1,720,978 research outputs found
Efficient deep UV detection in polycrystalline diamond by double collection mechanism
No full textThe realization of position sensitive detectors for deep UV light monitoring is reported. Simple voltage
division structures have been developed based on photolithography defined resistive element. Deviations
from linearity of few percentage with the beam impinging position have been achieved
Il Monitoraggio Dei Bacini Fluviali Mediante Elaborazione Di Immagini Sar Telerilevate
No full textCagliar
Metal/Diamond/ Vacuum-type photodetector for ultraviolet radiation
No full textA deep UV photodetector with Metal/Diamond/Vacuum (MDV)-type structure has been developed on CsI coated polycrystalline diamond film. The device operation is based on the simultaneous collection of both photogenerated carriers by internal drift and photoelectrons emitted in the vacuum.
The performance of the detectors have been analyzed by measuring the total photosignal obtained when only an anode voltage is applied. The spectral distribution of such a photosignal reflects both the photoemission and photocurrent characteristics, which are combined together.
In a simple model, the principle of operation of such device has been described in terms of two capacitors connected in series, with the applied anode voltage partitioned between the diamond film and the vacuum, depending on their dielectric constant and thickness values. It will be shown that photomodulation of the diamond surface voltage is able to add the spectral characteristics of photocurrent signal to those of photoemission and to increase the device responsivity with respect to conventional detector structures
Elementary iodine-doped activated carbon as an oxidizing agent for the treatment of arsenic-enriched drinking water
Full text linkAn activated carbon impregnated with elementary iodine (I2), named IodAC, characterized by oxidation capability, was developed and applied to oxidize arsenite, As(III), to arsenate, As(V), in arsenic-rich waters. Batch and column experiments were conducted to test the oxidation ability of the material. Comparisons with the oxidizing agents usually used in arsenic treatment systems were also conducted. In addition, the material has been tested coupled with an iron-based arsenic sorbent, in order to verify its suitability for the dearsenication of drinking waters. IodAC exhibited a high and lasting oxidation potential, since the column tests executed on water spiked with 50 mg/L of arsenic (100% arsenite) showed that 1 cc of IodAC (30 wt% I2) can oxidize about 25 mg of As(III) (0.33 mmol) before showing a dwindling in the oxidation ability. Moreover, an improvement of the arsenic sorption capability of the tested sorbent was also proved. The results confirmed that IodAC is suitable for implementation in water dearsenication plants, in place of the commonly used oxidizing agents, such as sodium hypochlorite or potassium permanganate, and in association with arsenic sorbents. In addition, the well-known antibacterial ability of iodine makes IodAC particularly suitable in areas (such developing countries) where the sanitation of water is a critical topic
Electronic properties of hydrogen and oxygen terminated surfaces of polycrystalline diamond films
No full text
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
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