Calculating dipole moments and atom coordinates using molecular models: A shadow projection method

1970 ◽  
Vol 47 (5) ◽  
pp. 389 ◽  
Author(s):  
D. M. McEachern ◽  
P. A. Lehmann
Keyword(s):  
Projection Method ◽  
Dipole Moments ◽  
Molecular Models ◽  
Shadow Projection

scholarly journals Shadow projection method for dipole moments

1970 ◽  
Vol 47 (8) ◽  
pp. 596
Author(s):  
D. M. McEachern ◽  
P. A. Lehmann
Keyword(s):  
Projection Method ◽  
Dipole Moments ◽  
Shadow Projection

Tomography on Point Projection X-Ray Microscope Using CCD Images

1999 ◽  
Vol 5 (S2) ◽  
pp. 352-353
Author(s):  
Sterling P. Newberry
Keyword(s):  
Data Base ◽  
Projection Method ◽  
Data Gathering ◽  
Cone Beam ◽  
Beam Angle ◽  
Laboratory Installation ◽  
X Ray ◽  
Recent Advances ◽  
Point Projection ◽  
Shadow Projection

Recent advances with the cone-beam approach to tomography at the Advanced Microscopy and Imaging Laboratory (AMIL) have opened the possibility of employing tomography with the Shadow Projection X-Ray Microscope routinely when the specimen properties require it. The AMIL approach has been tested on small objects, without magnification, using conventional dental x-ray sources and a modestly diverging beam angle. The shadow projection Microscope, by contrast has a tenfold greater divergence and magnifies the specimen from unity to three or more orders of magnitude in resolution beyond the previous tests. The reader is reminded of the simplicity of the xray projection method and of the clarity of its images in fig. 1 and 2. The microscope can be operated in any laboratory and readily transported to alternate locations. Now that the AMIL data base and algorithms for tomography can be handled by a Pentium II processor the data gathering and reconstructions can also be managed at any laboratory installation.

The Determination of Molecular Quantities from Measurements on Macroscopic Systems. I

1982 ◽  
Vol 37 (12) ◽  
pp. 1369-1395 ◽  
Author(s):  
Wolfgang Liptay ◽  
Detlev Wehning ◽  
Jürgen Becker ◽  
Torsten Rehm
Keyword(s):  
Optical Absorption ◽  
Molecular Model ◽  
Dipole Moments ◽  
Molecular Models ◽  
Electric Dipole Moments ◽  
Macroscopic System ◽  
True Model ◽  
Absorption Measurements ◽  
General Method

AbstractFor many molecules the determination of molecular quantities, as electric dipole moments or molar absorption coefficients, has to be based on measurements on solutions or other dense phases. The evaluation of such data is rather involved due to the interactions between neighboring molecules, and taking this into account, a general method is presented. Some quantities appropriate for the description of a macroscopic system (bulk quantities) are defined and their properties are discussed, especially partial molar quantities (PMQ's),which are well known from thermodynamics. To any PMQ some corresponding model molar quantities (MMQ's) can be introduced, each MMQ based on a particular molecular model. The MMQ's are related to the interesting molecular quantities and may allow their estimation. The values of PMQ's can be determined uniquely from experimental data, if the investigated system meets just a very few general requirements, whereas the values of the corresponding MMQ's are generally dependent on the chosen model and hence unique only, if a true model is available. As examples, approximate molecular models are introduced for MMQ's corresponding to the Gibbs energy and to quantities convenient for the evaluation of permittivity, optical absorption and electro-optical absorption measurements.

Edge shadow projection method for measuring the brightness of electron guns

2017 ◽  
Vol 88 (2) ◽  
pp. 023302 ◽  
Author(s):  
Cheolsu Han ◽  
Inho Sul ◽  
Boklae Cho
Keyword(s):  
Projection Method ◽  
Electron Guns ◽  
Shadow Projection

The Determination of Molecular Quantities from Measurements on Macroscopic Systems.II. The Determination of Electric Dipole Moments

1982 ◽  
Vol 37 (12) ◽  
pp. 1396-1408 ◽  
Author(s):  
Wolfgang Liptay ◽  
Jürgen Becker ◽  
Detlev Wehning ◽  
Werner Lang ◽  
Oswald Burkhard
Keyword(s):  
Electric Dipole ◽  
Dipole Moments ◽  
Spherical Approximation ◽  
Molecular Models ◽  
Approximation Model ◽  
Intrinsic Properties ◽  
Electric Dipole Moments ◽  
Ellipsoidal Approximation ◽  
Aromatic Molecules

AbstractSome bulk quantities appropriate for the description of dielectric and refractometric measurements on macroscopic systems are defined and their properties are discussed. Based on three molecular models (Lorentz model, Onsager model in spherical approximation, and in ellipsoidal approximation) model molar quantities are introduced, which depend on intrinsic properties of the molecule, i.e. the electric dipole moment and the polarizability. The relations will be applied for the evaluation of the results of dielectric and refractometric measurements on eight aromatic molecules.

scholarly journals Quantum chemical exercise linking computational chemistry to general chemistry topics

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Scott Simpson ◽  
Ashley Evanoski-Cole ◽  
Kellie Gast ◽  
Madeleine C. Wedvik ◽  
Patrick W. Schneider ◽  
...  
Keyword(s):  
General Chemistry ◽  
Quantum Chemical ◽  
Hypochlorous Acid ◽  
Dipole Moments ◽  
Student Understanding ◽  
Molecular Models ◽  
Student Responses ◽  
Post Exercise ◽  
Show Evidence ◽  
Basic Concepts

AbstractStudents in a second semester general chemistry course used quantum chemical calculations to investigate and reinforce general chemistry concepts. Students explored the isomers of hypochlorous acid, made predictions of miscibility via dipole moments calculated from ab-initio means, experimentally validated/disqualified their miscibility predictions, and used molecular models to visualize intermolecular attraction forces between various compounds. Student responses in pre-/post-exercise assessments show evidence of student learning. Responses in pre-/post-exercise surveys showed an increase in student understanding of basic concepts and of the importance of quantum mechanics in common general chemistry topics.

Accuracy in measuring the dimensions of components by the shadow projection method

1962 ◽  
Vol 5 (5) ◽  
pp. 362-367 ◽  
Author(s):  
V. P. Koronkevich ◽  
L. Ya. Gustyr'
Keyword(s):  
Projection Method ◽  
Shadow Projection
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