T-Thienprasert J.,Kasetsart University |
Rujirawat S.,Suranaree University of Technology |
Klysubun W.,Synchrotron Light Research Institute |
Duenow J.N.,National Renewable Energy Laboratory |
And 4 more authors.
Physical Review Letters | Year: 2013
The synchrotron x-ray absorption near edge structures (XANES) technique was used in conjunction with first-principles calculations to characterize Al-doped ZnO films. Standard characterizations revealed that the amount of carrier concentration and mobility depend on the growth conditions, i.e. H2 (or O2)/Ar gas ratio and Al concentration. First-principles calculations showed that Al energetically prefers to substitute on the Zn site, forming a donor AlZn, over being an interstitial (Ali). The measured Al K-edge XANES spectra are in good agreement with the simulated spectra of AlZn, indicating that the majority of Al atoms are substituting for Zn. The reduction in carrier concentration or mobility in some samples can be attributed to the AlZn-VZn and 2Al Zn-VZn complex formations that have similar XANES features. In addition, XANES of some samples showed additional features that are the indication of some α-Al2O3 or nAl Zn-Oi formation, explaining their poorer conductivity. © 2013 American Physical Society.
Kamon-In O.,Suranaree University of Technology |
Klysubun W.,Synchrotron Light Research Institute |
Limphirat W.,Synchrotron Light Research Institute |
Srilomsak S.,Suranaree University of Technology |
Meethong N.,Khon Kaen University
Physica B: Condensed Matter | Year: 2013
Recently, orthosilicate, Li2MSiO4 (where M=transition metal) materials have been attracting considerable attention for potential use as a new generation cathode for Li-ion batteries due to their safety, low toxicity, and low cost characteristics. In addition, the presence of two Li + ions in the molecule offers a multiple electron-charge transfer (M2+/M3+ and M3+/M4+ redox couples), thus allowing a high achievable capacity of more than 320 mA h/g per M unit. Good electrochemical properties of Li2FeSiO4 have been reported through several approaches such as downsizing of the particles, carbon-coating, etc. However, in addition to electrochemical performance, fundamental understanding regarding crystal, electronic and local structure changes during charge/discharge processes is also important and needs more rigorous investigation. In this work, lithium iron silicates (Li 2FeSiO4/C) in space group of Pnma: a=10.6671(3) Å, b=6.2689(2) Å, and c=5.0042(2) Å have been prepared by solid-state reaction. The synthesized as well as chemical delithiated samples have been characterized by XRD, HRTEM, AAS and XAS techniques. We will show the results focusing on Fe K-edge XANES, EXAFS, HRTEM and XRD of the Li 2-xFeSiO4 samples and discuss how the crystal, electronic, and local structure changes upon Li+ de-intercalation. © 2013 Elsevier B.V.
Thumanu K.,Synchrotron Light Research Institute |
Tanthanuch W.,Synchrotron Light Research Institute |
Ye D.,Suranaree University of Technology |
Sangmalee A.,Suranaree University of Technology |
And 3 more authors.
Journal of Biomedical Optics | Year: 2011
Stem cell-based therapy for liver regeneration has been proposed to overcome the persistent shortage in the supply of suitable donor organs. A requirement for this to succeed is to find a rapid method to detect functional hepatocytes, differentiated from embryonic stem cells. We propose Fourier transform infrared (FTIR) microspectroscopy as a versatile method to identify the early and last stages of the differentiation process leading to the formation of hepatocytes. Using synchrotron-FTIR microspectroscopy, the means of identifying hepatocytes at the single-cell level is possible and explored. Principal component analysis and subsequent partial leastsquares (PLS) discriminant analysis is applied to distinguish endoderm induction from hepatic progenitor cells and matured hepatocyte-like cells. The data are well modeled by PLS with endoderm induction, hepatic progenitor cells, and mature hepatocyte-like cells able to be discriminated with very high sensitivity and specificity. This method provides a practical tool to monitor endoderm induction and has the potential to be applied for quality control of cell differentiation leading to hepatocyte formation. © 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).
Poo-Arporn Y.,Synchrotron Light Research Institute |
Palangsuntikul R.,King Mongkut's University of Technology Thonburi
Journal of Nanoscience and Nanotechnology | Year: 2016
The in situ X-ray absorption near edge structure (XANES) measurement and linear combination fitting were applied to monitor phase transformation of titanium dioxide. In this study, TiO2 (TiSG) was prepared by a sol-gel method using titanium isopropoxide as a precursor. At low preparation temperature, the results revealed the formation of an amorphous structure. To obtain the anatase phase, the calcination at 843 K was necessary. Using phase fraction plot, TiO2 phase-transition can be observed at temperatures between 748 and 778 K and remain unchanged at 873 K. Copyright © 2016 American Scientific Publishers All rights reserved.
Sinyoung S.,King Mongkut's University of Technology Thonburi |
Songsiriritthigul P.,Synchrotron Light Research Institute |
Songsiriritthigul P.,Suranaree University of Technology |
Asavapisit S.,King Mongkut's University of Technology Thonburi |
And 2 more authors.
Journal of Hazardous Materials | Year: 2011
The behavior of chromium during the production of cement clinker, during the hydration of cement and during the leaching of cement mortars was investigated. The microstructures of clinker and mortar properties were investigated using free lime, XRD, SEM/EDS, and TG/DTA techniques. Chromium was found to be incorporated in the clinker phase. The formation of new chromium compounds such as Ca6Al4Cr2O15, Ca5Cr3O12, Ca5Cr2SiO12, and CaCr2O7, with chromium oxidation states of +3, +4.6, +5, and +6, respectively, was detected. After the hydration process, additional chromium compounds were identified in the mortar matrix, including Ca5(CrO4)3OH, CaCrO4·2H2O, and Al2(OH)4CrO4, with chromium oxidation states of +4.6, +6, and +6, respectively. Additionally, some species of chromium, such as Cr3+ from Ca6Al4Cr2O15 and Cr6+ from CaCr2O7, CaCrO4·2H2O, and Al2(OH)4CrO4, were leached during leaching tests, whereas other species remained in the mortar. The concentrations of chromium that leached from the mortar following U.S. EPA Method 1311 and EA NEN 7375:2004 leaching tests were higher than limits set by the U.S. EPA and the Environment Agency of England and Wales related to hazardous waste disposal in landfills. Thus, waste containing chromium should not be allowed to mix with raw materials in the cement manufacturing process. © 2011 Elsevier B.V.
Jaikaew W.,Suranaree University of Technology |
Patanakul R.,Synchrotron Light Research Institute |
Schulte A.,Suranaree University of Technology
Electroanalysis | Year: 2016
We report the first utilization of copper disk electrodes as suitable cathodic transducer platforms for glucose biosensors. Simple and cheap Cu disk electrodes were fabricated from ordinary electrical cable by cementing into a glass tube with epoxy resin and subsequent polishing to expose the active area. Glucose oxidase was immobilized on the electrode tips by entrapment in dropped and dried polymeric Nafion deposits. At a H2O2 detection potential of -0.15V vs. a reference electrode, the linear response range of fabricated cable Cu glucose biosensors was 20-1500μM, with a sensitivity of about 700nAμM-1cm-2. Quantitative analysis of glucose-supplemented buffer solutions showed a recovery of 106±4% (n=3). The principal advantage of the glucose biosensors described in this study, compared to other options, is the simplicity of the cathodic H2O2 readout, which exploits cheap and readily available electrical cable, without any extra surface modification with catalytically active micro- or nanomaterials. The analytical performance of the biosensor is competitive and suggests potential applications in routine glucose testing, in particular in academic teaching and research laboratories. The work is also a starting point for transfer of the methodology from simple cable Cu electrodes to arrays of miniaturized Cu sensors, using a combination of microlithography, electroforming and molding (LIGA). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Soontaranon S.,Synchrotron Light Research Institute |
Rugmai S.,Synchrotron Light Research Institute |
Rugmai S.,Suranaree University of Technology
Chinese Journal of Physics | Year: 2012
A Small Angle X-ray Scattering (SAXS) beamline has been constructed at the Siam Photon Laboratory (SPL) of the Synchrotron Light Research Institute (SLRI). The SAXS beamline is dedicated for nano structural characterization of materials. The synchrotron light originated from a bending magnet is monochromatized using a Double Multilayer Monochromater (DMM) to provide x-ray in the energy range of 6-9 keV. A toroidal mirror is used to focus x-ray to the sample position. The experimental station is equipped with a CCD detector, in which the sample-detector distance can be extended to up to 4 m. The beamline has been commissioned and opened for users in March 2011. The commissioning result of the beamline, including SAXS measurement of nano particles, is presented. © 2012 The Physical Society of the Republic of China.
Thungprasert S.,Chiang Mai University |
Sarakonsri T.,Chiang Mai University |
Klysubun W.,Synchrotron Light Research Institute |
Vilaithong T.,Chiang Mai University
Journal of Alloys and Compounds | Year: 2011
In this research, Pt-based ternary catalysts for proton exchange membrane fuel cell (PEMFC) have been successfully prepared by the solution route method. This type of catalyst was claimed to improve the activities of oxygen reduction reaction (ORR). The ternary catalyst was prepared using 10% platinum, 5% cobalt, and 5% chromium by weight support on untreated and treated carbons by reduction with NaBH4 at room temperature. The FTIR spectra showed a new functional group as carboxyl group on treated carbon using H2O 2. The XRD patterns for both carbon samples confirmed platinum and carbon phases in the products. The EDS spectra detected platinum, cobalt, chromium, oxygen and carbon atoms in the prepared catalysts. The XAS patterns revealed that the products were mixed Pt-CoO-Cr2O3 catalysts. The SEM and TEM images showed more dispersion of catalyst on the treated carbon support surface than on the untreated carbon support. Particles size were 3.97 nm for untreated carbon and 1.93 nm for treated carbon. Finally, the electrochemical property was tested by CV technique. It indicated that Pt-CoO-Cr2O3/C catalyst supported on treated carbon exhibited the highest performance among the prepared ternary alloy catalysts. © 2011 Elsevier B.V. All rights reserved.
Patton R.J.,University of Hull |
Klinkhieo S.,Synchrotron Light Research Institute
Proceedings of the 2010 American Control Conference, ACC 2010 | Year: 2010
This work is motivated by the challenge to develop an adaptive strategy for systems that are complex, have actuator faults and are difficult to control using linear methods. The novelty lies in combined use of LPV fault estimation and LPV fault compensation to meet active FTC performance requirements. The paper proposes a new design approach for systems which can be characterized via sets of LMIs and can be obtained using efficient interior-point algorithms. A polytopic LPV estimator is synthesized for generating actuator fault estimates used in an FTC scheme to schedule the nominal system state feedback gain, thereby maintaining the system performance over a wide operating range within a proposed polytopic model. The active FTC controller is a function of fault effect factors derived on-line. The effectiveness of the proposed method is demonstrated through a nonlinear two-link manipulator system with torque input faults at each joint. © 2010 AACC.
Juntong N.,Synchrotron Light Research Institute |
Krainara S.,Synchrotron Light Research Institute
IPAC 2014: Proceedings of the 5th International Particle Accelerator Conference | Year: 2014
The Siam Photon Source (SPS) is the 1.2 GeV second generation light source in Thailand. It is managed by the Synchrotron Light Research Institute (SLRI). The institute is located inside the campus of Suranaree University of Technology (SUT), which is approximately 20 km from the city of Nakhon Ratchasima (or normally called Korat). Korat is 250 km north-east of Bangkok. Two insertion devices (IDs) have been installed in the SPS storage ring during June to August 2013. These IDs require additional electrical field energy from RF cavity to compensate electron energy loss in the storage ring. The existing RF cavity has been pushed to its maximum capability and the new RF cavity is in the procurement process. The design and study of the new RF cavity will be presented. Electromagnetic fields of the cavity are studied together with the effects to electron beam instabilities. Copyright © 2014 CC-BY-3.0 and by the respective authors.