A previous paper [Applied Acoustics 66, pp.709-730, 2005] has shown that adding a quadratic residue diffuser (QRD) to the top of a T-shape barrier can provide better barrier performance than an equivalent purely absorptive barrier. In here, we extend the study to look at the performance when a QRD is made absorptive. This paper presents an investigation on the acoustic performance of a few well...

We improve the conversion efficiency of Ag2S quantum dot (QD)-sensitized TiO2 nanotube-array electrodes by chemically depositing ZnO recombination barrier layer on plain TiO2 nanotube-array electrodes. The optical properties, structural properties, compositional analysis, and photoelectrochemistry properties of prepared electrodes have been investigated. It is found that for the prepared electr...

BACKGROUND AND AIMS Localized proliferation of roots in nutrient-enriched patches seems to be an adaptive response in many plants, but its function is still debatable. To understand the efficiency and limitation of foraging behaviour, the impact of patch size and the presence or absence of a barrier to root proliferation within phosphorus (P)-enriched patches was examined. METHODS In pots fil...

GaN/GaInN asymmetric multiple quantum well light-emitting diodes with varying potential barrier thicknesses (5 and 15 nm) are grown by using metal organic chemical vapor deposition. The narrow structure improves the performance of device, including super-linear increase electroluminescence integral intensity, mitigation efficiency droop at high current density, reduction wavelength drift, forwa...

most common hypotheses of seizure initiation are increased neural excitation, decreased inhibition or both. but, the conditions that lead to these activation states not to be clear yet. recent studies challenge traditional concepts and indicate new evidence that a key epileptogenic process may actually begin in the blood vessel. seizures could be initiate by a variety of insults to the brain, s...

Introduction: Over recent years, various programs have been conducted to reduce noise, indicating the increasing concerns of society over noise pollution. This study has been performed to enhance the performance of parallel barriers on two sides of a highway considering the surrounding buildings. Material and Methods: The 2D boundary element simulation method was employed to predict the noise ...

When the quantum efficiency of a CdS/CdTe solar cell is measured under forward voltage, the measurement is likely affected by several factors including (1) the voltage dependence of the collection efficiency, (2) series resistance of the cell and instrumentation, (3) the electrical barrier of the back contact, (4) photoconductive effects in the CdS and CdTe, and (5) any secondary barrier in the...

Cystic fibrosis (CF) is an autosomal recessive disorder caused by mutations in CFTR genes that affect chloride ion channel. The CF is a good nominee for gene therapy as the asymptomatic carriers are phenotypically normal, and the desired cells are accessible for vector delivery. Gene therapy shows promising effects involving the correction of gene or replacement of the mutant gene with the func...

In this paper, the principal concepts of the energy flow/barrier analysis are used to define an accident as a series of events including failure of the control and protective barriers, which results exposure of a target to a hazardous agent. “Barrier structure” is introduced, as a combination of serial and parallel barriers, to calculate the severity of risks of accidents. It is defined for eac...