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Dr. Stefan Ručman
Mahidol University

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0 Crystal Engineering
0 Micro
0 Magnetic Field
0 nano and functional materials
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Short Biography

Biologist + Immunology + Nanoscience & Nanotechnology + Enviromental Science + Chemistry = Me

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Journal article
Published: 09 July 2021 in Molecules
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Pretreatment and codigestion are proven to be effective strategies for the enhancement of the anaerobic digestion of lignocellulosic residues. The purpose of this study is to evaluate the effects of pretreatment and codigestion on methane production and the hydrolysis rate in the anaerobic digestion of agricultural wastes (AWs). Thermal and different thermochemical pretreatments were applied on AWs. Sewage sludge (SS) was selected as a cosubstrate. Biochemical methane potential tests were performed by mixing SS with raw and pretreated AWs at different mixing ratios. Hydrolysis rates were estimated by the best fit obtained with the first-order kinetic model. As a result of the experimental and kinetic studies, the best strategy was determined to be thermochemical pretreatment with sodium hydroxide (NaOH). This strategy resulted in a maximum enhancement in the anaerobic digestion of AWs, a 56% increase in methane production, an 81.90% increase in the hydrolysis rate and a 79.63% decrease in the technical digestion time compared to raw AWs. On the other hand, anaerobic codigestion (AcoD) with SS was determined to be ineffective when it came to the enhancement of methane production and the hydrolysis rate. The most suitable mixing ratio was determined to be 80:20 (Aws/SS) for the AcoD of the studied AWs with SS in order to obtain the highest possible methane production without any antagonistic effect.

ACS Style

Lütfiye Dumlu; Asli Ciggin; Stefan Ručman; N. Perendeci. Pretreatment, Anaerobic Codigestion, or Both? Which Is More Suitable for the Enhancement of Methane Production from Agricultural Waste? Molecules 2021, 26, 4175 .

AMA Style

Lütfiye Dumlu, Asli Ciggin, Stefan Ručman, N. Perendeci. Pretreatment, Anaerobic Codigestion, or Both? Which Is More Suitable for the Enhancement of Methane Production from Agricultural Waste? Molecules. 2021; 26 (14):4175.

Chicago/Turabian Style

Lütfiye Dumlu; Asli Ciggin; Stefan Ručman; N. Perendeci. 2021. "Pretreatment, Anaerobic Codigestion, or Both? Which Is More Suitable for the Enhancement of Methane Production from Agricultural Waste?" Molecules 26, no. 14: 4175.

Journal article
Published: 29 January 2021 in Crystals
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Among the various methods for the preparation of nanoparticles, a sparking process at atmospheric pressure is of interest because it is a simple method for producing nanoparticles ranging from a few nanometer-sized particles to agglomerated film structures. In this research, we studied the effects of metal electrode properties on nanoparticle sizes. The experiments were carried out by applying a high voltage to different metal sparkling tips. The transfer of energies from positive ions and electron bombardments induced the melting and vaporization of electrode metals. Based on this research, we have developed a model to describe the formation of a nanoparticle film on the substrate, placed under the sparking gap, and the nanostructure produced by metal vapor on the sparking electrodes. The model provides a realistic tool that can be used for the design of a large-scale coating and the application of nanoparticles developed by this process for the filtration of PM2.5 mask fabric by air.

ACS Style

Tewasin Kumpika; Stefan Ručman; Siwat Polin; Ekkapong Kantarak; Wattikon Sroila; Wiradej Thongsuwan; Arisara Panthawan; Panupong Sanmuangmoon; Niwat Jhuntama; Pisith Singjai. Studies on the Characteristics of Nanostructures Produced by Sparking Discharge Process in the Ambient Atmosphere for Air Filtration Application. Crystals 2021, 11, 140 .

AMA Style

Tewasin Kumpika, Stefan Ručman, Siwat Polin, Ekkapong Kantarak, Wattikon Sroila, Wiradej Thongsuwan, Arisara Panthawan, Panupong Sanmuangmoon, Niwat Jhuntama, Pisith Singjai. Studies on the Characteristics of Nanostructures Produced by Sparking Discharge Process in the Ambient Atmosphere for Air Filtration Application. Crystals. 2021; 11 (2):140.

Chicago/Turabian Style

Tewasin Kumpika; Stefan Ručman; Siwat Polin; Ekkapong Kantarak; Wattikon Sroila; Wiradej Thongsuwan; Arisara Panthawan; Panupong Sanmuangmoon; Niwat Jhuntama; Pisith Singjai. 2021. "Studies on the Characteristics of Nanostructures Produced by Sparking Discharge Process in the Ambient Atmosphere for Air Filtration Application." Crystals 11, no. 2: 140.

Communication
Published: 17 December 2020 in Crystals
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The effects of a weak magnetic field on chemical reactions are still not well understood. In our research, we used a sparking discharge process to ionize and atomize different metal wires in ambient air under usual atmospheric conditions, with and without the presence of a magnetic field. Products were collected on a glass substrate and additionally characterized for the presence of nitrogen or nitride bonding with XPS. All samples sparked with no magnetic field provided an evidence of nitride formation. Additional characterization and comparison of samples prepared inside and outside a magnetic field was performed using FTIR and collected in deionized (DI) water to investigate the influence on conductivity and pH. When the magnetic field was present during sparking discharge, a higher concentration of nanoparticles was produced.

ACS Style

Stefan Ručman; Chatdanai Boonruang; Pisith Singjai. The Effect of a Weak Magnetic Field (0 T to 0.4 T) on the Valence Band and Intramolecular Hydrogen of Inorganic Aerosol Metal–Nitrogen Gas Chemical Reactions in a Sparking Discharge Process. Crystals 2020, 10, 1141 .

AMA Style

Stefan Ručman, Chatdanai Boonruang, Pisith Singjai. The Effect of a Weak Magnetic Field (0 T to 0.4 T) on the Valence Band and Intramolecular Hydrogen of Inorganic Aerosol Metal–Nitrogen Gas Chemical Reactions in a Sparking Discharge Process. Crystals. 2020; 10 (12):1141.

Chicago/Turabian Style

Stefan Ručman; Chatdanai Boonruang; Pisith Singjai. 2020. "The Effect of a Weak Magnetic Field (0 T to 0.4 T) on the Valence Band and Intramolecular Hydrogen of Inorganic Aerosol Metal–Nitrogen Gas Chemical Reactions in a Sparking Discharge Process." Crystals 10, no. 12: 1141.

Author correction
Published: 10 March 2020 in Scientific Reports
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An amendment to this paper has been published and can be accessed via a link at the top of the paper.

ACS Style

Stefan Ručman; Panich Intra; E. Kantarak; W. Sroila; Tewasin Kumpika; J. Jakmunee; W. Punyodom; Biljana Arsić; Pisith Singjai. Author Correction: Influence of the magnetic field on bandgap and chemical composition of zinc thin films prepared by sparking discharge process. Scientific Reports 2020, 10, 4645 -2.

AMA Style

Stefan Ručman, Panich Intra, E. Kantarak, W. Sroila, Tewasin Kumpika, J. Jakmunee, W. Punyodom, Biljana Arsić, Pisith Singjai. Author Correction: Influence of the magnetic field on bandgap and chemical composition of zinc thin films prepared by sparking discharge process. Scientific Reports. 2020; 10 (1):4645-2.

Chicago/Turabian Style

Stefan Ručman; Panich Intra; E. Kantarak; W. Sroila; Tewasin Kumpika; J. Jakmunee; W. Punyodom; Biljana Arsić; Pisith Singjai. 2020. "Author Correction: Influence of the magnetic field on bandgap and chemical composition of zinc thin films prepared by sparking discharge process." Scientific Reports 10, no. 1: 4645-2.

Journal article
Published: 29 January 2020 in Scientific Reports
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We examine the influence of the magnetic field on the chemical reaction of nitrogen and carbon dioxide in sparking electric discharge of zinc wires. Samples are prepared on Indium Tin Oxide (ITO) and quartz substrates in the form of thin films at 0 T, 0.2 T and 0.4 T. Different chemical composition of thin-films prepared by sparking discharge was obtained and verified by XPS, Raman and Cyclic voltammetry. Carbon dioxide conversion to carbonates was observed for zinc sparked in CO2 and nitrogen affecting crystallization of thin films was confirmed by XRD. Synthesis route for thin-film preparation used in this study is electric sparking discharge, convenient for fast ionization of metal and gasses. Band gap energy of thin films prepared by this method was starting from 2.81 eV and 4.24 eV, with the lowest band gaps prepared on ITO in 0.4 T. Differential Mobility Analysis (DMA) indicates smaller particles are fabricated by discharging zinc wires in a higher magnetic field. Nitridification of zinc nanoparticles occurred on 0.2 Tesla magnetic field strength and it was detectable even after XPS ion gun etching. Carbonation and nitridification of zinc thin films by sparking wires inside the magnetic field to observe the effect of the magnetic field on bandgap and chemical composition are confirmed by XPS.

ACS Style

Stefan Ručman; Panich Intra; E. Kantarak; W. Sroila; Tewasin Kumpika; J. Jakmunee; W. Punyodom; Biljana Arsić; Pisith Singjai. Influence of the magnetic field on bandgap and chemical composition of zinc thin films prepared by sparking discharge process. Scientific Reports 2020, 10, 1 -11.

AMA Style

Stefan Ručman, Panich Intra, E. Kantarak, W. Sroila, Tewasin Kumpika, J. Jakmunee, W. Punyodom, Biljana Arsić, Pisith Singjai. Influence of the magnetic field on bandgap and chemical composition of zinc thin films prepared by sparking discharge process. Scientific Reports. 2020; 10 (1):1-11.

Chicago/Turabian Style

Stefan Ručman; Panich Intra; E. Kantarak; W. Sroila; Tewasin Kumpika; J. Jakmunee; W. Punyodom; Biljana Arsić; Pisith Singjai. 2020. "Influence of the magnetic field on bandgap and chemical composition of zinc thin films prepared by sparking discharge process." Scientific Reports 10, no. 1: 1-11.

Journal article
Published: 13 September 2018 in Crystals
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Since the discovery of thin films, it has been known that higher crystallinity demands higher temperatures, making the process inadequate for energy-efficient and environmentally friendly methods of thin film fabrication. We resolved this problem by sparking metal wires in a 0.4 Tesla magnetic field at ambient conditions under ultra-pure nitrogen flow to replace the annealing of thin films, and thus designed an environmentally friendly and energy-efficient thin film fabrication method. We employed grazing incidence X-Ray Diffraction spectroscopy to characterize crystallinity of Iron, Nickel, Copper and Tungsten thin films prepared by a sparking discharge process in the presence of 0.4 T magnetic field at an ambient temperature of 25 °C. Control experiment was conducted by sparking without a magnetic field present and using ultra-pure nitrogen flow and ambient air containing oxygen. The Iron thin film prepared in ultra-pure nitrogen flow preserved crystallinity even after one year of ageing. Nickel exhibited higher crystallinity when sparked in nitrogen gas flow than when sparked in atmospheric air and was the only element to crystalize under atmospheric air. Tungsten successfully crystalized after just 40 min of sparking and aluminium failed to crystalize at all, even after 12 h of sparking under nitrogen flow.

ACS Style

Stefan S. Ručman; Winita Punyodom; Jaroon Jakmunee; Pisith Singjai. Inducing Crystallinity of Metal Thin Films with Weak Magnetic Fields without Thermal Annealing. Crystals 2018, 8, 362 .

AMA Style

Stefan S. Ručman, Winita Punyodom, Jaroon Jakmunee, Pisith Singjai. Inducing Crystallinity of Metal Thin Films with Weak Magnetic Fields without Thermal Annealing. Crystals. 2018; 8 (9):362.

Chicago/Turabian Style

Stefan S. Ručman; Winita Punyodom; Jaroon Jakmunee; Pisith Singjai. 2018. "Inducing Crystallinity of Metal Thin Films with Weak Magnetic Fields without Thermal Annealing." Crystals 8, no. 9: 362.

Preprint
Published: 07 June 2018
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Grazing incidence X-Ray Diffraction spectroscopy was employed to characterize crystallinity of Iron, Nickel, Copper and Tungsten, prepared by sparking discharge process in presence of 0.4 T magnetic field at ambient temperature 25 °C. Iron thin film preserved crystallinity even after one year of ageing. Nickel exhibit higher crystallinity when sparked in nitrogen gas flow from the one sparked in oxygen. Tungsten was successfully crystalized after just 40 minutes of sparking inside of magnetic field.

ACS Style

Stefan S. Ručman; Pisith Singjai; Winita Punyodom; Jaroon Jakmunee. Resolving the Problem of Thin Films Crystallinity at Ambient Temperature by Oriented Magnetic Fields. 2018, 1 .

AMA Style

Stefan S. Ručman, Pisith Singjai, Winita Punyodom, Jaroon Jakmunee. Resolving the Problem of Thin Films Crystallinity at Ambient Temperature by Oriented Magnetic Fields. . 2018; ():1.

Chicago/Turabian Style

Stefan S. Ručman; Pisith Singjai; Winita Punyodom; Jaroon Jakmunee. 2018. "Resolving the Problem of Thin Films Crystallinity at Ambient Temperature by Oriented Magnetic Fields." , no. : 1.

Journals
Published: 22 February 2018 in New Journal of Chemistry
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Products of ionised/vaporised iron and excited nitrogen gas were obtained via a sparking process in different magnetic fields.

ACS Style

Stefan R.; Jaroon Jakmunee; Winita Punyodom; Pisith Singjai; Stefan S Ručman. A novel strategy for longevity prolongation of iron-based nanoparticle thin films by applied magnetic force. New Journal of Chemistry 2018, 42, 4807 -4810.

AMA Style

Stefan R., Jaroon Jakmunee, Winita Punyodom, Pisith Singjai, Stefan S Ručman. A novel strategy for longevity prolongation of iron-based nanoparticle thin films by applied magnetic force. New Journal of Chemistry. 2018; 42 (7):4807-4810.

Chicago/Turabian Style

Stefan R.; Jaroon Jakmunee; Winita Punyodom; Pisith Singjai; Stefan S Ručman. 2018. "A novel strategy for longevity prolongation of iron-based nanoparticle thin films by applied magnetic force." New Journal of Chemistry 42, no. 7: 4807-4810.