Encapsulating metal nanoparticles inside carbon nanoflakes: a stable absorbent designed from free-standing sandwiched composites

A simple two-step method was used to achieve a stable free-standing sandwich shaped Ni/C nanoflakes absorber with higher conductive loss.

Compositional tailoring effect on electric field distribution for significantly enhanced breakdown strength and restrained conductive loss in sandwich-structured ceramic/polymer nanocomposites

A sandwich-structured ceramic/polymer dielectric nanocomposite with significantly enhanced breakdown strength and restrained conductive loss was obtained by tailoring filler contents.

Study on the Output Characteristics of Piezoelectricity Generator

. For the purpose of improving the output power of piezoelectricity generator (PG), this paper derivates the improving equivalent circuit of piezoelectricity element according to piezoelectricity effect. The dielectric loss and conductive loss are considered. The dielectric loss is caused by the hysteretic effect between leakage current and electric intensity in the medium inside. The conductive loss is caused by the ceramic particles boundary conditions. The relationship between output voltage and current is set up. The relationship between resistance and output power is set up. The relationship between output voltage and out power is set up. Those relationships are simulated and experimented. From the results, it is can be known that there is an optimum load(200 ) for the maximum output power (70 ) in condition of fixed structure, size and fixed excitation frequency and amplitude. With the increasing of voltage, the current is decreasing with parabolic form and the output power increases lowly to a maximum power firstly, and then decreases fast.

Newborn Hearing Screening with Combined Otoacoustic Emissions and Auditory Brainstem Responses

Accurate assessment of neonatal hearing screening performance is impossible without knowledge of the true status of hearing, a prohibitive requirement that necessitates a complete diagnostic evaluation on all babies screened. The purpose of this study was to circumvent this limitation by integrating two types of screening measures obtained near simultaneously on every baby. Peripheral auditory function was defined by otoacoustic emission results. A complete diagnostic evaluation was performed on every baby who received a "Refer" outcome for auditory brainstem response screening. The integrated results for auditory brainstem response screening in an unselected group of 300 newborns estimated sensitivity at 100%, specificity at 99.7%, overall referral rate at 2.0%, and a positive predictive value of 83.3%. Conductive loss associated with amniotic fluid in the middle ear can persist several weeks after birth; conductive loss can produce a "Refer" outcome for auditory brainstem response screening; and auditory neuropathy can be detected with screening measures. Prevalence results were consistent with the published literature. The implications of this study are that otoacoustic emissions and auditory brainstem measures provide much more information than either alone and that both are needed for a comprehensive hearing screening program.

Multi-Component Mixture Modeling for the Dielectric Properties of Rubber Wood at Microwave Frequencies

Summary Dielectric properties from 1 to 18 GHz of rubber wood are modeled using generalized mixture equations and also with equations proposed by Weiner, Kraszewski, Looyenga and Landou, Lichtenecker. Dielectric properties were measured with an open-ended coaxial line-sensor in three structural directions longitudinal, radial and tangential and at different moisture contents. The dielectric constants were predicted well by the Weiner model for all structural grain directions and it was found that the degree of binding decreases with increasing frequency. However, the Weiner model cannot be used for predicting the dielectric loss factor at frequencies below 3 GHz. This may be due to the high conductive loss in this frequency region. The lower value of the exponents in generalized mixture equation was found suitable for fitting the experimental data as well as the Kraszewski equation. Values predicted by Lichtenecker equations are in well agreement with the experimental data at higher microwave frequencies. The prediction of dielectric loss factor using Kraszewski, Looyenga equations were not possible at frequencies below 3 GHz since it is dominated by conductive loss. Above 3 GHz, it was well predicted by Kraszewski and Looyenga equations.