scholarly journals Advanced Wide-Field Broad-Passband Refracting Field Correctors for Large Telescopes

1984 ◽  
Vol 79 ◽  
pp. 519-548 ◽  
Author(s):  
H.W. Epps ◽  
J.R.P. Angel ◽  
E. Anderson
Keyword(s):  
Image Quality ◽  
Atmospheric Dispersion ◽  
Wide Field ◽  
Atmospheric Refraction ◽  
Optical Elements ◽  
Large Telescopes ◽  
The University ◽  
Near Future ◽  
Optical Manufacturing ◽  
Made In

AbstractA preliminary 30-arcmin prime focus (f/2.0) refracting field corrector system for the University of California Ten-Meter Telescope (UC TMT) is presented which features 1/4-arcsec images containing more than 80% of the energy, over limited passbands within the wavelength range λ3300Å to λ1.0µ. Provision has been made in this system for an atmospheric dispersion corrector (ADC) but same has not yet been realized. Optical elements herein are small enough that this design could be scaled up to a Fifteen-Meter NNTT/SMT.A compact 40-arcmin internal Cassegrain (f/1.75 hyperbola to f/5.0) broad-passband (λ3300Å to λ1.0µ) corrector, suitable for imaging and multi-object spectroscopy at the UC TMT, is presented which features 1/4-arcsec images containing more than 90% of the energy when averaged over field angle and color.Three 60-arcmin external Cassegrain correctors for 300-inch f/1.8 and f/2.0 parabolic primary mirrors are presented which are suitable for a Fifteen-Meter NNTT/MMT. Image quality is comparable to the UC TMT Cassegrain corrector and it exceeds that of the UC TMT preliminary prime focus corrector system by a substantial margin. Each of these correctors contains an ADC which has been implemented in one example, eliminating 4.0 arcsec of differential atmospheric refraction with an rms residual of +/-0.10 arcsec over the broad passband (λ3300Å to λ1.0µ). A 60-arcmin external Cassegrain (f/1.8 extreme hyperbola to f/4.5) corrector with ADC yields yet a factor two in image quality but said hyperbolic primary mirror would be incompatible with angular field requirements in the thermal infrared.A (300-inch) 40-arcmin external Cassegrain (f/1.0 parabola to f/4.0) broad-passband (λ3300Å to λ1.0µ) corrector with ADC is presented. Image quality is comparable to the previous Cassegrain correctors. The practicality of this design, together with recent advances in optical manufacturing capability of large, fast, nonspherical optics, suggests that relatively inexpensive compact telescopes of very large collecting area may be possible in the near future.

scholarly journals A New Type of Atmospheric Dispersion Corrector Suitable for Wide-Field High-Resolution Imaging and Spectroscopy on Large Telescopes

2021 ◽  
Vol 11 (14) ◽  
pp. 6261
Author(s):  
Andrew Rakich
Keyword(s):  
High Resolution ◽  
Atmospheric Dispersion ◽  
Wide Field ◽  
High Resolution Imaging ◽  
Dispersion Correction ◽  
Atmospheric Effect ◽  
New Type ◽  
Resolution Imaging ◽  
Imaging And Spectroscopy ◽  
Large Telescopes

Atmospheric dispersion produces spectral elongation in images formed by land-based astronomical telescopes, and this elongation increases as the telescope points away from the zenith. Atmospheric Dispersion Correctors (ADCs) produce compensating dispersion that can be adjusted to best cancel out the atmospheric effect. These correctors are generally of two basic types: Rotating Atmospheric Dispersion Correctors (R-ADCs), and Linear Atmospheric Dispersion Correctors (L-ADCs). Lately, a third type, the “Compensating Lateral ADC” (CL-ADC) has been proposed. None of these design approaches allow for large corrector systems (with elements greater than 1 m in diameter), in which the secondary spectrum is corrected to small residuals, of the order of tens’ of milliarcseconds. This paper describes a new type of large corrector (>1 m diameter elements), which can achieve the correction of the secondary spectrum to the order of 10 milliarcseconds. This correction is achieved by combining the R-ADC and CL-ADC approaches to dispersion correction. Only glass types readily available in metre diameters are required.

Spectrophotometric reductions with an IBM 1620

1966 ◽  
Vol 24 ◽  
pp. 116-117
Author(s):  
P.-I. Eriksson
Keyword(s):  
Astronomical Data ◽  
Spectrophotometric Data ◽  
Electronic Computers ◽  
The University ◽  
Near Future

Nowadays more and more of the reductions of astronomical data are made with electronic computers. As we in Uppsala have an IBM 1620 at the University, we have taken it to our help with reductions of spectrophotometric data. Here I will briefly explain how we use it now and how we want to use it in the near future.

MANAGEMENT OF THE SUCCESS OF STUDENT’S LEARNING BASED ON THE MARKOV MODEL

2018 ◽  
pp. 4-11
Author(s):  
M. V. Noskov ◽  
M. V. Somova ◽  
I. M. Fedotova
Keyword(s):  
Information System ◽  
Markov Process ◽  
Continuous Time ◽  
Information Technologies ◽  
Educational Process ◽  
Automated Information System ◽  
The Subject ◽  
The University ◽  
Independent Work ◽  
Near Future

The article proposes a model for forecasting the success of student’s learning. The model is a Markov process with continuous time, such as the process of “death and reproduction”. As the parameters of the process, the intensities of the processes of obtaining and assimilating information are offered, and the intensity of the process of assimilating information takes into account the attitude of the student to the subject being studied. As a result of applying the model, it is possible for each student to determine the probability of a given formation of ownership of the material being studied in the near future. Thus, in the presence of an automated information system of the university, the implementation of the model is an element of the decision support system by all participants in the educational process. The examples given in the article are the results of an experiment conducted at the Institute of Space and Information Technologies of Siberian Federal University under conditions of blended learning, that is, under conditions when classroom work is accompanied by independent work with electronic resources.

scholarly journals Simultaneity and Precise Time in Rotation

Universe ◽  
2019 ◽  
Vol 5 (12) ◽  
pp. 226 ◽  
Author(s):  
Don Koks
Keyword(s):  
Time Coordinate ◽  
Near Future ◽  
Precise Time ◽  
Made In

I analyse the role of simultaneity in relativistic rotation by building incrementally on its role in simpler scenarios. Historically, rotation has been analysed in 1 + 1 dimensions; but my stance is that a 2 + 1 -dimensional treatment is necessary. This treatment requires a discussion of what constitutes a frame, how coordinate choices differ from frame choices, and how poor coordinates can be misleading. I determine how precisely we are able to define a meaningful time coordinate on a gravity-free rotating Earth, and discuss complications due to gravity on our real Earth. I end with a critique of several statements made in relativistic precision-timing literature, that I maintain contradict the tenets of relativity. Those statements tend to be made in the context of satellite-based navigation; but they are independent of that technology, and hence are not validated by its success. I suggest that if relativistic precision-timing adheres to such analyses, our civilian timing is likely to suffer in the near future as clocks become ever more precise.

scholarly journals Microscopy for Children

2006 ◽  
Vol 14 (3) ◽  
pp. 53-53
Author(s):  
Caroline Schooley
Keyword(s):  
The United States ◽  
Educational Materials ◽  
Real Science ◽  
Curriculum Research ◽  
Early Decision ◽  
National Reputation ◽  
Science Educators ◽  
The University ◽  
Lawrence Hall Of Science ◽  
Made In

Precollege science education in the United States is not what it could, and should, be. Major changes are being made in the way science is taught, but delivering those changes to thousands of schools is an enormous task. Scientific societies are a major resource; they can organize and train member-volunteers to help teachers bring “real” science to the classroom. The Microscopy Society of America has become part of the effort with Project MICRO (Microscopy In Curriculum - Research Outreach). MICRO is putting MSA members, teaching materials, and microscopes in middle school classrooms nationwide. The idea began in 1993, but it has taken a lot of time and effort to implement.MSA's early decision to collaborate with experienced science educators at the Lawrence Hall of Science of the University of California at Berkeley was a wise one; their educational materials have a well-earned national reputation for excellence.

scholarly journals Self-splitting Abelian groups

2001 ◽  
Vol 64 (1) ◽  
pp. 71-79 ◽  
Author(s):  
P. Schultz
Keyword(s):  
Abelian Group ◽  
Direct Product ◽  
Free Module ◽  
Research Report ◽  
Original Form ◽  
Original Research ◽  
Direct Sum ◽  
The University ◽  
Torsion Free ◽  
Made In

G is reduced torsion-free A belian group such that for every direct sum ⊕G of copies of G, Ext(⊕G, ⊕G) = 0 if and only if G is a free module over a rank 1 ring. For every direct product ΠG of copies of G, Ext(ΠG,ΠG) = 0 if and only if G is cotorsion.This paper began as a Research Report of the Department of Mathematics of the University of Western Australia in 1988, and circulated among members of the Abelian group community. However, it was never submitted for publication. The results have been cited, widely, and since copies of the original research report are no longer available, the paper is presented here in its original form in Sections 1 to 5. In Section 6, I survey the progress that has been made in the topic since 1988.

scholarly journals The stellar structure of early-type galaxies: a wide-field Mitchell Spectrograph view

2016 ◽  
Vol 11 (S321) ◽  
pp. 288-288
Author(s):  
N. F. Boardman ◽  
A. Weijmans ◽  
R. C. E. van den Bosch ◽  
L. Zhu ◽  
A. Yildirim ◽  
...  
Keyword(s):  
Effective Radius ◽  
Stellar Structure ◽  
Wide Field ◽  
Early Type ◽  
Integral Field Spectroscopy ◽  
Field Spectroscopy ◽  
Integral Field ◽  
Made In

Much progress has been made in recent years towards understanding how early-type galaxies (ETGs) form and evolve. SAURON (Bacon et al. 2001) integral-field spectroscopy from the ATLAS3D survey (Cappellari et al. 2011) has suggested that less massive ETGs are linked directly to spirals, whereas the most massive objects appear to form from a series of merging and accretion events (Cappellari et al. 2013). However, the ATLAS3D data typically only extends to about one half-light radius (or effective radius, Re), making it unclear if this picture is truly complete.

scholarly journals “Our” Bodies: Property Rights in Human Tissue

1993 ◽  
Vol 8 (2) ◽  
pp. 113-138 ◽  
Author(s):  
Joan M. Gilmour
Keyword(s):  
Property Rights ◽  
Medical Research ◽  
Human Tissue ◽  
Effective Control ◽  
Technological Advances ◽  
The Supreme Court ◽  
The Many ◽  
Economic Goods ◽  
The University ◽  
Near Future

AbstractIn Moore v. Regents of the University of California, the Supreme Court of California held that the human source of blood and tissue used by his physician and other defendants in potentially lucrative medical research without his permission could not assert a legal claim that, in doing so, the defendants had deprived him of any property right in these materials or the cell line developed from them. He was, however, permitted to proceed with his claim that there had been a failure to obtain his informed consent to the excision or removal of these materials, given that their end uses were not disclosed. The decision in Moore is but one example of the range of new legal problems created by the many and rapid advances in biotechnology, and of the attempts courts are making to respond. The judgment raises questions about whether these types of issues as between the patient and medical, research, and pharmaceutical concerns can or ought to be analyzed in terms of property rights. Are the general justifications for recognizing proprietary rights that have traditionally been influential in judicial decisions useful or helpful in this context? And what of the identity of the decision-maker? In Moore, the majority was content to effectively delegate much of the decision-making authority to the U.S. Patent Office and the Office of Technology Assessment. While there are no Canadian decisions directly on point as yet, the pace of technological advances, the potential for economic gain, and the international nature of biotechnology enterprises all set the scene for these issues' coming before our courts in the near future. This paper begins to explore the implications of adopting an analytical model based on property rights and to address the fact that the biotechnology industry already operates on the premise that such material can be owned. It concludes that the current legal regime needs to be modified to allow effective control of these new realities and suggests principles that might be adopted to address important concerns that are raised by the transformation of human tissue and cells into economic goods.

Forestry education in Canada

1997 ◽  
Vol 73 (3) ◽  
pp. 341-347
Author(s):  
Claude Godbout
Keyword(s):  
Education System ◽  
Forest Sector ◽  
General Picture ◽  
Forestry Education ◽  
University Level ◽  
The University ◽  
Near Future

This paper aims at providing the reader with information about the forestry education system in Canada and its trends. As a basis for undertanding the framework of forestry education, a general picture of the Canadian forest sector is drawn and the main issues and concerns that will shape its evolution in the near future are presented.In a second part, after having described the current forestry education system with some emphasis on the university level, a summary of the challenges facing forestry education is presented. In the last part, a practical example of program revision influenced by these trends and challenges is presented in order to convey to the reader how a revised university forestry program can be designed to meet society's needs.

The Masks of Greek Tragedy as Point of Departure for Modern Performance

2001 ◽  
Vol 17 (3) ◽  
pp. 254-272 ◽  
Author(s):  
Chris Vervain ◽  
David Wiles
Keyword(s):  
Greek Tragedy ◽  
Research Programme ◽  
Cambridge University ◽  
Performance Space ◽  
And Performance ◽  
The University ◽  
Near Future ◽  
Point Of Departure ◽  
Valuable Point ◽  
New Comedy

In this article, David Wiles and Chris Vervain stake out the ground for a substantial programme of continuing research. Chris Vervain, coming from a background in visual and performance art, is in the first instance a maker of masks. She is also now writing a thesis on the masks of classical tragedy and their possibilities in modern performance, and, in association with the University of Glasgow, working on an AHRB research programme that involves testing the effect of Greek New Comedy masks in performance. David Wiles, Professor of Theatre at Royal Holloway, University of London, has published books on the masks of Greek New Comedy and on Greek performance space, and lectured on Greek masks. Most recently, his Greek Theatre Performance: an Introduction (Cambridge University Press, 2000) included an investigation of the classical mask and insights provided by the work of Lecoq. He is now planning a book on the classical Greek mask. Wiles and Vervain are both committed to the idea that the mask was the determining convention which gave Greek tragedy its identity in the ancient world, and is a valuable point of departure for modern practitioners engaging with the form. They anticipate that their research will in the near future incorporate a symposium and a further report on work-in-progress.

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