• Title/Summary/Keyword: school laboratory experiment

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Nanosecond Laser Cleaning of Aluminum Alloy Oxide Film

  • Hang Dong;Yahui Li;Shanman Lu;Wei Zhang;Guangyong Jin
    • Current Optics and Photonics
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    • v.7 no.6
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    • pp.714-720
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    • 2023
  • Laser cleaning has the advantages of environmental protection, precision, and high efficiency, and has good prospects for application in removing oxide films on the surface of aluminum alloy. This paper discusses the cleaning threshold and cleaning mechanism of aluminum alloy surface oxide film. A nanosecond pulsed laser was used to remove a 5-㎛-thick oxide film from the surface of 7A04 aluminum alloy, and the target surface temperature and cleaning depth were simulated. The effects of different laser energy densities on the surface morphology of the aluminum alloy were analyzed, and the plasma motion process was recorded using a high-speed camera. The temperature measurement results of the experiment are close to the simulation results. The results show that the laser cleaning of aluminum alloy oxide film is mainly based on the vaporization mechanism and the shock wave generated by the explosion.

Immunophenotype Characterization for Swine Selected Line, Which is Resistant for the Mycoplasma Pneumonia

  • Katayama, Masafumi;Fukuda, Tomokazu;Okamuara, Toshihiro;Suda, Yoshihito;Suzuki, Eisaku;Uenishi, Hirohide;Suzuki, Keiichi
    • Asian-Australasian Journal of Animal Sciences
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    • v.24 no.7
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    • pp.889-897
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    • 2011
  • Mycoplasma Pneumonia of swine (MPS) decreases the daily growth of pigs, and, co-infection with a virus sometimes causes severe pneumonia. Genetic selection of pigs resistant to the pulmonary MPS lesion might solve the economic loss due to MPS in animal production. Here, we examined the immunophenotype of Landrace line (Miyagino L2), genetically selected to reduce the incidence of pulmonary MPS lesion for 5 generations in Miyagi Prefecture Animal Industry Experiment Station. Although this line is expected to be resistant to the pulmonary MPS lesion, the biological characteristics of its immune function are not clear. We investigated details of the immunorelated phenotype of Miyagino L2 at the hematological and molecular biological level, including cytokine expression, and compared the results with that of non-genetically selected Landrace. Miyagino L2 showed decreased antigen-specific IgG and IgM production and increased CD8-positive T-cell population, and high levels of cortisol concentration, suggesting that the MPS-resistant phenotype is associated these immunological differences. Additionally, T-cell CD4 expression was highly correlated with the MPS expected breeding value. Although the detailed mechanisms underlying this high correlation remain unknown, our result suggested that the genetic selection of the expression level of CD4 might be useful to improve MPS resistance in pig production.

An Experimental Study about Tractive Performance of Tracked Vehicle on Deep-sea Soft Sediment Based on Design of Experiment Using Orthogonal Array (직교배열표 실험계획법에 의한 심해 연약지반용 무한궤도차량의 견인성능에 대한 실험적 연구)

  • Choi, Jong-Su;Hong, Sup;Kim, Hyung-Woo;Lee, Tae-Hee
    • Ocean and Polar Research
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    • v.26 no.2
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    • pp.333-339
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    • 2004
  • This paper is concerned with an experimental investigation about tractive performance of a tracked vehicle on extremely soft soil. A tracked vehicle model with principal dimensions of $0.9\;m(L)\;{\times}\;0.75\;m(B)\;{\times}\;0.4\;m(H)$ and the weight of 167 kg was constructed with a pair of driving chain links driven by two AC-servo motors. The tracks are configured with detachable grousers with variable span. Deep seabed was simulated by means of bentonite-water mixture in a soil bin of $6.0\;m(L)\;{\times}\;3.7\;m(B)\;{\times}\;0.7\;m(H)$. Slip of vehicle and driving torque of motor were measured with respect to experimental variables; grouser span, grouser chevron angle, driving speed, drawbar-pull weight, position of center-of-gravity and weight. $L_8$ orthogonal array is adopted for DOE (Design Of Experiment). The effects of experiment variables on traction performance are evaluated.

Comparison of a Microbiological Model Simulation with Microcosm Data

  • Lee, Jae-Young;Tett, Paul;Jones, Ken
    • Journal of the korean society of oceanography
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    • v.39 no.4
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    • pp.222-233
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    • 2004
  • Using nitrogen as the limiting nutrient, the default version of a microplankton-detritus model linked chlorophyll concentration to the autotroph nitrogen. However, phosphorus dynamics were added to simulate the results of a microcosm experiment. Using standard parameter values with a single value of microheterotroph fraction in the microplankton taken from the observed range, the best simulation successfully captured the main features of the time-courses of chlorophyll and particulate organic carbon, nitrogen and phosphorus, with root-mean-square error equivalent to 29% of particulate concentration. A standard version of microbiological model assumes complete internal cycling of nutrient elements; adding a term for ammonium and phosphate excretion by microheterotrophs did not significantly improve predictions. Relaxing the requirement for constant microheterotroph fraction resulted in an autotroph-heterotroph model AH, with dynamics resembling those of a Lotka-Volterra predator-prey system. AH fitted the microcosm data worse than did MP, justifying the suppression of Lotka-Volterra dynamics in MP. The paper concludes with a discussion of possible reasons for the success of the simple bulk dynamics of MP in simulating microplankton behaviour.

Inhibition of mouse SP2/0 myeloma cell growth by the B7-H4 protein vaccine

  • Mu, Nan;Liu, Nannan;Hao, Qiang;Xu, Yujin;Li, Jialin;Li, Weina;Wu, Shouzhen;Zhang, Cun;Su, Haichuan
    • BMB Reports
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    • v.47 no.7
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    • pp.399-404
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    • 2014
  • B7-H4 is a member of B7 family of co-inhibitory molecules and B7-H4 protein is found to be overexpressed in many human cancers and which is usually associated with poor survival. In this study, we developed a therapeutic vaccine made from a fusion protein composed of a tetanus toxoid (TT) T-helper cell epitope and human B7-H4IgV domain (TT-rhB7-H4IgV). We investigated the anti-tumor effect of the TT-rhB7-H4IgV vaccine in BALB/c mice and SP2/0 myeloma growth was significantly suppressed in mice. The TT-rhB7-H4IgV vaccine induced high-titer specific antibodies in mice. Further, the antibodies induced by TT-rhB7-H4IgV vaccine were capable of depleting SP2/0 cells through complement-dependent cytotoxicity (CDC) in vitro. On the other hand, the poor cellular immune response was irrelevant to the therapeutic efficacy. These results indicate that the recombinant TT-rhB7-H4IgV vaccine might be a useful candidate of immunotherapy for the treatment of some tumors associated with abnormal expression of B7-H4.

Enhanced Antitumor Effect of Curcumin Liposomes with Local Hyperthermia in the LL/2 Model

  • Tang, Jian-Cai;Shi, Hua-Shan;Wan, Li-Qiang;Wang, Yong-Sheng;Wei, Yu-Quan
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.4
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    • pp.2307-2310
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    • 2013
  • Curcumin previously was proven to inhibit angiogenesis and display potent antitumor activity in vivo and in vitro. In the present study, we investigated whether a combination curcumin with hyperthermia would have a synergistic antitumor effect in the LL/2 model. The results indicated that combination therapy significantly inhibited cell proliferation of MS-1 and LL/2 in vitro. LL/2 experiment model also demonstrated that the combination therapy inhibited tumor growth and prolonged the life span in vivo. Furthermore, combination therapy reduced angiogenesis and increased tumor apoptosis. Our findings suggest that the combination therapy exerted synergistic antitumor effects, providing a new perspective fpr clinical tumor therapy.

Simulation of impact toughness with the effect of temperature and irradiation in steels

  • Wang, Chenchong;Wang, Jinliang;Li, Yuhao;Zhang, Chi;Xu, Wei
    • Nuclear Engineering and Technology
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    • v.51 no.1
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    • pp.221-227
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    • 2019
  • One of the important requirements for the application of reduced activation ferritic/martensitic steel is to retain proper mechanical properties in irradiation and high temperature conditions. In order to simulate the impact toughness with the effect of temperature and irradiation, a simulation model based on energy balance method consisted of crack initiation, plastic propagation and cleavage propagation stages was established. The effect of temperature on impact toughness was analyzed by the model and the trend of the simulation results was basicly consistent with the previous experimental results of CLAM steels. The load-displacement curve was simulated to express the low temperature ductile-brittle transition. The effect of grain size and inclusion was analyzed by the model, which was consistent with classical experiment results. The transgranular-intergranular transformation in brittle materials was also simulated.

CLUSTER ANALYSIS FOR REGION ELECTRIC LOAD FORECASTING SYSTEM

  • Park, Hong-Kyu;Kim, Young-Il;Park, Jin-Hyoung;Ryu, Keun-Ho
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.591-593
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    • 2007
  • This paper is to cluster the AMR (Automatic Meter Reading) data. The load survey system has been applied to record the power consumption of sampling the contract assortment in KEPRI AMR. The effect of the contract assortment change to the customer power consumption is determined by executing the clustering on the load survey results. We can supply the power to customer according to usage to the analysis cluster. The Korea a class of the electricity supply type is less than other country. Because of the Korea electricity markets exists one electricity provider. Need to further divide of electricity supply type for more efficient supply. We are found pattern that is different from supplied type to customer. Out experiment use the Clementine which data mining tools.

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Experimental Study and Numerical Simulation of Cavity Oscillation in a Conical Diffuser

  • Chen, Chang-Kun;Nicolet, Christophe;Yonezawa, Koichi;Farhat, Mohamed;Avellan, Francois;Miyazawa, Kazuyoshi;Tsujimoto, Yoshinobu
    • International Journal of Fluid Machinery and Systems
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    • v.3 no.1
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    • pp.91-101
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    • 2010
  • Based on the one-dimensional stability analysis, the self-excited oscillation in hydraulic power generating systems was studied by a simple experiment and numerical simulation. It was shown that a cavity in a conical diffuser can cause surge. With the diffuser, a high amplitude and low frequency oscillation occurs at low cavitation number. This oscillation was not observed with the straight pipe. It was confirmed that the diffuser effect of the draft tube can be the cause of the full load surge in hydraulic power system. Numerical results were also analyzed to check the validity of the one-dimensional stability analysis.

Comparison of Conventional DC-DC Converter and a Family of Diode-Assisted DC-DC Converter in Renewable Energy Applications

  • Zhang, Yan;Liu, Jinjun;Ma, Xiaolong;Feng, Junjie
    • Journal of Power Electronics
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    • v.14 no.2
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    • pp.203-216
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    • 2014
  • In the conventional dc-dc converter, a pair of additional diode and the adjacent passive component capacitor/inductor can be added to the circuit with an X-shape connection, which generates a family of new topologies. The novel circuits, also called diode-assisted dc-dc converter, enhance the voltage boost/buck capability and have a great potential for high step-up/step-down power conversions. This paper mainly investigates and compares conventional dc-dc converter and diode-assisted dc-dc converter in wide range power conversion from the aspects of silicon devices, passive components requirements, electro-magnetic interference (EMI) and efficiency. Then, a comprehensive comparison example of a high step-up power conversion system was carried out. The two kinds of boost dc-dc converters operate under the same operation conditions. Mathematical analysis and experiment results verify that diode-assisted dc-dc converters are very promising for simultaneous high efficiency and high step-up/step-down power conversion in distributed power supply systems.