scholarly journals Possible Collaborative Network with Small Telescopes and a Standard CCD in Japan

1995 ◽  
Vol 148 ◽  
pp. 536-541
Author(s):  
Syuzo Isobe
Keyword(s):  
Detector System ◽  
Collaborative Network ◽  
Wide Field ◽  
Large Size

AbstractThere are two obvious ways to make a quick survey work. A: A telescope with a wide field and a large size detector. B: Many telescopes with a rather narrow field and a small size detector. In Japan, there are now 47 telescopes with diameters of 50-100 cm dedicated to public use. If we develop a simple-to-handle detector system, non-professional observers at each public observatory would have the possibility of joining a collaborative survey network. We started a test observation which is expected to extend to a survey network.

scholarly journals Hypophysectomy of birds. I-Technique, with a note a on results

1934 ◽  
Vol 115 (794) ◽  
pp. 402-409 ◽  
Keyword(s):  
Sex Hormones ◽  
Soft Palate ◽  
Reproductive System ◽  
Easy Access ◽  
Wide Field ◽  
Small Incision ◽  
Floor Of The Mouth ◽  
Secondary Sexual Characters ◽  
Large Size ◽  
Base Of The Skull

Hypophysectomy is now performed readily in many mammals and amphibians, but so far it has apparently not been successfully accomplished in birds. Fischera (1905) attempted to cauterize the pituitary body of the fowl, but obtained only dubious results. In view of our increasing knowledge of the reproductive system and secondary sexual characters of birds, it is evident that hypophysectomy would open up a wide field of investigation for work on sex hormones. The parapharyngeal route for removing the pituitary was precluded by the large size of the gullet, while the temporal route seemed to offer little hope. The extensibility of the mouth tissues, however, suggested that a buccal approach would be practicable. It was found barely possible to open the beak sufficiently to give easy access to the back of the mouth, but a comparatively small incision in the thin elastic floor of the mouth provided a ready approach to the soft palate and the base of the skull. We have found it possible to remove the pituitary with comparative ease by this transbuccal route, and the present paper is devoted to a description of the exact technique of the operation. The following description applies primarily to the fowl; notes on the differences found in other birds are given in Section III.

Design of Free-Form Surface Optic in Wide Field of View Off-Axis Optical System

2011 ◽  
Vol 50-51 ◽  
pp. 806-811 ◽  
Author(s):  
You Long ◽  
Ming Wu Kang ◽  
Xiao Xia Li
Keyword(s):  
Optical System ◽  
Simple Structure ◽  
Optical Design ◽  
Field Of View ◽  
Free Form ◽  
Wide Field ◽  
Design Specification ◽  
Large Size ◽  
Wide Field Of View ◽  
Free Form Surface

Design of off-axis system is a hot and difficult topic in optical design area. The wide field of view(WFOV) off-axis system this paper involved always have the drawbacks of complicated large size and great weight. This paper introduces an application of free-form surface(FFS) in WFOV off-axis optical system design, analyzes FFS optics’ material and fabrication methods. The system uses one FFS lens and one doublet, image quality meets the design specification, and characterizes by simple structure and lightweight.

Astrometric Properties of the KPNO 4m Telescope – Prime Focus CCD Detector System

1983 ◽  
Vol 62 ◽  
pp. 219-219
Author(s):  
David G. Monet
Keyword(s):  
Quantum Efficiency ◽  
Detector System ◽  
Wide Field ◽  
Minute Exposure ◽  
Ccd Detector ◽  
Set Up ◽  
Astrometric Binaries

A parallax program was started in July, 1980, using a CCD detector at the prime focus of the KPNO 4m telescope. The results obtained to date indicate that the centroids of stellar images can be measured to accuracies of 0.25 microns or better from each 2 minute exposure on stars of about 17th magnitude with a filter of 800 Angstroms width centered at 6500 Angstroms (the scale of the KPNO 4m with the doublet corrector is 19.60 milli-arc-seconds per micron). The current CCD, a Fairchild CCD 211, is of relatively low quantum efficiency, about 8%. The integration times become prohibitively short on 15th magnitude and brighter stars. This technology seems quite attractive for the observation of astrometric binaries, as accuracies of about 3 milli-arc-seconds are obtained with only 12 minutes of telescope time, and there is no special set-up required for each field. If time permits, some comments will be made about some preliminary astrometric tests of a 3-phase TI 800 × 800 CCD performed in January, 1981, in collaboration with Roger Lynds of the Sapce Telescope Wide Field Camera Team.

High-Resolution X-ray Spectroscopy Close to Room Temperature

1998 ◽  
Vol 4 (6) ◽  
pp. 622-631 ◽  
Author(s):  
L. Strüder ◽  
N. Meidinger ◽  
D. Stotter ◽  
J. Kemmer ◽  
P. Lechner ◽  
...  
Keyword(s):  
High Resolution ◽  
Count Rate ◽  
High Speed ◽  
Room Temperature ◽  
Single Photon ◽  
Low Noise ◽  
Detector System ◽  
Wide Field ◽  
X Rays ◽  
X Ray

Originally designed as position-sensitive detectors for particle tracking, silicon drift detectors (SDDs) are now used for high-count rate X-ray spectroscopy, operating close to room temperature. Their low-capacitance read-node concept places them among the fastest high-resolution detector systems. They have been used in a new spectrum of experiments in the wide field of X-ray spectroscopy: fluorescent analysis, diffrac-tometry, materials analysis, and synchrotron experiments such as X-ray holography and element imaging in scanning electron microscopes. The fact that the detector system can be used at room temperature with good spectroscopic performance and at −10°C with excellent energy resolution, avoiding liquid nitrogen for cooling and high-quality vacuum, guarantees a large variety of new applications, independent of the laboratory environment. A brief description of the device principles is followed by basics on low noise amplification. The performance results of a complete detector system are presented as well as some dedicated applications already realized, including use in a surface mapping instrument and use of a “mini-spectrometer” for the analysis of works of art. Fully depleted pn-charge-coupled devices (pn-CCDs) have been fabricated for the European X-ray Multi-Mirror mission (XMM) and the German X-ray satellite ABRIXAS, enabling high-speed, low-noise, position-resolving X-ray spectroscopy. The detector was designed and fabricated with a homogeneously sensitive area of 36 cm2. At −70°C it has a noise of 4 e- rms, with a readout time of the total focal plane array of 4 msec. The maximum count rate for single photon counting was 105 cps under flat field conditions. In the integration mode, more than 109 cps can be detected at 6 keV. Its position resolution is on the order of 100 μm. The quantum efficiency is higher than 90%, ranging from carbon K X-rays (277 eV) up to 10 keV.

Coherency loss in γ' precipitates in nickel-base superalloy

1983 ◽  
Vol 41 ◽  
pp. 244-245
Author(s):  
R. A. Ricks ◽  
Angus J. Porter
Keyword(s):  
Lattice Mismatch ◽  
Lattice Parameter ◽  
Nickel Base Superalloy ◽  
Large Size ◽  
The Matrix ◽  
Nimonic 80A ◽  
Interfacial Dislocations ◽  
Nickel Base ◽  
Coherency Loss ◽  
Nimonic 115

During a recent investigation concerning the growth of γ' precipitates in nickel-base superalloys it was observed that the sign of the lattice mismatch between the coherent particles and the matrix (γ) was important in determining the ease with which matrix dislocations could be incorporated into the interface to relieve coherency strains. Thus alloys with a negative misfit (ie. the γ' lattice parameter was smaller than the matrix) could lose coherency easily and γ/γ' interfaces would exhibit regularly spaced networks of dislocations, as shown in figure 1 for the case of Nimonic 115 (misfit = -0.15%). In contrast, γ' particles in alloys with a positive misfit could grow to a large size and not show any such dislocation arrangements in the interface, thus indicating that coherency had not been lost. Figure 2 depicts a large γ' precipitate in Nimonic 80A (misfit = +0.32%) showing few interfacial dislocations.

STM studies of crystal growth

1991 ◽  
Vol 49 ◽  
pp. 374-375
Author(s):  
M. G. Lagally
Keyword(s):  
Crystal Growth ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Sputter Deposition ◽  
Field Of View ◽  
Scanning Tunneling ◽  
Wide Field ◽  
Tunneling Microscopy ◽  
Wide Field Of View ◽  
The One

It has been recognized since the earliest days of crystal growth that kinetic processes of all Kinds control the nature of the growth. As the technology of crystal growth has become ever more refined, with the advent of such atomistic processes as molecular beam epitaxy, chemical vapor deposition, sputter deposition, and plasma enhanced techniques for the creation of “crystals” as little as one or a few atomic layers thick, multilayer structures, and novel materials combinations, the need to understand the mechanisms controlling the growth process is becoming more critical. Unfortunately, available techniques have not lent themselves well to obtaining a truly microscopic picture of such processes. Because of its atomic resolution on the one hand, and the achievable wide field of view on the other (of the order of micrometers) scanning tunneling microscopy (STM) gives us this opportunity. In this talk, we briefly review the types of growth kinetics measurements that can be made using STM. The use of STM for studies of kinetics is one of the more recent applications of what is itself still a very young field.

Imaging and diffraction modes in Scanning Transmission Electron Microscopy

1986 ◽  
Vol 44 ◽  
pp. 684-687
Author(s):  
J. M. Cowley ◽  
R. Glaisher ◽  
J. A. Lin ◽  
H.-J. Ou
Keyword(s):  
Scanning Transmission Electron Microscopy ◽  
High Efficiency ◽  
Fiber Optic ◽  
Image Intensifier ◽  
Detector System ◽  
Detector Plane ◽  
Secondary Electrons ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Special Detector

Some of the most important applications of STEM depend on the variety of imaging and diffraction made possible by the versatility of the detector system and the serial nature, of the image acquisition. A special detector system, previously described, has been added to our STEM instrument to allow us to take full advantage of this versatility. In this, the diffraction pattern in the detector plane may be formed on either of two phosphor screens, one with P47 (very fast) phosphor and the other with P20 (high efficiency) phosphor. The light from the phosphor is conveyed through a fiber-optic rod to an image intensifier and TV system and may be photographed, recorded on videotape, or stored digitally on a frame store. The P47 screen has a hole through it to allow electrons to enter a Gatan EELS spectrometer. Recently a modified SEM detector has been added so that high resolution (10Å) imaging with secondary electrons may be used in conjunction with other modes.

A New Detector System For The HB5 Stem Instrument

1985 ◽  
Vol 43 ◽  
pp. 134-135
Author(s):  
J.M. Cowley
Keyword(s):  
Dark Field ◽  
Detector System ◽  
Electron Holography ◽  
Small Specimen ◽  
Bright Field ◽  
Multiple Images ◽  
Practical Applications ◽  
Wide Range ◽  
Diffraction Patterns ◽  
Operational Modes

The HB5 STEM instrument at ASU has been modified previously to include an efficient two-dimensional detector incorporating an optical analyser device and also a digital system for the recording of multiple images. The detector system was built to explore a wide range of possibilities including in-line electron holography, the observation and recording of diffraction patterns from very small specimen regions (having diameters as small as 3Å) and the formation of both bright field and dark field images by detection of various portions of the diffraction pattern. Experience in the use of this system has shown that sane of its capabilities are unique and valuable. For other purposes it appears that, while the principles of the operational modes may be verified, the practical applications are limited by the details of the initial design.

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