Time filter

Source Type

Sakon Nakhon, Thailand

Kumharn W.,Sakon Nakhon Rajabhat University
Advances in Space Research | Year: 2014

Ozone (O3) and sulfur dioxide (SO2) in a vertical column of the atmosphere in Thailand were obtained from the Brewers#121 and #120. There are similarities between the O3 patterns obtained from the two sites, which are higher in the summer and rainy season compared with winter, although the magnitude of the change in Bangkok is greater than that in Songkhla. SO2 values showed the summer months provide the higher SO2 values in Bangkok, in contrast to Songkhla where the summer months give lower SO2 values. © 2014 COSPAR. Published by Elsevier Ltd. All rights reserved.

Thanwised P.,Khon Kaen University | Thanwised P.,Sakon Nakhon Rajabhat University | Wirojanagud W.,Khon Kaen University | Reungsang A.,Khon Kaen University
International Journal of Hydrogen Energy | Year: 2012

This study evaluated hydrogen production and chemical oxygen demand removal (COD removal) from tapioca wastewater using anaerobic mixed cultures in anaerobic baffled reactor (ABR). The ABR was conducted based on the optimum condition obtained from the batch experiment, i.e. 2.25 g/L of FeSO 4 and initial pH of 9.0. The effects of the varying hydraulic retention times (HRT: 24, 18, 12, 6 and 3 h) on hydrogen production and COD removal in a continuous ABR were operated at room temperature (32.3 ± 1.5 °C). Hydrogen production rate (HPR) increased with a reduction in HRT i.e. from 164.45 ± 4.14 mL H 2/L.d (24 h HRT) to 883.19 ± 7.89 mL H 2/L.d (6 h HRT) then decreased to 748.54 ± 13.84 mL H 2/L.d (3 h HRT). COD removal increased with reduction in HRT i.e. from 14.02 ± 0.58% (24 h HRT) to 29.30 ± 0.84% (6 h HRT) then decreased to 21.97 ± 0.94% (3 h HRT). HRT of 6 h was the optimum condition for ABR operation as indicated. © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Seetawan T.,Sakon Nakhon Rajabhat University
Applied Mechanics and Materials | Year: 2012

Low cost thermoelectric power generator (LTPG) used for generating electrical voltage, current and power is by designed and fabricated n-type CaMnO 3 and p-type Ca 3Co 4O 9 segments based oxide thermoelectric materials, ceramic substrates and copper electrodes. It was found that the thermoelectric generator 1 in 2 has contact resistance of ∼ 200 Ω voltage ∼ 0.2 V, current ∼ 0.4 mA, power of ∼ 0.1 mW and a conversion efficiency of ∼ 0.78 % in the test performed at differential temperature < 200 K. © (2012) Trans Tech Publications, Switzerland.

Kumharn W.,Sakon Nakhon Rajabhat University | Rimmer J.S.,University of Manchester | Smedley A.R.D.,University of Manchester | Webb A.R.,University of Manchester
Journal of Atmospheric and Oceanic Technology | Year: 2012

Aerosols play an important role in attenuating solar radiation reaching the earth's surface and are thus important inputs to climate models. Aerosol optical depth is routinely measured in the visible range but little data in the ultraviolet (UV) are available. In the UV range it can be determined from Langley plots of directsun measurements from the Brewer spectrophotometer (where conditions allow) and can also be determined as the residual once the ozone and sulfur dioxide have been accounted for in the extinction observed during a normal Brewer direct-sun measurement. By comparing aerosol optical depth derived from Brewer directsun data in both the United Kingdom and Malaysia, two very different locations, it is determined that while most of the existing global Brewer network could contribute to aerosol optical depth data, further analysis, such as calculation of the Å ngström parameter, would be dependent on latitude and sky conditions. © 2012 American Meteorological Society.

Seetawan T.,Sakon Nakhon Rajabhat University
Integrated Ferroelectrics | Year: 2014

The crystal structure and electronic structure of Ca0.8M 0.2MnO3 (M = Cu, Ag, and Bi) materials were simulated by DV-Xα method and Maxwell-Boltzmann distribution to evaluate the electrical resistivity and Seebeck coefficient. The lattice thermal conductivity was calculated by the classical molecular dynamics (MD) method. I was found that the crystal structure of these materials based on a framework of corner-sharing orthorhombic system. The Seebeck coefficient of materials increases with temperature. The electrical resistivity and thermal conductivity decreases with temperature and substituted metal for Ca site. The Ca0.8Bi 0.2MnO3 exhibited better thermoelectric performance and clearly showed concurrence between theoretical analysis and experimental data. © 2014 Taylor & Francis Group, LLC.

Discover hidden collaborations