5,333 research outputs found
Coarse-grained Description of Polymer Blends as Interacting Soft-Colloidal Particles
We present a theoretical approach which maps polymer blends onto mixtures of
soft-colloidal particles. The analytical mesoscale pair distribution functions
reproduce well data from united atom molecular dynamics simulations of
polyolefin mixtures without fitting parameters. The theory exactly recovers the
analytical expressions for density and concentration fluctuation structure
factors of soft colloidal mixtures (liquid alloys).Comment: 27 REVTex4 pages, 8 PostScript figures, 1 table accepted for
publication in Journal of Chemical Physic
The Church as the Missionary Body of Christ
The life or death of a church depends on how much its members are willing to proclaim the gospel to the world. If its ministers are satisfied merely with performing their functions and counselling religious people, if its members confess their faith just as far as it is socially acceptable, the church will grow more and more into a sterile institution that is far from the living church of the New Testament. The purpose of this study is therefore to ask what connexion may exist between the church and its mission to the world in both the generally accepted and in the disputed letters of Pau
A Radio Perspective on the Wet Merger Remnant NGC 34
We present VLA observations of the neutral hydrogen and radio continuum of
NGC 34 (= NGC 17 = Mrk 938). This object is an ideal candidate to study the
fate of gas in mergers, since, as shown by an optical study done by Schweizer &
Seitzer (2007), it is a gas-rich ("wet") merger remnant of two disk galaxies of
unequal mass hosting a strong central starburst and a weak AGN. We detect HI
emission from both tidal tails and from nearby galaxies, suggesting that NGC 34
is actually part of a gas-rich group and might have recently interacted with
one of its companions. The kinematics of the gas suggests this remnant is
forming an outer disk of neutral hydrogen from the gas of the northern tail. We
also detect broad HI absorption (514 +/- 21 km/s wide) at both negative and
positive velocities with respect to the systemic velocity. This absorption
could be explained by the motions of the tidal tails or by the presence of a
circumnuclear disk. In addition, we present radio-continuum images that show
both nuclear (62.4 +/- 0.3 mJy) and extra-nuclear emission (26.5 +/- 3.0 mJy).
The extra-nuclear component is very diffuse and in the shape of two radio
lobes, spanning 390 kpc overall. This emission could be a signature of an AGN
that has turned off, or it could originate from a starburst-driven superwind.
We discuss the possible scenarios that explain our observations, and what they
tell us about the location of the gas and the future evolution of NGC 34.Comment: 29 pages, 12 figures, 2 tables. Accepted for publication in the
Astronomical Journal. Figs. 1, 2 & 6 degraded to reduce file size
The Son of Man Again
In the Old Testament, ‘son of man' means (1) man in general, (2) the prophet, (3) the eschatological Israel. (1) appears, for example in Ps. viii. 5, is referred to in Heb. ii. 6 and is still present in the background of I Cor. xv. 27 and Eph. i. 2. (2) reflects the usage of Ezechiel. One should never forget that the term occurs here about eighty-seven times: the prophet is addressed as the son of man, filled with God's Spirit (ii. i ff.; iii. 24 f.; xi. 4 f.), watchman of Israel (iii. I7 xxxiii. 7), sent to a rebellious nation (ii. 3). The word of God is his food (ii. 8), but he lives among those who have eyes to see and yet do not see, ears to hear and yet do not hear (xii. 2), who talk about him and run after him, and yet do not do what he says (xxxiii. 30-2), because they think that God's judgement is still far off (xii. 27), so that his message remains riddles and parables for them (xvii. 2, cf. xxi. ). He must not only announce disaster (vi. i ff. etc.), but pronounce God's judgement over Israel (xx. xxii. xxiii. 36), even to kill them (xi. 4, 13; xxi. 19 ff.
Weed Aggressivity in Agronomic Crops
The quantity of herbicides applied in crops has disturbed environmentalists for many years and several environmental groups have voiced distress about the impact of herbicides on water quality, the food supply, and human health. These concerns are causing administrators, scientists, and farmers to search for farming practices and research programs that can effectively balance agri chemical usage with the protection of national resources, food supplies, and human health (Anonymous, 1989a; Anonymous, 1989b). Society will become more environmentally sensitive, and agricultural practices will become more environmentally friendly. Pesticides that cause unacceptable environmental damage or threaten health will be withdrawn. During the next 20 years many of today\u27s chemical pesticides will become obsolete. Certain environmentally friendly herbicides, like glyphosate, will still be used, often in combination with biotechnology, to replace less friendly herbicides (Schneiderman and Carpenter, 1990). Environmental pressures have led to a growing demand for an overall reduction in the use of pesticides and, in countries such as Denmark, Sweden, and the Netherlands, such a reduction has become formal government policy (Thomas, 1990). New research programs must be initiated that include on-farm studies of farming systems and the development of computer software and systems to aid farmers in the management and decision making needed to adopt alternative systems (Anonymous, 1989b)
Demonstration of a Weed Management Expert System for Crop Production
Abstract. The employment of a computer model to facilitate weed management decisions has the potential to reduce herbicide use when weed densities are below an economical threshold as opposed to applying prophylactic herbicide treatments in anticipation of weed problems. The computer model was constructed by linking two submodels representing soil-applied and postemergence weed management decisions. The models are farm specific, user friendly, and consider most herbicide options and herbicide efficacy by weed species. The submodels were developed in LOTUS
Keck Spectroscopy of Two Young Globular Clusters in the Merger Remnant NGC 3921
Low-resolution UV-to-visual spectra of two candidate globular clusters in the
merger remnant NGC 3921 are presented. These two clusters of apparent magnitude
V = 22.2 (Mv = -12.5) lie at projected distances of ~5 kpc from the center and
move with halo-type radial velocities relative to the local galaxy background.
Their spectra show strong Balmer absorption lines indicative of main-sequence
turnoffs dominated by A-type stars. Comparisons with model-cluster spectra
computed by Bruzual & Charlot and others yield cluster ages in the range of
200-530 Myr, and metallicities about solar to within a factor of three. Given
their small half-light radii (Reff < 5 pc) and ages corresponding to ~100 core-
crossing times, these clusters are gravitationally bound and, hence, indeed
young globulars. Assuming that they had Chabrier-type initial mass functions,
their estimated current masses are 2.3(+-0.1)x10^6 Msun and 1.5(+-0.1)x10^6
Msun, respectively, or roughly half the mass of omegaCen. Since NGC 3921 itself
shows many signs of being a 0.7(+-0.3) Gyr old protoelliptical, these two young
globulars of roughly solar metallicity and their many counterparts observed
with the Hubble Space Telescope provide supporting evidence that, in the
process of forming elliptical-like remnants, major mergers of gas-rich disks
can also increase the number of metal-rich globular clusters. (Abridged)Comment: 22 pages, 6 figures, accepted for publication in AJ, July 200
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