R&D of carbon nanotubes based nanocomposites for self-heating and de-icing applications

Icing is a problem that aerospace environment has to face. Ice accretion on aircraft surfaces can cause serious problems on flight safety, performances and efficiency. Several ice protection strategies have been developed to overcome the icing hazards in the aerospace industry. The electro-thermal method is one of the popular approaches to prevent ice accretion and accumulation on aircraft surfaces. Given the increasing requirement of composites on aircraft structures, metal frameworks/fibre reinforced composites have been developed as a de-icing solution for the new generation aircraft. Next-generation aircraft structures require increased strength and lightweight composite materials, which pushes a high interest in nanomaterial based composite. In this project it was proposed to fabricate self-heating nanocomposites from carbon nanotubes, as an effective de-icing approach in aerospace. Due to the natural advances of nanomaterials, the nanocomposite electro-thermal structures are also expected to offer enhanced mechanical properties. Carbon nanotubes have been used to fabricate carbon nanotube films (carbon nanotube buckypaper, CNP) that have been integrated into composite structures. The novelties of the project were the chemicals treatments used to improve the electrical conductivity of the carbon nanotubes buckypaper and the mechanical tests used to analyse the mechanical behaviour of the nanocomposites. Due to static and dynamic loads during the flight conditions, it is essential to understand the mechanical characteristics of the CNP-based composites. This work was focused, in accordance with the industrial partner, on improving the electrical characteristics of the nanocomposite without compromising the mechanical properties. Once the optimal electrical characteristics will be reach, the future work should be focused on improving the thermal properties of the nanocomposite to further increase the ice protection efficiency. The results showed that acid treatments of CNTs with nitric acid lead to an electrical conductivity improvement of CNT papers. The CNP showed promising electrical characteristics and heating performances for possible application in self-heating composites. Carbon nanotubes buckypapers embedded in fibre reinforced polymer composites have been fabricated by different processing approaches. Mechanical tests and the study of heating performance demonstrated that the CNP-based composite is a promising self-heating material candidate for ice protection of the aircraft surfaces

R&D of carbon nanotubes based nanocomposites for self-heating and de-icing applications

Icing is a problem that aerospace environment has to face. Ice accretion on aircraft surfaces can cause serious problems on flight safety, performances and efficiency. Several ice protection strategies have been developed to overcome the icing hazards in the aerospace industry. The electro-thermal method is one of the popular approaches to prevent ice accretion and accumulation on aircraft surfaces. Given the increasing requirement of composites on aircraft structures, metal frameworks/fibre reinforced composites have been developed as a de-icing solution for the new generation aircraft. Next-generation aircraft structures require increased strength and lightweight composite materials, which pushes a high interest in nanomaterial based composite. In this project it was proposed to fabricate self-heating nanocomposites from carbon nanotubes, as an effective de-icing approach in aerospace. Due to the natural advances of nanomaterials, the nanocomposite electro-thermal structures are also expected to offer enhanced mechanical properties. Carbon nanotubes have been used to fabricate carbon nanotube films (carbon nanotube buckypaper, CNP) that have been integrated into composite structures. The novelties of the project were the chemicals treatments used to improve the electrical conductivity of the carbon nanotubes buckypaper and the mechanical tests used to analyse the mechanical behaviour of the nanocomposites. Due to static and dynamic loads during the flight conditions, it is essential to understand the mechanical characteristics of the CNP-based composites. This work was focused, in accordance with the industrial partner, on improving the electrical characteristics of the nanocomposite without compromising the mechanical properties. Once the optimal electrical characteristics will be reach, the future work should be focused on improving the thermal properties of the nanocomposite to further increase the ice protection efficiency. The results showed that acid treatments of CNTs with nitric acid lead to an electrical conductivity improvement of CNT papers. The CNP showed promising electrical characteristics and heating performances for possible application in self-heating composites. Carbon nanotubes buckypapers embedded in fibre reinforced polymer composites have been fabricated by different processing approaches. Mechanical tests and the study of heating performance demonstrated that the CNP-based composite is a promising self-heating material candidate for ice protection of the aircraft surfaces

Electro-thermal and mechanical performance of multi-wall carbon nanotubes buckypapers embedded in fibre reinforced polymer composites for ice protection applications

Several ice protection strategies have been developed to overcome the icing hazards in the aerospace industry. The electro-thermal method is one of the popular approaches to prevent ice accretion and accumulation on aircraft surfaces. Given the increasing requirement of composites on aircraft structures, metal frameworks/fibre-reinforced composites have been developed as a de-icing solution for the new generation aircraft. The present work aimed to fabricate self-heating multi-wall carbon nanotubes based composites for ice protection and to study their electro-thermal and mechanical characteristics. Carbon nanotube buckypapers (CNPs) were prepared and embedded in fibre reinforced polymer composites by two methods: pre-preg and resin impregnation. The influence of the carbon nanotube network structure on the mechanical properties and electrical characteristics of the composites was evaluated. Mechanical tests, three-point flexural test and interlaminar shear strength test demonstrated improved mechanical characteristics of the CNP based composites. De-icing performance of the composites was conducted through a heating test in a climate chamber at −20℃. The results indicated that the CNP-based composite is a promising self-heating material candidate for ice protection systems

S1 ribosomal protein and the interplay between translation and mRNA decay

S1 is an ‘atypical’ ribosomal protein weakly associated with the 30S subunit that has been implicated in translation, transcription and control of RNA stability. S1 is thought to participate in translation initiation complex formation by assisting 30S positioning in the translation initiation region, but little is known about its role in other RNA transactions. In this work, we have analysed in vivo the effects of different intracellular S1 concentrations, from depletion to overexpression, on translation, decay and intracellular distribution of leadered and leaderless messenger RNAs (mRNAs). We show that the cspE mRNA, like the rpsO transcript, may be cleaved by RNase E at multiple sites, whereas the leaderless cspE transcript may also be degraded via an alternative pathway by an unknown endonuclease. Upon S1 overexpression, RNase E-dependent decay of both cspE and rpsO mRNAs is suppressed and these transcripts are stabilized, whereas cleavage of leaderless cspE mRNA by the unidentified endonuclease is not affected. Overall, our data suggest that ribosome-unbound S1 may inhibit translation and that part of the Escherichia coli ribosomes may actually lack S1

Synthesis and characterization of uhtc from preceramic polymer

Sintesi di UHTC tramite l'utilizzo di polimeri preceramici.\nCaratterizzazione tramite XRD, XRF, XPS e SE

Modifica via melt blending di acido polilattico per applicazioni nel campo del packaging: dispersione di nanocariche in miscele di PLA/PCL.

Produzione e caratterizzazione di sistemi polimerici biodegradabili e nanocomposit

Anti-Proliferative and Pro-Apoptotic Effects of Short-Term Inhibition of Telomerase In Vivo and in Human Malignant B Cells Xenografted in Zebrafish

Besides its canonical role in stabilizing telomeres, telomerase reverse transcriptase (TERT) may promote tumor growth/progression through extra-telomeric functions. Our previous in vitro studies demonstrated that short-term TERT inhibition by BIBR1532 (BIBR), an inhibitor of TERT catalytic activity, negatively impacts cell proliferation and viability via telomeres’ length-independent mechanism. Here we evaluate the anti-proliferative and pro-apoptotic effects of short-term telomerase inhibition in vivo in wild-type (wt) and tert mutant (terthu3430/hu3430; tert−/−) zebrafish embryos, and in malignant human B cells xenografted in casper zebrafish embryos. Short-term Tert inhibition by BIBR in wt embryos reduced cell proliferation, induced an accumulation of cells in S-phase and ultimately led to apoptosis associated with the activation of DNA damage response; all these effects were unrelated to telomere shortening/dysfunction. BIBR treatment showed no effects in tert−/− embryos. Xenografted untreated malignant B cells proliferated in zebrafish embryos, while BIBR pretreated cells constantly decreased and were significantly less than those in the controls from 24 to up to 72 h after xenotransplantation. Additionally, xenografted tumor cells, treated with BIBR prior- or post-transplantation, displayed a significant higher apoptotic rate compared to untreated control cells. In conclusion, our data demonstrate that short-term telomerase inhibition impairs proliferation and viability in vivo and in human malignant B cells xenografted in zebrafish, thus supporting therapeutic applications of TERT inhibitors in human malignancies

Styloid Jugular Nutcracker: The Possible Role of the Styloid Process Spatial Orientation—A Preliminary Morphometric Computed Study

Styloid Jugular Nutcracker (SJN, also known as Eagle Jugular Syndrome EJS) derives from a jugular stenosis caused by an abnormal styloid process, compressing the vessel in its superior portion (J3) against the C1 anterior arch. It could be considered a venous vascular variant of Eagle Syndrome (ES). Main clinical features of this ES variant are headache, pulsatile tinnitus and dizziness, possibly related to venous hypertension and impaired cerebral parenchyma drainage. In our opinion, conceptually, it is not the absolute length of the styloid bone that defines its abnormality, but its spatial direction. An elongated bone pointing outward far away from the midline could not compress the vein; vice versa, a short styloid process tightly adherent to the cervical spine could be pathological. To prove this hypothesis, we developed a semi-automatic software that processes CT-Angio images, giving quantitative information about distance and direction of the styloid process in three-dimensional space. We compared eight patients with SJN to a sample of healthy subjects homogeneous for sex and age. Our results suggest that SJN patients have a more vertically directed styloid, and this feature is more important than the absolute distance between the two bony structures. More studies are needed to expand our sample, including patients with the classic and carotid variants of Eagle Syndrome