52,193 research outputs found
Studies of vesicle distribution patterns in Hawaiian lavas
Basaltic lava flows are generally vesicular, and the broader facts relating to vesicle distribution have long been established; few studies have yet been made with a view to determining how and when vesicles form in the cooling history of the lava, explaining vesicle shape and size distribution, and gaining enough understanding to employ vesicles as a geological tool. Various avenues of approach exist by which one may seek to gain a better understanding of these ubiquitous structures and make a start towards developing a general theory, and three such avenues have recently been explored. One avenue involves the study of pipe vesicles; these are a well known feature of lava flows and are narrow pipes which occur near the base of many pahoehoe flow units. Another avenue of approach is that presented by the distinctive spongy pahoehoe facies of lava that is common in distal locations on Hawaiian volcanoes. A third avenue of approach is that of the study of gas blisters in lava. Gas blisters are voids, which can be as much as tens of meters wide, where the lava split along a vesicle-rich layer and the roof up-arched by gas pressure. These three avenues are briefly discussed
Carbons produced from known organic compounds 2. Anthracene-biphenyl and phenanthrene- biphenyl systems
Carbonization of binary mixtures of anthracene biphenyl and penanthrene bipheny
A Completely Invariant SUSY Transform of Supersymmetric QED
We study the SUSY breaking of the covariant gauge-fixing term in SUSY QED and
observe that this corresponds to a breaking of the Lorentz gauge condition by
SUSY. Reasoning by analogy with SUSY's violation of the Wess-Zumino gauge, we
argue that the SUSY transformation, already modified to preserve Wess-Zumino
gauge, should be further modified by another gauge transformation which
restores the Lorentz gauge condition. We derive this modification and use the
resulting transformation to derive a Ward identitiy relating the photon and
photino propagators without using ghost fields. Our transformation also
fulfills the SUSY algebra, modulo terms that vanish in Lorentz gauge
Long, paired A'A/Pahoehoe flows of Mauna Loa: Volcanological significance and insights they provide into volcano plumbing systems
The long lava flows of Mauna Loa, Hawaii have been cited as Earth's closed analogs to the large Martian flows. It is therefore important to understand the flow mechanics and characteristics of the Mauna Loa flows and to make use of these in an attempt to gain insights into Martian eruptive processes. Two fundamentally different kinds of long lava flows can be distinguished on Hawaiian volcanoes as in Martian flows. The two kinds may have identical initial viscosities, chemical compositions, flow lengths, and flow volumes, but their flow mechanisms and thermal energy budgets are radically different. One travels a distance set by the discharge rate as envisaged by Walker and Wadge, and the other travels a distance set mainly by the eruption duration and ground slope. In the Mauna Loa lavas, yield strength becomes an important flow morphology control only in the distal part of a'a lavas. The occurrence of paired flows on Mauna Loa yields insights into the internal plumbing systems of the volcano, and it is significant that all of the volume of the a'a flow must be stored in a magma chamber before eruption, while none of the volume of the pahoehoe needs to be so stored. Differentiation between the two kinds of flows on images of Martian volcanoes is possible and hence an improved understanding of these huge structures is acquired
Understanding the different rotational behaviors of No and No
Total Routhian surface calculations have been performed to investigate
rapidly rotating transfermium nuclei, the heaviest nuclei accessible by
detailed spectroscopy experiments. The observed fast alignment in No
and slow alignment in No are well reproduced by the calculations
incorporating high-order deformations. The different rotational behaviors of
No and No can be understood for the first time in terms of
deformation that decreases the energies of the
intruder orbitals below the N=152 gap. Our investigations reveal the importance
of high-order deformation in describing not only the multi-quasiparticle states
but also the rotational spectra, both providing probes of the single-particle
structure concerning the expected doubly-magic superheavy nuclei.Comment: 5 pages, 4 figures, the version accepted for publication in Phys.
Rev.
Dynamic absorption of carbon dioxide on microporous carbons
Adsorption of carbon dioxide on microporous carbon
Their Voices: Adolescents in Morelos, Mexico Speak About a School Based HIV/AIDS Intervention
Domiciliary occupational therapy for patients with stroke discharged from hospital: randomised controlled trial
OBJECTIVE: To establish if a brief programme of domiciliary occupational therapy could improve the recovery of patients with stroke discharged from hospital. DESIGN: Single blind randomised controlled trial. SETTING: Two hospital sites within a UK teaching hospital. SUBJECTS: 138 patients with stroke with a definite plan for discharge home from hospital. INTERVENTION: Six week domiciliary occupational therapy or routine follow up. MAIN OUTCOME MEASURES: Nottingham extended activities of daily living score and "global outcome" (deterioration according to the Barthel activities of daily living index, or death). RESULTS: By eight weeks the mean Nottingham extended activities of daily living score in the intervention group was 4.8 points (95% confidence interval -0.5 to 10.0, P=0.08) greater than that of the control group. Overall, 16 (24%) intervention patients had a poor global outcome compared with 30 (42%) control patients (odds ratio 0.43, 0.21 to 0.89, P=0.02). These patterns persisted at six months but were not statistically significant. Patients in the intervention group were more likely to report satisfaction with a range of aspects of services. CONCLUSION: The functional outcome and satisfaction of patients with stroke can be improved by a brief occupational therapy programme carried out in the patient's home immediately after discharge. Major benefits may not, however, be sustained
Associating object names with descriptions of shape that distinguish possible from impossible objects.
Five experiments examine the proposal that object names are closely linked torepresentations of global, 3D shape by comparing memory for simple line drawings of structurally possible and impossible novel objects.Objects were rendered impossible through local edge violations to global coherence (cf. Schacter, Cooper, & Delaney, 1990) and supplementary observations confirmed that the sets of possible and impossible objects were matched for their distinctiveness. Employing a test of explicit recognition memory, Experiment 1 confirmed that the possible and impossible objects were equally memorable. Experiments 2–4 demonstrated that adults learn names (single-syllable non-words presented as count nouns, e.g., “This is a dax”) for possible objectsmore easily than for impossible objects, and an item-based analysis showed that this effect was unrelated to either the memorability or the distinctiveness of the individual objects. Experiment 3 indicated that the effects of object possibility on name learning were long term (spanning at least 2months), implying that the cognitive processes being revealed can support the learning of object names in everyday life. Experiment 5 demonstrated that hearing someone else name an object at presentation improves recognition memory for possible objects, but not for impossible objects. Taken together, the results indicate that object names are closely linked to the descriptions of global, 3D shape that can be derived for structurally possible objects but not for structurally impossible objects. In addition, the results challenge the view that object decision and explicit recognition necessarily draw on separate memory systems,with only the former being supported by these descriptions of global object shape. It seems that recognition also can be supported by these descriptions, provided the original encoding conditions encourage their derivation. Hearing an object named at encoding appears to be just such a condition. These observations are discussed in relation to the effects of naming in other visual tasks, and to the role of visual attention in object identification
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