Numerical Analysis of Contra-Rotating Small Hydro-Turbine with Cylinder Spoke

Ding Nan,Toru Shigemitsu,Shengdun Zhao,Yasutoshi Takeshima 한국유체기계학회 2018 International journal of fluid machinery and syste Vol.11 No.1

Small hydropower is one of potential energy resource existing in our living environment and yet not been widely used. Small hydro-turbine is suitable in these energy resources while it still has some shortages, like performing low efficiency and easy to be out of control when there are foreign materials in the water. Thus we designed this contra-rotating small hydro-turbine to increase its efficiency and enhance its ability of keeping stable operation. The experimental apparatus was designed and assembled, and some experiments were conducted. A new kind of cylinder spoke, which supports the front and rear rotor, was adopted and the numerical analysis was carried out in this paper. As the numerical analysis results shown, the efficiency of test turbine with cylinder spoke increased in a wide range of flow rate. The maximum efficiency increased about 2.2%, reaching to 66.4%, and it was obtained at 1.25Qd. The internal flow condition, especially at the areas behind the spoke, was improved by the cylinder spoke.

Internal Flow and Performance with Foreign Vegetable Materials in a Contra-Rotating Small Hydro-Turbine

Nan, Ding,Shigemitsu, Toru,Zhao, Shengdun,Takeshima, Yasutoshi Korean Society for Fluid machinery 2017 International journal of fluid machinery and syste Vol.10 No.4

Small hydropower generation is one of important alternative energy, and potential of small hydropower is great. Efficiency of small hydro-turbine is lower than that of large one, and these small hydro-turbine's common problems are out of operation by foreign materials. Therefore, we adopted contra-rotating rotors, which can be expected to achieve high performance and enable to use low-solidity rotors to achieve stable operation. Experimental apparatus of the contra-rotating small hydro-turbine with 60mm casing diameter was manufactured and some experiments were conducted. In this research, the internal flow with foreign vegetable materials, i.e. leaves and grasses, were investigated by a high speed camera, and the performance experiments when two pieces of cudweeds were attached on the blade of front rotor were conducted. As the results shown, the passing rate of small leaves is 41.2% and all of the middle leaves can't pass through the contra-rotating small hydro-turbine. The highest efficiency also decreased about 13%, reaching to 51.2% at $1.4Q_d$, because of the foreign vegetable materials.

Test Information Collection System Design and Implementation of a Distributed Environment

Nan Ding 보안공학연구지원센터(IJGDC) 2013 International Journal of Grid and Distributed Comp Vol.6 No.4

Internal Flow and Performance with Foreign Vegetable Materials in a Contra-Rotating Small Hydro-Turbine

Ding Nan,Toru Shigemitsu,Shengdun Zhao,Yasutoshi Takeshima 한국유체기계학회 2017 International journal of fluid machinery and syste Vol.10 No.4

Small hydropower generation is one of important alternative energy, and potential of small hydropower is great. Efficiency of small hydro-turbine is lower than that of large one, and these small hydro-turbine’s common problems are out of operation by foreign materials. Therefore, we adopted contra-rotating rotors, which can be expected to achieve high performance and enable to use low-solidity rotors to achieve stable operation. Experimental apparatus of the contra-rotating small hydro-turbine with 60mm casing diameter was manufactured and some experiments were conducted. In this research, the internal flow with foreign vegetable materials, i.e. leaves and grasses, were investigated by a high speed camera, and the performance experiments when two pieces of cudweeds were attached on the blade of front rotor were conducted. As the results shown, the passing rate of small leaves is 41.2% and all of the middle leaves can’t pass through the contra-rotating small hydro-turbine. The highest efficiency also decreased about 13%, reaching to 51.2% at 1.4Qd, because of the foreign vegetable materials.

Numerical Analysis of Contra-Rotating Small Hydro-Turbine with Cylinder Spoke

Nan, Ding,Shigemitsu, Toru,Zhao, Shengdun,Takeshima, Yasutoshi Korean Society for Fluid machinery 2018 International journal of fluid machinery and syste Vol.11 No.1

Small hydropower is one of potential energy resource existing in our living environment and yet not been widely used. Small hydro-turbine is suitable in these energy resources while it still has some shortages, like performing low efficiency and easy to be out of control when there are foreign materials in the water. Thus we designed this contra-rotating small hydro-turbine to increase its efficiency and enhance its ability of keeping stable operation. The experimental apparatus was designed and assembled, and some experiments were conducted. A new kind of cylinder spoke, which supports the front and rear rotor, was adopted and the numerical analysis was carried out in this paper. As the numerical analysis results shown, the efficiency of test turbine with cylinder spoke increased in a wide range of flow rate. The maximum efficiency increased about 2.2%, reaching to 66.4%, and it was obtained at $1.25Q_d$. The internal flow condition, especially at the areas behind the spoke, was improved by the cylinder spoke.

Identification of highly pathogenic Beauveria bassiana strain against Pieris rapae larvae

Jun‐Nan Ding,Yong-cai LAI 한국곤충학회 2018 Entomological Research Vol.48 No.5

Seven different strains of Beauveria bassiana were used in a bioassay on Pieris rapae larvae. The results showed that an B. bassiana strain showed relatively high pathogenicity towards P. rapae larvae. The adjusted mortality rate was 92.86 %, and the infection rate was 85.71 % in 10 days post inoculation. Molecular identification was performed to identify the unknown strain. Internal Transcribed Spacer sequence analysis showed that the polymerase chain reaction amplicon length of the unknown strain of Beauveria sp. was 573 bp, and sequence similarity to the known B. bassiana sequences in the NCBI database was 99 %. The B. bassiana strain was named Bb01. The changes of proteins and PPO of P. rapae larvae infected by B. bassiana Bb01 strain at different times was determined. The activity of PPO increased in 1–6 d and decreased in 7 d again after inoculation. The B. bassiana invaded into the insect body affected the balance of the proteins and PPO.

Ultrastructural observations of Beauveria bassiana infection in Xylotrechus rusticus larvae

Jun‐Nan Ding,De-Fu CHI 한국곤충학회 2018 Entomological Research Vol.48 No.3

In the present study we investigated the infection process of Beauveria bassiana on Xylotrechus rusticus larvae using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The SEM results showed that B. bassiana spores germinated on the surface of the larval body and invaded the larva as an appressorium. The hyphae then germinated from the spores and spread throughout the larval body. After the death of the larva, conidiophores formed at one end of the hypha on the surface of the larval body and prepared for a new round of infection. The TEM results showed severe damage to the larval cuticle after hyphae infection. The structure of the cuticle became thinner and eventually flocculent; muscle tissues were dissociated and eventually stuck to the hyphae, and the corpus adiposum was loose and deformed, and eventually degraded.

18세기 초 조선연행사(朝鮮燕行使)의 진상의(陳尙義) 해적집단 관련 정보 수집활동

정신남 ( Ding Chen-nan ) 연세대학교 국학연구원 2017 동방학지 Vol.178 No.-

陳尙義 해적집단은 “四口通商의 시대”가 시작된 이래 廣東에서 출발하여 중국 동부 연해 전체에 걸쳐 활동했으며, 특히 조선과 가까운 遼東과 山東연해에서 활동한 해적들이었다. 조선에서는 이 해적집단의 존재를 파악하기 전부터 이미 중국 동부 연해에 나타나는 해적에 대해 상당한 관심을 가지고 관련 정보를 모으고 있었다. 따라서 연행사의 정보수집 활동을 통해서 陳尙義 해적집단을 알게 된 것은 결코 우연이 아니었다. 그 이후로도 이 해적집단에 대해서 지속적인 관심을 가졌으며, 그들이 재차 소요를 일으켰다는 정보도 입수하였다. 조선연행사는 陳尙義 해적집단 관련 정보 수집활동에서 주로 현지인 탐문을 진행하거나 청조의 공문서를 구입하거나 필사하는 등 방법을 활용하였다. 그리하여 조선 측 사료, 특히 연행록에는 陳尙義 해적집단과 관련된 기사가 다수실리게 되었다. 조선연행사에 의해 수집된 題本, 塘報와 같은 일부 청조 공문서는 그 眞僞를 더 검토해야 하지만 현재 중국에도 남아 있지 않는 희귀한 자료로서 그 나름의 가치를 지니고 있다. 조선연행사들의 관련 정보 수집활동 사례를 분석하는 것은 중국에서 발생한 특정 사건에 대한 조선사절단의 정보수집활동의 전모를 밝힐 수 있을 뿐만 아니라, 조선 측 사료에 실린 중국 기록의 가치를 역시 잘 보여줄 수 있다고 본다. Chen-Shangyi (陳尙義) pirates group rose from Guangdong Province in 168 4,the times of Four Port Trade System, and then expanded to the whole eastern coast with frequent activities covering Liaodong and Shandong, near Korea. The Joseon government had already got substantial information on pirates` rampancy on Chinese eastern coast before overhearing Chen-Shangyi pirates group through Joseon Emissaries` information collection. After that the government kept an eye on this pirate group and got the news of their rebellion again. Joseon Emissaries` obtained the information of Chen-Shangyi pirates group` activities mainly by inquiring local people as well as buying and copying Qing`s official documents, hence Korean historical documents, especially the Records of Trips to Beijing (燕行錄) include a lot of information on Chen-Shangyi pirates group. Although it is still need to recheck the facticity of Qing`s official documents such as Ti-Ben (題本) and Tang-Bao (塘報), these precious Korean documents that no longer exist in China have unique value. Through analyzing Joseon Emissaries` intelligence gathering of Chen-Shangyi pirates group, one can get a full view of Joseon Emissaries` process of intelligence gathering on China, and realize the value of the records relating to China in Korean historical documents.

Nanowire interface doping

Nan PAN,Yiming WU,Siwen ZHAO,Huaiyi DING,Xiaoping WANG,Yi LUO,J. G. HOU 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

Biocatalysis and Bioprocess Engineering : Heterologous Expression and Characterization of a Thermostable Exo-β-D-Glucosaminidase from Aspergillus oryzae

( Ding Xin Wu ),( Lin Chun Wang ),( Yuwei Li ),( Shu Miao Zhao ),( Nan Peng ),( Yun Xiang Liang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.2

An exo-β-D-glucosaminidase (AorCsxA) from Aspergillus oryzae FL402 was heterologously expressed and purified. The deduced amino acid sequence indicated that AorCsxA belonged to glycoside hydrolase family 2. AorCsxA digested colloid chitosan into glucosamine but not into chitosan oligosaccharides, demonstrating exo-β-D-glucosaminidase (CsxA) activity. AorCsxA exhibited optimal activity at pH 5.5 and 50°C; however, the enzyme expressed Pichia pastoris (PpAorCsxA) showed much stronger thermostability at 50°C than that expressed in Escherichia coli (EcAorCsxA), which may be related to glycosylation. AorCsxA activity was inhibited by EDTA and most of the tested metal ions. A single amino acid mutation (F769W) AorCsxA significantly enhanced the specific activity and hydrolysis velocity as revealed comparison of V_{max} and k_{cat} values with those of the wild-type enzyme. The three-dimensional structure suggested the tightened pocket at the active site of F769W enabled efficient substrate binding. The AorCsxA gene was heterologously expressed in P. pastoris, and one transformant was found to produce 222 U/ml activity during the high-cell-density fermentation. This AorCsxA-overexpressing P. pastoris strain is feasible for large-scale production of AorCsxA.