• Fire Science and Engineering
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• v.22 no.2
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• pp.57-62
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• 2008

Most of all the Korean home use a wallpaper as a decoration and finishing of interior. One of the fire spread factor in a house is a combustion of wall paper. There were some research concerning oxygen index in a ambient temperature. The purpose of this study is to investigate the difference of oxygen index of a wallpaper between ambient and high temperature and a effect on the fire spreading. Based on the result, the difference of oxygen index between ambient temperature and high temperature showed $5{\sim}8%$. Difference of 0.1% of oxygen index show big differences in combustion length of sample. Therefore, it was found that the decrease of oxygen index at elevated temperature is a important factor in fire spread.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.1
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• pp.57-64
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• 2003

The characteristics of fuel spray have an important effect on engine performance such as power, specific fuel consumption and emission because fuel spray controls the mixing and combustion process in an engine. Therefore, if the characteristics of fuel spray can be measured, they can be effectively used for improving engine performance. The major factors controlling fuel spray are injection pressure, ambient pressure and engine speed. In this study, the experiment is performed in a high temperature and high pressure chamber. In experiments, spray tip penetration, spray angle and spray tip velocity are measured at various injection pressure (10 and 14 MPa), ambient pressure(3,4 and 5 MPa), fuel pump speed(500, 700 and 900 rpm). Experimental results are useful for deriving an experimental spray equation and design an optimal engine. The results showed that injection pressure, ambient pressure and fuel pump speed are important factors influencing on the characteristics of spray. 1) Injection pressure influences on the characteristics of spray. That is, as injection pressure is increased, spray angle is decreased but spray penetration and spray tip velocity is increased. 2) Spray angle and spray penetration are increased as fuel pump speed is increased.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.2
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• pp.50-58
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• 2001

The purpose of this research is to obtain the information of the development process of a vaporizing GDI spray using exciplex fluorecence method. Fluorobenzene/DEMA system was used as the exciplex-forming dopants. The 2-D spray images of liquid and vapor phases were acquired, and the behavior of both phases was analyzed by the image processing. The experiment was performed at the three different ambient perssures and the ambient temperature of 273K and 473K. As the result of this work, it was found that the development characteristics of GDI spray have stronger effect on the ambient pressure than on the ambient temperature. With an increase of ambient pressure, the distribution of vapor phase was decreased and the concentration of that was denser. Two regions, namely cone and mixing regions could be identified from those resulrs.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.8
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• pp.1159-1163
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• 2006

This experiment was performed to examine the influences of high ambient temperature on milk production, nutrient digestibility, energy and protein sufficiency ratio, and plasma metabolites concentration in lactating cows. In a $2{\times}2$ crossover design, four multiparous lactating Holstein cows were maintained in a chamber under treatment of constant moderate ($18^{\circ}C$) ambient temperature (MT) or high ($28^{\circ}C$) ambient temperatures (HT). The DMI and milk protein yield were significantly lower in HT (p<0.05). The milk yield, milk lactose yield, and milk SNF yield tended to be lower in HT (p<0.10). No statistical differences for 4% fat-corrected milk and milk fat yield were observed. Rectal temperatures were significantly higher in HT than MT (p<0.05). The apparent DM, OM, ether extract, CF, and ash digestibility did not differ between treatments. On the other hand, the apparent CP digestibility was increased significantly (p<0.05) and nitrogen free extract tended to increase (p<0.10) in HT. The sufficiency ratio of ME and DCP intake for each requirement tended to be lower in HT than in MT (p<0.10). Concentrations of total protein (TP), albumin, and urea nitrogen in plasma did not differ between treatments. Plasma 3-methylhistidine (3MH) concentration as a marker of myofibrillar protein degradation tended to be higher in HT (p<0.15). In conclusion, high ambient temperature was associated with a lower energy and protein sufficiency ratio, and decreased milk protein production, even though the body protein mobilization tended to be higher.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.6
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• pp.102-109
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• 1994

As a fundamental study to apply high pressure injection system to direct injection diesel engine, fuel injection system and constant volume combustion chamber were made and the behaviors of evaporating spray with the variation of injection pressure and the ambient gas temperature were observed by using high speed camera, and the combusion characteristics with the variation of injection pressure and A/F ratio were analyzed. As injection pressure increases, spray tip penetration and spray angle increase and, as a results spray volume increases. This helps an uniform mixing of fuel and air. Spray liquid core length decreases as ambient gas temperature increases, while it decreases as injection pressure increases but the effect of ambient gas temperature is dorminant. As injection pressure increases, ignition delay is shortened and combustion rate being raised, maximum heat release rate increases. It become clear that High injection pressure has high level of potential to improve the performance of DI-diesel engine.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.3
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• pp.141-146
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• 2007

In this study, the effects of change in ambient gas viscosity on spray structure have been investigated in the high temperature and pressure field. To analyze the structure of evaporative diesel spray is important in speculation of mixture formation process. Emissions of diesel engines can be reduced by the control of the mixture formation process. Therefore, this study examines the evaporating spray structure in the constant volume chamber. The viscosity of ambient gas was selected as the experimental parameter, is changed from 21.7 mPa s to 32.1 mPa s by changing in ambient gas temperature. In order to obtain images of the liquid and vapor-phase of injected spray, exciplex fluorescence method was used in this study. The liquid and vapor-phase images were taken with 35mm still camera and CCD camera, respectively. Consequentially, it could be confirmed that the distribution of vapor concentration is more uniform in the case of the ambient gas with high viscosity than in that of the ambient gas with low viscosity.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.4
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• pp.556-563
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• 2018

Objective: Spirulina has been recognized formerly as a filamentous spiral-shaped blue- green algae but more recently as a genus of photosynthetic bacteria (Arthrospira). This microorganism is considered as a rich source of essential nutrients for human and animals. The present study was conducted to determine potential application of Spirulina for heat- exposed broilers. Methods: Two hundred and fifty Cobb 500 chicks with male to female in equal ratio with average initial weight of 615.6 g at 17 days of age were divided into 5 treatments with 5 replicates of 10 chicks. Treatment groups were as follows: positive and negative controls with 0% Spirulina supplement and three Spirulina receiving groups with 5 g/kg (0.5%), 10 g/kg (1%), and 20 g/kg (2%) supplementation. Spirulina receiving groups as well as positive control were exposed to high ambient temperature at $36^{\circ}C$ for 6 h/d from 38 to 44 days of age. Biochemical variables were measured in serum samples at 35, 38, 42, and 45 days of broiler chickens age. Results: The results showed that supplementation of the diet with Spirulina decreased concentration of stress hormone and some serum lipid parameters while enhanced humoral immunity response and elevated antioxidant status whereas it didn't meaningfully affect performance characteristics. Nevertheless, feed conversion ratio was improved numerically but not statistically in broilers fed with 1% Spirulina under high ambient temperature. Conclusion: Overall, the present study suggests that alleviation of adverse impacts due to high ambient temperature at biochemical level including impaired enzymatic antioxidant system, elevated stress hormone and lipid profile can be approached in broiler chickens through supplementation of the diet with Spirulina platensis.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.245-263
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• 2013

This study was conducted to find out the influence of elevated atmospheric $CO_2$ concentrations and air temperature on photosynthesis and fruit quality of 'Fuji'/M.9 apple trees and to investigate these to the effects of climate change during the last four years (2009-2012). The treatments employed were: 'Ambient' (ambient temperature + ambient $CO_2$ concentration); 'High $CO_2$' (ambient temperature + elevated $CO_2$ concentration); 'High Temp'. (elevated temperature + ambient $CO_2$ concentration); and 'High $CO_2$ + High Temp'. (elevated temperature + elevated $CO_2$ concentration). The elevated temperature plots were maintained at $4^{\circ}C$ higher than ambient air temperature, while the elevated $CO_2$ plots were maintained at 700 ${\mu}mol{\cdot}mol^{-1}$. Annual treatment period was applied from end of April to beginning of November for four years. Results showed that elevated $CO_2$ decreased stomatal conductance and leaf SPAD value, but increased photosynthetic rate, intercellular $CO_2$ concentration (Ci), and starch content of mesophyll tissue. In the vegetative growth, elevated temperature increased total number of shoot and total shoot growth per tree, but elevated $CO_2$ decreased average shoot length. In the fruit quality, elevated $CO_2$ increased soluble solid content, fruit red color, and ethylene production. In conclusion, elevated $CO_2$ increased photosynthetic rate of apples during the early growth, but effect of increased photosynthetic rate due to elevated $CO_2$ was decreased during latter growth stage. Elevated temperature, on the other hand, tended to decrease photosynthetic rate of apples during the early growth, but that tended to increase during latter growth stage. Both elevated $CO_2$ and temperature tended to decrease the degree of decreased photosynthetic rate due to each factor.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.3
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• pp.44-50
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• 2004

The purpose of this study is to improve the prediction ability of the atomization and vaporization processes of GDI spray under high-pressure and high-temperature conditions. Several models have been introduced and compared. The atomization process was modeled using hybrid breakup model that is composed of Conical Sheet Disintegration (CSD) model and Aerodynamically Progressed TAB(APTAB) model. The vaporization process was modeled using Spalding model, modified Spalding model and Abramzon ＆ Sirignano model. Exciplex fluorescence method was used for comparing the calculated with the experimental results. The experiment and calculation were performed at the ambient pressure of 0.5 MPa and 1.0 MPa and the ambient temperature of 473k. Comparison of caldulated and experimental spray characteristics was carried out and Abramzon ＆ Sirignano model and modified Spalding model had the better prediction ability for vaporization process than Spalding model.

• Journal of ILASS-Korea
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• v.20 no.3
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• pp.187-194
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• 2015

In this study, three visualization methods, Schlieren, Shadowgraph, and Mie-scattering, were applied to compare diesel and gasoline spray structures. Fuels were injected into a high pressure/high temperature constant volume chamber under the same ambient pressure and temperature condition of low load in gasoline direct injection compression ignition (GDCI) engine. Two injection pressures (40 and 80 MPa), two ambient pressures (4.2 and 1.7 MPa), and two ambient temperatures (908 and 677 K) were use. The images from the different methods were overlapped to show liquid and vapor phases more clearly. It was found that the gasoline fuel is more appropriate to form a lean mixture.