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31.
Allard A. Cossé Julie L. Todd Jocelyn G. Millar Lee Ann Martínez Thomas C. Baker 《Journal of chemical ecology》1995,21(11):1823-1836
We have identified five compounds from the headspace of calling male Mediterranean fruit flies (medfly),Ceratitis capitata (Wiedemann), and three compounds from the headspace of ripe mango (Mangifera indica L). using coupled gas chromatographic-electroantennographic (GC-EAG) recordings, coupled gas chromatographic-mass spectrometric (GC-MS) analysis, and electroantennographic (EAG) assays of standards. The male-produced volatiles eliciting responses from female antennae were ethyl-(E)-3-octenoate, geranyl acetate, (E,E)--farnesene, linalool, and indole. An EAG dose-response test of linalool enantiomers and indole with female medfly antennae showed relatively strong EAG activities, but no significant difference between (R)-(-)-linalool and (S)-(+)-linalool. The three mango volatiles were identified as (1S)-(-)--pinene, ethyl octanoate, and-caryophyllene. In addition, a strong antennal response was recorded from a contaminant,-copaene, present in a commercial sample of-caryophyllene. The EAG response amplitudes from both male and female antennae to the above three mango volatiles were significantly greater than to a hexanol control. For both male and female medfly antennae, the greatest EAG responses were elicited by-caryophyllene followed by ethyl octanoate. The mean EAG responses of female antennae to-caryophyllene and (1S)-(-)--pinene were significantly greater than those of male antennae. 相似文献
32.
Todd?L.?KurthEmail author Girma?Biresaw Atanu?Adhvaryu 《Journal of the American Oil Chemists' Society》2005,82(4):293-299
The frictional behaviors of methyl oleate (MO), methyl palmitate (MP), methyl laurate (ML), and methyl stearate (MSt) as additives
in hexadecane have been examined in a boundary lubrication test regime using steel contacts. It was found that the transient
attributes of coefficient of friction (COF)-time spectra are a sensitive measure of adsorption equilibria. Critical additive
concentrations were defined and used to perform novel and simple Langmuir analyses that provide an order of adsoprtion energies:
MSt>MP>MO≥ML. Application of Langmuir, Temkin, and Frumkin-Fowler-Guggenheim adsorption models via nonlinear fitting of a general cooperative model demonstrates the necessary inclusion of cooperative effects in the applied
model. In agreement with the qualitative features of steady-state COF-concentration plots, MSt modeling requires minimal cooperative
interaction terms. However, MO, MP, and ML data require large attractive interaction terms to be adequately fitted. Primary
adsorption energies calculated via the cooperative model are necessarily decreased, whereas total adsorption energies correlate well with values obtained via critical concentration analyses. These results and comparisons with previous adsorption studies of MO and MSt suggest that
primary (ester-surface) and secondary (alkyl-surface) adsorbate-adsorbent, adsorbate-adsorbare, and (free-additive) adsorpt-adsorpt
interactions collectively determine both the calculated primary and the cooperative interaction energies. 相似文献
33.
Design and Control of a Hyper-Redundant Manipulator for Mobile Manipulating Unmanned Aerial Vehicles
Manipulating objects using arms mounted to unmanned aerial vehicles (UAVs) is attractive because UAVs may access many locations that are otherwise inaccessible to other mobile manipulation platforms such as ground vehicles. Despite recent work, several major challenges remain to be overcome before it will be practical to manipulate objects from UAVs. Among these challenges are: (a) The constantly moving UAV platform and compliance of manipulator arms make it difficult to position the UAV and end-effector relative to an object of interest precisely enough for manipulation, and (b) The motions of the manipulator impact the stability of the host UAV, further complicating positioning. Solving these challenges will bring UAVs one step closer to being able to perform meaningful tasks such as infrastructure repair, disaster response, casualty extraction, and cargo resupply. Toward solutions to these challenges, this paper describes a hyper-redundant manipulator, manipulator control approaches and system design considerations to position the manipulator relative to objects of interest in such a way that impacts on platform stability are minimized. 相似文献
34.
Alaa?S.?Abd-El-AzizEmail author Nelson?M.?Pereira Waleed?Boraie Erin?K.?Todd Tarek?H.?Afifi Wes?R.?Budakowski Ken?J.?Friesen 《Journal of Inorganic and Organometallic Polymers and Materials》2005,15(4):497-509
The synthesis of the title complexes was achieved via the reaction of
-p-dichlorobenzene-
-cyclopentadienyliron cations with 4,4′-bis(4-hydroxyphenyl)valeric acid to produce the diiron complexes which were then reacted with a number of arylazo dyes to give cationic bis(cyclopentadienyliron)arene complexes containing the arylazo dyes. These iron-containing monomers were subsequently polymerized via nucleophilic aromatic substitution using 1,8-octanedithiol, 4,4′-thiobisbenzenethiol, or bisphenol A to produce the desired coloured cationic organoiron polymers. The weight – average molecular weights were estimated to range from 11,800 to 31,600. UV–vis studies conducted in dimethylformamide (DMF) showed that the metallated polymers exhibited
of 412–491 nm. Addition of HCl to the polymer solution caused a bathochromic shift into the range of 515–530 nm. Thermogravimetric analysis (TGA) revealed that the iron moieties were cleaved between 205 and 248 °C while the polyether/thioether backbone degraded between 380 and 613 °C. Differential scanning calorimetry (DSC) showed that the polymers exhibited glass transition temperatures (Tg) ranging from 106 to 184°C.This paper is dedicated to Professor Richard J. Puddephatt in recognition of his outstanding contribution to the field of metal-containing polymers. 相似文献
35.
Alaa S. Abd-El-Aziz T. Christopher Corkery Erin K. Todd Tarek H. Afifi Guozhang Ma 《Journal of Inorganic and Organometallic Polymers》2003,13(3):113-130
The synthesis of an aromatic ether complex of cyclopentadienyliron containing two terminal aldehyde groups was achieved via metal-mediated nucleophilic aromatic substitution reactions. This dialdehyde monomer was subsequently reacted with a variety of aliphatic and aromatic diamines to produce the corresponding soluble cationic organoiron polyether-imines. These cationic organometallic polymers were characterized using IR, 1H, and 13C NMR, viscosity and thermogravimetric analysis. Viscosity measurements showed that these polymers exhibited polyelectrolyte effects in DMSO solutions. Thermogravimetric analysis showed that decoordination of the iron moieties occurred at about 300°C for polymers with aliphatic spacers in their backbones, while the cyclopentadienyliron moieties were cleaved from the polymers with aromatic spacers in their backbones at about 200°C. Photolytic demetallation of the organoiron polymers resulted in the removal of the pendent cyclopentadienyliron moieties and allowed for the isolation of their organic analogs. While the organoiron polymers were soluble in polar organic solvents, the corresponding organic polymers exhibited very limited solubilities or were insoluble. The organic polymers had glass transition temperatures between 101 and 120°C 相似文献
36.
M.?Todd?GardnerEmail author Rebecca?May Cory?Beard Deep?Medhi 《Journal of Network and Systems Management》2016,24(3):711-745
Various natural and man-made disasters as well as major political events (like riots) have increased the importance of understanding geographic failures and how correlated failures impact networks. Since mission critical networks are overlaid as virtual networks over a physical network infrastructure forming multilayer networks, there is an increasing need for methods to analyze multilayer networks for geographic vulnerabilities. In this paper, we present a novel impact-based resilience metric. Our new metric uses ideas borrowed from performability to combine network impact with state probability to calculate a new metric called Network Impact Resilience. The idea is that the highest impact to the mission of a network should drive its resilience metric. Furthermore, we present a state space analysis method that analyzes multilayer networks for geographic vulnerabilities. To demonstrate the methods, the inability to provision a given number of upper layer services is used as the criteria for network failure. Mapping techniques for multilayer network states are presented. Simplifying geographic state mapping techniques to reduce enumeration costs are also presented and tested. Finally, these techniques are tested on networks of varying sizes. 相似文献
37.
David Hocker Yicong Zheng Robert Kosut Todd Brun Herschel Rabitz 《Quantum Information Processing》2016,15(11):4361-4390
There is a rich variety of physics underlying the fundamental gating operations for quantum information processing (QIP). A key aspect of a QIP system is how noise may enter during quantum operations and how suppressing or correcting its effects can best be addressed. Quantum control techniques have been developed to specifically address this effort, although a detailed classification of the compatibility of controls schemes with noise sources found in common quantum systems has not yet been performed. This work numerically examines the performance of modern control methods for suppressing decoherence in the presence of noise forms found in viable quantum systems. The noise-averaged process matrix for controlled one-qubit and two-qubit operations are calculated across noise found in systems driven by Markovian open quantum dynamics. Rather than aiming to describe the absolute best control scheme for a given physical circumstance, this work serves instead to classify quantum control behavior across a large class of noise forms so that opportunities for improving QIP performance may be identified. 相似文献
38.
Todd Zickler Satya P. Mallick David J. Kriegman Peter N. Belhumeur 《International Journal of Computer Vision》2008,79(1):13-30
Complex reflectance phenomena such as specular reflections confound many vision problems since they produce image ‘features’
that do not correspond directly to intrinsic surface properties such as shape and spectral reflectance. A common approach
to mitigate these effects is to explore functions of an image that are invariant to these photometric events. In this paper
we describe a class of such invariants that result from exploiting color information in images of dichromatic surfaces. These
invariants are derived from illuminant-dependent ‘subspaces’ of RGB color space, and they enable the application of Lambertian-based
vision techniques to a broad class of specular, non-Lambertian scenes. Using implementations of recent algorithms taken from
the literature, we demonstrate the practical utility of these invariants for a wide variety of applications, including stereo,
shape from shading, photometric stereo, material-based segmentation, and motion estimation. 相似文献
39.
By having IT address itself instead of the business and its customers, we've seen IT projects emerge that have no business value, creating the public perception of IT as a black hole of funding. This black-hole perception magnifies when the IT department doesn't partner with company stakeholders when addressing actual needs; rather, IT professionals create solutions based on what they want to provide instead of what the business requires. The author describes why it's essential for IT professionals to turn outward rather than inward. 相似文献
40.