[en] Chemical treatment process for the low level liquid radioactive waste generated at PINSTECH was previously optimized on lab-scale making use of coprecipitation of hydrous oxides of iron in basic medium. Ferrous sulfate was used as coagulant. Batch wise application of this procedure on pilot scale has been tested on a 1200 L batch volume of typical PINSTECH liquid waste. Different parameters and unit operations have been evaluated. The required data for the construction of a small size treatment plant envisioned can be used for demonstration/teaching purpose as well as for the decontamination of the waste effluents of the Institute. The lab-scale process parameters were verified valid on pilot scale. It was observed that reagent doses can further be economized with out any deterioration of the Decontamination Factors (DF) achieved or of any other aspect of the process. This simple, cost- effective, DF-efficient and time-smart batch wise process could be coupled with an assortment of other treatment operations thus affording universal application. Observations recorded during this study are presented. (author)

[en] Radiometric analysis of lunch served at PINSTECH cafeteria was carried out during the period from 1976 to 1984 by NaI (TI) scintillation detector, high resolution Ge(Li) detector gamma spectrometry system and low level beta counter. K-40 and Sr-90 were the most prominent radionuclides normally detected in all the lunch samples. Other radionuclides were below the measurement limits of our counting set up. Assuming 5 days a week and 50 weeks a year it can be safely stated that intake of K-40 and Sr-90 through LUNCH taken at PINSTECH cafeteria remains well below respective ALI's of these radionuclides. (author)

[en] A sensitive and specific method for uranium(6) determination using reverse phase ion-pair high performance liquid chromatography with UV detector has been developed. The developed method has been applied for the determination of uranium in a synthetic sample containing most of the interfering ions. Except iron most of the elements and anion which often interfere in uranium assay do not interfere in the present method. Interference of iron is masked by addition of 5mM/1 EDTA solution to the sample

[en] Thoracodorsal artery perforator flap (TAP) is a feasible option to reconstruct defects in upper limb where only skin and subcutaneous tissue is required. Methods: This case series was carried out at department of Plastic and Reconstructive Surgery Combined Military Hospital Rawalpindi. A total of 5 patients with upper limb defects were reconstructed with thoracodorsal artery musculocutaneous perforator flaps. Among them, 3 were pedicled and two free TAP flaps. All flaps except one pedicled flap were raised on a single perforator pedicle. Recipient sites were one axilla, two shoulder regions and two hands. The soft tissue defects in the patients had resulted from burns, trauma, wide local excision of synovial sarcoma and surgery for hidradenitis suppurativa. Preoperative hand held Doppler ultrasound was used to locate and mark the perforator. Results: All flaps survived without significant complications. All flaps were hyperemic in the immediate postoperative period. We designed and raised all the five flaps on eccentrically placed perforators. All the raised perforators originated from the descending branch of the thoracodorsal artery. The donor sites were closed primarily with linear scars in all cases except one, in which partial closure was accomplished with split thickness skin grafting (STSG). Conclusion: The thoracodorsal artery perforator flap has great potential for reconstructing large, relatively shallow, defects of upper limb because of its suitable skin quality, texture and appropriate thickness, as well as hidden donor site, a reliable pedicle and sparing of muscle unit. (author)

[en] Environmental gamma radiation levels in Lahore city were measured using the radiation monitor which employs G. M tube. Average absorbed dose rate in air varied from 140 nGy h/sup -1/ to 282 nGy h/sup -1/ with the mean value of 197 nGy h/sup -1/. The effective dose rate levels in Lahore city were found in the range of 860 plus minus 147 micro Sv y/sup -1/ to 1732 plus minus 187 micro Sv y/sup -1/ with the mean value of 1208 plus minus 244 micro Sv y/sup -1/, whereas annual average effective dose equivalent due to terrestrial component only is 275 micro Sv. The collective effective dose equivalent to the population in the city is 1432 man.Sv. y/sup -1/. These radiological doses are not posing any significant health hazards. (author)

[en] The biology and predatory potential of Coccinella septempunctata (Linn.) were studied on aphid, Schizaphis graminum (Rondani) at three constant temperatures 20+-1 degree C, 25+-1 degree C and 30+-1 degree C in Insectary-Bio Control Laboratories, National Agricultural Research Centre (NARC), Islamabad. The results revealed that incubation period of C. septempunctata was 5.12, 3.62 and 3.20 days with 75.6%, 82.0% and 71.2% hatchability, respectively. The larval durations were 29.5, 15.9 and 8.1 days with predatory potential of 573.7, 575.0 and 667.8 aphids per larvae. The results indicated that with increasing temperature, develop-mental duration decreases significantly. The pupal developmental duration was 14.0, 9.2 and 5.2 days, respectively which are significantly different from each other. The adult male and female longevity were 44.7, 37.7, 30.0 and 60.3, 58.9 and 43.7 days. Fecundity rate of females were 123.5, 251.5 and 293.2 eggs per female, respectively. This indicates that adult male and female developmental duration, female fecundity rate were significantly different from each other at three constant temperatures. Maximum female and male predatory potential was 3262.8 and 2571.7 aphids at 25 +-1 degree C while minimum was 2276.8 and 1890.6 aphids, respectively. (author)

[en] Monitoring of air-born organic and organic pollutants have always been a subject of concern to the environmentalists. Gases in particular Co/sub 2/, N/sub 2/O ad C/sub 4/ are responsible for global warming and have indirect impact on the environment. These gases are generally analyzed by gas chromatography. However on-site monitoring using this technique in rather difficult and it requires reasonable instrumental handling experience. The infrared-based technique is not only simple rather it also offers on advantage of on-site monitoring of a pollutant and eliminates the tedious job of sampling and its preservation. In the present work experimental conditions have been optimize for the selective detection of major global warming agents. Independent gas mixtures of Co/sub 2/, N/sub 2/O and C/sub 4/ have been prepared in pure helium gas by partial pressure method. The measured response of varied amount of each gas is found to be linear. The interference of these gases in presence of each other is also investigated. In this reference, gas mixtures of the gases are prepared considering the relevant concentration of each gas in the ambient air. The monitoring was found almost interference free at ambient concentration of these gases. The reliability can further be improved by incorporating the concentration trend of these gases. The reliability can further be improved by incorporating calibrated gas standard mixtures. (author)

[en] Disused sealed Radiation sources (DSRSs) pose radiological threat and concern globally to both public and the environment. The sources may get mislaid or lost if not properly managed due to their small physical size and therefore, need to be managed with an adequate nuclear waste management infrastructure and legal framework. Management of such moieties from upper half of the country has been entrusted to Radioactive Waste Management Group of Health Physics Division at Pakistan Institute of Nuclear Science and Technology, Islamabad Various types of DSRSs having a total activity of 91360 GBq have been collected from various end users such as nuclear medical centers and industries in the eastern and north-western parts of Pakistan. A conditioning procedure has been optimized and a few sources have been conditioned which are being studied. The procedure has yet to be approved from the regulatory authority. The results are promising satisfactory management parameters, reduced radiation risks and improved security of the sources have shown the viability of the procedure. The possibility of using DSRS as a radiological dispersal device, risk of improper handling, or loss of control, etc, has been reduced considerably and control over the spent SRS is facilitated. This paper briefly describes management parameters like legal infrastructure and control collection, conditioning and on-site interim storage, radiation safety and contamination control, quality assurance, documentation and inventory of DSRS in the country. (author)