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Papers by Inder Pal

237-244with excitations wavelength at 330 nm. The FTIR profile revealed that the glass has both B... more 237-244with excitations wavelength at 330 nm. The FTIR profile revealed that the glass has both BO3 and BO4 units. Due to presence New series of cadmium bismuth borate (CBBC) glasses have been developed by varying bismuth content in the chemical compositions of 20CdO.xBi2O3.(79.5-x)B2O3, where x = 15, 20, 25, 30 and 35 mol % Bi2O3, containing 0.5 mol% of Cu2+ ions. These glasses have been prepared by melt-quench technique (1150°C in air) for verifying there UV filtration performance. From the measurement of UV absorption spectra, both direct and indirect band gaps have been evaluated. Also different physical properties of the prepared glasses have also been studied. The refractive index of prepared glasses has been measured by using Brewster angle method. The amorphous nature of the glasses has been confirmed by X-ray diffraction. The spectroscopic properties of the glasses have been investigated using optical absorption spectra and fluorescence spectra. Optical transmission spectra...

Glasses with composition 20PbO.(79.5-x)Bi 2 O 3 .xSiO 2 (10 ≤ x ≤ 40) containing 0.5mol% of Er 3+... more Glasses with composition 20PbO.(79.5-x)Bi 2 O 3 .xSiO 2 (10 ≤ x ≤ 40) containing 0.5mol% of Er 3+ ions were prepared by melt-quench technique. An intense green luminescence bands with maximum around 516 nm and 536 nm are assigned to the 2 H 11/2 → 4 I 15/2 and 4 S 3/2 → 4 I 15/2 transitions respectively has been obtained. Optical absorption and fluorescence spectra were recorded at room temperature for all glass samples. Based on the Judd-Offelt theory, spectroscopic properties of Er 3+ ions are discussed by changing the host glass compositions. The intensity parameters Ω 2 , Ω 4 , and Ω 6 are determined by applying least square analysis method. The variation of Ω 2 with Bi 2 O 3 content has been attributed to changes in the rare earth oxygen covalency. Using these intensity parameters various radiative properties like spontaneous emission probability, branching ratio, radiative life time and stimulated emission cross-section of various emission lines have been evaluated. The amorph...

Journal of Alloys and Compounds, 2016

Glass samples with compositions xSm 2 O 3-(100-x)[0.1BaO-0.4ZnO-0.5B 2 O 3 ]; x = 0.5, 1.0, 1.5 a... more Glass samples with compositions xSm 2 O 3-(100-x)[0.1BaO-0.4ZnO-0.5B 2 O 3 ]; x = 0.5, 1.0, 1.5 and 2.0 have been prepared using melt quench technique. Optical absorption and fluorescence spectra have been recorded for prepared glass samples at room temperature. The spectral intensities of Sm 3+ transition observed in absorption spectra have been calculated by using Judd-Ofelt theory. The intensity parameters (Ω 2 , Ω 4 and Ω 6) have been estimated by applying least square fit method on the experimental (f exp) and calculated (f cal) oscillator strengths. The variation of Ω 2 observed with the increase in Sm 3+ ion concentration, is attributed to decease in covalency of rare earth oxygen bond due to change in optical basicity of host glass matrix. From the fluorescence spectra, four emission spectral lines have been observed that correspond to the transition from 4 G 5/2 ground state to lower lying 6 H 5/2 , 6 H 7/2 , 6 H 9/2 and 6 H 11/2 states with an excitation wavelength of 402 nm. The intensity parameters and the emission measurements have been used to estimate the various radiative parameters such as transition probabilities (A R), radiative lifetime (τ R), branching ratio (β R) and stimulated emission cross-sections (σ e) of luminescent levels. The value of σ e is found to decrease with increase in concentration of Sm 3+ ions and it possesses higher value for glass sample with x = 0.5 for transition lying in the visible region indicating its importance for photonic applications.

IOP Conference Series: Materials Science and Engineering, 2015

Bismuth borate glasses containing MoO3 content have been synthesized by the standard melt-quenchi... more Bismuth borate glasses containing MoO3 content have been synthesized by the standard melt-quenching technique. The samples have been characterized by X-ray diffraction and scanning electron microscopy. Frequency and temperature dependent conductivity measurements have been carried out in the range of 20Hz to 1MHz and in the temperature range of 373K to 623K respectively. The frequency dependent conductivity has been studied using both conductivity and modulus formalisms. The dielectric permittivity (e' and e"), electrical modulus (M*) and dielectric loss were also studied of the prepared glasses. The values of e' and e'' are found to decrease with increase in frequency.

International Journal of Modern Physics: Conference Series, 2013

Glasses with composition 20B2O3.(79.5-x)Bi2O3.xSiO2 (10 ≤ x ≤ 40) containing 0.5mol% of Er3+ ions... more Glasses with composition 20B2O3.(79.5-x)Bi2O3.xSiO2 (10 ≤ x ≤ 40) containing 0.5mol% of Er3+ ions were prepared by melt-quench technique. Optical absorption and fluorescence spectra were recorded at room temperature for all glass samples. Based on the Judd-Offelt theory, spectroscopic properties of Er3+ ions are discussed by changing the host glass compositions. The intensity parameters Ω2 , Ω4 , and Ω6 are determined by applying least square analysis method. The variation of Ω2 and Ω6 with Bi2O3 content has been attributed to changes in the asymmetry of the ligand field at the rare earth ion site and to the changes in the rare earth oxygen (RE-O) covalency. The variation of Ω4 with Bi2O3 content has been attributed to rigidity of the samples. Using these intensity parameters various radiative properties like spontaneous emission probability, branching ratio, radiative life time and stimulated emission cross-section of various emission lines have been evaluated. An intense green lum...

Glasses with composition 20CdO·xBi(2)O(3)·(79.5-x)B(2)O(3) (15≤x≤35, x in mol%) containing 0.5 mo... more Glasses with composition 20CdO·xBi(2)O(3)·(79.5-x)B(2)O(3) (15≤x≤35, x in mol%) containing 0.5 mol% of Er(3+) ions were prepared by melt-quench technique (1150°C in air). The amorphous nature of the glasses was confirmed by X-ray diffraction. The spectroscopic properties of the glasses were investigated using optical absorption spectra and fluorescence spectra. The phenomenological Judd-Ofelt intensity parameters Ω(λ) (λ=2, 4, 6) were determined from the spectral intensities of absorption bands in order to calculate the radiative transition probability (A(R)), radiative life time (τ(R)), branching ratios (β(R)) for various excited luminescent states. Using the near infrared emission spectra, full width at half maxima (FWHM), stimulated emission cross-section (σ(e)) and figure of merit (FOM) were evaluated and compared with other hosts. Especially, the numerical values of these parameters indicate that the emission transition (4)I(13/2)→(4)I(15/2) at 1.506 μm in Er(3+)-doped cadmium bismuth borate glasses may be useful in optical communication.

Glasses having compositions 20B2O3.(79.5-x)Bi2O3.xSiO2 (10 ≤ x ≤ 40) doped with 0.5 mol% of Sm 3+... more Glasses having compositions 20B2O3.(79.5-x)Bi2O3.xSiO2 (10 ≤ x ≤ 40) doped with 0.5 mol% of Sm 3+ ions were prepared by melt quench technique. The amorphous nature of the glasses was confirmed by X-ray diffraction studies. The spectroscopic properties of Sm 3+ ions in bismuth borosilicate glasses as a function of bismuth oxide were investigated using optical absorption and fluorescence spectra. The Judd-Ofelt theory has been employed to calculate transitions probability from the data of absorption cross-section of several f-f transitions. The intensity parameters Ω2 is related to the symmetry of glass hosts, where as the parameter Ω6 is inversely proportional to the rare earth oxygen (RE-O) covalency. The variation of Ω4 with Bi2O3 content has been attributed to rigidity of the samples. Using the Judd Ofelt intensity parameters the other radiative properties like radiative transition probability, radiative life time, branching ratio and the stimulated emission cross-sections of prepared BBSS glasses have been calculated. A bright fluorescent orange emission at 600 nm (4 G 5/2 → 6 H 7/2) of Sm 3+ ion has been investigated as a function of Bi2O3 in host glass. The radiative transition probabilities of Sm 3+ ions are large in bismuth borosilicate glasses, suggesting the suitability of these glasses as potential candidate for laser application.

International Journal of Modern Physics: Conference Series, 2013

Glasses having composition 20CdOxBi2O3(79.5-x)B2O30.5Pr6O11 with x varying from 15 to 35 mol% hav... more Glasses having composition 20CdOxBi2O3(79.5-x)B2O30.5Pr6O11 with x varying from 15 to 35 mol% have been synthesized. Optical absorption and fluorescence spectra were measured at ambient temperature. A close correlation is observed between the Bi2O3 content and the spectroscopic properties such as Judd-Ofelt intensity parameters Ωλ = (λ = 2, 4, 6) , radiative and structural properties of prepared glasses doped with Pr3+ ion. The variation of Ω2 with Bi2O3 content has been attributed to changes in the asymmetry of the ligand field at the rare earth (RE) ion site (due to structural change) and to changes in RE-O covalency, whereas the variation of Ω6 has been related to the variation in RE-O covalency. Following the luminescence spectra, various radiative properties like transition probability (Arad), radiative lifetime (τr), branching ratio (βr) and stimulated emission cross section (σ) have been calculated. The branching ratio for 3P0 → 3F2 transition of Pr3+ glass system arrive at 4...

The Australian Journal of Agricultural and Resource Economics, 2002

A comprehensive set of potential new feed grains for Australia was evaluated to help establish th... more A comprehensive set of potential new feed grains for Australia was evaluated to help establish the options with the highest priorities for research. The cost-reducing impacts of the different options were analysed using a linear-programming model that determined the least-cost feed rations for the different livestock industries. Economic welfare analysis was then used to estimate the size and distribution of the benefits of research from the feed grains quality-improving research. The analysis revealed that there are only limited opportunities to improve the productivity and competitiveness of Australia's livestock industries by improving the nutritional characteristics of feed grains. * The authors would like to acknowledge the contribution that Ahmed Hafi and Tony Edwards made to the data and the analysis that lies behind this paper. Without them, this analysis would not have been possible. The financial support of the Grains Research and Development Corporation for this work is gratefully acknowledged.

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2014

h i g h l i g h t s Optical properties of Sm 3+ doped lead bismuth silicate glasses have been stu... more h i g h l i g h t s Optical properties of Sm 3+ doped lead bismuth silicate glasses have been studied. Transition 4 G 5/2 ? 6 H 7/2 is responsible for reddish-orange luminescence. Covalency decreases with decrease in bismuth content. g r a p h i c a l a b s t r a c t Emission spectrum of 20PbOÁ69.5Bi 2 O 3 Á10SiO 2 Á0.5Sm 2 O 3 (PBSS1) sample.

Optical Materials, 2009

Glasses having composition 20ZnOÁxBi 2 O 3 Á(79 À x)B 2 O 3 (15 6 x 6 35 mol%) and doped with 1 m... more Glasses having composition 20ZnOÁxBi 2 O 3 Á(79 À x)B 2 O 3 (15 6 x 6 35 mol%) and doped with 1 mol% Sm 3+ ions have been prepared by melt quench technique. Optical absorption and fluorescence spectra have been recorded. Judd-Ofelt approach has been applied for the f M f transition of Sm 3+ ions to evaluate various intensity parameters (X 2 , X 4 , X 6). The variations in intensity parameters, radiative transition probabilities and hypersensitive band positions with composition have been discussed. The variation of X 2 with Bi 2 O 3 content have been attributed to change in the asymmetry of the ligand field at the rare earth ion site and to the changes in their rare earth-oxygen (RE-O) covalency, whereas the variation of X 6 is found to be strongly dependent on nephlauxetic effect. The shift of the hypersensitive band shows that the covalency of the RE-O bond increases with increase of Bi 2 O 3 content due to increased interaction between the Sm 3+ ion and non-bridging oxygens. The radiative transition probabilities for the Sm 3+ ions are large in zinc bismuth borate glasses, suggesting their suitability as laser material.

Modern Physics Letters B, 2013

The glasses of compositions x Fe 2 O 3⋅ (40 - x) Bi 2 O 3⋅60 B 2 O 3⋅2 V 2 O 5 have been prepared... more The glasses of compositions x Fe 2 O 3⋅ (40 - x) Bi 2 O 3⋅60 B 2 O 3⋅2 V 2 O 5 have been prepared by the standard melt-quenching technique. Amorphous nature of these samples is ascertained by XRD patterns. The presence of BO 3 and BO 4 units is identified by IR spectra of glass samples. The absorption edge (λ cut-off ) shifts toward longer wavelengths with an increase in Fe 2 O 3 content in the glass matrix. The values of optical band gap energy for indirect allowed and forbidden transitions have been determined and it is found to decrease with increase in transition metal ions. The Urbach's energy is used to characterize the degree of disorder in amorphous solids.

Journal of Alloys and Compounds, 2012

CS2-stabilized silver nanoparticles of ∼6 nm in diameter are prepared in aqueous solution via che... more CS2-stabilized silver nanoparticles of ∼6 nm in diameter are prepared in aqueous solution via chemical reduction of Ag + ions by KBH4 in the presence of CS2. The product is proven to be Ag by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and electron diffraction (ED) patterns. In the UV-visible spectra, an intense surface plasmon is built up at 350-500 nm, and it is centered at 395 nm after the reduction of Ag + ions. This can be assigned to a reaction product of Ag with CS2 because of the strong affinity of S on the surface of Ag particles. The silver nanoparticles in the presence of CS2 remain stable for months at room temperature. It is also found that the absorption band in the range 300-350 nm increases, is centered at 325 nm, and depends on the concentration of CS2, which maybe a derivative (CS or CnSm of CS2). Again the catalytic reduction of a dye, 2,7-dichlorofluorescein (DCF), in the presence of CS2-stabilized silver particles is investigated.

Journal of Alloys and Compounds, 2009

Sodium borosulfate glasses having composition xNa 2 SO 4 •(30−x)Na 2 O•70B 2 O 3 (1.5 ≤ x ≤ 9.0 m... more Sodium borosulfate glasses having composition xNa 2 SO 4 •(30−x)Na 2 O•70B 2 O 3 (1.5 ≤ x ≤ 9.0 mol%) were prepared by melt-quenching technique. The influence of Na 2 SO 4 on physical and thermal properties has been interpreted using density, molar volume and DSC data. The decrease in glass transition temperature (T g) with increase in Na 2 SO 4 content indicates that the average chain length of the host glass matrix decreases. The temperature-dependent conductivity data of the above glass samples have been obtained using impedance measurement in the temperature range 523-593 K and the frequency range 20 Hz to 1 MHz. The dc electrical conductivity (dc) follows Arrehenius relationship and activation energy is 0.83 ± 0.03 eV for ionic migration. The dc conductivity (at 553 K) of the glass with x = 1.5 mol% is 2.08 × 10 −4 −1 m −1 and it is 6.16 × 10 −4 −1 m −1 for x = 9 mol%. The ac conductivity obeys Almond-West type power law behaviour: (ω) = dc + ac (ω) = dc + Aω s. The behaviour of the complex permittivity, dielectric loss and dielectric modulus as a function of frequency was also investigated. An excellent time-temperature superposition in the imaginary part of dielectric modulus (M) confirms that the dynamical processes are temperature independent and is also an indicative of a common ion transport mechanism.

Journal of Alloys and Compounds, 2011

Glasses having composition 20ZnO•xBi 2 O 3 •(79.5 − x)B 2 O 3 •0.5Pr 6 O 11 were prepared by melt... more Glasses having composition 20ZnO•xBi 2 O 3 •(79.5 − x)B 2 O 3 •0.5Pr 6 O 11 were prepared by melt quench technique. The amorphous nature of the prepared glass samples was confirmed by X-ray diffraction. The spectroscopic properties of these glasses were investigated by recording optical absorption and fluorescence spectra. The structural investigations of the glasses were carried out by recording the IR spectra. The optical properties of Pr 3+ ions doped zinc borate glasses with varying concentration of bismuth oxide have been studied. The Judd-Ofelt intensity parameters˝ (= 2, 4, 6) and other radiative properties like radiative transition probability, radiative life time, branching ratio and stimulated emission crosssection of the prepared glasses have been calculated. The variation of˝2 with Bi 2 O 3 content has been attributed to changes in the asymmetry of the ligand field at the rare earth ion site and to the changes in their rare earth oxygen (RE-O) covalency. The branching ratio for 3 P 0 → 3 F 2 transition is 42% and the predicted spontaneous radiative transition probability rates are fairly high (14,347-14,607 s −1). This is beneficial for lasing emission. The stimulated emission cross-section for all the emission bands has been calculated.

Bioscience, Biotechnology, and Biochemistry, 1995

Four macrocarpals (macrocarpals A, B, E, and am-I) were isolated from the leaves of Eucalyptus am... more Four macrocarpals (macrocarpals A, B, E, and am-I) were isolated from the leaves of Eucalyptus amplifolia. Macrocarpal-am-l is a new macrocarpal in which the isopentyl phloroglucinol chromophore is coupled with the 1,10-secoaromadendrane skeleton. Its structure is elucidated by spectral techniques.

Indian Journal of Chemistry, 2010

Treatment of 2-methoxyaniline and 3,5-dichloroaniline with conc.H2SO4 in 2:1 molar ratio at RT af... more Treatment of 2-methoxyaniline and 3,5-dichloroaniline with conc.H2SO4 in 2:1 molar ratio at RT affords the corresponding sulphate salts. These salts have been characterized by X-ray diffraction and spectral analyses. Both these salts are found to form ring substituted ...

237-244with excitations wavelength at 330 nm. The FTIR profile revealed that the glass has both B... more 237-244with excitations wavelength at 330 nm. The FTIR profile revealed that the glass has both BO3 and BO4 units. Due to presence New series of cadmium bismuth borate (CBBC) glasses have been developed by varying bismuth content in the chemical compositions of 20CdO.xBi2O3.(79.5-x)B2O3, where x = 15, 20, 25, 30 and 35 mol % Bi2O3, containing 0.5 mol% of Cu2+ ions. These glasses have been prepared by melt-quench technique (1150°C in air) for verifying there UV filtration performance. From the measurement of UV absorption spectra, both direct and indirect band gaps have been evaluated. Also different physical properties of the prepared glasses have also been studied. The refractive index of prepared glasses has been measured by using Brewster angle method. The amorphous nature of the glasses has been confirmed by X-ray diffraction. The spectroscopic properties of the glasses have been investigated using optical absorption spectra and fluorescence spectra. Optical transmission spectra...

Glasses with composition 20PbO.(79.5-x)Bi 2 O 3 .xSiO 2 (10 ≤ x ≤ 40) containing 0.5mol% of Er 3+... more Glasses with composition 20PbO.(79.5-x)Bi 2 O 3 .xSiO 2 (10 ≤ x ≤ 40) containing 0.5mol% of Er 3+ ions were prepared by melt-quench technique. An intense green luminescence bands with maximum around 516 nm and 536 nm are assigned to the 2 H 11/2 → 4 I 15/2 and 4 S 3/2 → 4 I 15/2 transitions respectively has been obtained. Optical absorption and fluorescence spectra were recorded at room temperature for all glass samples. Based on the Judd-Offelt theory, spectroscopic properties of Er 3+ ions are discussed by changing the host glass compositions. The intensity parameters Ω 2 , Ω 4 , and Ω 6 are determined by applying least square analysis method. The variation of Ω 2 with Bi 2 O 3 content has been attributed to changes in the rare earth oxygen covalency. Using these intensity parameters various radiative properties like spontaneous emission probability, branching ratio, radiative life time and stimulated emission cross-section of various emission lines have been evaluated. The amorph...

Journal of Alloys and Compounds, 2016

Glass samples with compositions xSm 2 O 3-(100-x)[0.1BaO-0.4ZnO-0.5B 2 O 3 ]; x = 0.5, 1.0, 1.5 a... more Glass samples with compositions xSm 2 O 3-(100-x)[0.1BaO-0.4ZnO-0.5B 2 O 3 ]; x = 0.5, 1.0, 1.5 and 2.0 have been prepared using melt quench technique. Optical absorption and fluorescence spectra have been recorded for prepared glass samples at room temperature. The spectral intensities of Sm 3+ transition observed in absorption spectra have been calculated by using Judd-Ofelt theory. The intensity parameters (Ω 2 , Ω 4 and Ω 6) have been estimated by applying least square fit method on the experimental (f exp) and calculated (f cal) oscillator strengths. The variation of Ω 2 observed with the increase in Sm 3+ ion concentration, is attributed to decease in covalency of rare earth oxygen bond due to change in optical basicity of host glass matrix. From the fluorescence spectra, four emission spectral lines have been observed that correspond to the transition from 4 G 5/2 ground state to lower lying 6 H 5/2 , 6 H 7/2 , 6 H 9/2 and 6 H 11/2 states with an excitation wavelength of 402 nm. The intensity parameters and the emission measurements have been used to estimate the various radiative parameters such as transition probabilities (A R), radiative lifetime (τ R), branching ratio (β R) and stimulated emission cross-sections (σ e) of luminescent levels. The value of σ e is found to decrease with increase in concentration of Sm 3+ ions and it possesses higher value for glass sample with x = 0.5 for transition lying in the visible region indicating its importance for photonic applications.

IOP Conference Series: Materials Science and Engineering, 2015

Bismuth borate glasses containing MoO3 content have been synthesized by the standard melt-quenchi... more Bismuth borate glasses containing MoO3 content have been synthesized by the standard melt-quenching technique. The samples have been characterized by X-ray diffraction and scanning electron microscopy. Frequency and temperature dependent conductivity measurements have been carried out in the range of 20Hz to 1MHz and in the temperature range of 373K to 623K respectively. The frequency dependent conductivity has been studied using both conductivity and modulus formalisms. The dielectric permittivity (e' and e"), electrical modulus (M*) and dielectric loss were also studied of the prepared glasses. The values of e' and e'' are found to decrease with increase in frequency.

International Journal of Modern Physics: Conference Series, 2013

Glasses with composition 20B2O3.(79.5-x)Bi2O3.xSiO2 (10 ≤ x ≤ 40) containing 0.5mol% of Er3+ ions... more Glasses with composition 20B2O3.(79.5-x)Bi2O3.xSiO2 (10 ≤ x ≤ 40) containing 0.5mol% of Er3+ ions were prepared by melt-quench technique. Optical absorption and fluorescence spectra were recorded at room temperature for all glass samples. Based on the Judd-Offelt theory, spectroscopic properties of Er3+ ions are discussed by changing the host glass compositions. The intensity parameters Ω2 , Ω4 , and Ω6 are determined by applying least square analysis method. The variation of Ω2 and Ω6 with Bi2O3 content has been attributed to changes in the asymmetry of the ligand field at the rare earth ion site and to the changes in the rare earth oxygen (RE-O) covalency. The variation of Ω4 with Bi2O3 content has been attributed to rigidity of the samples. Using these intensity parameters various radiative properties like spontaneous emission probability, branching ratio, radiative life time and stimulated emission cross-section of various emission lines have been evaluated. An intense green lum...

Glasses with composition 20CdO·xBi(2)O(3)·(79.5-x)B(2)O(3) (15≤x≤35, x in mol%) containing 0.5 mo... more Glasses with composition 20CdO·xBi(2)O(3)·(79.5-x)B(2)O(3) (15≤x≤35, x in mol%) containing 0.5 mol% of Er(3+) ions were prepared by melt-quench technique (1150°C in air). The amorphous nature of the glasses was confirmed by X-ray diffraction. The spectroscopic properties of the glasses were investigated using optical absorption spectra and fluorescence spectra. The phenomenological Judd-Ofelt intensity parameters Ω(λ) (λ=2, 4, 6) were determined from the spectral intensities of absorption bands in order to calculate the radiative transition probability (A(R)), radiative life time (τ(R)), branching ratios (β(R)) for various excited luminescent states. Using the near infrared emission spectra, full width at half maxima (FWHM), stimulated emission cross-section (σ(e)) and figure of merit (FOM) were evaluated and compared with other hosts. Especially, the numerical values of these parameters indicate that the emission transition (4)I(13/2)→(4)I(15/2) at 1.506 μm in Er(3+)-doped cadmium bismuth borate glasses may be useful in optical communication.

Glasses having compositions 20B2O3.(79.5-x)Bi2O3.xSiO2 (10 ≤ x ≤ 40) doped with 0.5 mol% of Sm 3+... more Glasses having compositions 20B2O3.(79.5-x)Bi2O3.xSiO2 (10 ≤ x ≤ 40) doped with 0.5 mol% of Sm 3+ ions were prepared by melt quench technique. The amorphous nature of the glasses was confirmed by X-ray diffraction studies. The spectroscopic properties of Sm 3+ ions in bismuth borosilicate glasses as a function of bismuth oxide were investigated using optical absorption and fluorescence spectra. The Judd-Ofelt theory has been employed to calculate transitions probability from the data of absorption cross-section of several f-f transitions. The intensity parameters Ω2 is related to the symmetry of glass hosts, where as the parameter Ω6 is inversely proportional to the rare earth oxygen (RE-O) covalency. The variation of Ω4 with Bi2O3 content has been attributed to rigidity of the samples. Using the Judd Ofelt intensity parameters the other radiative properties like radiative transition probability, radiative life time, branching ratio and the stimulated emission cross-sections of prepared BBSS glasses have been calculated. A bright fluorescent orange emission at 600 nm (4 G 5/2 → 6 H 7/2) of Sm 3+ ion has been investigated as a function of Bi2O3 in host glass. The radiative transition probabilities of Sm 3+ ions are large in bismuth borosilicate glasses, suggesting the suitability of these glasses as potential candidate for laser application.

International Journal of Modern Physics: Conference Series, 2013

Glasses having composition 20CdOxBi2O3(79.5-x)B2O30.5Pr6O11 with x varying from 15 to 35 mol% hav... more Glasses having composition 20CdOxBi2O3(79.5-x)B2O30.5Pr6O11 with x varying from 15 to 35 mol% have been synthesized. Optical absorption and fluorescence spectra were measured at ambient temperature. A close correlation is observed between the Bi2O3 content and the spectroscopic properties such as Judd-Ofelt intensity parameters Ωλ = (λ = 2, 4, 6) , radiative and structural properties of prepared glasses doped with Pr3+ ion. The variation of Ω2 with Bi2O3 content has been attributed to changes in the asymmetry of the ligand field at the rare earth (RE) ion site (due to structural change) and to changes in RE-O covalency, whereas the variation of Ω6 has been related to the variation in RE-O covalency. Following the luminescence spectra, various radiative properties like transition probability (Arad), radiative lifetime (τr), branching ratio (βr) and stimulated emission cross section (σ) have been calculated. The branching ratio for 3P0 → 3F2 transition of Pr3+ glass system arrive at 4...

The Australian Journal of Agricultural and Resource Economics, 2002

A comprehensive set of potential new feed grains for Australia was evaluated to help establish th... more A comprehensive set of potential new feed grains for Australia was evaluated to help establish the options with the highest priorities for research. The cost-reducing impacts of the different options were analysed using a linear-programming model that determined the least-cost feed rations for the different livestock industries. Economic welfare analysis was then used to estimate the size and distribution of the benefits of research from the feed grains quality-improving research. The analysis revealed that there are only limited opportunities to improve the productivity and competitiveness of Australia's livestock industries by improving the nutritional characteristics of feed grains. * The authors would like to acknowledge the contribution that Ahmed Hafi and Tony Edwards made to the data and the analysis that lies behind this paper. Without them, this analysis would not have been possible. The financial support of the Grains Research and Development Corporation for this work is gratefully acknowledged.

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2014

h i g h l i g h t s Optical properties of Sm 3+ doped lead bismuth silicate glasses have been stu... more h i g h l i g h t s Optical properties of Sm 3+ doped lead bismuth silicate glasses have been studied. Transition 4 G 5/2 ? 6 H 7/2 is responsible for reddish-orange luminescence. Covalency decreases with decrease in bismuth content. g r a p h i c a l a b s t r a c t Emission spectrum of 20PbOÁ69.5Bi 2 O 3 Á10SiO 2 Á0.5Sm 2 O 3 (PBSS1) sample.

Optical Materials, 2009

Glasses having composition 20ZnOÁxBi 2 O 3 Á(79 À x)B 2 O 3 (15 6 x 6 35 mol%) and doped with 1 m... more Glasses having composition 20ZnOÁxBi 2 O 3 Á(79 À x)B 2 O 3 (15 6 x 6 35 mol%) and doped with 1 mol% Sm 3+ ions have been prepared by melt quench technique. Optical absorption and fluorescence spectra have been recorded. Judd-Ofelt approach has been applied for the f M f transition of Sm 3+ ions to evaluate various intensity parameters (X 2 , X 4 , X 6). The variations in intensity parameters, radiative transition probabilities and hypersensitive band positions with composition have been discussed. The variation of X 2 with Bi 2 O 3 content have been attributed to change in the asymmetry of the ligand field at the rare earth ion site and to the changes in their rare earth-oxygen (RE-O) covalency, whereas the variation of X 6 is found to be strongly dependent on nephlauxetic effect. The shift of the hypersensitive band shows that the covalency of the RE-O bond increases with increase of Bi 2 O 3 content due to increased interaction between the Sm 3+ ion and non-bridging oxygens. The radiative transition probabilities for the Sm 3+ ions are large in zinc bismuth borate glasses, suggesting their suitability as laser material.

Modern Physics Letters B, 2013

The glasses of compositions x Fe 2 O 3⋅ (40 - x) Bi 2 O 3⋅60 B 2 O 3⋅2 V 2 O 5 have been prepared... more The glasses of compositions x Fe 2 O 3⋅ (40 - x) Bi 2 O 3⋅60 B 2 O 3⋅2 V 2 O 5 have been prepared by the standard melt-quenching technique. Amorphous nature of these samples is ascertained by XRD patterns. The presence of BO 3 and BO 4 units is identified by IR spectra of glass samples. The absorption edge (λ cut-off ) shifts toward longer wavelengths with an increase in Fe 2 O 3 content in the glass matrix. The values of optical band gap energy for indirect allowed and forbidden transitions have been determined and it is found to decrease with increase in transition metal ions. The Urbach's energy is used to characterize the degree of disorder in amorphous solids.

Journal of Alloys and Compounds, 2012

CS2-stabilized silver nanoparticles of ∼6 nm in diameter are prepared in aqueous solution via che... more CS2-stabilized silver nanoparticles of ∼6 nm in diameter are prepared in aqueous solution via chemical reduction of Ag + ions by KBH4 in the presence of CS2. The product is proven to be Ag by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and electron diffraction (ED) patterns. In the UV-visible spectra, an intense surface plasmon is built up at 350-500 nm, and it is centered at 395 nm after the reduction of Ag + ions. This can be assigned to a reaction product of Ag with CS2 because of the strong affinity of S on the surface of Ag particles. The silver nanoparticles in the presence of CS2 remain stable for months at room temperature. It is also found that the absorption band in the range 300-350 nm increases, is centered at 325 nm, and depends on the concentration of CS2, which maybe a derivative (CS or CnSm of CS2). Again the catalytic reduction of a dye, 2,7-dichlorofluorescein (DCF), in the presence of CS2-stabilized silver particles is investigated.

Journal of Alloys and Compounds, 2009

Sodium borosulfate glasses having composition xNa 2 SO 4 •(30−x)Na 2 O•70B 2 O 3 (1.5 ≤ x ≤ 9.0 m... more Sodium borosulfate glasses having composition xNa 2 SO 4 •(30−x)Na 2 O•70B 2 O 3 (1.5 ≤ x ≤ 9.0 mol%) were prepared by melt-quenching technique. The influence of Na 2 SO 4 on physical and thermal properties has been interpreted using density, molar volume and DSC data. The decrease in glass transition temperature (T g) with increase in Na 2 SO 4 content indicates that the average chain length of the host glass matrix decreases. The temperature-dependent conductivity data of the above glass samples have been obtained using impedance measurement in the temperature range 523-593 K and the frequency range 20 Hz to 1 MHz. The dc electrical conductivity (dc) follows Arrehenius relationship and activation energy is 0.83 ± 0.03 eV for ionic migration. The dc conductivity (at 553 K) of the glass with x = 1.5 mol% is 2.08 × 10 −4 −1 m −1 and it is 6.16 × 10 −4 −1 m −1 for x = 9 mol%. The ac conductivity obeys Almond-West type power law behaviour: (ω) = dc + ac (ω) = dc + Aω s. The behaviour of the complex permittivity, dielectric loss and dielectric modulus as a function of frequency was also investigated. An excellent time-temperature superposition in the imaginary part of dielectric modulus (M) confirms that the dynamical processes are temperature independent and is also an indicative of a common ion transport mechanism.

Journal of Alloys and Compounds, 2011

Glasses having composition 20ZnO•xBi 2 O 3 •(79.5 − x)B 2 O 3 •0.5Pr 6 O 11 were prepared by melt... more Glasses having composition 20ZnO•xBi 2 O 3 •(79.5 − x)B 2 O 3 •0.5Pr 6 O 11 were prepared by melt quench technique. The amorphous nature of the prepared glass samples was confirmed by X-ray diffraction. The spectroscopic properties of these glasses were investigated by recording optical absorption and fluorescence spectra. The structural investigations of the glasses were carried out by recording the IR spectra. The optical properties of Pr 3+ ions doped zinc borate glasses with varying concentration of bismuth oxide have been studied. The Judd-Ofelt intensity parameters˝ (= 2, 4, 6) and other radiative properties like radiative transition probability, radiative life time, branching ratio and stimulated emission crosssection of the prepared glasses have been calculated. The variation of˝2 with Bi 2 O 3 content has been attributed to changes in the asymmetry of the ligand field at the rare earth ion site and to the changes in their rare earth oxygen (RE-O) covalency. The branching ratio for 3 P 0 → 3 F 2 transition is 42% and the predicted spontaneous radiative transition probability rates are fairly high (14,347-14,607 s −1). This is beneficial for lasing emission. The stimulated emission cross-section for all the emission bands has been calculated.

Bioscience, Biotechnology, and Biochemistry, 1995

Four macrocarpals (macrocarpals A, B, E, and am-I) were isolated from the leaves of Eucalyptus am... more Four macrocarpals (macrocarpals A, B, E, and am-I) were isolated from the leaves of Eucalyptus amplifolia. Macrocarpal-am-l is a new macrocarpal in which the isopentyl phloroglucinol chromophore is coupled with the 1,10-secoaromadendrane skeleton. Its structure is elucidated by spectral techniques.

Indian Journal of Chemistry, 2010

Treatment of 2-methoxyaniline and 3,5-dichloroaniline with conc.H2SO4 in 2:1 molar ratio at RT af... more Treatment of 2-methoxyaniline and 3,5-dichloroaniline with conc.H2SO4 in 2:1 molar ratio at RT affords the corresponding sulphate salts. These salts have been characterized by X-ray diffraction and spectral analyses. Both these salts are found to form ring substituted ...