3,111 research outputs found
Spectrometer
Ultraviolet spectrometer measures pure monochromatic wavelengths in predetermined narrow wave bands. Two stages are incorporated: stationary dispersed beam is intercepted by array of slits cut into plate at discrete wavelength locations; second stage is inverted spectrometer which recombines dispersed spectrum at single exit slit
Lunar nomenclature Interim report
Revised index of proposed names for craters on lunar far side with identifying bibliographical dat
Development of lunar nomenclature
A system of unification and standardization for lunar nomenclature was developed. The following recommendations were made for use in future lunar cartography: (1) satellite craters, previously designated by letters will be named; (2) names will no longer be restricted to scientists, but will also include great contributors to human knowledge and human culture; and (3) a system of grids for dividing the moon into 144 regions and subdividing these regions into 2304 provinces will be used
Redox reactions with empirical potentials: Atomistic battery discharge simulations
Batteries are pivotal components in overcoming some of today's greatest
technological challenges. Yet to date there is no self-consistent atomistic
description of a complete battery. We take first steps toward modeling of a
battery as a whole microscopically. Our focus lies on phenomena occurring at
the electrode-electrolyte interface which are not easily studied with other
methods. We use the redox split-charge equilibration (redoxSQE) method that
assigns a discrete ionization state to each atom. Along with exchanging partial
charges across bonds, atoms can swap integer charges. With redoxSQE we study
the discharge behavior of a nano-battery, and demonstrate that this reproduces
the generic properties of a macroscopic battery qualitatively. Examples are the
dependence of the battery's capacity on temperature and discharge rate, as well
as performance degradation upon recharge.Comment: 14 pages, 10 figure
Report no. 1 : Anton Bruun cruise A : Aden-Bombay, February-March, 1963
En route from the U. S. to Bombay, India during February - March, 1963
an unscheduled oceanographic section of 13 stations was made in the Arabian
Sea between Aden and Bombay. Standard hydrographic casts were made to 1400 meters
indicated depth (1000 meters at Stations 1-3) for meas9rement of temperature,
salinity, dissolved oxygen, phosphate, nitrite, nitrate and silicate. A
large, plastic sampler was used to obtain water samples from depths corresponding
to 100, 50, 25, 10 and 1% of the sunlight incident to the surface. These
samples were used for measurement of primary productivity (C-14 method), phytoplankton
pigments, particulate carbon, nitrogen and phosphorus
Soft deformable self-propelled particles
In this work we investigate the collective behavior of self-propelled
particles that deform due to local pairwise interactions. We demonstrate that
this deformation alone can induce alignment of the velocity vectors. The onset
of collective motion is analyzed. Applying a Gaussian-core repulsion between
the particles, we find a transition to disordered non-collective motion under
compression. We here explain that this reflects the reentrant fluid behavior of
the general Gaussian-core model now applied to a self-propelled system.
Truncating the Gaussian potential can lead to cluster crystallization or more
disordered cluster states. For intermediate values of the Gaussian-core
potential we for the first time observe laning for deformable self-propelled
particles. Finally, without the core potential, but including orientational
noise, we connect our description to the Vicsek approach for self-propelled
particles with nematic alignment interactions.Comment: 6 pages, 7 figure
Influence of the Amazon River outflow on the ecology of the western tropical Atlantic I. Hydrography and nutrient chemistry
The influence of the Amazon River discharge on the nutrient chemistry and biological productivity in the western tropical Atlantic and the eastern Caribbean was investigated during two oceanogr aphic cruises in the fall of 1964 and the spring of 1965, respectively. The river outflow is entrained in the Guiana Current and carried to the north and east, affecting an area that is at times a million square miles, as indicated by surface salinity...
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