Role of Magnesium in Soda-Lime Glasses: Insight into Structural, Transport, and Mechanical Properties through Computer Simulations

2008 ◽  
Vol 112 (29) ◽  
pp. 11034-11041 ◽  
Author(s):  
Alfonso Pedone ◽  
Gianluca Malavasi ◽  
M. Cristina Menziani ◽  
Ulderico Segre ◽  
Alastair N. Cormack
2016 ◽  
Vol 95 ◽  
pp. 247-255 ◽  
Author(s):  
Qiong Sheng ◽  
Yu Zhang ◽  
Chao Xia ◽  
Dashan Mi ◽  
Xiang Xu ◽  
...  

1999 ◽  
Vol 593 ◽  
Author(s):  
D. Tekleab ◽  
R. Czerw ◽  
A. Rubio ◽  
P.M. Ajayan ◽  
D.L. Carroll

ABSTRACTWe report the use of high power ultrasonic agitation to create inelastic deformations in multiwalled carbon nanotubes. Using STM coupled with TEM we show that this damage can range from kinking to breaking of continuous tube walls into segments. Such deformed tubes provide an insight into the role of re-hybridization in the electrical and mechanical properties of tubes.


2021 ◽  
Vol 130 (10) ◽  
pp. 105104
Author(s):  
Grant D. Smith ◽  
Scott Bardenhagen ◽  
John A. Nairn ◽  
Tony Zahrah ◽  
Joseph P. Hooper ◽  
...  

10.14311/917 ◽  
2008 ◽  
Vol 48 (1) ◽  
Author(s):  
M. Fischer ◽  
M. Mlček ◽  
S. Konvičková ◽  
O. Kittnar

Though congestive heart failure is a leading cause of death in our population, the pathophysiological mechanisms at molecular level remain to be elucidated. This paper discusses the contribution of NCX to the pathological pattern of intracellular calcium regulation and contraction on the basis of computer simulations of a virtual cell. The model comprises calcium handling mechanisms, troponin control and acto-myosin interactions. The contribution of NCX was studied by changing its activity and turning it off for some simulations.It was found that NCX helps to support diastolic function by reducing the Ca2 level during the diastole. At the same time there is a reduction in peak Cai and hence contraction. However, increased NCX activity does not seem to improve calcium handling and contraction crucially, as has been suggested by some authors.


Proceedings ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 2
Author(s):  
Josergio Zaragoza ◽  
Prashanth Asuri

Recent studies have expanded our understanding of the effects of nanoparticles on hydrogel mechanical properties. However, further studies are needed to validate the generality of these findings, as well as to determine the exact mechanisms behind the enhancements afforded by the incorporation of nanoparticles. In this study, we performed rotational rheological characterizations of chemically crosslinked poly(acrylamide) hydrogels incorporating silica nanoparticles to better understand the role of nanoparticles on the enhanced properties of hydrogel nanocomposites. Our results indicate that incorporating nanoparticles can lead to enhancements in hydrogel elastic moduli greater than the maxima obtainable through purely chemical crosslinking. Moreover, we find that the increases in elastic moduli due to the addition of nanoparticles not only depend on particle concentration, but also on the monomer and chemical crosslinker concentration. Finally, our data indicates a strong role for pseudo-crosslinking mediated by noncovalent interactions between the nanoparticles and hydrogel polymers on the observed reinforcements. Collectively, our results shed further insight into the role of nanoparticles on enhancements of mechanical properties of hydrogels and may thereby facilitate engineering specific mechanical properties in a wide range of hydrogel nanocomposite systems.


1992 ◽  
Vol 67 (01) ◽  
pp. 111-116 ◽  
Author(s):  
Marcel Levi ◽  
Jan Paul de Boer ◽  
Dorina Roem ◽  
Jan Wouter ten Cate ◽  
C Erik Hack

SummaryInfusion of desamino-d-arginine vasopressin (DDAVP) results in an increase in plasma plasminogen activator activity. Whether this increase results in the generation of plasmin in vivo has never been established.A novel sensitive radioimmunoassay (RIA) for the measurement of the complex between plasmin and its main inhibitor α2 antiplasmin (PAP complex) was developed using monoclonal antibodies preferentially reacting with complexed and inactivated α2-antiplasmin and monoclonal antibodies against plasmin. The assay was validated in healthy volunteers and in patients with an activated fibrinolytic system.Infusion of DDAVP in a randomized placebo controlled crossover study resulted in all volunteers in a 6.6-fold increase in PAP complex, which was maximal between 15 and 30 min after the start of the infusion. Hereafter, plasma levels of PAP complex decreased with an apparent half-life of disappearance of about 120 min. Infusion of DDAVP did not induce generation of thrombin, as measured by plasma levels of prothrombin fragment F1+2 and thrombin-antithrombin III (TAT) complex.We conclude that the increase in plasminogen activator activity upon the infusion of DDAVP results in the in vivo generation of plasmin, in the absence of coagulation activation. Studying the DDAVP induced increase in PAP complex of patients with thromboembolic disease and a defective plasminogen activator response upon DDAVP may provide more insight into the role of the fibrinolytic system in the pathogenesis of thrombosis.


2019 ◽  
Vol 58 (2) ◽  
pp. 249-259
Author(s):  
Joseph Acquisto

This essay examines a polemic between two Baudelaire critics of the 1930s, Jean Cassou and Benjamin Fondane, which centered on the relationship of poetry to progressive politics and metaphysics. I argue that a return to Baudelaire's poetry can yield insight into what seems like an impasse in Cassou and Fondane. Baudelaire provides the possibility of realigning metaphysics and politics so that poetry has the potential to become the space in which we can begin to think the two of them together, as opposed to seeing them in unresolvable tension. Or rather, the tension that Baudelaire animates between the two allows us a new way of thinking about the role of esthetics in moments of political crisis. We can in some ways see Baudelaire as responding, avant la lettre, to two of his early twentieth-century readers who correctly perceived his work as the space that breathes a new urgency into the questions of how modern poetry relates to the world from which it springs and in which it intervenes.


2014 ◽  
Vol 35 (1) ◽  
pp. 121-135 ◽  
Author(s):  
Tomasz Rydzkowski ◽  
Iwona Michalska-Pożoga

Abstract The paper presents the summary of research on polymer melt particle motion trajectories in a disc zone of a screw-disk extruder. We analysed two models of its structure, different in levels of taken simplifications. The analysis includes computer simulations of material particle flow and results of experimental tests to determine the properties of the resultant extrudate. Analysis of the results shows that the motion of melt in the disk zone of a screw-disk extruder is a superposition of pressure and dragged streams. The observed trajectories of polymer particles and relations of mechanical properties and elongation of the molecular chain proved the presence of a stretching effect on polymer molecular chains.


Letonica ◽  
2020 ◽  
Author(s):  
Māra Grudule

The article gives insight into a specific component of the work of Baltic enlightener Gotthard Friedrich Stender (1714–1796) that has heretofore been almost unexplored — the transfer of German musical traditions to the Latvian cultural space. Even though there are no sources that claim that Stender was a composer himself, and none of his books contain musical notation, the texts that had been translated by Stender and published in the collections “Jaunas ziņģes” (New popular songs, 1774) and “Ziņģu lustes” (The Joy of singing, 1785, 1789) were meant for singing and, possibly, also for solo-singing with the accompaniment of some musical instrument. This is suggested, first, by how the form of the translation corresponds to the original’s form; second, by the directions, oftentimes attached to the text, that indicate the melody; and third, by the genres of the German originals cantata and song. Stender translated several compositions into Latvian including the text of the religious cantata “Der Tod Jesu” (The Death of Jesus, 1755) by composer Karl Heinrich Graun (1754–1759); songs by various composers that were widely known in German society; as well as a collection of songs by the composer Johann Gottlieb Naumann (1741–1801) that, in its original form, was published together with notation and was intended for solo-singing (female vocals) with the accompaniment of a piano. This article reveals the context of German musical life in the second half of the 18th century and explains the role of music as an instrument of education in Baltic-German and Latvian societies.


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