Surat Bualert

Factors Affecting Sensitivity and Stability of Polycyclic Aromatic Hydrocarbons Determined by Gas Chromatography Quadrupole Ion Trap Mass Spectrometry

Abstract This study retrospectively analyzes the daily results of relative response factors (RRFs) of polycyclic aromatic hydrocarbons detected by gas chromatography–mass spectrometry (GC-MS). Although instrumental routine maintenance can enhance the reliability of measurement, there is no quantitative study to investigate the effects of glass liner contamination, manifold temperature drop, and column degradation on deteriorating sensitivities and stabilities of RRFs. This study demonstrates that by removing the contribution of outliners to the background level, great reductions of RRFs were achieved. Although several factors potentially undermined the analyzers confidence on data reliability, there were no significant differences on the relative sensitivities of RRFs.

Variation of Net Radiation and Solar Spectrum in Thailand

Variation of Net radiation and Solar spectrum in Thailand determine the Net radiation and Solar spectrum to compare the environment. The preparation databases amount of solar radiation to be aware change types quantity proportion and distribution of the ratio change each area can influence change the net radiation and spectrum of solar radiation that is received. Measuring and monitoring solar radiation at the wave length 350-1050 nm since November 2010 – February 2011 and March 2011 – March 2012 by instrument netradiometer, CNR4 and Spectroradiometer (EKO, MS-700). The results showed that net radiation was lowest in rainy season. In rainy season was highest decreasing percentage compared to summer. Seasonal variation of the averaged radiation at the wavelength range 351-1050nm showed a good agreement to net radiation, highest in summer rain and winter respectively. In the rainy season, massive cloud, and humidity in the air could absorb net radiation causes the net radiation decreasing at the wavelength range 700-1050 nm of the rainy season, more than other seasons. At the wavelength range 351-700nm, the net radiation decreasing in the winter caused by the stations location and wind direction which brought particles from the sea. Especially on sea salt affected the net radiation at the wave length range 351-700 nm. It showed a good agreement to [7] [10] which reported that in winter, % decrease was greater than any other seasons.

Carbon dioxide and methane emission rates from taxi vehicles in Thailand

ABSTRACT Due to the expansion of urban areas have been increasing levels of greenhouse gas emissions from taxi and passenger cars that use natural gas for vehicles (NGV) and liquid petroleum gas (LPG) as alternative fuels . The objective of this study was to evaluate the CO2 and CH4 emission of NGV and LPG taxis with different times from their engine ages compared to those from passenger cars. The driving tests were conducted at three driving speed ranges in Bangkok, Thailand. No significant differences in the CO2 emission rates from taxis and passenger cars using either NGV or LPG (174.5–227.0 g/km) were found. However, NGV taxis emitted the highest CH4 at all driving speeds, with an average emission of 1.33 g/km, higher than that from the LPG taxis. Comparing between taxis and passenger cars, the NGV taxis emitted the highest of CO2 and CH4 (13.8 ton CO2-eq/y), followed by LPG taxis (12.5 ton CO2-eq/y). The results obtained in this study can be used to create a database that supports the decision-making on development projects and to control GHG emission in Thailand.

Solar Spectrum Forcing Due to Soil Particle Concentration

The Solar spectrum forcing Due to Soil Particle Concentration to study about difference solar energy 3 unit on September 2012 at Petchburi province, Thailand. MS-700, Spectroradiometer was used to determined energy at the wave length 300-1050 nm and short-wave solar radiation. The soil particle was used in the experiment. The result showed that the particulate matter was decrease the shortwave radiation energy. The highest decreasing rate was near infrared range (-0.97%), it showed slightly effect on ultraviolet range (0.11%) and visible light rangeand (0.87%). The soil particle showed significantly effect on the proportion of short wave radiation energy. At the visible light showed percentage is the highest in 450-490 nm (16.0%) the lowest in 380-450 nm (11.0%).