Key to Writing Assignment #1
... 11. Quartz (SiO2) has a specific gravity of 2.65. Coesite and stishovite (both SiO2) were found in meteor craters in Arizona, and they have specific gravities of 3.01 and 4.35, respectively. Why? How is their occurrence related to the crater? Because all of these minerals have the same chemical comp ...
... 11. Quartz (SiO2) has a specific gravity of 2.65. Coesite and stishovite (both SiO2) were found in meteor craters in Arizona, and they have specific gravities of 3.01 and 4.35, respectively. Why? How is their occurrence related to the crater? Because all of these minerals have the same chemical comp ...
Structural basis for the fast phase change of DVD-RAM
... peculiar to non-crystalline materials, reflecting the lack of the long-range periodicity. These diffraction patterns show a highly disordered state (liquid state) in which both Ge2Sb2Te5 and GeTe have to undergo during a recording process (crystal-amorphous phase change) by a laser-heated melt-quenc ...
... peculiar to non-crystalline materials, reflecting the lack of the long-range periodicity. These diffraction patterns show a highly disordered state (liquid state) in which both Ge2Sb2Te5 and GeTe have to undergo during a recording process (crystal-amorphous phase change) by a laser-heated melt-quenc ...
of minerals!
... - differences result from the different elements used and the ways they are bonded ...
... - differences result from the different elements used and the ways they are bonded ...
Ettringite - Sulfato - ltmufrgs
... Ettringite is a beautiful and interesting mineral for collectors. It forms as a precipitate from hydrothermal solutions. It has a typically bright yellow color and a nice luster. For collectors who like good crystal formations, ettringite has that too. It will commonly form well shaped hexagonal pri ...
... Ettringite is a beautiful and interesting mineral for collectors. It forms as a precipitate from hydrothermal solutions. It has a typically bright yellow color and a nice luster. For collectors who like good crystal formations, ettringite has that too. It will commonly form well shaped hexagonal pri ...
Anhydrous guanine: a synchrotron study
... (Ozeki et al., 1969; Portalone et al., 1999) and uracil (Stewart & Jensen, 1967) have been known for some time, together with hydrates of cytosine (Jeffrey & Kinoshita, 1963; Neidle et al., 1976; Eisenstein, 1988; McClure & Craven, 1973) and thymine (Gerdil, 1961), but not of uracil. For some time, ...
... (Ozeki et al., 1969; Portalone et al., 1999) and uracil (Stewart & Jensen, 1967) have been known for some time, together with hydrates of cytosine (Jeffrey & Kinoshita, 1963; Neidle et al., 1976; Eisenstein, 1988; McClure & Craven, 1973) and thymine (Gerdil, 1961), but not of uracil. For some time, ...
2. Prediction of Crystal Structures
... diffusion-equation [8] and cluster methods [9]. Frequently combinations of these methods are used [10,12]. Since the energy hypersurface has a large number of local minima, the 'classical' minimization methods like steepest descent require several hundred runs starting from different points. These s ...
... diffusion-equation [8] and cluster methods [9]. Frequently combinations of these methods are used [10,12]. Since the energy hypersurface has a large number of local minima, the 'classical' minimization methods like steepest descent require several hundred runs starting from different points. These s ...
Enhancement of coherent X-ray diffraction from nanocrystals by
... Depending on the orientation of the individual nanocrystals the measured diffraction patterns showed nice three- and four-fold symmetry and typically 5 to 10 high contrast interference fringes in directions corresponding to the facets of the cubic shape of the crystals. Furthermore, we have investig ...
... Depending on the orientation of the individual nanocrystals the measured diffraction patterns showed nice three- and four-fold symmetry and typically 5 to 10 high contrast interference fringes in directions corresponding to the facets of the cubic shape of the crystals. Furthermore, we have investig ...
שקופית 1
... computers, which feed them into a complex decoding process resulting in three-dimensional images. The computer-assisted decoding relies on mathematical formulas and hypothetical structural models, based on data gathered through other methods. ...
... computers, which feed them into a complex decoding process resulting in three-dimensional images. The computer-assisted decoding relies on mathematical formulas and hypothetical structural models, based on data gathered through other methods. ...
Observation of sagittal X-ray diffraction by surface acoustic waves in
... Experimental setup: M1 is a parabolic mirror that makes the beam parallel. The desired X-ray energy between the SAWs and the radiation is then selected with a double-crystal Si(111) monochromator and the beam is focused onto the wavelength, as in equation (2). Fig. 5 sample with a second mirror, M2. ...
... Experimental setup: M1 is a parabolic mirror that makes the beam parallel. The desired X-ray energy between the SAWs and the radiation is then selected with a double-crystal Si(111) monochromator and the beam is focused onto the wavelength, as in equation (2). Fig. 5 sample with a second mirror, M2. ...
Protein structures uncovered
... irregular. Its polypeptide chain is folded into a unique conformation, which includes alpha helices and beta-pleated sheets. The precise way in which these are arranged together is called the tertiary structure. ...
... irregular. Its polypeptide chain is folded into a unique conformation, which includes alpha helices and beta-pleated sheets. The precise way in which these are arranged together is called the tertiary structure. ...
5.2 Composition and Structure of Minerals
... • The angle at which crystal faces meet is a characteristic for each type of mineral • Used to help identify the mineral ...
... • The angle at which crystal faces meet is a characteristic for each type of mineral • Used to help identify the mineral ...
Chemistry and Material Science 1. Physical Properties of Materials
... The technology developed by the semiconductor industry for growing single crystals has led to crystals of phenomenally high degrees of perfection. The elemental semiconductors (Si, Ge and gray Sn) share the diamond cubic structure. This structure is built on an FCC Bravais lattice with two atoms ...
... The technology developed by the semiconductor industry for growing single crystals has led to crystals of phenomenally high degrees of perfection. The elemental semiconductors (Si, Ge and gray Sn) share the diamond cubic structure. This structure is built on an FCC Bravais lattice with two atoms ...
I. Crystal nucleation and growth
... II. Textures and relations related to crystallization order As we discussed previously, crystals form in a specific sequence that depends on the magma initial composition. Crystal growing in the melt develop their own crystalline shapes (euhedral), whereas crystals developing at a latter stage are l ...
... II. Textures and relations related to crystallization order As we discussed previously, crystals form in a specific sequence that depends on the magma initial composition. Crystal growing in the melt develop their own crystalline shapes (euhedral), whereas crystals developing at a latter stage are l ...
The crystal structure of the RuvBL1/RuvBL2 complex
... We solved the first three-dimensional crystal structure of the human RuvBL complex. For crystallization purposes, domain II was truncated in both RuvBL1 and RuvBL2 monomers. The structure was initially determined using diffraction data from native crystals at 4 Å resolution, revealing a dodecamer fo ...
... We solved the first three-dimensional crystal structure of the human RuvBL complex. For crystallization purposes, domain II was truncated in both RuvBL1 and RuvBL2 monomers. The structure was initially determined using diffraction data from native crystals at 4 Å resolution, revealing a dodecamer fo ...
Mineral Formation
... amphibole and other minerals. Water in the magma can even facilitate pegmatite formation. Pegmatite is an igneous rock composed of mineral crystals generally with a diameter of several centimeters which, on rare occasions, can be meters. ...
... amphibole and other minerals. Water in the magma can even facilitate pegmatite formation. Pegmatite is an igneous rock composed of mineral crystals generally with a diameter of several centimeters which, on rare occasions, can be meters. ...
1. Show that only four types of rotational symmetry are possible. 2
... Quiz 1. Show that only four types of rotational symmetry are possible. 2. Why it is not possible to have 5, 7 or higher order symmetry in crystallography? 3. What is point group? How many point-groups are possible? 4. Find out the Hermann-Mauguin symbol for a cube. 5. For a point at xyz write a tran ...
... Quiz 1. Show that only four types of rotational symmetry are possible. 2. Why it is not possible to have 5, 7 or higher order symmetry in crystallography? 3. What is point group? How many point-groups are possible? 4. Find out the Hermann-Mauguin symbol for a cube. 5. For a point at xyz write a tran ...
Photonic Crystals
... MATERIAL: Alloys of III–Nitrides (GaN, InN and AlN) are ones of the most promising materials in modern photonics. They all have direct energy bandgap, which causes the high efficiency of photon’s emission, and absorption. In case of gallium nitride there is a possibility of forming solid solutions w ...
... MATERIAL: Alloys of III–Nitrides (GaN, InN and AlN) are ones of the most promising materials in modern photonics. They all have direct energy bandgap, which causes the high efficiency of photon’s emission, and absorption. In case of gallium nitride there is a possibility of forming solid solutions w ...
green and sustainable manufacturing awards presentation
... crystal agglomerates with precise control over size and polymorphic crystal form. Using the gained understanding, we will also design a novel continuous crystallization reactor for industrial scale manufacturing of API, thereby eliminating the need for downstream dry-milling and grinding and reducin ...
... crystal agglomerates with precise control over size and polymorphic crystal form. Using the gained understanding, we will also design a novel continuous crystallization reactor for industrial scale manufacturing of API, thereby eliminating the need for downstream dry-milling and grinding and reducin ...
Femtosecond X-ray measurement of coherent lattice vibrations near
... cycles of 467 fs, corresponding to a frequency n ¼ 2.12 THz. No effort has been made to take into account damping or changes in the cycle duration. We performed similar measurements for a crystal orientation in which the diffraction from (111) lattice planes could be recorded. In this case an initia ...
... cycles of 467 fs, corresponding to a frequency n ¼ 2.12 THz. No effort has been made to take into account damping or changes in the cycle duration. We performed similar measurements for a crystal orientation in which the diffraction from (111) lattice planes could be recorded. In this case an initia ...
Secondary electrons
... -Quantitative or qualitative chemical analysis of a very small focussed spot (<1um) on a polished sample surface. A nondestructive technique. Useful for: ...
... -Quantitative or qualitative chemical analysis of a very small focussed spot (<1um) on a polished sample surface. A nondestructive technique. Useful for: ...
C41021922
... potassium dihydrogen phosphate (KDP). Keywords: Optical; Elemental analysis; Structural properties; ...
... potassium dihydrogen phosphate (KDP). Keywords: Optical; Elemental analysis; Structural properties; ...
41-2 Interview
... Julia: We use very tiny amounts of protein solutions. I make a tiny drop of about 1 µl (0.001 cm3) then add substances that slowly make the protein precipitate. These are salts and chemicals called polyethylene glycols (PEGs). The mixture will vary depending on the protein. The drop is hung over a s ...
... Julia: We use very tiny amounts of protein solutions. I make a tiny drop of about 1 µl (0.001 cm3) then add substances that slowly make the protein precipitate. These are salts and chemicals called polyethylene glycols (PEGs). The mixture will vary depending on the protein. The drop is hung over a s ...
Crystal Structure and Functional Analysis of Glyceraldehyde
... structure is determeined by X-ray diffraction method. Three crystallizational conditons perform three structures: NAD-free, NAD-bound and sulfate-soaked. Similar to the published GAPDH structure, OsGAPDH shows homotetramer form and each subunit could be seperated to three domains: NAD-binding domain ...
... structure is determeined by X-ray diffraction method. Three crystallizational conditons perform three structures: NAD-free, NAD-bound and sulfate-soaked. Similar to the published GAPDH structure, OsGAPDH shows homotetramer form and each subunit could be seperated to three domains: NAD-binding domain ...
9.1.4 Other common usage diagnostics
... a) Path length and resolution. The practically attainable path length difference of the instrument is of the order of 20 m, for interferometer lengths of 2 m or less. However, since the resolution is given by dn/n ~ (l/r), this still corresponds to a resolution of the order of 5x10-6 at 8.5 keV. Fo ...
... a) Path length and resolution. The practically attainable path length difference of the instrument is of the order of 20 m, for interferometer lengths of 2 m or less. However, since the resolution is given by dn/n ~ (l/r), this still corresponds to a resolution of the order of 5x10-6 at 8.5 keV. Fo ...
Scanning Electron Microscopy / Electron Probe X
... most important contrast mechanism of backscattered electrons is the dependence of the backscattering coefficient on the mean atomic number: regions with higher atomic number elements appear brighter than lower atomic number elements in the BSE image. This allows phases with differences in atomic num ...
... most important contrast mechanism of backscattered electrons is the dependence of the backscattering coefficient on the mean atomic number: regions with higher atomic number elements appear brighter than lower atomic number elements in the BSE image. This allows phases with differences in atomic num ...
X-ray crystallography
X-ray crystallography is a tool used for identifying the atomic and molecular structure of a crystal, in which the crystalline atoms cause a beam of incident X-rays to diffract into many specific directions. By measuring the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their disorder and various other information.Since many materials can form crystals—such as salts, metals, minerals, semiconductors, as well as various inorganic, organic and biological molecules—X-ray crystallography has been fundamental in the development of many scientific fields. In its first decades of use, this method determined the size of atoms, the lengths and types of chemical bonds, and the atomic-scale differences among various materials, especially minerals and alloys. 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. X-ray crystal structures can also account for unusual electronic or elastic properties of a material, shed light on chemical interactions and processes, or serve as the basis for designing pharmaceuticals against diseases.In a single-crystal X-ray diffraction measurement, a crystal is mounted on a goniometer. The goniometer is used to position the crystal at selected orientations. The crystal is bombarded with a finely focused monochromatic beam of X-rays, producing a diffraction pattern of regularly spaced spots known as reflections. The two-dimensional images taken at different rotations are converted into a three-dimensional model of the density of electrons within the crystal using the mathematical method of Fourier transforms, combined with chemical data known for the sample. Poor resolution (fuzziness) or even errors may result if the crystals are too small, or not uniform enough in their internal makeup.X-ray crystallography is related to several other methods for determining atomic structures. Similar diffraction patterns can be produced by scattering electrons or neutrons, which are likewise interpreted by Fourier transformation. If single crystals of sufficient size cannot be obtained, various other X-ray methods can be applied to obtain less detailed information; such methods include fiber diffraction, powder diffraction and (if the sample is not crystallized) small-angle X-ray scattering (SAXS).If the material under investigation is only available in the form of nanocrystalline powders or suffers from poor crystallinity, the methods of electron crystallography can be applied for determining the atomic structure.For all above mentioned X-ray diffraction methods, the scattering is elastic; the scattered X-rays have the same wavelength as the incoming X-ray. By contrast, inelastic X-ray scattering methods are useful in studying excitations of the sample, rather than the distribution of its atoms.