Barrierless procedure for substitutionally doping graphene sheets with boron atoms: ab initio calculations

Using ab initio methods, we propose a simple and effective way to substitutionally dope graphene sheets with Boron. The method consists of selectively exposing each side of the graphene sheet to different elements. We first expose one side of the membrane to Boron, while the other side is exposed to Nitrogen. Proceeding this way, the B atoms will be spontaneously incorporated into the graphene membrane, without any activation barrier. In a second step, the system should be exposed to a H-rich environment, that will remove the CN radical from the layer and form HCN, leading to a perfect substitutional doping.Comment: Accepted Physical Review

In mold laser welding for high precision polymer based optical components

“Proceedings of PPS-29 : The 29th International Conference of the Polymer Processing Society - Conference Papers. ISBN 978-0-7354-1227-9”To Assemble a complete subsystem as a rear lamp, is necessary to have different machines and to perform several tasks. This necessity obliges the companies to have large structures to support all the assembling process. These huge structures are very costly and have as a consequence the reduction of the competitiveness of the companies. The process presented in this document has the intention of reducing the number of tasks needed to produce the final subsystem/product. To achieve this goal were combined several technologies, as in-mould assembling, laser welding and LEDs (light-emitting diode). One of the advantages of this process was the utilization of only one injection molding machine with three injection units to do all the assembling process. To achieve the main objective, firstly, the rear lamp was designed according to with the legislation of UNECE Vehicle Regulations - 1958 Agreements; Regulation No. 50 -Rev.2 - Position lamps, stop lamps, direction indicators for motorcycles. Posterior several polymeric materials were studied at different levels. Initial were studied several concentrations of carbon nanotubes mixed with PC (polycarbonate). This had the objective of determine, if these materials are suitable to conduct the necessary electric current to turn on the different LEDs. One of the main advantages of this process is the use of the laser transmission welded process. Since, with this welding technology is possible reduce the complexity of the final part. To understand the potentialities of this technology a combination of two materials was studied. The studied showed that all materials presented a high transparency to the laser beam. In terms of weld process, the study showed that the best welding conditions are the lowest velocity, diameter and power. With these studies was possible conclude that this new process is suitable to be implemented at the industrial level

Combination of laser welding with in-mould assembling into a single process

The search of a process capable of produce and assemble complex subsystems in a short period is the goal of any company. In the market it is possible to found several solutions. They go from simple glue to the complexes systems that use moulds, robot and other. These systems are part of a complex assembling line. In these lines are several different processes as welding, plastic and assembling process. This complex structure is costly, and in countries where the labour cost is high. To maintain the cost the companies are obliged to go overseas. The process presented had the objective of reducing the complexity of an assembling line. The reduction of the complexity is achieved through the combination of the in-mould assembly and the laser welding. The in-mould assembly is used to produce in the same mould several components. Laser welding is used to join different polymers. To study the viability of the process I was chosen a case study, in this case, a rear lamp. Firstly, it was modified to this new process, and then each component was studied individually. Finally, all the processes were combined and it was concluded that this process has viability and to make it possible producing a complex subsystem in one process

In mould laser welding for high precision polymer based optical components

Assembling a complete subsystem as a rear lamp, it is necessary several different machines and tasks, for producing the final product. The technology presented in this paper has de capability to reduce the number of tasks needed for producing a final subsystem/product. In this case will be necessary only one injection moulding machine with three injection units. This was achieved by combining several technologies, as in-mould assembling, laser welding and LEDs. The challenges began by studying several polymeric materials, for understanding their behavior when they are welded by a laser beam. This was helpful also for determine the best welding properties. At the same time were analyzed different conductive polymers. This had the objective to determine their suitability for conducting the electric current between the different LEDs. The development of the rear lamp was made take in consideration the legislation of UNECE Vehicle Regulations - 1958 Agreement; Regulation No. 50 -Rev.2 - Position lamps, stop lamps, direction indicators for motorcycles. The results obtained present good input for producing in the same machine a complete and functional rear lamp

Anti-money laundering in the United Kingdom: new directions for a more effective regime

Purpose: This paper aims to provide a more nuanced understanding of the effectiveness of the anti-money laundering (AML) regime in the UK and explore opportunities to improve policy and performance. Design/methodology/approach: Qualitative research design using semi-structured interviews and a focus group with practitioners from both public and private sectors. Findings: This paper identifies preventive measures are underfunded by the public sector; there is a disconnect between the regulatory requirement and the regulators’ supervisory approach leading to the ineffective application of the risk-based approach; and authorities have limited ability to stop low-utility reports. Increased collaboration across institutions and sectors, better utilisation of innovative technologies and a sustainable funding plan are needed to drive a collective response to money laundering. Research limitations/implications: Few practitioners in the industry have the knowledge and expertise to discuss the topic at a strategic level and participants were limited (n = 8). Practical implications: This paper adds to the growing corpus of research showing that the AML regime in the UK is ineffective and needs reform. Social implications: This paper encourages practitioners to improve the AML regime, this research contributes to the reform of the existing measures against financial crime. Originality/value: This paper presents new data from AML practitioners to provide a better understanding of the limitations of the AML regime in the UK

Retrofitting Practice of a 100kWth Coal/Biomass Air-firing Combustor to the Oxy-firing Mode: Experiences and the Experimental Results

Air-firing of the fossil fuels results to relatively low concentration of CO2 in flue gases which make the capture of CO2 difficult and expensive. Oxy-firing combustion is a novel method of using enriched oxygen for coal/biomass combustion with Recycled Flue Gases (RFG) to control the adiabatic flame temperature and to increase the CO2 concentration of the off-gases up to a 60-70% oxy-firing mode (compared to air-fired mode, around 12-14%). This new technology is being applied at Cranfield University to retrofit an existing 100kWth air-firing combustor to the oxy-firing mode. This paper presents the procedure of the modifications applied on the combustor and the excellent results obtained for co-firing of pulverised coal and biomass in this rig

Experimental validation of morphology simulation in glass fibre reinforced polycarbonate discs

As assessment is made between Moldflow simulations and experimentally determined fibre orientation distributions at three points along the flow path and 12 layers across the thickness. The material used is a 10% weight short glass fibre reinforced polycarbonate. With this material the physical interaction between fibres during flow is minimised. Centre gated circular discs, where both the shear and the extensional flows are present, were produced over a range of moulding conditions to analyse the effect of flow rate and melt temperature upon the fibre orientation. The fibre orientation was measured using image analysis tools in images obtained by reflection microscopy of polished sections, using the method proposed by Bay. The measurements were made in 12 layers across the thickness

Oxy-fuel Combustion for Carbon Capture and Sequestration (CCS) from a Coal/Biomass Power Plant: Experimental and Simulation Studies

Oxy-fuel combustion is a promising and relatively new technology to facilitate CO2 capture and sequestration (CCS) for power plants utilising hydrocarbon fuels. In this research experimental oxy-combustion trials and simulation are carried out by firing pulverised coal and biomass and co-firing a mixture of them in a 100 kW retrofitted oxy-combustor at Cranfield University. The parent fuels are coal (Daw Mill) and biomass cereal co-product (CCP) and experimental work was done for 100 % coal (w/w), 100 % biomass (w/w) and a blend of coal 50 % (w/w) and biomass 50 % (w/w). The recirculation flue gas (RFG) rate was set at 52 % of the total flue gas. The maximum percentage of CO2 observed was 56.7 % wet basis (73.6 % on a dry basis) when 100 % Daw Mill coal was fired. Major and minor emission species and gas temperature profiles were obtained and analysed for different fuel mixtures. A drop in the maximum temperature of more than 200 K was observed when changing the fuel from 100 % Daw Mill coal to 100 % cereal co-product biomass. Deposits formed on the ash deposition probes were also collected and analysed using the environmental scanning electron microscopy (ESEM) with energy-dispersive X-ray (EDX) technique. The high sulphur, potassium and chlorine contents detected in the ash generated using 100 % cereal co-product biomass are expected to increase the corrosion potential of these deposits. In addition, a rate-based simulation model has been developed using Aspen Plus® and experimentally validated. It is concluded that the model provides an adequate prediction for the gas composition of the flue gas

Isolation of hydrodynamic parameters for the fibre length attrition in injection-moulded short-fibre polymer composites

A comprehensive study of the fibre breakage mechanisms during mould filling in injection moulding of short-fibre polymer composites requires the isolation of the main parameters promoting fibre length attrition. In this work, hydrodynamic parameters such as injection flow rate and residence time in the range of injection moulding were isolated, and their effect on fibre length attrition was studied. Fibre breakage was quantified by means of a capillary rheometer attached to an injection moulding machine minimising fibre-equipment interactions. Fibre breakage increased linearly as a function of injection flow rate in the range of 30–120 cm3.s−1. It was also found that residence time in the order of milliseconds had a significant effect on fibre breakage. The results shown that longer fibres had less breakage probability, which contradicts the buckling failure theory for brittle fibres in a simple shear flow. This result was attributed to the similar rotation period of the fibres in comparison with the test residence times.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the “Universidad Nacional de Mar del Plata” (ING560/19, 15/G575) and the “Agencia Nacional de Promoción Cient´ıfica y Tecnológica” (PICT-2014-3228, PICT-2017-2458