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In April 2020, manufacturing of the ITER vacuum vessel (VV) first sector has been completed by the Korean domestic agency, manufacturing having started in February 2012. The ITER VV sector is the largest fusion VV structure in the world. Each step of the manufacturing was a challenge as a first-of-a-kind, and a French nuclear pressure vessel. The paper provides an overview of the major challenges which were overcome over the last 10 years.

In the twin roll strip casting process, coupled analyses of heat transfer and deformation for the casting roll are carried out by using the finite element program MARC to examine the thermal crown. The shrink fit effect and plastic deformation are considered. The result shows that the thermal crown is greatly influenced by the shrink fit and that the thermal crown for POSCO Pilot Caster 2 Copper Roll has an “M” shape. The effects of several factors on thermal crown are also investigated. The amount of thermal crown increases as the heat flux, casting speed, sleeve thickness and casting roll width increase. On the other hand, it decreases as the casting roll diameter increases.

A total of 360 Berkshire (hog) weighing 25 kg were fed experimental diets containing either dehulled soybean meal (DSBM) or non-dehulled soybean meal (NDSBM) as a major protein source until they reach 80 kg. The pigs were then fed the finisher diets either high (3,265 kcal/kg) or low (2,940 kcal/kg) in ME to evaluate the effects of dietary energy level for finisher phase on the growth performances, carcass and meat quality parameter. In growth performance, daily weight gain (kg/day) was higher (P

The secondary hardening and fracture behavior in P/M high speed steels of W–Mo–Cr–V(–Co) system has been investigated in terms of Co addition and austenitizing temperature. Austenitizing was conducted at 1100 and 1175 °C of relatively low and high temperatures, respectively. Tempering was performed in the range of 500–600 °C. Coarse primary carbides retained after heat treatment were V-rich MC and W–Mo-rich M6C types. Since the dissolution of W–Mo-rich M6C with relatively low stability was more promoted with increasing austenitizing temperature, the alloy content of the W and Mo in the matrix was enhanced. In turn, it gives a significant influence on the precipitation of fine secondary alloy carbides, that is, secondary hardening during tempering. The major secondary carbides were W–Mo–Cr-rich M2C type. The peak hardness was observed in the tempering range of 500–540 °C, depending on Co addition and austenitizing temperature. With an increase in austenitizing temperature, the aging deceleration was observed. This phenomenon may be attributed to the increased content of W and Mo in the matrix, both diffusing slowly in the matrix and inhibiting growth of M2C carbide, as compared to Cr. In addition, the aging acceleration occurred in the Co bearing alloy, promoting the precipitation of M2C carbides, as well as the overall increase in hardness. In general, the impact toughness was decreased with an increase in hardness. In addition, the impact toughness to hardness balance was lowered in the Co bearing alloy.

Calli were induced by culturing the leaf segment of Actinidia deliciosa A. arguta clone 118 on MS medium supplemented with 0.5 mg/L 2,4-D, 0.1 mg/L NAA and 0.05 mg/L BA for 8 weeks in light condition. The induced calli were inoculated in liquid MS medium containing 0.5 mg/L 2,4-D, 0.1 mg/L NAA, 0.05 mg/L BA and 3% sucrose to establish cell suspension culture. The cells at the exponential stage and the stationary stage could be observed between 5-11 days and after that 12 days in culture, respectively. The fresh weight of callus induced from the suspended cells did not vary much among the media containing eight different combinations of plant growth regulators tested. The highest frequency of shoot induction (88.3%) was observed in MS medium containing 2.0 mg/L zeatin. Either BA or zeatin mixed with thidiazuron (TDZ) seemed to be effective in shoot induction. The induced shoots were transferred to MS medium containing 0.2 mg/L zeatin for further shoot growth. And then the shoots were transferred to Standardi (ST) medium containing 1.0 mg/L indolebutyric acid (IBA) for rooting. Plantlets could be obtained through cell suspension culture of Actinidia deliciosa A. arguta clone 118.

High frequency somatic embryogenesis of Eleutheorcoccus chiisanensis was achieved through suspension culture of embryogenic cells in hormone-free Murashige and Skoog liquid medium supplemented with 30 g sucrose l-1. Cotyledonary somatic embryos were germinated and converted into plantlets using 20 microM: gibberellic acid which were then grown in a 10 l airlift bioreactor. HPLC analysis revealed the accumulation of eleutheroside B, E and E1 in the embryos and plantlets. Thus mass production of embryos and plantlets of E. chiisanensis can be achieved in liquid cultures and the biomass produced may become an alternative source of eleutherosides.

Strip casting process has been developed to manufacture thin steel strip, 2–4 mm thick, directly from molten metal fed in between two water-cooled casting rolls, and is being applied to the industrial steelmaking plants. The cast strip contains typically 2–6% delta ferrite in the microstructure at room temperature. This work studied the dissolution kinetics of delta ferrite in strip cast specimen in the temperature range of 1050–1200 °C by varying the annealing time. The morphology of delta ferrite in the cast strip was a vermicular type with a three-dimensional honeycomb network structure. At the early stage of delta ferrite dissolution, more than 50% of delta ferrite dissolved very rapidly regardless of annealing temperature. The rapid dissolution was mainly attributed to the excess Cr depletion in the delta ferrite resulting from the (Fe, Cr) carbide precipitation at interface boundary between delta ferrite and austenite phases. Subsequently, the dissolution was controlled by volume diffusion of Cr and Ni in the austenite phase. The analytical solution assuming the austenite phase as semi-infinite was successfully applied for the analysis of experimental data at 1150 °C. The activation energy for the dissolution was measured as 251.4 kJ mol−1, which is consistent with activation energy for volume diffusion of Cr.

Ground surface settlement due to tunnel excavation varies in magnitude and trend depending on several factors such as tunnel geometry, ground conditions, etc. Although there are several empirical and semi-empirical formulae available for predicting ground surface settlement, most of these do not simultaneously take into consideration all the relevant factors, resulting in inaccurate predictions. In this study, an artificial neural network (ANN) is incorporated with '113' of monitored field results to predict surface settlement for a tunnel site with prescribed conditions. To achieve this, a standard format (a protocol) for a database of monitored field data is first proposed and then used for sorting out a variety of monitored data sets available in KICT. Using the capabilities of pattern recognition and memorization of the ANN, an attempt is made to capture the rich physical characteristics smeared in the database and at the same time filter inherent noise in the monitored data. Here, an optimal neural network model is suggested through preliminary parametric studies. It is shown that preliminary studies for generating an optimal ANN under given training data sets are necessary because no analytical method for this purpose is available to date. In addition, this study introduces a concept of relative strength of effects (RSE) [Yang Y, Zhang Q. A heirarchical analysis for rock engineering using artificial neural networks. Rock Mechanics and Rock Engineering 1997; 30(4): 207–22] in sensitivity analysis for various major factors affecting the surface settlement in tunnelling. It is seen in some examples that the RSE rationally enables us to recognize the most significant factors of all the contributing factors. Two verification examples are undertaken with the trained ANN using the database created in this study. It is shown from the examples that the ANN has adequately recognized the characteristics of the monitored data sets retaining a generality for further prediction. It is believed that an ANN based hierarchical prediction procedure shown in this paper can be further employed in many kinds of geotechnical engineering problems with inherent uncertainties and imperfections.

Various modeling techniques, such as the channel network, joint network, REV (representative elementary volume) and non-REV methods are used to analyze the water and grout flow and solute transport in two distinct scales of observation, i.e. a laboratory-scale joint and a field-scale jointed rock mass. The objectives of this study are to compare the attributes of the employed numerical methods and to investigate the effects of joints on the migration of nuclides from the disposal vaults at various depths.

The importance of aerosols and aerosol processes has prompted considerable research into techniques for particulate characterization. As batch sampling probe techniques often introduce unacceptable perturbations into the flow and can have serious uncertainties associated with possible alterations of the aerosol in the sample line, in situ optical methods have received much interest. This paper is concerned with a laser light-scattering technique for in situ analysis of individual particles, the multiple-ratio single-particle counter (MRSPC). In particular a thorough study of the response characteristics of the MRSPC was completed, including both experimental and theoretical analyses of nonideal effects associated with particle size distribution measurements. The effects of unknown refractive index, nonspherical particle shape, size-selective sampling bias, and instrument resolution were considered. Theoretical predictions of MRSPC performance for these nonideal conditions were found to agree quite well with experiments performed here. The overall analysis indicates that the MRSPC can make in situ measurements of volume-equivalent size distributions of moderately nonspherical particles of unknown refractive index with uncertainties on the order of 50%.