Radiation induces turbulence in particle-laden fluids.

When a transparent fluid laden with solid particles is subject to radiative heating, non-uniformities in particle distribution result in local fluid temperature fluctuations. Under the influence of gravity, buoyancy induces vortical fluid motion which can lead to strong preferential concentration, enhancing the local heating and more non- uniformities in particle distribution. By employing direct numerical simulations this study shows that the described feedback loop can create and sustain turbulence. The velocity and length scale of the resulting turbulence is not known a priori, and is set by balance between viscous forces and buoyancy effects. When the particle response time is comparable to a viscous time scale, introduced in our analysis, the system exhibits intense fluctuations of turbulent kinetic energy and strong preferential concentration of particle

Second generation advanced reburning for high efficiency NO(x) control. Progress report, 1196

This project is designed to develop a family of novel NO{sub x} control technologies, called Second Generation Advanced Reburning (SGAR), which has the potential to achieve 90+% NO{sub x} control in coal fired boilers at a significantly lower cost than Selective Catalytic Reduction. Phase I consists of six tasks: Task 1.1 Project Coordination and Reporting/Deliverables; Task 1.2 Kinetics of Na{sub 2}CO{sub 3} Reactions with Flue Gas Components; Task 1.3 O.l x lO{sup 6}Btu/hr Optimization Studies; Task 1.4 1.0 x 10{sup 6} Btu/hr Process Development Tests; Task 1.5 Mechanism Development and Modeling; and Task 1. 6 Design Methodology and Application. The fourth reporting period (July 1 - September 30, 1996) included both experimental and modeling activities. The bench scale CTT experiments (Task 1.3) were completed. The 1 MMBtu/hr Boiler Simulator Facility (BSF) was prepared for the test program and experiments were conducted using natural gas (NG) as main and reburing fuels (Task 1.4). A few preliminary tests were also performed with coal firing. The results have been reduced and are reported. Initial experimental data were obtained on reactions of sodium promoters (Task 1.2) at the University of Texas in Austin (UT). The kinetic model was extended to include reactions of sulfur and sodium (Task 1.5)

Second Generation Advanced Reburning for High Efficiency NOx Control

This project is designed to develop a family of novel NO{sub x} control technologies, called Second Generation Advanced Reburning (SGAR) which has the potential to achieve 90+ NO{sub x} control in coal fired boilers at a significantly lower cost than Selective Catalytic Reduction. The ninth reporting period in Phase II (October 1-December 31, 1999) included preparation of the 10 x 10{sup 6} Btu/hr Tower Furnace for tests and setting the SGAR model to predict process performance under Tower Furnace conditions. Based on results of previous work, a paper has been prepared and submitted for the presentation at the 28 Symposium (International) on Combustion to be held at the University of Edinburgh, Scotland

Second Generation Advanced Reburning for High Efficiency NO(x) Control.

This project is designed to develop a family of novel NO{sub x} control technologies, called Second Generation Advanced Reburning which has the potential to achieve 90+% NO{sub x} control in coal fired boilers at a significantly lower cost than SCR. The eighth reporting period (July 1 - September 30, 1997) included experimental and final report preparation activities. Experiments on high-temperature reactions of sodium carbonate were completed at the University of Texas in Austin. This study revealed that sodium can affect NO{sub x} concentrations under both fuel-rich and fuel-lean conditions. The engineering design conducted during the previous reporting period was converted into retrofit hardware for the AR-Lean system and initial test results are presented and discussed. All information presented in this report is in summary form since a Draft Final project report was submitted to DOE FETC by July 31, 1997

Magnetic field effects on liquid metal free convection

International audienceWe provide a numerical analysis of three-dimensional free convection of a liquid in a Rayleigh-Bénard configuration,subject to a steady and uniform magnetic field, using the finite volume code Jadim. The influence of the Hartmann andRayleigh numbers are studied. We compare our results to several experimental works. As suggested by previousexperiments, the magnetic field tends to lower the heat transfer at the walls. This is caused by a significant alteration ofthe flow structures, due to the Lorentz force. For slightly overcritical Rayleigh numbers, two-dimensional rolls appearbut the flow structure rapidly becomes three-dimensional as we increase the Rayleigh number. The magnetic field tendsto destroy those structures and the transition to a 3D flow is delayed to higher values of the Rayleigh number, when theHartmann number is increased. We show that the averaged heat transfer at the walls decreases, although it remains ofthe same order of magnitude. However the local structure of heat transfer is altered

A Case Study Exploring Side-Channel Attacks On Pet Wearables

IoT has long since come to the pet industry resulting in a proliferation of data-intensive devices including tracking anything from activity, health, to location. The resulting ‘Internet of Pets’ is generating large volumes of animal data which, due to the close link between the digital profile of companion animals held as pets (e.g., cats and dogs) and their caregivers holds significant security and privacy implications. In this case study we explore the vulnerability of such pet wearables to side-channel attacks, describing our implementation of an electromagnetic attack on a now discontinued dog activity tracker. We show how we were able to successfully exfiltrate data from the device during the Base64 encoding process and discuss what implications this holds for the security of these devices, given the lack of protection that animal data is afforded under extant existing data protection policy and legislation

Second Generation Advanced Reburning for High Eficiency NO(x) Control

This project is designed to develop a family of novel NO{sub x} control technologies, called Second Generation Advanced Reburning which has the potential to achieve 90+% NO{sub x} control in coal fired boilers at a significantly lower cost than SCR. The sixth reporting period (January I - March 31, 1997) included both experimental and modeling activities. New kinetic experimental data for high-temperature decomposition of sodium carbonate were obtained in a flow reactor at the University of Texas in Austin. Pilot scale combustion tests in a 1.0 MMBtu/hr Boiler Simulator Facility were continued with firing coal and using natural gas as reburn fuel. The results demonstrate that over 90% NO control is achievable by injecting one or two N-agents with sodium promoters into the reburning zone and with the overfire air. Advanced reburning technologies does not cause significant byproduct emissions. The AR kinetic model was updated to include chemical reactions of sodium carbonate decomposition. Modeling was conducted on evaluation of the effect of sodium on process kinetics in the rebuming zone. This study revealed that increasing or decreasing radical concentrations in the presence of sodium can significantly affect the reactions responsible for NO reduction under fuel-rich conditions. The effect of mixing time on performance with sodium was also evaluated. Initial activities on engineering design methodology for second generation AR improvements are described

Second Generation Advanced Reburning for High Efficiency NOx Control

This project develops a family of novel Second Generation Advanced Reburning (SGAR) NO{sub x} control technologies, which can achieve 95% NO{sub x} control in coal fired boilers at a significantly lower cost than Selective Catalytic Reduction (SCR). The conventional Advanced Reburning (AR) process integrates basic reburning and N-agent injection. The SGAR systems include six AR variants: (1) AR-Lean--injection of the N-agent and promoter along with overfire air; (2) AR-Rich--injection of N-agent and promoter into the reburning zone; (3) Multiple Injection Advanced Reburning (MIAR)--injection of N-agents and promoters both into the reburning zone and with overfire air; (4) AR-Lean + Promoted SNCR--injection of N-agents and promoters with overfire air and into the temperature zone at which Selective Non-Catalytic Reduction (SNCR) is effective; (5) AR-Rich + Promoted SNCR--injection of N-agents and promoters into the reburning zone and into the SNCR zone; and (6) Promoted Reburning + Promoted SNCR--basic or promoted reburning followed by basic or promoted SNCR process. The project was conducted in two phases over a five-year period. The work included a combination of analytical and experimental studies to confirm the process mechanisms, identify optimum process configurations, and develop a design methodology for full-scale applications. Phase I was conducted from October, 1995 to September, 1997 and included both analytical studies and tests in bench and pilot-scale test rigs. Phase I moved AR technology to Maturity Level III-Major Subsystems. Phase II is conducted over a 45 month period (October, 1997-June, 2001). Phase II included evaluation of alternative promoters, development of alternative reburning fuel and N-Agent jet mixing systems, and scale up. The goal of Phase II was to move the technology to Maturity Level I-Subscale Integrated System. Tests in combustion facility ranging in firing rate from 0.1 x 10{sup 6} to 10 x 10{sup 6} Btu/hr demonstrated the viability of the AR technology. The performance goals of the project to reduce NO{sub x} by up to 95% with net emissions less than 0.06 lb/10{sup 6} Btu and to minimize other pollutants (N{sub 2}O and NH{sub 3}) to levels lower than reburning and SNCR have been met. Experimental data demonstrated that AR-Lean + SNCR and Reburning + SNCR are the most effective AR configurations, followed by AR-Lean and AR-Rich. Promoters can increase AR NO{sub x} reduction efficiency. Promoters are the most effective at small amounts of the reburning fuel (6-10% of the total fuel heat input). Promoters provide the means to improve NO{sub x} reduction and simultaneously decrease the amount of reburning fuel. Tests also showed that alkali-containing compounds are effective promoters of the AR process. When co-injected with N-agent, they provide up to 25 % improvement in NO{sub x} reduction. A detailed reaction mechanism and simplified representation of mixing were used in modeling of AR processes. Modeling results demonstrated that the model correctly described a wide range of experimental data. Mixing and thermal parameters in the model can be adjusted depending on characteristics of the combustion facility. Application of the model to the optimization of AR-Lean has been demonstrated. Economic analysis demonstrated a considerable economic advantage of AR technologies in comparison with existing commercial NO{sub x} control techniques, such as basic reburning, SNCR, and SCR. Particularly for deep NO{sub x} control, coal-based AR technologies are 50% less expansive than SCR for the same level of NO{sub x} control. The market for AR technologies is estimated to be above $110 million

Second Generation Advanced Reburning for High Efficiency NOx Control

This project is designed to develop a family of novel NO{sub x} control technologies, called Second Generation Advanced Reburning (SGAR) which has the potential to achieve 90+% NO{sub x} control in coal-fired boilers at a significantly lower cost than SCR. The twelfth reporting period in Phase II (July 3-October 15, 2000) included design validation AR-Lean tests (Task No.2.6) in the 10 x 10{sup 6} Btu/hr Tower Furnace. The objective of tests was to determine the efficiency of AR-Lean at higher than optimum OFA/N-Agent injection temperatures in large pilot-scale combustion facility. Tests demonstrated that co-injection of urea with overfire air resulted in NO{sub x} reduction. However, observed NO{sub x} reduction was smaller than that under optimum conditions

Myths and misconceptions about hypnosis and suggestion: Separating fact and fiction

We present 21 prominent myths and misconceptions about hypnosis in order to promulgate accurate information and to highlight questions for future research. We argue that these myths and misconceptions have (a) fostered a skewed and stereotyped view of hypnosis among the lay public, (b) discouraged participant involvement in potentially helpful hypnotic interventions, and (c) impeded the exploration and application of hypnosis in scientific and practitioner communities. Myths reviewed span the view that hypnosis produces a trance or special state of consciousness and allied myths on topics related to hypnotic interventions; hypnotic responsiveness and the modification of hypnotic suggestibility; inducing hypnosis; and hypnosis and memory, awareness, and the experience of nonvolition. By demarcating myth from mystery and fact from fiction, and by highlighting what is known as well as what remains to be discovered, the science and practice of hypnosis can be advanced and grounded on a firmer empirical footing