The influence of the preparation method of NiOx photocathodes on the efficiency of p-type dye-sensitised solar cells

Improving the efficiency of p-type dye-sensitized solar cells (DSCs) is an important part of the development of high performance tandem DSCs. The optimization of the conversion efficiency of p-DSCs could make a considerable contribution in the improvement of solar cells at a molecular level. Nickel oxide is the most widely used material in p-DSCs, due to its ease of preparation, chemical and structural stability, and electrical properties. However, improvement of the quality and conductivity of NiO based photocathodes needs to be achieved to bring further improvements to the solar cell efficiency. The subject of this review is to consider the effect of the preparation of NiO surfaces on their efficiency as photocathodes. (C) 2015 Elsevier B.V. All rights reserved

Nickel oxide photocathodes prepared using rapid discharge sintering for p-type dye-sensitized solar cells

This paper compares the photoelectrochemical performances of nickel oxide (NiO) thin films processed using two different sintering procedures: rapid discharge sintering (RDS) and conventional furnace sintering (CS). Prior to sintering, NiO nanoparticles were sprayed onto substrates to form loosely adherent nanoparticulate coatings. After RDS and furnace sintering the resultant NiO coatings were sensitized with erythrosine B dye and corresponding p-type dyesensitized solar cells were fabricated and characterized. NiO electrodes fabricated using the RDS technique exhibited a fourfold enhancement in electroactivity compared to CS electrodes. A possible explanation is the smaller sintered grain size and more open mesoporous structure achieved using the microwave plasma treatments

An n-sided polygonal model to calculate the impact of cyber security events

This paper presents a model to represent graphically the impact of cyber events (e.g., attacks, countermeasures) in a polygonal systems of n-sides. The approach considers information about all entities composing an information system (e.g., users, IP addresses, communication protocols, physical and logical resources, etc.). Every axis is composed of entities that contribute to the execution of the security event. Each entity has an associated weighting factor that measures its contribution using a multi-criteria methodology named CARVER. The graphical representation of cyber events is depicted as straight lines (one dimension) or polygons (two or more dimensions). Geometrical operations are used to compute the size (i.e, length, perimeter, surface area) and thus the impact of each event. As a result, it is possible to identify and compare the magnitude of cyber events. A case study with multiple security events is presented as an illustration on how the model is built and computed.Comment: 16 pages, 5 figures, 2 tables, 11th International Conference on Risks and Security of Internet and Systems, (CRiSIS 2016), Roscoff, France, September 201

Experimental study on the influence of drill wear in CFRP drilling processes

CO2 laser machining represents a flexible technique for the rapid fabrication of miniaturized polymer structures such as polymethylmethacrilate (PMMA) microfluidic devices. A model to estimate the main dimensions (depth and width) of laser machined channels is presented, depending on process parameters (incident power, scanning speed). Blind cavities, to be used as fluid collectors, are machined layer by layer using multiple overlapping sequences of straight grooves with different scanning directions. The proposed technique shows that the removal depth varies proportionally with the number of layers machined, while surface roughness is influenced by the grooves spacing and the orientation of the scanning direction between successive layers. A method for thermally bonding the PMMA sheets, constituting the 3D structure of the chip, is also presented. The combination of high temperatures and a low bonding pressures makes it possible to generate a bulk junction enabling good performances in terms of sealing characteristic

An Integrated Vision-Force System for Peg-in-hole Assembly Operations

In this article the integration of an artificial vision system and a 6-component force-torque sensor for high accuracy insertions is proposed. The former has the advantage of intervening before the contact of the two parts and providing an initial correction to allow the force sensor action; the latter is charged of completing the operation through the control of a neural network. An experimental facility has been developed for performance assessment. Two monochromatic CCD cameras are positioned with the optical axes perpendicular to each other, outside the working area in order not to interfere with the assembly operations. During tests it has been shown that the artificial vision system yields a fast, reliable and accurate measurement, by direct comparison with a co-ordinate-measuring machine. Results show that the use of an integrated vision-force sensor represents a complete solution to the peg-in-hole problem. Furthermore the 3-D localisation algorithm implemented on the vision system and the problems concerned with the system engineering are dealt with

A parametrically time-dependent methodology for reciprocating contact mechanics between viscoelastic solids

We implement an original Boundary Element methodology to study the reciprocating contact mechanics between linear viscoelastic materials. Results are shown for the case of a rigid sphere sinusoidally driven in sliding contact with a viscoelastic half-space. We observe the presence of multi-peaked pressure and displacement distributions; the hysteric friction curve is finally shown for different values of the frequency

Footprints of element mobility during metasomatism linked to a late Miocene peraluminous granite intruding a carbonate host (Campiglia Marittima, Tuscany)

The Campiglia Marittima magmatic-hydrothermal system includes a peraluminous granite, its carbonatic host, and skarn. The system evolved generating a time-transgressive exchange of major and trace elements between granite, metasomatic fluids, and host rock. The process resulted in partial metasomatic replacement of the granite and severe replacement of the carbonate host rocks. The fluid activity started during a late-magmatic stage, followed by a potassic–calcic metasomatism, ending with a lower temperature acidic metasomatism. During the late-magmatic stage, B-rich residual fluids led to the formation of disseminated tourmaline–quartz orbicules. High-temperature metasomatic fluids generated a pervasive potassic–calcic metasomatism of the granite, with replacement of plagioclase, biotite, ilmenite, and apatite by K-feldspar, phlogopite–chlorite–titanite, titanite–rutile, and significant mobilization of Fe, Na, P, Ti, and minor HFSE/REE. The metasomatized granite is enriched in Mg, K, Rb, Ba, and Sr, and depleted in Fe and Na. Ca metasomatism is characterized by crystallization of a variety of calc-silicates, focusing along joints into the granite (endoskarn) and at the marble/pluton contact (exoskarn), and exchange of HFSE and LREE with hydrothermal fluids. Upon cooling, fluids became more acidic and fluorine activity increased, with widespread crystallization of fluorite from disequilibrium of former calc-silicates. At the pluton-host boundary, fluids were accumulated, and pH buffered to low values as temperature decreased, leading to the formation of a metasomatic front triggering the increasing mobilization of REE and HFSE and the late crystallization of REE–HFSE minerals