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A New APS Journal Begins -- Editorial: Introducing Physical Review Fluids


Editorial: Introducing Physical Review Fluids

Welcome to the first issue of Physical Review Fluids (PRFluids), the newest journal
published by the American Physical Society (APS). The field of fluid mechanics is
vibrant, international, and dynamic, with many interdisciplinary applications across
all areas of the physical and biological sciences, as well as engineering. PRFluids
aims to serve these diverse communities by publishing the very highest quality
research in all aspects of fluid mechanics. We are delighted with the very strong
response PRFluids has received, as evidenced by the high quality of the papers
published in this first issue, which are authored by intellectual leaders in the field.

John Kim and Gary Leal, founding Editors of PRFluids, are joined by an outstanding
team of Associate Editors and Editorial Board members, each of whom are
accomplished leading researchers in their fields. PRFluids is the latest addition
to the renowned Physical Review (Phys. Rev.) family of journals, and it is created
with the same commitment to excellence, timeliness, and service. We look forward
to engaging a broad readership that extends beyond the usual fluid mechanics

PRFluids will publish papers both in the classical areas of fluid mechanics, and
also in the newer areas of the subject, such as flow problems involving complex
fluids, bio-fluid mechanics, and micro- and nano-fluid dynamics. The scope of the
journal will be reviewed regularly to ensure that it continues to serve the needs of
the community and captures the most interesting papers in the field.


The launch of PRFluids marks an exciting new initiative in fluid mechanics
publishing, and we are confident that it will quickly establish itself as the premier
journal in the field. However, the ultimate success of PRFluids depends upon the
quality of the submissions we receive. We call on all fluid mechanics researchers
to submit their best work to this journal and encourage their colleagues to do the
same. We look forward to receiving your contributions.

Published 2 May 2016
DOI: 10.1103/PhysRevFluids.1.010001


Here is Physical Review Fluids' homepage on the internet:

It looks like the first issue will be available online without cost to the reader through the end of 2016.

Here is the abstract of a paper on the formation of vortex rings:


PHYSICAL REVIEW FLUIDS 1, 012501(R) (2016)

Pressure evolution in the shear layer of forming vortex rings

Kristy Schlueter-Kuck*
Department of Mechanical Engineering, Stanford University, Stanford, California 94305, USA

John O. Dabiri†
Department of Civil and Environmental Engineering, and Department of Mechanical Engineering,
Stanford University, Stanford, California 94305, USA

(Received 10 February 2016; published 2 May 2016)

This study investigated the relationship between the pinch-off of axisymmetric vortex
rings and the evolution of pressure in the shear layer being entrained into the vortex
rings. A piston-cylinder apparatus was used to generate the vortex rings, and five cases
of constant piston acceleration over distances ranging from zero (impulsive start) to eight
piston diameters were investigated. It was determined that increasing the distance over
which the piston accelerated increased the dimensionless formation time at which the
vortex ring pinches off, consistent with previous observations. A limiting value of vortex
ring formation number of approximately seven is approached when the piston is accelerated
over more than six piston diameters. For each case, the evolution of pressure in the shear
layer was calculated based on PIV measurements of the velocity field and spatial integration
of the corresponding pressure gradients using a recently developed algorithm. Plots of the
shear layer pressure in X-T diagrams aided in identifying key features of the pressure
associated with the evolution of vortex rings, including a high-pressure region that forms
behind the leading ring. By extrapolating the motion of this high-pressure region back to
the nozzle exit plane in the X-T diagram, its time of first appearance can be estimated. It is
found that the appearance of the extrapolated local pressure maximum in the shear layer at
the nozzle exit plane coincides with vortex ring pinch-off, as conventionally quantified by
the vortex ring formation number.



Fluid mechanics is an interesting topic.

Does anyone know any good comprehensive texts for the field - ones that may be trying to update/replace Batchelor's book on the subject?

That is post number 3003: it seems like now is a good time for a break until after the election or so...à bientôt!

That is such a good quotation. Thanks for posting it!

In my opinion, it is always worth seeing it in context:

I, Candidate for Governor: And How I Got Licked
By Upton Sinclair


What Acting-Governor Merriam really thinks about
old age pensions is proved by his actions. He has been
acting for six months, and what has he done? Our law

provides a pension for needy persons over seventy years
of age, and fewer than twenty thousand persons are
getting less than twenty dollars per month each; about
eighty thousand more have proved their right to the
pension, but there is no money for them. Has Merriam
moved a finger to get that money, as ordered by the
law of the State? He called a special session of the
Legislature to pass certain fiscal measures; but no word
about money for old age pensions.


Acting Governor Merriam got the extra votes which
he needed, and now he is Governor-Elect, and the grin
is on his face, and on the faces of all the politicians
who worked for him, and of all the big business gentle-
men who put up his millions of dollars. The poor de-
luded old people can take their petitions to Congress
and to President Roosevelt, and cherish their dream of
two hundred dollars a month until they die.

The newspapers said it would be that way with our
fifty dollars a month pension. They would challenge
me to say where I was going to get that money, and
when I answered they did not publish what I said. Im-
possible for any editor of a commercial newspaper to
understand the difference between a profit system in a
state of collapse, driving the State and everybody in it
to bankruptcy, and a system of production for use in
process of growth, providing security and plenty for all.
I used to say to our audiences: "It is difficult to get a
man to understand something, when his salary depends
upon his not understanding it!"



"Or...maybe not." seems to be the course that has been and will be chosen by this and

probably future Administrations.

It seems that stating that "We tortured some folks..." will be the extent of the required penance.

The CIA Waterboarded the Wrong Man 83 Times in 1 Month
None of the allegations against Abu Zubaydeh turned out to be true. That didn’t stop the CIA from torturing him for years.
By Rebecca Gordon

April 25, 2016


The new Obama administration replied with a 109-page brief filed in the US District Court in the District of Columbia, which is legally designated to hear the habeas cases of Guantánamo detainees.

The bulk of that brief came down to a government argument that was curious indeed, given the years of bragging about Zubaydah’s central role in Al Qaeda’s activities. It claimed that there was no reason to turn over any “exculpatory” documents demonstrating that he was not a member of Al Qaeda, or that he had no involvement in 9/11 or any other terrorist activity—because the government was no longer claiming that any of those things were true.

The government’s lawyers went on to claim, bizarrely enough, that the Bush administration had never “contended that had any personal involvement in planning or executing…the attacks of September 11, 2001.” They added that “the Government also has not contended in this proceeding that, at the time of his capture, had knowledge of any specific impending terrorist operations”—an especially curious claim, since the prevention of such future attacks was how the CIA justified its torture of Zubaydah in the first place. Far from believing that he was “if not the number two, very close to the number two person in” Al Qaeda, as Secretary of Defense Donald Rumsfeld had once claimed, “the Government has not contended in this proceeding that was a member of al-Qaida or otherwise formally identified with al-Qaida.”


Seven years after the initial filing of Zubaydah’s habeas petition, the DC District Court has yet to rule on it. Given the court’s average 751-day turnaround time on such petitions, this is an extraordinary length of time. Here, justice delayed is truly justice denied.



Clinton has 1,705 pledged delegates and Sanders has 1,420 pledged delegates...

2026 are needed for a majority.

Interesting article...

Ballistic performance of composite metal foams

Matias Garcia-Avilaa(a), Marc Portanovab(b), Afsaneh Rabieia(a)

(a) Advanced Materials Research Lab, Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, USA
(b) Aviation Applied Technology Directorate (AATD), U.S. Army Research, Development & Engineering Center, Fort Eustis, USA

Available online 29 January 2015


The application of advance materials to manufacture hard armor systems has led to high performance ballistic protection. Due to its light-weight and high impact energy absorption capabilities, composite metal foams have shown good potential for applications as ballistic armor. A high-performance light-weight composite armor system has been manufactured using boron carbide ceramics as the strike face, composite metal foam processed by powder metallurgy technique as a bullet kinetic energy absorber interlayer, and aluminum 7075 or Kevlar™ panels as backplates with a total armor thickness less than 25 mm. The ballistic tolerance of this novel composite armor system has been evaluated against the 7.62 × 51 mm M80 and 7.62 × 63 mm M2 armor piercing projectiles according to U.S. National Institute of Justice (NIJ) standard 0101.06. The results showed that composite metal foams absorbed approximately 60–70% of the total kinetic energy of the projectile effectively and stopped both types of projectiles with less depth of penetration and backplate deformation than that specified in the NIJ 0101.06 standard guidelines. Finite element analysis was performed using Abaqus/Explicit to study the failure mechanisms and energy absorption of the armor system. The results showed close agreement between experimental and analytical results.


@11:04 - "Ok. If you see the person, David Hall, tell him he's not leaving jail either. Alright?"

That is a classic line.

Sen. Hill. Clinton: "I am the Senator from New York. I will never put my people's security at risk."

At 14:23 in the video:

The 13th anniversary of the invasion of Iraq was just last Sunday....

I am surprised that so little was said on DU regarding this topic. Maybe I just missed the threads.

Sec. Clinton says that she trusted W...

because he purportedly made sure that New York got the money that she requested for rebuilding after 9/11.

Hence, her vote to give W authority regarding Iraq.

So very many, many people got it right regarding W and his intent, but she did not.

Was it her supposedly mistaken assessment of W's character that allowed her to make the vote or was it the clouding effect of the money ($20 billion US according to the town hall) that she received from W on behalf of New York that allowed her to make the vote?

While admitting that this is beside your point, WMAP data and Planck data nevertheless yielded:

The Universe Is 13.82 Billion Years Old
By Phil Plait


The Universe is 13.82 billion years old.

The age of the Universe is a little bit higher than we expected. A few years ago, the WMAP spacecraft looked at the Universe much as Planck has, and for the time got the best determination of the cosmic age: 13.73 +/- 0.12 billion years old.

Planck has found that the Universe is nearly 100 million years older than that: 13.82 billion years.

At first glance you might think this is a really different number. But look again. The uncertainty in the WMAP age is 120 million years. That means the best estimate is 13.73 billion years, but it could easily be 13.85 or 13.61. Anything in that range is essentially indistinguishable in the WMAP data, and 13.73 is just in the middle of that range.

And that range includes 13.82 billion years. It’s at the high end, but that’s not a big deal. It’s completely consistent with the older estimate, but Planck’s measurements are considered to be more accurate. It will become the new benchmark for astronomers.



Gianni Infantino elected Fifa president after Zurich election

Source: The Guardian

Fifa has elected Gianni Infantino, a European football administrator born just six miles from Sepp Blatter’s birthplace, as its new president in a bid to restore the reputational damage wrought by his disgraced predecessor.

The Swiss-Italian Uefa general secretary only entered the race when Michel Platini was suspended then banned for six years for accepting a “disloyal payment” from Blatter in 2011.

But Infantino, who spent €500,000 of Uefa funds on touring the globe in the runup to the election, triumphed over the controversial Asian Football Confederation president, Sheikh Salman bin Ebrahim al-Khalifa, in the second round of voting by 115 votes to 88.

The Bahraini had assumed his presidential bid would end in a coronation when he resolved to stand after Platini’s withdrawal in October but his campaign has been marred by strenuously denied allegations over human rights breaches and vote buying in previous elections.

Read more: http://www.theguardian.com/football/2016/feb/26/gianni-infantino-elected-fifa-president-election
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