3,756 research outputs found
Gravity gradient preliminary investigations, part 2: Lunar tidal gravity gradients and stresses (exhibit C)
Preliminary analysis of the gravity gradients associated with gravity tides on the moon caused by the earth indicates that the relative changes in the gradients are very irregular, and large, and about 15 times greater than those experienced on earth. Thus gradients, in preference to gravity tides themselves, may well be an important key in correlating tide effects with lunar transient events and moonquakes, and also in determining triggering mechanisms for crustal movement and faulting. Preliminary analysis of lunar crustal stresses and strains caused by lunar gravity tides indicates that these factors may be more direct causative agents or triggering mechanisms. In particular, the cubic dilation undergoes relatively large changes and is about 11 times greater on the moon than on earth. Thus it should be correspondingly more important
Gravity gradient preliminary investigations on exhibit ''A'' Final report
Quartz microbalance gravity gradiometer performance test
LAWS simulation: Sampling strategies and wind computation algorithms
In general, work has continued on developing and evaluating algorithms designed to manage the Laser Atmospheric Wind Sounder (LAWS) lidar pulses and to compute the horizontal wind vectors from the line-of-sight (LOS) measurements. These efforts fall into three categories: Improvements to the shot management and multi-pair algorithms (SMA/MPA); observing system simulation experiments; and ground-based simulations of LAWS
Improved laboratory gradiometer can be a field survey instrument
Improvements made to quartz gradiometer minimize or eliminate disturbing effects from known error sources and permit sensitivity of + or - 1 times 10 to the minus 9th power/sec sq or better and measuring accuracy of + or - 5 times 10 to the minus 9th power/sec sq
Experimental demonstration of painting arbitrary and dynamic potentials for Bose-Einstein condensates
There is a pressing need for robust and straightforward methods to create
potentials for trapping Bose-Einstein condensates which are simultaneously
dynamic, fully arbitrary, and sufficiently stable to not heat the ultracold
gas. We show here how to accomplish these goals, using a rapidly-moving laser
beam that "paints" a time-averaged optical dipole potential in which we create
BECs in a variety of geometries, including toroids, ring lattices, and square
lattices. Matter wave interference patterns confirm that the trapped gas is a
condensate. As a simple illustration of dynamics, we show that the technique
can transform a toroidal condensate into a ring lattice and back into a toroid.
The technique is general and should work with any sufficiently polarizable
low-energy particles.Comment: Minor text changes and three references added. This is the final
version published in New Journal of Physic
The Icefield Ranges Research Project, 1970
In 1970 the Icefield Ranges Research Project (IRRP) conducted its tenth consecutive summer of interdisciplinary basic research in the St. Elias Mountains, Yukon Territory, and in the valley and plateau region to the east where all aspects of the environment reflect the influence of those mountains. Summer field investigations began in April and ended the last week in August. And for the first time since the Project's inception in 1961, two programs have continued through the winter (1970-71). This opportunity to continue studies all the year round was made possible by the winterization of a log house; the work, begun in 1967 on the north side of the runway near the Kluane Base Camp, was completed with modern facilities in June 1970. This short paper briefly reviews the programs which were accomplished during the 1970 field season within the broad categories of glaciology, geophysics, physical geography, biology, and human physiology
Stable Differences in Intrinsic Mitochondrial Membrane Potential of Tumor Cell Subpopulations Reflect Phenotypic Heterogeneity
Heterogeneity among cells that constitute a solid tumor is important in determining disease progression. Our previous work established that, within a population of metastatic colonic tumor cells, there are minor subpopulations of cells with stable differences in their intrinsic mitochondrial membrane potential (ΔΨm), and that these differences in ΔΨm are linked to tumorigenic phenotype. Here we expanded this work to investigate primary mammary, as well as colonic, tumor cell lines. We show that within a primary mammary tumor cell population, and in both primary and metastatic colonic tumor cell populations, there are subpopulations of cells with significant stable variations in intrinsic ΔΨm. In each of these 3 tumor cell populations, cells with relatively higher intrinsic ΔΨm exhibit phenotypic properties consistent with promotion of tumor cell survival and expansion. However, additional properties associated with invasive potential appear in cells with higher intrinsic ΔΨm only from the metastatic colonic tumor cell line. Thus, it is likely that differences in the intrinsic ΔΨm among cells that constitute primary mammary tumor populations, as well as primary and metastatic colonic tumor populations, are markers of an acquired tumor phenotype which, within the context of the tumor, influence the probability that particular cells will contribute to disease progression
The Icefield Ranges Research Project, 1969
The Icefield Ranges Research Project (IRRP) - as was visualized nearly ten years ago - becomes each year more and more a complete study of the environment dominated by the St. Elias Mountains, Canada/Alaska. Since 1967, IRRP has been composed of three closely-integrated research units, planned to achieve the proposed aims of IRRP as defined by Dr. W.A. Wood, the original Project Director, accepted by the Arctic Institute's Board of Governors in 1961, and endorsed by the IRRP Advisory Committee. This report reviews the work accomplished by a total of over 65 scientists, their assistants, and support personnel, during the 1969 summer field season, which opened in mid-May and ended the first week in September. It is composed of post-field summaries by principal investigators researching in the disciplines of glaciology, geophysics, physical geography, botany, zoology, archaeology and physiology
Monitoring global vegetation
An attempt is made to identify the need for, and the current capability of, a technology which could aid in monitoring the Earth's vegetation resource on a global scale. Vegetation is one of our most critical natural resources, and accurate timely information on its current status and temporal dynamics is essential to understand many basic and applied environmental interrelationships which exist on the small but complex planet Earth
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