Range and energy-loss measurement of238U in Makrofol-N using CR-39 track detector

A simple experimental technique has been described for measuring range and energy-loss of any heavy ion in any complex medium with the help of a sensitive solid state nuclear track detectors (SSNTDs). In this paper we present the results obtained from our measurements of ranges and energy-loss of 16.34 MeV/u²³⁸U in Makrofol-N using CR-39 track detector. Experimental ranges are compared with the corresponding theoretical values. The significance and scope of the present work are discussed.     

Fullerene formation in the tracks of energetic ions

Abstract

Chromatographic analyses of solvent extracts from graphite bombarded with 130MeV/amu ¹⁶¹Dy²²⁺ ions, and polyimide (kapton) bombarded with 5 MeV ⁶Li¹⁺ ions, give clear evidence for the in situ synthesis of buckminsterfullerene -C₆₀. The role played by the production of highly confined, dense assemblies of energetic electrons in this phase change is discussed.     

Performance of ferrite fillers on electrical behavior of polymer nanocomposite electrolyte

Dispersal of nanofillers in polymer electrolytes have shown to improve the ionic properties of Polyethylene oxide (PEO)-based polymer electrolytes in recent times. The effects of different nanoferrite fillers (i.e., Al–Zn ferrite, Mg–Zn ferrite, and Zn ferrite) on the electrical transport properties have been studied here on the composite polymer electrolyte system. The interaction of salt/filler with electrolyte has been investigated by XRD studies. SEM image and infrared spectral studies give an indication of nanocomposite formation. In conductivity studies, all electrolyte systems are seen to follow universal power law. Composition dependence (with ferrite filler) gives the maximum conductivity in [93PEO–7NH₄SCN]: X ferrite (where X?=?2% in Al–Zn ferrite, 1% Mg–Zn ferrite, and 1% Zn ferrite) system.     

Irradiation effect on the activation energy of thermal decomposition of polymers

The present work looks into the aspect of thermal modifications induced in polymers by proton irradiation. The kinetics of thermal decomposition of polymers is investigated by using the thermogravimetric (TG) technique. It has been observed that the degradation of polymers is a multi-step process that involves sequential and competing processes, and obeys the Arrhenius kinetics which allows us to connect the rate constant with the absolute temperature and the activation energy. The activation energy of thermal decomposition has been calculated from the TG curves, and its variation with different irradiation doses has been derived.     

One‐pot oxidation of aromatic and cyclic hydrocarbons using the Au (III) and Pd (II) catalyst under microwave irradiation

We report here in highly efficient one‐pot catalytic system which utilizes in situ generated sodium ferrate for the oxidation of aromatic and cyclic hydrocarbons in the presence of Au (III) and Pd (II) metal ions catalyst under ecofriendly green synthetic method. Results of these studies revealed that Au (III) catalytic system gave higher yield as compared with Pd (II) catalytic system because of the higher electrode potential of Au(III) than Pd(II). All compounds were characterized by infrared and NMR spectral analysis. Copyright © 2016 John Wiley & Sons, Ltd.     

Modeling and analysis of photoconductive detectors based on Hg<Subscript>1-<Emphasis Type="Italic">x</Emphasis></Subscript>Cd<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Te for free space optical communication

In this paper we report a theoretical analysis of a long wavelength photoconductive detector for characterizing and optimizing the device in respect of voltage responsivity, quantum efficiency, detectivity and noise equivalent power. The model has been applied to examine the potential of an n-type Hg_0.77Cd_0.23Te photoconductive detector for possible application in free space optical communication system operating at the atmospheric window near 9.6 μ m. In the present analysis we have taken into account all the major recombination mechanisms (e.g., Radiative, Auger, and Shockley-Read-Hall types) including the effect of surface recombination at the interfaces that shape the characteristics of photoconductor. The results obtained on the basis of our analysis reveal that in the absence of surface recombination the device exhibits a peak quantum efficiency of 90%, a maximum detectivity of 10⁸ MHz^1/2/W at 77 K, a 3 dB bandwidth of 117.86 MHz and noise voltage of 5.4 × 10⁻⁶ V/Hz^1/2. The sweep-out effect has been found to degrade the detectivity nearly by a factor of 10 at the same temperature and wavelength of operation. The estimated noise equivalent power of the photodetector is of the order of 10⁻⁹ W at 9.6 μm wavelength.     

Development of XUV lasers at the RAL Central Laser Facility

Recent progress in the development of XUV lasers by research teams using high-power and ultrashort-pulse Nd: glass and KrF laser facilities at the Rutherford Appleton Laboratory is reviewed. Injector-amplifier operation and prepulse enhanced output of the Ge XXIII collisional laser driven by a kilojoule glass laser, enhanced gain in CVI recombination with picosecond CPA drive pulses from a glass laser, and optical field ionization and XUV harmonic generation with a KrF CPA laser are described.     

Core–shell nanophosphor with enhanced NIR–visible upconversion as spectrum modifier for enhancement of solar cell efficiency

A distinct enhancement of upconversion luminescence from core to core/shell (C/S) structure under low flux near infrared (NIR) excitation at 976 nm has been achieved in lanthanide (Er³⁺, Yb³⁺)-doped NaYF₄ core with undoped NaYF₄ shell nanoparticles (NP). A green chemistry approach has been taken to synthesize monodisperse monophasic C/S NP with the core (~20 nm) and shell (~5 nm) crystallizing into cubic phase. Hydrophobic C/S NP have been further made hydrophilic by coating a transparent SHMP layer without affecting luminescence. C/S (NaYF₄: Er, Yb/NaYF₄) NP integrated dye-sensitized solar cell indicated 11.9% enhancement in overall conversion efficiency under AM 1.5 conditions, due to NIR–visible spectrum modification by fluorescent NPs. The results indicate great potential of such upconverting C/S nanophosphor in solar cell applications.     

An extensive indoor Rn/Rn monitoring in North-East India

The behaviour of ubiquitous radon (), thoron () and their progeny in the indoor atmosphere generally reflect a complex interplay between a number of processes, the most important of which are radioactive -decay, ventilation, attachment to aerosols and deposition on the surfaces. The present work involved a long-term (1997–2000) passive monitoring of and in the indoor environment of the North-Eastern region of India. This region being a zone of high seismicity, the indoor radon and thoron measurement of the region will provide a better insight and a valuable database for any study related to radon and thoron anomalies.     

Streaming instability of a dusty plasma in the presence of mass and charge variation

We study the effect of the mass and charge dynamics on the collective behaviour of a dusty plasma. It is shown that the finite non-zero streaming velocity of the dust grains leads to a novel coupling of the dust mass fluctuation with other dynamic variables of the plasma and the grains. The mass fluctuations causes a collisionless dissipation and provides an alternate channel for the beam mode instability to occur. Physically the negative energy wave associated with the beam mode couples to the mass fluctuation induced dissipative medium to produce the instability. We conclude that the higher value of the ion mass density to the dust mass density ratio reduces the threshold value for the onset of the instability. Its application in the astrophysical context is discussed.