47 research outputs found
An ancestral molecular response to nanomaterial particulates
The varied transcriptomic response to nanoparticles has hampered the understanding of the mechanism of action. Here, by performing a meta-analysis of a large collection of transcriptomics data from various engineered nanoparticle exposure studies, we identify common patterns of gene regulation that impact the transcriptomic response. Analysis identifies deregulation of immune functions as a prominent response across different exposure studies. Looking at the promoter regions of these genes, a set of binding sites for zinc finger transcription factors C2H2, involved in cell stress responses, protein misfolding and chromatin remodelling and immunomodulation, is identified. The model can be used to explain the outcomes of mechanism of action and is observed across a range of species indicating this is a conserved part of the innate immune system.Peer reviewe
Raman scattering study of the a-GeTe structure and possible mechanism for the amorphous-to-crystal transition
We report on an inelastic (Raman) light scattering study of the local
structure of amorphous GeTe films. A detailed analysis of the
temperature-reduced Raman spectra has shown that appreciable structural changes
occur as a function of temperature. These changes involve modifications of
atomic arrangements such as to facilitate the rapid amorphous-to-crystal
transformation, which is the major advantage of phase-change materials used in
optical data storage media. A particular structural model, supported by
polarization analysis, is proposed being compatible with the experimental data
as regards both the structure of a-GeTe and the crystallization transition. The
remarkable difference between the Raman spectrum of the crystal and the glass
can thus naturally be accounted for.Comment: Published in: J. Phys. Condens. Matter. 18, 965-979 (2006
Performance evaluation of a waste-heat driven adsorption system for automotive air-conditioning: Part I - Modeling and experimental validation
[EN] Adsorption systems driven by engine waste heat are one of the possible alternatives to the conventional automobile air conditioning in terms of energy savings and environmental issues. Assessment of this issue are carried in a two-part study. In this first part I, theoretical and experimental investigations were performed on a two bed, silica gel adsorption chiller for automotive applications. A prototype adsorption system with a total weight of about 86 kg was developed and tested to driven by low-grade waste heat. The single adsorbent bed consisted of three plate-fin heat exchangers connected in parallel. An improved non-equilibrium lumped parameter model was developed to predict the transient performance of the system. The model is fully dynamic and takes into account the mass transfer resistance and pressure drop for each component of the system. The results showed that the model is able to accurately predict the dynamic performance of the system under different operating conditions and configuration modes with a short calculation time. The tested chiller was able to produce an average cooling capacity of about 2.1 kW with a COP of 0.35 at the rated operating conditions. Heat recovery system results in increasing the COP by 43% and the cooling power by 4%. (C) 2016 Elsevier Ltd. All rights reserved.This work has been partially supported by the European project TOPMACS-Thermally Operated Mobile Air-Conditioning Systems, funded by the European Comission under the 6th European Community framework program FP6-SUSTDEV - Sustainable Development, Global Change and Ecosystems: thematic priority 6 under the Focusing and Integrating Community Research programme 2002-2006. (Contract Ref. TST4-CT-2005-012471. The authors are very grateful to the Energy Research Center of Netherlands (ECN) for their support in the experimental work.Verde Trindade, M.; Harby Mohamed Abd Alaal, K.; De Boer, R.; Corberán, JM. (2016). Performance evaluation of a waste-heat driven adsorption system for automotive air-conditioning: Part I - Modeling and experimental validation. Energy. 116:526-538. doi:10.1016/j.energy.2016.09.113S52653811
The Essential Elements of a Risk Governance Framework for Current and Future Nanotechnologies
Societies worldwide are investing considerable resources into the safe development and use of nanomaterials. Although each of these protective efforts is crucial for governing the risks of nanomaterials, they are insufficient in isolation. What is missing is a more integrative governance approach that goes beyond legislation. Development of this approach must b