DOCSLIB.ORG

Spectroscopy: Developments in Instrumentation and Analysis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Spectroscopy: Developments in Instrumentation and Analysis View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Grasas y Aceites (E-Journal) Grasas y Aceites Vol. 53. Fasc. 1 (2002), 45-63 45 Spectroscopy: Developments in Instrumentation and Analysis By Vincent Baeten and Pierre Dardenne Quality Department of Agricultural Products. Agricultural Research Centre of Gembloux. Chaussée de Namur, 24. 5030 Gembloux. Belgium. Tel: 32/81/62 03 50, Fax: 32/81/62 03 88. E-mail: [email protected] CONTENTS spectroscopy (NIR), mid-infrared spectroscopy (MIR) and Raman spectroscopy. The theoretical aspects related with these 1. Introduction techniques, the information that can supplied and the main 2. Why spectroscopic techniques features of the instrumentation are presented and briefly 2.1. Analytical characteristics discussed. The last part of the review concerns the application of 2.2. Spectroscopic characteristics the spectroscopy to food analysis, with special emphasis on the 2.3. Instrumental characteristics lipid analysis. The illustrations and examples have been chosen to 3. Some theoretical elements demonstrate the importance of spectroscopic techniques both in 3.1. Classical theory process (on-line) control and in laboratories for the analysis of 3.2. Quantum theory major or minor compounds. 3.3. Absorption and scattering: band position and intensity KEY-WORDS: Analysis - Authentication – Chemometrics - Mid- 4. Selecting the information infrared spectroscopy - Near-infrared spectroscopy - Raman spec- 5. Spectroscopic instrumentation troscopy. 5.1. Near-infrared instrument 5.1.1. Classical instrument 5.1.2. Microscope and camera 5.1.3. Sample presentation 5.2. Mid-infrared instrument 1. INTRODUCTION 5.2.1. Microscope and camera 5.2.2. Sample presentation 5.3. Raman instrument In recent years, spectroscopic techniques have 5.3.1. Microscope and camera come to be regarded as attractive and promising 5.3.2. Sample presentation analytical tools for analyses conducted in research, 6. Applications control or industrial laboratories. These techniques 6.1. Quantitative analysis 6.1.1. Determination of fat content are increasingly considered by analysts as an 6.1.2. Determination of major and minor components obvious solution. This trend stems from instrumental in lipid developments, the extensive use of computers and the 6.2. Qualitative analysis development of appropriate chemometric procedures. References Daily, new applications of spectroscopic techniques in RESUMEN the fields of chemistry, drugs, the agro-food sector, life Espectroscopía: Desarrollo en instrumentación y análisis. sciences and environmental analysis are being demonstrated and published. The objective should be Este artículo de revisión presenta las características, venta- not only to extend the field of application of jas, límites y potencial de tres técnicas espectroscópicas: las es- spectroscopic techniques, but also to use them as a pectroscopias del infrarrojo cercano, del medio infrarrojo y matter of course in control and industrial Raman. Se presentan, y discuten brevemente, los aspectos teóri- cos relacionados con estas técnicas, la información que pueden laboratories and to develop (according to suministrar, y las principales características de la instrumenta- internationally accepted guidelines) fully validated ción. La última parte de la revisión esta dedicada a las aplicacio- spectroscopic methods. nes de la espectroscopia en análisis de alimentos, con especial énfasis en análisis de lípidos. Las ilustraciones y los ejemplos se This paper presents the characteristics, advantages, han elegido para demostrar la importancia de las técnicas espec- limitations and potential of three spectroscopic troscópicas en los procesos en-línea y en los laboratorios en el techniques: near-infrared spectroscopy (NIR), mid-infrared análisis de componentes mayoritarios y minoritarios. spectroscopy (MIR) and Raman spectroscopy. PALABRAS-CLAVE: Análisis - Autentificación – Espectros- Special emphasis is placed on the application of copia infrarrojo cercano- Espectroscopia infrarrojo medio - Es- these techniques to lipid analysis. The illustrations pectroscopia Raman – Microscopio – Quimiometria. and examples have been chosen to demonstrate the importance of infrared (NIR and MIR) and Raman SUMMARY spectroscopies both in process (on-line) control and Spectroscopy: Developments in instrumentation and in laboratories for the analysis of major or minor analysis. compounds. There are many books and papers on the subject; most of the references included here This review presents the characteristics, advantages, limits have been selected for their relevance and clarity. and potential of three spectroscopic techniques: near-infrared 46 Grasas y Aceites Ta bl e I Analytical, spectroscopic and instrumental characteristics of NIR, MIR and Raman spectroscopies FEATURES NIR MIR Raman REFERENCES Rapid analysis -- -(Gerrard 1991) Simple analysis: concentration vs peak area /. -(Pelletier & Davis 1996) Qualitative and quantitative analysis -- -(Baranska 1987) None or reduced sample preparation -. -(Gerrard 1991) Standard calibration and transfert -. / procedures Validated methods (IUPAC, AOCS, ISO) /. / Sample form and sample size -- - No use of pollutant solvents -. - -- - ANALYTICAL Economic method (Scotter 1997; Murray 1999) (e.g. z saving of labour z reduction of samples to analyse) Direct, non-invasive and non destructive -- -(Gerrard 1991) In-situ analysis -. .(Hendra 1997) Emission process na na - (Vickers &Mann 1991) Intensity proportional to concentration na na - (Gerrard 1991) Well-resolved spectra /- -(Gerrard 1991; Wilson 1991) High resolution spectra -- - (Levin & Lewis 1990) Precise spectral frequency measurement -- -(Levin & Lewis 1990) Non-polar group information // -(Terpinski 1987) More significant information .- -(Schrader 1996; Olinga & Siesler, 2000) Structural selectivity / --(Olinga &Siesler, 2000) Signal intensity -- / Trace element determination /. -(Li-Chan 1996) SPECTROSCOPIC Fluorescence-free spectra na na . (Chase 1987) Spectra insensitive to temperature // -(Pelletier & Davis 1996) Sample presentation technique -. - Push-button instrumentation -- .(van de Voort 1994) Works well with aqueous samples ./ -(Vickers & Mann 1991) Suitable for use at-, on- and in-line process -. -(Scotter 1997; Hendra 1997) Compatible with suitable fibre optics -. -(Lewis et al. 1988; Gerrard 1991; Keller et al. al. 1993; Olinga & Siesler, 2000) Process monitoring -. -(Olinga & Siesler, 2000; Ozaki et al. 1992)19 Microscope -- -(Williams & Batchelder 1994) INSTRUMENTAL Camera (Multispectral measurement) -. / 2. WHY SPECTROSCOPIC TECHNIQUES to traditional, tedious and more time-consuming analytical methods. The advantages of NIR, MIR and Raman First, they are rapid, do not require reagents and spectroscopies are numerous and diversified. Table I are non-destructive. The best illustration of this is in shows the major characteristics of these techniques. protein analysis. The protein content of feedstuffs Note that some of these characteristics are the same and foodstuffs is traditionally determined using the as those of other spectroscopic techniques, such as Kjeldhal method. With this method a single analysis Nuclear Magnetic Resonance or Ultraviolet. The of one sample takes 3 hours and requires several characteristics are categorised into three groups: millilitres of different pollutant reagents (e.g., analytical, spectroscopic and instrumental. For each sulphuric acid) (Bertrand, 2000). Currently, with the characteristic and each technique, a diagram has been growing concern about analysts’ safety and added to indicate whether the characteristic is an environmental protection, laboratories try to keep at advantage ( ), a partial advantage (.) or a a minimum the quantity of potentially dangerous disadvantage (). References in which these reagents used in their analyses. In addition to the characteristics are discussed are included in the table. health and environmental aspects of the use of these 2.1. Analytical characteristics products, it is important to add the cost generated by the adequate treatment of the chemical waste. An The analytical characteristics of NIR, MIR and alternative to the Kjeldahl method is the Raman spectroscopies display certain advantages determination of protein content by NIR which takes that make these techniques attractive as alternatives less than a minute and does not require any Vol. 53. Fasc. 1 (2002) 47 reagents. A similar illustration can be provided with common to all three techniques, whereas others are regard to iodine value determination. The time specific to only one or two of the techniques. The required for a single determination using a classical characteristics in common are the high resolution of technique (i.e., the titrimetric or chromatographic the spectra obtained and the precise spectral method) is 30–60 minutes following the procedure frequency measurement that facilitates the chosen, whereas a spectroscopic determination mathematical treatment (e.g. spectral subtraction), takes about 5 minutes. Iodine value can be as well as the transfer of equation between measured by NIR, MIR or Raman spectroscopy instruments. From the spectroscopic point of view, a (Baeten et al., 2000). For the agro-food sector the general advantage of MIR and Raman speed of analysis is a crucial factor in process control spectroscopies is that bands are well resolved and where any delay in obtaining the analytical results can be assigned to specific chemical groups. There may
Load more

Recommended publications
  • Calcium and Potassium Spectra in the EUV
    atoms Review Calcium and Potassium Spectra in the EUV Elmar Träbert Fakultät für Physik und Astronomie, Ruhr-Universität Bochum, AIRUB, 44780 Bochum, Germany; [email protected]; Tel.: +49-234-322-3451; Fax: +49-234-321-4169 Received: 28 August 2020; Accepted: 2 October 2020; Published: 14 October 2020 Abstract: In online data bases, the entries on extreme ultraviolet (EUV) spectra of Ca are much more sparse than those of neighbouring elements such as Ar, K, Sc and Ti. This may be a result of experimental problems with Ca in the laboratory as well as of the limited role of multiply charged Ca ions in solar observations. Beam-foil EUV spectra of Ca and K are presented that provide survey data of a single element each. Keywords: atomic physics; EUV spectra; beam-foil spectroscopy 1. Introduction Early in the 19th century Wollaston and Fraunhofer detected dark lines in their prism spectra of the Sun, and Fraunhofer labelled the strongest of these lines by capital letters of the alphabet. A few decades later Kirchhoff and Bunsen recognized that those dark lines agreed in position with bright lines in the spectra of a flame seeded with specific materials. Thus it was eventually learned that Fraunhofer’s line ‘G’ (partly) originates from calcium (Ca, atomic number Z = 20) atoms, and his lines ‘H’ and ‘K’ belong to singly charged Ca+ ions. Evidently, Ca is abundant enough in the Sun to feature prominently in the solar visible spectrum. Subsequently, the various spectra of Ca have been studied in flames, arcs, sparks, and whatever plasma discharge light sources seemed appropriate, and the extent of the spectral coverage has expanded from the visible to the infrared (IR), ultraviolet (UV), vacuum ultraviolet (VUV, wavelengths below 200 nm), and extreme ultraviolet (EUV, wavelengths below 110 nm) to the X-ray range (wavelengths shorter than, say, 5 nm).
    [Show full text]
  • Spectroscopy
    Chapter 1, page 1 Spectroscopy An Introduction to the Theoretical and Experimental Fundamentals 1 Introduction In the year 1666 at Cambridge, Isaac Newton procured a triangular glass prism and let a ray of sunlight from a small round hole in the window illuminate it. He observed the image created thereby on a paper screen. The white light from the window dissociated into red, yellow, green, blue, and violet. He called the invisible colors in the white sunlight the “spectrum” (lat spectrum = image in the soul) [1]. It was at the end of the 19th century that the observation of spectra was first christened “Spectroscopy”. This word has both a Latin and Greek root (Greek skopein = to look). Arthur Schuster first used the term spectroscopy in 1882 during a lecture at the Royal Institution [2]. Newton led the way from speculation to spectral analysis by making exact measurement and having clear insights. The oldest observation of nature dealing with the properties of invisible light comes to us from the Roman scholar and philosopher Titus Carus Lucretius. Infrared spectroscopists therefore consider him to be their intellectual father. Around 60 B.C. he hypothesized the existence of infrared radiation: [3]: »Forsitan et rosea sol alte lampade lucens possideat multum caecis fervoribus ignem circum se, nullo qui sit fulgore notatus, aestifer ut tantum radiorum exaugeat ictum.« (original Latin) or freely translated into English: »Perhaps the sun, shining above with rosy lamp is surrounded by much fire and invisible heat. Thus the fire may be accompanied by radiance which increases the power of rays.« or translated by Knebel [3] into German: »Mag es auch sein, dass hoch die rosige Fackel der Sonne ringsum Feuer verbirgt in düsteren unscheinbaren Gluten, die beitragen, die Macht so heftiger Strahlen zu mehren«.
    [Show full text]
  • Outline of Physical Science
    Outline of physical science “Physical Science” redirects here. It is not to be confused • Astronomy – study of celestial objects (such as stars, with Physics. galaxies, planets, moons, asteroids, comets and neb- ulae), the physics, chemistry, and evolution of such Physical science is a branch of natural science that stud- objects, and phenomena that originate outside the atmosphere of Earth, including supernovae explo- ies non-living systems, in contrast to life science. It in turn has many branches, each referred to as a “physical sions, gamma ray bursts, and cosmic microwave background radiation. science”, together called the “physical sciences”. How- ever, the term “physical” creates an unintended, some- • Branches of astronomy what arbitrary distinction, since many branches of physi- cal science also study biological phenomena and branches • Chemistry – studies the composition, structure, of chemistry such as organic chemistry. properties and change of matter.[8][9] In this realm, chemistry deals with such topics as the properties of individual atoms, the manner in which atoms form 1 What is physical science? chemical bonds in the formation of compounds, the interactions of substances through intermolecular forces to give matter its general properties, and the Physical science can be described as all of the following: interactions between substances through chemical reactions to form different substances. • A branch of science (a systematic enterprise that builds and organizes knowledge in the form of • Branches of chemistry testable explanations and predictions about the • universe).[1][2][3] Earth science – all-embracing term referring to the fields of science dealing with planet Earth. Earth • A branch of natural science – natural science science is the study of how the natural environ- is a major branch of science that tries to ex- ment (ecosphere or Earth system) works and how it plain and predict nature’s phenomena, based evolved to its current state.
    [Show full text]
  • 1 CHAPTER 7 ATOMIC SPECTRA 7.1 Introduction Atomic Spectroscopy Is
    1 CHAPTER 7 ATOMIC SPECTRA 7.1 Introduction Atomic spectroscopy is, of course, a vast subject, and there is no intention in this brief chapter of attempting to cover such a huge field with any degree of completeness, and it is not intended to serve as a formal course in spectroscopy. For such a task a thousand pages would make a good start. The aim, rather, is to summarize some of the words and ideas sufficiently for the occasional needs of the student of stellar atmospheres. For that reason this short chapter has a mere 26 sections. Wavelengths of spectrum lines in the visible region of the spectrum were traditionally expressed in angstrom units (Å) after the nineteenth century Swedish spectroscopist Anders Ångström, one Å being 10 −10 m. Today, it is recommended to use nanometres (nm) for visible light or micrometres ( µm) for infrared. 1 nm = 10 Å = 10 −3 µm= 10 −9 m. The older word micron is synonymous with micrometre, and should be avoided, as should the isolated abbreviation µ. The usual symbol for wavelength is λ. Wavenumber is the reciprocal of wavelength; that is, it is the number of waves per metre. The usual symbol is σ, although ~ν is sometimes seen. In SI units, wavenumber would be expressed in m -1, although cm -1 is often used. The extraordinary illiteracy "a line of 15376 wavenumbers" is heard regrettably often. What is intended is presumably "a line of wavenumber 15376 cm -1." The kayser was an unofficial unit formerly seen for wavenumber, equal to 1 cm -1.
    [Show full text]
  • High-Resolution Spectroscopic Studies Of
    HIGH-RESOLUTION SPECTROSCOPIC STUDIES OF 15 ATMOSPHERIC GASES (C2H2-N2, O2, and NH3) HOIMONTI IMMACULATA ROZARIO Master of Science, University of Lethbridge, 2012 Master of Science, Jahangirnagar University, 2010 Bachelor of Science, Jahangirnagar University, 2009 A Thesis Submitted to the School of Graduate Studies of the University of Lethbridge in Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY Department of Physics and Astronomy University of Lethbridge LETHBRIDGE, ALBERTA, CANADA © Hoimonti Immacualata Rozario, 2019 HIGH-RESOLUTION SPECTROSCOPIC STUDIES OF ATMOSPHERIC GASES 15 (C2H2-N2, O2, and NH3) HOIMONTI IMMACULATA ROZARIO Date of Defence: March 27, 2019 Dr. Brant Billinghurst Senior Scientist PhD Co-supervisor Canadian Light Source Saskatoon, Saskatchewan Dr. Karl Staenz Professor PhD Co-supervisor Dr. Locke Spencer Associate Professor PhD Thesis Examination Committee Member Dr. Arundhati Dasgupta Associate Professor PhD Thesis Examination Committee Member Dr. Michael Gerken Professor PhD Internal External Examiner Dr. Ann-Lise Norman Professor PhD External Examiner University of Calgary Calgary, Alberta Dr. Craig Coburn Associate Professor PhD Chair, Thesis Examination Committee Dedication Page I would like to dedicate my PhD thesis work to my mother. iii Abstract With the modern technology and availability of spectrometer systems, it is possible to provide more accurate and new parameters to the spectroscopic databases. Accordingly, three spectroscopic studies were carried out in this thesis. The first study is intended to find the suitable line-shape models that can reproduce C2H2-N2 spectra best as well as retrieve reliable parameters, which are very useful for spectroscopic studies. The second project of oxygen A-band spectra is dedicated to retrieving a new parameter, called the speed- dependent parameter.
    [Show full text]
  • EUV Beam-Foil Spectra of Titanium, Iron, Nickel, and Copper
    atoms Article EUV Beam-Foil Spectra of Titanium, Iron, Nickel, and Copper Elmar Träbert 1,2 1 Fakultät für Physik und Astronomie, Ruhr-Universität Bochum, AIRUB, 44780 Bochum, Germany; [email protected]; Tel.: +49-2343223451; Fax: +49-2343214169 2 Lawrence Livermore National Laboratory, Physics Division, Livermore, CA 94550-9234, USA Abstract: Beam–foil spectroscopy offers the efficient excitation of the spectra of a single element as well as time-resolved observation. Extreme-ultraviolet (EUV) beam–foil survey and detail spectra of Ti, Fe, Ni, and Cu are presented, as well as survey spectra of Fe and Ni obtained at an electron beam ion trap. Various details are discussed in the context of line intensity ratios, yrast transitions, prompt and delayed spectra, and intercombination transitions. Keywords: atomic physics; EUV spectra; beam–foil spectroscopy 1. Introduction Bengt Edlén demonstrated by laboratory experiments in the 1940s [1] that the long- time mysterious solar corona lines (in the visible spectrum) originated from electric-dipole forbidden transitions in the ground configurations of highly charged ions of Ca, Fe, and Ni, a hypothesis Grotrian [2] had formulated on the basis of some of Edlén’s earlier measurements of X-ray transitions. When in the 1960s and 1970s sounding rockets and satellites heaved spectrometers beyond Earth’s atmosphere and thus opened the new Citation: Träbert, E. EUV Beam-Foil field of direct X-ray and EUV observations of highly charged ions in the solar corona, Spectra of Titanium, Iron, Nickel, and researchers marveled at the rich EUV and X-ray spectra, especially of Fe. Brian Fawcett, Copper.
    [Show full text]
  • UC Irvine Electronic Theses and Dissertations
    UC Irvine UC Irvine Electronic Theses and Dissertations Title Understanding the State of Bacterial Systems with Machine Learning-Enabled Interpretation of Surface Enhanced Raman Scattering Spectra Produced by Novel Nanomanufacturing Permalink https://escholarship.org/uc/item/1wr5x8tf Author Thrift, William John Publication Date 2019 License https://creativecommons.org/licenses/by-nc-nd/4.0/ 4.0 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA, IRVINE Understanding the State of Bacterial Systems with Machine Learning-Enabled Interpretation of Surface Enhanced Raman Scattering Spectra Produced by Novel Nanomanufacturing Dissertation submitted in partial satisfaction of the requirements for the degree of DOCTOR OF PHILOSOPHY in Materials Science and Engineering by William John Thrift Dissertation Committee: Professor Regina Ragan, Chair Professor Filippo Capolino Associate Professor Allon Hochbaum 2019 Portions of Chapter 3 and 10 reprinted with permission from Thrift, W. J. et al. ACS Nano 2017, 11 (11), 11317–11329. ©2017 American Chemical Society Portions of Chapter 4 and 10 reprinted with permission from Thrift, W. J. et al. Plasmonics: Design, Materials, Fabrication, Characterization, and Applications XV; International Society for Optics and Photonics, 2017; Vol. 10346, p 103461M. ©2017 International Society for Optics and Photonics Portions of Chapter 5 and 10 reprinted with permission from C. Q. Nguyen, et al. ACS Appl. Mater. Interfaces, 2018, 10, 12364–12373. ©2018 American Chemical Society Portions of Chapter 6 and 10 reprinted with permission from Thrift, W. J. et al. ACS sensors, 2019. ©2019 American Chemical Society All Other Materials © 2019 William John Thrift DEDICATION To the people who made this dissertation possible: my family, Regina, and Hurik.
    [Show full text]
  • Optical Astronomical Spectroscopy
    Optical Astronomical Spectroscopy C R Kitchin University of Hertfordshire Institute of Physics Publishing Bristol and Philadelphia Contents Preface xi PART 1 Atomic Processes 1 Introduction to Spectroscopy 1 1.1 Historical background 1 1.2 Types of spectroscopy 8 2 The Physics of Atoms and Molecules 14 2.1 Sommerfeld's refinements 17 2.2 Space quantization 20 2.3 Atomic structure 21 2.4 Other viewpoints 23 2.5 Quantum/wave mechanics 25 Atomic Energy Levels 28 3.1 Multiple electron atoms 29 3.2 L-S coupling 32 3.3 Space quantization 37 3.4 Term formation 37 3.5 Closed shells and subshells 39 3.6 Notation 39 3.7 Hyperfine structure 44 Transitions 46 4.1 Basics 46 4.2 Selection rules 48 4.3 Transition probabilities 53 4.4 Absorption and emission coefficients 57 4.5 Ionization and recombination 64 4.6 X-ray spectra 66 Spectra of Molecules 68 5.1 Introduction 68 5.2 Rotational transitions 70 5.3 Vibrational transitions 76 vn viii CONTENTS 5.4 Electronic transitions 84 6 Radiation in the Presence of Fields 91 6.1 Zeeman effect 91 6.2 Stark effect 91 6.3 Free-free radiation 96 6.4 Synchrotron and gyrosynchrotron radiation 101 6.5 Cerenkov radiation 110 6.6 The Faraday effect 110 7 Spectroscopy of Solid Materials 113 PART 2 Astronomical Spectroscopic Techniques 8 Optical Spectroscopes 119 8.1 Introduction 119 8.2 Diffraction gratings 120 8.3 Grating problems 129 8.4 Diffraction grating spectroscopes 133 8.5 Prisms 143 8.6 Prism spectroscopes 145 8.7 Fourier transform spectroscope (Michelson interferometer) 147 8.8 Fabry-Perot etalons 151 Specialized
    [Show full text]
  • An Update to the MARVEL Dataset and Exomol Line List for 12C2
    MNRAS 000,1–17 (2020) Preprint 11 September 2020 Compiled using MNRAS LATEX style file v3.0 12 An update to the MARVEL dataset and ExoMol line list for C2 Laura K. McKemmish,1? Anna-Maree Syme,1 Jasmin Borsovszky,1 Sergei N. Yurchenko,2 Jonathan Tennyson,2 Tibor Furtenbacher3 and Attila G. Császár3 1School of Chemistry, University of New South Wales, 2052 Sydney 2Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom 3Institute of Chemistry, ELTE Eötvös Loránd University and MTA-ELTE Complex Chemical Systems Research Group, H-1518 Budapest 112, P.O. Box 32, Hungary Accepted XXX. Received YYY; in original form ZZZ ABSTRACT The spectrum of dicarbon (C2) is important in astrophysics and for spectroscopic studies of plasmas and flames. The C2 spectrum is characterized by many band systems with new ones still being actively identified; astronomical observations involve eight of these bands. Recently, Furtenbacher et al. (2016, Astrophys. J. Suppl., 224, 44) presented a set of 5699 12 empirical energy levels for C2, distributed among 11 electronic states and 98 vibronic bands, derived from 42 experimental studies and obtained using the MARVEL (Measured Active Rotational-Vibrational Energy Levels) procedure. Here, we add data from 13 new sources and update data from 5 sources. Many of these 3 data sources characterize high-lying electronic states, including the newly detected 3 Pg state. Older studies have been included following improvements in the MARVEL procedure which allow their uncertainties to be estimated. These older works in particular determine 1 levels in the C Pg state, the upper state of the insufficiently characterized Deslandres– 1 1 d’Azambuja (C Pg–A Pu) band.
    [Show full text]
  • Outline of Natural Science
    Outline of natural science The following outline is provided as an overview of and study biological phenomena (organic chemistry, for topical guide to natural science: example). Natural science – a major branch of science that tries to explain, and predict, nature’s phenomena based on 2.1.1 Physics empirical evidence. In natural science, hypothesis must be verified scientifically to be regarded as scientific the- • • Physics – physical science that studies matter ory. Validity, accuracy, and social mechanisms ensur- and its motion through space-time, and related ing quality control, such as peer review and repeatabil- concepts such as energy and force ity of findings, are amongst the criteria and methods used • Acoustics – study of mechanical waves in for this purpose. Natural science can be broken into 2 solids, liquids, and gases (such as vibra- main branches: life science, and physical science. Each tion and sound) of these branches, and all of their sub-branches, are re- • ferred to as natural sciences. Agrophysics – study of physics applied to agroecosystems • Soil physics – study of soil physical 1 What type of thing is natural sci- properties and processes. • Astrophysics – study of the physical as- ence? pects of celestial objects • Astronomy – studies the universe beyond Natural science can be described as all of the following: Earth, including its formation and de- velopment, and the evolution, physics, • Branch of science – systematic enterprise that builds chemistry, meteorology, and motion of and organizes knowledge in the form of testable ex- celestial objects (such as galaxies, plan- planations and predictions about the universe.[1][2][3] ets, etc.) and phenomena that originate outside the atmosphere of Earth (such as • Major category of academic disciplines – an aca- the cosmic background radiation).
    [Show full text]
  • Dydaktyka Chemii (I Innych Przedmiotów Przyrodniczych) Od Czasów Alchemii Po Komputery
    Dydaktyka chemii (i innych przedmiotów przyrodniczych) od czasów alchemii po komputery monografia pod redakcją M. Nodzyńskiej ZAKŁAD CHEMII I DYDAKTYKI CHEMII UNIWERSYTET PEDAGOGICZNY im. Komisji Edukacji Narodowej KRAKÓW, 2011 1 Redakcja: Małgorzata Nodzyńska Recenzja: Jan Rajmund Paśko Projekt okładki: Paweł Cieśla Skład: Małgorzata Nodzyńska ISBN 978-83-7271-698-9 2 3 4 WSTĘP Wiadomości i umiejętności przyrodnicze były niezbędne naszemu gatunkowi jeszcze w czasach przed homo sapiens. Znajomość roślin jadalnych i trujących, zwyczajów zwierząt, umiejętność przechowywania żywności (wędzenie, suszenie) były niezbędne by przeżyć. Umiejętność wykonywania prostych narzędzi z kamieni, kości, drewna i ich wykorzystywania, produkcja broni (np. bolas, oszczep), umiejętność budowania schronienia czy pułapek na zwierzynę to tylko niektóre czynności niezbędne praludziom do ich egzystencji. Kolejne niezbędne umiejętności to: znajdowanie drogi, umiejętność posługiwanie się ogniem, otrzymywanie barwników. Wymienienie tylko tych kilku najbardziej podstawowych i oczywistych umiejętności pokazuje jak wielką wiedzę trzeba posiadać by przeżyć. Kolejne znajdowane przez arheologów artefakty świadczą o zainteresowaniach ludzi pierwotnych astronomią (np. kościana płytka z symbolami faz księżyca datowana na 32 tysiące lat czy konstrukcja sanktuarium megalitycznego z epoki neolitu – Stonehenge w Anglii, datowanego na ok. 3000-1700 p.n.e.). Wraz z rozwojem naszego gatunku ilość wiedzy gromadzonej przez naszych przodków była coraz większa i dotyczyła coraz to szerszego
    [Show full text]
  • Arthur L. Schawlow Papers SC0554
    http://oac.cdlib.org/findaid/ark:/13030/kt2q2nf1zn No online items Guide to the Arthur L. Schawlow Papers SC0554 Daniel Hartwig Department of Special Collections and University Archives October 2010 Green Library 557 Escondido Mall Stanford 94305-6064 [email protected] URL: http://library.stanford.edu/spc Note This encoded finding aid is compliant with Stanford EAD Best Practice Guidelines, Version 1.0. Guide to the Arthur L. Schawlow SC0554 1 Papers SC0554 Language of Material: English Contributing Institution: Department of Special Collections and University Archives Title: Arthur L. Schawlow papers creator: Schawlow, Arthur L. Identifier/Call Number: SC0554 Physical Description: 98.25 Linear Feet Date (inclusive): 1949-1997 Abstract: These papers primarily document Schawlow's career at Stanford and include correspondence, 1951-1995; lecture notes and class files, 1980-1988, containing problem sets and solutions, exams, and other information; grant files; records from participation in professional organizations including American Physical Society, American Institute of Physics, and the Optical Society of America; and reprints of his and his students' articles, 1949-1994. Also included is correspondence, clippings, and brochures pertaining to autism, 1981-1989, including typescript of "Our Autistic Son" by Aurelia T. and Arthur L. Schawlow. Immediate Source of Acquisition note Gift of Arthur Schawlow, 1997-1998. Information about Access This collection is open for research. Ownership & Copyright All requests to reproduce, publish, quote from, or otherwise use collection materials must be submitted in writing to the Head of Special Collections and University Archives, Stanford University Libraries, Stanford, California 94304-6064. Consent is given on behalf of Special Collections as the owner of the physical items and is not intended to include or imply permission from the copyright owner.
    [Show full text]