• 제목/요약/키워드: Seasons Change

검색결과 406건 처리시간 0.022초

Effect of wet treatment on the structure of various silkworm strain cocoons with different rearing seasons

  • Lee, Hye Gyeoung;Bae, Do Gyu;Um, In Chul
    • International Journal of Industrial Entomology and Biomaterials
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    • 제44권1호
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    • pp.4-11
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    • 2022
  • In this study, cocoons from different silkworm strains and rearing seasons were collected and immersed in water at elevated temperatures to investigate the effect of a wet treatment on their morphology and crystallinity. Untreated cocoons exhibited different crystallinities depending on the silkworm strain and rearing season; however, no distinct changes in their morphological structure were observed. Furthermore, after wet treatment, the differences in the crystallinities of cocoons disappeared. In addition, wet treatment of degummed silk (i.e., fibroin) did not change its crystallinity. These results indicate that different crystallinities of the untreated cocoons collected from various silkworm strains and rearing seasons are due to the different characteristics of sericin in the cocoons.

기온예상치를 고려한 모델에 의한 주간최대전력수요예측 (Weekly maximum power demand forecasting using model in consideration of temperature estimation)

  • 고희석;이충식;김종달;최종규
    • 대한전기학회논문지
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    • 제45권4호
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    • pp.511-516
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    • 1996
  • In this paper, weekly maximum power demand forecasting method in consideration of temperature estimation using a time series model was presented. The method removing weekly, seasonal variations on the load and irregularities variation due to unknown factor was presented. The forecasting model that represent the relations between load and temperature which get a numeral expected temperature based on the past 30 years(1961~1990) temperature was constructed. Effect of holiday was removed by using a weekday change ratio, and irregularities variation was removed by using an autoregressive model. The results of load forecasting show the ability of the method in forecasting with good accuracy without suffering from the effect of seasons and holidays. Percentage error load forecasting of all seasons except summer was obtained below 2 percentage. (author). refs., figs., tabs.

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Experimental research on dynamic characteristics of frozen clay considering seasonal variation

  • Xuyang Bian;Guoxin Wang;Yuandong Li
    • Geomechanics and Engineering
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    • 제36권4호
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    • pp.391-406
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    • 2024
  • In order to study the soil seasonal dynamic characteristics in the regions with four distinct seasons, the soil dynamic triaxial experiments were conducted by considering the environmental temperature range from -30℃ to 30℃. The results demonstrate that the dynamic soil properties in four seasons can change greatly. Firstly, the dynamic triaxial experiments were performed to obtain the dynamic stress-strain curve, elastic modulus, and damping ratio of soil, under different confining pressures and temperatures. Then, the experiments also obtain the dynamic cohesion and internal friction angle of the clay under the initial strain, and the changing rule was summarized. Finally, the results show that the dynamic elastic modulus and dynamic cohesion will increase significantly when the clay is frozen; as the temperature continues to decrease, this increasing trend will gradually slow down, and the dynamic damping ratio will go down when the freezing temperature decreases. In this paper, the change mechanism is objectively analyzed, which verifies the reliability of the conclusions obtained from the experiment.

서해 근소만에서 영양염의 조석 및 계절 변화 (Tidal and Seasonal Variations of Nutrients in Keunso Bay, the Yellow Sea)

  • 김동선;김경희
    • Ocean and Polar Research
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    • 제30권1호
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    • pp.1-10
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    • 2008
  • In order to find the effect of intertidal sediments on nutrient cycle in coastal environment, we measured ammonia, nitrate, phosphate, and silicate concentrations every hour during at least 12 hours in the entrance of Keunso Bay during four seasons. The content of ammonia and silicate do not change considerably with season, but nitrate shows large seasonal variation. In summer, nitrate concentration was much lower than in other seasons, which resulted from large biological uptake and active denitrification in intertidal sediments during summer. Phosphate also exhibit seasonal variations, but not that large like nitrate. N/P and N/Si ratios were lower in summer than in other seasons, which was due to active denitrification in the intertidal sediments during summer. For all seasons, ammonia concentrations were higher at low tide than at high tide, but nitrate concentrations were higher at high tide. Dissolved inorganic nitrogen concentrations measured in spring, summer, and winter were higher at high tide than at low tide, but in fall, they were higher at low tide than at high tide. For spring and winter, phosphate and silicate concentrations were higher at low tide than at high tide, while in summer and fall, they were higher at high tide than at low tide. In Keunso Bay, intertidal sediments affect significantly the nutrient cycle around the coastal areas. The intertidal sediments act as a source for ammonia and silicate, but as a sink for nitrate. However, phosphate is not considerably influenced by intertidal sediments.

계절의 변화 원인에 대한 초등학생들의 설명에서 확인된 정신 모델과 묘사적 몸짓의 관계 분석 (The Relationship between the Mental Model and the Depictive Gestures Observed in the Explanations of Elementary School Students about the Reason Why Seasons change)

  • 김나영;양일호;고민석
    • 대한지구과학교육학회지
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    • 제7권3호
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    • pp.358-370
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    • 2014
  • The purpose of this study is to analyze the relationship between the mental model and the depictive gestures observed in the explanations of elementary school students about the reason why seasons change. As a result of analysis in gestures of each mental model, mental model was remembered as "motion" in case of CM-type, and showed more "Exphoric" gestures that expressed gesture as a language. CF type is remembered in "writings or pictures," and metaphoric gestures were used when explaining some alternative concepts. CF-UM type explained with language in detail, and showed a number of gestures with "Lexical." Analyzing depictive gestures, even with sub-categories such as rotation, revolution and meridian altitude, etc., a great many types of gestures were expressed such as indicating with fingers, palms, arms, ball-point pens, and fists, etc., or drawing, spinning and indicating them. We could check up concept understandings of the students through this. In addition, as we analyzed inconsistencies among external representations such as verbal language and gesture, writing and gesture, and picture and gesture, we realized that gestures can help understanding mental models of the students, and sometimes, we could know that information that cannot be shown by linguistic explanations or pictures was expressed in gestures. Additionally, we looked into two research participants that showed conspicuous differences. One participant seemed to be wrong as he used his own expressions, but he expressed with gestures precisely, while the other participant seemed to be accurate, but when he analyzed gestures, he had whimsical concepts.

북서태평양 아열대 해역에서 침강입자 플럭스의 시·공간 변동 (Temporal and Spatial Variations of Sinking-particle Fluxes in the Northwestern Subtropical Pacific)

  • 김형직;형기성;유찬민;전동철;정진현;김부근;김동선
    • Ocean and Polar Research
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    • 제33권spc3호
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    • pp.385-395
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    • 2011
  • Time-series sediment traps were deployed at 1,000 m water depth of the northwestern subtropical Pacific from July 2009 to June 2010, with the aim of understanding temporal and spatial variations of sinking-particle fluxes. The opening and closing of the traps was synchronized at 18-day periods for 20 events. Total mass fluxes showed distinct seasonal variations with high values for the summer-fall seasons and relatively low values for winter-spring. This seasonal variation at two stations was characterized by a distinct difference in $CaCO_3$ fluxes between the two seasons. The enhanced $CaCO_3$ flux in the summer - fall seasons might be attributed to an increased planktonic foraminiferal flux. Total mass flux at FM10 station was nearly 50% higher than that at FM1 station. The difference in $CaCO_3$ fluxes between two stations contributed nearly 70% of the difference of total mass fluxes. The $CaCO_3$ flux was a major component controlling temporal and spatial variation of sinking - particle fluxes in the western subtropical Pacific Ocean.

Evaluation of Growth, Carcass, Immune Response and Stress Parameters in Naked Neck Chicken and Their Normal Siblings under Tropical Winter and Summer Temperatures

  • Rajkumar, U.;Reddy, M.R.;Rao, S.V. Rama;Radhika, K.;Shanmugam, M.
    • Asian-Australasian Journal of Animal Sciences
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    • 제24권4호
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    • pp.509-516
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    • 2011
  • The performance of naked neck and normal chicken was evaluated with respect to growth, carcass, immune, biochemical and stress parameters under winter and summer seasons to assess the suitability of naked neck birds under high temperatures in the global scenario of climate change. The growth performance was significantly ($p{\leq}0.05$) higher in naked neck chicken in the summer season. The dressing percentage was significantly ($p{\leq}0.05$) higher in naked neck birds in both winter and summer season because of reduced plumage. The thigh, giblet and feather proportion significantly ($p{\leq}0.05$) varied between naked neck and normal chickens in summer season. The humeral immune response to sheep red blood cells (SRBC), Newcastle disease vaccine (NDV) and cutaneous basophil hypersensitivity (CBH) did not show any significant differences among the chicken groups. The protein and cholesterol concentration observed was within the normal ranges. The total cholesterol levels in plasma were significantly ($p{\leq}0.05$) lower in naked neck birds in both the seasons. H:L ratio was significantly ($p{\leq}0.05$) lower in summer season indicating less stress in naked neck chicken. Basophil and eosinophil concentration was significantly ($p{\leq}0.05$) higher in normal chicken in summer. The lipid peroxidation was higher in full feathered birds under summer stress. The enzyme glutathione reductase (GR) levels were significantly higher during the summer and varied significantly ($p{\leq}0.05$) between the normal and naked neck chicken in both seasons. The results indicated that the naked neck birds performed significantly better at high ambient temperatures with respect to growth, carcass and biochemical parameters. It was concluded that the ability of the naked neck chicken to adapt to high temperatures foresees a viable option for the biological mitigation of climate change.

계절별 경관의 시각적 선호도 (Viewers' Visual Preferences of Seasonal Landscape)

  • 정윤희;신지훈;임승빈
    • 한국조경학회지
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    • 제30권4호
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    • pp.19-27
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    • 2002
  • When we research a landscape or make a Landscape Impact Assessment, we use the image of a specific season like summer or fall. Since there are four distinct seasons, each with a different landscape, researchers need to understand viewers′visual preferences for individual seasonal landscapes. The purpose of this study is to investigate viewers′visual preferences according to seasonal change and the respondent′s age, gender and profession. In this research, the independent variable is season: suing, summer, fall, winter and snowy winter. Three landscape types used in the experiment: forest, street and agriculture. Each landscape type has two sites for reliability. The assessment media for this research are pictures featuring landscapes taken in each of the four seasons. The study used the "paired comparison" method for taking the score of visual preference. The results of this study are as follows: 1. The summer landscape has the highest visual preference score. However, spring and fall landscapes should also be considered for visual landscape evaluation. 2. The visual preference of winter landscape covered with snow is very high, but since snow is temporal and irregular, it is difficult to consider this factor for visual landscape evaluation. 3. The visual preference score of winter is the lowest of four seasons. The attractive factors of spring are flowers, summer is greenery and fall is autumnal tints. But these are not present in winter. 4. The result of visual preferences according to age groups, gender and profession have no serious differences. 5. Visual preference to scenery of 4 seasons by age group was not different from general preference and thus was concluded to have no connection with age. 6. As a result from the research of visual preference to scenery of 4 seasons by sex, women were shown to like snow-scene more than men. This study presents an indication of general preferences of seasonal landscapes. It is expected that more advanced study will proceed after this one.

Seasonal atmospheric characteristics in a swine finishing barn equipped with a continuous pit recirculation system using aerobically treated manure

  • Choi, Yongjun;Ha, Duck-Min;Lee, Sangrak;Kim, Doo-Hwan
    • Animal Bioscience
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    • 제35권12호
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    • pp.1977-1985
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    • 2022
  • Objective: This study was conducted to determine the seasonal characteristics of odorous material emissions from a swine finishing barn equipped with a continuous pit recirculation system (CPRS) using aerobically treated manure. Methods: The CPRS consists of an aerobic manure treatment process and a pit recirculation system, where the solid fraction is separated and composted. The aerated liquid fraction (290.0%±21.0% per day of total stored pig slurry) is continuously recirculated to the top of the slurry in the pit. Four confinement pig barns in three piggery farms were used: two were equipped with CPRS, and the other two operated a slurry pit under the slatted floor across all seasons. Results: The indoor, exhaust, and outside odor intensities were significantly lower in the CPRS group than in the control group (p<0.001). In the CPRS group, the odor intensity outside was significantly lower in the fall than in the other seasons (p = 0.015). In the indoor atmosphere, the temperature and CO2, NH3, and H2S contents of the CPRS group were significantly lower than those of the control group (p<0.05). In the CPRS group, indoor temperature did not significantly change in the spring, summer, and fall seasons and was significantly lower in the winter (p = 0.002). NH3, H2S, methyl mercaptan, dimethyl disulfide, trimethylamine, phenol, indole, and skatole levels were significantly lower in the CPRS group than in the control group (p<0.05). There were significant seasonal differences on the odorous material in both the control and CPRS groups (p<0.05), but the pattern was not clear across seasons. Conclusion: The CPRS can reduce the indoor temperature in the summer to a level similar to that in the spring and fall seasons. The CPRS with aerated liquid manure is expected to reduce and maintain malodorous emissions within acceptable limits in swine facilities.

낙동강 물금 지점의 겨울 및 봄철 식물플랑크톤 생물량에 대한 기후변화 영향 (Effect of Climate Change for Diatom Bloom at Winter and Spring Season in Mulgeum Station of the Nakdong River, South Korea)

  • 정승현;박혜경;이혜진;이수형
    • 한국물환경학회지
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    • 제29권2호
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    • pp.155-164
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    • 2013
  • To confirm the relationship between climate change and Stephanodiscus in Mulgeum station of Nakdong River, Korea, this study was conducted. The temperature in crease by climate change was observed in the study site, where the temperature was gradually increased in most seasons, except for summer season. The mass proliferation of Stephanodiscus constantly appeared in every year, especially between November and March, and when Stephanodiscus abundance was above 90% in phytoplankton biomass. Among this period, phytoplankton biomass was high related with water temperature ($r^2$=0.249, P<0.01) than nutrient factors such as nitrogen and phosphorus in the study site. Finally, temperature by climate change can be regarded as the affecting factor for chl. a variation, because temperature was strongly related with water temperature ($r^2$=0.748, P<0.01). From 1997 to 2010, the annual maximum phytoplankton biomass was recorded in the range of temperature from $4.8^{\circ}C$ to $8.4^{\circ}C$, and the range was regarded as the temperature condition for the optimal growth of Stephanodiscus in the study site. On the optimal growth temperature, the trend of monthly average temperature corresponded to the trend of chl. a variation from November to March. In future, the increase of temperature by climate change can prolong Stephanodiscus blooming period in winter and spring seasons.