• Bulletin of the Korean Chemical Society
• /
• v.20 no.11
• /
• pp.1277-1280
• /
• 1999

An inexpensive ultrasonic nebulizer (USN) was developed utilizing a home humidifier. The ultrasonic transducer was taken from a commercial USN and the power supply was from a humidifier. Sample was continuously fed into the nebulizer and the detection limit was improved 3-20 times over a pneumatic nebulizer. Undesirably, noise in signal was also increased several times. 0.5 ppm of Mn was used as an internal reference and the "long-term" drift could be successfully corrected. Since the noise contained high and low frequency components, both could be effectively removed only by the real-time correction method such as the Myer-Tracy method, where the reference line was simultaneously monitored with the analytical lines. The performance of USN was tested with NIST SRMs and showed good agreement with the certified values.

• Progress in Superconductivity
• /
• v.7 no.1
• /
• pp.52-57
• /
• 2005

[ $YBa_{2}Cu_{3}O_y$ ] superconducting films were prepared on $LaAlO_3$(100) single crystal substrate by spray pyrolysis method. The precursor solution was prepared by dissolving nitrate powders in de-ionized water. Both of ultrasonic and concentric nebulizers were used in order to generate fine droplets of precursor solution. C-axis oriented films were obtained at deposition temperature of $750\~850^{\circ}C$ and working pressure of 100 Torr and 500 Torr. In case of ultrasonic nebulizer, films showed rough and porous surface morphology due to formation of enormous droplets, while smooth and dense films were obtained for concentric nebulizer. A transport $J_c$ value of $0.43\;MA/cm^2$ at 77 K and self field was achieved on $LaAlO_3$(100) single crystal substrate.

• Analytical Science and Technology
• /
• v.15 no.2
• /
• pp.127-134
• /
• 2002

Analytical method to determine rare earth elements which were extracted to organic phase by inductively coupled plasma mass spectrometry(ICP-MS) was investigated. Organic phase which had extracted rare earth elements was directly aspirated into ICP-MS by ultrasonic nebulizer(USN) in order to reduce solvent load to the plasma. Then, the count rate increased when MIBK(methyl isobutyl ketone) was added to EtOH(ethanol) but decreased when 0.03 M HEH(2-ethylhexyl-2-ethylhexyl phosphonic acid, $P_{507}$, PC88A) was added to solvent which mixed MIBK with EtOH. The optimal temperatures of desolvation system were -10 $^{\circ}C$ for the condenser and 150 $^{\circ}C$ for the heating tube. The optimal nebulizer flow rate which gave maximum count rate and minimum reflect power was 0.7 L/min. The optimal pH and extraction time were 4.3 and 10 min for MIBK-0.03 M HEH system. Detection limits which were obtained through calibration curves at the range of 0.2 ${\sim}$ 20 ng/mL were 0.02 ${\sim}$ 0.05 ng/mL under the optimal experimental conditions.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.10 no.1
• /
• pp.96-107
• /
• 2003

Objective: The purpose of this study was to identify the effects of tracheal suction and the effects of different methods of bronchodilator inhalation (Ultrasonic nebulizer: MDI puff, MDI puff with spacer) in VSD surgery patients. Material & Method: From June 2001 to March 2002, sixty consecutive patients were randomly assigned to a control group (n= 15), ultrasonic nebulizer group (n=15), metered dose inhalation (MDI) puff group (n=15) and MDI with spacer group (n=15). Vital signs (HR, BP, CVP), ABGA and pulmonary functions were measured before suction (baseline for suction), after suction, 15 minutes after suction (base of bronchodilator inhalation), 30 minutes after bronchodilator inhalation, and 2 hours after bronchodilator inhalation. Stastistical analysis was performed using SPSS software. Repeated measure ANOVA was used to examine the effects of tracheal suction. One way ANOVA with Bonferroni's correction and multiple range test (the least significant difference test) were used to examine the effects of albuterol inhalation. Result: 1. Heart .ate increased significantly immediately after suction (p<.01) and recovered 15 minutes after suction. 2. $PaO_2$ and PH decreased significantly immediately after suction (p<.05) and $PaO_2$ recovered 15 minutes after suction. $PaCO_2$ increased immediately after suction and significantly 15 minutes after suction (p<.01). But changes in vital signs and ABGA were within the normal range. 3. Tidal volume decreased significantly 15 minutes after suction (p<.05). 4. Changes of HR and tidal volume were greater in the nebuizer group compared to the other groups (p<.05) 30 minutes after bronchodilator inhalation and recovered 2 hours after bronchodilator inhalation. 5. Changes of airway deadspace was greater in the nebulizer group compared to the control group and MDI puff group 30 minutes after albuterol inhalation (p<.05) and at 2 hours (p<.01). Conclusion: Tracheal suction did not have significant effect on vital signs and pulmonary functions after OHS. Although the methods of bronchodilator inhalation did not showed any significant difference on pulmonary function, the nebulizer method increased $PaO_2$ (20%) and tidal volume transiently. If the patient needs bronchodilator inhalation with bronchospasm after OHS, the nebulizer method is the best choice. More study on the effects of bronchodilator inhalation in bronchospasm group is needed.

• Analytical Science and Technology
• /
• v.16 no.2
• /
• pp.134-142
• /
• 2003

Comparison of a microwave-assisted extraction with sonication extraction was performed for arsenic speciation in fish tissue with chromatographic separation and inductively coupled plasma mass spectrometry detection. The detection limits of arsenicals with ultrasonic nebulizerand cross-flow nebulizer were shown to be similar. The arsenicals investigated were arsenobetaine (AsB), arsenite [As(III)], dimethylarsine acid (DMA), monomethylarsonic acid (MMA), arsenate [As(v)], and phenylarsonic acid (PAA). Quantitative extraction of arsenicals from dogfish muscle, DORM-2, standard reference material of NRCC (National Research Council of Canada) was achieved using 50% (v/v) methanol-water in both extraction methods. Extraction efficiency of arsenobetaine in both methods is greater than 82% with RSDs on replicates of less than 5%. The concentrations of AsB determined in extract of microwave assisted extraction and sonication methods were $14.18{\pm}0.42mg\;kg^{-1}$ and $13.54 {\pm}0.84mg\;kg^{-1}$, respectively. And the concentrations of DMA were $0.45{\pm}0.06mg\;kg^{-1}$ and $0.44{\pm}0.06mg\;kg^{-1}$, respectively.

• Economic and Environmental Geology
• /
• v.29 no.1
• /
• pp.21-24
• /
• 1996

Inductively coupled plasma atomic emission spectrophotometer (ICP/AES) is a versatile modern instruments for the multi-element analysis, but quantitative analysis using ICP/AES with normal pneumatic nebulizer is not applicable for the measurement of elemental concentrations in water down to the drinkining water standard level except a few elements because of poor detection limits. However, the detection limit can be lowered enough to measure drinking water standard, if ultrasonic nebulizer and/or hydride vapor generator is attached. This method is tested with groundwater samples from Tajeon area. It is confirmed that the elemental concentrations in these samples are within the limit of drinking water standard for the most elements. However, uranium concentration is very high in some samples compared with the concentrations suggested by Environmental Protection Agency of U.S.A. There is no standard concentration level to this element in Korea and it should be prepared immediately.

• Bulletin of the Korean Chemical Society
• /
• v.22 no.8
• /
• pp.827-832
• /
• 2001

The excitation temperature and electron number density have been measured for end-on-view ICP discharge. In this work, end-on-view ICP-AES equipped with the newly developed “optical plasma interface (OPI)” was used to eliminate or remove the neg ative effects caused by end-on-plasma source. The axial excitation temperature was measured using analyte (Fe I) emission line data obtained with end-on-view ICP-AES. The axial electron number density was calculated by Saha-Eggert ionization equilibrium theory. In the present study, the effects of forward power, nebulizer gas flow rate and the presence of Na on the excitation temperature and electron number density have been investigated. For sample introduction, two kinds of nebulizers (pneumatic and ultrasonic nebulizer) were utilized.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.16 no.3
• /
• pp.464-471
• /
• 2002

Author applied several engineering methodologies to classical ultrasonic nebulizer to cope with it's demerits. After several trials and errors, we got the several meaningful results. To evaluate the modified ultrasonic nebulizer for inhalation toxicology of cadmium, author used light-scattering photometer. This paper is the one part of inhalation exposure systems for inhalation toxicology study of cadmium. According to the testing conditions, source temperature 50℃ and inlet-duct band temperature 150℃, aerosol generation results for sodium chloride and cadmium chloride were as followings: Coefficients of variation(CV) of sodium chloride and cadmium chloride for repeated trials were 3.38 and 4.77 for 10g, 2.47 and 5.02 for 5g, and 4.70 and 2.98 for 2.5g. All the CVs were within 10% of acceptance variability. Count Per Minute(CPM) changes of NaCl and CdCl₂ for 5 repeated trials were similar. CPM ratios of CdCl₂/NaCl were 1.13 for 10g, 0.76 for 5g, and 1.06 for 2.5g. Relative aerosol generation of cadmium chloride to sodium chloride was the highest in 10g. Efficiency increases of 24.50% for 5g NaCl, 14.91 % for 2.5g NaCl, and 16.48% for 2.5g CdCl₂ with respect to theoretical efficiency were observed but 0.04% efficiency decrease was observed in 5g CdC₂. According to the modifications of source temperature(20, 50, 70℃) and inlet-duct band temperature(20, 50, 100, 150, 200℃), aerosol generation results for NaCl and CdCl₂ were as followings: CPM trends for each quantity excepting 10g NaCl in inlet-duct band temperature 200℃ were similar, and the highest CPM was observed in source temperature 70℃ to each inlet-duct band temperature. The highest CPMs to 10, 5, and 2.5g NaCl were observed in source temperature 70℃ and inlet-duct band temperature 20℃. Aerosol generation of cadmium chloride was increased with the higher source temperature, excepting inlet-duct band temperature 200℃. The highest CPMs for 10, 5, and 2.5g CdCl₂ were observed in source temperature 70℃ and inlet-duct band temperature 20℃, and this trend was similar to NaCl aerosol generation The highest CPMs for 10, 5, and 2.5g CdCl₂ were observed in source temperature 70℃ and inlet-duct band temperature 20℃, and this result was similar to NaCl aerosol generation. Observed efficiencies of 5 and 2.5g NaCl were similar to ifs theoretical efficiency but -3.08% efficiency decrease of 5g CdCl₂, 17.47% efficiency increase of 2.5g CdCl₂ were observed. CPM ratio of CdCl₂/NaCl of 10g was different to 5 and 2.5g, and 2.5g ratio was higher than 5g ratio. In conclusion, to get maximum aerosol generation for NaCl and CdCl₂ will be the conditions that set the appropriate inlet-duct band temperature for each materials and increase the source temperature. Sodium chloride can be used to evaluate the performance and predict the concentration for cadmium aerosol in aerosol generator and inhalation exposure system.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.17 no.5
• /
• pp.1257-1263
• /
• 2003

The modified engineering methodology and the modified electronic circuit in classical ultrasonic principles were applied to ultrasonic aerosol nebulizer for inhalation toxicology study of cadmium aerosol. 1532.96ppm Cd nebulizing solution was used to generate cadmium aerosol for particle size analysis with the modifying source and inlet temperatures. The results of particle size analysis for cadmium aerosol were as following. The highest particle counting for source temperature 20℃ was 399.75 × 10² in inlet temperature 100℃ and particle diameter 0.75㎛. The highest particle counting for source temperature 50℃ was 399.70 × 10² in inlet temperature 50℃ and particle diameter 0.75㎛. The highest particle counting for source temperature 70℃ was 411.14 × 10² in inlet temperature 100℃ and particle diameter 0.75㎛. The ranges of geometric mean diameter were 0.74-0.79㎛ in source temperature 20℃, 0.65-0.72㎛ in source temperature 50℃, and 0.65-0.80㎛ in source temperature 70℃. The smallest geometric mean diameter was 0.65㎛ in source temperature 50, 70℃ and inlet temperature 20, 50℃, and the largest geometric mean diameter was 0.80㎛ in source temperature 70℃ and inlet temperature 100℃. The ranges of geometric standard deviation were 1.71-1.80 in source temperature 20℃, 1.27-1.61 in source temperature 50℃, and 1.27-2.29 in source temperature 70℃. The lowest geometric standard deviation was 1.27 in source temperature 50, 70℃ and inlet temperature 20, 50℃, and the highest geometric standard deviation was 2.29 in source temperature 70℃ and inlet temperature 100℃. Generated aerosol for cadmium inhalation toxicology study was polydisperse aerosol with the above geometric standard deviation 1.2. The ranges of mass median diameter(MMD) were 1.75-2.25㎛ in source temperature 20℃, 1.27-1.61㎛ in source temperature 50℃, and 1.27-2.29㎛ in source temperature 70℃. The smallest MMD was 1.27㎛ in source temperature 50, 70℃ and inlet temperature 20, 50℃, and the largest MMD was 2.29㎛ in source temperature 70℃ and inlet temperature 100℃. Cadmium chloride concentration in nebulizing solution affected the particle size and distribution of cadium aerosol in air. MMO for inhalation toxicology testing in OECD and EU is less than 3㎛ and EPA guidance is less than 4㎛. In our results, in source temperatures of 20, 50, 70℃, and inlet temperatures of 20, 50, 100, 150, 200, 250℃ were conformed to the those guidance.

• Journal of the Korean earth science society
• /
• v.42 no.4
• /
• pp.383-389
• /
• 2021

Several studies investigating the behavior and environmental distribution of rare earth elements (REEs) have been reviewed to determine the geochemical processes that may affect their concentrations and fractionation patterns in groundwater and whether these elements can be used as tracers for groundwater-rock interactions and groundwater flow paths in small catchments. Inductively coupled plasma-mass spectrometry (ICP-MS), equipped with an ultrasonic nebulizer and active-film multiplier detector, is routinely used as an analytical technique to measure REEs in groundwater, facilitating the analysis of dissolved REE geochemistry. This review focuses on the distribution of REEs in groundwater and their application as tracers for groundwater geochemistry. Our review of existing literature suggests that REEs in ice cores can be used as effective tracers for atmospheric particles, aiding the identification of source regions.