Biofuels News, Spring/Summer 2001, Vol. 4, No. 2 (open access)

Biofuels News, Spring/Summer 2001, Vol. 4, No. 2

Newsletter for the DOE biofuels program. This issue contains articles on the National Energy Policy Plan, national energy policy, the proposed budget for biofuels, and new faces at DOE.
Date: July 13, 2001
Creator: Tuttle, J.
System: The UNT Digital Library
Energy Savers---Tips on Saving Energy and Money at Home (Fifth Printing) (open access)

Energy Savers---Tips on Saving Energy and Money at Home (Fifth Printing)

Provides consumers with home energy and money savings tips such as insulation, weatherization, heating, cooling, water heating, energy efficient windows, landscaping, lighting, and energy efficient appliances.
Date: August 13, 2001
Creator: DOE Office of Building Technology, State and Community Programs
System: The UNT Digital Library
SINGLE CRYSTAL NEUTRON DIFFRACTION. (open access)

SINGLE CRYSTAL NEUTRON DIFFRACTION.

Single-crystal neutron diffraction measures the elastic Bragg reflection intensities from crystals of a material, the structure of which is the subject of investigation. A single crystal is placed in a beam of neutrons produced at a nuclear reactor or at a proton accelerator-based spallation source. Single-crystal diffraction measurements are commonly made at thermal neutron beam energies, which correspond to neutron wavelengths in the neighborhood of 1 Angstrom. For high-resolution studies requiring shorter wavelengths (ca. 0.3-0.8 Angstroms), a pulsed spallation source or a high-temperature moderator (a ''hot source'') at a reactor may be used. When complex structures with large unit-cell repeats are under investigation, as is the case in structural biology, a cryogenic-temperature moderator (a ''cold source'') may be employed to obtain longer neutron wavelengths (ca. 4-10 Angstroms). A single-crystal neutron diffraction analysis will determine the crystal structure of the material, typically including its unit cell and space group, the positions of the atomic nuclei and their mean-square displacements, and relevant site occupancies. Because the neutron possesses a magnetic moment, the magnetic structure of the material can be determined as well, from the magnetic contribution to the Bragg intensities. This latter aspect falls beyond the scope of the present unit; for …
Date: March 13, 2001
Creator: Koetzle, T. F.
System: The UNT Digital Library
SINGLE CRYSTAL NEUTRON DIFFRACTION. (open access)

SINGLE CRYSTAL NEUTRON DIFFRACTION.

Single-crystal neutron diffraction measures the elastic Bragg reflection intensities from crystals of a material, the structure of which is the subject of investigation. A single crystal is placed in a beam of neutrons produced at a nuclear reactor or at a proton accelerator-based spallation source. Single-crystal diffraction measurements are commonly made at thermal neutron beam energies, which correspond to neutron wavelengths in the neighborhood of 1 Angstrom. For high-resolution studies requiring shorter wavelengths (ca. 0.3-0.8 Angstroms), a pulsed spallation source or a high-temperature moderator (a ''hot source'') at a reactor may be used. When complex structures with large unit-cell repeats are under investigation, as is the case in structural biology, a cryogenic-temperature moderator (a ''cold source'') may be employed to obtain longer neutron wavelengths (ca. 4-10 Angstroms). A single-crystal neutron diffraction analysis will determine the crystal structure of the material, typically including its unit cell and space group, the positions of the atomic nuclei and their mean-square displacements, and relevant site occupancies. Because the neutron possesses a magnetic moment, the magnetic structure of the material can be determined as well, from the magnetic contribution to the Bragg intensities. This latter aspect falls beyond the scope of the present unit; for …
Date: March 13, 2001
Creator: Koetzle, T. F.
System: The UNT Digital Library