We study catalyst support interactions during chemical vapor deposition of carbon nanotubes by in situ X-ray photoelectron spectroscopy over a wide range of pressures. We observe Fe 2+ and 3+ interface states for metallic Fe on Al 2 O 3 in the absence of measurable Al reduction. This support interaction is much stronger than that on SiO 2 , and it restricts Fe surface mobility. The resulting much narrower Fe catalyst particle size distribution on Al 2 O 3 leads to a higher carbon nanotube nucleation density and a vertical nanotube alignment due to proximity effects. We record the growth kinetics of carbon nanotube forests by optical imaging to understand effects that contribute to growth termination.
In this paper we review the complex links that exist between the tourism industry and processes of economic development. A brief overview of the industry's economic role at the international and national scale leads us into a discussion of local and regional involvement in the tourism industry. We emphasize the need to develop a more rigorous understanding of the evolving tourism industry and how it in uences processes of local economic development. Following a review of the major theoretical frameworks that have been applied to help us understand these processes, we highlight the ways in which current attempts to understand the links between tourism and economic development are embracing the complexity of the industry and its in uence on everyday lives. We advocate 'new' ways of seeing and studying the economics of tourism geography, ways that re ect the cultural turn in the 'new' economic geography, and the increasing signi cance of networks and new information and communication technologies. We argue that a willingness to embrace complexity is essential if we are to unpack the 'glocal' nature of tourism development processes.
For the clinical delivery of immunotherapies it is anticipated that cells will be cryopreserved and shipped to the patient where they will be thawed and administered. An established view in cellular cryopreservation is that following freezing, cells must be warmed rapidly (≤5 minutes) in order to maintain high viability. In this study we examine the interaction between the rate of cooling and rate of warming on the viability, and function of T cells formulated in a conventional DMSO based cryoprotectant and processed in conventional cryovials. The data obtained show that provided the cooling rate is −1 °C min
−1
or slower, there is effectively no impact of warming rate on viable cell number within the range of warming rates examined (1.6 °C min
−1
to 113 °C min
−1
). It is only following a rapid rate of cooling (−10 °C min
−1
) that a reduction in viable cell number is observed following slow rates of warming (1.6 °C min
−1
and 6.2 °C min
−1
), but not rapid rates of warming (113 °C min
−1
and 45 °C min
−1
). Cryomicroscopy studies revealed that this loss of viability is correlated with changes in the ice crystal structure during warming. At high cooling rates (−10 °C min
−1
) the ice structure appeared highly amorphous, and when subsequently thawed at slow rates (6.2 °C min
−1
and below) ice recrystallization was observed during thaw suggesting mechanical disruption of the frozen cells. This data provides a fascinating insight into the crystal structure dependent behaviour during phase change of frozen cell therapies and its effect on live cell suspensions. Furthermore, it provides an operating envelope for the cryopreservation of T cells as an emerging industry defines formulation volumes and cryocontainers for immunotherapy products.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.