Marine Data Archive

The Marine Data Archive is a new web application developed by VLIZ. The purpose is to offer scientists, scientific research groups or project participants the possibility to archive and share their data files with a selected group of people. The MDA makes it possible to store data files in a fully documented way, including all necessary metadata (data about the data files).Why archive your data using the MDA?- Availability: whenever and wherever you like via the internet- Integrity: store the raw and processed data, incl. the program used to process the raw data- BackupEach file in the MDA is stored with metadata describing the data file. This documentation guarantees that the data in the files can be interpreted correctly. The required documentation is dependent on the particular data type ADCP; Meteo data; Image tracking set; botic trawl data), but generally includes information on:- what (biological, chemical, publication, photos)- conditions of use- objectivesThe MDA provides you with three workspaces:- private workspace: files and metadata are only accessible by yourself- public workspace: files and metadata in this workspace are accessible (at least 'read only' access rights) to everyone who has access to the MDA- shared workspace: files and data shared within a scientific research group, project,…So, depending on your personal profile and the folder and workspace you are working in, the type of access rights can be 'read only', 'write' or 'admin'. This means the user can respectively access, edit or administrate the files and metadata

Electronic and atomic shell structure in aluminum nanowires

We report experiments on aluminum nanowires in ultra-high vacuum at room temperature that reveal a periodic spectrum of exceptionally stable structures. Two "magic" series of stable structures are observed: At low conductance, the formation of stable nanowires is governed by electronic shell effects whereas for larger contacts atomic packing dominates. The crossover between the two regimes is found to be smooth. A detailed comparison of the experimental results to a theoretical stability analysis indicates that while the main features of the observed electron-shell structure are similar to those of alkali and noble metals, a sequence of extremely stable wires plays a unique role in Aluminum. This series appears isolated in conductance histograms and can be attributed to "superdeformed" non-axisymmetric nanowires.Comment: 15 pages, 9 figure

Using time-frequency analysis to determine time-resolved detonation velocity with microwave interferometry

Two time-frequency analysis methods based on the short-time Fourier transform (STFT) and continuous wavelet transform (CWT) were used to determine time-resolved detonation velocities with microwave interferometry (MI). The results were directly compared to well-established analysis techniques consisting of a peak-picking routine as well as a phase unwrapping method (i.e., quadrature analysis). The comparison is conducted on experimental data consisting of transient detonation phenomena observed in triaminotrinitrobenzene and ammonium nitrate-urea explosives, representing high and low quality MI signals, respectively. Time-frequency analysis proved much more capable of extracting useful and highly resolved velocity information from low quality signals than the phase unwrapping and peak-picking methods. Additionally, control of the time-frequency methods is mainly constrained to a single parameter which allows for a highly unbiased analysis method to extract velocity information. In contrast, the phase unwrapping technique introduces user based variability while the peak-picking technique does not achieve a highly resolved velocity result. Both STFT and CWT methods are proposed as improved additions to the analysis methods applied to MI detonation experiments, and may be useful in similar applications

M.R.N.I El testamento del cine clásico alemán: del Dr. Caligari al doctor Mabuse

Mares Aliaga, F. (1997). M.R.N.I El testamento del cine clásico alemán: del Dr. Caligari al doctor Mabuse. Banda aparte. (8):49-61. http://hdl.handle.net/10251/42230.Importación Masiva4961

Geant4 Monte Carlo simulation study of the secondary radiation fields at the laser-driven ion source LION

At the Center for Advanced Laser Applications (CALA), Garching, Germany, the LION (Laser-driven ION Acceleration) experiment is being commissioned, aiming at the production of laser-driven bunches of protons and light ions with multi-MeV energies and repetition frequency up to 1 Hz. A Geant4 Monte Carlo-based study of the secondary neutron and photon fields expected during LION’s different commissioning phases is presented. Goal of this study is the characterization of the secondary radiation environment present inside and outside the LION cave. Three different primary proton spectra, taken from experimental results reported in the literature and representative of three different future stages of the LION’s commissioning path are used. Together with protons, also electrons are emitted through laser-target interaction and are also responsible for the production of secondary radiation. For the electron component of the three source terms, a simplified exponential model is used. Moreover, in order to reduce the simulation complexity, a two-components simplified geometrical model of proton and electron sources is proposed. It has been found that the radiation environment inside the experimental cave is either dominated by photons or neutrons depending on the position in the room and the source term used. The higher the intensity of the source, the higher the neutron contribution to the total dose for all scored positions. Maximum neutron and photon ambient dose equivalent values normalized to 10(9) simulated incident primaries were calculated at the exit of the vacuum chamber, where values of about 85 nSv (10(9) primaries)(−1) and 1.0 μSv (10(9) primaries)(−1) were found

Observation of electronic and atomic shell effects in gold nanowires

The formation of gold nanowires in vacuum at room temperature reveals a periodic spectrum of exceptionally stable diameters. This is identified as shell structure similar to that which was recently discovered for alkali metals at low temperatures. The gold nanowires present two competing `magic' series of stable diameters, one governed by electronic structure and the other by the atomic packing.Comment: 4 pages, 4 figure

Capacitación para estudiantes de Administración de Empresas de II año, del Centro Regional Universitario de Coclé, en aplicación de la matemática, en la administración y economía. 2010

Objetivos Generales <Aplicar la Matemática en la Administración y Economía. Objetivos Específicos <Identificar la importancia de la Matemática en la Administración y Economía. <Resolver problemas de administración y economía, mediante procedimientos matemáticos. <Utilizar los cálculos matemáticos para tomar decisiones acertadas en la vida profesional

Heat generation in an elastic binder system with embedded discrete energetic particles due to high-frequency, periodic mechanical excitation

High-frequency mechanical excitation can induce heating within energetic materials and may lead to advances in explosives detection and defeat. In order to examine the nature of this mechanically induced heating, samples of an elastic binder (Sylgard 184) were embedded with inert and energetic particles placed in a fixed spatial pattern and were subsequently excited with an ultrasonic transducer at discrete frequencies from 100 kHz to 20 MHz. The temperature and velocity responses of the sample surfaces suggest that heating due to frictional effects occurred near the particles at excitation frequencies near the transducer resonance of 215 kHz. An analytical solution involving a heat point source was used to estimate heating rates and temperatures at the particle locations in this frequency region. Heating located near the sample surface at frequencies near and above 1 MHz was attributed to viscoelastic effects related to the surface motion of the samples. At elevated excitation parameters near the transducer resonance frequency, embedded particles of ammonium perchlorate and cyclotetramethylene-tetranitramine were driven to chemical decomposition

Karyology and Morphometrics of Three Species of \u3ci\u3eAkodon\u3c/i\u3e (Mammalia: Muridae) from Northwestern Argentina

Chromosomal and morphometric studies were conducted on a sample from an assemblage of Akodon spp. occurring in various patterns of sympatry from the provinces of Catamarca, Jujuy, Salta, and Tucumán, Argentina. Results showed three distinct morphometric groups based upon size. Size also varied with age, but there were no significant differences in measurements of males and females. The three morphometric groups have distinct karyotypes. Akodon caenosus Thomas is the smallest of the three, and has a karyotype of 2n = 34, FN = 40. A. boliviensis tucumanensis J. A. Allen is intermediate in size and has 2n = 40, FN = 40,41. Three variations in centromeric position of the X chromosomes and two autosome arm numbers were found. A. varius simulator Thomas is the largest in size, has a distinctive white chin-spot, and has 2n = 41,42 and FN = 42. Variation in diploid number is apparently due to centric fission or fusion

Karyology and Morphometrics of Three Species of \u3ci\u3eAkodon\u3c/i\u3e (Mammalia: Muridae) from Northwestern Argentina

Chromosomal and morphometric studies were conducted on a sample from an assemblage of Akodon spp. occurring in various patterns of sympatry from the provinces of Catamarca, Jujuy, Salta, and Tucumán, Argentina. Results showed three distinct morphometric groups based upon size. Size also varied with age, but there were no significant differences in measurements of males and females. The three morphometric groups have distinct karyotypes. Akodon caenosus Thomas is the smallest of the three, and has a karyotype of 2n = 34, FN = 40. A. boliviensis tucumanensis J. A. Allen is intermediate in size and has 2n = 40, FN = 40,41. Three variations in centromeric position of the X chromosomes and two autosome arm numbers were found. A. varius simulator Thomas is the largest in size, has a distinctive white chin-spot, and has 2n = 41,42 and FN = 42. Variation in diploid number is apparently due to centric fission or fusion