5,698 research outputs found
High frequency Scanning Gate Microscopy and local memory effect of carbon nanotube transistors
We use impedance spectroscopy to measure the high frequency properties of
single-walled carbon nanotube field effect transistors (swCN-FETs).
Furthermore, we extend Scanning Gate Microscopy (SGM) to frequencies up to
15MHz, and use it to image changes in the impedance of swCN-FET circuits
induced by the SGM-tip gate. In contrast to earlier reports, the results of
both experiments are consistent with a simple RC parallel circuit model of the
swCN-FET, with a time constant of 0.3 ms. We also use the SGM tip to show the
local nature of the memory effect normally observed in swCN-FETs, implying that
nanotube-based memory cells can be miniaturized to dimensions of the order of
tens of nm.Comment: 7 pages, 3 figures, to appear in Nano Letter
African American and European American Therapists’ Experiences of Addressing Race in Cross-Racial Psychotherapy Dyads
Using Consensual Qualitative Research, 12 licensed psychologists’ overall experiences addressing race in psychotherapy were investigated, as were their experiences addressing race in a specific cross-racial therapy dyad. Results indicated that only African American psychologists reported routinely addressing race with clients of color or when race was part of a client’s presenting concern. European American psychologists indicated that they would address race if clients raised the topic, and some reported that they did not normally address race with racially different clients. When discussing a specific cross-racial dyad, African American therapists more often than European American therapists addressed race because they perceived client discomfort. Only European American therapists reported feeling uncomfortable addressing race, but therapists of both races perceived that such discussions had positive effects
Space Separatism: Degree of Differentiation
Space is so important that the DOD recognizes it as one of five domains in which US forces operate (the other four are land, sea, air, and information). In 2001 Secretary of Defense Donald Rumsfeld designated the Department of the Air Force (DAF) the “Executive Agent for Space for the DOD.” Given the national importance of space activities, the formation of a separate space force has been a topic of persistent discussion in academic and doctrinal circles ever since the United States first entered the space age. Proponents of a separate force argue that because space is an inherently unique domain, forces operating there should be organized, trained, equipped, and funded separately—as are air, land, and sea forces. Opponents highlight the interconnectedness of space activities in the other domains as primary justification for maintaining the status quo
On the Electronic Transport Mechanism in Conducting Polymer Nanofibers
Here, we present theoretical analysis of electron transport in polyaniline
based (PANi) nanofibers assuming the metalic state of the material. To build up
this theory we treat conducting polymers as a special kind of granular metals,
and we apply the quantum theory of conduction in mesoscopic systems to describe
the transport between metallic-like granules. Our results show that the concept
of resonance electron tunneling as the predominating mechanism providing charge
transport between the grains is supported with recent experiments on the
electrical characterization of single PANi nanofibers. By contacting the
proposed theory with the experimental data we estimate some important
parameters characterizing the electron transport in these materials. Also, we
discuss the origin of rectifying features observed in current-voltage
characteristics of fibers with varying cross-sectional areas.Comment: 5 pages, 1 figure, accepted for publication in Phys. Rev. B, Vol.72,
xxxx (2005
Ultrafast carrier dynamics in thin-films of the topological insulator Bi2Se3
Transient reflectivity measurements of thin films, ranging from 6 to 40 nm in
thickness, of the topological insulator Bi2Se3 revealed a strong dependence of
the carrier relaxation time on the film thickness. For thicker films the
relaxation dynamics are similar to those of bulk Bi2Se3, where the contribution
of the bulk insulating phase dominates over that of the surface metallic phase.
The carrier relaxation time shortens with decreasing film thickness, reaching
values comparable to those of noble metals. This effect may result from the
hybridization of Dirac cone states at the opposite surfaces for the thinnest
films
Drug-Loaded, Bivalent-Bottle-Brush Polymers by Graft-through ROMP
Graft through ring-opening metathesis polymerization (ROMP) using ruthenium N heterocyclic carbene catalysts has enabled the synthesis of bottle-brush polymers with unprecedented ease and control Here we report the first bivalent-brush polymers, these materials were prepared by graft through ROMP of drug-loaded poly(ethylene glycol) (PEG) based macromonomers (MMs) Anticancer drugs doxorubicin (DOX) and camptothecin (CT) were attached to a norbornene alkyne-PEG MM via a photocleavable linker ROMP of either or both drug loaded MMs generated brush homo and copolymers with low polydispersities and defined molecular weights. Release of free DOX and CT from these materials was initiated by exposure to 365 nm light All of the CT and DOX polymers were at least 10 fold more toxic to human cancer cells after photoinitiated drug release while a copolymer carrying both CT and DOX displayed 30-fold increased toxicity upon irradiation Graft through ROMP of drug loaded macromonomers provides a general method for the systematic study of structure function relationships for stimuli responsive polymers in biological systems
Building sustainability into services marketing: expanding decision-making from a mix to a matrix
In line with the AMA\u27s revised (2007) definition of marketing, which aligns with the societal marketing orientation by requiring that Marketing create value not just for individual consumers and organisations but also for society at large, this paper proposes a Sustainability Services Marketing (SSM) framework. At present, services marketing managers have little guidance on how to pursue sustainability and achieve sustainable development goals. The SSM addresses this gap in a systematic, holistic and transparent way by ensuring sustainability cascades through the strategic marketing planning process. The traditional services marketing mix is expanded to include partnership, and the eight elements are cross-referenced against the three pillars of the triple bottom line - Planet, People and Profit - to produce the Sustainability Services Marketing Matrix (SSMM). The model is described and illustrated with brief case examples, and implications for theory and practice, and potential directions for further research are discussed
EPR Study of Spin Labeled Brush Polymers in Organic Solvents
Spin-labeled polylactide brush polymers were synthesized via ring-opening metathesis polymerization (ROMP), and nitroxide radicals were incorporated at three different locations of brush polymers: the end and the middle of the backbone, and the end of the side chains (periphery). Electron paramagnetic resonance (EPR) was used to quantitatively probe the macromolecular structure of brush polymers in dilute solutions. The peripheral spin-labels showed significantly higher mobility than the backbone labels, and in dimethylsulfoxide (DMSO), the backbone end labels were shown to be more mobile than the middle labels. Reduction of the nitroxide labels by a polymeric reductant revealed location-dependent reactivity of the nitroxide labels: peripheral nitroxides were much more reactive than the backbone nitroxides. In contrast, almost no difference was observed when a small molecule reductant was used. These results reveal that the dense side chains of brush polymers significantly reduce the interaction of the backbone region with external macromolecules, but allow free diffusion of small molecules
Supervisor Cultural Responsiveness and Unresponsiveness in Cross-Cultural Supervision
Thirteen supervisees’ of color and 13 European American supervisees’ experiences of culturally responsive and unresponsive cross-cultural supervision were studied using consensual qualitative research. In culturally responsive supervision, all supervisees felt supported for exploring cultural issues, which positively affected the supervisee, the supervision relationship, and client outcomes. In culturally unresponsive supervision, cultural issues were ignored, actively discounted, or dismissed by supervisors, which negatively affected the supervisee, the relationship, and/or client outcomes. European American supervisees’ and supervisees’ of color experiences diverged significantly, with supervisees of color experiencing unresponsiveness more frequently and with more negative effects than European American supervisees. Implications for research and supervision practice are discussed
Competitive advantage and fuel efficiency in aviation
This paper builds upon a resource based view of competitive advantage under a dynamic capabilities construct. Fuel efficiency measurement in the aviation industry can be incorporated into dynamic capabilities such as strategic decision making and alliancing. These dynamic capabilities can drive operational cost reductions, which in-turn can enhance profitability and establish a competitive advantage. To further this advantage, fuel efficiency can be embedded inside an organizational culture. A fuel efficiency focused organizational culture can be a valuable, rare, inimitable and non- substitutable resource. This paper proposes a model to merge the dynamic capabilities of strategic decision making and alliancing with organizational culture under fuel efficiency. Under this model, a fuel efficiency index is introduced to drive behavior and provide accountability. Effective use of the index has profit potential
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