Calitatea lucernei sub influenţa fertilizării în condiţiile din silvostepa Moldovei

in Ţenu, Ioan; Vîntu, Vasile; Jităreanu, Gerard (Eds.) Durable Agriculture and Food Security – Priority objectives in research activity of the Ph.D. students from the UASVM Iasi (2012, December 07)

The research conducted during 2011-2012, on the Ezăreni farm, has sought influence of fertilization on the leaves/stems ratio, crude protein content (CP), neutral detergent fiber content (NDF), acid ... [more ▼]

The research conducted during 2011-2012, on the Ezăreni farm, has sought influence of fertilization on the leaves/stems ratio, crude protein content (CP), neutral detergent fiber content (NDF), acid detergent fiber content (ADF) and relative feed value (RFV), of alfalfa (Medicago sativa L.) in the second and third year of vegetation, at the first cut. The studied experimental plots were v1- unfertilized (control plot), v2-N50P50, v3-N75P50 and v4-30 t/ha manure). The results showed that the fertilization negatively affected crude protein content of plants. Although the protein content of leaves was higher and that of strains was less affected, the leaves/stems ratio decided this indicator for plant production. Organic fertilization showed a highly significant positive effect on the content of plant leaves and stems in NDF and ADF. [less ▲]

YBa2Cu3O7-x thick films on silver tubes for magnetic shielding applications

Scientific conference (2012, December 07)

YBa2Cu3O7-x (YBCO) thick films are investigated for magnetic shielding applications at low frequencies (< 1 kHz). This requires deposition of YBCO on curved substrates such as tubes, half-tubes or even ... [more ▼]

YBa2Cu3O7-x (YBCO) thick films are investigated for magnetic shielding applications at low frequencies (< 1 kHz). This requires deposition of YBCO on curved substrates such as tubes, half-tubes or even more complex shapes. Electrophoretic Deposition (EPD) is an efficient method to achieve this goal: positively-charged YBCO particles suspended in a non aqueous medium drift towards the substrate, used as negative electrode for the application of the electric field. A crucial point is then to optimize the heat treatment of the as-deposited layers in order to achieve suitable superconducting properties. In the present work, we have developed a new suspension formulation in butanol, using a suitable surfactant to stabilize the suspension of YBCO powder (grain size < 2 µm). The EPD parameters (deposition voltage, deposition time, number of layers,...) have been selected to provide uniform layers of YBCO on silver substrates of various shapes. In the proposed communication, we shall discuss in detail the optimization of the heat treatments to achieve densification, peritectic recombination and oxygenation of the YBCO thick films deposited on silver. Scanning electron microscopy coupled with energy dispersive analysis was extensively used to characterize the (i) density / porosity, (ii) presence of macro-cracks, (iii) thickness uniformity, (iv) secondary phase content. We shall then present the characterization of the superconducting properties of the best films. Typically, a uniformly coated 55μm-thick YBCO film on a curved Ag substrate shows a magnetic Tc onset at 92.2 K and sharp resistive transition (< 1K). [less ▲]

Understanding the 3D morphology of the Jovian aurora using Juno-UVS observations: simulations and tomographic reconstruction

Conference (2012, December 06)

The aurora at Jupiter is a spectacular signature of the many processes taking place in the Jovian magnetosphere, such as magnetic reconnection, large scale electric currents, moon-magnetosphere ... [more ▼]

The aurora at Jupiter is a spectacular signature of the many processes taking place in the Jovian magnetosphere, such as magnetic reconnection, large scale electric currents, moon-magnetosphere interactions, etc. As a consequence, this aurora is extremely complex and dynamic, powered by a variety of phenomena that we have only begun to unravel. The 3D morphology of the aurora can provide a way to untangle the different processes at play. As a polar orbiter, Juno will provide unprecedented global and close-up views of Jupiter’s auroral emissions. As it flies at low altitude over auroral curtains, spots and patches, it will provide views of these features from multiple points, allowing the retrieval of their 3D structure. The ultraviolet spectrograph on board Juno (Juno-UVS) is designed to observe auroral emissions in the 68 to 210 nm range. It is equipped with a scan mirror targeting up to +/-30 degrees off axis of the spacecraft rotation plane. We have built a planning tool to determine which auroral targets of interest, such as a satellite footprint for example, is observable by the instrument at any time during the mission. We have also built a simulation tool that allows us to generate realistic views of the Jovian aurora as observed by Juno-UVS. The purpose of this tool is to 1) fine-tune the selection algorithm to identify the most valuable data in the harsh radiation environment encountered around Jupiter, and 2) serve as a test bed for adapting tomographic algorithms to the Juno-UVS dataset. Tomographic reconstruction will allow estimation of the position and horizontal extent of the auroral regions of interest, as well as their vertical emission structure, which may be used to characterize the energy distribution of the precipitating particles responsible for the features. [less ▲]

Excess Return Forecast Using a Dynamic Asset Class Factor Model

E-print/Working paper (2012)

We propose a Dynamic Hierarchical Factor Model using Asset classes to predict mutual funds excess returns. We use different forecast combination schemes of bivariate model considering each asset class ... [more ▼]

We propose a Dynamic Hierarchical Factor Model using Asset classes to predict mutual funds excess returns. We use different forecast combination schemes of bivariate model considering each asset class factor in isolation. Primary analysis highlights the importance to account for asset class specific variations together with between classes or common variations. Further refinements of the a priori repartition are however in order. Forecasting performance of the model outperforms the historical mean benchmark both in terms of MSPE and utility based criteria. A forecasting exercise matching more closely real-time conditions must be undertaken to validate these initial results. [less ▲]

Anomalous OI-989 Å intensity profile: solving an old mystery.

Poster (2012, December 06)

Sounding rocket measurements conducted in 1988 under high solar activity conditions had revealed that the intensity of the thermospheric OI emission at 989 Å presents an anomalous vertical profile ... [more ▼]

Sounding rocket measurements conducted in 1988 under high solar activity conditions had revealed that the intensity of the thermospheric OI emission at 989 Å presents an anomalous vertical profile. Observation presents an intensity much higher than what can be expected compared with theoretical results including the photochemical sources of excited oxygen and the radiative transfer of the photons of the OI-989 sextuplet especially above the exobase. Attempts were conducted to clarify the discrepancy by including the non-thermal O(3P) population that appears around the exobase and higher, and that can scatter Doppler-shifted photons of the line profile farther from the rest wavelength. All attempts based on detail modeling of the photochemical processes and radiative transfer revealed unable to account for the discrepancy. Recently the FUV and EUV solar flux has been obtained at very high spectral resolution with the SOHO-SUMER instrument, revealing a significant solar oxygen emission at 989 Å, i.e. a source of photons that had never been accounted for before. In this study, we compute the radiative transfer of the OI-989 Å multiplet including the photochemical sources of excited oxygen, the scattering of incident solar photons and the effect of non-thermal atoms. We find a good agreement with the previous sounding rocket observation, solving the old mystery. We also compare the model simulations with the observations of the STP-78 satellite to better determine the relative importance of the various parameters at work in the radiative transfer of the OI-989 Å multiplet. [less ▲]

Pistes pour une mesure de la compétence numérique

in Questions Vives : Recherches en Education (2012), 7(17),

Nowadays, in the educational field, digital literacy is considered absolutely necessary for students and citizens. If it is occasionally easy to observe the good practice of learners, there remains to ... [more ▼]

Nowadays, in the educational field, digital literacy is considered absolutely necessary for students and citizens. If it is occasionally easy to observe the good practice of learners, there remains to determine how to train them and how to certify their abilities. The visaTICE project tries to face both issues. In this project, certification is a big challenge, but another challenge is to set up a system that takes into account the school context but that is not constrained by it. Presently the visaTICE project has developed online courses, tests, ability trees, coach training programs, which can be used in different contexts but we are not able to prove now, neither the training efficiencies, nor the suitability of the certification tests. A significant number of students will participate in the certification test for the first time in May 2012. Up to now, the collaborative design principle applied in visaTICE acts as a warranty. [less ▲]

Using a 2D Model of the Io Plasma Torus to Investigate the Effects of Density Variations on the Morphology and Intensity of the Io Footprint

Poster (2012, December 06)

Io is the primary source of plasma in the Jovian magnetosphere, continuously releasing approximately 1 ton/s of SO2 from volcanic eruptions. The interaction of Io with Jupiter’s magnetosphere is strongly ... [more ▼]

Io is the primary source of plasma in the Jovian magnetosphere, continuously releasing approximately 1 ton/s of SO2 from volcanic eruptions. The interaction of Io with Jupiter’s magnetosphere is strongly influenced by the density structure of the resulting plasma torus and the position of Io relative to the center of the torus [Bonfond et al. 2008]. This unusual interaction produces a complex auroral feature on Jupiter’s ionosphere known as the Io footprint. Hubble Space Telescope (HST) observations of Jupiter’s far-UV aurora during spring 2007 showed an increased number of isolated auroral blobs along with a continuous expansion of Jupiter’s main auroral oval over a few months. These blobs were associated with several large injections of hot plasma between 9 and 27 Jovian radii. These events coincided with a large volcanic eruption of the Tvashtar Paterae on Io, as observed by the New Horizons spacecraft [Spencer et al., 2007]. This, in turn, may have resulted in a significant increase in the plasma torus density. Besides, on June 7th, 2007, the Io footprint momentarily became so faint that it disappeared under a diffuse patch of emission remaining from an injection blob [Bonfond et al., 2012]. The goal of the present study is to examine the relationship between the increased density of the plasma torus and the dimming of the Io footprint. We implement a 2D model of the Io plasma torus that treats the variable-density torus as being composed of discrete layers of uniform density. As the co-rotating plasma in the plasma torus impinges on Io, Alfvén waves are launched at a pushback angle obtained from Gurnett and Goertz [1981]. The waves propagate inside the plasma torus through reflection and refraction at density discontinuities where they lose some of their initial energy. Using the above model, we can track the Alfvén wave fronts in the plasma torus and determine the longitude at which they exit the torus along with the corresponding remaining energy. Since Alfvén waves are capable of accelerating charged particles along magnetic field lines, we assume that the discrete Io footprint features are created at these longitudes, and that the intensity of each of these features is positively correlated to the energy transported by the wave front as it exits the plasma torus. Therefore, the model allows us to investigate both the effects of density changes and of Io’s position in the plasma torus on the intensity and the morphology of the Io footprint. In this context, the model enables us to determine the density increase in the plasma torus required to explain the apparent disappearance of Io footprint given its position at that time. [less ▲]

Characterization of Volatile Organic Compounds from Human Analogue Decomposition Using Thermal Desorption Coupled to Comprehensive Two-Dimensional Gas Chromatography-Time-of-Flight Mass Spectrometry

in Analytical Chemistry (2012), 85

Complex processes of decomposition produce a variety of chemicals as soft tissues, and their component parts are broken down. Among others, these decomposition byproducts include volatile organic ... [more ▼]

Complex processes of decomposition produce a variety of chemicals as soft tissues, and their component parts are broken down. Among others, these decomposition byproducts include volatile organic compounds (VOCs) responsible for the odor of decomposition. Human remains detection (HRD) canines utilize this odor signature to locate human remains during police investigations and recovery missions in the event of a mass disaster. Currently, it is unknown what compounds or combinations of compounds are recognized by the HRD canines. Furthermore, a comprehensive decomposition VOC profile remains elusive. This is likely due to difficulties associated with the nontarget analysis of complex samples. In this study, cadaveric VOCs were collected from the decomposition headspace of pig carcasses and were further analyzed using thermal desorption coupled to comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (TD-GC × GC−TOFMS). Along with an advanced data handling methodology, this approach allowed for enhanced characterization of these complex samples. The additional peak capacity of GC × GC, the spectral deconvolution algorithms applied to unskewed mass spectral data, and the use of a robust data mining strategy generated a characteristic profile of decomposition VOCs across the various stages of soft-tissue decomposition. The profile was comprised of numerous chemical families, particularly alcohols, carboxylic acids, aromatics, and sulfides. Characteristic compounds identified in this study, e.g., 1-butanol, 1-octen-3-ol, 2-and 3-methyl butanoic acid, hexanoic acid, octanal, indole, phenol, benzaldehyde, dimethyl disulfide, and trisulfide, are potential target compounds of decomposition odor. This approach will facilitate the comparison of complex odor profiles and produce a comprehensive VOC profile for decomposition. [less ▲]

Durabilité de lots de bois de peuplier modifié thermiquement

Conference (2012, December 05)

Coronary heart disease: the MONICA-BELLUX Register

Conference (2012, December 05)

Background : Cardiovascular diseases contribute to 42% of overall mortality in the European Union. Over a third of deaths from CVD are from coronary heart disease and just over a quarter are from ... [more ▼]

Background : Cardiovascular diseases contribute to 42% of overall mortality in the European Union. Over a third of deaths from CVD are from coronary heart disease and just over a quarter are from cerebrovascular disease (stroke). Standardized death rates for heart disease have fallen dramatically in the last 25 years in Western Europe, both for men and for women. Multinational MONItoring of trends and determinants in CArdiovascular disease The MONICA Project : A major source of information on cardiovascular diseases established in the early 1980s under the auspices of WHO, to monitor trends in cardiovascular diseases and to relate these to risk factor changes over a ten year period. There were a total of 37 MONICA Collaborating Centres in 21 countries (including 29 populations in 16 European countries). The ten year data collection was completed in the late 1990s, though several Centres are still active today. Conclusions : CVD registers remain nevertheless an invaluable source for monitoring levels and trends in incidence and case fatality. Trends in incidence rates and in case fatality rates can significantly differ from one another. This situation requires better detection of individuals at risk. The intervention component of the BELLUX register is well-suited for this task. [less ▲]