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Articles 1741 - 1770 of 4868

Full-Text Articles in Physical Sciences and Mathematics

Efficient Strong Designated Verifier Signature Schemes Without Random Oracle Or With Non-Delegatability, Q Huang, G Yang, D S Wong, Willy Susilo Jan 2011

Efficient Strong Designated Verifier Signature Schemes Without Random Oracle Or With Non-Delegatability, Q Huang, G Yang, D S Wong, Willy Susilo

Faculty of Informatics - Papers (Archive)

Designated verifier signature (DVS) allows a signer to convince a designated verifier that a signature is generated by the signer without letting the verifier transfer the conviction to others, while the public can still tell that the signature must be generated by one of them. Strong DVS (SDVS) strengthens the latter part by restricting the public from tellingwhether the signature is generated by one of them or by someone else. In this paper, we propose two new SDVS schemes. Compared with existing SDVS schemes, the first new scheme has almost the same signature size and meanwhile, is proven secure in …

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Experimental Investigation Of The Vibration Characteristics Of A Magnetorheological Elastomer Sandwich Beam Under Non-Homogeneous Small Magnetic Fields, Guoliang Hu, Miao Guo, Weihua Li, Haiping Du, Gursel Alici Jan 2011

Experimental Investigation Of The Vibration Characteristics Of A Magnetorheological Elastomer Sandwich Beam Under Non-Homogeneous Small Magnetic Fields, Guoliang Hu, Miao Guo, Weihua Li, Haiping Du, Gursel Alici

Faculty of Informatics - Papers (Archive)

In this study, a magnetorheological elastomer (MRE) was manufactured and tested, and a MRE sandwich beam was also fabricated from a MRE between two thin aluminum layers. An experimental test rig was set up to investigate the vibration response of the MRE sandwich beam under a non-homogeneous magnetic field. The experimental results show that the first natural frequency of the MRE sandwich beam decreased as the magnetic field applied to the beam was moved from the clamped end of the beam to the free end of the beam. It is also noted that the MRE sandwich beam had the capability …

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Offline Programming For A Complex Welding System Using Delmia Automation, Joseph Polden, Zengxi Pan, Nathan P. Larkin, Stephen Van Duin, John Norrish Jan 2011

Offline Programming For A Complex Welding System Using Delmia Automation, Joseph Polden, Zengxi Pan, Nathan P. Larkin, Stephen Van Duin, John Norrish

Faculty of Informatics - Papers (Archive)

This paper presents an offline programming (OLP) system for a complex robotic welding cell using DELMIA Automation. The goals of this research are aimed at investigating the feasibility of taking a commercially available robotic simulation package, DELMIA, and to use a Visual Basic Automation interface to reduce the programming time by creating automated ‘modules’ to carry out some of the tasks in the OLP process. The paper first investigates and presents the structure of OLP as a discreet method of individual steps. These steps are then evaluated for their potential as an automation candidate. The methods in which these steps …

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Improving Bdd Cryptosystems In General Lattices, Willy Susilo, Thomas V. Plantard, Michael Rose Jan 2011

Improving Bdd Cryptosystems In General Lattices, Willy Susilo, Thomas V. Plantard, Michael Rose

Faculty of Informatics - Papers (Archive)

No abstract provided.

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Age Estimation Based On Extended Non-Negative Matrix Factorization, Ce Zhan, Wanqing Li, Philip Ogunbona Jan 2011

Age Estimation Based On Extended Non-Negative Matrix Factorization, Ce Zhan, Wanqing Li, Philip Ogunbona

Faculty of Informatics - Papers (Archive)

Previous studies suggested that local appearance-based methods are more efficient than geometric-based and holistic methods for age estimation. This is mainly due to the fact that age information are usually encoded by the local features such as wrinkles and skin texture on the forehead or at the eye corners. However, the variations of theses features caused by other factors such as identity, expression, pose and lighting may be larger than that caused by aging. Thus, one of the key challenges of age estimation lies in constructing a feature space that could successfully recovers age information while ignoring other sources of …

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Lifespan Theorem For Simple Constrained Surface Diffusion Flows, Glen Wheeler Jan 2011

Lifespan Theorem For Simple Constrained Surface Diffusion Flows, Glen Wheeler

Faculty of Informatics - Papers (Archive)

We consider closed immersed hypersurfaces in R3 and R4 evolving by a special class of constrainedsurfacediffusionflows. This class of constrainedflows includes the classical surfacediffusionflow. In this paper we present a LifespanTheoremfor these flows, which gives a positive lower bound on the time for which a smooth solution exists, and a small upper bound on the total curvature during this time. The hypothesis of the theorem is that the surface is not already singular in terms of concentration of curvature. This turns out to be a deep property of the initial manifold, as the lower bound on maximal time obtained depends …

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Threshold Ring Signature Without Random Oracles, Tsz Hon Yuen, Joseph K. Liu, Man Ho Allen Au, Willy Susilo, Jianying Zhou Jan 2011

Threshold Ring Signature Without Random Oracles, Tsz Hon Yuen, Joseph K. Liu, Man Ho Allen Au, Willy Susilo, Jianying Zhou

Faculty of Informatics - Papers (Archive)

In this paper, we present the notion and construction of threshold ring signature without random oracles. This is the first scheme in the literature that is proven secure in the standard model. Our scheme extends the Shacham-Waters signature from PKC 2007 in a non-trivial way. We note that our technique is specifically designed to achieve a threshold ring signature in the standard model. Interestingly, we can still maintain the signature size to be the same as the Shacham-Waters signature, while only a tiny computation cost is added.

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Electronic Cash With Anonymous User Suspension, Man Ho Au, Willy Susilo, Yi Mu Jan 2011

Electronic Cash With Anonymous User Suspension, Man Ho Au, Willy Susilo, Yi Mu

Faculty of Informatics - Papers (Archive)

Electronic cash (E-cash) is the digital counterpart of cash payment. They allow users to spend anonymously unless they “double spend” their electronic coins. However, it is not possible to prevent users from misbehaving under some other subjective definitions of misbehavior, such as money laundering. One solution is to incorporate a trusted third party (TTP), which, upon complaint, uses its power to deanonymize the suspected user. This solution, known as fair e-cash, is not fully satisfactory since additional measure has to be taken to stop misbehaving users from further abusing the system after they have been identified. We present a e-cash …

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Pricing Of Volatility Derivatives Using 3/2-Stochastic Models, Joanna Goard Jan 2011

Pricing Of Volatility Derivatives Using 3/2-Stochastic Models, Joanna Goard

Faculty of Informatics - Papers (Archive)

Analytic solutions are found for prices of both variance and volatility swaps and VIX options under new 3/2- stochastic models for the dynamics of the underlying assets. The main features of the new stochastic differential equations are an empirically validated cv3/2 diffusion term, a nonlinear drift providing a balancing effect of a stronger mean reversion with high volatility, and for the case of the variance and volatility swaps, a free function of time as a moving target in the reversion term, allowing additional flexibility for model calibration against market data.

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The Effect Of Incomplete Mixing Upon The Performance Of A Membrane-Coupled Anaerobic Fermentor, Ahmed Hussein Msmali, Mark I. Nelson, John M. Kavanagh Jan 2011

The Effect Of Incomplete Mixing Upon The Performance Of A Membrane-Coupled Anaerobic Fermentor, Ahmed Hussein Msmali, Mark I. Nelson, John M. Kavanagh

Faculty of Informatics - Papers (Archive)

We consider a model to describe the performance of a membrane-coupled anaerobic fermentor which was developed and calibrated using experimental data by Kim and Chung (2010). The model consists of six differential equations, modelling the concentration of five biochemical species and the rate of gasification. In the original work it was assumed that reactor is well-mixed. We use a two parameter mixing model to investigate the effect of incomplete mixing upon the performance of this process. The parameters in the mixing mode are the size of the stagnant region and a parameter controlling the degree of mixing between the regions. …

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Ontology Based Search Mechanism In Bilingual Database Resource, Norasykin Mohd Zaid, Sim Kim Lau Jan 2011

Ontology Based Search Mechanism In Bilingual Database Resource, Norasykin Mohd Zaid, Sim Kim Lau

Faculty of Informatics - Papers (Archive)

The focus of our research is to investigate how ontology based search system can help a novice researcher in literature search in an online academic database. In this paper, we will describe ontology construction which is based on the existing relational database system. We will demonstrate three solutions using this ontology to resolve our problems in synonym relation, short-form-term and full-term search, and bilingual retrieval.

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Vibration Control Of Seat Considering Vehicle Suspension And Human-Body Models, Haiping Du, Weihua Li, Nong Zhang Jan 2011

Vibration Control Of Seat Considering Vehicle Suspension And Human-Body Models, Haiping Du, Weihua Li, Nong Zhang

Faculty of Informatics - Papers (Archive)

Vehicle seat suspension is one of very important components to provide ride comfort, in particular, commercial vehicles, to reduce driver fatigue due to long hours driving. This paper presents a study on active control of seat suspension to reduce vertical vibration transmitted from uneven road profile to driver body. The control problem will be firstly studied by proposing an integrated seat suspension model which includes vehicle chassis suspension, seat suspension, and driver body model. This is a new concept in the field of study because most of the current active and semi-active seat suspension studies only consider seat suspension or …

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Partially Overlapped Range Images Registration Based On Fringe Pattern Profilometry, Xiaochen He, Jiangtao Xi, Yanguang Yu Jan 2011

Partially Overlapped Range Images Registration Based On Fringe Pattern Profilometry, Xiaochen He, Jiangtao Xi, Yanguang Yu

Faculty of Informatics - Papers (Archive)

Registration of two three-dimensional (3-D) point sets is a fundamental problem of 3-D shape measurement and modeling pipeline. This paper investigates the automatic pair-wise method to register partially overlapped range images generated by self-developed fringe pattern profilometry (FPP) system. The method is based on the classic iterative closest point (ICP) algorithm but combined with several extensions to adapt to the experimental data. Firstly, the distance function for correspondence finding is modified to be the weighted linear combination of positions and Euclidean invariant features for improving the probability of convergence. In addition, outliers can be discarded through robust statistics and adaptive …

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Heaven And Hell: Visions For Pervasive Adaptation, Ben Paechter, Jeremy Pitt, Nikola Serbedzija, Katina Michael, Jennifer Willies, Ingi Helgason Jan 2011

Heaven And Hell: Visions For Pervasive Adaptation, Ben Paechter, Jeremy Pitt, Nikola Serbedzija, Katina Michael, Jennifer Willies, Ingi Helgason

Faculty of Informatics - Papers (Archive)

With everyday objects becoming increasingly smart and the "info-sphere" being enriched with nano-sensors and networked to computationally-enabled devices and services, the way we interact with our environment has changed significantly, and will continue to change rapidly in the next few years. Being user-centric, novel systems will tune their behaviour to individuals, taking into account users' personal characteristics and preferences. But having a pervasive adaptive environment that understands and supports us "behaving naturally" with all its tempting charm and usability, may also bring latent risks, as we seamlessly give up our privacy (and also personal control) to a pervasive world of …

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Modelling Pattern Formation In Plants, M P. Edwards, S Pereverzyev, R S. Anderssen Jan 2011

Modelling Pattern Formation In Plants, M P. Edwards, S Pereverzyev, R S. Anderssen

Faculty of Informatics - Papers (Archive)

Performing simulations with simple models is a key activity in the recovery of information about the mechanisms which underlie the observed dynamics of biological processes, such as the posi- tioning of the hairs (trichomes) on the leaves of plants. The discovery of a robust representative model is a highly non-trivial process. Without appropriate constraints to regularize the choice of a model, the non-uniqueness of possibilities is vast. As acknowledged by Young (1983) in his modelling of pea leaf development, the degree of non-uniqueness can be reduced by constraining the model to reproduce the patterns observed in mutants as well as …

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The Application Of Location Based Services In National Emergency Warning Systems: Sms, Cell Broadcast Services And Beyond, Anas Aloudat, Katina Michael Jan 2011

The Application Of Location Based Services In National Emergency Warning Systems: Sms, Cell Broadcast Services And Beyond, Anas Aloudat, Katina Michael

Faculty of Informatics - Papers (Archive)

Location-based services can be broadly defined as any service that provides information pertinent to the current location of an active mobile handset at a specific window of time, regardless of the underlying delivery technology used to convey its information. To date, the short message service and cell broadcast service have been utilised by several countries during emergencies, however the future indicates that these services while cost-effective today, will almost certainly be superseded in the next five to ten years by newer more powerful capabilities. The path forward in location-based emergency services in Australia is given against a backdrop of the …

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Optimistic Fair Exchange Of Ring Signatures, Lie Qu, Guilin Wang, Yi Mu Jan 2011

Optimistic Fair Exchange Of Ring Signatures, Lie Qu, Guilin Wang, Yi Mu

Faculty of Informatics - Papers (Archive)

An optimistic fair exchange (OFE) protocol is an effective tool helping two parties exchange their digital items in an equitable way with assistance of a trusted third party, called arbitrator, who is only required if needed. In previous studies, fair exchange is usually carried out between individual parties. When fair exchange is carried our between two members from distinct groups, anonymity of the signer in a group could be necessary for achieving better privacy. In this paper, we consider optimistic fair exchange of ring signatures (OFERS), i.e. two members from two different groups can exchange their ring signatures in …

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Towards Greater Systemisation In Ci Research: An Exploration Of Social Development As A Framework For Comparison And Understanding, William Tibben Jan 2011

Towards Greater Systemisation In Ci Research: An Exploration Of Social Development As A Framework For Comparison And Understanding, William Tibben

Faculty of Informatics - Papers (Archive)

The theme of complexity alludes to the difficulties community informatics (CI) researchers face when analysing use of ICTs by communities. In response, de Moor (2009a, 2009b) and Stillman (2010) identify the need for greater systemisation of CI research that enables complex socio-technical processes to be analysed over multiple cases. The principle by which such systemisation should occur is open to debate. It seems improbable that a single theoretical approach, at least in the short term, is going to satisfy everyone as greater systemisation is pursued. The paper suggests that, as a first step, efforts should be devoted to better appreciation …

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A Mathematical Model For The Biological Treatment Of Industrial Wastewater In A Reactor Cascade, Rubayyi Turki Alqahtani, Mark I. Nelson, Annette L. Worthy Jan 2011

A Mathematical Model For The Biological Treatment Of Industrial Wastewater In A Reactor Cascade, Rubayyi Turki Alqahtani, Mark I. Nelson, Annette L. Worthy

Faculty of Informatics - Papers (Archive)

Many industrial processes, particularly in the food industry, produce slurries or wastewaters containing high concentrations of biodegradable organic materials. Before these contaminated wastewaters can be discharged the concentration of the biodegradable organic pollutant must be reduced. One way to do this is to pass the wastewater through a bioreactor containing biomass which grows through consumption of the pollutant. Anaerobic conditions are often favoured for the processing of waste materials with high levels of biodegradable organic pollutants as these can be removed with low investment and operational costs. We investigate the steady state effluent concentration leaving a cascade of two reactors. …

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Development Of A Peer-To-Peer Information Sharing System Using Ontologies, Ghassan Beydoun, Graham Low, Numi Tran, Paul Bogg Jan 2011

Development Of A Peer-To-Peer Information Sharing System Using Ontologies, Ghassan Beydoun, Graham Low, Numi Tran, Paul Bogg

Faculty of Informatics - Papers (Archive)

Most existing agent-oriented methodologies ignore system extensibility, interoperability and reusability issues. Ontologies have been found to play a significant role in facilitating interoperability, reusability, MAS development activities (including MAS analysis and agent knowledge modeling) and MAS run-time operation (including agent communication and reasoning). However, most of the existing AOSE methodologies do not provide support for ontology-based MAS development. We present software engineering requirements for ontology-based development for MAS and examine an existing methodology, MOBMAS - a "Methodology for Ontology-Based MASs", which makes use of ontologies as a modeling tool. In this examination, we highlight how MOBMAS can be extended to …

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Post-Release Mortality Of Angled Sand Mullet (Myxus Elongatus: Mugilidae), Matt K. Broadhurst, Paul A. Butcher, Brian R. Cullis Jan 2011

Post-Release Mortality Of Angled Sand Mullet (Myxus Elongatus: Mugilidae), Matt K. Broadhurst, Paul A. Butcher, Brian R. Cullis

Faculty of Informatics - Papers (Archive)

Grey mullets (Mugilidae) are important to recreational fisheries throughout the developed world. In Australia, several species are angled and then released in large numbers; all with virtually unknown fate. In response to the need for such data to facilitate effective stock management, this study sought to quantify the post-release mortality and key causal factors for sand mullet (Myxus elongatus). A total of 125 fish were conventionally angled, and then released along with 50 controls into floating cages in a south eastern Australian estuary, where they were monitored for four days. Five treatment fish died, providing a non-significant mortality of 4%. …

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Detecting Humans Under Occlusion Using Variational Mean Field Method, Duc Thanh Nguyen, Philip Ogunbona, Wanqing Li Jan 2011

Detecting Humans Under Occlusion Using Variational Mean Field Method, Duc Thanh Nguyen, Philip Ogunbona, Wanqing Li

Faculty of Informatics - Papers (Archive)

This paper proposes a human detection method using variational mean field approximation for occlusion reasoning. In the method, parts of human objects are detected individually using template matching. Initial detection hypotheses with spatial layout information are represented in a graphical model and refined through a Bayesian estimation. In this paper, mean field method is employed for such an estimation. The proposed method was evaluated on the popular CAVIAR-INRIA dataset. Experimental results show that the proposed algorithm is able to detect humans in severe occlusion within reasonable processing time.

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A Preliminary Investigation Of Complex Adaptive Systems As A Model For Explaining Organisational Change Caused By The Introduction Of Health Information Systems, Kieren Diment, Ping Yu, Karin Garrety Jan 2011

A Preliminary Investigation Of Complex Adaptive Systems As A Model For Explaining Organisational Change Caused By The Introduction Of Health Information Systems, Kieren Diment, Ping Yu, Karin Garrety

Faculty of Informatics - Papers (Archive)

This paper documents the preliminary development of a framework for evaluating organisational change processes during the implementation of an electronic nursing documentation system in residential aged care facilities. It starts with a brief outline of organisational change processes. This is followed by a more detailed exposition of the principles underlying complex adaptive systems (CAS) theory, where we explain how mathematical concepts can be used to illuminate qualitative research approaches. Finally we present some preliminary findings on the facilitators and barriers for the introduction of the electronic documentation system, explained with reference to the CAS theory, based on analysis of interviews …

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Direct Observation Of Nodes And Twofold Symmetry In Fese Superconductor, Canli Song, Yi-Lin Wang, Peng Cheng, Yeping Jiang, Wei Li, Tong Zhang, Zhi Li, Ke He, Lili Wang, Jin-Feng Jia, Hsiang-Hsuan Hung, Congjun Wu, Xu-Cun Ma, Xi Chen, Qi-Kun Xue Jan 2011

Direct Observation Of Nodes And Twofold Symmetry In Fese Superconductor, Canli Song, Yi-Lin Wang, Peng Cheng, Yeping Jiang, Wei Li, Tong Zhang, Zhi Li, Ke He, Lili Wang, Jin-Feng Jia, Hsiang-Hsuan Hung, Congjun Wu, Xu-Cun Ma, Xi Chen, Qi-Kun Xue

Australian Institute for Innovative Materials - Papers

We investigated the electron-pairing mechanism in an iron-based superconductor, iron selenide (FeSe), using scanning tunneling microscopy and spectroscopy. Tunneling conductance spectra of stoichiometric FeSe crystalline films in their superconducting state revealed evidence for a gap function with nodal lines. Electron pairing with twofold symmetry was demonstrated by direct imaging of quasiparticle excitations in the vicinity of magnetic vortex cores, Fe adatoms, and Se vacancies. The twofold pairing symmetry was further supported by the observation of striped electronic nanostructures in the slightly Se-doped samples. The anisotropy can be explained in terms of the orbital-dependent reconstruction of electronic structure in FeSe.

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Chitosan Adhesive Films For Photochemical Tissue Bonding, Antonio Lauto, Damia Mawad, Matthew Barton, Sabine C. Piller, Leonardo Longo Jan 2011

Chitosan Adhesive Films For Photochemical Tissue Bonding, Antonio Lauto, Damia Mawad, Matthew Barton, Sabine C. Piller, Leonardo Longo

Australian Institute for Innovative Materials - Papers

Photochemical tissue bonding (PTB) is a promising sutureless technique for tissue repair. PTB is often achieved by applying a solution of rose bengal (RB) between two tissue edges, which are irradiated by a green laser to crosslink collagen fibers with minimal heat production. In this study, RB has been incorporated in chitosan films to create a novel tissue adhesive that is laser-activated. Materials and Methods. Adhesive films, based on chitosan and containing ∼0.1wt% RB were manufactured and bonded to calf intestine by a solid state laser (wavelength =532nm, Fluence ∼110J/cm2, spot size ∼5 mm). A single-column tensiometer, interfaced with a …

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Negotiating Change: Working With Children And Their Employers To Transform Child Domestic Work In Iringa, Tanzania, Natascha Klocker Jan 2011

Negotiating Change: Working With Children And Their Employers To Transform Child Domestic Work In Iringa, Tanzania, Natascha Klocker

Faculty of Science - Papers (Archive)

This paper documents the practical and action-oriented findings of an investigation into child domestic work undertaken in Iringa, Tanzania from 2005 to 2007. It provides an overview of the experiences of both child domestic workers and their employers, before discussing their suggestions for how child domestic working arrangements may be improved. The latter sections of the paper relate the attempts to regulate child domestic work that emerged from such dialogue. In providing detailed information on that process, the paper is positioned within the field of action research and resists the boundary frequently applied between academia and activism. It also moves …

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Synthesis And Structural Characterization Of 1-[2-(5-Nitro-1h-Indol-2-Yl)Phenyl]Methylpyridinium Chloride, John B. Bremner, Siritron Samosorn, Brian W. Skelton, Allan White Jan 2011

Synthesis And Structural Characterization Of 1-[2-(5-Nitro-1h-Indol-2-Yl)Phenyl]Methylpyridinium Chloride, John B. Bremner, Siritron Samosorn, Brian W. Skelton, Allan White

Faculty of Science - Papers (Archive)

In the course of studies on hybrid antibacterials incorporating 2-aryl-5-nitro-1Hindolemoieties as potential bacterial NorA efflux pump inhibitors, the compound 1-[2-(5-nitro-1H-indol-2-yl)phenyl]methylpyridinium chloride (2) was synthesized and structurallycharacterized. This pyridinium chloride salt crystallized in the monoclinic space groupP21/c with the following unit cell dimensions: a 10.274(3) A, b 13.101(4) A, c 13.439(4)A, B 107.702(7)deg, V 1723.2(9) A3, Z (f.u.) = 4; R1 = 0.048, and wR2 = 0.13. Of interest inthe single crystal X-ray structure is the (intramolecular) disposition of the pyridinium planeover the indole heterocyclic residue [interplanar dihedral angle 17.91(4)deg].

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Toward Accurate Co2 And Ch4 Observations From Gosat, A Butz, S Guerlet, O Hasekamp, D Schepers, A Galli, Ilse Aben, C Frankenberg, J-M Hartmann, H Tran, A Kuze, Gretchen Keppel-Aleks, G C. Toon, Debra Wunch, P Wennberg, Nicholas M. Deutscher, David W. Griffith, Ronald Macatangay, Janina Messerschmidt, Justus Notholt, Thorsten Warneke Jan 2011

Toward Accurate Co2 And Ch4 Observations From Gosat, A Butz, S Guerlet, O Hasekamp, D Schepers, A Galli, Ilse Aben, C Frankenberg, J-M Hartmann, H Tran, A Kuze, Gretchen Keppel-Aleks, G C. Toon, Debra Wunch, P Wennberg, Nicholas M. Deutscher, David W. Griffith, Ronald Macatangay, Janina Messerschmidt, Justus Notholt, Thorsten Warneke

Faculty of Science - Papers (Archive)

The column-average dry air mole fractions of atmospheric carbon dioxide and methane (XCO2 and XCH4) are inferred from observations of backscattered sunlight conducted by the Greenhouse gases Observing SATellite (GOSAT). Comparing the first year of GOSAT retrievals over land with colocated ground-based observations of the Total Carbon Column Observing Network (TCCON), we find an average difference (bias) of-0.05% and-0.30% for XCO2 and XCH4 with a station-to-station variability (standard deviation of the bias) of 0.37% and 0.26% among the 6 considered TCCON sites. The root-mean square deviation of the bias-corrected satellite retrievals from colocated TCCON observations amounts to 2.8 ppm for …

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The Long Life Of Birds: The Rat-Pigeon Comparison Revisited, William A. Buttemer, Anthony J. Hulbert, M K. Montgomery Jan 2011

The Long Life Of Birds: The Rat-Pigeon Comparison Revisited, William A. Buttemer, Anthony J. Hulbert, M K. Montgomery

Faculty of Science - Papers (Archive)

The most studied comparison of aging and maximum lifespan potential (MLSP) among endotherms involves the 7-fold longevity difference between rats (MLSP 5y) and pigeons (MLSP 35y). A widely accepted theory explaining MLSP differences between species is the oxidative stress theory, which purports that reactive oxygen species (ROS) produced during mitochondrial respiration damage bio-molecules and eventually lead to the breakdown of regulatory systems and consequent death. Previous rat-pigeon studies compared only aspects of the oxidative stress theory and most concluded that the lower mitochondrial superoxide production of pigeons compared to rats was responsible for their much greater longevity. This conclusion is …

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Methane Observations From The Greenhouse Gases Observing Satellite: Comparison To Ground-Based Tccon Data And Model Calculations, Robert Parker, Hartmut Boesch, Austin Cogan, Annemarie Fraser, Liang Feng, Paul Palmer, Janina Messerschmidt, Nicholas M. Deutscher, David W. Griffith, Justus Notholt, Paul O. Wennberg, Debra Wunch Jan 2011

Methane Observations From The Greenhouse Gases Observing Satellite: Comparison To Ground-Based Tccon Data And Model Calculations, Robert Parker, Hartmut Boesch, Austin Cogan, Annemarie Fraser, Liang Feng, Paul Palmer, Janina Messerschmidt, Nicholas M. Deutscher, David W. Griffith, Justus Notholt, Paul O. Wennberg, Debra Wunch

Faculty of Science - Papers (Archive)

We report new short-wave infrared (SWIR) column retrievals of atmospheric methane (X CH4) from the Japanese Greenhouse Gases Observing SATellite (GOSAT) and compare observed spatial and temporal variations with correlative ground-based measurements from the Total Carbon Column Observing Network (TCCON) and with the global 3-D GEOS-Chem chemistry transport model. GOSAT X CH4 retrievals are compared with daily TCCON observations at six sites between April 2009 and July 2010 (Bialystok, Park Falls, Lamont, Orleans, Darwin and Wollongong). GOSAT reproduces the site-dependent seasonal cycles as observed by TCCON with correlations typically between 0.5 and 0.7 with an estimated single-sounding precision between 0.4-0.8%. …

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