Sodium alginate-based wall materials microencapsulated Lactobacillus plantarum CICC 20022: characteristics and survivability study

Lihua Zhang,Peixin Tang,Shunfeng Li,Xia Wang,Wei Zong 한국식품과학회 2022 Food Science and Biotechnology Vol.31 No.11

In this study, microcapsules of Lactobacillus plantarum CICC 20022 (L. plantarum CICC 20022) were prepared by extrusion technique using sodium alginate (SA), sodium alginate-sodium caseinate (SA-SC) and sodium alginate-whey protein isolate (SA-WPI) as wall materials, respectively. Results showed that the best encapsulation yield of L. plantarum CICC 20022 was SA-WPI. Morphology and texture analysis showed that the microcapsules prepared by the SA-WPI system presented a more compact internal structure and higher resistance to external pressure. Fourier-transform infrared spectroscopy and low field nuclear magnetic resonance analysis demonstrated that the hydrogen bonding ability and network structure of the SA were improved by the addition of WPI. The survivability of L. plantarum CICC 20022 entrapped with the SA-WPI system was improved during freeze-drying and simulated gastrointestinal digestion. Therefore, the SA-WPI system can potentially be used as the vector of L. plantarum CICC 20022 in food applications.

An Efficient and Mild Oxidation of α-Isophorone to Ketoisophorone Catalyzed by N-Hydroxyphthalimide and Copper Chloride

Lihua Chen,Ruiren Tang,Zhongying Li,Shan Liang 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.2

N-hydroxyphthalimide (NHPI) and copper chloride (CuCl2) were first utilized for aerobic oxidation of α-isophorone (α-IP) to ketoisophorone (KIP) and the effects of co-catalysts, temperature, reaction time, solvent,amount of CuCl2 and pressure of oxygen were investigated extensively. NHPI/CuCl2 turned out to be highly efficient to this oxidation with up to 91.3% conversion and 81.0% selectivity under mild conditions. And various hydrocarbons including benzylic compounds, cycloalkene and its derivatives were also oxidized smoothly under optimized conditions. Moreover, the possible reaction mechanism was proposed and verified by FT-IR spectra.

Preparation, characterization and catalytic performance of HPW-TUD-1 catalyst on oxidative desulfurization

Ling Tang,Lihua Kang,Mingyuan Zhu,Guangqin Luo,Bin Dai 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.2

By incorporating H3PW12O40 (HPW) heteropolyacid into mesoporous TUD-1 materials, a series of HPWTUD-1 catalysts were synthesized. Nitrogen adsorption–desorption isotherm, XRD and FTIR characterizations showed that these catalyst exhibited mesoporous structure, and HPW presented in the catalysts with Keggin structure. The catalytic performances of the HPW-TUD-1 catalysts were tested through the oxidative desulfurization (ODS) process of dibenzothiophene (DBT) model oil. The results showed that the obtained 20HPW-TUD-1 catalyst displayed excellent catalytic activity and recover ability for ODS. The desulfurization rate of DBT reached up to 98.1%, and almost no catalytic activity loss was observed after three recycles of the catalyst.

An Efficient and Mild Oxidation of α-Isophorone to Ketoisophorone Catalyzed by N-Hydroxyphthalimide and Copper Chloride

Chen, Lihua,Tang, Ruiren,Li, Zhongying,Liang, Shan Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.2

N-hydroxyphthalimide (NHPI) and copper chloride ($CuCl_2$) were first utilized for aerobic oxidation of ${\alpha}$-isophorone (${\alpha}$-IP) to ketoisophorone (KIP) and the effects of co-catalysts, temperature, reaction time, solvent, amount of $CuCl_2$ and pressure of oxygen were investigated extensively. NHPI/$CuCl_2$ turned out to be highly efficient to this oxidation with up to 91.3% conversion and 81.0% selectivity under mild conditions. And various hydrocarbons including benzylic compounds, cycloalkene and its derivatives were also oxidized smoothly under optimized conditions. Moreover, the possible reaction mechanism was proposed and verified by FT-IR spectra.

Mechanical Properties of High Mg-Content Al-Mg-Sc-Zr Alloy Fabricated by Selective Laser Melting

Hao Tang,Yaoxiang Geng,Jinjie Luo,Junhua Xu,Hongbo Ju,Lihua Yu 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.8

The efects of process parameters and aging treatment on the microstructure and mechanical properties of selective lasermelting (SLM) fabricated high Mg-content Al-Mg-Sc-Zr aluminum alloy were systematically studied. Our experiment resultsshow that the samples exhibit good processability with porosity less than 1%. The increase of Mg content in Al-Mg-Sc-Zris benefcial to reduce the texture of the alloy. The laser scanning speed has a large infuence on the Vickers hardness ofas-fabricated samples. The maximum microhardness of as-fabricated sample reaches 148±2 HV with a compression yieldstrength of 342±7 MPa. After aging treatment, the distinction in microhardness of the samples obtained under diferent laserscanning speed is obviously reduced, and the mechanical properties of the samples are further improved with a maximummicrohardness of 175±5 HV and a maximum compressive yield strength of 476±10 MPa, which are superior to the knownAl-Mg-Sc-Zr alloy with same Sc and Zr content fabricated by SLM. In this study, a novel high Mg-content Al-Mg-Sc-Zraluminum alloy specifcally for SLM with good processability and mechanical properties was reported.

An Improved Energy Recovery Clamp Circuit for PWM Converters with a Wide Range of Input Voltage

Honnyong Cha,Lihua Chen,Fang Z. Peng,Qingsong Tang 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-

A full-bridge dc-dc converter employing diode rectifier in the output experiences severe voltage overshoot and oscillation problem across the diode rectifier caused by the interaction between the junction capacitance of the rectifier diode and the leakage inductance of transformer. The pronounced reverse-recovery current of high power diodes enforces these issues significantly by increasing power loss and voltage overshoot. Conventional energy recovery clamping circuits suffer from high voltage overshoot if the input voltage of converter is wide. In this work, a novel energy recovery clamp circuit is proposed to overcome this problem. Performance of the proposed circuit is verified both theoretically and experimentally with a 70 ㎾ dc-dc converter.

Modeling and performance evaluation of a piezoelectric energy harvester with segmented electrodes

Wang, Hongyan,Tang, Lihua,Shan, Xiaobiao,Xie, Tao,Yang, Yaowen Techno-Press 2014 Smart Structures and Systems, An International Jou Vol.14 No.2

Conventional cantilevered piezoelectric energy harvesters (PEHs) are usually fabricated with continuous electrode configuration (CEC), which suffers from the electrical cancellation at higher vibration modes. Though previous research pointed out that the segmented electrode configuration (SEC) can address this issue, a comprehensive evaluation of the PEH with SEC has yet been reported. With the consideration of delivering power to a common load, the AC outputs from all segmented electrode pairs should be rectified to DC outputs separately. In such case, theoretical formulation for power estimation becomes challenging. This paper proposes a method based on equivalent circuit model (ECM) and circuit simulation to evaluate the performance of the PEH with SEC. First, the parameters of the multi-mode ECM are identified from theoretical analysis. The ECM is then established in SPICE software and validated by the theoretical model and finite element method (FEM) with resistive loads. Subsequently, the optimal performances with SEC and CEC are compared considering the practical DC interface circuit. A comprehensive evaluation of the advantageous performance with SEC is provided for the first time. The results demonstrate the feasibility of using SEC as a simple and effective means to improve the performance of a cantilevered PEH at a higher mode.

Modelling and Validation of Electret-based Vibration Energy Harvesters in View of Charge Migration

Zhaoshu Yang,Lihua Tang,Kai Tao,Kean C. Aw 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.1

One of the key problems of electret-based vibration energy harvester (eVEH) modelling is that the surface voltage itself cannot precisely reveal the charge storage characteristics of the electret fabricated by different processes. In this paper, we endeavor to interpret the charge migration mechanism of the eVEH with electrets fabricated by different processes. Based on the above analysis, a unified analytical model of the eVEH is derived accordingly. The dynamic response and voltage output predicted by this model are verifi ed numerically by the equivalent circuit simulation and experimentally with an out-of-plane eVEH prototype. According to the analysis, the maximum power output is approximately 255 μW when the prototype works at its resonance frequency and the vibration amplitude is 1 mm. This paper elucidates the working principle of the eVEH and provides a framework for further theoretical study of eVEHs from the first principle.

Modeling and performance evaluation of a piezoelectric energy harvester with segmented electrodes

Hongyan Wang,Lihua Tang,Xiaobiao Shan,Tao Xie,Yaowen Yang 국제구조공학회 2014 Smart Structures and Systems, An International Jou Vol.14 No.2

Conventional cantilevered piezoelectric energy harvesters (PEHs) are usually fabricated with continuous electrode configuration (CEC), which suffers from the electrical cancellation at higher vibration modes. Though previous research pointed out that the segmented electrode configuration (SEC) can address this issue, a comprehensive evaluation of the PEH with SEC has yet been reported. With the consideration of delivering power to a common load, the AC outputs from all segmented electrode pairs should be rectified to DC outputs separately. In such case, theoretical formulation for power estimation becomes challenging. This paper proposes a method based on equivalent circuit model (ECM) and circuit simulation to evaluate the performance of the PEH with SEC. First, the parameters of the multi-mode ECM are identified from theoretical analysis. The ECM is then established in SPICE software and validated by the theoretical model and finite element method (FEM) with resistive loads. Subsequently, the optimal performances with SEC and CEC are compared considering the practical DC interface circuit. A comprehensive evaluation of the advantageous performance with SEC is provided for the first time. The results demonstrate the feasibility of using SEC as a simple and effective means to improve the performance of a cantilevered PEH at a higher mode.

Intestinal segment and vitamin D3 concentration affect gene expression levels of calcium and phosphorus transporters in broiler chickens

Jincheng Han,Lihua Wu,Xianliang Lv,Mengyuan Liu,Yan Zhang,Lei He,Junfang Hao,Li Xi,Hongxia Qu,Chuanxin Shi,Zhiqiang Li,Zhixiang Wang,Fei Tang,Yingying Qiao 한국축산학회 2023 한국축산학회지 Vol.65 No.2

Two experiments were conducted in this research. Experiment 1 investigated the spatial expression characteristics of calcium (Ca) and phosphorus (P) transporters in the duodenum, jejunum, and ileum of 21-day-old broilers provided with adequate nutrient feed. Experiment 2 evaluated the effects of dietary vitamin D3 (VD3) concentration (0, 125, 250, 500, 1,000, and 2,000 IU/kg) on growth performance, bone development, and gene expression levels of intestinal Ca and P transporters in 1–21-day-old broilers provided with the negative control diet without supplemental VD3. Results in experiment 1 showed that the mRNA levels of calcium- binding protein 28-kDa (CaBP-D28k), sodium-calcium exchanger 1 (NCX1), plasma membrane calcium ATPase 1b (PMCA1b), and IIb sodium-phosphate cotransporter (NaPi-IIb) were the highest in the broiler duodenum. By contrast, the mRNA levels of inorganic phosphate transporter 1 (PiT-1) and 2 (PiT-2) were the highest in the ileum. Results in experiment 2 showed that adding 125 IU/kg VD3 increased body weight gain (BWG), feed intake (FI), bone weight, and percentage and weight of Ca and P in the tibia and femur of 1–21-day-old broilers compared with the negative control diet (p < 0.05). The rise in dietary VD3 levels from 125 to 1,000 IU/kg further increased the BWG, FI, and weights of the bone, ash, Ca, and P (p < 0.05). No difference in growth rate and leg bone quality was noted in the broilers provided with 1,000 and 2,000 IU/kg VD3 (p > 0.05). Supplementation with 125–2,000 IU/kg VD3 increased the mRNA abundances of intestinal Ca and P transporters to varying degrees. The mRNA level of CaBP-D28k increased by 536, 1,161, and 28 folds in the duodenum, jejunum, and ileum, respectively, after adding 1,000 IU/kg VD3. The mRNA levels of other Ca and P transporters (PMCA1b, NCX1, NaPi-IIb, PiT-1, and PiT-2) increased by 0.57–1.74 folds by adding 1,000–2,000 IU/kg VD3. These data suggest that intestinal Ca and P transporters are mainly expressed in the duodenum of broilers. Moreover, the addition of VD3 stimulates the two mineral transporter transcription in broiler intestines.