Tunable adhesion and slip on a bio-mimetic sticky soft surface

Soft Matter ◽  
2019 ◽  
Vol 15 (44) ◽  
pp. 9031-9040 ◽  
Author(s):  
Saumyadwip Bandyopadhyay ◽  
S. M. Sriram ◽  
Vartika Parihar ◽  
Sunando Das Gupta ◽  
Rabibrata Mukherjee ◽  
...  

By tuning the extent of submergence of the rose petal structures with silicone oil, we could alter the adhesion characteristics of the surface on demand, while retaining its slippery characteristics for a wide range of the pertinent parameters.

Author(s):  
Jeremias Prassl

The rise of the gig economy is disrupting business models across the globe. Platforms’ digital work intermediation has had a profound impact on traditional conceptions of the employment relationship. The completion of ‘tasks’, ‘gigs’, or ‘rides’ in the (digital) crowd fundamentally challenges our understanding of work in modern labour markets: gone are the stable employment relationships between firms and workers, replaced by a world in which everybody can be ‘their own boss’ and enjoy the rewards—and face the risks—of independent businesses. Is this the future of work? What are the benefits and challenges of crowdsourced work? How can we protect consumers and workers without stifling innovation? Humans as a Service provides a detailed account of the growth and operation of gig-economy platforms, and develops a blueprint for solutions to the problems facing on-demand workers, platforms, and their customers. Following a brief introduction to the growth and operation of on-demand platforms across the world, the book scrutinizes competing narratives about ‘gig’ work. Drawing on a wide range of case studies, it explores how claims of ‘disruptive innovation’ and ‘micro-entrepreneurship’ often obscure the realities of precarious work under strict algorithmic surveillance, and the return to a business model that has existed for centuries. Humans as a Service shows how employment law can address many of these problems: gigs, tasks, and rides are work—and should be regulated as such. A concluding chapter demonstrates the broader benefits of a level playing field for consumers, taxpayers, and innovative entrepreneurs.


2021 ◽  
Vol 7 (3) ◽  
pp. 171
Author(s):  
Reannon L. Smith ◽  
Tom W. May ◽  
Jatinder Kaur ◽  
Tim I. Sawbridge ◽  
Ross C. Mann ◽  
...  

The Podosphaera tridactyla species complex is highly variable morphologically and causes powdery mildew on a wide range of Prunus species, including stone fruit. A taxonomic revision of the Po. tridactyla species complex in 2020 identified 12 species, seven of which were newly characterised. In order to clarify which species of this complex are present in Australia, next generation sequencing was used to isolate the fungal ITS+28S and host matK chloroplast gene regions from 56 powdery mildew specimens of stone fruit and ornamental Prunus species accessioned as Po. tridactyla or Oidium sp. in Australian reference collections. The specimens were collected in Australia, Switzerland, Italy and Korea and were collected from 1953 to 2018. Host species were confirmed using matK phylogenetic analysis, which identified that four had been misidentified as Prunus but were actually Malusprunifolia. Podosphaera species were identified using ITS+28S phylogenetic analysis, recognising three Podosphaera species on stone fruit and related ornamental Prunus hosts in Australia. These were Po.pannosa, the rose powdery mildew, and two species in the Po. tridactyla species complex: Po. ampla, which was the predominant species, and a previously unidentified species from peach, which we describe here as Po. cunningtonii.


2006 ◽  
Vol 59 (2) ◽  
pp. 109 ◽  
Author(s):  
Nina Morgner ◽  
Hans-Dieter Barth ◽  
Bernhard Brutschy

A new version of laser mass-spectrometry is presented, which allows the quantitative analysis of specific biocomplexes in native solution. On-demand micro droplets, injected into vacuum, are irradiated by mid IR-laser pulses. Above a certain intensity threshold they explode due to the transmitted energy, setting free a fraction of the charged biomolecules which are then mass-analyzed. Amounts of analyte in the attomolar range may be detected with the ion intensity being linear over a wide range of molarity. Evidence is given that this method is soft, tolerant against various buffers, reflects properties of the liquid phase, and suitable for studying noncovalently bonded specific complexes. This is highlighted by results from antibiotics specifically binding into the minor groove of duplex DNA.


Author(s):  
Daithí Mac Síthigh

The purpose of this chapter is to explain, in the context of telecommunications law and regulation, the regulation by EU and UK law of audiovisual and radio media services. Overarching principles are found in the Audiovisual Media Services Directive, which takes an approach described as technologically neutral, but established two top-level categories of regulation, for television (or linear) services and on-demand (or non-linear) services. In the case of television services, a wide range of standalone works and comprehensive Sections or chapters on the regulation of broadcasting are available. As such, the focus here (with a view to the interests of readers) is on licensing of content and multiplex services by Ofcom and the handling of complaints about those services, with a bias towards the standard licences for services on cable, satellite, internet, and digital terrestrial platforms, and the regulation of DTT multiplexes and of on-demand services, as opposed to detailed description of the BBC and the commercial public service broadcasters. Indeed, the European Court of Human Rights has regularly found that the regulation of communications infrastructure can have a real impact on the receiving and imparting of information.


Author(s):  
Hooman Foroughi ◽  
Masahiro Kawaji

The flow characteristics of a highly viscous oil and water mixture in a circular microchannel have been investigated. Water and silicone oil with a viscosity of 863 mPa.s were injected into a fused silica microchannel with a diameter of 250 μm. Before each experiment, the microchannel was initially saturated with either oil or water. In the initially oil-saturated case, different liquid-liquid flow patterns were observed and classified over a wide range of oil and water flow rates. As a special case, the flow of water at zero oil flow rate in a microchannel initially filled with silicone oil was also studied. When the microchannel was initially saturated with water, the oil formed a jet in water at the injection point but developed an instability at the oil-water interface downstream and eventually broke up into droplets.


1991 ◽  
pp. 135-140 ◽  
Author(s):  
Ph. BARTHE ◽  
V. VAILLANT ◽  
S. GUDIN
Keyword(s):  
The Rose ◽  

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Gracious Ngaile ◽  
Frank Botz

Although water/oil-graphite emulsions are widely used in warm forging processes, they carry environmental concerns. In an attempt to replace graphite-based lubricants in warm forging of aluminum alloys, two variants of boron-nitride-silicone lubricants were formulated. The two variants were made by dispersing boron nitride powder in polydimethyl siloxane oil at concentrations of 1% and 8%. The formulated lubricants were initially tested for their thermal degradation characteristics using a thermogravimetric analyzer and compared to the thermal degradation behavior of graphite and silicone oil lubricants. Ring compression tests were then carried out at 260°C and 370°C. Boron-nitride-silicone lubricant variants did not show significant difference in performance as die temperature was increased from 260°Cto370°C. This is in contrast to graphite, which performed much better at 260°C than at 370°C, due to thermal oxidation. On the other hand, silicone oil exhibited the worst performance at 260°C and the best performance at 370°C. In both boron nitride lubricant variants, the polydimethyl siloxane facilitated hydrostatic/hydrodynamic lubrication at 260°C, with boron nitride acting as a barrier film that reduced friction. However, the lubrication mechanisms changed at 370°C, where the depolymerization of polydimethyl siloxane led to formation of silica due to thermal oxidation. Silica, together with boron nitride, acted as a film barrier with low shear strength. The dual lubrication mechanisms make boron-nitride-silicone lubricants suitable for a wide range of aluminum forging temperatures.


2013 ◽  
Vol 779-780 ◽  
pp. 64-67
Author(s):  
Xiao Hua Yang ◽  
Jian Hua Xiao ◽  
Jun Fei Ou

Like lotus leaf and rose petal, the canna leaf also has excellent super hydrophobicity.The purpose of this paper is to systematically study the super hydrophilicity of canna leaf. Using SEM to observe the morphology of the canna leaf, and analytical balance to measure the adhensive force between water droplet and the leaf . This paper shows that the first type of the canna leaf which has co-exsitence of the nanocrumb and micro-scale convex cells has the high contact angle and low contact angle hysteresis similar to lotus leaf. The another type on the leaf has high contact angle but high adhesion in a certain extent like the rose petal effect, whose microstructure unitarily simple has the micro convex cells, do not distributed anything of nanoscale.


2009 ◽  
Vol 20 (01) ◽  
pp. 45-55
Author(s):  
REGANT Y. S. HUNG ◽  
H. F. TING

The advance of wireless and mobile technology introduces a new type of Video-on-Demand (VOD) systems, namely the mobile VOD systems, that provide VOD services to mobile clients. It is a challenge to design broadcasting protocols for such systems because of the following special requirements: (1) fixed maximum bandwidth requirement: the maximum bandwidth required for broadcasting a movie should be fixed and independent of the number of requests, (2) load adaptivity: the total bandwidth usage should be dependent on the number of requests; the fewer the requests the smaller the total bandwidth usage, and (3) clients sensitivity: the system should be able to support clients with a wide range of heterogeneous capabilities. In the literature, there are some partial solutions that give protocols meeting one or two of the above requirements. In this paper, we give the first protocol that meets all of the three requirements. The performance of our protocol is optimal up to a small constant factor.


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