The center path of the 21 June 2020 solar eclipse, which passed through Guam (13.62°N, 144.86°E, 94.6% obscuration), United States, at end its journey, provides a peculiar opportunity to study ionospheric changes as moon shadow moves into nightside. In this study, remote-sensing observations ionosphere taken from ionosonde, and total electron content International GNSS Service over were analyze...

Economists have speculated for at least a century that the social return to education may exceed the private return. In this paper, I estimate spillovers from college education by comparing wages for otherwise similar individuals who work in cities with di*erent shares of college graduates in the labor force. A key issue in this comparison is the presence of unobservable characteristics of indi...

Context. The contrast of granulation is an important quantity characterizing solar surface convection. Aims. We compare the intensity contrast at 630 nm, observed using the Spectro-Polarimeter (SP) aboard the Hinode satellite, with the 3D radiative MHD simulations of Vögler & Schüssler (2007). Methods. A synthetic image from the simulation is degraded using a theoretical point-spread function o...

Context. Among optical stellar interferometers, the CHARA Array located at Mt Wilson in California offers the potential of very long baselines (up to 330 m) and the prospect of coupling multiple beam combiners. This paper presents the principle and the measured performance of VEGA, Visible spEctroGraph and polArimeter installed in September 2007 at the coherent focus of the array. Aims. With 0....

Bu çalışmada, saf nikel oksit (NiO) ve Evropiyum (Eu) katkılı NiO nanoparçacıklar sol-jel yöntemi kullanılarak sentezlendi. Ni kaynağı olarak Nikel (II) asetat tetrahidrat Eu ise klorür kullanıldı. Sentezleme işlemi 80 ℃’de 3 saat sürede gerçekleştirildi. Sentezlenen 450 1 süreyle tavlandı. Nanoparçacıkları oluşturan bileşikler X-ışını kırınımı (XRD) analiz edildi. Nanoparçacıkların morfolojile...

For sensing systems that characterize the spectro-polarimetric radiance reaching the camera, the origin of the sensed phenomenology is a complex mixture of sources. While some of these sources do not contribute to the polarimetric signature, many do such as the downwelled sky polarization, the target and background pBRDF(polarimetric bi-directional reflectance distribution function), the upwell...