Thermographic laser Doppler velocimetry using the phase-shifted luminescence of BAM:Eu2+ phosphor particles for thermometry

Simultaneous point measurements of gas velocity and temperature were recently demonstrated using thermographic phosphors as tracer particles. There, continuous wave (CW) excitation was used and the spectral shift of the luminescence was detected with a two-colour intensity ratio method to determine the gas temperature. The conventional laser Doppler velocimetry (LDV) technique was employed for velocimetry. In this paper, an alternative approach to the gas temperature measurements is presented, which is instead based on the temperature-dependence of the luminescence lifetime. The phase-shift between the luminescence signal and time-modulated excitation light is evaluated for single BaMgAl10O17:Eu2+ phosphor particles as they cross the probe volume. Luminescence lifetimes evaluated in the time domain and frequency domain indicate that in these experiments, interferences from in-phase signals such as stray excitation laser light are negligible. The dependence of the phase-shift on flow temperature is characterised. In the temperature sensitive range above 700 K, precise gas temperature measurements can be obtained (8.6 K at 840 K) with this approach

On the use of phosphor thermometry for temperature monitoring in manufacturing processes

In the metalworking industry, continuous monitoring and control of temperature is vital to enhance process efficiency, reduce wastage, and attain product reliability in high-value manufacturing processes. The capabilities of conventional techniques such as the use of thermocouples and infrared thermometry for measuring temperature in these processes are limited. For example, in forging processes, there may be a need for mechanical alteration of the die to accommodate thermocouples for die surface temperature measurements, and with infrared thermometry, knowledge of the emissivity of the surfaces of process components is required for accurate temperature measurements. Given that phosphor thermometry has not previously been used in manufacturing processes, here, we report its potential implementation using the phosphor Mg4FGeO6:Mn for measurements of die surface temperature in a forging press. First, with this phosphor, laboratory trials were conducted to describe the cyclic heating of a die by pre-heated billets, which is a process leading to thermal fatigue that requires monitoring in practical applications. Then, the phosphor thermometry technique was demonstrated for die temperature measurements on a 2100 tonne screw press at the Advanced Forming and Research Centre (AFRC). The results show that phosphor thermometry is a candidate technique that would potentially enable more accurate measurements not possible by other techniques in this manufacturing process

A Framework to Estimate the Potential and Costs for the Control of Fine Particulate Emissions in Europe

This paper presents a methodology for estimating primary PM emissions in Europe and the costs involved to reduce these emissions from the various sources in the European countries. The framework developed is compatible with existing approaches to estimate emissions and costs for SO2, NOx, NH3 and VOC in the RAINS model. Emissions of PM are released from a large variety of sources with significant technical and economic differences. The emission characteristic of the sources is also strongly influenced by country-specific conditions. The method applied considers the crucial parameters and allows sectoral and regional variation. The emissions of particulate matter (PM) in the RAINS model are calculated for three different size classes (i) fine fraction (PM2.5), (ii) coarse fraction (PM10 - PM2.5) and (iii) large particles (PM_>10 mu m). A methodology has been developed to estimate emission control costs of standard technologies under the specific conditions characteristic for the various European countries. Based on the assumption of the general availability of control technologies with equal technical properties and costs, a number of country-specific circumstances (level of technological advancement, installation size distribution, labor costs, etc.) are used to estimate the costs for the actual operation of pollution control equipment. Based on the developed methodology, a first estimate of the PM emissions in Europe was derived for the years 1990, 1995 and 2010. This estimate must be considered as preliminary, since many of the emission factors need revision and update with additional information. The projections for the year 2010 assume full implementation of the current legislation on emission controls, e.g., the EURO-IV emission standards resulting from the Auto Oil process for mobile sources, and regulations relating to the large combustion plant directive of the European Union. Major reductions in PM emissions occurred between 1990 and 1995, mainly because of the economic restructuring in Eastern Europe where many old coal power stations were retired. Between 1990 and 1995, TSP emissions declined by 41 percent; for 2010 a decline of 58 percent is projected. Emission reductions are most efficient for larger particles; for 2010, PM10 is calculated to decline by 56 percent, and PM2.5 by 48 percent. Consequently, fine fraction (PM2.5) will be relatively more important in the future (38 percent of TSP in 2010) compared to 31 percent of TSP in 1990. In 1990, combustion in energy industries, small non-industrial combustion sources, production processes and road transport contributed about 20 percent each to total TSP emissions in the EU-15. In the non-EU countries, small sources and power plants were responsible for more than 30 percent each, while road transport contributed only three percent of TSP. In those countries, small sources (domestic coal and wood combustion) are expected to increase their share to 45 percent in 2010, while in the EU-15 mobile sources will become the most important source category for TSP emissions (45 percent). For PM2.5, mobile sources were the largest contributor in 1990 in the EU-15 countries (31 percent). This share is expected to decline slightly by 2010 (28 percent) due to the strict regulations that were recently introduced. In the non-EU countries, industrial production processes were the largest source of PM2.5 emissions (36 percent), while in 2010 small combustion sources in the domestic sector will dominate (38 percent). The present implementation (version 1.03) of the RAINS PM module on the Internet (www.iiasa.ac.at/~rains/PM/pm-home.html) provides free access to the input data and results to facilitate interaction with national experts

Relationship Reciprocation Modulates Resource Allocation in Adolescent Social Networks: Developmental Effects

Adolescence is characterized as a period of social reorientation toward peer relationships, entailing the emergence of sophisticated social abilities. Two studies (Study 1: N = 42, ages 13–17; Study 2: N = 81, ages 13–16) investigated age group differences in the impact of relationship reciprocation within school-based social networks on an experimental measure of cooperation behavior. Results suggest development between mid- and late adolescence in the extent to which reciprocation of social ties predicted resource allocation. With increasing age group, investment decisions increasingly reflected the degree to which peers reciprocated feelings of friendship. This result may reflect social-cognitive development, which could facilitate the ability to navigate an increasingly complex social world in adolescence and promote positive and enduring relationships into adulthood

The role of ethanol or acetaldehyde in the biosynthesis of ethylene in carnation (Dianthus caryophyllus L.) cv. Yellow Candy

Abstract Carnation (Dianthus caryophyllus L.) cv. Yellow Candy flowers were treated with ethanol solution (4%) in the absence or presence of 1 or 10 mM L-methionine, or ethanol or acetaldehyde solution (0.05%), in the absence or presence of 1 mM aminocyclopropane carboxylic acid (ACC). Spermidine in petals was measured over time in flowers treated with 4% ethanol or distilled water. Ethanol treatment significantly increased vase life by 10 days; methionine had no significant effect. The vase life of ACC-treated flowers was reduced by 4 days, the ethylene climacteric peak advanced by 5 days and ethylene production was increased in comparison with flowers not treated with ACC. In the absence of ACC, ethanol solution significantly increased vase life of carnation cv. Yellow Candy by 5 days and inhibited ethylene production, whereas in the presence of ACC, ethanol neither increased vase life nor inhibited ethylene production. Acetaldehyde also failed to increase vase life of carnation cv. Yellow Candy either in the absence or presence of ACC. There was no difference between spermidine content of ethanol-or distilled water-treated flowers. It was concluded that 4% ethanol failed to inhibit conversion of methionine to S-adenosyl methionine (SAM) because ethanol failed to inhibit production of spermidine. Furthermore, ethanol or acetaldehyde also failed to inhibit conversion of ACC to ethylene

Future air quality in Europe: a multi-model assessment of projected exposure to ozone

In order to explore future air quality in Europe at the 2030 horizon, two emission scenarios developed in the framework of the Global Energy Assessment including varying assumptions on climate and energy access policies are investigated with an ensemble of six regional and global atmospheric chemistry transport models. <br><br> A specific focus is given in the paper to the assessment of uncertainties and robustness of the projected changes in air quality. The present work relies on an ensemble of chemistry transport models giving insight into the model spread. Both regional and global scale models were involved, so that the ensemble benefits from medium-resolution approaches as well as global models that capture long-range transport. For each scenario a whole decade is modelled in order to gain statistical confidence in the results. A statistical downscaling approach is used to correct the distribution of the modelled projection. Last, the modelling experiment is related to a hind-cast study published earlier, where the performances of all participating models were extensively documented. <br><br> The analysis is presented in an exposure-based framework in order to discuss policy relevant changes. According to the emission projections, ozone precursors such as NO<sub>x</sub> will drop down to 30% to 50% of their current levels, depending on the scenario. As a result, annual mean O<sub>3</sub> will slightly increase in NO<sub>x</sub> saturated areas but the overall O<sub>3</sub> burden will decrease substantially. Exposure to detrimental O<sub>3</sub> levels for health (SOMO35) will be reduced down to 45% to 70% of their current levels. And the fraction of stations where present-day exceedences of daily maximum O<sub>3</sub> is higher than 120 μg m<sup>−3</sup> more than 25 days per year will drop from 43% down to 2 to 8%. <br><br> We conclude that air pollution mitigation measures (present in both scenarios) are the main factors leading to the improvement, but an additional cobenefit of at least 40% (depending on the indicator) is brought about by the climate policy

On-Line Temperature Measurement Inside a Thermal Barrier Sensor Coating During Engine Operation

Existing thermal barrier coatings (TBCs) can be adapted enhancing their functionalities such that they not only protect critical components from hot gases but also can sense their own material temperature or other physical properties. The self-sensing capability is introduced by embedding optically active rare earth ions into the thermal barrier ceramic. When illuminated by light, the material starts to phosphoresce and the phosphorescence can provide in situ information on temperature, phase changes, corrosion, or erosion of the coating subject to the coating design. The integration of an on-line temperature detection system enables the full potential of TBCs to be realized due to improved accuracy in temperature measurement and early warning of degradation. This in turn will increase fuel efficiency and will reduce CO 2 emissions. This paper reviews the previous implementation of such a measurement system into a Rolls-Royce jet engine using dysprosium doped yttrium-stabilized-zirconia (YSZ) as a single layer and a dual layer sensor coating material. The temperature measurements were carried out on cooled and uncooled components on a combustion chamber liner and on nozzle guide vanes (NGVs), respectively. The paper investigates the interpretation of those results looking at coating thickness effects and temperature gradients across the TBC. For the study, a specialized cyclic thermal gradient burner test rig was operated and instrumented using equivalent instrumentation to that used for the engine test. This unique rig enables the controlled heating of the coatings at different temperature regimes. A long-wavelength pyrometer was employed detecting the surface temperature of the coating in combination with the phosphorescence detector. A correction was applied to compensate for changes in emissivity using two methods. A thermocouple was used continuously measuring the substrate temperature of the sample. Typical gradients across the coating are less than 1 K/lm. As the excitation laser penetrates the coating, it generates phosphorescence from several locations throughout the coating and hence provides an integrated signal. The study successfully proved that the temperature indication from the phosphorescence coating remains between the surface and substrate temperature for all operating conditions. This demonstrates the possibility to measure inside the coating closer to the bond coat. The knowledge of the bond coat temperature is relevant to the growth of the thermally grown oxide (TGO) which is linked to the delamination of the coating and hence determines its life. Further, the data are related to a one-dimensional phosphorescence model determining the penetration depth of the laser and the emission