1,720,966 research outputs found
Pembuatan dan Karakterisasi Radioisotop Tulium-170 ( 170 Tm)
Full text linkTulium-170 ( 170 Tm) merupakan radioisotop pemancar β yang memiliki T1/2 = 128,4 hari dan E β (maksimum) sebesar 0,968 MeV. Radioisotop 170 Tm selain pemancar β juga memancarkan sinar γ dengan energi sebesar 84 keV (3,26%) yang dapat digunakan untuk penyidikan (imaging) selama terapi berlangsung. Berdasarkan sifat radionuklidanya, 170 Tm dapat digunakan sebagai radioisotop alternatif dalam pembuatan radiofarmaka untuk paliatif pengganti 89 SrCl2. Pembuatan radioisotop 170 Tm telah dilakukan menggunakan sasaran tulium oksida (Tm2O3) alam yang diiradiasi di fasilitas iradiasi RSG-G.A. Siwabessy – Serpong. Bahan sasaran dilarutkan dengan larutan HCl 1 N sambil dikisatkan perlahan-lahan sampai hampir kering, kemudian dilarutkankembali dengan akuabides steril. Larutan 170 TmCl3 diuji melalui pemeriksaan kemurnian radiokimia dengan cara kromatografi kertas dan elektroforesis kertas. Aktivitas dan kemurnian radionuklida larutan 170 TmCl3 ditentukan dengan menggunakan alat cacah spektrometer γ saluran ganda. Larutan radioisotop 170 TmCl3 yang diperoleh mempunyai pH antara 1,5 – 2, terlihat jernih, mempunyai aktivitas jenis dan konsentrasi radioaktif masing-masing sebesar 1,9– 2,7 mCi/mg dan 17 - 24 mCi/mL pada saat end of irradiation (EOI). Larutan 170 TmCl3 mempunyai kemurnian radiokimia sebesar 99,14 ± 0,42% dan kemurnian radionuklida sebesar100%. Hasil uji stabilitas larutan radioisotop 170 TmCl3 terhadap waktu penyimpanan menunjukkan bahwa setelah disimpan selama stabil dengan kemurnian radiokimia sebesar 99,43 ± 0,56%
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
