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Hybrid Type (hybrid + type)

Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

Numerical simulation of a dam break for an actual river terrain environment

HYDROLOGICAL PROCESSES, Issue 4 2007
C. B. Liao
Abstract A two-dimensional (2D) finite-difference shallow water model based on a second-order hybrid type of total variation diminishing (TVD) approximate solver with a MUSCL limiter function was developed to model flooding and inundation problems where the evolution of the drying and wetting interface is numerically challenging. Both a minimum positive depth (MPD) scheme and a non-MPD scheme were employed to handle the advancement of drying and wetting fronts. We used several model problems to verify the model, including a dam break in a slope channel, a dam break flooding over a triangular obstacle, an idealized circular dam-break, and a tide flow over a mound. Computed results agreed well with the experiment data and other numerical results available. The model was then applied to simulate the dam breaking and flooding of Hsindien Creek, Taiwan, with the detailed river basin topography. Computed flooding scenarios show reasonable flow characteristics. Though the average speed of flooding is 6,7 m s,1, which corresponds to the subcritical flow condition (Fr < 1), the local maximum speed of flooding is 14·12 m s,1, which corresponds to the supercritical flow condition (Fr , 1·31). It is necessary to conduct some kind of comparison of the numerical results with measurements/experiments in further studies. Nevertheless, the model exhibits its capability to capture the essential features of dam-break flows with drying and wetting fronts. It also exhibits the potential to provide the basis for computationally efficient flood routing and warning information. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Phase transformation behaviour and bending properties of hybrid nickel,titanium rotary endodontic instruments

INTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2007
Y. Hayashi
Abstract Aim, To investigate the bending properties of hybrid rotary nickel,titanium endodontic instruments in relation to their transformation behaviour. Methodology, Four types of nickel,titanium rotary endodontic instruments with different cross-sectional shapes (triangular-based and rectangular-based) and different heat treatment conditions (super-elastic type and hybrid type with shape memory effect) were selected to investigate bending properties and phase transformation behaviour. Bending load of the instruments was measured in a cantilever-bending test at 37 °C with the maximum deflection of 3.0 mm. A commercial rotary instrument, ProFile (PF; Dentsply Maillefer, Ballaigues, Switzerland) was used as a reference for the bending test. Phase transformation temperatures were calculated from the diagrams obtained from differential scanning calorimetry. Data were analysed by anova and Scheffe's test. Results, The bending load values of the hybrid type that had undergone additional heat treatment at the tip were significantly lower (P < 0.05) than those of the super-elastic type with no additional heat treatment. The bending load values of rectangular-based cross-sectional shaped instruments were significantly lower (P < 0.05) than those of triangular-based cross-sectional shaped instruments. Phase transformation temperatures (Ms and Af points) of the hybrid type were significantly higher (P < 0.05) than the super-elastic type. The Mf and As points of the tip part were significantly higher (P < 0.05) than those of the whole part of the hybrid instrument. Conclusions, Additional heat treatment of hybrid nickel,titanium instruments may be effective in increasing the flexibility of nickel,titanium rotary instruments. [source]

Standard and Swedish variant types of the hybrid alder Phytophthora attacking alder in Hungary,

PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 4 2003
Zoltán Á Nagy
Abstract A new Phytophthora disease of common alder (Alnus glutinosa) similar to that previously reported in several countries in Europe has been observed in Hungary. Based on these earlier studies, the alder Phytophthora was considered likely to be a hybrid between P cambivora and a P fragariae -like species: across Europe a range of new alder Phytophthora is spreading that comprise a range of heteroploid hybrids including a ,standard' hybrid type and several other hybrid types termed ,variants'. Phenotypic and molecular features of the pathogen in Hungary were characterised and compared with isolates from elsewhere. The morphologies of five isolates from one region (Hévíz) resembled the common, ,standard' type, whereas the three isolates from another region (Hanság) exhibited traits similar to those of one of the ,variant' types, ie the Swedish ,variant'. Molecular markers of these two groups of Hungarian isolates also represented a good fit to those of the standard type and the Swedish variant, respectively. Isozyme patterns and profiles of restriction fragments of the entire internal transcribed spacer (ITS) region or mitochondrial DNAs and of RAPD-PCR products did not differ within a group, but distinct polymorphisms were exhibited between the two groups of isolates. Southern analysis of random amplified polymorphic DNA (RAPD) revealed the homologous nature of co-migrating bands of P cambivora and the isolates of alder Phytophthora. Furthermore, restriction fragment profiles of the ITS region of ribosomal DNAs and the mtDNAs were consistent with reported biparental origin of alder Phytophthora. The hybrid status of these continuously evolving pathogens raises many issues and challenges concerning efficient control measures. © 2003 Society of Chemical Industry [source]

Lycopene content differs among red-fleshed watermelon cultivars,

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2001
Penelope Perkins-Veazie
Abstract Lycopene, a carotenoid, has antioxidant properties that may reduce the incidence of certain cancers. Watermelon (Citrullus lanatus (Thunb) Matsum & Nakai) is a natural source of lycopene, with a reported average content of 48.7,µg,g,1 fresh weight based on samples taken from retail produce. This study demonstrated the variability of lycopene content in 11 red-fleshed watermelon cultivars grown at one location, representing seedless, open-pollinated and hybrid types, and in commercially shipped hybrid and seedless melons, representing seasonal production periods. Tristimulus colorimeter a* and chroma values were positively correlated with lycopene values, but linear or quadratic regressions of colorimeter data against lycopene values were not significant. Tristimulus colorimeter readings from cut melons were compared to amounts of lycopene extracted from the same melons. Lycopene content varied widely among cultivars, with four cultivars having mean values greater than 65.0,µg,g,1 fresh weight. Seedless types sampled tended to have higher amounts of lycopene (>50.0,µg,g,1 fresh weight) than seeded types. Watermelon lycopene content changed for some cultivars with production season. Published in 2001 for SCI by John Wiley & Sons, Ltd [source]

Standard and Swedish variant types of the hybrid alder Phytophthora attacking alder in Hungary,

Nitrogen uptake and utilization efficiency of European maize hybrids developed under conditions of low and high nitrogen input

PLANT BREEDING, Issue 6 2002
T. Presterl
Abstract Maize varieties with improved nitrogen(N)-use efficiency under low soil N conditions can contribute to sustainable agriculture. Tests were carried to see whether selection of European elite lines at low and high N supply would result in hybrids with differential adaptation to these contrasting N conditions. The objective was to analyze whether genotypic differences in N uptake and N-utilization efficiency existed in this material and to what extent these factors contributed to adaptation to low N supply. Twenty-four hybrids developed at low N supply (L × L) were compared with 25 hybrids developed at high N supply (H × H). The N uptake was determined as total above-ground N in whole plants, and N-utilization efficiency as the ratio between grain yield and N uptake in yield trials at four locations and at three N levels each. Highly significant variations as a result of hybrids and hybrids × N-level interaction were observed for grain yield as well as for N uptake and N-utilization efficiency in both hybrid types. Average yields of the L × L hybrids were higher than those of the H × H hybrids by 11.5% at low N supply and 5.4% at medium N level. There was no significant yield difference between the two hybrid types at high N supply. The L × L hybrids showed significantly higher N uptake at the low (12%) and medium (6%) N levels than the H × H hybrids. In contrast, no differences in N-utilization efficiency were observed between the hybrid types. These results indicate that adaptation of hybrids from European elite breeding material to conditions with reduced nitrogen input was possible and was mainly the result of an increase in N-uptake efficiency. [source]