25 research outputs found
Hydrogen Fuel Cell Gasket Handling and Sorting With Machine Vision Integrated Dual Arm Robot
Recently demonstrated robotic assembling technologies for fuel cell stacks used fuel cell components manually pre-arranged in stacks (presenters), all oriented in the same position. Identifying the original orientation of fuel cell components and loading them in stacks for a subsequent automated assembly process is a difficult, repetitive work cycle which if done manually, deceives the advantages offered by automated fabrication technologies of fuel cell components and by robotic assembly processes. We present an innovative robotic technology which enables the integration of automated fabrication processes of fuel cell components with robotic assembly of fuel cell stacks into a fully automated fuel cell manufacturing line. This task, which has not been addressed in the past uses a Yaskawa Motoman SDA5F dual arm robot with integrated machine vision system. The process is used to identify and grasp randomly placed, slightly asymmetric fuel cell components having a total alpha-plus-beta symmetry angle of 720o, to reorient them all in the same position and stack them in presenters for a subsequent robotic assembly process. The dual arm robot technology is selected for increased productivity and ease of gasket handling during reorientation. The initial position and orientation of the gaskets is identified by image analysis using a Cognex machine vision system with fixed camera. The process was demonstrated as part of a larger endeavor of bringing to readiness advanced manufacturing technologies for alternative energy systems, and responds the high priority needs identified by the U.S. Department of Energy for fuel cells manufacturing research and development
Bridging the Gap between Automated Manufacturing of Fuel Cell Components and Robotic Assembly of Fuel Cell Stacks
Recently demonstrated robotic assembling technologies for fuel cell stacks used fuel cell components manually pre-arranged in stacks (presenters). Identifying the original orientation of fuel cell components and loading them in presenters for a subsequent automated assembly process is a difficult, repetitive work cycle which if done manually, deceives the advantages offered by either the automated fabrication technologies for fuel cell components or by the robotic assembly processes. We present for the first time a robotic technology which enables the integration of automated fabrication processes for fuel cell components with a robotic assembly process of fuel cell stacks into a fully automated fuel cell manufacturing line. This task uses a Yaskawa Motoman SDA5F dual arm robot with integrated machine vision system. The process is used to identify and grasp randomly placed, slightly asymmetric fuel cell components, to reorient them all in the same position and stack them in presenters in preparation for a subsequent robotic assembly process. The process was demonstrated as part of a larger endeavor of bringing to readiness advanced manufacturing technologies for alternative energy systems, and responds the high priority needs identified by the U.S. Department of Energy for fuel cells manufacturing research and development
Design and Demonstration of Automated Technologies for the Fabrication and Testing of PEM Fuel Cell Systems
This paper describes the research efforts at Georgia Southern University to develop robotic technologies for the fabrication of fuel cell components and stacks, as well as the design and fabrication of a High Temperature Proton Exchange Membrane Fuel Cell (HT-PEMFC) power system to be used as motive power and auxiliary power unit (APU) for a long range, unmanned, fully autonomous forest rover. The paper describes a manufacturing workcell consisting of a Yaskawa Motoman SDA5F dual arm robot with machine vision used for sorting, reorientation and stacking fuel cell components in presenters in preparation for their subsequent robotic assembly in fuel cell stacks. It also describes a manufacturing workcell consisting of a Fanuc LR Mate 200iD robot, an in-house made computer numerically controlled (CNC) router and programmable logic controller (PLC) used for automated fabrication of graphite bipolar plates for fuel cells. It presents the design and integration of a fully automated test stand used for testing fuel cells up to 4 kWe power and the design and fabrication of a 250 W, 166 cm2 active area fuel cell stack prototype. The operation characteristics of this short stack prototype are studied before a larger 3 kW fuel cell system will be built
The common marmoset genome provides insight into primate biology and evolution
We report the whole-genome sequence of the common marmoset (Callithrix jacchus). The 2.26-Gb genome of a female marmoset was assembled using Sanger read data (6×) and a whole-genome shotgun strategy. A first analysis has permitted comparison with the genomes of apes and Old World monkeys and the identification of specific features that might contribute to the unique biology of this diminutive primate, including genetic changes that may influence body size, frequent twinning and chimerism. We observed positive selection in growth hormone/insulin-like growth factor genes (growth pathways), respiratory complex I genes (metabolic pathways), and genes encoding immunobiological factors and proteases (reproductive and immunity pathways). In addition, both protein-coding and microRNA genes related to reproduction exhibited evidence of rapid sequence evolution. This genome sequence for a New World monkey enables increased power for comparative analyses among available primate genomes and facilitates biomedical research application. © 2014 Nature America, Inc
Comparative and demographic analysis of orang-utan genomes
Orang-utan- is derived from a Malay term meaning man of the forest- and aptly describes the southeast Asian great apes native to Sumatra and Borneo. The orang-utan species, Pongo abelii (Sumatran) and Pongo pygmaeus (Bornean), are the most phylogenetically distant great apes from humans, thereby providing an informative perspective on hominid evolution. Here we present a Sumatran orang-utan draft genome assembly and short read sequence data from five Sumatran and five Bornean orang-utan genomes. Our analyses reveal that, compared to other primates, the orang-utan genome has many unique features. Structural evolution of the orang-utan genome has proceeded much more slowly than other great apes, evidenced by fewer rearrangements, less segmental duplication, a lower rate of gene family turnover and surprisingly quiescent Alu repeats, which have played a major role in restructuring other primate genomes. We also describe a primate polymorphic neocentromere, found in both Pongo species, emphasizing the gradual evolution of orang-utan genome structure. Orang-utans have extremely low energy usage for a eutherian mammal, far lower than their hominid relatives. Adding their genome to the repertoire of sequenced primates illuminates new signals of positive selection in several pathways including glycolipid metabolism. From the population perspective, both Pongo species are deeply diverse; however, Sumatran individuals possess greater diversity than their Bornean counterparts, and more species-specific variation. Our estimate of Bornean/Sumatran speciation time, 400,000years ago, is more recent than most previous studies and underscores the complexity of the orang-utan speciation process. Despite a smaller modern census population size, the Sumatran effective population size (N e) expanded exponentially relative to the ancestral N e after the split, while Bornean N e declined over the same period. Overall, the resources and analyses presented here offer new opportunities in evolutionary genomics, insights into hominid biology, and an extensive database of variation for conservation efforts. © 2011 Macmillan Publishers Limited. All rights reserved
The Atacama Cosmology Telescope: CMB Polarization at
We report on measurements of the cosmic microwave background (CMB) and
celestial polarization at 146 GHz made with the Atacama Cosmology Telescope
Polarimeter (ACTPol) in its first three months of observing. Four regions of
sky covering a total of 270 square degrees were mapped with an angular
resolution of . The map noise levels in the four regions are between 11
and 17 K-arcmin. We present TT, TE, EE, TB, EB, and BB power spectra from
three of these regions. The observed E-mode polarization power spectrum,
displaying six acoustic peaks in the range , is an excellent fit
to the prediction of the best-fit cosmological models from WMAP9+ACT and Planck
data. The polarization power spectrum, which mainly reflects primordial plasma
velocity perturbations, provides an independent determination of cosmological
parameters consistent with those based on the temperature power spectrum, which
results mostly from primordial density perturbations. We find that without
masking any point sources in the EE data at , the Poisson tail of
the EE power spectrum due to polarized point sources has an amplitude less than
K at at 95\% confidence. Finally, we report that
the Crab Nebula, an important polarization calibration source at microwave
frequencies, has 8.7\% polarization with an angle of when smoothed with a Gaussian beam.Comment: 16 pages, 15 figures, 5 table
French NGOs and the state: Paving the way for a new partnership?
This paper asks whether French non-governmental organisations (NGOs) have fallen into line with the trend towards partnership with the state that has marked the Northern non-profit sector, most notably Anglo-American NGOs, over the last two decades. It shows how French NGO-state relations were poor over the early post-colonial years. It then demonstrates how, over the global era, the French government has made overtures and how NGOs, particularly developmental NGOs (NGDOs), have embraced these legal, financial and consultative concessions, while refusing to see them as the basis of a mutually consenting partnership. Finally, it explains the continuing lack of French NGDO-state rapport in terms of Resource Dependence theory