Technological change as a trade-off between social construction and technological paradigms

The theory of social construction of technology (SCOT) and the theory of technological paradigms (TTP) are normally regarded as competing or even incompatible perspectives on technological change. In this paper, we show how and when the perspectives are complementary by comparing how the theories conceptualise technology development, understand stakeholders, and determine driving forces for technological change. When stakeholders have different relations to the innovation process, and when the outcome of the innovation process is open, we argue that the two theories could be complementary tools for analysing the process. When using SCOT and TTP as complementary analytical tools, it becomes easier to understand and design innovation processes in which different stakeholders are attached to roles where they are able to contribute in the most productive ways.     

Math, verbal, and general academic self-concept: The internal/external frame of reference model and gender differences in self-concept structure.

Tested predictions from H. W. Marsh's (see record 1987-17104-001) internal/external (I/E) frame of reference model (measuring cognitive dimensions of math and verbal self-concepts [S-Cs]), and gender differences in the structure of academic S-C were examined through path analyses of data from 231 Norwegian 6th-grade students (117 boys and 114 girls). Math and verbal S-Cs on a cognitive level were defined as success expectations on defined tasks. No strong support was found for the I/E model: Math and verbal S-Cs were highly correlated, and no significant negative direct effects were found of verbal achievement on math S-C or of math achievement on verbal S-C for boys, although a negative direct effect of verbal achievement on math S-C was found for girls. The results differed from previous research measuring evaluative dimensions of math and verbal S-Cs, suggesting either remarkable cultural differences or that academic S-Cs are more complex than has been assumed. The structure of S-C differed for boys and girls; math and verbal S-Cs related differently to general academic S-C. The gender differences are discussed in terms of sex stereotypes. This study has implications for research on academic S-C and gender differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Reduced-Basis Element Method

Reduced basis methods are particularly attractive to use in order to diminish the number of degrees of freedom associated with the approximation of a set of partial differential equations. The main idea is to construct ad hoc basis functions with a large information content. In this note, we propose to develop and analyze reduced basis methods for simulating hierarchical flow systems, which is of relevance for studying flows in a network of pipes, an example being a set of arteries or veins. We propose to decompose the geometry into generic parts (e.g., pipes and bifurcations), and to contruct a reduced basis for these generic parts by considering representative geometric snapshots. The global system is constructed by gluing the individual basis solutions together via Lagrange multipliers.     

Promoting Bacillus cereus spore germination for subsequent inactivation by mild heat treatment

Sublethal heat treatment may activate dormant spores and thereby potentiate the conversion of spores to vegetative cells. As the germinated spore is known to possess lower heat resistance than its dormant counterpart, it has been postulated that double heat treatment, i.e., spore heat activation followed by germination and then by heat inactivation, can be used to control spores in foods. Production of refrigerated processed foods of extended durability often includes more than one heat treatment of the food components. This work simulates conventional heat treatment procedures and evaluates double heat treatment as a method to improve spore control in model food matrixes of meat broth and cream sauce. Bacillus cereus NVH 1230-88 spores were supplemented in food model matrixes and heat activated at 70°C and then heat inactivated at 80 or 90°C. The samples were held at 29 to 30°C for 1 h between primary and secondary heat treatments, to allow spore germination. Nutrients naturally present in the food matrixes, e.g., amino acids and inosine, could act as germinants that induce germination. The levels of germinants could be too low to produce effective germination within 1 h. Following primary heat treatment, some samples were therefore supplemented with a combination of L-alanine and inosine, a germinant mixture known to be effective for B. cereus spores. In both matrixes, a combination of double heat treatment (heat activation, germination, and inactivation) and addition of germinants gave a reduction in spore counts equivalent to or greater than that obtained with a single heat treatment for 12 min at 90°C. Addition of germinants was essential to induce effective germination in cream sauce during 1 h at 29 to 30°C, and germinants were therefore a crucial supplement to obtain an effect of double heat treatment in this matrix. These data will be valuable when setting up temperature-time-germinant combinations for an optimized spore reduction in mild-heat-treated foods.     

Intermediates in the Methanol-to-hydrocarbons (MTH) Reaction: A Gas Phase Study of the Unimolecular Reactivity of Multiply Methylated Benzenium Cations

In order to reach a deeper insight into the reaction mechanism of the zeolite catalyzed methanol to hydrocarbons reaction (MTH), the proposed reaction intermediates, i.e., a series of multiply methyl-substituted benzenium ions has been generated in the gas phase by chemical ionization. The fragmentations of the corresponding long-lived (metastable) ions have been investigated. While expulsion of H₂ dominates for the lower homologues, elimination of methane dominates for the higher homologues, accompanied by increasing amounts CH₃^·. Loss of larger fragments relevant to the MTH-reaction, in particular ethene, propene and even butene, is also observed in minor amounts. This latter finding is consistent with a proposed reaction cycle in the MTH reaction known as the paring mechanism, and the feasibility of this mechanism has thus been demonstrated. The metastable gas-phase ions studied here are considerably more energetic than those residing in a zeolite catalyst, but they were found to decompose with markedly higher selectivity towards alkenes as compared to those activated by collision-induced dissociation (CID).     

Accuracy of employee reports on changes in pay.

To test the validity of perceived change measures, questionnaires were administered to 246 employees before and after automation. Actual and perceived change in pay was the one aspect of change studied. "Data are presented on the degree of accuracy of employee reports, on the nature of the deviations between reports and actuality, and on the relationship of the deviations to potential explanatory variables." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

212 transmission electron microscopy applied to phase transformations in ball bearings

$\text{2}\text{1}\text{2}$D transmission electron microscopy has been applied to rolling contact-fatigued ball bearings. The $\text{2}\text{1}\text{2}$D technique implies that correlations between image features and the object lattice structure are transformed to a stereoscopic effect, using defocused dark-field image pairs. During contact fatigue, the martensite matrix may decay and be transformed to new phases. Particularly, a carbon-enriched phase has been studied. The findings indicate areas of probable nucleation sites and areas being dilated due to internal stresses. The phase is constituted of a lattice structure with minor and regular variations in the g-vector, involving vector orientation and magnitude.     

Determination of the botanical origin of honey by Fourier-transformed infrared spectroscopy: an approach for routine analysis

Fourier-transformed infrared spectroscopy has been established for analysing most of the physical–chemical parameters of honey. Additionally this technique can be used for determination of the botanical origin of a honey sample by comparison of the mid-infrared spectra. In this study calibrations for authentification of the main regional honey types should be developed to be able to measure simultaneously physical–chemical properties and the botanical origin at a minimum of time and at low costs. Honey samples from local beekeepers were collected and characterized by standard methods. The most common honey types were used for calibration. We recorded the mid infrared spectrum from each honey sample. Classification models were achieved by PCA-calibration and validated with samples from various botanical origins. Honey of Brassica spp., Robinia pseudoacacia, Calluna vulgaris, Trifolium spp., Tilia spp., Helianthus annuus, Centaurea cyanus and honeydew honey was used for calibration. Afterwards the calibration models were improved during routine analysis. Most of the honey samples from rape, false acacia, heather and honeydew can be classified correctly by the FTIR in consideration of the physical–chemical and sensorial properties.