A
bstract
We compute all the tree-level contributions to the Wilson coefficients of the dimension-six Standard-Model effective theory in ultraviolet completions with general scalar, spinor and vector ...field content and arbitrary interactions. No assumption about the renormalizability of the high-energy theory is made. This provides a complete ultraviolet/infrared dictionary at the classical level, which can be used to study the low-energy implications of any model of interest, and also to look for explicit completions consistent with low-energy data.
This paper analyses a CO
2
capture system based on calcium looping, designed for power plants that operate with very low capacity factors and large load fluctuations, including shut-down and start-up ...periods. This can be achieved by decoupling the operation of the carbonator and calciner reactors and connecting them to piles filled with CaO or CaCO
3
. When the power plant enters into operation, calcined solids are fed into the carbonator to provide the necessary flow of CaO for capturing CO
2
and storing the carbonated solids. An oxy-CFB calciner designed to have a modest thermal capacity and operate continuously refills the CaO pile. Mass and energy balances of the entire system, combined with state-of-the-art performance criteria for reactor design, have been solved to identify suitable operating windows. An analysis of the effect of the CaO reactivity of the material stored in the piles indicates that temperatures of around 500-600 °C in the carbonator are compatible with the storage of solids at low temperature (<250 °C). This, together with the low inherent cost of the material, allows large piles of stored material. Electricity costs between 0.13-0.15 $ per kWh
e
are possible for the system proposed in contrast to standard CaL systems where the cost would increase to above 0.19 $ per kWh
e
when forced to operate at low capacity. The proposed concept could be integrated into existing power plants operating as back-ups in renewable energy systems in preference to other CO
2
capture technologies that are heavily penalized when forced to operate under low capacity factors.
This work presents a highly flexible calcium looping CO
2
capture system able to adapt to existing power plants forced to operate under very low capacity factors.
A
bstract
The invariance of physical observables under redefinitions of the quantum fields is a well-known and important property of quantum field theory. We study perturbative field redefinitions in ...effective theories, paying special attention to higher-order effects and their impact on matching to an ultraviolet theory at the classical and quantum levels.
The use of Ca(OH)2 as a CO2 sorbent instead of CaO in calcium looping systems has the advantage of a much faster reaction rate of carbonation and a larger conversion degree to CaCO3. This work ...investigates the carbonation kinetics of fine Ca(OH)2 particles (<10 μm) in a range of reaction conditions (i.e., 350–650 °C and CO2 concentrations up to 25%v) that could be of interest for applications where a short contact time is expected between the solids and the gases (i.e., entrained bed carbonator reactors). For this purpose, experiments in a drop tube reactor with short reaction times (i.e., below 6 s) have been carried out. High carbonation conversions up to 0.7 have been measured under these conditions, supporting the viability of using entrained carbonator reactors. The experimental results have been fitted to a shirking core model, and the corresponding kinetic parameters for the carbonation reaction have been determined.
A
bstract
We study the impact of the leading non-renormalizable terms in the effective field theory that describes general extensions of the Standard Model with vector-like quarks that can decay into ...Standard Model particles. Dropping the usual assumption of renormalizability has several phenomenological consequences for the production and decay of the heavy quarks and also for Higgs physics. The most dramatic effects, including those associated with a long lifetime, occur for vector-like quarks with non-standard quantum numbers.
Introduction: As is known, the effects of extreme temperatures on mortality are characterised by an annual periodicity, with a rise centred in the winter months. The most recent epidemiological ...studies show that mortality caused by cold waves is, in many cases, comparable to that caused by the severest heat waves. This study sought to quantify the rise in mortality due to extreme cold and the factors that determine the relationship between these variables in Castile-La Mancha (Spain). Methods: We examined the effect of extreme winter temperature on daily non accidental cause mortality in Castile — La Mancha from 1975 to 2003, for all ages. Quantitative analyses were performed using ARIMA models, with other covariates, such as influenza, pressure trends, relative humidity, and cold wave duration and chronological number. Results: There were two mortality peaks: a short-term peak (with a lag of 3 to 7 days); and a longer term peak (of under two weeks). Excess mortality during cold waves was around 10% per degree centigrade below the threshold temperature for all the provinces except Guadalajara, where an increase of only 4.61% was detected. Mortality increased in response to rises in cold-wave duration and relative humidity. Cold waves occurring at the end of the “winter” season caused the greatest mortality. Conclusions: This study confirms that daily mortality in Castile — La Mancha increases during cold waves. Efficient cold-wave prevention plans must therefore be implemented. Such plans should be based on in-depth knowledge of the causes that underlie and modulate the relationship between low temperatures and health effects.
All the climate-change studies undertaken to date agree that one of the principal consequences of this phenomenon is the increase in heat waves, which, without exception, are linked to marked rises ...in mortality. The characteristics that modulate and determine the relationship between high temperatures and health must therefore be ascertained in the greatest possible detail, so that really effective prevention plans can be designed to address temperature extremes.
We examined the effect of heat waves on daily non-accidental-cause mortality across all age groups in the Castile-La Mancha region (Spain) from 1975 to 2003. Quantitative analyses were performed using autoregressive integrated moving average (ARIMA) models, with other covariates, such as pressure trends, relative humidity, and duration and chronological number of heat waves.
Mortality increased significantly with respect to the mean, when temperatures exceeded the designated provincial thresholds in Castile-La Mancha. For each degree centigrade that temperatures exceeded these thresholds, the percentage increase in mortality amounted to increases of approximately 12% over the daily mean, albeit with clear provincial variations. The longest heat waves were associated with daily mortality, with those at the end of summer causing the lowest mortality. Meteorological situations most closely associated with increases in mortality were cyclonic conditions accompanied by low humidity.
Spatio-temporal variability in the temperature–mortality relationship must be studied in order to enable really effective heat-wave prevention plans to be drawn up. The influence of variables, such as heat-wave duration or time of appearance, is important in the total increase in mortality during temperature extremes. Since parameters, such as humidity or pressure trends, can play very different roles in different geographical settings, they should be analysed separately from temperature.
► One of the principal consequences of the climate change is the increase in heat waves. ► We examined the effect of heat waves on daily non-accidental-cause mortality in the Castile-La Mancha Region (Spain). ► Mortality increased when temperatures exceeded the designated Castile-La Mancha provincial thresholds and varies by province. ► The longest heat waves were associated with daily mortality and those at the end of summer cause the lowest mortality. ► The percentile at which the heat-wave threshold temperature occurs is inversely proportional to each province's old-age index.
The use of Ca(OH)
as a CO
sorbent instead of CaO in calcium looping systems has the advantage of a much faster reaction rate of carbonation and a larger conversion degree to CaCO
. This work ...investigates the carbonation kinetics of fine Ca(OH)
particles (<10 μm) in a range of reaction conditions (i.e., 350-650 °C and CO
concentrations up to 25%
) that could be of interest for applications where a short contact time is expected between the solids and the gases (i.e., entrained bed carbonator reactors). For this purpose, experiments in a drop tube reactor with short reaction times (i.e., below 6 s) have been carried out. High carbonation conversions up to 0.7 have been measured under these conditions, supporting the viability of using entrained carbonator reactors. The experimental results have been fitted to a shirking core model, and the corresponding kinetic parameters for the carbonation reaction have been determined.
Following the 2003 heat wave, many European countries implemented heat-wave prevention plans. A number of aspects can prove fundamental in determining the effectiveness of such plans, and of these we ...sought to analyse the criteria used to define threshold temperatures and trigger a higher level of intervention.
Retrospective study of the days on which heat-wave thresholds were exceeded during the period 1974–2003 was conducted. We compared when and at what level the heat-wave prevention plan would have been activated using a statistical–meteorological criterion (as applied by the Spanish Ministry of Health & Consumer Affairs) versus a temperature–mortality criterion.
The number of days on which the threshold was exceeded was far higher when the temperature–mortality criterion was applied.
The temperature percentile at which a heat wave occurred was different for each province analysed and was inversely proportional to its respective ageing index.
Using both criteria, there was an increase in heat-wave days per decade.
The establishment of a heat-wave threshold temperature must be based on knowledge of the cause–effect relationship between temperature and the health of a given population. Mortality is an appropriate indicator of population health. The future effects of climate change render it essential for this relationship to be studied on a local scale, so as to enable truly efficient prevention plans to be drawn up.
Some aspects of the time‐spatial variability of the phase speed of the internal bore generated almost every tidal cycle in Camarinal Sill, are revised using a set of high resolution experimental data ...collected in two different positions of the Strait during May 2003. This variability is mainly driven by the intense tidal currents, comparable with the intrinsic propagation velocity of the first mode baroclinic bore. It is shown that the importance of the diurnal tide in the Strait of Gibraltar induces a considerable diurnal inequality on the bore velocity, with an observed maximum difference of 0.7 ms−1 between the speed of two consecutives bores propagating along the eastern part of the Strait. A regularly spatial pattern has been also found: the internal bore reaches its maximum velocity in Tarifa Narrows. A theoretical estimation predicts an extreme phase speed of 2.6 ms−1 during our period of study.
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