DOCSLIB.ORG

Isotopes, Interfaces, and Geochemical Transformations August 7-8, 2017 Geosciences Research Program, Office of Basic Energy Sciences

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Isotopes, Interfaces, and Geochemical Transformations August 7-8, 2017 Geosciences Research Program, Office of Basic Energy Sciences Shining New Light on the Structure and Crystallization of Amorphous (Basic) Calcium Carbonate Novel synthesis: Scientific Achievement Rate of mixing is the key For the first time, the locations and hydrogen- bonded network in amorphous (basic) calcium carbonate, A(B)CC, have been measured directly using neutron diffraction on deuterated reactants and the key role that water and hydroxide play in stabilizing and controlling the A(B)CC structure has been revealed. Significance and Impact A(B)CC to calcite & portlandite crystallization This work provides insights into controlling the synthesis, crystallization and polymorphous state of A(B)CC and the roles of water and dissolved species. Research Details − Novel synthesis based on kinetically controlled Bound D2O/OD species are captured by Neutron PDF processes and fast centrifugal mixing of solutions − In situ neutron diffraction used to follow the crystallization pathway Wang, H.-W.; Daemen, L.L.; Cheshire, C.C.; Kidder, M.K.; Stack, A.G.; Allard, L.F.; − Neutron Pair Distribution Functions (PDF) showed Neuefeind, J.; Olds, D.; Liu, J; Page, K. Synthesis and Structure of Synthetically Pure and superior sensitivity to pairs involving deuterium and Deuterated Amorphous (Basic) Calcium Carbonates. Chem. Comm. 2017, 53, 2492-2495. carbon FOREWORD “Isotopes, Interfaces, and Geochemical Transformations” is the 22nd in a series of Geosciences Research Program Symposia dating from 1995. These symposia are topically focused meetings for principal investigators in the program and provide opportunities for our investigators to give presentations on their BES-supported research. It is hoped that this meeting will provide an environment conducive to building collaborations and identifying opportunities for new research directions. In addition to seven topical sessions, this year’s program has a poster session and an invited evening talk to be given by Prof. Woody Fischer of Caltech. I would like to thank this year’s Session Chairs: Bill Casey (UC Davis), Ian Bourg (Princeton), Sue Brantley (Penn State), Dave Dixon (Alabama), Paul Fenter (Argonne), Mike Hochella (Virginia Tech/PNNL), and Arndt Schimmelmann (Indiana). I would also like to thank Diane Marceau of the Chemical Sciences, Geosciences, and Biosciences (CSGB) Division and Connie Lansdon of the Oak Ridge Institute for Science and Educations (ORISE) for their excellent contributions in organizing the technical and logistical aspects of this meeting. Finally, I thank all the scientists whose vision and creativity in research and dedication and thoughtfulness in peer review have shaped the ongoing research mission of the Office of Basic Energy Sciences Geosciences Program. Looking forward to an outstanding series of presentations. Jim Rustad Geosciences Research Program Office of Basic Energy Sciences US Department of Energy Cover Images Top left: Molecular-level simulation of aggregated gibbsite particles, Greathouse et al. Sandia National Laboratories. •– •– 3- Top right: Photo-redox generation of C2O4 and CO2 in Fe(C2O4)3 Gilbert et al., Lawrence Berkeley National Lab and Pacific Northwest National Laboratory. Middle: Ion microprobe transect of 18O isotope variation in diagenetic carbonate cement. Valley et al., University of Wisconsin. Bottom left: Dynamics of rubidium sorption observed with time-resolved resonant anomalous x-ray reflectivity. Lee et al., Argonne National Laboratory. Bottom right: Neutron diffraction has been used to study the structure of amorphous calcium carbonate and its transformation to calcite, portlandite and lime. Stack et al. Oak Ridge National Laboratory. Agenda 2017 Geosciences Program PI Meeting U.S. Department of Energy Office of Basic Energy Sciences Chemical Sciences, Geosciences & Biosciences Division (CSGB) Sunday Aug 6 4:00-6:00 pm Registration (if you miss this, you may register in the morning) 8:00-11:00 pm Informal and optional no-host reception at the Black Olive Bar & Grill (in the National Conference Center facility) Monday Aug 7 7:00 am Breakfast 7:55 am Welcome, Jim Rustad, BES Geosciences Program Manager 8:00 am BES/CSGB Update and Outlook Bruce Garrett, CSGB Division Director Session 1 New Measurements in Isotope Geochemistry Bill Casey, Session Chair 8:30 am Isotopic structures of natural organic molecules John Eiler, Caltech 9:00 am Intra-molecular isotope study of light hydrocarbons Juske Horita, Texas Tech 9:30 am In situ microanalysis of O & C isotope ratios in carbonate cements: SIMS standardization and preliminary data from the Bakken formation John Valley, University of Wisconsin 10:00 am Break Session 2 Interfacial and Isotope Geochemistry Ian Bourg, Session Chair 10:30 am Controls on the isotopic composition and Mg/Ca of calcite Don DePaolo, Lawrence Berkeley National Laboratory 11:00 am Electrochemical kinetic isotope fractionation: theory and experiments Abby Kavner, UCLA 11:30 am Clumped isotope signatures in carbonate minerals Aradhna Tripati, UCLA 12:00 pm Lunch Monday Aug 7 (cont.) Session 3 Mineral and Surface Energetics Sue Brantley, Session Chair 1:30 pm Energetics of water, carbon dioxide, and ethanol adsorption on mineral surfaces Alex Navrotsky, UC Davis 2:00 pm Calorimetric insights into mineral-water interfaces: deciphering the anatomy of an enthalpy Nadine Kabengi, Georgia State 2:30 pm Ab initio thermodynamics of hydrated Mg and Ca carbonates Anne Chaka, Pacific Northwest National Laboratory 3:00 pm Break Session 4 3:30 pm Geosciences Program notes Jim Rustad, BES Geosciences Program Manager 4:00 pm Poster Session 6:00 pm Dinner 7:30 pm Invited Keynote Lecture Manganese and the development of photosynthesis Woody Fischer, Caltech Tuesday Aug 8 7:30 am Breakfast Session 5 Crystal Growth Dave Dixon, Session Chair 8:30 am Particle mediated growth of iron oxides Jim De Yoreo, Pacific Northwest National Laboratory 9:00 am Kinetics and thermodynamics of CaCO3 nucleation in an organic matrix Trish Dove, Virginia Tech 9:30 am Crystallization by particle attachment (CPA) in biominerals Pupa Gilbert, University of Wisconsin 10:00 Break Tuesday Aug 8 (cont.) Session 6 Mineral-Water Interfaces Paul Fenter, Session Chair 10:30 am Interfacial geochemistry of nanopores: Molecular behavior in subsurface environments Jeff Greathouse, Sandia National Laboratory 11:00 am Real-time observations of cation exchange at the muscovite (001) – water interface Sang Soo Lee, Argonne National Laboratory 2+ 11:30 am Comparison of H2O and Sr positions on barite {001} studied by atomic-scale simulation and X-ray scattering Jim Kubicki, University of Texas, El Paso 12:00 pm Lunch Session 7 Redox Processes Jim Rustad, Session Chair 1:30 pm Unraveling interfacial atom and electron exchange mechanisms in Fe(II)- catalyzed iron oxide recrystallization Kevin Rosso, Pacific Northwest National Laboratory 2:00 pm Kinetics of redox reactions of actinides on semiconducting minerals, as well as studtite and U60 clusters Udo Becker, University of Michigan 2:30 pm Iron redox and photo-redox reaction mechanism from time-resolved spectroscopy Ben Gilbert, Lawrence Berkeley National Laboratory 3:00 pm Break Session 8 Geochemical Transformations Arndt Schimmelmann, Session Chair 3:30 pm Diffusion and solubility of volatiles in cryptocrystalline materials and simple oxides: CO2 and N2 in chert and C isotopes in polycrystalline MgO Bruce Watson, Rensselaer Polytechnic Institute 4:00 pm Nanoscale stress-corrosion of silicate glass in aqueous solutions Louise Criscenti, Sandia National Laboratory 4:30 pm Insights into geochemical transformations probed by examining solution and solid phase structures using neutron diffraction and atomic-scale simulation Andrew Stack, Oak Ridge National Laboratory 5:00 pm Closing, Jim Rustad, DOE/OBES Posters Piotrek Zarzycki, Lawrence Berkeley National Laboratory Reactive molecular dynamics as a unique tool for understanding reactivity of mineral surfaces: Fe(II)-catalyzed recrystallization of goethite Paul Fenter, Argonne National Laboratory Imaging complex reactions at mineral-water interfaces Arndt Schimmelmann, Indiana University Genesis, storage, producibility, and natural leakage of shale gas Sue Brantley, Pennsylvania State University Investigating the roughness and advance rate of the weathering interface: shale, schist, diabase, granite, volcaniclastics, and serpentinite Dave Dixon, University of Alabama Computational studies of geochemical nanoparticles: A bottom-up approach Bill Casey, UC Davis An NMR probe for solution spectroscopy at geochemical pressures Mike Hochella, Virginia Tech New light shed on important Earth-relevant redox reactions observed at the nanoscale Ian Bourg, Princeton Stern layer structure and energetics at mica-water interfaces Vitaliy Starchenko, Oak Ridge National Laboratory Simulation of fracture dissolution in rocks: A 3D approach Anastasia Ilgen, Sandia (Jeff Greathouse/Louise Criscenti presenting) Adsorption of copper and iron on mesoporous alumina and silica Yuxin Wu, Lawrence Berkeley National Laboratory Geophysical methods for geochemical and hydrological process at mineral-water interfaces of geological media Isotopic structures of natural organic molecules John Eiler, Caltech We are in a period of remarkable innovation of the technologies, methods and fields of application of measurements of isotopic contents of natural and synthetic materials. Arguably the most complex and quickly changing part of
Recommended publications
  • ESD Distinguished Scientist Seminar Series

    ESD Distinguished Scientist Seminar Series

    94720 Berkeley, CA Road One Cyclotron Laboratory National Berkeley Lawrence Earth SciencesDivision DIRECTIONS By BART Take the Richmond line to the downtown Berkeley exit -- not the North Berkeley exit, and not the Ashby exit, just the Berkeley exit. Get off at the Berkeley exit, go up to the street level, and find our shuttle bus stop. It is on the north side of Center Street at its intersection with Shattuck Avenue next to the bank automatic teller machine. By LBNL Bus You can then take the shuttle bus to the Lab. ESD Distinguished Please note, visitors are required to bring visitor bus pass (can be requested through Visitor Pass Scientist Seminar site https://visitorpass.lbl.gov/public_html/login.jsp), Series email, or permission from lab host written on department letterhead. Please contact Yingying Kooyman at 510-486-4539 or at Topic: Investigating the physical basis [email protected] for details. of biomineralization Speaker: Patricia Dove By Car Virginia Tech Take Highway 80 to the University Avenue exit. 10:30 AM-12:00 noon Drive east on University Avenue until Oxford Bldg. 50 Auditorium Street. Turn left on Oxford. Go two blocks to Hearst Street. Turn right on Hearst until you hit Friday, January 15, 2010 LBNL. Lawrence Berkeley National Laboratory For inquiries, please contact: Caption describing picture or graphic. Yingying Kooyman 510-486-4539 Web site: http://esdnews.wordpress.com/distinguished- scientist-seminar-series/ ABSTRACT BIOGRAPHICAL SKETCH SCHEDULE The ability of organisms to mineralize Patricia M. Dove is a Professor of tissues into skeletons and other Geochemistry in the Department of functional structures is a crowning Geosciences at Virginia Tech.
  • 4 Nuclear Magnetic Resonance

    4 Nuclear Magnetic Resonance

    Chapter 4, page 1 4 Nuclear Magnetic Resonance Pieter Zeeman observed in 1896 the splitting of optical spectral lines in the field of an electromagnet. Since then, the splitting of energy levels proportional to an external magnetic field has been called the "Zeeman effect". The "Zeeman resonance effect" causes magnetic resonances which are classified under radio frequency spectroscopy (rf spectroscopy). In these resonances, the transitions between two branches of a single energy level split in an external magnetic field are measured in the megahertz and gigahertz range. In 1944, Jevgeni Konstantinovitch Savoiski discovered electron paramagnetic resonance. Shortly thereafter in 1945, nuclear magnetic resonance was demonstrated almost simultaneously in Boston by Edward Mills Purcell and in Stanford by Felix Bloch. Nuclear magnetic resonance was sometimes called nuclear induction or paramagnetic nuclear resonance. It is generally abbreviated to NMR. So as not to scare prospective patients in medicine, reference to the "nuclear" character of NMR is dropped and the magnetic resonance based imaging systems (scanner) found in hospitals are simply referred to as "magnetic resonance imaging" (MRI). 4.1 The Nuclear Resonance Effect Many atomic nuclei have spin, characterized by the nuclear spin quantum number I. The absolute value of the spin angular momentum is L =+h II(1). (4.01) The component in the direction of an applied field is Lz = Iz h ≡ m h. (4.02) The external field is usually defined along the z-direction. The magnetic quantum number is symbolized by Iz or m and can have 2I +1 values: Iz ≡ m = −I, −I+1, ..., I−1, I.
  • Effect of Electronegative Elements on the NMR Chemical Shift in Some Simple R-X Organic Compounds

    Effect of Electronegative Elements on the NMR Chemical Shift in Some Simple R-X Organic Compounds

    IOSR Journal of Applied Physics (IOSR-JAP) e-ISSN: 2278-4861.Volume 6, Issue 4 Ver. III (Jul-Aug. 2014), PP 45-56 www.iosrjournals.org Effect of electronegative elements on the NMR chemical shift in some simple R-X organic compounds Muhammad A. AL-Jalali1, Yahia M. Mahzia2 1Physics Department, Faculty of Science, Taif University, Taif, AL-Haweiah, , P. O. Box 888, Zip code 21974, Kingdom of Saudi Arabia 2Physics Department, Faculty of Science, Damascus University, Damascus, Syrian Arab Republic. Abstract: Organic halides and other organic compounds that contain electronegative elements, have a strong chemical shift and a brilliant NMR spectrum will prevail. Relationship between 1H, 13C NMR chemical shift and Electronegativity in some simple R-X organic compounds (X=F, Cl, Br, I, O, H, ...R=CH3 or CH3-CH2-) give nonlinear equation, as well as a power series equation appears between nuclear magnetogyric ratio, magnetic shielding constant and chemical shift, which are not included in the theoretical expressions. More investigations required to remove the discrepancy between the theoretical and the experimental results. Keywords: Electronegativity, chemical shift, shielding constant, magnetogyric ratio. I. Introduction Nuclear magnetic resonance, or NMR is a physical phenomenon was observed in 1945[1,2], which occurs when the nuclei of certain atoms, firstly, subject to nuclear Zeeman effect[3,4,5]will Precession with the Larmor frequency [6, 7]. Secondly, exposed to an oscillating electromagnetic field (radio waves), then if the radio wave frequency exactly matches the precession frequency, the resonance phenomenon will happen and this is the so-called nuclear magnetic resonance. However, experimentally, it has been noticed [8, 9, 10] that a nucleus may have a different resonant frequency for a given applied magnetic field in different chemical compounds, this difference in resonant frequency is called the chemical shift or sometimes fine structure.
  • The Chemical Shift Chem 117 the Chemical Shift Key Questions (1) What Controls Proton Chemical Shifts? Eugene E

    The Chemical Shift Chem 117 the Chemical Shift Key Questions (1) What Controls Proton Chemical Shifts? Eugene E

    E. Kwan Lecture 2: The Chemical Shift Chem 117 The Chemical Shift Key Questions (1) What controls proton chemical shifts? Eugene E. Kwan January 26, 2012. H H H H 0.86 ppm 5.28 2.88 Br Scope of Lecture 16.4 proton chemical problem shift trends diamagnetic vs. (2) What controls carbon chemical shifts? solving paramagnetic O O shielding O CH2 H C OH the chemical 3 H3C CH3 basic DEPT 49.2 49.2 40.5 69.2 and COSY shift H-bonding and solvent (3) What are COSY and DEPT? What useful information effects spin-orbit coupling, can they give about a structure? carbon chemical effect of unsaturation shift trends 123 Helpful References 10 0 1. Nuclear Magnetic Resonance Spectroscopy... Lambert, J.B.; 1 Mazzola, E.P. Prentice-Hall, 2004. (Chapter 3) 2 2. The ABCs of FT-NMR Roberts, J.D. University Science Books, 2000. (Chapter 10) 3 3. Spectrometric Identification of Organic Compounds (7th ed.) Silverstein, R.M.; Webster, F.X.; Kiemle, D.J. Wiley, 2005. (useful charts in the appendices of chapters 2-4) 10 4. Organic Structural Spectroscopy Lambert, J.B.; Shurvell, H.F.; Lightner, D.A.; Cooks, R.G. Prentice-Hall, 1998. I thank Professors William F. Reynolds (Toronto) and Gene Mazzola (Maryland/FDA) for providing some useful 5. Organic Structure Analysis Crews, P. Rodriguez, J.; Jaspars, material for this lecture. The section on chemical shifts M. Oxford University Press, 1998. is based on the discussion in Chapter 3 of reference 1. E. Kwan Lecture 2: The Chemical Shift Chem 117 Proton Chemical Shifts Clearly, the regions overlap: reference: Lambert and Mazzola, Chapter 3.
  • NMR Chemical Shifts of Common Laboratory Solvents As Trace Impurities

    NMR Chemical Shifts of Common Laboratory Solvents As Trace Impurities

    7512 J. Org. Chem. 1997, 62, 7512-7515 NMR Chemical Shifts of Common Laboratory Solvents as Trace Impurities Hugo E. Gottlieb,* Vadim Kotlyar, and Abraham Nudelman* Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900, Israel Received June 27, 1997 In the course of the routine use of NMR as an aid for organic chemistry, a day-to-day problem is the identifica- tion of signals deriving from common contaminants (water, solvents, stabilizers, oils) in less-than-analyti- cally-pure samples. This data may be available in the literature, but the time involved in searching for it may be considerable. Another issue is the concentration dependence of chemical shifts (especially 1H); results obtained two or three decades ago usually refer to much Figure 1. Chemical shift of HDO as a function of tempera- more concentrated samples, and run at lower magnetic ture. fields, than today’s practice. 1 13 We therefore decided to collect H and C chemical dependent (vide infra). Also, any potential hydrogen- shifts of what are, in our experience, the most popular bond acceptor will tend to shift the water signal down- “extra peaks” in a variety of commonly used NMR field; this is particularly true for nonpolar solvents. In solvents, in the hope that this will be of assistance to contrast, in e.g. DMSO the water is already strongly the practicing chemist. hydrogen-bonded to the solvent, and solutes have only a negligible effect on its chemical shift. This is also true Experimental Section for D2O; the chemical shift of the residual HDO is very NMR spectra were taken in a Bruker DPX-300 instrument temperature-dependent (vide infra) but, maybe counter- (300.1 and 75.5 MHz for 1H and 13C, respectively).
  • Robert N. Ulrich

    Robert N. Ulrich

    Robert N Ulrich 595 Charles E Young Drive East, Slichter Hall RM 2855 Los Angeles, CA 90095 [email protected] — https://www.robertnulrich.com/ — (703) 851-7276 Education University of California, Los Angeles September 2017 – Present Ph.D., Geochemistry Virginia Polytechnic Institute and State University August 2013 – May 2017 B.S., Chemistry B.S., Geosciences Honors and Awards National Science Foundation Graduate Research Fellow Fall 2018 - Present Reclaiming STEM Cohort Member (Inaugural class) Summer 2018 - Present Center for Diverse Leadership in Science Graduate Fellow Summer 2018 - Present COACh Travel Scholarship ($800) Fall 2018 Point Foundation Scholarship Semifinalist Spring 2018 Scientist Biography feature in book for Pearson Education’s Elevate Science California Program Fall 2017 Short biography in new textbooks to showcase scientists from underrepresented groups and their research UCLA Office of Instructional Development Mini-grant ($250) Fall 2017 To help pay for transportation to take students on a field trip for Env Sci M10 – Introduction to Environmental Science UCLA Graduate Division Fellowship Award ($10,000) Fall 2017 Thomas T. Jeffries Endowed Fund Scholarship ($1,000) Spring 2016 Dean’s List All semesters 2014 - 2017 Research Experience University of California, Los Angeles – Advisor, Dr. Aradhna Tripati (current projects) September 2017 – Present Graduate Student Researcher, Using multiple geochemical tracers to shed light on a newly-discovered major mineral formation pathway for biominerals Purpose: To determine
  • 2013 Annual VAS & VJAS Meetings at Virginia Polytechnic Institute And

    2013 Annual VAS & VJAS Meetings at Virginia Polytechnic Institute And

    Volume XXIII, Issue 2 September-October, 2013 2013 Annual VAS & VJAS Meetings at Virginia Polytechnic Institute and State University Virginia Tech President, Charles W. Steger, and Senior Vice President and Provost, Mark McNamee, welcomed attendees at the 91st VAS and 72nd VJAS Annual Meetings with warm hospitality and exciting STEM offerings, May 21-24, 2013. Special thanks go to the Local Ar- rangements Committee Co-Chairs, Peter Kennelly and Ashley Roberts, her capable staff, and everyone at Tech who contributed their time, effort, expertise, and financial support to make this event a success. Virginia Tech faculty provided one of many highlights; almost every Tech undergraduate and graduate STEM pro- Virginia Tech ,President, gram was represented in the Exhibits/ Dr. Charles W. Steger Posters Hall! It was a great experience for everyone, to be able to share their interests with so many Tech professors. For three days, the Junior Academy, immersed 1,000 Virginia students, teachers, mentors, and several parents, in the STEM- rich atmosphere of one of America’s premier research universi- ties. Over $40,000 in scholarships and prizes were awarded. Dr. Peter Kennelly at the VAS & VJAS Career Fair Over 924 submitted papers were reviewed and commented on 2013 Annual Meeting by a three-member Continued, See “Annual Meeting at Tech,” Page 2 Fall Undergraduate Research Conference Submission Deadline: October 4, 2013 The Fall Undergraduate Research Conference to inspire and support Virginia’s future scientists will convene on Saturday, October 26, 2013 at J. Sargeant Reynolds Community College. All Faculty mentors through-out the Commonwealth are invited to encour- age their undergraduate students to submit grant appli- cations describing proposed investigations by the deadline: October 4, 2013.
  • Article Is Available Online Is One of the Most Comprehensive Ways to Envision Such at Doi:10.5194/Bg-13-2257-2016-Supplement

    Article Is Available Online Is One of the Most Comprehensive Ways to Envision Such at Doi:10.5194/Bg-13-2257-2016-Supplement

    Biogeosciences, 13, 2257–2277, 2016 www.biogeosciences.net/13/2257/2016/ doi:10.5194/bg-13-2257-2016 © Author(s) 2016. CC Attribution 3.0 License. Molecular characterization of dissolved organic matter from subtropical wetlands: a comparative study through the analysis of optical properties, NMR and FTICR/MS Norbert Hertkorn1, Mourad Harir1, Kaelin M. Cawley2, Philippe Schmitt-Kopplin1, and Rudolf Jaffé2 1Helmholtz Zentrum München, German Research Center for Environmental Health, Research Unit Analytical Biogeochemistry (BGC), Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany 2Southeast Environmental Research Center, and Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33199, USA Correspondence to: Rudolf Jaffé (jaffer@fiu.edu) Received: 23 July 2015 – Published in Biogeosciences Discuss.: 25 August 2015 Revised: 22 December 2015 – Accepted: 7 February 2016 – Published: 19 April 2016 Abstract. Wetlands provide quintessential ecosystem ser- relative disparity was largest between the Everglades long- vices such as maintenance of water quality, water supply and short-hydroperiod samples, whereas Pantanal and Oka- and biodiversity, among others; however, wetlands are also vango samples were more alike among themselves. Other- among the most threatened ecosystems worldwide. Natural wise, molecular divergence was most obvious in the case dissolved organic matter (DOM) is an abundant and criti- of unsaturated protons (δH > 5 ppm). 2-D NMR spectroscopy cal component in wetland biogeochemistry. This study de- for a particular sample revealed a large richness of aliphatic scribes the first detailed, comparative, molecular characteri- and unsaturated substructures, likely derived from microbial zation of DOM in subtropical, pulsed, wetlands, namely the sources such as periphyton in the Everglades.
  • Acceptance of the Dana Medal of the Mineralogical Society of America for 2002

    Acceptance of the Dana Medal of the Mineralogical Society of America for 2002

    American Mineralogist, Volume 88, pages 947–948, 2003 Acceptance of the Dana Medal of the Mineralogical Society of America for 2002 MICHAEL F. HOCHELLA JR. Nanogeoscience and Technology Laboratory, Department of Geological Sciences, Virginia Tech, Blacksburg, Virginia 24061, U.S.A. I read several years ago about a Noble Laureate in chemis- try who was being interviewed by a reporter. He was asked what it takes to win a Noble Prize. Without hesitation, the chem- ist said that it took three things. First, being a genius was defi- nitely not required. Being reasonably intelligent was perfectly fine. Second, you needed to be a hard worker. (I remember thinking at that point in reading this story that the great major- ity of all successful scientists that I have ever known have ful- filled these two criteria. What then was the third, and presumably deciding factor, which resulted in winning a Nobel Prize. I read on anxiously.) Third, you not only had to be at the right place at the right time, but you had to be very, very fortu- nate! Indeed. And that is why I never even gave serious thought to winning a science prize of any sort. Not to mention that I have been accused in the past of being a dilettante geochemist. That comment must have had some element of truth because it struck a nerve. The proper response to that kind of comment is, FIGURE 1. The state of the Nanogeoscience and Technology “Don’t you ever call me a geochemist!” as I learned from my Laboratory in the Department of Geological Sciences at Virginia Tech wife, Prof.
  • Measuring T1 and T2 Relaxation Times

    Measuring T1 and T2 Relaxation Times

    Relaxation Measurements Two Relaxation Mechanisms 90° pulse T1: Spin‐lattice or longitudinal relaxation is the average lifetime of the nuclei in the higher spin state T2: Spin‐spin or transverse relaxation corresponds to a de‐coherence of the transverse nuclear spin magnetization Spin‐Lattice Relaxation Time or T1 • Any factor which slows molecular motion (e.g. increasing solution viscosity, aggregation, or rigidifying the molecule) shortens the spin‐lattice relaxation time • A short T1 favors sensitivity but too short can result in line broadening and degradation of resolution since T2 cannot be longer than T1 • 3 principal magnetic interactions that contribute to T1 relaxation of spin ½ nuclei: o Dipole‐dipole interaction ‐ the nucleus experiences a fluctuating field due to the motions of neighboring dipoles, unpaired electrons, or other nuclei o Chemical shift anisotropy ‐ chemical shielding of the nucleus is a function of molecular orientation with respect to B0 field direction o Spin rotation interaction –small magnetic fields are induced at the nucleus as a molecule reorients; this field fluctuates because the motions are not uniform but proceed by a series of small jumps • Small amounts of paramagnetic substances speed up relaxation • Inversion recovery experiment measures T1 T1 Measurement: Inversion Recovery Parameters to note & Optimize • To change the value of the delay, d7, a variable delay list must be created. • In the acquisition parameters a VDLIST can be generated which contains values that typically cover a time range which extends past vdlist the expected T1 value. 0.05 0.5 Iz = I0(1‐2exp(‐d7/T1) 1.0 1.5 ln(I0‐Iz) = ln(2I0)‐d7/T1 2 Tnull = T1*ln2 4 6 8 Spin‐Spin Relaxation Time or T2 • T1 = T2 when molecular tumbling is fast compared with the Larmor frequency; this is the condition for small molecules.
  • Robert N. Ulrich

    Robert N. Ulrich

    Robert N Ulrich 11000 Weyburn Dr. Apt 724 Los Angeles, CA 90024 [email protected] — (703) 851-7276 Education University of California, Los Angeles September 2017 – Present Ph.D., Geochemistry Virginia Polytechnic Institute and State University August 2013 – May 2017 B.S., Chemistry, 3.52 GPA B.S., Geosciences, 3.74 GPA Research Experience University of California, Los Angeles – Advisor, Dr. Aradhna Tripati September 2017 – Present Graduate Student Researcher, Using multiple geochemical tracers to shed light on a newly-discovered major mineral formation pathway for biominerals Purpose: To determine the effect of the amorphous calcium carbonate (ACC) precursor on the clumped isotope signatures of crystalline polymorphs of calcium carbonate in both inorganic and organic synthesis. Techniques: GC-MS, vacuum line, acid digestion, apparatus design, flow-through experiments Virginia Tech Biogeochemistry Lab – Advisor, Dr. Patricia Dove June 2015 – June 2017 Undergraduate Student Researcher, The Mg-dependent solubility and local structure of Amorphous Calcium Carbonate (ACC) Purpose: Quantify the solubility product, Ksp, of ACC at standard temperature and pressure using 2+ - experimental methods that determine the effect of Mg and HCO3 concentrations. Techniques: pH measurements, flow-through experiments, XRD, SEM, APS synchrotron Undergraduate Student Researcher, Establishing Composition Systematics in the American Lobster Homarus americanus Purpose: Quantify distribution of elements magnesium, calcium, strontium, and phosphorus in the mineral and organic components of the lobster exoskeleton and determine relationships to the function of body components. Techniques: chemical extraction, ICP-OES, pH measurements, titrations Virginia Tech Sedimentary Systems Lab – Advisor, Dr. Brian Romans August – December 2014 Undergraduate Student Researcher, Petrographic characterization of axial versus marginal submarine channel sandstones, Tres Pasos Formation Purpose: Determine relationships between location within an oil field reservoir and quality or type of sediment.
  • NMR Spectroscopy

    NMR Spectroscopy

    NMR spectroscopy • Not a single technique but a large set of related techniques • “simple” 1H-NMR • 13C NMR • 2D experiments 1 Nuclear Spin Angular momentum of spinning charge described by quantum spin number “I” Intrinsic magnitude of generated dipole = I = 0, 1/2, 1, 3/2… Spinning nucleus generates a magnetic dipole (µ) Criteria for spin: Atomic mass Atomic # I Example even even 0 12C, 16O, 34S odd odd or even half integer 1H (1/2); 13C (1/2); 15N (3/2) even odd integer 14N (1), 2H (1) Spin ½ nuclei in magnetic field (e.g. 1H and 13C) In the absence of a magnetic field, these spins have the same energy and are randomly aligned #orientations with respect to an applied B = 2I+1 B0 In an external magnetic field (B0) spin ½ can align with the magnetic field or against it (2)(1/2)+1 = 2 ΔE energy difference magnetogyric ratio hγB0 γB0 γ ΔE= ν= resonant frequency 2π 2π ν The difference in energy between the two spin states depends on B: ΔE increases with B β-spin hν ΔE depends on B, so the frequency of light needed to flip the nuclei will depend on Energy B α-spin applied magnetic field (B) 4 Common NMR active nuclei 2πµ γ = hI 7 -1 -1 Nucleus Natural Abundance γ (10 radT s ) 1H 99.9844 26 753 13C 1.108 6 728 19F 100 25 179 31P 100 10 840 1 13 νC = 0.25νΗ For a B0 where ν=200 MHz ( H) ν ≈ 50 MHz ( C) Energy difference and population The number of nuclei in the two states α and β are determined by Boltzmann distribution: N upper = e-ΔE/kT Nlower Since the α-spin state is lower in energy, it is more populated (more nuclei have α than β).