A 3.6V Rail-to-Rail Operational Amplifier with Constant g<SUB>m</SUB>

Chang Gao,Qiang Li,Jing Wang,Yasuaki Inoue 대한전자공학회 2015 ITC-CSCC :International Technical Conference on Ci Vol.2015 No.6

A 3.6V CMOS rail-to-rail operational amplifier with a novel constant gm (transconductance) biasing circuit is proposed. The rail-to-rail input stage is realized by connecting two complementary differential pairs in parallel. To obtain constant gm across the whole common mode input range, the drain currents of differential pairs are precisely controlled by proposed biasing circuit. This design is verified by simulation using a 0.18㎛ CMOS process. Simulation result shows a rail-to-rail input/output range and a constant gm with ±2.45% variation. Also an open loop gain of 88dB, unity gain bandwidth of 1.17MHz and phase margin of 63° are achieved.

ADAPTIVE ENERGY MANAGEMENT STRATEGY OF FUEL CELL ELECTRIC VEHICLE

Yan Sun,Changgao Xia,Bifeng Yin,Yingxiao Yu,Jiangyi Han,Haiyu Gao 한국자동차공학회 2022 International journal of automotive technology Vol.23 No.5

The energy management strategy (EMS) can efficiently split the power among different sources for a fuel cell electric vehicle (FCEV). This paper puts forward how to cooperate with a proton exchange membrane fuel cell as the primary energy source, and a ultracapacitor as the auxiliary energy storage. Firstly, the test bench of fuel cell is built and the characteristic of fuel cell is tested. A model of vehicle is built in AMESim software based on the real parameters of vehicle especially the characteristic of fuel cell. Secondly, the traditional power following strategy is introduced and an optimal energy management strategy is proposed. The demand power is decomposed by quadratic utility function (QUF) and Karush-Kuhn-Tucker (KKT) condition. In order to balance the vehicle economy and durability of fuel cell, the multi-objective artificial bee colony algorithm (MOABC) and pareto solution set are used to solve the optimal balance coefficient in the algorithm. The simulation results show that compared with the traditional strategy under one WLTP driving cycle, the novel strategy can reduce the fuel cell degradation by 25.08 %, and the equivalent hydrogen consumption can be also reduced.

Medium Optimization using Mathematical Statistics for Production of β-Carotene by Blakeslea trispora and Fermenting Process Regulation

Zuowen Yan,Changgao Wang,Jianguo Lin,Jun Cai 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.6

Optimization of medium components forenhancement of β-carotene production by Blakesleatrispora was achieved using mathematical statistics. Optimum concentrations of components using Plackett-Burman design and response surface methodology (RSM)were D-glucose 7.16%, wheat bran extract 4.08%, MgSO40.04%, soybean oil 3%, thiamine 0.01%, soybean meal1%, and KH2PO4 0.2%. Maximum production of β-carotene using optimized medium was 643 mg/L in ashake flask. A predicted value of 669 mg/L was based onresults of an RSM regression. The optimum aeration rate of1.5 vvm produced 866 mg/L and the optimum agitationspeed of 100 rpm produced 975 mg/L of β-carotene. The tof a quadratic model using regression derived coefficientswas significant. Maximum production of β-carotene usingthe optimized medium in a stirred tank reactor (10 L) at anoptimal aeration rate and an optimum agitation speed withaddition of 0.1%(v/v) β-ionone was 1,357 mg/L.

Purification and characterization of exo-polygalacturonase from Zygoascus hellenicus V25 and its potential application in fruit juice clarification

Xiaohua Lu,Jianguo Lin,Changgao Wang,Xin Du,Jun Cai 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.5

The purification and characterization of the extracellular polygalacturonase from Zygoascus hellenicus V25 submerged culture using orange peel waste were investigated. This polygalacturonase, with a molecular weight of 75.28 kDa, was purified to 16.89 purification fold with a recovery of 18.46% and specific activity of 2469.77 U/mg protein by ammonium sulfate precipitation, DEAE cellulose chromatography, and Sephadex G-100 gel filtration. The enzyme exhibited maximum activity at 60oC and pH 5.0 and was stable over a wide range of pH levels (3.0-11.0). Moreover, enzyme activity was enhanced by Cu2+ and cysteine, whereas it was strongly inhibited by Hg2+. The extent of enzymatic hydrolysis was negatively correlated with the degree of pectin esterification. Km and Vmax values of the polygalacturonase were 5.44 mg/mL and 61.73 μmol/(min·mg), respectively. The polygalacturonase was applied in the juice clarification of four fruits, and results showed that the percentage transmittance at 660 nm increased by 3.51, 4.36, 8.04, and 12.2%.

Biotransformation and detoxification of aflatoxin B1 by extracellular extract of Cladosporium uredinicola

Shuai Shao,Jun Cai,Xin Du,Changgao Wang,Jianguo Lin,Jun Dai 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.6

Aflatoxin contamination of food and grain poses a serious economic and health problem globally. Aflatoxin B1 (AFB1) is extremely mutagenic and toxic as well as a potent carcinogen to both humans and livestock. In this study, the degradation of AFB1 by extracellular extract of Cladosporium uredinicola was examined using high-performance liquid chromatography (HPLC), thin-layer chromatography (TLC), and liquid chromatography mass spectrometry. Within 24 h of incubation, AFB1 was efficiently eliminated by the culture supernatant of C. uredinicola (84.5±5.7%) at 37oC; the elimination was proven to be enzymatic, and the enzyme was thermostable. The biotransformation products of AFB1 detected by HPLC and TLC were proven to be the same compound. Analysis with LCMS showed that AFB1 was bio-transformed to a structurally different compound (m/z=365 [M+Na]+), which is first reported. The cytotoxicity study to HeLa cells indicated that culture supernatant-treated AFB1 is less toxic as compared with AFB1.

Purification and characterization of exo-polygalacturonase from Zygoascus hellenicus V25 and its potential application in fruit juice clarification

Lu, Xiaohua,Lin, Jianguo,Wang, Changgao,Du, Xin,Cai, Jun 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.5

The purification and characterization of the extracellular polygalacturonase from Zygoascus hellenicus V25 submerged culture using orange peel waste were investigated. This polygalacturonase, with a molecular weight of 75.28 kDa, was purified to 16.89 purification fold with a recovery of 18.46% and specific activity of 2469.77 U/mg protein by ammonium sulfate precipitation, DEAE cellulose chromatography, and Sephadex G-100 gel filtration. The enzyme exhibited maximum activity at $60^{\circ}C$ and pH 5.0 and was stable over a wide range of pH levels (3.0-11.0). Moreover, enzyme activity was enhanced by $Cu^{2+}$ and cysteine, whereas it was strongly inhibited by $Hg^{2+}$. The extent of enzymatic hydrolysis was negatively correlated with the degree of pectin esterification. $K_m$ and $V_{max}$ values of the polygalacturonase were 5.44 mg/mL and $61.73{\mu}mol/(min{\cdot}mg)$, respectively. The polygalacturonase was applied in the juice clarification of four fruits, and results showed that the percentage transmittance at 660 nm increased by 3.51, 4.36, 8.04, and 12.2%.

Biotransformation and detoxification of aflatoxin B₁ by extracellular extract of Cladosporium uredinicola

Shao, Shuai,Cai, Jun,Du, Xin,Wang, ChangGao,Lin, JianGuo,Dai, Jun 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.6

Aflatoxin contamination of food and grain poses a serious economic and health problem globally. Aflatoxin $B_1$ ($AFB_1$) is extremely mutagenic and toxic as well as a potent carcinogen to both humans and livestock. In this study, the degradation of $AFB_1$ by extracellular extract of Cladosporium uredinicola was examined using high-performance liquid chromatography (HPLC), thin-layer chromatography (TLC), and liquid chromatography mass spectrometry. Within 24 h of incubation, $AFB_1$ was efficiently eliminated by the culture supernatant of C. uredinicola ($84.5{\pm}5.7%$) at $37^{\circ}C$; the elimination was proven to be enzymatic, and the enzyme was thermostable. The biotransformation products of $AFB_1$ detected by HPLC and TLC were proven to be the same compound. Analysis with LCMS showed that $AFB_1$ was bio-transformed to a structurally different compound ($m/z=365[M+Na]^+$), which is first reported. The cytotoxicity study to HeLa cells indicated that culture supernatant-treated $AFB_1$ is less toxic as compared with $AFB_1$.