the accurate prediction of protein stability is one of the most challenging goals in protein formulation and delivery. in this study, a gradient rp-hplc method is described for the separation of human growth hormone (hgh) variants as deamidated and oxidized forms. the methodology employed a polymeric poly (styrene-co-divinylbenzene) column and a 1ml/min flow rate of a linear gradient of 0.1% v/...

Due to issues with Pb toxicity, there is an urgent need for high performance Pb-free alternatives to Pb-based piezoelectric ceramics. Although pure BaTiO3 material exhibits fairly low piezoelectric coefficients, further designing of such a material system greatly enhances the piezoelectric response by means of domain engineering, defects engineering, as well as phase boundary engineering. Espec...

This study demonstrates a method for harvesting the electrical power by the piezoelectric actuator from vibration energy. This paper presents the energy harvesting technique using the piezoelectric element of a bimorph type driven by a geared motor and a vibrator. The geared motor is a type of PWM controlled device that is a combination of an oval shape cam with five gears and a speed controlle...

OBJECTIVES/HYPOTHESIS A piezoelectric sensor, floating piezoelectric microphone, driven by acoustic vibration of the ossicles, is one possible design for a microphone for a totally implantable cochlear implant. The purpose of the article was to study the frequency response of the floating piezoelectric microphone and to identify the ideal feasible position in the ossicular chain. STUDY DESIGN...

Theoretical calculations have been performed to study the effects of piezoelectric fields in superlattice systems. The results show that cubic strained superlattices and quantum wells subjected to variable temperature and pressure exhibit changes in their piezoelectric fields. We consider superlattice systems grown in arbitrary directions, with a thickness smaller and larger than the critical t...

Recently, efforts have been made to manufacture self-sensing smart composites by integrating piezoelectric sensors with laminates. However, the interleaving of pressure sensors, such as polymeric films, dramatically reduces impact resistance hosting laminates, and consequently, delamination can occur. This study aimed fabricate a composite material embedding nanofibers poly(vinylidenefluoride-t...

In this study buckling analysis of solid rectangular plate made of porous material bounded with the layers of piezoelectric actuators in undrained condition is investigated. Porous material properties vary through the thickness of plate with a specific function. Distributing of the pores through the plate thickness is assumed to be the nonlinear nonsymmetric distribution. The ...

in this paper, a nonlinear free vibration analysis of thin annular functionally graded (fg) plate integrated with two uniformly distributed actuator layers made of piezoelectric (pzt4) material on the top and bottom surfaces of the annular fg plate is presented based on kirchhoff plate theory. the material properties of the fgm core plate are assumed to be graded in the thickness direction acco...

We propose a new 1–3 piezoelectric composite comprised of armchair single-walled carbon nanotubes imbedded in a piezoceramic matrix which we call a NRPEC (nanotube reinforced 1–3 piezoelectric composite). Values of effective piezoelectric and elastic moduli of the NRPEC determined through a micromechanical analysis are found to be significantly higher than those of the 1–3 piezoelectric composi...

A rapid surge in the research on piezoelectric sensors is occurring with the arrival of the Internet of Things. Single-phase oxide piezoelectric materials with giant piezoelectric voltage coefficient (g, induced voltage under applied stress) and high Curie temperature (Tc) are crucial towards providing desired performance for sensing, especially under harsh environmental conditions. Here, we re...