• Title/Summary/Keyword: Reverse cycle

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Opportunities and Challenges for the Development of Chinese Intelligent Manufacturing Science and Technology Enterprises with "Anti-Globalization"

  • JINMING ZHANG;ZIYANG LIU
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2023.01a
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    • pp.443-445
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    • 2023
  • Following the global financial crisis, the global value chain contracted, and characteristics of "reverse globalization" of the economy and trade gradually emerged. This is due to the term "reverse globalization" referring to a shift away from globalization. Within a short period of time, the phenomenon known as "reverse globalization" developed as an inescapable obstacle, coinciding with the development and dissemination of the COVID-19 virus. At some time in the distant future, the "reverse globalization" of economic trade and the "globalization" of the digital economy will co-dominate the shifting trend of the global economic landscape. This will happen gradually over time. The goal of this research is to look at the minor changes that happened in the methods and techniques used by the economic mechanism known as "globalization against the flow." It employs Chinese smart manufacturing companies as a model and proposes a digital drive model to investigate the prospects and constraints of smart manufacturing technology enterprise innovation development under "reverse globalization," with the goal of establishing a digital innovation development path. The theoretical insights given in this study have the potential to serve as a reference for China as it attempts to build a new growth pattern based on a double-cycle and promote a new type of globalization.

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Cooling Characteristics of Refrigerated Vehicles with Heat Storage Materials in Thermobank (냉동탑차의 Thermobank 열저장 매체에 따른 냉각성능 비교)

  • Mun, Je-Cheol;Choi, Kwang-Il;Oh, Jong-Taek;Kim, Jai-Hoon
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.810-814
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    • 2009
  • A experimental study of a high efficiency transport refrigeration system for sliced-raw fish transportation is presented in this paper. The refrigeration system, that is powered by the car engine, is equipped with heat storage for reverse cycle-hot gas defrost; the stored heat is used during defrost cycle of the system. The heat storage has size $400(L){\times}350(W){\times}250(H)\;mm$ and made of fin-tube heat exchanger. System performance and container operating conditions are experimentally investigated and analyzed under cooling and defrosting conditions with heat storage materials. The water is faster about 30% than paraffin in cooling-down time of heat storage materials with load and unload.

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Analysis of Design and Part Load Performance of Micro Gas Turbine/Organic Rankine Cycle Combined Systems

  • Lee, Joon-Hee;Kim, Tong-Seop
    • Journal of Mechanical Science and Technology
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    • v.20 no.9
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    • pp.1502-1513
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    • 2006
  • This study analyzes the design and part load performance of a power generation system combining a micro gas turbine (MGT) and an organic Rankine cycle (ORC). Design performances of cycles adopting several different organic fluids are analyzed and compared with performance of the steam based cycle. All of the organic fluids recover greater MGT exhaust heat than the steam cycle (much lower stack temperature), but their bottoming cycle efficiencies are lower. R123 provides higher combined cycle efficiency than steam does. The efficiencies of the combined cycle with organic fluids are maximized when the turbine exhaust heat of the MGT is fully recovered at the MGT recuperator, whereas the efficiency of the combined cycle with steam shows an almost reverse trend. Since organic fluids have much higher density than steam, they allow more compact systems. The efficiency of the combined cycle, based on a MGT with 30 percent efficiency, can reach almost 40 percent. hlso, the part load operation of the combined system is analyzed. Two representative power control methods are considered and their performances are compared. The variable speed control of the MGT exhibits far better combined cycle part load efficiency than the fuel only control despite slightly lower bottoming cycle performance.

Some Enzymes of Tricarboxylic Acid Cycle and Metabolites of Carbohydrate Metabolism in Adult Isoparorchis hypselobagri(Digenea: Trematoda) During in vitro Starvation

  • Bera, Bireshwar;Manna, Buddhadeb
    • International Journal of Industrial Entomology and Biomaterials
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    • v.18 no.2
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    • pp.91-95
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    • 2009
  • The presence of considerable amount of enzymes of TCA cycle isocitrate dehydrogenase (ICDH-NADP+, EC1.1.1.42), $\alpha$-ketogluterate dehydrogenase ($\alpha$-KGD, EC1.2.4.2) and malate dehydrogenase (MDH, EC1.1.1.37) in fresh control and in vitro starved adult Isoparorchis hypselobagri establish the functional TCA cycle in this fluke. The major metabolic end products are pyruvate, lactate, oxaloacetate and malate. The ratio of oxaloacetate/malate assess that oxaloacetate is reduced to malate and in this fluke the reverse TCA cycle is active. The pyruvate/lactate ratio shows pyruvate is reduced to lactate and the fluke is homolactate farmenters.

A Study on the Scavenging Efficiency Evaluation for the RSSV Configuration of 2-Stroke Engine with Popet Valve Type Using Single-Cycle Method (Single-Cycle 기법을 이용한 포핏밸브형 2-행정기관의 RSSV 형상에 따른 소기효율 측정에 관한 연구)

  • 이진욱;강건용;정용일;이주헌;박정규
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.2
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    • pp.69-79
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    • 1997
  • This paper deals with the measurement and analysis on the scavenging performance of the oppet-valve type two-stroke engine with different shroud system. The scavenging flow characteristics is investigated by flow visualization under steady condition, in which a dye is introduced into single-cycle method using the difference of specific gravity between two working fluids is used to evaluate the scavenging efficiency and the trapping efficiency. The 90° shroud system was found to be the highest efficiency system through both flow visualization and single-cycle test, as well as the shroud system to generally be efficient for reducing a short-circuiting flow during scavenging process in a two-stoke engine.

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Performance Test of 2 kW Class Reverse Brayton Refrigeration System (냉동능력 2 kW 급 역브레이튼 극저온 냉각시스템 성능시험)

  • KO, JUNSEOK;LEE, KEUN-TAE;PARK, SEONG-JE;KIM, JONGWOO;CHOO, SANGYOON;HONG, YONG-JU;IN, SEHWAN;PARK, JIHO;KIM, HYOBONG;YEOM, HANKIL
    • Transactions of the Korean hydrogen and new energy society
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    • v.31 no.5
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    • pp.429-435
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    • 2020
  • This paper describes the experimental study of reverse-Brayton refrigeration system for application to high temperature superconductivity electric devices and LNG re-liquefaction. The reverse-Brayton refrigeration cycle is designed with operating pressure of 0.5 and 1.0 MPa, cooling capacity of 2 kW at 77 K, and neon as a working fluid. The refrigeration system is developed with multi scroll compressor, turbo expander and plate heat exchanger. From experiments, the performance characteristics of used components is measured and discussed for 77-120 K of operating temperature. The developed refrigeration system shows the cooling capacity of 1.23 kW at 77 K and 1.64 kW at 110 K.

Effect of Reverse Cyclic Loading on the Fracture Resistance Curve of Nuclear Piping Material (역사이클하중이 원자력 배관재료의 파괴저항곡선에 미치는 영향)

  • Weon, Jong-Il;Seok, Chang-Sung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.23 no.7 s.166
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    • pp.1112-1119
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    • 1999
  • Fracture resistance(J-R) curves, which are used for the elastic-plastic fracture mechanics analyses, are known to be dependent on the cyclic loading history. The objective of this paper is to study the effect of reverse cyclic loading on J-R curves in CT specimens. The effect of two parameters was observed on the J-R curves during the reverse cyclic loading. One was the minimum-to-maximum load ratio(R) and the other was the incremental plastic displacement(${\delta}_{cycle}/{\delta}_i$), which is related to the amount of crack growth that occurs in a cycle. Fracture resistance test on CT specimens with varying load ratio and incremental plastic displacement were performed. For the SA 516 Gr. 70 steel, the results showed that the J-R curves were decreased with decreasing the load ratio and the incremental plastic displacement. When the load ratio was set to -1, the results of the J-R curves and the $J_i$ value were about $40{\sim}50$ percent of those for the monotonic loading condition. Also on condition that the incremental plastic displacement reached 1/40, the J-R curves and the $J_i$ value were about $50{\sim}60$ percent of those for the incremental plastic displacement of 1/10.

Study on Selection of Water Treatment Filtration System to Cope with Climate Change (기후변화 대응을 위한 수처리 여과시스템 선정 방안 연구)

  • Hwang, Yun-Bin;Park, Ki-Hak
    • Journal of Climate Change Research
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    • v.9 no.1
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    • pp.75-80
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    • 2018
  • The problem of water shortages and water related disasters caused by climate change has increased the seriousness of water problems and the importance of water treatment technology capable of securing clean water is expanding. In this study, we analyzed not only the water pollutant generated by the filtration system technology of various water treatment technologies but also the indirect greenhouse gas emissions generation, and analyzed the influence on the environment. The subjects of study are Fabric Filter, Reverse Osmosis System and Pressurized Microfiltration Device which are widely used for water treatment and we analyzed the impact on the environment using the Life Cycle Assessment (LCA) method using the electricity amount necessary for use, the water purification efficiency, the throughput per ton and the cost. The amount of greenhouse gas generated when the Pressurized Microfiltration Device operates for 1 year is $2.15E+04kg\;CO_2-eq$., Fabric Filter is $3.29E+04kg\;CO_2-eq$., and Reverse Osmosis System is $1.68E+05kg\;CO_2-eq$. As a result of analyzing the amount of greenhouse gas generated at the time of purifying 1 ton of the Pressurized Microfiltration Device and the conventional filtration system, the Pressurized Microfiltration Device was $20.5g\;CO_2-eq$., Fabric Filter was $34.7g\;CO_2-eq$., and Reverse Osmosis System was $191.7g\;CO_2-eq$. The amount of greenhouse gas generated was calculated to be 41.0% less than that of the Fabric Filter by the Pressurized Microfiltration Device and 89.3% less than the Reverse Osmosis System. From the viewpoint of climate change, it is necessary to select a filtration system that takes climate change into account, not from the viewpoint of water quality removal efficiency and economic efficiency according to future water treatment applications, and it is necessary to select a water treatment filtration system more researches and improvements will be made for.

The Characteristics of Backfire for a Free-Piston Hydrogen Fueled Engine with Reverse Uni-flow Scavenging (Reverse uni-flow 소기방식을 갖는 2행정 프리피스톤 수소기관의 역화 현상에 관한 연구)

  • Byun, Chang-Hee;Choi, Kwan-Yeon;Back, Dae-Ha;Lee, Jong-Tae
    • Transactions of the Korean hydrogen and new energy society
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    • v.21 no.2
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    • pp.98-103
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    • 2010
  • In order to develop two-stroke free-piston hydrogen engine to obtain high thermal efficiency and low emission, backfire occurrence have to be prevented. In this research, backfire characteristics are analyzed as functions of the intake valve opening timing and compression chamber pressure under piston by using RICEM (Rapid Intake Compression Expansion Machine) that has reverse uni-flow scavenging. As the result, reverse uni-flow scavenging is advantage about back fire. but, it exists suitable intake valve opening timing and its timing become known that equivalence ratio 1 retard until the piston rises. Also, To rise chamber pressure of lower piston, this does not cause backfire occurs in equivalent ratio 0.6 observed back fire. Therefore, 2cycle hydrogen fueled free-piston engine is undesirable scavenging compression by compressing the piston.

An Efficient Implementation of Kruskal's and Reverse-Delete Minimum Spanning Tree Algorithm (Kruskal과 역-삭제 최소신장트리 알고리즘의 효율적 구현 방법)

  • Choi, Myeong-Bok;Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.2
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    • pp.103-114
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    • 2013
  • This paper suggests a method to reduce the number of performances of Kruskal and Reverse-delete algorithms. Present Kruskal and Reverse-delete algorithms verify whether the cycle occurs within the edges of the graph. For this reason, they have problems of unnecessarily performing extra algorithms from the edges, even though they've already obtained the minimum spanning tree. This paper, first of all, suggests the 1st method which reduces the no. of performances by introducing stop point criteria of algorithm, but at the same time, performs algorithms from all the edges, just like how Kruskal and Reverse-delete algorithms. Next, it suggests the 2nd method which finds the minimum spanning tree from the remaining edges after getting rid of all the unnecessary edges which are considered not to affect the minimum spanning tree. These suggested methods have an effect of terminating algorithm at least 1.4 times and at most 3.86times than Kruskal and Reverse-delete algorithms, when applied to the real graphs. We have found that the 2nd method of the Reverse-delete algorithm has the fastest speed in terminating an algorithm, among 4 algorithms which are results of the 2 suggested methods being applied to 2 algorithms.