An experimental study on bioremediation and photolysis of enrofloxacin

Recent studies have identified the occurrence of a vast number of pharmaceuticals into the municipal wastewater through excreted urine and feces. Some of these pharmaceutical compounds are degraded in the environment. However, there have been reports on the presence of pharmaceutical active compounds in drinking water. Concerns have been raised over the potential adverse effects of these pharmaceuticals on public health and the aquatic environment. In order to investigate the removal process of pharmaceutical enrofloxacin, a unit consisting of a structured packing rotating biological contactor (spRBC) was designed and constructed as a biological treatment unit. The removal rate reached a maximum of 70% in this biological unit. In the meantime, the effect of photolysis process on the effluent of the biological unit was also studied. In the direct photolysis, the removal performance reached 51% and by adding H2O2 the removal efficiency was increased to 87%. The removal efficiency for the entire system including spRBC and an ultraviolet radiation unit was 94%.

Design of Active Phased Array Antenna in Wind Profiling Radar

The active phased array antenna is a direction of modern radar development. But it is expensive. So the key in meteorological radar design is to get high ratio of capability and cost. We used 400 cross-polarization half wave diploes as radiation unit to get a high efficiency and reliability antenna, it also has low side lobe by Taylor weighting. 20 transmit/receive(T/R) modules produced too little heat to disperse, so it can be cooled by nature wind. 40 power dividers which one is divided into twenty parts and 1 power combiner decreased transmission loss. This antenna is fit for the need of wind profiling radar.

A Design of Ultrawide Band Planar Monopole Antenna Based on Microstrip Pentagonal Patch

An ultra-wide band planar monopole antenna is presented in this paper. This antenna uses a pentagonal patch as radiation unit and is fed by a microstrip line. The relevant simulation is performed by using Ansoft HFSS. The return loss curve and the radiation patterns of this new antenna are given. And the effect of the size of the various parts of the antenna on the reflection loss is analyzed. Experimental results show that the proposed antenna provides an ultra-wide bandwidth (1.70~12.90 GHz) for return loss less than -10dB (VSWR<2). It is suitable for current ultra-wide band communication systems.

X-ray powder diffraction analysis of K3Nb3WO9(AsO4)2

K3Nb3WO9(AsO4)2 has been investigated by means of X-ray powder diffraction. Powder diffraction data were obtained by conventional diffractometer with Kα radiation. Unit-cell dimensions were determined by an indexing program based on variation of parameters by successive dichotomies. An orthorhombic cell (space group Pnma) was found with a=15.001 (1) Å, b=14.814(1) Å, c=7.2374 (8) Å, and V=1608.4 (4) A3. The figures of merit were calculated to be M(20)=35.9 and F(20)=70.8 (0.0055,51).

X-Ray Powder Diffraction Analysis of Barium Titanyl Oxalate Tetrahydrate

Barium titanyl oxalate tetrahydrate, Ba(TiO)(C2O4)2.4H2O, has been investigated by means of X-ray powder diffraction. Precise powder diffraction data were obtained by a conventional diffractometer with strictly monochromatic radiation. Unit cell dimensions were determined by an indexing program based on the variation of parameters by successive dichotomies. A monoclinic cell was found, a=14.044(2)Å, b=13.812(2)Å, c=13.382(2)Å, β=91.48(1); V=2594.9Å3, which is characterized by the figures of merit M20=46.5 and F30=107(0.0056, 50). The complete powder pattern was reviewed by means of the program NBS*AIDS83 and the 81 first lines were indexed. Structural imperfections were not detected from the diffraction line widths, which are comparable to the instrumental resolution.