Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 10 of 10
Full-Text Articles in Physics
Helium-4 Solid-Liquid Interface Mobility And Ultrasonic Energy Absorption Mechanisms, M. B. Manning, Matthew J. Moelter, C. Elbaum
Helium-4 Solid-Liquid Interface Mobility And Ultrasonic Energy Absorption Mechanisms, M. B. Manning, Matthew J. Moelter, C. Elbaum
Physics
The first measurements of acoustic reflection, together with acoustic transmission at the solid-liquid interface of 4He, are used to determine the total relative acoustic energy absorption at the interface as a function of temperature. Based on these results, a new mechanism for the temperature dependence of the kinetics of growth and interface mobility is proposed.
A Chronology Of Energy Conservation And Production, David W. Hafemeister
A Chronology Of Energy Conservation And Production, David W. Hafemeister
Physics
No abstract provided.
Physics Of Some Environmental Aspects Of Energy, David W. Hafemeister
Physics Of Some Environmental Aspects Of Energy, David W. Hafemeister
Physics
Approximate numerical estimates are carried out on the following environmental effects from energy production and conservation: (1) The greenhouse effect caused by increased CO2 in the atmosphere; (2) Loss of coolant accidents in nuclear reactors; (3) Increased radon concentrations in buildings with very low air infiltration rates; (4) Acid rain from the combustion of fossil fuels; and (5) Explosions of liquified natural gas (LNG).
Energy Conservation In Large Buildings, A. Rosenfeld, David W. Hafemeister
Energy Conservation In Large Buildings, A. Rosenfeld, David W. Hafemeister
Physics
As energy prices rise, newly energy aware designers use better tools and technology to create energy efficient buildings. Thus the U.S. office stock (average age 20 years) uses 250 kBTU/ft2 of resource energy, but the guzzler of 1972 uses 500 (up × 2), and the 1986 ASHRAE standards call for 100–125 (less than 25% of their 1972 ancestors). Surprisingly, the first real cost of these efficient buildings has not risen since 1972. Scaling laws are used to calculate heat gains and losses of buildings to obtain the ΔT(free) which can be as large as 15–30 °C (30–60 °F) for …
Emerging Technologies For Verification Of Arms Control Treaties, David W. Hafemeister
Emerging Technologies For Verification Of Arms Control Treaties, David W. Hafemeister
Physics
Progress in the technical means of monitoring to verify compliance to arms control treaties is discussed in the following areas: Real-time surveillance with charge-coupled devices in the visible and infrared; image enhancement with digital 1 image processing and with adaptive optics; imaging with radars based on satellites and on the ground; seismic monitoring with high frequency discrimination and with unattended in-country seismic stations; and nuclear weapons test monitoring with the global positioning satellite system.
Reduction Of Mammalian Ferritin, G. D. Watt, Richard B. Frankel, G. C. Papaefthymiou
Reduction Of Mammalian Ferritin, G. D. Watt, Richard B. Frankel, G. C. Papaefthymiou
Physics
Mammalian ferritin from horse spleen undergoes an electrochemical or chemical reduction reaction in which each iron atom present is reduced by one electron (2300 electrons per ferritin molecule containing 2300 Fe3+ ions). Midpoint potentials of -190 mV, -310 mV, and -416 mV were determined at pH 7.0, 8.0, and 9.0. This variation of potential with pH indicates that ≈ 2 H+ are transferred to the core for each Fe3+ reduced to Fe2+. Mössbauer measurements of partially reduced ferritin give spectra that consist of a ferric quadrupole doublet with a superposed ferrous quadrupole doublet. The relative …
A Birefringence Relaxation Determination Of Rotational Diffusion Of Magnetotactic Bacteria, Charles Rosenblatt, Richard B. Frankel, Richard P. Blakemore
A Birefringence Relaxation Determination Of Rotational Diffusion Of Magnetotactic Bacteria, Charles Rosenblatt, Richard B. Frankel, Richard P. Blakemore
Physics
The orientational relaxation of the magnetotactic bacterium Aquaspirillum magnetotacticum is observed by the decay of the optical birefringence upon switching off an aligning magnetic field. The data yield a rotational diffusion constant Dr ≅ 0.13 s1 and information about cell sizes that is consistent with optical microscopy data.
Mossbauer Spectroscopy Of Iron Biomineralization Products In Magnetotactic Bacteria, Richard B. Frankel, Georgia C. Papaefthymiou, Richard P. Blakemore
Mossbauer Spectroscopy Of Iron Biomineralization Products In Magnetotactic Bacteria, Richard B. Frankel, Georgia C. Papaefthymiou, Richard P. Blakemore
Physics
No abstract provided.
Advances In Verification Technology, David W. Hafemeister
Advances In Verification Technology, David W. Hafemeister
Physics
The alleged limits of verification techniques have been used to justify lack of action at the negotiating table, but advances in computer science and optics should help dispel doubts about the verifiability of treaties
Microaerobic Conditions Are Required For Magnetite Formation Within Aquaspirillum Magnetotacticum, R. P. Blakemore, K. A. Short, D. A. Bazylinski, Charles Rosenblatt, Richard B. Frankel
Microaerobic Conditions Are Required For Magnetite Formation Within Aquaspirillum Magnetotacticum, R. P. Blakemore, K. A. Short, D. A. Bazylinski, Charles Rosenblatt, Richard B. Frankel
Physics
The amount of magnetite (Fe3O4) within magnetosomes of the microaerophilic bacterium Aquaspirillum magnetotacticum varies with oxygen and nitrogen supply. The development of optical methods for directly measuring cell magnetism in culture samples has enabled us to quantitate bacterial Fe3O4 yields. We measured final cell yields, average cell magnetic moments, and magnetosome yields of growing cells. Cultures were grown with NO3-, NH4+, or both, in sealed, unshaken vials with initial headspace Po2 values ranging from 0 (trace) to 21 kPa.
More than 50% of cells had detectable …