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991.
Kimberly Belli Sara Wadia-Fascetti Carey Rappaport 《Canadian Metallurgical Quarterly》2011,25(1):10-20
Integrated sensor and media modeling environment has been developed to simulate subsurface sensing systems and environmental parameters relevant to the subsurface sensing modalities. The modeling environment is designed to represent complexity in subsurface features, sensor models, and the integration of the sensors with the subsurface environment. The ability to model complex subsurface environments and any potential random distribution of subsurface properties allows for realistic modeling of heterogeneous subsurface environments such as bridged deck/pavement systems. Many applications can benefit from the modeling, simulation, and interpretation capabilities in the new modeling environment that supports improved understanding of system behavior through simulations to evaluate the ability of a particular modality to detect defects. While numerous modeling packages exist to simulate different wave-based modalities, the integrated sensor and media modeling environment is developed to, in a straightforward manner, physically represent the complex subsurface civil infrastructure environment. Physical modeling capabilities enable the object-oriented programming environment facility portability to other application domains as a generic volume serves as the boundaries for internal elements modeled to represent realistic changes in material properties and buried objects. Model development is demonstrated on a realistic bridge deck example. 相似文献
992.
Callahan Kristin L.; Scaramella Laura V.; Laird Robert D.; Sohr-Preston Sara L. 《Canadian Metallurgical Quarterly》2011,25(1):68
Neighborhood dangerousness and belongingness were expected to moderate associations between harsh parenting and toddler-age children's problem behaviors. Fifty-five predominantly African American mothers participated with their 2-year old children. Neighborhood danger, neighborhood belongingness, and children's problem behaviors were measured with mothers' reports. Harsh parenting was measured with observer ratings. Analyses considered variance common to externalizing and internalizing problems, using a total problems score, and unique variance, by controlling for internalizing behavior when predicting externalizing behavior, and vice versa. Regarding the common variance, only the main effects of neighborhood danger and harsh parenting were significantly associated with total problem behavior. In contrast, after controlling for externalizing problems, the positive association between harsh parenting and unique variance in internalizing problems became stronger as neighborhood danger increased. No statistically significant associations emerged for the models predicting the unique variance in externalizing problems or models considering neighborhood belongingness. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
993.
Mei Li Sara Johnson Hongtao Guo Erik Dujardin Stephen Mann 《Advanced functional materials》2011,21(5):851-859
The mechanism of gold nanoparticle chain assembly associated with the induction of electric dipole–dipole interactions arising from the partial ligand exchange of surface‐adsorbed citrate ions by mercaptoethanol is investigated. UV‐vis spectrophotometry and electron microscopy are used, respectively, to determine the kinetics and time‐dependent structural changes associated with formation of the 1D nanoparticle superstructures between 5 and 50 °C. The results indicate that assembly of the plasmonic nanoparticle networks is extremely sensitive to changes in temperature. Formation of the nanoparticle chains is optimized at 25–30 °C and follows first order kinetics with increasing reaction rates attained for higher initial nanoparticle concentrations. Below 25 °C, plasmonic nanoparticle networks are produced but at a considerably reduced rate. In contrast, above 30 °C, short‐chain networks form rapidly but the process is superseded by a secondary mechanism that limits chain growth and produces small fragments and isolated Au nanoparticles. The changes in assembly behavior are attributed to the temperature‐dependent ordering and disordering of mercaptoethanol molecules associated with the gold nanoparticle surface. The results provide a general mechanistic model for the self‐assembly of metallic nanoparticles based on ligand‐induced electric dipolar interactions, which are globally under thermodynamic control but sensitive to kinetic aspects. It is also shown that the dipolar mechanism can be further exploited to introduce larger nanoparticles as topological dopants that reside specifically at branching points or termini in the self‐assembled 1D nanoparticle networks. 相似文献
994.
Movassaghian S Barzegar-Jalali M Alaeddini M Hamedyazdan S Afzalifar R Zakeri-Milani P Mohammadi G Adibkia K 《Drug development and industrial pharmacy》2011,37(7):849-854
Administration of lidocaine and nonsteroidal anti-inflammatory drugs (NSAIDs) as a routine procedure for relief of dental pains by and large is restricted due to some side effects. Amitriptyline (AM) has long been known to exert analgesic activity as a result of blocking the Na? channels. The objective of the present investigation was to prepare suitable buccoadhesive tablets using cellulose derivatives in order to obtain new formulations containing AM to provide local analgesic action. The tablets were evaluated in terms of physical characteristics, mucoadhesion performance, drug release, and in vivo assessment of analgesic efficiency. Tablets containing higher amounts of high-viscosity hydroxypropylmethyl cellulose (HPMC-K4M) significantly demonstrated enhanced adhesive performances. On the other hand, presence of sodium carboxymethyl cellulose (NaCMC) in formulations including HPMC of lower-viscosity grade (HPMC-E5LV) provided further adhesiveness by increase in viscosity. Rate of drug release from HPMC-E5LV tablets was significantly higher than the HPMC-K4M tablets. Kinetically, patterns of AM release from the tablets fitted best to Higuchi model. Moreover, in a randomized double-blind trial, analgesic efficiency of the prepared bioadhesive tablets was revealed to be satisfactory. It is suggested that applying the topical AM mucoadhesive tablet containing the low amount of drug is a safe and promising alternative to relief the pain in the buccal region. 相似文献
995.
Au/Pd octopods and concave core@shell Au@Pd nanocrystals have been prepared by coupling for the first time a seed-mediated synthetic method with co-reduction. The integration of these two methods is central to the formation of these binary Au/Pd nanocrystals wherein the kinetics of seeded growth are manipulated via the co-reduction technique to control the final morphology of the nanocrystals. Significantly, the synthesis of these structures under similar reaction conditions illustrates that they are structurally related kinetic products. Detailed characterization by STEM-EDX analysis highlights the unique structural features of these nanocrystals and indicates that Pd localizes on the higher-energy features of the nanocrystals. Optical and electrocatalytic characterization also demonstrates their promise as a new class of multifunctional nanostructures. 相似文献
996.
Li Y Tan H Yang XY Goris B Verbeeck J Bals S Colson P Cloots R Van Tendeloo G Su BL 《Small (Weinheim an der Bergstrasse, Germany)》2011,7(4):475-483
Very uniform and well shaped Mn3O4 nano‐octahedra are synthesized using a simple hydrothermal method under the help of polyethylene glycol (PEG200) as a reductant and shape‐directing agent. The nano‐octahedra formation mechanism is monitored. The shape and crystal orientation of the nanoparticles is reconstructed by scanning electron microscopy and electron tomography, which reveals that the nano‐octahedra only selectively expose {101} facets at the external surfaces. The magnetic testing demonstrates that the Mn3O4 nano‐octahedra exhibit anomalous magnetic properties: the Mn3O4 nano‐octahedra around 150 nm show a similar Curie temperature and blocking temperature to Mn3O4 nanoparticles with 10 nm size because of the vertical axis of [001] plane and the exposed {101} facets. With these Mn3O4 nano‐octahedra as a catalyst, the photodecomposition of rhodamine B is evaluated and it is found that the photodecomposition activity of Mn3O4 nano‐octahedra is much superior to that of commercial Mn3O4 powders. The anomalous magnetic properties and high superior photodecomposition activity of well shaped Mn3O4 nano‐octahedra should be related to the special shape of the nanoparticles and the abundantly exposed {101} facets at the external surfaces. Therefore, the shape preference can largely broaden the application of the Mn3O4 nano‐octahedra. 相似文献
997.
Berthing T Bonde S Sørensen CB Utko P Nygård J Martinez KL 《Small (Weinheim an der Bergstrasse, Germany)》2011,7(5):640-647
Nanowires (NWs) are attracting more and more interest due to their potential cellular applications, such as delivery of compounds or sensing platforms. Arrays of vertical indium-arsenide (InAs) NWs are interfaced with human embryonic kidney cells and rat embryonic dorsal root ganglion neurons. A selection of critical cell functions and pathways are shown not to be impaired, including cell adhesion, membrane integrity, intracellular enzyme activity, DNA uptake, cytosolic and membrane protein expression, and the neuronal maturation pathway. The results demonstrate the low invasiveness of InAs NW arrays, which, combined with the unique physical properties of InAs, open up their potential for cellular investigations. 相似文献
998.
3-Methoxy-3-methyl-1-butanol [CH(3)OC(CH(3))(2)CH(2)CH(2)OH] is used as a solvent for paints, inks, and fragrances and as a raw material for the production of industrial detergents. A rate constant of (1.64 ± 0.18) × 10(-11) cm(3) molecule(-1) s(-1) for the reaction of 3-methoxy-3-methyl-1-butanol with OH radicals has been measured at 296 ± 2 K using a relative rate method, where the indicated error is the estimated overall uncertainty. Acetone, methyl acetate, glycolaldehyde, and 3-methoxy-3-methylbutanal were identified as products of the OH radical-initiated reaction, with molar formation yields of 3 ± 1%, 35 ± 9%, 13 ± 3%, and 33 ± 7%, respectively, at an average NO concentration of 1.3 × 10(14) molecules cm(-3). Using a 12-h average daytime OH radical concentration of 2 × 10(6) molecules cm(-3), the calculated lifetime of 3-methoxy-3-methyl-1-butanol with respect to reaction with OH radicals is 8.5 h. Potential reaction mechanisms are discussed. 相似文献
999.
Sara Cerri Manfred A. Bohn Klaus Menke Luciano Galfetti 《Propellants, Explosives, Pyrotechnics》2014,39(2):192-204
Several ADN‐based rocket propellant formulations containing different pre‐polymers (GAP diol/triol, Desmophen® 2200), curing agents (BPS, Desmodur® N100, Desmodur® N3400), plasticizers (BDNPA‐F, TMETN), and filler types (Al, HMX) have been manufactured. Propellant formulations were characterized by tensile tests, SEM analyses and DMA measurements. The study has focused on characterizations of the propellants in terms of evaluation of the strength and strain capability, investigation of the presence/absence of dewetting phenomena, compatibility issues and evaluation of the glass transition temperature. Ammonium perchlorate‐based propellant formulations have also been manufactured and analyzed in order to make comparisons. Aging was investigated using mass loss measurements. 相似文献
1000.
This paper introduces a research methodology that adds sophistication to the innovation process for agricultural goods. In recognition of the importance of innovation for the long‐term success of firms and the need for market analysis that goes beyond traditional sensory and consumer preference testing, it is demonstrated how to measure the monetary value consumers place on new market goods. In experimental markets, New Zealand (NZ) consumers were willing to pay on average approximately NZ$0.44 per 100 g to exchange the common green‐fleshed Hayward variety for a new‐to‐market red‐ and yellow‐fleshed kiwifruit variety. At the time of the study this was equivalent to a 179% retail price premium. Knowledge that this new variety was not genetically modified increased the price premium to 240%. These results were elicited from convenience samples and should be treated with caution if used as the sole basis for price setting. Copyright © 2005 Society of Chemical Industry 相似文献