Windbreak-Grown Casuarina and Eucalyptus Trees for Unbleached Kraft Pulp

A laboratory-scale evaluation was conducted of juvenile windbreak-grown Casuarina and Eucalyptus trees for kraft pulp production. Test results of unscreened pulp yields, pulp chemical analyses, and handsheet physical properties indicated that windbreak-grown materials are suitable for unbleached kraft pulp. Casuarina gave the best pulp yield and had higher tear strength than Eucalyptus, but both species were superior to kraft pulps from agricultural raw materials such as rice straw and Thymelia, which are currently used in Egypt. For both species, the best kraft pulping schedule tested was a 4:1 liquor-to-wood ratio with 20% active alkali with additional conditions constant. Scanning electron micrographs of handsheets helped explain the observed differences in physical properties between the two species. Mixing of Casuarina and Eucalyptus raw material prior to pulping shows promise for unbleached kraft pulp production

The potential of metering roundabouts: influence in transportation externalities

Roundabouts are increasingly being used on busy arterial streets for traffic calming purposes. However, if one roundabout leg is near a distribution hub, e.g. parking areas of shopping centers, the entry traffic volumes will be particularly high in peak hours. This paper investigated a partial-metering based strategy to reduce traffic-related costs in a corridor. Specifically, the resulting traffic performance, energy, environmental and exposure impacts associated with access roundabouts were studied in an urban commercial area, namely: a) to characterize corridor operations in terms of link-specific travel time, fuel consumption, carbon dioxide and nitrogen oxides emissions, and noise costs; b) to propose an optimization model to minimize above outputs; and c) to demonstrate the model applicability under different traffic demand and directional splits combinations. Traffic, noise and vehicle dynamics data were collected from a corridor with roundabouts and signalized intersections near a commercial area of Guimarães, Portugal. Microscopic traffic and emission modeling platforms were used to model traffic operations and estimate pollutant emissions, respectively. Traffic noise was estimated with a semi-dynamical model. Link-based cost functions were developed based on the integrated modeling structure. Lastly, a Sequential quadratic programming type approach was applied to find optimal timing settings. The benefit of the partial-metering system, in terms of costs, could be up to 13% with observed traffic volumes. The efficiency of the proposed system increased as entering traffic at the metered approaches increased (~7% less costs). The findings let one to quantify metering benefits near shopping areas