[en] Excitation functions were measured by the stacked-foil technique for (d,xn) reactions on natural tellurium up to E=14 MeV as well as for (d,xn) and some other competing reactions on 96.45% enriched /sup 122/ Te up to E=35 MeV. Thick target yields were calculated for the formation of /sup 121/I, /sup 122/ I and /sup 123/ I. The optimum energy range for production of /sup 123/ I via the /sup 122/ Te(d,n)/sup 123/ I reaction is E=14-8 MeV, and the theoretical thick target yield 1.7 mCi/mue Ah. A comparison of the the three direct methods of production of /sup 123/ I viz. /sup 124/ Te(p,2n)/sup 123/ I and /sup 122/ Te(d,n)/sup 123/ I reactions, are given. Fission neutron spectrum averaged cross sections were measured for the first time for the reactions /sup 124/ Xe(n,p)/sup 124/ I, /sup 126 Xe(n,p)/sup 126/ I, /sup 130/ Xe(n,p)/sup 130/ I, /sup 131/ Xe(n,p)/sup 131/ I and /sup 124/ Xe(n,2n)/sup 123/ Xe by activation technique using radiochemical separation and high resolution gamma-ray spectroscopy. These reaction are discussed in the context of /sup 123/ I production using fast neutrons. An intense d(Be) breakup neutron source or an intense DT neutron generator, on the the other hand, can lead to about 100 mCi of high purity /sup 123/ I, if 99.8% enriched /sup 124/ Xe is used as target material. (Orig./A.B.)

[en] The NUClear DATAbase (NUCDATA) has been developed and implemented specifically for Neutron Activation Analysis research. The database was derived mainly from NUDAT. It provides access to nuclear data along with some programs for quick calculations for 408 radioisotopes. The database contains gamma energies, intensities, half-lives and cross-section data

[en] A proficiency test (PT) was organized within the framework of international Atomic Energy Agency (IAEA) project INT/1/054, entitled 'Preparation' of Reference Materials and Organization of Proficiency Test Rounds'. This exercise served to estimate the proficiency of the analytical laboratories from participating countries. This report presents the results of the proficiency test exercise on the proposed Mushroom Reference Material for the determination of natural levels of radionuclides. Laboratories from 6 different countries submitted data on the following three radionuclides: /sup 134/Cs, /sup 137/Cs, /sup 40/K. Results for /sup 134/Cs, 137/sup 137/Cs, and /sup 40/K in the mushroom reference material were reported by three or more participating laboratories and could be subjected to statistical evaluation. The original data of these raionuclides was subjected to a computer program 'Histo Vession 2.1' provided by IAEA. The four outlier tests i.e. Dixon, Grubbs, Skewness and Kurtosis were applied to the data sets. All values for these three radionuclides were accepted by the software. Consensus (overall) mean value, absolute standard deviation, relative standard deviation, standard error, median and range of values for these three radionuclides have been are obtained (at significance level 0.05). the consensus mean values and confidence intervals are given./sup 134/Cs: 4.4 Bq/kg (3.4-5.3 Bq/kg) /sup 137/Cs: 2899 Bq/kg (2740-3058 Bq/kg) /sup 40/K: 1136 Bq/kg (1046-1226 Bq/kg). (author)

[en] Due to the significance of industrial waste water pollution, which creates severe health hazards in humans, this study concentrates over the reduction and determination of the amounts of toxic metals/pollution parameters in the effluents leached from different processes of the textile industry. The concentrations of metal ions were measured by using neutron activation analysis (NAA) technique. The values of toxic metals such as As (49.1 ± 1.8 mg/L), Cu (42.7 ± 1.5 mg/L), Ni (41.1 ± 3.3 mg/L), Mn (51.1 ± 0.7 mg/L), Sb (1.89 ± 0.04 mg/L), Se (0.41 ± 0.01 mg/L), Co (7.5 ± 0.3 mg/L), Cr (8.5 ± 0.5 mg/L) and Cd (1.21 ± 0.08 mg/L) were found very high in crude textile's effluents as compared to their standard recommended limits. The immense variation observed among the injurious pollutants of the effluents i.e. pH, temperature, electrical conductivity, turbidity, biological oxygen demands, chemical oxygen demands, total suspended solids, total dissolved solids, total solids etc. The toxic metals and injurious pollutants in the unprocessed effluents have been reduced in the post filtration effluents up to 98% and 96% respectively with the help of an ultra-filtration membrane therapy unit. (author)

[en] The use of radioisotopes and radiation is very important in the research of life sciences, especially in pharmaceutical science. A wide variety of radioisotopes are used for medical, industrial, research and development applications. Radioisotopes can be prepared in nuclear reactor or in accelerator. At Pakistan Institute of Nuclear Science and Technology (PINSTECH) for the last three decades, nuclear cross-section measurement studies were performed involving various types of nuclear reactions like (n, ), (n,2n), (n,p), (n,alpha) and others to identify potential for the formation of a suitable therapeutic or diagnostic radionuclide through reactor. PINSTECH is also producing various types of radioisotopes like /sup 24/Na, /sup 35/S, /sup 42/K, /sup 99/mTc, /sup 59/Fe, /sup 82/Br, /sup 192/Ir, /sup 197/Hg, /sup 203/Hg, /sup 198/Au, /sup 32/P, /sup 51/Cr and /sup 131/I as well as radiopharmaceuticals labeled with these radionuclides. About 80% of the radioisotopes produced at PINSTECH are used for diagnosis and treatment of various diseases by Nuclear Medical Centers. The radiochemical separations play vital role in analytical techniques, nuclear cross-section measurement studies and radioisotopes production. Frequently, Ion-exchange, Solvent extraction, Distillation, Chromatography, Co-precipitation and Adsorption techniques are employed to isolate the desired radionuclide to facilitate its precise and accurate determination in a complex matrix. It becomes all the more significant when it comes to the determination of trace elements in a given matrix. (author)

[en] The industrial pollution is exponentially growing in the developing countries due to the discharge of untreated effluents from the industries in the open atmosphere. This may cause severe health hazards in the general public. To reduce this effect, it is essential to remove the toxic and heavy metals from the effluents before their disposal into the biosphere. In this context, samples of the effluents were collected from the textile/yarn, ceramics and pulp/paper industries and the concentrations of the toxic metal ions were determined using neutron activation analysis (NAA) technique. The observed concentration values of the As, Cr and Fe ions, in the unprocessed industrial effluents, were 4.91 ± 0.8, 9.67 ± 0.7 and 9.71 ± 0.8 mg/L, respectively which was well above the standard recommended limits (i.e. 1.0, 1.0 and 2.0 mg/L, respectively). In order to remove the toxic metal ions from the effluents, the samples were treated with pea nut husk fence. After this treatment, 91.5% arsenic, 81.9% chromium and 66.5% iron metal ions were successfully removed from the effluents. Then the treated effluents contained concerned toxic metal ions concentrations within the permissible limits as recommended by the national environmental quality standards (NEQS). (author)

[en] The concentration of 18 minor and trace elements (essential, toxic and nonessential) in infant head hair was determined. The data provide the base-line values of these elements in head hair of infants of low- and medium-income group subjects. The statistical results show that there are significant correlations between some elements such as: Ca-Zn, Ca-Fe, Mg-Ca, Mg-Mn and Mg-Fe. The results obtained have been compared with the data reported in the literature. Our data show compatibility of elemental contents of infant head hair with those from some of the other geological regions but also deviate in some cases. (orig.)

[en] Excitation functions were measured by the stacked foil technique for (d,xn) reactions on natural tellurium up to Esub(d) = 14 MeV as well as for (d,xn) and some other reactions on 96.45% enriched ¹²²Te up to Esub(d) = 35 MeV. Thick target yields were calculated for the formation of ¹²¹I, ¹²²I and ¹²³I. The optimum energy range for the production of ¹²³I via the ¹²²Te(d,n)¹²³I reaction is Esub(d) = 14→8 MeV, and the theoretical thick target yield 1.7 mCi/μAh. The practical yield for a compact cyclotron with an on-target energy of 12.7 MeV is only 0.5 mCi/μAh. Using a high-current target system and separation of radioiodine via dry distillation, batch yields of 60 mCi ¹²³I are obtained. The level of ¹²⁴I-impurity at EOB is 0.08%. However, about 1.50% ¹³⁰I is also formed. A comparison of the three direct methods of production of ¹²³I, viz, ¹²⁴Te(p,2n)¹²³I, ¹²³Te(p,n)¹²³I and ¹²²Te(d,n)¹²³I reactions is given. The (d,n) reaction is most suitable as far as the ¹²⁴I-impurity level is concerned. The significantly higher yields of the (p,2n) process, however, may still justify the use of that reaction for large scale production of ¹²³I. (author)

[en] Samples of sand and manufactured building materials collected from the Rawalpindi/Islamabad area have been analyzed for the primordial natural radionuclides ²³⁸U, ²³²Th and ⁴⁰K using γ-ray spectrometry. The uranium and thorium contents have also been determined by instrumental neutron activation analysis (INAA). The specific activities of these radionuclides in the samples are compared with those of the world averages for soil. The comparison shows that, of the nine samples analyzed, only the three brick samples have higher activities than the world averages for soil. The specific activities in these materials, having a radium equivalent activity of less than 370 Bq kg^-1, when evaluated for radiological effects show that all materials meet the external γ-ray dose limitation of 1.5 mSv y^-1. The γ-spectrometric and INAA techniques complemented each other well in this study

[en] With the inception of Pakistan Atomic Energy Commission (PAEC) in 1956, peaceful uses of atomic energy commenced for the benefit of scientific community as well as masses of Pakistan. Radiochemistry played a vital role right from the beginning. The research and development in this field accelerated soon after the criticality of the first research reactor named as Pakistan Research Reactor (PARR-1) at the Pakistan Institute of Nuclear Science and Technology (PINSTECH), Islamabad. The first radioisotope produced at PARR-1 for application in nuclear medicine was ¹³¹I. Later on, many other radioisotopes were prepared and radiopharmaceuticals were synthesised for their use in industry and hospitals. Besides providing pure radioactive tracers for nuclear medicine, radiochemistry also enhanced the detection limit of impurities at all stages of nuclear fuel cycle for power generation. In 1983, research in the field of nuclear data measurement began. The main aim was to identify suitable conditions for the production of radionuclides for cancer diagnostics, treatment and therapy. With the establishment of a second research reactor (PARR-2) at PINSTECH, research in neutron activation analysis, radioisotope production and separation studies gained more momentum and many research articles were published. Solvent extraction, adsorption and ion-exchange were the main routes of separation in those studies. Separation of heavy metals and treatment of waste generated in a nuclear power plant are other important aspects related to environmental restoration and nuclear waste management, where radiochemistry is required. In future, work in radiochemistry will be continued on similar lines to develop novel radiopharmaceuticals, identify indigenous schemes for nuclear waste management and work out intelligent procedures for material characterization for benefit to mankind, especially the people of Pakistan. (orig.)