MAGY: An innovative high voltage–low current power supply for gyrotron

From the electrical point of view, the body and the anode of high power gyrotrons behave as capacitive loads. A highly dynamic power supply is, therefore, hard to achieve. The MAGY concept (Modulator for the Anode of a triode type GYrotron) embodies an innovative solution to manage the capacitive current ensuring a very low ripple on the output voltage. It consists of a series of independent, bi-directional and regulated DC sources. Compared to existing topologies, this solution requires a smaller number of power modules. It avoids internal high frequency modulation and simultaneously offers high resolution of the output voltage and a wide range of operating scenarios.     

Polycarbonate-based ordered arrays of electrochemical nanoelectrodes obtained by e-beam lithography

Ordered arrays of nanoelectrodes for electrochemical use are prepared by electron beam lithography (EBL) using polycarbonate as a novel e-beam resist. The nanoelectrodes are fabricated by patterning arrays of holes in a thin film of polycarbonate spin-coated on a gold layer on Si/Si(3)N(4) substrate. Experimental parameters for the successful use of polycarbonate as high resolution EBL resist are optimized. The holes can be filled partially or completely by electrochemical deposition of gold. This enables the preparation of arrays of nanoelectrodes with different recession degree and geometrical characteristics. The polycarbonate is kept on-site and used as the insulator that separates the nanoelectrodes. The obtained nanoelectrode arrays (NEAs) exhibit steady state current controlled by pure radial diffusion in cyclic voltammetry for scan rates up to approximately 50 mV s( - 1). Electrochemical results showed satisfactory agreement between experimental voltammograms and suitable theoretical models. Finally, the peculiarities of NEAs versus ensembles of nanoelectrodes, obtained by membrane template synthesis, are critically evaluated.     

Time relations between scientific production and patenting of knowledge: the case of nanotechnologies

Nanosciences and nanotechnologies are considered important for the development of science, technology and innovation, and the study of their characters can be a great help to the decisions of policy makers and of practitioners. This work is centred on the issue of the time relations between science and technology/innovation, and in particular on the speed of transfer of science-generated knowledge towards its exploitation in patenting. A methodology based on patent citations is used in order to measure the time lag between cited journal articles and citing patent, and thus the time proximity between the two steps. Keywords regarding nanotechnology/nanoscience items are searched in order to collect data useful for the analysis. Collateral measures, performed on another class of materials and on the spatial origin of citing/cited documents, help giving evidence of the peculiarity of the behaviour and on its nature. The most representative time lag between production of scientific knowledge and its technological exploitation appears being around 3–4 years.     

The effects of water management on annual maximum floods of Lake Como and River Adda at Lecco (Italy)

This paper presents the results of an analysis aimed to assess the impact exerted on the flood regime of Lake Como and its emissary by different kinds of waterworks in the Adda basin (Italy). This includes construction of reservoirs in the Alps, increase in flow capacity of the exutory and regulation of Lake Como. The assessment of the management effect on peak floods is of particular interest as flood damages could be particularly heavy in densely populated areas along the lake banks and in the river flood plain downstream of the lake. The analysis is carried out by comparing the annual maxima of Lake Como levels and the river Adda discharges at Lecco, at the lake exutory, in different real and hypothetical situations. Both the construction of alpine reservoirs and the improvement of flow capacity of the exutory decrease lake levels and flood discharges, while lake regulation (for irrigation and power production) increases them. The overall effect is a generalised reduction of the flood levels and a slight increase in the discharges with return periods lower than 10 years. The discharges with higher return periods, instead, remain unchanged. The difference between peak and mean daily discharges negligible in all cases disappears altogether for return periods higher than 10 years.     

达涅利中板和炉卷轧机自动控制技术:Trametal,Valsider,KSC.

达涅利自动化公司在最近两年得到3个中板／炉卷轧机自动控制系统订货合同。这些自动控制系统是建立在达涅利HiPAC平台和建立在基于VME基础上的标准高性能平台上。介绍了这3套轧机的自动控制系统。其中Trametal中板轧机在意大利，Valsider炉卷轧机也在意大利，新建的宽板轧机KSC在伊朗。     

OPERATING PROBLEMS OF DISTILLATION COLUMNS: A DISCUSSION

A qualitative knowledge of how a continuous distillation column is expected to react to a physical parameter variation is often required, both in simulation and in practical operation. The topic is discussed in this paper with the aim to indicate some simple predictive rules concerning the steady-state variations, both under open- and closed-loop control. The binary distillation in conventional and non-conventional columns is examined in detail; some indications are also given for the multicomponent distillation in conventional columns. Geometrical constraints and asymptotic solutions are the basis for the adopted approach.     

The influence of ramped forcing on safe basins in a mechanical oscillator

This paper considers the behaviour of a mechanical oscillator with cubic nonhnearity subjected to a forcing excitation whose frequency remains constant while the amphtude is ramped, growing until it reaches a predetermined value. Behaviour of the system under such forcing is investigated with direct comparison with its constant-amplitude counterpart. We focus our attention on the nature of the basins of attraction noting the appearance of fractal basin boundaries which herald the onset of a loss of structural integrity and in particular we study transient behaviour captured within a safe basin. As might be expected,reduced forcing amplitudes lead to initial transients whose characteristics delay bifurcational events. However, it is noted with serendipity that the rate at which the system isramped does not follow a simple monotonic relationship.     

Reduction rules for time Petri nets

 The goal of net reduction is to increase the effectiveness of Petri-net-based real-time program analysis. Petri-net-based analysis, like all reachability-based methods, suffers from the state explosion problem. Petri net reduction is one key method for combating this problem. In this paper, we extend several rules for the reduction of ordinary Petri nets to work with time Petri nets. We introduce a notion of equivalence among time Petri nets, and prove that our reduction rules yield equivalent nets. This notion of equivalence guarantees that crucial timing and concurrency properties are preserved. Received September 12, 1994/July 4, 1995