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Clinical Characteristics and Adherence of Patients Who Were Prescribed Home Oxygen Therapy Due to Chronic Respiratory Failure in One University Hospital: Survey after National Health Insurance Coverage (한 대학병원에서 조사된 재택산소요법을 받고 있는 환자의 특성과 재택산소요법 처방에 대한 순응도: 건강보험급여전환 후 조사)

  • Koo, Ho-Seok;Song, Young Jin;Lee, Seung Heon;Lee, Young Min;Kim, Hyun Gook;Park, I-Nae;Jung, Hoon;Choi, Sang Bong;Lee, Sung-Soon;Hur, Jin-Won;Lee, Hyuk Pyo;Yum, Ho-Kee;Choi, Soo Jeon;Lee, Hyun-Kyung
    • Tuberculosis and Respiratory Diseases
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    • v.66 no.3
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    • pp.192-197
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    • 2009
  • Background: Despite the benefits of home oxygen therapy in patients suffering chronic respiratory failure, previous reports in Korea revealed lower compliance to oxygen therapy and a shorter time for oxygen use than expected. However, these papers were published before oxygen therapy was covered by the national insurance system. Therefore, this study examined whether there were some changes in compliance, using time and other clinical features of home oxygen therapy after insurance coverage. Methods: This study reviewed the medical records of patients prescribed home oxygen therapy in our hospital from November 1, 2006 to September 31, 2008. The patients were interviewed either in person or by telephone to obtain information related to oxygen therapy. Results: During study period, a total 105 patients started home oxygen therapy. The mean age was 69 and 60 (57%) were male. The mean oxygen partial pressure in the arterial blood was 54.5 mmHg and oxygen saturation was 86.3%. Primary diseases that caused hypoxemia were COPD (n=64), lung cancer (n=14), Tb destroyed lung (n=12) and others. After oxygen therapy, more than 50% of patients experienced relief of their subjective dyspnea. The mean daily use of oxygen was 9.8${\pm}$7.3 hours and oxygen was not used during activity outside of their home (mean time, 5.4${\pm}$3.7 hours). Twenty four patients (36%) stopped using oxygen voluntarily 7${\pm}$4.7 months after being prescribed oxygen and showed a less severe pulmonary and right heart function. The causes of stopping were subjective symptom relief (n=11), inconvenience (n=6) and others (7). Conclusion: The prescription of home oxygen has increased since national insurance started to cover home oxygen therapy. However, the mean time for using oxygen is still shorter than expected. During activity of outside their home, patients could not use oxygen due to the absence of portable oxygen. Overall, continuous education to change the misunderstandings about oxygen therapy, more economic support from national insurance and coverage for portable oxygen are needed to extend the oxygen use time and maintain oxygen usage.

Status of Tuberculosis Control in Rural Area (일부 농촌지역 결핵환자들의 관리 양상)

  • Park, Chan-Byoung;Chun, Byung-Yeol;Yeh, Min-Hae
    • Journal of agricultural medicine and community health
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    • v.18 no.2
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    • pp.141-151
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    • 1993
  • This study was done about 371 tuberculosis(TB) patients composed 195 newly registered at Kyungju Gun Health Center from May 1989 to April 1990 (Group A) and 176 being treated at hospitals or private clinics from January 1988 to November 1989(Group B). When Group A patients visited and newly registered at Health Center, data was obtained by interviewing with a prepared questionnaire paper. And well trained inquirer visited Group B patients and obtained data by the same method from February 1990 to April 1990. The results are as follows ; Group A was generally lower than Group B in socioeconomic status and in family history of TB, the rate of Group A was 24.1% and higher than 11.9% in Group B(p<0.05). Knowledge about TB was improved more than past, but those who answered that TB is 'a communicable disease' were 59.5% in Group A and 51.7% in Group B(p<0.05). Those answered that TB is 'a inherited disease' were 9.2% and 11.4% each. And 1.7% of Group B answered that TB is 'a incurable disease'. Knowledge about TB treatment also was improved more than past, but in the rate of those who answered that TB is a curable disease provided by well treatment Group B(77.8%) was worse than Group A(91.3%). The rate of those who answered that TB were been able to cure by regularly anti-TB medication were 98.0% in Group A and 89.8% in Group B. Its difference was statistically significant. The rate that patients took the first diagnosis and wanted to receive treatments at the same organ were 34.9% of Group A at Health Center and 72.2% of Group B at hospitals or private clinics. And its difference was statistically significant. In the reasons that Group B knew Health Center treated pulmonary TB but they was treated at hospitals or private clinics, unreliability to Health Center was 48.1%. The reasons that Group A was treated at Health Center were 'because of trust' 63.1%, 'because of low cost' 50.3%, 'because of low cost except trust' 9.3%, 'no specific reasons' 27.7%. In the courses of knowing that TB was controlled at Health Center, 'by neighborhood, health worker and doctors' were 84.9% in Group A and 69.0% in Group B. But 'by TV or radio' were 8.2% in Group A and 14.7% in Group B, 'by school education' 2.5% in Group A and 6.2% in Group B. Conclusively, Group A patients were lower than Group B in socioeconomic status, but better than in knowledge about TB. Its reasons was suggested that Health Center had controlled TB patients better than hospitals and private clinics. But considering, that difference in the rate of the same organ for the first diagnosis and treatment, that the only 63.0% of Group A have treated due to 'reliability to Health Center', and that 48.1% of Group B knew that Health Center treated pulmonary TB but didn't visit it due to 'unreliability to Health Center', that public relations(PR) about use Health Center for pulmonary TB and health education for TB was thought to have to strengthened.

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A study on the gratification of the patient in the Dental Hospital (치과병원 내원환자의 만족도 조사분석)

  • Kim, Min-Young;Lee, Keun-Woo;Moon, Hong-Suk;Chung, Moon-Kyu
    • The Journal of Korean Academy of Prosthodontics
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    • v.46 no.1
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    • pp.65-82
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    • 2008
  • Statement of problem : Today's market economy has been changed more and more to consumer concerned. It is owing to not only consumers ' rising standard of living and education, but also purchasers' easy accessibilities to products through various mass media. The consumer centered market system, where customer can choose items with diverse alternatives to satisfy their self esteem, is also applied to the field of medical business, and accelerated by an increasing income level of shoppers and introducing the whole nations' medical insurance system. Today, the medical industry has become competitive due to increasing number of medical institutions and medical personnel, and this offers wide choices to consumers in the medical market place. At this point of time, it is essential to survey on the primary factor of gratification for the patient in the Dental clinic, as well as on the problems and suggestions in medical service. Purpose : The analysis in this study shows essential factors and expected influential elements in satisfaction of the patient in the Dental Hopsital, and strategic suggestions for the provider of dental service, which can be of benefit to the prospective customer as well as can make improvement in the quality of dental treatment service. Material and method : This study had been researched by collecting and analyzing the organized questionnaires, which were filled in directly from 784 patients, who visit Dental Hospital, Yonsei University in Seoul, from January 23rd to April 15th. Result : It can be summarized like the followings. 1. The social and demographical peculiarities of respondents are as follows. Samples of gender and marital status are adequately extracted, but data on occupation and treatment are are under a bias toward students, undergraduates and graduate students, and orthodontics. 2. 74% of patients who answer the questionnaire were highly satisfied with the service of dental clinic in the section of overall satisfaction. 3. The survey result about specific service of dental treatment, within sections of independent variables, is like the followings; Patients are highly gratified with service system, kindness, explanation, explanation on expected waiting hours, reservation system, emergency measures, expert treatment, existence of knowledge of dentistry, size of hospital, disinfection, equipment and parking, but lowly satisfied with expense of treatment, preparatory hours for treatment, waiting hours, treatment hours and the period of subscription. 4. The correlation analysis showed that there is no significant linear relationship between the independent variables. 5. The probit regression analysis showed that 8 out of 34 independent variables explained the dependent variables at the level of 0.01. 6. It shows that 8 independent variables, which can affect customers 'satisfaction, are clearing up of inconvenience, service system, kindness, explanation, treatment hours per attendance, reservation system, existence of knowledge of dentistry, and contentment of equipment in the hospital. Conclusion : The consumer's satisfaction totally relies on subjective evaluations of customers. Providing appropriate service, which can meet the criteria for the customer who demands various wares, pursues luxury goods, and expects high quality of medical service, is essential to fulfill patients' satisfaction. Many medical institutions do their best to satisfy their customer, touch their consumer, and offer patience centered services, and it is also applied to the field of dentistry. Establishing brand new strategic managements and elevating the quality of dental service based on this survey are required to improve the satisfaction of patience in the Dental Hospital.

The Characteristics of REM Sleep-Dependent Obstructive Sleep Apnea and NREM Sleep-Dependent Obstructive Sleep Apnea (렘수면 의존성 수면무호흡증과 비렘수면 의존성 수면무호흡증의 특징)

  • Seo, Min Cheol;Choi, Jae-Won;Joo, Eun-Jeoung;Lee, Kyu Young;Bhang, Soo-Young;Kim, Eui-Joong
    • Sleep Medicine and Psychophysiology
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    • v.24 no.2
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    • pp.106-117
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    • 2017
  • Objectives: Obstructive sleep apnea (OSA) is a sleep-related breathing disorder that is characterized by repetitive collapse or partial collapse of the upper airway during sleep in spite of ongoing effort to breathe. It is believed that OSA is usually worsened in REM sleep, because muscle tone is suppressed during REM sleep. However, many cases showed a higher apnea-hypopnea index (AHI) during NREM sleep than during REM sleep. We aimed here to determine the characteristics of REM sleep-dependent OSA (REM-OSA) and NREM sleep-dependent OSA (NREM-OSA). Methods: Five hundred sixty polysomnographically confirmed adult OSA subjects were studied retrospectively. All patients were classified into 3 groups based on the ratio between REM-AHI and NREM-AHI. REM-OSA was defined as REM-AHI/NREM-AHI > 2, NREM-OSA as NREM-AHI/REM-AHI > 2, and the rest as sleep stage-independent OSA (IND-OSA). In addition to polysomnography, questionnaires related to subjective sleep quality, daytime sleepiness, and emotion were completed. Chi-square test, ANOVA, and ANCOVA were performed. Results: There was no age difference among subgroups. The REM-OSA group was comprised of large proportions of mild OSA and female OSA patients. These patients experienced poor sleep and more negative emotions than other two groups. The AHI and oxygen desaturation index (ODI) were lowest in REM-OSA. Sleep efficiency and N3 percentage of REM-OSA were higher than in NREM-OSA. The percentage of patients who slept in a supine position was higher in REM-OSA than other subgroups. IND-OSA showed higher BMI and larger neck circumference and abdominal circumference than REM-OSA. The patients with IND-OSA experienced more sleepiness than the other groups. AHI and ODI were highest in IND-OSA. NREM-OSA presented the shortest total sleep time and the lowest sleep efficiency. NREM-OSA showed shorter sleep latency and REM latency and higher percentage of N1 than those of REM-OSA and the highest proportion of those who slept in a lateral position than other subgroups. NREM-OSA revealed the highest composite score on the Horne and ${\ddot{O}}stberg$ questionnaire. With increased AHI severity, the numbers of apnea and hypopnea events during REM sleep decreased, and the numbers of apnea and hypopnea events during NREM sleep increased. The results of ANCOVA after controlling age, sex, BMI, NC, AC, and AHI showed the lowest sleep efficiency, the highest AHI in the supine position, and the highest percentage of waking after sleep onset in NREM-OSA. Conclusion: REM-OSA was associated with the mild form of OSA, female sex, and negative emotions. IND-OSA was associated with the severe form of OSA. NREM-OSA was most closely related to position and showed the lowest sleep efficiency. Sleep stage-dependent characteristics could provide better understanding of OSA.

Graves' Disease in Prepubertal Children Compared with Pubertal Children (소아 Graves병의 임상적 고찰 : 사춘기 이전군과 사춘기군의 비교)

  • Kim, Hyun Mi;Yoon, Ju Yun;Jung, Min Ho;Suh, Byung Kyu;Lee, Byung Churl
    • Clinical and Experimental Pediatrics
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    • v.46 no.1
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    • pp.76-82
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    • 2003
  • Purpose : The aim of this study was to determine whether differences exist in the presentation, clinical course, and outcome of Graves' disease between prepubertal children and adolescents. Methods : A retrospective chart review of 14 prepubertal(PREPUB, $7.2{\pm}0.9yr) and 38 pubertal (PUB, $12.4{\pm}1.5yr$) children with Graves' disease between January 1989 and November 1995 at St. Mary's Hospital and Kangnam St. Mary's Hospital was undertaken. Results : There were no significant differences in $T_3$, $T_4$, TSH between two the groups at diagnosis. The PUB group had significantly higher titers of antimicrosomal antibody(positive dilution factor $11,727.3{\pm}22,888.4$) than did the PREPUB group($2,111.5{\pm}2,285.0$, P<0.001). The PREPUB group had significantly higher titers of TSH-binding inhibitory immunoglobulin(TBII, $62.5{\pm}39.6$) than did the PUB group($44.9{\pm}10.4$, P<0.05) before treatment started. The duration(months) of medical therapy before thyroid function tests were normalized was longer in the PREPUB group than in the PUB group($T_3:6.8{\pm}5.0$ vs. $5.4{\pm}13.2$, $T_4:2.3{\pm}1.9$ vs. $2.1{\pm}2.2$, $TBII:26.7{\pm}24.0$ vs. $20.8{\pm}12.1$), especially that of TSH was significantly longer in the PREPUB group($14.6{\pm}11.0$ vs. $6.8{\pm}7.8$, P< 0.05). Total length of medical therapy was significantly longer in the PREPUB group than the PUB group($52.3{\pm}19.3$ vs. $37.9{\pm}16.3months$, P<0.01). During three years of antithyroid drug therapy, in the PREPUB group, the remission rate was lower and the relapse rate was higher than in the PUB group. Total length of treatment correlated negatively with chronological age(P=0.03). Conclusion : Prepubertal children require longer medical therapy to achieve a remission than do pubertal children. But there is an obvious need for more studies because of the small number of patients and the short duration of the follow-up.

Physicochemical Properties of Pearl Oyster Muscle and Adductor Muscle as Pearl Processing Byproducts (진주 가공부산물(육 및 패주)의 이화학적 특성)

  • Kim, Jin-Soo;Kim, Hye-Suk;Oh, Hyeun-Seok;Kang, Kyung-Tae;Han, Gang-Uk;Kim, In-Soo;Jeong, Bo-Young;Moon, Soo-Kyung;Heu, Min-Soo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.4
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    • pp.464-469
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    • 2006
  • This study was conducted to evaluate a knowledge on food components of muscle and adductor muscle of pearl oyster (Pinctada fucata martensii) as pearl processing byproducts. The concentrations of mercury and chromium as heavy metal were not detected in both pearl oyster muscle and adductor muscle, and those of cadmium and lead were 0.06 ppm and 0.11 ppm in only pearl oyster muscle, respectively. Thus, the heavy metal levels of pearl processing byproducts were below the reported safety limits. The volatile basic nitrogen (VBN) content and pH of pearl oyster muscle were 11.6 mg/100g and 6.31 and those of abductor muscle were 8.6 mg/100 g and 6.33, respectively. It was concluded that pearl oyster muscle and adductor muscle might not invoke health risk in using food resource. The contents of crude protein (16.5%) and total amino acid (15,691 mg/100 g) of adductor muscle were higher than those of muscle (11.2% and 10,131 mg/100 g) and oyster (12.1% and 11,213 mg/100 g) as a control. The contents of calcium and phosphorus were 95.4 mg/100 g and 116.0 mg/100 g in muscle, 75.2 mg/100g and 148.1 mg/100 g in adductor muscle, respectively. The calcium level based on phosphorus was a good ratio for absorbing calcium. The free amino acid contents and taste values were 635.5 mg/100 g and 40.2 in muscle, and 734.9 mg/100 g and 24.1 in adductor muscle, respectively, but that (882.8 mg/100 g and 40.2) of oyster was higher than those of pearl processing byproducts. Based on the results of physicochemical and nutritional properties, pearl oyster muscle and adductor muscle can be utilized as a food resource.

Clinical Analysis of Acute Respiratory Tract Infections by Influenza Virus in Children (인플루엔자 바이러스에 의한 소아 급성 호흡기 감염증의 유행 및 임상 양상)

  • Kwon, Min Kyoung;Kim, Mi Ran;Park, Eun Young;Lee, Kon Hee;Yoon, Hae Sun;Kim, Kwang Nam;Lee, Kyu Man
    • Clinical and Experimental Pediatrics
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    • v.45 no.12
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    • pp.1519-1527
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    • 2002
  • Purpose : Although influenza virus is one of the most important causes of acute respiratory tract infections(ARTIs) in children, virus isolation is not popular and there are only a few clinical studies on influenza in Korea. We evaluated the epidemiologic and clinical features of ARTIs by influenza virus in children. Methods : From February 1995 to August 2001, nasopharyngeal aspirations were obtained and cultured for the isolation of influenza virus in children admitted with ARTIs. The medical records of patients with influenza virus infection were reviewed retrospectively. Results : Respiratory viruses were isolated in 997(22.0%) out of 4,533 patients examined, and influenza virus was isolated in 164 cases(3.6%). Influenza virus was isolated year after year mainly from December to April of next year. The ratio of male and female was 1.9 : 1 with a median age of 15 months. The most common clinical diagnosis of influenza virus infection was pneumonia, and fever and cough developed in most patients. There was no difference between influenza A and B infection in clinical diagnoses and symptoms. All patients recovered without receiving antiviral treatment except for one patient diagnosed with pneumonia who had underlying disease of Down syndrome with ventricular septal defect. Conclusion : ARTIs caused by influenza virus developed every winter and spring during the period of study. Because fatal complication can develop in the high risk group, prevention, early diagnosis and proper management of influenza should be emphasized.

Motives for Writing After-Purchase Consumer Reviews in Online Stores and Classification of Online Store Shoppers (인터넷 점포에서의 구매후기 작성 동기 및 점포 고객 유형화)

  • Hong, Hee-Sook;Ryu, Sung-Min
    • Journal of Distribution Research
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    • v.17 no.3
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    • pp.25-57
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    • 2012
  • This study identified motives for writing apparel product reviews in online stores, and determined what motives increase the behavior of writing reviews. It also classified store customers based on the type of writing motives, and clarified the characteristics of internet purchase behavior and of a demographic profile. Data were collected from 252 females aged 20s' and 30s' who have experience of reading and writing reviews on online shopping. The five types of writing motives were altruistic information sharing, remedying of a grievance and vengeance, economic incentives, helping new product development, and the expression of satisfaction feelings. Among five motives, altruistic information sharing, economic incentives, and helping new product development stimulate writing reviews. Store customers who write reviews were classified into three groups based on their writing motive types: Other consumer advocates(29.8%), self-interested shoppers(40.5%) and shoppers with moderate motives(29.8%). There were significant differences among three groups in writing behavior (the frequency of writing reviews, writing intent of reviews, duration of writing reviews, and frequency of online shopping) and age. Based on results, managerial implications were suggested. Long Abstract : The purpose of present study is to identify the types of writing motives on online shopping, and to clarify the motives affecting the behavior of writing reviews. This study also classifies online shoppers based on the motive types, and identifies the characteristics of the classified groups in terms of writing behavior, frequency of online shopping, and demographics. Use and Gratification Theory was adopted in this study. Qualitative research (focus group interview) and quantitative research were used. Korean women(20 to 39 years old) who reported experience with purchasing clothing online, and reading and writing reviews were selected as samples(n=252). Most of the respondents were relatively young (20-34yrs., 86.1%,), single (61.1%), employed(61.1%) and residents living in big cities(50.9%). About 69.8% of respondents read and 40.5% write apparel reviews frequently or very frequently. 24.6% of the respondents indicated an "average" in their writing frequency. Based on the qualitative result of focus group interviews and previous studies on motives for online community activities, measurement items of motives for writing after-purchase reviews were developed. All items were used a five-point Likert scale with endpoints 1 (strongly disagree) and 5 (strongly agree). The degree of writing behavior was measured by items concerning experience of writing reviews, frequency of writing reviews, amount of writing reviews, and intention of writing reviews. A five-point scale(strongly disagree-strongly agree) was employed. SPSS 18.0 was used for exploratory factor analysis, K-means cluster analysis, one-way ANOVA(Scheffe test) and ${\chi}^2$-test. Confirmatory factor analysis and path model analysis were conducted by AMOS 18.0. By conducting principal components factor analysis (varimax rotation, extracting factors with eigenvalues above 1.0) on the measurement items, five factors were identified: Altruistic information sharing, remedying of a grievance and vengeance, economic incentives, helping new product development, and expression of satisfaction feelings(see Table 1). The measurement model including these final items was analyzed by confirmatory factor analysis. The measurement model had good fit indices(GFI=.918, AGFI=.884, RMR=.070, RMSEA=.054, TLI=.941) except for the probability value associated with the ${\chi}^2$ test(${\chi}^2$=189.078, df=109, p=.00). Convergent validities of all variables were confirmed using composite reliability. All SMC values were found to be lower than AVEs confirming discriminant validity. The path model's goodness-of-fit was greater than the recommended limits based on several indices(GFI=.905, AGFI=.872, RMR=.070, RMSEA=.052, TLI=.935; ${\chi}^2$=260.433, df=155, p=.00). Table 2 shows that motives of altruistic information sharing, economic incentives and helping new product development significantly increased the degree of writing product reviews of online shopping. In particular, the effect of altruistic information sharing and pursuit of economic incentives on the behavior of writing reviews were larger than the effect of helping new product development. As shown in table 3, online store shoppers were classified into three groups: Other consumer advocates (29.8%), self-interested shoppers (40.5%), and moderate shoppers (29.8%). There were significant differences among the three groups in the degree of writing reviews (experience of writing reviews, frequency of writing reviews, amount of writing reviews, intention of writing reviews, and duration of writing reviews, frequency of online shopping) and age. For five aspects of writing behavior, the group of other consumer advocates who is mainly comprised of 20s had higher scores than the other two groups. There were not any significant differences between self-interested group and moderate group regarding writing behavior and demographics.

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Difference in Chemical Composition of PM2.5 and Investigation of its Causing Factors between 2013 and 2015 in Air Pollution Intensive Monitoring Stations (대기오염집중측정소별 2013~2015년 사이의 PM2.5 화학적 특성 차이 및 유발인자 조사)

  • Yu, Geun Hye;Park, Seung Shik;Ghim, Young Sung;Shin, Hye Jung;Lim, Cheol Soo;Ban, Soo Jin;Yu, Jeong Ah;Kang, Hyun Jung;Seo, Young Kyo;Kang, Kyeong Sik;Jo, Mi Ra;Jung, Sun A;Lee, Min Hee;Hwang, Tae Kyung;Kang, Byung Chul;Kim, Hyo Sun
    • Journal of Korean Society for Atmospheric Environment
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    • v.34 no.1
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    • pp.16-37
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    • 2018
  • In this study, difference in chemical composition of $PM_{2.5}$ observed between the year 2013 and 2015 at six air quality intensive monitoring stations (Bangryenogdo (BR), Seoul (SL), Daejeon (DJ), Gwangju (GJ), Ulsan (US), and Jeju (JJ)) was investigated and the possible factors causing their difference were also discussed. $PM_{2.5}$, organic and elemental carbon (OC and EC), and water-soluble ionic species concentrations were observed on a hourly basis in the six stations. The difference in chemical composition by regions was examined based on emissions of gaseous criteria pollutants (CO, $SO_2$, and $NO_2$), meteorological parameters (wind speed, temperature, and relative humidity), and origins and transport pathways of air masses. For the years 2013 and 2014, annual average $PM_{2.5}$ was in the order of SL ($${\sim_=}DJ$$)>GJ>BR>US>JJ, but the highest concentration in 2015 was found at DJ, following by GJ ($${\sim_=}SJ$$)>BR>US>JJ. Similar patterns were found in $SO{_4}^{2-}$, $NO_3{^-}$, and $NH_4{^+}$. Lower $PM_{2.5}$ at SL than at DJ and GJ was resulted from low concentrations of secondary ionic species. Annual average concentrations of OC and EC by regions had no big difference among the years, but their patterns were distinct from the $PM_{2.5}$, $SO{_4}^{2-}$, $NO_3{^-}$, and $NH_4{^+}$ concentrations by regions. 4-day air mass backward trajectory calculations indicated that in the event of daily average $PM_{2.5}$ exceeding the monthly average values, >70% of the air masses reaching the all stations were coming from northeastern Chinese polluted regions, indicating the long-range transportation (LTP) was an important contributor to $PM_{2.5}$ and its chemical composition at the stations. Lower concentrations of secondary ionic species and $PM_{2.5}$ at SL in 2015 than those at DJ and GJ sites were due to the decrease in impact by LTP from polluted Chinese regions, rather than the difference in local emissions of criteria gas pollutants ($SO_2$, $NO_2$, and $NH_3$) among the SL, DJ, and GJ sites. The difference in annual average $SO{_4}^{2-}$ by regions was resulted from combination of the difference in local $SO_2$ emissions and chemical conversion of $SO_2$ to $SO{_4}^{2-}$, and LTP from China. However, the $SO{_4}^{2-}$ at the sites were more influenced by LTP than the formation by chemical transformation of locally emitted $SO_2$. The $NO_3{^-}$ increase was closely associated with the increase in local emissions of nitrogen oxides at four urban sites except for the BR and JJ, as well as the LTP with a small contribution. Among the meterological parameters (wind speed, temperature, and relative humidity), the ambient temperature was most important factor to control the variation of $PM_{2.5}$ and its major chemical components concentrations. In other words, as the average temperature increases, the $PM_{2.5}$, OC, EC, and $NO_3{^-}$ concentrations showed a decreasing tendency, especially with a prominent feature in $NO_3{^-}$. Results from a case study that examined the $PM_{2.5}$ and its major chemical data observed between February 19 and March 2, 2014 at the all stations suggest that ambient $SO{_4}^{2-}$ and $NO_3{^-}$ concentrations are not necessarily proportional to the concentrations of their precursor emissions because the rates at which they form and their gas/particle partitioning may be controlled by factors (e.g., long range transportation) other than the concentration of the precursor gases.

Pilot-scale Applications of a Well-type Reactive Barrier using Autotrophic Sulfur-oxidizers for Nitrate Removal (독립영양 황탈질 미생물을 이용한 관정형 반응벽체의 현장적용성 연구)

  • Lee, Byung-Sun;Um, Jae-Yeon;Lee, Kyu-Yeon;Moon, Hee-Sun;Kim, Yang-Bin;Woo, Nam-C.;Lee, Jong-Min;Nam, Kyoung-Phile
    • Journal of Soil and Groundwater Environment
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    • v.14 no.3
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    • pp.40-46
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    • 2009
  • The applicability of a well-type autotrophic sulfur-oxidizing reactive barrier (L $\times$ W $\times$ D = $3m\;{\times}\;4\;m\;{\times}\;2\;m$) as a long-term treatment option for nitrate removal in groundwater was evaluated. Pilot-scale (L $\times$ W $\times$ D = $8m\;{\times}\;4\;m\;{\times}\;2\;m$) flow-tank experiments were conducted to examine remedial efficacy of the well-type reactive barrier. A total of 80 kg sulfur granules as an electron donor and Thiobacillus denitrificans as an active bacterial species were prepared. Thiobacillus denitrificans was successfully colonized on the surface of the sulfur granules and the microflora transformed nitrate with removal efficiency of ~12% (0.07 mM) for 11 days, ~24% (1.3 mM) for 18 days, ~45% (2.4 mM) for 32 days, and ~52% (2.8 mM) for 60 days. Sulfur granules attached to Thiobacillus denitrificans were used to construct the well-type reactive barrier comprising three discrete barriers installed at 1-m interval downstream. Average initial nitrate concentrations were 181 mg/L for the first 28 days and 281 mg/L for the next 14 days. For the 181 mg/L (2.9 mM) plume, nitrate concentrations decreased by ~2% (0.06 mM), ~9% (0.27 mM), and ~15% (0.44 mM) after $1^{st}$, $2^{nd}$, and $3^{rd}$ barriers, respectively. For the 281 mg/L (4.5 mM) plume, nitrate concentrations decreased by ~1% (0.02 mM), ~6% (0.27 mM), and ~8% (0.37 mM) after $1^{st}$, $2^{nd}$, and $3^{rd}$ barriers, respectively. Nitrate plume was flowed through the flow-tank for 49 days by supplying $1.24\;m^3/d$ of nitrate solution. During nitrate treatment, flow velocity (0.44 m/d), pH (6.7 to 8.3), and DO (0.9~2.8 mg/L) showed little variations. Incomplete destruction of nitrate plume was attributed to the lack of retention time, rarely transverse dispersion, and inhibiting the activity of denitrification enzymes caused by relatively high DO concentrations. For field applications, it should be considered increments of retention time, modification of well placements, and intrinsic DO concentration.