5,870 research outputs found
Lu-177g produced with high specific activity by deuteron irradiation for metabolic radiotherapy
No full textLu-177g is a low energy negatron emitter that, thanks to its favourable decay properties (t(1/2) = 6.734 d, negatron emission 100 %, E(β,max) = 489.3 keV, = 163 keV, Eγ = 208.4 keV), is one of the most promising radionuclide to be used in nuclear medicine, especially in metabolic radiotherapy of cancer of small dimensions. This RN is mainly produced in thermal nuclear reactor in two different ways: the first in carrier added (CA) form by (n,γ) reaction on enriched target of Lu-176 leading to a lower specific activity (AS), compared with the theoretical carrier free value AS(CF) = 4.05 GBq•μg^-1, the second in no carrier added (NCA) form by (n,γ) reaction on enriched target of Yb-176 followed by negatron decay leading, after selective separation of Lu from Yb, to a higher AS. This latter case shows no evidence of production of the long-lived impurity Lu-177m. An alternative method is to produce Lu-177 by the deuteron activation of natural or enriched in 176Yb targets. In this case, the routes of interest are the indirect reaction Yb-176(d,p)Yb-177 that decays by negatron emission to Lu-177g and the direct reaction Yb-176(d,n)Lu-177(g+m).
In order to optimize the Lu-177g production the thin target yields (ttys) of the nuclear reactions involved were measured as a function of the projectiles energy by the stacked-foil technique irradiating Yb targets of natural composition at the MC40 cyclotron of the JRC, Ispra, Italy, that can deliver deuterons with energies up to 19 MeV. The measurements, done at the radiochemistry laboratory of LASA by high resolution gamma spectrometry (HPGe detectors), were started few hours from the EOB (end of bombardment) and were carried on for many months, till more than one year, after the irradiation.
The excitation functions of all radionuclides produced were measured and compared with the data, if present, published in the unique previous literature publication. It was determined the decay curve of Yb-177 and the growth curve of the cumulative (direct and indirect) production of Lu-177g. The analysis of these curves conduct to the evidence that the predominant route for the production of Lu-177g is the indirect reaction Yb-176(d,p)Yb-177, that decays to Lu-177g. The direct reaction Yb-176(d,n)Lu-177(g+m) is observable only above 13 MeV and contributes for only 4% of the total in correspondence of 14.6 MeV. In the spectra acquired one year from the EOB the γ lines of Lu-177m are not presented. By detection limit method the activity of Lu-177m at the EOB is been evaluated, in the worst case, less than 0.07% of total activity of Lu-177.
The production of Lu-117g by deuteron irradiation of Yb targets will be competitive with neutron activation. The deuteron activation for 12 hours of a thick target of Yb-176 (100% enriched) with E(in) = 12.5 MeV, ΔE = 10.0 MeV, I = 100 μA can produce up to 10 GBq of cumulative Lu-177g
Representing fuzzy numbers for fuzzy calculus
Full text linkIn this paper we illustrate the LU representation of fuzzy numbers and present an LU-fuzzy calculator, in order to explain the use of the LU-fuzzy model and to show the advantage of the parametrization. The model can be applied either in the level-cut or in generalized LR frames. The hand-like fuzzy calculator has been developed for the MSWindows platform and produces the basic fuzzy calculus: the arithmetic operations (scalar multiplication, addition, subtraction, multiplication, division) and the fuzzy extension of many univariate functions (exponential, logarithm, power with numeric or fuzzy exponent, sin, arcsin, cos, arccos, tan, arctan, square root, Gaussian, hyperbolic sinh, cosh, tanh and inverses, erf and erfc error functions, cumulative standard normal distribution).Fuzzy Sets, LU-fuzzy Calculator, Fuzzy Calculus, Parametric LU represemtation
Enhanced photocurrent gain and spectrum range based on the composite consisting of SnO2 nanowires and CdSe quantum dots
No full textRealtà, realismo, straniamento : Auerbach e il romanzo cavalleresco fino a Cervantes
No full textAuerbach’s research, besides exploring the three main fields the author explicitly names (i.e. the succession of different and differently grounded forms of realism in literary fiction, the alternate splitting and melting of styles, the link between literary work and a Christian vision of the world), in various chapters of Mimesis, and particularly in chs. 2, 6, 12, 14 and 20, is also focused, albeit only implicitly, on the developments of a further distinctive feature in Western literature, which is the emergence of subjectivity in the representation of reality. Focusing mainly on the chapter on courtly romance (ch. 6) and on the Quijote (ch. 14), this essay will examine Auerbach’s interpreting work on texts that adopt, in different ways, a ‘subjective point of view’; this kind of interpretation is, in part, unexpectedly similar to the approach of other critics and theorists of literature contemporary to Auerbach, like Bachtin, Américo Castro and Viktor Šklovskij
Shedding light on the black hole: The roll-out of broadband access networks by private operators
No full textSeveral market studies have indicated that the roll-out of broadband has significant economic and social relevance. The investments in broadband infrastructures needed to realise these economic and social benefits are, however, high-risk. This is firstly caused by the fact that the roll-out of access networks is extremely costly and requires high initial investments. Moreover, the multidisciplinary environment and involvement of many actors with diverging objectives and interests cause high complexity. Moreover, the market for broadband is changing fast and continuously. Although broadband has been on the academic research agenda for quite some time, this has as yet not resulted in a structured insight into the decision-making process around the upgrading of broadband networks, seen from the perspective of private operators and taking into account the vast complexity of the surroundings in which this decision-making process takes place in. The objective of this research was to provide a unifying theory combining technical, economic, market-related and regulatory factors with regard to an evolutionary, flexible approach of network upgrading from a decision-maker perspective. The result of this research is a robust, explanatory, parsimonious model for the impact and outcomes of broadband roll-out. This model provides a certain degree of stability in this multidisciplinary, unpredictable and highly dynamic research field.Technology, Policy and Managemen
An LU-fuzzy calculator for the basic fuzzy calculus
Full text linkThe LU-model for fuzzy numbers has been introduced in [4] and applied to fuzzy calculus in [9]; in this paper we build an LU-fuzzy calculator, in order to explain the use of the LU-fuzzy representation and to show the advantage of the parametrization. The calculator produces the basic fuzzy calculus: the arithmetic operations (scalar multiplication, addition, subtraction, multiplica- tion, division) and the fuzzy extension of many univariate functions (power with integer positive or negative exponent, exponential , logarithm, general power function with numeric or fuzzy exponent, sin, arcsin, cos, arccos, tan, arctan, square root, Gaussian and standard Gaussian functions, hyperbolic sinh, cosh, tanh and inverses, erf error function and complementary erfc error function, cu- mulative standard normal distribution). The use of the calculator is illustrated.Fuzzy Sets, LU-fuzzy Calculator, Fuzzy Calculus
A one-transistor synapse circuit with an analog LMS adaptive feedback for neural network VLSI
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