X-Ray Crystallography and Its Applications (original) (raw)
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Physics Education, 1995
X-ray Crystallography is a scientific method used to determine the arrangement of atoms of a crystalline solid in three dimensional space. This technique takes advantage of the interatomic spacing of most crystalline solids by employing them as a diffraction gradient for x-ray light, which has wavelengths on the order of 1 angstrom (10-8 cm).
X-Ray Diffraction and Characterization of Crystalline Materials
International Conference on Information Engineering, Management and Security 2014, 2014
X-ray crystallography is a tool used for determining the atomic and molecular structure of a crystals .Although Bragg's law nλ = 2d sinΘ was used to explain the interference pattern of X-rays scattered by crystals, diffraction has been developed to study the structure of all states of matter with any beam, e.g., ions, electrons, neutrons, and protons, with a wavelength similar to the distance between the atomic or molecular structures of interest.The method also revealed the structure and function of many biological molecules, including vitamins, drugs, proteins and nucleic acids such as DNA. X-ray crystallography is still the chief method for characterizing the atomic structure of new materials and in discerning materials that appear similar by other experiments.
POWDER X-RAY CRYSTALLOGRAPHY-A POWERFUL TOOL OF ANALYSIS AND IDENTIFICATION
The International journal of analytical and experimental modal analysis, 2020
X-ray Crystallography is aAnalytical and primary method, Commonly it is useful for the Drug designing. It is a accurate technique for the analysis and identification of molecular and atomic structure of crystal and its properties includes identification of size of atom, length and identify electron density, mean position of atom etc. Crystalline molecule causes beam of x-ray to diffract/disperse in to various directions and forms a various pattern/shapes, this type of pattern is known as X-ray diffraction (XRD). Crystallography technique and X-ray Diffraction method is useful in various different fields such as-Pharmaceutical industry, Nano science, Geological science, Material science, Forensic science, mineralogy, electronic devices and Currently it is useful for analysis and identification of active pharmaceutical ingredients (API) in pharmaceutical industry for the production of new medicine and new chemical entities and also involve in drug design process. Powder X-ray diffraction (PXRD) is also useful for the identification of Inorganic or organic both crystalline nano-materials and identify its structural properties. It is Useful for both analysis like qualitative analysis and quantitative analysis. It is aessential technique for identification of crystal material from semi-crystalline sample such as Polymer, cotton & unshaped/amorphous material. The main aim of this study was to promote the knowledge about the PXRD and its application/use in various fields.
X-Ray Applications in Food and Agriculture: A Review
Transactions of the ASABE, 2013
X-ray imaging studies in the food and agriculture sector were surveyed. This survey of the literature revealed that x-ray hardware and software have improved considerably since 1990s, when digital x-ray imaging studies began. X-ray imaging has been extensively researched for food inspection. Additionally, there are studies utilizing x-rays to characterize plant and soil properties. Poor image contrast, due to similarity in the attenuation properties of an object and its background, pose a challenge in image segmentation. Development of local adaptive approaches has improved image segmentation and classification accuracies. Hardware developments have resulted in commercial-grade x-ray inspection systems. Future developments in x-ray generation and detection technologies, advances in image processing algorithms, and worldwide food safety concerns indicate increased opportunities for x-ray inspection in the food and agriculture sector.
Journal of Emerging Science and Technology, 2021
The food sector has grown in lockstep with the rise of human civilisation. In prehistoric times, humanity's daily food intake was primarily comprised of vegetables, fruits, and meat. However, there has been a growing demand for processed foods in recent years to meet the requirements of a growing population and to address scarcities in various places with extreme climatic conditions. Processed foods must possess certain basic characteristics in order to be acceptable to consumers. Alterations with regard to flavours, colour, preservatives, stabilizers, anti-oxidants, emulsifying and buffering agents are some of the food quality influencing features. To fit customer tastes, the number of additives added to foods is increasing by the day, resulting in a commensurate increase in market potential. The presence of such food additives in production processes is routinely monitored by means of various analytical methods among which diffraction of x-ray is one. This paper reviewed advances in X-Ray Diffraction (XRD) techniques as applied to food quality evaluation which is among the timely emerging issues that would benefit food industries and their consumers as well. The importance of XRD cannot thus be overstated. It is used to determine polymorphism, Crystallinity, and amorphism, among others. Such characteristics aid in the regulation of food quality evaluation features like food texture and stability under various processing and storage settings. Relevant studies on basic food constituents such as carbohydrates, lipids, and confectioneries have also benefited from XRD.
Colloids and Surfaces B: Biointerfaces, 2013
Energy dispersive X-ray (EDX) is a technique rarely used for organic powders. Nevertheless, this technique is of great interest in the characterization of milk particle surface. In order to validate the method, the EDX technique was tested on pure milk components, on model powders composed of different ratio of lactose/whey proteins and on whole milk powders presenting or not free fat at the surface. For all these powders, satisfactory results were obtained with correct experimental atomic percentages in comparison with expected theoretical percentages. The technique was then applied to skimmed and whole milk powders sieved in 4 fractions. The surface and the core (cut particle) were analyzed by EDX and compared. A relationship between the particle size and the surface composition was observed. X-ray photoelectron spectroscopy (XPS) often used to characterize milk powder surface, however no differences were observed between surface and core composition using this method. The depth of analysis by EDX is far more significant (1 m) in comparison to that of the XPS (5 nm); hence it was concluded that the analysis of cut particle by EDX was not interesting since too close to the results obtained at the surface. Finally, the technique was coupled with XPS and successful hypothesis concerning composition gradients were done.
X - RAY DIFFRACTION: Instrumentation and Applications
Critical reviews in analytical chemistry / CRC, 2015
X-ray diffraction (XRD) is a powerful nondestructive technique for characterizing crystalline materials. It provides information on structures, phases, preferred crystal orientations (texture), and other structural parameters, such as average grain size, crystallinity, strain, and crystal defects. X-ray diffraction peaks are produced by constructive interference of a monochromatic beam of X-rays scattered at specific angles from each set of lattice planes in a sample. The peak intensities are determined by the distribution of atoms within the lattice. Consequently, the X-ray diffraction pattern is the fingerprint of periodic atomic arrangements in a given material. This review summarizes the scientific trends associated with the rapid development of the technique of X-ray diffraction over the past five years pertaining to the field of pharmaceutical industry, forensic science, geological applications, microelectronics and glass industry, as well as in corrosion analysis.
X-ray based techniques used in materials analysis and control
2013
This work provides some results obtained by application of X-ray based techniques for the characterization of various industrial, environmental and new synthesized materials with regard of micro-composition and structure. The employed techniques are X-Ray Fluorescence (XRF) with energy dispersion (ED-XRF) and coupled with scanning electron microscopy (SEM-EDX), and X-ray Diffraction (XRD). Aspects concerning the limit of detection, the number of elements analyzed, matrix effects and spectral interferences in XRF, and its complementarity with other micro-analytical techniques are highlighted.
X-ray Radiography and Material Analysis
TheSASEncyclopediaofArchaeologicalSciences.EditedbySandraL.LópezVarela. JohnWiley&Sons,Inc.Published2019byJohnWiley&Sons,Inc., 2019
X-rays for the analysis of archaeological objects constructed with different materials have begun more than a century ago. Nevertheless, it was only during the last half of the 20th century that this technique began to be more systematically used, especially with human and animal bone remains, as well as with ceramic and metallic objects. Considered as one of the non-invasive and destructive techniques, radiography has been preferably used as a diagnostic tool to detect constructive techniques not visible to the naked eye, as well as defects and other morphological, structural and metrical characteristics of the materials constituting the archaeological objects.
A sample holder for in-house X-ray powder diffraction studies of protein powders
Journal of Applied Crystallography, 2011
A sample holder for handling samples of protein for in-house X-ray powder diffraction (XRPD) analysis has been made and tested on lysozyme. The use of an integrated pinhole reduced the background, and good signal-to-noise ratios were obtained from only 7 ml of sample, corresponding to approximately 2-3 mg of dry protein. The sample holder is further adaptable to X-ray absorption spectroscopy (XAS) measurements. Both XRPD and XAS at the Zn K-edge were tested with hexameric Zn insulin.