A comparative study of methods for modelling the structural stiffness of generator components

Direct-drive generators are low speed electrical machines requiring robust and large supporting structures designed to resist the significant loads present during assembly and operation. Generator structures have to be stiff, especially in the radial direction for radial-flux machines. This paper presents three different structural modelling approaches: finite element, analytical and hybrid (a combination of the results obtained from dimensional studies and finite element analyses). These are used along with models of electromagnetic active material, to parametrically calculate the minimum structural stiffness and mass of the components forming the machine

Structural analysis and characterization of radial flux PM generators for direct-drive wind turbines

Wind turbine direct-drive generator structures are analysed in order to optimise and reduce mass. A method for modelling key stiffness parameters including a magnetic air-gap stiffness is outlined. Different approaches are used to parametrically calculate structural stiffness and mass. Finite element and analytical techniques are used to model mode 0 and mode 1 deflections and these can be used along with parametric models of electromagnetically active material

In vitro and in vivo expression of foreign genes by transmissible gastroenteritis coronavirus-derived minigenomes

A helper-dependent expression system based on transmissible gastroenteritis coronavirus (TGEV) has been developed using a minigenome of 3·9 kb (M39). Expression of the reporter gene {beta}-glucuronidase (GUS) (2–8 µg per 106 cells) and the porcine respiratory and reproductive syndrome virus (PRRSV) ORF5 (1–2 µg per 106 cells) has been shown using a TGEV-derived minigenome. GUS expression levels increased about eightfold with the m.o.i. and were maintained for more than eight passages in cell culture. Nevertheless, instability of the GUS and ORF5 subgenomic mRNAs was observed from passages five and four, respectively. About a quarter of the cells in culture expressing the helper virus also produced the reporter gene as determined by studying GUS mRNA production by in situ hybridization or immunodetection to visualize the protein synthesized. Expression of GUS was detected in the lungs, but not in the gut, of swine immunized with the virus vector. Around a quarter of lung cells showing replication of the helper virus were also positive for the reporter gene. Interestingly, strong humoral immune responses to both GUS and PRRSV ORF5 were induced in swine with this virus vector. The large cloning capacity and the tissue specificity of the TGEV-derived minigenomes suggest that these virus vectors are very promising for vaccine development

Drug Abuse Prevention Campaigns in Chile (2004-2014): Between Prohibitionism and Stigmatisation

This paper studies the presence and reproduction of the ‘prohibitionist’ paradigm in the Chilean state’s drug policy by studying its drug abuse prevention campaigns. By means of a content analysis of the television spots broadcast between 2004 and 2014, the discursive and ideological elements present in these campaigns were examined. First and foremost, the results show that, despite institutional change and the creation of bodies such as the National Service for the Prevention and Rehabilitation of Drug and Alcohol Use (SENDA) and the National Council for Narcotics Control (CONACE), the state’s discourse has remained focused on the prohibitionist paradigm, resorting to highly stereotyped emotional messages. Secondly, drug consumption has been stigmatised and framed in profoundly dramatic contexts in which users belong to the criminal underworld or have physical and/or cognitive impairments. Thirdly, notwithstanding the fact that there are certain differences between the communication approaches employed by the SENDA and the CONACE, the discourses of both institutions are very uniform and reductionist. In order to design more efficient media campaigns, target audiences should be encouraged to analyse and ponder reflectively on the issue by conveying rational messages that contrast facts and data and offer a positive vision stressing the benefits of a healthy lifestyle.Este artículo cuestiona la presencia y reproducción del paradigma “prohibicionista” en la política de drogas del Estado chileno, a través del estudio de sus campañas de comunicación para la prevención del consumo de drogas. Mediante un análisis de contenido de los spots televisivos aparecidos entre 2004-2014 se estudiaron los elementos discursivos e ideológicos presentes en las campañas. Los resultados mostraron primero que, pese al cambio institucional y la creación de organismos como SENDA y CONACE, los contenidos elaborados y reproducidos por el discurso estatal se han mantenido enfocados en el paradigma prohibicionista recurriendo a mensajes emocionales, muy estereotipados. Segundo, que el usuario de drogas está estigmatizado y se sitúa en contextos con fuerte carga dramática donde los consumidores pertenecen al ámbito criminal o al de la discapacidad intelectual. Tercero, que a pesar de que existen ciertas diferencias en el tratamiento comunicacional entre SENDA y CONACE, ambas instituciones mantienen un discurso muy homogéneo y reduccionista. Para lograr una mejor eficiencia de las campañas mediáticas, por el contrario, debería inducirse al receptor a realizar un análisis y reflexión crítica en torno al tema y mostrar mensajes racionales que contrasten hechos y datos y ofrezcan una visión positiva que refuerce los beneficios de un estilo de vida saludable

Equation of state description of the dark energy transition between quintessence and phantom regimes

The dark energy crossing of the cosmological constant boundary (the transition between the quintessence and phantom regimes) is described in terms of the implicitly defined dark energy equation of state. The generalizations of the models explicitly constructed to exhibit the crossing provide the insight into the cancellation mechanism which makes the transition possible.Comment: 3 pages, talk given at TAUP200

Calibration of CR-39 solid state nuclear track detector

Nowadays there are increasing uses of SSNTD on scientific works in Thailand. Currently we are using SSNTD as an important tool for confirming active fault zones in a province in which a new nuclear research reactor has been proposed to come up. Soil gas radon was measured by both active and passive methods. In the latter case CR-39 SSNTD was installed in a PVC tube of 50 cm long by 5 cm in diameter. The tubes were placed in 50-cm deep holes lining perpendicular to the faults’ trace for one week. In this paper we describe the method and the results on calibrating these detectors using a radon chamber and a NIST-traceable radium-226 standard source.Author Affiliation: P Wanabongse, B Sola, J Jamsangtong and S Rattanabussayaporn 1. Thailand Institute of Nuclear Technology, 16 Vibhavadi Rangsit Road, Chatuchak, Bangkok 10900, Thailand 2Department of Nuclear Technology, Chulalongkorn University, Payathai Road, Patoomwon Bangkok 10330, Thailand 3Office of Atoms for Peace, 16 Vibhavadi Rangsit Road, Chatuchak, Bangkok 10900, Thailand E-mail : [email protected] Institute of Nuclear Technology, 16 Vibhavadi Rangsit Road, Chatuchak, Bangkok 10900, Thailand 2Department of Nuclear Technology, Chulalongkorn University, Payathai Road, Patoomwon Bangkok 10330, Thailand 3Office of Atoms for Peace, 16 Vibhavadi Rangsit Road, Chatuchak, Bangkok 10900, Thailan

A lightweight approach for airborne wind turbine drivetrains

Buoyant airborne wind turbines are devices capable of harnessing stronger winds at higher altitudes and with their automated and rapidly deployable system they are suited to niche applications such as emergency power generation. Although much of the wind turbine technology for these systems is common with their ‘grounded’ cousins, an additional design limitation is the requirement for the wind turbine equipment to be lightweight. This paper concentrates on the drivetrain of the wind turbine and the different potential ways of reducing its mass. A buoyant airborne wind turbine with different types of drivetrains, going from gearless to geared systems with distinct gear ratios, has been analysed. Special attention was paid to the mass of the supporting structure of the permanent magnet electrical generator and this was minimized by utilising low density materials, such as composites, in its design. The model showed that a significant reduction in the mass of the drivetrain can be achieved in the gearless case by using materials with a higher ratio of Young’s Modulus to density for the electrical machine supporting structure. For the geared systems, mass decrease was less significant as the gearbox mass had also to be considered. Keywords: Airborne, lightweight, generator structure, composite material

Implementing quantum gates on oriented optical isomers

Optical enantiomers are proposed to encode molecular two-qubit information processing. Using sequences of pairs of nonresonant optimally polarized pulses, different schemes to implement quantum gates, and to prepare entangled states, are described. We discuss the role of the entanglement phase and the robustness of the pulse sequences which depend on the area theorem. Finally, possible scenarios to generalize the schemes to n-qubit systems are suggested. © 2004 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70017/2/JCPSA6-120-23-10955-1.pd

Technological Feasibility of Lattice Materials by Laser-Based Powder Bed Fusion of A357.0

Lattice materials represent one of the utmost applications of additive manufacturing. The promising synergy between additive processes and topology optimization finds full development in achieving components that comprise bulky and hollow areas, as well as intermediate zones. Yet, the potential to design innovative shapes can be hindered by technological limits. The article tackles the manufacturability by laser-based powder bed fusion (L-PBF) of aluminum-based lattice materials by varying the beam diameter and thus the relative density. The printing accuracy is evaluated against the distinctive building phenomena in L-PBF of metals. The main finding consists in identification of a feasibility window that can be used for development of lightweight industrial components. A relative density of 20% compared with fully solid material (aluminum alloy A357.0) is found as the lowest boundary for a 3-mm cell dimension for a body-centered cubic structure with struts along the cube edges (BCCXYZ) and built with the vertical edges parallel to the growth direction to account for the worst-case scenario. Lighter structures of this kind, even if theoretically compliant with technical specifications of the machine, result in unstable frameworks