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This paper describes a dynamic price mechanism to coordinate eletric power generation from micro Combined Heat and Power (micro-CHP) systems in a network of households. It is assumed that the households are prosumers, i.e. both producers and consumers of electricity. The control is done on household level in a completely distributed manner. Avoiding a centralized controller both eases computation complexity and preserves communication structure in the network. Local information is used to decide to turn on or off the micro-CHP, but through price signals between the prosumers the network as a whole operates in a cooperative way.

Tephra layers with Icelandic provenance have been identified across the North Atlantic region in terrestrial, lacustrine, marine and glacial environments. These tephra layers are used as marker horizons in tephrochronology including climate studies, archaeology and environmental change. The major element chemistries of 19 proximally deposited Holocene Icelandic silicic tephra layers confirm that individual volcanic systems have unique geochemical signatures and that eruptions from the same system can often be distinguished. In addition, glass trace element chemistry highlights subtle geochemical variations between tephra layers which appear to have identical major element chemistry and thus allows for the identification of some, if not all, tephra layers previously considered identical in composition. This paper catalogues the compositional variation between the widespread Holocene Icelandic silicic tephra deposits. [ABSTRACT FROM AUTHOR]

The U.S. Corn Belt is highly productive with respect to grain and livestock commodities but often neglects to deliver other benefits such as soil stability, nutrient retention, and clean water. New precision technologies and conservation planning frameworks offer opportunities to adapt the current agricultural system to meet environmental goals along with production by strategically placing best management practices (BMPs) to target and address specific in‐field resource concerns. To understand farmers' and farmland owners' willingness to participate in such targeting schemes, we conducted in‐depth interviews with 18 farmers and farmland owners whose fields were targeted for soil and nutrient loss in two watersheds in central Iowa. We examined their current application of BMPs and opportunities and constraints to further adoption. We found that farmers and farmland owners often recognized the importance of producing a diverse suite of on‐ and off‐farm environmental benefits but lacked the context, information, certainty, and strong incentives to manage for them. Interviewees were generally receptive to using technologies to target BMPs to areas with resource concerns but expressed concerns about applications on their own land. They specifically perceived challenges related to cost, management complexity, coordination with government programs, and loss of autonomy. For broad acceptance, a spatially targeted conservation approach would need to be paired with expanded partnerships, trusted technical service, and adaptation incentives to reduce farm‐level economic trade‐offs. Key Points: We examine factors that could influence the application of spatial targeting for soil conservation and water quality in the U.S. Corn BeltInterviewees expressed general support of spatial targeting but expressed concern when their own fields were identified for conservationFuture application of spatial targeting will require collaborative partnerships and adaptive incentives to overcome present barriers [ABSTRACT FROM AUTHOR]

We have performed viscosity and dynamic light scattering measurements on the system 3-methylpyridine, water, and heavy water. This system displays a closed-loop coexistence curve which shrinks with increasing H2O/D2O ratio until the upper and lower consolute points merge at a double critical point. Our measurements were performed to study critical phenomena in this mixture in both the phase-separating and non-phase-separating regimes. We have found that the correlation length derived from our measurements diverges in both regimes with a power-law dependence on temperature relative to the double critical point temperature. The power-law exponent was double that usually found in ising-like liquid systems when the system was asymptotically far from the double critical point. Implications of this work for other non-phase-separating yet nonideal systems is discussed. [ABSTRACT FROM AUTHOR]

Basalt eruptions at Grímsvötn volcano, Iceland, are generally of low intensity; however, occasionally, an order of magnitude larger eruptions occur. In order to discuss the reasons for this difference, the degassing budget of S and Cl and crystallization conditions of the eruptive magma were determined from volatile concentration measured in melt inclusion (MI) and groundmass glass and thermobarometry, respectively. Tephra of two of the largest historical eruptions (2011 and 1873) and two much smaller eruptions (2004 and 1823) were investigated. Sulfur and Cl concentrations are higher in groundmass glass of the smaller eruptions due to incomplete outgassing caused by melt quenching in contact with glacial water. Sulfur concentration and degassing budget correlate with erupted magma volumes. Higher volatile concentrations of MI from the larger eruptions reflect important recharge of gas-rich magma from depth. The recharge causes a high-magnitude eruption followed by increased eruption frequency over the following decades. Pressure and temperature estimates of crystallization are obtained through equilibrium clinopyroxene-glass pairs, where crystals adjacent to, and in textural equilibrium with, both groundmass glass and that of MI were measured. An average crystallization pressure of 4 ± 1 kbar corresponding to approximately 15 ± 5 km depth was obtained together with a considerable temperature range, 1065-1175°C. Similar crystallization depths are obtained for the basalt of the 2014-2015 Bárðarbunga rifting event and to a low resistivity layer revealed by magnetotelluric surveys. Therefore, an important magma storage depth is inferred at lower crustal depth above the center of the Iceland mantle plume. [ABSTRACT FROM AUTHOR]

In this paper, wake interaction resulting from two stall regulated turbines aligned with the incoming wind is studied experimentally and numerically. The experimental work is based on a full-scale remote sensing campaign involving three nacelle mounted scanning lidars. A thorough analysis and interpretation of the measurements is performed to overcome either the lack of or the poor calibration of relevant turbine operational sensors, as well as other uncertainties inherent in resolving wakes from full-scale experiments. The numerical work is based on the in-house EllipSys3D computational fluid dynamics flow solver, using large eddy simulation and fully turbulent inflow. The rotors are modelled using the actuator disc technique. A mutual validation of the computational fluid dynamics model with the measurements is conducted for a selected dataset, where wake interaction occurs. This validation is based on a comparison between wake deficit, wake generated turbulence, turbine power production and thrust force. An excellent agreement between measurement and simulation is seen in both the fixed and the meandering frame of reference. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In the present paper, single-wake dynamics have been studied both experimentally and numerically. The use of pulsed lidar measurements allows for validation of basic dynamic wake meandering modeling assumptions. Wake center tracking is used to estimate the wake advection velocity experimentally and to obtain an estimate of the wake expansion in a fixed frame of reference. A comparison shows good agreement between the measured average expansion and the Computational Fluid Dynamics (CFD) large eddy simulation-actuator line computations. Frandsen's expansion model seems to predict the wake expansion fairly well in the far wake but lacks accuracy in the outer region of the near wake. An empirical relationship, relating maximum wake induction and wake advection velocity, is derived and linked to the characteristics of a spherical vortex structure. Furthermore, a new empirical model for single-wake expansion is proposed based on an initial wake expansion in the pressure-driven flow regime and a spatial gradient computed from the large-scale lateral velocities, and thus inspired by the basic assumption behind the dynamic wake meandering model. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Dyspnoea, a much less specific symptom of ischaemia than chest discomfort, is common among obese patients. Patients with dyspnoea often undergo stress testing as part of their evaluation. We sought to examine the yield of stress testing in non-elderly, obese, sedentary patients with dyspnoea on exertion ( DOE) as a chief complaint.We reviewed stress echocardiograms carried out on 203 patients in a stress testing laboratory at a major tertiary care centre. Of these, 81 (40%) fell into a group that was at low risk for coronary artery disease ( CAD) by clinical criteria. Ischaemia was detected in two patients in the low-risk group (2.5%), and these results were likely false positives. In the higher risk group, 9.0% of functional tests showed ischaemia; after further testing, 2.5% of the higher risk patients were found to have obstructive coronary lesions. Clinical follow-up was performed for a mean of 815 days. New obstructive coronary disease was detected in 1.6% of all patients, and these patients were from the higher risk group. In obese sedentary patients with DOE but otherwise at low risk of coronary disease stress testing is of very low yield. DOE is generally not an anginal equivalent in this patient population. [ABSTRACT FROM AUTHOR]

The article discusses a plan for monitoring how soil and water conservation practices are being maintained. Topics covered include the aspects of the social monitoring plan, a step-by-step guide in the development of the plan, a detailed explanation of each step and a list of questions that may provide key information. Also presented are tables and templates that can be used in the monitoring plan.

An x-ray streak camera platform has been characterized and implemented for use at the National Ignition Facility. The camera has been modified to meet the experiment requirements of the National Ignition Campaign and to perform reliably in conditions that produce high electromagnetic interference. A train of temporal ultra-violet timing markers has been added to the diagnostic in order to calibrate the temporal axis of the instrument and the detector efficiency of the streak camera was improved by using a CsI photocathode. The performance of the streak camera has been characterized and is summarized in this paper. The detector efficiency and cathode measurements are also presented. [ABSTRACT FROM AUTHOR]

The ice nucleation ability of volcanic ash particles collected close to the Icelandic volcano Eyjafjallajökull during its eruptions in April and May 2010 is investigated experimentally, in the immersion and deposition modes, and applied to atmospheric conditions by comparison with airborne measurements and microphysical model calculations. The number of ash particles which are active as ice nuclei (IN) is strongly temperature dependent, with a very small minority being active in the immersion mode at temperatures of 250-263 K. Average ash particles show only a moderate effect on ice nucleation, by inducing freezing at temperatures between 236 K and 240 K (i.e. approximately 3-4 K higher than temperatures required for homogeneous ice nucleation, measured with the same instrument). By scaling the results to aircraft and lidar measurements of the conditions in the ash plume days down wind of the eruption, and by applying a simple microphysical model, it was found that the IN active in the immersion mode in the range 250-263 K generally occurred in atmospheric number densities at the lower end of those required to have an impact on ice cloud formation. However, 3-4 K above the homogeneous freezing point, immersion mode IN number densities a few days down wind of the eruption were sufficiently high to have a moderate influence on ice cloud formation. The efficiency of IN in the deposition mode was found to be poor except at very cold conditions (<238K), when they reach an efficiency similar to that of mineral dust with the onset of freezing at 10% supersaturation with respect to ice, and with the frozen fraction nearing its maximum value at a supersaturation 20%. In summary, these investigations suggest volcanic ash particles to have only moderate effects on atmospheric ice formation. [ABSTRACT FROM AUTHOR]

The article presents a study that evaluates the triggering mechanism for the 2010 summit euption at Eyjafjallajökull volcano in South Iceland. It suggests that detailed sampling during the entire eruption was essential for deciphering the complex magmatic processes at play, namely the dynamic magma mixing. It indicates that the rapid compositional changes in the eruptive products suggest that magma mingling occurs on a timescale of few hours to days.

The article presents the study on the remobilization of silicic intrusion by mafic magmas caused by the 2010 eruption of Eyjafjallajökull volcano in South Iceland. The study states that the change in magma composition suggests binary mixing process with changing end-member compositions and proportions. The study also mentions that magnesium (mg)-rich basalt was the caused of the volcanic eruption in 2010.

The article presents a study which describes the processing of data from the Global Navigation Satellite System Receiver for Atmospheric Sounding (GRAS) instrument on the Metop-A satellite. It mentions that GRAS is an instrument for the radio occultation (RO) sounding of the Earth's atmosphere, and gathers data from Global Positioning System (GPS) satellite constellation. It notes that the data from GRAS still have error characteristics, indicating a negative bias.

On April 14, 2010, when meltwaters from the Eyjafjallajökull glacier mixed with hot magma, an explosive eruption sent unusually fine-grained ash into the jet stream. It quickly dispersed over Europe. Previous airplane encounters with ash resulted in sandblasted windows and particles melted inside jet engines, causing them to fail. Therefore, air traffic was grounded for several days. Concerns also arose about health risks from fallout, because ash can transport acids as well as toxic compounds, such as fluoride, aluminum, and arsenic. Studies on ash are usually made on material collected far from the source, where it could have mixed with other atmospheric particles, or after exposure to water as rain or fog, which would alter surface composition. For this study, a unique set of dry ash samples was collected immediately after the explosive event and compared with fresh ash from a later, more typical eruption. Using nanotechniques, custom-designed for studying natural materials, we explored the physical and chemical nature of the ash to determine if fears about health and safety were justified and we developed a protocol that will serve for assessing risks during a future event. On single particles, we identified the composition of nanometer scale salt coatings and measured the mass of adsorbed salts with picogram resolution. The particles of explosive ash that reached Europe in the jet stream were especially sharp and abrasive over their entire size range, from submillimeter to tens of nanometers. Edges remained sharp even after a couple of weeks of abrasion in stirred water suspensions. [ABSTRACT FROM AUTHOR]

The article presents a study which examines the Global Navigation Satellite System Receiver for Atmospheric Sounding (GRAS) instrument for radio occultation (RO) sounding of the Earth's atmosphere. The GRAS instrument was launched by the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) on-board of the Metop-A stellite. Comparison of data from the GRAS and Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) are highlighted.