• 제목/요약/키워드: pH variation

검색결과 1,310건 처리시간 0.033초

Introgression of Sex-Limited Larval Markings to a Productive Multivoltine Strain of Silkworm Bombyx mori L.

  • Rao, D. Raghavendra;Singh Ravindra;Basavaraja H.K.;Kariappa B.K.;Dandin S.B.;Rufaie S.Z. Haque
    • International Journal of Industrial Entomology and Biomaterials
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    • 제13권1호
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    • pp.7-14
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    • 2006
  • A breeding programme was initiated during 2001 to introduce sex-limited larval markings to a productive multivoltine breed - BL67 from an inbred sex-limited line, MY1 (SL) maintained at Central Sericultural Research and Training Institute, Mysore. Introgressive hybridization, recurrent backcrossing for six generations followed by sib-mating resulted in synthesis of a new multivoltine silkworm breed BL67 (SL) with sex-limited larval markings. The new breed was studied for combining ability by crossing with eight bivoltine breeds viz., $NB_4D_2,\;CSR_2,\;CSR_2 (SL),\;CSR_2,\;CSR_4,\;CSR_8,\;CSR_{18}\;and\;CSR_{19}$. General combining ability effects of the new breed showed its superiority over the popular Pure Mysore by expressing significant GCA effects for six out of twelve characters whereas the results are on par with the original multivoltine breed. The hybrid $BL67(SL){\times}CSR2(SL)$ excelled in several quantitative characters such as pupation rate (90.2%), cocoon weight (1.97 g), cocoon shell weight (40 cg), cocoon shell ratio (20.3%), filament length (918 m), denier (2.96), raw silk percentage (14.96%) and neatness (90 p). Studies on cocoon size variability revealed that the cocoons of $BL67(SL){\times}CSR2(SL)$ were found comparatively uniform showing less standard deviation of 6.55 and co-efficient of variation of 3.91 %. The suitability of newly developed breed for easy grain age operation and commercial exploitation with promising hybrid have been discussed.

감마선 조사가 휴민산 염소화에 의한 THMs 생성능 및 수질특성에 미치는 영향 (Effect of γ-ray Irradiation on THMs Formation and Water Quality Characteristics in the Chlorination of Humic Acid Contaming Water)

  • 강철호;임현우;정성운;최종혁;김종훈;최용욱;이면주
    • 한국물환경학회지
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    • 제26권6호
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    • pp.1034-1039
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    • 2010
  • Variation of formation potential of THM (THMFP) by chlorination of humic acid and characteristics of water quality with ${\gamma}$-ray irradiation were investigated, which were divided into two categories by the order of ${\gamma}$-ray irradiation and chlorination in water treatment process. The group A consisted of the ${\gamma}$-ray irradiation followed by chlorination process of humic acid, and the group B consisted of the chlorination followed by ${\gamma}$-ray irradiation process. The pH, ORP, $UV_{254}$, and DOC decreased rapidly with an increase in ${\gamma}$-ray irradiation of 3 kGy. while conductivity was little changed. Maximum degradation ratio of chloroform in THMs of group A was 82%, while that in group B was 69%. No brominated THMs were detected at high irradiation (>3 kGy). We found that group A water treatment process was more effective in lowering the THMFP than that of group B.

광촉매(光觸媒) 산화(酸化) 반응(反應)을 이용한 클로로페놀 분해(分解)에 관한 연구(硏究) (A Study on the Removal of Chloro-Phenols by Photocatalytic Oxidation)

  • 이상협;박주석;박중현
    • 상하수도학회지
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    • 제9권4호
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    • pp.87-96
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    • 1995
  • The Electron/Hole Pair is generated when the activation energy produced by ultraviolet ray illuminates to the semiconductor and OH- ion produced by water photocleavage reacts with positive Hole. As a results, OH radical acting as strong oxidant is generated and then Photocatalytic oxidation reaction occurs. The photocatalytic oxidation can oxidate the non-degradable and hazardous organic substances such as pesticides and aromatic materials easier, safer and shorter than conventional water treatment process. So in this study, many factors influencing the oxidation of chlorophenols, such as inorganic electrolytes addition, change of oxygen and nitrogen atmosphere, temperature, pH, oxygen concentration, chlorophenol concentration, were throughly examined. According to the experiments observations, it is founded that the rate of chlorophenol oxidation follows a first-order reaction and the modified Langmuir-Hinshelwood relationship. And the photocatalytic oxidation occurs only when activation energy acting as Electron/Hole generation, oxygen acting as electron acceptor to prevent Electron/Hole recombination, $TiO_2$ powder acting as photocatalyst are present. The effects of variation of dissolved oxygen concentration, temperature and inorganic electrolytes concentration on 2-chlorophenol oxidation are negligible. And the lower the organic concentration, the higher the oxidation efficiency becomes. Therefore, the photocatalytic oxidation is much effective to oxidation of hazardous substances at very low concentration. The oxidation is effective in the range of 0.1 g/L-10 g/L of $TiO_2$. Finally when the ultra-violet ray is illuminated to $TiO_2$, the surface characteristics of $TiO_2$ change and Adsorption/Desorption reaction on $TiO_2$ surface occurs.

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수질오염 감시체계 구축을 위한 수질 데이터의 통계적 예측 가능성 검토 (A Study on the Statistical Predictability of Drinking Water Qualities for Contamination Warning System)

  • 박노석;이영주;채선하;윤석민
    • 상하수도학회지
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    • 제29권4호
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    • pp.469-479
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    • 2015
  • This study have been conducted to analyze the feasibility of establishing Contamination Warning System(CWS) that is capable of monitoring early natural or intentional water quality accidents, and providing active and quick responses for domestic C_water supply system. In order to evaluate the water quality data set, pH, turbidity and free residual chlorine concentration data were collected and each statistical value(mean, variation, range) was calculated, then the seasonal variability of those were analyzed using the independent t-test. From the results of analyzing the distribution of outliers in the measurement data using a high-pass filter, it could be confirmed that a lot of lower outliers appeared due to data missing. In addition, linear filter model based on autoregressive model(AR(1) and AR(2)) was applied for the state estimation of each water quality data set. From the results of analyzing the variability of the autocorrelation coefficient structure according to the change of window size(6hours~48hours), at least the window size longer than 12hours should be necessary for estimating the state of water quality data satisfactorily.

대두분 품질에 미치는 가열처리조건에 관한 연구 (Studies on the effect of heating conditions on the quality of soybean flours)

  • 이성갑;김준평
    • 기술사
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    • 제17권4호
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    • pp.28-39
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    • 1984
  • Experiments were carried out for the development of a processing method of soybean into full-fat or defatted flour, using two varieties of soybean (kwangkyo produced in Korea and Bragg produced in India) Samples were subjected to dry dehulling, size reduction and wet heat treatment processes to make soybean flours. The quality of soybean flours were evaluated, and the results obtained were summarized as follows. 1. Crude fiber content of dehulled soybean was under 3.0% which indicated satisfactory dehulling, and there was no significant difference in crude fibre content between two varieties. 2. When dehulled soybean was cracked into soy grits by a hammer mill, 98.71∼98.86% of the soy grit was in the range of 10∼18 mesh which was the optimum size of particle for quick and uniform penetration of heat into the intra-particle air spaces. 3. Moisture content of soy flour after steam treatment at 15 psig for 5 to 30 min was only 0.29∼1.68% which did not hinder the next milling operation. 4. From the color analysis of soy flours, it was observed that the dominant wavelength for all the samples are in a very narrow range from 575 to 581 nm and the color variation was from yellow to yellowish orange. Twenty to twenty five % higher reflectance was observed in the defatted flours than full fat flours. The % chroma of the defatted flour slightly increased as the duration of steaming of soy grits increased, whereas that of the full-fat flour did not. 5. The protein extractability in the defatted flour at pH 7.6 showed progressive decrease in solubility from 48.40% (Bragg), 75.20% (kwangkyo) for untreated flours to 9.75% (Bragg), 26.27% (kwangkyo) for 30 min steaming. But Kwangkyo variety showed twice higher protein extractability than Bragg variety.

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The Leaching Behavior of Unirradiated $UO_2$ Pellets in Wet Storage and Disposal Conditions

  • Park, Geun-Il;Lee, Hoo-Kun
    • Nuclear Engineering and Technology
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    • 제28권4호
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    • pp.349-358
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    • 1996
  • The leaching behavior of uranium from unirradiated CANDU UO$_2$ fuel pellet in the spent fuel wet storage and disposal conditions has been investigated. A modified IAEA leach test method was used, and then the extent of leaching was monitored by analysis for uranium in the leachant. The leach test has been performed in various leachants(demineralized water and boric acid solution at pH=6, synthetic granite groundwater) for a long-term period of 5.4 years, and the effect of temperature on the leach rate of uranium has been analyzed. The leach rates of uranium at $25^{\circ}C$ were dependent on the leachants. Over initial 100 days of leach periods, the leach rate in groundwater was the highest in three leachants and no significant differences of leach rates ore observed in the demineralized oater and boric acid solution. But these leach rates in three leachants around 2,000 days at $25^{\circ}C$ appeared to be reached the steady rates in the range of 1~5$\times$10$^{-8}$ g/$\textrm{cm}^2$ day. The leach rate of uranium in groundwater shooed to be independent of the temperature, but those in both demineralized water and boric acid solution increased with temperature. These results show that the leaching behavior of uranium from UO$_2$ fuel in both the demineralized water ann boric acid may be controlled tv the surface oxidative.dissolution reaction of UO$_2$ and the leach rate of uranium in groundwater at room temperature could mainly be controlled by the complex reaction of dissolved uranyl ions with carbonate ions and no variation of leach rate of UO$_2$ in groundwater with temperature may be due to the local deposition of passivating uranyl phases on the surface.

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음식폐기물로부터 유도된 퇴비가 채소류의 발아 및 생육에 미치는 영향 (Effects of Compost Derived from Food Wastes on Germination and Growth of Vegetables)

  • 박석환
    • 한국환경보건학회지
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    • 제27권3호
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    • pp.21-26
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    • 2001
  • This study was performed to define the physicochemical characteristics of food waste and food wastewater, and to find the effect of salinity variation experiment, the samples of 1, 2, 3 and 4 were prepared by the salinity of 1.0%, 1.5%, 2.0% and 2.5%, respectively. In experiment, aerobic composting reactors were operated by the model which was composed of half an hour's stirring and 2 hour's aeration per day, for 45 days. Seeds of vegetables of Chinese cabbage and red pepper were seeded at compost-free control, compost 1, 2, 3 and compost 4 for the sake of investigation of germination rate and growth rate of those. The followings are the conclusions that were derived from this study. 1. In food waste, the moisture content was 60%, organic compound content was 95%, total carbon was 47.5%, total nitrogen was 1.6%(therefore, C/N ratio was 30). The values of pH were 4.0 and 3.8 the values of salinity were 0.9% and 1.2%, and the values of conductivity were 7.8 mS/cm and 18.0 mS/cm, respectively. 2. In salinity experiment, the reduction rate of volume was increased(40%) when the salinity was decreased(1.0%). Also, the reduction rate of mass was increased(52%) when the salinity was decreased(1.0%). This fact denotes that salinity hinders the process of composting. 3. Germination rate and growth rate of Chinese cabbage are more excellent than those of red pepper(97.14%, 5.2:2.5 cm). 4. In Chinese cabbage, germination rate and growth rate at compost with the lowest salinity are more excellent than those at compost-free control(97:94%, 5.2:4.5 cm).

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한라산 지역 용천수의 수리지화학적 특성 (Hydrogeochemical Characteristics of Spring Water in Halla Mountain Region, Cheju Island)

  • 윤정수;박상운
    • 한국지구과학회지
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    • 제21권1호
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    • pp.81-92
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    • 2000
  • 본 연구는 한라산 지역에 분포하는 대표적인 9개 용천수에 대한 고도별 수질특성과 그 진화과정을 연구하였다. 조사 지역 9개 용천수의 수질분석결과 관음사용천수는 수소이온 농도에서 비정상적인 수질특성을 보였다. 해발고도 1000m 이하에 위치하는 영실, 남국선원, 성판악, 어리목 및 관음사용천수에서는 염소이온, 황산이온, 질산성질소 및 나트륨이온 함량이 높아 주변 육상오염원들에 의해 오염이 진행 중인 용천수로 분류된다. 중탄산이온, 황산이온 및 수소이온 농도는 강수량이 많았을 때 그 농도가 증가하였으며, 염소이온, 칼슘이온 및 질산성질소 농도는 강수량이 많았을 때 그 농도가 감소하였고, 마그네슘이온, 나트륨이온 및 전기비전도도 농도는 강수량의 영향이 미미하였다. 한라산 용천수는 백록담 담수와 윗세오름용천수를 제외한 전 용천수가 나트륨 또는 칼륨형(sodium or potassium type)과 중탄산형(bicarbonate type)의 용천수군으로 구분된다.

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영국 고원지대(Moorland)의 이탄 토양에서 애지렁이 추출을 위한 수분깔때기의 최적조건 (Optimal Conditions for the Wet Funnel Extraction of Enchytraeidae from Peat Soils of Moorlands in England)

  • 권태성
    • 한국토양동물학회지
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    • 제5권2호
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    • pp.63-70
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    • 2000
  • 영국의 고원지대 (Moorland)의 이탄토양 (blanket bog peat soil에 서식하는 애지렁이 정량조사를 위한 수분갈때기추출법의 효율에 미치는 수온, 물의 량, 추출시간의 복합적인 효과를 조사하였다. 이탄 토양에서 애지렁이 추출을 위한 최적조건은 물의 양과 초기 수온에 관계없이 표면수의 최종 온도는 35$^{\circ}C$이고, 추출시간은 6시간이었다. O'Connor의 방법 (최종 온도 40-45$^{\circ}C$,열의 점진적인 증가, 3시간 추출)은 비교적 늪은 온도와 짧은 추출시간으로 인해, 추출효율에 변이가 심하였다. 열을 가하지 않고 장시간 추출하는 방식은 열을 가하는 방식에 비해 추출효율이 현저히 낮았다.

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전주지역 강수의 황동위원소비와 대기오염원의 추적자로서 그 유용성 (Sulfur Isotopic Ratios in Precipitation around Chonju-city, Korea and Its Availability as a Tracer of the Source of Atmospheric Pollutants)

  • 나춘기;김선영;전서령;이무성;정재일
    • 자원환경지질
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    • 제28권3호
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    • pp.243-249
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    • 1995
  • In order to investigate the origin of sulfate in rain waters and to evaluate the feasibility of using sulfur isotope method as a tracer of atmospheric pollutants, the sulfur isotopic ratio of sulfate in rain waters collected in Chonju city from October 1994 to March 1995 was monitored and was compared with those of possible sources proposed by previous works. The pH of rain waters shows an intermediate acidic range from 4.45 to 6.88 and their daily variation appears to be well correlated with to the amount of precipitation. The sulfur isotopic ratios of sulfate in rain waters show a highly restricted range from 0.0 to + 1.8‰. The ${\delta}^{34}S$ values are similar to those of soil and pine tree surrounding Chonju city, but largely deviate from those of China. D-parameter($d={\delta}D-8{\delta}^{18}O$) of rain waters varies from 9.4 to 28.8. The values indicate that the rain waters in Chonju city are originated from the rainy front of China continent. All data obtained from this study suggested that sulfate in the rain waters collected in Chonju city was mainly derived from the sulfur dioxide gas emitted by the petroleum combustion. Therefore, sulfur isotopic study for the precipitation provided an excellent tool for environmental assessment in this region and for tracing the source of atmospheric pollutants.

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