This paper reports about a new proposed methodology, where active energy meters are tested under conditions directly recorded at installation sites. This allows for the reproduction of specific, not only realistic, low power quality as observed on the field. A portable instrument is employed to sample on-field voltage and current waveforms, which are then replicated in a laboratory setting using a phantom power generator with a bandwidth covering up to the 40 th harmonic. The recording site chosen is the coupling section between the distribution grid and a photovoltaic energy production facility with a nominal power of 50 kW. Laboratory recreated waveforms are used to tested three-phase commercial static energy meters. The selected models encompass those utilized by energy providers at the point of common coupling, as well as meters typically employed for in-line monitoring by end users. The key focus is on the reading error of the measured active energy when subjected to conditions mimicked from on-field measurements, in comparison with a reference meter.

Metrological characterisation of static energy meters under realistic low power quality conditions is a basic requirement for proper grid control and fair energy billing. The paper reports about a new proposed methodology, where the meters are tested under conditions directly recorded at installation sites. The waveforms of voltages and currents are sampled using a portable instrument; they are reproduced in laboratory conditions with a phantom power generator, with a bandwidth covering up to the 40th harmonic. The recording site is a photovoltaic energy production facility, having a a nominal power of 50 kW, at the coupling section to the grid. These waveforms were then reproduced in the laboratory, and tested on different models of single- and three-phase commercial static energy meters; the models chosen represent both energy meters used by energy providers at the point of common-coupling, and also meters typically used for in-line monitoring by end users. The quantity of interest is the reading error of the measured energy, when tested with the conditions reproduced from the on-field measurements, in comparison with a reference meter. All tested energy meter models comply with the present international documentary standards, which require tests under low power quality conditions; nevertheless, there are models that show unacceptable errors (up to 25%) in the measurement of active energy when tested with the on-field recorded waveforms. This suggests that the standardised testing waveforms might, in some cases, be not fully representative of the actual conditions encountered in the field.

In this work we present a method for testing static active energy meters in low power quality conditions recorded at installation sites.Voltage and current waveforms recorded on the field with a calibrated portable instrument were reproduced with an accurate phantom power generator up to the 40 th harmonic.The error on the active energy measurement of an energy meter under test (W DUT ) in conditions reproduced from the on-field measurements was evaluated in comparison with a reference meter (W REF ).On-field data were recorded at a 50 kW self production photovoltaic facility.This method allows the laboratory reproduction of realistic (distorted) on-field conditions in a metrologically traceable framework.

A calibration/verification testbed for electrical energy meters is under development at the Istituto Nazionale di Ricerca Metrologica, the National Metrology Institute of Italy. The testbed will be employed for the calibration of commercial static power energy meters under low power conditions and for simulating the verification in the field of energy meters under real operational conditions. The activity is in collaboration with the Ministry for Economic Development and aims to the future development of regulatory documents for energy metering verification.

New low molar mass (M-n similar to 20 kg mol(-1)) polystyrene-b-poly(methyl methacrylate-co-perfluorohexylethyl acrylate) (PS-b-P(MMA-co-FA)) block copolymers were synthesized all consisting of similar to 70 mol% PS block and similar to 30 mol % P(MMA-co-FA) block. The amount of FA counits in the latter block was increased (0.5, 1, 3 and 4 mol%) in order to enhance the incompatibility between the two blocks and to form different self-assembled nanostructures. The block copolymers were thermally annealed by Rapid Thermal Processing (RTP) over wide ranges of temperatures and times. Complementary SEM and AFM analyses evidenced that the introduction of FA counits above a critical content (similar to 2 mol%) drove a self-assembly process through mixed morphologies. These were formed at a distance from the polymer-air interface and consisted of perpendicular cylinders of P(MMA-co-FA) in a PS matrix laying at the substrate- polymer interface, and surmounted PS stripes and PS dots. Modification by low amounts of FA produced block copolymer samples that self-assembled in new, mixed nanostructures, even though they possessed much lower molar masses than those of analogous well established PS-b-PMMA block copolymers.

Lithography on a sub-100 nm scale is beyond the diffraction limits of standard optical lithography but is nonetheless a key step in many modern technological applications. At this length scale, there are several possible approaches that require either the preliminary surface deposition of materials or the use of expensive and time-consuming techniques. In our approach, we demonstrate a simple process, easily scalable to large surfaces, where the surface patterning that controls pore formation on highly doped silicon wafers is obtained by an electrochemical process. This method joins the advantages of the low cost of an electrochemical approach with its immediate scalability to large wafers.

The organic/inorganic interface in thin nanosized porous structures has a key role in determining the final properties of the composite materials. By use of the porous silicon/eumelanin hybrids as a case study, the role of this interface was investigated by experimental and computational methods. Our results show that an increased polymer density close to the hybrid interface strongly modifies the diffusion of the chemical species within the polymer molecule, affecting then the oxidation level of the pores’ inner Si surface. We observed a greater stability induced by increased pore diameter, a behavior that with computational and chemical arguments we attributed to a modified diffusion of the hydrogen peroxide toward the Si/eumelanin interface. Our results show that the overall behavior of a polymer when inserted in a tiny nanoscale structure must be taken into account for a correct understanding and control of the hybrids properties and that the formation of the interface alone may not be sufficient.

The self-assembly (SA) of diblock copolymers (DBCs) based on phase separation into different morphologies of small and high-density features is widely investigated as a patterning and nanofabrication technique. The integration of conventional top-down approaches with the bottom-up SA of DBCs enables the possibility to address the gap in nanostructured lateral length standards for nanometrology, consequently supporting miniaturization processes in device fabrication. On this topic, we studied the pattern characteristic dimensions (i.e., center-to-center distance L0 and diameter D) of a cylinder-forming polystyrene-b-poly( methyl methacrylate) PS-b-PMMA (54 kg mol-1, styrene fraction 70%) DBC when confined within periodic SiO2 trenches of different widths (W, ranging between 75 and 600 nm) and fixed length (l, 5.7 μm). The characteristic dimensions of the PMMA cylinder structure in the confined configurations were compared with those obtained on a flat surface (L0 = 27.8 ± 0.5 nm, D = 13.0 ± 1.0 nm). The analysis of D as a function of W evolution indicates that the eccentricity of the PMMA cylinders decreases as a result of the deformation of the cylinder in the direction perpendicular to the trenches. The center-to-center distance in the direction parallel to the long side of the trenches (L0l) is equal to L0 measured on the flat surface, whereas the one along the short side (L0w) is subjected to an appreciable variation (ΔL0w = 5 nm) depending on W. The possibility of finely tuning L0w maintaining constant L0l paves the way to the realization of a DBC-based transfer standard for lateral length calibration with periods in the critical range between 20 and 50 nm wherein no commercial transfer standards are available. A prototype transfer standard with cylindrical holes was used to calibrate the linear correction factor c(Δx')xx' of an atomic force microscope for a scan length of Δx' = 1 μm. The relative standard uncertainty of the correction factor was only 1.3%, and the second-order nonlinear correction was found to be significant.

Ordered magnetic nanodot arrays with extremely high density provide unique properties to the growing field of nanotechnology. To overcome the size limitations of conventional lithography, a fine-tuned sputtering deposition process on mesoporous polymeric template fabricated by diblock copolymer self-assembly is herein proposed to fabricate uniform and densely spaced nanometer-scale magnetic dot arrays. This process was successfully exploited to pattern, over a large area, sputtered Ni80Fe20 and Co thin films with thicknesses of 10 and 13 nm, respectively. Carefully tuned sputter-etching at a suitable glancing angle was performed to selectively remove the magnetic material deposited on top of the polymeric template, producing nanodot arrays (dot diameter about 17 nm). A detailed study of magnetization reversal at room temperature as a function of sputter-etching time, together with morphology investigations, was performed to confirm the synthesis of long-range ordered arrays displaying functional magnetic properties. Magnetic hysteresis loops of the obtained nanodot arrays were measured at different temperatures and interpreted via micromagnetic simulations to explore the role of dipole-dipole magnetostatic interactions between dots and the effect of magnetocrystalline anisotropy. The agreement between measurements and numerical modelling results indicates the use of the proposed synthesis technique as an innovative process in the design of large-area nanoscale arrays of functional magnetic elements.

The metal assisted etching mechanism for Si nanowire fabrication, triggered by doping type and level and coupled with choice of metal catalyst, is still very poorly understood. We explain the different etching rates and porosities of wires we observe based on extensive experimental data, using a new empirical model we have developed. We establish as a key parameter, the tunneling through the space charge region (SCR) which is the result of the reduction of the SCR width by level of the Si wafer doping in the presence of the opposite biases of the p- and n-type wafers. This improved understanding should permit the fabrication of high quality wires with predesigned structural characteristics, which hitherto has not been possible.

A multifunctional, semitransparent photovoltaic device is proposed for harvesting sunlight over a tunable spectral range extending from the UV to the IR. Self-assembled monolayers of nanospheres applied to luminescent concentrators provide a photon management architecture, which relies on luminescence and diffraction of light. The light diffraction is tuned by changing the sphere diameter to match the transparency region of the fluorophores. The importance of each optical mechanism is inferred from a systematic experimental investigation of the external quantum efficiency of fabricated devices, and from the calculation of the resulting photocurrent under the AM 1.5 solar spectrum. Compared to the conventional luminescent concentrator, relative photocurrent improvements are shown between 50% and 500% depending on the spectral properties of the device components. It has been demonstrated how to tailor the photovoltaic performances, the color and the degree of transparency of the device to provide a versatile photovoltaic unit for sustainable building-integrated applications.

The ordering process of asymmetric PS-b-PMMA block copolymers (BCPs) is investigated on flat SiO2 surfaces and on topographically patterned substrates. The topographic patterns consist of periodic gratings of 10 trenches defined by conventional top-down approaches and subsequently neutralized using a P(S-r-MMA) random copolymer (RCP). When the ordering process is accomplished on a flat surface at a temperature ranging between 180 and 230 °C, cylindrical microdomains perpendicularly oriented with respect to the substrate are observed irrespective of annealing temperature. In contrast, when the ordering process occurs on topographically patterned substrates, different phenomena have to be considered. The simultaneous effect of the flow around the gratings and the BCP flux from the zone located between adjacent trenches (mesa) into the inner part of the trenches results in significant thickness variations of the confined BCP film. Therefore, the amount of BCP inside the trenches depends on the width of the mesa region, which acts as a BCP reservoir. Moreover, within each trench group, the BCP thickness progressively decreases from the external to the central trenches composing the periodic grating. The thickness variation of the BCP film within the trenches strongly affects the ordering process, ultimately leading to different orientations of the microdomains within the trenches. In particular, when the annealing temperature is 190 °C a precise confinement of the BCP within the trenches featuring a perpendicular cylinder morphology is observed. At higher temperatures, mixed or parallel orientations of the microdomains are obtained depending on the width of the trenches in the periodic grating.

Summary form only given. Synthesis of nanopatterned magnetic materials offers advanced capabilities in tailoring material structures and opens up new opportunities for engineering innovative devices (i .e . electronic and biomedical) . In the frame of magnetic materials, the most demanding application consists in fabricating high-density arrays for use in data storage and magnetic sensors for spintronics [1] . In the last decade, many routes for the reliable fabrication of magnetic nanostructures have been extensively investigated, including top-down lithography and bottom-up self-assembly processes . Conventional electron beam lithography (EBL) soon turned out to be limited by low-speed and high costs while self-assembling emerged as a viable and handy alternative technique for designing nanostructures over a wide area on magnetic thin films . In the last decade, nanolithography routes based on self-assembling of polystyrene nanospheres resulted to be a viable and easy-to-use process to pattern a variety of magnetic thin films with mean nanostructure diameter as low as 70 nm [2] . To overcome such a limitation, the capability of soft materials such as block copolymers (BC) to form a rich variety of low-dimensional, uniform periodic patterns have been exploited . This class of polymers offers unique opportunities to develop large area nanometer scale features having domain spacing typically dependent on molecular weight, segment size, and the strength of interaction between the blocks . In this work, block-copolymer (BCP) - based lithography has been exploited to fabricate uniform, densely spaced nanometer - scaled on Ni80Fe20 and Co sputtered thin film having 10 nm thickness by a novel process shown in Fig 1 (panel 1) . In particular, a Random Copolymer (RCP) brush layer was grafted on the Si substrate in order to obtain the surface neutralization . A PS-b-PMMA Block Copolymer (BCP) film was subsequently deposited on the RCP, obtaining cylindrical features perpendicularly oriented with respect to the substrate . In this way, a patterned nanostructure having cylindrical features has been realized . The self-organization is promoted by means of a thermal annealing higher than the glass transition temperature of the BCP [3] . The magnetic layer is then deposited by RF sputtering . A careful evaluation of the propagation effect of the nanometric pattern to the magnetic thin film has been performed with the aim to optimise nanostructures and preserve the magnetic properties of the continuous film . A systematic morphological study has been made by Scanning Electron (SEM) microscopy . A SEM image of a Ni80Fe20 dot array is reported as an example in Fig . 1 (panel 2, mean dot diameter 17 nm) where a very fine, well ordered dotted structure arranged in an hexagonal lattice is observed . Room-temperature magnetic behavior has been studied by magnetisation measurements by means of ultra-sensitive magnetometry techniques following the hysteresis loop changes at each stage of the synthesis process . Hysteresis loops of patterned films have been measured as a function of temperature in the interval 5 - 300 K . Selected loops indicating their temperature behavior are reported in Fig 1 (panel 3) . A sudden increase of coercive field is observed in the curve at 5 K . In particular, coercive field behavior as function of measuring temperature is characterised by an almost constant value up to reach 50 K followed by an increase up to the lowest temperature . Micromagnetic simulations have been performed to analyze the effect on hysteresis loops of the patterned film morphological properties taking into account different magnetic anisotropy values and investigating the influence of non-complete hexagonal order (presence of nanodomains and local defects, as dot interconnections) on magnetic behavior.