• Journal of the Korean Chemical Society
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• v.11 no.1
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• pp.28-32
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• 1967

The direct acid leaching of domestic Marmatite concentrate at elevated temperatures and pressures was investigated. Almost 100 percent of zinc was extracted from the concentrate liberating free sulfur in 4 hours at $100^{\circ}C$ when the oxygen partial pressure was 5 atm. in sulfuric acid solution. By applying the Arrhenius equation to leach reaction in the range of $60^{circ}$ to $100^{\circ}C$ at the same oxygen partial pressure, 15.7 kcal per mole of activation energy was calculated. At the initial stage of leaching, the rate of reaction increased linearly by increasing temperature and pressure. The concentration of sulfuric acid gave minor effect to leaching velocity in the range of 5 to 20 percent. The particle size should be under 270 mesh for 100 percent extraction of zinc.

• Journal of Korean Academy of Nursing
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• v.45 no.4
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• pp.483-494
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• 2015

Purpose: This study identified effects of dietary and physical activity interventions including dietary interventions or physical activity interventions alone or combined dietary-physical activity interventions to improve symptoms in metabolic syndrome including abdominal obesity, high triglycerides, low high density lipoprotein cholesterol, elevated blood pressure, and elevated fasting glucose through meta-analysis. Methods: Articles on metabolic syndrome X published from 1988 to 2013 were searched through electronic databases, Google Scholar, and reference reviews. Methodological quality was assessed by the checklist, SIGN (Scottish Intercollegiate Guidelines Network). Results: In the meta-analysis, there were 9 articles reporting 13 interventions with 736 participants. Using random effect models, the dietary and/or physical activity interventions showed a lower mean difference in waist circumference ( - 1.30 cm, 95% CI: - 2.44~ - 0.15, p=.027). The combined dietary-physical activity interventions showed a lower mean difference in waist circumference ( - 2.77 cm, 95% CI: - 4.77~ - 0.76, p=.007) and systolic blood pressure ( - 5.44 mmHg, 95% CI: - 10.76~ - 0.12, p=.044). Additionally, interventions of over 24 weeks yielded a lower mean difference in waist circumference ( - 2.78 cm, 95% CI: - 4.69~ - 0.87, p=.004) and diastolic blood pressure ( - 1.93 mmHg, 95% CI: - 3.63~ - 0.22, p=.026). Conclusion: The findings indicate that dietary and/or physical activity interventions for metabolic syndrome reduce central obesity with no adverse effects. This finding provides objective evidences for dietary and physical activity management on metabolic syndrome as an efficient intervention.

• Journal of Trauma and Injury
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• v.32 no.2
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• pp.86-92
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• 2019

Purpose: There is increasing interest in intra-abdominal pressure (IAP) and intra-abdominal hypertension (IAH) in critically ill patients. This study investigated the effects and outcomes of elevated IAP in a trauma intensive care unit (ICU) population. Methods: Eleven consecutive critically ill patients admitted to the trauma ICU at Pusan National University Hospital Regional Trauma Center were included in this study. IAP was measured every 8-12 hours (intermittently) for 72 hours. IAP was registered as mean and maximal values per day throughout the study period. IAH was defined as $IAP{\geq}12mmHg$. Abdominal compartment syndrome was defined as $IAP{\geq}20mmHg$ plus ${\geq}1$ new organ failure. The main outcome measure was in-hospital mortality. Results: According to maximal and mean IAP values, 10 (90.9%) of the patients developed IAH during the study period. The Sequential Organ Failure Assessment (SOFA) score was significantly higher in patients with $IAP{\geq}20mmHg$ than in those with IAP <20 mmHg (16 vs. 5, p=0.049). The hospital mortality rate was 27.3%. Patients with a maximum $IAP{\geq}20mmHg$ exhibited significantly higher hospital mortality rates (p=0.006). Non-survivors had higher maximum and mean IAP values. Conclusions: Our results suggest that an elevated IAP may be associated with a poor prognosis in critically ill trauma patients.

• Journal of the Korea Fashion and Costume Design Association
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• v.21 no.4
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• pp.55-67
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• 2019

This study analyzed the fabric and product size of the burn patient's custom compression garment and measured the pressure applied by the garment to assess whether proper pressure is being delivered for treatment. The test clothes were presented to the market by body size and commissioned with the same design. The subjects selected four people close to the average body size of men in their 20s determined by 7th Size Korea. The experiment was conducted by wearing a compression suit, performing activities and measuring changes in the pressure of the garment according to changes in posture. The fabric used for the compressive clothing was not ruptured even at 216 kPa, the elasticity recovery rate was measured between 80.5 and 94.5%. The product dimensions of the experimental clothing varied by up to 8cm from brand to brand, requiring the standardization of compression clothing. The experiment showed that four types of compression suit varied in pressure, and the pressure range, excluding the gastric arm (17.9mmHg), was between 2.5-14.1mmHg, which failed to meet the level of pressurization for treatment purposes. The clothing pressure in the chest area dropped when performing movements rather than standing still. This was interpreted to be a result of reduced the adhesion of the compression suit during operation. The peak pressure (31.68mmHg) and the lowest pressure (2.2mmHg) was noted in the scapula, indicating that no pressure was being transmitted on the vertebrae. The pressure of the garment on the right shoulder blade was elevated in a supine position. Because much time is spent laying down, it is necessary for the pattern design to accommodate for the increased clothing pressure on the shoulder blades. Standardization of the level of pressurization for burn patient's custom-made pressure suits for each stage of treatment is urgently required.

• The Korean Journal of Pharmacology
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• v.8 no.1
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• pp.49-57
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• 1972

Ginseng, the Korean medicinal radix, has been widely used in the Chinese medicine as well as in the folk remedies for many centuries. It is claimed from experience that ginseng exerts multiple therapeutic effects in a large variety of disorders. Despite of its popularity, the chemical analysis and pharmacological study of ginseng are not firmly established. Although there are some scattered reports of ginseng effects on blood pressure, there are few reports on hypertension especially. Recently, Lee & Cho (1971) reported that the administration of ginseng significantly supresses the production of renal hypertension. This study was undertaken to reevaluate the effect of ginseng on renal hypertension and to determine whether ginseng also supresses on neurogenic hypertension, and to clarify the mechanism of this antihypertensive effect. Male rats, weighing around 180 gm on an average were used. Renal hypertension was induced by Grollman's method under general anesthesia with 35mg/kg of pentobarbital sodium. Ginseng effect on blood pressure was observed on normal, renal hypertensive and neurogenic hypertensive rats respectively. Ginseng alcohol extract (40mg/kg) was administered daily subcutaneously from 3 days prior to producing hypertension. And in renal hypertensive rats, the effects of histamine and Avil on blood pressure were also observed. Histamine (0.05mg/kg) and Avil (0.025mg/kg) were also administered daily I.M. from 3 days prior to kidney-8-ligature. The results of the experiments are as follows: 1) No significant difference was observed in blood pressure between the normotensive control and ginseng-treated normotensive rats. 2) In renal hypertensive control, the mean blood pressure already was significantly elevated on 15th day and gradually elevated. The administration of ginseng significantly supresses the production of renal hypertension from 30th day as compared with control rats. 3) The mean blood pressure in neurogenic hypertensive control was average 143.1 mmHg on 7th day. On the other hand, in ginseng treated-neurogenic hypertensive rats, the mean blood pressure was average 125.5mmHg. The administration of ginseng significantly supresses the production of neurogenic hypertension as compared with control rats. 4) In renal hypertensive rats, the administration of histamine and Avil did not differ with control rats. 5) In ginseng-treated renal hypertensive rats, cholesterol contents of plasma, adrenal, kidney and spleen were slightly decreased.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.1
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• pp.9-25
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• 1994

In the present study, the Reynolds-averaged Navier-Stokes equations, together with the equations of the $k-{\varepsilon}$ model of turbulence, were solved numerically in a general body-fitted coordinate system for three-dimensional turbulent flows around the six basic shapes of the magnetically levitated train(MAGLEV). The numerical computations were conducted on the MAGLEV model configurations to provide information on shapes of this type very near the elevated track at a constant Reynolds number of $1.48{\times}10^{6}$ based on the body length. The coordinate system was generated by numerically solving a set of Poisson equations. The convective transport equations were discretized using the finite-analytic scheme which employed analytic solutions of the locally-linearized equations. A time marching algorithm was employed to enable future extensions to be made to handle unsteady and fully-elliptic problems. The pressure-velocity coupling was treated with the SIMPLER-algorithm. Of particular interests were wall effect by the elevated track on the aerodynamic forces and flow characteristics of the six models calculated. The results indicated that the half-circle configuration with extended sides and with smooth curvature of sides was desirable because of the low aerodynamic forces and pitching moment. And it was found that the separation bubble was occured at wake region in near the elevated track.

• Journal of Korea Foundry Society
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• v.31 no.1
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• pp.11-17
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• 2011

The effect of CaO addition to AM60B Mg alloy on tensile properties has been investigated, with focus on strength and ductility at room and elevated temperatures. The 0.25-0.65wt% CaO added AM60B Eco-Mg diecastings were prepared by high pressure die casting using Buhler 1,450-ton cold chamber machine without $SF_6$ and $SO_2$ gases. The microstructures and tensile properties of each alloy were tested. The results show that the grains of AM60B are refined and the mechanical properties increase with CaO addition at room temperature. The improvement of strength and ductility is prominent at 0.45-0.55wt% CaO addition. Also, improved mechanical properties are maintained at elevated temperature of $150^{\circ}C$. CaO addition results in $Al_2Ca$ phase formation mostly on the grain boundaries. This phase leads to the refinement of grain structures and improvement of ductility as well as strength. The suppression of ${\beta}-Mg_{17}Al_{12}$ phase as well as the decrease of fracture surface porosity and other casting defects caused by melt cleanliness also contribute to the enhancement of mechanical properties of AM60B Eco-Mg at room and elevated temperature.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.2
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• pp.139-147
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• 2016

Performances of urethane packing in the hydraulic breaker were analyzed using a finite element method. Because of high temperature and high pressure in the hydraulic breaker, it is better to use urethane rather than rubber as a packing material. We obtained the physical properties of urethane at elevated temperature by the tensile test. We analyzed buffer seal and U-packing maintaining the pressure and preventing oil leakage. Deformation, stress distribution, contact length, contact pressure of packing at each pressure step were obtained using finite element analysis. As the temperature increases, stress and contact force tend to decrease at low pressure. As the gap between piston and cylinder increases, contact length and contact forces decrease. Consequently, it is possible to design the packing section using these analyses, and construct a system to predict the possibility of oil leakage in the hydraulic breaker.

• Journal of Chest Surgery
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• v.18 no.1
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• pp.79-85
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• 1985

The effect of graded increments in positive end-expiratory pressure [PEEP] on hemodynamics required to ventilate 8 critically ill patients is reported. Acute respiratory insufficiency was a cause of death in only one patient of drug inoxication among the 8 patients studied. The cardiac output was not changed significantly after the increment of PEEP to the level of 20 cm H2O. The heart rate was increased significantly from 15 cm H2O PEEP [P<0.01] as compared to 0 cm H2O PEEP; and the stroke volume was decreased significantly from 15 cm H2O PEEP [P<0.05]. The blood pressure was not affected at any level of PEEP, but the pulmonary artery pressure was elevated significantly at 10 cm H2O PEEP [P<0.01]. The right ventricular transmural filling pressure was not affected at the level of 10 cm H2O PEEP, but from 15 cm H2O PEEP it was increased significantly. With the increment of PEEP, the left ventricular stroke work index was decreased slightly; and at 20 cm H2O PEEP, it was decreased significantly. The right ventricular stroke work index was increased only at 10 cm H2O PEEP. The systemic vascular resistance was decreased significantly from 15 cm H2O PEEP [P<0.01].

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.10a
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• pp.115-124
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• 1995

The purpose of the present study was to address whether the in vivo noradrenergic neural activities in the locus coeruleus are involved in the regulation of blood pressure. Two groups of the animals were prepared, 1) SHR and 2) age-matched normotensive control, WKY. At the age of 6 and 16 weeks, blood pressure and the releases of NE from the locus coeruleus in SHR and KWY were measured by in vivo microdialysis at three different conditions: 1) normal, 2) elevated state of blood pressure by systemic injected phenylephrine and 3) increased state of neural activity by perfused phenylephrine into the locus coeruleus. The basal release of NE of SHR were significantly higher than that of WKY, Phenylephrine treatment caused elevation of blood pressure in both SHR and WKY in dose-dependent manner. Following phenylephrine injection, the releases of NE from the locus coeruleus of SHR were significantly decreased, whereas the significant change of NE in WKY was observed in the highest dose of phenylephrine. Phenylephrine perfusion into the locus coeruleus through microdialysis probe caused pressor responses and the pressor response in SHR was greater compared with that in WKY. The results from the present study suggests that the noradrenergic nervous system in the locus coeruleus may contribute as one of the development and maintenance factors for hypertension in SHR.