• Title/Summary/Keyword: plant transfer

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Fluid Flow and Heat Transfer Inside a Solar Chimney Power Plant

  • Gholamalizadeh, Ehsan;Chung, Jae Dong
    • Plant Journal
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    • v.14 no.1
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    • pp.42-46
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    • 2018
  • The flow and heat transfer characteristics inside a solar chimney power plant system are analyzed in this article. 3-D model with the $k-{\varepsilon}$ turbulence closure was developed. In this model, to solve the radiative transfer equation the discrete ordinates radiation model was implemented, using a two-band radiation model. To simulate radiation effects from the sun's rays, the solar ray tracing algorithm was coupled to the calculation via a source term in the energy equation. Simulations were carried out for a system with the geometry parameters of the Manzanares power plant. Based on the numerical results, the velocity and temperature distributions were illustrated and the results were validated by comparing with experimental data of the Manzanares prototype power plant. Moreover, temperature profile of the ground surface of the system was illustrated.

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Unsupervised Transfer Learning for Plant Anomaly Recognition

  • Xu, Mingle;Yoon, Sook;Lee, Jaesu;Park, Dong Sun
    • Smart Media Journal
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    • v.11 no.4
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    • pp.30-37
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    • 2022
  • Disease threatens plant growth and recognizing the type of disease is essential to making a remedy. In recent years, deep learning has witnessed a significant improvement for this task, however, a large volume of labeled images is one of the requirements to get decent performance. But annotated images are difficult and expensive to obtain in the agricultural field. Therefore, designing an efficient and effective strategy is one of the challenges in this area with few labeled data. Transfer learning, assuming taking knowledge from a source domain to a target domain, is borrowed to address this issue and observed comparable results. However, current transfer learning strategies can be regarded as a supervised method as it hypothesizes that there are many labeled images in a source domain. In contrast, unsupervised transfer learning, using only images in a source domain, gives more convenience as collecting images is much easier than annotating. In this paper, we leverage unsupervised transfer learning to perform plant disease recognition, by which we achieve a better performance than supervised transfer learning in many cases. Besides, a vision transformer with a bigger model capacity than convolution is utilized to have a better-pretrained feature space. With the vision transformer-based unsupervised transfer learning, we achieve better results than current works in two datasets. Especially, we obtain 97.3% accuracy with only 30 training images for each class in the Plant Village dataset. We hope that our work can encourage the community to pay attention to vision transformer-based unsupervised transfer learning in the agricultural field when with few labeled images.

The improvement method for power plant boiler temperature nonuniformity of heat transfer tube bank flow path (발전용 보일러 전열 튜브 유로내 온도분포 불균일 개선기법)

  • Jung, Hoon;Kim, Bum-Shin;Jang, Suck-Won;Ahn, Yeon-Shik;Park, Gun-Bok;Whang, Jung-Ho
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.837-841
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    • 2001
  • Almost all power plant boiler has temperature distribution nonuniformity problem in heat transfer tube flow path. It can cause hot spot damage of superheated or reheated heat transfer section and reduce maintenance schedule when nonuniformity is severe. There are two solutions for improvement temperature nonuniformity. one is change of gas flow distribution of gas path and the other is contorl steam flow in tube bank. Of course, first method is very difficulty to apply but second method is'nt. In this paper, control steam flow is used to solve temperature nonuniformity of power plant boiler.

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A Study on the Heat Transfer in boiler through the performance test in thermal power plant (화력발전소 보일러내의 열전달에 관한 연구)

  • Kwon, Y.S.;Suh, J.S.
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.2064-2069
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    • 2004
  • The main reason to analyze heat transfer in boiler inside through the performance test in fossil power plant is to increase plant high efficiency and energy saving movement in the government. Tins study intends to have trend and analyze the boiler heat transfer through the performance test, so it may give us the heat distribution in boiler inside in super-critical and sub-critica1 pressure type power plant

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Development of a Robotic Transplanter for Pot-Seedlings of Plant Factory (식물공장용 포트묘 로봇 이식기 개발)

  • 류관희;김기영;류영선;한재성;신태웅
    • Journal of Biosystems Engineering
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    • v.23 no.3
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    • pp.277-284
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    • 1998
  • This study was conducted to develop m automatic pot-seedling transplanter for plant factory. The transplanter consists of a gripper, row-spacing control device, nursing tray transfer system, growing trough transfer system, and gripper moving device. The gripper picks up pot-seedling. The gripper moving device moves the gripper between nursing tray and growing-flat. Nursing trays are moved to workspace by the nursing tray transfer system. The growing trough transfer system was developed to move growing trough to workspace. The row-spacing control device was used to adjust the distance between adjacent plants traversely. The results of this study are as follows. The transplanting capacity of the developed transplanter was 7.1 seconds per cycle or 1.18 second per pot-seedling. Successful planting was 98.9% without seedlings and 95.8% with seedlings.

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A Study on the Heat Transfer Reduction due to the Clinker in the Thermal Poorer Plant (화력발전소에서 용융회가 열전달 감소에 미치는 영향에 관한 연구)

  • Kang, H.C.;Lee, K.W.
    • Journal of Power System Engineering
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    • v.4 no.1
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    • pp.13-19
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    • 2000
  • This study was conducted for the heat transfer reduction due to the clinker formed in the furnace of the thermal power plant. The thermal properties of clinker such as thermal conductivity, specific heat, density and void fraction were measured. The thermal conductivities of the clinker were ranged $0.32-0.54W/m{\cdot}K$ and the average specific heat and the void fraction were $930J/kg{\cdot}K$ and 0.36 respectively. The thermal resistance of clinker was the greatest among the thermal resistances. It was found that the clinker reduces more than 90% of the heat transfer if the clinker is thicker than 10 cm.

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Effect of Rice Straw Compost on Cadmium Transfer and Metal-ions Distribution at Different Growth Stages of Soybean

  • Jung, Ha-il;Chae, Mi-Jin;Kong, Myung-Suk;Kang, Seong-Soo;Kim, Yoo-Hak
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.6
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    • pp.644-650
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    • 2016
  • In soil-to-plant transfer of heavy metals, the amount absorbed and accumulated varies depending on the environment conditions. The absorption rate of cadmium (Cd) in plants differs considerably depending on the bioavailability of Cd in the soil, while usage by various organic matters is also reported to affect absorption patterns. Therefore, this study aimed to identify the difference in the transfer of essential metal ions and Cd to various plant parts when rice straw compost was used to cultivate soybean (Glycine max L. cv. Daepung). In the two-leaf stage of soybean cultivated in a greenhouse, Cd was mixed in the soil, after which the Cd and essential metal ions contents, and physiological changes of soybean seedlings were studied on the 15th and 25th day. The Cd toxicity in the plant was reduced with the use of rice straw compost. Further, the Cd content varied with the plant part, and was higher in young leaves (3rd and 4th leaf) than in the stem. When analyzed by leaf age, the Cd transfer was highest in young leaves (3rd and 4th leaf), followed by mature leaves (1st and 2nd leaf). While there was no significant difference between plant tissues in the absorption rate of copper (Cu) and zinc (Zn) when rice straw compost was used against Cd toxicity, the absorption rate of manganese (Mn) and iron (Fe) showed a significant decline in both the control and rice straw compost treatment conditions, as well as a significant difference between leaf ages. Therefore, these results confirm that the use of rice straw compost against Cd toxicity is effective, and implies that the rate of Cd transfer in the soybean plant varies significantly with leaf age.

Estimation of radiostrontium, radiocesium and radiobarium transfer from arid soil to plant: A case study from Kuwait

  • Aba, Abdulaziz;Ismaeel, Anfal;Al-Boloushi, Omar
    • Nuclear Engineering and Technology
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    • v.53 no.3
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    • pp.960-966
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    • 2021
  • A technical approach to design and carry out an experiment to determine the uptake of selected radionuclides in site-specific conditions in Kuwait was developed and successfully executed for developing a radioecological decision support system. The radionuclides from soil-to-plant transfer factors have been obtained for leafy and non-leafy vegetables, and root crops cultivated in Kuwait. Two types of vegetated soils were selected and spiked with high concentrations of three relatively short-lived selected radionuclides (85Sr, 134Cs, and 133Ba). The highest strontium and barium transfer factors were found in the order: leafy vegetables > root crops > non-leafy vegetables. The approximate range of radiocesium transfer factor was found to be low in all plant groups and was comparable to those reported elsewhere in different soil types of temperate and tropical environments. A strong negative correlation between the obtained transfer factors and the distribution coefficient of the radionuclide in soil was found. It is recommended to adopt the newly derived parameters for the sensitive areas in Kuwait and other Gulf countries instead of using the generic parameters, whenever dose calculation codes are used. This will help to more accurately assess and predict the end results of the committed effective dose equivalent through ingestion pathway.

Flow and Heat Transfer Analysis of Reactor Coolant Pump in Transient Conditions (원자로 냉각재 펌프의 과도 상태의 유동 및 열전달 해석 연구)

  • Hur, N.;Kim, S.;Yoo, K.-P.;Kim, S. T.
    • 유체기계공업학회:학술대회논문집
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    • 1999.12a
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    • pp.245-251
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    • 1999
  • The structural analysis of a reactor coolant pump(RCP) of a nuclear power plant is very important for the safety assessment of the plant. Accurate boundary conditions for the heat transfer coefficient are required for reliable thermal stress analysis of the pump casing, especially in transient operations of the pump since the coolant properties are largely dependent on operational conditions. In the present study, a 3D mixed flow type coolant pump was modeled from the RCP drawings and analyzed in the steady state and number of transient flow conditions by using a commercial code STAR-CD. From the result of the computation, it is seem that the average heat transfer coefficients for the cases considered are found to be the suggested values of the manufacturer, Westinghouse Energy System. The unevenness in local heat transfer coefficients, however, is found to be considerable so that the use of average heat transfer coefficients in all boundaries might not give reliable thermal stresses.

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Transfer of RNA from Methylmercury-agarose Gel to Nitrocellulose Membrane (메칠머큐리젤에 분리된 리보핵산의 니트로셀루로스막으로 이동)

  • 안정선
    • Journal of Plant Biology
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    • v.30 no.2
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    • pp.109-116
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    • 1987
  • Effects of staining, buffer washing and denaturing agents on the transferrability of RNA fractionated on a methylmercury hydroxide-agarose gel to a nitrocellulose membrane were studied. Ethidium bromide staining and ammonium acetate buffer washing inhibited RNA transfer, while 3% HCHO and 0.5 M NaOH treatments stimulated transfer which was negated in the ammonium acetate buffer. Accordingly, maintenance of primary structure of RNA was proved to be essential for transferring RNA from the methylmercury hydroxideagarose gel to the nitrocellulose membrane.

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