X-ray photoelectron spectroscopy analysis of whole cells and isolated cell walls of gram-positive bacteria: comparison with biochemical analysis.

Currently, polymeric insulation materials are widely used for energy saving in buildings. Despite of all benefits, these materials are generally sensitive to heat and highly flammable. This work discusses possibility to improve heat resistance of expanded polystyrene (EPS) foam using thin silicon dioxide (SiO2) films deposited by magnetron sputtering technique. In order to increase surface energy and adherence of SiO2 thin films to substrate EPS was plasma pretreated before films’ depositions using pulsed DC plasma generator for 40 s in argon gas. SiO2 formation was done in reactive argon and oxygen gas atmosphere. Laboratory made equipment was used for flame torch–induced heat resistance experiments. Results showed that silicon oxide films remains stable during heat resistance experiments up to 5 s and fully protects polystyrene (PS) substrate. Films are relatively stable for 30 s and 60 s and partially protect PS from melting and ignition. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy analysis confirmed that SiO2 layer, which is distributed uniformly on the EPS surface, could work as a good heat resistant material.

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[68] Isolation of cell walls from gram-positive bacteria

Methods in Enzymology - Biomembranes Part A ◽

10.1016/0076-6879(74)31071-3 ◽

1974 ◽

pp. 653-667 ◽

Cited By ~ 4

Author(s):

Milton R.J. Salton

Keyword(s):

Cell Walls ◽

Gram Positive ◽

Gram Positive Bacteria

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Effect of Sodium Metabisulfite on Selective Flotation of Chalcopyrite and Molybdenite

Minerals ◽

10.3390/min11121377 ◽

2021 ◽

Vol 11 (12) ◽

pp. 1377

Author(s):

Yuki Semoto ◽

Gde Pandhe Wisnu Suyantara ◽

Hajime Miki ◽

Keiko Sasaki ◽

Tsuyoshi Hirajima ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Separation Efficiency ◽

Diesel Oil ◽

Sodium Metabisulfite ◽

Depressing Effect ◽

Spectroscopy Analysis ◽

X Ray ◽

Selective Flotation

Sodium metabisulfite (MBS) was used in this study for selective flotation of chalcopyrite and molybdenite. Microflotation tests of single and mixed minerals were performed to assess the floatability of chalcopyrite and molybdenite. The results of microflotation of single minerals showed that MBS treatment significantly depressed the floatability of chalcopyrite and slightly reduced the floatability of molybdenite. The results of microflotation of mixed minerals demonstrated that the MBS treatment could be used as a selective chalcopyrite depressant in the selective flotation of chalcopyrite and molybdenite. Furthermore, the addition of diesel oil or kerosene could significantly improve the separation efficiency of selective flotation of chalcopyrite and molybdenite using MBS treatment. A mechanism based on X-ray photoelectron spectroscopy analysis results is proposed in this study to explain the selective depressing effect of MBS on the flotation of chalcopyrite and molybdenite.

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ANTIMICROBIAL ACTIVITY OF COPPER KAOLINITE AND SURFACTANT MODIFIED COPPER KAOLINITE AGAINST GRAM POSITIVE AND GRAM NEGATIVE BACTERIA

Jurnal Teknologi ◽

10.11113/jt.v78.7827 ◽

2016 ◽

Vol 78 (3-2) ◽

Author(s):

Nor Syafawani Sarah Md Saad ◽

Nik Ahmad Nizam Nik Malek ◽

Chun Shiong Chong

Keyword(s):

Antimicrobial Activity ◽

Synergistic Effects ◽

Wide Spectrum ◽

Copper Nitrate ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

X Ray ◽

Gram Positive Bacteria ◽

Diffusion Technique

The aim of this research was to determine the antimicrobial activity of kaolinite modified with antimicrobial compounds against Gram positive and Gram negative bacteria. Copper kaolinite (Cu-kaolinite) was prepared by loading raw kaolinite with copper nitrate trihydrate (CuNO3) while surfactant modified Cu-kaolinite (SM-Cu-kaolinite) was prepared by adding cationic surfactants hexadecyltrimethyl ammonium (HDTMA) on Cu-Kaolinite. Samples was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analyzer. The antimicrobial activity of the samples was tested against Gram negative bacteria (Escherichia coli ATCC 11229 and Pseudomonas aeruginosa ATCC 15442), and Gram positive bacteria (Staphylococcus aureus ATCC 6538 and Enterococcus faecalis ATCC 29212) through disc diffusion technique (DDT) and minimum inhibition concentration (MIC). The results showed that the antimicrobial activity of Cu-kaolinite increased after modified with HDTMA due to the synergistic effects of Cu ions and HDTMA molecules on the kaolinite. The antimicrobial activity for surfactant modified Cu-kaolinite was greater for Gram positive bacteria compared to Gram negative bacteria. In conclusion, the attachment of HDTMA on Cu-kaolinite contributed to the enhanced antimicrobial activity against wide spectrum of bacteria (Gram positive and Gram negative bacteria).

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