59 research outputs found
Discriminant Function Analysis of Miocene Volcaniclastic Rocks from North-Western Croatia Based on Geochemical Data
Preliminary results of discriminant function analysis of geochemical data of Miocene volcanic and volcaniclastic rocks revealed that it is possible to distinguish rocks of different ages, namely Egerian-Eggenburgian, Karpatian and Badenian. On the basis of calculated coefficients of classification functions, presented in the paper, it is possible to indicate the age of Miocene volcanic and volcaniclastic rocks if their trace element content is known. The analysis also showed that, especially in the case of volcaniclastic rocks, the mineral and petrological composition of the rocks should also be considered. Most of the investigated volcaniclastic rocks from the Mozdjenec and Kalnik areas, the age of which was unknown, are, according to discriminant function analysis, of Egerian-Eggenburgian age
Effect of stress-triaxiality on void growth in dynamic fracture of metals: a molecular dynamics study
The effect of stress-triaxiality on growth of a void in a three dimensional
single-crystal face-centered-cubic (FCC) lattice has been studied. Molecular
dynamics (MD) simulations using an embedded-atom (EAM) potential for copper
have been performed at room temperature and using strain controlling with high
strain rates ranging from 10^7/sec to 10^10/sec. Strain-rates of these
magnitudes can be studied experimentally, e.g. using shock waves induced by
laser ablation. Void growth has been simulated in three different conditions,
namely uniaxial, biaxial, and triaxial expansion. The response of the system in
the three cases have been compared in terms of the void growth rate, the
detailed void shape evolution, and the stress-strain behavior including the
development of plastic strain. Also macroscopic observables as plastic work and
porosity have been computed from the atomistic level. The stress thresholds for
void growth are found to be comparable with spall strength values determined by
dynamic fracture experiments. The conventional macroscopic assumption that the
mean plastic strain results from the growth of the void is validated. The
evolution of the system in the uniaxial case is found to exhibit four different
regimes: elastic expansion; plastic yielding, when the mean stress is nearly
constant, but the stress-triaxiality increases rapidly together with
exponential growth of the void; saturation of the stress-triaxiality; and
finally the failure.Comment: 35 figures, which are small (and blurry) due to the space
limitations; submitted (with original figures) to Physical Review B. Final
versio
Upper Cretaceous-Palaeogene Tholeiitic Basalts of the Southern Margin of the Pannonian Basin: Pozeska gora Mt. (Croatia)
According to the geological relationships in the region of Pozeska gora Mt. (the southern margin of the Pannonian Basin, northern Croatia), basic eruptive rocks are considered to be of Upper Cretaceous-Palaeogene age. Detailed petrographic examination, based on physiographic description, the chemical composition of major and trace elements, rare earth elements and stable isotopes, indicates that these primary tholeiitic basalts have variable structural-textural characteristics, and were postmagmatically affected by metamorphic processes. Tholeiitic basalts originated from the upper mantle, and were placed in the form of subaquatic effusions in the extensional zones within continental crust
Consistent Anisotropic Repulsions for Simple Molecules
We extract atom-atom potentials from the effective spherical potentials that
suc cessfully model Hugoniot experiments on molecular fluids, e.g., and
. In the case of the resulting potentials compare very well with the
atom-atom potentials used in studies of solid-state propertie s, while for
they are considerably softer at short distances. Ground state (T=0K) and
room temperatu re calculations performed with the new potential resolve
the previous discrepancy between experimental and theoretical results.Comment: RevTeX, 5 figure
Theoretical and technological building blocks for an innovation accelerator
The scientific system that we use today was devised centuries ago and is
inadequate for our current ICT-based society: the peer review system encourages
conservatism, journal publications are monolithic and slow, data is often not
available to other scientists, and the independent validation of results is
limited. Building on the Innovation Accelerator paper by Helbing and Balietti
(2011) this paper takes the initial global vision and reviews the theoretical
and technological building blocks that can be used for implementing an
innovation (in first place: science) accelerator platform driven by
re-imagining the science system. The envisioned platform would rest on four
pillars: (i) Redesign the incentive scheme to reduce behavior such as
conservatism, herding and hyping; (ii) Advance scientific publications by
breaking up the monolithic paper unit and introducing other building blocks
such as data, tools, experiment workflows, resources; (iii) Use machine
readable semantics for publications, debate structures, provenance etc. in
order to include the computer as a partner in the scientific process, and (iv)
Build an online platform for collaboration, including a network of trust and
reputation among the different types of stakeholders in the scientific system:
scientists, educators, funding agencies, policy makers, students and industrial
innovators among others. Any such improvements to the scientific system must
support the entire scientific process (unlike current tools that chop up the
scientific process into disconnected pieces), must facilitate and encourage
collaboration and interdisciplinarity (again unlike current tools), must
facilitate the inclusion of intelligent computing in the scientific process,
must facilitate not only the core scientific process, but also accommodate
other stakeholders such science policy makers, industrial innovators, and the
general public
Emerging Technologies for the Detection of Rabies Virus: Challenges and Hopes in the 21st Century
The diagnosis of rabies is routinely based on clinical and epidemiological information, especially when exposures are reported in rabies-endemic countries. Diagnostic tests using conventional assays that appear to be negative, even when undertaken late in the disease and despite the clinical diagnosis, have a tendency, at times, to be unreliable. These tests are rarely optimal and entirely dependent on the nature and quality of the sample supplied. In the course of the past three decades, the application of molecular biology has aided in the development of tests that result in a more rapid detection of rabies virus. These tests enable viral strain identification from clinical specimens. Currently, there are a number of molecular tests that can be used to complement conventional tests in rabies diagnosis. Indeed the challenges in the 21st century for the development of rabies diagnostics are not of a technical nature; these tests are available now. The challenges in the 21st century for diagnostic test developers are two-fold: firstly, to achieve internationally accepted validation of a test that will then lead to its acceptance by organisations globally. Secondly, the areas of the world where such tests are needed are mainly in developing regions where financial and logistical barriers prevent their implementation. Although developing countries with a poor healthcare infrastructure recognise that molecular-based diagnostic assays will be unaffordable for routine use, the cost/benefit ratio should still be measured. Adoption of rapid and affordable rabies diagnostic tests for use in developing countries highlights the importance of sharing and transferring technology through laboratory twinning between the developed and the developing countries. Importantly for developing countries, the benefit of molecular methods as tools is the capability for a differential diagnosis of human diseases that present with similar clinical symptoms. Antemortem testing for human rabies is now possible using molecular techniques. These barriers are not insurmountable and it is our expectation that if such tests are accepted and implemented where they are most needed, they will provide substantial improvements for rabies diagnosis and surveillance. The advent of molecular biology and new technological initiatives that combine advances in biology with other disciplines will support the development of techniques capable of high throughput testing with a low turnaround time for rabies diagnosis
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