• 한국연초학회지
• /
• 제1권1호
• /
• pp.39-45
• /
• 1979

극단의 土壤水分( 4 %, 24% )과 溫度(33$^{\circ}C$, -2$^{\circ}C$)에서 뿌리혹線筮의 生存率을 조사한 결과 土壤水分 함량에 따른 차이는 인정되지 않았고, 溫度 處理의 경우 33$^{\circ}C$에서는 Meloidogyne incognita, -2$^{\circ}C$에서는 M. hapla의 생존율이 높았으며, M. arenaria는 兩 處理에서 양자의 중간 정도의 반응을 보였다. 低溫처리에서 tolerance의 증가는 모든 線筮에서 인정되었으며 특히 M. hapla의 tolerance가 가장 높았다.

• 한국전기전자재료학회논문지
• /
• 제19권4호
• /
• pp.344-349
• /
• 2006

A sublimation epitaxial method, referred to as the Closed Space Technique (CST) was adopted to produce thick SiC epitaxial layers for power device applications. We aimed to systematically investigate the dependence of SiC epilayer quality and growth rate during the sublimation growth using the CST method on various process parameters such as the growth temperature and working pressure. The etched surface of a SiC epitaxial layer grown with low growth rate $(30{\mu}m/h)$ exhibited low etch pit density (EPD) of ${\sim}2000/cm^2$ and a low micropipe density (MPD) of $2/cm^2$. The etched surface of a SiC epitaxial layer grown with high growth rate (above $100{\mu}m/h$) contained a high EPD of ${\sim}3500/cm^2$ and a high MPD of ${\sim}500/cm^2$, which indicates that high growth rate aids the formation of dislocations and micropipes in the epitaxial layer. We also investigated the Schottky barrier diode (SBD) characteristics including a carrier density and depletion layer for Ni/SiC structure and finally proposed a MESFET device fabricated by using selective epilayer process.

• 대한화학회지
• /
• 제11권1호
• /
• pp.1-7
• /
• 1967

熱天秤을 利用하여 窒素氣流中에서 $200^{\circ}C$以下의 여러 溫度에 걸쳐 國産無煙炭內의 化合水分에 對하여 考察하였다. 無煙炭內의 化合水分 含量은 $150^{\circ}C$에서 0.3~0.5%, $175^{\circ}C$에서 0.1~0.2%, $200^{\circ}C$에서 0.06~0.1% 였다. 한편 成型孔炭의 燃燒速度는 無煙炭의 個個의 特性에 따라 다르며 孔炭內에 適量의 水分이 存在할 때는 乾燥된 狀態時보다 燃燒速度가 促進되었다. 또한 乾燥孔炭中의 酸素擴散速度는 含水時보다 크지만 擴散速度는 燃燒速度에 直接的인 關係가 없었다.

• 한국응용곤충학회지
• /
• 제47권4호
• /
• pp.365-368
• /
• 2008

싸리수염진딧물(Aulacorthum solani Kaltenbach)의 성충 수명과 산자수를 $12.5{\sim}25^{\circ}C$, 상대습도 $60{\sim}70%$, 광주기 16L:8D 조건에서 조사하여 생명표를 작성하였다. 싸리수염진딧물 성충은 $12.5{\sim}25^{\circ}C$에서의 수명이 $34.3{\sim}10.5$일로 온도의 상승에 따라 성충기간이 짧아졌다. 산자수는 $15^{\circ}C$에서 74.1마리로 최고치를 보였으며, $15{\sim}25^{\circ}C$에서는 온도가 상승함에 따라 산자수가 감소하였으나, $12.5^{\circ}C$에서는 47.0마리로 온도가 낮아짐에 따라 산자수가 적어지는 경향을 보였다. 또한 싸리수염진딧물 성충의 일일 산자수는 $20^{\circ}C$에서 2.9마리였고, $12.5^{\circ}C$에서 1.4마리와 $30^{\circ}C$에서 1.3마리로 온도가 높거나 낮아지면 일일산자수가 적어졌다. 싸리수염진딧물 약충 발육시 사망률과 성충 수명, 산자수를 이용하여 생명표를 작성하였는데 싸리수염진딧물은 순증가율(Ro)이 $15^{\circ}C$에서 58.7, 내적자연증가율($r_m$)은 $20^{\circ}C$에서 0.27, 기간증가율(${\lambda}$)은 $20^{\circ}C$에서 1.32이었으며, 배수기간(Dt)은 $20^{\circ}C$에서 2.52, 세대기간(T)은 $22.5^{\circ}C$에서 10.99로 가장 짧았다.

• 한국수정란이식학회:학술대회논문집
• /
• 한국수정란이식학회 2002년도 국제심포지엄
• /
• pp.103-103
• /
• 2002

This study was conducted to investigate cryopreservation of pearl oyster, Pinctada fucata martensii larvae. Four cooling rates (-0.25, -0.5, -0.75 and -1.0$^{\circ}C$/min.) were used to examine a proper cooling rate during cryopreservation of trochophores before seeding temperature (-12$^{\circ}C$). Seven developmental stages (early and late trochophores, early and late D-shaped larvae and early, middle and late umbo stage larvae) and different sugars (fructose, glucose and sucrose) were used to investigate optimal larval stage and effective sugar in cryopreservation of larvae. The survival rates of frozen-thawed trochophores increased at cooling rate of -1.0$^{\circ}C$/min. As larval developing, survival rate of frozen-thawed larvae increased, except umbo stage larvae, and especially late D-shaped larvae highly survived as 91%. Addition of sugar revealed positive effect on cryopreservation in this experiment and 0.2 M glucose and sucrose mixed with 2.0 M dimethyl sulfoxide significantly enhanced survival rate of larvae (P<0.05). The results of our study indicate that desirable cooling rate, developmental stages of larvae and effective sugar far cryopreservation of pearl oyster, P. fucata martensii larvae are -1$^{\circ}C$/min, late D-shaped larvae and 0.2 M glucose and sucrose, respectively.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2002년도 전력전자학술대회 논문집
• /
• pp.727-729
• /
• 2002

In this paper, we proposed quad variable rates ADPCM coding method and its implementation on C6000 DSP, which is modified from the standard ADPCM of ITU G.726 for speech quality improvement considering the environmental noise Four coding rates, 16Kbps, 24Kbps, 32Kbps and 40Kbps are used for speech window samples and the rate decision threshold is decided by the environmental noise level. The object of the proposed method is to reduce the coding rate while retaining the speech quality and the speech quality is considerably close to 40Kbps single rate coder with the coding rate close to 16Kbps single rate coder under the environmental noise. The environmental noise level affects the coding rate and the noise level is calculated per every speech window samples. At high noise level, more samples are coded at higher rates to enhance the quality, but at low noise level, only the big speech signals are coded at higher rates and more speech samples are coded at lower coding rates to reduce the coding rates. The influence of the noise on tile speech signal is considerably high for small signals and the small signal has the higher ZCR (zero crossing rate). The method is simulated in PC and to be implemented on C6000 floating point DSP board in real time operations.

• 한국약용작물학회지
• /
• 제11권4호
• /
• pp.284-288
• /
• 2003

This study was conducted to classify photosynthesis rate and changes of rutin content of Korean buckwheat (cv. Chunchon-jaerae and Yangjeul-memil) treated with salinity, UV-C and low temperature. In case of cv. Chunchon-jaerae and Yangjeul-memil, according to the salt stress, transpiration rate, stomatal conductance and photosynthesis rate were decreased. Both cultivars also showed decrease of transpiration rate and photosynthesis rate under the UV-C. Rutin contents within leaf and stem of cv. Yangjeul-memil were decreased when NaCl concentration was high. Rutin contents within leaf and stem of cv. Yangjeul-memil were generally decreased when the time laps under the UV-C stress. Rutin contents within leaf and stem of cv. Chunchon-jaerae was also generally decreased when the time laps under the low temperature stress.

• 한국전기전자재료학회논문지
• /
• 제15권9호
• /
• pp.776-782
• /
• 2002

The microstructure, V-Ι characteristics, and stability of ZnO-P $r_{6}$ $O_{11}$ CoO-C $r_2$ $O_3$- $Y_2$ $O_3$-based varistor ceramics were investigated with cooling rate in the range of 2~8$^{\circ}C$/min. The cooling rate relatively weakly affected the microstructure, the varistor voltage, and the leakage current in the V-Ι characteristics. But the nonlinear exponent relatively strongly affected by cooling rate. The cooling rate also greatly affected the stability of V-Ιand dielectric characteristics for DC accelerated aging stress. On the whole, the varistors cooled with 4$^{\circ}C$/fin exhibited the highest performance in the densification, nonlinearity, and stability. Especially, they exhibited a high stability, in which the variation rate of the varistor voltage( $V_{1㎃}$), the nonlinear exponent($\alpha$), and the dissipation factor(tan $\delta$) is -1.4%, -4.9%, and ＋60.0%, respectively, under DC accelerated aging stress such as 0.95 $V_{1㎃}$15$0^{\circ}C$/12 h)

• 한국패류학회지
• /
• 제20권2호
• /
• pp.107-110
• /
• 2004

The filtration rate and oxygen consumption of Anadara granosa bisenensis were measured at 4 different temperature (10$^{\circ}C$, 15$^{\circ}C$, 20$^{\circ}C$, and 25$^{\circ}C$) and 4 different salinity levels (20, 25, 35, and 40 psu), using an direct method under laboratory conditions. The samples were divided into two groups: a large-sized group (shell length: 34.58 ${\pm}$ 2.23 mm, body weight: 12.43 ${\pm}$ 0.44 g) and a small-sized group (shell length: 20.60 ${\pm}$ 0.85 mm, body weight: 4.41 ${\pm}$ 2.30 g). Filtration rate and oxygen consumption increased with the increase of various temperatures and salinity levels. Also, the filtration rate and oxygen consumption of the small-sized group were higher than those of the large-sized group. These results indicate that the filtration rate and oxygen consumption of Anadara granosa bisenensis depends on environmental conditions, especially on water temperature and salinity.

• Fisheries and Aquatic Sciences
• /
• 제17권2호
• /
• pp.229-247
• /
• 2014

Seven feeding trials were conducted to determine the effects of feeding rate and frequency in the Korean rockfish Sebastes schlegeli at seven different water temperatures. Two feeding-rate experiments for 5-g Korean rockfish at $17^{\circ}C$ and $20^{\circ}C$; three feeding rate experiments for 16-g Korean rockfish at $16^{\circ}C$ and $24^{\circ}C$; and finally, two feeding frequency experiments for 93- and 100-g at $15^{\circ}C$ and $20^{\circ}C$ were conducted. Twenty fish averaging $5.5{\pm}0.2$ g ($mean{\pm}SD$) were randomly distributed into 18 indoor tanks containing 40-L seawater from a semi-recirculation system. Fish were fed a commercial diet for 4 weeks at water temperatures of $17^{\circ}C$ and $20^{\circ}C$. Two feeding trials were conducted to determine the optimum feeding frequency in growing Korean rockfish reared at temperatures of $15^{\circ}C$ and $19^{\circ}C$. Broken line regression analysis of weight gain (WG) indicated that the optimum feeding rates of 5-g growing Korean rockfish were 4.48% (BW/day; BW, body weight) at $17^{\circ}C$ and 4.83% (BW/day) at $20^{\circ}C$. Broken line regression analysis of WG showed optimum feeding rates of 16-g juvenile Korean rockfish of 3.41% (BW/day) at $16^{\circ}C$, 3.75% (BW/day) at $20^{\circ}C$, and 3.34% (BW/day) at $24^{\circ}C$. The biological performance, results, along with morphological indices and serological characteristics, suggest that a feeding frequency of 1 meal/day was optimal to improve WG in growing Korean rockfish grown from 93 to 133 g at a water temperature of $15^{\circ}C$, and 100 to 132 g at $19^{\circ}C$.