Germination and Growth of Native and Invasive Plants on Soil Associated with Biological Control of Tamarisk (Tamarix spp.)

Introductions of biocontrol beetles (tamarisk beetles) are causing dieback of exotic tamarisk in riparian zones across the western United States, yet factors that determine plant communities that follow tamarisk dieback are poorly understood. Tamarisk-dominated soils are generally higher in nutrients, organic matter, and salts than nearby soils, and these soil attributes might influence the trajectory of community change. To assess physical and chemical drivers of plant colonization after beetle-induced tamarisk dieback, we conducted separate germination and growth experiments using soil and litter collected beneath defoliated tamarisk trees. Focal species were two common native (red threeawn, sand dropseed) and two common invasive exotic plants (Russian knapweed, downy brome), planted alone and in combination. Nutrient, salinity, wood chip, and litter manipulations examined how tamarisk litter affects the growth of other species in a context of riparian zone management. Tamarisk litter, tamarisk litter leachate, and fertilization with inorganic nutrients increased growth in all species, but the effect was larger on the exotic plants. Salinity of 4 dS m 1 benefitted Russian knapweed, which also showed the largest positive responses to added nutrients. Litter and wood chips generally delayed and decreased germination; however, a thinner layer of wood chips increased growth slightly. Time to germination was lengthened by most treatments for natives, was not affected in exotic Russian knapweed, and was sometimes decreased in downy brome. Because natives showed only small positive responses to litter and fertilization and large negative responses to competition, Russian knapweed and downy brome are likely to perform better than these two native species following tamarisk dieback

Stochastic Synthetic Data Generation for Electric Net Load and Its Application

The increasing integration of renewable energy in electric power systems focuses attention on realistic representation of ”net load” because it aggregates the information from both demand and the renewable supply side; net load is the remaining demand that must be met by non-renewable resources. However, the net load data is not readily accessible because of cost, privacy, and security concerns. Furthermore, even if historical data is available, multiple stochastic scenarios are often needed for a wide range of power system applications. To address these issues, this paper proposes a stochastic synthetic net load profile generation approach. A seasonal detrending technique is combined with the modified Fractional Gaussian Noise method to deal with the complex multi-periodic seasonal trends in the net load profile. A thorough statistical validation and temporal correlation check are performed to show the quality of the synthetic data. The benefits of the synthetic data are demonstrated by a microgrid energy management problem

Human Rights Litigation Against Corporations After Jesner v. Arab Bank

In this paper, Dr. Reed explores issues of corporate civil liability for human rights violations. The paper analyzes the recent U.S. Supreme Court ruling in Jesner v. Arab Bank where the Court rejected federal subject-matter jurisdiction over corporate defendants under the Alien Tort Statute. The paper then moves beyond the Supreme Court ruling to identify potential legal exposure for corporations outside the Alien Tort Statute

Exploring a Direct Policy Search Framework for Multiobjective Optimization of a Microgrid Energy Management System

With an increasing focus on integration of distributed energy resources, it is likely that microgrids will proliferate globally. Microgrid systems will be expected to achieve multiple stakeholder objectives, motivating the study of microgrid operations using a multiobjective framework. A multiobjective perspective has the potential balance the trade-offs implicit to efficient use of available resources. To address this challenge, this paper proposes a simulation based parametric approach for multiobjective optimization for microgrid energy management. The methodology generates a Pareto-approximate set of control policies, to provide a microgrid controller with diverse alternative strategies for utilizing resources to balance competing objectives. The policies also help to illustrate the complex relationships between the objectives, and the consequences of compromises across performance. The methodology is implemented on a test microgrid and the potential benefits are demonstrated with a set of illustrative case studies

Germination and Growth of Native and Invasive Plants on Soil Associated with Biological Control of Tamarisk (Tamarix spp.)

Introductions of biocontrol beetles (tamarisk beetles) are causing dieback of exotic tamarisk in riparian zones across the western United States, yet factors that determine plant communities that follow tamarisk dieback are poorly understood. Tamarisk-dominated soils are generally higher in nutrients, organic matter, and salts than nearby soils, and these soil attributes might influence the trajectory of community change. To assess physical and chemical drivers of plant colonization after beetle-induced tamarisk dieback, we conducted separate germination and growth experiments using soil and litter collected beneath defoliated tamarisk trees. Focal species were two common native (red threeawn, sand dropseed) and two common invasive exotic plants (Russian knapweed, downy brome), planted alone and in combination. Nutrient, salinity, wood chip, and litter manipulations examined how tamarisk litter affects the growth of other species in a context of riparian zone management. Tamarisk litter, tamarisk litter leachate, and fertilization with inorganic nutrients increased growth in all species, but the effect was larger on the exotic plants. Salinity of 4 dS m 1 benefitted Russian knapweed, which also showed the largest positive responses to added nutrients. Litter and wood chips generally delayed and decreased germination; however, a thinner layer of wood chips increased growth slightly. Time to germination was lengthened by most treatments for natives, was not affected in exotic Russian knapweed, and was sometimes decreased in downy brome. Because natives showed only small positive responses to litter and fertilization and large negative responses to competition, Russian knapweed and downy brome are likely to perform better than these two native species following tamarisk dieback

A new narrow-beam, multi-frequency, scanning radiometer and its application to in-flight icing detection

AbstractA one degree beamwidth, multi-frequency (20 to 30 and 89GHz), dual-polarization radiometer with full azimuth and elevation scanning capabilities was built with the purpose of improving the detection of in-flight icing hazards to aircraft in the near airport environment. This goal was achieved by collocating the radiometer with Colorado State University's CHILL polarized Doppler radar and leveraging the similar beamwidth and volume scan regiments of the two instruments. The collocated instruments allowed for the liquid water path and water vapor measurements derived from the radiometer to be merged with the radar moment fields to determine microphysical and water phase characteristics aloft. The radiometer was field tested at Colorado State University's CHILL radar site near Greeley, Colorado during the summer of 2009. Instrument design, calibration, and initial field testing results are discussed in this paper

Development of Constructed Wetlands for the Reuse of Wastewat r in Semi-Arid Regions

Hill Air Force Base (AFB), UT, is responsible for the operation and maintenance of the Utah Test and Training Range (UTTR). The range contains waste-water treatment and disposal facilities that consist of two infiltration ponds operated in parallel, followed by an emergency overflow basin that safeguards against unexpectedly high flow rates. A previous evaluation concluded that the existing facilities should be replaced, at a relatively high cost and with no possibility for beneficial water reuse. The U.S. Army Construction Engineering Research Laboratories (USACERL) was requested to further evaluate the system and to identify cost-effective, feasible alternatives. USACERL researchers identified a potential process train that included retention of the existing ponds, use of a constructed wetland for further treatment following the ponds, construction of a small basin following the wetland to improve wildlife habitat, and the possibility of pumping treated effluent back to the built-up portion of Hill AFB for reuse as landscape irrigation

On the size-dependent fatigue behaviour of laser powder bed fusion Ti-6Al-4V

A sample size effect which influences the fatigue behaviour of laser powder bed fusion Ti-6Al-4V is identified and quantified. Two cylindrical samples are considered: ∅ 1.3 mm and ∅ 2.0 mm. The larger specimen demonstrates better fatigue resistance particularly in the high-cycle regime, with the differing surface roughness contributing to this effect. It is also confirmed that processing-induced porosity can compromise the fatigue performance even when the initiation sites are surface defects. The larger contribution of porosity to the fatigue fracture process of the larger specimen results in a higher scatter in the fatigue life. Differences in microstructure do not seem to contribute strongly to the variation in fatigue properties of the two specimens, but we present some evidence that the coarser microstructure of the larger specimen promotes a stronger tolerance to defects and induces more tortuous crack paths which hinders fatigue crack growth