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- Author or Editor: M. Zafar x
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Abstract
The role of nitrate ions in uranyl ions transport across TBP-kerosene oil supported liquid membranes (SLM) at varied concentrations of HNO3 and NaNO3 has been studied. It has been found that nitrate ions move faster compared to uranyl ions at the uranium feed solution concentrations studied. The nitrate to uranyl ions flux ratio vary from 355 to 2636 under different chemical conditions. At low uranium concentration the nitrate ions transport as HNO3 · TBP, in addition to as UO2(NO3)2 · 2TBP type complex species. The flux of nitrate ions is of the order of 12.10 · 10–3 mol · m–2 · s–1 compared to that of uranium ions (4.56 · 10–6 mol · m–2 · s–1). The permeability coefficient of the membrane for nitrate ions varies with chemical composition of the feed solution and is in the order of 2.5 · 10–10 m–2 · s–1. The data is useful to estimate the nitrate ions required to move a given amount of uranyl ions across such an SLM and in simple solvent extraction.
Abstract
To study the impurity elements, which render color-induced topaz long lived radionuclides, three samples of topaz, from three different cities of the Northern Pakistan (Baltistan, Gilgit and Mardan) were analyzed using k 0 instrumental neutron activation analysis (k 0-INAA). The samples were irradiated in Pakistan Research Reactor-1 (PARR-1) and PARR-2 at Pakistan Institute of Nuclear Science & Technology (PINSTECH), Islamabad. The method was validated by analyzing IAEA-S7 reference material. In three samples a total of 22 trace level impurity elements were quantified. Among impurities, 10 elements including As, Ce, Ga, Ge, La, Na, Sb, Sc, U and Zn were common in topaz of all the three places. The storage time has been calculated for each sample required to bring the induced radioactivity down to permissible level given by US National Regulatory Commission.
Pollen morphology of 16 species belonging to 8 different families; Apocynaceae, Brassicaceae, Capparaceae, Euphorbiaceae, Fabaceae, Poaceae, Solanaceae and Zygophyllaceae were analysed from Khyber Pakhtunkhwa with the help of microscopic techniques. Both qualitative and quantitative features of pollen were examined including polar and equatorial diameter, colpus length and width, exine sculpturing, pores number, pollen shape, number of sterile and fertile pollen using Leica microscope (D1000) fitted with camera Meiji Infinity 1 and examined statistically by software IBM SPSS Statistics 20. Pollen observed were small to large with suboblate, oblate-spheroidal, prolate-spheroidal and subprolate shape. Exine ornamentations were reticulate and psilate type in all the studied plants. Colpi and pores of the selected plants observed are tricolporate, tricolpate and monoporate. The present study showed that both spring and autumn seasons are the prominent seasons for honey production and beekeeping industries in Khyber Pakhtunkhwa. Brassica camp-estris is the most visited species by honeybees in the study area. Melliferous plants gave knowledge about botanical origin of honey and geographical origin of honeybees. The current study identified numerous bee forage plants which may help to raise the concept of cultivation of melliferous herbaceous plants by the local people, to be used for honey production. The identification of these potential sources may help the beekeepers to increase the honey production and increase in agricultural yields through pollinations.
