Internal Gettering as a Function of the Wafer Position in the Original Crystal Rod

ESPRIT ’90 ◽  
1990 ◽  
pp. 77-87
Author(s):  
K. Graff
Keyword(s):  
Original Crystal

scholarly journals The cardioprotective effects of the new crystal form of puerarin in isoproterenol-induced myocardial ischemia rats based on metabolomics

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yuzhi Zhou ◽  
Mengru Li ◽  
Jia Song ◽  
Yongqiang Shi ◽  
Xuemei Qin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Myocardial Ischemia ◽  
Cardiac Tissue ◽  
Crystal Form ◽  
Cardiac Marker ◽  
Cardiac Tissues ◽  
Stress Indices ◽  
Cardioprotective Effects ◽  
Original Crystal ◽  
Better Than

Abstract Puerarin has shown unique pharmacological effects on myocardial ischemia (MI). Changing the crystal form is an effective approach to improve the cardioprotective effects of puerarin. However, the mechanisms of the new crystal form of puerarin are unclear. In this study, an electrocardiogram, echocardiography, cardiac marker enzymatic activity, oxidative stress indices, and myocardial histology analysis of cardiac tissues were performed to evaluate the cardioprotective effects of the new crystal form of puerarin. Moreover, serum and cardiac tissue metabolomics based on nuclear magnetic resonance (NMR) were used to investigate the potential mechanism of the new crystal form. The results indicated that the new crystal form of puerarin (30 mg/kg) could improve oxidative stress indices, and these improvements were similar to those of the original crystal form of puerarin (120 mg/kg). The new crystal form of puerarin (30 mg/kg) could effectively improve the activities of cardiac marker enzymes, and the improvement effects were better than those of the original crystal form (120 mg/kg). Moreover, metabolomics analysis showed that amino acid metabolism, oxidative stress and energy metabolism were disturbed after MI and could be improved by puerarin. These results demonstrated that the new crystal form of puerarin was effective in treating MI.

ZONES: a search/match database for single-crystal electron diffraction

2002 ◽  
Vol 35 (5) ◽  
pp. 552-555 ◽  
Author(s):  
Haskell V. Hart
Keyword(s):  
Analytical Chemistry ◽  
Electron Diffraction ◽  
Personal Computer ◽  
Materials Science ◽  
Crystal Data ◽  
Double Diffraction ◽  
Selected Area Electron Diffraction ◽  
Unit Cells ◽  
Crystal Electron ◽  
Original Crystal

ZONES is a relational database built from NIST Crystal Data for the identification of single crystals by selected area electron diffraction (SAED) and elemental analysis using MicrosoftAccess 97for the personal computer (subsequently converted toAccess 2000). The two largest experimentaldspacings and included angle in a zone are matched against values calculated from reduced unit cells, thereby fully and rigorously incorporating the effects of double diffraction. A total of 79136 inorganic phases are included with original Crystal Data reference codes, allowing access to all the information in NIST Crystal Data. Specific examples illustrate the robustness of this approach. This database will be most useful to researchers in mineralogy, metallurgy, materials science, forensics and analytical chemistry who seek to identify well characterized phases with known unit cells.

scholarly journals V.—A Description of the Big Diamond recently found in the Premier Mine, Transvaal

1905 ◽  
Vol 2 (4) ◽  
pp. 170-172 ◽  
Author(s):  
F. H. Hatch ◽  
G. S. Corstorphine
Keyword(s):  
South African ◽  
The South ◽  
Size And Shape ◽  
The World ◽  
The Face ◽  
Points Of View ◽  
Original Crystal ◽  
Actual Size

Great interest has been excited, not only in the Transvaal, but throughout the world, by the discovery at the Premier Mine, on Wednesday, the 25th January, 1905, of the largest diamond hitherto known. The stone was found by Mr. Wells, Surface Manager, in the yellow ground about 18 feet from the surface, a brilliant flash of light from a projecting corner having caught his attention. After a preliminary cleaning it weighs 3,024¾ carats. According to Gardner Williams the South African carat is equivalent to 3.174 grains; consequently the diamond weighs 9600.5 grains troy or 1.37 lbs. avoirdupois. Through the courtesy of the Directors of the Company, we have been enabled to make an examination of the stone, with the following result:—Roughly speaking, it measures. 4 by 2½12 by 2 inches; but its size and shape will be best realized by reference to the photographs reproduced on Plates VII and VIII, which represent the diamond from four different points of view and its actual size. These beautiful photographs were taken by Mr. E. H. V. Melvill for the purposes of this description. The stone is bounded by eight surfaces, four of which are faces of the original crystal, and will be referred to in this description under the letters A, B, C, D, and four are cleavage surfaces, the cleavage being of course parallel to the face of the octahedron. In the following description these cleavage surfaces are referred to under the letters E, F, G, H. They are distinguished from the original octahedral faces by greater regularity and smoothness.

RINGS: a new search/match database for identification by polycrystalline electron diffraction

2002 ◽  
Vol 35 (5) ◽  
pp. 546-551 ◽  
Author(s):  
David R. Denley ◽  
Haskell V. Hart
Keyword(s):  
Analytical Chemistry ◽  
Electron Diffraction ◽  
Elemental Analysis ◽  
Materials Science ◽  
Crystal Data ◽  
Double Diffraction ◽  
Selected Area Electron Diffraction ◽  
Unit Cells ◽  
Polycrystalline Solids ◽  
Original Crystal

RINGS is a relational database built from NIST Crystal Data for the identification of polycrystalline solids by selected area electron diffraction (SAED) and elemental analysis using MicrosoftAccess 97(subsequently converted toAccess 2000). Experimentaldspacings are matched against values calculated from reduced unit cells, thereby fully and rigorously incorporating the effects of double diffraction. A total of 79136 inorganic phases are included with original Crystal Data reference codes, allowing access to all the information in NIST Crystal Data. Specific examples illustrate the advantages over previous approaches to the problem. This database will be most useful to researchers in mineralogy, metallurgy, materials science, forensics and analytical chemistry who seek to identify well characterized phases with known unit cells.

scholarly journals Preparation of anisole in phenol by Zn/HZSM-5 catalyst from walnut shell catalyzed liquefaction

BioResources ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 1628-1641
Author(s):  
Jianxiang Liu ◽  
Yuhan Lu ◽  
Ruiling Wang ◽  
Yuanbo Huang ◽  
Can Liu ◽  
...  
Keyword(s):  
Small Molecule ◽  
Mass Difference ◽  
Walnut Shell ◽  
Narrow Pore Size Distribution ◽  
Peak Intensity ◽  
Promotional Effect ◽  
Stretching Vibration ◽  
Signal Peak ◽  
Original Crystal ◽  
Uniform Particle Size

The promotional effect of Zn was investigated relative to the calcining activation of HZSM-5. It was found that the lignin separated from walnut shell could be liquefied into small molecular ethers such as anisole by the promotional effect of the modified catalyst. Experimental results showed that, after the loading of Zn, the HZSM-5 catalyst retained its original crystal structure, which exhibited good metal dispersion. Besides, due to the existence of two interactions respectively of Zn with Al and Zn with a Brønsted-Lowry acid on the Zn/HZSM-5 catalyst surface, the remaining catalyst intergranular distance increased, particularly for the 2% Zn/HZSM-5 catalyst. The inside of the catalyst was in a state of spherical particle aggregation with a narrow pore size distribution and uniform particle size. The peak intensity of the Si-O stretching vibration was affected by the content of Zn, which was least affected for the 2% Zn/HZSM-5 catalyst. The signal peak of this small molecule ether was not found in the absence of the metal ions, and the catalytic effect of 2% Zn/HZSM-5 was more distinct. Calculated by the mass difference method, the yield of the liquid via the 2% Zn/HZSM-5 catalyst was 59.8%, including phenol and small molecule ethers represented by anisole.

scholarly journals Facile Preparation and Characteristic Analysis of Sulfated Cellulose Nanofibril via the Pretreatment of Sulfamic Acid-Glycerol Based Deep Eutectic Solvents

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2778
Author(s):  
Weidong Li ◽  
Yu Xue ◽  
Ming He ◽  
Jiaqiang Yan ◽  
Lucian A. Lucia ◽  
...  
Keyword(s):  
Cellulose Nanofibrils ◽  
Deep Eutectic Solvent ◽  
Sulfamic Acid ◽  
Deep Eutectic Solvents ◽  
Uv Resistance ◽  
Cellulose Nanofibril ◽  
Characteristic Analysis ◽  
Maximum Reduction ◽  
High Degree ◽  
Original Crystal

A deep eutectic solvent (DES) composed of sulfamic acid and glycerol allowed for the sustainable preparation of cellulose nanofibrils (CNF) with simultaneous sulfation. The reaction time and the levels of sulfamic acid demonstrated that fibers could be swelled and sulfated simultaneously by a sulfamic acid-glycerol-based DES and swelling also promoted sulfation with a high degree of substitution (0.12). The DES-pretreated fibers were further nanofibrillated by a grinder producing CNF with diameters from 10 nm to 25 nm. The crystallinity ranged from 53–62%, and CNF maintained the original crystal structure. DES pretreatment facilitated cellulose nano-fibrillation and reduced the energy consumption with a maximum reduction of 35%. The films prepared from polyvinyl alcohol (PVA) and CNF showed good UV resistance ability and mechanical properties. This facile and efficient method provided a more sustainable strategy for the swelling, functionalization and nano-fibrillation of cellulose, expanding its application to UV-blocking materials and related fields.

scholarly journals A Pseudouridine Isoxazolidinyl Nucleoside Analogue Structural Analysis: A Morphological Approach

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3381
Author(s):  
Giuseppe Floresta ◽  
Venerando Pistarà ◽  
Kirsten E. Christensen ◽  
Emanuele Amata ◽  
Agostino Marrazzo ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Wild Type ◽  
Single Crystal Diffraction ◽  
Crystallization Method ◽  
In Silico Study ◽  
Morphological Approach ◽  
Docking Approach ◽  
Polymorphic Forms ◽  
Original Crystal ◽  
Microscopy Images

An in silico study has been conducted upon (3′RS,5′SR)-5-[2′-benzyl-5′-hydroxymethyl-1′,2′-isoxazolidin-3′-yl]uracil through a molecular dynamics/docking approach that highlights its potential inhibitory activity upon the wild-type pseudouridine 5′-monophosphate glycosidase. The crystal structure of this compound has been solved by means of X-ray single crystal diffraction and the data inferred were used to predict its crystal morphology. These data were compared with optical microscopy images and confirmed the validity of the computed models. This robust approach, already used for several other different compounds, provides a fast and reliable tool to standardize a crystallization method in order to get similar and good quality crystals. As different crystal shapes could be associated with different polymorphic forms, this method could be considered a fast and cheap screening to choose among different and coexistent polymorphic forms. Furthermore, a match with the original crystal structure of pseudouridine 5′-monophosphate is provided.

scholarly journals Preparation and Photoluminescence of Transparent Poly(methyl methacrylate)-Based Nanocomposite Films with Ultra-High-Loading Pendant ZnS Quantum Dots

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1217 ◽  
Author(s):  
Jinku Xu ◽  
Dongmei Li
Keyword(s):  
Quantum Dots ◽  
Thermogravimetric Analysis ◽  
Methyl Methacrylate ◽  
Nanocomposite Films ◽  
High Loading ◽  
Pmma Film ◽  
X Ray Diffraction ◽  
Poly Methyl Methacrylate ◽  
Transmission Electron ◽  
Original Crystal

Transparent nanocomposite films containing quantum dots are popular because of their extensive applications. However, nanoparticles tend to aggregate, resulting in phase separation of the nanoparticles in the polymer matrix. Herein, we present a bulk thermo-curing copolymerization method to fabricate poly(methyl methacrylate)-based nanocomposite films with ultra-high-loading ZnS quantum dots (ZnS/PMMA), utilizing polymerizable group-capped ZnS and monomer of methyl methacrylate (MMA). We found that the nanocomposite film is highly transparent, although the transmittance decreases with the ZnS content, especially at the wavelength between 300 nm and 400 nm. The results from X-ray diffraction (XRD), transmission electron microscopy (TEM), and dynamic mechanical thermal analysis (DMTA) show that the ZnS quantum dots maintain their original crystal structure, and are uniformly dispersed in the nanocomposite films, even with a very high ZnS content (41 wt %, determined by thermogravimetric analysis). The thermogravimetric analysis shows that the nanocomposite films possess a better thermal stability than that of pure PMMA film. The photoluminescence measurements show that ZnS/PMMA nanocomposite films have good optical properties. The fluorescence intensity increases with the increment of free ZnS content to 30 wt %, and then decreases due to self-reabsorption at a higher ZnS content. The transparent ZnS/PMMA nanocomposite films have a potential application as photoluminescence material.

Xenocrystic richterite in an olivine-nephelinite: destabilisation and diffusion phenomena

1993 ◽  
Vol 57 (388) ◽  
pp. 515-525
Author(s):  
Christiane Wagner ◽  
Abdelkader Mokhtari ◽  
Danielle Velde
Keyword(s):  
Reaction Zone ◽  
Diffusion Coefficients ◽  
Solidus Temperature ◽  
Mass Balance Calculation ◽  
Temperature Diffusion ◽  
Diffusion Phenomena ◽  
Compositional Variations ◽  
And Diffusion ◽  
Crystallisation Sequence ◽  
Original Crystal

AbstractA partly destabilised Na-richterite has been found in an olivine-nephelinite from Morocco. The riehterite crystal (600 × 420 μm) is surrounded by a reaction zone (400-700 μm) of K- and Si-rich glass containing small (<50 μm) olivine (Fo80-83%) and endiopside crystals. Outwards, another zone is formed of normal magmatic minerals and circumscribes the original crystal, indicating that the destabilisation event took place at the end of the crystallisation sequence. Estimated ascent time of about 100 hours would have completely decomposed an isolated richterite crystal, which suggests that the amphibole was originally included in a xenolith. A mass-balance calculation shows that the fichterite isovolumic decomposition was accompanied by exchanges with the magma. The loss of Na from the reaction zone and the gain of AI from the magma allowed the precipitation of an analcime-rich zone observed around the destabilised amphibole and the concentration of K in the reaction zone glass. Compositional variations, Fe and Ti increase and Mg, Ca and F decrease at the richterite edge are interpreted as the result of a diffusion process. No alkali gradients are observed. The diffusion phenomenon lasted less than 100 hours and ceased to be operative at a temperature of 900-950°C i.e. just below the solidus temperature. Diffusion coefficients for the amphibole are proposed: e.g 10−9 cm2 s−1 for K2O and 10−10 for FeO at 900°C

scholarly journals EFFECT OF ETHANOL-WATER COMPOSITION ON CLINDAMYCIN HYDROCHLORIDE PSEUDOPOLYMORPHISM

2016 ◽  
Vol 8 (11) ◽  
pp. 269 ◽  
Author(s):  
Ilma Nugrahani ◽  
Silvana Anggraeni
Keyword(s):  
Room Temperature ◽  
Crystal Form ◽  
Recrystallization Process ◽  
Polarization Microscopy ◽  
X Ray ◽  
Water Composition ◽  
Infra Red ◽  
Long Time ◽  
Ethanol In Water ◽  
Original Crystal

Objective: Formation of clindamycin hydrochloride (clindamycin HCl) in monohydrate-ethanolate from the recrystallization process with ethanol–water (5:2) has been reported a long time ago. However, the effect of ethanol-water compositions into pseudo-polymorphism formation and its stability of was not reported yet. This study aimed to investigate the effect of ethanol-water proportion on the formation of clindamycin HCl-monohydrate and its ethanol solvate.Methods: Clindamycin HCl was recrystallized with the various percentages of ethanol. The fresh and after storage for 24 h at humidity and room temperature (25±2 °C, RH: 70±1%) crystals were characterized by FTIR (Fourier transform infra-red), PXRD (powder x-ray diffractometer), and DTA (differential scanning calorimeter). The study of desolvation/dehydration then was observed with a polarization microscopy-plate heater.Results: The results showed that monohydrate crystal was obtained from recrystallization in a concentration less than 50% ethanol in water. Next, the ethanolate was produced from the solvent of>70% ethanol. Meanwhile, the 50–70 % ethanol produced a hydrate–ethanolate, crystal, which has both hydrate and ethanol in its lattice. This hydrate-ethanolates was unstable, even in ambient temperature.Conclusion: Concentration of ethanol in water as the solvent will determine the clindamycin HCl pseudo polymorphism, which will back to its original crystal form by the time of storage.

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