• Title/Summary/Keyword: PM from the atmosphere

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Factors Influencing Mental Health among Late School age Children (학령기 후기 아동의 정신건강과 영향요인)

  • Lee, Hyun-Ju;Kim, Hee-Kyung
    • The Journal of Korean Academic Society of Nursing Education
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    • v.18 no.1
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    • pp.149-158
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    • 2012
  • Purpose: The purpose of this study was to identify the factors influencing mental health among late elementary age children. Methods: The research design was a secondary data analysis. Data were collected from 746 students in grades 5 or 6, and analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients and stepwise multiple regression with the SPSS/PC 18.0 program. Results: The average score of mental health was $3.42{\pm}0.55$. There were significant differences in mental health according to health status, economic status, scholastic performance, relationships with friends, relationships with the teachers, atmosphere of the home, number of siblings and the source of trouble. Stepwise multiple regression analysis showed influencing factors of stress, negative reaction under stress, self-esteem, teacher support, and friend support support and explained 41.4% of total variance in late elementary age children's mental health. Conclusion: These results may contribute to a better understanding of mental health in late elementary age children. The results of the present study indicate a need to develop nursing interventions to prevent and manage elementary school-age children's negative reaction under stress.

Characterization of BST films for high tunable thin film capacitor

  • No, Ji-Hyeong;Song, Sang-U;Kim, Ji-Hong;Go, Jung-Hyeok;Mun, Byeong-Mu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.179-179
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    • 2009
  • This is for the electrical characterization by IDC pattern using BST$(Ba_{0.5}Sr_{0.5}TiO_3)$ thin film. BST materials had been chosen for high frequency applications due to it's high permitivity and tunability. The BST thin films have been deposited on $Al_2O_3$ Substrates by Nd-YAG pulsed laser deposition with a 355nm wavelength at $700\;^{\circ}C$. The post deposition annealing at $750^{\circ}C$ in flowing $O_2$ atmosphere for 1 hours. The capacitance of IDC patterns have been measured from 1 to 10 GHz as a function of electric field ($\pm40$ KV/cm) at room temperature using inter-digital Au electrodes deposited on top of BST. The IDC patterns have three type of fingers number. For the 10 pairs finger was the best capacitance onto $Al_2O_3$ substrate. The capacitance was 0.9pF. Also Dielectric constant was been 351 at 100 mTorr and annealing temperature $750^{\circ}C$ for 1 hour. The loss tangent was been 0.00531.

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Effects of Hafnium Addition on the Pitting Corrosion Behavior of Ti Alloys in Electrolyte Containing Chloride Ion (염소이온 함유된 용액에서 Ti합금의 부식특성에 미치는 Hafnium함량의 영향)

  • Kim, Sung-Hwan;Choe, Han-Cheol
    • Corrosion Science and Technology
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    • v.11 no.5
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    • pp.191-195
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    • 2012
  • The aim of this study was to investigate effects of hafnium content on the corrosion behavior of Ti alloys in electrolyte containing chloride ion. For this study, Ti-Hf binary alloys contained 10 wt%, 20 wt% and 30 wt% Hf were manufactured in a vacuum arc-melting furnace and subjected to heat treatment for 12h at $1000^{\circ}C$ in an argon atmosphere. The pitting corrosion behavior of the specimens was examined through potentiodynamic and potentiostatic tests in 0.9 wt% NaCl electrolyte at $36.5{\pm}1^{\circ}C$. The corrosion morphology of Ti-xHf alloys was investigated using optical microscopy (OM) and X-ray diffractometer (XRD). From the optical microstructures and XRD results, needle-like martensite ($\alpha$') phases of the Ti-xHf alloys increased with an increase of Hf addition. Corrosion current density $(I_{corr})$ and current density $(I_{300mV})$ in passive region decreased, whereas, corrosion potential increased with Hf content. At the constant potential ($300mV_{SCE}$), current density decreased as time increased.

The Low Temperature Deposition of CrN Films by the AIP Method (아크 이온플레이팅법에 의한 저온 CrN 합성)

  • Cho, Yong K.;Kim, Sang K.;Lee, Won B.;Kim, Sung W.
    • Journal of the Korean Society for Heat Treatment
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    • v.20 no.2
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    • pp.78-83
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    • 2007
  • CrN coatings were deposited by cathodic arc ion plating method on the SKD11 steel substrates. Atmosphere temperature of $350^{\circ}C$, arc current of 90 A, nitrogen partial pressure of 1.0-5.3 Pa, and negative bias voltage of 30-135 V were selected. The characteristics of microstructure were investigated with XRD. Hardness, adhesion and friction coefficient measured by microhardness tester, scratch tester, and ball on disk tribometer. Microstructures depended on nitrogen partial pressure and bias voltage. The preferred orientation of the films was changed from (200) to (111) with decreasing pressure and increasing bias voltage. Adhesion properties related with microstructure, but microstructure changes slightly influenced on hardness and friction properties. The critical load.($Lc_1$) and hardness of CrN films deposited at 5.3 Pa, -30 V condition were 55 N(HF1), $2157{\pm}47\;Hk_{0.025}$. The friction coefficient were about 0.5 under dry condition.

Non-edible Vegetable Oils for Alternative Fuel in Compression Ignition Engines

  • No, Soo-Young
    • Journal of ILASS-Korea
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    • v.14 no.2
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    • pp.49-58
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    • 2009
  • Non-edible vegetable oils instead of edible vegetable oils as a substitute for diesel fuel are getting a renewed attention because of global reduction of green house gases and concerns for long-term food and energy security. Out of various non-edible vegetable oils, karanja, mahua, linseed, rubber seed and cotton seed oils are selected in this study. A brief review of recent works related to the application of the above five vegetable oils and its derivatives in CI engines is presented. The production technologies of biodiesel based on non-edible vegetable oils are introduced. Problems in vegetable oil or biodiesel fuelled CI engine are included. In addition, future works related to spray characteristics of non-edible vegetable oil or biodiesel from it are discussed. The biodiesel fuel, irrespective of the feedstock used, results in a decrease in the emission of hydrocardon (HC), carbon monoxide (CO), particulate matter (PM) and sulphur dioxide ($SO_2$). It is also said to be carbon neutral as it contributes no net carbon dioxide to the atmosphere. Only oxides of nitrogen (NOx) are reported to increase which is due to oxygen content in the biodiesel fuel. The systematic assessment of spray char-acteristics of neat vegetable oils and its blends, neat biodiesel and its blends f3r use as diesel engine fuels is required.

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Electrical Characterization of BST Thin Film by IDC pattern (IDC 패턴에 따른 BST 전기적 특성)

  • Roh, Ji-Hyoung;Kim, Sung-Su;Song, Sang-Woo;Kim, Ji-Hong;Koh, Jung-Hyuk;Moon, Byung-Moo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.200-200
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    • 2008
  • This paper reports on electrical characterization by IDC pattern using BST$(Ba_{0.5}Sr_{0.5}TiO_3)$ thin film. BST thin films have been deposited on $Al_2O_3$ Substrates by Nd-YAG pulsed laser deposition with a 355nm wavelength at $700^{\circ}C$. The post deposition annealing at $750^{\circ}C$ in flowing $O_2$ atmosphere for I hours. The capacitance of IDC patterns have been measured from 1 to 10 GHz as a function fo electric field (${\pm}40$ KV/cm) at room temperature using interdiigitated Au electrodes deposited on top of BST. The IDC patterns have three type of fingers number. For the finger paris was increased onto $Al_2O_3$, the capacitance increased. The capacitance of 5 pairs finger was 0.3pF and 10 pairs finger was 0.9pF.

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Monitoring of Particulate Matter and Analysis of Black Carbon and Some Particle Containing Toxic Trace in the City of Yaoundé, Cameroon

  • Tchuente, Siaka Y.F.;Saidou, Saidou;Yakum, N.Y.;Kenmoe, N.X.;Abdourahimi, Abdourahimi
    • Asian Journal of Atmospheric Environment
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    • v.7 no.2
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    • pp.120-128
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    • 2013
  • The concentration and composition of particulate matter (PM) in the atmosphere can directly reflect the environmental pollution. The atmospheric pollution in some Cameroonian cities is increasing with the industrial development and urbanization. Air pollution is inherently complex, containing PM of varied size and composition. This PM exists as a dynamic cloud interacting with sunlight and is modified by the meteorology. The reflectometer and the EDXRF spectrometry are applied to determine the concentration of some specific elements at four sites in the city of Yaound$\acute{e}$. The particular aim of the present work is to put in place data base on air pollution in urban area and elaborate regulations on the emissions issued to industrial and vehicle activities. This study provides an overview of the concentration of black carbon and some specific elements in the air, which have impacts on human health. The measurement was done by distinguishing the size of particle. So that, the particle with aerodynamic diameter between $2.5-10{\mu}m$ (so-called coarse particle) and aerodynamic diameter < $2.5{\mu}m$ (so-called fine particle) were considered to obtain more information about levels of the inhalable fraction of the location. The results obtained in four locations of the city of Yaound$\acute{e}$ show that the black carbon concentration is very considerable, the element sulfur is a major pollutant and the concentration of fine particle is very greater. The results obtained of fine and coarse filters range from $5-17{\mu}g/m^3$ and $10-18{\mu}g/m^3$ for the black carbon. S, Cu, Zn, Pb, Cd, As, Se and Hg are the specific findings of this work. The pollutants with a greater concentration are S, Pb, and Zn. These later seem to be non-uniformly, non-regular in some location and high compared to other countries. This work allows us to make a potential relation between pollutants and emission sources. In this framework, some suggestions have been proposed to reduce emissions for an improvement of the air quality in the environment and thus, the one of the city of Yaound$\acute{e}$.

The Knowledge, Attitude and Behavior on Smoking in Elementary School Students (초등학생의 흡연지식.흡연태도와 흡연행동에 관한 연구)

  • Lee, Kwang-Ok;Choi, Hye-Young
    • Research in Community and Public Health Nursing
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    • v.11 no.1
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    • pp.209-221
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    • 2000
  • I began the study to identify the issues related to knowledge. attitude and behavior regarding smoking by sixth graders. which will ultimately lead to the development of a smoking prevention program that will not only help deter school-age children from smoking, but also make them aware of the more desirable behaviors and techniques for healthier life. The results are as follows: 1. Smoking Behavior: Of the focus group. 4.15% are current smokers and 18.23% are ever smokers. 2. Correlation between smoking knowledge and ever smoking: Ever smoking sample($11.10{\pm}3.66$) is less knowledge able than the never-smoking sample($12.17{\pm}3.95$), (t=3.23. p=.001). 3. Correlation between smoking attitude and ever smoking: Ever smoking sample($28.12{\pm}8.51$) was less desirable than the never-smoking sample($l2.17{\pm}3.95$). (t=8.24, p=.000). 4. Correlation between smoking Knowledge and smoking attitude: knowledge about smoking and attitude toward smoking are quantitatively correlated in such way that the more knowledgeable the child is about smoking. the more desirable the attitude toward smoking is(r=.17. p=.000). 5. Correlation between socio-anthropological characteristics and ever smoking: family . atmosphere($x^2$=16.49. p=.001), school life ($x^2$=l1.58, p= .003), grades in school( $x^2$=11.89. p=.003), gender($x^2$=8.97. p=.003). friends' gathering place($x^2$=13.19. p=.02), marital status of parents(p* =.03). and family's financial status($x^2$=6.71. p=.035). In addition, Correlation between somking-environmental characteristics and ever smoking: number of friends who smoke($x^2$=76.01. p=.001). information source for smoking($x^2$=48.03. p=.001), whether or not siblings smoke($x^2$=26.07, p=.001), whether or not female relatives smoke ( $x^2$= 15.65. p= .001), whether or not father smokes ($x^2$= 12.10. p= .007), errands to buy cigarettes for someone($x^2$=9.18. p=.010), and whether or not male relatives smoke ($x^2$=8.82. p=.35) 6. Results of the logistic analysis performed to identify the factors correlated to ever smoking show that: one point decrease in attitude score translates to 25.39 times' increase in ever smoking one person decrease in the number of friends who smoke translates to 0.66 times' decrease in ever smoking: the group where the father has quit smoking has 1.40 times more ever smoking than the group where the father does not smoke at all: and likewise, the group where the father currently smokes has 1.40 times more ever smoking than the group where the father has quit smoking. 7. The overall cause-and-effect relationship between the ever smoking and the related factors: attitude toward smoking caused ever smoking by -.43, smoking by friends, by .12, marital status of arents, by .05, school life. by .04, gender, by -.03, and smoking by father, by -.02. Knowledge about smoking (t=-1.67) did not cause significant effects on ever smoking.

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Characteristics of Aerosol Mass Concentration and Chemical Composition of the Yellow and South Sea around the Korean Peninsula Using a Gisang 1 Research Vessel (기상1호에서 관측된 한반도 서해 및 남해상의 에어로졸 질량농도와 화학조성 특성)

  • Cha, Joo Wan;Ko, Hee-Jung;Shin, Beomchel;Lee, Hae-Jung;Kim, Jeong Eun;Ahn, Boyoung;Ryoo, Sang-Boom
    • Atmosphere
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    • v.26 no.3
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    • pp.357-372
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    • 2016
  • Northeast Asian regions have recently become the main source of anthropogenic and natural aerosols. Measurement of aerosols on the sea in these regions have been rarely conducted since the experimental campaigns such as ACE-ASIA (Asian Pacific Regional Aerosol Characterization Experiment) in 2001. Research vessel observations of aerosol mass and chemical composition were performed on the Yellow and south sea around the Korean peninsula. The ship measurements showed six representative cases such as aerosol event and non-event cases during the study periods. On non-event cases, the anthropogenic chemical and natural soil composition on the Yellow sea were greater than those on the south sea. On aerosol event cases such as haze, haze with dust, and dust, the measured mass concentrations of anthropogenic chemical and element compositions were clearly changed by the events. In particular, methanesulfonate ($MSA^-$, $CH_3SO_3^-$), a main component of natural oceanic aerosol important for sulfur circulation on Earth, was first observed by the vessel in Korea, and its concentration on the Yellow sea was three times that on the south sea during the study period. Sea salt concentration important to chemical composition on the sea is related to wind speed. Coefficients of determination ($R^2$) between wind speed and sea salt concentration were 0.68 in $PM_{10}$ and 0.82 in $PM_{2.5}$. Maximum wave height was not found to be correlated to the sea salt concentration. When sea-salt comes into contact with pollutants, the total sea-salt mass is reduced, i.e., a loss of $Cl^-$ concentration from NaCl, the main chemical composing sea salt, is estimated by reaction with $HNO_3$(gas) and $H_2SO_4$(gas). The $Cl^-$ concentration loss by $SO_4^{2-}$ and $NO_3^-$ more easily increased for $PM_{10}$ compared to $PM_{2.5}$. The results of this study will be applied to verifying a dust-haze forecasting model. In addition, continued vessel measurements of aerosol data will become important to research for climate change studies in the future.

Reliability Assessment of Temperature Indicator for Simplified Measurement on Conservation Environment of Cultural Heritage (문화재 보존환경 간이 측정을 위한 온도지시카드 신뢰성 평가)

  • Lim, Bo-A;Shin, Eun-Jeong;Lee, Sun-Myung
    • 보존과학연구
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    • s.31
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    • pp.59-68
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    • 2010
  • Cultural heritages are damaged by surrounding several environmental factors. Main factors are temperature, humidity, light, atmosphere and indoor pollutant, organism, etc. Therefore, to prevent damage of cultural heritage from such environmental factor, conservation environment monitoring becomes more important. Indicator is one of the simple method for environment monitoring. It can be used without expensive and complex equipments. However, it should be performed scientific examination for application to cultural heritage. In this study, some Temperature Indicators were chosen and reliability assessment was carried out for application to cultural heritage. Brightness($L^*$) is selected for reliability assessment factor. As a result of lab test, Temperature Indicators were not influenced greatly in humidity change. When they were exposed to setting temperature, the color was changed in setting temperature area and ${\pm}2^{\circ}C$ part of setting temperature. Especially brightness value was high in setting temperature area. Also, Temperature Indicators were stabilized after about 16 minutes when were exposed to temperature difference of $10^{\circ}C$ and when temperature difference with exposure environment is smaller, stabilization time shortened. Therefore, it is a possible to confirm that selected Temperature Indicator is reliable product through measurement of color difference value and naked eye observation.

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