scholarly journals Fabrication of Three-Dimensional Piezoelectric Ceramics Using the Dispenser System

2019 ◽  
Vol 16 (3) ◽  
pp. 136-140
Author(s):  
Shuto Matsuda ◽  
Tadashi Fujii ◽  
Naoya Nakada ◽  
Tomoaki Karaki ◽  
Tatsunori Kakuda
Keyword(s):  
Three Dimensional ◽  
Piezoelectric Ceramics ◽  
Polyvinyl Butyral ◽  
Uniaxial Pressure ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
X Ray ◽  
Acoustic Wave Sensors ◽  
Paste Extrusion ◽  
Wave Sensors

Abstract We fabricated lead-free (K,Na,Li)NbO3 (KNLN) and BaTiO3 (BT) piezoelectric ceramics using a dispenser system. After dissolving polyvinyl butyral in ethanol, a paste for extrusion was fabricated by mixing KNLN or BT ceramic powders. After several times of paste extrusion with a dispenser system, degreasing was performed at 650°C. The KNLN moldings were sintered, at 1,100–1,170°C, and sintering of BT moldings were performed by two-step sintering at 1,320°C and 1,150°C. From the x-ray diffraction pattern, the fabricated KNLN ceramics had a perovskite structure. The density of the KNLN and BT moldings fabricated by the dispenser system was 3.94 and 5.42 g/cm3, respectively. In addition, the BT moldings had the dielectric constant εr = 1.95 × 103. The Curie temperature of the BT moldings was confirmed at about 125°C, as with the BT piezoelectric ceramics fabricated by uniaxial pressure molding. The BT moldings had the piezoelectric constant d33 = 60 pC/N. The fabrication methods studied in this work provided the potential to fabricate simple three-dimensional piezoelectric ceramic devices for applications in acoustic wave sensors.

Microstructural mapping of C60 phase transformation into disordered graphite at high pressure, using X-ray diffraction microtomography

2010 ◽  
Vol 44 (1) ◽  
pp. 163-171 ◽  
Author(s):  
Michelle Álvarez-Murga ◽  
Pierre Bleuet ◽  
Leonel Marques ◽  
Christophe Lepoittevin ◽  
Nathalie Boudet ◽  
...  
Keyword(s):  
High Pressure ◽  
Phase Transformation ◽  
Phase Distribution ◽  
Three Dimensional ◽  
Fiber Texture ◽  
Uniaxial Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Non Invasive ◽  
Transmission Electron

An extended use of synchrotron-based X-ray diffraction microtomography (XRD-µCT) to study simultaneously the phase distribution and microstructure in phase-transformation processes is proposed. This three-dimensional non-invasive imaging approach has been applied to understand the phase transformation of C60 rhombohedral polymer (C60R) into disordered graphite (DG) at high pressure and high temperature. The heterogeneous sample was synthesized (5 GPa, 1100 K) using a Paris–Edinburgh cell and selective image reconstructions were achieved for all different phases present in this sample. The XRD-µCT analysis evidences elongated DG domains with a fiber texture where nested (002)DGplanes show ±70° preferential orientation relative to the compression axis. In contrast C60R domains are found to be small and spotty, preferentially in the middle of the sample. The parent and product phases are mutually interpenetrative and exhibit a crystallographic relationship. This study evidences that formation of (002)DGplanes occurs parallel to {111}C60Cpseudo-cubic planes. Among these four possible alignments, uniaxial pressure favors one [111]C60Cdirection. Transmission electron microscopy observations validate these nondestructive XRD-µCT results.

Ribosome Structural Organization

1974 ◽  
Vol 32 ◽  
pp. 332-333
Author(s):  
James A. Lake
Keyword(s):  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Small Subunit ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Specific Antibodies ◽  
X Ray ◽  
E Coli ◽  
Complete Sequences

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.

Raman And Fluorescence Spectra Observed in Laser Microprobe Measurements of Several Compositions in the Ln-Ba-Cu-O System

1990 ◽  
Vol 48 (2) ◽  
pp. 278-279
Author(s):  
Edgar S. Etz ◽  
Thomas D. Schroeder ◽  
Winnie Wong-Ng
Keyword(s):  
Fluorescence Spectra ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Raman Microprobe ◽  
Methods Of Synthesis ◽  
Compositional Homogeneity ◽  
Processing Techniques

We are investigating by Raman microprobe measurements the superconducting and related phases in the LnBa2Cu3O7-x (for x=0 to 1) system where yttrium has been replaced by several of the lanthanide (Ln = Nd,Sm,Eu,Ho,Er) elements. The aim is to relate the observed optical spectra (Raman and fluorescence) to the compositional and structural properties of these solids as part of comprehensive materials characterization. The results are correlated with the methods of synthesis, the processing techniques of these materials, and their superconducting properties. Of relevance is the substitutional chemistry of these isostructural systems, the differences in the spectra, and their microanalytical usefulness for the detection of impurity phases, and the assessment of compositional homogeneity. The Raman spectra of most of these compounds are well understood from accounts in the literature.The materials examined here are mostly ceramic powders prepared by conventional solid state reaction techniques. The bulk samples are of nominally single-phase composition as determined by x-ray diffraction.

scholarly journals An investigation of polyhedral deformation in two mixed-metal diarsenates: SrZnAs2O7and BaCuAs2O7

2015 ◽  
Vol 71 (4) ◽  
pp. 330-337 ◽  
Author(s):  
Sabina Kovač ◽  
Ljiljana Karanović ◽  
Tamara Đorđević
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
General Formula ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Open Framework ◽  
Geometrical Characteristics ◽  
Barium Copper

Two isostructural diarsenates, SrZnAs2O7(strontium zinc diarsenate), (I), and BaCuAs2O7[barium copper(II) diarsenate], (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The three-dimensional open-framework crystal structure consists of corner-sharingM2O5(M2 = Zn or Cu) square pyramids and diarsenate (As2O7) groups. Each As2O7group shares its five corners with five differentM2O5square pyramids. The resulting framework delimits two types of tunnels aligned parallel to the [010] and [100] directions where the large divalent nine-coordinatedM1 (M1 = Sr or Ba) cations are located. The geometrical characteristics of theM1O9,M2O5and As2O7groups of known isostructural diarsenates, adopting the general formulaM1IIM2IIAs2O7(M1II= Sr, Ba, Pb;M2II= Mg, Co, Cu, Zn) and crystallizing in the space groupP21/n, are presented and discussed.

A new model for packing of type-I collagen molecules in the native fibril

1981 ◽  
Vol 1 (10) ◽  
pp. 801-810 ◽  
Author(s):  
Karl A. Piez ◽  
Benes L. Trus
Keyword(s):  
Type I Collagen ◽  
Hexagonal Lattice ◽  
Three Dimensional ◽  
Equatorial Region ◽  
Type I ◽  
X Ray Diffraction ◽  
X Ray ◽  
Left Handed ◽  
Crystal Model ◽  
Collagen Molecules

A specific fibril model is presented consisting of bundles of five-stranded microfibrils, which are usually disordered (except axially) but under lateral compression become ordered. The features are as follows (where D = 234 residues or 67 nm): (1) D-staggered collagen molecules 4.5 D long in the helical microfibril have a left-handed supercoil with a pitch of 400–700 residues, but microfibrils need not have helical symmetry. (2) Straight-tilted 0.5-D overlap regions on a near-hexagonal lattice contribute the discrete x-ray diffraction reflections arising from lateral order, while the gap regions remain disordered. (3) The overlap regions are equivalent, but are crystallographically distinguished by systematic displacements from the near-hexagonal lattice. (4) The unit cell is the same as in a recently proposed three-dimensional crystal model, and calculated intensities in the equatorial region of the x-ray diffraction pattern agree with observed values.

scholarly journals Acemetacin cocrystals and salts: structure solution from powder X-ray data and form selection of the piperazine salt

IUCrJ ◽  
2014 ◽  
Vol 1 (2) ◽  
pp. 136-150 ◽  
Author(s):  
Palash Sanphui ◽  
Geetha Bolla ◽  
Ashwini Nangia ◽  
Vladimir Chernyshev
Keyword(s):  
Hydrogen Bonds ◽  
Dissolution Rate ◽  
Aqueous Medium ◽  
Acid Amide ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Reference Drug ◽  
X Ray ◽  
Time Period ◽  
Solid Form

Acemetacin (ACM) is a non-steroidal anti-inflammatory drug (NSAID), which causes reduced gastric damage compared with indomethacin. However, acemetacin has a tendency to form a less soluble hydrate in the aqueous medium. We noted difficulties in the preparation of cocrystals and salts of acemetacin by mechanochemical methods, because this drug tends to form a hydrate during any kind of solution-based processing. With the objective to discover a solid form of acemetacin that is stable in the aqueous medium, binary adducts were prepared by the melt method to avoid hydration. The coformers/salt formers reported are pyridine carboxamides [nicotinamide (NAM), isonicotinamide (INA), and picolinamide (PAM)], caprolactam (CPR),p-aminobenzoic acid (PABA), and piperazine (PPZ). The structures of an ACM–INA cocrystal and a binary adduct ACM–PABA were solved using single-crystal X-ray diffraction. Other ACM cocrystals, ACM–PAM and ACM–CPR, and the piperazine salt ACM–PPZ were solved from high-resolution powder X-ray diffraction data. The ACM–INA cocrystal is sustained by the acid...pyridine heterosynthon and N—H...O catemer hydrogen bonds involving the amide group. The acid...amide heterosynthon is present in the ACM–PAM cocrystal, while ACM–CPR contains carboxamide dimers of caprolactam along with acid–carbonyl (ACM) hydrogen bonds. The cocrystals ACM–INA, ACM–PAM and ACM–CPR are three-dimensional isostructural. The carboxyl...carboxyl synthon in ACM–PABA posed difficulty in assigning the position of the H atom, which may indicate proton disorder. In terms of stability, the salts were found to be relatively stable in pH 7 buffer medium over 24 h, but the cocrystals dissociated to give ACM hydrate during the same time period. The ACM–PPZ salt and ACM–nicotinamide cocrystal dissolve five times faster than the stable hydrate form, whereas the ACM–PABA adduct has 2.5 times faster dissolution rate. The pharmaceutically acceptable piperazine salt of acemetacin exhibits superior stability, faster dissolution rate and is able to overcome the hydration tendency of the reference drug.

2D X-ray diffraction and molecular modelling of the crystalline structure of polyesters under uniaxial stress

2021 ◽  
pp. 096739112199822
Author(s):  
Ahmed I Abou-Kandil ◽  
Gerhard Goldbeck
Keyword(s):  
Crystalline Structure ◽  
Molecular Modelling ◽  
Three Dimensional ◽  
Uniaxial Stress ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Modelling Techniques ◽  
Diffraction Patterns

Studying the crystalline structure of uniaxially and biaxially drawn polyesters is of great importance due to their wide range of applications. In this study, we shed some light on the behaviour of PET and PEN under uniaxial stress using experimental and molecular modelling techniques. Comparing experiment with modelling provides insights into polymer crystallisation with extended chains. Experimental x-ray diffraction patterns are reproduced by means of models of chains sliding along the c-axis leading to some loss of three-dimensional order, i.e. moving away from the condition of perfect register of the fully extended chains in triclinic crystals of both PET and PEN. This will help us understand the mechanism of polymer crystallisation under uniaxial stress and the appearance of mesophases in some cases as discussed herein.

A New POM-Based Supramolecular Compound: Synthesis, Structure and Adsorptive Property of [Cu(phen)2]3[W6O19]

2014 ◽  
Vol 919-921 ◽  
pp. 2013-2016 ◽  
Author(s):  
Ya Bing Liu ◽  
Hong Jie Wang ◽  
Hong Kai Zhao
Keyword(s):  
Three Dimensional ◽  
Building Blocks ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Hybrid Compound ◽  
Adsorptive Property ◽  
X Ray ◽  
Hydrogen Bonding Interactions ◽  
Compound Synthesis ◽  
Metal Organic

A POM - based organice - inorganic hybrid compound with the chemical formula of[Cu (phen)2]3[W6O19] (phen = 1,10-phenanthroline) (1) has been hydrothermally synthesized andstructurally characterized by the elemental analysis, and single crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic space groupC2/c witha=18.319(4) Å,b= 17.311(4) Å,c= 22.248(4) Å,β= 112.40(3) o,V= 6523(2) Å3,Z= 4, R1= 0.0448, andwR2=0.1218. Compound 1 consists of the [W6O19]3-building blocks and [Cu (phen)2]+metal organic cationic moieties, which are packed together via the extensive hydrogen-bonding interactions to form a three-dimensional supramolecular framework. The adsorption of methylene blue (MB) under UV irradiation with 1 as the heterogeneous adsorbent has been investigated, showing a good adsorptive property of 1 for MB degradation.

scholarly journals Synthesis of Three-Dimensional Fe3O4/Graphene Aerogels for the Removal of Arsenic Ions from Water

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Yan Ye ◽  
Da Yin ◽  
Bin Wang ◽  
Qingwen Zhang
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
3D Structure ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Aerogels ◽  
Transmission Electron ◽  
Potential Applications ◽  
Removal Of Arsenic

We report the synthesis of three-dimensional Fe3O4/graphene aerogels (GAs) and their application for the removal of arsenic (As) ions from water. The morphology and properties of Fe3O4/GAs have been characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and superconducting quantum inference device. The 3D nanostructure shows that iron oxide nanoparticles are decorated on graphene with an interconnected network structure. It is found that Fe3O4/GAs own a capacity of As(V) ions adsorption up to 40.048 mg/g due to their remarkable 3D structure and existence of magnetic Fe3O4nanoparticles for separation. The adsorption isotherm matches well with the Langmuir model and kinetic analysis suggests that the adsorption process is pseudo-second-ordered. In addition to the excellent adsorption capability, Fe3O4/GAs can be easily and effectively separated from water, indicating potential applications in water treatment.

scholarly journals Synthesis, Crystal Structure, and Properties of a New Coordination Polymer Built from N/O-Donor Mixed Ligands

Crystals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 372
Author(s):  
Mei-An Zhu ◽  
Shuai-Shuai Han ◽  
Feng Deng ◽  
Jia-Le Li ◽  
Shui-Sheng Chen
Keyword(s):  
Coordination Polymer ◽  
Weak Interactions ◽  
Three Dimensional ◽  
Luminescent Properties ◽  
Tridentate Ligand ◽  
Supramolecular Polymer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mixed Ligands ◽  
Benzenedicarboxylic Acid

The coordination polymer, namely, [Cd(H2L)(nobda)]n (1) was prepared by the reaction of Cd(NO3)2·4H2O with 4-amino-1,2-benzenedicarboxylic acid (H2nobda) and 1,4-di(1H-imidazol-4-yl)benzene (H2L), and characterized by single-crystal X-ray diffraction, elemental analysis, infrared (IR) spectroscopy, thermogravimetric analysis, and powder X-ray diffraction (PXRD). The carboxylic acid of H2nobda ligands was completely deprotonated to be nobda2− anions, which act as tridentate ligand to connect the Cd2+ to form two-dimensional (2D) network, while the neutral H2L ligands serve as a linear didentate bridge to connect two adjacent Cd2+ ions upper and down the 2D layer. The adjacent 2D layers were further linked into the three-dimensional (3D) supramolecular polymer by the weak interactions such as hydrogen bonds and π−π stacking interactions. The ultraviolet-visible (UV-vis) absorption spectra and luminescent properties in the solid state at room temperature have been investigated.

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