scholarly journals Plastically Bendable Crystals of Flufenamic Acid Form III

2020 ◽  
Author(s):  
Yu Liu ◽  
Keke Zhang ◽  
Jun Xu ◽  
Songgu Wu ◽  
Junbo Gong
Keyword(s):  
Research Field ◽  
Organic Crystal ◽  
Flufenamic Acid ◽  
X Ray Diffraction ◽  
Interesting Phenomenon ◽  
Plastic Bending ◽  
Spatially Resolved ◽  
Slip Planes ◽  
Bending Mechanism ◽  
Basic Features

Abstract Bendable organic crystal is a burgeoning research field due to interesting phenomenon and broad application prospects. Here we report a plastic bendable pharmaceutical crystal, flufenamic acid (FFA) form Ⅲ crystal. The crystal exhibits plastic bending when the force is applied on (100) face. The column-like structure and the slip planes among them are the basic features responsible for the exceptional plasticity. The spatially resolved atomic-level studies via X-ray diffraction and micro-Raman reveal the structural perturbations in FFA crystal after bending, illustrating that the packing in each “column” is also critical for the plastic bending, which contributes to the exploration of plastic bending mechanism and inspires the design of flexible organic crystal materials.

scholarly journals Spatially Resolved Forming Mechanisms Detection in Single Point Incremental Forming Using Synchrotron Based Texture Analysis

2021 ◽  
Author(s):  
Mateus Dobecki ◽  
Alexander Poeche ◽  
Walter Reimers
Keyword(s):  
Texture Analysis ◽  
Incremental Forming ◽  
Single Point ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Forming Mechanism ◽  
Spatially Resolved ◽  
Step Down ◽  
Stress States

AbstractDespite the ongoing success of understanding the deformation states in sheets manufactured by single-point incremental forming (SPIF), the unawareness of the spatially resolved influence of the forming mechanisms on the residual stress states of incrementally formed sheet metal parts impedes their application-optimized use. In this study, a well-founded experimental proof of the occurring forming mechanisms shear, bending and stretching is presented using spatially resolved, high-energy synchrotron x-ray diffraction-based texture analysis in transmission mode. The measuring method allows even near-surface areas to be examined without any impairment of microstructural influences due to tribological reactions. The depth-resolved texture evolution for different sets of forming parameters offers insights into the forming mechanisms acting in SPIF. Therefore, the forming mechanisms are triggered explicitly by adjusting the vertical step-down increment Δz for groove, plate and truncated cone geometries. The texture analysis reveals that the process parameters and the specimen geometries used lead to characteristic changes in the crystallites’ orientation distribution in the formed parts due to plastic deformation. These forming-induced reorientations of the crystallites could be assigned to the forming mechanisms by means of defined reference states. It was found that for groove, plate and truncated cone geometries, a decreasing magnitude of step-down increments leads to a more pronounced shear deformation, which causes an increasing work hardening especially at the tool contact area of the formed parts. Larger step-down increments, on the other hand, induce a greater bending deformation. The plastic deformation by bending leads to a complex stress field that involves alternating residual tensile stresses on the tool and residual compressive stresses on the tool-averted side incrementally formed sheets. The present study demonstrates the potential of high-energy synchrotron x-ray diffraction for the spatially resolved forming mechanism research in SPIF. Controlling the residual stress states by optimizing the process parameters necessitates knowledge of the fundamental forming mechanism action.

scholarly journals Spatial expression analyses of the putative oncogene ciRS-7 in cancer reshape the microRNA sponge theory

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Lasse S. Kristensen ◽  
Karoline K. Ebbesen ◽  
Martin Sokol ◽  
Theresa Jakobsen ◽  
Ulrik Korsgaard ◽  
...  
Keyword(s):  
Cancer Research ◽  
Stromal Cells ◽  
Stromal Cell ◽  
Expression Patterns ◽  
Research Field ◽  
Circular Rnas ◽  
Spatially Resolved ◽  
Cellular Expression ◽  
Competitive Endogenous Rnas ◽  
Microrna Sponge

Abstract Circular RNAs (circRNAs) have recently gained substantial attention in the cancer research field where most, including the putative oncogene ciRS-7 (CDR1as), have been proposed to function as competitive endogenous RNAs (ceRNAs) by sponging specific microRNAs. Here, we report the first spatially resolved cellular expression patterns of ciRS-7 in colon cancer and show that ciRS-7 is completely absent in the cancer cells, but highly expressed in stromal cells within the tumor microenvironment. Additionally, our data suggest that this generally apply to classical oncogene-driven adenocarcinomas, but not to other cancers, including malignant melanoma. Moreover, we find that correlations between circRNA and mRNA expression, which are commonly interpreted as evidence of a ceRNA function, can be explained by different cancer-to-stromal cell ratios among the studied tumor specimens. Together, these results have wide implications for future circRNA studies and highlight the importance of spatially resolving expression patterns of circRNAs proposed to function as ceRNAs.

Phase composition depth profiles using spatially resolved energy dispersive X-ray diffraction

2004 ◽  
Vol 37 (6) ◽  
pp. 967-976 ◽  
Author(s):  
Andrew C. Jupe ◽  
Stuart R. Stock ◽  
Peter L. Lee ◽  
Nikhila N. Naik ◽  
Kimberly E. Kurtis ◽  
...  
Keyword(s):  
Phase Composition ◽  
Spatial Resolution ◽  
Zinc Coating ◽  
High Energy ◽  
Sulfate Attack ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spatially Resolved ◽  
Composition Profiles

Spatially resolved energy dispersive X-ray diffraction, using high-energy synchrotron radiation (∼35–80 keV), was used nondestructively to obtain phase composition profiles along the radii of cylindrical cement paste samples to characterize the progress of the chemical changes associated with sulfate attack on the cement. Phase distributions were acquired to depths of ∼4 mm below the specimen surface with sufficient spatial resolution to discern features less than 200 µm thick. The experimental and data analysis methods employed to obtain quantitative composition profiles are described. The spatial resolution that could be achieved is illustrated using data obtained from copper cylinders with a thin zinc coating. The measurements demonstrate that this approach is useful for nondestructively visualizing the sometimes complex transformations that take place during sulfate attack on cement-based materials. These transformations can be spatially related to microstructure as seen by computed microtomography.

scholarly journals Controllably realizing elastic/plastic bending based on a room-temperature phosphorescent waveguiding organic crystal

2019 ◽  
Vol 10 (1) ◽  
pp. 227-232 ◽  
Author(s):  
Hao Liu ◽  
Zhengyi Bian ◽  
Qinyu Cheng ◽  
Linfeng Lan ◽  
Yue Wang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Organic Crystal ◽  
Plastic Bending ◽  
Elastic Bending ◽  
Elastic Plastic

The room-temperature phosphorescent DBBZL crystals could exhibit reversible bending and irreversible bending based on one crystal. These flexible crystals exhibit good waveguiding property in straight state, elastic bending state and plastic bending state, demonstrating the application of flexibility.

Theoretical and experimental study of the gradient properties and the resulting local crystalline structure and orientation in magnetron-sputtered CrAlN coatings with lateral composition and thickness gradient

2017 ◽  
Vol 50 (4) ◽  
pp. 1000-1010
Author(s):  
Bärbel Krause ◽  
Michael Stüber ◽  
Anna Zimina ◽  
Ralph Steininger ◽  
Mareike Trappen ◽  
...  
Keyword(s):  
Target Surface ◽  
Sample Surface ◽  
Composition Gradient ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Al Content ◽  
Spatially Resolved ◽  
Composition Profiles ◽  
Face Centered

Cr–Al–N coatings with a lateral composition gradient were deposited from two segmented Cr/Al targets with different segment size, thus covering the Al content range 0.22 ≲ c ≲ 0.87 and a thickness range from several hundred nanometres to several micrometres. The two-dimensional thickness and composition profiles were determined nondestructively from X-ray fluorescence maps. The results were reproduced by simulations of the flux distribution on the sample surface, combiningTRIDYNsimulations of the reactive sputter process at the target surface andSIMTRAsimulations of the subsequent transport through the gas phase. The phase formation was studied by spatially resolved X-ray diffraction and X-ray absorption spectroscopy at the Cr Kedge. Forc ≲ 0.69, a single-phase solid solution face-centered cubic (f.c.c.) (Cr,Al)N phase was found, and for 0.69 ≲ c ≲ 0.87 coexisting f.c.c. (Cr,Al)N and hexagonal close packed (h.c.p.) (Cr,Al)N phases were observed. The biaxial texture formation in nearly the entire composition range indicates a zone T growth. Four, mainly composition-dependent, texture regions were identified. All observed textures are closely related to textures reported for the h.c.p. AlN and f.c.c. CrN parent phases. Forc ≳ 0.69, a strong thickness dependence of the textures was observed. The measurements reveal an orientation relation between different f.c.c. and h.c.p. textures, indicating that local epitaxy might play a role in the structure formation.

D008 External Sulfate Attack on Cement Examined by Spatially Resolved Energy Dispersive Synchrotron X-ray Diffraction and Computed Microtomography

2003 ◽  
Vol 18 (2) ◽  
pp. 181-181
Author(s):  
A. P. Wilkinson ◽  
A. C. Jupe ◽  
K. E. Kurtis ◽  
N. N. Naik ◽  
S. D. Shastri ◽  
...  
Keyword(s):  
Sulfate Attack ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spatially Resolved ◽  
Computed Microtomography

scholarly journals Polarization spectroscopy methods in the determination of interactions of small molecules with nucleic acids – tutorial

2018 ◽  
Vol 14 ◽  
pp. 84-105 ◽  
Author(s):  
Tamara Šmidlehner ◽  
Ivo Piantanida ◽  
Gennaro Pescitelli
Keyword(s):  
Nucleic Acids ◽  
Small Molecules ◽  
Helical Structure ◽  
Linear Dichroism ◽  
Research Field ◽  
X Ray Diffraction ◽  
Polarization Spectroscopy ◽  
Dna And Rna

The structural characterization of non-covalent complexes between nucleic acids and small molecules (ligands) is of a paramount significance to bioorganic research. Highly informative methods about nucleic acid/ligand complexes such as single crystal X-ray diffraction or NMR spectroscopy cannot be performed under biologically compatible conditions and are extensively time consuming. Therefore, in search for faster methods which can be applied to conditions that are at least similar to the naturally occurring ones, a set of polarization spectroscopy methods has shown highly promising results. Electronic circular dichroism (ECD) is the most commonly used method for the characterization of the helical structure of DNA and RNA and their complexes with ligands. Less common but complementary to ECD, is flow-oriented linear dichroism (LD). Other methods such as vibrational CD (VCD) and emission-based methods (FDCD, CPL), can also be used for suitable samples. Despite the popularity of polarization spectroscopy in biophysics, aside several highly focused reviews on the application of these methods to DNA/RNA research, there is no systematic tutorial covering all mentioned methods as a tool for the characterization of adducts between nucleic acids and small ligands. This tutorial aims to help researchers entering the research field to organize experiments accurately and to interpret the obtained data reliably.

Investigation of Crystallization in an Amorphous Cu-Based Alloy by X-Ray

2008 ◽  
Vol 589 ◽  
pp. 131-136
Author(s):  
E. Nagy ◽  
Dóra Janovszky ◽  
Mária Svéda ◽  
Kinga Tomolya ◽  
L.K. Varga ◽  
...  
Keyword(s):  
Amorphous Alloys ◽  
Crystallization Process ◽  
Reference Data ◽  
Diffraction Method ◽  
Research Field ◽  
High Price ◽  
Ti Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Significant Research

Recently one of the most significant research-field in the development of amorphous alloys is the research of the Cu-based amorphous alloys. The Zr-based alloys developed earlier can be replaced by the newly developed Cu-based alloys as the high price of the Zr-based alloys limits their utilization in spite of their favourable properties. Production of Cu-based alloys having the same or more favourite properties than Zr-based alloys is cheaper and this fact can promote their increasing utilization. Cu-Zr-Ti and Cu-Hf-Ti alloy systems – they are Cu-based alloys – have excellent mechanical properties. In this paper investigations of crystallization of amorphous Cu44,25Zr36Ag14,75Ti5 powder produced by ball milling (these processes have not been investigated yet according to the reference data) are described. In the course of investigation of the crystallization process, samples were heated to a temperature of investigation by means of a DSC equipment and the developed state was frozen by chilling. The investigation of the developed structure and to identify the phases formed during heat treatment, X-ray diffraction method was used.

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