Diamonds are Forever and Zirconium is for Submarines

2013 ◽  
Author(s):  
Lars Öhrström
Keyword(s):  
Transition Metals ◽  
Periodic Table ◽  
Chemical Properties ◽  
Pure Metal ◽  
Cubic Zirconia ◽  
Love Story ◽  
Zirconium Silicate ◽  
Similar Chemical ◽  
Engagement Rings

The appearance of a diamond engagement ring in the long and convoluted love story between Botswana’s First Lady Detective, Mma Ramotswe, and the owner and brilliant mechanic of Tlokweng Road Speedy Motors, Mr J. L. B. Matekoni, seems to signal an end to this particular sub-plot, stretching over several volumes of Alexander McCall Smith’s bestselling and original series of crime novels (that we met in Chapter 1). However, a slight problem involving cubic zirconia is discovered, and the story lingers on until the next book in the series. Similar names for elements and their compounds are a nuisance in chemistry, but oft en arise historically, and zirconium is just one such example. Apart from the pure metal we have zircon and zirconia, all three of which have important applications. Zircon is zirconium silicate, with the formula ZrSiO4, and cubic zirconia is a special form of zirconium dioxide, ZrO2. The latter, as you may have guessed, is an excellent diamond substitute in, among other applications, engagement rings. We are not going to dwell on the details of the element zirconium, but you should know that within the Periodic Table it is located in the large middle chunk called the transition metals. You have probably heard of its cousin titanium, immediately above it, and a sibling, hafnium, straight down the ladder. Why do I call them siblings? Because in the Periodic Table elements in the same column tend to have similar chemical properties. In particular, in the family of transition metals in the central section containing 27 elements—each with a number of properties in common—the two lower elements in each column tend to be the most similar. The similar chemical properties of zirconium and titanium means that we can usually find zirconium where we mine the much more plentiful titanium, and also that once we have separated the titanium from zirconium there will be a small quantity of hafnium trailing along—an impurity that is much harder to get rid of. The sleek jeweller in Gaborone will not care if his fake diamonds contain trace levels of HfO2 mixed with the ZrO2.

scholarly journals Shellfish Chitosan Potential in Wine Clarification

2021 ◽  
Vol 11 (10) ◽  
pp. 4417
Author(s):  
Veronica Vendramin ◽  
Gaia Spinato ◽  
Simone Vincenzi
Keyword(s):  
Molecular Structure ◽  
Chemical Properties ◽  
Allergic Reactions ◽  
Chitin Content ◽  
Deacetylation Degree ◽  
Physical Chemical ◽  
Similar Chemical ◽  
Fungal Chitosan ◽  
Significant Difference ◽  
Fish Industry

Chitosan is a chitin-derived fiber, extracted from the shellfish shells, a by-product of the fish industry, or from fungi grown in bioreactors. In oenology, it is used for the control of Brettanomyces spp., for the prevention of ferric, copper, and protein casse and for clarification. The International Organisation of Vine and Wine established the exclusive utilization of fungal chitosan to avoid the eventuality of allergic reactions. This work focuses on the differences between two chitosan categories, fungal and animal chitosan, characterizing several samples in terms of chitin content and degree of deacetylation. In addition, different acids were used to dissolve chitosans, and their effect on viscosity and on the efficacy in wine clarification were observed. The results demonstrated that even if fungal and animal chitosans shared similar chemical properties (deacetylation degree and chitin content), they showed different viscosity depending on their molecular weight but also on the acid used to dissolve them. A significant difference was discovered on their fining properties, as animal chitosans showed a faster and greater sedimentation compared to the fungal ones, independently from the acid used for their dissolution. This suggests that physical–chemical differences in the molecular structure occur between the two chitosan categories and that this significantly affects their technologic (oenological) properties.

scholarly journals Phosphate Buffer Solubility and Oxidative Potential of Single Metals or Multielement Particles of Welding Fumes

Atmosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 30
Author(s):  
Manuella Ghanem ◽  
Esperanza Perdrix ◽  
Laurent Yves Alleman ◽  
Davy Rousset ◽  
Patrice Coddeville
Keyword(s):  
Transition Metals ◽  
Phosphate Buffer ◽  
Soluble Fraction ◽  
Certified Reference Materials ◽  
Health Effect ◽  
Oxidative Capacity ◽  
Pure Metal ◽  
Welding Fumes ◽  
Oxidative Potential ◽  
Potential Health

To evaluate the chemical behavior and the health impact of welding fumes (WF), a complex and heterogeneous mixture of particulate metal oxides, two certified reference materials (CRMs) were tested: mild steel WF (MSWF-1) and stainless steel WF (SSWF-1). We determined their total chemical composition, their solubility, and their oxidative potential in a phosphate buffer (PB) solution under physiological conditions (pH 7.4 and 37 °C). The oxidative potential (OPDTT) of WF CRMs was evaluated using an acellular method by following the dithiothreitol (DTT) consumption rate (µmol DTT L−1 min−1). Pure metal salts present in the PB soluble fraction of the WF CRMs were tested individually at equivalent molarity to estimate their specific contribution to the total OPDTT. The metal composition of MSWF-1 consisted mainly of Fe, Zn, Mn, and Cu and the SSWF-1 composition consisted mainly of Fe, Mn, Cr, Ni, Cu, and Zn, in diminishing order. The metal PB solubility decreased from Cu (11%) to Fe (approximately 0.2%) for MSWF-1 and from Mn (9%) to Fe (<1%) for SSWF-1. The total OPDTT of SSWF-1 is 2.2 times the OPDTT of MSWF-1 due to the difference in oxidative capacity of soluble transition metals. Cu (II) and Mn (II) are the most sensitive towards DTT while Cr (VI), Fe (III), and Zn (II) are barely reactive, even at higher concentrations. The OPDTT measured for both WF CRMs extracts compare well with simulated extracts containing the main metals at their respective PB-soluble concentrations. The most soluble transition metals in the simulated extract, Mn (II) and Cu (II), were the main contributors to OPDTT in WF CRMs extracts. Mn (II), Cu (II), and Ni (II) might enhance the DTT oxidation by a redox catalytic reaction. However, summing the main individual soluble metal DTT response induces a large overestimation probably linked to modifications in the speciation of various metals when mixed. The complexation of metals with different ligands present in solution and the interaction between metals in the PB-soluble fraction are important phenomena that can influence OPDTT depletion and therefore the potential health effect of inhaled WF.

scholarly journals Role of the periodic table in discovery of new elements

2011 ◽  
Vol 1 (1) ◽  
pp. 1-5 ◽  
Author(s):  
D.C. Hoffman
Keyword(s):  
Periodic Table ◽  
Predictive Power ◽  
Chemical Elements ◽  
Chemical Properties ◽  
Negative Effects ◽  
Current Form ◽  
Future Role ◽  
History Of ◽  
Chemical Techniques

AbstractThis year (2009) marks the 140th Anniversary of Mendeleev's original 1869 periodic table of the elements based on atomic weights. It also marks the 175th anniversary of his birth in Tolbosk, Siberia. The history of the development of periodic tables of the chemical elements is briefly reviewed beginning with the presentation by Dmitri Mendeleev and his associate Nikolai Menshutkin of their original 1869 table based on atomic weights. The value, as well as the sometimes negative effects, of periodic tables in guiding the discovery of new elements based on their predicted chemical properties is assessed. It is noteworthy that the element with Z=101 (mendelevium) was identified in 1955 using chemical techniques. The discoverers proposed the name mendelevium to honor the predictive power of the Mendeleev Periodic Table. Mendelevium still remains the heaviest element to have been identified first by chemical rather than nuclear or physical techniques. The question concerning whether there will be a future role for the current form of the periodic table in predicting chemical properties and aid in the identification of elements beyond those currently known is considered.

Group III-Sb Metamorphic Buffer on Si for p-Channel all-III-V CMOS: Electrical Properties, Growth and Surface Defects

2015 ◽  
Vol 1790 ◽  
pp. 13-18
Author(s):  
Shun Sasaki ◽  
Shailesh Madisetti ◽  
Vadim Tokranov ◽  
Michael Yakimov ◽  
Makoto Hirayama ◽  
...  
Keyword(s):  
Surface Defects ◽  
Lattice Mismatch ◽  
Chemical Properties ◽  
Antiphase Domain ◽  
Hole Transport ◽  
Heteroepitaxial Growth ◽  
Group Iii ◽  
Similar Chemical ◽  
Unintentional Doping ◽  
P Type

ABSTRACTGroup III-Sb compound semiconductors are promising materials for future CMOS circuits. Especially, In1-xGaxSb is considered as a complimentary p-type channel material to n-type In1-xGaxAs MOSFET due to the superior hole transport properties and similar chemical properties in III-Sb’s to those of InGaAs. The heteroepitaxial growth of In1-xGaxSb on Si substrate has significant advantage for volume fabrication of III-V ICs. However large lattice mismatch between InGaSb and Si results in many growth-related defects (micro twins, threading dislocations and antiphase domain boundaries); these defects also act as deep acceptor levels. Accordingly, unintentional doping in InGaSb films causes additional scattering, increase junction leakages and affects the interface properties. In this paper, we studied the correlations between of defects and hole carrier densities in GaSb and strained In1-xGaxSb quantum well layers by using various designs of metamorphic superlattice buffers.

Quantum Mechanics and the Periodic Table

2019 ◽  
Author(s):  
Eric Scerri
Keyword(s):  
Quantum Mechanics ◽  
Quantum Theory ◽  
Periodic Table ◽  
Chemical Properties ◽  
Pauli Exclusion Principle ◽  
Niels Bohr ◽  
Exclusion Principle ◽  
Old Quantum Theory ◽  
Set Up ◽  
Three Body

In chapter 7, the influence of the old quantum theory on the periodic system was considered. Although the development of this theory provided a way of reexpressing the periodic table in terms of the number of outer-shell electrons, it did not yield anything essentially new to the understanding of chemistry. Indeed, in several cases, chemists such as Irving Langmuir, J.D. Main Smith, and Charles Bury were able to go further than physicists in assigning electronic configurations, as described in chapter 8, because they were more familiar with the chemical properties of individual elements. Moreover, despite the rhetoric in favor of quantum mechanics that was propagated by Niels Bohr and others, the discovery that hafnium was a transition metal and not a rare earth was not made deductively from the quantum theory. It was essentially a chemical fact that was accommodated in terms of the quantum mechanical understanding of the periodic table. The old quantum theory was quantitatively impotent in the context of the periodic table since it was not possible to even set up the necessary equations to begin to obtain solutions for the atoms with more than one electron. An explanation could be given for the periodic table in terms of numbers of electrons in the outer shells of atoms, but generally only after the fact. But when it came to trying to predict quantitative aspects of atoms, such as the ground-state energy of the helium atom, the old quantum theory was quite hopeless. As one physicist stated, “We should not be surprised . . . even the astronomers have not yet satisfactorily solved the three-body problem in spite of efforts over the centuries.” A succession of the best minds in physics, including Hendrik Kramers, Werner Heisenberg, and Arnold Sommerfeld, made strenuous attempts to calculate the spectrum of helium but to no avail. It was only following the introduction of the Pauli exclusion principle and the development of the new quantum mechanics that Heisenberg succeeded where everyone else had failed.

Analytical Methodology from Lavoisier to Mendeleev

2014 ◽  
Author(s):  
Marco Fontani ◽  
Mariagrazia Costa ◽  
Mary Virginia Orna
Keyword(s):  
Chemical Change ◽  
Chemical Properties ◽  
Professional Activity ◽  
Analytical Methodology ◽  
Long Run ◽  
Similar Chemical ◽  
Experimental Errors ◽  
Ancient Times ◽  
Almost All ◽  
Physical And Chemical

Within the period covered by Part II, 1789–1869, 37 true elements, almost all of them metals, were discovered. Prior to this time, about 14 metals had been discovered, excluding those that had been known from ancient times. The discovery of the elements during this period of interest is intimately related to the analytical methodologies available to chemists, as well as to a growing consciousness of just what an element is. Because these methods were also available to the less competent who may have lacked the skills to use them or the knowledge to interpret their results, their use also led to as many, if not more, erroneous discoveries in the same period. One can number among the major sources of error faulty interpretation of experimental data, the “rediscovery” of an already known element, sample impurities, very similar chemical properties (as in the case of the rare earths), the presence of an element in nature in very scarce or trace amounts, gross experimental errors, confusion of oxides and earths with their metals, and baseless dogmatic pronouncements by known “authorities” in the field. Antoine Laurent Lavoisier’s conceptualization of what constitutes an element was a radical break from the principles of alchemy. His stipulation that an element is a substance that cannot be further decomposed conferred an operational, pragmatic, concrete definition on what had previously been a more abstract concept. At the other end of the spectrum was the intuition of Dmitri Mendeleev who, contrary to the prevailing acceptance of Lavoisier’s concept, stressed the importance of retaining a more abstract, more fundamental sense of an element—an idea that in the long run enabled the development of the periodic table. What both men had in common is that they defined and named individual elements as those components of substances that could survive chemical change and whose presence in compounds could explain their physical and chemical properties. Mendeleev’s table has been immortalized in every chemistry classroom—and also concretely in Saint Petersburg, the city that saw most of his professional activity, by a spectacular building-sized model The analytical chemist depends on both of these concepts and indeed, analytical practice preceded Lavoisier’s concept by at least a century.

Twinkle, Twinkle Little Star

2019 ◽  
pp. 46-53
Author(s):  
Nicholas Mee
Keyword(s):  
Nineteenth Century ◽  
Quantum Mechanics ◽  
Chemical Composition ◽  
Hydrogen Atom ◽  
Periodic Table ◽  
Chemical Properties ◽  
Spectral Lines ◽  
Exclusion Principle ◽  
Middle Years ◽  
Absorption Of Light

The emission and absorption of light by atoms produces discrete sets of spectral lines that were a vital clue to unravelling the structure of atoms and their elucidation was an important step towards the development of quantum mechanics. In the middle years of the nineteenth century Bunsen and Kirchhoff discovered that spectral lines can be used to determine the chemical composition of stars. Following Rutherford’s discovery of the nucleus, Bohr devised a model of the hydrogen atom that explained the spectral lines that it produces. His work was developed further by Pauli, who postulated the exclusion principle in order to explain the structure of other types of atom. This enabled him to explain the layout of the Periodic Table and the chemical properties of the elements.

Energy Dispersive X-Ray Fluorescence (EDXRF) Analysis as a Reliable Nondestructive Industrial Tool

1979 ◽  
Vol 23 ◽  
pp. 157-161
Author(s):  
L. E. Miller ◽  
H. J. Abplanalp
Keyword(s):  
Alloy Composition ◽  
Chemical Properties ◽  
Nondestructive Analysis ◽  
Destructive Testing ◽  
Roughness Effects ◽  
Destructive Sampling ◽  
X Ray ◽  
The Past ◽  
Edxrf Analysis ◽  
Similar Chemical

For the past several years the Boeing Aerospace Company has been implementing advanced nondestructive chemical analysis methods to improve product reliability and reduce material inspection costs. Previous testing of incoming material for conformance to vendor test reports or of production materials for verification of alloy composition, had consisted of either time-consuming destructive testing or nondestructive chemical spot testing, which often was insensitive to differences between alloys of similar chemical properties. Beginning in 1974, development of EDXRF techniques was initiated to provide a rapid nondestructive analysis capability for both laboratory and factory use. For materials containing elements easily excited by EDXRF methods, costly destructive sampling and testing can be avoided. Generally, chips, wire, barstock, sheet or plate can be analyzed using an annular radioactive source. The uniformity of the X-ray flux diminishes sample geometry and surface roughness effects.

Using Electron Energy-Loss Spectroscopy (EELS) To Study Rare Earth Elements In Natural Crystals

2000 ◽  
Vol 6 (S2) ◽  
pp. 206-207
Author(s):  
Huifang Xu
Keyword(s):  
Rare Earth ◽  
Energy Loss ◽  
Rare Earth Elements ◽  
Electron Energy ◽  
Energy Resolution ◽  
Electron Energy Loss Spectroscopy ◽  
Relative Concentration ◽  
Chemical Properties ◽  
Similar Chemical ◽  
Electron Energy Loss

Because of similar chemical properties of the rare earth elements (Ree), whole series of the Ree may occur in natural Ree-bearing crystals. Relative concentration of the Ree may vary as the crystallization environments change. Electron energy-dispersive spectroscopy (EDS) associated with TEM is unable to resolve Ree and other coexistence elements, such as Ba nd Ti, because of peak overlap and energy resolution (∼ 150 eV) of EDS. Figure A indicate multiple peaks from Ce only. The Cu peaks are from Cu grid holding the specimen. Electron energy-loss spectroscopy (EELS) with energy resolution of < 1 eV is able to resolve all Ree in natural Ree-bearing crystals.Natural carbonate crystals from a Ree ore deposit were investigated by using EELS associated with field emission-gun (FEG) TEM. The crystals are in a chemical series of BaCO3 - Ree(CO3)F [1]. In Figure B, EEL spectra A and B are from Ce-rich and La-rich bastnaesite (Ree(CO3)F), respectively; spectrum D is from cordylite (BaCO3 (Ree(CO3)F); spectrum E is from huanghoite (BaCO3 Ree(CO3)F), spectrum F is from BaCO3; spectrum C is from an unknown Ree-rich phase.

Sign in / Sign up

Export Citation Format

Share Document