Different combination of raw materials and nucleating agents were incorporated in the batch of nepheline-pyroxene glass to
demonstrate their effect on the crystallization process. The effect of TiO2, Cr2O3 and LiF with respect to crystallization of base glass was studied by differential thermal analysis (DTA).These materials
improved the crystallization of glass between 50 to 150C of heat treatment. When LiF+TiO2 and TiO2+Cr2O3 were put together in the glass batches, the rate of crystallization of glass was increased in the same manner. The presence
of TiO2+LiF+Cr2O3 improved the crystallization of the glass by decreasing the heat temperature by about 60C. CaO/MgO and CaO/Na2O ratios played an important role in the rate of crystal growth. The increase in the CaO/MgO ratio lowers the crystallization
temperature by values ranging between 37 and 46C.
Radiolabeled somatostatin analogues, including octreotate have been used for targeted radiotherapy of neuroendocrine tumors
such as lymphoma, breast cancer, small-cell lung cancer and melanoma. In this paper, studies on the optimization of the production
of 177Lu, 166Ho and 153Sm radionuclides in Pakistan Atomic Research Reactor (PARR-I) and the investigations on the labeling of DOTA-Tyr-3 Octreotate
with 131I, 177Lu, 166Ho and 153Sm have been reported. The labeled DOTA-Tyr3-Octreotate complexes were found to be stable in acetate/ascorbate buffer and
saline at room temperature (18–22°C). The biodistribution studies of 177Lu-DOTA-Tyr-3 Octreotate in rat model indicated that the critical organ for this complex was the pancreas and the excretion
route was through kidney.
The adsorption of mercury on zirconium oxide from aqueous solution has been studied in relation to concentration of adsorbent and adsorbate. The influence of contact time, buffer composition, pH, and foreign ions was also investigated. Thiosulfate, iodide, thiocyanate, EDTA, cyanide and Li(I) drastically reduced adsorption. Adsorption of other metal ions under the same conditions was also investigated. Based on these data, separation of mercury from antimony and neodymium can be achieved.
The use of locally available mineral clay for the removal of radionuclides from the low and intermediate level liquid waste has been studied. Adsorption behavior of this naturally available inorganic adsorbent is reported. The factors such as contact time, nature of the waste, pH and adsorption capacity have been considered. These optional physico-chemical conditions suggest an effective use of this locally available adsorbent for the decontamination of the liquid radioactive waste at Pakistan Institute of Nuclear Science and Technology (PINSTECH), Islamabad.
Authors:M. Siddique, M. Anwar-ul-Islam, N. Butt, N. Hussain, S. Rehman, and M. Arshed
Room temperature corrosion studies have been made on the rust of commercially available mild steel in a simulated acid rain
environment using the method of transmission Mössbauer spectroscopy. The main corrosion products identified are α-FeOOH, γ-FeOOH,
and a product with unfamiliar parameters which seems to be amorphous in nature (being very large linewidth −2.5 mm/s) and
may be considered as an intermediate phase. A small amount of γ-Fe2O3 (6–8%) is also observed.
Authors:M. Arshed, M. Siddique, M. Anwar-ul-Islam, N. Hussain, K. Shahid, and N. Butt
The Mössbauer technique has been used to study the oxidation of alloy 1.4306S (SS-304L) at 1200°C exposed in atmospheres of air and steam, for, 1, 6, 24, 100 and 400 hours. By oxidation in air the major products are -FE2O3, -FE2O3, and Fe3O4 while, during oxidation in steam they are -FeOOH, -Fe2O3 and Fe3O4. A minor phase detected following both kinds of oxidation may be ascribed to MnCrFeO4, Cr2FeO4, -FeOOH and -FeOOH produced in steam only while the base material is found following air oxidation. The proportion of Fe3O4 on the scale remains constant for all exposure durations in air oxidation, while it becomes constant in steam oxidation only in cases where the entire sample has been oxidized.
Authors:S. K. Durrani, K. Saeed, A. H. Qureshi, M. Ahmad, M. Arif, N. Hussain, and T. Mohammad
Yttrium aluminum garnet (YAG) and neodymium-doped yttrium aluminum garnet (Nd-YAG) nano-crystalline powders were successfully grown using cost effective sol spray process without the addition of any chelating agent or organic templates. Thermal decomposition behavior was studied by thermogravimetry (TG) and differential thermal analysis (DTA). Results revealed that crystallization of YAG started around 920 °C. The shrinkage/expansion behavior of synthesized powder was examined by dilatometer and revealing that sintering kinetics of these materials can be related to the evaporation of binder and formation of crystalline phases. Nano-crystallinity and garnet structure of YAG and Nd-YAG specimens were analyzed by Raman, fourier transform infra red (FTIR), and X-ray diffraction (XRD) techniques. XRD patterns were indexed using Rietveld refinement method. Smaller lattice parameter and a small change in atomic position of oxygen were found in Nd-YAG when compared with YAG structure. Scanning electron microscope (SEM) results indicated that particle size of Nd-YAG was <150 nm. The morphology of Nd-YAG nanosized powder was rounded in shape.
Authors:Mouheddin Alhaffar, Rami Suleiman, S. M. Shakil Hussain, and Bassam El Ali
Ultranox626 as a diphosphite ligand showed high selectivity and good yields when used with Rh(CO)2(acac) as a catalyst precursor in the hydroformylation of allylbenzene derivatives producing aldehydes, and also in the one-pot hydroformylation–acetalization forming acetals. These reactions proceed smoothly and effectively to produce the linear aldehydes or acetals with high selectivity. The recycling of the rhodium catalyst was carried out after the careful screening and optimization of the reaction conditions in order to maximize the conversion and the selectivity of the reactions.