In this paper, we experimentally compare the field emission characteristics of two different cathodes based on polyacrylonitrile fibers (PAN fibers) and carbon nanotube (CNT filaments). The main purpose study was to properties materials for cathode unit a luminescent lamp. current-voltage, current watt-watt fabricated were measured. A comparison current-voltage made studied shows that minimum o...

In the past few years many interesting developments have come from studies using the electron microscope. Some of these new methods and discoveries already have a clinical application, others offer a hope of clinical applications and developments in the future. This account will be restricted to work published since 1965. Capabilities and Limitations Though its appearance is impressive and its ...

abstract   background: the compounds which contain nitrogen entering the environment can cause some problems, such as eutrophication for water resources and potential risk for human health because of methemoglobinemia and cancer. biological techniques are effective in removing nitrate. the aim of this study was to remove nitrate from groundwater using denitrification. the main objectives of thi...

We describe an accurate and precise calibration procedure for multichannel optical pyrometers such as the 6-channel, 3-ns temporal resolution instrument used in the Caltech experimental geophysics laboratory. We begin with a review of calibration sources for shock temperatures in the 3000-30,000 K range. High-power, coiled tungsten halogen standards of spectral irradiance appear to be the only ...

THE choroidal coat of the eye consists of a dense continuous network of vessels and yet it is a striking feature of choroidal disease that the lesions often remain remarkably circumscribed. It is the purpose of this paper to review the problem of selective localization of pathological changes within the choroid in relation to its vascular anatomy, with particular reference to certain findings (...