In development of novel chemical fertiliser loss control techniques for promoting agriculture, nanomaterials and nanotechnology have been involved in applications. In this study a type of natural nanoclay material, attapulgite, was applied after electron beam treatment of the as-mined material as a chemical fertiliser loss control agent (LCA). The LCA was mixed with normal chemical fertiliser to form loss control fertiliser (LCF). The LCF was applied to Thai rice growing in a farm field. In the aqueous phase, LCF self-assembled to form 3D micro/nano networks. The fertiliser could form fibrous crystals with the clay rods as the nucleus, obtaining a higher nitrogen spatial scale, so that the nutrient could be retained by the soil filtering layer, and thus nitrogen loss was reduced. Two types of LCFs, machine-made and manmade, were applied. After the LCF was applied, the growth and crop yield of the rice were studied and compared with that obtained with normal fertiliser, and the pH, N and K in soil were measured and analysed. On the control of releasing nitrogen, the two LCFs played some roles compared with the fertiliser control, particularly for some varieties, and the machine-made LCF performed better. On the control of the soil pH to be not too acidic, the manmade LCF performed better but was variety dependent. On the control of releasing K, a comparison showed that the manmade LCF was better than the machine-made LCF. The differences in the LCF behaviour should be correlated with the LCF structure which was due to how they were made.

Pt-based ternary compounds supported on carbon have been proposed as a catalyst for oxygen reduction reaction (ORR), with relatively low over-potential, leading to high reaction rates compared to Pt/C catalysts. In this research, samples of 20% wt platinum-copper-nickel (at 2 : 1 : 1 and 6 : 1 : 1 ratios) supported on treated carbon (N115 and Vulcan XC-72) were prepared by solution route method, using NaBH4 as a reducing agent. The XRD patterns of the product samples match well with the simulated PtCuNi alloy cubic structure and carbon phases. The SEM and TEM images show well-dispersed metal particles on the treated carbon supports. Metal particle sizes, measured from TEM micrographs, were 2.50-3.00 nm. The electrochemical performance of the PtCuNi alloy at the ratio of 6 : 1 : 1 on carbon Vulcan XC-72 delivered the highest current of 278.70 A/cm(2) . g(pt) at 600 mV.

The production and the utilization of four fundamental probes, namely, electron, ion, neutron and photon probes, have played a vital role in the research and development in modern science and technology. These probes are generated by various types of particle accelerators. In Thailand, beams of charged particles are accelerated to energies ranging from keV to GeV. Low-energy (<200 keV) heavy-ion implanters are applied to research in material surface modification, biology and nanotechnology whereas the MeV tandem accelerator is employed in material surface analysis and lithography. Relativistic femtosecond electron beams are used to produce transition radiation with wavelengths in the tera-Hertz (THz) region. Synchrotron radiation is generated from a 1.2-GeV electron synchrotron coupled to a storage ring. The details of present and future accelerator R & D activities are presented and discussed.

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 H2O2. 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 3.97nm for untreated carbon and 1.93nm 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.

Coherent transition radiation in a THz regime generated from a femtosecond electron bunch is explored for its potential use in imaging applications. Due to water sensitivity, the THz imaging experiment is performed on a proton exchange membrane fuel cell (PEMFC) to assess the ability to quantify water in the flow field of the cell. In this investigation, the PEMFC design and the experimental setup for the THz imaging is described. The results of the THz images in the flow field are also discussed.

We have measured double-differential cross sections for 175 MeV quasi-monoenergetic neutrons on oxygen. The detector setup used in MEDLEY consists of eight Si-Si-CsI telescopes designed to detect light ions (up to A=4), with a low-energy threshold and over an angular domain ranging from 20 degrees to 160 degrees, in steps of 20 degrees. The Delta E - E technique is used to identify the light ions. Suppression of events induced by neutrons in the low-energy tail of the neutron field is achieved by time-of-flight techniques. The data are normalised relative to elastic np scattering measured in one of the telescopes at 20 degrees. We present preliminary double-differential production cross sections for protons, deuterons and a particles and compare them with theoretical reaction model calculations.

This review summarizes recent progress of a newly developed novel bioengineering technology, namely low-energy ion beam bioengineering (IBB), achieved at Chiang Mai University, Thailand. Low-energy IBB has demonstrated powerful impacts and highly potential applications on biology, agriculture, horticulture and life science owing to multiple-factor interaction between energetic ions and biological organisms as well as low-cost and convenience in operation. Since late 1990s, IBB research programs have been vigorously carried out at Chiang Mai University. A group of scientists consisting of physicists, biologists, horticulturists, agriculturists, chemists, and medical scientists have developed special IBB ion beam lines and relevant techniques to use low-energy ion beam bombardment of biological organisms to induce mutation breeding and gene transfer. Besides the IBB applications, research interests are also focused onto basic mechanisms on ion interaction with DNA and biological cells to reveal physics and biology involved in the ion beam inductions of mutation and gene transfer. The results have been applied to serve developments of local agriculture and horticulture and promote national scientific research qualities. The contents include introductions to low-energy IBB techniques and facilities, and chapters on ion beam induced gene transfer, ion interaction with the cell envelope, ion beam induced mutation, and ion interaction with living cells and DNA.

The present study describes the preparation of catalyst nanocomposites comprised of 20 wt.% Pt-Co-Cr (2 : 1 : 1) particles attached on the surface of carbon Vulcan XC-72R by microwave radiation; cases of carbon being chemically treated and untreated are considered. Ethylene glycol was used as the solvent and electron source for the microwave-assisted reduction reaction, whereas H2PtCl6 center dot xH(2)O, Co(NO3)(3) center dot 6H(2)O and Cr(NO3)(3) center dot 9H(2)O were used as metal precursors. The C powder surface was chemically modified by stirring the C in 8N H2O2 for 48 h. For the nanocomposite in which C was not treated, EDS analysis showed a content of 4.9 wt.% Pt and 1.2 wt.% Cr with only a trace amount of Co. Higher Pt and Cr contents were observed in the catalyst sample prepared from treated carbon (5.6% Pt and 2.2% Cr), but no Co was detected. Chromium appeared as Cr3O4 in both samples confirmed by the XAS spectrum. The obtained phase was therefore Pt-Cr3O4/C for both samples. The TEM results indicated that the average particle size of Pt-Cr3O4 was 2.22+/-0.41 nm on treated C and 1.93+/-0.34 nm on untreated C. By the CV technique, it was observed that the catalytic activity of the treated carbon Pt-Cr3O4 catalyst was not only higher than that of the untreated carbon Pt-Cr3O4 catalyst, but also higher than that of the standard platinum catalyst.

In this paper we present a novel method to induce gene transfer in yeast (Saccharomyces cerevisiae) using a low-energy ion beam. By accelerating nitrogen ions to the 50-60 keV energy range with ions fluences of 1-100 x 10(15) ions/cm(2), yeast cells were bombarded to characterize the decrease in survival with increasing energy level. Using bombardment conditions optimized for yeast cell survival (50 keV with ion fluences of 1 and 2 x 10(15) ions/cm(2)), a compatible plasmid vector (pYES2) was successfully introduced into the yeast cell with higher concentrations of the plasmid providing improved plasmid transfer. To investigate expression of exotic genes in yeast, two marker genes - GFP and lipoic acid synthetase from Bacillus licheniformis - were chosen to subdone into pYES2 (designed pYGFP and pYlip respectively), and subsequently transformed into the cells. After 10 h of induction, the expression levels of these genes were analyzed. The pYGFP transformed yeast exhibited a high intensity of GFP protein in the yeast cells and the pYLip showed the expected additional protein-band at 34 kDa detected by SDS-polyacrylamide gel electrophoresis. As a method to transform yeast, low-energy ion beam bombardment is both highly efficient and since yeast can be transformed in less than 10 min, much more rapid than other yeast transformation methods. (C) 2009 Elsevier B.V. All rights reserved.

Low-energy ion beam biotechnology, as a newly established and developed highly interdisciplinary technology, has been vigorously applied to modification of horticultural plants for induction of mutations at Chiang Mai University (CMU). Chiang Mai is the horticultural center of Thailand with a magnificent variety of floral resources thanks to its peculiarly favorable environment and climate. Ion beam bombardment induced mutations of flowers have further exploited the horticultural potential. This paper reports recent progress in research and applications of ion beam biotechnology for floral mutation at CMU. Ions at low energies of several tens of keV were implanted into flower seeds, buds and receptacles of various species in vacuum to fluences of an order of 1016 ions/cm2 using self-developed special techniques for the living organism survival. A broad spectrum of mutants has been obtained including changes in phenotypes such as the flower color, color intensity, flower shape, and petal shape and size. DNA-fingerprint analysis revealed changes at the DNA level. Physical mechanisms involved in the ion beam induction have been investigated, and however still remained obscure.

Ion implantation was applied as an effective method to gemological modification of Thai local natural corundum including sapphire and ruby for enhancement of the essential qualities of the gemstones. Oxygen and nitrogen ions at medium and low energies to various fluences were implanted to the natural gemstones. The heavy ion irradiation modifies the color to desirable colors and improves the color distribution, transmission and lustre. These modifications lead to the improvement of quality of gemstones and thus the market value. Possible mechanisms of these modifications have been proposed. The main cause for these modifications could be the changes in oxidation states of impurity metals, induction of charge transfer from one metal cation to other and the production of color centres.

This work was aimed at locating the gene involved in antifungal ability of bacterium Bacillus licheniformis into yeast by application of low energy ion beam. Nitrogen ions were used to bombard the bacterial cells under vacuum condition at energy 30 keV with a fluence of 10(16) ions/cm(2). The HAT-RAPD marker revealed the modified polymorphism fragment (615 bp) presenting in the wild type but not in the bacterial mutant. This fragment was subcloned into pGEM-T easy vector and then sequenced. When the sequence of this fragment was compared with those already contained in the database, the fragment was found to be related to the lipase gene. in order to transfer the full gene, the amplified fragment of 615 bp was subcloned into a high expression vector, pYES2. Low energy ion beam was applied again but for the gene transfer into the Saccharomyces cerevisiae strain W303C. Nitrogen ions bombarded the yeast cells under vacuum condition at an energy of 50 keV with ion fluences of 5-20 x 10(15) ions/cm(2). After the treatment, the cells were screened by medium selection and restriction enzymes. The putative gene was expressed in yeast and the ability of the protein was observed by Dual culture technique with inhibition of plant disease fungal. The results provided evidence for the presence of the useful gene in the final product yeast with the assistance of low energy ion beams. (C) 2009 Elsevier B.V. All rights reserved.

Recently, programs of surface modification of materials for local industries by ion beams and plasma have been vigorously carried out and related facilities, technologies and applications have been continuously developed at Chiang Mai University on the basis of previous work. Some examples are presented. Punching tools from local industry were N-ion implanted with a specially designed process to achieve both high hardness and impact toughness so as to increase the lifetime of the tools by 3–4 times. High-fluence N-ion implantation in stainless steel of the fuel cell plates increased corrosion resistance. Plasma immersion ion implantation and deposition (PIII/D) coated diamond-like carbon (DLC) thin films on various substrate materials such as stainless steel of the fuel cell plates, glass of the plastic lens mould, and magnets of the dental rectification accessories to improve both mechanical and chemical properties. Plasma treatment of commercial textiles modified the wettability of the material. The development in the ion beam and plasma applications for industries has promoted research for understanding physics involved as well as student education of the university.

Since non-noble metal-based catalysts have more activity and selectivity in four electron oxygen reduction than platinum-based catalysts for PEMFC cathodes, the development of non-noble metal-based catalysts has been of interest. Iron-based non-noble metal catalysts were prepared by supporting various oxides and tetraphenylporphyrin complexes of iron on carbon supports by a chemical process followed by heat treatment at various temperatures. Depending on these procedures, Fe3O4 and Fetetraphenylporphyrin catalysts supported on carbon were obtained. X-ray diffraction patterns of both Fe3O4 and Fetetraphenylporphyrin based catalysts indicated the crystallographic structure of Fe3O4; however, selected area diffraction patterns obtained from the TEM technique showed the Fe3N phase in Fe-tetraphenylporphyrin catalysts supported on carbon. Moreover, TEM images of Fe3O4 based catalysts showed a smaller particle size and more uniform distribution than Fetetraphenylporphyrin-based catalysts. Among the catalysts prepared, Fe-tetraphenylporphyrin catalyst supported on carbon with a heat treatment at 600 C showed the highest electrochemical activity in an oxygen reduction reaction.

Amorphous carbon (a-C) films were deposited on Si(1 0 0) wafers by a filtered cathodic vacuum arc (FCVA) plasma source. A negative electrical bias was applied to the silicon substrate in order to control the incident energy of carbon ions. Effects of the electrical bias on the a-C/Si interface characteristics were investigated by using standard Rutherford backscattering spectrometry (RBS) in the channeling mode with 2.1-MeV He2+ ions. The shape of the Si surface peaks of the RBS/channeling spectra reflects the degree of interface disorder due to atomic displacement from the bulk position of the Si crystal. Details of the analysis method developed are described. It was found that the width of the a-C/Si interface increases linearly with the substrate bias voltage but not the thickness of the a-C film.

Hydrophobicity of Thai silk has been improved by plasma treatment using SF,, gases discharged by an inductively coupled plasma (ICP). The plasma was generated under a pressure range of 1.3-40.0 Pa while the RF power input is in a range of 20-100 W. A single RF compensated Langmuir probe and optical emission spectroscopy (OES) were used for the plasma diagnostics. The mechanisms responsible for the hydrophobic behavior were evaluated by SEM. X-ray photoelectron spectroscopy (XPS), attenuated total reflection (ATR) infrared spectroscopy, and were compared with quantum mechanical calculation. ATR-IR detected slightly changes for the peak intensities of the bands located in the frequency region of 1000-1050 cm(-1). XPS analysis results show the presence of CF-CF group as the increment of C/F ratio with increasing pressures. The results also agree with the density functional calculation. A fluorine radical shows the deposition by CH+F-CF+H- reaction. (C) 2008 Elsevier B.V. All rights reserved.

In order to develop a high-quality ion beam line for bioengineering research and applications, the ion beam emittance of a beam line was measured to provide information on designing the following beam optics to meet the ion beam's bioengineering requirements. The measurement was based on the transformation matrix theory for electrostatic and magnetic devices. The experimental setup included an ion source, an Einzel lens, a self-developed quadrupole magnetic lens and a multi-wire beam profile monitor. In the measurement, the beam size was first measured at the beam profile monitor as a function of focusing and was then fitted to the transformation matrix parameters. Finally, the best-fitted parameters were used to construct the phase ellipse of the beam's emittance. The details on the relevant theory and measurement are described and the results are presented.

The ion beam intensity distribution in an ion-beam-bombarded area is particularly important for treating biological targets that are location-sensitive to ion energy and fluence. In order to investigate the beam intensity distribution, we carried out a theoretical calculation. The theoretical study was started from an assumption of a certain 3-D distribution of the beam intensity for a fixed beam spot and was followed by integration to describe a scanning of this beam spot within a certain target area. The details of the calculations with an example of Gaussian distribution for the initial fixed beam spot are presented. The calculated result was compared with an experimentally-measured ion-beam intensity distribution, and good agreement was achieved. The scanning ion-beam intensity distribution was applied to guide ion-beam-induced gene transfer in biological cells such as the bacteria E. coli.

Low-energy ion beam biotechnology has seen rapid development worldwide in recent years. This is an important expansion of studies on ion beam modification of solid materials, vastly different from and more complex than the latter. Among other novelties, we have focused our interest on ion beam bombardment effects on plant and bacterial cell envelopes and tried to understand mechanisms involved in ion beam-induced gene transfer. Through a comprehensive investigation, we have discovered ion beam-induced formation of nanocrater-like structures in the cell envelope, a general phenomenon of ion beam bombardment of cells; these structures may act as pathways for exogenous macromolecule transfer. We have also quantitatively obtained abnormally great penetration depth and sputtering of ions in the cell envelope. All these results are significantly advantageous for ion beam processing of biological cells.