Uranium, determination powder

In addition to meeting the foregoing requirements, a good internal standard will be easy to add uniformly and precisely, and (preferably) no appreciable amount of the element St (free or combined) will be present in the sample before the addition. Cope29 provides an excellent illustration of these points. He found that yttrium nitrate dissolved in ethyl alcohol could be added to a powdered uranium mineral in a mortar, whereupon grinding immediately to dryness dispersed the internal standard (yttrium) so uniformly that uranium could be satisfactorily determined in certain minerals. But the mineral euxenite is an exception, for it contains both yttrium and uranium, and this complicates the uranium determination with yttrium as internal standard. 

Uranium and oxygen uranium atomic ratio by the ignition (gravimetric) impurity correction method CI453 standard test method for the determination of uranium by ignition and oxygen to uranium ratio (0/U) atomic ratio of nuclear grade uranium dioxide powders and pellets Carbon (total) by direct combustion-thermal conductivity method... 

C1457 standard test method for determination of total hydrogen content of uranium oxide powders and pellets by carrier gas extraction Uranium isotopic analysis by mass spectrometry... 

Bertine et al. [99] have discussed the determination of uranium in deep sea sediments and water utilising the fission track technique. In this technique a weighed aliquot (50-100 mg) of the powdered sample is made into a pel-... 

Cardiovascular Effects. No cardiovascular effects have been reported in humans after inhalation exposure to uranium. No effect on blood pressure or pulse rate was observed in a man accidentally exposed to powdered uranium tetrafluoride for 5 minutes (Zhao and Zhao 1990). Air concentration and mean particle size of the powder were not determined. Electrocardiograms and chest X-rays were normal shortly after the accident and over a 7.5-year follow-up period. 

Emission spectrography is used to determine the content of impurities in samples of uranium and plutonium oxide powders and pellets. 

The solid state structure of rutherfordine, UO2CO3, has been determined from crystals of both the natural mineral and synthetic samples (see Figure 50). It has a layered structure in which the local coordination environment of the uranyl ion is hexagonal bipyramidal, with the uranyl units perpendicular to the orthorhombic plane. Each uranium atom forms six equatorial bonds with the oxygen atoms from two bidentate and two monodentate carbonates. The neptunyl and plutonyl analogs are isostructural with UO2CO3 based on Rietveldt analysis of powder X-ray diffraction data. 

The structure of Th2(P04)2P030H(H20) has recently been determined in space group P2 [31], This compound has also been reported to have orthorhombic s mimetry [32] and it is likely that it is actually pseudosymmetric. The matrix 102/100/010] transforms the monoclinic P cell reported in the stmcture refinement to a pseudo-orthorhombic C setting, a 21.36, b 6.70, c 7.02 A, p 89.8°, which is extremely similar to the cell reported solely from powder data a 21.37, b 6.70, c 7.02 A, p 90° [32]. In contrast, the uranium analog U2(P04)2P030H(H20) has cell dimensions similar to its Th analog in the orthorhombic setting, but monoclinic symmetry a 21.15 b 6.61 c 6.99 A, p 91.7° its stmcture has not been refined [35]. 

Uranium Dioxide in Molten Lithium Nitrate/Potassium Nitrate Eutectic. The behavior of uranium dioxide in a molten lithium nitrate/potassium nitrate eutectic was investigated. Our goal was to determine whether a soluble uranium species could be produced using a nitric-acid vapor sparge. The materials used were a lithium nitrate/potassium nitrate eutectic mixture, pure nitric acid (100% HNO3), and powdered uranium dioxide. The mass ratio of uranium dioxide to the nitrate melt was 1 100. 

The curcumin method (in either the rosocyanin or rubrocurcumin version) has been applied for determining traee amounts of boron in biologieal materials [10], soils and plants [17], waters [51], silicon [52], chlorosilanes [20], uranium [1,53], zirconium and its alloys [53,54], nickel [55,56], copper alloys [56], cast iron and steel [12,57-59], beryllium and magnesium [53], and phosphates [2]. This method was also used for determining boric acid admixtures (about 0.05%) in powdered boron [11]. Some synthetic compounds having the structure similar to that of curcumin, were used in determining boron in water [60]. 

A series of catalysts was prepared to study the effect of substituting titanium, zirconium, or tin for antimony in the USb3O2 Q lattice. The crystalline phases present in these materials were determined by X-ray powder diffraction. To provide a basis for comparison with the prior art, catalyst 1 listed in Table I was prepared following the published recipe ( ). This catalyst represents the old uranium-antimony oxide catalyst without any silica binder. The crystalline phases detected in catalyst 1 were USb3O2 Q and Sb20 as expected (3,4). 

Sintered membranes are made on a fairly large scale from ceramic materials, glass, graphite and metal powders such as stainless steel and tungsten.9 The particle size of the powder is the main parameter determining the pore sizes of the final membrane, which can be made in the form of discs, candles, or fine-bore tubes. Sintered membranes are used for the filtration of colloidal solutions and suspensions. This type of membrane is also marginally suitable for gas separation. It is widely used today for the separation of radioactive isotopes, especially uranium. 

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