복숭아혹진딧물의 포식기생자인 콜레마니진디벌의 기능반응을 온도별(15, 20, 25, 30°C) 복숭아혹진딧물 밀도를 달리하여(2, 4, 8, 16, 32, 64, 128마리) 평가하였다. 모든 온도 처리에서 콜레마니진디벌은 제 3 유형의 기능반응을 보였다. 30°C에서 공격률(0.0043 day-1)은 높았지만 처 리시간(0.9268 day)은 다른 온도보다 길었다. 추정된 처리시간은 온도가 15°C에서 25°C로 증가할수록 감소하였다. 콜레마니진디벌의 24시간동 안 최대 공격률은 15, 20, 25, 30°C에서 29.1, 31.9, 59.3, 25.9이었다. 온도처리별 복숭아혹진딧물 기생률은 유사한 특징을 나타내었다. 가장 높 은 기생률은 15, 20, 25, 30°C에서 복숭아혹진딧물 32, 32, 16, 32마리에 대해 0.52, 0.54, 0.57, 0.40이었으며 25°C에서 콜레마니진디벌의 기생 력이 가장 높게 나타났다. 본 연구는 복숭아혹진딧물의 생물적 방제원으로서 콜레마니진디벌의 효율성을 여러 온도조건에서 평가하였다.
본 연구는 부화 온도가 맹꽁이(Kaloula borealis) 알의 부화 기간에 영향을 미치는 여부를 알아보기 위해 수행되었다. 본 연구에서 맹꽁이 알에서 올챙이가 생긴 것을 기준으로 알 부화 과정을 기록했다. 연구 결과 맹꽁이의 모든 알은 산란 후 48시간 이내에 부화하였으며, 28.1%(±10.8, n=52)가 24시간 이내에, 99.9%(±0.23, n=49)가 산란 후 48시간 이내에 부화했다. 수온의 차이에 따라 맹꽁이 알의 평균 부화율은 유의미한 차이를 나타냈다. 산란 후 15~24시간 사이의 평균 부화율은 24.1(±0.2)°C보다 21.1(±0.2)°C의 수온에서 더 높았다. 본 연구 결과는 비교적 낮은 수온에서 빠른 부화가 되는데 이는 비가 오는 계절에 일시적인 연못이나 웅덩이에 알을 낳는 번식 습성으로 웅덩이가 마르기 전에 빠른 부화가 필요하기 때문으로 추측한다. 본 연구 결과는 멸종위기종인 맹꽁이 알의 최적 부화온도를 이해하는데 도움이 된다.
This study was conducted to examine the microbiological quality indicators (total bacterial count and coliform count) and physicochemical quality indicators (pH, redness, volatile basic nitrogen [VBN] content) of meat according to various storage temperatures (20~15oC) and packaging methods (wrap, vacuum). Based on these results, we proposed a safe consumption period. Redness, pH, and VBN content were not considered appropriate for setting the expiration date, as the redness and pH of the meat after spoilage were better than the standard values for both vacuum and wrap packaging (p<0.05). Additionally, the VBN content at 2 and 4oC increased slightly (fresh level) until the initial time of spoilage (1.0×106 colony-forming unit [CFU]/cm2) and then increased rapidly thereafter. Therefore, the results were not consistent with microbial spoilage. When the decay point was evaluated based on the presence of microorganisms, vacuum packaging extended the storage period approximately 2.5-fold when compared with wrap packaging, and the meat could be stored at 2 or 4oC for 40 or 23 days, respectively. Therefore, to evaluate meat quality, microbial indicators should be considered first. The microbiological standards proposed in this study can be used for safety management during the distribution of meat. However, to ensure meat safety, additional investigations of appropriate indicators of freshness must be conducted.
매미나방(Lymantria dispar)은 나비목(Lepidoptera) 독나방과(Lymantriidae)에 속하는 해충으로 매미나방은 한국, 일본, 시베리아, 유 럽, 북아메리카 등에 분포하며, 주로 배나무, 사과나무, 블루베리 등의 식물을 가해하는 광식성 해충이다. 매미나방은 수목해충으로 관리되어 왔 으나 최근 산림 발생지 인접 농경지로 유입 빈도가 높아지면서 방제 대책이 수립되지 않은 농작물에 피해가 심하다. 본 연구는 매미나방(L. dispar)의 방제기술의 일환으로 매미나방 발육에 미치는 온도의 영향을 알아보기 위해 2021년 전라남도 장흥군 황금측백나무에서 채집한 알집을 이용해 18, 21, 24, 27, 30, 33°C (14L:10D, 상대습도 60±5%) 항온조건에서 온도별, 발육단계별 발육기간을 조사하였다. 매미나방 유충의 발 육속도는 온도가 높을수록 빨라졌으나, 매미나방 유충의 생존율이 33°C에서 가장 낮게 나타났다. 따라서 발육적온은 30°C였으며, 30°C에서 총 발육기간은 암컷 43.8일, 수컷 42.5일 소요되었다. 암컷과 수컷 발육영점온도는 각각 13.1°C, 12.5°C, 유효적산온도는 각각 641.1 DD, 657.8 DD였다.
This research was conducted to analyze the relationship between the induction time of runners and the growing degree days for domestic strawberry cultivars, 'Sulhyang' and 'Arihyang'. Runners were induced at 15-day intervals over five periods, starting from late April to early June, and the study compared the number of runner formations and temperature changes for each period while it also investigated the plantlet quality on the transplanting date. Based on back calculations from the transplanting date of September 18th, 'Sulhyang' required induction from late April to early May to achieve 70-day-old plantlets and from late April to mid-May for 60-day-old plantlets. On the other hand, 'Arihyang' needed induction from late April for 70-day-old plantlets and from late April to early May for 60-day-old plantlets. To secure about 20 daughter plants, the growing degree days needed to be around 1,000°C, and a delay in runner induction led to a delay in formation of daughter plants. The relationship between growing degree days and runner formation was expressed as the following quadratic equations: for 'Sulhyang,' y = 9E-06x2 + 0.0124x – 2.4806 (R2 = 0.9696), and for 'Arihyang,' y = 1E-06x2 + 0.0192x – 2.9274 (R2 = 0.9431), and these equations showed high correlations. The crown diameter on the transplanting date was thickest in mid-May for 'Sulhyang', and it tended to increase with delayed runner induction for 'Arihyang'. In conclusion, this study confirmed that the number of daughter plants and growth characteristics varied depending on strawberry cultivars and the timing of runner inducement time. The relationship equations derived through measurements of growing degree days can be used as the fundamental data for reasonable production of daughter plants in the future.
좁은가슴잎벌레는 십자화과작물을 가해하는 해충으로 알려져 있다. 본 연구는 온도가 좁은가슴잎벌레의 발육단계별 발육기간, 성충의 수 명과 산란특성에 미치는 영향을 파악하고자 성충 전 발육단계는 15, 20, 25, 27.5°C에서, 성충은 10, 15, 20, 25, 27.5°C 항온조건에서 조사하였 다. 알과 유충은 항온조건에서 다음 발육 단계로 성공적으로 발육하였다. 알, 유충, 번데기의 발육기간은 온도가 상승할수록 짧아지는 경향을 보 였다. 좁은가슴잎벌레의 발육영점온도, 유효적산온일도는 선형회귀분석을 통해 추정하였으며 알에서 성충출현까지 발육영점온도와 유효적산온 일도는 8.7°C와 344.73DD였다. 좁은가슴잎벌레 발육단계별 최저, 최고 온도의 한계는 Briere함수를 이용하여 추정하였으며 알에서 성충출현 까지 최저, 최고한계는 5.3°C와 40.4°C였다. 성충은 10°C와 27.5°C 범위에서 산란이 가능하였고 21.7°C에서 최대 약 627.5개의 알을 낳는 것 으로 추정되었다. 노화율, 나이별 생존율, 나이별 누적산란율, 온도의존 산란수와 관련된 성충모델들을 작성하였다. 본 연구에서 제시한 온도발육 모형과 성충산란모형은 좁은가슴잎벌레 개체군동태를 이해하는데 유용할 것이며 십자화과작물의 종합적 해충군관리체계를 마련하는데 기초자 료로 활용될것으로 기대된다.
Cnidium officinale M. is an important crop that is widely used as a raw material for health functional foods. However, it is experiencing cultivation difficulties due to climate change and abnormally high temperatures. In response to this problem, the characteristics and main causes of the high-temperature damage occurring in C. officinale M. cultivation fields were analyzed. A survey of five farmhouse fields in Jecheon and Bonghwa, major C. officinale M. cultivation areas in Korea in 2018, indicated that about 5% to 37% of the cultivation fields in Jecheon and 5% to 15% of the fields in Bonghwa died from wilting. The high-temperature damage of the C. officinale M. fields is divided into two categories: upper leaves drying due to solar radiation and temperature, and lower leaves dying serially to the radiant heat of the vinyl mulch. Damage caused by radiant heat was typically greater. This is due to the greenhouse effect that occurs in the small space between the black vinyl mulching and the soil. The heat radiated to the surface of the ridge creating an environmental condition that greatly exceeded the atmospheric temperature especially on hot days. As a result, short plants with underground parts, such as C. officinale M., can suffer more high-temperature damage than other plants, so it is considered that it is necessary to develop related technologies such as mulching materials that can reduce pavement temperature in the future.
The influence of MgO addition on the densification and microstructure of alumina (Al2O3) was studied. Compacted alumina specimens were manufactured using ball-milling and one-directional pressing followed by sintering at temperatures below 1700oC. Relative density, shrinkage, hardness, and microstructure were investigated using analytical tools such as FE-SEM, EDS, and XRD. When the MgO was added up to 5.0 wt% and sintered at 1500oC and 1600oC, the relative density exhibited an average value of 97% or more at both temperatures. The maximum density of 99.2% was with the addition of 0.5 wt% MgO at 1500oC. Meanwhile, the specimens showed significantly lower density values when sintered at 1400oC than at 1500oC and 1600oC owing to the relatively low sintering temperature. The hardness and shrinkage data also showed a similar trend in the change in density, implying that the addition of approximately 0.5 wt% MgO can promote the densification of Al2O3. Studying the microstructure confirmed the uniformity of the sintered alumina. These results can be used as basic compositional data for the development of MgOcontaining alumina as high-dielectric insulators.
Cyanobacteria Pseudanabaena strains are known to produce 2-MIB (odorous material) in freshwater systems, thereby causing problems in water use. However, their physiological responses to environmental factors in relation with 2-MIB production is not well explored. This study was conducted to evaluate the effect of temperature on the growth and 2-MIB production of Pseudanabaena redekei. The experimental cyanobacteria strains were separated from the Uiam Reservoir (North Han River) and cultured in the BG-11 medium. Temperature was set to 10, 15, 20, 25, and 30℃ for the experiment, in the reflection of the seasonal water temperature variation in situ. For each temperature treatment, cyanobacterial biomass (Chl-a) and 2-MIB concentration (intra-cellular and extra-cellular fractions) were measured every 2 days for 18 days. Both maximal growth and total 2-MIB production of P. redekei appeared at 30℃. While intra-cellular 2-MIB contents were similar (26~29 ng L-1) regardless of treated temperatures, extra-cellular 2-MIB concentration was higher only in high temperature conditions (25~30℃), indicating that the extents of 2-MIB biosynthesis and release by P. redekei vary with temperature. The 2-MIB productivity of P. redekei was much higher in low-temperature conditions (10~15℃) than high temperature conditions (25~30℃). This study demonstrated that temperature was a critical factor contributing to 2-MIB biosynthesis and its release in cell growth (r=0.605, p<0.01). These results are important to understand the dynamics of 2-MIB in the field and thereby provide basic information for managing odorous material in drinking water resources.
본 연구는 국내 산림생명자원 중 광나무의 대량생산을 위한 기초연구로, Priming 처리에 따른 발아 효율성 및 유묘 생육특성에 미치는 영향을 구명하고자 수행하였다. 종자 Priming처리는 대조구, GA3 (10, 100, 200 ㎎·L-1), Ca (NO3)2 (50, 100, 200 mM), KNO3 (50, 100, 200 mM)를 24시간 처리하여 발아특성을 분석하였고, 순화재배에 따른 생육특성 및 활착률을 조사하여 수확량을 비교·분석하였다. 발아특성은 25℃·KNO3 100 mM에서 발아율이 유의적으로(p<0.001) 높았으며, 평균발아일수는 10.3~18.1일로 15℃에서 대체적으로 빠른 발아일수를 나타냈다(p<0.001). 발아속도 및 발아균일지수 또한 25℃·KNO3 100 mM에서 유의적으로 높은 값을 보였다(p<0.001). 생육특성의 경우 2 5℃·KNO3 100 mM 처리에서 유근 길이(5.1±2.4 ㎝), 초장(5.7±0.7 ㎝), 근장(16.6±2.0 ㎝), 건중량(0.079 g)이 유의적으로 가장 높게 나타났다 (p<0.001). 유묘활력지수 또한 25℃·KNO3 100 mM 처리에서 1418.3으로 높았으며, 가장 높은 수확량(16.8 g/㎡)을 나타냈다. 결과적으로 25℃, KNO3 100 mM 처리 시 실내발아에서 발아효율성을 높일 수 있었으며, 순화재배 시 우수한 유묘 생육을 보여 수확량을 증진시킬 수 있었다.
본 연구는 서울대공원 인공사육장에서 남생이(Mauremys reevesii) 알의 부화온도 차이에 따른 부화기간과 성장에 영향을 주는지 알아보고자 연구했다. 전체 201개의 남생이 알을 26(n=89)℃, 28(n=75)℃ 그리고 32(n=37)℃에서 각각 부화시켰다. 남생이 알의 부화온도와 부화기간은 온도에 따라 유의미한 차이를 나타내었다. 본 연구에서 부화 온도가 높을수록 부화율이 증가하였다. 26℃, 28℃, 그리고 32℃에서 부화한 알의 부화 기간은 각각 66.1(±4.0, n=52)일, 65.3(±3.3, n=44)일 그리고 58.8(±7.7, n=31)일이었다. 부화율은 32℃(83.8%)가 26℃(58.4%)와 28℃(58.7%)보다 상대적으로 높았다. 32℃에서 부화 한 14일 된 새끼의 몸무게가 26℃와 28℃에서 부화한 14일 된 새끼의 몸무게보다 높았다. 그렇지만 부화 후 180일과 270일에 새끼의 몸무게는 부화 온도에 따라 큰 차이가 없었다. 본 연구에서 한국산 남생이(M. reevesii) 알의 부화 온도가 부화 기간과 성장 초기 남생이의 체중에 유의한 영향을 미치는 것으로 나타났다.
백은무(Kalanchoe pumila)는 돌나물과(Crassulaceae)에 속 한 다육식물의 일종이다. 이 종은 학술적으로는 알려진 바가 거의 없는 미지의 식물이나 군생하여 자라며 분홍색 꽃을 개화 하기 때문에 관상가치가 높다. 이에 따라 본 연구에서는 온도 처리에 따른 백은무의 생육과 개화특성에 대해서 조사하였다. 온도는 주간/야간의 온도를 20/15, 24/19, 28/23, 32/27℃ 의 네 가지 단계로 설계하였다. 결과에서 백은무는 20/15℃ 처리구에서 초폭, 줄기의 지름, 피복면적, 엽수, 엽장, 엽폭, 지상부와 지하부의 생체중과 건물중, 꽃대의 길이, 꽃수, 화 장, 화폭이 가장 높은 것으로 나타났다. 따라서 백은무는 상대 적으로 저온의 환경에서 더 많은 탄소동화작용을 수행하는 것 으로 보인다. 한편, 24/19℃ 처리구에서는 초장과 정규식생지 수를 나타내는 normalized difference vegetation index (NDVI)가 가장 높은 것으로 나타났으며, 28/23℃ 처리구에서 는 근장과 안토시아닌 반사 지수 2를 나타내는 anthocyanin reflectance index 2(ARI2)가 가장 높은 것으로 나타났다. 32/27℃ 처리구에서는 대부분의 매개변수가 가장 낮은 것으 로 나타났으며, 생육이 거의 정지된 것으로 판단된다. 특히 과 거 연구에서 스트레스 지수로 활용된 매개변수인 CIELAB L* 과 b*는 32/27℃ 처리구에서 가장 높게 나타났다. 상관관계 분석에서는 L*은 지상부와 지하부의 생체중 및 건물중과 음의 상관관계를 가지는 것으로 나타나 잎의 명도(lightness)가 높 을수록 식물의 생육에 부정적인 것으로 평가되었다. 추가적으 로 b*도 이와 유사한 결과를 나타내었다. 결과적으로 백은무 의 식물체 크기를 유의미하게 증대시키고 개화 품질을 촉진시 켜 관상가치를 극대화하기 위해서는 20/15℃ 수준에서 재배 할 것을 권고한다.
This study was conducted in an indoor cultivation room and chamber where environmental control is possible to investigate the effect of temperature and irrigation interval on photosynthesis, growth and growth analysis of potted seedling cucumber. The light intensity (70 W·m-2) and humidity (65%) were set to be the same. The experimental treatments were six combinations of three different temperatures, 15/10℃, 25/20℃, and 35/25°C, and two irrigation intervals, 100 mL per day (S) and 200 mL every 2 days (L). The treatments were named 15S, 15L, 25S, 25L, 35S, and 35L. Seedlings at 0.5 cm in height were planted in pots (volume:1 L) filled with sandy loam and treated for 21 days. Photosynthesis, transpiration rate and stomatal conductance at 14 days after treatment were highest in 25S. These were higher in S treatments with a shorter irrigation interval than L treatments. Total amount of irrigation water was supplied evenly at 2 L, but the soil moisture content was highest at 15S and lowest at 25S > 15L > 25L, 35S and 35L in that order. Humidity showed a similar trend at 15/10℃ (61.1%) and 25/20℃ (67.2%), but it was as high at 35/25°C (80.5%). Cucumber growth (plant height, leaf length, leaf width, chlorophyll content, leaf area, fresh weight and dry weight) on day 21 was the highest in 25S. Growth parameters were higher in S with shorter irrigation intervals. Yellow symptom of leaf was occurred in 89.9% at 35S and 35L, where the temperature was high. Relative growth rate (RGR) and specific leaf weight (SLA) were high at 25/20℃ (25S, 25L), RGR tended to be high in the S treatment, and SLA in the L treatment. Water use efficiency (WUE) was high in the order of 25S, 25L > 15S > 15L, 35S, and 35L. As a result of the above, the growth and WUE were high at the temperature of 25/20℃.
In this study, crystallization was effectively suppressed in Al-based metallic glasses (Al-MGs) during pulverization by cryo-milling by applying an extremely low processing temperature and using a surfactant. Before Al-MGs can be used as an additive in Ag paste for solar cells, the particle sizes of the Al-MGs must be reduced by milling. However, during the ball milling process crystallization of the Al-MG is a problem. Once the Al-MG is crystallized, they no longer exhibit glass-like behavior, such as thermoplastic deformation, which is critical to decrease the electrical resistance of the Ag electrode. The main reason for crystallization during the ball milling process is the heat generated by collisions between the particles and the balls, or between the particles. Once the heat reaches the crystallization temperature of the Al-MGs, they start crystallization. Another reason for the crystallization is agglomeration of the particles. If the initially fed particles become severely agglomerated, they coalesce instead of being pulverized during the milling. The coalesced particles experience more collisions and finally crystallize. In this study, the heat generated during milling was suppressed by using cryo-milling with liquid-nitrogen, which was regularly fed into the milling jar. Also, the MG powders were dispersed using a surfactant before milling, so that the problem of agglomeration was resolved. Cryo-milling with the surfactant led to D50 = 10 um after 6 h milling, and we finally achieved a specific contact resistance of 0.22 mΩcm2 and electrical resistivity of 2.81 μΩcm using the milled MG particles.
This study was conducted to evaluate the filtration performance according to the feed temperature composed of NaCl and the operating pressure of the brackish water reverse osmosis (BWRO) process. The temperature is known that decides the filtration performance of reverse osmosis (RO). It is noted that temperature increase activates the permeate of salts due to augment of diffusivity and mass transfer. Filtration of the lab-scale RO system was performed with constant pressure and the constant flow was simulated. The salt rejection measured by the concentration of the feed and permeate was compared with water permeability and salt permeability in the conditions containing various temperatures (5, 10, 15, 20, 25, and 30℃) and pressures (10, 12, 15, and 18 bar). An increase in feed temperature from 5 °C to 30 °C caused a 4.65% decrease in salt rejection in CSM, due to an increase in salt permeability (4.06 times) rather than an increase in water permeability (2.62 times). Specific energy consumption (SEC) was calculated by using an electricity meter set in the RO system. It was expected that the SEC by the increases in temperature and pressure decreased due to the viscosity decline of the feed and the permeate flux augment, respectively. The SEC decreased by 63.4% in CSM and by 54.3% in Nittodenko when the feed temperature increased from 5 °C to 30 °C. It discussed how to operate the optimal RO process through the effect of temperature and operating pressure and the comparison of SEC.
Perilla plant is a special crop that is used as oilseed and food in Korea. Root lesion nematodes have caused great damage to perilla plants, so for effective management of root lesion nematodes, it is necessary to understand their ecology in perilla. In this study, we investigated the effect of temperature in the development of Pratylenchus penetrans (Pp) and Pratylenchus vulnus (Pv) when the nematodes infected the perilla plant. To estimate the effect of temperature, we assessed the reproduction factor (RF); final population/initial population (Pf/Pi) of these two nematode species. We used perilla plants as inoculated hosts and investigated the density of nematodes at 10 weeks after inoculation. As a result, the RF of Pp was highest at 20°C (0.41 (1st test), 2.2 (2nd test)) followed by 25, 30, and 15°C. The RF of Pv was highest at 30°C (9.84 (1st test), 31.39 (2nd test)), followed by 25, 20, and 15°C. Comparing the RF by temperature between Pp and Pv, Pv was higher than Pp at all temperatures used in the test. This study showed the optimal development temperature of Pp was 20-25°C and Pv was 30°C, respectively.
The germination characteristics of the resting cysts of Pheopolykrikos hartmannii collected from the southern coastal sediments of Korea were studied at different temperature conditions, and the morphology and phylogeny of the germlings were examined. The resting cysts of Ph. hartmannii were round and characterized by a red accumulation body and many arrow-like spines and could germinate at temperature of 10 to 30°C. High germination rates (>90%) were observed at 15 and 20°C, indicating that the resting cysts could act as seed populations for the bloom initiation of Ph. hartmannii in Korean coastal waters in early summer or early fall. The morphology of the germlings was generally consistent with the previous description, and an apical groove characterized by a fully enclosed loop was observed. Phylogenetic analysis based on large SubUnit (LSU) rRNA gene sequences revealed that the germlings shared an identical sequence with the Korean and American isolates of Ph. hartmannii and was a sister clade of Polykrikos species.
The purpose of this study was to investigate the effects of root zone temperatures (RZT) on the germination of bell peppers and tomatoes. Bell peppers and tomatoes had the highest germination rates (85% and 90%, respectively) at 25oC air temperature. Besides, the first germination of bell peppers was shifted by one day ahead. Bell peppers had the highest germination rate of 72,100, and 100%, respectively, when the RZT was adjusted to 30oC at airtemperature of 20, 25, and 30oC, and when the air temperature was adjusted to 35oC, the germination rate was the highest (70%) when the RZT was 15oC. Tomatoes had the highest germination rate at 20oC of the RZT at all atmospheric temperatures. A local cooling and heating system was established to improve the germination rate by controlling the RZT during the low and high temperature period. The optimum RZT for seedlings during the low and high temperature period was investigated.