The onset of fragmentation in binary liquid drop collisions

2012 ◽  
Vol 702 ◽  
pp. 5-25 ◽  
Author(s):  
C. Planchette ◽  
E. Lorenceau ◽  
G. Brenn

AbstractBinary collisions of drops of immiscible liquids are investigated experimentally at well-defined conditions of impact. In the experiments we vary all relevant properties of an aqueous and an oil phase, the impact parameter, the drop size and the relative velocity. The drops observed after the collisions exhibit three main phenomena: full encapsulation, head-on fragmentation, and off-centre fragmentation. The regimes characterized by these phenomena replace the ones observed in binary collisions of drops of the same liquid: coalescence, reflexive separation, and stretching separation. Our aim is a universal description of the two fragmentation thresholds of such collisions. Based on the capillary instability and an energy balance, we establish for head-on collisions a scaling law for the evolution of the threshold impact velocity with the properties of the liquids and the droplet size. The fragmentation threshold for off-centre collisions is compared to established models from the literature, which appear unsatisfactory. Introducing an effective impact parameter, which accounts empirically for the deformation and rotation of the drops upon impact, we describe this fragmentation threshold in a universal way. For both fragmentation thresholds, the agreement between experimental data and their theoretical representation is very good. Our work yields new insight into binary collisions of drops and proposes a perspective to develop a more general description with implications for binary collisions of drops of a single liquid as well.

2011 ◽  
Vol 690 ◽  
pp. 512-535 ◽  
Author(s):  
Ilia V. Roisman ◽  
Carole Planchette ◽  
Elise Lorenceau ◽  
Günter Brenn

AbstractThis experimental and theoretical study is devoted to the investigation of head-on collisions of two drops of immiscible liquids. In the experiments, pairs of drops are made to collide at well-defined kinetic and geometric conditions. The sizes and relative velocity of the colliding drops close to the point of impact are measured by means of image processing. The deformed states after the impact, their evolution with time, and their stability are studied by visualization. The theory considers the dynamics of the rim formed at the edge of a radially spreading lamella due to capillary forces at the free surfaces of the lamella and at the liquid/liquid interface. The equations of the rim formation and motion are obtained from the volume, mass and momentum balance equations which account for the inertial, viscous and capillary effects. The theory predicts the evolution of the main geometrical parameters of the liquid mass formed by the drop collision: thickness of the lamella, diameter, and size of the rim cross-section. The theoretical predictions agree well with the experimental data, although no adjustable parameters are used in the model.


2019 ◽  
Vol 34 (32) ◽  
pp. 1950259 ◽  
Author(s):  
S. M. Troshin ◽  
N. E. Tyurin

We comment briefly on relations between the elastic and inelastic cross-sections valid for the shadow and reflective modes of the elastic scattering. Those are based on the unitarity arguments. It is shown that the redistribution of the probabilities of the elastic and inelastic interactions (the form of the inelastic overlap function becomes peripheral) under the reflective scattering mode can lead to increasing ratio of [Formula: see text] at the LHC energies. In the shadow scattering mode, the mechanism of this increase is a different one, since the impact parameter dependence of the inelastic interactions probability is central in this mode. A short notice is also given on the slope parameter and the leading contributions to its energy dependence in both modes.


Sexualities ◽  
2020 ◽  
pp. 136346072098169
Author(s):  
Aidan McKearney

This article focuses on the experiences of gay men in the rural west and northwest region of Ireland, during a period of transformational social and political change in Irish society. These changes have helped facilitate new forms of LGBTQI visibility, and local radicalism in the region. Same-sex weddings, establishment of rural LGBT groups and marching under an LGBT banner at St Patricks Day parades would have been unthinkable in the recent past; but they are now becoming a reality. The men report continuing challenges in their lives as gay men in the nonmetropolitan space, but the emergence of new visibility, voice and cultural acceptance of LGBT people is helping change their lived experiences. The study demonstrates the impact of local activist LGBT citizens. Through their testimonies we can gain an insight into the many, varied and interwoven factors that have interplayed to create the conditions necessary for the men to: increasingly define themselves as gay to greater numbers of people in their localities; to embrace greater visibility and eschew strategies of silence; and aspire to a host of legal, political, cultural and social rights including same-sex marriage. Organic forms of visibility and local radicalism have emerged in the region and through an analysis of their testimonies we can see how the men continue to be transformed by an ever-changing landscape.


2021 ◽  
pp. 026975802110106
Author(s):  
Raoul Notté ◽  
E.R. Leukfeldt ◽  
Marijke Malsch

This article explores the impact of online crime victimisation. A literature review and 41 interviews – 19 with victims and 22 with experts – were carried out to gain insight into this. The interviews show that most impacts of online offences correspond to the impacts of traditional offline offences. There are also differences with offline crime victimisation. Several forms of impact seem to be specific to victims of online crime: the substantial scale and visibility of victimhood, victimisation that does not stop in time, the interwovenness of online and offline, and victim blaming. Victims suffer from double, triple or even quadruple hits; it is the accumulation of different types of impact, enforced by the limitlessness in time and space, which makes online crime victimisation so extremely invasive. Furthermore, the characteristics of online crime victimisation greatly complicate the fight against and prevention of online crime. Finally, the high prevalence of cybercrime victimisation combined with the severe impact of these crimes seems contradictory with public opinion – and associated moral judgments – on victims. Further research into the dominant public discourse on victimisation and how this affects the functioning of the police and victim support would be valuable.


BMC Medicine ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Bimandra A. Djaafara ◽  
Charles Whittaker ◽  
Oliver J. Watson ◽  
Robert Verity ◽  
Nicholas F. Brazeau ◽  
...  

Abstract Background As in many countries, quantifying COVID-19 spread in Indonesia remains challenging due to testing limitations. In Java, non-pharmaceutical interventions (NPIs) were implemented throughout 2020. However, as a vaccination campaign launches, cases and deaths are rising across the island. Methods We used modelling to explore the extent to which data on burials in Jakarta using strict COVID-19 protocols (C19P) provide additional insight into the transmissibility of the disease, epidemic trajectory, and the impact of NPIs. We assess how implementation of NPIs in early 2021 will shape the epidemic during the period of likely vaccine rollout. Results C19P burial data in Jakarta suggest a death toll approximately 3.3 times higher than reported. Transmission estimates using these data suggest earlier, larger, and more sustained impact of NPIs. Measures to reduce sub-national spread, particularly during Ramadan, substantially mitigated spread to more vulnerable rural areas. Given current trajectory, daily cases and deaths are likely to increase in most regions as the vaccine is rolled out. Transmission may peak in early 2021 in Jakarta if current levels of control are maintained. However, relaxation of control measures is likely to lead to a subsequent resurgence in the absence of an effective vaccination campaign. Conclusions Syndromic measures of mortality provide a more complete picture of COVID-19 severity upon which to base decision-making. The high potential impact of the vaccine in Java is attributable to reductions in transmission to date and dependent on these being maintained. Increases in control in the relatively short-term will likely yield large, synergistic increases in vaccine impact.


2021 ◽  
Vol 45 (10) ◽  
pp. 4756-4765
Author(s):  
Daoxing Chen ◽  
Liting Zhang ◽  
Yanan Liu ◽  
Jiali Song ◽  
Jingwen Guo ◽  
...  

EGFR L792Y/F/H mutation makes it difficult for Osimertinib to recognize ATP pockets.


Livestock ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 176-179
Author(s):  
Chris Lloyd

The Responsible Use of Medicines in Agriculture Alliance (RUMA) was established to promote the highest standards of food safety, animal health and animal welfare in the British livestock industry. It has a current focus to deliver on the Government objective of identifying sector-specific targets for the reduction, refinement or replacement of antibiotics in animal agriculture. The creation and roll out of sector specific targets in 2017 through the RUMA Targets Task Force, has helped focus activity across the UK livestock sectors to achieve a 50% reduction in antibiotic use since 2014. This has been realised principally through voluntary multi-sector collaboration, cross sector initiatives, codes of practice, industry body support and farm assurance schemes. This article provides an overview of RUMA's work to date providing insight into the methods used to create the targets, why they are so important, the impact they are having and how ongoing support and robust data are vital components in achieving the latest set of targets.


2021 ◽  
Vol 22 (7) ◽  
pp. 3577
Author(s):  
Victor Camberos ◽  
Jonathan Baio ◽  
Ana Mandujano ◽  
Aida F. Martinez ◽  
Leonard Bailey ◽  
...  

Understanding the transcriptomic impact of microgravity and the spaceflight environment is relevant for future missions in space and microgravity-based applications designed to benefit life on Earth. Here, we investigated the transcriptome of adult and neonatal cardiovascular progenitors following culture aboard the International Space Station for 30 days and compared it to the transcriptome of clonally identical cells cultured on Earth. Cardiovascular progenitors acquire a gene expression profile representative of an early-stage, dedifferentiated, stem-like state, regardless of age. Signaling pathways that support cell proliferation and survival were induced by spaceflight along with transcripts related to cell cycle re-entry, cardiovascular development, and oxidative stress. These findings contribute new insight into the multifaceted influence of reduced gravitational environments.


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