937 research outputs found
The temporal evolution of the normalized web distance: Is a âWirikuta empowermentâ of the Huichol measurable on the internet?
Purpose:
The purpose of this paper is to assess whether the temporal evolution of the normalized web distance (NWD) between significant terms concerning, e.g., a case of online activism can be used as a meta-data technique to measure evolution over time of, e.g., progress or decline of social empowerment.
Design/methodology/approach:
The NWD between two terms has been identified as a quantitative measure for semantic proximity, ascertaining a defining relation between them. A trend analysis is made by performing on the internet a time window restrained series measurement of NWD of all combinations of key-terms and classifier-terms. Case defining key-terms, positive and negative discourse polarizing classifier-terms, and neutral classifier-terms for negative control need to be determined by discourse analysis of information on a targeted case. An example of NWD evolution from 1994 until 2013 is presented to measure the empowerment effects of the Wirikuta online movement on the Huichol people in Mexico.
Findings:
The application of the NWD temporal evolution method to the Wirikuta case shows a slight but significant semantic change of the key-terms with respect to some of the positive and negative classifier-terms. The neutral classifier correctly shows no significant distance variation, as required for valid application of the method. The method provides indications for a complex image of empowerment of the Huichol identity.
Research limitations/implications:
The accuracy of the method is limited due to short-term and between-user variability of the search toolâs page counts. More reliable access to a web-index will be required for more accurate NWD-based trend analysis.
Practical implications:
The monitoring of temporal NWD evolution provides a potential tool for more comprehensive trend description compared to classical frequency based methods.
Originality/value:
Trend analysis is key to internet research, to which the temporal NWD method provides an innovative contribution
Archaeology of the Brasada: A Cultural Resources Assessment of the Chevron Resources Company Properties in Northeastern Duval County, Texas
Within the past decade, cultural resource management has become an increasingly significant aspect of archaeological investigations in southern Texas. Twenty-five new sites were identified, recorded, and assessed as the result of a 4000-acre cultural resources survey in northeastern Duval County, southern Texas, by the Center for Archaeological Research, The University of Texas at San Antonio, from October to December 1981. The investigations were carried out under the requirements and guidelines of the National Historic Preservation Act of 1966, as amended, the Vernon Texas Civil Statute 4590f, as amended, and the Guidelines for Archeological Investigations of Mining Areas in Texas (Texas Historical Commission 1981)
Ab initio study of ferromagnetism in Ga1âxCrxN thin films
Electronic structure and magnetic properties of Ga1-xCrxN thin films are studied using the gradient corrected density functional method and a supercell slab model. Calculations are carried out by varying the concentration of doped Cr atoms and the sites they occupy. Cr atoms are found to prefer to reside on the surface sites and cluster around N as Mn atoms do. However, unlike Mn-doped GaN, Cr-doped GaN is found to be ferromagnetic for all concentrations studied. The calculated ferromagnetism is in agreement with recent experimental observations
Metastability of a gold nanoring: Density-functional calculations
First-principles calculations based on gradient corrected density functional theory show that a cluster of as few as 90 gold atoms can be stabilized in a ring structure having fcc (111) motif with the binding energy/atom and interatomic distance approaching 91% and 96% of the bulk values, respectively. Although the ring structure lies 0.139eV/atom higher in energy than a polyicosahedral structure, the calculated frequencies are real. Thus under appropriate experimental conditions it may still be possible to synthesize a metastable form of gold nanoring, as found in the recent experiment
Counting Rotten Apples: Student Achievement and Score Manipulation in Italian Elementary Schools
Magnetic properties of Ni2.18Mn0.82Ga Heusler alloys with a coupled magnetostructural transition
Polycrystalline Ni2.18Mn0.82Ga Heusler alloys with a coupled
magnetostructural transition are studied by differential scanning calorimetry,
magnetic and resistivity measurements. Coupling of the magnetic and structural
subsystems results in unusual magnetic features of the alloy. These uncommon
magnetic properties of Ni2.18Mn0.82Ga are attributed to the first-order
structural transition from a tetragonal ferromagnetic to a cubic paramagnetic
phase.Comment: 4 pages, 4 figures, revtex
Interfacial layering in a three-component polymer system
We study theoretically the temporal evolution and the spatial structure of
the interface between two polymer melts involving three different species (A,
A* and B). The first melt is composed of two different polymer species A and A*
which are fairly indifferent to one another (Flory parameter chi_AA* ~ 0). The
second melt is made of a pure polymer B which is strongly attracted to species
A (chi_AB 0). We then show
that, due to these contradictory tendencies, interesting properties arise
during the evolution of the interface after the melts are put into contact: as
diffusion proceeds, the interface structures into several adjacent
"compartments", or layers, of differing chemical compositions, and in addition,
the central mixing layer grows in a very asymmetric fashion. Such unusual
behaviour might lead to interesting mechanical properties, and demonstrates on
a specific case the potential richness of multi-component polymer interfaces
(as compared to conventional two-component interfaces) for various
applications.Comment: Revised version, to appear in Macromolecule
Developments in the negative-U modelling of the cuprate HTSC systems
The paper deals with the many stands that go into creating the unique and
complex nature of the HTSC cuprates above Tc as below. Like its predecessors it
treats charge, not spin or lattice, as prime mover, but thus taken in the
context of the chemical bonding relevant to these copper oxides. The crucial
shell filling, negative-U, double-loading fluctuations possible there require
accessing at high valent local environment as prevails within the mixed valent,
inhomogeneous two sub-system circumstance of the HTSC materials. Close
attention is paid to the recent results from Corson, Demsar, Li, Johnson,
Norman, Varma, Gyorffy and colleagues.Comment: 44 pages:200+ references. Submitted to J.Phys.:Condensed Matter, Sept
7 200
Density functional calculations of nanoscale conductance
Density functional calculations for the electronic conductance of single
molecules are now common. We examine the methodology from a rigorous point of
view, discussing where it can be expected to work, and where it should fail.
When molecules are weakly coupled to leads, local and gradient-corrected
approximations fail, as the Kohn-Sham levels are misaligned. In the weak bias
regime, XC corrections to the current are missed by the standard methodology.
For finite bias, a new methodology for performing calculations can be
rigorously derived using an extension of time-dependent current density
functional theory from the Schroedinger equation to a Master equation.Comment: topical review, 28 pages, updated version with some revision
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