Application of response surface methodology for uranium(VI) adsorption using hydroxyapatite prepared from eggshells waste material: study of influencing factors and mechanism.

Hydroxyapatite (HAp) was synthesized from biowaste hen eggshells by wet precipitation method in which calcium hydroxide and phosphoric acid were used as precursors. The effectiveness of uranium(VI) adsorption onto HAp was investigated by batch adsorption experiments from aqueous solutions. The obtained HAp powder was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectrometry, point of zero charge and Scanning electron microscope.

Development of in-house RIA kit for progesterone in cow's skim milk.

A radioimmunoassay (RIA) method for progesterone has been developed. It has been validated for the determination of progesterone in cow skim milk. The main reagents used in the development work were prepared and characterized in-house.

The synergistic effect of gamma irradiation and alkaline soaking at low temperature on the pre-deacetylation of α-chitin: Optimization by design of experiment.

The effect of gamma irradiation and alkaline soaking time at low temperature (4 °C) as a pretreatment of α-chitin before its N-deacetylation and the effect temperature, NaOH concentration and the reaction time traditionally used during the deacetylation process were studied by applying a factorial experimental design. The top and bottom levels applied for each factor were 1-25 kGy for γ irradiation dose, 2-18 hours for alkaline soaking time at low temperature (4 °C), 50-85 °C for temperature, 35-60% for NaOH concentration and 30-90 min for reaction time. The measured response of deacetylation degree (DD) was determined by FTIR.

Performance revaluation of a N-type coaxial HPGe detector with front edges crystal using MCNPX.

The MCNPX code was used to determine the efficiency of a N-type HPGe detector after two decades of operation. Accounting for the roundedness of the crystal`s front edges and an inhomogeneous description of the detector's dead layers were shown to achieve better agreement between measurements and simulation efficiency determination. The calculations were experimentally verified using point sources in the energy range from 50keV to 1400keV, and an overall uncertainty less than 2% was achieved.

In-house preparation and evaluation of (125)I-histamine progesterone tracer for radioimmunoassay of progesterone.

The progesterone tracer for the development of in-house radioimmunoassay was prepared in two steps clearly described. First, activation of 11α-hemisuccinate progesterone (progesterone-11 α HS) and labeling of histamine with (125)I, and second, conjugation of activated 11α-HS progesterone with iodinated histamine. The purification of the tracer was carried out by gel filtration on Sephadex G-25.