Continuous casting of steel involving different grades in the same casting sequence remains a challenge to billet caster operators. The intermixed composition obtained during the grade change does not meet the specifi...Continuous casting of steel involving different grades in the same casting sequence remains a challenge to billet caster operators. The intermixed composition obtained during the grade change does not meet the specification of either grade and must be downgraded. Incorrect identification of this intermixed region may result in non-conforming products reaching the customer. In this study, a numerical model based on CFD (computational fluid dynamics approach) has been developed which predicts the start and end of the intermixed composition and the tonnage to be downgraded under different casting conditions. This model was validated and the results were in good agreement with the actual plant data for a 6-strand billet caster at LD-1 of TATA Steel, India. This model is used to calculate transition tonnage for different scenarios, e.g. when one of the outermost strands is not functional or some combinations are not functional and varying casting speed during operation. Furthermore, impact of different design of baffles on performance of Tundish has been evaluated to find a way to reduce transition or intermixed composition.展开更多
Spathoglottis plicata Blume. is a horticulturally important vulnerable ground orchid with beautiful flowers blooming round the year. Highfrequency protocorm-like body(PLB) formation was established via callus culture ...Spathoglottis plicata Blume. is a horticulturally important vulnerable ground orchid with beautiful flowers blooming round the year. Highfrequency protocorm-like body(PLB) formation was established via callus culture from vegetative tissues of in vitro germinated seedlings of S.plicata. Media containing MS salts and Gamborg's B5 vitamins supplemented with 1.0 mg·L^(-1) 2,4-dichlorophenoxyacetic acid(2,4-D), 3.0 mg·L^(-1) α-naphthaleneacetic acid(NAA), 1.0 mg·L^(-1) kinetin(KIN), and 10%(v/v) ‘Aloe vera gel'(Av G) were effective in fragile calli induction. A maximum of(22.3 ± 0.52) PLBs were induced from about 250 mg callus within 45–55 days in the presence of 2.0 mg·L^(-1) NAA and 3.0 mg·L^(-1) 6-benzylaminopurine(BAP). Briefly, 3.0% sodium alginate was found to be most suitable for the formation of an appropriate shape and good germination rates(86.7%)of artificial seeds. Out of three different temperatures(4, 15, and 24 °C), the best result was achieved at 4 °C with 66.7% germinability even after90 days of storage. Plantlets were acclimatized with 86.6% survival rate and 76.3% of these plants produced flowers within 12–15 months of field transfer. Chromosomal studies revealed cytological stability of all regenerants containing 2 n = 40 chromosomes as in the parental plants.The present protocol can be applied reliably for the purposes of large-scale commercial propagation and short-term conservation of this orchid.展开更多
文摘Continuous casting of steel involving different grades in the same casting sequence remains a challenge to billet caster operators. The intermixed composition obtained during the grade change does not meet the specification of either grade and must be downgraded. Incorrect identification of this intermixed region may result in non-conforming products reaching the customer. In this study, a numerical model based on CFD (computational fluid dynamics approach) has been developed which predicts the start and end of the intermixed composition and the tonnage to be downgraded under different casting conditions. This model was validated and the results were in good agreement with the actual plant data for a 6-strand billet caster at LD-1 of TATA Steel, India. This model is used to calculate transition tonnage for different scenarios, e.g. when one of the outermost strands is not functional or some combinations are not functional and varying casting speed during operation. Furthermore, impact of different design of baffles on performance of Tundish has been evaluated to find a way to reduce transition or intermixed composition.
文摘Spathoglottis plicata Blume. is a horticulturally important vulnerable ground orchid with beautiful flowers blooming round the year. Highfrequency protocorm-like body(PLB) formation was established via callus culture from vegetative tissues of in vitro germinated seedlings of S.plicata. Media containing MS salts and Gamborg's B5 vitamins supplemented with 1.0 mg·L^(-1) 2,4-dichlorophenoxyacetic acid(2,4-D), 3.0 mg·L^(-1) α-naphthaleneacetic acid(NAA), 1.0 mg·L^(-1) kinetin(KIN), and 10%(v/v) ‘Aloe vera gel'(Av G) were effective in fragile calli induction. A maximum of(22.3 ± 0.52) PLBs were induced from about 250 mg callus within 45–55 days in the presence of 2.0 mg·L^(-1) NAA and 3.0 mg·L^(-1) 6-benzylaminopurine(BAP). Briefly, 3.0% sodium alginate was found to be most suitable for the formation of an appropriate shape and good germination rates(86.7%)of artificial seeds. Out of three different temperatures(4, 15, and 24 °C), the best result was achieved at 4 °C with 66.7% germinability even after90 days of storage. Plantlets were acclimatized with 86.6% survival rate and 76.3% of these plants produced flowers within 12–15 months of field transfer. Chromosomal studies revealed cytological stability of all regenerants containing 2 n = 40 chromosomes as in the parental plants.The present protocol can be applied reliably for the purposes of large-scale commercial propagation and short-term conservation of this orchid.
