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Description: Modifications were made in the Carlson and Banks procedure for the spectrophotometric determination of silicon in beryllium metal and oxide. The refractory oxide is dissolved directly in hydrofluoric acid. The identical procedure is used for metal after ignition to the oxide. Concentrations of beryllium over certain limits have a quenching effect on the fluorescence of the aluminum-Portachrome Blue Black R complex. The determination of trace amounts of aluminum in beryilium can be carried out despite this quenching effect by the method of standard addition. Samples of plutonium sulfate tetrahydrate prepared 9 to 12 months earlier were under investigation to determine the suitability of this compound as a primary analytical standard of plutonium. The compound was determined experimentally to contain four molecules of water of crystallization. Plutonium sulfate tetrahydrate was found to lose a major portion of its water of crystallization when heated at 115 ts C. Indications, but no conclusive evidence, of the existence of another intermediate hydrate of plutonium(IV) sulfate, were found. Microscopic examination of 1-year-old crystals of Pu(S0/sub 4/)/sub 2/.4H/sub 2/0 shows no evidence of the effect of any alpha radiolysis on the water of crystallization. Continued exposure to a fluctuating atmosphere caused no apparent changes in crystal structure or weight. Heating Pu(SO/sub 4/)/sub 2/.4H/sub 2/0 to 325 ts C produced a dehydrated salt of weight equivalent to the formula, Pu(S0/sub 4/)/sub 2/. This material, although slightly hygroscopic, can be readily dried at 120 ts C and appears to be satisfactory for further investigation of its suitability as an alternate primary stand ard of plutonium. A method is presented for the rapid determination of milligram quantities of sulfateiIn pure plutonium sulfates. Plutonium is adsorbed on a cation resin and an acidimetric titration is made of the displaced hydrogen ion which is equivalent to the sulfate content of the ...
Date: January 1, 1961
Creator: Rodden, C.J.
Partner: UNT Libraries Government Documents Department

Trace Elements, With Special Reference to Mercury, in Fish Collected Upstream and Downstream of Los Alamos National Laboratory

Description: Trace elements (Ag, As, Ba, Be, Cr, Cd, Cu, Hg, Ni, Pb, Sb, Se, and Tl) were determined in muscle (fillet) of average sized fish (mostly carp, catfish, and sucker) collected from the confluences of major canyons that cross Los Alamos National Laboratory (LANL) lands with the Rio Grande (RG). Also, trace elements were determined in fish from reservoirs upstream (Abiquiu [AR]) and downstream (Cochiti [CR]) of LANL from 1991 through 1999. In general, all of the (mean) trace elements, including Hg, were either at the limits of detection (LOD) or in low concentrations at all study sites. Of the trace elements (e.g., Ba, Cu, and Hg) that were found to be above the LOD in fish muscle collected from LANL canyons/RG, none were in significantly higher (p < 0.05) concentrations than in muscle of fish collected from background locations. Mercury concentrations (mean of means) in fish from AR (all other trace elements were at LOD) were significantly higher (p < 0.10) than Hg concentrations in fish from CR, and Hg concentrations in fish collected from both reservoirs exhibited significantly (AR = p <0.05 and CR = p < 0.10) decreasing trends over time.
Date: November 1, 1999
Creator: Fresquez, P. R.; Huchton, J. D. & Mullen, M. A.
Partner: UNT Libraries Government Documents Department

Formation of Radioactive Citrulline During PhotosyntheticC14O2-Fixation by Blue-Green Algae

Description: Citrilline has been isolated and identified from extracts of Nostoc muscorum. All members of the Cyanophyceae hitherto investigated show a relatively large amount of the CO fixed during photosynthesis in citrulline (ranging as high as 20% in Nostoc) when compared to the trace amounts found in the Chlorophyceae. Nostoc also has the ability to fix C{sup 14} in citrulline during dark fixation, but at a rate slower than in light. As no free urea or arginine was found in Nostoc, it is likely that citrulline is functioning in reactions other than those leading to arginine and urea synthesis. Other possible functions for citrulline are briefly discussed.
Date: August 28, 1956
Creator: Linko, Pekka; Holm-Hansen, O.; Bassham, J.A. & Calvin, M.
Partner: UNT Libraries Government Documents Department

BioWatch in a Box

Description: BioWatch, the U.S. Department of Homeland Security (DHS) environmental monitoring program, has been successfully operating in many of the nation's urban centers since early 2003. This early warning environmental monitoring system can detect trace amounts of biological materials in the air, and has been used to provide information to assist public health experts determine whether detected materials are due to an intentional release (bioterrorism incident) or due to minute quantities that occur naturally in the environment. BioWatch information enables federal, state, and local officials to more quickly determine appropriate emergency response, medical care and consequence management.
Date: February 1, 2006
Creator: McBride, M T; Dzentis, J M & Meyer, R M
Partner: UNT Libraries Government Documents Department


Description: Uranium-(VI) phases are the primary alteration products of the UO{sub 2} in spent nuclear fuel and the UO{sub 2+x}, in natural uranium deposits. The U(VI)-phases generally form sheet structures of edge-sharing UO{sub 2}{sup 2+} polyhedra. The complexity of these structures offers numerous possibilities for coupled-substitutions of trace metals and radionuclides. The incorporation of radionuclides into U(VI)-structures provides a potential barrier to their release and transport in a geologic repository that experiences oxidizing conditions. In this study, we have used natural samples of UO{sub 2+x}, to study the U(VI)-phases that form during alteration and to determine the fate of the associated trace elements.
Date: February 21, 2006
Creator: Deditius, A.P.; Utsunomiya, S. & Ewing, R.C.
Partner: UNT Libraries Government Documents Department

The age of the martian meteorite Northwest Africa 1195 and the differentiation history of the shergottites

Description: Samarium-neodymium isotopic analyses of unleached and acid-leached mineral fractions from the recently identified olivine-bearing shergottite Northwest Africa 1195 yield a crystallization age of 348 {+-} 19 Ma and an {var_epsilon}{sub Nd}{sup 143} value of +40.1 {+-} 1.3. Maskelynite fractions do not lie on the Sm-Nd isochron and appear to contain a martian surface component with low {sup 147}Sm/{sup 144}Nd and {sup 143}Nd/{sup 144}Nd ratios that was added during shock. The Rb-Sr system is disturbed and does not yield an isochron. Terrestrial Sr appears to have affected all of the mineral fractions, although a maximum initial {sup 87}Sr/{sup 86}Sr ratio of 0.701614 {+-} 16 is estimated by passing a 348 Ma reference isochron through the maskelynite fraction that is least affected by contamination. The high initial {var_epsilon}{sub Nd}{sup 143} value and the low initial {sup 87}Sr/{sup 86}Sr ratio, combined with the geologically young crystallization age, indicate that Northwest Africa 1195 is derived from a source region characterized by a long-term incompatible element depletion. The age and initial Sr and Nd isotopic compositions of Northwest Africa 1195 are very similar to those of Queen Alexandra Range 94201, indicating these samples were derived from source regions with nearly identical Sr-Nd isotopic systematics. These similarities suggest that these two meteorites share a close petrogenetic relationship and might have been erupted from a common volcano. The meteorites Yamato 980459, Dar al Gani 476, Sayh al Uhaymir 005/008, and Dhofar 019 also have relatively old ages between 474-575 Ma and trace element and/or isotopic systematics that are indicative of derivation from incompatible-element-depleted sources. This suggests that the oldest group of meteorites is more closely related to one another than they are to the younger meteorites that are derived from less incompatible-element-depleted sources. Closed-system fractional crystallization of this suite of meteorites is modeled with the MELTS algorithm ...
Date: April 5, 2007
Creator: Symes, S; Borg, L; Shearer, C & Irving, A
Partner: UNT Libraries Government Documents Department


Description: Potassium, the reaction product of graphite with potassium, and the reaction product of irradiated graphite with potassium were subjected to hydrolysis. The gases evolved from the respective samples were analyzed mass spectroscopically. Hydrocarbons (methane and a trace of ethane) were found in the gas evolved from the irradiated graphite compound only, and the quantity was about that which would have been expected from the number of non-aggregated displaced atoms. The result was obtained for a single set of experiments and must be considered suggestive rather than conclusive. (auth)
Date: September 12, 1955
Creator: Primak, W.L. & Quarterman, L.A.
Partner: UNT Libraries Government Documents Department

Petrology and Geochemistry of Boninite Series Volcanic Rocks,Chichi-jima, Bonin Islands, Japan

Description: An Eocene submarine boninite series volcanic center isexposed on the island of Chichi-jima, Bonin Islands, Japan. Five rocktypes, boninite, bronzite andesite, dacite, quartz dacite, and rhyolite,were distinguished within the boninite volcanic sequence on the basis ofpetrographic and geochemical observations. Boninite lavas contain highmagnesium, nickel, and chromium contentsindicative of primitive melts,but have high silica contents relative to other mantle-derived magmas.All boninite series lavas contain very low incompatible elementconcentrations, and concentrations of high-field strength elements inprimitive boninite lavas are less than half of those found in depletedmid-ocean ridge basalts. Abundances of large-ion lithophile elements arerelatively high in boninite series lavas, similar to the enrichmentsobserved in many island arc lavas. Trends for both major and traceelement data suggest that the more evolved lavas of the boninite magmaseries were derived primarily through high-level fractionalcrystallization of boninite. Textural features, such as resorption andglomeroporphyrocrysts, and reverse chemical zonations suggest that magmamixing contributed to the development of the quartz dacitelavas.
Date: January 1, 1977
Creator: Dobson, Patrick F.; Blank, Jennifer G.; Maruyama, Shigenori & Liou, J.G.
Partner: UNT Libraries Government Documents Department

Very first tests on SOLEIL regarding the Zn environment in pathological calcifications made of apatite determined by X-ray absorption spectroscopy

Description: This very first report of a X-ray absorption spectroscopy experiment on Soleil is part of a more large long term study dedicated to ectopic calcifications. Such biological entities composed of various inorganic and/or organic compounds contain also trace elements. In the case of urinary calculi, different papers already published point out that these oligo elements may promote or inhibit crystal nucleation or growth of mineral or organic species involved. By using such tool specific to synchrotron radiation i.e. determine the local environment of oligoelements and thus their occupation site, we contribute to our understanding of the role of trace elements in ectopic calcifications.
Date: October 1, 2008
Creator: Bazin, D.; Carpentier, X.; Traxer, O.; Thiaudiere, D.; Somogyi, A.; Reguer, S. et al.
Partner: UNT Libraries Government Documents Department

Geochemical Signatures as a Tool for Vermiculite Provenance Determination

Description: Thirty-eight samples of known origin (China, Libby MT, South Africa, South Carolina) and 6 vermiculite product samples of unknown origin were analyzed for major and trace elements, including rare earth elements to determine the feasibility of distinguishing the provenance of the samples based upon a geochemical signature. Probability plots suggest that two of the four groups (Libby, South Carolina) were comprised of two subgroups. Results of hierarchical cluster analysis are highly sensitive to the linkage method chosen. Ward’s method is the most useful for this data and suggests that there are five groups within the data set (South African samples, two subsets of the Libby samples, a subset of the South Carolina samples, and a second subset of the South Carolina samples combined with the China samples). Similar results were obtained using k-cluster analysis. Neither clustering method was able to distinguish samples from China from the South Carolina samples. Discriminant analysis was used on a four-category model comprised of the original four groups and on a six-category model comprised of the five categories identified from the cluster analysis but with the China samples grouped into a sixth category. The discriminant/classification model was able to distinguish all of the groups including the China samples from one another for both the four- and six-category models with 100% of the samples properly classified. The 6 unknown product samples were classified with a probability of consistency of 99%. Both discriminant models were also run with a subset of our analyte set to be consistent with the smaller Gunter et al., (2005) analyte set. Twenty vermiculite samples (nine of known origin and eleven of unknown origin) from their study were classified based on our discriminant models with the reduced set of analytes. Of the twenty samples, Gunter et al. (2005) was able to classify 16 ...
Date: September 1, 2008
Creator: Wright, Karen E. & Palmer, Carl D.
Partner: UNT Libraries Government Documents Department

Evaluation of kinetic phosphorescence analysis for the determination of uranium

Description: In the past, New Brunswick Laboratory (NBL) has used a fluorometric method for the determination of sub-microgram quantities of uranium. In its continuing effort to upgrade and improve measurement technology, NBL has evaluated the commercially-available KPA-11 kinetic phosphorescence analyzer (Chemchek, Richland, WA). The Chemchek KPA-11 is a bench-top instrument which performs single-measurement, quench-corrected analyses for trace uranium. It incorporates patented kinetic phosphorimetry techniques to measure and analyze sample phosphorescence as a function of time. With laser excitation and time-corrected photon counting, the KPA-11 has a lower detection limit than conventional fluorometric methods. Operated with a personal computer, the state-of-the-art KPA-11 offers extensive time resolution and phosphorescence lifetime capabilities for additional specificity. Interferences are thereby avoided while obtaining precise measurements. Routine analyses can be easily and effectively accomplished, with the accuracy and precision equivalent to the pulsed-laser fluorometric method presently performed at NBL, without the need for internal standards. Applications of kinetic phosphorimetry at NBL include the measurement of trace level uranium in retention tank, waste samples, and low-level samples. It has also been used to support other experimental activities at NBL by the measuring of nanogram amounts of uranium contamination (in blanks) in isotopic sample preparations, and the determining of elution curves of different ion exchange resins used for uranium purification. In many cases, no pretreatment of samples was necessary except to fume them with nitric acid, and then to redissolve and dilute them to an appropriate concentration with 1 M HNO{sub 3} before measurement. Concentrations were determined on a mass basis ({micro}g U/g of solution), but no density corrections were needed since all the samples (including the samples used for calibration) were in the same density matrix (1 M HNO{sub 3}). A statistical evaluation of the determination of uranium using kinetic phosphorimetry is described in this report, along with ...
Date: December 1, 1997
Creator: Croatto, P.V.; Frank, I.W.; Johnson, K.D.; Mason, P.B. & Smith, M.M.
Partner: UNT Libraries Government Documents Department