Search results for "MR"
showing 10 items of 3001 documents
TRACE Code Analyses for the IAEA ICSP on “Integral PWR Design Natural Circulation Flow Stability and Thermo-Hydraulic Coupling of Containment and Pri…
2011
Considering the world energy demand increase in order to fulfill an environmental and economic sustainability, the energy policy of each country has to diversify the sources of energy and use stable, safe energy production option able of producing electricity in a clean way contributing in cutting the CO2 emission. In the framework of the sustainable development, today the use of advanced nuclear power plant, have an important role in the environmental and economic sustainability of country energy strategy. In the last 20 years, in fact, the international community, taking into account the operational experience of the nuclear reactors, starts the development of new advanced reactor designs…
TRACE and RELAP5 Codes for Beyond Design Accident Condition Simulation in the SPES3 Facility
2012
Code validation on qualified experimental data is a fundamental issue in the design and safety analyses of nuclear power plants. The SPES3 facility is being built at the SIET laboratories for an integral type SMR simulation, in the frame of an R&D program on nuclear fission, funded by the Italian Ministry of Economic Development and led by ENEA. The facility, based on the IRIS reactor design, reproduces the primary, secondary and containment systems with 1:100 volume scale, full elevation and prototypical fluid and thermal-hydraulic conditions. It is suitable to test the plant response to design and beyond design accidents in order to verify the effectiveness of the primary and containm…
Analyses of the OSU-MASLWR Experimental Test Facility
2012
Today, considering the sustainability of the nuclear technology in the energy mix policy of developing and developed countries, the international community starts the development of new advanced reactor designs. In this framework, Oregon State University (OSU) has constructed, a system level test facility to examine natural circulation phenomena of importance to multi-application small light water reactor (MASLWR) design, a small modular pressurized water reactor (PWR), relying on natural circulation during both steady-state and transient operation. The target of this paper is to give a review of the main characteristics of the experimental facility, to analyse the main phenomena characteri…
TRANS-CRANIAL MRI-GUIDED FOCUSED ULTRASOUND SURGERY (TCMRGFUS): ITALIAN AND WORLD-FIRST EXPERIENCE AT 1.5 TESLA
2016
Introduction: Transcranial magnetic resonance-guided focused ultrasound surgery (tcMRgFUS) is a promising new technology for the noninvasive treatment of various brain disorders. Here, we present our preliminary results achieved with the first Italian installation of a transcranial MRI-guided focused ultrasound surgery (tcMRgFUS) certified system for functional neurosurgery. Technical issues faced to achieve a safe and effective treatment will be discussed focusing on MR high-resolution live imaging and thermometry sequences optimization. Materials and Methods: Patient enrollment was based on indication for functional neurosurgery and evidence of medication-refractory disease; a detailed me…
GEL DOSIMETERS FOR RADIOTHERAPY APPLICATIONS: RESULTS OF A “RESEARCH PROJECT OF NATIONAL INTEREST” (PRIN)
2016
Introduction: Gel dosimeters for three-dimensional mapping of radiotherapy doses were introduced at Yale University in the mid-1980’s. Soon after, research and development in this field also started in Italy. Early work was done at the Istituto Superiore di Sanità and at the Universities of Pisa and Milan. Several institutes now collaborate on this topic with the goal of developing new formulations of hydrogel matrices with improved characteristics of stability, sensitivity and spatial resolution compared to those of earlier Fricke-gel and polymer-gel systems. Materials and methods: Contrary to earlier gels based on natural gelling agents, such as porcine skin gelatin and/or agarose, which …
Multiparametric MRI-based Dosimetric Parameters Best Predict Short-term Time Course of PSA After Iodine 125 Permanent Prostate Implantation for Local…
2012
International audience; D90% and V150% of the entire prostate are recognized as the best dosimetric predictors of outcome after 125 I permanent prostate implantation (PPI). The purpose of this study was 2-fold: 1) to determine the relationship between dose-volume parameters of the Dominant Intraprostatic Lesion (DIL) when compared to the prostate and early biochemical outcome after PPI; 2) to define if dose-volume parameters of the central gland (CG), the peripheral zone (PZ) and the DIL could best predict PSA bounce occurrence. The time course of PSA and mechanisms of bounces still remain unclear after PPI. Patients who had a higher dose in the DIL had a worse PSA level at 1 year which is …
Synthesis and structure verification of two previously uncharacterized pentachlorobiphenyls: PCB 108 and PCB 127
1992
Abstract The synthesis and structure verification of two previously uncharacterized polychlorinated biphenyl (PCB) congeners mono- ortho -substituted 2,3,3′,4,5′-pentachlorobiphenyl (PCB 108) and non- ortho -substituted 3,3′,4,5,5′-pentachlorobiphenyl (PCB 127) is described. The synthesis was done by the method of aromatic arylation in the presence of isopentyl nitrite. The purification and separation of the compounds was done by flash-chromatography on Al2O3- and charcoal columns. The structures were verified by 1H NMR, 13C NMR, IR and mass spectroscopy.
Model compounds of spent bleach liquor: 2,3,6-trichloro-p-cymenene and 2,3,5-trichloro-p-cymenene
1991
Abstract 2,3,6-Trichloro-p-cymene (1) was synthesized by chlorination of p-cymene. A reaction mixture was distilled in a Fischer-Spaltrohr distilling apparatus. One fraction contained small quantities of chlorinated cymenenes (two isomers) which were concentrated by preparative gas chromatography. Their FTIR and mass spectra were recorded. In earlier paper the structures of 2,3,6-trichloro-p-cymenene were verified by means of its coupled 13C NMR and mass spectra. In the present work the mass and FTIR spectral data of 2,3,5-trichloro-p-cymenene and 2,3,6-trichloro-p-cymenene are published.
Characterization of Hardwood Soda-AQ Lignins Precipitated from Black Liquor through Selective Acidification
2016
In the development of integrated biorefinery process alternatives to produce value-added by-products, various black liquors from sulfur-free pulping processes offer potential feedstocks for recovering their main chemical constituents, lignin and aliphatic carboxylic acids. In this study, lignin fractions were obtained from silver birch (Betula pendula) soda-anthraquinone black liquor by carbonation (pH to about 8.5) or by acidification (pH to about 2) with H2SO4 after carbonation or directly. These fractions were characterized by Fourier transform infrared (FTIR), ultraviolet (UV), energy dispersive X-ray fluorescence (ED XRF), and 13C nuclear magnetic resonance (13C NMR) spectroscopy. In a…
Internal dynamics and energy transfer in dansylated POPAM dendrimers and their eosin complexes.
2010
Internal dynamics of dansylated poly(propyleneamine) dendrimers (POPAM, G1-G4) in solution and excitation energy transfer from dansyls to eosin in POPAM-eosin complexes have been studied by time-resolved fluorescence spectroscopy and molecular dynamics (MD) simulations. Combining the results from fluorescence anisotropy and the MD simulation studies suggests three time domains for the internal dynamics of the G3 and G4 generations, about 60 ps for motions of the outer-sphere dansyls, 500-1000 ps for restricted motions of back-folded dansyls, and 1500-2600 ps for the overall rotation. For the smaller generations, the contribution from the restricted motions was not entirely evident. Eosin bi…