Features Choice of Light Sources for Bio-Technical Life Support Systems for Space Applications

The historical aspects and prospects of the use of artificial light sources in the biological and technical systems of life support for space applications are considered. According to the given data, the most promising for such systems are LED light sources. Based on the results of photobiological studies it is shown that radiation, perceived by a man as white, in his spectral efficiency unreliable differs from radiation, a spectral curve similar to the average action spectrum of photosynthesis the green sheet (“Phyto”). In accordance with this, the possibility of choosing either a phyto spectrum or a spectrum close to the equal energy for the cultivation of plants in life support systems is justified.

Analysis of the Characteristics on Dielectric Barrier Discharges Depending on the Relative Permittivity and Frequency

Various studies are being conducted on the application of DBD (Dielectric barrier discharges). The internal dielectric has a very important characteristic on DBD, thus we analyze of the characteristics on dielectric barrier discharges depending on the relative permittivity and frequency. Through simulation, the discharge voltage was calculated based on relative permittivity and frequency of real used dielectrics (Green sheet, Down dielectric, white dielectric). We investigate that increased relative permittivity and fast frequency occur the decrease of the firing voltage. Also, we investigate the frequency dependence of the dielectric constant and dielectric loss of dielectric layers measured at a frequency region of 100Hz to 10MHz. In a condition of drive within 1MHz, with regard to the change of real and imaginary part according to frequency, it has quite stable dielectric constant in the condition of drive within 1MHz.

Co-firing of PZT–PMS–PZN/Ag Multilayer Actuator Prepared by Tape-Casting Method

Multilayer ceramic actuator composed of piezoelectrically active 0.90Pb(Zr0.48Ti0.52)O3–0.05Pb(Mn1/3Sb2/3)O3–0.05Pb(Zn1/3Nb2/3)O3 (PZT–PMS–PZN) layers and electrically conducting silver metal layers were fabricated. Low-temperature sinterable PZT–PMS–PZN ceramics were used as the piezoelectric layers, and silver paste was used as the conductive inner-electrode layers. PZT–PMS–PZN powder, adding 1% CuO as a sintering agent, was prepared by a conventional solid-state reaction process. The green sheet was fabricated by tape-casting method. Silver inner-electrode was printed on the green-tape sheets and the sheets were stacked, warm-pressed, and sintered at 900°C for 4 h after burning out the organic additions. The sintered multilayer ceramics actuator shows distinct layers with few defects in the interfaces. The thicknesses of the piezoelectric and conducting layers are about 40 and 6 μm, respectively. The multilayer PZT–PMS–PZN actuator, composed of 60 active piezoelectric layers, presents a longitudinal displacement of about 2.7 μm at an applied voltage of 80 V, approximately 0.1% of the total thickness of itself.

Fabrication of Ultrathin Free-Standing Ceramic Chips Based on Printing Technology

In order to obtain high quality ultrathin free-standing ceramic chips, a new manufacturing process based on the screen printing and the cold isostatic pressing process has been developed. 1) In this process, an ultrathin free-standing green sheet (less than 20 μm thick) can be achieved successfully as shown in Fig. 1. After sintering, an ultrathin free-standing ceramic chip (less than 20 μm thick) with good density uniformity, can be obtained as shown in Fig. 2. In addition, the thicknesses of the ultrathin chips can be adjusted by changing the printing parameters for different application requirements. Such process can significantly widen the scope and applicability of the ultrathin chips in many kinds of materials.