scholarly journals Scalable photonic-based nulling interferometry with the dispersed multi-baseline GLINT instrument

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Marc-Antoine Martinod ◽  
Barnaby Norris ◽  
Peter Tuthill ◽  
Tiphaine Lagadec ◽  
Nemanja Jovanovic ◽  
...  

AbstractCharacterisation of exoplanets is key to understanding their formation, composition and potential for life. Nulling interferometry, combined with extreme adaptive optics, is among the most promising techniques to advance this goal. We present an integrated-optic nuller whose design is directly scalable to future science-ready interferometric nullers: the Guided-Light Interferometric Nulling Technology, deployed at the Subaru Telescope. It combines four beams and delivers spatial and spectral information. We demonstrate the capability of the instrument, achieving a null depth better than 10−3 with a precision of 10−4 for all baselines, in laboratory conditions with simulated seeing applied. On sky, the instrument delivered angular diameter measurements of stars that were 2.5 times smaller than the diffraction limit of the telescope. These successes pave the way for future design enhancements: scaling to more baselines, improved photonic component and handling low-order atmospheric aberration within the instrument, all of which will contribute to enhance sensitivity and precision.

2014 ◽  
Vol 25 (3-4) ◽  
pp. 69-76
Author(s):  
G. A. Mustafayeva

Scales (Hemiptera, Diaspididae) are the dangerous crop and park-ornamental plant pests. They reproduce very quickly and cause great harm to plants, sometimes even lead to their complete destruction. Scales suck juices from plants, cause premature drying, dying and falling off leaves, dry branches, deformation of leaves, fruits and shoots, reducing annual growth of plants. Therefore the fight with these pests is rather topical in the agriculture. In this connection in this work the analysis of bioecological peculiarities of oleander scale on the territory of Azerbaijan, and also the detection of species content of parasites and predators, which regulate their number is conducted. We will mark that oleander scales in the wild there are the entomophages are vermin and predators that reduce their quantity. For realization of biological fight against people we studied the bioenvironmental features of wreckers, and also educed specific composition of vermin and predators that regulate their quantity. In a biological fight against these wreckers, one of basic questions is study of specific composition of these entomophages. The faunistic material on entomophages of this pest was collected from different biocenosis; the researched works were conducted in the laboratory and field conditions in Azerbaijan. The advanced and research studies that we conducted gave an opportunity to educe entomophages oleander scale that inflicts an enormous damage to the agricultural cultures and park-decorative plants. The method of breeding of effective types of entomophages is studied in laboratory terms. Firstly the biology of oleander scale on Apsheron peninsula and in Guba Khachmazskii area was studied. The results of long-term studies showed that oleander scale, having distributed on Apsheron peninsula, on olive trees gives 3 generations. Only adult female animals and maggots of I and II age spend winter. Awakening of the scales on olives takes place in March-April. In II and III decade of April the male animals begin their flight. In Guba Khachmazskii area the biology of this scale, dwelling on oleander bush was studied. On this plant the scale gives 3 generations. Young female animals, and also maggots of I and II age winter. As a result of the works conducted the following entomophages of oleander scale were detected: predator Rhyzobius lophanthae Blaisd, Chilocorus bipustulatus L., Chilocorus renupustulatus L; parasites: Aphytis chilensis Howаrd, Aspidiotiphagus citrinus Graw, Encarsia aurantii (Howard). The habitat of Rhyzobius lophanthae is Australia. At the end of the last century of this predatory beetle left to California, from there left to Italy and in other Mediterranean countries. In 1947 by chance was left to Georgia (Abkhazia). Maybe these useful predators in Azerbaijan were from Georgia. For diluting the entomophages from the local indigenous fauna the potato tubers were used, on which firstly the oleander scales, and then road-beetles Rhyzobius lophanthae, Chilocorus bipustulatus reproduced themselves. In the laboratory conditions the methods of diluting of these Coccinellidae was developed. Thus, firstly the way of diluting parasites of oleander scale was studied and developed – Aphytis chilensis Howard, Aspidiotiphagus citrinus Graw и Encarsia antantii (Howard). It was detected that predatory entomophage-chilocor in the natural conditions is ineffective, as their maggots and chrysalises are affected by other local parasites. In the laboratory conditions this beetle produce itself very well on the potato tubers, infected by oleander scale. However, we should note that among entomophage parasites Aphytis chilensis plays the huge role in destruction of scales. In dependence on the weather conditions this macrophage in the nature can give 3–4 generations. Also it was proved that beetle Rhyzobius lophanthae in the biological fight can be applied against all round scales. This predator is effective entomophage of oleander, olive scale, black pine-leaf scale, white peach scale, European fruit scale and cactus scale. In connection with this, Rhyzobius lophanthae can be applied in the biological fight against oleander scale and presently is irreplaceable and perspective entomophage. 


Religions ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 206
Author(s):  
Pål Ketil Botvar

The Norwegian National Day (17 May, also referred to as Constitution Day) stands out as one of the most popular National Day celebrations in Europe. According to surveys, around seven out of every 10 Norwegians take part in a public celebration during this day. This means that the National Day potentially has an impact on the way people reflect upon national identity and its relationship to the Lutheran heritage. In this paper, I will focus on the role religion plays in the Norwegian National Day rituals. Researchers have described these rituals as both containing a significant religious element and being rather secularized. In this article, I discuss the extent to which the theoretical concepts civil religion and religious nationalism can help us understand the role of religion, or the absence of religion, in these rituals. Based on surveys of the general population, I analyze both indicators of civil religion and religious nationalism. The two phenomena are compared by looking at their relation to such items as patriotism, chauvinism, and xenophobia. The results show that civil religion explains participation in the National Day rituals better than religious nationalism.


1988 ◽  
Vol 10 (1) ◽  
pp. 37-42 ◽  
Author(s):  
M. J. Wheeler ◽  
Linzi Waiters

The Kemtek 1000 Sample Processor has been evaluated for precision, accuracy, speed and reliability. Precision was better than 1.0% at all volumes tested and accuracy within ±5%. A l00-tube assay could be set up within 15 min when patient specimens plus two reagents were sampled using a two probe system. Carry-over could be reduced to <0.01% by using a sufficient number of wash steps, the latter being related to the assay requirements. Evidence was found for adsorption of protein to the probe tubing but inaccuracies due to this could be reduced by introducing wash steps between samples. Problems over 12 months have been minor and quickly resolved. The authors were pleased with the way the processor performed and their staffhave confidence in leaving it to set up their assays.


2021 ◽  
Vol 9 ◽  
Author(s):  
Deen Wang ◽  
Xin Zhang ◽  
Wanjun Dai ◽  
Ying Yang ◽  
Xuewei Deng ◽  
...  

Abstract A 1178 J near diffraction limited 527 nm laser is realized in a complete closed-loop adaptive optics (AO) controlled off-axis multi-pass amplification laser system. Generated from a fiber laser and amplified by the pre-amplifier and the main amplifier, a 1053 nm laser beam with the energy of 1900 J is obtained and converted into a 527 nm laser beam by a KDP crystal with 62% conversion efficiency, 1178 J and beam quality of 7.93 times the diffraction limit (DL). By using a complete closed-loop AO configuration, the static and dynamic wavefront distortions of the laser system are measured and compensated. After correction, the diameter of the circle enclosing 80% energy is improved remarkably from 7.93DL to 1.29DL. The focal spot is highly concentrated and the 1178 J, 527 nm near diffraction limited laser is achieved.


1992 ◽  
Vol 10 (1) ◽  
pp. 71-73 ◽  
Author(s):  
R.G. Marson ◽  
T.R. Bedding ◽  
J.G. Robertson

AbstractThe technique of aperture synthesis is well developed in radio astronomy. When applied to the optical regime, aperture synthesis allows one to partially overcome the blurring effects of the atmosphere and increase the angular resolution of large telescopes to the diffraction limit. MAPPIT (Masked APerture-Plane Interference Telescope) is a multi-element interferometer which operates at the coude focus of the 3.9 m Anglo-Australian Telescope. This instrument has recently been reconfigured to operate in a dispersed mode so that simultaneous observations in a band of wavelengths are possible. We will discuss this instrument’s new mode and present observations of the double star δ Sco and an angular diameter of the previously unresolved red giant β Gru.


2016 ◽  
Vol 2 ◽  
pp. 122
Author(s):  
Jaime Almansa Sánchez

While Archaeology started to take form as a professional discipline, Alternative Archaeologies grew in several ways. As the years went by, the image of Archaeology started being corrupted by misconceptions and a lot of imagination, and those professionals that were claiming to be scientists forgot one of their first responsibilities; the public. This lack of interest is one of the reasons why today, a vast majority of society believes in many clichés of the past that alternative archaeologists have used to build a fictitious History that is not innocent at all. From UFOs and the mysteries of great civilizations to the political interpretation of the past, the dangers of Alternative Archaeologies are clear and under our responsibility. This paper analyzes this situation in order to propose a strategy that may make us the main characters of the popular imagery in the mid-term. Since confrontation and communication do not seem to be effective approaches, we need a change in the paradigm based on Public Archaeology and the increase of our presence in everyday life.


Author(s):  
Anthony Minnaar

While it would appear that the motivations to incorporate the Directorate of Special Operations (DSO) or Scorpions into a new South African Police Service directorate are largely politically driven, there are a number of practical obstacles standing in the way of a ‘smooth’ incorporation. Foremost among these is the manner of operations of the Scorpions, the way that they investigate certain crimes by means of prosecution-led teams, and their more effective use of intelligence-driven crime information. This is diametrically opposed to the SAPS investigation modus operandi, which is largely reactive. Furthermore, many of the Scorpions investigators, representing as they do a vast pool of built up experience and expertise, do not want to serve in the SAPS under the latter’s investigating regime. Other sticking points would be the fact that they are paid infinitely better than SAPS detectives, are better funded and resourced, have a far lighter case load (and one shared in a team) – all in direct contrast to members of the SAPS.


The Luna 24 mission sampled a variety of lithologies in a single core. Two of these lithologies, a metabasalt (24196) and a crushed basalt (24170) have been subjected to 40 Ar- 39 Ar dating experiments to determine if metamorphism significantly post-dated basalt extrusion. The metabasalt exhibited symptoms of both solar wind contamination and 39 Ar recoil; in view of these effects an age may only be defined by making extreme assumptions. High temperature release fractions give an age of 3.36 ± 0.11 Ga, while the cumulate 40 Ar/ 39 Ar ratio gives 3.14 ± 0.16 Ga; both are comparable with the basalt (24170) age and suggest that the metabasalts represent thermally penecontemporaneously metamorphosed flow margins, rather than the products of later impact events. The feldspar from the microgabbro yielded an age of 3.37 ± 0.20 Ga. The ratios of cosmogenic 38 Ar to Ca in pyroxene and feldspar are within error identical, indicating that 38 Ar production from Fe in the pyroxene is small. This is the first definitive use of Fe-produced 38 Ar as a spectral hardness indicator and implies that the microgabbro received much of its cosmic ray exposure at depth in the regolith. By taking account of the dependence of 38 Ar production rate with depth it is inferred that the microgabbro layer was deposited within the last 350-500 Ma. By implication, the regolith layers above the microgabbro at the Luna 24 site are younger. The metabasalt has an identical cosmogenic 38 Ar/Ca ratio; however, because of the decrease of production rate with depth it could have experienced a 20 % pre-exposure before deposition of the microgabbro. Spectral information has also been obtained from a reappraisal of published argon data and indicates a much harder spectrum for a near surface sample. The way in which the Ca- and Fe-produced 38 Ar e follow the broad trend of the instantaneous production profiles suggests that the regolith at the Luna 24 site has been relatively undisturbed for much of the last 300 Ma.


Author(s):  
Frederick Douglass
Keyword(s):  

Journey to my new master’s—meditations by the way—view of Covey’s residence—the family—the author’s awkwardness as a field hand—a cruel beating—why it was given—description of Covey—first adventure at ox driving—hair breadth escapes—ox and man alike property—Covey’s manner of proceeding to whip—hard labor better than the whip...


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