Characterization of Process Conditions in Industrial Stainless Steelmaking Electric Arc Furnace Using Optical Emission Spectrum Measurements

Emission spectroscopy is a potential method for gaining information on electric arc furnace (EAF) process conditions. Previous studies published in literature on industrial EAF emission spectra have focused on a smaller scales and DC arc furnaces. In this study emission spectrum measurements were conducted for 140t AC stainless steelmaking EAF at Outokumpu Stainless Oy, Tornio Works, Finland. Four basic types of emission spectra were obtained during the EAF process cycle. The first one is obscured by scrap steel, the second is dominated by thermal radiation of the slag, the third is dominated by alkali peaks and sodium D-lines and the fourth is characterized by multiple atomic emission peaks. The atomic emission peaks were identified by comparing them to the NIST database for atomic emission lines and previous laboratory measurements on EAF slag emission spectra. The comparison shows that the optic emission of an arc is dominated by slag components. Plasma conditions were analyzed by deriving plasma temperature from optical emissions of Ca I lines. The analysis suggests that accurate information on plasma conditions can be gained from outer plasma having a plasma temperature below 7000 K (6727 °C).     

Glass transition and water plasticization effects on crispness of a snack food extrudate

Abstract

A crispy snack model, composed of maltodextrin, wheat flour, salt, and water, with a clearly measurable glass transition was designed and produced by extrusion. The material was used to investigate effects of glass transition and water plasticization on mechanical properties and sensory crispness. Water sorption and the glass transition temperature range were determined gravimetrically and using differential scanning calorimetry (DSC) for samples stored at 0 to 85% relative humidity (RH), respectively. Mechanical properties were determined for extradates rehumidified at 0 to 76% RH. Three sensory panels evaluated crispness intensities of extrudates rehumidified at 33 to 76% RH by either breaking samples with fingers (Finger Task), biting using the incisor teeth (Bite Task), or biting and chewing (Bite‐and‐Chew Task). The extrudate was plasticized by water, as observed from a typical decrease of Tg with increasing water content. Changes in mechanical properties and loss of crispness occurred at an intermediate water activity level coinciding with the extent of plasticization depressing the Tg to below ambient temperature. The changes in mechanical properties and sensory crispness intensities with increasing water activity had sigmoid shapes following the Fermi's model. Loss of crispness as a result of water plasticization is likely to apply to a number of low‐moisture food materials, although various mechanical and sensory properties do not necessarily change in unison as the materials undergo a glass transition.     

Oviposition Stimulant for a Gall-Inducing Sawfly, Euura lasiolepis, on Willow is a Phenolic Glucoside

The ovipositional stimulation for the shoot galling sawfly, Euura lasiolepis, whose natural host is the North American willow, Salix lasiolepis, was studied in response to its original host, Finnish willows, poplar species, and individual phenolic glucosides and fractions. The major phenolic glucosides in the natural host were salicortin and tremulacin, which were also the major components in the Finnish S. purpurea and S. rosmarinifolia. The natural host, S. lasiolepis, was chosen over six Finnish willow species in multiple-choice tests. Multiple-choice tests with six Finnish willow species and one Finnish popular species showed that S. rosmarinifolia was significantly more attractive than any of the other species by at least 16-fold. No-choice testing with phenolic glucosides showed the tremulacin fraction to be the significant ovipositional stimulant, which elicited probes with the ovipositor at least 19 times more frequently than other glucosides. A tremulacin fraction at 1.5% elicited significantly more probes than a tremulacin fraction tested at 0.4%. In addition, tremulacin was the only glucoside to induce prolonged and repeated probing with the ovipositor, lasting a mean of 6.4 sec per bout per female. Only single probes lasting a fraction of a second were observed in response to other glucosides. This is the second study showing a direct effect of a phenolic glucoside as an ovipositional stimulant for a sawfly, and it also suggests the existence of a mechanism that enables females to respond positively in a graded way to shoot length heterogeneity in host plants and populations.     

Guest Editorial: MLSP 2020 Special Issue

Journal of Signal Processing Systems -     

Inheritance patterns of phenolics in F1, F2, and back-cross hybrids of willows: implications for herbivore responses to hybrid plants

The aim of this study was to determine the inheritance pattern of phenolic secondary compounds in pure and hybrid willows and its consequences for plant resistance to leaf-feeding insects. F1, F2, and back-cross hybrids along with pure species were produced by hand pollination of pure, naturally-growing Salix caprea (L., Salicaceae) and S. repens (L.) plants. Leaf concentrations of condensed tannins and seven different phenolic glucosides were determined by using butanol-HCl and HPLC analyses. Insect herbivore leaf damage was measured on the same leaves as used for chemical analyses. We found hybrids to be approximately intermediate between the parental species: S. caprea with high levels of condensed tannins and no phenolic glucosides, and S. repens with low levels of condensed tannins and high levels of phenolic glucosides. We also found a negative correlation between concentrations of condensed tannins and phenolic glucosides, suggesting a trade-off in production of these two substances. F2 hybrids and the hybrid back-crossed to S. caprea were significantly more damaged by insect herbivores than the parental species and the F1 hybrid, indicating reduced resistance and possibly a selective disadvantage for these hybrid categories.     

Intraspecific Competition, Growth, Chemistry, and Susceptibility to Voles in Seedlings of Betula pendula

We studied the effects of the intensity of intraspecific competition, as indicated by seedling density, and competitive success within populations, as indicated by seedling size, on the secondary chemistry of the stems of silver birch seedlings and their palatability to field voles. We found that the size of seedlings and their total phenolic concentrations were inversely related to stand density. Voles, however, did not discriminate between seedlings grown at the densities studied. Variation in competitive success was associated with several phenomena. Seedling size was positively related to the concentrations of several secondary compounds and to vole preferences, but negatively related to nitrogen concentration. We suggest that the ecological consequences of variation in seedling size cannot be predicted without knowledge of the mechanism behind the variation.     

Modeling the timing of cuts in automatic editing of concert videos

Multimedia Tools and Applications - Increasing amount of video content is being recorded by people in public events. However, the editing of such videos can be challenging for the average user. We...     

Importance of phenolic glucosides in host selection of shoot galling sawfly,Euura amerinae,onSalix pentandra

The effects of phenolic glucosides on the oviposition behavior ofEuura amerinae L. (Hymenoptera: Tenthredinidae) were tested in multiple oviposition experiments using different shoot length categories ofSalix pentandra L. (with different amounts of phenolic glucosides) and in experiments with pure phenolic glucosides (salidroside, arbutin, salicin, 90% salicortin, 90% 2-O-acetylsalicortin) or composite total fractions of phenolic glucosides from three willow species (S. pentandra, S. myrsinifolia Salisb.,S. triandra L.). This was the first time that the effects of pure phenolic glucosides on the oviposition behavior of sawfly species were tested. Total fraction of phenolic glucosides fromS. pentandra and its main individual glucoside, 2-O-acetyl-salicortin, stimulated the strongest ovipositional behavior inE. amerinae. The results show clearly that females ofE. amerinae can recognize and choose their host willow,S. pentandra, on the basis of phenolic glucosides. Moreover, they are probably able to use phenolic glucosides as a cue in shoot selection within host-plant individuals.