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931.
Siddharth S. Ray 《Fuel》2009,88(9):1629-1633
In this work, we have studied the quantitative composition of seven lube oils obtained from different refineries by Nuclear Magnetic Resonance (NMR) spectroscopy and Gas Chromatography (GC) methods. A trend of low temperature flow behavior of these lube oils has been correlated with the composition, i.e. n-alkane, iso-alkanes and aromatics. The pour point of these lube oils does not depend only on distribution of n-alkanes, rather with quantity and types of other molecules like iso-alkanes and aromatics. Two alkylacrylate co-polymers with different mole fractions of co-monomers synthesized by free radical mechanism are used as pour point depressant (PPD) additives. Effectiveness of additive is dependent on polar aromatic type molecules along with iso-alkane type molecules in lube oil. 相似文献
932.
Male-Produced Aggregation Pheromone of the Cerambycid Beetle <Emphasis Type="Italic">Rosalia funebris</Emphasis> 总被引:2,自引:2,他引:0
Ann M. Ray Jocelyn G. Millar J. Steven McElfresh Ian P. Swift James D. Barbour Lawrence M. Hanks 《Journal of chemical ecology》2009,35(1):96-103
We report the identification, synthesis, and field bioassays of a volatile, male-produced aggregation pheromone of a long-horned
beetle, the banded alder borer, Rosalia funebris Mots. Headspace collections from males contained a major male-specific compound, (Z)-3-decenyl (E)-2-hexenoate, and several minor components, identified as (Z)-3-decenol, (Z)-3-nonenyl (E)-2-hexenoate, and (Z)-3-decenyl (E)-3-hexenoate. The antennae of both males and females responded strongly to (Z)-3-decenyl (E)-2-hexenoate. We collected significant numbers of adult R. funebris in field bioassays using traps baited with this compound. This pheromone structure is unprecedented in the literature of
cerambycid pheromones and distinct from the more common diol/hydroxyketone pheromone motif of many other species of the diverse
subfamily Cerambycinae. This is the first pheromone identified for a species in the tribe Rosaliini.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
933.
Pinak Pani Biswas Rishi Srivastava Subhabrata Ray Amar Nath Samanta 《Mechatronics》2009,19(4):548-561
The process investigated herein is the quadruple tank system that is stable only within a limited zone of operating parameters. The process model has been developed from fundamentals and tuned with experimental data. A controller design based on feedback linearization has been tested on this process model. Coupling feedback linearization with sliding mode algorithm provides robust control of the process and performs far superior to conventional PI control. A PC based controller interfaced to the experimental quadruple tank experimental set up has been used to implement this algorithm and test its performance. Inserting a ‘boundary layer’ around the sliding surface reduced the ‘chattering’ associated with sliding mode control. The implemented controller provides robust control and excellent set point tracking. 相似文献
934.
Blair Beadnell Mark Nason Pamela A. Stafford David B. Rosengren Ray Daugherty 《Accident; analysis and prevention》2012
Objective
We compared a group-delivered, theory-based, motivation-enhancing program (PRIME For Life® – PFL, n = 450) to an intervention as usual (IAU, n = 72).Method
Individuals convicted of a substance related offense in North Carolina, typically first offense alcohol and drug-impaired driving, participated in a PFL or IAU group. We compare the interventions on program satisfaction and changes made from preintervention to postintervention, and examined the moderating effects of demographics and alcohol dependence level.Results
When significant, findings varied in magnitude from small to medium effects. Participants in both interventions showed intentions to use statistically significantly less alcohol and drugs in the future compared to their previous use, and differences between the groups were not statistically significant. Otherwise, findings favored PFL. PFL exhibited greater benefit than IAU on understanding tolerance, perceived risk for addiction, problem recognition, and program satisfaction. Additionally, IAU perceived less risk for negative consequences postintervention than they had at preintervention. Moderation analyses showed that the between-condition findings occurred regardless of gender, age, education, and number of alcohol dependence indicators. Additionally, younger people and those with more dependence indicators – groups of particular concern – showed the greatest change.Conclusions
Findings suggest that a motivation-enhancing approach can be effective in producing short-term change in factors that can help facilitate and sustain behavioral change. This is consistent with previous research on the use of motivational approaches, and extends such findings to suggest promise in group-based settings and with people across demographic categories and dependence levels. Future research should focus on larger studies looking at long-term behavioral change, including recidivism. 相似文献935.
A. Mathur S.S. Roy K.S. Hazra S. Wadhwa S.C. Ray S.K. Mitra D.S. Misra J.A. McLaughlin 《Materials Chemistry and Physics》2012
This paper highlights the changes in micro-structural and field emission properties of vertically aligned carbon nanotubes (VACNTs) via oxygen plasma treatment. We find that exposure of very low power oxygen plasma (6 W) at 13.56 MHz for 15–20 min, opens the tip of vertically aligned CNTs. Scanning electron microscopy and transmission electron microscopy images were used to identify the quality and micro-structural changes of the nanotube morphology and surfaces. Raman spectra showed that the numbers of defects were increased throughout the oxygen plasma treatment process. In addition, the hydrophobic nature of the VACNTs is altered significantly and the contact angle decreases drastically from 110° to 40°. It was observed that the electron field emission (EFE) characteristics are significantly enhanced. The turn-on electric field (ETOE) of CNTs decreased from ∼0.80 V μm−1 (untreated) to ∼0.60 V μm−1 (oxygen treated). We believe that the open ended VACNTs would be immensely valuable for applications such as micro/nanofluidic based filtering elements and display devices. 相似文献
936.
Jang EY Carretero-González J Choi A Kim WJ Kozlov ME Kim T Kang TJ Baek SJ Kim DW Park YW Baughman RH Kim YH 《Nanotechnology》2012,23(23):235601
Reduced graphene oxide nanoribbon fibers were fabricated by using an electrophoretic self-assembly method without the use of any polymer or surfactant. We report electrical and field emission properties of the fibers as a function of reduction degree. In particular, the thermally annealed fiber showed superior field emission performance with a low potential for field emission (0.7?V?μm(-1)) and a giant field emission current density (400?A?cm(-2)). Moreover, the fiber maintains a high current level of 300?A?cm(-2) corresponding to 1?mA during long-term operation. 相似文献
937.
Gulab N. Jham Bryan R. Moser Shailesh N. Shah Ronald A. Holser Onkar D. Dhingra Steven F. Vaughn Mark A. Berhow Jill K. Winkler-Moser Terry A. Isbell Ray K. Holloway Erin L. Walter Ricardo Natalino Jason C. Anderson David M. Stelly 《Journal of the American Oil Chemists' Society》2009,86(9):917-926
Wild mustard (Brassica juncea L.) oil is evaluated as a feedstock for biodiesel production. Biodiesel was obtained in 94 wt.% yield by a standard transesterification
procedure with methanol and sodium methoxide catalyst. Wild mustard oil had a high content of erucic (13(Z)-docosenoic; 45.7 wt.%) acid, with linoleic (9(Z),12(Z)-octadecadienoic; 14.2 wt.%) and linolenic (9(Z),12(Z),15(Z)-octadecatrienoic; 13.0 wt.%) acids comprising most of the remaining fatty acid profile. The cetane number, kinematic viscosity,
and oxidative stability (Rancimat method) of the methyl esters was 61.1, 5.33 mm2 s−1 (40 °C) and 4.8 h (110 °C), respectively. The cloud, pour and cold filter plugging points were 4, −21 and −3 °C, respectively.
Other properties such as acid value, lubricity, free and total glycerol content, iodine value, Gardner color, specific gravity,
as well as sulfur and phosphorous contents were also determined and are discussed in light of biodiesel standards ASTM D6751
and EN 14214. Also reported are the properties and composition of wild mustard oil, along with identification of wild mustard
collected in Brazil as Brassica juncea L. (2n = 36) as opposed to the currently accepted Sinapis arvensis L. (2n = 18) classification. In summary, wild mustard oil appears to be an acceptable feedstock for biodiesel production.
Disclaimer: Product names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants
the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others
that may also be suitable. 相似文献
938.
Here we provide a summary and brief review of some of the work done with solid 4He at the University of Massachusetts Amherst below a sample pressure of 28?bar. The motivation for the work has been to attempt to pass 4He atoms through solid 4He without directly applying mechanical pressure to the solid itself. The specific technique chosen is limited to pressures near the melting curve and was initially designed to provide a yes/no answer to the question of whether or not it might be possible to observe such a mass flux. The thermo-mechanical effect and direct mass injection have been separately used to create chemical potential differences between two reservoirs of superfluid 4He connected to each other through superfluid-filled Vycor rods in series with solid 4He, which is in the hcp region of the phase diagram. The thermo-mechanical effect is a more versatile approach. And, in a particular symmetric application it is designed to provide a mass flux with little or no net increase in the density of the solid. Our observations, off but near the melting curve, have included: (1)?the presence of an increasing DC flux of atoms through the solid-filled cell with decreasing temperature below ≈650?mK and no flux above this temperature; (2)?the presence of a flux minimum and flux instability in the vicinity of 75–80?mK, with a flux increase at lower temperatures; (3)?the temperature dependence of the flux above 100?mK and the dependence of the flux on the net driving chemical potential difference provide interesting insights on the possible mechanism that leads to the flux above 100?mK. The most recent data suggest that whatever is responsible for the flux in solid 4He, at least for T>100?mK, may be an example of a Bosonic Luttinger liquid. 相似文献
939.
An integrated fiber-optic sensor is described that uses incoherent broadband cavity enhanced absorption spectroscopy for sensitive detection of aqueous samples in nanoliter volumes. Absorption was measured in a 100 μm gap between the ends of two short segments of multimode graded-index fiber that were integrated into a capillary using a precision machined V-grooved fixture that allowed for passive fiber alignment. The other ends of the fibers were coated with dielectric mirrors to form a 9.5 cm optical resonator. Light from a fiber-coupled superluminescent diode was directly coupled into one end of the cavity, and transmission was measured using a fiber-coupled silicon photodiode. Dilute aqueous solutions of near infrared dye were used to determine the minimum detectable absorption change of 2.4×10(-4) under experimental conditions in which pressure fluctuations limited performance. We also determined that the absolute minimum detectable absorption change would be 1.6×10(-5) for conditions of constant pressure in which absorption measurement is limited by electronic and optical noise. Tolerance requirements for alignment are also presented. 相似文献
940.
Li Li Xiangdong Yao Chenghua Sun Aijun Du Lina Cheng Zhonghua Zhu Chengzhong Yu Jin Zou Sean C. Smith Ping Wang Hui‐Ming Cheng Ray L. Frost Gao Qing Lu 《Advanced functional materials》2009,19(2):265-271
Ammonia borane (AB) has attracted tremendous interest for on‐board hydrogen storage due to its low molecular weight and high gravimetric hydrogen capacity below a moderate temperature. However, the slow kinetics, irreversibility, and formation of volatile materials (trace borazine and ammonia) limit its practical application. In this paper, a new catalytic strategy involved lithium (Li) catalysis and nanostructure confinement in mesoporous carbon (CMK‐3) for the thermal decomposition of AB is developed. AB loaded on the 5% Li/CMK‐3 framework releases ~7 wt % of hydrogen at a very low temperature (around 60 °C) and entirely suppresses borazine and ammonia emissions that are harmful for proton exchange membrane fuel cells. The possible mechanism for enhanced hydrogen release via catalyzed thermal decomposition of AB is discussed. 相似文献