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☑ Composition dependence structural and optical properties of the CuInGaSe nanocrystals

Abhay Kumar Singh*a, P. Senthamaraib, R. Ganesana

aDepartment of Physics, Indian Institute of Science, Bangalore-560012, India
bDepartment of Physics, Anna University of Technology, Trichy, India

Email:abhaysngh@rediffmail.com*

  • subtitlesGRAPHICAL ABSTRACT
  • subtitlesABSTRACT

    This report demonstrates colloidal route synthesis of the Cu24In16Ga4Se56 and Cu24In16Ga7Se53 nanocrystals at temperature ~ 1500C. Materials crystallographic phase formations analysis is performed using the X-ray diffraction, micro-morphology from the Transmission Electron Microscopy and stoichiometric homogeneity by the energy dispersive X-ray mapping. Modification in the bonds feature and the chemical environment are studied with the X-ray photoelectron spectroscopy. The optical properties of the materials are described with the help of UV/Visible, FT-IR transparency and photoluminescence spectroscopy. The synthesized nanocrystals/ particles size are obtained around ~ 40 nm to ~ 60 nm. The optical energy band gaps are evaluated 1.30 eV and 1.39 eV for the Cu24In16Ga4Se56 and Cu24In16Ga7Se53 compositions. A higher order photoluminescence is noticed for the Cu24In16 Ga 7 Se53 composition, while the FT-IR transparency is unchanged in these materials.

  • gamesKEYWORDS

    CIGS; Sole gel; Nanomaterials; Semiconducting materials; Crystal morphology; Optical properties.

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☑ Geochemical Characterization and Mineralogy Control of Rocks to Assign Overburden Management

Waterman Sulistyana Bargawa* and Ira Mughni Pratiwi**

Master of Mining Engineering UPNVYK, Jalan SWK 104 Condongcatur Yogyakarta Indonesia

Email:waterman.sulistyana@gmail.com*, mughniira@gmail.com**

  • subtitlesABSTRACT

    This research is conducted at coal mine, located on Barito Basin, South Kalimantan, Indonesia. The purpose is to characterize geochemistry and mineralogy control of rocks for acid mine drainage prediction to prevent acid mine drainage formation. Rocks geochemical characterization of PAF (Potential acid Forming), NAF (Non Acid Forming), and uncertain material is obtained based on result of overburden geochemincal test comprise paste pH, NAG (Net Acid Generating), TS (Total Sulphur), ANC (Acid Neutralization Capacity), percentage of rocks mineral composition analyzed using XRD. The result of this reasearch shows material is classified into NAF material (81%) and PAF LC (Low Capacity) material (5%); PAF MC (Medium Capacity) material (10%); PAF HC (High Capacity) material (1%); an uncertain data (3%). NAF material is dominated by mudstone. Based on the research material of neutralization is low and comprise of silica, plagioclase, and aluminosilicate mineral thus acid mine drainage formation should be prevented uses dry cover method with encapsulation.

  • gamesKEYWORDS

    Acid mine drainage; Geochemical characterization; Mineralogy; Overburden.

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☑ Study on Strength Characteristics of Hybrid Fibre Reinforced Concrete with Mineral Admixtures

G. Nandini Devi

Department of Civil Engineering, Adhiyamaan College of Engineering, Hosur, Tamilnadu, India

Email:gdevi80@gmail.com

  • subtitlesABSTRACT

    Concrete is a brittle material with a low tensile strength. Fibres when added to concrete increases strength, toughness and ductility. The addition of fibres improves the post-cracking behaviour of concrete. In this project, the strength characteristics of hybrid fibre reinforced concrete is studied experimentally by testing cubes, cylinders and prisms under compression, tension and flexure. Fibres used are glass and steel fibres. The combinations of different types of fibres potentially will improve the overall performance of concrete. Admixtures silica fume and fly ash improves workability of concrete. M25 grade concrete was investigated with addition of steel fibres and glass fibres with admixtures silica fume and fly ash. The test results shows that use of hybrid fibre reinforced concrete with admixtures improves compression, split tensile and flexural performance.

  • gamesKEYWORDS

    Fibre Reinforced Concrete, Glass Fiber, Steel Fiber, Fly Ash, Silica Fume.

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