A micro-discharge air plasma jet was developed operated at low frequency (50 Hz) ac high voltage (kV). The micro-discharge plasma jet was generated by feeding air through a dielectric installed between two disk-shaped electrodes with a hole of 1 mm diameter in the center. Both of the electrodes were made of copper. The micro-discharge in the dielectric is evolved as a plasma jet from the outer electrode through its hole. The ac power supply was a neon light transformer. Optical emission spectroscopy was employed to study the plasma discharge characteristics. Specair software was used to analyze the collected spectrum. The reduced electric field and electron density of plasma as well as rotational and vibrational temperatures, referring to ion or gas and electron temperature respectively were measured by processing emission spectrum.

Displayers tend to become three-dimensional. The most advantage of holographic 3D displays is the possibility to observe 3D images without using glasses. The quality of created images by this method has surprised everyone. In this paper, the experimental steps of making a transmission hologram have been mentioned. In what follows, current advances of this science-art will be discussed. The aim of this paper is to study the recent improvements in creating three-dimensional images and videos by means of holographic techniques. In the last section we discuss the potentials of holography to be applied in future.

In this paper, applications of holography in the solar energy, photovoltaic concentration, daylighting, illumination, and thermal blocking have been investigated. Holographic elements can be used to concentrate the radiation of the sun onto photovoltaic cells. Moreover the sun radiation is diffracted by the hologram. This has the advantage that proper photovoltaic cells can be installed in different spectral regions. Holographic daylighting systems can diffract sunlight efficiently up to the ceiling in the room. Holograms can be fabricated to reflect or block certain wavelength regions. Holograms are designed for a wavelength in the infrared region and a typical incidence angle of the summer sunlight. In this case the infrared radiation is reflected in the summer and heating of the rooms can be reduced, also, energy for cooling by air conditioners can be reduced. In winter, that the angle of incidence is smaller, a larger wavelength region is reflected, where the infrared intensity is very low.