Search results for "Bridge"

2019

The preparation of unprecedented 6,12-disubstituted methanodibenzo[b,f][1,5]dioxocins from pyrrolidine catalyzed self-condensation of 2′-hydroxyacetophenones is herein described. This method provides easy access to this highly bridged complex core, resulting in construction of two C–O and two C–C bonds, a methylene bridge and two quaternary centers in a single step. The intricate methanodibenzo[b,f][1,5]dioxocin compounds were obtained in up to moderate yields after optimization of the reaction conditions concerning solvent, reaction times and the use of additives. Several halide substituted methanodibenzo[b,f][1,5]dioxocins could be prepared from correspondent 2′-hydroxyacetophenones.

Applicazione delle Linee guida italiane alle valutazioni di sicurezza strutturale del ponte Corleone sulla tangenziale di Palermo

2022

The "nominal life" of a large part of existing reinforced and prestressed concrete bridges, in Italy, is expiring, often in the absence of ordinary or extraordinary maintenance. Consequently, the Italian infrastructural network is in a critical phase, followed by the alarmed awareness of the public opinion, especially after the collapse of the Polcevera viaduct. Specific guidelines on risk classifi-cation, management, safety assessment, monitoring of existing bridges have been issued by the Superior Council of Public Works in 2020, to address the emergency. Between ‘50s and ‘70s of the last century, important examples of reinforced and prestressed concrete bridges were built in Italy by the…

Ecological Networks and Planning

2017

This chapter focuses on the regulation issue of the ecological networks/connections within planning instruments. In effect, the paradigm of ecological networks can be adopted within planning instruments to bridge the split existing in current development patterns between the use of the land and conservation of nature. About this issue, the work clearly explains the critical aspects, also referring to different ecological network models and specific local realities. In relation to this perspective, the most commonly adopted approach for the introduction of ecological networks into the planning process is the ecosystemic approach which, when applied to territory planning, shows it is particul…

Coulomb blockade thermometer: Tests and instrumentation

1998

Coulomb blockade thermometry (CBT) provides a simple method for absolute thermometry in every day laboratory use at cryogenic temperatures. CBT has been found insensitive to even high magnetic fields. We review the principles and the operation of CBT and the fabrication of the sensors, and present new data on radiation hardness and stability of the sensors. We describe the instrumentation of CBT in detail. We have developed two signal conditioning units for CBT measurements. One is a modified alternating current resistance bridge, a versatile laboratory instrument operating with a PC computer, and the other one is a simple stand-alone instrument for direct temperature reading. Test results …

MgO Magnetic Tunnel Junction Electrical Current Sensor With Integrated Ru Thermal Sensor

2013

Full Wheatstone bridge electrical current sensor incorporating 114 MgO-based magnetic tunnel junction elements (3 × 30 μm2) connected in series was produced for improved electrical robustness. To that end, magnetic tunnel junctions with R × A ~7 KΩ μm2 tunneling magnetoresistance of 200%, were produced. The sensor was designed with an integrated Ru thin film resistive thermal detector (RTD) for temperature drift monitoring and compensation. In order to achieve a full bridge signal, a U-shaped copper trace was placed under a printed circuit board (PCB) specifically designed for this type of device. The resulting device exhibit sensitivities of 63.9 V/Oe/A in a 75 Oe linear range biased with …

Note: A non-invasive electronic measurement technique to measure the embedded four resistive elements in a Wheatstone bridge sensor

2015

The work shows a measurement technique to obtain the correct value of the four elements in a resistive Wheatstone bridge without the need to separate the physical connections existing between them. Two electronic solutions are presented, based on a source-and-measure unit and using discrete electronic components. The proposed technique brings the possibility to know the mismatching or the tolerance between the bridge resistive elements and then to pass or reject it in terms of its related common-mode rejection. Experimental results were taken in various Wheatstone resistive bridges (discrete and magnetoresistive integrated bridges) validating the proposed measurement technique specially whe…

Pulmonary hypertension in pediatrics. a feasible approach to bridge the gap between real world and guidelines

2019

Pulmonary hypertension (PH) is quite infrequent in pediatric age and its most common etiologies include idiopathic pulmonary arterial hypertension, PH related to congenital heart diseases, bronchopulmonary dysplasia (chronic lung disease), persistence of pulmonary hypertension of the newborn, and congenital diaphragmatic hernia. The developed for adult patients PH classification shows limitations when applied to pediatric subjects since the underlying causes are markedly different between the two ages. In 2011, the Pulmonary Vascular Research Institute Panama Task Force outlined the first specific pediatric pulmonary hypertensive vascular disease diagnostic classification, including 10 main…

Enhanced modulation strategy for 7-level voltage waveform in asymmetrical 5-level Cascaded H-Bridge Inverters

2022

The CHBMI performance optimization can be reached both with hardware and software solutions. Generally, asymmetrical configurations allow the extension of the voltage levels number and the implementation of an innovative modulation strategy allows for improving the performance in terms of harmonic distortion and conversion efficiency. This work is devoted to the development of a modulation strategy that allows improving the performance of an asymmetrical single-phase five-level Cascaded H-Bridge Inverter generating a 7-level voltage waveform. Thus, a digital approach and corresponding digital functions are presented. Subsequently, the impact of the dead time and the influence on the voltage…

Functional distinction between Cln1p and Cln2p cyclins in the control of the Saccharomyces cerevisiae mitotic cycle.

2004

Abstract Cln1p and Cln2p are considered as equivalent cyclins on the basis of sequence homology, regulation, and functional studies. Here we describe a functional distinction between the Cln1p and Cln2p cyclins in the control of the G1/S transition. Inactivation of CLN2, but not of CLN1, leads to a larger-than-normal cell size, whereas overexpression of CLN2, but not of CLN1, results in smaller-than-normal cells. Furthermore, mild ectopic expression of CLN2, but not of CLN1, suppresses the lethality of swi4swi6 and cdc28 mutant strains. In the absence of Cln1p, the kinetics of budding, initiation of DNA replication, and activation of the Start-transcription program are not affected; by cont…

El trabajo en red y la cooperación como elementos para la mejora escolar

2021

La escuela es un entorno enriquecido de aprendizaje, pero no es el único entorno educativo. La misión educativa de la escuela debe contemplar la coordinación escuela-familia como rasgo de su proyecto social. Buena parte de este puente se fundamenta en el diálogo desde la participación de la familia con el desarrollo educativo integral, base de la noción democratizadora de la escuela. Por ello, esta aportación aborda el trabajo en red como elemento para la mejora escolar desde la cooperación. Se focaliza en el trabajo en red al servicio del aprendizaje y el conocimiento y en los equipos cooperativos como unidad de trabajo en red. Una muestra de esta forma de trabajo se concreta en dos experi…