DOCSLIB.ORG

Europium in the Limelight

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Europium in the Limelight in your element Europium in the limelight Jean-Claude Bünzli sheds light on why europium — an element that is neither abundant in the Earth’s crust nor involved in biological processes — has nevertheless attracted a great deal of interest from chemists. he story starts at the end of the Paris (at that time, neither francium nor sensitive biomedical analyses that use nineteenth century, when gifted lutetium were known). Europium metal time-resolved luminescence. Such analyses Tscientists were systematically filling is now known to be highly reactive; the are routinely carried out in most hospitals in gaps in Mendeleev’s table by deciphering element’s most stable oxidation state is +3, and medical laboratories. Luminescent atomic optical spectra. Today this task but the +2 state also occurs in solid-state bioprobes based on europium and other seems rather easy, and could be carried out compounds and water. lanthanides are now ubiquitous in the life by undergraduate students. At the time, Georges Urbain, a brilliant young sciences, including bio-imaging. Fortunately, however, poorly performing instruments chemist who inherited Demarçay’s one kilogram of europium is sufficient for and difficulties in purifying samples spectroscopic equipment, observed in almost one billion analyses — which means were major hindrances. As a result, the 1906 a very bright red emission that these applications are not history of lanthanide discovery is full of for yttrium oxide doped with threatened by the shortage of incorrect claims and heated disputes among europium3. This was the start rare-earth elements feared by would-be discoverers. of a long career for europium industrialized nations after the The first, somewhat furtive, signal as an active component recent restrictions on exports by from element 63 was recorded in 1885 by in phosphorescent the Chinese government. Sir William Crookes, who found an materials — not only A recently anomalous red line (609 nm) in the as a red, but also a proposed application emission spectrum of a samarium blue emitter, because that could have sample. In 1892–3, Paul-Émile LeCoq de its reduced divalent far-reaching Boisbaudran — the discoverer of gallium, form (EuII) emits in this importance to the samarium and dysprosium — confirmed spectral range. Phosphors fast-growing world population the existence of this band and detected based on red EuIII, green is in agriculture. Plastics doped a further green band (535 nm). Enter TbIII and blue EuII emitters, with traces of divalent europium Eugène-Anatole Demarçay who, in 1896, or a combination thereof, and monovalent copper have after patient fractionation of samarium can convert UV radiation into been shown to efficiently convert oxide, determined the presence of a new visible light. These materials play the UV portion of solar energy into visible rare-earth element between samarium essential roles worldwide in applications light. This process is rather ‘green’ (the and gadolinium. He isolated it in 1901, such as X-ray-intensifying screens, complementary colour of red). Using these and ended the note in which he reported cathode-ray tube or plasma-display panels, plastics to cover greenhouses has enhanced this discovery with “I propose for the new and have also been used more recently in the amount of visible light received by element the name europium, with symbol energy-saving fluorescent lamps and light- plants, leading to crop yields roughly Eu, and atomic weight 151 (approx.)”1. emitting diodes. 10% higher. The reason why Demarçay decided on The luminescence of trivalent europium Such an increase could cover the growing this name remains a mystery. Interestingly, can also be sensitized by organic aromatic need for food over several decades without he was not affiliated to any university, molecules, making such complexes useful in expanding the cultivated surface — showing and had been running an independent a variety of highly sensitive applications such that europium is possibly heading towards laboratory after an unsuccessful application as security inks and bar codes. For example, another bright future. ❐ to the Academy of Sciences. He was a when the European Union launched its rather eclectic scientist who had dealt with single currency in 2002, the euro bills JEAN-CLAUDE BÜNZLI is at the Swiss organic, organometallic and inorganic were printed with an anticounterfeiting Federal Institute of Technology Lausanne chemistry before becoming a talented ink at least one component of which is (EPFL), CH-1015 Lausanne, Switzerland; spectroscopist. He had also toured several a europium phosphor, most probably a and at the Center for Next Generation countries to study their geology and tris(β-diketonate), yielding an orange–red Photovoltaic Systems, Korea University, culture2. It is plausible that this opening to emission under UV light. The greenish-blue ChungNam-do 339-700, South Korea. all aspects of chemistry and to the world emission from the same banknotes could e-mail: [email protected] led him to chose Europe over France or well arise from divalent europium but this is References mere conjecture. 1. Demarçay, A. E. C. R. Acad. Sci. Paris 132, 1484–1486 (1901) Since the beginning of the 1980s, 2. http://www.chem.unt.edu/Rediscovery/Demarcay.pdf europium has played a major role in highly 3. Urbain, G. C. R. Acad. Sci. Paris 142, 205–207 (1906). Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg 696 NATURE CHEMISTRY | VOL 2 | AUGUST 2010 | www.nature.com/naturechemistry © 2010 Macmillan Publishers Limited. All rights reserved.
Load more

Recommended publications
  • Historical Development of the Periodic Classification of the Chemical Elements
    THE HISTORICAL DEVELOPMENT OF THE PERIODIC CLASSIFICATION OF THE CHEMICAL ELEMENTS by RONALD LEE FFISTER B. S., Kansas State University, 1962 A MASTER'S REPORT submitted in partial fulfillment of the requirements for the degree FASTER OF SCIENCE Department of Physical Science KANSAS STATE UNIVERSITY Manhattan, Kansas 196A Approved by: Major PrafeLoor ii |c/ TABLE OF CONTENTS t<y THE PROBLEM AND DEFINITION 0? TEH-IS USED 1 The Problem 1 Statement of the Problem 1 Importance of the Study 1 Definition of Terms Used 2 Atomic Number 2 Atomic Weight 2 Element 2 Periodic Classification 2 Periodic Lav • • 3 BRIEF RtiVJiM OF THE LITERATURE 3 Books .3 Other References. .A BACKGROUND HISTORY A Purpose A Early Attempts at Classification A Early "Elements" A Attempts by Aristotle 6 Other Attempts 7 DOBEREBIER'S TRIADS AND SUBSEQUENT INVESTIGATIONS. 8 The Triad Theory of Dobereiner 10 Investigations by Others. ... .10 Dumas 10 Pettehkofer 10 Odling 11 iii TEE TELLURIC EELIX OF DE CHANCOURTOIS H Development of the Telluric Helix 11 Acceptance of the Helix 12 NEWLANDS' LAW OF THE OCTAVES 12 Newlands' Chemical Background 12 The Law of the Octaves. .........' 13 Acceptance and Significance of Newlands' Work 15 THE CONTRIBUTIONS OF LOTHAR MEYER ' 16 Chemical Background of Meyer 16 Lothar Meyer's Arrangement of the Elements. 17 THE WORK OF MENDELEEV AND ITS CONSEQUENCES 19 Mendeleev's Scientific Background .19 Development of the Periodic Law . .19 Significance of Mendeleev's Table 21 Atomic Weight Corrections. 21 Prediction of Hew Elements . .22 Influence
    [Show full text]
  • The Rare Earths II
    Redis co very of the Elements The Ra re Earth s–The Con fusing Years I A gallery of rare earth scientists and a timeline of their research I I James L. Marshall, Beta Eta 1971 , and Virginia R. Marshall, Beta Eta 2003 , Department of Chemistry, University of North Texas, Denton, TX 76203-5070, [email protected] The rare earths after Mosander. In the pre - vi ou s HEXAGON “Rediscovery” article, 1p we were introduced to the 17 rare earths, found in the f-block and the Group III chemical family of Figure 1. Important scientists dealing with rare earths through the nineteenth century. Johan Gadolin the Periodic Table. Because of a common (1760 –1852) 1g —discovered yttrium (1794). Jöns Jacob Berzelius (1779 –1848) and Martin Heinrich valence electron configuration, the rare earths Klaproth (1743 –1817) 1d —discovered cerium (1803). Carl Gustaf Mosander (1787 –1858) 1p —discovered have similar chemical properties, and their lanthanum (1839), didymium (1840), terbium, and erbium (1843). Jean-Charles deGalissard Marignac chemical separation from one another can be (1817 –1894) 1o —discovered ytterbium (1878) and gadolinium (1880). Per Teodor Cleve (1840 –1905) 1n — difficult. From preparations of the first two rare discovered holmium and thulium (1879). Lars Fredrik Nilson (1840 –1899) 1n —discovered scandium earth element s—yttrium and ceriu m—the (1879). Paul-Émile Lecoq de Boisbaudran (1838 –1912) —discovered samarium (1879) and dysprosium Swedish chemist Carl Gustaf Mosander (Figure (1886). 1b Carl Auer von Welsbach (1858 –1929) 1c —discovered praseodymium and neodymium (1885); 1, 2) was able to separate four additional ele - co-discovered lutetium (1907).
    [Show full text]
  • Sterns Lebensdaten Und Chronologie Seines Wirkens
    Sterns Lebensdaten und Chronologie seines Wirkens Diese Chronologie von Otto Sterns Wirken basiert auf folgenden Quellen: 1. Otto Sterns selbst verfassten Lebensläufen, 2. Sterns Briefen und Sterns Publikationen, 3. Sterns Reisepässen 4. Sterns Züricher Interview 1961 5. Dokumenten der Hochschularchive (17.2.1888 bis 17.8.1969) 1888 Geb. 17.2.1888 als Otto Stern in Sohrau/Oberschlesien In allen Lebensläufen und Dokumenten findet man immer nur den VornamenOt- to. Im polizeilichen Führungszeugnis ausgestellt am 12.7.1912 vom königlichen Polizeipräsidium Abt. IV in Breslau wird bei Stern ebenfalls nur der Vorname Otto erwähnt. Nur im Emeritierungsdokument des Carnegie Institutes of Tech- nology wird ein zweiter Vorname Otto M. Stern erwähnt. Vater: Mühlenbesitzer Oskar Stern (*1850–1919) und Mutter Eugenie Stern geb. Rosenthal (*1863–1907) Nach Angabe von Diana Templeton-Killan, der Enkeltochter von Berta Kamm und somit Großnichte von Otto Stern (E-Mail vom 3.12.2015 an Horst Schmidt- Böcking) war Ottos Großvater Abraham Stern. Abraham hatte 5 Kinder mit seiner ersten Frau Nanni Freund. Nanni starb kurz nach der Geburt des fünften Kindes. Bald danach heiratete Abraham Berta Ben- der, mit der er 6 weitere Kinder hatte. Ottos Vater Oskar war das dritte Kind von Berta. Abraham und Nannis erstes Kind war Heinrich Stern (1833–1908). Heinrich hatte 4 Kinder. Das erste Kind war Richard Stern (1865–1911), der Toni Asch © Springer-Verlag GmbH Deutschland 2018 325 H. Schmidt-Böcking, A. Templeton, W. Trageser (Hrsg.), Otto Sterns gesammelte Briefe – Band 1, https://doi.org/10.1007/978-3-662-55735-8 326 Sterns Lebensdaten und Chronologie seines Wirkens heiratete.
    [Show full text]
  • Rounding up Lutetium Lars Öhrström Suspects That As Time Goes By, We May See More of Lutetium — the Last of the Lanthanoids
    in your element Rounding up lutetium Lars Öhrström suspects that as time goes by, we may see more of lutetium — the last of the lanthanoids. e’ll always have Paris” Rick says motexafin (based on the ‘texaphyrins’), a “ to Ilsa in their final goodbye on sub-class of porphyrin-like macrocycles Wthe foggy airstrip of Casablanca with five instead of four nitrogen atoms in in the eponymous film. However, the an approximately planar ring. Motexafin question among chemists about the element lutetium, which features Lu3+ and two lutetium, named after Lutetia, as the French acetate counter-ions coordinated on either capital was known in Roman times, is not so side of the macrocycle, is potentially a good much about having it (it is more abundant photosensitizer in dynamic phototherapy than silver in the Earth’s crust), but rather and has been going through phase I trials where to place it on the map. against prostate cancer2. With its valence electron configuration Uses of the naturally occurring element [Xe]4f 146s25d1, element 71 seems to belong are otherwise scarce, but its isotope Lu-177 is to group 3, but we often see it placed at successfully used in experimental and clinical BRITTA LANGEN, BRITTA SWEDEN UNIVERSITY OF GOTHENBURG, the very end of the lanthanoid series. Its treatments against some severe cancers by downstairs neighbour lawrencium, for which Illustration of a radiolabelled somatostatin hooking it up to a tetraazacyclododecane- experimental data are much more difficult to analogue built using PyMOL (https://pymol.org) tetraacetate (DOTA) ligand grafted to obtain, is in the same ambiguous situation.
    [Show full text]
  • Alpha-Decay Half-Life of Hafnium Isotopes Reinvestigated by a Semi-Empirical Approach∗
    Alpha-decay half-life of Hafnium isotopes reinvestigated by a semi-empirical approach∗ O.A.P. Tavares a, E.L. Medeiros a,y, and M.L. Terranova b aCentro Brasileiro de Pesquisas F´ısicas- CBPF/MCTIC Rua Dr. Xavier Sigaud 150, 22290-180 Rio de Janeiro-RJ, Brazil bDipartimento di Science e Tecnologie Chimiche Universit`adegli Studi di Roma \TorVergata" via dela Ricerca Scientifica s/n, 00133 Roma, Italy 156{162;174;176 Abstract - New estimates of partial α-decay half-life, T1=2, for Hf isotopes by a semi- empirical, one-parameter model are given. The used model is based on the quantum mechanical tunneling mechanism through a potential barrier, where the Coulomb, centrifugal and overlapping components to the barrier have been considered within the spherical nucleus approximation. This approach enables to reproduce, within a factor 2, the measured T1=2 of ground-state to ground- state (gs{gs) α-transitions for the artificially produced 156{162Hf isotopes. Half-life predictions for α-transitions from the ground-state of 159;161Hf isotopes to the first gamma-excited level of 155;157Yb 16 isotopes are reported for the first time. The model also provides T1=2-values of (2:43 ± 0:28) × 10 a and (1:47 ± 0:19) × 1020 a for the naturally occurring 174Hf and 176Hf isotopes, respectively, in quite good agreement with a number of estimates by other authors. In addition, the present methodology indicates that 174;176Hf isotopes exhibit α-transition to the first gamma-excited level of their daughter Ytterbium isotopes which half-lives are found (0:9±0:1)×1018 a and (0:72±0:08)×1022 a, respectively, with a chance of being measured by improved α-detection and α-spectrometry methods available nowadays.
    [Show full text]
  • Hexagon Fall
    Redis co very of the Elements The Rare Earth s–The Beginnings I I I James L. Marshall, Beta Eta 1971 , and Virginia R. Marshall, Beta Eta 2003 , Department of Chemistry, University of North Texas, Denton, TX 76203-5070, [email protected] 1 Rare earths —introduction. The rare earths Figure 1. The “rare earths” are defined by IUPAC as the 15 lanthanides (green) and the upper two elements include the 17 chemically similar elements of the Group III family (yellow). These elements have similar chemical properties and all can exhibit the +3 occupying the f-block of the Periodic Table as oxidation state by the loss of the highest three electrons (two s electrons and either a d or an f electron, well as the Group III chemical family (Figure 1). depending upon the particular element). A few rare earths can exhibit other oxidation states as well; for These elements include the 15 lanthanides example, cerium can lose four electrons —4f15d 16s 2—to attain the Ce +4 oxidation state. (atomic numbers 57 through 71, lanthanum through lutetium), as well as scandium (atomic number 21) and yttrium (atomic number 39). The chemical similarity of the rare earths arises from a common ionic configuration of their valence electrons, as the filling f-orbitals are buried in an inner core and generally do not engage in bonding. The term “rare earths” is a misnome r—these elements are not rare (except for radioactive promethium). They were named as such because they were found in unusual minerals, and because they were difficult to separate from one another by ordinary chemical manipula - tions.
    [Show full text]
  • Periodic Table 1 Periodic Table
    Periodic table 1 Periodic table This article is about the table used in chemistry. For other uses, see Periodic table (disambiguation). The periodic table is a tabular arrangement of the chemical elements, organized on the basis of their atomic numbers (numbers of protons in the nucleus), electron configurations , and recurring chemical properties. Elements are presented in order of increasing atomic number, which is typically listed with the chemical symbol in each box. The standard form of the table consists of a grid of elements laid out in 18 columns and 7 Standard 18-column form of the periodic table. For the color legend, see section Layout, rows, with a double row of elements under the larger table. below that. The table can also be deconstructed into four rectangular blocks: the s-block to the left, the p-block to the right, the d-block in the middle, and the f-block below that. The rows of the table are called periods; the columns are called groups, with some of these having names such as halogens or noble gases. Since, by definition, a periodic table incorporates recurring trends, any such table can be used to derive relationships between the properties of the elements and predict the properties of new, yet to be discovered or synthesized, elements. As a result, a periodic table—whether in the standard form or some other variant—provides a useful framework for analyzing chemical behavior, and such tables are widely used in chemistry and other sciences. Although precursors exist, Dmitri Mendeleev is generally credited with the publication, in 1869, of the first widely recognized periodic table.
    [Show full text]
  • Europium-Doped Phosphors for Lighting: the Past, the Present and the Future
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Ghent University Academic Bibliography Europium-doped phosphors for lighting: the past, the present and the future Dirk Poelman*, Philippe F. Smet Lumilab, Dept. Solid State Sciences, Ghent University, Krijgslaan 281/S1, B-9000 Gent, Belgium *[email protected] The past Europium, the 63rd element of the periodic table, was isolated and identified as one of the last in the rare earth series by Eugène-Anatole Demarçay in 1901, and named after the European continent. Europium does not occur as a metallic element in nature, as it readily oxidizes. It is found in small quantities (of the order of 1 ppm) in the earth crust. It is mined from a few minerals, where the Eu-content can reach a few tenths of % [1]. Fluorite (CaF2), a mineral which is widely found in nature, has been known to be luminescent since early times, and gave its name to the process of fluorescence. A specific mine in England, the Blue John Cavern, was known for its blue fluorescing fluorite crystals [2]. Later, it was found that not the CaF2 itself is luminescent, but rather the Eu2+ ions which are incorporated as impurities in the crystals are responsible for the blue fluorescence. Therefore, the history of Eu-doped phosphors dates back thousands of years. 3+ When in the 1960s, europium-doped yttrium orthovanadate (YVO4:Eu ) was developed as a red phosphor, this formed the breakthrough of color television: until then, no bright phosphors were available for the red 3+ component of CRTs.
    [Show full text]
  • Europium-DTPA: a Gadolinium Analogue Traceable by Fluorescence Microscopy
    1137 Dyke Award Europium-DTPA: A Gadolinium Analogue Traceable by Fluorescence Microscopy Allen D. Elster1 A lanthanide series chelate, europium(Eu)-DTPA, was synthesized to serve as a Susan C. Jackels2 histochemical analogue for the widely used MR contrast agent gadolinium(Gd)-DTPA. Nina S. Allen3 Eu and Gd, being neighboring elements on the periodic table, share many fundamental Ron C. Marrache2 properties, including ionic radius, valence, and chemical reactivity. Eu-DTPA, however, possesses one important physical property not shared by Gd-DTPA: luminescence under ultraviolet light. The feasibility of detecting Eu-DTPA in animal tissues under fluorescence microscopy was systematically evaluated and documented. Distinctive orange-red luminescence of Eu-DTPA could be observed in the kidneys, livers, dura, choroid, and pituitary glands of rats after intravascular injection. No lumi­ nescence was detected in areas of brain beyond an intact blood-brain barrier. When the brain was locally injured by an experimental laceration, however, leakage of Eu-DTPA was detected. Electron probe microanalysis confirmed the parallel presence or absence of simultaneously injected Eu-DTPA and Gd-DTPA in all tissues studied. Fluorescence microscopy with Eu-DTPA has thus been validated as a method for tracing the distri­ bution of Gd-DTPA at the microscopic level. AJNR 10:1137-1144, November/December 1989 The recent development of paramagnetic MR contrast agents such as gadolinium (Gd)-DTPA has been received by the radiologic community with justifiable enthu­ siasm. Like their iodinated counterparts in CT, MR contrast agents appear to offer increased sensitivity and specificity for detecting and characterizing a number of diseases affecting the nervous system [1-11 ].
    [Show full text]
  • Separation of Radioactive Elements from Rare Earth Element-Bearing Minerals
    metals Review Separation of Radioactive Elements from Rare Earth Element-Bearing Minerals Adrián Carrillo García 1, Mohammad Latifi 1,2, Ahmadreza Amini 1 and Jamal Chaouki 1,* 1 Process Development Advanced Research Lab (PEARL), Chemical Engineering Department, Ecole Polytechnique de Montreal, C.P. 6079, Succ. Centre-ville, Montreal, QC H3C 3A7, Canada; [email protected] (A.C.G.); mohammad.latifi@polymtl.ca (M.L.); [email protected] (A.A.) 2 NeoCtech Corp., Montreal, QC H3G 2N7, Canada * Correspondence: [email protected] Received: 8 October 2020; Accepted: 13 November 2020; Published: 17 November 2020 Abstract: Rare earth elements (REE), originally found in various low-grade deposits in the form of different minerals, are associated with gangues that have similar physicochemical properties. However, the production of REE is attractive due to their numerous applications in advanced materials and new technologies. The presence of the radioactive elements, thorium and uranium, in the REE deposits, is a production challenge. Their separation is crucial to gaining a product with minimum radioactivity in the downstream processes, and to mitigate the environmental and safety issues. In the present study, different techniques for separation of the radioactive elements from REE are reviewed, including leaching, precipitation, solvent extraction, and ion chromatography. In addition, the waste management of the separated radioactive elements is discussed with a particular conclusion that such a waste stream can be
    [Show full text]
  • Europium Oxide As a Perfect Electron Spin Filter by Tiffany S
    Europium Oxide as a Perfect Electron Spin Filter by Tiffany S. Santos S.B., Materials Science and Engineering, Massachusetts Institute of Technology, 2002 Submitted to the Department of Materials Science and Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy of Materials Science and Engineering at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY June 2007 @ Massachusetts Institute of Technology 2007. All rights reserved. Author. ...... .. ... .. ... ....... Department of Materials Science and Engineering /3 A0 May 17, 2007 Certified by ...... ... , .... .... ........ ... Dr. Jagadeesh Moodera Senior Research Scientist and Group Leader a .- Thesis Supervisor Certified by ............... .. .. ............ ... Prof. Caroline Ross Professor of Materials Science and Engineering Thesis Supervisor Accepted by... .......................... Prof. Samuel Allen Chairman, Departmental Committee on Graduate Students MASSACHUSETTS INSTriUTE. OF TECHNOLOGY JUL 0 5 2007 ARCHNES LIBRARIES Europium Oxide as a Perfect Electron Spin Filter by Tiffany S. Santos Submitted to the Department of Materials Science and Engineering on May 17, 2007, in partial fulfillment of the requirements for the degree of Doctor of Philosophy of Materials Science and Engineering Abstract Essential to the emergence of spin-based electronics is a source of highly polarized elec- tron spins. Conventional ferromagnets have at best a spin polarization P~50%. Europium monoxide is a novel material capable of generating a highly spin-polarized current when used as a tunnel barrier. EuO is both a Heisenberg ferromagnet (Tc=69 K) and a semiconductor. Exchange splitting of the conduction band creates different tunnel barrier heights for spin-up and spin-down electrons, thus filtering the spins during tunneling. High-quality EuO films at the monolayer level is necessary for efficient spin-filtering.
    [Show full text]
  • BNL-79513-2007-CP Standard Atomic Weights Tables 2007 Abridged To
    BNL-79513-2007-CP Standard Atomic Weights Tables 2007 Abridged to Four and Five Significant Figures Norman E. Holden Energy Sciences & Technology Department National Nuclear Data Center Brookhaven National Laboratory P.O. Box 5000 Upton, NY 11973-5000 www.bnl.gov Prepared for the 44th IUPAC General Assembly, in Torino, Italy August 2007 Notice: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The publisher by accepting the manuscript for publication acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. This preprint is intended for publication in a journal or proceedings. Since changes may be made before publication, it may not be cited or reproduced without the author’s permission. DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or any third party’s use or the results of such use of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof or its contractors or subcontractors.
    [Show full text]