• Fire Science and Engineering
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• v.29 no.6
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• pp.119-128
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• 2015

A fire broke out in a working wood-burning stove and destroyed an idyllic house about two years after it was built. This study analyzed data provided through the court by the fire station, police station, fire insurance investigation agency, house construction company, and wood-burning stove maker Based on the fire pattern of low-temperature long-term ignition that remained in the studs, the fire was found to be caused by the conduction of heat in the fire box to the studs of the wall next to the wood-burning stove. A fire simulation showed that the low-temperature long-term ignition of the studs next to the wood-burning stove occurred because a hole was not made for ventilation in the chimney.

• Fisheries and Aquatic Sciences
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• v.2 no.2
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• pp.210-217
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• 1999

Chemical oxygen demand (COD), phytoplankton cell number and chlorophyll-a concentration (Chl-a), sediment mean grain size and ignition loss were studied to determine their temporal trends in the study area. Historical data of COD, cell number and Chl-a were gathered from the late 1960s or early 1980s to 1997, and trends in temporal domain were obtained from a simple regression. Sediments for grain size and ignition loss (as organic contents in sediments) were sampled from the Chokchon macrotidal flat bimonthly from September 1990 to November 1996, and were analyzed using the decomposition method of time series analysis. In general, the first three data showed increasing trends based on regression analysis. The trends of sediment grain size fluctuated in a neutral pathway while those of ignition loss yielded no increasing pattern. In contrast with the suggestions from Ahn and Choi (1998) who reported a coarsening variation in sediment grain size to be a cause of the directional and remarkable changes of macrofaunal communities in this area, we could not find such a corresponding variation pattern from our samples. In diagnosing eutrophication, a paradoxical phenomenon was encountered between the trends in water column (COD, cell number and Chl-a) and sediment (ignition loss) data. In this paper, we inferred the possible processes that produce the discrepancy. Some explanations and biological responses to eutrophication were predicted and discussed.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.5
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• pp.469-474
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• 2010

Gasoline engines have proven their utility in light, medium and heavy duty vehicles. Concern about long term availability of petroleum and the environment norms by the increased vehicular emission have mandated the search for safe fuel. CNG is an environmentally clean alternative to the existing spark ignition engines with the advantages of minimum change. A higher octane number and a higher self ignition temperature make it an attractive gaseous fuel. The thermal efficiency is better than gasoline for the same engine. The reduced carbon mono oxide, carbon di-oxide, hydrocarbon emissions is a favorable outcome along with a slight increase in $NO_x$ emission when compared with gasoline fuel to a dual fuel mode in the existing spark ignition engines. The result from the experiment shows that CNG could be a potential substitute fuel that maintains performance and emissions characteristics in gasoline engines.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2126-2130
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• 2008

Gasoline engine have proved its utility in light, medium and heavy duty vehicle in every sector of the world community. The concern about long term availability of petroleum and the increasing threat for the environment by the increasing load of vehicular emission, compel the technology to upgrade itself for meeting the challenges. CNG is environmentally clean alternative to the existing SI Engines with out much change in the hardware. Many researchers have found this as a potential substitute to meet the energy requirement. Higher octane number and higher self ignition temperature make it a good gaseous fuel. Although power output is slightly lesser than the gasoline it's thermal efficiency is better than the gasoline for the same SI Engine. Results showed that reduced CO, hydrocarbon emissions is a favorable outcome, with slight increase in $NO_x$ emission when compared with gasoline fuel to dual fuel mode in the existing SI Engines.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.4
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• pp.79-88
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• 2020

Hypergolic propellants have been widely used for space propulsion systems based their long-term storability and high ignition reliability. Since conventional hypergolic propellants are highly toxic and carcinogenic, handling and operating costs are significant. To overcome the drawbacks, numerous studies have been actively performed to develope new hypergolic propellants, ensuring that the combinations are high performance, low toxicity and low environmental impact. In the present study, a comprehensive survey was conducted to summarize the research and development of green hypergolic propellants involving hydrogen peroxide, nitric acid, and ionic liquids.

• Computers and Concrete
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• v.7 no.1
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• pp.17-38
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• 2010

This research aimed to investigate the influence of high-volume mineral admixtures (MAs), i.e., fly ash and slag, on the hydration characteristics and microstructures of cement pastes. Degree of cement hydration was quantified by the loss-on-ignition technique and degree of pozzolanic reaction was determined by a selective dissolution method. The influence of MAs on the pore structure of paste was measured by mercury intrusion porosimetry. The results showed that the hydration properties of the blended pastes were a function of water to binder ratio, cement replacement level by MAs, and curing age. Pastes containing fly ash exhibited strongly reduced early strength, especially for mix with 45% fly ash. Moreover, at a similar cement replacement level, slag incorporated cement paste showed higher degrees of cement hydration and pozzolanic reaction than that of fly ash incorporated cement paste. Thus, the present study demonstrates that high substitution rates of slag for cement result in better effects on the short- and long-term hydration properties of cement pastes.

• Journal of the Korean Institute of Gas
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• v.13 no.6
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• pp.39-43
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• 2009

Gasoline engine have proved its utility in light, medium and heavy duty vehicle in every sector of the world community. The concern about long term availability of petroleum and the increasing threat for the environment by the increasing load of vehicular emission, compel the technology to upgrade itself for meeting the challenges. CNG is environmentally clean alternative to the existing SI Engines with out much change in the hardware. Many researchers have found this as a potential substitute to meet the energy requirement. Higher octane number and higher self ignition temperature make it a good gaseous fuel. Although power output is slightly lesser than the gasoline it's thermal efficiency is better than the gasoline for the same SI Engine. Results showed that reduced CO, hydrocarbon emissions is a favorable outcome, with slight increase in NOx emission when compared with gasoline fuel to dual fuel mode in the existing SI Engines.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.3
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• pp.175-181
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• 2000

This study was carried out to investigate the change of soil physical properties in long-term fertilized paddy soils with a Fine silty family of Typic Halpaqueps (Pyeongtaeg series). Treatments fertilized consisted of no fertilizer, compost, NPK, NPK+compost for thirty one years and of NPK+silicate for seventeen years. Water stable aggregate and degree of aggregate stability, which were higher in surface-soil than sub-soil, were high in order of NPK + compost > NPK + silicate > compost > NPK > no fertilizer plot. The ratio of aggregate larger than 0.5mm was high at compost and silicate plots but that smaller than 0.5mm was high at no fertilizer and NPK plots. And this aggregate stability showed negative correlation with soil hardness and bulk density ; positive correlation with sedimentation volume of soils in water. Sedimentation volume of soils in water was a little higher in surface-soil than sub-soil and in wet soil than dry soil, respectively. Pore space ratio and water retention capacity of soils were the most increased by the application of compost and not affected by silicate as in cases of liquid limit and plastic limit. Ignition loss of soils was high in order of NPK + compost > compost > NPK + silicate > NPK > no fertilizer plot. And field shattering ratio of soil mass smaller than 25.4mm was relatively high in NPK + compost, compost, and silicate plots.

• Fisheries and Aquatic Sciences
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• v.14 no.3
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• pp.205-209
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• 2011

Organic pollution causes eutrophication and dystrophication, which occur when excessive amounts of organic matter enters seawater. Eutrophication can contaminate sediment and harm aquaculture. Polychaeta species have been shown to restore eutrophic sediment. In this study, we used peptone to simulate a eutrophic environment and detect the levels at which eutrophication became toxic to the polychaete Perinereis aibuhitensis. Peptone concentrations were 0, 100, 200, and 500 mg/L. The median lethal concentrations were 950.35 mg/L at 48 h, 340.34 mg/L at 72 h, and 120.22 mg/L at 96 h, which are much higher than those of other aquatic species. Polychaeta species are highly tolerant of eutrophication. During the 15-day long-term experiment, sediment loss on ignition, as well as seawater total organic carbon and total nitrogen all decreased significantly (P<0.05). However, $NH_4^+$ concentration increased with time. Perinereis aibuhitensis slowed the increment of $NH_4^+$ but could not prevent its increase. Our results indicate that this polychaete is helpful in the recovery of seawater and sediment from eutrophication.

• Journal of ILASS-Korea
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• v.14 no.2
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• pp.49-58
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• 2009

Non-edible vegetable oils instead of edible vegetable oils as a substitute for diesel fuel are getting a renewed attention because of global reduction of green house gases and concerns for long-term food and energy security. Out of various non-edible vegetable oils, karanja, mahua, linseed, rubber seed and cotton seed oils are selected in this study. A brief review of recent works related to the application of the above five vegetable oils and its derivatives in CI engines is presented. The production technologies of biodiesel based on non-edible vegetable oils are introduced. Problems in vegetable oil or biodiesel fuelled CI engine are included. In addition, future works related to spray characteristics of non-edible vegetable oil or biodiesel from it are discussed. The biodiesel fuel, irrespective of the feedstock used, results in a decrease in the emission of hydrocardon (HC), carbon monoxide (CO), particulate matter (PM) and sulphur dioxide ($SO_2$). It is also said to be carbon neutral as it contributes no net carbon dioxide to the atmosphere. Only oxides of nitrogen (NOx) are reported to increase which is due to oxygen content in the biodiesel fuel. The systematic assessment of spray char-acteristics of neat vegetable oils and its blends, neat biodiesel and its blends f3r use as diesel engine fuels is required.