Cement degradation in CO2 storage sites: a review on potential applications of nanomaterials

© 2018 The Author(s) Carbon capture and sequestration (CCS) has been employed to reduce global warming, which is one of the critical environmental issues gained the attention of scientific and industrial communities worldwide. Once implemented successfully, CCS can store at least 5 billion tons of CO2per year as an effective and technologically safe method. However, there have been a few issues raised in recent years, indicating the potential leakages paths created during and after injection. One of the major issues might be the chemical interaction of supercritical CO2with the cement, which may lead to the partial or total loss of the cement sheath. There have been many approaches presented to improve the physical and mechanical properties of the cement against CO2attack such as changing the water-to-cement ratio, employing pozzolanic materials, and considering non-Portland cements. However, a limited success has been reported to the application of these approaches once implemented in a real-field condition. To date, only a few studies reported the application of nanoparticles as sophisticated additives which can reinforce oil well cements. This paper provides a review on the possible application of nanomaterials in the cement industry where physical and mechanical characteristics of the cement can be modified to have a better resistance against corrosive environments such as CO2storage sites. The results obtained indicated that adding 0.5 wt% of Carbon NanoTubes (CNTs) and NanoGlass Flakes (NGFs) can reinforce the thermal stability and coating characteristics of the cement which are required to increase the chance of survival in a CO2sequestrated site. Nanosilica can also be a good choice and added to the cement by as much as 3.0 wt% to improve pozzolanic reactivity and thermal stability as per the reports of recent studies

Can the response to a platinum-based therapy be predicted by the DNA repair status in non-small cell lung cancer?

Preclinical evidence has been accumulating on the impact of the DNA repair status on the sensitivity/resistance to anticancer agents in different tumor types, including lung cancer. The possibility to predict the response to therapy, and specifically to platinum agents, based on tumor specific DNA repair functionality would enable to tailor its use only in those patients with maximum chances to respond, avoiding the burden of toxicity in those ones with lesser chances. We here reviewed the clinical evidence on the prognostic role of DNA repair markers and/or functional assays in predicting the response to a platinum-based chemotherapy in lung cancer patients. Consequently, we focused on those proteins involved in pathways repairing platinum induced DNA inter-strand and intra-strand crosslinks. Most promising clinical trials targeting the nucleotide repair protein ERCC1 in non-small cell lung cancer later on suffered from serious drawbacks. Nevertheless, these results spurred a variety of preclinical studies on a multitude of alternative DNA repair markers. However so far, no one of the analyzed DNA repair markers can be considered a reliable and mature biomarker for selecting patients. We discuss the reasons for such failure which discloses novel strategies for the future. © 2016 Elsevier Ltd

Autosomal recessive segregation of a truncating mutation of anti-Mullerian type II receptor in a family affected by the persistent Mullerian duct syndrome contrasts with its dominant negative activity in vitro.

Anti-Mullerian hormone belongs to the TGFbeta family whose members exert their effects by signaling through two related serine/threonine kinase receptors. Mutations of the anti-Mullerian hormone type II receptor occur naturally, causing the persistent Mullerian duct syndrome. In a family with two members with persistent Mullerian duct syndrome and one normal sibling, we detected two novel mutations of the anti-Mullerian hormone type II receptor gene. One, transmitted by the mother to her three sons, is a deletion of a single base leading to a stop codon, causing receptor truncation after the transmembrane domain. The other, a missense mutation in the substrate-binding site of the kinase domain, is transmitted by the father to the two sons affected by persistent Mullerian duct syndrome, indicating a recessive autosomal transmission as in other cases of persistent Mullerian duct syndrome. Truncating mutations in receptors of the TGFbeta family exert dominant negative activity, which was seen only when each of the mutant anti-Mullerian hormone receptors was overexpressed in an anti-Mullerian hormone-responsive cell line. We conclude that assessment of dominant activity in vitro, which usually involves overexpression of mutant genes, does not necessarily produce information applicable to clinical conditions, in which mutant and endogenous genes are expressed on a one to one basis

Cross-correlation of random fields: mathematical approach and applications

International audienceRandom field cross-correlation is a new promising technique for seismic exploration, as it bypasses shortcomings of usual active methods. Seismic noise can be considered as a reproducible, stationary in time, natural source. In the present paper we show why and how cross-correlation of noise records can be used for geophysical imaging. We discuss the theoretical conditions required to observe the emergence of the Green's functions between two receivers from the cross-correlation of noise records. We present examples of seismic imaging using reconstructed surface waves from regional to local scales. We also show an application using body waves extracted from records of a small-scale network. We then introduce a new way to achieve surface wave seismic experiments using cross-correlation of unsynchronized sources. At a laboratory scale, we demonstrate that body wave extraction may also be used to image buried scatterers. These works show the feasibility of passive imaging from noise cross-correlation at different scales

Kinetic study of silica gels by a new rheological ultrasonic investigation

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Amine degradation in CO₂ capture. 3. New degradation products of MEA in liquid phase: Amides and nitrogenous heterocycles

International audienceTo reduce greenhouse gas emissions from fossil fuel power plants, post combustion CO2 capture with amine-based solvent is the most mature technology. Ethanolamine (MEA), the benchmark amine, is the most studied amine but some degradation products are still unknown and for an environmental acceptance, it is important to identify them. In this work eleven amides and nitrogenous heterocycles were identified in a pilot plant liquid sample. Among them seven molecules were never reported in literature. Different analytical methods were developed especially HS-SPME coupled to GC/MS. Mechanisms of formation were proposed for each molecule and were validated in most cases