Radiometric analysis of rock and soil samples of Leepa Valley; Azad Kashmir, Pakistan

In this article, we present results obtained from a radiometric survey that was conducted in the Leepa Valley of Azad Jammu & Kashmir, Pakistan. The purpose of current study is to appraise the radioactivity levels and the associated health hazards due to the terrestrial radionuclide in soil and rock samples. In this regard, 16 soil and 17 rock samples were collected from different locations of the Leepa Valley. After processing the samples, activity concentrations of primordial (²³²Th, ²²⁶Ra and ⁴⁰K) and anthropogenic (¹³⁷Cs) radionuclides were determined using a P-type coaxial high purity germanium detector. From the results obtained the mean activity concentrations of radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K in the soil samples were found to be 31.25 ± 0.46, 44.1 ± 1.07 and 575 ± 8.89 Bq kg^?1 respectively. Whilst, in rock samples ²²⁶Ra, ²³²Th and ⁴⁰K mean activities were found as 28.46 ± 0.45, 48.63 ± 1.12 and 666.7 ± 9.39 Bq kg^?1, respectively. The ¹³⁷Cs concentration level in soil and rock samples is found to be 15.04 ± 0.29 and 5.7 ± 0.16 Bq kg^?1, respectively. The average radium equivalent activity (R _aeq) was found as 143.16 and 142.93 Bq kg^?1 in soil and rock samples, respectively. These findings are less than the recommended safe value of 370 Bq kg^?1 as given in OECD report (1979). The values of external (H _ex) and internal hazard index (H _in) are also less than unity. Mean value of absorbed dose rate was found as 69.78 nGy h^?1 for the soil samples, which is in good agreement with the world wide average value (70 nGy h^?1). Mean value of absorbed dose rate from rock samples was found as 70.01 nGy h^?1. Mean values of the annual effective dose is also lower than the values reported for different other countries of the world.     

Blue‐to‐Orange Color‐Tunable Laser Emission from Tailored Boron‐Dipyrromethene Dyes

A series of meso‐substituted boron‐bipyrromethene (BODIPY) dyes are synthesized and their laser and photophysical properties systematically studied. Laser emission covering a wide visible spectral region (from blue to orange) is obtained by just changing the electron donor character of the heteroatom at position 8. The additional presence of methyl groups at positions 3 and 5 results in dyes with a photostability similar to that of the unsubstituted dye but with much improved efficiency. Correlation of the lasing properties of the different dyes to their photophysical properties provides inklings to define synthetic strategies of new BODIPY dyes with enhanced efficiency and modulated wavelength emission over the visible spectral region.     

Pechini based titanium sol as a matrix in TiO<Subscript>2</Subscript> pastes for dye-sensitized solar cell application

The influence that the degree of polyesterification has on a titanium sol (Ti-sol) prepared via the Pechini method that acts as a matrix in TiO₂ pastes used for dye sensitized solar cells is reported. The different content of the polyester in the Ti-sol was realized by varying the heating time of the Ti-sol. Titanium dioxide pastes were prepared by introducing a commercial TiO₂ nanopowder into the Ti-sols. The TiO₂ layers were tested as photoanodes in dye-sensitized solar cells (DSSCs). The most appropriate degree of polyesterification was achieved by heating the Ti-sol for 0.5 and 1 h, while longer heating deteriorates the TiO₂ layer morphology. The highest efficiency of the DSSCs based on an ionic liquid electrolyte was 6.3% measured under standard test conditions (100 mW/cm², AM 1.5, 25 °C).     

The potential applications of ZnO nanoparticles conjugated with ALA and photofrin as a biomarker in HepG2 cells

Drug delivery into the malignant cell is a basic requirement for effectiveness of photosensitizing systems for photodynamic therapy (PDT). For anticancer tumoricidal drugs, e.g., 5-aminolevulinic acid (ALA), zinc oxide (ZnO) nanoparticles (NPs) are used as efficient intracellular photosensitizer carriers. Apoptotic effect of tumoricidal drugs (ALA and Photofrin cells in the presence and absence of ZnO NPs using confocal microscopy as well as Neutral Red Assay (NRA). In dark, ZnO NPs conjugated with ALA or Photofrinhas been found to have a remarkable fluorescence in Hepatucellular carcinoma (HepG2) cells. This fact illustrates the great potential of ZnO NPs as biomarker in relevant clinical and biomedical applications.     

The role of sensitivity of ALA (PpIX)-based PDT on Human embryonic kidney cell line (HEK293T)

Present study evaluates the effects of photodynamic therapy (PDT) with aminolevulinic acid (5-ALA) as photo sensitizer using Human embryonic kidney (HEK293T) cell line as an experimental model. Porphyrins derivatives are used as active cytotoxic antitumor agents in PDT. Above mentioned cell line were irradiated with red light (a diode laser, λ = 635 nm) at different doses (0–160 J/cm²) of light. The influence/effectiveness of incubation time, various concentrations of aminolevulinic acid (5-ALA) and light doses on the cellular viability was studied. HEK293T cells were deliberated by exposing the ALA-PpIX (0–1000 μg/ml) of concentrations. The optimal uptakes of photosensitizer (PS) in cell lines were investigated by means of spectro photo metric measurements. Cells viability was determined by means of neutral red assay (NRA). It was observed that alone, neither photosensitizer nor light dose have significant effect on cells viability, but optimal concentration of PS along with suitable dose of light exhibit effective impact on the viability of cell. Our results showed that light doses of 40 J/cm² demonstrates effective PDT outcome for HEK293T cell line when incubated with 400 μg/ml, with wrapping up view that HEK293T cell line is very sensitive to ALA-mediated PDT as compared to cell line published in our data. At the end results has been verified by using reactive oxygen species (ROS) measure test.     

Nuclear spectroscopy near the proton drip line in the lanthanide region: The122La nucleus

Excited states in the very neutron-deficient¹²²La nucleus have been established for the first time using the⁹²Mo(⁴⁰Ca, 2α1p1n) reaction at beam energies of 190 and 200MeV. The observed transitions were grouped in three bands. Configurations have been assigned to the observed bands based on the properties extracted from the experimental data and on cranked shell model calculations.     

Magnetic and microstructural properties of M-type strontium hexaferrites with Pr–ZnAl substitution

We have investigated the influence of Pr–ZnAl substitution on the magnetic and microstructural properties of M-type strontium hexaferrites Sr_1.0-xPr_xFe_12.0-x(Zn_0.5Al_0.5)_xO₁₉ (0.0 ≤ x ≤ 0.5) synthesized by the standard ceramic method. X-ray diffraction (XRD) was carried out to determine the crystal structure and the phase identification of the hexaferrites showed that a single magnetoplumbite phase was exhibited in the hexaferrites with Pr–ZnAl content (x) from 0.0 to 0.4 and impurity phase α-Fe₂O₃ was observed in the structure when Pr–ZnAl content (x)?=?0.5. The morphology of the hexaferrites was analyzed by a field emission scanning electron microscopy (FE-SEM). The representative FE-SEM micrographs showed that the particles were regular hexagonal platelets and the average grain size basically kept unchanged with increasing Pr–ZnAl content (x). A magnetic property measurement system was used to measure the magnetic properties of the hexaferrites. The remanence (B_r), maximum energy product [(BH)_max] and H_k/H_cj ratio decreased with increasing Pr–ZnAl content (x) from 0.0 to 0.5. The intrinsic coercivity (H_cj) and magnetic induction coercivity (H_cb) first increased with increasing Pr–ZnAl content (x) from 0.0 to 0.1, and decreased with increasing Pr–ZnAl content (x) from 0.1 to 0.2, and then increased when Pr–ZnAl content (x) ≥ 0.2.     

Microstructural and magnetic properties of Pr–BiCo co-substituted M-type Sr–Ca hexaferrites

We have synthesized the Pr–BiCo substituted hexaferrites with compositions of Sr_0.8-xCa_0.2Pr_xFe_12.0-x(Bi_0.5Co_0.5)_xO₁₉ (0.0?≤?x?≤?0.5) by the standard ceramic method. Results of X-ray diffraction analysis exhibits that the synthesized hexaferrites with x from 0.0 to 0.3 are in single magetoplumbite structure, and impurity phases are observed when x?≥?0.4. The surface morphology of magnets shows that hexaferrite grains have a hexagonal platelet shape with clear grain boundaries. The remanence first increases with x from 0.0 to 0.1, and then decreases when x?≥?0.1. The intrinsic coercivity decreases with x from 0.0 to 0.1, and then increases when x?≥?0.1. With x from 0.0 to 0.4, the changing trend of magnetic induction coercivity is in agreement with that of H_cj, while at x?≥?0.4, H_cb decreases. The maximum energy product initially increases with x from 0.0 to 0.2, and then decreases when x?≥?0.2.     

Single step conversion of UO2 and U3U8 into uranyl sulphate solution

A direct and simple method for the conversion of UO₂ and U₃O₈ powder into uranyl sulphate solution is described, eliminating many tedious chemical steps. UO₂ and U₃O₈ are not soluble in concentrated or dilute sulphuric acid, as uranium in lower oxidation state does not react with sulphuric acid. However, nitric acid oxidizes uranium from lower valency to higher valency state, i.e., tetravalent to the hexavalent uranyl ion in solution. Sufficient amount of sulphuric acid present in the reaction mixture makes it possible for uranyl ions, formed by oxidation of nitric acid, to react with sulphuric acid forming uranyl sulphate.     

Integrating the use of linear and dynamic programming methods for dairy cow diet formulation

Despite many refinements that have been made to the basic Linear Programming model used to find economically optimal diets for dairy cows, the sequential nature of the physical and physiological changes that a cow goes through during lactation have not been incorporated into the modelling process satisfactorily. This paper demonstrates how it can be achieved by integrating the use of both Linear and Dynamic Programming methods to optimise the economic performance of a dairy cow over its entire lactation. Linear Programming generates solutions for each potential liveweight change occurring during each of eleven four week periods over the lactation, then the use of DP allows both the selection of the optimal sequence of liveweight changes during the lactation and the specification of rations associated with this optimal path.