• Journal of Biosystems Engineering
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• v.41 no.4
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• pp.337-341
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• 2016

Purpose: Evaluation of atmospheric conditions for proper timing of spray application is important to prevent off-target movement of crop protection materials. Susceptible crops can be damaged downwind if proper application procedure is not followed. In our previous study, hourly data indicated unfavorable conditions, primarily between evening 18:00 hrs in the evening and 6:00 hrs next morning, during clear conditions in the hot summer months in the Mississippi delta. With the requirement of timely farm operations, sub-hourly data are required to provide better guidelines for pilots, as conditions of atmospheric stability can change rapidly. Although hourly data can be interpolated to some degree, finer resolution for data acquisition of the order of 15 min would provide pilots with more accurate recommendations to match the data recording frequency of local weather stations. Methods: In the present study, temperature and wind speed data obtained at a meteorological tower were re-sampled to calculate the atmospheric stability ratio for sub-hour and hourly recommendations. High-precision evaluation of temperature inversion periods influencing atmospheric stability was made considering strength, time of occurrence, and duration of temperature inversion. Results and Discussion: The results indicated that atmospheric stability could be determined at different time intervals providing consistent recommendations to aerial applicators, thereby avoiding temperature inversion with minimal off-target drift of the sprayed liquid.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.407-411
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• 1997

Effects of heating time and storage temperature on the oxidative stability of heated palm oil were studied. Palm oil was heated at $150^{\circ}C$ for 0, 1, 10 or 20 min and stored at 4, 20 or $65^{\circ}C$. The oxidative stability of the sample was evaluated by determining peroxide value of the oil and measuring the volatiles in the headspace of the sample. Significant difference in the peroxide or volatile formation was observed (p<0.05) in heated palm oils between samples stored at 4 or $20^{\circ}C$ and those stored at $65^{\circ}C$. Pentane, hexanal, heptane and total volatiles increased with heating time, while storage temperature did not significantly affect their formation, indicating that heating time played more important role in volatile formation in the heated palm oil than storage temperature. However, adverse results were observed for the formation of peroxide. The interaction effect of heating time and storage temperature on the oxidative stability of heated palm oil was also observed.

• Archives of Pharmacal Research
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• v.20 no.2
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• pp.171-175
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• 1997

The stability of ondansetron and fluconazole in 5% dextrose injection and normal saline during simulated Y-site injection at room temperature was studied. Ondansetron 0.03, 0.1 and 0.3 mg/ml were admixed 1:1 with fluconazole 2 mg/ml. The solutions were stored at room temperature and samples were retrieved at time 0, 1, 2, 4 and 12 hr for immediate assay. At the time of the assay and before any dilution, each sample was visually inspected for clarity, color, precipitation, and the pH was determined. Drug concentrations were measured by a stability-indicating high performance liquid chromatograph. Ondansetron 0.03, 0.1 and 0.3 mg/ml were stable when mixed with concentration of fluconazole 2 mg/ml. There were no change in clarity and color and no precipitates in any admixture for 12 hr of inspection. The pH measurements did not have a particular trend in any direction over time.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.7 s.172
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• pp.155-163
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• 2005

Pressure heating rollers with temperature control were mounted to a flat cable laminating machine (FCLM). Pressure heating rollers should be heated up to the setting temperature $(175^{\circ}C)$ and kept on to producing good quality flexible flat cables (FFC). Existing Pressure heating rollers took more than 70minutes to the setting temperature and did not keep on the setting temperature in production. Temperature controller, electric power controller, material and diameter of rollers and heat capacities were changed to improve the temperature control of the pressure heat rollers for better production of the FFC. Thus, the reaching time to the setting temperature (RT), temperature stability time (TST) and temperature hunting (TH) were measured and compared with the existing pressure rollers case. The RT of A roller was shortened by 50minutes, and B roller was shortened by 15minutes. The TST of A roller was shortened by 13minutes, and B roller was shortened by 15minutes. The THs of both A and B rollers were settled up to ${\pm}5^{\circ}C$. Finally, the productivity of the FCLM and the quality of the FFC were increased.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.6
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• pp.670-677
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• 2007

The stability of CGAs(colloidal gas aphrons) prepared from non-ionic and ionic surfactants was investigated. Those surfactants were sodium dodecyl sulfate(SDS), Triton X-100, Tween 80 and Quillaja Saponin. The stability of CGAs prepared from single surfactants or mixed surfactants(two components) using a CGA generate. was investigated as functions of temperature, surfactant concentration and stirring time. Saponin among the single surfactants has shown the longest duration time(143 min) and then, Triton X-100, SDS, and Tween 80 were followed by at room temperature. In case of CGAs heated up to $70^{\circ}C$, SDS endured for 116 min but Saponin lasted for only 105 mit which was a considerable reduction of the duration time of CGAs at room temperature. For mixed surfactant pairs, stability of any one pairs stood between the two. That meant no synergic effect for surfactant blending. At the higher temperature, Saponin+Triton X-100 was disclosed to be the lowest, 53 min meanwhile Saponin+SDS was the highest at ambient temperature. The CGAs, initially about 140 ${\mu}m$ in diameter, began to grow right after the agitation to be about 190 ${\mu}m$ owing to coalescence of the bubbles and then became to collapse. When heated, CGAs including Saponin tended to be smaller while the others to be larger. In summary, we found that the stability of CGAs or the duration time was greater for single surfactants and at room temperature rather than for mixed surfactants that caused substantial intermolecular interactions in the CGA structure and at the higher temperature.

• Journal of Food Hygiene and Safety
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• v.12 no.2
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• pp.107-110
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• 1997

To examine the effects of residual phosphorus content on color reversion and storage stability of corn germ oil, the changes of Lovibond total color and stability of oxidation were determined according to the different storage periods at room and incubating temperature, respectively. The residual phosphorus content and storage temperature had the synergistic effect on color reversion during short time storage. The extent of color change was the greatest when oils were stored for 1.0∼1.5 years at room temperature and thereafter gradually tended to reverse color reversion. It is supposed that the double bonds of carotenoids in oils were oxidized and then turned to the volatiles such as epoxide, ionone, and etc. In contrast, the residual phosphorus content increased oxidation stability of oils. The residual phosphorus content was closely correlated with the color reversion and storage stability, respectively.

• International Journal of Industrial Entomology and Biomaterials
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• v.45 no.2
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• pp.93-98
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• 2022

To assess the feasibility of silk sericin for non-textile application, the storage stability and biological safety of sericin were examined. It was extracted at 37℃, 70℃, 100℃, and 121℃ for 1, 3, and 5 h to elucidate the effect of extraction condition on the stability and safety of silk sericin. The solubility was increased till approximately 26% with extraction temperature of 121℃ for 1 h. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that the molecular weight distribution depended on the extraction conditions. Extracted sericin displayed typical UV absorption bands upon spectrometric analysis. To examine the reproducibility of its obtained conformation, sericin was extracted thrice and its circular dichroism (CD) spectra was measured each time. Most CD spectra showed reproducibility regardless of temperature and time except under 100℃ extraction condition. The diversity of CD spectrum showed gradual reduction and was finally coincident with extraction time from 1 to 5 h. Notably, sericin has a negative peak of approximately 200 nm attributed to random coil conformation, regardless of extraction condition. However, at the 100℃ extraction condition, sericin showed both bands to be negative bands of approximately 200 and 220 nm, respectively. Sericin was centrifuged to determine the stability of storage conditions. The sericin extracted at 100℃ and 121℃ for 1 h was found to form gel rapidly within 1 h, but at 121℃ condition, the gel fraction was approximately 20% within 1 h which retained its phase regardless of storage time. The gel fraction of sericin extracted at 100℃ for 5 h increased with time, however at the 121℃ for 5 h condition, the gel fraction was measured to be less than 10% regardless of increase in storage time. Petriflim^TM AC plates test showed that sericin was safe from aerobic bacteria activity by extraction under high temperature.

• Korean Journal of Poultry Science
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• v.17 no.2
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• pp.127-133
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• 1990

This study was undertaken to find out the effect of heating time and temperature, pH and NaCl concentration on the heat stability of egg albumen gel during heat treatment. With the transient decrease at 110-$130^{\circ}C$, hardness of heat-set albumen gel was increased as the heating temperature increased. The cohesiveness showed similar trend as well. The lightness was decreased while the yellowness was increased as the heating time and temperature increased. Heat-set albumen gel showed maximum hardness at pH 4.5-5.0 and pH 9.0 High heat treatment($120^{\circ}C$, 30min) showed higher hardness at alkaline range compared to low heat treatment($96^{\circ}C$, 30min.). Color of the albumen gel was relatively dark at acidic range and bright at alkaline range. High heat treatment caused darker albumen gel at alkaline range and brighter albumen gel at acidic range. The addition of NaCl increased hardness and cohesiveness of the albumen gel and improved the lightness after high heat treatment regardless of NaCl concentration.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.1
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• pp.64-70
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• 2007

Raising exhaust gas temperature during cold-start period is very crucial to improve emission performance of SI engines because it enhances the performance of catalyst in the early stage of engine start. In this study, control variables such as ignition timing, idle speed actuator(ISA) opening and fuel injection duration were extensively investigated to analyze variations in exhaust gas temperature and engine stability during cranking period. Experimental results showed that spark timing affected engine stability and exhaust gas temperature but the effects were small. On the other hand, shortened injection duration and increased ISA opening led to a significant increase in exhaust gas temperature. Under such conditions, increase in cranking time was also observed, showing that it becomes harder to start the engine. Based on these observations, a pseudo fuel-air ratio, defined as a ratio of fuel injection time to degree of ISA opening, was introduced to analyze the experimental results. In general, decrease in pseudo fuel-air ratio raised exhaust gas temperature with the cost of stable and fast cranking. On the contrary, an optimal range of the pseudo fuel-air ratio was found to be between 0.3 to 0.5 where higher exhaust gas temperatures can be obtained without sacrificing the engine stability.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.6
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• pp.1157-1165
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• 2009

In AC-PDP, it is necessary to achieve high luminance efficiency, high luminance and high definition by adopting technologies such as high xenon concentration, MgO doping, and long gap. However, it is very difficult to apply above technologies because they make the driving voltage margin reduced. Especially, high Xe concentration technology for high efficacy makes not only the driving voltage margin reduced but also the stability of reset discharge decreased at low temperature. In this paper, we studied temperature and voltage dependent stability of reset discharge and present the experimental results of the discharge characteristics at low temperature. In addition, we suggested the mechanism of bright noise and black noise at low temperature. Finally, we proposed double reset waveform to improve the bright noise and descending scan time method to improve the black noise.