2,652 research outputs found
Potassium metasomatism of volcanic and sedimentary rocks in rift basins, calderas and detachment terranes
The chemical, mineralogical, and oxygen-isotopic changes accompanying K-metasomatism are described. The similarities with diagenetic reactions in both deep marine and alkaline, saline-lake environments are noted. The common occurrence of K-metasomatism in upper-plate rocks of detachment terranes indicates that the early stage of severe regional extension causes crustal downwarping and, in arid to semi-arid regions, development of closed hydrographic basins
Geologic analysis of ERTS-1 imagery for the State of New Mexico
There are no author-identified significant results in this report
Hydrogel microparticles from lithographic processes: Novel materials for fundamental and applied colloid science
In recent years, there has been a surge in methods to synthesize geometrically and chemically complex microparticles. Analogous to atoms, the concept of a “periodic table” of particles has emerged and continues to be expanded upon. Complementing the natural intellectual curiosity that drives the creation of increasingly intricate particles is the pull from applications that take advantage of such high-value materials. Complex particles are now being used in fields ranging from diagnostics and catalysis, to self-assembly and rheology, where material composition and microstructure are closely linked with particle function. This is especially true of polymer hydrogels, which offer an attractive and broad class of base materials for synthesis. Lithography affords the ability to engineer particle properties a priori and leads to the production of homogenous ensembles of particles. This review summarizes recent advances in synthesizing hydrogel microparticles using lithographic processes and highlights a number of emerging applications. We discuss advantages and limitations of current strategies, and conclude with an outlook on future trends in the field.National Science Foundation (U.S.) (Grant DMR-1006147)Novartis-MIT Center for Continuous ManufacturingNational Institute for Biomedical Imaging and Bioengineering (U.S.) (Grant R21EB008814
PETAAL : Protection Environnement et Technologie des Arbres d’Alignements
Programme d’études coordonné par le centre technique Plante & Cité
Avec le soutien du Fond Unique Interministériel et du Conseil Régional des Pays de la Loir
Breaking the Redshift Deadlock - I: Constraining the star formation history of galaxies with sub-millimetre photometric redshifts
Future extragalactic sub-millimetre and millimetre surveys have the potential
to provide a sensitive census of the level of obscured star formation in
galaxies at all redshifts. While in general there is good agreement between the
source counts from existing SCUBA (850um) and MAMBO (1.25mm) surveys of
different depths and areas, it remains difficult to determine the redshift
distribution and bolometric luminosities of the sub-millimetre and millimetre
galaxy population. This is principally due to the ambiguity in identifying an
individual sub-millimetre source with its optical, IR or radio counterpart
which, in turn, prevents a confident measurement of the spectroscopic redshift.
Additionally, the lack of data measuring the rest-frame FIR spectral peak of
the sub-millimetre galaxies gives rise to poor constraints on their rest-frame
FIR luminosities and star formation rates. In this paper we describe
Monte-Carlo simulations of ground-based, balloon-borne and satellite
sub-millimetre surveys that demonstrate how the rest-frame FIR-sub-millimetre
spectral energy distributions (250-850um) can be used to derive photometric
redshifts with an r.m.s accuracy of +/- 0.4 over the range 0 < z < 6. This
opportunity to break the redshift deadlock will provide an estimate of the
global star formation history for luminous optically-obscured galaxies [L(FIR)
> 3 x 10^12 Lsun] with an accuracy of 20 per cent.Comment: 14 pages, 22 figures, submitted to MNRAS, replaced with accepted
versio
PETAAL Protection of border tree environment and technology
The sycamore lace bug has been identified as one of the main phytosanitary problems for managers of tree-planted heritage sites within green areas in 36,000 French regional authorities. The spread of this pest nationally and the predominance of sycamores in towns makes the bug one of the first pests to receive phytosanitary intervention in our green spaces. The move from chemical control, which is currently used, to biological control is governed by environmental and societal issues and embodies ongoing major technical innovation within green areas
Lithologic discrimination and alteration mapping from AVIRIS Data, Socorro, New Mexico
Geologic maps are, by their very nature, interpretive documents. In contrasts, images prepared from AVIRIS data can be used as uninterpreted, and thus unbiased, geologic maps. We are having significant success applying AVIRIS data in this non-quantitative manner to geologic problems. Much of our success has come from the power of the Linked Windows Interactive Data System. LinkWinds is a visual data analysis and exploration system under development at JPL which is designed to rapidly and interactively investigate large multivariate data sets. In this paper, we present information on the analysis technique, and preliminary results from research on potassium metasomatism, a distinctive and structurally significant type of alteration associated with crustal extension
SANEPIC: A Map-Making Method for Timestream Data From Large Arrays
We describe a map-making method which we have developed for the Balloon-borne
Large Aperture Submillimeter Telescope (BLAST) experiment, but which should
have general application to data from other submillimeter arrays. Our method
uses a Maximum Likelihood based approach, with several approximations, which
allows images to be constructed using large amounts of data with fairly modest
computer memory and processing requirements. This new approach, Signal And
Noise Estimation Procedure Including Correlations (SANEPIC), builds upon
several previous methods, but focuses specifically on the regime where there is
a large number of detectors sampling the same map of the sky, and explicitly
allowing for the the possibility of strong correlations between the detector
timestreams. We provide real and simulated examples of how well this method
performs compared with more simplistic map-makers based on filtering. We
discuss two separate implementations of SANEPIC: a brute-force approach, in
which the inverse pixel-pixel covariance matrix is computed; and an iterative
approach, which is much more efficient for large maps. SANEPIC has been
successfully used to produce maps using data from the 2005 BLAST flight.Comment: 27 Pages, 15 figures; Submitted to the Astrophysical Journal; related
results available at http://blastexperiment.info/ [the BLAST Webpage
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