Large displacement flows in granular solids occur whenever silos are discharged. Measurements of pressures during flow, combined with visual observations of flow patterns and control tests on the ensiled solids, have revealed several phenomena contributing to pressure variations during flow. Not only are the pressure variations time dependent within a single silo, but significant systematic differences are found between one silo and another, even when the two are superficially identical and contain similar ensiled materials. One serious outcome is that silo pressures are quite unsymmetrical even in symmetrical silos, and this is a most dangerous phenomenon for the safety of the silo structure.

Purpose: Construction is repeatedly criticised for its low productivity based on statistical data that do not represent the output of construction adequately. The purpose of this paper is to improve the understanding of construction output – being the numerator in construction productivity calculations – by focussing on changes in quantity of the products, product characteristics and composition of the aggregate rather than as changes in price. Design/methodology/approach: The research design of this study applies statistical data from the national accounts along with data from four paradigmatic case studies of social housing projects covering a period of 50 years. Findings: The results indicate that while construction output prices have increased threefold over the past 50 years, improvements in performance can only explain approximately 20 per cent. Research limitations/implications: The developed four-step method has demonstrated its value as a means to measure changes in the characteristics of the product, but more studies on the actual figures and results over time and regions are required before solid conclusions can be drawn. Social implications: This study has added new knowledge of construction output that supports the development of a more accurate construction statistics, which in turn can assist the design of more effective and evidence-based policies for improving construction productivity. Originality/value: This paper describes and demonstrates a novel performance-based methodology for addressing changes in the characteristics of the products in a longitudinally perspective, which can potentially provide a better understanding of changes in productivity.

A new species of Barathronus (Ophidiiformes: Aphyonidae) is described from a single, mature male specimen (101 mm SL) bottom trawled on the continental slope of Rio Grande do Norte, northeastern Brazil, between 1,964 and 2,045 m depth. The new species is diagnosed among congeners by the following combination of characters: peritoneum transparent, deep-set eyes not visible, eight fangs on vomer, anal fin rays 69, predorsal length 42.0% SL, preanal length 49.5% SL, penis long, slender, and lacking a pair of lobes at its base, and presence of a ventral flexure of the anterior 2-3 vertebrae. Additionally, morphological data of three specimens of Barathronus bicolor collected in Brazilian waters are presented and compared with those from 51 specimens from the western Central Atlantic.