14 research outputs found
Development of Models to Simulate Tracer Tests for Characterization of Enhanced Geothermal Systems
A recent report found that power and heat produced from enhanced (or engineered) geothermal systems (EGSs) could have a major impact on the U.S energy production capability while having a minimal impact on the environment. EGS resources differ from high-grade hydrothermal resources in that they lack sufficient temperature distribution, permeability/porosity, fluid saturation, or recharge of reservoir fluids. Therefore, quantitative characterization of temperature distributions and the surface area available for heat transfer in EGS is necessary for the design and commercial development of the geothermal energy of a potential EGS site. The goal of this project is to provide integrated tracer and tracer interpretation tools to facilitate this characterization. This project was initially focused on tracer development with the application of perfluorinated tracer (PFT) compounds, non-reactive tracers used in numerous applications from atmospheric transport to underground leak detection, to geothermal systems, and evaluation of encapsulated PFTs that would release tracers at targeted reservoir temperatures. After the 2011 midyear review and subsequent discussions with the U.S. Department of Energy Geothermal Technology Program (GTP), emphasis was shifted to interpretive tool development, testing, and validation. Subsurface modeling capabilities are an important component of this project for both the design of suitable tracers and the interpretation of data from in situ tracer tests, be they single- or multi-well tests. The purpose of this report is to describe the results of the tracer and model development for simulating and conducting tracer tests for characterizing EGS parameters
Health and social problems associated with recent Novel Psychoactive Substance (NPS) use amongst marginalised, nightlife and online users in six European countries.
Continued diversification and use of new psychoactive substances (NPS) across Europe remains a public health challenge. The study describes health and social consequences of recent NPS use as reported in a survey of marginalised, nightlife and online NPS users in the Netherlands, Hungary, Portugal, Ireland, Germany and Poland (n = 3023). Some respondents were unable to categorise NPS they had used. Use of âherbal blendsâ and âsynthetic cannabinoids obtained pureâ was most reported in Germany, Poland and Hungary, and use of âbranded stimulantsâ and âstimulants/empathogens/nootropics obtained pureâ was most reported in the Netherlands. Increased heart rate and palpitation, dizziness, anxiety, horror trips and headaches were most commonly reported acute side effects. Marginalised users reported substantially more acute side effects, more mid- and long-term mental and physical problems, and more social problems. Development of country-specific NPS awareness raising initiatives, health and social service needs assessments, and targeted responses are warranted
High-energy synchrotron diffraction study of a transformation induced plasticity steel during tensile deformation
Experimental Evaluation of Kinetic and Thermodynamic Reaction Parameters of Colloidal Nanocrystals
The unique properties of colloidal
semiconductor nanocrystals,
or quantum dots, have attracted enormous interest in a wide range
of applications, including energy, lighting, and biomedical fields.
However, widespread implementation is hampered by the difficulty of
developing large-scale and inexpensive synthesis routes, mainly due
to our limited knowledge of formation reaction parameters. We report
here a simple yet powerful method to experimentally determine critically
important reaction parameters such as rate constants, activation barriers,
equilibrium constants and reaction enthalpies. This method was applied
to wurtzite cadmium selenide nanocrystals, yielding activation energies
for growth and dissolution of 14 ± 6 kJ mol<sup>â1</sup> and 27 ± 8 kJ mol<sup>â1</sup>, respectively, and a
reaction enthalpy for nanocrystal growth of â15 ± 7 kJ
mol<sup>â1</sup>. Moreover, the Gibbs free energy for growth
was found to be negative at low temperatures, whereas dissolution
becomes the spontaneous process above 150 °C
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Development of Models to Simulate Tracer Tests for Characterization of Enhanced Geothermal Systems
A recent report found that power and heat produced from enhanced (or engineered) geothermal systems (EGSs) could have a major impact on the U.S energy production capability while having a minimal impact on the environment. EGS resources differ from high-grade hydrothermal resources in that they lack sufficient temperature distribution, permeability/porosity, fluid saturation, or recharge of reservoir fluids. Therefore, quantitative characterization of temperature distributions and the surface area available for heat transfer in EGS is necessary for the design and commercial development of the geothermal energy of a potential EGS site. The goal of this project is to provide integrated tracer and tracer interpretation tools to facilitate this characterization. This project was initially focused on tracer development with the application of perfluorinated tracer (PFT) compounds, non-reactive tracers used in numerous applications from atmospheric transport to underground leak detection, to geothermal systems, and evaluation of encapsulated PFTs that would release tracers at targeted reservoir temperatures. After the 2011 midyear review and subsequent discussions with the U.S. Department of Energy Geothermal Technology Program (GTP), emphasis was shifted to interpretive tool development, testing, and validation. Subsurface modeling capabilities are an important component of this project for both the design of suitable tracers and the interpretation of data from in situ tracer tests, be they single- or multi-well tests. The purpose of this report is to describe the results of the tracer and model development for simulating and conducting tracer tests for characterizing EGS parameters