Search results for "Lead"
showing 10 items of 1360 documents
The strain response of piezoelectric multilayer actuators under combined action of electric field and in-plane uniform load
1997
Abstract The driving field governed strain of lead zirconate titanate piezoelectric multilayer actuators have been made within the 107 N/m2 stress and the 3 · 106 V/m triangle-like upward-down-ward driving voltage. A slow strain component as well as a specific relaxation pattern are detected being additional to the periodic part and attributed to the trapped space charge effects favored by nonuniform electric field of the multilayer.
Interface Effects in Ferroelectric Thin Films
1998
Dielectric, ferroelectric and piezoelectric characteristics in sol-gel derived and pulsed laser deposited (PLD) lead zirconate titanate (PZT), La modified lead titanate (PLT) and zirconate titanate (PLZT) ferroelectric thin films are investigated focusing on maintenance of thin film ferroelectric (FE) properties in a variety of thin film-electrodesubstrate interfaces. Interferometric studies of piezoelectric response of the heterostructures were performed with respect to a DC electrical bias and AC measurement frequency. The asymmetry of piezoelectric coefficient (d33) hysteresis, diminished values of d33, frequency-displacement and spot size — deformation behaviour in the ferroelectric het…
Fabrication of an extremely cheap poly(3,4-ethylenedioxythiophene) modified pencil lead electrode for effective hydroquinone sensing
2021
Hydroquinone (HQ) is one of the major deleterious metabolites of benzene in the human body, which has been implicated to cause various human diseases. In order to fabricate a feasible sensor for the accurate detection of HQ, we attempted to electrochemically modify a piece of common 2B pencil lead (PL) with the conductive poly(3,4-ethylenedioxythiophene) or PEDOT film to construct a PEDOT/PL electrode. We then examined the performance of PEDOT/PL in the detection of hydroquinone with different voltammetry methods. Our results have demonstrated that PEDOT film was able to dramatically enhance the electrochemical response of pencil lead electrode to hydroquinone and exhibited a good linear co…
Growth and Characterization of Ordered PbO[sub 2] Nanowire Arrays
2008
Large arrays of PbO 2 nanowires having high aspect ratios (length-to-width ratio) were grown by potentiostatic electrodeposition into anodic alumina templates under anodic polarization. Different electrolytic solutions were used in order to obtain nanowires of pure α-PbO 2 , pure β-PbO 2 , and a a + β mixture, We have found that, in a lead nitrate bath, a crystallographic structure of nanowires depends on pH; this latter was varied adding diluted nitric acid to the electrolyte. Nanowires of pure β-PbO 2 were obtained at pH 0.6, while mixed α-PbO 2 + β-PbΟ 2 nanowires were grown at pH 2. Pure α-phase was obtained in a bath containing lead acetate at pH 6.6. In all deposition conditions, nano…
Aging, rejuvenation, and memory phenomena in a lead-based relaxor ferroelectric
2002
Isothermal aging and temperature cycle experiments were done on the relaxor ferroelectric lead magnesium niobate mixed with 10% lead titanate (PMN-10PT) around and below the diffuse maximum of the dielectric loss. With increasing aging time tw the isothermal evolution of the linear susceptibility follows a power law and does not show frequency scaling. The non-linear susceptibility, however, obeys nearly perfect ωt w-scaling. After aging the sample at a single temperature we observed both rejuvenation and memory effects in temperature cycle experiments. This observation indicates symmetric behavior in the sense that it shows up irrespective of whether cooling with subsequent re-heating or h…
"One-touch" voltammetry of microparticles for the identification of corrosion products in archaeological lead
2011
Voltammetry of microparticles is applied to the identification of lead corrosion products by means of an essentially non-invasive 'one-touch' technique based on the use of graphite pencil. This methodology permits the mechanical attachment of few nanograms of sample from the surface of lead archaeological artefacts to a paraffin-impregnated graphite electrode, which, upon immersion in aqueous electrolytes, provides distinctive voltammetric responses for litharge and cotunnite- anglesite-, cerusite-based corrosion products. The reported method is applied to the identification of corrosion products in archaeological lead pieces from different Iberian sites in Valencia (Spain). © 2011 WILEY-VC…
SU-E-T-691: Shielding Evaluation of a Treatment Room with An Electronic Brachytherapy System
2015
Purpose: Esteya™ (Elekta) is a brachytherapy electronic system used for treating skin cancer lesions. This unit is based on a 69.5 kV X-ray source and a surface applicator which produces a circular beam of a specific diameter, which varies from 1 to 3 cm. This study aims to establish the radiation protection measures for the system. Methods: A characterization of the scattered and leakage radiation of the system was implemented by means of experimental measurements. The scattered radiation measurements were performed with a Berthold LB133 ionization chamber, evaluating the dose rate for different distances from the applicator surface. The patient was simulated through water equivalent solid…
Calibration of a thermoluminescent dosimeter worn over lead aprons in fluoroscopy guided procedures
2018
Fluoroscopy guided interventional procedures provide remarkable benefits to patients. However, medical staff working near the scattered radiation field may be exposed to high cumulative equivalent doses, thus requiring shielding devices such as lead aprons and thyroid collars. In this situation, it remains an acceptable practice to derive equivalent doses to the eye lenses or other unprotected soft tissues with a dosimeter placed above these protective devices. Nevertheless, the radiation backscattered by the lead shield differs from that generated during dosimeter calibration with a water phantom. In this study, a passive personal thermoluminescent dosimeter (TLD) was modelled by means of …
Grain growth in Na 0.5 Bi 0.5 TiO 3 -based solid solutions
2019
This paper discusses effects of different dopants, sintering technique and parameters on microstructure and properties of pure and Yb, Er-doped Na0.5Bi0.5TiO3 (NBT). All stoichiometric compositions follow the abnormal grain growth mechanism (AGG) and exhibit a bimodal grain size distribution. Bi over-stoichiometry, two step sintering and hot pressing are effective inhibitors of AGG. Microstructure of sintered NBT greatly influences such properties as dielectric permittivity and depolarization temperature.
Sustainable metabolic engineering for sustainability optimisation of industrial biotechnology
2021
Industrial biotechnology represents one of the most innovating and labour-productive industries with an estimated stable economic growth, thus giving space for improvement of the existing and setting up new value chains. In addition, biotechnology has clear environmental advantages over the chemical industry. Still, biotechnology’s environmental contribution is sometimes valued with controversy and societal aspects are frequently ignored. Environmental, economic and societal sustainability of various bioprocesses becomes increasingly important due to the growing understanding about complex and interlinked consequences of different human activities. Neglecting the sustainability issues in th…