• Title/Summary/Keyword: Surface recovery

Search Result 826, Processing Time 0.023 seconds

Influence of Short-term Application of Abscisic Acid in Nutrient Solution on Growth and Drought Tolerance of Tomato Seedlings (토마토 육묘과정에서 단기간 ABA처리가 묘소질과 건조내성에 미치는 영향)

  • Kim, Il-Seop;Vu, Ngoc-Thang;Vo, Hoang-Tung;Choi, Ki-Young;Kim, Young Shik
    • Journal of Bio-Environment Control
    • /
    • v.24 no.1
    • /
    • pp.13-20
    • /
    • 2015
  • This study was conducted to evaluate influence of short-term application of abscisic acid (ABA) in nutrient solution on growth and drought tolerance of tomato seedlings. The treatments included four ABA concentrations (0.5, 1, 2, $3mg{\cdot}L^{-1}$) and control (non-treatment) were applied to the nutrient solution in a hydroponic system. On the $5^{th}$ and $10^{th}$ day after growing in the nutrient solution containing ABA, seedlings were transferred to -5 bars of PEG-8000 in a growth chamber to induce water stress. Except for stem diameter and fresh and dry weight of root, there were no statistical differences in other growth parameters among control, 0.5 and $1mg{\cdot}L^{-1}$ of ABA treatments. Seedlings growths were strongly inhibited in nutrient solution containing 2 and $3mg{\cdot}L^{-1}$ of ABA. The root growth such as fresh and dry weigh of root, total root surface area, and average root diameter was slightly enhanced in $1mg{\cdot}L^{-1}$ of ABA treatment. The elevation of ABA concentrations in nutrient solution resulted in the decrease in transpiration rate and increase in stomatal diffusive resistance and leaf temperature of tomato seedlings. The initiations of seedling wilting after treating in -5 bars of PEG were delayed from 10 hrs in control to 30 hrs in ABA applied treatments. Additionally, the high percentages of recovered seedlings were observed in 0.5 and $1mg{\cdot}L^{-1}$ of ABA treatments after re-irrigation. Therefore, short-term application of $1mg{\cdot}L^{-1}$ of ABA in the nutrient solution stimulated the root growth and drought tolerance of tomato seedlings by delaying the start time of wilting point and enhancing the recovery after re-irrigation.

The Effects of Solidified Sewage Sludge as a Soil Cover Material for Cultivation of Bioenergy Crops in Reclaimed Land (에너지작물 재배를 위한 간척지 토양의 토양복토재로써 하수슬러지 고화물의 이용효과)

  • An, Gi-Hong;Koo, Bon-Cheol;Choi, Yong-Hwan;Moon, Youn-Ho;Cha, Young-Lok;Bark, Surn-Teh;Kim, Jung-Kon;Yoon, Yong-Mi;Park, Kwang-Guen;Kim, Jang-Taeck
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.57 no.3
    • /
    • pp.238-247
    • /
    • 2012
  • To determine the possibility of solidified se wage sludge for use as a soil cover material in reclaimed land, the growth of energy crops and soil chemical properties investigated in each experimental plots during 2 years (2010 and 2011). The experimental plots consisted of the mixing with solidified sewage sludge plot (SS50), the covering with solidified sewage sludge plot (SS100), and the original reclaimed land plot (ORL) on reclaimed land for the intended landfill in Sudokwon Landfill Site Management Corporation (SLC). Plant height, measured in the second year (2011), was highest in the Geodae 1 grown at plots treated with solidified sewage sludge. The growth of energy crops cultivated in both SS50 and SS100 were better than in ORL. The contents of organic matter (OM) and total nitrogen (T-N) at both SS50 and SS100 were considerably higher than that of the ORL over 2 years. However, the soil from ORL showed higher salinity with high contents of exchangeable $Na^+$ cation than that of SS50 and SS100 over 2 years. We consider that soil chemical and physical properties on reclaimed land used in this study could be improved by the application of solidified sewage sludge due to following reasons. Firstly, the application of solidified sewage sludge may provide soil nutrients on reclaimed land i.e. the growth of energy crops better than in ORL, resulted in more OM and T-N contents in SS50 and SS100. Secondly, the top layers mixed or covered with solidified sewage sludge on reclaimed land may be prevented the salinity accumulation due to capillary rise to surface soil, and improved the cultivation layer for effectively propagating the rhizomes of energy crops. Thus the solidified sewage sludge may be a great soil cover materials for cultivation of bioenergy crops in reclaimed land.

Residue Study for Bisphenol A in Agricultural Reservoirs (농업용 저수지에서 Bisphenol A의 잔류실태조사)

  • Cho, Il Kyu;Nam, Hyo Song;Jeon, Yongbae;Park, Jun sung;Na, Tae Wong;Kim, Back Jong;Kan, Eunsung
    • Korean Journal of Environmental Agriculture
    • /
    • v.35 no.4
    • /
    • pp.270-277
    • /
    • 2016
  • BACKGROUND: Significant amount of bisphenol A has been released from the manufacturing process of plastics, epoxy resins, dental material and flame retardants. Bisphenol A has been detected at trace levels in wastewater, surface water, landfill leachate and drinking water. However, the residual survey of bisphenol A has not been performed in agricultural reservoir beside agricultural environment cultivating crops. This study was conducted to monitor the residual bisphenol A in national agricultural reservoirs and understand a level of contamination of bisphenol A in the agricultural environment in Korea. METHODS AND RESULTS: The water and water sediment were collected at agricultural reservoirs in Chungnam, Chungbuk, Kyunggi, Jeonnam, Jeonbuk, Kyungnam and Kyungbuk province. Bisphenol A was analyzed by the LC-MS/MS with triple quad 4500. The recovery of water and water sediment in the agricultural reservoirs showed the level of 95.7~97.2% and 91.5~100.3%, respectively. CONCLUSION: Bisphenol A was detected at the level of $0.05{\mu}g/L{\sim}0.18{\mu}g/L$ and $0.1{\mu}g/kg{\sim}34{\mu}g/kg$ in water and water sediment of the reservoirs, respectively. Based on the results, the residue of bisphenol A will be tried in the crops surrounding these agricultural reservoirs where bisphenol A detected above $10{\mu}g/kg$ of bisphenol A.

Determination of the Levels of Bisphenol A Diglycidyl Ether (BADGE), Bisphenol F Diglycidyl Ether (BFDGE) and Their Reaction Products in Canned Foods Circulated at Korean Markets (캔 제품의 bisphenol A diglycidyl ether (BADGE), bisphenol F diglycidyl ether (BFDGE) 유도체 및 분해산물 분석법)

  • Kim, Hee-Yun;Lee, Jin-Sook;Cho, Min-Ja;Yang, Ji-Yeon;Baek, Ji-Yun;Cheong, So-Young;Choi, Sun-Hee;Kim, Young-Seon;Choi, Jae-Chun
    • Korean Journal of Food Science and Technology
    • /
    • v.42 no.1
    • /
    • pp.8-13
    • /
    • 2010
  • Bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE) were obtained by a polymerization reaction of epichlorohydrin (ECH) with bisphenol A (BPA) or bisphenol F (BPF). These compounds are commonly used as monomers or additives such as a polymerization stabilizer and a hydrochloric acid scavenger of epoxy resin, polyvinyl chloride (PVC)-containing organosols and polyester lacquers, that are applied to the internal surface of most canned foods to impart chemical resistance. The unreacted BADGE, BFDGE and their reaction products migrating from epoxy resin, PVC-containing organosol and/or polyester lacquer-based food packaging materials into the foods have recently become an issue of great concern because of increased customer demand for safety. This study was conducted to develop a rapid and sensitive simultaneous analysis method based on HPLC/FLD and HPLC/APCI-mass and to evaluate the concentration of BADGE, BFDGE and their metabolites, BADGE $H_2O$, BADGE $2H_2O$, BADGE HCl, BADGE 2HCl, BADGE HCl $H_2O$, BFDGE $H_2O$, BFDGE $2H_2O$, BFDGE HCl, BFDGE 2HCl and BFDGE HCl $H_2O$ for 133 canned food samples. The method provided a linearity of 0.9997-0.9999, a limit of detection of $0.01-0.13\;{\mu}g/mL$, a limit of quantitation of $0.03-0.44\;{\mu}g/mL$ and a recovery (%) of 85.64-118.18. The number of samples containing BADGE, BFDGE or their metabolites were: 28/133 (21.1%), with levels of 0.400-0.888 mg/kg being observed for aqueous foods (19/133) and 0.093-0.506 mg/kg being observed for oily foods (9/133).

Worker Exposure and Volatilization Pattern of Cadusafos, Ethoprophos and Probenazole after Applying Granular Type Formulation on Soil in Greenhouse (시설재배지에서 토양처리농약 Cadusafos, Ethoprophos와 Probenazole 입제 처리 후 휘산 양상과 농작업자 노출)

  • Park, Byung-Jun;Lee, Ji-Ho
    • Korean Journal of Environmental Agriculture
    • /
    • v.30 no.2
    • /
    • pp.160-165
    • /
    • 2011
  • BACKGROUND: This study carried out to fate of pesticide and investigate worker exposure of pesticide in air after applying granular type pesticide formulation on soil in greenhouse for preventing farmer's pesticide intoxication. METHODS AND RESULTS: The recovery of pesticide, cadusafos, ethoprophos and probenazole on absorbent in air were ranged 80.9~121.1% in charcoal and 90.6~99.0% in XAD-4, respectively. Emission rate of in lysimeter was higher 3~5 times than that of pesticides from topsoil not added water at $35^{\circ}C$ plot after applying a mixture of granular formulation and soil. The ethoprophos concentration in air, 50 cm high from soil surface at greenhouse, was reached the highest 186.4 ${\mu}g/m^3$ within 13 hours and were ranged 17.8~186.4 ${\mu}g/m^3$ during 46 hours after applying granular formulation at dose rate 150 g a.i./245 $m^2$. The cadusafos concentration in air at greenhouse was reached the highest 37.3 ${\mu}g/m^3$ within 39 hours and were ranged 10.0~37.3 ${\mu}g/m^3$ during 46 hours after applying granular formulation at dose rate 180 g a.i./245 $m^2$. The probenazole concentration in air at greenhouse was reached the highest 1.45 ${\mu}g/m^3$ within 37 hours and were ranged 0.23~1.45 ${\mu}g/m^3$ during 46 hours after applying granular formulation at dose rate 144 g a.i./245 $m^2$. CONCLUSION(s): The result of the reentry interval study demonstrated that reentry intervals for ethoprophos and cadusafos are longer than 48 hours.

Optimization for Underwater Welding of Marine Steel Plates (선박용 강판의 수중 용접 최적화에 관한 연구)

  • 오세규
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.20 no.1
    • /
    • pp.49-59
    • /
    • 1984
  • Optimizing investigation of characteristics of underwater welding by a gravity type arc welding process was experimentally carried out by using six types of domestic coated welding electrodes for welding of domestic marine structural steel plates (KR Grade A-1, SWS41A, SWS41B,) in order to develop the underwater welding techniques in practical use. Main results obtained are summarized as follows: 1. The absorption speed of the coating of domestic coated lime titania type welding-electrode became constant at about 60 minutes in water and it was about 0.18%/min during initial 8 minutes of absorption time. 2. Thus, the immediate welding electrode could be used in underwater welding for such a short time in comparison with the joint strength of in-atmosphere-and on-water-welding by dry-, wet-or immediate-welding-electrode. 3. By bead appearance and X-ray inspection, ilmenite, limetitania and high titanium oxide types of electrodes were found better for underwater-welding of 10 mm KR Grade A-1 steel plates, while proper welding angle, current and electrode diameter were 6$0^{\circ}C$, above 160A and 4mm respectively under 28cm/min of welding speed. 4. The weld metal tensile strength or proof stress of underwater-welded-joints has a quadratic relationship with the heat input, and the optimal heat input zone is about 13 to 15KJ/cm for 10mm SWS41A steel plates, resulting from consideration upon both joint efficiency of above-100% and recovery of impact strength and strain. Meanwhile, the optimal heat input zone resulting from tension-tension fatigue limit above the base metal's of SWS41A plates is 16 to 19KJ/cm. Reliability of all the empirical equations reveals 95% confidence level. 6. The microstructure of the underwater welds of SES41A welded in such a zone has no weld defects such as hydrogen brittleness with supreme high hardness, since the HAZ-bond boundary area adjacent to both surface and base metal has only Hv400 max with the microstructure of fine martensite, bainite, pearlite and small amount of ferrite.

  • PDF

Development and Validation of Analytical Method for Determination of Biphenyl Analysis in Foods (식품 중 비페닐 분석법 개발 및 유효성 검증)

  • Kim, Jung-Bok;Kim, Myung-Chul;Song, Sung-Woan;Shin, Jae-Wook
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.46 no.4
    • /
    • pp.459-464
    • /
    • 2017
  • Biphenyl is used as an intermediate in the production of crop protection products, a solvent in pharmaceutical production, and as a component in the preservation of citrus fruits in many countries. Biphenyl is not authorized for use and also does not have standards or specifications as a food additive in Korea. National and imported food products are likely to contain biphenyl. Therefore, control and management of these products is required. In this study, a simple analytical method was developed and validated using HPLC to determine biphenyl in food. These methods are validated by assessing certain performance parameters: linearity, accuracy, precision, recovery, limit of detection (LOD), and limit of quantitation (LOQ). The calibration curve was obtained from 1.0 to $100.0{\mu}g/mL$ with satisfactory relative standard deviations (RSD) of 0.999 in the representative sample (orange). In the measurement of quality control (QC) samples, accuracy was in the range of 95.8~104.0% within normal values. The inter-day and inter-day precision values were less than 2.4% RSD in the measurement of QC samples. Recoveries of biphenyl from spiked orange samples ranged from 92.7 to 99.4% with RSD between 0.7 and 1.7% at levels of 10, 50, and $100{\mu}g/mL$. The LOD and LOQ were determined to be 0.04 and $0.13{\mu}g/mL$, respectively. These results show that the developed method is appropriate for biphenyl identification and can be used to examine the safety of citrus fruits and surface treatments containing biphenyl residues.

Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2011 (설비공학 분야의 최근 연구 동향: 2011년 학회지 논문에 대한 종합적 고찰)

  • Han, Hwa-Taik;Lee, Dae-Young;Kim, Seo-Young;Choi, Jong-Min;Paik, Yong-Kyoo;Kim, Su-Min
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.24 no.6
    • /
    • pp.521-537
    • /
    • 2012
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2011. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends of thermal and fluid engineering have been surveyed as groups of fluid machinery and fluid flow, thermodynamic cycle, and new and renewable energy. Various topics were presented in the field of fluid machinery and fluid flow. Research issues mainly focused on the rankine cycle in the field of thermodynamic cycle. In the new and renewable energy area, researches were presented on geothermal energy, fuel cell, biogas, reformer, solar water heating system, and metane hydration. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer, nanofluids and industrial heat exchangers. Researches on heat transfer characteristics included heat transfer above liquid helium surface in a cryostat, methane hydrate formation, heat and mass transfer in a liquid desiccant dehumidifier, thermoelectric air-cooling system, heat transfer in multiple slot impinging jet, and heat transfer enhancement by protrusion-in-dimples. In the area of pool boiling and condensing heat transfer, researches on pool boiling of water in low-fin and turbo-B surfaces, pool boiling of R245a, convective boiling two-phase flow in trapezoidal microchannels, condensing of FC-72 on pin-finned surfaces, and natural circulation vertical evaporator were actively performed. In the area of nanofluids, thermal characteristics of heat pipes using water-based MWCNT nanofluids and the thermal conductivity and viscosity were measured. In the area of industrial heat exchangers, researches on fin-tube heat exchangers for waste gas heat recovery and Chevron type plate heat exchanger were implemented. (3) Refrigeration systems with alternative refrigerants such as $CO_2$, hydrocarbons, and mixed refrigerants were studied. Heating performance improvement of heat pump systems were tried applying supplementary components such as a refrigerant heater or a solar collector. The effects of frost growth were studied on the operation characteristic of refrigeration systems and the energy performance of various defrost methods were evaluated. The current situation of the domestic cold storage facilities was analyzed and the future demand was predicted. (4) In building mechanical system fields, a variety of studies were conducted to achieve effective consumption of heat and maximize efficiency of heat in buildings. Various researches were performed to maximize performance of mechanical devices and optimize the operation of HVAC systems. (5) In the fields of architectural environment and energy, diverse purposes of studies were conducted such as indoor environment, building energy, and renewable energy. In particular, renewable energy and building energy-related researches have mainly been studied as reflecting the global interests. In addition, various researches have been performed for reducing cooling load in a building using spot exhaust air, natural ventilation and energy efficiency systems.

The Limitation of Air Carriers' Cargo and Baggage Liability in International Aviation Law: With Reference to the U.S. Courts' Decisions (국제항공법상 화물.수하물에 대한 운송인의 책임상한제도 - 미국의 판례 분석을 중심으로 -)

  • Moon, Joon-Jo
    • The Korean Journal of Air & Space Law and Policy
    • /
    • v.22 no.2
    • /
    • pp.109-133
    • /
    • 2007
  • The legal labyrinth through which we have just walked is one in which even a highly proficient lawyer could easily become lost. Warsaw Convention's original objective of uniformity of private international aviation liability law has been eroded as the world community ha attempted again to address perceived problems. Efforts to create simplicity and certainty of recovery actually may have created less of both. In any particular case, the issue of which international convention, intercarrier agreement or national law to apply will likely be inconsistent with other decisions. The law has evolved faster for some nations, and slower for others. Under the Warsaw Convention of 1929, strict liability is imposed on the air carrier for damage, loss, or destruction of cargo, luggage, or goods sustained either: (1) during carriage in air, which is comprised of the period during which cargo is 'in charge of the carrier (a) within an aerodrome, (b) on board the aircraft, or (c) in any place if the aircraft lands outside an aerodrome; or (2) as a result of delay. By 2007, 151 nations had ratified the original Warsaw Convention, 136 nations had ratified the Hague Protocol, 84 had ratified the Guadalajara Protocol, and 53 nations had ratified Montreal Protocol No.4, all of which have entered into force. In November 2003, the Montreal Convention of 1999 entered into force. Several airlines have embraced the Montreal Agreement or the IATA Intercarrier Agreements. Only seven nations had ratified the moribund Guatemala City Protocol. Meanwhile, the highly influential U.S. Second Circuit has rendered an opinion that no treaty on the subject was in force at all unless both affected nations had ratified the identical convention, leaving some cases to fall between the cracks into the arena of common law. Moreover, in the United States, a surface transportation movement prior or subsequent to the air movement may, depending upon the facts, be subject to Warsaw, or to common law. At present, International private air law regime can be described as a "situation of utter chaos" in which "even legal advisers and judges are confused." The net result of this barnacle-like layering of international and domestic rules, standards, agreements, and criteria in the elimination of legal simplicity and the substitution in its stead of complexity and commercial uncertainty, which manifestly can not inure to the efficient and economical flow of world trade. All this makes a strong case for universal ratification of the Montreal Convention, which will supersede the Warsaw Convention and its various reformulations. Now that the Montreal Convention has entered into force, the insurance community may press the airlines to embrace it, which in turn may encourage the world's governments to ratify it. Under the Montreal Convention, the common law defence is available to the carrier even when it was not the sole cause of the loss or damage, again making way for the application of comparative fault principle. Hopefully, the recent entry into force of the Montreal Convention of 1999 will re-establish the international legal uniformity the Warsaw Convention of 1929 sought to achieve, though far a transitional period at least, the courts of different nations will be applying different legal regimes.

  • PDF

Specific Absorption Coefficients for the Chlorophyll and Suspended Sediment in the Yellow and Mediterranean Sea (황해와 지중해에서의 클로로필 및 부유입자의 비흡광계수 연구)

  • 안유환;문정언
    • Korean Journal of Remote Sensing
    • /
    • v.14 no.4
    • /
    • pp.353-365
    • /
    • 1998
  • Light absorption coefficient per unit mass of particles, i.e., specific absorption coefficient, is important as one of the main parameters in developing algorithms for ocean color remote sensing. Specific absorption coefficient of chlorophyll ($a^*_{ph}$) and suspended sediment ($a^*_{ss}$) were analyzed with a spectrophotometer using the "wet filter technique" and "Kishino method" for the seawater collected in the Yellow and Mediterranean Sea. An improved data-recovery method for the filter technique was also developed using spectrum slopes. This method recovered the baselines of spectrum that were often altered in the original methods. High $a^*_{ph}({lambda})$ values in the oligotrophic Mediterranean Sea and low values in the Yellow Sea were observed, ranging 0.01 to 0.12 $m^2$/mg at the chlorophyll maximum absorption wavelength of 440 nm. The empirical relationship between $a^*_{ph}$(440nm) and chlorophyll concentrations () was found to fit a power function ($a^*_{ph}$=0.039 $^{-0.369}$), which was similar to Bricaud et al. (1995). Absorption specific coefficients for suspended sediment ($a^*_{ss}$) did not show any relationship with concentrations of suspended sediment. However, an average value of $a^*_{ss}$ ranging 0.005 - 0.08 $m^2$/g at 440nm, was comparable to the specific absorption coefficient of soil (loess) measured by Ahn (1990). The morepronounced variability of $a^*_{ss}$ than $a^*_{ph}$ was determined from the variable mixing ratio values between particulate organic matter and mineral. It can also be explained by a wide size-distribution range for SS which were determined by their specific gravity, bottom state, depth and agitation of water mass by wind in the sea surface.