A momentum-space Argonne V18 interaction

This paper gives a momentum-space representation of the Argonne V18 potential as an expansion in products of spin-isospin operators with scalar coefficient functions of the momentum transfer. Two representations of the scalar coefficient functions for the strong part of the interaction are given. One is as an expansion in an orthonormal basis of rational functions and the other as an expansion in Chebyshev polynomials on different intervals. Both provide practical and efficient representations for computing the momentum-space potential that do not require integration or interpolation. Programs based on both expansions are available as supplementary material. Analytic expressions are given for the scalar coefficient functions of the Fourier transform of the electromagnetic part of the Argonne V18. A simple method for computing the partial-wave projections of these interactions from the operator expressions is also given.Comment: 61 pages. 26 figure

A hybrid combination of substitution and transposition ciphers for efficient encryption using graph labeling

In this study, we conceptualise a hybrid approach of plaintext encryption by making use of Substitution and Transposition cipher technique namely Playfair Cipher and Simple Columnar Transposition. Both the Ciphers are Symmetric Encryption Technique and the need for developing such a hybrid is to inherit the positive traits as well as restrict certain limitations of both the techniques to a considerable extent. The resulting hybrid text is further subjected to Graph Labeling Technique as the receiver receives the ciphertext in the form of a Graph structure together with a clue to determine the type of labeling used and the ciphertext sequence. Here we adopt two varied labeling techniques namely Simply Sequentially Additive labeling and Distance two labeling for some Tree related Graphs and the corresponding Decryption of the Cipher Graph yields the desired plaintext.Publisher's Versio

Towards a cyberterrorism life-cycle (CLC) model

Cyberterrorism has emerged as a new threat in the Information and Communication Technology (ICT) landscape. The ease of use, affordability, remote capabilities and access to critical targets makes cyberterrorism a potential threat to cause wide-scale damage. Cyberterrorism is often incorrectly perceived as encompassing all cybercrimes. However, cyberterrorism differs from cybercrime in various ways including motivation, attack goals, techniques and effects. Motivations for cyberterrorism, which is similar to terrorism in general, stem from religious, social and political views. Cyberterrorists generally would seek to have high impact in order to gain publicity for their cause, whereas cybercriminals often prefer to have their acts undetected in order to hide their financial theft, fraud or espionage. Therefore, there are various factors that drive the development of a cyberterrorist. This paper proposes a model for the development of cyberterrorism in order to show the various influential forces. The Cyberterrorism Life-Cycle (CLC) model presented in this paper is composed of five phases: Prepare, Acquaint, Choose, Execute, and Deter (PACED). In addition the paper looks at various factors, including social, practices, objectives, targets and countermeasures, which are mapped onto the PACED phases in order to show the interaction and dynamic nature during the life-cycle development

Building an ontology for cyberterrorism

Cyberterrorism and the use of the Internet for cyberterrorism is an emerging field. Often cyberterrorism activities overlap with traditional hacking and Information and Communication Technology (ICT) Infrastructure exploitation. As a result, the defining and differentiating characteristics of cyberterrorism can easily be misunderstood. The use of an ontology specifically developed for cyberterrorism, will provide a common framework to share conceptual models. By using an ontology, the internal and external environment of a field (in this case, cyberterrorism) can be captured together with the relationships between the environments. This paper proposes an ontology to identify whether a cyber event can be classified as a cyberterrorist attack or a support activity. The role of the cyberterrorism ontological model will be to provide a better structure and depiction of relationships, interactions and influencing factors by capturing the content and boundaries in the field of cyberterrorism

Two-Nucleon Scattering without partial waves using a momentum space Argonne V18 interaction

We test the operator form of the Fourier transform of the Argonne V18 potential by computing selected scattering observables and all Wolfenstein parameters for a variety of energies. These are compared to the GW-DAC database and to partial wave calculations. We represent the interaction and transition operators as expansions in a spin-momentum basis. In this representation the Lippmann-Schwinger equation becomes a six channel integral equation in two variables. Our calculations use different numbers of spin-momentum basis elements to represent the on- and off-shell transition operators. This is because different numbers of independent spin-momentum basis elements are required to expand the on- and off-shell transition operators. The choice of on and off-shell spin-momentum basis elements is made so that the coefficients of the on-shell spin-momentum basis vectors are simply related to the corresponding off-shell coefficients.Comment: 14 pages, 8 Figures, typos correcte

Field emission properties of nano-composite carbon nitride films

A modified cathodic arc technique has been used to deposit carbon nitride thin films directly on n+ Si substrates. Transmission Electron Microscopy showed that clusters of fullerene-like nanoparticles are embedded in the deposited material. Field emission in vacuum from as-grown films starts at an electric field strength of 3.8 V/micron. When the films were etched in an HF:NH4F solution for ten minutes, the threshold field decreased to 2.6 V/micron. The role of the carbon nanoparticles in the field emission process and the influence of the chemical etching treatment are discussed.Comment: 22 pages, 8 figures, submitted to J. Vac. Sc. Techn.

Nucleon-Nucleon Interaction: A Typical/Concise Review

Nearly a recent century of work is divided to Nucleon-Nucleon (NN) interaction issue. We review some overall perspectives of NN interaction with a brief discussion about deuteron, general structure and symmetries of NN Lagrangian as well as equations of motion and solutions. Meanwhile, the main NN interaction models, as frameworks to build NN potentials, are reviewed concisely. We try to include and study almost all well-known potentials in a similar way, discuss more on various commonly used plain forms for two-nucleon interaction with an emphasis on the phenomenological and meson-exchange potentials as well as the constituent-quark potentials and new ones based on chiral effective field theory and working in coordinate-space mostly. The potentials are constructed in a way that fit NN scattering data, phase shifts, and are also compared in this way usually. An extra goal of this study is to start comparing various potentials forms in a unified manner. So, we also comment on the advantages and disadvantages of the models and potentials partly with reference to some relevant works and probable future studies.Comment: 85 pages, 5 figures, than the previous v3 edition, minor changes, and typos fixe

Neutron-diffraction studies of amorphous CNx materials

The results of neutron-diffraction experiments performed on two samples of amorphous CNx, with nitrogen concentrations of 5 and 30 at. %, prepared by a combination of filtered cathodic are and Kaufman-type ion source, are presented. Increasing the N content of the samples is seen to cause a decrease of the average bond length and the first coordination number. An increase in the average bond angle from 113 degrees to 121 degrees is also observed. The pair-distribution functions indicate that N incorporation results in some transformation of sp(3) C sites to sp(2) sites, but there is no evidence for N inducing the formation of crystalline graphitic clusters, and the overall structure remains amorphous. A direct subtraction of the two data sets emphasizes the loss of sp(3) bonds and the increasing sp(2) character of the higher-N-content sample, and shows the occurrence of a variety of bonding environments for N. More limited information on second neighbor correlations involving N is also revealed

Mapping past human land use using archaeological data: A new classification for global land use synthesis and data harmonization

In the 12,000 years preceding the Industrial Revolution, human activities led to significant changes in land cover, plant and animal distributions, surface hydrology, and biochemical cycles. Earth system models suggest that this anthropogenic land cover change influenced regional and global climate. However, the representation of past land use in earth system models is currently oversimplified. As a result, there are large uncertainties in the current understanding of the past and current state of the earth system. In order to improve repre- sentation of the variety and scale of impacts that past land use had on the earth system, a global effort is underway to aggregate and synthesize archaeological and historical evi- dence of land use systems. Here we present a simple, hierarchical classification of land use systems designed to be used with archaeological and historical data at a global scale and a schema of codes that identify land use practices common to a range of systems, both imple- mented in a geospatial database. The classification scheme and database resulted from an extensive process of consultation with researchers worldwide. Our scheme is designed to deliver consistent, empirically robust data for the improvement of land use models, while simultaneously allowing for a comparative, detailed mapping of land use relevant to the needs of historical scholars. To illustrate the benefits of the classification scheme and meth- ods for mapping historical land use, we apply it to Mesopotamia and Arabia at 6 kya (c. 4000 BCE). The scheme will be used to describe land use by the Past Global Changes (PAGES) LandCover6k working group, an international project comprised of archaeologists, historians, geographers, paleoecologists, and modelers. Beyond this, the scheme has a wide utility for creating a common language between research and policy communities, link- ing archaeologists with climate modelers, biodiversity conservation workers and initiatives.publishedVersio

Mapping past human land use using archaeological data: A new classification for global land use synthesis and data harmonization

In the 12,000 years preceding the Industrial Revolution, human activities led to significant changes in land cover, plant and animal distributions, surface hydrology, and biochemical cycles. Earth system models suggest that this anthropogenic land cover change influenced regional and global climate. However, the representation of past land use in earth system models is currently oversimplified. As a result, there are large uncertainties in the current understanding of the past and current state of the earth system. In order to improve representation of the variety and scale of impacts that past land use had on the earth system, a global effort is underway to aggregate and synthesize archaeological and historical evidence of land use systems. Here we present a simple, hierarchical classification of land use systems designed to be used with archaeological and historical data at a global scale and a schema of codes that identify land use practices common to a range of systems, both implemented in a geospatial database. The classification scheme and database resulted from an extensive process of consultation with researchers worldwide. Our scheme is designed to deliver consistent, empirically robust data for the improvement of land use models, while simultaneously allowing for a comparative, detailed mapping of land use relevant to the needs of historical scholars. To illustrate the benefits of the classification scheme and methods for mapping historical land use, we apply it to Mesopotamia and Arabia at 6 kya (c. 4000 BCE). The scheme will be used to describe land use by the Past Global Changes (PAGES) LandCover6k working group, an international project comprised of archaeologists, historians, geographers, paleoecologists, and modelers. Beyond this, the scheme has a wide utility for creating a common language between research and policy communities, linking archaeologists with climate modelers, biodiversity conservation workers and initiatives