The effects of composition, temperature and sample size on the sintering of chem-prep high field varistors.

The sintering behavior of Sandia chem-prep high field varistor materials was studied using techniques including in situ shrinkage measurements, optical and scanning electron microscopy and x-ray diffraction. A thorough literature review of phase behavior, sintering and microstructure in Bi{sub 2}O{sub 3}-ZnO varistor systems is included. The effects of Bi{sub 2}O{sub 3} content (from 0.25 to 0.56 mol%) and of sodium doping level (0 to 600 ppm) on the isothermal densification kinetics was determined between 650 and 825 C. At {ge} 750 C samples with {ge}0.41 mol% Bi{sub 2}O{sub 3} have very similar densification kinetics, whereas samples with {le}0.33 mol% begin to densify only after a period of hours at low temperatures. The effect of the sodium content was greatest at {approx}700 C for standard 0.56 mol% Bi{sub 2}O{sub 3} and was greater in samples with 0.30 mol% Bi{sub 2}O{sub 3} than for those with 0.56 mol%. Sintering experiments on samples of differing size and shape found that densification decreases and mass loss increases with increasing surface area to volume ratio. However, these two effects have different causes: the enhancement in densification as samples increase in size appears to be caused by a low oxygen internal atmosphere that develops whereas the mass loss is due to the evaporation of bismuth oxide. In situ XRD experiments showed that the bismuth is initially present as an oxycarbonate that transforms to metastable {beta}-Bi{sub 2}O{sub 3} by 400 C. At {approx}650 C, coincident with the onset of densification, the cubic binary phase, Bi{sub 38}ZnO{sub 58} forms and remains stable to >800 C, indicating that a eutectic liquid does not form during normal varistor sintering ({approx}730 C). Finally, the formation and morphology of bismuth oxide phase regions that form on the varistors surfaces during slow cooling were studied

Photo-induced pyridine substitution in cis-[Ru(bpy)(2)(py)(2)]Cl-2 : a snapshot by time-resolved X-ray solution scattering

Determination of transient structures in light-induced processes is a challenging goal for time-resolved techniques. Such techniques are becoming successful in detecting ultrafast structural changes in molecules and do not require the presence of probe-like groups. Here, we demonstrate that TR-WAXS (Time-Resolved Wide Angle X-ray Scattering) can be successfully employed to study the photochemistry of cis-[Ru(bpy)(2)(py)(2)]Cl-2, a mononuclear ruthenium complex of interest in the field of photoactivatable anticancer agents. TR-WAXS is able to detect the release of a pyridine ligand and the coordination of a solvent molecule on a faster timescale than 800 ns of laser excitation. The direct measurement of the photodissociation of pyridine is a major advance in the field of time-resolved techniques allowing detection, for the first time, of the release of a multiatomic ligand formed by low Z atoms. These data demonstrate that TR-WAXS is a powerful technique for studying rapid ligand substitution processes involving photoactive metal complexes of biological interest

Physical and Link Layer in Power Line Communications Technologies

PLC technology1 - Power Line Communications- refers to the transmission of data using the domestic as well as the low-voltage electrical net. Depending on the type of network used as support it is divided in PLC indoor and outdoor. The first refers to the use of the domestic network and uses higher frequencies (5 MHz to 30 or 40 MHz). Outdoor PLC uses the distribution network and low frequencies of 1 MHz to 5 or 10 MHz. It employs the OFDM multiplexation technique- Orthogonal Frequency Division Multiplexing- which divides the frequency spectrum in narrow channels with independent carriers. At the level of media access protocol, it generally uses those which are compatible with the IEEE 802 norm, with controlled access to avoid collisions. OFDM modulation achieves transmission speeds which are suitable for multimedia services and applications as well as those of critical mission currently used, and with security conditions when facing a noisy channel such as the power network.II Workshop de Arquitecturas, Redes y Sistemas OperativosRed de Universidades con Carreras en Informática (RedUNCI

Physical and Link Layer in Power Line Communications Technologies

PLC technology1 - Power Line Communications- refers to the transmission of data using the domestic as well as the low-voltage electrical net. Depending on the type of network used as support it is divided in PLC indoor and outdoor. The first refers to the use of the domestic network and uses higher frequencies (5 MHz to 30 or 40 MHz). Outdoor PLC uses the distribution network and low frequencies of 1 MHz to 5 or 10 MHz. It employs the OFDM multiplexation technique- Orthogonal Frequency Division Multiplexing- which divides the frequency spectrum in narrow channels with independent carriers. At the level of media access protocol, it generally uses those which are compatible with the IEEE 802 norm, with controlled access to avoid collisions. OFDM modulation achieves transmission speeds which are suitable for multimedia services and applications as well as those of critical mission currently used, and with security conditions when facing a noisy channel such as the power network.II Workshop de Arquitecturas, Redes y Sistemas OperativosRed de Universidades con Carreras en Informática (RedUNCI

An Overview of MPLS Technology: Quality of Service and Traffic Engineering

This paper provides an overview of Multi-Protocol Label Switching Technology (MPLS). Distinctive issues are presented as well as Quality of Service (QoS). Traffic Engineering (TE) features are discussed. It also describes current network trends where Internet Protocol (IP) is the predominant technology and points out the advantages of MPLS for data, voice, and video information transport.II Workshop de Arquitecturas, Redes y Sistemas OperativosRed de Universidades con Carreras en Informática (RedUNCI

Quality of service and availability in a full mesh WAN using IP/MPLS : Case study: the network at the Department of Justice in Argentina

At the Argentine Department of Justice (Ministerio Público Fiscal de la República Argentina), a project is developed to set up a WAN with national coverage, quality of service, and IP/MPLS/VPN links. The project focuses on quality of service, a direct result from the selected technology. In previous work, studies explored these issues. Hence, the project enabled the implementation of the examined theory. The advantages of MPLS technology are evaluated to determine quality standards in VoIP, videoconference, mission critical appli-cations, e-mail, web access, and others. Other aspects of LANs are analyzed to obtain an availability level compatible to the required needs. The Project in-clude practical recommendations to adequate the LAN to the desired availability levels.IV Workshop Arquitectura, Redes y Sistemas Operativos (WARSO)Red de Universidades con Carreras en Informática (RedUNCI

Communication access to small and remote communities: the Corral de Lorca project

Throughout Argentina, like in many developing countries, several ru-ral areas with low population density are present. This distribution becomes an obstacle when seeking solutions to provide broadband services with an efficient internet connection. Alternative solutions are explored which differ from those regularly implemented in developed countries. The solutions examined are re-lated to the use of long range wireless technologies, such as microwaves, 802.11, WiMax, CDMA450 and others with similar features. The reasons be-hind the implementation of these networks are associated to the speed and lack of difficulty of their set up, as well as the capability to use frequencies without requiring previous authorization. In addition, they avoid reliance on local com-munication operators. The present work discusses the implementation of 802.11 technology in these areas. Its behavior is analyzed for large coverage areas which differ from the well known solutions employed in large urban settings, where its application for short distances is consistent to its design. In particular, the case of the Corral de Lorca village, in the Argentine province of Mendoza, is presented.IV Workshop Arquitectura, Redes y Sistemas Operativos (WARSO)Red de Universidades con Carreras en Informática (RedUNCI

Applicability of HRM analysis for carnaroli rice authentication based on polymorphisms of the waxy gene

Rice (Oryza sativa L.) is a staple food and one of the most important cereals in the worldwide. Italy, the leading rice producer in Europe, holds nearly 200 different varieties in the available germplosm [1]. The Carnaroli rice is a high quality and priced variety belonging to the group of ja ponica ecotype, produced mainly in Piedmont. it is considered one of the finest Italian rice varieties due to its excellent cooking resistance, given by a low tendency to lose starch and a good ability to absorb liquid while creaming, being, thus, ideal for the preparation of traditional risotto. Italian rice varieties hove different characteristics, from which the starch composition is a highly relevant parameter. Together with amylopectin, amylose is the main component of starch, whose ratio is determinant for the rice cooking properties. After cooking, varieties with high amylose content have dry, firm and separate groins, while low amylose ones usually hove tender, cohesive and glossy texture [2]. Amylose synthesis is catalysed by the granule bound starch synthase (GBSS) that is encoded by the Waxy gene (Wx), being located on the chromosome 6. Various nucleotide polymorphisms have been associated with the Wx gene, namely (CT)n repeats and several single nucleotide polymorphisms (SNP) [2]. The aim of this work was to propose a new method based on high resolution melting (HRM) analysis, exploiting those polymorphisms to differentiate Carnaroli rice from other closely related varieties.This work has been supported by the European project FOODINTEGRITY (FP7-KBBE- 2013-single-stage, No 613688), by FCT (Fundação para a Ciencia e Tecnologia) through project UID/QUI/50006/2013 - POCI/ 01/0145/FEDER/ 007265 with financial support from FCT /MEC through national funds and eo-financed by FED ER. under the Partnership Agreement PT2020 and by the project NORTE-01-0145-FEDER-000011. L. Grazina and J. Costa ore grateful to grants (SFRH/ BD/132462/2017 and SFRH/BPD/102404/2014, respectively) from FCT financed by POPH-QREN (subsidised by FSE and MCTES).info:eu-repo/semantics/publishedVersio