Controlled release nanoparticulate matter delivery system

A controlled release nanoparticulate matter delivery system includes a plurality of thermoresponsive modules containing a respective nanoparticulate matter. Each thermoresponsive module is selectively operable in at least one of a heating mode that releases the nanoparticulate matter and a cooling mode that inhibits release of the nanoparticulate matter. A control module is in electrical communication with the plurality of thermoresponsive modules. The control module is configured to determine a temperature of each thermoresponsive module and to select the at least one heating mode and cooling mode based on the temperature. The heating and cooling mode may be selected in response to a desired dosing profile and/or a biometric condition.Board of Regents, University of Texas Syste

I-mode studies at ASDEX Upgrade: L-I and I-H transitions, pedestal and confinement properties

The I-mode is a plasma regime obtained when the usual L-H power threshold is high, e.g. with unfavourable ion B ∇ direction. It is characterised by the development of a temperature pedestal while the density remains roughly as in the L-mode. This leads to a confinement improvement above the L-mode level which can sometimes reach H-mode values. This regime, already obtained in the ASDEX Upgrade tokamak about two decades ago, has been studied again since 2009 taking advantage of the development of new diagnostics and heating possibilities. The I-mode in ASDEX Upgrade has been achieved with different heating methods such as NBI, ECRH and ICRF. The I-mode properties, power threshold, pedestal characteristics and confinement, are independent of the heating method. The power required at the L-I transition exhibits an offset linear density dependence but, in contrast to the L-H threshold, depends weakly on the magnetic field. The L-I transition seems to be mainly determined by the edge pressure gradient and the comparison between ECRH and NBI induced L-I transitions suggests that the ion channel plays a key role. The I-mode often evolves gradually over a few confinement times until the transition to H-mode which offers a very interesting situation to study the transport reduction and its link with the pedestal formation. Exploratory discharges in which n = 2 magnetic perturbations have been applied indicate that these can lead to an increase of the I-mode power threshold by flattening the edge pressure at fixed heating input power: more heating power is necessary to restore the required edge pressure gradient. Finally, the confinement properties of the I-mode are discussed in detail.European Commission (EUROfusion 633053

Connecting the Sun and the Solar Wind: The First 2.5 Dimensional Self-consistent MHD Simulation under the Alfv\'en Wave Scenario

The solar wind emanates from the hot and tenuous solar corona. Earlier studies using 1.5 dimensional simulations show that Alfv\'{e}n waves generated in the photosphere play an important role in coronal heating through the process of non-linear mode conversion. In order to understand the physics of coronal heating and solar wind acceleration together, it is important to consider the regions from photosphere to interplanetary space as a single system. We performed 2.5 dimensional, self-consistent magnetohydrodynamic simulations, covering from the photosphere to the interplanetary space for the first time. We carefully set up the grid points with spherical coordinate to treat the Alfv\'{e}n waves in the atmosphere with huge density contrast, and successfully simulate the solar wind streaming out from the hot solar corona as a result of the surface convective motion. The footpoint motion excites Alfv\'{e}n waves along an open magnetic flux tube, and these waves traveling upwards in the non-uniform medium undergo wave reflection, nonlinear mode conversion from Alfv\'{e}n mode to slow mode, and turbulent cascade. These processes leads to the dissipation of Alfv\'{e}n waves and acceleration of the solar wind. It is found that the shock heating by the dissipation of the slow mode wave plays a fundamental role in the coronal heating process whereas the turbulent cascade and shock heating drive the solar wind.Comment: 7 pages, 7 figures, accepted for publication in Ap

Learning occupants’ indoor comfort temperature through a Bayesian inference approach for office buildings in United States

A carefully chosen indoor comfort temperature as the thermostat set-point is the key to optimizing building energy use and occupants’ comfort and well-being. ASHRAE Standard 55 or ISO Standard 7730 uses the PMV-PPD model or the adaptive comfort model that is based on small-sized or outdated sample data, which raises questions on whether and how ranges of occupant thermal comfort temperature should be revised using more recent larger-sized dataset. In this paper, a Bayesian inference approach has been used to derive new occupant comfort temperature ranges for U.S. office buildings using the ASHRAE Global Thermal Comfort Database. Bayesian inference can express uncertainty and incorporate prior knowledge. The comfort temperatures were found to be higher and less variable at cooling mode than at heating mode, and with significant overlapped variation ranges between the two modes. The comfort operative temperature of occupants varies between 21.9 and 25.4 °C for the cooling mode with a median of 23.7 °C, and between 20.5 and 24.9 °C for the heating mode with a median of 22.7 °C. These comfort temperature ranges are similar to the current ASHRAE standard 55 in the heating mode but 2–3 °C lower in the cooling mode. The results of this study could be adopted as more realistic thermostat set-points in building design, operation, control optimization, energy performance analysis, and policymaking

Radiative heating in the kinetic mode of AGN feedback

AGN feedback is now widely believed to play a crucial role in the co-evolution between the central black hole and its host galaxy. Two feedback modes have been identified, namely the radiative and kinetic modes, which correspond to the luminous AGNs and low-luminosity AGNs (LLAGNs), respectively. In this paper, we investigate the radiative heating in the kinetic mode. This process is potentially important because: 1) the radiation power of LLAGNs is higher than the jet power over a wide parameter range, 2) the spectral energy distribution of LLAGNs is such that the radiative heating is more effective compared to that of luminous AGNs with the same luminosity, and 3) most of the time in the lifecycle of an AGN is spent in the LLAGNs phase. In this paper, adopting the characteristic broad-band spectral energy distributions of LLAGNs, we calculate the value of "Compton temperature" ($T_{\rm c}$), which determines the radiative heating by Compton scattering. We find that $T_{\rm c}\sim (5-15)\times 10^7$ K, depending on the spectrum of individual LLAGN and at which distance from the black hole we evaluate the heating. We also compare this heating process with other radiative heating and cooling processes such as photoionization/recombination. Our result can be used for an accurate calculation of the radiative heating in the study of AGN feedback.Comment: 9 pages, 3 figures, 3 tables. ApJ accepte

Catalytic combustion of actual low and medium heating value gases

Catalytic combustion of both low and medium heating value gases using actual coal derived gases obtained from operating gasifiers was demonstrated. A fixed bed gasifier with a complete product gas cleanup system was operated in an air blown mode to produce low heating value gas. A fluidized bed gasifier with a water quench product gas cleanup system was operated in both an air enriched and an oxygen blown mode to produce low and medium, heating value gas. Noble metal catalytic reactors were evaluated in 12 cm flow diameter test rigs on both low and medium heating value gases. Combustion efficiencies greater than 99.5% were obtained with all coal derived gaseous fuels. The NOx emissions ranged from 0.2 to 4 g NO2 kg fuel

On electron heating in a low pressure capacitively coupled oxygen discharge

We use the one-dimensional object-oriented particle-in-cell Monte Carlo collision code oopd1 to explore the charged particle densities, the electronegativity, the electron energy probability function (EEPF), and the electron heating mechanism in a single frequency capacitively coupled oxygen discharge when the applied voltage amplitude is varied. We explore discharges operated at 10 mTorr, where electron heating within the plasma bulk (the electronegative core) dominates, and at 50 mTorr where sheath heating dominates. At 10 mTorr the discharge is operated in combined drift-ambipolar (DA) and $\alpha$-mode and at 50 mTorr it is operated in pure $\alpha$-mode. At 10 mTorr the effective electron temperature is high and increases with increased driving voltage amplitude, while at 50 mTorr the effective electron temperature is much lower, in particular within the electronegative core, where it is roughly 0.2 - 0.3 eV, and varies only a little with the voltage amplitude

Electron heating mode transitions in dual frequency capacitive discharges

The authors consider electron heating in the sheath regions of capacitive discharges excited by a combination of two frequencies, one much higher than the other. There is a common supposition that in such discharges the higher frequency is the dominant source of electron heating. In this letter, the authors discuss closed analytic expressions quantifying the Ohmic and collisionless electron heating in a dual frequency discharge. In both cases, the authors show that the lower frequency parameters strongly influence the heating effect. Moreover, this influence is parametrically different, so that the dominant heating mechanism may be changed by varying the low frequency current density