DETECTING DAMAGED ZONES ALONG SMART SELFSENSORY CARBON BASED TRC BY TDR

The study aims to investigate the ability of smart self-sensory carbon roving to detect damaged zones in TRC structures. State of the art monitoring procedures are based on integrative measurements and accordingly are limited in detecting only the occurrence of damage. This study aims to handle this limitation and offers to adopt the Time Domain Reflectometer (TDR) technique. The TDR concept is widely used in Bayonet Nut Coupling (BNC) cables to identify defects along the cable (opens, shorts, etc.). The current study adopts its principle to carbon rovings. To simulate the BNC cable configuration, the study offers to connect two parallel carbon rovings to the TDR Data Acquisition (DAQ) system. The proposed monitoring technique is investigated by loading two textile reinforced MPC beams under uniaxial tensile loading. Results show the potential of the suggested technique to locate damage zones in TRC structures and highlights its limitation

Understanding Traffic Accidents among Young Drivers in Qatar

Young drivers are generally associated with risky driving behaviors that can lead to crash involvement. Many self-report measurement scales are used to assess such risky behaviors. This study is aimed to understand the risky driving behaviors of young adults in Qatar and how such behaviors are associated with crash involvement. This was achieved through the usage of validated self-report measurement scales adopted for the Arabic context. A nationwide cross-sectional and exploratory study was conducted in Qatar from January to April 2021. Due to the Covid-19 pandemic, the survey was conducted online. Therefore, respondents were selected conveniently. Hence, the study adopted a non-probability sampling method in which convenience and snowball sampling were used. A total of 253 completed questionnaires were received, of which 57.3% were female, and 42.7% were male. Approximately 55.8% of these young drivers were involved in traffic accidents after obtaining their driving license. On average, most young drivers do have some risky driving behavior accompanied by a low tendency to violate traffic laws, and their driving style is not significantly controlled by their personality on the road. The older young drivers are more involved in traffic accidents than the younger drivers, i.e., around 1.5 times more likely. Moreover, a young male driver is 3.2 times less likely to be involved in traffic accidents than a female driver. In addition, males are only 0.309 times as likely as females to be involved in an accident and have approximately a 70% lower likelihood of having an accident versus females. The analysis is complemented with the association between young drivers' demographic background and psychosocial-behavioral parameters (linking risky driving behavior, personality, and obligation effects on crash involvement). Some interventions are required to improve driving behavior, such as driving apps that are able to monitor and provide corrective feedback. 2022 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This research and APC was funded by the Qatar National Research Fund (QNRF), grant number NPRP12S-0129-190017.Scopu

Effect of temperature on passive film formation of UNS N08031 Cr-Ni alloy in phosphoric acid contaminated with different aggressive anions

tThe influence of temperature and the effect of aggressive anions on the electrochemical behaviour of UNSN08031 stainless steel in a contaminated phosphoric acid solution were evaluated. Stabilisation of thepassive film was studied by potentiodynamic polarisation curves, potentiostatic tests, electrochemicalimpedance spectroscopy (EIS) measurements, Mott Schottky analysis and X-ray photoelectron spec-troscopy (XPS). The stability of the passive film was found to decrease as temperature increases. The filmformed on the stainless steel surface was a n-type semiconductor and the XPS spectrum revealed thepresence of fluoride ions.Authors express their gratitude to the Ministry of Education of Spain (MHE2011-00202) for its financial support during the stay at University of Manchester, to MAEC of Spain (PCI Mediterraneo C/8196/07, C/018046/08, D/023608/09 and D/030177/10) and to the Generalitat Valenciana (GV/2011/093) for the financial support. The authors would also like to acknowledge the support of the School of Materials at the University of Manchester for providing analytical and technical support for the study.Escrivá Cerdán, C.; Blasco Tamarit, ME.; García García, DM.; García Antón, J.; Akid, R.; Walton, J. (2013). Effect of temperature on passive film formation of UNS N08031 Cr-Ni alloy in phosphoric acid contaminated with different aggressive anions. Electrochimica Acta. 111:552-561. https://doi.org/10.1016/j.electacta.2013.08.040S55256111

Insulin-like growth factor - Oestradiol crosstalk and mammary gland tumourigenesis

Development and differentiation of the mammary gland are dependent on the appropriate temporal expression of both systemically acting hormones and locally produced growth factors. A large body of evidence suggests that molecular crosstalk between these hormonal and growth factor axes is crucial for appropriate cell and tissue function. Two of the most important trophic factors involved in this process are the oestrogen (E) and insulin-like growth factor (IGF) molecular axes. The reciprocal crosstalk that exists between these pathways occurs at transcriptional/post-transcriptional and translational/post-translational levels regulate the expression and activity of genes involved in this process. In a clinical context an important consequence of such crosstalk in the mammary gland is the role which it may play in the aetiology, maintenance and development of breast tumours. Although oestradiol (E2) acting through oestrogen receptors α and β (ERα/β) is important for normal mammary gland function it can also provide a mitogenic drive to ER+ breast tumours. Therefore over several years anti-oestrogen therapeutic regimens in the form of selective oestrogen receptor modulators (SERMs - e.g. tamoxifen), aromatase inhibitors (AI e.g. anastrozole) or selective oestrogen receptor down regulators (SERDs - e.g. fulvestrant) have been used in an adjuvant setting to control tumour growth. Although initial response is usually encouraging, large cohorts of patients eventually develop resistance to these treatments leading to tumour recurrence and poor prognosis. There are potentially many routes by which breast cancer (BC) cells could escape anti-oestrogen based therapeutic strategies and one of the most studied is the possible growth factor mediated activation of ER(s). Because of this, growth factor modulation of ER activity has been an intensively studied route of molecular crosstalk in the mammary gland. The insulin-like growth factors (IGF-1 and -2) are amongst the most potent mitogens for mammary epithelial cells and there is accumulating evidence that they interact with the E2 axis to regulate mitogenesis, apoptosis, adhesion, migration and differentiation of mammary epithelial cells. Such interactions are bi-directional and E2 has been shown to regulate the expression and activity of IGF axis genes with the general effect of sensitising breast epithelial cells to the actions of IGFs and insulin. In this short review we discuss the evidence for the involvement of crosstalk between the insulin-like growth factor (IGF) and oestrogen axes in the mammary gland and comment on the relevance of such studies in the aetiology and treatment of BC

Overexpression of E2F-5 correlates with a pathological basal phenotype and a worse clinical outcome

The purpose of the present study is to identify genes that contribute to cell proliferation or differentiation of breast cancers independent of signalling through the oestrogen receptor (ER) or human epidermal growth factor receptor 2 (HER2). An oligonucleotide microarray assayed 40 tumour samples from ER(+)/HER2(−), ER(+)/HER2(+), ER(−)/HER2(+), and ER(−)/HER2(−) breast cancer tissues. Quantitative reverse transcriptase PCR detected overexpression of a cell cycle-related transcription factor, E2F-5, in ER-negative breast cancers, and fluorescence in situ hybridisation detected gene amplification of E2F-5 in 5 out of 57 (8.8%) breast cancer samples. No point mutations were found in the DNA-binding or DNA-dimerisation domain of E2F-5. Immunohistochemically, E2F-5-positive cancers correlated with a higher Ki-67 labelling index (59.5%, P=0.001) and higher histological grades (P=0.049). E2F-5-positive cancers were found more frequently in ER(−)/progesterone receptor (PgR)(−)/HER2(−) cancer samples (51.9%, P=0.0049) and in breast cancer samples exhibiting a basal phenotype (56.0%, P=0.0012). Disease-free survival in node-negative patients with E2F-5-positive cancers was shorter than for patients with E2F-5-negative cancers. In conclusion, we identify, for the first time, a population of breast cancer cells that overexpress the cell cycle-related transcription factor, E2F-5. This E2F-5-positive breast cancer subtype was associated with an ER(−)/PgR(−)/HER2(−) status, a basal phenotype, and a worse clinical outcome

Physicochemical Characterization of Passive Films and Corrosion Layers by Differential Admittance and Photocurrent Spectroscopy

Two different electrochemical techniques, differential admittance and photocurrent spectroscopy, for the characterization of electronic and solid state properties of passive films and corrosion layers are described and critically evaluated. In order to get information on the electronic properties of passive film and corrosion layers as well as the necessary information to locate the characteristic energy levels of the passive film/electrolyte junction like: flat band potential (Ufb), conduction band edge (EC) or valence band edge (EV), a wide use of Mott-Schottky plots is usually reported in corrosion science and passivity studies. It has been shown, in several papers, that the use of simple M-S theory to get information on the electronic properties and energy levels location at the film/electrolyte interface can be seriously misleading and/or conflicting with the physical basis underlying the M-S theory. A critical appraisal of this approach to the study of very thin and thick anodic passive film grown on base-metals (Cr, Ni, Fe, SS etc..) or on valve metals (Ta, Nb, W etc..) is reported in this work, together with possible alternative approach to overcome some of the mentioned inconsistencies. At this aim the theory of amorphous semiconductor Schottky barrier, introduced several years ago in the study of passive film/electrolyte junction, is reviewed by taking into account some of the more recent results obtained by the present authors. Future developments of the theory appears necessary to get more exact quantitative information on the electronic properties of passive films, specially in the case of very thin film like those formed on base metals and their alloys. The second technique described in this chapter, devoted to the physico-chemical characterization of passive film and corrosion layers, is a more recent technique based on the analysis of the photo-electrochemical answer of passive film/electrolyte junction under illumination with photons having suitable energy. Such a technique usually referred to as Photocurrent Spectroscopy (PCS) has been developed on the basis of the large research effort carried out by several groups in the 1970’s and aimed to investigate the possible conversion of solar energy by means of electrochemical cells. In this work the fundamentals of semiconductor/electrolyte junctions under illumination will be highlighted both for crystalline and amorphous materials. The role of amorphous nature and film thickness on the photo-electrochemical answer of passive film/solution interface is reviewed as well the use of PCS for quantitative analysis of the film composition based on a semi-empirical correlation between optical band gap and difference of electronegativity of film constituents previously suggested by the present authors. In this frame the results of PCS studies on valve metal oxides and valve metal mixed oxides will be discussed in order to show the validity of the proposed method. The results of PCS studies aimed to get information on passive film composition and carried out by different authors on base metals (Fe, Cr, Ni) and their alloys, including stainless steel, will be also compared with compositional analysis carried out by well-established surface analysis techniques

Fabrication and Characterization of Gate-All-Around Stacked-Nanowire/Nanosheet MOS transistors realized by a Gate-Last approach for sub-7 nm technology nodes.

La diminution de la taille des transistors actuellement utilisés en microélectronique ainsi que l’augmentation de leurs performances demeure encore au centre de toutes les attentions. Cette thèse propose d’étudier et de fabriquer des transistors à base de nanofils empilés. Cette architecture avec des grilles enrobantes est l’ultime solution pour concentrer toujours plus de courant électrique dans un encombrement minimal. Les simulations ont par ailleurs révélé le potentiel des nanofeuillets de silicium qui permettent à la fois d’optimiser l’espace occupé tout en proposant des performances supérieures aux dispositifs actuels. L’importance de l’ajout de certaines étapes de fabrication a également été soulignée. En ce sens, deux séries d’étapes de fabrication ont été proposées : la première option vise à minimiser le nombre de variations par rapport à ce qui est aujourd’hui en production tandis que la deuxième alternative offre potentiellement de meilleures performances au prix de développements plus importants. Les transistors ainsi fabriqués proposent des performances prometteuses supérieures à ce qui a pu être fabriqué dans le passé notamment grâce à l’introduction de contraintes mécaniques importantes favorables au transport du courant électrique.The future of the transistors currently used in Microelectronics is still uncertain: shrinking these devices while increasing their performances always remains a challenge. In this thesis, stacked nanowire transistors are studied, fabricated and optimized. This architecture embeds gate all around which is the ultimate solution for concentrating always more current within a smaller device. Simulations have shown that silicon nanosheets provide an optimal utilization of the space with providing increased performances over the other technologies. Crucial process steps have also been identified. Subsequently, two process flows have been suggested for the fabrication of SNWFETs. The first approach consists in minimizing the number of variations from processes already in mass production. The second alternative has potentially better performances but its development is more challenging. Finally, the fabricated transistors have shown improved performances over state-of-the-art especially due to mechanical stress induced for improving electric transport

Fabrication et caractérisation de transistors MOS à base de nanofils de silicium empilés et à grille enrobante réalisés par approche Gate-Last pour les noeuds technologiques sub-7 nm.

The future of the transistors currently used in Microelectronics is still uncertain: shrinking these devices while increasing their performances always remains a challenge. In this thesis, stacked nanowire transistors are studied, fabricated and optimized. This architecture embeds gate all around which is the ultimate solution for concentrating always more current within a smaller device. Simulations have shown that silicon nanosheets provide an optimal utilization of the space with providing increased performances over the other technologies. Crucial process steps have also been identified. Subsequently, two process flows have been suggested for the fabrication of SNWFETs. The first approach consists in minimizing the number of variations from processes already in mass production. The second alternative has potentially better performances but its development is more challenging. Finally, the fabricated transistors have shown improved performances over state-of-the-art especially due to mechanical stress induced for improving electric transport.La diminution de la taille des transistors actuellement utilisés en microélectronique ainsi que l’augmentation de leurs performances demeure encore au centre de toutes les attentions. Cette thèse propose d’étudier et de fabriquer des transistors à base de nanofils empilés. Cette architecture avec des grilles enrobantes est l’ultime solution pour concentrer toujours plus de courant électrique dans un encombrement minimal. Les simulations ont par ailleurs révélé le potentiel des nanofeuillets de silicium qui permettent à la fois d’optimiser l’espace occupé tout en proposant des performances supérieures aux dispositifs actuels. L’importance de l’ajout de certaines étapes de fabrication a également été soulignée. En ce sens, deux séries d’étapes de fabrication ont été proposées : la première option vise à minimiser le nombre de variations par rapport à ce qui est aujourd’hui en production tandis que la deuxième alternative offre potentiellement de meilleures performances au prix de développements plus importants. Les transistors ainsi fabriqués proposent des performances prometteuses supérieures à ce qui a pu être fabriqué dans le passé notamment grâce à l’introduction de contraintes mécaniques importantes favorables au transport du courant électrique