During hazardous geophysical mass flows, such as rock or snow avalanches, debris flows and volcanic pyroclastic flows, a continuous exchange of material can occur between the slide and the bed. The net balance between erosion and deposition of particles can drastically influence the behaviour of these flows. Recent advances in describing the non-monotonic effective basal friction and the internal granular rheology in depth averaged theories have enabled small scale laboratory experiments (see fig. 1) to be quantitatively reproduced and can also be implemented in large scale models to improve hazard mitigation.
{"title":"Modelling erosion and deposition in geophysical granular mass flows","authors":"S. Viroulet, Christopher G. Johnson, J. Gray","doi":"10.1051/EPN/2021106","DOIUrl":"https://doi.org/10.1051/EPN/2021106","url":null,"abstract":"During hazardous geophysical mass flows, such as rock or snow avalanches, debris flows and volcanic pyroclastic flows, a continuous exchange of material can occur between the slide and the bed. The net balance between erosion and deposition of particles can drastically influence the behaviour of these flows. Recent advances in describing the non-monotonic effective basal friction and the internal granular rheology in depth averaged theories have enabled small scale laboratory experiments (see fig. 1) to be quantitatively reproduced and can also be implemented in large scale models to improve hazard mitigation.","PeriodicalId":52467,"journal":{"name":"Europhysics News","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83691534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As we recall the major contributions of Professor Dennis Gabor that resulted in his Nobel Prize in Physics in 1971 for the invention of holography, it is interesting to put his impact on science, technology, as well as humanity, in a broader context so as to better understand his experiences, and recognize the very significant role that he played in his time.
{"title":"Nobel prize 50 years ago","authors":"Erol Gelenbe","doi":"10.1051/epn/2021507","DOIUrl":"https://doi.org/10.1051/epn/2021507","url":null,"abstract":"As we recall the major contributions of Professor Dennis Gabor that resulted in his Nobel Prize in Physics in 1971 for the invention of holography, it is interesting to put his impact on science, technology, as well as humanity, in a broader context so as to better understand his experiences, and recognize the very significant role that he played in his time.","PeriodicalId":52467,"journal":{"name":"Europhysics News","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90337582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To protect fifteen northern European countries against sea level rise, a highly ambitious plan was put forward to build massive sea dams across the North Sea and the English Channel, which will cut off the North Sea from the rest of the Atlantic Ocean.
{"title":"NEED Northern European Enclosure Dam","authors":"S. Groeskamp, J. Kjellsson","doi":"10.1051/EPN/2021201","DOIUrl":"https://doi.org/10.1051/EPN/2021201","url":null,"abstract":"To protect fifteen northern European countries against sea level rise, a highly ambitious plan was put forward to build massive sea dams across the North Sea and the English Channel, which will cut off the North Sea from the rest of the Atlantic Ocean.","PeriodicalId":52467,"journal":{"name":"Europhysics News","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87555797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years there have been regular reports about a new generation of batteries in which the liquid electrolyte is replaced by a solid material: the solid-state batteries. With a higher energy density and a better safety than current batteries, solid-state batteries potentially would boost electric mobility by enhancing the driving distance of e-cars and prevent extreme battery fires. Why are they not yet implemented in the latest generation of e-cars?
{"title":"Where are those promising solid-state batteries?","authors":"M. Wagemaker, M. Huijben, M. Tromp","doi":"10.1051/epn/2021504","DOIUrl":"https://doi.org/10.1051/epn/2021504","url":null,"abstract":"In recent years there have been regular reports about a new generation of batteries in which the liquid electrolyte is replaced by a solid material: the solid-state batteries. With a higher energy density and a better safety than current batteries, solid-state batteries potentially would boost electric mobility by enhancing the driving distance of e-cars and prevent extreme battery fires. Why are they not yet implemented in the latest generation of e-cars?","PeriodicalId":52467,"journal":{"name":"Europhysics News","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83389069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Calorimetry is an important measurement technique in experimental particle physics. Although calorimeters based on liquefied noble gases were first proposed 50 years ago, they continue to play an important role in modern particle physics and have substantially contributed to the discovery of the Higgs boson at the Large Hadron Collider (LHC) at CERN in 2012.
{"title":"Noble liquid calorimetry at the LHC and prospects of its application in future collider experiments","authors":"M. Aleksa","doi":"10.1051/epn/2021306","DOIUrl":"https://doi.org/10.1051/epn/2021306","url":null,"abstract":"Calorimetry is an important measurement technique in experimental particle physics. Although calorimeters based on liquefied noble gases were first proposed 50 years ago, they continue to play an important role in modern particle physics and have substantially contributed to the discovery of the Higgs boson at the Large Hadron Collider (LHC) at CERN in 2012.","PeriodicalId":52467,"journal":{"name":"Europhysics News","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80189348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nuclear fusion is one of the most promising energy sources to satisfy our future needs. However, several open challenges are yet to be solved for the realisation of fusion electricity. Among the crucial issues, it is key to develop innovative solutions to increase the lifetime of the components inside a fusion reactor.
{"title":"The lifetime of components in a fusion reactor","authors":"G. Dose","doi":"10.1051/epn/2021503","DOIUrl":"https://doi.org/10.1051/epn/2021503","url":null,"abstract":"Nuclear fusion is one of the most promising energy sources to satisfy our future needs. However, several open challenges are yet to be solved for the realisation of fusion electricity. Among the crucial issues, it is key to develop innovative solutions to increase the lifetime of the components inside a fusion reactor.","PeriodicalId":52467,"journal":{"name":"Europhysics News","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86297706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Sands, L. Kormos, J. Nowak, Helen Vaughan, A. Voice, Stan Zochowski
{"title":"Moving teaching online during the COVID-19 pandemic","authors":"D. Sands, L. Kormos, J. Nowak, Helen Vaughan, A. Voice, Stan Zochowski","doi":"10.1051/EPN/2020406","DOIUrl":"https://doi.org/10.1051/EPN/2020406","url":null,"abstract":"","PeriodicalId":52467,"journal":{"name":"Europhysics News","volume":"48 1","pages":"30-32"},"PeriodicalIF":0.0,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74856731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Being critical, i.e. able to process and distill relevant information, is crucial for living systems. Learning distinguishes living from inanimate matter. Quantifying this distinction may provide a “life meter” [1] that, for example, can allow us to detect alien life forms in astrobiology. Living systems also respond in an anomalous manner to perturbations, as compared to inanimate matter, unless the latter is poised at a critical state (in the statistical physics sense). I argue below that these two notions of criticality are only apparently different, because a system that learns is inherently critical, also in the statistical physics sense.
{"title":"On the importance of being critical","authors":"M. Marsili","doi":"10.1051/epn/2020508","DOIUrl":"https://doi.org/10.1051/epn/2020508","url":null,"abstract":"Being critical, i.e. able to process and distill relevant information, is crucial for living systems. Learning distinguishes living from inanimate matter. Quantifying this distinction may provide a “life meter” [1] that, for example, can allow us to detect alien life forms in astrobiology. Living systems also respond in an anomalous manner to perturbations, as compared to inanimate matter, unless the latter is poised at a critical state (in the statistical physics sense). I argue below that these two notions of criticality are only apparently different, because a system that learns is inherently critical, also in the statistical physics sense.","PeriodicalId":52467,"journal":{"name":"Europhysics News","volume":"19 1","pages":"42-44"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79312838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A living cell contains flexible, semi-flexible and stiff filaments, forming the cell skeleton, called the cytoskeleton, the detail of which is described in Timon Idema's article. How does this filamentous network rearrange to drive cell shape changes to achieve cell functions such as division and motility? With the metaphor of a spaghetti bowl, the force you need to apply when tossing with your spoon depends on spaghetti (or filament) density, how much they are cooked (their flexibility), and how they stick together. In particular, cells or cell assemblies are elastic, especially at short time scales: when deformed, they recover their initial shape. Pinch your cheek for a few seconds, it will go back. However, at longer time scales, over minutes, days, years, cells can flow: they are viscous. Look at your elbow skin and compare it with a baby one : it has flown. Unlike macromolecular polymer networks (or a spaghetti bowl), living matter is alive, consumes chemical energy through hydrolysis of adenosine triphosphate. Proteins in the cytoskeletal network assemble, slide, or change conformation, therefore complexifying the simple picture of passive elasticity and viscosity. These cytoskeletal networks are able to actively deform a membrane, and drive cell shape changes. The cell membrane separates the cell content from the outside and has a bending energy that amounts to a few dozen times the thermal energy, it is soft and deformable therefore fluctuate at room (or body) temperature. Underneath the cell membrane lies a network of branched and entangled protein filaments (Blanchoin et al., 2014). Actin filaments have the peculiar property that their growth is activated at the membrane through the formation of new branches in the network. "Simplicity is complexity resolved" is a quote from the famous sculptor Constantin Brancusi. Likewise, physicists try to make things simple, as a cell is a complex system. Strippeddown experimental systems were developed that reconstitute cell functions with purified components. Whereas one single filament would simply push by growing against the membrane, strikingly, the complex growth of a branched network generates both inward and outward membrane deformations, which is an extraordinary property of these networks. This push or pull depend on the detailed organisation of the network, the growth velocity of their filaments, and membrane tension, as supported by models based either on reaction kinetics or cooperative properties of actin networks (Dürre et al., 2018; Simon et al., 2019). Further modeling, inspired by these controlled experiments, will help to decipher how cells control their membrane deformations for various functions, from virus uptake to cell motility which dysfunction leads to various diseases. n
活细胞包含柔性、半柔性和刚性细丝，形成细胞骨架，称为细胞骨架，其细节在Timon Idema的文章中有描述。这个丝状网络是如何重新排列来驱动细胞形状的变化，从而实现细胞的功能，如分裂和运动?以意大利面碗为例，当你用勺子搅拌时，你需要施加的力取决于意大利面(或面条丝)的密度，它们煮熟的程度(它们的柔韧性)，以及它们如何粘在一起。特别是，细胞或细胞组合具有弹性，特别是在短时间尺度上:当变形时，它们会恢复其初始形状。捏你的脸颊几秒钟，它就会复原。然而，在更长的时间尺度上，如几分钟、几天、几年，细胞可以流动:它们是粘性的。看看你肘部的皮肤，把它和婴儿的皮肤比较一下:它已经飞走了。与大分子聚合物网络(或意大利面碗)不同，生物是有生命的，通过三磷酸腺苷的水解来消耗化学能。细胞骨架网络中的蛋白质聚集、滑动或改变构象，因此使被动弹性和粘性的简单图景变得复杂。这些细胞骨架网络能够主动地使细胞膜变形，并驱动细胞形状的变化。细胞膜将细胞内容物与外界分离，并且具有相当于热能几十倍的弯曲能，它柔软且可变形，因此在室温(或身体)温度下波动。细胞膜下是一个由分支和纠缠的蛋白丝组成的网络(Blanchoin et al.， 2014)。肌动蛋白丝具有一种特殊的特性，即它们的生长是在膜上通过在网络中形成新的分支而被激活的。“简单就是解决复杂”是著名雕塑家康斯坦丁·布朗库西的名言。同样地，物理学家试图把事情简单化，因为细胞是一个复杂的系统。开发了简化的实验系统，用纯化的成分重建细胞功能。然而，一个单丝只会通过生长来推动膜，引人注目的是，一个分支网络的复杂生长会产生向内和向外的膜变形，这是这些网络的一个非凡特性。这种推或拉取决于网络的详细组织，其细丝的生长速度和膜张力，并得到基于反应动力学或肌动蛋白网络协同特性的模型的支持(d rre等人，2018;Simon et al.， 2019)。受这些受控实验的启发，进一步的建模将有助于破译细胞如何控制其膜变形以实现各种功能，从病毒摄取到细胞运动(功能障碍导致各种疾病)。n
{"title":"Living Soft Matter Physics : active protein networks govern cell shape changes","authors":"C. Sykes","doi":"10.1051/epn/2020501","DOIUrl":"https://doi.org/10.1051/epn/2020501","url":null,"abstract":"A living cell contains flexible, semi-flexible and stiff filaments, forming the cell skeleton, called the cytoskeleton, the detail of which is described in Timon Idema's article. How does this filamentous network rearrange to drive cell shape changes to achieve cell functions such as division and motility? With the metaphor of a spaghetti bowl, the force you need to apply when tossing with your spoon depends on spaghetti (or filament) density, how much they are cooked (their flexibility), and how they stick together. In particular, cells or cell assemblies are elastic, especially at short time scales: when deformed, they recover their initial shape. Pinch your cheek for a few seconds, it will go back. However, at longer time scales, over minutes, days, years, cells can flow: they are viscous. Look at your elbow skin and compare it with a baby one : it has flown. Unlike macromolecular polymer networks (or a spaghetti bowl), living matter is alive, consumes chemical energy through hydrolysis of adenosine triphosphate. Proteins in the cytoskeletal network assemble, slide, or change conformation, therefore complexifying the simple picture of passive elasticity and viscosity. These cytoskeletal networks are able to actively deform a membrane, and drive cell shape changes. The cell membrane separates the cell content from the outside and has a bending energy that amounts to a few dozen times the thermal energy, it is soft and deformable therefore fluctuate at room (or body) temperature. Underneath the cell membrane lies a network of branched and entangled protein filaments (Blanchoin et al., 2014). Actin filaments have the peculiar property that their growth is activated at the membrane through the formation of new branches in the network. \"Simplicity is complexity resolved\" is a quote from the famous sculptor Constantin Brancusi. Likewise, physicists try to make things simple, as a cell is a complex system. Strippeddown experimental systems were developed that reconstitute cell functions with purified components. Whereas one single filament would simply push by growing against the membrane, strikingly, the complex growth of a branched network generates both inward and outward membrane deformations, which is an extraordinary property of these networks. This push or pull depend on the detailed organisation of the network, the growth velocity of their filaments, and membrane tension, as supported by models based either on reaction kinetics or cooperative properties of actin networks (Dürre et al., 2018; Simon et al., 2019). Further modeling, inspired by these controlled experiments, will help to decipher how cells control their membrane deformations for various functions, from virus uptake to cell motility which dysfunction leads to various diseases. n","PeriodicalId":52467,"journal":{"name":"Europhysics News","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90838139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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