Harvesting multi-frequency sound energy from environmental noise is a meaningful topic to supply for potential devices. In this work, we constructed an array of Helmholtz resonators (HRs) with cross-linked polypropylene (IXPP) ferroelectret films on the inner walls HR cavities, whose resonant frequencies range 300 800 Hz and quasi-static piezoelectric coefficient d33 230 pC/N. The harvesting pe...

Abstract Lead-free (K0.48Na0.48Li0.04)(Nb0.95Sb0.05)O3 (KNLNS) ceramics have been successfully optimized for the calcination and two-step sintering temperatures. The experimental results reveal that KNLNS powder calcined at 850 or 900 °C presented a pure perovskite phase with an orthorhombic phase. particle size was in range of 0.1–0.4 m. temperature (range: 950 to 1100 °C) significantly affec...

5-6 MHz PMNT/epoxy 1-3 composites were prepared by a modified dice-and-fill method. They exhibit excellent properties for ultrasonic transducer applications, such as ultrahigh thickness electromechanical coupling coefficient k(t) (85.7%), large piezoelectric coefficient d33 (1209 pC/N), and relatively low acoustic impedance Z (1.82 × 107 kg/(m2·s)). Besides, two types of Time-of-Flight Diffract...

This paper presents an investigation on dielectric and mechanical nonlinear properties in Mn-doped PMN-35PT ceramics. The structural study of the ceramics verifies that the 1% mol Mn doped PMN-35PT is a pure perovskite phase with a tetragonal symmetry. SEM micrograph shows the same microstructural morphology of an undoped ceramic. From the EPR spectra, it has been concluded that the major part ...

Shikimate kinase (SK), which catalyzes the specific phosphorylation of the 3-hydroxyl group of shikimic acid in the presence of ATP, is the enzyme in the fifth step of the shikimate pathway for biosynthesis of aromatic amino acids. This pathway is present in bacteria, fungi, and plants but absent in mammals and therefore represents an attractive target pathway for the development of new antimic...

Aim: To dosimetrically compare and evaluate Intensity Modulated Radiation Therapy (IMRT) versus conventional five field radiotherapy (5FCRT) in postmastectomy radiotherapy (PMRT). Material and Methods: This study included 25 consecutive patients for PMRT. Target volumes (chest wall, axilla, supraclavicular regions [SCF]) and normal structures (lungs, heart, spinal cord, opposite breast) were de...

The present work makes use of experimental ac complex impedance data to obtain the electrical parameters like electrical conductivity and activation energy of ((Bi0.5Na0.5)0.94Ba0.06TiO3+0.2 wt%Nb2O5)– PVDF 0-3 composites with 10, 20 and 30 vol. percentage of ((Bi0.5Na0.5)0.94Ba0.06TiO3+0.2 wt%Nb2O5) in the frequency range 1kHz–1 MHz over a temperature range of 35C-145°C. SEM micrographs exhibi...

Economic globalization causes an increasing international fragmentation (disintegration) of value-added-chains, whereby firms outsource components of production to foreign markets. There is a high level of concern about unwelcome distributional effects. This paper provides a theoretical treatment of this issue within a general Heckscher-Ohlin framework, allowing for an arbitrary number of goods...

The piezoelectric effect of biological piezoelectric materials promotes bone growth. However, the material should be subjected to stress before it can produce an electric charge that promotes bone repair and reconstruction conducive to fracture healing. A novel method for in vitro experimentation of biological piezoelectric materials with physiological load is presented. A dynamic loading devic...

Ferroelectrets have promoted a variety of exciting flexible sensors, actuators, and microenergy harvesters. However, most ferroelectrets been fabricated from non-degradable petro-based resins, thus the recycling these materials constitutes big challenge. This article reports biodegradable bioabsorbable ferroelectret films made polylactic acid (PLA) resins for highly sensitive transducer applica...