834 resultados para Research on humanities
Resumo:
In the investigation of real loading capacities in concrete bridge deck slabs,the study of this type of structure was carried out with consideration of compressive membrane action.A series of experimental test of steel-concrete bridge structures was developed with the analysis of influences from the varying of structural parameters on loading capacities,including reinforcement percentages,supporting beam sizes and concrete compressive strength.Through the study of the experimental results,it was found that the real structural loading capacities are larger than those predicted by current design methods.Therefore,based on the previous research,a prediction method for loading capacities of concrete bridge deck slabs was established with consideration of CMA,which was built based on the plastic ultimate analysis.In this method,the lateral restraint stiffness subjected by concrete bridge deck slabs was provided.The proposed theoretical model is capable of predicting the loading capacities of this type of structure accurately with comparison of results from several bridge deck experimental tests.
Resumo:
Over recent years the findings of a number of quantitative research studies have been published in the UK on gender and achievement. Much of this work has emanated from Stephen Gorard and his colleagues and has not only been highly critical of existing approaches to handling quantitative data but has also suggested a number of alternative and, what they claim to be, more valid ways of measuring differential patterns of achievement and underachievement between groups. This article shows how much of this work has been based upon rather under-developed measures of achievement and underachievement that tend, in turn, to generate a number of misleading findings that have questionable implications for practice. It will be argued that this body of work provides a useful case study in the problems of quantitative research that fails to engage adequately with the substantive theoretical and empirical literature and considers some of the implications of this for future research in this area.
Resumo:
A quantitative research on S and SO2 poisoning Pt/Vulcan carbon (Pt/VC) catalysts for fuel cells was conducted by the three-electrode method. Pt/VC electrodes were contaminated by submersion in a SO2- containing solution made up of 0.2 mM Na2SO3 and 0.5 M H2SO4 for different periods of time, and held at 0.05 V (vs. RHE) in 0.5 M H2SO4 solutions in order to gain zero-valence sulfur (S0) poisoned electrodes. The sulfur coverage of Pt was determined from the total charge consumed as the sulfur was oxidized from S0 at 0.05 V (vs. RHE) to sulfate at >1.1 V (vs. RHE). The summation of initial coverage of S0 (S) and coverage of H (H) are approximately equal to 1 (H + S = 1) when 0.5