A Study on a High-Temperature/High-Pressure Washing System in which High-Temperature Water is Generated in a Low-Pressure Boiler and High-Pressure Water is Generated Thereafter in a Compressor

Dong-Hyun Cho(조동현) 한국기계가공학회 2019 한국기계가공학회지 Vol.18 No.1

This study was conducted on a high-temperature/high-pressure washer in which low-pressure cold water in a boiler is heated to a temperature range of 70~80°C by supplying diesel combustion heat. The high-temperature water is sent to a compressor to increase its pressure to 200 bar, thereby making high-temperature/high-pressure water, which is sprayed through a spray nozzle. In the results of this study, the spray temperature of the high-pressure washing was shown to be the highest when the ratio between the actual amount of combustible air and the theoretical amount of air was 1:1 and the energy consumption rate of the low-pressure boiler type high-pressure washer was shown to be much lower than that of the high-pressure boiler type high-pressure washer.

High-calorific bio-hydrogen production under self-generated high-pressure condition

Lee, Mo-Kwon,Sivagurunathan, Periyasamy,Yun, Yeo-Myeong,Kang, Seoktae,Na, Jeong-Geol,Kim, Dong-Hoon Elsevier 2018 Bioresource technology Vol.264 No.-

<P><B>Abstract</B></P> <P>For the use of biologically produced H<SUB>2</SUB>, removal of CO<SUB>2</SUB> is an indispensable process. Unlike conventional CO<SUB>2</SUB> removal methods, this study proposed a self-generated high-pressure dark fermentation (HPDF) process as a novel strategy for directly producing high-calorific bio-H<SUB>2</SUB>. The pressure was automatically increased by self-generated gas, while the maximum pressure inside fermenter was restricted to 1, 3, 5, 7, and 10 bar in a batch operation. As the pressure increased from 1 to 10 bar, the H<SUB>2</SUB> content increased from 55% to 80%, whereas the H<SUB>2</SUB> yield decreased from 1.5 to 0.9 mol H<SUB>2</SUB>/mol hexose<SUB>added</SUB>. The highest H<SUB>2</SUB> content of 80% was obtained at both of 7 and 10 bars. Increased lactate production with increased abundance of lactic acid bacteria was observed at high-pressure. Despite the lower H<SUB>2</SUB> yields at high-pressure conditions, HPDF was found to be economically beneficial for obtaining high-calorific bio-H<SUB>2</SUB> owing to the low CO<SUB>2</SUB> removal cost.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel approach for bio-H<SUB>2</SUB> upgrading under high-pressure dark fermentation. </LI> <LI> High H<SUB>2</SUB> content up to 80% was achieved at 7 and 10 bar. </LI> <LI> H<SUB>2</SUB> yield was decreased as pressure increased. </LI> <LI> Increased abundance of lactate producers but decreased abundance of <I>Clostridium</I> sp. </LI> <LI> The benefit for obtaining high-calorific bio-H<SUB>2</SUB> was increased by high-pressure. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

축광 성능을 갖는 고압용 장거리 호스 개발에 관한 연구

한용택,나병균,최진성,민세홍 한국화재소방학회 2017 한국화재소방학회논문지 Vol.31 No.5

This study describes the development of a long-distance hose for ultra-high pressure operation, which can be used inconjunction with an ultra-high pressure pump and can be effectively applied to the fire suppression of high-rise buildings anda long, large tunnels. Also, it has phosphorescent properties, which can help to secure the withdrawal route of the fire-fighterswhen they are threatened by the fire. We developed an ultra-high pressure hose aiming at a pressure of 3 MPa and a flowrate of 2000 lpm and developed an ultra-high pressure fire hose that can withstand this very high pressure by using a doublejacket, triple polyurethane coating and warf (Wp) of 52. In order to ensure the performance of the developed ultra-highpressure hose, its structure, appearance, leakage at high pressure, length and elongation were inspected by a certifiedcertification agency, who also subjected it to a peeling test, friction test, breaking pressure test and free fall test. Also, it wasstudied in addition to the luminescent high-pressure hose for fire-fighting. In the phosphorescence test, the luminancemeasurement value was more than the reference value of the luminance test after 40 minutes, which confirmed that itsperformance was satisfactory for fire-fighting products. In the future, if such an ultra-high pressure fire hose werecommercialized and applied in the field, it could contribute to securing improved fire suppression and safer exit from fires,as compared to the fire hoses currently used in the suppression of fires in skyscraper buildings and long tunnels. 본 연구에서는 초고압 펌프의 개발과 같이 사용할 수 있는 초고압용 장거리 호스 개발에 관한 연구이며, 접근과방수거리의 도달이 어려운 초고층 건물 및 대심도 터널의 화재진압에 효율적으로 적용이 가능함과 동시에 축광 성능을 포함하여 소방관의 화재 진압 시 퇴로 확보에도 도움이 될 수 있는 초고압용 호스의 개발에 관한 연구이다. 호스의 성능으로서 압력 3 MPa, 유량 2000 lpm을 목표로 초고압 호스를 개발하였으며, 2중의 자켓과 3중의 폴리우레탄 코팅 및 52의 경사를 사용하여 매우 촘촘하고 높은 고압에도 견딜 수 있는 초고압 소방호스를 개발하였다. 개발된초고압 호스의 성능을 확보하기 위하여 구조 및 외관, 고압에서의 누수, 길이, 신장률, 박리시험, 마찰시험, 파단압시험 및 자유낙하 시험 등이 공인된 인증기관에서 수행되었으며 수행결과 성능에 이상이 없는 것으로 파악되었다. 또한 소방관의 화재진압 시 퇴로를 확보하기 위한 축광 성능의 초고압 호스에 추가하여 연구 및 개발하였으며, 휘도시험의 값으로 축광의 발광시험 개시부터 40분 후까지 휘도 측정치가 휘도시험의 기준 값 이상으로 충분히 확보되는 것을 확인할 수 있었다. 향후, 이와 같은 초고압용 소방용 호스가 상용화가 되어 현장에서 적용된다면 초고층 건물의 화재진압 및 장대터널에서의 화재진압에 있어서 현재 사용되고 있는 소방호스 보다 개선된 화재 진압 및 안전한 퇴로를 확보하는 측면에서 기여할 수 있을 것으로 판단된다.

High Temperature- and High Pressure-Processed Garlic Improves Lipid Profiles in Rats Fed High Cholesterol Diets

Sohn, Chan-Wok,Kim, Hyun-Ae,You, Bo-Ram,Kim, Min-Jee,Kim, Hyo-Jin,Lee, Ji-Yeon,Sok, Dai-Eun,Kim, Jin-Hee,Lee, Kun-Jong,Kim, Mee-Ree The Korean Society of Food Science and Nutrition 2012 Journal of medicinal food Vol.15 No.5

Garlic protects against degenerative diseases such as hyperlipidemia and cardiovascular diseases. However, raw garlic has a strong pungency, which is unpleasant. In this study, we examined the effect of high temperature/high pressure-processed garlic on plasma lipid profiles in rats. Sprague-Dawley rats were fed a normal control diet, a high cholesterol (0.5% cholesterol) diet (HCD) only, or a high cholesterol diet supplemented with 0.5% high temperature/high pressure-processed garlic (HCP) or raw garlic (HCR) for 10 weeks. The body weights of the rats fed the garlic-supplemented diets decreased, mostly because of reduced fat pad weights. Plasma levels of total cholesterol (TC), low-density lipoprotein cholesterol, and triglyceride (TG) in the HCP and HCR groups decreased significantly compared with those in the HCD group. Additionally, fecal TC and TG increased significantly in the HCP and HCR groups. It is notable that no significant differences in plasma or fecal lipid profiles were observed between the HCP and HCR groups. High temperature/high pressure-processed garlic contained a higher amount of S-allyl cysteine than raw garlic (P<.05). The results suggest that high temperature/high pressure-processed garlic may be useful as a functional food to improve lipid profiles.

중년 남성에서 고정상혈압에 의한 고혈압발생 위험 규명을 위한 코호트내 환자-대조군 연구

안윤옥,배종면,Ahn, Yoon-Ok,Bae, Jong-Myon 대한예방의학회 1999 Journal of Preventive Medicine and Public Health Vol.32 No.4

Objectives : High-normal blood pressure' is a factor influencing decision to initiate targeted intensive intervention strategy in westernized populations. JNC-VI offered the vigorous lifestyle modification for persons with 'high-normal blood pressure', who could be early detected. As a hypertension seems to be the result of multiple genetic factors operating in concert with associated environmental factors, it will be necessary to identify the high-normal blood pressure as a risk factor of hypertension for applying primary prevention strategy in Korean people. Methods : Although cohort study design might be adequate to recruit incidence cases, to keep time sequence of events, and to prevent information bias, nested case-control study was chosen for avoiding measurement errors because hypertension is a benign disease. Source population was the 'Seoul Cohort' participants and follow-up was done by using Korea Medical Insurance Corporation's database on the utilization of health services from 1 Jan93 to 30Jun97. Incidence cases were ascertained through the chart review, telephone contacts, and direct blood pressure measurements. Controls included the pairing of 4 individuals to each case on the basis of age. Results : As 75% of 247 incident cases had high-normal blood pressure, the crude odds ratio for hypertension was 2.04 (95% CI 1.47-2.83). Another statistically significant risk factors of hypertension were body mass index, dietary fiber, alcohol consumption, weekly activity and history of quitting smoking. The multivariate odds ratio of high-normal blood pressure adjusted for all risk factors was 1.84 (95% CI 1.31-2.56). Among high-normal blood pressure group, body mass index, weekly ethanol amounts, weekly physical activity, and dietary fiber except history of quitting smoking were still risk factors of hypertension. Conclusion : 'High-normal blood pressure' is a risk factor for hypertension in Korean middle-aged men, which represents that the vigorous lifestyle modification for persons with 'high-normal blood pressure' is need.

해양플랜트용 고차압 제어밸브의 해석 및 설계

장성철(Sung Cheol Jang),박태수(Tae-Soo Park),허남수(Nam-Soo Hur),김인환(In-Whan Kim) 한국기계가공학회 2015 한국기계가공학회지 Vol.14 No.5

In this study, the multi-disk of a high-pressure drop control valve is designed and manufactured. Then, the flow rate and high-pressure drop of fluids flowing in the high-pressure drop control valve is CAE/CFD. This study involves numerical analysis for the Zambil offshore project of a high-pressure drop control valve. ANSYS used a solver for offshore structures analysis. A high-pressure drop control valve, which transforms the power transfer of a system by reducing the inlet pressure of 345bar to the outlet pressure of 112bar, is a fundamental component in the offshore process. This study not only analyzes the relation between pressure drop and fluid velocity in a trim by using fluid analysis, but also examines the possibility of cavitation in a valve in addition to the plot for the extension of lifespan. It is demonstrated that the pressure drop from 345bar to 112bar is more feasible in the presence of the trim, which can induce a continuous and diminutive pressure drop in order to prevent cavitation in a high-pressure drop control valve.

Effect of pressure on the short-range structure and speciation of carbon in alkali silicate and aluminosilicate glasses and melts at high pressure up to 8 GPa: ¹³C, ²⁷Al, ¹⁷O and ²⁹Si solid-state NMR study

Kim, Eun Jeong,Fei, Yingwei,Lee, Sung Keun Pergamon Press 2018 Geochimica et cosmochimica acta Vol.224 No.-

<P><B>Abstract</B></P> <P>Despite the pioneering efforts to explore the nature of carbon in carbon-bearing silicate melts under compression, <I>experimental</I> data for the speciation and the solubility of carbon in silicate melts above 4 GPa have not been reported. Here, we explore the speciation of carbon and pressure-induced changes in network structures of carbon-bearing silicate (Na<SUB>2</SUB>O-3SiO<SUB>2</SUB>, NS3) and sodium aluminosilicate (NaAlSi<SUB>3</SUB>O<SUB>8</SUB>, albite) glasses quenched from melts at high pressure up to 8 GPa using multi-nuclear solid-state NMR. The <SUP>27</SUP>Al triple quantum (3Q) MAS NMR spectra for carbon-bearing albite melts revealed the pressure-induced increase in the topological disorder around 4 coordinated Al (<SUP>[4]</SUP>Al) without forming <SUP>[5,6]</SUP>Al. These structural changes are similar to those in volatile-free albite melts at high pressure, indicating that the addition of CO<SUB>2</SUB> in silicate melts may not induce any additional increase in the topological disorder around Al at high pressure. <SUP>13</SUP>C MAS NMR spectra for carbon-bearing albite melts show multiple carbonate species, including <SUP>[4]</SUP>Si(CO<SUB>3</SUB>)<SUP>[4]</SUP>Si, <SUP>[4]</SUP>Si(CO<SUB>3</SUB>)<SUP>[4]</SUP>Al, <SUP>[4]</SUP>Al(CO<SUB>3</SUB>)<SUP>[4]</SUP>Al, and free CO<SUB>3</SUB> <SUP>2–</SUP>. The fraction of <SUP>[4]</SUP>Si(CO<SUB>3</SUB>)<SUP>[4]</SUP>Al increases with increasing pressure, while those of other bridging carbonate species decrease, indicating that the addition of CO<SUB>2</SUB> may enhance mixing of Si and Al at high pressure. A noticeable change is not observed for <SUP>29</SUP>Si NMR spectra for the carbon-bearing albite glasses with varying pressure at 1.5–6 GPa. These NMR results confirm that the densification mechanisms established for fluid-free, polymerized aluminosilicate melts can be applied to the carbon-bearing albite melts at high pressure.</P> <P>In contrast, the <SUP>29</SUP>Si MAS NMR spectra for partially depolymerized, carbon-bearing NS3 glasses show that the fraction of <SUP>[5,6]</SUP>Si increases with increasing pressure at the expense of Q<SUP>3</SUP> species (<SUP>[4]</SUP>Si species with one non-bridging oxygen as the nearest neighbor). The pressure-induced increase in topological disorder around Si is evident from an increase in peak width of <SUP>[4]</SUP>Si with pressure. <SUP>17</SUP>O NMR spectrum shows that the fraction of Na⋯O <SUP>[5]</SUP>Si in carbon-bearing NS3 glasses is less than that of carbon-free NS3 glasses at 6 GPa potentially due to the formation of bridging carbonate species. While its presence is not evident from the <SUP>17</SUP>O NMR spectrum primarily due to low carbon concentration, <SUP>13</SUP>C MAS NMR results imply the formation of bridging carbonates, <SUP>[4]</SUP>Si(CO<SUB>3</SUB>)<SUP>[4]</SUP>Si, above 6 GPa. The spin-lattice relaxation time (<I>T</I> <SUB>1</SUB>) of CO<SUB>2</SUB> in albite melts increases with increasing pressure from 42 s (at 1.5 GPa) to 149 s (at 6 GPa). Taking the pressure-induced change in <I>T</I> <SUB>1</SUB> of carbon species into consideration, total carbon content in carbon-bearing albite melts increases with pressure from ∼1 wt% at 1.5 GPa to ∼4.1 wt% at 6 GPa. The results also reveal a noticeable drop in the peak intensity of free carbonates in carbon-bearing NS3 melts at 6 GPa, implying a potential non-linear change in the carbon solubility with pressure. The current results of carbon speciation in the silicate melts above 4 GPa provide an improved link among the atomic configurations around carbon species, their carbon contents, and isotope composition of carbon-bearing melts in the upper mantle.</P>

하이힐 굽 높이에 따른 보행 시 족저압 변화 비교 분석

박종진 한국운동역학회 2009 한국운동역학회지 Vol.19 No.4

We aimed to determine the effect of heel height on foot pressure by comparing and analyzing data on foot pressure in shoes with different heel heights. On the basis of a previous study, we selected 3cm and 7cm as the shoe heel heights preferred by female college students. We divided 10 female students into forefoot and hindfoot to measure vertical force, maximum pressure, and average pressure. The average pressure on the forefoot was higher and that on the hindfoot was lower in the case of 7cm high-heeled shoes. The maximum pressure on the forefoot was significantly higher in the case of the 7cm heel height (p<.05). The vertical force, maximum pressure, and average pressure on the hindfoot were also significantly higher in the case of the 7cm heel height (p<.05). The results showed that wearing 7cm high-heeled shoes exerted greater maximum pressure on the forefoot and greater vertical force, maximum pressure, and average pressure on the hindfoot. This leads to increase in confining pressure caused by high pressure distribution over the forefoot and increase in the pressure on the hindfoot, which may cause deformation of toes and heel pain over a long period. Therefore, female college students who wish to wear high heels are recommended to wear 3cm high-heeled shoes rather than 7cm high-heeled shoes. 본 연구는 구두 굽 높이 변화에 따른 보행 시 족저압력을 비교, 분석함으로써 구체적인 데이터를 정량화하여 높은 굽을 착용함으로 인한 전족부의 압력 증가가 발에 미치는 영향을 알아보고자 한다. 본 연구에 사용된 구두는 선행연구를 바탕으로 여대생이 선호하는 구두 굽 높이 3cm, 7cm를 선택하였으며 여대생 10명을 대상으로 발을 전족부와 후족부로 나누어 수직힘, 최대압력, 평균압력을 측정하였다. 그 결과 전족부에서의 평균압력은 7cm 높이 구두가 높게 나타났으며, 후족부에서는 7cm 높이 구두가 낮게 나타났다. 통계처리 결과 전족부위에서는 3cm 굽 높이와 7cm 굽 높이의 최대압력 비교에서 유의한 차이가 나타났으며(p<.05), 후족부위에서는 수직힘, 최대압력, 평균압력 모두 유의한 차이가 나타났다(p<.05). 이상과 같이 구두를 착용함으로서 전족부의 최대압력이 높아지는 것은 물론이고 후족부위의 수직힘, 최대압력, 평균압력도 높아지는 것을 알 수 있었다. 이러한 현상은 전족부위에 높은 압력분포로 구속압이 증가하여 발가락의 변형을 유발할 수 있으며 후족부위에 압력증가는 장시간 착용 시 뒤꿈치의 통증을 유발할 수 있다. 따라서 굽이 있는 구두를 착용할 때 굽 높이가 7cm일 때 보다는 3cm일 때, 굽 높이가 낮을수록 전족부의 변형 예방과 후족부의 통증을 줄일 수 있을 것으로 기대된다.

허혈성 심질환 환자에서 Sirolimus 용출성 스텐트 삽입술시 과확장의 안전성과 효과

이승은,배우형,김남식,윤성한,이한철,김준,김준홍,전국진,홍택종,신영우 대한노인병학회 2008 Annals of geriatric medicine and research Vol.12 No.1

Background: We have no information about the safety and effectiveness when we perform overdilating a sirolimuseluting stent (SES) with high pressure. In some specific animal model, the study reported overdilatation of SES with high pressure resulted in increase of restenosis. The aim of this study was to evaluate the safety and effectiveness of overdilatation of SES with high pressure. Methods: 97 patients underwent PCI using SES between August 2003 and July 2005 were divided into two group(high pressure group, low pressure group), stents were implanted with high pressure (>18 atm) and low pressure (<12 atm). We compared between the two group of safety of stents, major adverse cardiac events (MACE), rate of restenosis, late loss. Results: In high pressure group, there are more type C lesion (51% vs 38%, p<0.01). There were no significant differences between the two groups regarding MACE (12.8% vs 17.2%, p=0.78), in-stent restenosis rate (2.6 % vs 5.2%, p=0.65). There are small increasing of late loss in high pressure group, but no statistically significant difference (0.30 vs 0.15, p=0.05). Conclusion: Implantation of SES overdilated with high pressure is able to be performed safely to obtain wider inner lumen of stents.

Studies on Injection and Mixture Characteristics of High Pressure H₂ and O₂ under Ar atmosphere

( Deng Jun ),( Gong Xuehai ),( Gong Yinchun ),( Li Liguang ) 한국액체미립화학회 2017 한국액체미립화학회 학술강연회 논문집 Vol.2017 No.-

Facing with the hydrogen energy era in future, the development of high-efficiency and zero-emissions of power system is a worldwide problem and challenge. As a potential way to achieve high-efficiency and zero-emissions, the main idea of argon cycled engine concept is to use hydrogen as fuel and pure oxygen as oxidant in the combustion cycle of traditional internal combustion engine, and use Ar (with the specific heat ratio of up to 1.67) as intake charge instead of N₂. Argon cycled engine can substantially increase the theoretical thermal efficiency of traditional combustion engine and meanwhile avoid NOx emissions problem. Since N₂ is replaced with Ar, the in-cylinder ambient density increases, which makes the in-cylinder mixture process of the direct injected gas an outstanding problem. In this paper, studies on penetration length, cone angle, entrainment rate, under-expanded region and other characteristics of H₂ and O₂ injection into the Ar environment were conducted based on experimental method. Based on the high background pressure constant volume chamber and the high-speed camera system, the shape of gas jets under different conditions was studied by shadowing method. Maximum injection pressure is 10MPa. Maximum environment pressure is 1.2MPa.The experimental results show that increase of the injection pressure or the decrease of the environmental pressure leads to significant increases of the gas penetration length. Jet penetration length of O₂ is slightly lower than H₂ by 0-6%. The cone angle of the gas jet increases slightly with the increase of the injection pressure and the ambient pressure. Under all the experimental pressure boundary conditions, the H₂ jet cone angles are between 32 ° and 38 ° and the cone angles of the O₂ jet are between 22 ° and 28 °; The entrainment rate of the gas jet increases with increment of the injection pressure, the ambient pressure and the injection duration. Jet entrainment rate of O₂ is 2.43 to 2.98 times higher than H₂ jet.