scholarly journals Determination of the optical turbulence parameters from the adaptive optics telemetry: critical analysis and on-sky validation

2018 ◽  
Vol 57 (27) ◽  
pp. 7837 ◽  
Author(s):  
Laurent Jolissaint ◽  
Sam Ragland ◽  
Julian Christou ◽  
Peter Wizinowich
Keyword(s):  
Adaptive Optics ◽  
Critical Analysis ◽  
Optical Turbulence ◽  
Turbulence Parameters

Daytime optical turbulence profiling with a profiler of the differential solar limb

2020 ◽  
Vol 499 (2) ◽  
pp. 1909-1917
Author(s):  
Tengfei Song ◽  
Zhanchuan Cai ◽  
Yu Liu ◽  
Mingyu Zhao ◽  
Yuliang Fang ◽  
...  
Keyword(s):  
Atmospheric Turbulence ◽  
Adaptive Optics ◽  
Solar Limb ◽  
Coefficient Matrix ◽  
Image Motion ◽  
Index Structure ◽  
Test Results ◽  
Optical Turbulence ◽  
Optical Telescopes ◽  
Turbulence Parameters

ABSTRACT Atmospheric turbulence reduces the image quality and resolution of ground-based optical telescopes. Future large solar telescopes (e.g. the CGST, China Giant Solar Telescope) should be equipped with adaptive optics (AO) systems. The design of AO systems is associated with atmospheric optical turbulence parameters, especially the profile of the refractive index structure $C_{n}^{2}(h)$. With the solar differential image motion monitor (S-DIMM) and the profiler of the moon limb (PML), a simplified version of a PML, termed a profiler of the differential solar limb (PDSL), was built in order to determine the daytime $C_{n}^{2}(h)$ and other atmospheric turbulence parameters. A PDSL with differential solar limb fluctuations was used to determine the turbulence profiling, and the extended solar limb extends the range of separation angles for a higher resolution of the height profile. The PDSL structure and its performance are described. In addition, numerical simulations were conducted to verify the effectiveness of the method. As revealed from the simulation results, the layered integral coefficient matrix is capable of solving the discretization error and enhancing the inversion accuracy of the turbulence contour. The first test results at Mt Wumingshan (a candidate site for the CGST) are presented.

Research progress in electroanalytical techniques for determination of antimalarial drugs in pharmaceutical and biological samples

RSC Advances ◽  
2016 ◽  
Vol 6 (62) ◽  
pp. 57580-57602 ◽  
Author(s):  
Neeta Thapliyal ◽  
Tirivashe E. Chiwunze ◽  
Rajshekhar Karpoormath ◽  
Rajendra N. Goyal ◽  
Harun Patel ◽  
...  
Keyword(s):  
Biological Samples ◽  
Critical Analysis ◽  
Pharmaceutical Formulations ◽  
Antimalarial Drugs ◽  
Research Progress ◽  
Electroanalytical Methods ◽  
Biological Matrices

The review focusses on the role of electroanalytical methods for determination of antimalarial drugs in biological matrices and pharmaceutical formulations with a critical analysis of published voltammetric and potentiometric methods.

scholarly journals Metaphysical Anthropocentrism, Limitrophy, and Responsibility: An Explication of the Subject of Animal Rights

2018 ◽  
Vol 21 ◽  
pp. 1-29
Author(s):  
Jan-Harm De Villiers
Keyword(s):  
Animal Rights ◽  
Critical Analysis ◽  
De Novo ◽  
Social Regulation ◽  
Traditional Model ◽  
Conceptual Level ◽  
The Subject ◽  
Metaphysical Tradition ◽  
Point Of Departure

This article undertakes a critical analysis of subjectivity and exposes the metaphysical and anthropocentric quasi-transcendental conditions that give rise to the construct(ion) of the Subject. I locate a critical moment for the metaphysical Subject in the work of Martin Heidegger which, whilst sadly not sustained in his later writings, provides a point of departure for an examination of the significance that animality plays in the metaphysical tradition and its constitutive relation to the construct of subjectivity. I discern this relation to be violent and sacrificial and draw on Jacques Derrida's nonanthropocentric ethics against the background of Drucilla Cornell's ethical reading of deconstruction to construct a critique of approaches that assimilate animals to the traditional model of subjectivity in order to represent their identity and interests in the legal paradigm. The main argument that I seek to advance is that such an approach paradoxically re-constructs the classical humanist subject of metaphysics and re-establishes the subject-centred system that silences the call of the animal Other, thereby solidifying and extending the legitimacy of a discourse and mode of social regulation that is fundamentally anthropocentric. I examine how we can address, incapacitate and move beyond this schemata of power through a rigorous deconstruction of the partitions that institute the Subject and how deconstruction clears a space for a de novo determination of the animal "subject" that can proceed from different sites of nonanthropocentric interruption. What follows is a call to refuse the mechanical utilisation of traditional legal constructs and I argue in favour of an approach to the question of the animal (in law) that identifies and challenges anthropocentrism as its critical target. I ultimately propose a critical engagement with the underlying metaphysical support of animal rights at a conceptual level, rather than simply utilising the law pragmatically as an instrument of immediate resolution.    

Determination of Women Collective Farming Groups in Kerala towards Attaining Goals: A Critical Analysis

2021 ◽  
pp. 82-88
Author(s):  
T. Shahlas Binth ◽  
Basavaraj Hulagur ◽  
S. B. goudappa ◽  
Jagrati B. Deshmanya
Keyword(s):  
Critical Analysis ◽  
Collective Farming

scholarly journals Forecasting seeing for the Maunakea Observatories

2020 ◽  
Vol 496 (4) ◽  
pp. 4734-4748
Author(s):  
Ryan Lyman ◽  
Tiziana Cherubini ◽  
Steven Businger
Keyword(s):  
Adaptive Optics ◽  
Atmospheric Stability ◽  
Weather Conditions ◽  
Image Resolution ◽  
Image Motion ◽  
Optical Turbulence ◽  
Observational Measures ◽  
Weather Model ◽  
Operational Forecasting

ABSTRACT Optical turbulence greatly impacts the range and quality of astronomical observations. Advanced knowledge of the expected atmospheric optical turbulence provides important guidance that helps astronomers decide which instrument to schedule and enables them to optimize the adaptive optics technology that improves image resolution. Along with forecasts of weather conditions, prediction of the optical observing quality on the Maunakea summit has been a goal for the Maunakea Weather Center (MKWC) since its inception more than 20 yr ago. Forecasting optical turbulence, and its derivative, ‘seeing’, has proven to be quite challenging because optical turbulence is too small and complex to directly capture with a regional weather model. Fortunately, the permanent installation of a Differential Image Motion Monitor (DIMM) and Multi-Aperture Scintillation Sensor (MASS) at the summit of Maunakea has made seeing observations available during the last decade, providing valuable feedback to the MKWC. This paper summarizes the experience at MKWC in anticipating optical turbulence for the summit of Maunakea accrued through years of daily operational forecasting, and continuous comparison between MKWC official forecasts, model guidance, and observational measures of seeing. Access to a decade seeing observations has allowed quantification the factors that impact seeing, including wind shear, atmospheric stability patterns, and optical turbulence, and to document the seasonal and intra-seasonal variations in seeing. Consequently, the combination of experience gained, and custom model guidance has led to more accurate seeing forecasts (rms errors averaging <0.25 arcsec since 2012) for the Maunakea astronomical observatories.

scholarly journals Atmospheric Characterization Based on Relative Humidity Control at Optical Turbulence Generator

Atmosphere ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 550
Author(s):  
Jhonny Villamizar ◽  
Manuel Herreño ◽  
Omar Tíjaro ◽  
Yezid Torres
Keyword(s):  
Relative Humidity ◽  
Laser Beam ◽  
Optical Axis ◽  
Optical Turbulence ◽  
Air Velocity ◽  
Limited Effect ◽  
Horizontal Path ◽  
Physical Variables ◽  
Turbulence Parameters ◽  
Turbulence Generator

In atmospheric turbulence, relative humidity has been almost a negligible variable due to its limited effect, compared with temperature and air velocity, among others. For studying the horizontal path, a laser beam was propagated in a laboratory room, and an Optical Turbulence Generator (OTG) was built and placed along the optical axis. Additionally, there was controlled humidity inside the room and measuring of some physical variables inside the OTG device for determining its effects on the laser beam. The experimental results show the measurements of turbulence parameters C n 2 , l o , and σ I 2 from beam centroids fluctuations, where increases in humidity generated stronger turbulence.

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