• Applied Biological Chemistry
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• v.27 no.2
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• pp.86-94
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• 1984

The changes of the volatiles from apple fruits were examined with Mallus pumila Miller var. Fuji, Ralls Janet and Jonathan harvested at the preclimacteric stage and stored under the normal atmospheric pressure of 760mmHg and subatmospheric pressure of 380mmHg at the temperature of 1 and $20^{\circ}C$ each. The production of the volatites in the normal storage temperature increased markedly up to around 30 days on storage and then decreased rapidly, whereas that of the volatiles in the low storage temperature increased slowly before decreasing. The changing pattern of volatiles from apples during storage at the normal atmospheric pressure was more remarkable than that of volatiles produced at the subatmospheric pressure. During storage, most of flavoring materials were increased, and the decrease of the content of esters was more rapid than that of alcohols and aldehydes among the volatiles. The amounts of the volatiles in Fuji apples during ripening at $20^{\circ}C$ after removing from the subatmospheric pressure storage for 90 days at $1^{\circ}C$ were nearly maximum at 3 days on ripening.

• Journal of the Korean Society of Combustion
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• v.16 no.3
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• pp.33-40
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• 2011

Combustion experiments were conducted at three different fuels ($CH_4$, $C_2H_4$ and $C_3H_8$) to investigate the effects of combustor pressure (30 ~ -30 kPa) on combustion charateristics and reaction zone structure. Regardless of the fuels, emission index of CO (EICO) increased with decreasing combustor pressure, and EICO of $C_2H_4$ was mostly affected by changing combustor pressure at subatmospheric pressure. In order to observe reaction zone, $OH^*$, $CH^*$ and ${C_2}^*$ chemiluminescence intensity were measured. The sequence of the chemiluminescence intensity peak position was affected by chemical characteristics of fuels rather than changing combustor pressure. The emission zone thickness of $C_2H_4$ and $C_3H_8$, defined by the full width at half maximum (FWHM) of $CH^*$ intensity profile, were increased with decreasing combustor pressure. however, the thickness of $C_2H_4$ exhibited the opposite tendency due to the characteristics of the fuel as the bond structure.

• Journal of ILASS-Korea
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• v.1 no.4
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• pp.46-53
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• 1996

The present study is aiming at improving the performance of main nozzle of an air jet loom with a modified reed and auxiliary nozzles. The double coaxial pipe jets consisting of a central air jet and an annular air jet have been experimentally investigated. The duter jet has a potential core and a constant velocity. The inner jet through an inner long pipe is induced by the subatmospheric pressure near the inner nozzle edge, and the jet velocity of an inner pipe is always lower than that of a outer pipe. The static pressures of the main nozzle over a wide range of the nozzle tank pressure were measured, and the nozzle velocity and Mach numbers were analytically calculated. Experiment81 results indicate that the critical condition of Mach number of unity to occur at the two positions in a main nozzle; one of them is the needle tip and the other is the acceleration tube exit An increase in the tank pressure causes the critical throat condition to occur at the two positions above. The velocity of acceleration-tube exit is maximum at the critical length L* and flow patter in acceleration-tube over critical lengh remains unstable.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.5
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• pp.413-416
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• 2010

Fleischmann et al. first described the concept of using sub-atmospheric pressure to treat open or infected wounds in 1993. Since then, Argenta and Morykwas developed subatmospheric, or negative pressure dressings in 1997 as a means of managing complicated wounds. Since its introduction in 1997, the vacuum-assisted closure (VAC) system has been used widely in general plastic surgery, general surgery, and orthopedic surgery to manage complicated wounds of the torso and extremities. However, there is a paucity of literature describing its use in the head and neck region, particularly in oral and maxillofacial surgery. We report a successful case of postoperative orocutaneous fistula closure using a VAC system in a 59-year male with a review of the relevant literature.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.1
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• pp.95-103
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• 1999

Low pressure combustion characteristics of the composite solid propellants were studied in terms of the propellant burning rate, ignition processes, and the structure of the extinguished surfaces. Optical Vacuum Strand Burner(OVSB) system was designed and configured for this purpose. Burning rates of the propellants were measured at subatmospheric pressure by developed test method in OVSB. The ignition and combustion phenomena of the studied propellants in the combustion chamber of OVSB were recorded and analyzed with the camera and VCR(30 frames/s). Burning surfaces of the propellants were extinguished by rapid depressurization method and analyzed with Scanning Electron Microscope(SEM).

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.1
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• pp.64-70
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• 1984

In this experiment, the changes in the components of carbohydrate and their enzyme activities were investigated to study the conversion of sugars in tomato under sub-atmospheric pressure storage .The results obtained are as follows: The soluble sugars in tomato fruits were, for the most part, fructose and glucose together with small quantity of sucrose and maltose. The content of fructose increased throughout the storage, while that of glucose increased at an early stage but decreased at the latter part, and that of sucrose decreased drastically with progress of storage. The activity of ${\alpha}-amylase$ and invertase playing important roles in conversion of sugars showed a rapid increase at onset of respiration climacteric, resulting that the content of total soluble sugar showed a tendency to decrease strikingly, whereas those of starch and sucrose to decrease rapidly. Thus, the effect of temperature was more pronounced than that of pressure.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.5
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• pp.861-868
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• 2022

The purpose of this study is to design an effective atmospheric environment system through the design of the dust collection in the air shot room being operated in a domestic shipyard. The ventilation system in the current air shot room mostly uses a dust collecting filter to filter internal particles and releases them in the atmosphere. A conventional design was made too much. In order to prevent an error and draw an optimal design, Computational fluid dynamics (CFD) tried to be applied only to air shot room. In the advanced design technique, computer simulation was conducted to secure basic design data. In order to find the basic design of the ventilation system and the flow field in the air shot room at propeller mold workplace of a shipyard, the CFD was conducted. In the case of Model-1 as a conventional workplace, where air flows in the inlet due to the subatmospheric pressure generated by inhalation of an air blower and flows out to the outlet, a discharge flow rate was somewhat low, and there was the holdup zone in the room. In the case of Model-2 as an improved model, the ventilation system was improved in the Push-Pull type, and the holdup of the internal flow field was improved.

• Korean Chemical Engineering Research
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• v.56 no.2
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• pp.222-228
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• 2018

Benzene is one of the most widely used basic materials in the petrochemical industry. Generally, benzene exists as a mixture with alcohols rather than as a pure substance. Further, the alcohols-added mixtures usually exhibit an azeotropic composition. In this context, knowledge of the phase equilibrium behavior of the mixture is essential for its separation and purification. In this study, the vapor-liquid equilibrium data were measured in favor of a recirculating VLE apparatus under constant pressure for the 1 - propanol / benzene system. The measured vapor - liquid equilibrium data were also correlated by using the UNIQUAC and WILSON models and the thermodynamic consistency test based on the Gibbs/Duhem equation was followed. The results of the phase equilibrium experiment revealed RMSEs (Root Mean Square Error) and AADs (Average Absolute Deviation) of less than 0.05 for both models, indicating a good agreement between the experimental value and the calculated value. The results of the thermodynamic consistency test also confirmed through the residual term within ${\pm}0.2$.

• Current Research on Agriculture and Life Sciences
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• v.3
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• pp.92-98
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• 1985

The experiments were conducted to investigate the activity changes of peroxidase, existence of isoenzyme and the changes of reserved substances in tomato under subatmospheric pressure storage condition. The results obtained were as follows: 1. Soluble fraction showed the highest peroxidase activity and followed by cell wall fraction, mitochondria fraction and ribosome fraction in that order. 2. Peroxidase activity was decreased during the ripening and senescence period in tomato. Especially, peroxidase activity in tomato was higher at a room temperature ($25^{\circ}C$) than at a low temperature ($15^{\circ}C$). The decreasing inclination was similar in both treatment. The peroxidase activity was higher in 380 Torr, than in 570 Torr. 3. At least, two isoperoxidases(Soluble or solubilized) were identified from different extraction procedures. Three of four isoenzymes were recognized from a vertical slab of polyacrylamide gel electrophoresis. 4. The changes of components in tomato under SAP were generally affected by temperature and pressure. Especially, quality of tomato stored at a low temperature ($15^{\circ}C$) and SAP (380 Torr.) was best during storage.

• Korean Journal of Food Science and Technology
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• v.20 no.1
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• pp.63-71
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• 1988

Total lipid contents of tomato fruits were 97.6mg% and composed of neutral lipid(45.1mg%), phospholipid(31.2mg%) and glycolipid(12.4mg%). The contents of neutral lipid were slowly increased from the period of climacteric rise, but those of glycolipid and phospholipid were slowly decreased at the end of storage period. Major fatty acids in all lipids were identified to be palmitic, stearic, linoleic and oleic acids. The contents of linoleic acid in all lipids at $25^{\circ}C$ and those in neutrallipid at $15^{\circ}C$ were decreased, while those in phospholipid were slightly increased during storage. The contents of palmitic acid in neutral lipid were decreased, whereas those in glycolipid and phospholipid have a tendency to increase during storage. As for normal atmospheric pressure-normal temperature(NAP-N) condition, volatiles from homogenated tomato fruits were positively correlated with palmitic acid of neutral lipid, whereas negatively correlated with linoleic acid. As for subatmospheric pressure-low temperature(SAP-L) condition, the relationship between volatiles and fatty acids of neutral lipid was similar to NAP-N condition. Volatiles were positively correlated with linoleic acid of glycolipid and stearic acid of phosholipid, whereas negatively correlated with oleic acid of glycolipid and palmitic acid of phospholipid, respectively.