A comparative study is conducted on the structure, electronic and spectroscopic properties of Ag2SO4 and LiAgSO4. Both the sulphates crystallise in an orthorhombic structure with the same space group of Fddd (70). A red shift in Raman modes indicates the stiffness of the crystal Ag2SO4 over LiAgSO4. From ESR, it is observed that these sulphates has Mn2+ impurities leading to the gav= 2.1040 at a field of 3255 G. This indicates that the Mn2+ ions have an environment close to octahedral symmetry. The g value corresponding to Ag2SO4 is 2.3005. The endothermic peaks in LiAgSO4 at 388.8 and 4200C are due to the formation of BCC structure of LiAgSO4. The peak at 420.90C in Ag2SO4 may be due to the phase transition of β-Ag2SO4 particles to α-Ag2SO4 on heating.
A detailed study of Transition Metal Complexes of a Schiff base with its Phys...Abhishek Ghara
The many activities of metal ions in biology have stimulated the development of metal based therapeutics. It has been found that biologically active compounds become more effective and bacteriostatic upon chelation with metal ions also the biological activity of many drugs has been shown to be enhanced on complexing with metal ions, hence promoting their use in Pharmacology. The present work deals with the synthesis of metal complexes derived from a novel Schiff base drug synthesized from urea and salicylaldehyde and its physico-chemical analysis to find out ligand- metal ratio of this complex in solution. For the structure elucidation of these complexes “Monovariation method (Mole ratio method/ Yoe-Jones Method)” has been used to ascertain the ligand-metal ratio in the complex. The stability constant of the formed complex was calculated by molar conductance measurement using Modified Job’s method (Method of Continuous Variations). The analysis has been carried out using conductometry. To confirm metal-ligand ratio, conductometric titrations were carried out at room temperature using analytical grade metal salts. Titrations were carried out with “systronics conductivity-meter” using dip type conductivity cell having cell constant 1 at room temperature.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Theoretical work submitted to the Journal should be original in its motivation or modeling structure. Empirical analysis should be based on a theoretical framework and should be capable of replication. It is expected that all materials required for replication (including computer programs and data sets) should be available upon request to the authors.
A detailed study of Transition Metal Complexes of a Schiff base with its Phys...Abhishek Ghara
The many activities of metal ions in biology have stimulated the development of metal based therapeutics. It has been found that biologically active compounds become more effective and bacteriostatic upon chelation with metal ions also the biological activity of many drugs has been shown to be enhanced on complexing with metal ions, hence promoting their use in Pharmacology. The present work deals with the synthesis of metal complexes derived from a novel Schiff base drug synthesized from urea and salicylaldehyde and its physico-chemical analysis to find out ligand- metal ratio of this complex in solution. For the structure elucidation of these complexes “Monovariation method (Mole ratio method/ Yoe-Jones Method)” has been used to ascertain the ligand-metal ratio in the complex. The stability constant of the formed complex was calculated by molar conductance measurement using Modified Job’s method (Method of Continuous Variations). The analysis has been carried out using conductometry. To confirm metal-ligand ratio, conductometric titrations were carried out at room temperature using analytical grade metal salts. Titrations were carried out with “systronics conductivity-meter” using dip type conductivity cell having cell constant 1 at room temperature.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Theoretical work submitted to the Journal should be original in its motivation or modeling structure. Empirical analysis should be based on a theoretical framework and should be capable of replication. It is expected that all materials required for replication (including computer programs and data sets) should be available upon request to the authors.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Crystallization kinetics and phase transformation in amorphous Fe74Co10B16 an...IJERA Editor
Crystallization kinetics and phase transformation studies have been carried out on amorphous Fe74Co10B16 (S1) and Fe67Co18B14Si1 (S2) alloys using Mossbauer Spectroscopy (MS), Electrical Resistivity (ER), Differential Scanning Calorimetry(DSC), X-ray Diffraction(XRD) and Transmission Electron Microscopy(TEM) to determine the thermal stability. Results show that the transformation to an equilibrium crystalline state occurs through a two step process. Crystallization process is associated with precipitation of two or more phases which are magnetic in nature. From DSC curves, the activation energy of sample S2 has been calculated using Kissinger, Matusita-Sakka and Augis-Bennet methods and the average value is found to be 211 kJ/mol. The detected phases upon crystallization in the samples are α–(Fe-Co) and (Fe-Co)2B. Exact compositions of these phases in the completely crystallized sample are found to be α–(Fe0.7Co0.3) and (Fe0.3Co0.7)2B.
Critical magnetic fields of superconducting aluminum-substituted Ba8Si42Al4 c...Yang Li
In recent years, efforts have been made to explore the superconductivity of clathrates containing crystalline frameworks of group-IV elements. The superconducting silicon clathrate is unusual in that the structure is dominated by strong sp3 covalent bonds between silicon atoms, rather than the metallic bonding that is more typical of traditional superconductors. This paper reports on critical magnetic fields of superconducting Al-substituted silicon clathrates, which were investigated by transport, ac susceptibility, and dc magnetization measurements in magnetic fields up to 90 kOe. For the sample Ba8Si42Al4, the critical magnetic fields were measured to be HC1=40.2 Oe and HC2=66.4 kOe. The London penetration depth of 4360A ° and the coherence length 70A ° were obtained, whereas the estimated Ginzburg–Landau parameter 62 revealed that Ba8Si42Al4 is a strong type-II superconductor.
C3N5: A Low Bandgap Semiconductor Containing an Azo-linked Carbon Nitride Fra...Pawan Kumar
Modification of carbon nitride based polymeric 2D materials for tailoring their optical, electronic and chemical properties for various applications has gained significant interest. The present report demonstrates the synthesis of a novel modified carbon nitride framework with a remarkable 3:5 C:N stoichiometry (C3N5) and an electronic bandgap of 1.76 eV, by thermal deammoniation of the melem hydrazine precursor. Characterization revealed that in the C3N5 polymer, two s-heptazine units are bridged together with azo linkage, which constitutes an entirely new and different bonding fashion from g-C3N4 where three heptazine units are linked together with tertiary nitrogen. Extended conjugation due to overlap of azo nitrogens and increased electron density on heptazine nucleus due to the aromatic π network of heptazine units lead to an upward shift of the valence band maximum resulting in bandgap reduction down to 1.76 eV. XRD, He-ion imaging, HR-TEM, EELS, PL, fluorescence lifetime imaging, Raman, FTIR, TGA, KPFM, XPS, NMR and EPR clearly show that the properties of C3N5 are distinct from pristine carbon nitride (g-C3N4). When used as an electron transport layer (ETL) in MAPbBr3 based halide perovskite solar cells, C3N5 outperformed g-C3N4, in particular generating an open circuit photovoltage as high as 1.3 V, while C3N5 blended with MAxFA1–xPb(I0.85Br0.15)3 perovskite active layer achieved a photoconversion efficiency (PCE) up to 16.7%. C3N5 was also shown to be an effective visible light sensitizer for TiO2 photoanodes in photoelectrochemical water splitting. Because of its electron-rich character, the C3N5 material displayed instantaneous adsorption of methylene blue from aqueous solution reaching complete equilibrium within 10 min, which is significantly faster than pristine g-C3N4 and other carbon based materials. C3N5 coupled with plasmonic silver nanocubes promotes plasmon-exciton coinduced surface catalytic reactions reaching completion at much low laser intensity (1.0 mW) than g-C3N4, which showed sluggish performance even at high laser power (10.0 mW). The relatively narrow bandgap and 2D structure of C3N5 make it an interesting air-stable and temperature-resistant semiconductor for optoelectronic applications while its electron-rich character and intra sheet cavity make it an attractive supramolecular adsorbent for environmental applications.
A new technique to measure oxygen reduction kinetics underneath coatings using hydrogen permeation from the back side. Huge step towards characterising buried interface reactivity.
Pure and Al substituted Langanite
(La3Ga5.5Nb0.5O14) ceramics have been synthesized
by solid state sintering method and studied their
structural, dielectric and electrical properties. The
crystalline nature was confirmed by powder XRD
studies. The ac conductivity and dielectric
properties of La3Ga5.5-xAlxNb0.5O14 samples were
examined by using complex impedance technique.
Surface morphology and elemental composition
were studied by energy-dispersive x-ray
spectroscopy and scanning electron microscopy.
The frequency dependence of dielectric constant,
dielectric loss and AC conductivity were studied in
the frequency range of 100 KHz to 3 MHz at
different temperatures. The activation energy was
calculated using Arrhenius plot. The lattice
parameter, grain size, dielectric constant and AC
conductivity of pure LGN ceramics were deeply
affected by Al substitution in pure LGN.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
A study of micro structural, magnetic and electrical properties of La-Co-Sm n...IJECEIAES
A Lanthanum (La 3+ ) doped Samarium-Cobalt nanoferrites (La_x,Co_0.2,Sm_0.2,Fe_(2-x) O_4, where x=0.0,0.5,1.0) have been synthesized by sol-gel method in citrate media. Obtained spinal ferrites micro structure properties have been investigated by XRD, FTIR, SEM-EDX, and TEM-SAED techniques. All the samples are nano in size with significant hysteresis. Micro structural analysis by XRD confirms the obtained samples showing the single phase cubic spinal structures with an average crystal size found from 12 nm to 25 nm, while the average particles sizes identified from TEM analysis are ranging from 21.5nm-26.8 nm (~23.4nm) and from 20.5 nm to 28(~26.4nm) nm for x=0.5,1.0. The lattice parameter found to be a= 8.402, 8.423, 8.467Å for the respective values of x= 0.0, 0.05, and 1.0. Electrical properties show increase in dc resistivity with increase in La ion concentration. Finally, it was concluded that the doping of Lanthanum ion (La 3+ ) in the ferrites structure is found to influencing the structural and electrical properties without scarifying the ferromagnetic character.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Crystallization kinetics and phase transformation in amorphous Fe74Co10B16 an...IJERA Editor
Crystallization kinetics and phase transformation studies have been carried out on amorphous Fe74Co10B16 (S1) and Fe67Co18B14Si1 (S2) alloys using Mossbauer Spectroscopy (MS), Electrical Resistivity (ER), Differential Scanning Calorimetry(DSC), X-ray Diffraction(XRD) and Transmission Electron Microscopy(TEM) to determine the thermal stability. Results show that the transformation to an equilibrium crystalline state occurs through a two step process. Crystallization process is associated with precipitation of two or more phases which are magnetic in nature. From DSC curves, the activation energy of sample S2 has been calculated using Kissinger, Matusita-Sakka and Augis-Bennet methods and the average value is found to be 211 kJ/mol. The detected phases upon crystallization in the samples are α–(Fe-Co) and (Fe-Co)2B. Exact compositions of these phases in the completely crystallized sample are found to be α–(Fe0.7Co0.3) and (Fe0.3Co0.7)2B.
Critical magnetic fields of superconducting aluminum-substituted Ba8Si42Al4 c...Yang Li
In recent years, efforts have been made to explore the superconductivity of clathrates containing crystalline frameworks of group-IV elements. The superconducting silicon clathrate is unusual in that the structure is dominated by strong sp3 covalent bonds between silicon atoms, rather than the metallic bonding that is more typical of traditional superconductors. This paper reports on critical magnetic fields of superconducting Al-substituted silicon clathrates, which were investigated by transport, ac susceptibility, and dc magnetization measurements in magnetic fields up to 90 kOe. For the sample Ba8Si42Al4, the critical magnetic fields were measured to be HC1=40.2 Oe and HC2=66.4 kOe. The London penetration depth of 4360A ° and the coherence length 70A ° were obtained, whereas the estimated Ginzburg–Landau parameter 62 revealed that Ba8Si42Al4 is a strong type-II superconductor.
C3N5: A Low Bandgap Semiconductor Containing an Azo-linked Carbon Nitride Fra...Pawan Kumar
Modification of carbon nitride based polymeric 2D materials for tailoring their optical, electronic and chemical properties for various applications has gained significant interest. The present report demonstrates the synthesis of a novel modified carbon nitride framework with a remarkable 3:5 C:N stoichiometry (C3N5) and an electronic bandgap of 1.76 eV, by thermal deammoniation of the melem hydrazine precursor. Characterization revealed that in the C3N5 polymer, two s-heptazine units are bridged together with azo linkage, which constitutes an entirely new and different bonding fashion from g-C3N4 where three heptazine units are linked together with tertiary nitrogen. Extended conjugation due to overlap of azo nitrogens and increased electron density on heptazine nucleus due to the aromatic π network of heptazine units lead to an upward shift of the valence band maximum resulting in bandgap reduction down to 1.76 eV. XRD, He-ion imaging, HR-TEM, EELS, PL, fluorescence lifetime imaging, Raman, FTIR, TGA, KPFM, XPS, NMR and EPR clearly show that the properties of C3N5 are distinct from pristine carbon nitride (g-C3N4). When used as an electron transport layer (ETL) in MAPbBr3 based halide perovskite solar cells, C3N5 outperformed g-C3N4, in particular generating an open circuit photovoltage as high as 1.3 V, while C3N5 blended with MAxFA1–xPb(I0.85Br0.15)3 perovskite active layer achieved a photoconversion efficiency (PCE) up to 16.7%. C3N5 was also shown to be an effective visible light sensitizer for TiO2 photoanodes in photoelectrochemical water splitting. Because of its electron-rich character, the C3N5 material displayed instantaneous adsorption of methylene blue from aqueous solution reaching complete equilibrium within 10 min, which is significantly faster than pristine g-C3N4 and other carbon based materials. C3N5 coupled with plasmonic silver nanocubes promotes plasmon-exciton coinduced surface catalytic reactions reaching completion at much low laser intensity (1.0 mW) than g-C3N4, which showed sluggish performance even at high laser power (10.0 mW). The relatively narrow bandgap and 2D structure of C3N5 make it an interesting air-stable and temperature-resistant semiconductor for optoelectronic applications while its electron-rich character and intra sheet cavity make it an attractive supramolecular adsorbent for environmental applications.
A new technique to measure oxygen reduction kinetics underneath coatings using hydrogen permeation from the back side. Huge step towards characterising buried interface reactivity.
Pure and Al substituted Langanite
(La3Ga5.5Nb0.5O14) ceramics have been synthesized
by solid state sintering method and studied their
structural, dielectric and electrical properties. The
crystalline nature was confirmed by powder XRD
studies. The ac conductivity and dielectric
properties of La3Ga5.5-xAlxNb0.5O14 samples were
examined by using complex impedance technique.
Surface morphology and elemental composition
were studied by energy-dispersive x-ray
spectroscopy and scanning electron microscopy.
The frequency dependence of dielectric constant,
dielectric loss and AC conductivity were studied in
the frequency range of 100 KHz to 3 MHz at
different temperatures. The activation energy was
calculated using Arrhenius plot. The lattice
parameter, grain size, dielectric constant and AC
conductivity of pure LGN ceramics were deeply
affected by Al substitution in pure LGN.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
A study of micro structural, magnetic and electrical properties of La-Co-Sm n...IJECEIAES
A Lanthanum (La 3+ ) doped Samarium-Cobalt nanoferrites (La_x,Co_0.2,Sm_0.2,Fe_(2-x) O_4, where x=0.0,0.5,1.0) have been synthesized by sol-gel method in citrate media. Obtained spinal ferrites micro structure properties have been investigated by XRD, FTIR, SEM-EDX, and TEM-SAED techniques. All the samples are nano in size with significant hysteresis. Micro structural analysis by XRD confirms the obtained samples showing the single phase cubic spinal structures with an average crystal size found from 12 nm to 25 nm, while the average particles sizes identified from TEM analysis are ranging from 21.5nm-26.8 nm (~23.4nm) and from 20.5 nm to 28(~26.4nm) nm for x=0.5,1.0. The lattice parameter found to be a= 8.402, 8.423, 8.467Å for the respective values of x= 0.0, 0.05, and 1.0. Electrical properties show increase in dc resistivity with increase in La ion concentration. Finally, it was concluded that the doping of Lanthanum ion (La 3+ ) in the ferrites structure is found to influencing the structural and electrical properties without scarifying the ferromagnetic character.
Microstructural and Dielectric Characterization of Sr doped Ba(Fe0.5Ta0.5)O3 ...theijes
Solid state reaction method was used to synthesize Ba1-xSrx(Fe0.5Ta0.5)O3 ceramic(x=0, 0.1, 0.2, 0.3, 0.4 and 0.5). The raw materials of making Sr doped Ba(Fe0.5Ta0.5)O3 were BaCO3, SrCO3, Fe2O3, Ta2O5 (purity better than 99%). Pellet and ring shaped samples prepared from each composition were sintered at 1400 and 1450ºC for 5 hour. The phase formation of Ba1-xSrx(Fe0.5Ta0.5)O3 was checked using X-ray diffraction (XRD) technique and observed a cubic perovskite crystal structure in space group Pm3m (221). Microstructure of the individual compound was examined by the field emission scanning electron micrograph (FESEM). Grain size was found to be varied with Sr content. The lattice parameter decreased with increasing Sr content. Dielectric spectroscopy was applied to investigate the electrical properties of BSFT at room temperature and in a frequency range of 100Hz–100 MHz. An analysis of the dielectric constant εʹ and loss tangent tan with frequency was performed assuming a distribution of relaxation times. The low frequency dielectric dispersion corresponds to the DC electrical conductivity.
Study of Microstructural, Electrical and Dielectric Properties of La0.9Pb0.1M...Scientific Review SR
The present work studies the microstructural and electrical properties of La0.9Pb0.1MnO3 and La0.8Y0.1Pb0.1MnO3 ceramics synthesized by solid-state route method. Microstructure and elemental analysis of both samples were carried out by field emission scanning electron microscope (FESEM) and energy dispersive spectroscopy (EDS) method, respectively. Phase analysis by X-ray diffraction (XRD) indicated formation of single phase distorted structure. The XRD data were further analyzed by Rietveld refinement technique. Raman analysis reveals that Y atom substitutes La site into the LPMO with shifting of phonon modes. The temperature variation of resistivity of undoped and Y-doped La0.9Pb0.1MnO3 samples have been investigated. The electrical resistivity as a function of temperature showed that all samples undergo an metal-insulator (M-I) transition having a peak at transition temperature TMI. Y-doping increases the resistivity and the metal-insulator transition temperature (TMI) shifts to lower temperature. The temperature-dependent resistivity for temperatures less than metal-insulator transition is explained in terms the quadratic temperature dependence and for T > TMI, thermally activated conduction (TAC) is appropriate. Variation of frequency dispersion in permittivity and loss pattern due to La-site substitution in LPMO was observed in the dielectric response curve.
IOSR Journal of Applied Physics (IOSR-JAP) is an open access international journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Synthesis and Characterisation of Copper Oxide nanoparticlesIOSR Journals
Cupric oxide (CuO) nanoparticles were prepared by the chemical route by calcinations at a higher temperature from 300oC to 400 oC. For the comparison transmission electron microscopy (TEM) and x-ray diffraction (XRD) measurements were made through JCPDS. There is good agreement between data produced by spectroscopy and the microscopic measurements.
Determination of nonlinear absorption (β) and refraction (n2)by the Z-scan me...IOSR Journals
Potassium Pentaborate nonlinear optical (NLO) material was synthesized by the solution growth method. The grown crystals were subjected to structural, optical and mechanical property studies. Crystal with excellent transparency were grown with maximum size of 9mm×8mm×5mm and the grown crystals were characterized by single crystal Single crystal XRD, FT-IR, TGA-DTA&DSC, and UV–vis-NIR studies. The crystal belongs to orthorhombic with a space group of mm2 having unit-cell dimensions a = 11.068Åb= 11.175Å c = 9.058Åand α = 90°; β = 90°; and γ =90°; Z=4, at 298(2) K. The second-order nonlinear optical property of the polycrystalline sample has been confirmed by Kurtz-Perry powder SHG analysis. Third order nonlinear optical properties were also studied by Z-scan techniques. Nonlinear absorption and nonlinear refractive index were found out and the third order bulk susceptibility of compound was also calculated.
Spectroscopic and Physical Properties of Mn2+ spin probe in RO-P2O5-ZnO-Pb3O4...IJERA Editor
RO-P2O5-ZnO-Pb3O4 (R=Li, Na and K) glasses containing 0.1concentrations of MnO have been prepared. The structural, optical and physical properties of prepared glasses are studied by XRD, UV-Visible, EPR and FTIR techniques. The nature of local symmetry and structural information of the neighboring atoms of dopant ions (Mn2+) in the host matrix have been understood by evaluating the crystal field strength (Dq) and Racah (B & C) parameters. The combined analysis of optical absorption and EPR spectroscopy has indicated that the manganese ions exist in Mn2+ (in octahedral) local coordination sites. FTIR results showed that PO4 are the main structural unit of the glass system and the manganese ions are located in the glass matrix network.
Emeraldine-salt polyaniline form (ES-PANI) was chemically synthesized using hydrochloric acid at time
synthesis ranging from 0.5 to 48 h and characterized by X-ray diffraction (XRD), LeBail fit, Small-angle
X-ray diffraction (SAXD), Small-angle X-ray Scattering (SAXS) and Scanning Electron Microscopy
(SEM). Crystallinity and crystal data (a = 5.7122, b = 17.8393, c = 22.8027, a = 83.1575, b = 84.6971 and
c = 88.4419) were obtained by XRD and showed that the crystallinity did not vary with the time
synthesis. LeBail fit revealed that the crystallites were very small lamellae with global average size
around 39 Å. By SAXS it was obtained the particle Radius of Giration (Rg) of 320 Å. The maximum particle
size (Dmax) of 650 Å was obtained from the pair-distance distribution function (p(r)). SEM images showed
a fiber morphology formed by interconnected non homogeneous nanospheres. Electrical conductivity of
the samples was in 1.84 104 S/cm.
IMPROVEMENT IN MORPHOLOGICAL AND ELECTRO-MAGNETIC BEHAVIOUR OF HARD FERRITE P...Editor IJMTER
The Ni-Ir substituted strontium ferrite of Sr(Ni-Ir)xFe12-2xO19 (x = 0.02 & 0.08) were
synthesized by sol-gel auto combustion technique and characterized using X-ray diffraction (XRD),
Transmission Electron Microscopy (TEM) for morphological behaviour with electrical
characteristics using Impedance Analyzer. XRD results confirmed the formation of a single phase
M-type hexagonal unit cell of space group P63/mmc. The increase in Ni-Ir concentration increases
the lattice parameter. TEM analysis of the sample demonstrates the formation of nano-size particles
which decreases with substitution. In this paper we reported the variation of dielectric constant,
dielectric loss, tangent loss, conductivity and magnetic behaviour with composition with temperature
and frequency analysis of the sample. The migration of Fe3+ ion from octahedral to tetrahedral site
decreases the dielectric constant with increase in Ni-Ir concentration. Activation energies were
found similar with calculated at ferromagnetic and paramagnetic region. The material study we
confined that the activation energy in the paramagnetic region is higher than that in the
ferromagnetic region. The enhanced resistivity of Ni-Ir substituted strontium hexaferrites is a
prospective application in high frequency and in microwave devices development.
Structure, microstructure and dielectric study of (ba0.6 sr0.4)(zr0.6ti0.4)o3...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Study of Boron Based Superconductivity and Effect of High Temperature Cuprate...IOSR Journals
This paper illustrates the main normal and Boron superconducting state temperature properties of magnesium diboride, a substance known since early 1950's, but lately graded to be superconductive at a remarkably high critical temperature Tc=40K for a binary synthesis. What makes MgB2 so special? Its high Tc, simple crystal construction, large coherence lengths, high serious current densities and fields, lucidity of surface boundaries to current promises that MgB2 will be a good material for both large scale applications and electronic devices. Throughout the last seven month, MgB2 has been fabricated in various shape, bulk, single crystals, thin films, ribbons and wires. The largest critical current densities >10MA/cm2 and critical fields 40T are achieved for thin films. The anisotropy attribution inferred from upper critical field measurements is still to be resolved, a wide range of values being reported, γ = 1.2 ÷ 9. Also there is no consensus about the existence of a single anisotropic or double energy cavity. One central issue is whether or not MgB2 represents a new class of superconductors, being the tip of an iceberg that waits to be discovered. Until now MgB2 holds the record of the highest Tc among simple binary synthesis. However, the discovery of superconductivity in MgB2 revived the interest in non-oxides and initiated a search for superconductivity in related materials, several synthesis being already announced to become superconductive: TaB2, BeB2.75, C-S composites, and the elemental B under pressure.
Similar to Thermal and spectroscopy studies of Ag2SO4 and LiAgSO4 (20)
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.
Thermal and spectroscopy studies of Ag2SO4 and LiAgSO4
1. IOSR Journal of Applied Physics (IOSR-JAP)
e-ISSN: 2278-4861.Volume 4, Issue 2 (Jul. - Aug. 2013), PP 39-43
www.iosrjournals.org
www.iosrjournals.org 39 | Page
Thermal and spectroscopy studies of Ag2SO4 and LiAgSO4
S. Rama Rao1
, Ch. Bheema Lingam2, 3
, D. Rajesh2
, R.P.Vijayalakshmi1, C. S.
Sunandana2
1
Departmet of Physics, College of Sciences, Sri Venkateswara University, Tirupati 517502,
2
School of Physics and 3ACRHEM, University of Hyderabad, Hyderabad 500 046, INDIA.
Abstract: A comparative study is conducted on the structure, electronic and spectroscopic properties of
Ag2SO4 and LiAgSO4. Both the sulphates crystallise in an orthorhombic structure with the same space group of
Fddd (70). A red shift in Raman modes indicates the stiffness of the crystal Ag2SO4 over LiAgSO4. From ESR,
it is observed that these sulphates has Mn2+
impurities leading to the gav= 2.1040 at a field of 3255 G. This
indicates that the Mn2+
ions have an environment close to octahedral symmetry. The g value corresponding to
Ag2SO4 is 2.3005. The endothermic peaks in LiAgSO4 at 388.8 and 4200
C are due to the formation of BCC
structure of LiAgSO4. The peak at 420.90
C in Ag2SO4 may be due to the phase transition of β-Ag2SO4 particles
to α-Ag2SO4 on heating.
I. Introduction
Due to the single or successive reversible structural transitions for piezoelectric properties and high
ionic conductivity of Alkali metal sulphates (Li2SO4, Na2SO4, K2SO4, Rb2SO4 and Cs2SO4) have attracted
contemporary researchers [1-7]. The sliver and thallium based sulphate crystals are attractive due to the distinct
conductivity behaviour of Ag+ and Tl+ [8-12]. The mixed sulphates such as AgLiSO4, NaLiSO4, RbAgSO4,
KLiSO4 and TlAgSO4 with two monovalent cations are known to be good solid electrolytes [11]. The fast-ion
conduction in solids is a paradigm for structure-property relation. The structure factor can involve coordination
geometry number, face-sharing sites in the structure and lattice disorder [13]. The structure of high conducting
phase α- Ag2SO4 is isomorphous with that of the conducting phase Na2SO4 –I space group p63/mnc and both
possess parallel properties linked to fast cation conductivity. The thermal properties are primarily interest due to
their potential applications in electrochemical devices such as sensors [14]. A measurement of temperature
depending on the electrical and thermal conductivities can serve as a useful tool in the study of ion transport in
ionic crystals. Silver sulphate, a non-alkali metal sulphate, is an exception which shows high cationic
conductivity inspite of the bigger size of Ag+. It undergoes a structural phase transition from the high
temperature highly conducting hexagonal α-phase to the low temperature moderately conducting orthorhombic
β-phase at 4160
C. It attracted scant attention until its application potential in SOx(x=2, 3) galvanic sensors was
proved [15]. Study on the role of electronic structure and the influence of lattice distortion caused by iso-valent
cations on the mobility of Ag+ in orthorhombic β-Ag2SO4 is necessary to understand the fundamental
conduction mechanism and simultaneously to obtain an apt silver sulphate based material for SO2 gas sensor
[16]. If silver sulphate diffuses into the battery electrolyte, metallic silver could get deposited on the negative
plates. Fortunately, metallic silver has a relatively high hydrogen over-voltage, and contamination of the
negative electrodes with small quantities of metallic silver should have only a minor effect on their self-
discharge. Diffusion of silver sulphate into the battery electrolyte can be restricted by decreasing the diameter of
the micro-fiber glass plug separator, by increasing its length and its density (compactness), and adding a gelling
agent. On the basis of Fick’s law, one can estimate that it should be possible to limit the diffusion into the
battery electrolyte (at 2580
C) to less than 0.1 mg of metallic silver per year [17]. New solid-state
electrochemical sensors using Li2SO4-Ag2SO4 solid electrolytes have been recently developed to measure
SO2 and/or SO3 in gas mixtures. The sensors which consist of a two-phase electrolyte and a solid Ag-
(Ag2SO4) reference electrode exhibit excellent behaviour. For example, they have long-term
electrochemical stability and accurate potentiometric responses are obtained over a six month period. The
presence of significant concentrations of CO2 and H20 in the gas mixture has no effect on the sensor
response. Thus these sensors have potential applications as reliable detectors and monitors of SO2 and/or
SO3 concentrations in various gaseous atmospheres[18-20]. For the equimolar compositions of the two
phases the electrical conductivity and the diffusion coefficients of Li+, Ag+ and Na+ at 823K are nearly
the same for the two abundant cations, while they are considerably smaller for the cation that is present
at low concentration. Additional evidence that the two abundant cations have nearly the same mobility
in the bcc phase is obtained from a trans- port number study for (Li, Ag)2SO4 [21-24].
Submitted Date 27 June 2013 Accepted Date: 02 July 2013
2. Thermal and spectroscopy studies of Ag2SO4 and LiAgSO4
www.iosrjournals.org 40 | Page
II. Experimental
2.1 Synthesis
The materials used in this experiment Li2SO4.H2O (Alfa) and Ag2SO4 (AR) were been mixed in 1:1
ratio and grinded for one hour in a agate mortor and then transferred to heater. The powder is heated at 200o
C
for 10 hours, and subsequently cooled to room temperature. LiAgSO4 was again thoroughly grinded and used
for further characterization.
2.2 Instrumentation
The crystal structure of the samples was characterized by X-ray powder diffractometer using Co Kα
radiation (λ = 1.7889 Å). The morphologies and chemical composition of these samples were obtained by Field
emission scanning microscopy (FESEM) and for chemical composition using energy dispersive X- ray
scattering (EDS) analysis (a model no ULTRA- 55, ZEISS, Japan).Raman spectra were recorded at 300K in a
backscattering geometry with Horiba JobinYvon, LabRAM- HR800 micro-Raman system using 514.5 nm
excitation from Ar+ gas laser. The differential scanning calorimetry (DSC) was done using DuPont 9900 model
DSC instrument. Finally, the electron spin resonance spectra (EPR) were recorded on a JEOL9FE-3X) X-Band
spectrometer under optimized conditioned of modulation amplitude, receiver gain, time constant and scan time.
III. Results And Discussion
3.1 Structure and morphology
The structure and morphology of Ag2SO4 and LiAgSO4 are studied using XRD and FESEM-EDS, the
corresponding XRD pattern is given in Figs.1 and 2. From Fig.1A, the XRD pattern of Ag2SO4 is identified as
orthorhombic (a= 5.817, b=12.70 and c=10.269) with the space group of Fddd (70). The diffraction peaks
observed from XRD are (040), (202), (331), (151), (511), (260), (602), (642), (800), and (084). The peaks (602)
and (800) are found to be high intensive. The obtained XRD pattern matches well with the standard data
(JCPDS card no. 07-0203) as reported here in. Whereas, the XRD pattern (see Fig.2A) of LiAgSO4 is also
identified as orthorhombic (a=10.25, b=12.69 and c=5.843). The diffraction peaks from XRD are observed as
(200), (040), (311), (022), (202), (331), (151), (351), (062), (080), (333), (371), and (602). The peak (220) is
found to be high intensive. The obtained XRD pattern matches well with the standard data (JCPDS card no. 52-
1211). The structure details of Ag2SO4 and LiAgSO4 are in good agreement with the previous studies. Then the
morphology and surface characteristics of Ag2SO4 and LiAgSO4 are understood from the FEMSEM. LiAgSO4
samples have nano particles with the average size of 100-120 nm which is shown in Fig.2B. In the case of
Ag2SO4, the average particle size is found to be 10-20 nm (see Fig.1B). The elemental analysis of LiAgSO4 and
Ag2SO4 samples was determined by using EDS technique. The EDS clearly shows the formation of Ag, O and S
elements, formation of LiAgSO4 and Ag2SO4 and the EDS analysis confirms that the chemical composition of
LiAgSO4 and Ag2SO4 is almost in stoichiometric ratios.
3.2 Raman Spectroscopy and phase transition
The obtained Raman spectra of LiAgSO4 and Ag2SO4 are shown in Fig.3A. One external mode is
observed in both the spectra, in accordance with the model that the high- conducting solid phases with
reorienting sulphate ions. The spectra look similar to those of the melts, which is a general finding for
superionic materials. The observed mode frequencies for LiAgSO4 and Ag2SO4 are ν1, ν2, ν3 and ν4 which are
basically from sulphate –ion intermolecular vibrations. Furthermore, the mode frequencies of solid phases agree
with previous calculations [18-25]. This confirms our synthesis and structure of the LiAgSO4 and Ag2SO4. We
observed 91.6 cm-1
as νext. The intense peak at 970 cm-1
is denoted as ν1, whereas 427 and 457 cm-1
are under the
ν2 band. The peaks 1007 cm-1
and 1045 cm-1
are ν3 band. The ν4 consists of 623 cm-1
mode. ν1 and ν4 modes
decreases with increasing size of the alkali metal cations. By comparing with Raman spectra of Ag2SO4, it is
observed that the intensity of ν2 and ν4 bands decreases i.e they are inactive. Whereas the intensity of ν3 band
increases i.e it is active. The intensity of ν1 band remains same.
3.3 Differential Scanning calorimetry
A typical DSC curve of heat flow vs sample temperature consists of a series of peaks measured against
a standard sample (Iridium) in upward as well as downward direction. The position, shape and the number of
peaks will help in identifying the thermal events occurring in the substance. More importantly, since the areas
under the peaks are related to the enthalpy of transmission, these facts are used for quantitative determination of
thermodynamic quantities. Any phenomenon that produces enthalpy changes or change of heat capacity is
denoted by DSC. Physical changes in solids may involve evolution or absorption of heat. This is viewed in DSC
as an exothermic or endothermic peak. A transition such as melting or a structural phase transition yields an
endothermic, while an amorphous to crystalline transition gives an exothermic. DSC analysis of the Ag2SO4 and
LiAgSO4 is carried out at the heating rate 10C/min up to 6000
C as shown in Fig.3B. A strong H2O peak present
3. Thermal and spectroscopy studies of Ag2SO4 and LiAgSO4
www.iosrjournals.org 41 | Page
at 141.13 in LiAgSO4, interestingly it is not found in Ag2SO4. The small endothermic peaks in LiAgSO4 at
388.8 and 4200
C are due to the formation of BCC structure of LiAgSO4. Knowing that a mechanical mixture
cannot be absolutely homogenous, the small endothermic peak at 515.90
C is observed in LiAgSO4. And the
thermal effect starting at 542.80
C is purely from the melting point of the BCC LiAgSO4. The peak at 420.90
C in
Ag2SO4 may due to the phase transition of β-Ag2SO4 particles to α-Ag2SO4 on heating. On heating, the excess
heat flow at the structural transition was recorded as DSC signal by S.W.Tao et al noticed two small anomalies
at 427.7C and 567.90
C. It was found that the anomaly depended on the turning temperature at which a cooling
run was changed to a heating run [22].
3.4 Electron spin resonance
Electron spin resonance is a specific microscopic probe to examine molecular environments in
crystalline and disordered systems. Under favourable circumstances, it is possible to create and stabilize
paramagnetic radicles which may reflect certain aspects of dynamics- which may be characteristic of the system
itself. Presently we describe our efforts to stabilize and identify molecular paramagnetic radicles in Ag2SO4 and
LiAgSO4. The ESR spectra of Ag2SO4 and LiAgSO4 are shown in Figs.3C and D. The ESR signals suggesting a
common origin for the paramagnetic centres are involved. In the spectra of LiAgSO4, we observed six sharp
peaks almost with equal spacing 98 G. These are due to Mn2+
impurity present in LiAgSO4. The gav = 2.1040 at
a field of 3255G and g cen = 2.1238 at a field 3219.9 G. This is due to the presence of Mn2+
ions in an
environment close to octahedral symmetry. The g value corresponding to Ag2SO4 is 2.3005.
3.5 Fourier Transform Infrared Spectroscopy
In order to get some structural information of Ag2SO4 and LiAgSO4 solid solution, IR absorption
spectra of a mechanically mixed powder are shown in Figs.4A and B. The free sulphate SO4
2-
ion belongs to the
high symmetry point group. For LiAgSO4, four fundamental internal vibration modes are observed; the
symmetric stretching mode ν1 and the doubly degenerate symmetric bending mode ν2 are IR inactive. The
asymmetric stretching mode ν3 and ν4 are both triply degenerate and IR active. The spectra show an increase of
IR transmission, inactive absorption ν1 around 619.18 cm-1
and ν2 is around 997.26 cm-1
. More over the
broadening of the IR active absorption ν3 around 1112.33 cm-1
and ν4 around 646.58 cm-1
indicates the decrease
in symmetry of the SO4
2-
ions due to the incorporation of Li+
ions in to the interstitial positions and/or Ag+
lattice sites, resulting in the change of structural environment. That is, IR spectra indirectly demonstrate the
formation of LiAgSO4 phase. The higher order modes are due to the presence of H2O, which are belongs to O-H
vibrations. For Ag2SO4, only two modes are observed at 991.78 and 1128.77 cm-1
.
IV. Conclusions
A comparative study conducted on the structure, electronic and spectroscopic properties of Ag2SO4 and
LiAgSO4 is reported. Both the sulphates crystallised in orthorhombic structure with the same space group of
Fddd (70). A red shift in Raman modes indicates the stiffness of the crystal Ag2SO4 over LiAgSO4. From ESR, it
is observed that these sulphates have Mn2+
impurities leading to the gav= 2.1040 at a field 3255 G. This is due to
Mn2+
ions in an environment close to octahedral symmetry. The g value corresponding to Ag2SO4 is 2.3005. The
endothermic peaks in LiAgSO4 at 388.8 and 4200
C are due to the formation of BCC structure of LiAgSO4. The
peak at 420.90
C in Ag2SO4 may due to the phase transition of β-Ag2SO4 particles to α-Ag2SO4 on heating.
References
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Figure captions
Fig.1. The (A) X-ray diffraction, (B) FESEM and (C) EDS of Ag2SO4.
Fig.2. The (A) X-ray diffraction, (B) FESEM and (C) EDS of LiAgSO4
Fig.3. (A) Raman spectroscopy, (B) DSC and (C), (D) ESR of Ag2SO4 and LiAgSO4
Fig.5. FTIR of (A) Ag2SO4 and (B) LiAgSO4.
Figure 1: S. Rama Rao et al
Figure 2: S. Rama Rao et al
Figure 3: S. Rama Rao et al
5. Thermal and spectroscopy studies of Ag2SO4 and LiAgSO4
www.iosrjournals.org 43 | Page
Figure 4: S. Rama Rao et al