• Title/Summary/Keyword: pressure management

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Investigating the Partial Substitution of Chicken Feather for Wood Fiber in the Production of Wood-based Fiberboard (목질 섬유판 제조에 있어 도계부산물인 닭털의 목섬유 부분적 대체화 탐색)

  • Yang, In;Park, Dae-Hak;Choi, Won-Sil;Oh, Sei Chang;Ahn, Dong-uk;Han, Gyu-Seong;Oh, Seung Won
    • Korean Chemical Engineering Research
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    • v.56 no.4
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    • pp.577-584
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    • 2018
  • This study was conducted to investigate the potential of chicken feather (CF), which is a by-product in poultry industry, as a partial substitute of wood fiber in the production of wood-based fiberboard. Keratin-type protein constituted the majority of CF, and its appearance did not differ from that of wood fiber. When the formaldehyde (HCHO) adsorptivities of CF compared by its pretreatment type, feather meal (FM), which was pretreated CF with high temperature and pressure and then grounded, showed the highest HCHO adsorptivity. In addition, there was no difference between the adsorbed HCHO amounts, which was measured by dinitrophenylhydrazine method, of scissors-chopped CF and CF beated with an electrical blender. Mechanical properties and HCHO emission of medium-density fiberboards (MDF), which were fabricated with wood fiber and 5 wt% CF, beated CF or FM based on the oven-dried weight of wood fiber, were not influenced by the pretreatment type of CF. However, when the values compared with those of MDF made with just wood fiber, thickness swelling and HCHO emission of the MDF were improved greatly with the addition of CF, beated CF or FM. Based on the results, it might be possible to produce MDF with improved dimensional stability and low HCHO emission if CF, beated CF or FM is added partially as a substitute of wood fiber in the manufacturing process of MDF produced with the conventional urea-formaldehyde resin of $E_1$ grade. However, the use of CF or FM in the production of MDF has a low economic feasibility at the current situation due to the securing difficulty and high cost of CF. In order to enhance the economic feasibility, it requires to use CF produced at small to medium-sized chicken meat plants. More importantly, it is considered that the technology developed from this research has a great potential to make provision for the prohibition of animal-based feed and to dispose environmentally avian influenza-infected poultry.

The Macroeconomic Impacts of Korean Elections and Their Future Consequences (선거(選擧)의 거시경제적(巨視經濟的) 충격(衝擊)과 파급효과(波及效果))

  • Shim, Sang-dal;Lee, Hang-yong
    • KDI Journal of Economic Policy
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    • v.14 no.1
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    • pp.147-165
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    • 1992
  • This paper analyzes the macroeconomic effects of elections on the Korean economy and their future ramifications. It measures the shocks to the Korean economy caused by elections by taking the average of sample forecast errors from four major elections held in the 1980s. The seven variables' Bayesian Vector Autoregression Model which includes the Monetary Base, Industrial Production, Consumption, Consumer Price, Exports, and Investment is based on the quarterly time series data starting from 1970 and is updated every quarter before forecasts are made for the next quarter. Because of this updating of coefficients, which reflects in part the rapid structural changes of the Korean economy, this study can capture the shock effect of elections, which is not possible when using election dummies with a fixed coefficient model. In past elections, especially the elections held in the 1980s, $M_2$ did not show any particular movement, but the currency and base money increased during the quarter of the election was held and the increment was partly recalled in the next quarter. The liquidity of interest rates as measured by corporate bond yields fell during the quarter the election and then rose in the following quarter, which is somewhat contrary to the general concern that interest rates will increase during election periods. Manufacturing employment fell in the quarter of the election because workers turned into campaigners. This decline in employment combined with voting holiday produce a sizeable decline in industrial production during the quarter in which elections are held, but production catches up in the next quarter and sometimes more than offsets the disruption caused during the election quarter. The major shocks to price occur in the previous quarter, reflecting the expectational effect and the relaxation of government price control before the election when we simulate the impulse responses of the VAR model, imposing the same shocks that was measured in the past elections for each election to be held in 1992 and assuming that the elections in 1992 will affect the economy in the same manner as in the 1980s elections, 1992 is expected to see a sizeable increase in monetary base due to election and prices increase pressure will be amplified substantially. On the other hand, the consumption increase due to election is expected to be relatively small and the production will not decrease. Despite increased liquidity, a large portion of liquidity in circulation being used as election funds will distort the flow of funds and aggravate the fund shortage causing investments in plant and equipment and construction activities to stagnate. These effects will be greatly amplified if elections for the head of local government are going to be held this year. If mayoral and gubernatorial elections are held after National Assembly elections, their effect on prices and investment will be approximately double what they normally will have been have only congressional and presidential elections been held. Even when mayoral and gubernatorial elections are held at the same time as congressional elections, the elections of local government heads are shown to add substantial effects to the economy for the year. The above results are based on the assumption that this year's elections will shock the economy in the same manner as in past elections. However, elections in consecutive quarters do not give the economy a chance to pause and recuperate from past elections. This year's elections may have greater effects on prices and production than shown in the model's simulations because campaigners' return to industry may be delayed. Therefore, we may not see a rapid recall of money after elections. In view of the surge in the monetary base and price escalation in the periods before and after elections, economic management in 1992 should place its first priority on controlling the monetary aggregate, in particular, stabilizing the growth of the monetary base.

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Seasonal Variations of Evapotranspiration Observed in a Mixed forest in the Seolmacheon Catchment (설마천 유역의 혼효림에서 관측된 증발산의 계절변화)

  • Kwon, Hyo-Jung;Lee, Jung-Hoon;Lee, Yeon-Kil;Lee, Jin-Won;Jung, Sung-Won;Kim, Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.11 no.1
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    • pp.39-47
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    • 2009
  • The importance of securing water resources and their efficient management has attracted more attention recently due to water deficit. In water budget analysis, however, evapotranspiration(${\lambda}E$) has been approximated as the residual in the water balance equation or estimated from empirical equations and assumptions. To minimize the uncertainties in these estimates, it is necessary to directly measure ${\lambda}E$. In this study, using the eddy covariance technique, we have measured ${\lambda}E$ in a mixed forest in the Seolmacheon catchment in Korea from September 2007 to December 2008. During the growing season(May-July), ${\lambda}E$ in this mixed forest averaged about $2.2\;mm\;d^{-1}$, whereas it was on average $0.5\;mm\;d^{-1}$ during the non-growing season in winter. The annual total ${\lambda}E$ in 2008 was $581\;mm\;y^{-1}$, which is about 1/3 of the annual precipitation of 1997 mm. Despite the differences in the amount and frequency of precipitation, the accumulated ${\lambda}E$ during the overlapping period(i.e., September to December) for 2007 and 2008 was both ${\sim}110$ mm, showing virtually no difference. The omega factor, which is a measure of decoupling between forest and the atmosphere, was on average 0.5, indicating that the contributions of equilibrium ${\lambda}E$ and imposed ${\lambda}E$ to the total ${\lambda}E$ were about the same. The results suggest that ${\lambda}E$ in this mixed forest was controlled by various factors such as net radiation, vapor pressure deficit, and canopy conductance. In this study, based on the direct measurements of ${\lambda}E$, we have quantified the relative contribution of ${\lambda}E$ in the water balance of a mixed forest in the Seolmacheon catchment. In combination with runoff data, the information on ${\lambda}E$ would greatly enhance the reliability of water budget analysis in this catchment.

Elevated C-reactive Protein Levels are a Sign of Pulmonary Arterial Hypertension in AECOPD (만성 폐쇄성 폐질환 급성 악화 시 C-반응단백과 폐동맥 고혈압의 관계)

  • Kim, So Ri;Choe, Yeong Hun;Lee, Ka Young;Min, Kyung Hoon;Park, Seoung Ju;Lee, Heung Bum;Lee, Yong Chul;Rhee, Yang Keun
    • Tuberculosis and Respiratory Diseases
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    • v.64 no.2
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    • pp.125-132
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    • 2008
  • Background: In chronic obstructive pulmonary disease (COPD) patients, the serum levels of C-reactive protein (CRP) are elevated and an increase of CRP is more exaggerated in the acute exacerbation form of COPD (AECOPD) than in stable COPD. Pulmonary arterial hypertension is a common complication of COPD. An increased level of CRP is known to be associated with the risk of systemic cardio-vascular disorders. However, few findings are available on the potential role of CRP in pulmonary arterial hypertension due to COPD. Methods: This study was performed prospectively and the study population was composed of 72 patients that were hospitalized due to AECOPD. After receiving acute management for AECOPD, serum CRP levels were evaluated, arterial oxygen pressure ($PaO_2$), was measured, and the existence of pulmonary arterial hypertension under room air inhalation was determined in the patients. Results: The number of patients with pulmonary arterial hypertension was 47 (65.3%)., There was an increased prevalence of pulmonary arterial hypertension and an increase of serum CRP levels in patients with the higher stages of COPD (e.g., patients with stage 3 and stage 4 disease; P<0.05). The mean serum CRP levels of patients with pulmonary arterial hypertension and without pulmonary arterial hypertension were $37.6{\pm}7.4mg/L$ and $19.9{\pm}6.6mg/L$, respectively (P<0.05). However, there was no significant difference of the mean values of $PaO_2$ between patients with pulmonary arterial hypertension and without pulmonary arterial hypertension statistically ($77.8{\pm}3.6mmHg$ versus $87.2{\pm}6.0mmHg). Conclusion: We conclude that higher serum levels of CRP can be a sign for pulmonary arterial hypertension in AECOPD patients.

Effect of Weight Control Program on Obesity Degree and Blood Lipid Levels among Middle-aged Obese Women (중년여성대상 체중조절 프로그램이 체구성 및 혈액지질 개선에 미치는 영향)

  • Nam Jung-He
    • The Korean Journal of Food And Nutrition
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    • v.19 no.1
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    • pp.70-78
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    • 2006
  • This study was performed to investigate the effect of 12-week weight control program including nutrition education, diet therapy and regular exercise on body weight, obesity degree, BMI and blood lipid levels among middle aged obese women. The 31 middle aged obese women participated in the weight control program for 12-week. The body weight, body composition, blood lipid levels and food habit were measured before and after the weight control program. Changes in body weight after 12 week weight control program showed the slight reduction from $67.4{\pm}10.8kg\;to\;65.1{\pm}9.2kg$. Obesity degree and BMI were decreased from $128.4{\pm}19.1%,\;27.8{\pm}3.9\;to\;123.4{\pm}15.7%,\;26.8{\pm}3.0$, respectively. Waist-hip ratio was also decreased from $0.98{\pm}10.16\;to\;0.94{\pm}0.04$. LBM was also slightly reduced from $39.9{\pm}5.6kg\;to\;37.0{\pm}8.5kg$ with the reduction of body fat. The levels of systolic blood pressure, total cholesterol and triglyceride were slightly decreased, HDL-chol level was significantly increased from $43.1{\pm}14.1mg/dL\;to\;50.4{\pm}16.5mg/dL$. Waist-hip ratio was also slightly decreased after 12 weeks. Food habit score was significantly increased after nutriton education and personal counseling about their eating behaviors and nutritional status.

A Study on the Analysis of Functional Components and Antioxidative Activity in Mulberry (Morus alba) Silage (뽕나무(Morus alba) 사일리지의 기능성 성분 및 항산화 활성 분석에 관한 연구)

  • Jeon, Byong-Tae;Kim, Yeong-Kyu;Lee, Sang-Moo;Park, Jae-Hyun;Sung, Si-Heung;Park, Pyo-Jam;Kim, Sung-Jin;Moon, Sang-Ho
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.29 no.3
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    • pp.263-268
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    • 2009
  • This study was conducted to determine application possibility of mulberry (Morus alba) silage as a functional feed in feeding management of Korean native cattle for high quality beef production by analysing active components and antioxidative activity. The chemical analysis of mulberry silage indicates that the content of dry matter, crude protein, ether extract, crude fiber and crude ash was $28.41{\pm}3.12%,\;12.43{\pm}0.28%,\;2.47{\pm}0.18%,\;20.29{\pm}0.75%\;and\;6.98{\pm}0.12%$, respectively. The content of 1-deoxynojirimycin (1-DNJ), which is representative active ingredient of mulberry and blood sugar descending component, was 0.568 mg/g and the content of $\gamma$-Aminobutyric acid (GABA), which is blood pressure descending component, was 5,936.22 pmol. Mulberry silage used in this study did not contain flavonoids but did contain total phenols for 21.69 ${\mu}g/mg$. 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was increased with increasing the concentration of mulberry silage extracts and there was above 50% of scavenging activity at the concentration of 0.25 mg/ml. Hydroxyl radical scavenging activity was also increased with increasing the concentration of silage extracts. Alkyl radical scavenging activity was high at the low concentration of silage extracts, which was above 50% of scavenging activity at the concentration of 0.125 mg/ml. The result of this study indicated that there was high possibility of mulberry silage as a functional feed for beef cattle.

A Study on the Factors that Determine the Initial Success of Start-Up (스타트업의 초기 성공을 결정하는 요인에 관한 연구)

  • Lee, Hyun Ho;Yun, Hwangbo;Gong, Chang-Hoon
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.12 no.1
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    • pp.1-13
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    • 2017
  • The purpose of this study is to find out which factors determine the success of start-up in the initial market and what are the most important determinants. For the empirical analysis, the questionnaire related to the analysis of success factors for start-up success was designed according to the quantitative analysis (AHP technique). First, we selected 8 representative success factors for successful start-up in the initial market. In order to determine the degree of priority among these factors, we surveyed 12 entrepreneurs who are interested in entrepreneurship, universities, research institutes, and public officials. As a result of the empirical analysis, 51% of the funds in the tier 1 were ranked as the top priority to determine success factors. Followed by research and development (32.5%), management (8.7%) and marketing (7.8%). In particular, when each of the four items is calculated as 100 according to the result of the tier 1, and the tier 2 is converted, the foreign investment is analyzed as 43.7%. It was followed by 15.14% of R & D facilities, 14.07% of ideas, 8.7% of managerial ability, 7.29% of domestic investment, 5.85% of buyer feedback, 3.3% of development strategy and 1.95% of marketing strategy. Among the eight success factors, overseas investment items showed the closest preference to half, and it was the most important variable that determines the success or failure of market entry. The implication of this study is that many start-ups in Korea expect to receive investment and support from overseas accelerators. This means that overseas investment itself has been recognized as a start-up that makes services and products that can be used in the global market. A high preference for attracting foreign investment is due to the fact that the amount of investment is larger than that of Korea and that it can flexibly cope with the pressure on the performance compared to domestic investors. In this study, it was meaningful that we could confirm this fact through questionnaires of start-up experts. In future research, we need to find a viable alternative through studying how to provide start-up to foreign direct investment at the national level.

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Pulmonary Thromboendarterectomy for Pulmonary Hypertension Caused by Chronic Pulmonary Thromboembolism (만성폐색전중으로 인한 폐동맥고혈압 환자에서 시행한 폐동맥내막절제술)

  • Song Seung-Hwan;Jun Tae-Gook;Lee Young-Tak;Sung Ki-Ick;Yang Ji-Hyuk;Choi Jin-Ho;Kim Jin-Sun;Kim Ho-Joong;Park Pyo-Won
    • Journal of Chest Surgery
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    • v.39 no.8 s.265
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    • pp.626-632
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    • 2006
  • Background: Pulmonary hypertension caused by chronic pulmonary embolism is underrecognized and carries a poor prognosis. Medical therapy is generally unsatisfactory and palliative. With the improvement of operative technique and postoperative management, pulmonary endarterectomy has been the treatment of choice for this condition. Material and Method: Between January 2001 and December 2005, eleven patients were received pulmonary endarterectomy. All patients had chronic dyspnea and exercise intolerance. Diagnosis was made with cardiac echocardiography, lung perfusion scan and computed tomography. Before the operation, Greenfield vena cava filter were placed in all patient except one. Deep hypothermic circulatory arrest was used for the distal-most portion of the endarterectomy procedure. More than moderate degree of tricuspid reguirgitation was repaired during operation. Result: There was no early and late death. Right ventricular systolic pressure was reduced significantly after operation from $91{\pm}21$ mmHg to $40{\pm}17$ mmHg on echocardiography (p=0.001). NYHA class and tricuspid reguirgitaion were improved postoperatively. Although mild reperfusion injury in three case and postoperative delirium in one case were observed, all of them recovered without complication. Conclusion: Pulmonary thromboendarterctomy offers to patient an acceptable morbidity rate and anticipation of clinical improvement. This method is safe and effective operation for pulmonary hypertension caused by chronic pulmonary thromboembolism.

Kinetics of the Reaction of Carbon Dioxide with AMP and Piperazine (AMP에 Piperazine을 첨가한 CO2 흡수 동역학)

  • Jang, Sang-Yong;Song, Ju-Seouk;Cho, Sang-Won;Oh, Kwang-Joong
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.3
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    • pp.485-494
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    • 2000
  • According to the worldwide interest in controlling $CO_2$ which contributes to green house effect. new techniques of reducing $CO_2$ are under development. We have developed new technique for reducing $CO_2$. In low $CO_2$ concentration. the chemical absorption method is useful. In this study. the kinetics of the reaction between $CO_2$ and the sterically hindered amine solution with piperazine. have been investigated from measurements of the rate of absorption of $CO_2$ in the stirred vessel that has a horizontal liquid-gas interface, in the temperature range $30{\sim}70^{\circ}C$. The experiments were carried out in the range 10.130~20.260 kPa of partial pressure of $CO_2$, and in aqueous $2.0kmol/m^3$ AMP solution with $0{\sim}0.4kmol/m^3$ piperazine The experimental results are as follows: 1) The absorption rate of $CO_2$ into aqueous AMP + piperazine solution is gett ng faster than that of aqueous AMP absorbents with temperature. Because the activation energy of piperazine 57.147 kJ/mol is higher than that of AMP 41.7kJ/mol. therefore the effect of piperazine on absorption rate increases with temperature. 2) Compared with aqueous AMP solution. the absorption rate of $CO_2$ into AMP + piperazine solution increases from 6.33% at $30^{\circ}C$ to 12% at $70^{\circ}C$, so AMP + piperazine solution is thought to be a better than AMP solution, 3) The reaction rate constants of piprazine in aqueous AMP solution with $CO_2$ have been determined as 217.21, 420.46, 707.00 and $3162.167m^3/kmol{\cdot}s$ respectively at 30, 40, 50 and $70^{\circ}C$ but these results are higher than those of Xu which were 186.7. 367.32. 693.01. $2207.65m^3/kmol{\cdot}s$ at 30, 40, 55, $70^{\circ}C$in aqueous MDEA solution. So the regression analysis of the data has led to the following equation In $k_p$ =28.324-6934.7/T.

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A Study on Nutrient Intakes and Blood Parameters of Adult Men and Women with Metabolic Syndrome (대사증후군을 가진 성인남녀의 영양소 섭취상태와 혈액성상에 관한 연구)

  • Choi, Mi-Kyeong;Jun, Ye-Sook;Bae, Yun-Jung;Sung, Chung-Ja
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.3
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    • pp.311-317
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    • 2007
  • The purpose of this study is to evaluate the nutrient intake and selected blood parameters of adults with metabolic syndrome (MS) and to provide data in forming a dietary guideline for the prevention of chronic diseases. Subjects were recruited and divided into two groups according to the NCEP-ATP III criteria and WHO Asia-Pacific Area criteria for obesity. MS group was defined as subjects who have three or more risk factors and control group was defined as those with two or less of the risk factors. The average age, height, weight, body mass index (BMI) were 58.8 years, 158.0 cm, 66.3 kg, $26.5\;kg/m^{2}$, respectively, in the MS group; and 58.4 years, 158.9 cm, 59.6 kg, $23.5\;kg/m^{2}$, respectively, in the control group. The weight and BMI in the MS group were significantly higher than those in the control (p<0.001). There was no significant difference in the food and nutrient intake between the MS and control group. Male subjects in the MS group showed significantly higher intake of mushrooms than those in the control (p<0.05). Egg consumption in the MS group was significantly lower than those in the control (p<0.01). Consumption of vegetables and fiber was significantly lower for female subjects in the MS group than those in the control (p<0.05). Serum GPT, AI and WBC count in the MS group (27.8 IU/L, 3.7, $5964.2\;{\mu}/L$) were significantly higher than those in the control (22.6 IU/L, 3.2, $5250.0\;{\mu}/L$; p<0.01, p<0.001, p<0.01). In conclusion, consuming fiber and vegetables may prevent and reduce metabolic syndrome in adult men and women, and this study demonstrates the need for proper dietary management for them.