• Bulletin of the Korean Chemical Society
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• v.22 no.12
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• pp.1341-1344
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• 2001

Comparison of sulfur dioxide primary standard gases of the Korea Research Institute of Standards and Science (KRISS, Korea) and the National Physical Laboratory (NPL, UK) was performed. 100 ${\times}$10-6 mol/mol and 1,000 ${\times}$10-6 mol /mol primary standard gases (designated NPL S115 and S114, respectively) prepared gravimetrically and validated in NPL were used as transfer standards. Transfer standards were analyzed by NDIR sulfur dioxide analyzer and compared with KRISS PSM 112-03-624 and PSM 112-03-625 prepared gravimetrically. Adsorption corrected relative deviations of the primary standard gases were agreed to within 0.1%, and this agreement is within the expanded uncertainties (k = 2) of the primary standards at the two laboratories.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.2
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• pp.331-341
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• 2018

Hazardous air pollutants(HAPs) in the atmosphere are regulated as major air pollutants in Korea by the Air Pollution Control Act. In order to manage and control HAPs, accurate standards, which are traceable to the International System of Units(SI), are required. In this study, primary standard gas mixtures(PSMs) of volatile organic compounds(VOCs) which are specified as HAPs were developed at $1{\mu}mol/mol$ levels. The selected fourteen VOCs include Benzene, Toluene, Ethylbenzene, m-Xylene, Styrene, o-Xylene, Chloroform, 1,1,2-Trichloroethane, Trichloroethylene, Tetrachloroethylene, 1,1-Dichloroethane, Carbon tetrachloride, 1,3-Butadiene, and Dichloromethane. The HAPs PSMs were gravimetrically prepared in aluminum cylinders and their consistency was verified within the relative expanded uncertainty of 0.71% (k=2). Potential adsorption loss onto the internal surface of cylinders was estimated by cylinder-to-cylinder division method. No adsorption loss was observed within the uncerainty of 0.53%. The long-term stability of the HAPs PSMs was evaluated comparing with freshly prepared HAPs PSMs. The HAPs PSMs were stable for one year within the uncertainty of 0.38%. The final uncertainty of the PSMs was determined by combining the preparation uncertainty, verification uncertainty, and stability uncertainty. Finally, traceable and stable HAPs PSMs at $1{\mu}mol/mol$ levels were developed with the uncertainty of less than 0.76% in high-pressure aluminum cylinders.

• Analytical Science and Technology
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• v.30 no.5
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• pp.287-294
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• 2017

As the demand for natural gas increases with industrial development, the supply of natural gas is expected to become unstable with a shortage of imported natural gas. It is hence necessary to meet this demand by introducing and developing various types of natural gas, such as pipeline natural gas (PNG) and substituted natural gas (SNG), in addition to liquefied natural gas (LNG). The components included in PNG as well as their concentrations must be measured accurately, and a standard gas should be developed to accurately measure hydrocarbons ($C_6-C_{10}$), which are trace components included in natural gas. The components in the primary standard gas mixtures (PSMs) developed in the present study were hexane, heptane, octane, nonane, and decane with concentrations of $10-30{\mu}mol/mol$ with methane as the balance gas. Standard hydrocarbon ($C_6-C_{10}$) gas mixtures were prepared in aluminum cylinders by a gravimetric method with traceability following ISO 6142 with raw material gases, for which the purity of each component was analyzed completely. The prepared standard gas mixtures were analyzed by to evaluate the preparation consistency between the standard gas mixtures, the adsorbability of the cylinders, the variation of the stability, and the uncertainty. The results showed that aluminum cylinders have little adsorptive loss on their internal surfaces with excellent long-term stability. The developed standard gas mixture, containing hexane, heptane, octane, nonane, and decane with concentrations of $10-30{\mu}mol/mol$, showed an uncertainty in a range of 0.79 % - 1.63 %.

• Analytical Science and Technology
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• v.27 no.6
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• pp.357-363
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• 2014

Isoprene is a one of the biogenic volatile organic compounds (BVOCs) and it is known as a source of the tropospheric ozone and formaldehyde. In addition, isoprene is a trace component of the exhaled breath and it is a potential biomarker for the diagnosis of diseases such as lung cancer. In these regards, isoprene gas standards are required for the accurate measurement of isoprene in air samples. To establish a standard for isoprene gas, gravimetric preparation and characterization of primary gas standards were studied. The primary gas standards were produced independently in 4 aluminum cylinders and concentrations were examined by GC-FID. As a result, the uncertainty of the gravimetric preparations including purity of the raw material was 0.01% and reproducibility of the preparation of independent 4 cylinders was 0.08%. The primary gas standards for isoprene showed 14 months of long-term stability. The relative expended uncertainty of 2.8% (95% of confidence level, k=1.96) was assigned to the certified value of 10 ${\mu}mol$/mol level of isoprene based on the quantitative evaluation of the purity, weighing, reproducibility, adsorption and long-term stability.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.121-126
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• 2009

This study analyzed the standard school's energy usage and patterns as the zero-energy goal of primary school building, and proposed the energy reduction process of school building using energy analysis computing simulation tool. As a analysis simulation tool, Visual DOE 4.0 is used. For analysis of actual energy usage, selected primary school that is standard in the nation's energy consumption. Standard of the school's energy consumption analysis were devided into electric and gas energy. Input parameters of the simulation program based on the literature material and field survey material. after, but it was calibrated to comparison with the standard school's energy consumption. Finally, its energy usage analyzed by component and made the priority order of energy saving. Applied energy saving technologies are envelopment insulation, high efficiency lighting, high performance HAVC system and used active equipment system of solar collector and photovoltaic generation for additional savings.

• Journal of the Korean Institute of Gas
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• v.22 no.2
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• pp.46-51
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• 2018

Hydrogen sulfide from landfill and sewage treatment plant is a major odor component and causes many civil petitions. Rapidly developing industries release hydrogen sulfide, an odorous gas, to the atmosphere. This study aims to develop a $10{\mu}mol/mol$ concentration level hydrogen sulfide primary standard gas for odor measurement. The hydrogen sulfide gas was prepared at a nominal concentration of $10{\mu}mol/mol$ in nitrogen using the gravimetric method described in ISO 6142. Replicate standard gases were produced in 4 aluminium cylinders, and their concentrations were verified by GC-AED. The uncertainty of production was less than 0.50 %, and the variation of the 4 replicates was 0.22 %. The wall adsorption of hydrogen sulfide in cylinders was 0.10 % at 1500 psi, and the concentration was estimated to be long-term stable for one year. The relative expanded uncertainty of the preparation consistency, adsorption and long-term stability of this hydrogen sulfide standard gas was less than 1.05 % (95 % of confidence level, k=2).

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.3
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• pp.320-328
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• 2016

Among biogenic volatile organic compounds (BVOCs) in the natural ecosystem, monoterpenes, along with isoprene, play important roles in atmospheric chemistry and make significant impacts on air pollution and climate change, especially due to their contribution to secondary organic aerosol production and photochemical ozone formation. It is essential to measure monoterpene concentrations accurately for understanding their oxidation processes, emission processes and estimation, and interactions between biosphere and atmosphere. Thus, traceable calibration standards are crucial for the accurate measurement of monoterpenes at ambient levels. However, there are limited information about developing calibrations standards for monoterpenes in pressured cylinders. This study describes about developing primary standard gas mixtures (PSMs) for monoterpenes at about 2 nmol/mol, near ambient levels. The micro-gravimetric method was applied to prepare monoterpene (${\alpha}$-pinene, 3-carene, R-(+)-limonene, 1,8-cineole) PSMs at $10{\mu}mol/mol$ and then the PSMs were further diluted to 2 nmol/mol level. To select an optimal cylinder for the development of monoterpene PSMs, three different kinds of cylinders were used for the preparation and were evaluated for uncertainty sources including long-term stability. Results showed that aluminum cylinders with a special internal surface treatment (Experis) had little adsorption loss on the cylinder internal surface and good long-term stability compared to two other cylinder types with no treatment and a special treatment (Aculife). Results from uncertainty estimation suggested that monoterpene PSMs can be prepared in pressured cylinders with a special treatment (Experis) at 2 nmol/mol level with an uncertainty of less than 4%.

• Bulletin of the Korean Chemical Society
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• v.25 no.2
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• pp.233-236
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• 2004

Total impurity analysis of a primary standard solution is one of the essential procedures to determine an accurate concentration of the standard solution by the gravimetry. Bi impurity is determined in Pb standard solutions by inductively coupled plasma mass spectrometry (ICP-MS). The direct nebulization of the Pb standard solution produces a significant amount of the Pb matrix-induced molecular ions which give rise to a serious spectral interference to the Bi determination. In order to avoid the spectral interference from the interferent $^{208}PbH^+$, the hydride generation method is employed for the matrix separation. The Bi hydride vapor is generated by reaction of the sample solution with 1% sodium borohydride solution. The vapor is then directed by argon carrier gas into the ICP after separation from the mixture solution in a liquid-gas separator made of a polytetrafluoroethylene membrane tube. The presence of 1000 ${\mu}$g/mL Pb matrix caused reduction of the bismuthine generation efficiency by about 40%. The standard addition method is used to overcome the chemical interference from the Pb matrix. Optimum conditions are investigated for the hydride-generation ICPMS. The detection limit of this method is 0.5 pg/mL for the sample solutions containing 1000 ${\mu}$g/mL Pb matrix.

• Journal of the Korean Institute of Gas
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• v.25 no.4
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• pp.49-56
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• 2021

Liquefied Petroleum Gas is divided into liquefied gases containing propane (C₃H₈) and butane (C₄H₁₀). The quality of LPG varies greatly depending on the composition of the mixture, so it is important to measure the composition accurately. It is difficult to determine the composition of the mixture because liquid and gas coexist at room temperature. Therefore, the uncertainty in determining the concentration of hydrocarbons by component is high, and there are many problems that differ from the actual content standard. Therefore, it is necessary to develop a mixed liquid propane standard gas for the composition and accurate concentration of hydrocarbon substances. Mixed liquid propane standard gas is manufactured into bellows-type constant-pressure cylinders by ISO-6142 (2015). The homogeneity of the four standard gases manufactured was confirmed to be GC-FID. The manufacturer's uncertainty of expansion was 0.01 % to 0.30 % and homogeneity was 0.03 % to 0.25 %. In this mixed liquid propane standard gas, the relative expansion uncertainty of weight method, manufacturing consistency, cylinder adsorption and long-term stability was developed within 0.26 %-1.3 9% (95% of confidence level, k=2).

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.38-44
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• 2000

Compared to other waste, waste tire has much discharge quantity and calorie. When we use waste heat from waste tire, it can be definitely better substitute energy than coal and anthracite in high oil price age. To use as a basic data for providing low cost and highly effective heating system, following conclusion was founded. Annual waste tire production was 19,596 million in 1999, Recycling ratio was almost 55% and more than 8.78 million was stored. Waste tire has lower than 1.5% sulfur contain ratio which is resource of an pollution, So it is a waste fuel which can be combustion based on current exhaust standard value without any extra SOx exclusion materials. Waste tire has 9,256Kcal/kg calorific value and it is higher than waste rubber, waste rubber, waste energy as same as B-C oil. When primary and second air quantity was 1.6, 8.0 Nm$^3$/min, dry gas production time was 270min and total combustion time was 360 min. In the SOx, NOx, HC of air pollution material density were lower than exhaust standard value at the back of cyclone and dusty than exhaust standard value without dust collector.