Browsing by Author "PTT Public Company Limited"

Filter results by typing the first few letters
Now showing 1 - 8 of 8
  • No Thumbnail Available
    PublicationMetadata only
    Clinical validation of a Cas13-based assay for the detection of SARS-CoV-2 RNA
    (2020-01-01) Maturada Patchsung; Krittapas Jantarug; Archiraya Pattama; Kanokpol Aphicho; Surased Suraritdechachai; Piyachat Meesawat; Khomkrit Sappakhaw; Nattawat Leelahakorn; Theerawat Ruenkam; Thanakrit Wongsatit; Niracha Athipanyasilp; Bhumrapee Eiamthong; Benya Lakkanasirorat; Thitima Phoodokmai; Nootaree Niljianskul; Danaya Pakotiprapha; Sittinan Chanarat; Aimorn Homchan; Ruchanok Tinikul; Philaiwarong Kamutira; Kochakorn Phiwkaow; Sahachat Soithongcharoen; Chadaporn Kantiwiriyawanitch; Vinutsada Pongsupasa; Duangthip Trisrivirat; Juthamas Jaroensuk; Thanyaporn Wongnate; Somchart Maenpuen; Pimchai Chaiyen; Sirichai Kamnerdnakta; Jirawat Swangsri; Suebwong Chuthapisith; Yongyut Sirivatanauksorn; Chutikarn Chaimayo; Ruengpung Sutthent; Wannee Kantakamalakul; Julia Joung; Alim Ladha; Xin Jin; Jonathan S. Gootenberg; Omar O. Abudayyeh; Feng Zhang; Navin Horthongkham; Chayasith Uttamapinant; PTT Public Company Limited; Vidyasirimedhi Institute of Science and Technology; McGovern Institute; Society of Fellows, Harvard University; Massachusetts Institute of Technology; Mahidol University; Faculty of Medicine, Siriraj Hospital, Mahidol University; Harvard University; Howard Hughes Medical Institute; Burapha University; Broad Institute; Massachusetts Consortium on Pathogen Readiness
    © 2020, The Author(s), under exclusive licence to Springer Nature Limited. Nucleic acid detection by isothermal amplification and the collateral cleavage of reporter molecules by CRISPR-associated enzymes is a promising alternative to quantitative PCR. Here, we report the clinical validation of the specific high-sensitivity enzymatic reporter unlocking (SHERLOCK) assay using the enzyme Cas13a from Leptotrichia wadei for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)—the virus that causes coronavirus disease 2019 (COVID-19)—in 154 nasopharyngeal and throat swab samples collected at Siriraj Hospital, Thailand. Within a detection limit of 42 RNA copies per reaction, SHERLOCK was 100% specific and 100% sensitive with a fluorescence readout, and 100% specific and 97% sensitive with a lateral-flow readout. For the full range of viral load in the clinical samples, the fluorescence readout was 100% specific and 96% sensitive. For 380 SARS-CoV-2-negative pre-operative samples from patients undergoing surgery, SHERLOCK was in 100% agreement with quantitative PCR with reverse transcription. The assay, which we show is amenable to multiplexed detection in a single lateral-flow strip incorporating an internal control for ribonuclease contamination, should facilitate SARS-CoV-2 detection in settings with limited resources.
  • No Thumbnail Available
    PublicationMetadata only
    Dependence of MWCNT production via co-pyrolysis of industrial slop oil and ferrocene on growth temperature and heating rate
    (2020-09-01) Weerawut Chaiwat; Napat Kaewtrakulchai; Pimpage Sangsiri; Apiluck Eiad-ua; Winadda Wongwiriyapan; Nawin Viriya-empikul; Komkrit Suttiponpanit; Tawatchai Charinpanitkul; PTT Public Company Limited; Chulalongkorn University; King Mongkut's Institute of Technology Ladkrabang; Thailand National Nanotechnology Center; Mahidol University; Research Network of NANOTEC-KU on Nanocatalyst and Nanomaterials for Sustainable Energy and Environment
    © 2020 Elsevier B.V. Multi-walled carbon nanotubes (MWCNTs) could be produced from industrial slop oil via pyrolysis with the presence of ferrocene. Dependence of characteristics of the produced MWCNTs on their growth temperature and heating rate of mixtures of industrial slop oil and ferrocene was experimentally investigated. With low-molecular weighted hydrocarbon, the resultant MWCNTs with nominal diameters of 10–50 nm and yields of 45–65 wt% could be produced within a growth temperature range of 750–950 °C. Meanwhile, high-molecular weighted hydrocarbon could provide substantial yield of MWCNTs only within the growth temperature range of 850–950 °C. It was found that a higher heating rate of 9 °C/min could result in preferable production of MWCNTs with higher purity. Based on comprehensive analyses, a schematic pathway of MWCNT production via co-pyrolysis of mixtures of industrial slop oil and ferrocene was proposed.
  • No Thumbnail Available
    PublicationMetadata only
    Effect of CuO/ZnO catalyst preparation condition on alcohol-assisted methanol synthesis from carbon dioxide and hydrogen
    (2019-08-02) S. Likhittaphon; R. Panyadee; W. Fakyam; S. Charojrochkul; T. Sornchamni; N. Laosiripojana; S. Assabumrungrat; P. Kim-Lohsoontorn; PTT Public Company Limited; Chulalongkorn University; Thailand National Metal and Materials Technology Center; Mahidol University; King Mongkut s University of Technology Thonburi
    © 2018 Hydrogen Energy Publications LLC CuO/ZnO catalysts are synthesized using a co-precipitation method with different precipitation temperatures (298–353 K) and pH values (5–9). A conventional precipitation is compared to an ultrasonic-assisted precipitation at each precipitating temperature. Methanol is directly synthesized from CO2 and H2 (1:3 mol ratio) through an alcohol-assisted reaction (423 K, 5 MPa, 24 h) by using different alcohols (ethanol, propanol and butanol) as a medium. There are two parts for the challenge of this research, including the preparation of CuO/ZnO catalysts using an ultrasonic-assisted precipitation and, methanol synthesis through an alcohol-assisted method. It is found that the precipitation temperature and pH value significantly affect the catalyst properties and the reaction activity. An ultrasonic irradiation helps facilitate the crystalline phase formation and decrease precipitation temperature. The highest yield of methanol is obtained when CuO/ZnO is precipitated at 333 K from the conventional precipitation (31%) while it is at 313 K from the ultrasonic-assisted precipitation (32%). In addition, the different type of alcohol strongly affects methanol yield and CO2 conversion. The use of larger alcohol molecules offers higher CO2 conversion but lower methanol yield.
  • No Thumbnail Available
    PublicationMetadata only
    Effect of strontium and zirconium doped barium cerate on the performance of proton ceramic electrolyser cell for syngas production from carbon dioxide and steam
    (2019-08-02) J. Sarabut; S. Charojrochkul; T. Sornchamni; N. Laosiripojana; S. Assabumrungrat; U. Wetwattana-Hartely; P. Kim-Lohsoontorn; PTT Public Company Limited; King Mongkut's University of Technology North Bangkok; Chulalongkorn University; Thailand National Metal and Materials Technology Center; Mahidol University; King Mongkut s University of Technology Thonburi
    © 2018 Hydrogen Energy Publications LLC Syngas has been produced from carbon dioxide (CO2) and steam using a proton ceramic electrolyser cell. Proton-conducting electrolytes which exhibit high conductivity can suffer from low chemical stability. In this study, to optimize both proton conductivity and chemical stability, barium cerate and doped barium cerate are synthesized using solid state reaction method: BaCeO3 (BC), Ba0.6Sr0.4CeO3-α (BSC), Ba0.6Sr0.4Ce0.9Y0.1O3-α (BSCY), and BaCe0.6Zr0.4O3-α (BCZ). The BC, BSC, and BSCY are calcined at 1100 °C for 2 h and BCZ is calcined at 1300 °C for 12 h, respectively. All samples exhibit 100% perovskite and crystallite sizes equal 37.05, 28.46, 23.65 and 17.46 nm for BC, BSC, BSCY and BCZ, respectively. Proton conductivity during steam electrolysis as well as catalytic activity toward the reverse water gas shift reaction (RWGS) is tested between 400 and 800 °C. The conductivity increases with temperature and the values of activation energy of conduction are 64.69, 100.80, 103.78 and 108.12 kJ mol−1 for BSCY, BC, BSC, and BCZ, respectively. It is found that although BCZ exhibits relatively low conductivity, the material provides the highest CO yield at 550–800 °C, followed by BSCY, BSC, and BC, correlating to the crystallite size and BET surface area of the samples. Catalytic activity toward RWGS of composited Cu and electrolytes is also measured. Additional Cu (60 wt%) significantly increases catalytic activity. The CO yield increases from 3.01% (BCZ) to 43.60% (Cu/BCZ) at 600 °C and CO can be produced at temperature below 400 °C. There is no impurity phase detected in BCZ sample after exposure to CO2-containing gas mixture (600 °C for 5 h) while CeO2 phase is detected in BSC and BSCY and both CeO2 and BaO are observed in BC sample.
  • No Thumbnail Available
    PublicationMetadata only
    Efficient mercury removal at ultralow metal concentrations by cysteine functionalized carbon-coated magnetite
    (2020-11-02) Assadawoot Srikhaow; Teera Butburee; Weeraphat Pon-On; Toemsak Srikhirin; Kanchana Uraisin; Komkrit Suttiponpanit; Suwilai Chaveanghong; Siwaporn Meejoo Smith; PTT Public Company Limited; Kasetsart University; Thailand National Nanotechnology Center; Mahidol University; Center of Sustainable Energy and Green Materials and Department of Chemistry
    © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This work reports the preparation and utility of cysteine-functionalized carbon-coated Fe3 O4 materials (Cys-C@Fe3 O4) as efficient sorbents for remediation of Hg(II)-contaminated water. Efficient removal (90%) of Hg(II) from 1000 ppb aqueous solutions is possible, at very low Cys-C@Fe3 O4 sorbent loadings (0.01 g sorbent per liter of Hg(II) solution). At low metal concentrations (5–100 ppb Hg(II)), where adsorption is typically slow, Hg(II) removal efficiencies of 94–99.4% were achievable, resulting in final Hg(II) levels of <1.0 ppb. From adsorption isotherms, the Hg(II) adsorption capacity for Cys-C@Fe3 O4 is 94.33 mg g−1, around three times that of carbon-coated Fe3 O4 material. The highest partition coefficient (PC) of 2312.5 mgg−1 µM−1 was achieved at the initial Hg (II) concentration of 100 ppb, while significantly high PC values of 300 mgg−1 µM−1 and above were also obtained in the ultralow concentration range (≤20 ppb). Cys-C@Fe3 O4 exhibits excellent selectivity for Hg(II) when tested in the presence of Pb(II), Ni(II), and Cu(II) ions, is easily separable from aqueous media by application of an external magnet, and can be regenerated for three subsequent uses without compromising Hg(II) uptake. Derived from commercially available raw materials, it is highly possible to achieve large-scale production of the functional sorbent for practical applications.
  • No Thumbnail Available
    PublicationMetadata only
    Erratum to ‘Effect of strontium and zirconium doped barium cerate on the performance of proton ceramic electrolyser cell for syngas production from carbon dioxide and steam’ [Int J Hydrogen Energy 44 (2019) 20634–20640] (International Journal of Hydrogen Energy (2019) 44(37) (20634–20640), (S0360319918323450), (10.1016/j.ijhydene.2018.07.121))
    (2021-02-19) J. Sarabut; S. Charojrochkul; T. Sornchamni; N. Laosiripojana; S. Assabumrungrat; U. W. Hartley; P. Kim-Lohsoontorn; PTT Public Company Limited; King Mongkut's University of Technology North Bangkok; Chulalongkorn University; Thailand National Metal and Materials Technology Center; Mahidol University; King Mongkut's University of Technology Thonburi
    The publisher regrets that Dr. Wetwatana-Hartley's name was spelled in correctly in the original article and should have appeared as above. The publisher would like to apologise for any inconvenience caused.
  • No Thumbnail Available
    PublicationMetadata only
    Sensitivity Enhancement of Benzene Sensor Using Ethyl Cellulose-Coated Surface-Functionalized Carbon Nanotubes
    (2018-01-01) Thanattha Chobsilp; Worawut Muangrat; Chaisak Issro; Weerawut Chaiwat; Apiluck Eiad-Ua; Komkrit Suttiponparnit; Winadda Wongwiriyapan; Tawatchai Charinpanitkul; PTT Public Company Limited; Shinshu University; Chulalongkorn University; King Mongkut's Institute of Technology Ladkrabang; Mahidol University; Burapha University
    © 2018 Thanattha Chobsilp et al. A hybrid sensor based on the integration of functionalized multiwalled carbon nanotubes (MWCNTs) with ethyl cellulose (EC) was fabricated for sensitivity enhancement of benzene detection. To functionalize the surface of MWCNTs, MWCNTs were treated with hydrochloric acid for 60 min (A60-MWCNTs), while other MWCNTs were treated with oxygen plasma for 30, 60, 90, and 120 min (P30-MWCNTs, P60-MWCNTs, P90-MWCNTs, and P120-MWCNTs, resp.). Pristine MWCNTs, A-MWCNTs, and P-MWCNTs were dispersed in 1,2-dichloroethane, then dropped onto a printed circuit board consisting of Cu/Au electrodes used as the sensor platform. Next, EC was separately spin coated on the pristine MWCNTs, A-MWCNTs, and P-MWCNTs (EC/MWCNTs, EC/A-MWCNTs, and EC/P-MWCNTs, resp.). All sensors responded to benzene vapor at room temperature by increasing their electrical resistance which was sensitive to benzene vapor. The EC/P90-MWCNTs enabled an approximately 11-fold improvement in benzene detection compared to EC/MWCNTs. The sensitivity of all sensors would be attributed to the swelling of EC, resulting in the loosening of the MWCNT network after benzene vapor exposure. The differences of the sensing responses of the EC/MWCNTs, EC/A-MWCNTs, and EC/P-MWCNTs would be ascribed to the differences in crystallinity and functionalization of MWCNT sidewalls, suggesting that acid and oxygen plasma treatments of MWCNTs would be promising techniques for the improvement of benzene detection.
  • No Thumbnail Available
    PublicationMetadata only
    Temperature dependence of iron oxide-graphene oxide properties for synthesis of carbon nanotube/graphene hybrid material
    (2020-01-01) Oukrit Thonganantakul; Sira Srinives; Weerawut Chaiwat; Konrat Kerdnawee; Komkrit Suttiponparnit; Tawatchai Charinpanitkul; PTT Public Company Limited; Chulalongkorn University; Mahidol University; Research Network of NANOTEC-KU on Nanocatalyst and Nanomaterials for Sustainable Energy and Environment
    © 2020 Elsevier B.V. Iron oxide embedded on graphene oxide (Fe2O3/GO) was prepared by chemical exfoliation followed by wet impregnation. Reduced Fe2O3/GO could be employed as catalyst for synthesizing carbon nanotubes CNTs via catalytic chemical vapor deposition CCVD of n-hexane within a temperature range of 700-1000 °C. It was found that during the synthesis process, pretreatment affected the transformation of iron nanoparticles in the Fe2O3/GO, leading to significant difference in formation of carbon nanoparticles. When the Fe2O3/GO was employed within a temperature range of 700−900 °C, Fe2O3 was reduced to α-Fe, yielding CNT growth on the graphene surface. However, the α-Fe could be transformed to γ-Fe when the Fe2O3/GO was subject to the temperature of 1000 °C, resulting in formation of carbon spheres instead of CNTs. After experimentally verified, conceptual scenarios of CNT/graphene hybrid material formation with respect to the pretreatment and synthesis temperature were proposed and discussed.