scholarly journals Expected performances of the Characterising Exoplanet Satellite (CHEOPS)

2020 ◽  
Vol 635 ◽  
pp. A22 ◽  
Author(s):  
A. Deline ◽  
D. Queloz ◽  
B. Chazelas ◽  
M. Sordet ◽  
F. Wildi ◽  
...  
Keyword(s):  
Light Curve ◽  
High Precision ◽  
Background Level ◽  
Monte Carlo Algorithm ◽  
Complete Analysis ◽  
Transiting Planets ◽  
End To End ◽  
Set Up ◽  
The Impact

Context. The characterisation of Earth-size exoplanets through transit photometry has stimulated new generations of high-precision instruments. In that respect, the Characterising Exoplanet Satellite (CHEOPS) is designed to perform photometric observations of bright stars to obtain precise radii measurements of transiting planets. The CHEOPS instrument will have the capability to follow up bright hosts provided by radial-velocity facilities. With the recent launch of the Transiting Exoplanet Survey Satellite (TESS), CHEOPS may also be able to confirm some of the long-period TESS candidates and to improve the radii precision of confirmed exoplanets. Aims. The high-precision photometry of CHEOPS relies on careful on-ground calibration of its payload. For that purpose, intensive pre-launch campaigns of measurements were carried out to calibrate the instrument and characterise its photometric performances. This work reports on the main results of these campaigns. It provides a complete analysis of data sets and estimates in-flight photometric performance by means of an end-to-end simulation. Instrumental systematics were measured by carrying out long-term calibration sequences. Using an end-to end model, we simulated transit observations to evaluate the impact of in-orbit behaviour of the satellite and to determine the achievable precision on the planetary radii measurement. Methods. After introducing key results from the payload calibration, we focussed on the data analysis of a series of long-term measurements of uniformly illuminated images. The recorded frames were corrected for instrumental effects and a mean photometric signal was computed on each image. The resulting light curve was corrected for systematics related to laboratory temperature fluctuations. Transit observations were simulated, considering the payload performance parameters. The data were corrected using calibration results and estimates of the background level and position of the stellar image. The light curve was extracted using aperture photometry and analysed with a transit model using a Markov chain Monte Carlo algorithm. Results. In our analysis, we show that the calibration test set-up induces thermally correlated features in the data that can be corrected in post-processing to improve the quality of the light curves. We find that on-ground photometric performances of the instrument measured after this correction is of the order of 15 parts per million over five hours. Using our end-to-end simulation, we determine that measurements of planet-to-star radii ratio with a precision of 2% for a Neptune-size planet transiting a K-dwarf star and 5% for an Earth-size planet orbiting a Sun-like star are possible with CHEOPS. These values correspond to transit depths obtained with signal-to-noise ratios of 25 and 10, respectively, allowing the characterisation and detection of these planets. The pre-launch CHEOPS performances are shown to be compliant with the mission requirements.

scholarly journals On the relativistic Lagrange-Laplace secular dynamics for extrasolar systems

2014 ◽  
Vol 9 (S310) ◽  
pp. 74-77
Author(s):  
M. Sansottera ◽  
L. Grassi ◽  
A. Giorgilli
Keyword(s):  
Normal Form ◽  
Relativistic Effects ◽  
Secular Dynamics ◽  
Extrasolar Systems ◽  
Term Evolution ◽  
Numerical Integrations ◽  
Long Time ◽  
Set Up ◽  
The Impact

AbstractWe study the secular dynamics of extrasolar planetary systems by extending the Lagrange-Laplace theory to high order and by including the relativistic effects. We investigate the long-term evolution of the planetary eccentricities via normal form and we find an excellent agreement with direct numerical integrations. Finally we set up a simple analytic criterion that allows to evaluate the impact of the relativistic effects in the long-time evolution.

scholarly journals Assessment of the impact of the BN-800 reactor operation on the radionuclides content in local foodstuffs in the vicinity of Beloyarsk NPP

2020 ◽  
Vol 13 (3) ◽  
pp. 38-50
Author(s):  
A. V. Panov ◽  
A. V. Trapeznikov ◽  
N. N. Isamov ◽  
A. V. Korzhavin ◽  
V. K. Kuznetsov ◽  
...  
Keyword(s):  
Specific Activity ◽  
Background Level ◽  
Artificial Radionuclides ◽  
Private Households ◽  
Wide Range ◽  
Continue Research ◽  
Permissible Levels ◽  
Aerosol Emissions ◽  
The Impact

The research results are presented as an analysis of long-term data on the effect of gas-aerosol emissions and liquid discharges of Beloyarsk NPP and the Institute of Reactor Materials on the content of artificial radionuclides in local foodstuffs. It was noted that the distance and directions from radiation-hazardous facilities do not significantly affect the accumulation of 90Sr and 137Cs in potatoes and milk. The investigation of a wide range of foodstuffs from the private households of 23 settlements, forests, rivers, and a reservoir of the 30-km zone of the Beloyarsk NPP influence showed that the operation of the BN-800 reactor since 2016 did not lead to a registered increase in the content of artificial radionuclides in agricultural and natural foodstuffs. The maximum specific activities of 90Sr (0.84 Bq/kg) and 137Cs (0.26 Bq/kg) in root vegetables, potatoes, melons and vegetables were noted before the start of operation of the new power unit and were 45 and 300 times, respectively, lower than the current SanPiN standards. The highest content of 90Sr in milk (0.41 Bq/l) was 60 times lower than the requirements of SanPiN, 137Cs (0.11 Bq/l) was 900 times less than the permissible levels. In poultry, the specific activity of 90Sr (0.2-0.3 Bq/kg) and 137Cs (0.13-0.16 Bq/kg) has remained stable low in recent years, and the standardised content of 137Cs in beef (maximum 0.12 Bq/kg) more than 1.5 thousand times lower than the requirements of SanPiN. The highest concentration of 137Cs in wild berries, found in strawberries (1.27 Bq/kg), was 125 times less than SanPiN standards. The content of 90Sr in mushrooms was at the level of 0.1-2.5 Bq/kg, the content of 137Cs is slightly higher than - 0.6-5.8 Bq/kg. The maximum recorded specific activity of 137Cs in mushrooms was more than 80 times lower than the requirements of SanPiN. During the observation period, a decrease of up to 20% or more in the content of artificial radionuclides in samples of 5 fish species was noted; the maximum levels of 90Sr and 137Cs in it were 14 times lower than the strictest SanPiN standards (using fish for baby food). Selective radiation monitoring of foodstuffs of Beloyarsk NPP area aimed at 3H and 14C showed that the content of these radionuclides in foodstuffs was low, close to the background level. In agricultural products, 3H and 14C accumulated to a greater extent in potatoes and milk, and in natural products – in rough boletus and bream. There was noted a need to continue research on the accumulation of 3H and 14C in foodstuffs of Beloyarsk NPP vicinity.

scholarly journals Will Green Finance Contribute to a Green Recovery? Evidence From Green Financial Pilot Zone in China

2021 ◽  
Vol 9 ◽  
Author(s):  
Jun Hu ◽  
Juncheng Li ◽  
Xiangyu Li ◽  
Yueyue Liu ◽  
Wenwei Wang ◽  
...  
Keyword(s):  
Eastern Region ◽  
Finance Reform ◽  
Long Run ◽  
Green Finance ◽  
Implementation Effect ◽  
Development Levels ◽  
Set Up ◽  
The Impact ◽  
Micro Enterprises

In the post-epidemic era, green finance plays a more significant role in supporting the “green recovery” of the economy, so it is necessary to evaluate the implementation effect of previous green financial policies. In 2017, the green finance reform and innovation pilot zone set up in five provinces and autonomous regions made an exploration in the development of green finance. From the perspective of micro-enterprises, can this policy play a beneficial policy effect in the long run? Based on the quasi-natural experiment of green finance pilot, using the data of A-share listed companies, this paper empirically tests the impact of pilot policies on the long-term value of green enterprises in pilot areas. It is found that, compared with non-pilot zones, the green finance pilot enables a significant increase in the Tobin Q-measured value of green enterprises in the pilot zones. Heterogeneity analysis shows that green finance pilot has a more significant impact on non-state-owned enterprises, enterprises in traditional industries, large enterprises, and enterprises in the eastern region of China. Green finance pilot zone can achieve better policy effects in areas with stronger environmental impact regulation and higher financial development levels. The mechanism test shows that the green finance pilot affects the long-term value of green enterprises through the capital market effect improving the stock trading activity of enterprises and through the real effect improving the operational efficiency and profitability of enterprises. From the perspective of micro-enterprises, this paper enriches the research on the development effect of green finance and provides theoretical support for the effect evaluation of green finance pilot policies.

Photometric results of the long-term monitoring of the active asteroid (596) Scheila

2020 ◽  
Author(s):  
Zhong-Yi Lin ◽  
Chen-Yen Hsu
Keyword(s):  
Light Curve ◽  
Rotation Period ◽  
Impact Event ◽  
Mean Values ◽  
Photometric Observations ◽  
The Mean ◽  
The Difference ◽  
The Impact ◽  
Term Monitoring

<p>(596) Scheila was observed to have an active appearance as a result of impact event in late 2010. In additional the coma feature, the shape of light curve had been found the difference probably fresh material or surface properties changed around the impact site. In this study, we present the results of our monitoring observations obtained in 2014 and 2019-2020. The mean values of the color indices (B−V = (0.75 ± 0.08)<sup>m</sup>, V−R = (0.45 ± 0.04)<sup>m</sup>, and R−I = (0.44 ± 0.09)<sup>m</sup>) agree well with the values for asteroids of the D-types. The rotation period of the asteroid estimated from photometric observations in 2014 is 15.8 ± 0.1 h. The shape of the light curve is similar as that found after impact event. Furthermore, we did not find any rotational color variability in B-V, V-R and R-I diagrams, meaning the observed surface in this observing period of 2019-2020 is homogeneous.</p>

scholarly journals Increased grazing drives homogenisation but reduced grazing increases turnover in upland habitat mosaics

2021 ◽  
Author(s):  
Robin J. Pakeman ◽  
Debbie A. Fielding
Keyword(s):  
Large Scale ◽  
Grazing Intensity ◽  
Sheep Grazing ◽  
Species Replacement ◽  
Habitat Mosaics ◽  
Trade Offs ◽  
Set Up ◽  
Original Species ◽  
The Impact

AbstractMany ecosystems are grazed by livestock or large, wild herbivores and exist as mosaics of different vegetation communities. Changing grazing could have an impact on heterogeneity as well as on composition. A long-term, large-scale grazing experiment that maintained existing low-intensity sheep grazing, tripled it, removed it and partially substituted sheep grazing by cattle grazing was set up on a mosaic of upland vegetation types. The impact of changing grazing regimes was assessed in terms of changes in temporal and spatial species and functional beta diversity. Removal of grazing had the highest impact on species replacement, whilst increased grazing was closest to maintaining the original species complement. Wet heath and Molina mire had the lowest turnover, but wet heath showed the highest changes in unidirectional abundance as it contained species capable of increasing in abundance in response to changing grazing intensity. Agrostis-Festuca and Nardus grasslands displayed the highest level of balanced species replacement reflecting their more dynamic vegetation. In functional terms, there was no clear separation of communities based on their grazing preference, all were relatively resistant to change but Nardus grassland was the most resistant to the removal of grazing. The increased offtake associated with increased grazing led to a degree of homogenisation as grazing tolerant species associated with preferred communities increased in the unpreferred ones. Decisions about grazing management of the uplands involve many trade-offs, and this study identified potential trade-offs between stability and homogenisation to add to existing ones on the biodiversity of different groups of species and on ecosystem services.

scholarly journals Cumulative Effects of Chemical Spills Using a Spatial Temporal Dynamics Analysis Algorithm

2021 ◽  
Author(s):  
Mihaela Dimca-Panaitescu
Keyword(s):  
Temporal Dynamics ◽  
Cumulative Effects ◽  
Long Term Effects ◽  
Environmental Properties ◽  
Chemical Spills ◽  
History Of ◽  
Set Up ◽  
Event Based ◽  
The Impact

The increasing number of accidents involving chemical spills demands development of not only feasible emergency strategies, but also a consistent framework to protect the environment and prevent accidents. This can be possible only by a sound understanding of the environmental impact of spills and their potential long-term effects. Furthermore, the impact assessment of chemical spills can not be done disregarding the spatial-temporal pattern of previous exposures reciprocally influenced by both chemical and environmental properties. In this context, the thesis proposes a general framework to quantify the cumulative effects of chemical spills at any given point of a certain area based on a “present” history of exposure coupled with chemical and environmental properties designated as relevant to predict possible pictures o f future exposure and estimate in advance potential alarming levels of pollution. To achieve this purpose, the following objectives are set up. The first objective is to develop a four-dimensional model to simulate a single-spill event based on certain assumptions about chemical and soil characteristics. The second objective is to develop an algorithm to assess the cumulative effects of chemical spills on a selected area using the model for a single-spill event while taking into account the effects of those spills of the spatial-temporal zone adjacent to the study area.

SEZs alone will not reduce poverty in Mexico

2016 ◽  
Keyword(s):  
Special Economic Zones ◽  
Federal Law ◽  
Content Type ◽  
Industrial Corridor ◽  
Set Up ◽  
Economic Zones ◽  
The Impact ◽  
Sensitive Issues ◽  
Lazaro Cardenas

Subject The challenges facing special economic zones. Significance The Federal Law of the Special Economic Zones (SEZs) entered into force on June 1. SEZs are to be set up in Lazaro Cardenas (Michoacan), Puerto Chiapas (Chiapas), the trans-Tehuantepec Isthmus industrial corridor joining Coatzacoalcos (Veracruz) with Salina Cruz (Oaxaca), and the oil corridor between Campeche and Tabasco. The first anchor companies in each zone are to be established by 2018. Impacts Poor economic growth for the foreseeable future will limit the impact of the SEZs. Promises that the SEZs will be operating by 2018, an electoral year, could lead to rushed implementation, risking long-term sustainability. Political capital from the SEZs will be constrained by public frustration with other sensitive issues such as corruption and crime.

Vibration Tests of the Processing Shaft Cascading Structure in High Speed and High Precision PCB Drilling Machine

2012 ◽  
Vol 246-247 ◽  
pp. 1263-1267
Author(s):  
Feng Gong ◽  
Yan Ping Tan ◽  
Ji Bin Li
Keyword(s):  
High Precision ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Drilling Machine ◽  
Guide Rail ◽  
Basic Part ◽  
Free Mode ◽  
Set Up ◽  
Vibration Tests ◽  
The Impact

It is necessary to study the dynamic characteristics of the structure of processing shaft cascade in high speed and high precision PCB drilling machine because of its great impact on the drilling precision. As a basic part, the dynamic characteristics of the structure of cascade depend on the dynamic characteristics of the Z-axis floor. Based on it, firstly, the free mode test is conducted on the Z-axis floor, the same as the modes that it is just set up on the guide rail, the cascade is added and the motor spindle has been added on the Z-axis floor. From the four situations, the modal pa-rameters are gained in the tests. Then the ODS test is carried out and the vibration is analyzed in the real situation. The vibration tests of the cascade comprehensively acquire dynamic characteristics from the Z-axis floor before being assembled to the Z-axis floor which is entirely cascaded on the Z axis. Acknowledge of the impact that the vibrations bring to the drilling precision of the drilling machine provides the direction of improving the structure.

scholarly journals Differences in water balance between grassland and forest watersheds using long-term data, derived using the CoupModel

2017 ◽  
Vol 49 (1) ◽  
pp. 72-89 ◽  
Author(s):  
Erik MirHadi Madani ◽  
Per Erik Jansson ◽  
Ian Babelon
Keyword(s):  
Water Balance ◽  
Forest Cover ◽  
Land Use Changes ◽  
Daily Basis ◽  
Discharge Data ◽  
Forest Watersheds ◽  
Set Up ◽  
Similar Good ◽  
The Impact

Abstract To quantify the role of land cover during a period of climate change, the runoff response is studied for Plynlimon in Wales, UK. The main objective was two-fold: (i) to create a protocol for modeling water balance on a daily basis; and (ii) to describe the extent to which the impact of land-use changes can be identified and supported by the long-term monitoring data of runoff from two neighboring watersheds with different land covers. The process-oriented CoupModel platform was used to set up the model with a well-defined uncertainty for selected parameters. The behavioral ensembles were applied to simulated daily discharge data for the period of 1992–2010 using subjective criteria to reduce the prior 35,000 candidates with a random uniform distribution of 40 parameters. The accepted ensemble was reduced to 100 candidates by accepting the best root-mean-square error (RMSE) on the accumulated residuals during the simulation period. Similar good performance for the entire period and both watersheds was obtained. The differences in interception evaporation accounted for the most important differences between forest and grassland. The obtained residual demonstrated that changes in the forest cover had an impact on the water balance during the first part of the simulation period.

scholarly journals The BBC Persian Service and the Islamic Revolution of 1979

2010 ◽  
Vol 3 (2) ◽  
pp. 216-241 ◽  
Author(s):  
Annabelle Sreberny ◽  
Massoumeh Torfeh
Keyword(s):  
Islamic Republic ◽  
World War ◽  
Television Channel ◽  
The Us ◽  
Foreign Office ◽  
Heated Debate ◽  
Set Up ◽  
The Impact ◽  
Oil Company

AbstractThis paper is the second part of a work in progress that examines the impact of seventy years of BBC Persian broadcasts to Iran. The Persian Service, established in December 1940, was originally set up by the Foreign and Commonwealth Office (FCO) as one of thirty-eight language services broadcasting to strategically important areas of the world during World War Two. The first piece of research looked at three historic moments when the influence of BBC Persian broadcasts was hotly debated: the toppling of the pro-German Shah of Iran, Reza Pahlavi, in 1941; the late 1940s, when Iran's nationalist leader, Mohammad Mossadeq, championed oil nationalization and challenged the rights hitherto enjoyed by the Anglo-Iranian Oil Company; and the US-led coup of 1953 that returned the young Mohammad Reza Pahlavi to the throne. The present research focuses on a period that many Iranians consider the most influential in terms of all BBC broadcasts to Iran. The BBC Persian Service (BBCPS) became a household name during 1978, the year leading up to the revolution of 11 February 1979. Many Iranians at home and abroad tuned in to hear the latest news and developments, even as the Shah of Iran accused the BBC of fomenting revolution, an argument echoed thirty years later in the responses of the Islamic Republic to the launch of the new Persian television channel in January 2009. The research shows clearly how difficult it had become for the FCO to uphold the independence of the BBC and support their closest friend in the region when he believed that the British government must be in charge. There was indeed heated debate and discussion inside the Foreign Office as to whether Britain was sacrificing its long-term interests by allowing the BBC to continue its broadcasts when even the British ambassador in Tehran was suggesting the service should be closed down.

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