Improved multi-spectral polarimetric observations of UTLS aerosol and cloud from stratospheric balloon with the Aerosol Limb Imager

<p>The Aerosol Limb Imager (ALI) is a multi-spectral imager capable designed to observe aerosol extinction and particle size profiles in the upper-troposphere lower-stratosphere. ALI uses a system of linear polarizers, a liquid crystal rotator, and an acoustic-optic tunable filter to select the linear polarization state and wavelength of limb scattered sunlight radiance between 600 nm and 1500 nm. From stratospheric balloon, spectral images have spatial resolution of <100 meters at the tangent point, and can produce useful aerosol observations between 5 km and 30 km in altitude. Of novelty is the polarimetric capability of ALI, which uses the orthogonal polarization states to detect cloud in the spectral data and facilitate its distinction from aerosol. Two previous iterations of the ALI instrument concept have already been successfully demonstrated, once in 2014 and again in 2018. Currently, a third iteration is being developed which improves upon the thermal, structural, and optical performance of the previous iterations. This improved iteration is scheduled for demonstration as part of the HEMERA program out of Kiruna, Sweden in the summer of 2021. This demonstration serves the larger objective of further proving the engineering and scientific readiness of the ALI instrument concept for eventual high-altitude aircraft and satellite platform deployments.  ALI is a proposed Canadian contribution to the NASA A-CCP satellite mission study.</p>

Measuring the distance to the black hole candidate X-ray binary MAXI J1348–630 using H i absorption

ABSTRACT We present neutral hydrogen (H i) absorption spectra of the black hole candidate X-ray binary (XRB) MAXI J1348–630 using the Australian Square Kilometre Array Pathfinder (ASKAP) and MeerKAT. The ASKAP H i spectrum shows a maximum negative radial velocity (with respect to the local standard of rest) of −31 ± 4 km s−1 for MAXI J1348–630, as compared to −50 ± 4 km s−1 for a stacked spectrum of several nearby extragalactic sources. This implies a most probable distance of $2.2^{+0.5}_{-0.6}$ kpc for MAXI J1348–630, and a strong upper limit of the tangent point distance at 5.3 ± 0.1 kpc. Our preferred distance implies that MAXI J1348–630 reached 17 ± 10 per cent of the Eddington luminosity at the peak of its outburst, and that the source transited from the soft to the hard X-ray spectral state at 2.5 ± 1.5 per cent of the Eddington luminosity. The MeerKAT H i spectrum of MAXI J1348–630 (obtained from the older, low-resolution 4k mode) is consistent with the re-binned ASKAP spectrum, highlighting the potential of the eventual capabilities of MeerKAT for XRB spectral line studies.

New Higher-Order Correction of GNSS RO Bending Angles Accounting for Ionospheric Asymmetry: Evaluation of Performance and Added Value

The residual ionospheric error (RIE) from higher-order terms in the refractive index is not negligible when using global navigation satellite system (GNSS) radio occultation (RO) data for climate and meteorology applications in the stratosphere. In this study, a new higher-order bending angle RIE correction named “Bi-local correction approach” has been implemented and evaluated, which accounts for the ray path splitting of the dual-frequency GNSS signals, the altitude of the low Earth orbit (LEO) satellite, the ionospheric inbound (GNSS to tangent point) vs. outbound (tangent point to LEO) asymmetry, and the geomagnetic field. Statistical results based on test-day ensembles of RO events show that, over the upper stratosphere and mesosphere, the order of magnitude of the mean total RIE in the bi-local correction approach is 0.01 μrad. Related to this, the so-called electron-density-squared (Ne2) and geomagnetic (BNe) terms appear to be dominant and comparable in magnitude. The BNe term takes negative or positive values, depending on the angle between the geomagnetic field vector and the direction of RO ray paths, while the Ne2 term is generally negative. We evaluated the new approach against the existing “Kappa approach” and the standard linear dual-frequency correction of bending angles and found it to perform well and in many average conditions similar to the simpler Kappa approach. On top of this, the bi-local approach can provide added value for RO missions with low LEO altitudes and for regional-scale applications, where its capacity to account for the ionospheric inbound-outbound asymmetry as well as for the geomagnetic term plays out.

Programmable Chess Sowing

One of the options for solving the problem of placing plants with the shape of the feeding area close to the circular one is to use a chess method of seeding. The development of precision farming and automation systems creates prerequisites for programmable chess seeding based on local coordination of the seeding unit. (Research purpose) The research purpose is in building and analyzing models of programmable chess seeding using an algorithm for separate control of even and odd seeding sections with local coordination of the seeder and precision farming elements. (Materials and methods) For the analysis of the algorithm separate control of odd and even partitions of seeders in the software package Matlab Simulink a simulation model of staggered planting was built based on the following assumptions: reference line distances on opposite edges of the field parallel to the surface field of the flat, air resistance is ignored, sliding or slipping distance measuring wheel is not presented, the seeds are sown in the furrow with the free fall acceleration and fixed in the tangent point with the ground, the speed of a drill is variable. (Results and discussion) To visualize the operation of the algorithm for controlling the flaps of even and odd sections of the drill, the article presents a graph of the placement of seeds relative to the specified position of opening the flaps in several rows of seeding. Authors have described analytical dependencies for calculating the offset of opening the shutters of seed sections, which are used in a special program for selecting the optimal number of encoder pulses. It was found that this minimizes the values of the offset ΔL per 1000 meters of passage (ΔL = 8.48 × 10-5 - 8.50 × 10-5 meters) and ensures precise coordination of the seeder's actuators in the field. (Conclusions) It was found that an increase in the speed of the seeder leads to a violation of the chess scheme of placing seeds on the field due to their spread in the furrow. It was found that to reduce the spread of seeds in the furrow and comply with the staggered distribution scheme, it is necessary to upgrade the coulter system of the rowed seeder or to carry out sowing at a speed below 2.5 meters per second, which will negatively affect the productivity of the sowing unit.

THE ROLE OF RELIGIOUS COURT IN PREVENTION UNDERAGE MARRIAGE

Indonesia is the second highest country in ASEAN in the prevalence of underage marriage after Cambodia and ranks 7th highest in the world for the absolute number of child brides. The tangent point of child marriage with the Religious Court enters through the case of marriage dispensation. As the authority of the Religious Courts, marriage dispensation is very dilemmatic and debatable because simultaneously the case is biased in value, between benefit, harmness, and community behavior. In sociology, society always changes and the difference is only in the nature or level of change. One of the fundamental aspects of the reflection of the Religious Court decisions that put forward efforts to prevent child marriages is to narrow the space for filing child marriage cases, examine the case more carefully by adding to the burden of proof, and the commitment of the parties to respond to the negative consequences of child marriages.

Sliding Dynamics of a Filippov Forest-Pest Model with Threshold Policy Control

A novel Filippov forest-pest system with threshold policy control (TPC) is established while an economic threshold (ET) is used to guide switching. The aim of our work is to address how to reasonably and successfully control pests by means of sliding dynamics for the Filippov system. On the basis of the above considerations, conditions for the existence and stability of equilibria of subsystems are addressed, and the sliding segments and several types of equilibria of the proposed system are defined. These equilibria include the regular/virtual equilibrium, pseudoequilibrium, boundary equilibrium, and tangent point. Further, not only are the relations between nullclines and equilibria of the Filippov system discussed, but the relations between pseudoequilibrium, nullclines, and the sliding segment are discussed. More importantly, four cases of sliding bifurcations of the Filippov system with respect to different types of equilibria of subsystems are investigated, and the corresponding biological implications concerning integrated pest management (IPM) are analyzed. Our results show that the points of intersection between nullclines are equilibria of the system, and the two endpoints of the sliding segment are on the nullclines. It is also verified that the pseudoequilibrium is the point of intersection of the sliding segment and nullclines of the Filippov system, and the pseudoequilibrium exists on the sliding segment. More interestingly, sliding dynamics analysis reveals that the Filippov system has sliding limit cycles, a bistable state and a stable refuge equilibrium point, and the optimal time and strategy for controlling pests are provided.

Racing videogame players’ driving experience in natural context does not affect gaze strategy towards tangent point during simulated curve negotiation, but the curvature angle does

During curve negotiation, drivers tend to look at the tangent point of the curve (TP) to control steering. There is a lack of evidence on how experiences of natural and simulated driving are related. The purpose of this study was to investigate effects of experience in natural driving on gaze behavior of racing videogame players. Additionally, it aimed to identify possible effects of curvature angle on fixation patterns. Twenty video game players composed two groups: drivers-gamers and no-drivers-gamers. Participants had their eye movements recorded while performing three laps racing on a videogame circuit, which had eleven curves. Areas of interest were defined relative to TP: 3 degrees, 10 degrees of visual angle, and Others. Dependent variables were: Number of Fixations and Total Duration of Fixations. Results showed that natural context driving experience did not change the tangent point visual strategy during curve negotiation in a racing videogame environment. All participants spent approximately half of their number of fixations and total fixation time within 10 degrees around the tangent point. Curvature angles modified fixation patterns, causing higher number of fixations and total fixation time during sharper curves.

Molecular bow shock in the 3 kpc Norma Arm

A molecular bow shock (MBS) at G24.4+00+112 (l ∼ 24${^{\circ}_{.}}$4, b ∼ 0°, vLSR ∼ 112 km s−1) is studied using the 12CO(J = 1–0)-line survey obtained with the Nobeyama 45 m telescope at 20″ (0.71 pc) resolution. The terminal velocity uniquely locates the object at the tangent point of the 3 kpc expanding arm (Norma arm) with the distance of 7.3 kpc. The bow ridge extends over ∼160 pc (1${^{\circ}_{.}}$3) perpendicularly to the galactic plane, and is concave to a ring of H ii-regions centered on G24.6+00 at the same distance. The edge on the down-stream (higher longitude) side of the MBS is extremely sharp, and is associated with several elephant trunks in gear-to-gear contact with the H ii regions. On the up-stream (lower longitude) side of MBS, a broad H i bow is associated at the same velocity. The coherently ordered structure of H i, CO, and H ii gases indicates H i-to-H2transition at the galactic shock followed by efficient star formation due to dual compression, where the molecular gas is shock-compressed from the up-stream side by galactic shock and from the down-stream side by H ii expansion. We propose a scenario of galactic sequential star formation along the spiral arms. We also discuss related ISM phenomena such as the hydraulic jump, bow shock, and Rayleigh–Taylor instability occurring around the MBS.