• 한국미생물·생명공학회지
• /
• 제27권2호
• /
• pp.166-171
• /
• 1999

This study was conducted to investigate the removal rate of nitrogen and phosphorus, and lipid production from a swine wastewater by Botryococcus braunii UTEX 572 in an outdoor photobioreactor. B. braunii successfully predominated in competition with bacteria and other algae, especially Oscillatoria, which were grown spontaneously in a secondary-treated swine wastewater, under the conditions of incubation temperature at $25^{\circ}C$ and increased inoculum amount at 287mg/l. There was a significant relationship between dry weight of B. braunii and absorbance of culture solution at 680mn(r2=0.967), suggesting that the latter is as good as the former commonly used for the measurement of algal biomass which is considerably time-consuming. The removal rates of COD, TOC, total nitrogen, and total phosphorus from the swine wastewater were 33.2$\pm$2.6% and 32.8$\pm$3.2, respectively, which showing no different between them. These results suggested that the mass cultivation of B. braunii in an outdoor photobioreactor could be used for the advanced treatment of swine wastewater and lipid production.

• International Journal of Air-Conditioning and Refrigeration
• /
• 제13권2호
• /
• pp.107-118
• /
• 2005

An experimental investigation was made to study two-phase flow distribution in a T-type distributor of slit fin-and-tube heat exchanger using R-22. Experiments were carried out under the conditions of saturation temperature of $5^{\circ}C$ and mass flow rate varying from 0.6 to 1.2kg/min. The inlet air has dry bulb temperature of $27^{\circ}C$, relative humidity of 50% and air velocity varying from 0.63 to 1.71m/s. A comparison was made between the predictions from the previously proposed tube-by-tube method and the present experimental data for the heat transfer rate of evaporator. Results show that $82.5\%$ increase of air velocity is needed for T-type distributor with four outlet branches than that of two outlet branches under the superheat of $5^{\circ}C$, which resulted in increasing of air-side pressure drop of $130\%$ for the former as compared to the latter.

• 한국항해학회지
• /
• 제8권1호
• /
• pp.17-48
• /
• 1984

The economy of ship's size and speed is affected by the freight rates, sailing distances, cargo handling rates, fuel oil prices and even interest rates of the borrowed funds. It can be a step more powerful measures if the economic evaluation model takes in a cargo lot size which prevails in the shipping markets. This paper has dealt with hypothetical cargo lots which happen to the market with uniform distribution in probability. The evaluation models are either profit maximization method or cost minimization method. The former compares among different voyages in profitability to the invested funds, the later defines the transportation efficiency in ton-mile unit and be used in comparing two or more transportation means. This paper adopted both of above methods to derive out ships economical evaluation contours for the various ship's speed and deadweight for certain cargo lot sizes, which can be used as important managerial decision data in purchasing ships or selecting a most profitable one among the proposed voyages. This evaluation contours will also be efficiently used in appraising so called "handy size ships" in connection with port water depth and conditions of voyage tracks.ge tracks.

• 열처리공학회지
• /
• 제8권2호
• /
• pp.137-148
• /
• 1995

The nitridation kinetics of titanium powder were studied by isothermal and non-isothermal (dynamic) methods in high purity nitrogen under I atm pressure. For the comparison with nitridation, the oxidation kinetics of titanium powder were also studied in dry oxygen at I atm pressure. An automatic recording electrobalance was used to measure the weight gain as a function of time and temperature. For the reaction with nitrogen, the nitride was formed at over $700^{\circ}C$. The reaction with nitrogen followed the parabolic rate law, and the activation energy was calculated to be 31 kcal/mol in the isothermal method (above $900^{\circ}C$). The non-stoichiometric TiNx has been synthesized by the nitridation at a proper temperature and time, followed by the homogenizing treatment above $1100^{\circ}C$. In comparison with the stoichiometric $TiN_{1.0}$ and the non-stoichiometric TiNx ($TiN_{0.5}$ and $TiN_{0.65}$), the hot oxidation characteristics of the former is superior to that of the latter. However, both non-stoichiometric nitrides make little difference in the hot oxidation characteristics.

• 한국농공학회지
• /
• 제16권2호
• /
• pp.3361-3394
• /
• 1974

The purpose of this thesis is to disclose some characteristics of water consumption in relation to the quantities of dry matters through the growing period for two statured varieties of paddy rice which are a tall statured variety and a short one, including the water consumption during seedling period, and to find out the various coefficients of evapotranspiration that are applicable for the water use of an expected yield of the two varieties. PAL-TAL, a tall statured variety, and TONG-lL, a short statured variety were chosen for this investigation. Experiments were performed in two consecutive periods, a seedling period and a paddy field period, In the investigation of seedling period, rectangular galvanized iron evapotranspirometers (91cm${\times}$85cm${\times}$65cm) were set up in a way of two levels (PAL-TAL and TONG-lL varieties) with two replications. A standard fertilization method was applied to all plots. In the experiment of paddy field period, evapotanspiration and evaporation were measured separately. For PAL-TAL variety, the evapotranspiration measurements of 43 plots of rectangular galvanized iron evapotranspirometer (91cm${\times}$85cm${\times}$65cm) and the evaporation measurements of 25 plots of rectangular galvanized iron evaporimeter (91cm${\times}$85cm${\times}$15cm) have been taken for seven years (1966 through 1972), and for TONG-IL variety, the evapotranspiration measurements of 19 plots and the evaporation measurements of 12 plots have been collected for two years (1971 through 1972) with five different fertilization levels. The results obtained from this investigation are summarized as follows: 1. Seedling period 1) The pan evaporation and evapotranspiration during seedling period were proved to have a highly significant correlation to solar radiation, sun shine hours and relative humidity. But they had no significant correlation to average temperature, wind velocity and atmospheric pressure, and were appeared to be negatively correlative to average temperature and wind velocity, and positively correlative to the atmospheric pressure, in a certain period. There was the highest significant correlation between the evapotranspiration and the pan evaporation, beyond all other meteorological factors considered. 2) The evapotranpiration and its coefficient for PAL-TAL variety were 194.5mm and 0.94∼1.21(1.05 in average) respectively, while those for TONG-lL variety were 182.8mm and 0.90∼1.10(0.99 in average) respectively. This indicates that the evapotranspiration for TONG-IL variety was 6.2% less than that for PAL-TAL variety during a seedling period. 3) The evapotranspiration ratio (the ratio of the evapotranspiration to the weight of dry matters) during the seedling period was 599 in average for PAL-TAL variety and 643 for TONG-IL variety. Therefore the ratio for TONG-IL was larger by 44 than that for PAL-TAL variety. 4) The K-values of Blaney and Criddle formula for PAL-TAL variety were 0.78∼1.06 (0.92 in average) and for TONG-lL variety 0.75∼0.97 (0.86 in average). 5) The evapotranspiration coefficient and the K-value of B1aney and Criddle formular for both PAL-TAL and TONG-lL varieties showed a tendency to be increasing, but the evapotranspiration ratio decreasing, with the increase in the weight of dry matters. 2. Paddy field period 1) Correlation between the pan evaporation and the meteorological factors and that between the evapotranspiration and the meteorological factors during paddy field period were almost same as that in case of the seedling period (Ref. to table IV-4 and table IV-5). 2) The plant height, in the same level of the weight of dry matters, for PAL-TAL variety was much larger than that for TONG-IL variety, and also the number of tillers per hill for PAL-TAL variety showed a trend to be larger than that for TONG-IL variety from about 40 days after transplanting. 3) Although there was a tendency that peak of leaf-area-index for TONG-IL variety was a little retarded than that for PAL-TAL variety, it appeared about 60∼80 days after transplanting. The peaks of the evapotranspiration coefficient and the weight of dry matters at each growth stage were overlapped at about the same time and especially in the later stage of growth, the leaf-area-index, the evapotranspiration coefficient and the weight of dry matters for TONG-IL variety showed a tendency to be larger then those for PAL-TAL variety. 4) The evaporation coefficient at each growth stage for TONG-IL and PAL-TALvarieties was decreased and increased with the increase and decrease in the leaf-area-index, and the evaporation coefficient of TONG-IL variety had a little larger value than that of PAL-TAL variety. 5) Meteorological factors (especially pan evaporation) had a considerable influence to the evapotranspiration, the evaporation and the transpiration. Under the same meteorological conditions, the evapotranspiration (ET) showed a increasing logarithmic function of the weight of dry matters (x), while the evaporation (EV) a decreasing logarithmic function of the weight of dry matters; 800kg/10a x 2000kg/10a, ET=al+bl logl0x (bl>0) EV=a2+b2 log10x (a2>0 b2<0) At the base of the weight of total dry matters, the evapotranspiration and the evaporation for TONG-IL variety were larger as much as 0.3∼2.5% and 7.5∼8.3% respectively than those of PAL-TAL variety, while the transpiration for PAL-TAL variety was larger as much as 1.9∼2.4% than that for TONG-IL variety on the contrary. At the base of the weight of rough rices the evapotranspiration and the transpiration for TONG-IL variety were less as much as 3.5% and 8.l∼16.9% respectively than those for PAL-TAL variety and the evaporation for TONG-IL was much larger by 11.6∼14.8% than that for PAL-TAL variety. 6) The evapotranspiration coefficient, the evaporation coefficient and the transpiration coefficient and the transpiration coefficient were affected by the weight of dry matters much more than by the meteorological conditions. The evapotranspiratioa coefficient (ETC) and the evaporation coefficient (EVC) can be related to the weight of dry matters (x) by the following equations: 800kg/10a x 2000kg/10a, ETC=a3+b3 logl0x (b3>0) EVC=a4+b4 log10x (a4>0, b4>0) At the base of the weights of dry matters, 800kg/10a∼2000kg/10a, the evapotranspiration coefficients for TONG-IL variety were 0.968∼1.474 and those for PAL-TAL variety, 0.939∼1.470, the evaporation coefficients for TONG-IL variety were 0.504∼0.331 and those for PAL-TAL variety, 0.469∼0.308, and the transpiration coefficients for TONG-IL variety were 0.464∼1.143 and those for PAL-TAL variety, 0.470∼1.162. 7) The evapotranspiration ratio, the evaporation ratio (the ratio of the evaporation to the weight of dry matters) and the transpiration ratio were highly affected by the meteorological conditions. And under the same meteorological condition, both the evapotranspiration ratio (ETR) and the evaporation ratio (EVR) showed to be a decreasing logarithmic function of the weight of dry matters (x) as follows: 800kg/10a x 2000kg/10a, ETR=a5+b5 logl0x (a5>0, b5<0) EVR=a6+b6 log10x (a6>0 b6<0) In comparison between TONG-IL and PAL-TAL varieties, at the base of the pan evaporation of 343mm and the weight of dry matters of 800∼2000kg/10a, the evapotranspiration ratios for TONG-IL variety were 413∼247, while those for PAL-TAL variety, 404∼250, the evaporation ratios for TONG-IL variety were 197∼38 while those for PAL-TAL variety, 182∼34, and the transpiration ratios for TONG-IL variety were 216∼209 while those for PAL-TAL variety, 222∼216 (Ref. to table IV-23, table IV-25 and table IV-26) 8) The accumulative values of evapotranspiration intensity and transpiration intensity for both PAL-TAL and TONG-IL varieties were almost constant in every climatic year without the affection of the weight of dry matters. Furthermore the evapotranspiration intensity appeared to have more stable at each growth stage. The peaks of the evapotranspiration intensity and transpiration intensity, for both TONG-IL and PAL-TAL varieties, appeared about 60∼70 days after transplanting, and the peak value of the former was 128.8${\pm}$0.7, for TONG-IL variety while that for PAL-TAL variety, 122.8${\pm}$0.3, and the peak value of the latter was 152.2${\pm}$1.0 for TONG-IL variety while that for PAL-TAL variety, 152.7${\pm}$1.9 (Ref.to table IV-27 and table IV-28) 9) The K-value in Blaney & Criddle formula was changed considerably by the meteorological condition (pan evaporation) and related to be a increasing logarithmic function of the weight of dry matters (x) for both PAL-TAL and TONG-L varieties as follows; 800kg/10a x 2000kg/10a, K=a7+b7 logl0x (b7>0) The K-value for TONG-IL variety was a little larger than that for PAL-TAL variety. 10) The peak values of the evapotranspiration coefficient and k-value at each growth stage for both TONG-IL and PAL-TAL varieties showed up about 60∼70 days after transplanting. The peak values of the former at the base of the weights of total dry matters, 800∼2000kg/10a, were 1.14∼1.82 for TONG-IL variety and 1.12∼1.80, for PAL-TAL variety, and at the base of the weights of rough rices, 400∼1000 kg/10a, were 1.11∼1.79 for TONG-IL variety and 1.17∼1.85 for PAL-TAL variety. The peak values of the latter, at the base of the weights of total dry matters, 800∼2000kg/10a, were 0.83∼1.39 for TONG-IL variety and 0.86∼1.36 for PAL-TAL variety and at the base of the weights of rough rices, 400∼1000kg/10a, 0.85∼1.38 for TONG-IL variety and 0.87∼1.40 for PAL-TAL variety (Ref. to table IV-18 and table IV-32) 11) The reasonable and practicable methods that are applicable for calculating the evapotranspiration of paddy rice in our country are to be followed the following priority a) Using the evapotranspiration coefficients based on an expected yield (Ref. to table IV-13 and table IV-18 or Fig. IV-13). b) Making use of the combination method of seasonal evapotranspiration coefficient and evapotranspiration intensity (Ref. to table IV-13 and table IV-27) c) Adopting the combination method of evapotranspiration ratio and evapotranspiration intensity, under the conditions of paddy field having a higher level of expected yield (Ref. to table IV-23 and table IV-27). d) Applying the k-values calculated by Blaney-Criddle formula. only within the limits of the drought year having the pan evaporation of about 450mm during paddy field period as the design year (Ref. to table IV-32 or Fig. IV-22).

• 치위생과학회지
• /
• 제14권1호
• /
• pp.51-58
• /
• 2014

본 연구의 목적은 근로자의 구강건조증상과 다양한 구강자각증상에 대하여 알아보고 근로자의 구강건강관련 삶의 질에 미치는 요인들에 대해 조사 분석하여 근로자의 구강건강증진을 도모하는 프로그램개발을 위한 기초자료를 제공하고자 2012년 8월 1일부터 9월 20일까지 전라북도 소재의 5개의 산업장 근로자를 대상으로 분석한 결과 다음과 같은 결론을 얻었다. 1. 구강건조증상은 사무직 근로자가 2.59점으로 영업직 근로자 1.71점보다 유의하게 구강건조증상 정도가 높았다 (p<0.001). 2. OHIP-14는 비정규직이 2.05점, 정규직이 1.82점으로 나타났다(p<0.00 1). 3. 구강건조증상은 OHIP-14와 양의 상관관계를 보였다 (r=0.456). OHIP-14는 연령과는 양의 상관관계를 보였으며 (r=0.209), 최종학력과 음의 상관관계를 보였다(r=-0.136). 4. 구강건조증상이 심할수록(${\beta}=0.383$, p<0.001), 연령이 높을수록(${\beta}=0.221$, p<0.001), 치과질환을 갖고 있다고 느꼈을 때(${\beta}=0.146$, p<0.01) OHIP-14에 유의하게 영향을 미치는 요인으로 나타났다. 결론적으로 위와 같이 근로자들의 구강건강관련 삶의 질에 영향을 미치는 요인을 참고하여 산업장 근로자의 구강건강증진을 도모하는 프로그램을 개발하고 국가보건정책 부분에서 산업구강보건 개선을 위해 적극 고려해야 할 것으로 생각된다.

• 한국식품과학회지
• /
• 제25권3호
• /
• pp.232-237
• /
• 1993

호주밀인 Australian standard white(ASW) 밀가루의 제면 적성을 알아보기 위하여, 단백질 함량이 같은 HRW-WW와 HRW-ASW의 혼합 밀가루를 만들어 이들 밀가루의 물리적 특성과 첨가제(소금 1.7%, 알칼리제 0.17%)의 영향을 분석하고, 건면을 제조하여 건면의 조리 성질과 조리된 국수의 관능검사를 실시하였다. 파리노그람에서 HRW-WW와 HRW-ASW 혼합 밀가루의 흡수율은 각각 57.5 및 59.2%이었으며, 소금을 첨가한 경우에는 밀가루의 흡수율이 약 2%, 혼합 밀가루의 흡수율은 약 1% 정도 감소되었으나 알칼리제는 밀가루 또는 혼합 밀가루의 흡수율에는 영향을 주지 않았다 소금과 알칼리제는 밀가루 및 혼합 밀가루의 반죽 강도를 증가시켰으며 그 효과는 소금만 첨가했을 때가 더욱 뚜렷하였다. 아밀로그람에 있어서 HRW-WW와 HRW-ASW 밀가루는 비슷한 아밀로그람 커브를 보였으며 점도도 비슷하였다. 조리에 따른 건면의 무게와 부피 증가율은 HRW-WW와 HRW-ASW 혼합 밀가루로 만든 두 국수사이에 뚜렷한 차이를 보이지 않았다. 그러나 알칼리제를 첨가한 국수의 경우에 있어서 부피 증가는 소금만 첨가한 경우보다 낮았다. 건면의 파쇄력 값과 조리된 국수의 절단력 값을 t-test 검정 결과 두 국수 사이에는 유의적 차이를 보이지 않았다. 또한 이들 값은 소금만 첨가한 국수보다 알칼리제를 함께 첨가한 국수가 모두 높았다. 조리된 국수의 관능검사에 있어서 HRW-WW와 HRW-ASW 혼합 밀가루로 만든 두 국수는 첨가제에 관계없이 유의적으로 달랐으나 그 차이는 미미한 것으로 인식되었다. 국수에 대한 기호도 평가에서는 두 국수 사이에 유의적 차이를 보이지 않았다.

• Journal of Plant Biology
• /
• 제11권1호
• /
• pp.7-14
• /
• 1968

Buckwheat seeds produced in previous year (1965) in an experimental pot culture in which nine levels of P-32 ranging from $1.4{\times}10-4 to 3.3{\times}104$\mu$c/pot(as of 27 July 1965)$, with the same specific activity, had been applied to the corresponding pots respectively, were used this year(1996) in water and soil culture as well as in germination test to investigate the feature and extent of possible residual effects of P-32 incorporated upon germination and plant growth, and the following results were obtained: 1. Under the given experimental conditions both stimulative and inhibitory effects of radiation were observed. 2. The germination rate of the seeds was lower at the higher level of P-32 aplication ranging from $3.0{\times}103 to 3.3{\times}104$\mu$c/pot$ and higher at 0.2 $\mu$c P/pot than the control. 3. Among the seeds produced at the higher level of application about 80% was failed to germinate, owing to the radiation injury. The remaining 80% was failed to germinate, owing to the radiation injury. The remaining 80% survived the damaging effect and showed vigorous growth and increased yield. The latter group of seeds thus proved themselves to be more radioresistant than the former. 4. The survived seeds produced later more straw and root on dry weight basis. The higher the level of P-32 applied, the stronger the stimulative effect showed in vegetative growth. 5. No radiation effect on linear growth of the plants was observed in the soil culture. 6. The dry weight of straw produced showed little difference at the moderate range compared with that of control in the soil culture. At high level of application, i.e. over $\mu$c P32/pot, however, the production was increased by 12-37% of control. 7. As for the dry weight of root harvested, the P-32 treatment over 24$\mu$c P32/pot produced 82-155% more than the control, whereas little difference was observed under 2.2$\mu$c P32/pot. 8. The seed production increased in general by the P-32 treatments. Particularly at the moderate level of application the rate of increase amounted to 70% of the control. 9. Those individual plants which survived damaging effects of radiation at the germinating stage shwoed remarkable stimulative effects both in vegetative and in reproductive stage of growth.

• 한국산림과학회지
• /
• 제111권4호
• /
• pp.630-643
• /
• 2022

본 연구는 소나무의 생중량 및 건중량 추정식을 도출하고, 이를 이용하여 중량표를 작성하기 위해 수행되었다. 생중량 및 건중량을 산정하기 위해 이용한 식은 흉고직경만을 이용하는 1변수식, 흉고직경과 수고를 이용하는 2변수식을 적용하였다. 생중량 및 건중량을 산정하기 위해 각 식은 적합도 지수, 표준오차, 잔차도 등의 통계량을 이용하여 검증하였다. 또한 최적식은 통계적 검증을 거쳤으며, 도출된 계수로서 중량을 계산하여 적용성을 검토하였다. 분석결과, 1변수식에서는 W = bD+cD²이 선정되었으며, 2변수식에서는 때 W = aD^bH^c가 선정이 되었다. 1변수 최적추정식의 적합도지수는 0.87~0.92 범위였으며, 2변수 중량추정식 적합도지수는 0.94~0.98 범위로, 두 가지 식 모두 적합도가 높았다. 최적 추정식을 이용하여 새로운 중량표를 작성하고 이전 중량표와 비교 분석하였다. 분석결과, 강원지방소나무는 이전 중량표의 값이 더 높은 반면, 중부지방소나무는 새롭게 작성된 중량표의 값이 더 높았다.

• 벤처혁신연구
• /
• 제5권2호
• /
• pp.85-99
• /
• 2022

시판되고 있는 실험용 및 산업용 건조기는 일반 드라이오븐, 열풍 순환 건조기, 진공건조기, 동결건조기 등으로 구분되고 기능, 크기 및 용량 등에 따라 그 종류도 다양하다. 그러나 제품의 품질 제어 및 성능 개선을 위해 중요한 요소인 수분측정이 적용되지 않아 현재는 건조 종료 후 임의로 중량을 칭량하기 때문에 매우 수동적이다. 일반적으로 수분을 측정하기 위한 방법은 직접적인 측정법과 간접적인 측정법으로 구분되고 수분 분리 전.후의 질량 또는 부피 변화와 같은 직접적인 측정법이 주로 이용된다. 상대적으로 열전도도, 마이크로파 등과 같은 간접적인 측정법은 측정 장비를 활용하기 때문에 적용이 제한적이다. 본 연구에서는 오픈소스 기반의 아두이노를 이용하여 비교적 손쉽게 수분측정 시스템을 설계하여 외부 환경요인에 영향 받지 않고 수분 변화량 및 무게 변화를 실시간으로 모니터링 하였다. 구체적으로 수분 민감도 물질 및 식품 건조에 적합한 60℃와 80℃에서 작동할 수 있는 온.습도 및 로드셀 측정 센서를 건조기 내부에 패키징하여 각종 변화량을 측정하였다. 또한 바나나, 배, 톱밥의 유기 시료를 이용한 반복적인 실험을 통해서도 건조시간 및 온도에 따른 증발율 변화와 로드셀 측정값에 있어 안정적인 응답특성을 나타냄으로써 성능 안전성을 확보할 수 있었다. 향후 온.습도 범위의 확대와 CFD(Computational Fluid Dynamics) 프로그램과의 비교 분석을 통해 신뢰도를 더욱 향상시킬 수 있을 것으로 판단된다.