Does ADS 9346 have a low-mass companion?

Based on the photographic and CCD observations of the relative motion of the A and B components of the binary system ADS 9346 obtained with the 26-inch refractor of Pulkovo Observatory during 1979–2019, we discover an invisible companion associated with star A. Comparison of the ephemerides with the positional and spectroscopic observations allowed us to calculate the preliminary orbit of the photocenter (P = 15 yr). The minimal mass of the companion is approximately 0.13 M ⊙. The existence of the invisible low-mass companion is implied by the IR-excess based on IRAS data. To confirm this, additional observations of the radial velocity near the periastron need to be carried out.

Highly Efficient Iron Oxide Nanoparticles Immobilized on Cellulose Nanofibril Aerogels for Arsenic Removal from Water

The application and optimal operation of nanoparticle adsorbents in fixed-bed columns or industrial-scale water treatment applications are limited. This limitation is generally due to the tendency of nanoparticles to aggregate, the use of non-sustainable and inefficient polymeric resins as supporting materials in fixed-bed columns, or low adsorption capacity. In this study, magnesium-doped amorphous iron oxide nanoparticles (IONPs) were synthesized and immobilized on the surface of cellulose nanofibrils (CNFs) within a lightweight porous aerogel for arsenic removal from water. The IONPs had a specific surface area of 165 m2 g−1. The IONP-containing CNF aerogels were stable in water and under constant agitation due to the induced crosslinking using an epichlorohydrin crosslinker. The adsorption kinetics showed that both As(III) and As(V) adsorption followed a pseudo second-order kinetic model, and the equilibrium adsorption isotherm was best fitted using the Langmuir model. The maximum adsorption capacities of CNF-IONP aerogel for As(III) and As(V) were 48 and 91 mg As g-IONP−1, respectively. The optimum IONP concentration in the aerogel was 12.5 wt.%, which resulted in a maximum arsenic removal, minimal mass loss, and negligible leaching of iron into water.

A-36 Case Study of Cerebellar Cognitive Affective Syndrome in 17-Year-Old Male with Cerebellar Arachnoid Cyst

Objective Arachnoid cysts are often congenital and asymptomatic, however, they may contribute to neurocognitive symptoms when there is a mass effect on the brain. This case study describes how a 17-year-old with cerebellar arachnoid cyst, and minimal mass effect exhibited symptoms of cerebellar cognitive affective syndrome (CCAS), which has been mostly associated with brain tumor or injury in prior research. Method In this case study, a posterior cerebellar arachnoid cyst (midline) was identified incidentally (via CT scan and later MRI) following a panic attack associated with face twitching, motor tremors, and clumsiness. Background history was collected via medical records, neurologist consultation, and parent and patient interview. Patient history was significant for speech, language, motor, and academic delays. Results Results of a comprehensive evaluation revealed deficits in perceptual reasoning, visual memory, fine motor functioning, attention, processing speed, executive functioning, social cognition and receptive/expressive language. Multi-informant ratings indicated anxiety. Reading, writing, and mathematics fell several years below grade- level in the context of low average intellectual ability (WAIS-IV: GAI = 88). Conclusions Many deficits in this neuropsychological profile are typically subsumed by the cerebellum or its associated networks, and overlap with CCAS. The findings of this case study warrant consideration by clinicians of functional impairment related to cerebellar cysts and expansion of our knowledge-base of cerebellar function.

Blow-up solutions with minimal mass for nonlinear Schrödinger equation with variable potential

This paper studies the mass-critical variable coefficient nonlinear Schrödinger equation. We first get the existence of the ground state by solving a minimization problem. Then we prove a compactness result by the variational characterization of the ground state solutions. In addition, we construct the blow-up solutions at the minimal mass threshold and further prove the uniqueness result on the minimal mass blow-up solutions which are pseudo-conformal transformation of the ground states.

ВИЗНАЧЕННЯ ПОТРІБНОГО ПИТОМОГО НАВАНТА-ЖЕННЯ НА КРИЛО РАКЕТИ

Wing loading severely affects the mass of a missile as well as its flight performance. For airplanes this parameter must not exceed allowable values calculated from different requirements especially related to such cases as lift-off, landing, cruise flight and aircraft maneuverability. For missiles wing loading is determined considering launch conditions and providing the necessary maneuverability. Appropriate estimation of wing loading at the initial design stages guarantees the minimal mass of an aircraft with all tactical requirements met.Review of available literature, related to missile design, has shown that the problem of optimal wing loading estimation contains lengthy and quite approximate analytical expressions.This article is dedicated to the development of a missile wing loading estimation technique that provides minimal propellant mass fraction and total mass of an aircraft while meeting tactical requirements.Impact of wing loading onto propellant mass fraction, maximal maneuverability and total mass of a missile is considered. The algorithm of optimal wing loading estimation, which provides necessary tactical characteristics of a missile being designed, is proposed. We define simple polynomial approximations of both the trajectory and the velocity profile. Further analysis is being conducted using two considerations: for an air-based missile the value of wing loading has to provide flight during launch without fall movement as well as the maximal maneuverability at the moment when a missile intercepts the target.It is shown that for the wing loading in the range from 300 to 1000 kg/m2 the propellant mass fraction changes rapidly, and inaccurate selection of wing loading may lead to obtaining of an incorrect value of propellant mass fraction. For maximal maneuverability less than 40, inappropriate selection of wing loading may cause significant numerical error. Analysis of relation between wing loading and total mass of a missile revealed that there is a critical value of wing loading which depends on initial data and represents the low limit of an acceptable range.

Hawking evaporation of Einstein–Gauss–Bonnet AdS black holes in $$D\geqslant 4$$ dimensions

Einstein–Gauss–Bonnet theory is a string-generated gravity theory when approaching the low energy limit. By introducing the higher order curvature terms, this theory is supposed to help to solve the black hole singularity problem. In this work, we investigate the evaporation of the static spherically symmetric neutral AdS black holes in Einstein–Gauss–Bonnet gravity in various spacetime dimensions with both positive and negative coupling constant $$\alpha $$ α . By summarizing the asymptotic behavior of the evaporation process, we find the lifetime of the black holes is dimensional dependent. For $$\alpha >0$$ α > 0 , in $$D\geqslant 6$$ D ⩾ 6 cases, the black holes will be completely evaporated in a finite time, which resembles the Schwarzschild-AdS case in Einstein gravity. While in $$D=4,5$$ D = 4 , 5 cases, the black hole lifetime is always infinite, which means the black hole becomes a remnant in the late time. Remarkably, the cases of $$\alpha >0, D=4,5$$ α > 0 , D = 4 , 5 will solve the terminal temperature divergent problem of the Schwarzschild-AdS case. For $$\alpha <0$$ α < 0 , in all dimensions, the black hole will always spend a finite time to a minimal mass corresponding to the smallest horizon radius $$r_{min}=\sqrt{2|\alpha |}$$ r min = 2 | α | which coincide with an additional singularity. This implies that there may exist constraint conditions to the choice of coupling constant.