Louis, Godfrey; Santhosh Kumar, A(Society of Photo-Optical Instrumentation Engineers, 2008)
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Abstract:
The red cells found in the red rain in Kerala, India are now considered as a possible case of extraterrestrial life form.
These cells can undergo rapid replication even at an extreme high temperature of 300 deg C. They can also be cultured in
diverse unconventional chemical substrates. The molecular composition of these cells is yet to be identified. This paper
reports the unusual autofluorescence characteristic of the cultured red rain cells. A spectrofluorimetric study has been
performed to investigate this, which shows a systematic shift of the fluorescence emission peak wavelength as the
excitation wavelength is increased. Conventional biomolecules are not known to have this property. Details of this
investigation and the results are discussed.
Anantharaman, M R; Al-Harthi, S H; Mohammed, Elzain; Muataz, Al-Barwani; Amal, Kora'a; Thomas, Hysen; Myo, Tay Zar Myint(Springer, 2012)
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Abstract:
Roughness and defects induced on few-layer graphene (FLG) irradiated by Ar+ ions at different energies were
investigated using X-ray photoemission spectroscopy (XPS) and atomic force microscopy techniques. The results
provide direct experimental evidence of ripple formation, sp2 to sp3 hybridized carbon transformation, electronic
damage, Ar+ implantation, unusual defects and edge reconstructions in FLG, which depend on the irradiation
energy. In addition, shadowing effects similar to those found in oblique-angle growth of thin films were seen.
Reliable quantification of the transition from the sp2-bonding to sp3-hybridized state as a result of Ar+ ion irradiation
is achieved from the deconvolution of the XPS C (1s) peak. Although the ion irradiation effect is demonstrated
through the shape of the derivative of the Auger transition C KVV spectra, we show that the D parameter values
obtained from these spectra which are normally used in the literature fail to account for the sp2 to sp3 hybridization
transition. In contrast to what is known, it is revealed that using ion irradiation at large FLG sample tilt angles can
lead to edge reconstructions. Furthermore, FLG irradiation by low energy of 0.25 keV can be a plausible way of
peeling graphene layers without the need of Joule heating reported previously
Description:
Al-Harthi et al. Nanoscale Research Letters 2012, 7:466
Junaid, Bushiri M; Mahadevan Pillai, V P; Pradeep, T; Jayasree, R S; Nayar, V U(Elsevier, 1997)
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Abstract:
FTIR and Raman spectra of FeClMoO4 single crystal and polycrystalline Na2MoO4, Na2MoO4·2H2O and
Na2MoO4·2D2O are recorded and analysed. The band positions for different modes suggest that MoO4 tetrahedron
is more distorted in FeClMoO4. The larger splitting observed for the bending modes and partial retention of
degeneracy of the asymmetric stretching mode indicate that angular distortion is greater than liner distortion in
MoO4 2 ion in FeClMoO4 confirming x-ray data. The non-appearance of the n1 and n2 modes in the IR and partial
retention of the degeneracies of various modes show that MoO4 2 ion retains Td symmetry in Na2MoO4. Wavenumber
values of the n1 mode indicate that the distortion of MoO4 tetrahedra in the four crystals are in the order
FeClMoO4\ Na2MoO4·2H2O\Na2MoO4·2D2O\Na2MoO4. The water bands suggest the presence of two
crystallographically distinct water molecules in Na2MoO4·2H2O. They form strong hydrogen bonds
Junaid, Bushiri M; Antony, C J; Michel, Fleck(Elsevier, May 27, 2007)
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Abstract:
The Raman and FTIR spectra of [C(NH2)3]2M(SO4)2 ·6H2O (withM= Co, Fe, Ni) were recorded and analysed. The observed spectral bands
are assigned in terms of vibrations of guanidinium ions, sulphate groups and water molecules. The analysis shows that the sulphate tetrahedra
are distorted from their free state symmetry Td to C1. This is attributed to the presence of hydrogen bonds from water molecules. The order of
distortion of the metal oxygen octahedra influenced the distortion of the sulphate tetrahedra. The appearance of 1– 3 modes of water molecules
above 3300 cm−1 indicates the presence of weak hydrogen bonds
Junaid, Bushiri M; Kochuthresia, T C; Athimoolam, S; Ramakrishnan, V; Vaidyan, V K(Scientific Research Publishing, January 10, 2013)
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Abstract:
Th(BrO3)3·H2O single crystals were grown from its aqueous solution at room temperature. Single crystal XRD, Raman and FTIR techniques were used to investigate the crystal structure. The crystal structure was solved by Patterson method. The as grown crystals are in monoclinic system with space group P21/c. The unit cell parameters are a = 12.8555(18) Å, b = 7.8970(11) Å, c = 9.0716(10) Å, = 90°, = 131.568° and = 90° and unit cell volume is 689.1(2) Å3. Z = 8, R factor is 5.9. The Raman and FTIR studies indicate the lowering of symmetry of bromate anion from C3V to C1. Hydrogen bonds with varying strengths are present in the crystal. The centrosymmetric space group P21/c of the crystal is confirmed by the non-coincidence of majority of Raman and IR bands
Description:
Crystal Structure Theory and Applications, 2013, 2, 70-74