Sediment yield in the San Pedro Lake watershed, inferred from sedimentation in the lake, can be related to land use changes shown on aerial photographs taken during the period 1943-1994. In this watershed, which covers 4Á5 km 2 of mountainous terrain in San Pedro County, central Chile, the area of native forest species decreased from 70 per cent in 1943 to 13 per cent in 1994. During this same period, the area of pine plantations increased from 4 to 46 per cent. To study effects of these changes, we took a core from the centre of the lake and estimated sedimentation rates by 210 Pb dating, which we checked with 137 Cs and pine pollen. The results show that sedimentation rate ranged from 5 mg cm À2 a À1 in the late 1800s to 60 mg cm À2 a À1 in the late 1960s. These rates, together with assumptions about the production and delivery of the sediment, give corresponding figures for sediment yields with maximum values close to 1 t ha À1 a À1 . Sediment yield between 1955 and 1994 closely tracks the total land use change that can be detected, irrespective of land use type, on sets of aerial photographs taken four to 18 years apart. However, this measure of land use change, while convenient and successful as a predictor of historical erosion, may be unreliable because it probably excludes many changes that occurred in long intervals between successive photographs.

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In this study, a new biobased isosorbide urethane methacrylic monomer [isosorbide‐derived urethane dimethacrylate (Is‐UDMA)] was evaluated as a replacement for currently used bisphenol A glycerolate dimethacrylate (Bis‐GMA) based dental restorative materials. Dental composites were prepared at different Is‐UDMA and Bis‐GMA concentrations. For these composites, the photocuring kinetics, volumetric shrinkage, viscoelastic properties, water sorption, and solubility were evaluated. The photocuring kinetics, followed by real‐time IR spectroscopy, showed higher double‐bond conversion (DC) values for the formulations containing the Is‐UDMA monomer; the highest DC (82%) was achieved by the formulation prepared with only the Is‐UDMA monomer. The volumetric shrinkage was reduced to 23.7% as compared with the dental resin formulated with Bis‐GMA. The viscoelastic properties of the formulations containing both Is‐UDMA and Bis‐GMA monomers in a 50:50 composition were superior to the rest of the tested formulations, including those prepared with pure polymers. This behavior was explained in terms of a compromise between crosslinking and rigidity (or flexibility) of the resulting polymer network. A preliminary test on microleakage in a dental enamel demonstrated that the new Is‐UDMA monomer is a potential replacement for the Bis‐GMA monomer in dental restorative materials. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44591.

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Vessels produce oily wastewater during evolutions including engine room operations and maintenance, cargo operations, deck machinery operations, washdown, and runoff. Currently, technologies require effluent be gathered in a central tank for treatment or managed through best management practices. Technologies to remove oil include gravity separation, filtration, absorption, coalescing, centrifuging, and flocculation. The majority of the technologies require periodic replacement of treatment materials associated with oil removal. These technologies may lose efficiency due to vessel motion. In this article we introduce a simple, efficient, eco-friendly procedure using readily available materials and equipment for fabricating high-performance magnetic polydimethylsiloxane (PDMS) nanocomposite sponges for oil-water separation. The magnetic sponges are resistant to corrosive chemicals, exhibit high sorption capacities for oils and cleaning agents, and selective sorption for oil from oil-water emulsions. The sponges can be reused multiple times with no signs of deterioration. They are magnetically controllable and will hold position when magnetized, allowing for separations not compromised by vessel motion. The magnetic PDMS nanocomposite sponge(s) provide a promising technology for removing oil from vessel water discharges. 1. Introduction The removal of oil from water discharges is a concern for all vessels. Oil comingling with water discharges may occur at various locations on the vessel during operations and repair evolutions. These occurrences include the following:Engine room repairs and operationsMachinery leakagesEngine room and other bilge accumulationsCargo pumping operationsDeck washdown and drainageCargo gear and deck equipment leakagesCargo and portable cargo handling equipment leakagesScrubber effluent discharges for vessels equipped with SOx scrubbing equipmentAccidental oil discharges Increasing environmental regulations and awareness have resulted in more stringent regulations regarding oil in vessel discharges. Challenges to oil removal from water discharges include a wide variation in oil grades, chemicals used for treatment and maintenance, solids entrainment, and biologic contaminants. Effective treatment of water to reduce onboard quantities may be a challenge depending on the mixture and location of the effluent on board. Use of a common and simple-to-use technology for removal of oil from water discharges is advantageous to the vessel owner. Although one size does not fit all, a simple design with good efficiency and reusability is desirable. Magnetic nanocomposite sponges (MNSs) meet these requirements.