• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.2
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• pp.132-140
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• 2009

Recently, the interest in the development of high efficiency Diesel engine technology using alternative fuel has been on the rise and related studies are being performed. Therefore, the DME(Dimethyl Ether), an oxygen containing fuel as an alternative fuel for light oil that can be used for diesel engines since it generates very little smoke. But it is unavoidable that the modification of a fuel supply system in an engine to application of the DME fuel because of DME fuel properties. So, in this study, a DME high pressure pump for a common-rail fuel supply system has been composed and the test results of the pump have been presented. As the results of the tests, it is confirmed that DME pump inlet pressure, pump speed and common-rail pressure effects on the volumetric efficiencies of the pump. Finally, it is defined that the optimum plunger volume of a DME pump has to be extended to the minimum 150% compared to a Diesel pump plunger volume considering DME fuel properties and volumetric efficiencies characteristics at same specifications of the high pressure pump.

• Nutrition Research and Practice
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• v.7 no.5
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• pp.385-392
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• 2013

Although several studies have assessed the influence of the glycemic index on body weight and blood pressure among adults, limited evidence exists for the pediatric age population. In the current study, we compared the effects of low glycemic index (LGI) diet to the healthy nutritional recommendation (HNR)-based diet on obesity and blood pressure among adolescent girls in pubertal ages. This 10-week parallel randomized clinical trial comprised of 50 overweight or obese and sexually mature girls less than 18 years of age years, who were randomly assigned to LGI or HNR-based diet. Macronutrient distribution was equivalently prescribed in both groups. Blood pressure, weight and waist circumference were measured at baseline and after intervention. Of the 50 participants, 41 subjects (include 82%) completed the study. The GI of the diet in the LGI group was $42.67{\pm}0.067$. A within-group analysis illustrated that in comparison to the baseline values, the body weight and body mass index (not waist circumference and blood pressure) decreased significantly after the intervention in both groups (P = 0.0001). The percent changes of the body weight status, waist circumference and blood pressure were compared between the two groups and the findings did not show any difference between the LGI diet consumers and those in the HNR group. In comparison to the HNR, LGI diet could not change the weight and blood pressure following a 10-week intervention. Further longitudinal studies with a long-term follow up should be conducted in this regard.

• The Journal of Internal Korean Medicine
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• v.27 no.2
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• pp.416-428
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• 2006

Objectives : Arterial stiffness and pulse pressure are related to cardiovascular and cerebrovascular survival and longevity. This study is aimed at examining the effects of Chungpyesagan-tang on arterial stiffness and Pulse pressure in acute stroke Patients. Methods: The subject of this study was acute strike Patients within 1 week after ictus, with Cardio-ankle vascular index(CAVI) higher than 9.0. They were divided into two groups: A treatment group (n=44) and a control group(n=46). For two weeks, Chungpyesagan-tang was given to the former, other herbal medicines to the latter. used for stroke patients for the control group for 2 weeks. At the end of first and second week, CAVI, pulse Pressure, National Institute of Health stroke scale(NIHSS), Modified Barthel Index(MBI) were measured. Serum lipid Profile, aspartate transaminase(AST), alanine transaminase(ALT). blood urea nitrogen(BUN), creatinine were also measured at the end of the study. Results : After 2 weeks, CAVI and Pulse Pressure in Chungpyesagan-tane group were significantly tower than those in the control group(P<0.05). NIHSS and MBI were improved in both groups. But there was no significant difference between the treatment group and the control group in terms of the NIHSS and MBI. Conclusions : We suggest Chungpyesagan-tanghas desirable effects on arterial stiffness and Pulse Pressure of acute stroke patients. It can improve morbidity and mortality of patients on the basis of influencing vascular stiffness and increased pulse pressure.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.4
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• pp.84-91
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• 2006

In this study, the effect of EGR and fuel injection pressure on the characteristics of combustion and emission performance of the common-rail diesel engine is investigated using DME fuel as a smoke-free alternative fuel. Because the heating value and density of DME fuel are lower than those of diesel fuel, the injection duration of the DME engine is relatively longer than the injection duration of the diesel engine with the same injection pressure. However, the higher injection pressure can shorten the injection duration for the DME engine. Although the smoke level of the DME engine is much lower than that of the diesel engine, the NOx is at a level similar to that of the diesel engine. As a proposed solution for this, the EGR technique is empirically applied to the DME engine. In the experiments, the injection pressure was changed from 200bar to 400bar, and the EGR rate was limited under 40%. With the same injection timing and fuel amount, the experiment results indicated that the increase of injection pressure led to the increase of IMEP while decreasing HC and CO emissions. However, the NOx emission tends to increase as the injection pressure becomes higher. On the other hand, as the EGR rate was increased, NOx emission and A/F were reduced while the HC and CO emissions were increased. Because HC and CO emissions have the critical A/F point where the emissions of HC and CO are rapidly increased, it is proposed that the EGR rate must be limited under the critical EGR rate.

• Journal of Pharmacopuncture
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• v.16 no.1
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• pp.37-42
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• 2013

Objective: The aim of this experiment was to investigate the effect and the mechanism of Geumgoeshingi-whan (GGSGW) Pharmacopuncture at the acupoint GV 4 on the blood pressure in spontaneously hypertensive rats (SHR). Methods: SHR were injected with normal saline solution (Control-SHR group)or GGSGW Pharmacopuncture (GGSGW-SHR group) at the acupoint GV 4. The systolic arterial blood pressure and renal parameters were measured for two weeks. Results: The systolic arterial blood pressure was decreased significantly after GGSGW Pharmacopuncture at the acupoint GV 4 in SHR, followed by a significant rise in creatine clearance. The plasma levels of aldosterone were decreased significantly after GGSGW Pharmacopunctureas were the plasma levels of atrial natriuretic peptide (ANP). Conclusion: These results suggest that the blood pressure was decreased significantly after GGSGW Pharmacopuncture at the acupoint GV 4 in SHR and that the depressor response of the blood pressure was related to decreases in the plasma levels of aldosterone and ANP.

• Journal of Korean Clinical Nursing Research
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• v.28 no.1
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• pp.45-53
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• 2022

Purpose: The purpose of this study was to evaluate risk factors of pressure injuries in patients after neurosurgery. Methods: A retrospective case-control study was conducted using 273 patients undergoing neurosurgery admitted to a general hospital from 2015 to 2021. Data were collected from September 1 to 30, 2021. The data were analyzed using the SPSS/WIN 26.0 program. Results: Risk factors significantly influencing the occurrence of pressure injuries in the patients undergoing neurosurgery were hypertension (OR=3.12, p=.024), postoperative hypoalbuminemia (OR=0.30, p=.028), and prolonged operative duration (OR=1.00, p=.001). The regression model explained 86.0% of the variance of the outcome variable. Conclusion: In order to prevent surgery-related pressure injuries in patients undergoing neurosurgery, thorough blood pressure management, avoidance of hypoalbuminemia, and preventive nursing intervention considering operative duration are required.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.75-85
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• 2021

The broadband noise can be dominant or important for total characteristics for marine propeller noise representing the minimum base of self-noise. Accurate prediction of such noise is crucial for survivability of underwater military vessels. While the FW-H Formulation 1B can be used to predict broadband trailing edge noise, the method required experiment measurements of surface pressure correlations, showing its limitations in generality. Therefore, in this study, the methods are developed to utilize wall pressure spectrum models to overcome those limitations. Chase model is adopted to represent surface pressure along with the developed formulations to reproduce pressure statistics. Newly developed method is validated with the experiments of airfoils at different velocities. Thereafter, with its feasibility and generality, the procedure incorporating computational fluid dynamics is established and performed for a propeller behind submarine hull. The results are compared with the experiments conducted at Large Cavitation Tunnel, thus showing its usability and robustness.

• Journal of Powder Materials
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• v.22 no.1
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• pp.6-9
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• 2015

In this study, the behavior of densification of copper powders during high-pressure torsion (HPT) at room temperature is investigated using the finite element method. The simulation results show that the center of the workpiece is the first to reach the true density of copper during the compressive stage because the pressure is higher at the center than the periphery. Subsequently, whole workpiece reaches true density after compression due to the high pressure. In addition, the effective strain is increased along the radius during torsional stage. After one rotation, the periphery shows that the effective strain is increased up to 25, which is extensive deformation. These high pressure and severe strain do not only play a key role in consolidation of copper powders but also make the matrix harder by grain refinement.

• The Journal of Internal Korean Medicine
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• v.42 no.2
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• pp.122-130
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• 2021

The purpose of this study is to report the effect of Korean medicine treatment on a pressure sore in a stroke patient. An 86-year-old female patient diagnosed with spontaneous intracerebral hemorrhage in the right basal ganglia had symptoms of left hemiparesis, dysphagia, and a 4.5-cm-by-2.5-cm left trochanteric pressure sore. Clinical outcomes were measured using the National Pressure Ulcer Advisory Panel (NPUAP) pressure injury stages, the Agency for Health Care Policy and Research (AHCPR) pressure ulcer stages, and the Braden scales. Treatment with Korean medicine, including acupuncture, herbal medicine, and dressing therapy, significantly improved the trochanteric pressure sore, as reflected by a NPUAP stage change from III to I, an AHCPR stage change from III to I, and a Braden scale change from 13 to 18. These findings suggest that Korean medicine treatment may be effective to treat pressure sores in stroke patients.

• Progress in Superconductivity
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• v.10 no.2
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• pp.133-138
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• 2009

The $Nd_{1+x}Ba_{2-x}Cu_3O_{7-{\delta}}$(Nd123) superconductor exhibits high performance in high magnetic field and high temperature. We have studied phase stability for Nd123 under reduced oxygen partial pressure and various heat-treatment conditions. The main phase is Nd123 and some samples contain small amounts of Nd422 depending on the temperature and oxygen partial pressure. The decomposition temperature decreases with decreasing oxygen partial pressure from $1052^{\circ}C(P(O_2)$=150 Torr) to about $845^{\circ}C(P(O_2)$=0.1 Torr). The liquidus line was steeper temperature with decreasing oxygen partial pressure. In same condition of oxygen partial pressure, the region of stable Nd123 phase was formed at slightly higher temperature than the region of stable YBCO phase.