Design of power and phase feedback control system for ion cyclotron resonance heating in the Experimental Advanced Superconducting Tokamak

Liu L.N.,Zheng W.M.,Zhang X.J.,Yang H.,Yuan S.,Mao Y.Z.,Zhang W.,Zhu G.H.,Wang L.,Qin C.M.,Zhao Y.P.,Cheng Y.,Zhang K. 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.1

Ion cyclotron range of frequency (ICRF) heating system is an important auxiliary heating method in the experimental Advanced Superconducting Tokamak (EAST). In EAST, several megawatts of power are transmitted with coaxial transmission lines and coupled to the plasma. For the long pulse and high power operation of the ICRF waves heating system, it is very important to effectively control the power and initial phase of the ICRF signals. In this paper, a power and phase feedback control system is described based on field programmable gate array (FPGA) devices, which can realize complicated algorithms with the advantages of fast running and high reliability. The transmitted power and antenna phase are measured by a power and phase detector and digitized. The power and phase feedback control algorithms is designed to achieve the target power and antenna phase. The power feedback control system was tested on a dummy load and during plasma experiments. Test results confirm that the feedback control system can precisely control ICRF power and antenna phase and is robust during plasma variations.

Substitution of Wheat for Corn in Beef Cattle Diets: Digestibility, Digestive Enzyme Activities, Serum Metabolite Contents and Ruminal Fermentation

Liu, Y.F.,Zhao, H.B.,Liu, X.M.,You, W.,Cheng, H.J.,Wan, F.C.,Liu, G.F.,Tan, X.W.,Song, E.L.,Zhang, X.L. Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.10

The objective of this study was to evaluate the effect of diets containing different amounts of wheat, as a partial or whole substitute for corn, on digestibility, digestive enzyme activities, serum metabolite contents and ruminal fermentation in beef cattle. Four Limousin${\times}$LuXi crossbred cattle with a body weight ($400{\pm}10kg$), fitted with permanent ruminal, proximal duodenal and terminal ileal cannulas, were used in a $4{\times}4$ Latin square design with four treatments: Control (100% corn), 33% wheat (33% substitution for corn), 67% wheat (67% substitution for corn), and 100% wheat (100% substitution for corn) on a dry matter basis. The results showed that replacing corn with increasing amounts of wheat increased the apparent digestibility values of dry matter, organic matter, and crude protein (p<0.05). While the apparent digestibility of acid detergent fiber and neutral detergent fiber were lower with increasing amounts of wheat. Digestive enzyme activities of lipase, protease and amylase in the duodenum were higher with increasing wheat amounts (p<0.05), and showed similar results to those for the enzymes in the ileum except for amylase. Increased substitution of wheat for corn increased the serum alanine aminotransferase concentration (p<0.05). Ruminal pH was not different between those given only corn and those given 33% wheat. Increasing the substitution of wheat for corn increased the molar proportion of acetate and tended to increase the acetate-to-propionate ratio. Cattle fed 100% wheat tended to have the lowest ruminal $NH_3-N$ concentration compared with control (p<0.05), whereas no differences were observed among the cattle fed 33% and 67% wheat. These findings indicate that wheat can be effectively used to replace corn in moderate amounts to meet the energy and fiber requirements of beef cattle.

Effects of Three Feeding Systems on Production Performance, Rumen Fermentation and Rumen Digesta Particle Structure of Beef Cattle

Liu, Y.F.,Sun, F.F.,Wan, F.C.,Zhao, H.B.,Liu, X.M.,You, W.,Cheng, H.J.,Liu, G.F.,Tan, X.W.,Song, E.L. Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.5

The effects of three different feeding systems on beef cattle production performance, rumen fermentation, and rumen digesta particle structure were investigated by using 18 Limousin (steers) with a similar body weight ($575{\pm}10kg$) in a 80-d experiment. The animals were equally and randomly divided into three treatment groups, namely, total mixed ration group (cattle fed TMR), SI1 group (cattle fed concentrate firstly then roughage), and SI2 group (cattle fed roughage firstly then concentrate). The results showed that the average daily gain was significantly higher in cattle receiving TMR than in those receiving SI1 and SI2 (p<0.05). Consumption per kg weight gain of concentrate, silage, and combined net energy (NEmf) were significantly decreased when cattle received TMR, unlike when they received SI1 and SI2 (p<0.05), indicating that the feed efficiency of TMR was the highest. Blood urea nitrogen (BUN) was significantly decreased when cattle received TMR compared with that in cattle receiving SI1 (p<0.05), whereas there was no difference compared with that in cattle receiving SI2. Ammonia nitrogen concentration was significantly lower in cattle receiving TMR than in those receiving SI1 and SI2 (p<0.05). The rumen area of cattle that received TMR was significantly larger than that of cattle receiving SI1 (p<0.05), but there was no difference compared with that of cattle receiving SI2. Although there was no significant difference among the three feeding systems in rumen digesta particle distribution, the TMR group trended to have fewer large- and medium-sized particles and more small-sized particles than those in the SI1 and SI2 groups. In conclusion, cattle with dietary TMR showed increased weight gain and ruminal development and decreased BUN. This indicated that TMR feeding was more conducive toward improving the production performance and rumen fermentation of beef cattle.

Effects of Free-range Farming on Carcass and Meat Qualities of Black-feathered Taiwan Native Chicken

Cheng, F.Y.,Huang, C.W.,Wan, T.C.,Liu, Y.T.,Lin, L.C.,Lou Chyr, Chu-Ying Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.8

The effects of free-range farming, compared to a conventional production system, on carcass and meat qualities were studied using black-feathered Taiwan native chickens. Twenty 16-week old females were purchased separately from a free-range farm and a conventional production farm and used for this study. The results showed similarities in the live weight (roughly 2.1 kg), dressing percentage (69%) and meat percentage (19%) of deboned leg quarter. Significant differences (p<0.05) found for the free-range chickens included: a higher percentage of meat for the breast, an increased crude protein content and chewiness value for the breast, but decreased crude fat content and lower hardness and fracturablility values for the leg quarter. Significantly higher L* values were found for the breast and leg meat of conventionally produced chickens, whereas no significant differences were found for WHC and purge loss between the breast and the leg, and between the two production systems as well. Results of sensory evaluation showed a significant preference for leg over breast meat (p<0.05). The scores of all the attributes including aroma, flavor, firmness, tenderness, juiciness and overall acceptability of leg meat from free-range chickens were slightly higher than for conventional chickens, while the reverse was true for breast meat, though no significant difference could be found. Free-range Taiwan native chicken appeared to yield the best of the results, with flavorful yet tender leg meat for higher sensory satisfaction, and high-protein but low-fat breast meat for healthier diet choice.

Enhanced x-ray irradiation-induced cancer cell damage by gold nanoparticles treated by a new synthesis method of polyethylene glycol modification

Liu, Chi-Jen,Wang, Chang-Hai,Chien, Chia-Chi,Yang, Tsung-Yeh,Chen, Shin-Tai,Leng, Wei-Hua,Lee, Cheng-Feng,Lee, Kuen-Ho,Hwu, Y,Lee, Yao-Chang,Cheng, Chia-Liang,Yang, Chung-Shi,Chen, Y J,Je, J H,Margari IOP Pub 2008 Nanotechnology Vol.19 No.29

<P>We explored a very interesting gold nanoparticle system—pegylated gold in colloidal solution—and analyzed its uptake by mice colorectal adenocarcinoma CT26 tumor cells and the impact on the cell’s response to x-ray irradiation. We found that exposure to polyethylene glycol (PEG) modified (‘pegylated’) 4.7 ± 2.6 nm gold nanoparticles synthesized by a novel synchrotron-based method enhances the response of CT26 cells to x-ray irradiation. Transmission electron microscopy (TEM) and confocal microscopy revealed that substantial amounts of such nanoparticles are taken up and absorbed by the cells and this conclusion is supported by quantitative induced coupled plasma (ICP) results. Standard tests indicated that the internalized particles are highly biocompatible but strongly enhance the cell damage induced by x-ray irradiation. Synchrotron radiation Fourier transform infrared (SR-FTIR) spectromicroscopy analyzed the chemical aspects of this phenomenon: the appearance of C = O stretching bond spectral features could be used as a marker for cell damage and confirmed the enhancement of the radiation-induced toxicity for cells.</P>

Measurement of the ICRH antenna phasing using antenna strap probe based diagnostic system in EAST tokamak

Liu L.N.,Liang Q.C.,Yang H.,Zhang X.J.,Yuan S.,Mao Y.Z.,Zhang W.,Zhu G.H.,Wang L.,Qin C.M.,Zhao Y.P.,Cheng Y.,Zhang K. 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.10

To operate the ion cyclotron resonance heating (ICRH) antennas in a better heating state and produce relatively low impurities, it is necessary to control the antenna spectrum by changing the antenna phasing. As the electrical length of the antenna feeding transmission lines is changing as a matter of the standing wave pattern at the ceramic supports, 90 elbows, T-connectors and antenna loops, we chose to measure the current at the grounding points of the antenna loops by antenna strap probe. The voltage drops along a small, several millimeter-long paths at the end of the antenna loops give a signal that is proportional to the current in the antenna loop. Through the simulation of the antenna strap probe and the actual measurement of the antenna phasing under vacuum conditions, the reliability of the antenna strap probe based diagnostic system have been successfully proved. Moreover, this system was successfully applied to the ICRH daily experiments in the spring of 2021. In the near future, the active realtime feedback control of the antenna phasing system will be developed based on this diagnostic system in the EAST tokamak.

Controlling field-emission patterns of isolated single-walled carbon nanotube rope (3 pages)

Tong, Y.,Lim, S. C.,Park, K. A.,Jeong, H. J.,Jeong, S. Y.,Lee, Y. H.,Liu, C.,Cheng, H.-M.,Choi, Y. AMERICAN INSTITUTE OF PHYSICS 2005 APPLIED PHYSICS LETTERS Vol.87 No.4

Temporal-spatial structures of plasmas flows and turbulence around tearing mode islands in the edge tokamak plasmas

Zhao, K.J.,Nagashima, Y.,Li, F.M.,Shi, Yuejiang,Diamond, P.H.,Dong, J.Q.,Itoh, K.,Itoh, S.-I.,Zhuang, G.,Liu, H.,Chen, Z.P.,Cheng, J.,Nie, L.,Ding, Y.H.,Hu, Q.M.,Chen, Z.Y.,Rao, B.,Cheng, Z.F.,Gao, L. IOP 2017 Nuclear fusion Vol.57 No.12

<P>The temporal-spatial structures of plasma flows and turbulence around tearing mode islands are presented. The experiments were performed using Langmuir probe arrays in the edge plasmas of J-TEXT tokamak. The correlation analyses clearly show that the flows have similar structures of <I>m</I>/<I>n</I>  =  3/1 as the magnetic island does (<I>m</I> and <I>n</I> are the poloidal and toroidal mode numbers, respectively). The sign of the potential fluctuations for the flows inverses and the powers significantly reduce at <I>q</I>  =  3 surface. Approaching to the last closed flux surface for the magnetic islands, the radially elongated flow structure forms. The flows are concentrated near separatrix and show quadrupole structures. The turbulence is concentrated near X-point and partly trapped inside the magnetic islands.</P>

Field Dependencies of Electronic Trapping and Detrapping Behaviors in Thin SiOxNy Films

Yang, B. L.,Wong, H.,ChEng, Y. C.,Liu, B. Y. 대한전자공학회 1991 ICVC : International Conference on VLSI and CAD Vol.2 No.1

A systematic investigation on the field dependencies of electronic trapping and detrapping processes in thin (100∼200Å) SiO_xN_y films is conducted in this work. The field dependencies of these behaviors are collected from three ways: the electronic conduction, field-assisted detrapping, and the flatband shift due to the electric feld stressing. Results show that the current conduction in SiO_xN_y films at electric field lower than 8 MV/cm is trap-assisted. In detrapping study, we found that most of the traps in the insulator has a energy level greater than 1.0 eV and re-trapping phenomenon is pronounced when an electric field is used to accelerate the detrapping. A nonlinear relationship is found between the flatband shift and stressing electric field. The maximum flatband voltage is found after the SiO_xN_y has been stressed at 10 MV/cm for either 1.5 or 15 min. These observations are explained with the trapping and trap generation kinetics.

ELECTRON TRAPPING AND DETRAPPING BEHAVIORS OF THIN THERMALLY NITRIDED OXIDES

ChEng, Y. C.,Wong, H.,Lo, H. B.,Lai, P. T.,Liu, Z. H. 대한전자공학회 1989 ICVC : International Conference on VLSI and CAD Vol.1 No.1

This work reports the electron trapping and de trapping behaviors of thin ($lt;300Å) thermally grown oxide annealed in pure ammonia at high temperature ($gt;1000℃). The phenomena are investigated by using the low-frequency noise measurement on MOSFETs, monitoring the flatband-voltage shift of MOS capacitor subjected to electron injection and shift of Fowler-Nordheim (FN) curve in high field region. Results indicate that the nitrided samples have particularly higher interface trap density at 0.43eV (below the conduction band of silicon) and a larger capture cross section than the conventional oxides, and the estimated centroid of the trap distribution is very close to the silicon-oxide interface. In addition, the trapped charge density is found to have a strong dependence on the nitridation conditions, and is lower for higher oxide field due to an increase of detrapping rate. On the other hand, electron conduction in the nitrided oxide films is mainly governed by the FN mechanism in low field ($lt;7 MV/cm) region and by the Pool-Frankel mechanism in highfield region where the traps assist the conduction.