The Early Years of X-Ray Diffraction and X-Ray Spectrometry

1995 ◽  
Vol 39 ◽  
pp. 1-11
Author(s):  
J. L. de Vries
Keyword(s):  
The Netherlands ◽  
Early Years ◽  
X Ray Diffraction ◽  
Parental Home ◽  
Only Child ◽  
Technical School ◽  
X Ray ◽  
The Family ◽  
The Right ◽  
The University

Wilhelm Conrad Röntgen was born on 27-03-1845, 150 years ago, in Lennep- Remscheid in Westphalen, Germany, from a German father and a Dutch mother. He remained an only child. When he was 3 years old, the family moved to Apeldoom in the Netherlands. His parental home exists and will be the Röntgen bar. After going to school in Apeldoorn, he went to a technical school in Utrecht, where he finished in 1865. He enrolled in the University of Utrecht in the Netherlands, but found that he did not have the right certificates to pass the examinations. He then went to Zurich to the newly stifted Eidgenössische Technische Hochschule, where restrictions were less severe. In 18869, he got his doctorate on ‘Thermodynamics of gases.’ He was a brilliant student with a wide variety of interests.

Low temperature x-ray microanalysis of frozen-hydrated tobacco leaves

1984 ◽  
Vol 42 ◽  
pp. 284-285
Author(s):  
S. Edith Taylor ◽  
Patrick Echlin ◽  
May McKoon ◽  
Thomas L. Hayes
Keyword(s):  
Low Temperature ◽  
Lemna Minor ◽  
Root Tips ◽  
Tobacco Leaves ◽  
X Ray ◽  
Whole Cells ◽  
Carbon Coated ◽  
The Right ◽  
Beam Currents ◽  
The University

Low temperature x-ray microanalysis (LTXM) of solid biological materials has been documented for Lemna minor L. root tips. This discussion will be limited to a demonstration of LTXM for measuring relative elemental distributions of P,S,Cl and K species within whole cells of tobacco leaves.Mature Wisconsin-38 tobacco was grown in the greenhouse at the University of California, Berkeley and picked daily from the mid-stalk position (leaf #9). The tissue was excised from the right of the mid rib and rapidly frozen in liquid nitrogen slush. It was then placed into an Amray biochamber and maintained at 103K. Fracture faces of the tissue were prepared and carbon-coated in the biochamber. The prepared sample was transferred from the biochamber to the Amray 1000A SEM equipped with a cold stage to maintain low temperatures at 103K. Analyses were performed using a tungsten source with accelerating voltages of 17.5 to 20 KV and beam currents from 1-2nA.

scholarly journals Crystal Chemical Relations in the Shchurovskyite Family: Synthesis and Crystal Structures of K2Cu[Cu3O]2(PO4)4 and K2.35Cu0.825[Cu3O]2(PO4)4

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 807
Author(s):  
Ilya V. Kornyakov ◽  
Sergey V. Krivovichev
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Structural Complexity ◽  
Crystal Chemical ◽  
X Ray Diffraction ◽  
Complexity Measures ◽  
X Ray ◽  
The Family ◽  
Similarities And Differences ◽  
Related Compounds

Single crystals of two novel shchurovskyite-related compounds, K2Cu[Cu3O]2(PO4)4 (1) and K2.35Cu0.825[Cu3O]2(PO4)4 (2), were synthesized by crystallization from gaseous phase and structurally characterized using single-crystal X-ray diffraction analysis. The crystal structures of both compounds are based upon similar Cu-based layers, formed by rods of the [O2Cu6] dimers of oxocentered (OCu4) tetrahedra. The topologies of the layers show both similarities and differences from the shchurovskyite-type layers. The layers are connected in different fashions via additional Cu atoms located in the interlayer, in contrast to shchurovskyite, where the layers are linked by Ca2+ cations. The structures of the shchurovskyite family are characterized using information-based structural complexity measures, which demonstrate that the crystal structure of 1 is the simplest one, whereas that of 2 is the most complex in the family.

Dalnegroite, Tl5–xPb2x(As,Sb)2l–xS34, a new thallium sulphosalt from Lengenbach quarry, Binntal, Switzerland

2009 ◽  
Vol 73 (6) ◽  
pp. 1027-1032 ◽  
Author(s):  
F. Nestola ◽  
A. Guastoni ◽  
L. Bindi ◽  
L. Secco
Keyword(s):  
Polarized Light ◽  
New Mineral ◽  
X Ray Diffraction ◽  
X Ray ◽  
Elemental Concentrations ◽  
Reflected Light ◽  
Mohs Hardness ◽  
The Mean ◽  
The University ◽  
Probable Space

AbstractDalnegroite, ideally Tl4Pb2(As12Sb8)Σ20S34, is a new mineral from Lengenbach, Binntal, Switzerland. It occurs as anhedral to subhedral grains up to 200 μm across, closely associated with realgar, pyrite, Sb-rich seligmanite in a gangue of dolomite. Dalnegroite is opaque with a submetallic lustre and shows a brownish-red streak. It is brittle; the Vickers hardness (VHN25) is 87 kg mm-2(range: 69—101) (Mohs hardness ∼3—3½). In reflected light, dalnegroite is highly bireflectant and weakly pleochroic, from white to a slightly greenish-grey. In cross-polarized light, it is highly anisotropic with bluish to green rotation tints and red internal reflections.According to chemical and X-ray diffraction data, dalnegroite appears to be isotypic with chabournéite, Tl5-xPb2x(Sb,As)21-xS34. It is triclinic, probable space groupP1, witha= 16.217(7) Å,b= 42.544(9) Å,c= 8.557(4) Å, α = 95.72(4)°, β = 90.25(4)°, γ = 96.78(4)°,V= 5832(4) Å3,Z= 4.The nine strongest powder-diffraction lines [d(Å) (I/I0) (hkl)] are: 3.927 (100) (10 0); 3.775 (45) (22); 3.685 (45) (60); 3.620 (50) (440); 3.124 (50) (2); 2.929 (60) (42); 2.850 (70) (42); 2.579 (45) (02); 2.097 (60) (024). The mean of 11 electron microprobe analyses gave elemental concentrations as follows: Pb 10.09(1) wt.%, Tl 20.36(1), Sb 23.95(1), As 21.33(8), S 26.16(8), totalling 101.95 wt.%, corresponding to Tl4.15Pb2.03(As11.86Sb8.20)S34. The new mineral is named for Alberto Dal Negro, Professor in Mineralogy and Crystallography at the University of Padova since 1976.

Unfulfilled Promise: Palestinian Family Reunification and the Right of Return

2016 ◽  
Vol 45 (3) ◽  
pp. 24-39
Author(s):  
Nabila El-Ahmed ◽  
Nadia Abu-Zahra
Keyword(s):  
United Nations ◽  
Family Reunification ◽  
The State ◽  
Early Years ◽  
Successor State ◽  
Palestinian Refugees ◽  
Right Of Return ◽  
The Family ◽  
The Creation ◽  
The Right

This article argues that Israel substituted the Palestinian refugees' internationally recognized right of return with a family reunification program during its maneuvering over admission at the United Nations following the creation of the state in May 1948. Israel was granted UN membership in 1949 on the understanding that it would have to comply with legal international requirements to ensure the return of a substantial number of the 750,000 Palestinians dispossessed in the process of establishing the Zionist state, as well as citizenship there as a successor state. However, once the coveted UN membership had been obtained, and armistice agreements signed with neighboring countries, Israel parlayed this commitment into the much vaguer family reunification program, which it proceeded to apply with Kafkaesque absurdity over the next fifty years. As a result, Palestinians made refugees first in 1948, and later in 1967, continue to be deprived of their legally recognized right to return to their homes and their homeland, and the family reunification program remains the unfulfilled promise of the early years of Israeli statehood.

scholarly journals Radiographic aspects of acute community-acquired bacterial pneumonia and pulmonary tuberculosis in children

2021 ◽  
Author(s):  
Rivo Lova Herilanto Rakotomalala ◽  
Harimino Mireille Rakotondravelo ◽  
Andrianina Harivelo Ranivoson ◽  
Annick Lalaina Robinson
Keyword(s):  
Community Acquired Pneumonia ◽  
University Hospital ◽  
Radiographic Images ◽  
X Ray ◽  
Male Predominance ◽  
Mother And Child ◽  
Chest X Ray ◽  
The Right ◽  
The University ◽  
Tuberculosis In Children

Background: The etiological diagnosis of pneumonia is often difficult because of the impossibility of microbiological confirmation most of the time. Therefore, chest X-ray is still essential for a positive diagnosis and etiological orientation. The main objective of our study was to describe the radiographic aspects of acute community-acquired pneumonia and tubercular pneumonia in children.Methods: This was a descriptive retrospective study conducted at the university hospital mother and child of Tsaralalana from January 1st to July 31st, 2017.Results: Sixty-nine cases of pneumonia were included, including 13 cases of TB pneumonia and 46 cases of acute community-acquired pneumonia. The average age was 36.68 months with a male predominance. Clinically, respiratory functional signs predominated in both cases. Alteration in general condition was mainly observed in tubercular pneumonia (26.08%). Alveolar syndromes were present in 43.47% of TB pneumonias and 36.94% of acute community-acquired pneumonia. With regard to the radiographic images, alveolar involvement was common to both types of pneumonia; the nodular image was present in 8.69% of the tubercular pneumonias and 2.17% of the acute community-acquired pneumonia; the cavity image was present only in the tubercular pneumonia (p=0.04); the right-sided location predominated in both cases.Conclusions: X-ray images were common to both TB pneumonia and acute community-acquired pneumonia; some images were specific to TB pneumonia. However, the etiologic orientation of pneumonia is based on a combination of epidemiologic, clinical, and radiographic evidence.

Structure Refinements of the Layered Intergrowth Phases SbIIISbV x A 1−x TiO6 (x≃0, A = Ta, Nb) Using Synchrotron X-ray Powder Diffraction Data

1997 ◽  
Vol 53 (6) ◽  
pp. 861-869 ◽  
Author(s):  
C. D. Ling ◽  
J. G. Thompson ◽  
S. Schmid ◽  
D. J. Cookson ◽  
R. L. Withers
Keyword(s):  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Homologous Series ◽  
Rietveld Method ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Synchrotron Source ◽  
X Ray ◽  
The Family

The structures of the layered intergrowth phases SbIIISb^{\rm V}_xAl-xTiO6 (x \simeq 0, A = Ta, Nb) have been refined by the Rietveld method, using X-ray diffraction data obtained using a synchrotron source. The starting models for these structures were derived from those of Sb^{\rm III}_3Sb^{\rm V}_xA 3−xTiO14 (x = 1.26, A = Ta and x = 0.89, A = Nb), previously solved by single-crystal X-ray diffraction. There were no significant differences between the derived models and the final structures, validating the approach used to obtain the models and confirming that the n = 1 and n = 3 members of the family, Sb^{\rm III}_nSb^{\rm V}_xA n−xTiO4n+2 are part of a structurally homologous series.

A first Mn member in the struvite morphotropic series, CsMn(H2O)6(PO4): hydrothermal synthesis, crystal structure and interconnections within the family of related phosphates

2018 ◽  
Vol 74 (8) ◽  
pp. 936-943
Author(s):  
Galina V. Kiriukhina ◽  
Olga V. Yakubovich ◽  
Ekaterina M. Kochetkova ◽  
Olga V. Dimitrova ◽  
Anatoliy S. Volkov
Keyword(s):  
Crystal Structure ◽  
Ionic Radius ◽  
The Novel ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Cell Parameters ◽  
Structural Relationships ◽  
The Family

Caesium manganese hexahydrate phosphate, CsMn(H2O)6(PO4), was synthesized under hydrothermal conditions. Its crystal structure was determined from single-crystal X-ray diffraction data. The novel phase crystallizes in the hexagonal space group P63 mc and represents the first manganese member in the struvite morphotropic series, AM(H2O)6(TO4). Its crystal structure is built from Mn(H2O)6 octahedra and PO4 tetrahedra linked into a framework via hydrogen bonding. The large Cs atoms are encapsulated in the framework cuboctahedral cavities. It is shown that the size of the A + ionic radius within the morphotropic series AM(H2O)6(XO4) results is certain types of crystal structures and affects the values of the unit-cell parameters. Structural relationships with Na(H2O)Mg(H2O)6(PO4) and the mineral hazenite, KNa(H2O)2Mg2(H2O)12(PO4)2, are discussed.

scholarly journals The three-dimensional structure of a class-Pi glutathione S-transferase complexed with glutathione: the active-site hydration provides insights into the reaction mechanism

1998 ◽  
Vol 333 (3) ◽  
pp. 811-816 ◽  
Author(s):  
Antonio PÁRRAGA ◽  
Isabel GARCÍA-SÁEZ ◽  
Sinead B. WALSH ◽  
Timothy J. MANTLE ◽  
Miquel COLL
Keyword(s):  
Conformational Changes ◽  
Active Site ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Glutathione S Transferase ◽  
X Ray ◽  
The Right

The structure of mouse liver glutathione S-transferase P1-1 complexed with its substrate glutathione (GSH) has been determined by X-ray diffraction analysis. No conformational changes in the glutathione moiety or in the protein, other than small adjustments of some side chains, are observed when compared with glutathione adduct complexes. Our structure confirms that the role of Tyr-7 is to stabilize the thiolate by hydrogen bonding and to position it in the right orientation. A comparison of the enzyme–GSH structure reported here with previously described structures reveals rearrangements in a well-defined network of water molecules in the active site. One of these water molecules (W0), identified in the unliganded enzyme (carboxymethylated at Cys-47), is displaced by the binding of GSH, and a further water molecule (W4) is displaced following the binding of the electrophilic substrate and the formation of the glutathione conjugate. The possibility that one of these water molecules participates in the proton abstraction from the glutathione thiol is discussed.

Powder X-Ray Diffraction Data for the Superconducting Phase TlCaBa2Cu2O7−δ

1992 ◽  
Vol 7 (2) ◽  
pp. 115-116 ◽  
Author(s):  
Terry L. Aselage ◽  
Michael O. Eatough
Keyword(s):  
Cuprate Superconductors ◽  
General Interest ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
Pure Compound ◽  
Group 14 ◽  
X Ray ◽  
Superconducting Phases ◽  
The Family ◽  
Unit Cells

High temperature superconducting phases in the Tl-Ca-Ba-Cu-O system are ideally represented by the formula TlmCan−1Ba2CunO2(n+1)+m, with m either 1 or 2 and n = 1 to at least 3 (Parkin et at., 1988). Each of these phases contains one or more of the nearly planar CuO2sheets common to the cuprate superconductors. A single Ca atom separates adjacent CuO2sheets (n > 1). Single or double rock salt-like Tl-O layers are separated from the Can−1CunO2nregions by single Ba-O layers. Each of the Ca-containing members of this family crystallizes in a tetgragonal unit cell, with space group 14/mmm for the m = 2 series and P4/mmm for the m = 1 series.Despite the general interest in this family of superconductors, little has been reported about the m = 1, n = 2 member, TlCaBa2Cu2O7−δ, hereafter called 1122. This lack of work is due at least in part to the difficulty in synthesizing the pure compound (Michel et at., 1991). Additionally, technological interest has focused on members of the family with higher superconducting transition temperatures, particularly Tl2Ca2Ba2Cu3Oywith Tcup to 125 K. The critical temperature of 1122 has been reported from as low as 50 K (Hervieu et al., 1988) to as high as 103 K (Morosin et al., 1988), and at several values in between (Ganguli et al., 1988; Liang et al., 1988). Most of the samples had other superconducting phases in addition to 1122. Because of the nearly identical a axis lengths of the unit cells of the Tl-family of superconductors, syntactic intergrowths may be present in such multiphase samples.

Preparation and Characterization of Alpha Cellulose of Pineapple (Ananas comosus) Leaf Fibres (PALF)

2014 ◽  
Vol 895 ◽  
pp. 147-150 ◽  
Author(s):  
Nur Ain Ibrahim ◽  
Noriean Azraaie ◽  
Nurul Aimi Mohd Zainul Abidin ◽  
Nur Amira Mamat Razali ◽  
Fauziah Abdul Aziz ◽  
...  
Keyword(s):  
Low Cost ◽  
Research Work ◽  
Natural Fibre ◽  
Ananas Comosus ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Family ◽  
Main Component

The main component in natural fibre is cellulose (C6H10O5)n. Cellulose from agricultural by-product is abundant, low cost, eco-friendly, biodegradable, and renewable. This research work was prepared alpha cellulose from pineapple leaf fibre (PALF), which obtained from the leaves of pineapple plant, Ananas comosus belonged to the family Bromeliaceae. The treated and untreated samples were characterized using X-ray diffraction (XRD).

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