scholarly journals L2-CalSat: A Calibration Satellite for Ultra-Sensitive CMB Polarization Space Missions

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3361
Author(s):  
Francisco J. Casas ◽  
Enrique Martínez-González ◽  
Juan Bermejo-Ballesteros ◽  
Sergio García ◽  
Javier Cubas ◽  
...  
Keyword(s):  
Precise Measurement ◽  
Reference Signal ◽  
Space Missions ◽  
Microwave Background ◽  
Polarization Component ◽  
Cmb Polarization ◽  
Before And After ◽  
Huge Impact ◽  
Technological Developments ◽  
New Generation

In this work, the use of a calibration satellite (L2-CalSat) flying in formation with a Cosmic Microwave Background (CMB) polarization mission in an orbit located at the second Lagrange point, is proposed. The new generation of CMB telescopes are expected to reach unprecedented levels of sensitivity to allow a very precise measurement of the B-mode of polarization, the curl-like polarization component expected from gravitational waves coming from Starobinski inflationary models. Due to the CMB polarized signal weakness, the instruments must be subjected to very precise calibration processes before and after launching. Celestial sources are often used as external references for calibration after launch, but these sources are not perfectly characterized. As a baseline option, L2-CalSat is based on the CubeSat standard and serves as a perfectly known source of a reference signal to reduce polarization measurements uncertainty. A preliminary design of L2-CalSat is described and, according to the scanning strategy followed by the telescope, the influence of the relative position between the spacecrafts in the calibration process is studied. This new calibration element will have a huge impact on the performance of CMB space missions, providing a significant improvement in the measurements accuracy without requiring new and costly technological developments.

scholarly journals Craftsmen, Artillery, and War Production in Renaissance Florence

Vulcan ◽  
2016 ◽  
Vol 4 (1) ◽  
pp. 1-26
Author(s):  
Fabrizio Ansani
Keyword(s):  
Cast Iron ◽  
Military Officers ◽  
State Archive ◽  
Significant Growth ◽  
Leading Role ◽  
Before And After ◽  
Technological Developments ◽  
Renaissance Florence ◽  
War Production ◽  
Public Demand

This article examines technological developments in the production of weapons, especially firearms, during the Florentine Quattrocento, from the early conflicts against the Visconti (1423–1433) until the first years of the Pisan War (1494–1499). The aim is an analysis of the qualitative standards achieved by gunmakers and gunpowder makers before and after the appearance and the assimilation of the most efficient French ordnance into Italian warfare. Data have been collected from the State Archive of Florence. Fiscal sources (catasto, decima) and the documentation of guilds (fabbri and speziali) provided the information on craftsmen and their workshops. The registers of military officers (Dieci di Balìa and Otto di Pratica) show the leading role that public demand played in the introduction of technical changes and innovative tools such as new furnaces, bronze cannons, cast iron shot, and corned powder. The same records provide information about the spread of innovations and the migration of artisans. The results of the research demonstrate that the commune actually enhanced its management of war production, fostering improvements in the fabrication of firearms and a significant growth in the weapons market. Numerous artisans were employed in manufacturing munitions and in supplying soldiers and fortresses, and some famous artists, such as Andrea del Verrocchio, may have been involved in casting beautiful firearms for the Florentine Republic in this period.

scholarly journals Thermal and radiation driving can produce observable disc winds in hard-state X-ray binaries

2020 ◽  
Vol 492 (4) ◽  
pp. 5271-5279 ◽  
Author(s):  
Nick Higginbottom ◽  
Christian Knigge ◽  
Stuart A Sim ◽  
Knox S Long ◽  
James H Matthews ◽  
...  
Keyword(s):  
Black Hole ◽  
Binary Systems ◽  
Velocity Structure ◽  
Spectral Energy ◽  
X Ray ◽  
Black Hole Binaries ◽  
Soft State ◽  
Before And After ◽  
Hard State ◽  
New Generation

ABSTRACT X-ray signatures of outflowing gas have been detected in several accreting black hole binaries, always in the soft state. A key question raised by these observations is whether these winds might also exist in the hard state. Here, we carry out the first full-frequency radiation hydrodynamic simulations of luminous (${L = 0.5 \, L_{\mathrm{\mathrm{ Edd}}}}$) black hole X-ray binary systems in both the hard and the soft state, with realistic spectral energy distributions (SEDs). Our simulations are designed to describe X-ray transients near the peak of their outburst, just before and after the hard-to-soft state transition. At these luminosities, it is essential to include radiation driving, and we include not only electron scattering, but also photoelectric and line interactions. We find powerful outflows with ${\dot{M}_{\mathrm{ wind}} \simeq 2 \, \dot{M}_{\mathrm{ acc}}}$ are driven by thermal and radiation pressure in both hard and soft states. The hard-state wind is significantly faster and carries approximately 20 times as much kinetic energy as the soft-state wind. However, in the hard state the wind is more ionized, and so weaker X-ray absorption lines are seen over a narrower range of viewing angles. Nevertheless, for inclinations ≳80°, blueshifted wind-formed Fe xxv and Fe xxvi features should be observable even in the hard state. Given that the data required to detect these lines currently exist for only a single system in a luminous hard state – the peculiar GRS 1915+105 – we urge the acquisition of new observations to test this prediction. The new generation of X-ray spectrometers should be able to resolve the velocity structure.

scholarly journals An Event Study Analysis of Political Events, Disasters, and Accidents for Chinese Tourists to Taiwan

2018 ◽  
Vol 10 (11) ◽  
pp. 4307
Author(s):  
Chia-Lin Chang ◽  
Shu-Han Hsu ◽  
Michael McAleer
Keyword(s):  
Event Study ◽  
Fundamental Equation ◽  
Rate Of Change ◽  
Group Type ◽  
Political Events ◽  
Before And After ◽  
Huge Impact ◽  
Chinese Tourists ◽  
Conditional Variance Models ◽  
The Taiwan Strait

The number of Chinese tourists visiting Taiwan has been closely related to the political relationship across the Taiwan Strait. The occurrence of political events and disasters or accidents have had, and will continue to have, a huge impact on the Taiwan tourism market. To date, there has been relatively little empirical research conducted on this issue. Tourists are characterized as being involved in one of three types of tourism: group tourism (group-type), individual tourism (individual-type), and medical cosmetology (medical-type). We use the fundamental equation in tourism finance to examine the correlation that exists between the rate of change in the number of tourists and the rate of return on tourism. Second, we use the event study method to observe whether the numbers of tourists have changed abnormally before and after the occurrence of major events on both sides of the Strait. Three different types of conditional variance models, namely, the Generalized Autoregressive Conditional Heteroscedasticity, GARCH (1,1), Glosten, Jagannathan and Runkle, GJR (1,1) and Exponential GARCH, EGARCH (1,1), are used to estimate the abnormal rate of change in the number of tourists. The empirical results concerning the major events affecting the changes in the numbers of tourists from China to Taiwan are economically significant, and confirm the types of tourists that are most likely to be affected by such major events.

scholarly journals Correlation Functions of CMB Anisotropy and Polarization

1999 ◽  
Vol 183 ◽  
pp. 104-104
Author(s):  
Kin-Wang Ng
Keyword(s):  
Correlation Function ◽  
Stokes Parameters ◽  
Temperature Anisotropy ◽  
Microwave Background ◽  
Signal To Noise ◽  
Polarization Experiment ◽  
Promising Tool ◽  
Cmb Polarization ◽  
Full Analysis ◽  
Cross Correlations

While the temperature anisotropy of the cosmic microwave background is proved to be a promising tool for probing the early Universe, the CMB polarization is another important clue for extracting more cosmic information. We give a full analysis of the auto- and cross-correlations between the CMB Stokes parameters. In particular, we derive the windowing function for an antenna with Gaussian response in polarization experiment, and construct correlation function estimators corrected for instrumental noise. They are applied to calculate the signal to noise ratios for future MAP and Planck anisotropy and polarization measurements.

scholarly journals Empowering junior doctors: a qualitative study of a QI programme in South West England

2018 ◽  
Vol 94 (1116) ◽  
pp. 571-577 ◽  
Author(s):  
Natasha J Doran ◽  
Rob Bethune ◽  
Joanne Watson ◽  
Katherine Finucane ◽  
Andrew Carson-Stevens
Keyword(s):  
Patient Safety ◽  
Improve Patient Safety ◽  
Qualitative Interviews ◽  
Working Environment ◽  
Junior Doctors ◽  
Effect Change ◽  
Medical Careers ◽  
South West ◽  
Before And After ◽  
New Generation

AimTo explore how the South-West Foundation Doctor Quality Improvement programme affected foundation year 1 (F1) doctors’ attitudes and ability to implement change in healthcare.MethodsTwenty-two qualitative interviews were carried out with two cohorts of doctors. The first F1 group before and after their participation in the QI programme; the second group comprised those who had completed the programme between 1 and 5 years earlier. Qualitative data were analysed using thematic analysis techniques.Results Prior to taking part in the QI programme, junior doctors’ attitudes towards QI were mixed. Although there was agreement on the importance of QI in terms of patient safety, not all shared enthusiasm for engaging in QI, while some were sceptical that they could bring about any change. Following participation in the programme, attitudes towards QI and the ability to effect change were significantly transformed. Whether their projects were considered a success or not, all juniors reported that they valued the skills learnt and the overall experience they gained through carrying out QI projects. Participants reported feeling more empowered in their role as junior doctors, with several describing how they felt ‘listened to’ and able to ‘have a voice’, that they were beginning to see things ‘at systems level’ and learning to ‘engage more critically’ in their working environment.Conclusions Junior doctors are ideally placed to engage in QI. Training in QI at the start of their medical careers may enable a new generation of doctors to acquire the skills necessary to improve patient safety and quality of care.

Population decline of Globodera rostochiensis in Western Serbia

Nematology ◽  
2017 ◽  
Vol 19 (2) ◽  
pp. 185-195
Author(s):  
Nikola Grujić ◽  
Milan Radivojević
Keyword(s):  
Climatic Factors ◽  
Population Decline ◽  
Potato Cultivar ◽  
Potato Production ◽  
Globodera Rostochiensis ◽  
Initial Population ◽  
Management Procedures ◽  
Before And After ◽  
New Generation ◽  
Annual Decline

Annual decline rates of potato cyst nematode (PCN) populations have been extensively studied. They vary considerably due to many factors, including potato cultivar, initial PCN density and climatic factors. Information is needed on PCN decline in potato fields in the specific conditions of Western Serbia, which is the centre for most of the local potato production, especially seed potato. We investigated the decline of Globodera rostochiensis over 1 or 2 years under the influence of PCN-resistant potato cv. Agria in the field and microplots. Decline was compared with fallow in Ponikve, near the original record of G. rostochiensis. Population decline in the field after cv. Agria was approximately 80%. In two parts of the field where potato cv. Agria was cropped once or twice with fallow before and after, the viable PCN population declined over 9 years to about 1% of initial values. In a third part of the field, left fallow for 9 years, 15% of the initial population was still viable, after an annual decline rate of 9.4%. The influence of volunteer potatoes on maintaining PCN populations was also examined. In the microplots, with a higher density of volunteers compared to the field, PCN decline under resistant potato cv. Agria was 70%. At crop harvest a new generation was recorded, suggesting its possible formation on susceptible volunteer potato. The full cysts represented 1% of all cysts examined and 13% of total second-stage juveniles found in the samples. The information will be useful for improvement of management procedures.

Gender Issues in the New Generation Jail

1995 ◽  
Vol 75 (2) ◽  
pp. 203-221 ◽  
Author(s):  
PATRICK G. JACKSON ◽  
CINDY A. STEARNS
Keyword(s):  
State Of The Art ◽  
Gender Issues ◽  
Equal Treatment ◽  
Female Inmates ◽  
Jail Inmates ◽  
Before And After ◽  
Survey Instruments ◽  
Male Inmates ◽  
New Generation ◽  
New Facility

There is little research on women in jails and “new generation” jails in particular. This study examines how women and men inmates adapted to a state-of-the-art new generation jail. Inmates were surveyed 6 months before and after the new facility opened. Standardized survey instruments were used to assess inmate perceptions of the jail environment, other inmates, staff, and the facility as well as inmate stress. The results indicate that female inmates show declines on most measures of inmate satisfaction, both among themselves and in comparison to male inmates. Males, by contrast, show substantial improvements. The article examines a variety of reasons for the disparate gender outcomes. The conclusion is that equal treatment in the new generation jail led to negative outcomes for women.

scholarly journals Optimal strategy for polarization modulation in the LSPE-SWIPE experiment

2018 ◽  
Vol 609 ◽  
pp. A52 ◽  
Author(s):  
A. Buzzelli ◽  
P. de Bernardis ◽  
S. Masi ◽  
N. Vittorio ◽  
G. de Gasperis
Keyword(s):  
Power Spectrum ◽  
Polarization Modulation ◽  
Microwave Background ◽  
Angular Power Spectrum ◽  
Half Wave ◽  
Wide Range ◽  
Cmb Polarization ◽  
Systematic Effects ◽  
Single Detector ◽  
Frequency Map

Context. Cosmic microwave background (CMB) B-mode experiments are required to control systematic effects with an unprecedented level of accuracy. Polarization modulation by a half wave plate (HWP) is a powerful technique able to mitigate a large number of the instrumental systematics. Aims. Our goal is to optimize the polarization modulation strategy of the upcoming LSPE-SWIPE balloon-borne experiment, devoted to the accurate measurement of CMB polarization at large angular scales. Methods. We departed from the nominal LSPE-SWIPE modulation strategy (HWP stepped every 60 s with a telescope scanning at around 12 deg/s) and performed a thorough investigation of a wide range of possible HWP schemes (either in stepped or continuously spinning mode and at different azimuth telescope scan-speeds) in the frequency, map and angular power spectrum domain. In addition, we probed the effect of high-pass and band-pass filters of the data stream and explored the HWP response in the minimal case of one detector for one operation day (critical for the single-detector calibration process). We finally tested the modulation performance against typical HWP-induced systematics. Results. Our analysis shows that some stepped HWP schemes, either slowly rotating or combined with slow telescope modulations, represent poor choices. Moreover, our results point out that the nominal configuration may not be the most convenient choice. While a large class of spinning designs provides comparable results in terms of pixel angle coverage, map-making residuals and BB power spectrum standard deviations with respect to the nominal strategy, we find that some specific configurations (e.g., a rapidly spinning HWP with a slow gondola modulation) allow a more efficient polarization recovery in more general real-case situations. Conclusions. Although our simulations are specific to the LSPE-SWIPE mission, the general outcomes of our analysis can be easily generalized to other CMB polarization experiments.

scholarly journals Simultaneous determination of the cosmic birefringence and miscalibrated polarization angles from CMB experiments

2019 ◽  
Vol 2019 (8) ◽  
Author(s):  
Yuto Minami ◽  
Hiroki Ochi ◽  
Kiyotomo Ichiki ◽  
Nobuhiko Katayama ◽  
Eiichiro Komatsu ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Power Spectra ◽  
Microwave Background ◽  
Polarization Data ◽  
Satellite Mission ◽  
Cmb Polarization ◽  
Angle Alpha ◽  
The Difference ◽  
Polarization Spectra

Abstract We show that the cosmic birefringence and miscalibrated polarization angles can be determined simultaneously by cosmic microwave background (CMB) experiments using the cross-correlation between $E$- and $B$-mode polarization data. This is possible because the polarization angles of the CMB are rotated by both the cosmic birefringence and miscalibration effects, whereas those of the Galactic foreground emission are rotated only by the latter. Our method does not require prior knowledge of the $E$- and $B$-mode power spectra of the foreground emission, but uses only the knowledge of the CMB polarization spectra. Specifically, we relate the observed $EB$ correlation to the difference between the observed$E$- and $B$-mode spectra in the sky, and use different multipole dependences of the CMB (given by theory) and foreground spectra (given by data) to derive the likelihood for the miscalibration angle $\alpha$ and the birefringence angle $\beta$. We show that a future satellite mission similar to LiteBIRD can determine $\beta$ with a precision of 10 arcmin.

eScience for molecular-scale simulations and the e Minerals project

2008 ◽  
Vol 367 (1890) ◽  
pp. 967-985 ◽  
Author(s):  
E.K.H Salje ◽  
E Artacho ◽  
K.F Austen ◽  
R.P Bruin ◽  
M Calleja ◽  
...  
Keyword(s):  
Data Representation ◽  
Information Delivery ◽  
Metadata Management ◽  
Data Systems ◽  
Large Parameter ◽  
Xml Data ◽  
Molecular Scale ◽  
Technological Developments ◽  
Metadata Harvesting ◽  
New Generation

We review the work carried out within the e Minerals project to develop eScience solutions that facilitate a new generation of molecular-scale simulation work. Technological developments include integration of compute and data systems, developing of collaborative frameworks and new researcher-friendly tools for grid job submission, XML data representation, information delivery, metadata harvesting and metadata management. A number of diverse science applications will illustrate how these tools are being used for large parameter-sweep studies, an emerging type of study for which the integration of computing, data and collaboration is essential.

Sign in / Sign up

Export Citation Format

Share Document