85 resultados para Conservação ex situ
Resumo:
We present a new route towards customizing the surface properties of microfluidic channels, by a forest of in situ grown multiwalled carbon nanotubes (CNT). Local distortions of the electrical field direction are used to control the direction of the carbon nanotube growth. © 2005 Materials Research Society.
Resumo:
The stability of the underground structure is very important not only from the point of view of the structure itself, but also from the point of view of other structures. Therefore, the evaluation of the process of deterioration can help us very much. In the first part of the paper the ageing of the structures in the scope of their life cycle will be described. The whole process of deterioration is important but limited to certain time intervals and is able to give signals about changes in macro-scale. The second part of the paper is focused on the adaptation of new methods: micro technology of monitoring - such as MEMS (Micro Electrical Mechanical Systems) and wireless technologies for data transfer. It is obvious that such new technologies have to be assessed for the ability to deliver data continuously and for their safety and solidity. At the end of the paper the application of the measurements on the Prague metro's lining is mentioned. © 2007 Taylor & Francis Group.
Resumo:
Transmission imaging with an environmental scanning electron microscope (ESEM) (Wet STEM) is a recent development in the field of electron microscopy, combining the simple preparation inherent to ESEM work with an alternate form of contrast available through a STEM detector. Because the technique is relatively new, there is little information available on how best to apply this technique and which samples it is best suited for. This work is a description of the sample preparation and microscopy employed by the authors for imaging bacteria with Wet STEM (scanning transmission electron microscopy). Three different bacterial samples will be presented in this study: first, used as a model system, is Escherichia coli for which the contrast mechanisms of STEM are demonstrated along with the visual effects of a dehydration-induced collapse. This collapse, although clearly in some sense artifactual, is thought to lead to structurally meaningful morphological information. Second, Wet STEM is applied to two distinct bacterial systems to demonstrate the novel types of information accessible by this approach: the plastic-producing Cupriavidus necator along with wild-type and ΔmreC knockout mutants of Salmonella enterica serovar Typhimurium. Cupriavidus necator is shown to exhibit clear internal differences between bacteria with and without plastic granules, while the ΔmreC mutant of S. Typhimurium has an internal morphology distinct from that of the wild type.
Resumo:
We report on an inexpensive, facile and industry viable carbon nanofibre catalyst activation process achieved by exposing stainless steel mesh to an electrolyzed metal etchant. The surface evolution of the catalyst islands combines low-rate electroplating and substrate dissolution. The plasma enhanced chemical vapour deposited carbon nanofibres had aspect-ratios > 150 and demonstrated excellent height and crystallographic uniformity with localised coverage. The nanofibres were well-aligned with spacing consistent with the field emission nearest neighbour electrostatic shielding criteria, without the need of any post-growth processing. Nanofibre inclusion significantly reduced the emission threshold field from 4.5 V/μm (native mesh) to 2.5 V/μm and increased the field enhancement factor to approximately 7000. © 2011 Elsevier B.V. All rights reserved.
Resumo:
Transmission imaging with an environmental scanning electron microscope (ESEM) (Wet STEM) is a recent development in the field of electron microscopy, combining the simple preparation inherent to ESEM work with an alternate form of contrast available through a STEM detector. Because the technique is relatively new, there is little information available on how best to apply this technique and which samples it is best suited for. This work is a description of the sample preparation and microscopy employed by the authors for imaging bacteria with Wet STEM (scanning transmission electron microscopy). Three different bacterial samples will be presented in this study: first, used as a model system, is Escherichia coli for which the contrast mechanisms of STEM are demonstrated along with the visual effects of a dehydration-induced collapse. This collapse, although clearly in some sense artifactual, is thought to lead to structurally meaningful morphological information. Second, Wet STEM is applied to two distinct bacterial systems to demonstrate the novel types of information accessible by this approach: the plastic-producing Cupriavidus necator along with wild-type and δmreC knockout mutants of Salmonella enterica serovar Typhimurium. Cupriavidus necator is shown to exhibit clear internal differences between bacteria with and without plastic granules, while the δmreC mutant of S. Typhimurium has an internal morphology distinct from that of the wild type. © 2012 Wiley Periodicals, Inc.
Resumo:
Technology roadmapping has been used to strategise the development of energy technologies. However, there have been limited roadmapping applications that analyse the emergence of a new energy technology that then forms a new industry and propels broad-based low-carbon economic growth. This paper, therefore, attempts to develop a roadmapping framework by integrating the lifecycle analysis tool, in order to strategise the emergence of dimethyl ether, an alternative energy based on advanced engineering technologies such as carbon capture and storage. This paper compares two scenarios of dimethyl ether vs. diesel and finds that the superiority of dimethyl ether will not arise until 2030, when the complementary engineering technologies become available. This proposed framework can also be generalised to other clean energy industries, and we anticipate our paper will spark inspiration for roadmapping and strategising the 'right' technologies for the growth of Chinese energy industries. Copyright © 2012 Inderscience Enterprises Ltd.