Since 1996 a monitoring campaign of the Galactic Bulge region has been performed by the BeppoSAX Wide Field Cameras in the 2–28 keV band. This allowed accurate and unbiased studies of classes of objects. In particular the type-I X-ray bursters, whose distribution is concentrated in the monitored sky region, have been investigated. High luminos-ity radius-expansion bursts have been observed from...

The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft completed three flybys of Mercury in 2008–2009. During the first and third of those flybys, MESSENGER passed behind the planet from the perspective of Earth, occulting the radio-frequency (RF) transmissions. The occultation start and end times, recovered with 0.1 s accuracy or better by fitting edgediffract...

Geodesy is the science of measurement or mapping of the properties of the Earth’s surface. A good example of an interesting problem in geodesy is the gravitation acceleration g(λ) on earth as a function of the latitude λ = π/2 − θ. (The angle θ in spherical coordinates is sometimes called the co-latitude angle.) For background, also read Marion # 10-7 and 10-20. Newton already suggested in Prin...

In these lectures we will develop a quantitative model to describe the structure of the observable Universe as a whole. To begin, let us review the relevant physical scales. An Earth mass is 6× 1027 g ≃ 3 × 1051 GeV/c2 ≃ 3× 10−6 M⊙. Its radius is 6.4 × 10 8 cm. It spins around the Sun, which has a mass M⊙ = 2 × 10 33 g ≃ 1057 GeV/c2 and radius R⊙ ≃ 7 × 10 10 cm. The Earth-Sun distance is 1AU = ...

The n-body problem for low-thrust vehicles with optimal thrust control is formulated for the case of constant thrust with coast. A successive two-body approximation to the n-body problem is also developed under the assumption of tangential thrust during the planetocentric leg. This approximation involves one arbitrary parameter the planetocentric radius at the patch point whose best value can b...

Metaheuristic optimization algorithms present an effective method for solving several problems from various types of applications and fields. Several metaheuristics evolutionary have been emerged recently in the literature gained widespread attention, such as particle swarm (PSO), whale algorithm (WOA), grey wolf (GWO), genetic (GA), gravitational search (GSA). According to literature, no one m...

Mechanisms of uptake of rare earth elements (REEs) were investigated, particularly those by REE accumulator species (autumn fern). Rare earth elements are practically insoluble under natural conditions, suggesting some unknown mechanism in REE accumulator species. In the present investigation, two notable phenomena were observed. (I) Concerning the ionic-radius dependence of REE uptake by leave...