Determination of plutonium in soil and bottom sediments in the region of the scientific-research institute of atomic reactors

Scientific-Industrial Firm The Radium Institute. Scientific-Research Institute of Atomic Reactors, Dimitrovgrad. Translated from Atomnaya Énergiya, Vol. 75, No. 4, pp. 319-324, October, 1993.     

Preparation of unsupported granulated triuranium octoxide and its use as catalyst of conversion of ammonium nitrate to nitrogen in an NH<Subscript>4</Subscript>NO<Subscript>3</Subscript>–H<Subscript>2</Subscript>O vapor–gas mixture

Formulation of the forming paste for preparing unsupported granulated triuranium octoxide U₃O₈ was developed. The mixture contains U₃O₈ and (NH₄)₂U₂O₇ in a weight ratio from 1: 1 to 1: 1.5, and also water in an amount of 25–40 wt % relative to the sum of the dry components. Calcination of crude granules at 800–1100°С results in formation of strong ceramic granules with 57–45% open porosity, consisting of U₃O₈. Granulated U₃O₈ efficiently catalyzes the conversion of ammonium nitrate to nitrogen in an NH₄NO₃–H₂O vapor–gas mixture with the addition of ammonium carbonate. The absence of support makes the catalyst composition more definite and simplifies its regeneration.     

Recognition of liquid and flesh food using an `electronic tongue'

An electronic tongue comprising thirty potentiometric chemical sensors and pattern recognition tools for data processing was used for the analysis of mineral waters, coffee, soft drinks and flesh food, namely fish. The electronic tongue appeared to be capable of distinguishing between different sorts of beverages: natural and artificial mineral waters, individual and commercial brands of coffee, and commercial and experimental samples of soft drinks containing different sweeteners. A quantitative correlation between human perception and `electronic tongue' output was obtained. Taste parameter assessments produced by a professional taste panel was used for `electronic tongue' calibration. It was found that the `electronic tongue' is capable of distinguishing sea water and freshwater fish and monitoring their spoilage.     

Model Study of Migration Behavior in Floods of 241Am and 152Eu Associated with Humus Compounds in Floodplain Soils of the Yenisei River

It is demonstrated in model experiments that in the presence of Ca ions (typomorphous cations of water of the Yenisei River) fulvic acids of floodplain soils and associated radionuclides (Am, Eu) form poorly soluble mixed Ca, Fe, Al(Am, Eu) fulvates. As a result, under the flooding conditions the migration of Am and Eu in the form of solubilized organomineral complexes is practically totally suppressed. With decreasing pH in the model system from 8 to 6 the mobility of the radionuclides noticeably increases.     

基于脉冲激光沉积的新型镉离子薄膜传感器

采用用于镉离子选择电极的硫属玻璃（Cd Ag As I S）制备敏感材料,结合脉冲激光沉积技术与光寻址电位传感器的特点,在光寻址电位传感器表面上沉积对镉离子敏感的薄膜材料,研制了一种新型镉离子敏感薄膜传感器.该传感器基底为N型单晶硅片,金属接触层为Cr/Au.通过实验得出该传感器的检出下限为1.15×10-7 mol/L,响应时间小于2 min,适用溶液pH范围为4～7,具有测量快速灵活、所需样品少、测量下限低等特点.该传感器对干扰离子具有较好的抑制能力.该传感器采用交流光激发电流信号进行测量,相对于离子选择电极,灵敏度得到了提高.实验结果表明脉冲激光沉积方法是制备薄膜微型传感器的一种新的有效手段.     

Hot Particles of the Second Kind in Flood Lands of the Yenisei River

Specific modification of hot particles found in flood-land soils of the Yenisei River was studied. In contrast to the known hot particles (hot particles of the first kind), newly found hot particles are referred to as hot particles of the second kind. Abundance, radionuclide composition, and other characteristics of hot particles of the first and second kinds are compared.     

Dynamics of radiostrontium leaching from radioactively contaminated floodplain soils of the Yenisei River

Gleyzation-mediated leaching of radiostrontium from floodplain soils of the Krasnoyarsk Mining and Chemical Combine (MCC) activity zone [Atamanovskii Island (front part), Oseredysh Island (front part), and Berezovyi Island (rear part)] is studied with model systems. Leaching of radiostrontium from waterlogged soils is analyzed in terms of the model of anaerobic biosolubilization of gel films. The leaching of radiostrontium is found to correlate with that of iron, confirming the cosolubilization model. Addition of glucose (0.5%) as a stimulant for growth of iron-reducing microorganisms increases the dynamic coefficient of radiostrontium leaching, particularly in soils with lower organic matter content. The model experiments showed that the radiostrontium leaching rate from floodplain soil is higher by 2–3 orders of magnitude than that of radio-cesium, suggesting the possibility of escape of radiostrontium from the floodplain of the Yenisei River with the intrasoil runoff. This conclusion is supported by the experimental data on the ⁹⁰Sr/¹³⁷Cs ratio in the floodplain of the Yenisei River downstream of MCC (0.01–0.1).     

脉冲激光沉积技术制备的薄膜传感器的研究

基于脉冲激光沉积（PLD）技术在光寻址电位传感器（LAPS）表面上制备了FeGeSbSe硫系玻璃薄膜，合成的靶材成分为Fe1.2(Ge28Sb12Se60)98.8，在Si/SiO2基质上的金属层为Cr/Au，硫系玻璃薄膜对Fe3＋敏感，显示了良好的重复性和稳定性.在1×10－5～1×10－2 mol/L呈现线性，斜率为(56±2) mV/decade，检测下限为5×10－6 mol/L，当浓度高于1×10－4 mol/L时，响应时间不超过40 s；当低于此浓度时，响应时间不超过2 min.     

箱体式低压真空等离子体表面处理在非织造过滤产品上的应用

介绍了低压真空等离子体技术及表面处理设备。经等离子体涂层处理的过滤介质可用于不同气体和液体的过滤,如汽车用空气过滤、柴油过滤、血液过滤以及制成具有99%渗透效率的口罩和永久亲水性的电池隔膜等。     

Speciation and Migration Behavior of Pu and Am in Floodplain Soils and Bottom Sediments of the Yenisei River

Am and Pu speciation in floodplain soils and bottom sediments of the Yenisei River is studied. Pu is more tightly associated with amorphous hydroxides as compared to Am. Am associated with organic matter is potentially more mobile than Pu. Model experiments showed that fulvic acids decelerate Am sorption from water to floodplain soil.