• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2002.10a
• /
• pp.169-172
• /
• 2002

In this study, the effects of the number of coat and immersion period on strength properties, waterproofness and chemical resistance of painted and immersed cement mortars using two admixture were examined. Test results showed that the flexural and the compressive strengths of the coated and immersed cement mortars increase with increasing number of coat and immersion period. The water absorption of the coated and immersed cement mortars tended to decrease with increasing number of coated and immersion period. In the case of the change of weight and the immersion period for the solutions, a decreasing tendency was shown as the immersion period increases regardless of solution, with a little variation.

• Korean Journal of Poultry Science
• /
• v.24 no.1
• /
• pp.17-28
• /
• 1997

This experiment was carried out to investigate the effects of different chilling and packing methods on physico-chernical properties of cold-stored chicken breast and thigh meats. Dehoned chicken breast and thigh meats were chilled either air spray or ice-water immersion method. The chilled meats were either vacuum packed or atmosphere packed, and stored at -2˚C for 1, 3, 7, 11, 15, and 20 days. The pH of both immersion chilled meats and vacuum packed meats were higher than those of their counterparts(P<0.05). The pH of atmosphere packed meats increased as the storage period extended. The moisture contents of vacuum packed meats were remarkably higher than those of atmosphere packed meats. The pH of all treatments decreased as the storage period extended. The shear values of air spray chilled and vacuum packed breast meats were significantly higher than immersion chilled and vacuum packed ones. However, immersion chilled and atmosphere packed breast meats were significantly higher than those of air spray chilled and atmosphere packed breast meats. The shear values of immersion chilled and vacuum packed thigh meats were significantly higher than those of immersion chilled and vacuum packed thigh meats. In atmosphere packed thigh meats, air spray chilling method showed higher shear values than those of immersion chilled thigh meats. In thigh muscle, tenderness values tended to decrease as the storage period extended(P<0.05). Contents of water soluble proteins of vacuum packed and air spray chilled breast and thigh meats were higher than those of their counterparts as the storage period extended(P<0.05). The contents of water soluble proteins significantly decreased as the storage period extended. Salt soluble proteins of atmosphere packed breast and thigh meats were remarkably higher than those of vacuum packed ones(P<0.05). Total lipid contents of atmosphere packed and air spray chilled breast and thigh meats were higher than those of atmosphere packed and immersion chilled meats as the storage period extended. The vacuum packed meats were significantly higher in total lipid contents than those of atmosphere packed meats. The storage period decreased the total lipid contents of cold chicken, Major fatty acids in cold-stored chicken were oleic, palmitic, linoleic and stearic acids, regardless of chilling method. Unsaturated fatty acids of all treatments decreased, but saturated fatty acids increased as the storage period extended.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.8
• /
• pp.178-185
• /
• 1999

In tool condition monitoring systems, parameters should be set to a certain threshold. In many cases, however, the threshold is dependent on cutting conditions, especially the radial immersion ratio. In this presented is a method of on-line estimation of the radial immersion ratio in face milling. When a tooth finishes sweeping, a sudden drop of cutting force occurs. The force drop is equal to the cutting force that acting on a tooth at the swept angle of cut and can be acquired from cutting force signals in feed and cross-feed directions. Average cutting force per tooth period can also be calculated from cutting force signals in two directions. The ratio to cutting forces in two directions acting on a tooth at a certain swept angle of cut and the ratio of average cutting forces in two directions per tooth period are functions of the swept angle of cut and the ratio of radial to tangential cutting forces. Using these parameters, the radial immersion ratio is estimated. Various experiments are performed to verify the proposed method. The results show that the radial immersion ratio can be estimated by this method regardless of other cutting conditions.

• The Korean Journal of Physiology and Pharmacology
• /
• v.4 no.3
• /
• pp.253-261
• /
• 2000

Head-out water immersion induces marked increase in the cardiac stroke volume. The present study was undertaken to characterize the stroke volume change by analyzing the aortic blood flow and left ventricular systolic time intervals. Ten men rested on a siting position in the air and in the water at $34.5^{circ}C$ for 30 min each. Their stroke volume, heart rate, ventricular systolic time intervals, and aortic blood flow indices were assessed by impedance cardiography. During immersion, the stroke volume increased 56%, with a slight (4%) decrease in heart rate, thus cardiac output increased ${\sim}50%.$ The slight increase in R-R interval was due to an equivalent increase in the systolic and diastolic time intervals. The ventricular ejection time was 20% increased, and this was mainly due to a decrease in pre-ejection period (28%). The mean arterial pressure increased 5 mmHg, indicating that the cardiac afterload was slightly elevated by immersion. The left ventricular end-diastolic volume index increased 24%, indicating that the cardiac preload was markedly elevated during immersion. The mean velocity and the indices of peak velocity and peak acceleration of aortic blood flow were all increased by ${\sim}30%,$ indicating that the left ventricular contractile force was enhanced by immersion. These results suggest that the increase in stroke volume during immersion is characterized by an increase in ventricular ejection time and aortic blood flow velocity, which may be primarily attributed to the increased cardiac preload and the muscle length-dependent increase in myocardial contractile force.

• Journal of Nutrition and Health
• /
• v.44 no.5
• /
• pp.378-383
• /
• 2011

This study examined the effect of supplementary selenium on leukocytes and heat shock protein (HSP) 70 expression in serum during half-body immersion. The subjects were male college tennis athletes. All subjects participated in two repeated experiments with a 1 week interval. During the 30 min intermittent half-body immersion, subjects were given 500 mL of water with or without selenium (100 ${\mu}g$). Blood samples were taken from the antecubital vein, and differential counts were made. Serum HSP70 protein was analyzed using a commercial ELISA kit. After half-body immersion, leukocytes and lymphocytes increased significantly but neutrophils decreased significantly in both trials (with or without selenium). Selenium supplementation, compared with placebo, decreased levels of leukocytes, neutrophils, and monocytes, but not lymphocytes, to the resting level or below 60 min after immersion. Only lymphocytes continued to increase in both trials during the recovery period. Serum HSP70 protein level did not change after immersion, but it decreased 60 min after immersion with the administration of selenium. In conclusion, supplementary selenium reduced the systemic immune response and serum HSP70 protein accumulation after half-body immersion.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.12 no.1
• /
• pp.733-742
• /
• 2020

Taking the cylindrical float of the floating fence of a floating litter collection device as the research object, based on the shallow immersion characteristics of the cylindrical float, the Morison equation is modified, and the interaction between regular waves and the partially immersed horizontal cylindrical float is discussed in combination with scale model test. The results show that the modified Morison equation can accurately predict the wave force of the horizontal cylindrical float and reveal the influence of amplitude, immersion depth and period on the wave force of the cylindrical float. For partially immersed cylindrical floats, the wave force increases with the increase in wave height and decays with the increase in period. The positive value distribution of the wave force is larger than that of the negative direction, and the difference between the positive and negative directions is mainly affected by the immersion depth.

• Journal of Ocean Engineering and Technology
• /
• v.30 no.4
• /
• pp.327-333
• /
• 2016

Reinforced concrete structures have found wide usage in land and maritime applications. However, the corrosion of reinforced concrete has been recognized as a serious problem from economic and safety standpoints. In previous studies, the corrosion behavior of the inner steel bar embedded in mortar (W/C: 0.4, 0.5) was investigated using electrochemical methods. In this study, multiple mortar test specimens (W/C: 0.6) with six different cover thicknesses were prepared and immersed in flowing seawater for five years. Subsequently, equations related to the cover thickness, period of immersion, and corrosion characteristics of the embedded steel bar were evaluated using electrochemical methods. Prior to immersion, the corrosion potentials indicated an increase with increasing cover thickness, and after five years, all corrosion potentials demonstrated a trend in the positive direction irrespective of the cover thickness. However, the relationships between the corrosion potential and cover thickness were not in complete agreement. Furthermore, after five years, all of the corrosion potentials indicated values that were nobler compared to those obtained prior to immersion, and their corrosion current densities also decreased compared to their values obtained prior to immersion. It was considered that the embedded steel bar was easily corroded because of the aggression of water, dissolved oxygen, and chloride ions; a higher W/C ratio also assisted the corrosion process. The corrosive products deposited on the surface of the steel bar for five years cast a resistance polarizing effect shifting the corrosion potential in the nobler direction. Consequently, it was considered that the W/C ratio of 0.6 showed nearly same results as those of W/C of 0.4 and 0.5. Therefore, the corrosion potential as well as various parameters such as the cover thickness, period of immersion, and W/C ratio must be considered at once for a more accurate evaluation of the corrosion property of reinforced steel exposed to marine environment for a long period.

• Journal of Life Science
• /
• v.13 no.1
• /
• pp.34-41
• /
• 2003

The hatching of fertilized egg and early development of larval black seabream, Acanthopngrus schlegeli by immersion of 3,5,3'-triiodo-L-thyronine ($T_3$) with doses of 0.01~0.5 ppm in tank were examined for early development periods and compared with control fish immersed by 0.1 N NaOH and 99% alcohol. Larvae were fed with rotifers for first 5 days during experimental period. Yolk absorption of larvae from $T_3$ immersion groups were significantly faster than that of control. Although hatching times among each groups were not significant difference. the hatching rates of larvae in higher doses (0.1 ppm and 0.5 ppm $T_3$ groups) were significantly lower than control. The results of $T_3$ immersion experiments to newly hatching larvae indicated that exogenous $T_3$induced significant faster the absorption of yolk and oil globule, faster the development of myotome and digestive duct and higher the growth rate of larvae than larvae of control. These results indicate that $T_3$ immersion supplements appear to confer a distinct advantage to eggs and larvae of black seabream, which is in early fragile developmental stage.

• Korean journal of food and cookery science
• /
• v.22 no.3 s.93
• /
• pp.379-385
• /
• 2006

The purpose of this study was to investigate the effects of immersion period after tumbling on the physicochemical properties of boiled pork loin with soy sauce. After the samples were tumbled for 30 min with soy sauce (1.5% salt concentration), they were immersed for 1, 5 or 10 days. Boiled pork loin was cooked at an internal temperature to $75^{\circ}C$. Cooking yields of boiled pork loin were significantly increased with increasing immersion period. The reduction in diameter and thickness for pork loin were significantly decreased with increasing immersion period, but moisture content and water holding capacity were increased. Shear force in the immersed samples after tumbling was significantly lower than in the control. In sensory evaluation color, flavor, texture, and juiciness of boiled pork loin immersed after tumbling should higher ratings than those of control.

• The Korean Journal of Physiology
• /
• v.3 no.1
• /
• pp.59-66
• /
• 1969

Experiments on thermoregulatory responses to cold immersion stimulus were carried out in September, 1968 (summer studies) and February, 1969 (winter studies). Eight each of ama and control subject were selected at random from a same community in Yong-Do Island, Pusan. The results obtained are summarized as follows: 1) The rate of fall in muscle temperature of forearm during a 30 min-immersion in $6^{\circ}C$ water bath was significantly slower in the ama in winter and was about the same in the two groups in summer. However, the magnitude of change in the skin temperature and the heat fluxes observed during immersion period was not significantly different either between groups or between seasons. 2) Both finger blood flow and skin temperature during one hr-immersion in $6^{\circ}C$ water bath decreased significantly in the ama as compared to the control. The magnitude of cold-induced vasodilatation during immersion period was significantly greater in the control in winter. However, the time of onset and blood flow at onset showed no significant relation between groups. 3) The magnitude of reactive hyperemia after a 5 min-arterial occlusion in both air and $15^{\circ}C$ water bath was significantly lower in the ana than in the control. In control subjects, post-occluded blood flow in water was significantly greater than in air, while in the ama it decreased to 1/2 of control values. The time required for the return of blood flow to resting values in the air was faster in the ama than in the control but was the same in water in the two groups. 4) The results suggest that vasoconstrictor tone increased in the ama in winter, indicating the development of vascular adaptation as a part of cold acclimatization.