Search

In the present study, radiation shielding and protection ability of prepared Flyash-lime-Gypsum (FaLG) bricks has been studied in terms of energy exposure build up factors and dose parameters. The energy exposure build up factors of Flyash-lime-Gypsum (FaLG) bricks have been calculated for the energy range of 0.015 MeV–15 MeV and for penetration depth upto 40 mfp directly using a new and simplified Piecewise Linear Spline Interpolation Method (PLSIM). In this new method, the calculations of G.P fitting parameters are not required. The verification and accuracy of this new method has been checked by comparing the results of exposure build up factor for NBS concrete calculated using present method with the results obtained by using G.P fitting method. Further, the relative dose distribution and reduced exposure dose rate for various radioactive isotopes without any shielding material and with Flyash-lime-Gypsum (FaLG) bricks have been calculated in the energy range of 59.59–1332 keV. On the basis of the obtained results, it has been reported that the prepared Flyash-lime-Gypsum (FaLG) bricks possess satisfactory radiation shielding properties and can be used as environmentally safe storage facilities for low level nuclear waste.

The phase evolution studies of zirconia, with 4–16 mol-% doping of calcium, have been carried out after sintering the pellets at 1400°C. From the X-ray diffractometer patterns, it is evident that t...

In the present work, the synthesis of novel nanocomposite adsorbent based on graft copolymer of Poly(AA)/GG incorporated silver nanoparticles (AgNPs) has been carried out for the elimination of Methylene blue (MB) dye from the aqueous phase. The characterization of synthesized nanocomposite has been carried out by using various analytical techniques such as UV–Vis, FTIR, XRD, FE-SEM, EDX, DLS and BET studies. The UV–Vis, DLS and XRD studies revealed the stable formation of AgNPs inside the polymer matrix with an average size of 100 ± 1 nm. The − 26.40 mV value of Zeta potential also confirms the stability of AgNPs inside the polymer matrix. Furthermore, the resultant adsorbent with an improved adsorption capacity is used to eliminate the MB dye from liquid phase. The parameters such as adsorbent dose and pH of dye solution in adsorption process are optimized. Moreover, the study of the adsorption kinetics and isotherm indicate that the pseudo-second-order kinetics and Langmuir isotherm model is more suitable for describing the experimental adsorption data having maximum adsorption capacity of 833.33 mg/g. Further, the positive values of enthalpy and entropy change specify that the adsorption of MB dye onto the surface of AgNPs/GG/Poly(AA) is endothermic, spontaneous and favorable process. Hence, In-situ synthesis of AgNPs inside polymer and grafting of AA as monomer onto GG has proven to be accountable for the substantial changes in adsorption capacity for removal of MB dye from aqueous phase. Therefore, the resultant AgNPs/GG/Poly(AA) nanocomposite may prove to be a noble adsorbent for the removal of MB dye from the liquid phase.

Polyaniline (PANI) film synthesized by cyclic voltammetry method. Rectangular strip of stainless steel (SS) is used to construct low cost electrode for Supercapacitors. PANI films are characterized by Field-emission scanning electron microscopy (FE-SEM), X-ray diffraction analysis (XRD). Chemical structure and electronic behavior of PANI film is carried out by Fourier transform infrared (FTIR), and ultraviolet-visible (UV-Vis) spectroscopy, respectively. The electrochemical performance of PANI film carried out by cyclic voltammetry in 1M H2SO4 giving specific capacitance of 346 Fg-1 at sweep rate 10 mVs-1 with 63% capacitance retention after 1000 cycles at sweep rate 100 mVs-1.

A novel ecofriendly microwave-assisted xanthan gum-cl-poly (acrylic acid)/AgNPs (MW-XG-cl-pAA/AgNPs) hydrogel nanocomposite has been synthesized by using free radical graft polymerization method. Xanthan gum (XG) acts as stabilizer to produce stable uniform AgNPs in the presence of stem extract of Nepeta leucophylla inside the polymer network. The evidence of incorporation of AgNPs inside the polymer matrix, grafting of acrylic acid (AA) onto backbone XG, surface morphology, crystallinity, thermal properties and effective loading of KCl inside the synthesized hydrogel nanocomposite are attained by using various analytical techniques, such as ultraviolet–visible, Fourier transform infrared, field emission scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction and thermogravimetric analysis. The influence of incorporation of silver nanoparticles inside polymer matrix is also examined. Moreover, in order to explore the swelling and releasing kinetic behavior of synthesized nanocomposite mathematical modeling (Fick’s law) has been used here. Here, the resulting nanocomposite is used for the application of water retention potential of different soil samples and controlled release of KCl. It is evident from the studies that the synthesized nanocomposite acts as water reservoir in different types of soil and maintains the moisture for more than 60 days. Further, the high value of initial diffusion coefficient ( $$ 5.458 \times 10^{ - 6}\,{\text{m}}^{2} /{\text{h}} $$ ) as compared to late diffusion coefficient ( $$ 1.453 \times 10^{ - 7} {\text{m}}^{2} /{\text{h}} $$ ) represents the controlled release of KCl. Hence, the synthesized nanocomposite with controlled release and decent water retention can prevent the serious environmental hazards.

The effects of target thickness on the shape of the bremsstrahlung energy spectrum in Pb for 89Sr beta particles are studied in the photon energy region of 1–100 keV. The thicknesses of the Pb targets chosen for present study are 53, 223, 552, 677, 908 and 1352 mg/cm2. The bremsstrahlung energy spectrum, only at target thickness of 677 mg/cm2 is found to be closer to the Avdonina and Pratt (1999) theory for total bremsstrahlung with the variation of +3%, −2%, +2%, −13%, −39% and 69% at 1, 4, 10, 30, 60 and 100 keV, respectively. The polarization bremsstrahlung is limited up to a particular target thickness at low-energy region, suppressing the bremsstrahlung at high-energy region.

Dye-Sensitized Solar Cells (DSSCs) are the promising low-cost solar cells to convert solar energy into electric energy. In this study, TiO2 based Dye-Sensitized Solar Cell is fabricated. TiO2 paste is prepared by using ethanol as a solvent. A thin layer of TiO2 paste is coated on ITO conducting glass, which acts as a working electrode. The counter electrode is prepared by pencil graphite paste using ethanol as a solvent and coated on ITO conducting glass. The dye solution is prepared by adding commercially available methylene blue dye to ethanol and deionized water. From XRD studies, the average crystallite size of TiO2 powder is found to be 88.46 nm. This indicates that the nanostructure of the TiO2 having a large surface to volume ratio playing a vital role in the absorption of solar radiations by the material. J-V characteristics of fabricated DSSC were studied to evaluate its performance in terms of a short circuit current, open-circuit voltage, and fill factor. The performance of DSSC may be enhanced by decreasing the crystallite size of TiO2.

In present communication, gamma and neutron shielding ability of CRT panel (CRT-P), CRT funnel (CRT-F), LCD, and commercial borosilicate (BS) waste glasses has been studied in terms of energy exposure build up factors and fast neutron removal cross-section. The energy exposure build up factors of aforesaid waste glasses for the energy range of 0.015 MeV to 15 MeV and for penetration depth upto 40 mfp have been calculated directly using simple Log Interpolation Method without using multistep G.P. fitting method. On the basis of obtained results, it has been reported that these waste glasses possess satisfactory shielding characteristics and can be used as aggregate for making high density concrete storage facilities for safe disposal of nuclear waste.

Nanofibers (NFs) are fibers with diameters in the nanometer range and have found numerous applications due to their unique properties. Researchers are still trying to improve the properties of electrospun-based fibers by using unique nanomaterials for solving environmental problems especially the treatment of wastewater. The modification of NFs has been carried out by decorating and embedding the various types of nanoparticles, such as noble metals, carbon nanomaterials, and metal oxide nanoparticles onto the surface of the membrane. The decorated surface of the NFs membrane possesses high surface area, surface energy, additional functionality, and anti-fouling properties that make them a suitable candidate for wastewater treatment application. This chapter highlights the modern trends in the surface engineering of NFs via electrospinning embedded nanoparticles (NPs) for wastewater treatment. The shape and size of Ag and Au NPs prepared under different reducing and stabilizing agents are also reviewed. The electrospun polymer NFs embedded with different NPs and surface modifications of NF membranes are discussed. The critical issues related to the use of electrospun polymer NFs embedded with different NPs for wastewater treatment along with a concluding note on possible future directions on this have also been included.

Absorption jump factors and jump ratios parameters are required in many areas of industries. Lanthanum is utilized in picture industry and for studio lighting and projection. Due to this reason it is important to calculate the absorption jump factor (J) and jump ratios(r) of lanthanum compounds to explore the potential applications of these compounds. The jump factors and jump series have been calculated using mass attenuation coefficient. The theoretical values of mass attenuation coefficient were obtained by using WinXCom, based on the mixture rule. The jump ratios (r1,2,3) and jump factors (J1,2,3), of Lanthanum compounds have been calculated for the first time. These different compounds have different jump ratios and jump factors for Lanthanum compounds near edges. It is expected that mass attenuation coefficient for Lanthanum compounds will vary near edge. It is found value of jump ratios for K, L1, L2, L3 vary from 1.653 to 5.853, vary from 1.069 to 1.153, vary from 1.2 to 1.351 and vary from 1.316 to 2.814 respectively. It is also seen that value of jump factor for K, L1, L2, L3 vary from 0.395 to 0.829, vary from 0.065 to 0.133, vary from 0.116 to 0.26 and vary from 0.240 to 0.647 respectively. No experimental or theoretical values of these parameters are available in literature for comparison.

2 D materials show fascinating properties for their applications in advanced technology. Tungsten Diselenide (WSe2), a family of transition-metal dichalcogenides, has greatly inspired researchers to take up challenges in energy storage, optoelectronic and electronic applications. We have synthesized WSe2 using hydrothermal technique via the reaction of sodium tungstate and selenium power with the assistance of sodium borohydride, a reducing agent and N, N- dimethylformamide (DMF) and deionized water have been utilized as double solvent. The structural and the surface morphological properties of WSe2 have been studied using X-ray diffraction and Field Emission Scanning Electron Microscope (FESEM) which approve the high crystallinity and reveal the most thermodynamically stable Hexagonal phase of WSe2. The successful synthesis of this new class of 2D material motivated us to perform ion beam bombardment experiments for modifying its properties especially for energy applications.

Zirconia (ZrO2) has a unique property of changing the crystalline phase from monoclinic to cubic at a higher temperature. This leads to its versatile applications in the fields of nuclear reactors, oxygen detectors, solid oxide fuel cells etc. Yttria doped zirconia has been studied extensively for transformation and stabilization of its cubic phase at room temperature. Whereas, the reports on such accounts with calcium doping are rare. In present study, the crystalline structure of Ca-doped zirconia (8 mol % Ca) as prepared by the solid-state reaction technique and sintered at 1000 °C in air, is compared with that of pure zirconia. From the X-ray diffractometer patterns recorded in θ-2θ geometry, it is evident that the pure zirconia exists only in the monoclinic phase. Further, the XRD of Ca-doped zirconia and its Rietveld refinement revealed the stabilization of zirconia in the monoclinic and cubic phase. The cubic phase stabilization in zirconia at room temperature with calcium doping opened up the possibilities of tailoring its properties more precisely via ion implantation.

Bio-fabrication of silver nanoparticles, using stem extracts of Nepeta leucophylla and their photocatalytic degradation activity, has been undertaken. The synthesized silver nanoparticles are chara...

Silver nanoparticles containing superabsorbent nanocomposite based on grafted copolymer of Guar gum/polyacrylic acid (GG/Poly(AA)) have been are synthesized by two step free radical graft copolymerization using ammonium persulphate (APS) as initiator and N, N′–methylenebisacrylamide (MBA) as cross-linking agent. The synthesized nanocomposite superabsorbent is characterized using various analytical techniques, such as, ultraviolet–visible spectroscopy, Fourier transformed infrared spectroscopy, X-ray diffractometry, Field Emission Scanning Electron Microscopy, Energy dispersive X-ray spectroscopy and thermal gravimetric analysis. The UV–vis, EDX and XRD studies revealed that silver nanoparticles (AgNPs) are successfully incorporated inside the polymer of GG/Poly(AA). The grafted crosslinking of backbone guar gum with acrylic acid and incorporation of silver nanoparticles are confirmed from the FTIR spectrogram. In addition to this, effect of several synthesis parameters, such as, concentration of guar gum, concentration of monomer, initiator and cross-linker are also studied. Furthermore, under optimized reactions conditions the influence of several parameters like pH, temperature and time on swelling behavior of superabsorbent nanocomposite is studied in double deionized water and found to be 1700%. The swelling behavior of nanocomposite has been also inspected in various saline solutions. It is evident that the AgNPs/GG/Poly(AA) nanocomposite superabsorbent may be used for water absorption purpose in many applications.

Bioinspired silver nanoparticles were synthesized using nontoxic, eco-friendly, and novel root extract of Nepeta leucophylla. The reduction of silver nitrate salt into nanoparticles is perf...

The measurement of Absorption edge parameters of the L III edge of pure elements Hg, Tl, Pb and Bi along with their compounds HgCl2, HgO, HgF2, TlCl, Tl2O3, PbCl2, PbF2, Pb3O4, BiF3, BiCl3 and Bi2O3 has been done using EDXRF technique. In the present measurements 241Am (59.54 keV) radioactive source of activity 100 mCi along with CANBERRA make cryo-cooled Si (Li) detector is used. The measured results are compared with theoretically calculated values from FFAST version 2.1 (Chantler et al., 2005) and shows good agreement with each other within experimental uncertainties within 3.5%. It is observed that the values of absorption edge parameters of the LIII edge depends slightly on the chemical environment and shows almost constant behaviour with effective atomic number ( Z eff )

We demonstrated a facile electrochemical and photocatalytic degradation of MB dye using eco-friendly nanocomposites based on reduced graphene oxide/silver nanowires (rGO/AgNWs). The deposition of rGO onto stainless steel (SS) has been performed by an electroplating method and then AgNWs are decorated onto rGO with uniform distribution and strong interactions. The synthesized nanocomposite has been characterized by various analytical techniques such as UV–Vis, XRD, FTIR, FESEM, EDX, Raman and TGA/DSC. The rGO/AgNWs nanocomposite is used as anode in electrochemical and as photocatalyst in photocatalytic degradation experiment. The effect of various parameters, type of electrolyte, pH, voltage applied, concentration of electrolyte on electrochemical degradation of MB dye is also investigated. Various nanocomposites with different wt.% of Ag is synthesized in order to explore the influence of AgNWs onto percentage degradation. The rGO/AgNWs with 9.5 wt% shows maximum percentage degradation for electrochemical and photocatalytic degradation of about 99 and 98.36%, respectively, due to the presence of AgNWs which enhance the conductivity and surface area. The rate constant and activation energy are also calculated from degradation kinetics studies. Hence, it is expected that the rGO/AgNWs nanocomposite is promising photocatalyst and electrode which may prove to be a noble material for environment remedial application.

Total bremsstrahlung spectral photon distribution generated in thick targets of lead compounds Pb(CH3COO)2·3H2O, Pb(NO3)2 and PbCl2 by 90Sr beta particles has been investigated theoretically and experimentally in the photon energy region 1–10 keV. The experimental results are compared with the theoretical models describing ordinary bremsstrahlung and the theoretical model which includes polarization bremsstrahlung into ordinary bremsstrahlung, in stripped approximation. It is observed that the experimental results show better agreement with the model which describes bremsstrahlung in stripped approximation in the energy range 3–10 keV. However, the results show positive deviation in the photon energy region of 1–3 keV. Further, it has been found that there is a continuous decrease of polarization bremsstrahlung contribution into ordinary bremsstrahlung in the formation of total bremsstrahlung spectra with increase in photon energy. The suppression of polarization bremsstrahlung has been observed due to the presence of large fraction of low Z elements in the compounds. The results clearly indicate that polarization bremsstrahlung plays an important role in the formation of total bremsstrahlung spectra in compounds in the studied energy region.

The total bremsstrahlung spectra in the thick targets of lead acetate trihydrate (Pb(CH 3 COO) 2 ·3H 2 O), lead nitrate Pb(NO 3 ) 2 and lead chloride (PbCl 2 ) produced by 90 Sr beta particles have been investigated in the photon energy region of 10–100 keV. The experimental bremsstrahlung spectra have been compared with the theoretical models Elwert corrected (non relativistic) Bethe Heitler theory, modified Elwert factor (relativistic) Bethe Heitler theory for ordinary bremsstrahlung and modified Elwert factor (relativistic) Bethe Heitler theory which includes polarization bremsstrahlung in the stripped atom approximation. The experimental results show better agreement with theoretical model that includes polarization bremsstrahlung in stripped approximation in the photon energy region below 30 keV. However, at higher photon energy region 30–100 keV, the theoretical model which describes ordinary bremsstrahlung is more accurate to describe the experimental bremsstrahlung spectra. The experimental results show positive deviations from the entire theoretical models at higher energy end of the spectrum. The results indicate that polarization bremsstrahlung plays important role in the formation of total bremsstrahlung spectra in lead compounds produced by continuous beta particles at low photon energy region of 10–30 keV.

In the present paper, the formation of bremsstrahlung spectra by ordinary bremsstrahlung (OB) and polarization bremsstrahlung (PB) in metallic targets by 35S beta particles has been investigated in the photon energy region of 1–100 keV. From the experimental measurements and the theoretical results obtained from Elwert corrected (non-relativistic) Bethe Heitler (EBH) theory, modified Elwert factor (relativistic) (FmodBH) theories for OB and Avdonina and Pratt (FmodBH+PB) theory for total bremsstrahlung (BS) having the contribution of PB into OB, it has been found that the contribution of PB into BS in a target is limited to a low energy region only and also varies with the atomic number of target material. The FmodBH+PB theory is in agreement with the experimental results in low energy regions of the target, whereas at high energy region FmodBH is found to give better agreement. Further, the present experimental results indicate that the screening effects in the Coulombic bremsstrahlung process cannot be neglected in the high energy region, and the multiple scattering and secondary electron emissions effects in thick target are required to be taken into account in describing the bremsstrahlung process.

Dielectric characterization of rapeseed ( Brassica napus L.) in the temperature range of 20–60 °C and at moisture contents of 8.5, 12.5 and 16% wet basis (w.b.) was performed by determining the dielectric constant and loss factor at frequencies from 10 to 3000 MHz. This range of frequencies includes the ISM (Industrial, Scientific and Medical) frequencies of 13, 27, 40, 915 and 2450 MHz. An open-ended coaxial probe (Speag DAK, 12) and a vector network analyzer (Agilent Technologies, E5071C) were used to measure the dielectric properties (dielectric constant and loss factor). Compressed ground samples of rapeseed at densities nearly equivalent to seed density were used. Determined data at the ISM frequencies was fitted to polynomials to represent the dependence of the dielectric constant as well as the loss factor on temperature and moisture content. The calculated penetration depth of the electromagnetic field in rapeseed at the ISM frequencies shows that at a given moisture content and temperature, it decreases with increasing frequency. The reported data are useful in designing and developing radio-frequency (RF) and microwave (MW) applicators for dielectric heating of rapeseed.

Total bremsstrahlung (BS) spectra in thick targets of Al, Ti, Sn and Pb produced by beta emitter 90Sr (End point energy=546 keV) are studied in the photon energy range of 1–100 keV. The experimentally measured BS spectra are compared with the theoretical spectral distributions calculated from Elwert corrected (non relativistic) Bethe–Heitler [EBH] theory, modified Elwert factor (relativistic) Bethe–Heitler [Fmod BH] theory for ordinary bremsstrahlung (OB) and the Avdonina and Pratt [Fmod BH+PB] theory, which include the contribution of polarization bremsstrahlung (PB) into OB. The present results are indicating the correctness of Fmod BH+PB theory in the low energy region, where PB dominates into the BS, but at the middle and higher photon energy region of the bremsstrahlung spectrum, the Fmod BH theory is more close to the experimental results. The description of the bremsstrahlung process in stripped atom (SA) approximation, which indicates the suppression of the bremsstrahlung at higher energy ends due to the production of PB in the low energy region, needs further considerations. Hence, the present measurements for BS for different target materials indicates that the considerations of the screening effects along with other secondary effects during the interaction of incident electrons with the target nuclei are important while describing the production of bremsstrahlung, particularly for the higher energy regions.

In this work, the target of zirconia with 2-inch diameter is prepared from the powder form having a particle size 5 µm by giving 4 tonnes of pressure in the hydraulic press. The prepared target is sintered at 1000-degree Celsius for 10 hrs. Yttria-stabilized zirconia target is also obtained in a similar process. The structural properties of both targets are investigated using Ɵ-2Ɵ geometry of X-ray diffractometer system. The changes in structure are studied in doped and undoped zirconia. The structural findings are showing the transformation of phase with doping. These studies help to understand the structural properties of zirconia with and without doping for technological application.

In the present study, the green microwave assisted synthesis of gold nanoparticles imbedded in XG/Poly(AA) biodegradable nanocomposite for controlled delivery of amoxicillin has been reported. The evidence of in-situ synthesis of gold nanoparticles by plant extract of Nepeta leucophylla as reducing agent inside the polymer matrix, grafting of acrylic acid (AA) onto backbone XG, surface morphology, crystallinity, thermal properties and loading of amoxicillin inside the MW-AuNPs/XG/Poly(AA) nanocomposite are investigated using various characterization techniques, such as, UV–Vis, XRD, FTIR, TGA/DSC, FE-SEM, EDX, TEM, DLS and Nitrogen adsorption-desorption isotherms (BET studies). The biodegradation test of synthesized nanocomposite has been performed by soil burial method for 75 days. The evidence of biodegradability of MW-AuNPs/XG/Poly(AA) nanocomposite is confirmed by FTIR and FE-SEM micrographs. The release profiles of amoxicillin drug from synthesized nanocomposite has been investigated for different pH (2.4, 7.0 and 9.2) at 37 °C using Korsmeyer–Peppas model. Here, the maximum drug loading efficiency is found to be about 85% and release of drug is large in basic medium as compare to acidic and neutral. It is expected that the present work may provide a noble method for synthesis of biodegradable nanocomposite with decent antioxidant potential for controlled release of amoxicillin.

L III jump ratio, jump factor and its related parameters for Pt and Tl have been measured by using photons of energy 59.54 keV from 241 Am source. The measurements are made by using gamma attenuation method in secondary excitation geometry with high resolution (155 eV at 5.9 keV) Si(Li) detector. X-rays energies, above and below the L III edge for the targets of Pt and Tl are obtained by using secondary target of Br, Co, Cu, Fe, Ga, Ni, Pt, Se, Sr, Tl and Zn. The measurements are compared with the theoretical values of total attenuation cross-sections, L III Jump ratio, jump factor; Davisson–Krichner ratio and L III sub-shell oscillator strength obtained by using mass attenuation coefficients from WinXCom. It is observed that the measured values are in good agreement with theoretical results. These measurement shall enhances the understanding of material characteristics of Pt and Tl, as these are widely used in biological, chemical, medical, electronics and petroleum industry.

A modified form of existing geometrical set-up of sample holder and coaxial line probe which is coupled with Agilent E5071C vector network analyzer, is used to determine the dielectric constant e ′ and loss factor e ″ of corn flour at tapped densities 0.69, 0.63, 0.54 and 0.46 g/cm 3 that correspond to moisture contents 8.8%, 12.6%, 17.4% and 22.7% wet basis respectively; and in the temperature and frequency ranges 25–75 °C and 0.2–10 GHz respectively. Measurements made at tapped density helps in designing microwave (MW) applicators as this density remains almost unchanged under unintentionally produced mechanical impacts, when flour is transported from grinding unit to applicators. Results show that e ′ decreases smoothly with increase in frequency at all temperatures and tapped densities, while e ″ decreases up to ∼1 GHz and then starts increasing. At a given frequency, change in both e ′ and e ″ with tapped density does not follow a particular trend for temperatures up to 50 °C; while increasing trend with decrease in tapped density is observed above 50 °C. Under strict controlled conditions such as power of electromagnetic field, exposure time, and desired maximum temperature of corn flour to get the acceptable quality of flour, these dielectric properties are beneficial to develop MW applicators for the purpose of thermal treatment to flour.

The internal bremsstrahlung (IB) spectrum of 89Sr, which is a unique first forbidden beta emitter, is studied in the 1–100 keV photon energy regime. The IB spectrum is experimentally measured using a Si(Li) detector, which is efficient in this photon energy regime, and is compared with the IB distributions that are predicted by the Knipp, Uhlenbeck and Bloch (KUB), Nilsson, and Lewis and Ford theories. In the soft energy regime up to 15 keV, the measured results are in agreement with all the aforementioned theories. However, from 16–30 keV, the experimental results are in agreement with the Lewis and Ford theory, which applies to forbidden transitions, and at higher photon energies, the Nilsson theory best describes the measured results. The differences among the different theories also increase with the photon energy. The effect of the electrostatic Coulomb field on the IB process for beta emitters with different end-point energies is investigated by comparing the ratio of the IB probabilities predicted using the KUB and Nilsson theories for 35S and 89Sr, i.e., soft and hard beta emitters, respectively. The Coulomb effect is shown to be significant in the high photon energy regime and for beta emitters with low end-point energies.

Effect of chemical environment on the K shell absorption edge parameters i.e. jump factor ( J K ), jump ratio ( r K ) and number of protons in terms of effective atomic number ( Z eff ) has been measured from the study of interaction of photons with pure elements (Zn, Zr, Cd, Ba, Pb) and their compounds [Zn(CH 3 COO) 2 , ZnSO 4 , ZnCl 2 , ZnO, Zr(OH) 4 , ZrN, ZrO 2 , ZrOCl 2 , CdCl 2 , CdCO 3 , Cd(NO 3 ) 2 , Cd(OH) 2 , BaSO 4 , BaCl 2 , Ba(NO 3 ) 2 , BaCO 3 , BaCl 2 ⋅2H 2 O, PbCl 2 , PbO, PbCO 3 , Pb(NO 3 ) 2 , Pb 3 O 4 , Pb(CH 3 COO) 2 ⋅3H 2 O] using Si(Li) detector and EDXRF technique. 59.54-keV gamma ray photons from 241 Am radioactive source have been used for the measurement of K shell absorption edge parameters J K , r K and Z eff . Different values of J K , r K and Z eff have been measured for the same element with different ligands group in the given elemental compounds. All measured results were compared with theoretically calculated values from WinXCOM (Gerward et al., 2001). It is found that measured values are in agreement with the theoretical values within experimental uncertainties of 6%. It is observed that the J K , r K and Z eff are affected in the different chemical environment due to presence of ligand group attached with element. Maximum change in the values of J K , r K and Z eff are observed in case of compounds containing –Cl 2 & –(CH 3 COO) 2 as a ligand group. Further, maximum variation of >20% in the Z eff for Zn and Pb compounds is also observed. From the present measurements, it is found that the J K , r K and Z eff depend on the chemical environment of the compound under investigation. These parameters may be helpful to understand the physical behavior and chemical structure of the compounds.

The linear and mass attenuation coefficient of non-uniform thick samples of oxides of lanthanide (Pr6O11, Nd2O3, Gd2O3, Tb4O7, Ho2O3 and Er2O3) has been measured by gamma ray photons of energy 59.54 keV obtained from 100 mCi radioactive source of 241Am. Advanced Two Media (ATM) methods Gupta et al. (2013) is simplified by considering air as first medium and metallic foil as second medium. In the present measurements this consideration simplifies the mathematical complexities and laboratory work to find the attenuation coefficients of non-uniform thick samples. The values of attenuation coefficient were then used to calculate effective atomic numbers (Zeff), interaction cross-section (σ) and effective electron densities (Neff) of lanthanide oxides. The method is validated by measuring linear/mass attenuation coefficient and other parameters for Mo, Ag, Sn, W and Pb of uniform thickness. The measured results are compared with the theoretical values from WinXcom Gerward et al. (2001). It is found that measured values are in agreement within 2% of theoretical results. The measurement of linear attenuation coefficient, effective atomic numbers (Zeff), interaction cross-section and effective electron densities (Neff) enhances the understanding of material characteristics. Presently studied materials i.e. oxides of Lanthanide are widely used as glass colouring agent and in electronic sensing devices.

An experimental measurement has been carried out for measuring the absorption edge parameters i.e. jump ratio and jump factor for elements of lanthanide series “La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb” ( Z =57–70) by using an EDXRF technique. Measured values of such parameters have been compared with theoretical values to check the experimental uncertainties and it was found that experimental results are in good agreement with theoretical values of Chantler et al. (2005, 〈 http://physics.nist.gov/ffast 〉, NIST, Gaithersburg).

The general aim of this work was to study the effects of swift heavy ions on the properties of electrochemically synthesized Ag-polypyrrole composite thin films. Initially, polypyrrole (PPy) films were electrochemically synthesized on indium tin oxide coated glass surfaces using a chronopotentiometery technique, at optimized process conditions. The prepared PPy films have functioned as working electrodes for the decoration of submicron Ag particles on the surface of the PPy films through a cyclicvoltammetry technique. Towards probing the effect of swift heavy ion irradiation on the structural and morphological properties, the composite films were subjected to a 40 MeV Li 3+ ion beam irradiation for various fluences (1 × 10 11 , 1 × 10 12 and 1 × 10 13 ions/cm 2 ). Comparative microstructural investigations were carried out after the different ion fluences using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy and micro-Raman spectroscopy techniques. Raman and SEM studies revealed that the structure of the films became disordered after irradiation. The SEM studies of irradiated composite films show significant changes in their surface morphologies. The surface was smoother at lower fluence but craters were observed at higher fluence.

A facile electrochemical synthesis of Au-polypyrrole (Au-PPy) composite films has been reported. The synthesized composite films were irradiated with a 1.25 MeV Co-60 gamma radiation with doses ranging from 500 to 1500 kGy and the corresponding changes in structural properties of the composites were studied. The structural investigation of Au-PPy composite films were performed by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and micro-Raman spectroscopic techniques. XRD studies showed the variation in peak intensities after gamma irradiation. Different parameters like crystallite size, micro strain, dislocation density and distortion parameters were calculated from XRD spectra. Observed results indicate the formation of an ordered system in the irradiated composite films. SEM micrograph showed significant interactions between the Au-particles and PPy film after gamma irradiation. Raman spectra show an overall increase in peak intensity after gamma irradiation.

Au–polyaniline (Au–PANI) thin films were prepared by an electrochemical process. Au–PANI films were irradiated with 100 MeV O7+ and 120 MeV Ni9+ ion beams with fluences varying from 3 × 1011 ions/cm2 to 3 × 1012 ions/cm2. The effects of heavy ions on the structural, chemical and morphological properties of the composite films were studied by using X-ray diffraction, Raman and scanning electron microscopy techniques. X-ray spectra showed the gradual decrease in the peak intensity after irradiation. The interchain distance, interplanar distance, micro strain, dislocation density and distortion parameters were calculated. The analysis revealed a noticeable changes in these parameters after irradiation for both cases. The results showed the formation of clusters with a porous structure after irradiation. The effect of irradiation was greater in case of 120 MeV Ni9+ rather than 100 MeV O7+ ions due to their high electronic energy loss in Au–PANI. I–V characteristic measurements were carried out as a function of ion fluence. The results are discussed on the basis of linear energy transfer (LET) of the irradiated ions.

In this work, polypyrrole (PPy) microspheroidals were synthesized by chronopotentiometry on conducting indium tin oxide (ITO) substrate. These prepared PPy microspheroidals were subjected to surface modification by Ag nanostructures using cyclic voltammetery (CV). The decoration of Ag nanostructures on PPy surface was characterized by UV–visible spectroscopy (UV–vis), X-ray diffraction (XRD), Fourier transform infrared (FTIR), energy dispersion X-ray spectroscopy (EDX) and scanning electron microscopy (SEM). SEM images show nanostar like structures with slight aggregation of Ag nanostructures on the PPy surface. The average particle size of PPy was found to increase from 7.3 to 30 nm after decoration with Ag nanostructure. Further, the XRD patterns shows a decrease in interchain separation and inter planar distance after the impregnation of Ag nanostructures in the PPy film when compared with pure PPy film. FTIR and Raman spectra displayed main vibrational bands; including the characteristic peaks. Raman spectra also show the signature of polaron and bipolaron states. Electrical conductivity of the Ag nanostructure decorated PPy microspheroidals has been measured by the two probe method. A possible mechanism for the formation of Ag-PPy nanostructure has been proposed.

Linear attenuation coefficient of irregular targets having unknown thickness (La, Pr, Nd, Gd, Tb, Ho and Er) and regular targets of known thickness (Mo, Ag, Sn, W and Pb) at 59.54 keV have been measured by using a new technique named Advanced Two Media (ATM) method. In this modified Advanced Two Media method pure metallic foils have been used as a mediums 1 and 2. The obtained results from Advanced Two Media method and transmission geometry are in good agreement with theoretical values of WinXCOM.

In this paper, two-step electrochemical synthesis method is reported for the fabrication of Au–polyaniline (Au–PANI) composite film. Initially, PANI film was electrochemically synthesized by using chronopotentiometery with optimized process parameters on platinum electrode. The synthesized PANI film acts as working electrode for the decoration of Au particles on the surface of PANI film by using cyclovoltammetry (CV) technique. Later, these films were irradiated under high vacuum (∼5 × 10−6 Torr) at room temperature with 40 MeV C5+ ion beam at various fluences ranging from 1 × 1011 to 1 × 1013 ions/cm2. The Au–PANI composite films were characterized before and after irradiation by using micro-Raman, X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The characteristic peaks of the Raman spectrum of Au–PANI composite films were reduced after irradiation. XRD spectra exhibited the decrease in the peak intensity. Moreover, interchain distance, interplanar distance, micro strain, dislocation density and distortion parameters were calculated. The analysis revealed a significant variation in these parameters with an increase in the ion fluence, which is in line with the Raman analysis. SEM shows the formation of clusters with porous structure after irradiation.

This experimental study investigated the modification of chemical and structural properties of PM-355 films by irradiation of 1.25 MeV 60Co γ-radiations at doses ranging from 0–675 kGy. The induced modifications were followed by micro-Raman and X-ray diffraction (XRD) spectroscopy. Further, the induced modifications were confirmed by UV–Visible spectroscopy. Raman spectra show that the films are highly disordered at the highest gamma dose. The XRD pattern of PM-355 shows the decreasing intensity of peak positions with an increase in the gamma dose, which suggests the loss of crystallinity of the films due to irradiation. Observed results indicate the formation of a disordered system in the irradiated films. Furthermore, the crystallite size for pristine and bombarded sample has been calculated. Moreover, interchain distance, micro strain, interplanar distance, dislocation density and distortion parameters were calculated. The analysis revealed a significant increase in micro strain, dislocation density and distortion parameters with an increase of gamma dose, which is in line with the Raman analysis. With increasing γ-dose, the value of the direct and indirect band gap found to decrease. To the best of our knowledge, this work is the first to show the simultaneous existence of direct as well as the indirect band gap in PM-355 polymer.

We have electrochemically synthesized polyaniline nano fibers with optimized process parameters (viz. concentration of monomer and dopant, applied current density, deposition time, etc.) on ITO coated glass substrate. The nano fibers of polyaniline were subjected to UV Visible, SEM and Raman spectroscopy. UV Vis spectra show two prominent peaks at 317 and 418 nm, which confirm the presence of different forms of polyaniline. Raman spectra confirm the formation of polyaniline. SEM image of synthesized nano fibers showed a flower like structure with an isotropic growth rate. Copyright © 2012 VBRI press.

Makrofol-KG polycarbonate (M-KG PC) films are irradiated with 150 MeV Ni 11+ and 100 MeV O 7+ ion beams at various fluences ranging from 1 × 10 11 to 3 × 10 12 ions/cm 2 . We have investigated the effect of irradiation parameters such as energy and ions fluence on optical, structural and chemical properties of the studied polymer, respectively. UV–Visible, Fourier Transform Infrared (FTIR) and X-ray diffraction (XRD) spectral studies have been employed in the present investigation. UV–Visible spectra exhibit a shift towards the higher wavelength regime after irradiation. This shift clearly reflects decrease in optical band gap after irradiation. The FTIR spectrum shows a decrease in intensity of the typical bands whereas the formation of new bands indicates the degradation of the polymer after irradiation. The XRD pattern of M-KG PC shows the decreasing intensity of peak positions with increase in ions fluence, which suggests loss of crystallinity of the films due to irradiation. Observed results indicate the formation of disordered system in the irradiated films. Magnitude of effect of irradiation is greater in case of 150 MeV Ni 11+ rather than 100 MeV O 7+ ions due to high electronic energy loss of Ni 11+ ions in M-KG PC. The results can be correlated on the basis of linear energy transfer (LET) of the irradiated ions.

We report a study on the carbon ion beam induced modifications on optical, structural and chemical properties of polyallyl diglycol carbonate (PADC) commercially named as CR-39 and Polyethyleneterepthalate (PET) polymer films. These films were then irradiated by 55 MeV C 5+ ion beam at various fluences ranging from 1×10 11 to 1×10 13 ions/cm 2 . The pristine as well as irradiated samples were subjected to UV–Visible spectral study (UV–Vis), Photoluminescence (PL), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. It has been found that ion irradiation may induce a sort of defects in the polymers due to chain scission and cross linking as observed from PL spectral study. It is revealed from UV–Vis spectra absorption edge shifted towards longer wavelength region after irradiation with increasing ion fluence. This shift clearly reflects decrease in optical band gap. The XRD study indicates the gradual decrease in intensity in case of PADC with increasing ion fluence. However, the intensity pattern increased in case of PET at fluence of 10 11 ion/cm 2 then decreased with further increase in fluence. Crystalline size of PADC was found to be decreasing gradually with increase of ion fluence. Whereas, the crystalline size of PET films found to increase with lower fluence and decreases with higher ion fluence. FTIR spectrum also shows the change in intensity of the typical bands after irradiation in the both the polymers. The results so obtained can be used successfully in heavy ions dosimetry using well reported techniques.

Total mass attenuation coefficient, total photon interaction cross-section, effective atomic numbers ( Z eff ) and electron densities ( N e ) of Aniline (C 6 H 5 NH 2 ), Cyclohexane (C 6 H 12 ), Glycerine (C 3 H 5 (OH) 3 ), Butyl alcohol N-(C 4 H 9 OH), DMSO – dimethyl sulfoxide (C 2 H 6 OS), Methyl ethyl-ketone (C 4 H 8 O), Xylene (C 8 H 10 ), Acetophenone (C 8 H 8 O) and Triethyl amine (C 6 H 15 N) have been measured at 59.54 keV energy photon emitted by 100 mCi 241 Am point source employing narrow beam transmission geometry. Obtained results have been compared with theoretically calculated values of XCOM (Berger and Hubbel, 1987) and FFAST ( Chantler et al., 2005 ). Mixture rule was employed to calculated theoretical mass attenuation coefficient values for each sample. Good agreement has been observed between experimental and theoretical values within experimental uncertainties.

Role of polarization Bremsstrahlung in the formation of total Bremsstrahlung (BS) spectra in thick targets of Al, Ti, Sn and Pb, produced by complete absorption of 90Sr beta particles having an energy range of 0–546 keV, are studied in the photon energy region of 5 to 10 keV. The theoretical BS spectral photon distributions, obtained from Elwert corrected (nonrelativistic) Bethe–Heitler theory, a modified Elwert factor (relativistic) Bethe–Heitler theory that describe ordinary Bremsstrahlung (OB) and a modified Elwert factor (relativistic) Bethe–Heitler theory for BS spectra that includes the polarization Bremsstrahlung (PB) into OB in stripped atom approximation, were compared with the experimentally measured BS spectral photon distributions. It has been observed that the experimental results are in agreement with the modified Elwert factor (relativistic) Bethe–Heitler theory at photon energy from 5 to 10 keV. It has been also observed that the contribution of PB into OB decreases with increase in end-point energy of beta emitter and the energy of the emitted photon. Further, it has been found that the contribution of PB into OB increases with increase in atomic number of the target atom. This indicates the importance of PB in the formation of BS produced by continuous beta particle. Copyright © 2012 John Wiley & Sons, Ltd.

We have investigated neutron irradiation effects on the optical, structural and chemical properties of polyallyl diglycol carbonate (PADC) polymer, commercially named as CR-39. For this purpose, PADC samples were exposed with 4 MeV Am–Be neutron source at fluences varying from 2.36 × 10 6 to 5.94 × 10 7 n/cm 2 . The modifications so induced were analyzed using UV–Visible spectroscopy, X-ray diffraction Measurement (XRD), Photoluminescence (PL) and Fourier Transform infrared (FTIR) spectroscopy in the total attenuation reflection (ATR) mode. UV–Vis spectra of pristine and neutron irradiated PADC polymer sheets exhibit a decreasing trend in optical band gap. This decline in optical band gap with increasing fluence has been discussed on the basis of neutron irradiation induced defects in PADC. The XRD pattern of PADC shows the decreasing intensity of peak positions with increasing in fluence, which suggest that semicrystallinity of PADC changes slightly to amorphous phase after irradiation. At low fluence, crystallinity was found to increase but at higher fluence, it decreased which could be ascribed to neutron- induced defects in the polymer samples. Crystallite size calculated using Scherrer formula indicates a change and reflects the formation of disordered system in the irradiated polymer samples. The PL spectra show that the intensity of PL peak decreased with increase in fluence, which may be due to the disordered system via creation of defects in the irradiated polymer. The FTIR spectrum shows an overall reduction in intensity of the typical bands, indicating the degradation of PADC polymer after irradiation. These results so obtained can be used successfully in dosimetery using well reported protocols.