Reference material for radionuclides in sediment IAEA-384 (Fangataufa Lagoon sediment)

Author Posting. © Springer, 2007. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Journal of Radioanalytical and Nuclear Chemistry 273 (2007): 383-393, doi:10.1007/s10967-007-6898-4.A reference material designed for the determination of anthropogenic and natural radionuclides in sediment, IAEA-384 (Fangataufa Lagoon sediment), is described and the results of certification are presented. The material has been certified for 8 radionuclides (40K, 60Co, 155Eu, 230Th, 238U, 238Pu, 239+240Pu and 241Am). Information values are given for 12 radionuclides (90Sr, 137Cs, 210Pb (210Po), 226Ra, 228Ra, 232Th, 234U, 235U, 239Pu, 240Pu and 241Pu). Less reported radionuclides include 228Th, 236U, 239Np and 242Pu. The reference material may be used for quality management of radioanalytical laboratories engaged in the analysis of radionuclides in the environment, as well as for the development and validation of analytical methods and for training purposes. The material is available from IAEA in 100 g units

Reference Material for Radionuclides in Sediment, IAEA-384 (Fangataufa Lagoon Sediment)

The IAEA Marine Environment Laboratory (IAEA-MEL) in Monaco has conducted intercomparison exercises on radionuclides in marine samples for many years as part of its contribution to the IAEA's program of Analytical Quality Control Services (AQCS). An important part of the AQCS program has been a production of Reference Materials (RMs) and their provision to radioanalytical laboratories. The RMs have been developed for different marine matrices (sediment, water, biota), with accuracy and precision required for the present state of the art of radiometrics and mass spectrometry methods. The RMs have been produced as the final products of world-wide intercomparison exercises organized during last 30 years. A total of 44 intercomparison exercises were undertaken and 39 RMs were produced for radionuclides in the marine environment. All required matrices (seawater, biota, sediment) have been covered with radionuclide concentrations ranging from typical environmental levels to elevated levels affected by discharges from nuclear reprocessing plants. The long-term availability of RMs (over 10 years) requires the use of very specific techniques to collect and pretreat large quantities of material (e.g., in excess of 100 kg) in order to ensure sample stability and homogenization of any analytes of interest. The production of a RM is therefore a long process, covering the identification of needs, sample collection, pre-treatment, homogenization, bottling, distribution to laboratories, evaluation of data, preliminary reporting, additional analyses in expert laboratories, certification of the material, and finally issuing the RM. In this paper we describe a reference material IAEA-384, Fangataufa lagoon sediment, designed for determination of anthropogenic and natural radionuclides in the marine environment. This RM has been prepared with the aim of testing the performance of analytical laboratories to measure the activity of these radionuclides in a sediment sample contaminated by elevated levels of fallout from nuclear weapons tests. Participating laboratories were requested to determine as many radionuclides as possible by radiometric (alpha, beta and gamma-spectrometry) as well as by mass spectrometry methods (e.g., ICPMS - Inductively Coupled Plasma Mass Spectrometry, TIMS - Thermal Ionization Mass Spectrometry, AMS - Accelerator Mass Spectrometry)

Designing a System of Liquid Cooling for Industrial Microwave Installations

The paper considers the issue on ensuring a thermal regime of the magnetron's anode unit by replacing an air-cooling system with the system of liquid cooling. It has been argued that a liquid cooling system is most suitable for magnetrons, for which currently an air-cooling system is implied, although they are not designed for a continuous operation in the structure of industrial microwave installations. Arranging the system of liquid cooling would makes it possible for a magnetron to work over long time without overheating and under favorable conditions, which rule out a possibility to clog the heat exchange surface with particles and dust, as well as the occurrence of overheating of the anode unit's surface. The basic element of the proposed system for liquid cooling is a cooling jacket, which represents an annular channel made from a heat-conducting material. Cooling jacket is mounted directly on the anode unit; in this case, a compression ratio of surfaces and the thickness of an air gap must ensure a minimum total thermal resistance. In order to determine heat transfer coefficients, an empirical dependence was established, which reflects the fact that when cooling the anode units the rational regimes are the viscous and transitional motion modes. The basic thermal characteristics of the cooling process have been defined, which include a coefficient of heat transfer, change in a heat-carrier temperature, the maximally permissible temperature at inlet. Calculations were carried out for two types of heat-carriers: water and a 54 % aqueous solution of ethylene glycol. A circuit for the system of liquid cooling has been proposed, which implies cooling from 1 to 6 magnetrons. Applying a given circuitry and choosing the rational estimated modes make it possible to solve the task on improving production efficiency, as well as reliability of microwave equipment

Determination of 222 Rn absorption properties of polycarbonate foils by liquid scintillation counting. Application to 222 Rn measurements

Proceeding of the 20th International Conference on Radionuclide Metrology and its Applications (ICRM), 8-11 June 2015, Vienna, Austria. Organizer TU Wien. Editors Franz-Josef Maringer, Dirk Arnold, Uwe Wätjen.International audienceThis work demonstrates that a Liquid Scintillation Counting (LSC) technique using a Triple to Double Coincidence Ratio counter with extending dead-time is very appropriate for the accurate measurement of Rn-222 activity absorbed in thin polycarbonate foils. It is demonstrated that using a toluene-based LS cocktail, which dissolves polycarbonates, the Rn-222 activity absorbed in thin Makrofol N foil can be determined with a relative standard uncertainty of about 0.7%. A LSC-based application of the methodology for determination of the diffusion length of Rn-222 in thin polycarbonate foils is proposed and the diffusion length of Rn-222 in Makrofol N (38.9 +/- 1.3 gm) and the partition coefficient of Rn-222 in Makrofol N from air (112 +/- 12, at 20 degrees C) and from water (272 +/- 17, at 21 degrees C) are determined. Calibration of commercial LS spectrometers for Rn-222 measurements by LSC of thin polycarbonate foils is performed and the minimum detectable activities by this technique are estimated

Long-acting contraceptive agents: Levonorgestrel esters of unsaturated acids

10 pages, 1 scheme.-- Available online 10 January 2003.Esters of levonorgestrel (13β-ethyl-17β-ethynyl-17β-hydroxygon-4-en-3-one) with a variety of unsaturated carboxylic acids have been synthesized for evaluation as potential long-acting, injectable contraceptive agents.The authors thank the World Health Organization for financial support of this work

Случай мукормикоза придаточных пазух носа у пациентки с инфекцией COVID-19

Наведений опис клінічного випадку інфекції COVID-19, що ускладнилася розвитком мукормікозу придаткових пазух носа у пацієнтки на тлі супутньої хронічної патології (гіпертонічна хвороба, цукровий діабет, ожиріння, ішемічна хвороба серця). Використання в терапії тоцілізумабу і тривалий курс дексаметазону привели до зниження імунітету на тлі порушення обміну речовин, яке існувало у пацієнтки до хвороби. Ці фактори сприяли приєднанню генералізованої бактеріально-грибкової інфекції з ураженням придаткових пазух і подальшою генералізацією з вихідом в сепсис. Тривала терапія антибіотиками широкого спектра дії і протигрибковими препаратами, оперативне втручання з метою санації первинного вогнища були неефективними.A clinical case of COVID-19 infection complicated by the development of mucormycosis of the paranasal sinuses in a patient with concomitant chronic pathology (hypertension, diabetes, obesity, coronary heart disease) was described. The use of tocilizumab in therapy and a long course of dexamethasone led to a decrease in immunity against the background of metabolic disorders that existed in the patient before the disease. These factors contributed to the accession of generalized bacterial-fungal infection with lesions of the paranasal sinuses and subsequent generalization with sepsis. Prolonged therapy with broad-spectrum antibiotics and antifungal drugs, surgery to rehabilitate the primary focus were ineffective.Приведено описание клинического случая инфекции COVID-19, осложнившейся развитием мукормикоза придаточных пазух носа у пациентки на фоне сопутствующей хронической патологии (гипертоническая болезнь, сахарный диабет, ожирение, ишемическая болезнь сердца). Использование в терапии тоцилизумаба и длительный курс дексаметазона привели к снижению иммунитета на фоне нарушения обмена веществ, который существовал у пациентки до болезни. Эти факторы способствовали присоединению генерализованной бактериально-грибковой инфекции с поражением придаточных пазух и последующей генерализацией с выходом в сепсис. Длительная терапия антибиотиками широкого спектра действия и противогрибковыми препаратами, оперативное вмешательство с целью санации первичного очага были неэффективными