Numerical simulations and surrogate-based optimization of cavitation performance for an aviation fuel pump

Xing’an Zhao,Biao Huang,Tairan Chen,Guoyu Wang,Deming Gao,Jing Zhao 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.2

We used computational modeling to investigate the cavitation performance of an aviation fuel pump, and optimize structural parameters using the surrogate-based method. In the numerical simulation, a rotation-curvature correction was adapted to the k-ε turbulence model, and a four-component surrogate fuel was selected to reproduce the physical properties of the China RP-3 kerosene. Then the performance of the aviation fuel pump was predicted. In the optimization, based on the series of the numerical results, Surrogate-based analysis and optimization (SBAO) was used to optimize the structural parameters of the fuel pump (the variation of the outlet blade angle for the inducer △β b1 and the variation of the inlet blade angle for the impeller △β b2 ). The results show that the prediction of cavitation performance agrees well with the experimental data. The results show that cavitation areas are mainly distributed in the inlet of the inducer. The volume of cavities grows with the decreasing NPSHa. The head of the fuel pump has a sudden head-drop when NPSHa ≤ 5.64 m. Furthermore, the surrogate-based approach is available in structural optimization of the fuel pump. The cavitation performance of the optimized pump improved about 22 % with a little drop of head coefficient when △β b1 = 4.33° and △β b2 = 3.24°. The numerical approach employed in this paper can accurately predict the cavitating flow of the high rotating speed fuel pump and the surrogate-based method is available in the structural optimization for a better cavitation performance.

Production of Transgenic Pigs with an Introduced Missense Mutation of the Bone Morphogenetic Protein Receptor Type IB Gene Related to Prolificacy

Zhao, Xueyan,Yang, Qiang,Zhao, Kewei,Jiang, Chao,Ren, Dongren,Xu, Pan,He, Xiaofang,Liao, Rongrong,Jiang, Kai,Ma, Junwu,Xiao, Shijun,Ren, Jun,Xing, Yuyun Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.7

In the last few decades, transgenic animal technology has witnessed an increasingly wide application in animal breeding. Reproductive traits are economically important to the pig industry. It has been shown that the bone morphogenetic protein receptor type IB (BMPR1B) A746G polymorphism is responsible for the fertility in sheep. However, this causal mutation exits exclusively in sheep and goat. In this study, we attempted to create transgenic pigs by introducing this mutation with the aim to improve reproductive traits in pigs. We successfully constructed a vector containing porcine BMPR1B coding sequence (CDS) with the mutant G allele of A746G mutation. In total, we obtained 24 cloned male piglets using handmade cloning (HMC) technique, and 12 individuals survived till maturation. A set of polymerase chain reactions indicated that 11 of 12 matured boars were transgene-positive individuals, and that the transgenic vector was most likely disrupted during cloning. Of 11 positive pigs, one (No. 11) lost a part of the terminator region but had the intact promoter and the CDS regions. cDNA sequencing showed that the introduced allele (746G) was expressed in multiple tissues of transgene-positive offspring of No.11. Western blot analysis revealed that BMPR1B protein expression in multiple tissues of transgene-positive $F_1$ piglets was 0.5 to 2-fold higher than that in the transgene-negative siblings. The No. 11 boar showed normal litter size performance as normal pigs from the same breed. Transgene-positive $F_1$ boars produced by No. 11 had higher semen volume, sperm concentration and total sperm per ejaculate than the negative siblings, although the differences did not reached statistical significance. Transgene-positive $F_1$ sows had similar litter size performance to the negative siblings, and more data are needed to adequately assess the litter size performance. In conclusion, we obtained 24 cloned transgenic pigs with the modified porcine BMPR1B CDS using HMC. cDNA sequencing and western blot indicated that the exogenous BMPR1B CDS was successfully expressed in host pigs. The transgenic pigs showed normal litter size performance. However, no significant differences in litter size were found between transgene-positive and negative sows. Our study provides new insight into producing cloned transgenic livestock related to reproductive traits.

Compact Reconfigurable Wideband Inverted-F Antenna for LTE MIMO Mobile Applications

ZHAO, Xing,CHOI, Jaehoon 'Institute of Electronics, Information and Communi 2014 IEICE TRANSACTIONS ON COMMUNICATIONS - Vol.eb97 No.9

<P>In this paper, compact reconfigurable wideband Inverted-F Antenna (IFA) elements are proposed for a Long Term Evolution (LTE) mobile terminal. The proposed inverted-F antenna has a very simple planar arrangement. A capacitive coupling feed strip is employed to modify the input impedance matching. A chip inductor is connected in series to the feeding point to realize the wideband property. The whole Multiple-Input Multiple-Output (MIMO) antenna system consists of two similar inverted-F antenna elements. Antenna element #1 has a wideband property with a 6-dB bandwidth from 0.74 to 0.9 GHz. To further expand the bandwidth, antenna element #2 has a reconfigurable property through the use of a Positive Intrinsic-Negative (PIN) diode. Antenna element #2 has a 6-dB bandwidth from 0.74 to 0.84 GHz when the PIN diode is on and from 0.79 to 0.9 GHz when the PIN diode is off. Moreover, the proposed MIMO antenna has a low radiation-pattern-based envelope correlation coefficient (ECC), which is less than 0.15 over LTE bands 4, 5, 13, and 14.</P>

Simple 프로세스로 제조된 TiO2 페이스트를 이용한 염료감응 태양전지의 전기화학적 특성

Xing Guan Zhao,박주영,구할본 한국전기전자재료학회 2014 전기전자재료학회논문지 Vol.27 No.11

In this work, in order to manufacture the photoelectrode of dye-sensitized solar cells, thedifferent anatase TiO2 paste was prepared by simple route using hydrothermal method. In comparisonwith the traditional preparing process, the hydrothermally synthesized TiO2 gel was used to make pastedirectly. Thus, the making process was simplified and the solar conversion efficiency was improved. Incomparison with 5.34% solar energy efficiency of HP-1 photoelectrode, the 6.23% efficiency of HDP-1electrode was improved by 16.67%. This is because hydrothermally synthesized TiO2 gel was used tomake paste directly, the dispersibility between TiO2 particles was improved and get the smoothernetwork, leading to the charge transport ability of the electron generated in dye molecular was improved. Further, HDP-2 photoelectrode delivered the best results with Voc (open circuit voltage), Jsc (shortcircuit current density) FF (fill factor) and η(solar conversion efficiency) were 0.695 V, 15.81 mA cm-2,61.48% and 6.80%, respectively. In comparison with 5.34% of HP-1 photoelectrode, it was improved by27.34%. 본 실험에서는 수열합성법을 통하여 순수한 아나타제 TiO2를 제조부터 TiO2 페이스트 제조하기까지의 공정을 간소화하였다. 기존의 제조공정에 비해 수열합성한 TiO2 졸을 직접 페이스트화 시키는 공정은 많이 간소화되었고, 이를 염료감응 태양전지 광전극에 적용한 결과, 광전변환 효율을 향상시켰다. HP-1 전극 효율 5.34%에 비해 HDP-1 전극의 경우 6.23%로 16.67% 향상되었다. 이는 TiO2 졸을 직접 페이스트화 시킴으로써 TiO2 입자 간의 분산 특성을 향상시키고 원활한 네트워크로 인해 염료분자에서 생성된 전자들의 전하수송 능력이 향상되었기 때문이다. 또한, HDP-2 전극의 경우 Voc, Jsc, FF 및 η은 각각 0.695 V, 15.81 mA cm-2, 61.48% 및 6.80%로 가장 높았으며 HP-1 전극 5.34%에 비해 27.34% 향상되었다.

Introducing Network Situation Awareness into Software Defined Wireless Networks

( Xing Zhao ),( Tao Lei ),( Zhaoming Lu ),( Xiangming Wen ),( Shan Jiang ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.3

The concept of SDN (Software Defined Networking) endows the network with programmability and significantly improves the flexibility and extensibility of networks. Currently a plenty of research works on introducing SDN into wireless networks. Most of them focus on the innovation of the SDN based architectures but few consider how to realize the global perception of the network through the controller. In order to address this problem, a software defined carrier grade Wi-Fi framework called SWAN, is proposed firstly. Then based on the proposed SWAN architecture, a blueprint of introducing the traditional NSA (Network Situation Awareness) into SWAN is proposed and described in detail. Through perceiving various network data by a decentralized architecture and making comprehension and prediction on the perceived data, the proposed blueprint endows the controllers with the capability to aware of the current network situation and predict the near future situation. Meanwhile, the extensibility of the proposed blueprint makes it a universal solution for software defined wireless networks SDWNs rather than just for one case. Then we further research one typical use case of proposed NSA blueprint: network performance awareness (NPA). The subsequent comparison with other methods and result analysis not only well prove the effectiveness of proposed NPA but further provide a strong proof of the feasibility of proposed NSA blueprint.

Insulated Interlayer for Efficient and Photostable Electron-Transport-Layer-Free Perovskite Solar Cells

Zhao, Pengjun,Han, Manhyung,Yin, Wenping,Zhao, Xing,Kim, Seul Gi,Yan, Yaping,Kim, Minwoo,Song, Young Jae,Park, Nam Gyu,Jung, Hyun Suk American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.12

<P>Currently, the most efficient perovskite solar cells (PSCs) mainly use planar and mesoporous titanium dioxide (TiO<SUB>2</SUB>) as an electron-transport layer (ETL). However, because of its intrinsic photocatalytic properties, TiO<SUB>2</SUB> can decompose perovskite absorber and lead to poor stability under solar illumination (ultraviolet light). Herein, a simplified architectural ETL-free PSC with enhanced efficiency and outstanding photostability is produced by the facile deposition of a bathocuproine (BCP) interlayer. Power conversion efficiency of the ETL-free PSC improves from 15.56 to 19.07% after inserting the BCP layer, which is the highest efficiency reported for PSCs involving an ETL-free architecture, versus 19.03% for the n-i-p full device using TiO<SUB>2</SUB> as an ETL. The BCP interlayer has been demonstrated to have several positive effects on the photovoltaic performances of devices, such as “modulation doping” of the perovskite layer, modification of FTO surface work function, and enhancing the charge-transfer efficiency between FTO and perovskite. Moreover, the BCP-based ETL-free devices exhibit outstanding photostability: the unencapsulated BCP-based ETL-free PSCs retain over 90% of their initial efficiencies after 1000 h of storage in air and maintain 92.2% after 450 h of exposure to full solar irradiation (without a UV filter), compared to only 14.1% in the n-i-p full cells under the same condition.</P> [FIG OMISSION]</BR>

MIMO Antenna Using Resonance of Ground Planes for 4G Mobile Application

Xing Zhao,Kyeol Kwon,Jeahoon Choi 한국전자파학회JEES 2013 Journal of Electromagnetic Engineering and Science Vol.13 No.1

Effects of rapid thermal annealing on structural, magnetic and optical properties of Ni-doped ZnO thin films

Xing Zhao,Erjia Liu,R.V. Ramanujan,Jingsheng Chen 한국물리학회 2012 Current Applied Physics Vol.12 No.3

XPS depth profiles were used to investigate the effects of rapid thermal annealing under varying conditions on the structural, magnetic and optical properties of Ni-doped ZnO thin films. Oxidization of metallic Ni from its metallic state to two-valence oxidation state occurred in the film annealed in air at 600 ℃, while reduction of Ni2+ from its two-valence oxidation state to metallic state occurred in the film annealed in Ar at 600 and 800 ℃. In addition, there appeared to be significant diffusion of Ni from the bottom to the top surface of the film during annealing in Ar at 800 ℃. Both as-deposited and annealed thin films displayed obvious room temperature ferromagnetism (RTFM) which was from metallic Ni, Ni2+or both with two distinct mechanisms. Furthermore, a significant improvement in saturation magnetization (Ms) in the films was observed after annealing in air (Ms= 0.036 mB/Ni) or Ar (Ms= 0.033 mB/Ni) at 600 ℃ compared to that in as-deposited film (Ms = 0.017 mB/Ni). An even higher Ms value was observed in the film annealed in Ar at 800 ℃ (Ms= 0.055 mB/Ni) compared to that at 600 ℃ mainly due to the diffusion of Ni. The ultraviolet emission of the Ni-doped ZnO thin film was restored during annealing in Ar at 800 ℃, which was also attributed to the diffusion of Ni.

Utilizing bee foraging behavior in mutational salp swarm for feature selection: a study on return-intentions of overseas Chinese after COVID-19

Xing Jie,Zhao Qinqin,Chen Huiling,Zhang Yili,Zhou Feng,Zhao Hanli 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.6

We present a bee foraging behavior-driven mutational salp swarm algorithm (BMSSA) based on an improved bee foraging strategy and an unscented mutation strategy. The improved bee foraging strategy is leveraged in the follower location update phase to break the fixed range search of salp swarm algorithm, while the unscented mutation strategy on the optimal solution is employed to enhance the quality of the optimal solution. Extensive experimental results on public CEC 2014 benchmark functions validate that the proposed BMSSA performs better than nine well-known metaheuristic methods and seven state-of-the-art algorithms. The binary BMSSA (bBMSSA) algorithm is further proposed for feature selection by using BMSSA as the selection strategy and support vector machine as the classifier. Experimental comparisons on 12 UCI datasets demonstrate the superiority of bBMSSA. Finally, we collected a dataset on the return-intentions of overseas Chinese after coronavirus disease (COVID-19) through an anonymous online questionnaire and performed a case study by setting up a bBMSSA-based feature selection optimization model. The outcomes manifest that the bBMSSA-based feature selection model exhibits a conspicuous prowess, attaining an accuracy exceeding 93%. The case study shows that the development prospects, the family and job in the place of residence, seeking opportunities in China, and the possible time to return to China are the critical factors influencing the willingness to return to China after COVID-19.

Tuning the Interfacial Area and Porosity of TiO₂ Film for Enhanced Light Harvesting in DSSC

Zhao, Xing Guan,Park, Ju-Young,Jin, En Mei,Gu, Hal-Bon The Electrochemical Society 2015 Journal of the Electrochemical Society Vol.162 No.1

<P>Pyrene is used as the template material in the preparation of porosity in TiO<SUB>2</SUB> films. Pores are created in the TiO<SUB>2</SUB> film, using a range of pyrene amounts (0, 2, 3, 4 wt%), to increase the light harvesting efficiency and electron charge capabilities at the TiO<SUB>2</SUB> film/dye/electrolyte interface. The specific surface area of the TiO<SUB>2</SUB> film increases from 49.2 to 115.8 m<SUP>2</SUP> g<SUP>−1</SUP> as the porosity are created with 3% pyrene added TiO<SUB>2</SUB> film (TiO<SUB>2</SUB>-pyrene-3). The pore volume of TiO<SUB>2</SUB>-pyrene-3 is 0.35 cm<SUP>3</SUP> g<SUP>−1</SUP>. The charge transfer of TiO<SUB>2</SUB>-pyrene-3 based dye-sensitized solar cell (DSSC) is faster than the other TiO<SUB>2</SUB> films. For TiO<SUB>2</SUB>-pyrene-3, the electron transport time is 4.19 ms and the electron recombination time is 34.82 ms. The diffusion coefficient is 8.36 × 10<SUP>−5</SUP> cm<SUP>2</SUP> s<SUP>−1</SUP> for TiO<SUB>2</SUB>-pyrene-0 and increases to 1.39 × 10<SUP>−4</SUP> cm<SUP>2</SUP> s<SUP>−1</SUP> for TiO<SUB>2</SUB>-pyrene-3. TiO<SUB>2</SUB>-pyrene-3 has the highest solar conversion efficiency of 7.58%, an increase of 11.47% over that of TiO<SUB>2</SUB>-pyrene-0, 6.80%.</P>