Search results for "Lithium"

High precision hyperfine measurements in Bismuth challenge bound-state strong-field QED

2017

Electrons bound in highly charged heavy ions such as hydrogen-like bismuth 209Bi82+ experience electromagnetic fields that are a million times stronger than in light atoms. Measuring the wavelength of light emitted and absorbed by these ions is therefore a sensitive testing ground for quantum electrodynamical (QED) effects and especially the electron–nucleus interaction under such extreme conditions. However, insufficient knowledge of the nuclear structure has prevented a rigorous test of strong-field QED. Here we present a measurement of the so-called specific difference between the hyperfine splittings in hydrogen-like and lithium-like bismuth 209Bi82+,80+ with a precision that is improve…

Tunable field effect properties in solid state and flexible graphene electronics on composite high – low k dielectric

2016

We demonstrate tunable field effect properties in solid state and flexible graphene field effect devices (FEDs) fabricated using a poly(methylmethacrylate) (PMMA) and lithium fluoride (LiF) composite dielectric. Increasing the concentration of LiF in the composite dielectric increases the capacitance, which thereby reduces the operating gate voltages of FEDs significantly from 10 V to 1 V to achieve similar conductivity. Electron and hole mobility of 350 and 310 cm2/V at VD = −5 V are obtained for graphene FEDs with 10% LiF concentration in the composite. Composite dielectric also enabled excellent FEDs on flexible substrates without any significant change in mobility and resistance. Flexib…

Asymmetric Homoaldol Reactions with Cyclohex-2-enylN,N-Diisopropylcarbamate: Kinetic Resolution, Elucidation of the Stereochemical Course and Applica…

2007

Enantio-enriched cyclohex-2-enyl N,N-diisopropylcarbamate (5) is stereospecifically deprotonated by sec-butyllithium/(–)-sparteine (9) to form the configurationally stable lithium complex 7·9. A kinetic resolution of rac-5 by n-butyllithium/(–)-sparteine (9) yielded (R)-5 with up to 99 % ee. Electrophilic substitution with tin electrophiles proceeds in a anti-SE′ fashion as shown by chemical correlations. The synthesized allylstannanes 10 undergo a highly stereospecific TiCl4-mediated homoaldol reaction with various aldehydes, yielding syn-configured homoaldol products 12. These were transferred into all-cis-configured hexahydroisobenzofuran-4(1H)-ones 22 by BF3·OEt2-mediated reactions with…

EFFECT OF THE IMPase INHIBITOR L690,330 ON SEA URCHIN DEVELOPMENT

1998

Abstract A variety of concentrations of the IMPase inhibitor L690,330 were added to sea urchin embryos. Immediate arrest of development was obtained for concentrations from 7.5 m m on. Concentrations lower than 3.5 m m permitted gastrulation but inhibited skeletogenesis and disturbed elongation along the animal–vegetal axis. The latter results are similar to those obtained by counteracting lithium effect with myoinositol, which are suggested to be due to partial relief of IMPase inhibition.

1992

The kinetics and the molecular weight distributions (MWD) in the anionic polymerization of tert-butyl acrylate (tBuA) in tetrahydrofuran at 23 ± 3°C were investigated. Tert-butyl α-lithioisobutyrate (tBiB-Li) was used as the initiator in the absence and presence of the additives lithium chloride and lithium tert-butoxide (tBuOLi). A flow tube reactor was used which allowed very rapid mixing of reagents, within milliseconds. The polymerization is extremely fast, half-lives being 0,01 s for the system without additive, 0,05 s for LiCl and 3 s for tBuOLi as an additive. The rate of termination was estimated from the strong UV absorption of the enolized β-oxoester end group formed. The number-a…

Fabrication of cobalt and cobalt oxide/graphene composites: towards high-performance anode materials for lithium ion batteries.

2010

The Jiles Atherton Model for Description Of Hysteresis in Lithium Battery

2013

In this paper Jiles Atherton (JA) Model is used to obtain a mathematical model of the hysteresis in lithium battery. JA Model allows to describe both the hysteresis and the dynamical features of charging and discharging cycles in a lithium battery. The identification of the model is obtained by using a neural network technique developed for magnetic systems. The model is validated on some experimental tests on commercial batteries.

Engineering design and steady state thermomechanical analysis of the IFMIF European lithium target system

2013

In the framework of the current IFMIF Engineering Validation and Engineering Design Activities (IFMIF/EVEDA) phase, ENEA is responsible for the design of the European concept of the IFMIF lithium target system which foresees the possibility to periodically replace only the most irradiated and thus critical component (i.e., the backplate) while continuing to operate the rest of the target for a longer period (bayonet backplate concept). In this work, the results of the steady state thermomechanical analysis of the IFMIF EU target assembly are briefly reported highlighting the relevant indications obtained with respect to the fulfillment of the design requirements. © 2013 IEEE.

An Innovative Conversion Device to the Grid Interface of Combined RES-Based Generators and Electric Storage Systems

2015

This paper is focused on the development of an innovative device, which is based on a bidirectional converter, for the interface to the supply utility grid of combined renewable-energy-source-based generators and electric storage systems. The device can be controlled so as to ease the interface between the low-voltage grid and photovoltaic or wind generators combined with lithium-ion $\hbox{LiFePO}_{4} $ batteries, taking into account the requirements of the reference technical standards for users connection and offering different ancillary services. The operational functioning of the device, the architecture, and its electronic components, as well as laboratory and field test activities an…

A bidirectional converter for the integration of LiFePO4 batteries with RES-based generators. Part II: Laboratory and field tests

2014

This paper presents a device for controlling and connecting combined Renewable Energy Sources (RES)-based generators and electric storage systems to the supply utility grid. The device is a bidirectional converter that can be controlled in order to facilitate the interface between the low voltage grid and small generators combined with Li-ion batteries, contemporary addressing the requirements of the reference technical standards for users connection and providing different ancillary services. The paper describes the laboratory and field test activities carried out by the DEIM of the University of Palermo and ENEA during 2013.