외부 유역의 유기물 부하량도 크게 나타났다. 진양호와 같이 체류시간이 짧은 호수는 체류시간이 긴 호수들에 비해 자체생성유기물의 비중이 낮기 때문에 유역에서 발생되는 유기물의 처리효율을 높일 경우 수질 개선효과가 크게 나타날 것으로 보이며 아울러 부영양화 원인물질인 인, 질소는 비점오염원에 대한 관리에 초점을 맞춰야 할 것으로 보인다.

To determine the appropriate harvest maturity of mulberry to prolong the freshness during distribution, mulberries were classified into three groups (80%, 90%, and 100%) based on their degree of maturity and then compared for their firmness, color, anthocyanin, soluble solids content, pH, titratable acidity, viable cell, mold and sensory quality. They were then investigated for quality changes by maturity under different distribution temperature at 20℃, 10℃ and 0℃. Immediately after harvest, the 80% matured mulberries were shown to be the firmest and 1.74 and 2.64 times firmer than 90% and 100% matured mulberries respectively. The more mature the mulberries were the lower the “a” value was while anthocyanin content was higher. The soluble solids content and pH of mulberries increased as they matured. Less mature the mulberries were the higher titratable acidity was and lower microbial levels in mulberries were. In terms of sensory quality, color of the 100% matured mulberries was the highest but the 90% matured mulberries were most preferred based on other sensory indexes. In comparison to storability of mulberries by maturity, although the firmness of the 80% matured mulberry decreased rapidly, they were the firmest during distribution periods. The level of mold of the 100% matured mulberries was higher than others. Moreover, the more mature mulberries were the quicker they deteriorated. According to quality indexes, depending on maturity and sensory evaluation of mulberry distributed at different temperatures, the storability of the 80 and 90% matured mulberries were higher than that of the 100% matured mulberries. In conclusion, judging by their sensory quality, the 90% matured mulberries were more appropriate for harvesting than the 80% matured mulberries.

For the investigation of the quality loss of mulberry during distribution, the deterioration rate, microorganism growth, and sensory quality of mulberry kept at 20, 10 and 0℃, respectively, were investigated. Based on the results, the optimum temperature for extending the freshness of mulberry was examined in the temperature range of -1.5 to 1.5℃. The level of mold in the mulberry kept at 20 and 10℃, respectively, was much higher than that kept at 0℃. The quality of the mulberry deteriorated seriously after two days at 20℃, after six days at 10℃, and after 12 days at 0℃. The marketability of mulberry as determined via sensory evaluation was much more prolonged by decreasing the keeping temperature from 20 to 0℃. To extend the freshness of mulberry using these results, the optimum temperature was evaluated at the range of -1.5 to 1.5℃ for 25 days. During storage, the changes in the color and pH of the berry were not significantly different by storage temperature, but the microbial levels and deterioration rate increased in the order of 1.5, 0, and -1.5℃. In particular, the firmness of the mulberry decreased rapidly at 1.5℃, showing a significant difference from the others. The titratable acidity and sugar contents decreased gradually at all the applied temperatures. The anthocyanin content decreased sharply at 1.5℃ but gently changed at -1.5℃. Through the sensory results of this study, it was adjudged that the marketability of mulberry could be maintained about 0.7 times at 1.5℃ and 1.3 times at -1.5℃ compared with the marketability at 0℃, respectively.

To extend the shelf-life of freshly cut lotus roots, the effect of their heat treatment in water at 50℃ was investigated and compared with that of their treatment using 1 percent ascorbic acid and citric acid during their storage. In addition, consecutive heat and acid treatment was applied to freshly cut lotus roots to determine its synergy effect. The level of molds in the sample that was treated with 50℃ water for 60 minutes was the lowest among the treatments and 3.89 log CFU/g after 12-day storage, whereas the population of the control was 6.81 log CFU/g for the same number of days. During the storage, the surface color of the samples showed higher ΔE values and lower L values than that of the initial sample. The color with the heat treatment hardly changed, unlike in the control. The consecutive treatments with hot water and acid showed less quality loss than the simple heat treatment. The marketable quality was maintained for three days without any treatment, for nine days with the heat treatment, and for 12 days with the consecutive treatments of hot water and acid. The consecutive treatments with hot water and acid, especially with 1 percent citric acid, extended the shelf-life of the freshly cut lotus roots by inhibiting the growth of microorganisms and the browning.

This study was conducted to investigate runoff characteristics of non-point pollutants source at the urban area in boeun area, Chungbuk Province. The monitoring site covering the watershed of 2.11 km 2 contains about 40.3 % of total watershed with the urban area. The monitoring was conducted with six events for five months and Event Mean Concentration(EMC) and Site Mean Concentration(SMC) of SS, BOD, CODMn, T-N, T-P were calculated on the result of the water quality parameters. As a result of the comparion between Arithmetic Mean Concentration and Event Mean Concentration, it showed that over all Event Mean Concentration was higher than Arithmetic Mean Concentration. And it showed that SS, BOD, T-P featured the first-flushing effect, showing relatively high concentration in early-stage storm event.