Search for intermediate mass magnetic monopoles and nuclearites with the SLIM experiment

SLIM is a large area experiment (440 m²) installed at the Chacaltaya cosmic ray laboratory since 2001, and about 100 m² at Koksil, Himalaya, since 2003. It is devoted to the search for intermediate mass magnetic monopoles (10⁷–10¹³ GeV/c²) and nuclearites in the cosmic radiation using stacks of CR-39 and Makrofol nuclear track detectors. In four years of operation it will reach a sensitivity to a flux of about 10^-15 cm^-2 s^-1 sr^-1. We present the results of the calibration of CR-39 and Makrofol and the analysis of a first sample of the exposed detector.     

Nanoparticulate cerium dioxide and cerium dioxide-titanium dioxide composite thin films on glass by aerosol assisted chemical vapour deposition

Two series of composite thin films were deposited on glass by aerosol assisted chemical vapour deposition (AACVD)—nanoparticulate cerium dioxide and nanoparticulate cerium dioxide embedded in a titanium dioxide matrix. The films were analysed by a range of techniques including UV-visible absorption spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive analysis by X-rays. The AACVD prepared films showed the functional properties of photocatalysis and super-hydrophilicity. The CeO₂ nanoparticle thin films displaying photocatalysis and photo-induced hydrophilicity almost comparable to that of anatase titania.     

Cusp and Regular Ion-Acoustic Solitons

Cups and regular smooth solitons are studied using the fluid model in cylindrical geometry for parallel propagating ion-acoustic waves in a low β plasma. It is found that smooth solitons only occur in the supersonic regime, whereas cusp solitons occur both in supersonic and subsonic regimes. In the supersonic regime, the amplitude and the width of cusp solitons increase when the Mach number M increases and initial electric field E ₀ decreases. However, the amplitude of smooth regular solitons increases and their width decreases when E ₀ increases and M decreases. For the subsonic case, both the amplitude as well as the width of a cusp solitons increase when M increases and E ₀ decreases. Corresponding to these cusp and regular solitons, bipolar electric field structures are also studied. These results may be helpful in understanding the properties of ion-acoustic regular and cusp solitons in space plasmas.     

Emission of intermediate mass fragments in the heavy ion interaction of (14.0 MeV/u) Pb+Au

We have studied the heavy ion interactions of (14.0 MeV/u) Pb + Au using two threshold detectors, mica and CN-85. A thin layer of Au was deposited on each of the three mica and two CN-85 detector pieces. These target-detector assemblies were exposed to a beam of 14.0 MeV/u Pb ions having the fluence of 1.5×10⁶ cm² at GSI, Darmstadt, Germany. After removing the target material and etching the samples in appropriate etchants, we scanned 32.29 cm² and 24.97 cm² area of mica and CN-85, respectively. Based on the observed number of events of various multiplicities, we have determined the total as well as partial experimental reaction cross-sections. It is shown that a significant number of intermediate mass fragments are emitted alongwith the heavy fragments in the present reaction.     

Spectrophotometric determination of novalgin in tablets by use of potassium iodate

An indirect colour reaction has been studied for determination of novalgin in tablets. The method is simple, rapid and reproducible with a relative standard deviation of 0.2%. Novalgin is determined spectrophotometrically by means of its colour reaction with potassium iodate. Beer's law is obeyed over the range 1-10 mg of drug. A tentative reaction mechanism has been proposed.     

Production of iodine-124

Iodine-124 is produced in high yield by the¹²⁴Te/d, 2n/¹²⁴I reaction and >99.5% radionuclidic purity at 48 h post irradiation. The production yield was 0.55±0.06 mCi/Ah. Radiochemical separation and targetry methodology are described.For earlier papers in this series see: R.M. Lambrecht and M. Sajjad, Radiochimica Acta /in press/.     

Calibration of the Makrofol–DE nuclear track detector using relativistic lead ions

We present the calibration of the Makrofol–DE nuclear track detector (NTD) using Pb-ions of 158 GeV/amu. Improvements in the post-etched surfaces, reduction in the surface background of the Makrofol–DE NTDs and high-contrast tracks were achieved with the appropriate addition of ethyl alcohol in KOH aqueous solutions. The calibration of Makrofol–DE has shown for the first time all the peaks arising due to nuclear fragments with Z52. The measurement of the cone heights shows well-separated individual peaks for Z/β=59–82 and 83 (charge pickup).     

Synergic extraction of Pr(III), Ho(III) and Er(III) with a mixture of 2-thenoylltrifluoroacetone and tribenzylamine

Synergic solvent extraction of Pr(III), Ho(III) and Er(III) was carried out at pH3.5 with a mixture of 2-thenoyltrifluoroacetone (HTTA) and tribenzylamine (TBA) from perchlorate media, having ionic strength 0.1M(H⁺, ClO ₄ ^– ). The stoichiometmric composition of all three synergic adducts was established to be Pr(TTA)₃·3TBA, Ho(TTA)₃·3TBA and Er(TTA)₃·3TBA. The formation constants K_TTA and K_syn and stability constant ±_syn were also computed and found to be in the order ErHo>Pr. The effect of various anions on the extraction has also been studied.     

Organic and inorganic ion-exchange beads as indicators in redox and precipitation titrations

Resin beads in the Fe(III) or p-dimethylaminobenzylidene-rhodanine form are used as indicators in precipitation titrations with K(3)Fe(CN)(6), and Ag(+). Resin beads with dipheny lamine adsorbed on them can be used as indicators in cerimetric titrations. They have some advantages over conventional indicators.