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Abstract: A 56‐day experiment was conducted to investigate the effect of no carbohydrate addition applied to control water quality in water‐reusing biofloc systems for tilapia (GIFT Oreochromis niloticus) cultivation. Reusing water‐contained flocs was initially inoculated into six 300 L indoor tanks. Thirty fish (average individual weight 99.62 ± 7.34 g) were stocked in each tank. Glucose was extra added into three tanks (GLU‐tanks) according to biofloc technology, while other tanks were no carbohydrate added (NCA‐tanks). Concentrations of total ammonia nitrogen in GLU‐tanks and NCA‐tanks were fairly consistent and below 4.74 ± 0.35 mg/L. Nitrite concentrations in NCA‐tanks were significantly lower than GLU‐tanks, which were below 0.59 ± 0.10 mg/L during the later culture period. NCA‐tanks achieved a low relative abundance of denitrifiers and high concentrations of nitrate. Soluble reactive phosphorous in NCA‐tanks was consistently increased, which was decreased to a low level in GLU‐tanks. However, growth parameters in NCA‐tanks were similar to GLU‐tanks (p > .05) and reach a high finial density of 24.32 ± 1.04 kg/m3. Cetobacterium sp. was the first‐dominant bacterial genus in all tanks, which was a commonly indigenous bacterium in the intestinal tract of freshwater fish. The results demonstrate the feasibility of no carbohydrate addition in water‐reusing biofloc systems for tilapia. [ABSTRACT FROM AUTHOR]

ABSTRACT A five-port power divider with single-ended input and two differential-ended outputs is proposed. The frequency ranges from 9 to 11 GHz with a central frequency of 10 GHz. A stepped impedance line with open stubs is used between differential pairs for broadening the bandwidth and miniaturization of the divider. The divider is fabricated and the measurement results comply with the simulation. A proper performance for differential mode signal is achieved. The insertion loss is within 1.8 dB, the isolation is more than 15 dB, and the return loss is more than 11 dB. In addition, the common mode suppression is reached as well. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2669-2673, 2015 [ABSTRACT FROM AUTHOR]

• Extra added carbohydrate with C/NO3--N ratio ≥ 2 at denitrification phase is advisable for nitrogen removal after a nitrification-based BFT aquaculture cycle. • The highest nitrogen recycling rate (23.08 mg-N·g-C-1) could be achieved when the extra added C/NO3–-N ratio was 4.16. • Denitrifying bacteria and denitrifying polyphosphate accumulating organisms were the dominant bacteria during the denitrification process. In the current study, we set up a denitrification process to remove the nitrogen pollutants, especially nitrate (NO 3 –-N), from the wastewater after a nitrification-based biofloc technology (BFT) aquaculture cycle. Five different treatments (CN0, CN1, CN2, CN4 and CN6, respectively) were used, which involved addition of extra carbohydrate with variable ratios of elementary organic carbon to NO 3 –-N by weight (C/NO 3 –-N ratio equal to 0, 1, 2, 4, and 6, respectively). With CN2, CN4, and CN6 treatments, NO 3 –-N was decreased (with increasing alkalinity) to ≤ 6.42 ± 0.30 mg·L−1 and low amounts (close to zero) of nitrite (NO 2 –-N) were achieved. However, there were high concentrations of residual NO 3 –-N and/or NO 2 –-N in CN0 and CN1. CN2 achieved the best denitrification, wherein 81.00 ± 0.95% of the initial input nitrogen was removed. By fitting the equations, the highest nitrogen recycling rate (23.08 mg-N·g-C−1) was achieved with a C/NO 3 –-N ratio of 4.16. Denitrifying bacteria were the dominant bacteria in all extra carbohydrate added treatment groups. Although denitrifying polyphosphate accumulating organisms contributed to the removal of phosphorus, high concentrations of residual soluble reactive phosphate (SRP) were observed in all treatment groups. Overall, extra addition of carbohydrate with C/NO 3 –-N ratio ≥ 2 is advisable for nitrogen removal, while the highest nitrogen recycling rate will be achieved with a ratio of 4.16. [ABSTRACT FROM AUTHOR]