Shape-Shifting Material Can Morph, Reverse Itself Using
Heat, Light - A new material developed by University
of Colorado Boulder engineers can transform into complex,
pre-programmed shapes via light and temperature stimuli,
allowing a literal square peg to morph and fit into a round
hole before fully reverting to its original form. The controllable
shape-shifting material, described today in the journal
Science Advances, could have broad applications for manufacturing,
robotics, biomedical devices and artificial muscles. "The
ability to form materials that can repeatedly oscillate
back and forth between two independent shapes by exposing
them to light will open up a wide range of new applications
and approaches to areas such as additive manufacturing,
robotics and biomaterials", said Christopher Bowman, senior
author of the new study and a Distinguished Professor in
CU Boulder's Department of Chemical and Biological Engineering
(CHBE). Previous efforts have used a variety of physical
mechanisms to alter an object's size, shape or texture with
programmable stimuli. However, such materials have historically
been limited in size or extent and the object state changes
have proven difficult to fully reverse. The new CU Boulder
material achieves readily programmable two-way transformations
on a macroscopic level by using liquid crystal elastomers
(LCEs), the same technology underlying modern television
displays. The unique molecular arrangement of LCEs make
them susceptible to dynamic change via heat and light.
Of Two New Chinese Dinosaurs By International Research Team
- Professor Jonah Choiniere from the University of the
Witwatersrand, Johannesburg, South Africa was a leading
member of the team and is a co-author on the research. The
dinosaurs are both alvarezsaurs, an enigmatic group of theropod
[meat-eating] dinosaurs, which have many similarities with
birds and which show adaptations thought to be related to
eating insects that live in colonies. "Alvarezsaurs are
weird animals," said Choiniere. "With their strong, clawed
hands and weak jaws, they appear to be the dinosaurian analogue
to today's aardvarks and anteaters." But alvarezsaurs did
not originally eat insects. The earliest members of the
group had more typically meat-eating teeth and hands, useful
for catching small prey. Only later-evolving members reduced
their teeth and evolved a hand with a huge, single claw
capable - perhaps - of tearing open rotting logs and anthills.
"The new fossils have long arms, and so show that alvarezsaurs
evolved short arms only later in their evolutionary history,
in species with small body sizes. This is quite different
to what happens in the classic example of tyrannosaurs,
which have short arms and giant size," said co-author Professor
Roger Benson of Oxford University. Bannykus and Xiyunykus
are important because they show transitional steps in the
process of alvarezsaurs adapting to new diets.
Mother, Denisovan Father! - Together with their sister
group the Neandertals, Denisovans are the closest extinct
relatives of currently living humans. "We knew from previous
studies that Neandertals and Denisovans must have occasionally
had children together", says Viviane Slon, researcher at
the MPI-EVA and one of three first authors of the study.
"But I never thought we would be so lucky as to find an
actual offspring of the two groups." The ancient individual
is only represented by a single small bone fragment. "The
fragment is part of a long bone, and we can estimate that
this individual was at least 13 years old", says Bence Viola
of the University of Toronto. The bone fragment was found
in 2012 at Denisova Cave (Russia) by Russian archaeologists.
It was brought to Leipzig for genetic analyses after it
was identified as a hominin bone based on its protein composition.
"An interesting aspect of this genome is that it allows
us to learn things about two populations - the Neandertals
from the mother's side, and the Denisovans from the father's
side", explains Fabrizio Mafessoni from the MPI-EVA who
co-authored the study. The researchers determined that the
mother was genetically closer to Neandertals who lived in
western Europe than to a Neandertal individual that lived
earlier in Denisova Cave. This shows that Neandertals migrated
between western and eastern Eurasia tens of thousands of
years before their disappearance. Analyses of the genome
also revealed that the Denisovan father had at least one
Neandertal ancestor further back in his family tree. "So
from this single genome, we are able to detect multiple
instances of interactions between Neandertals and Denisovans",
says Benjamin Vernot from the MPI-EVA, the third co-author
of the study. "It is striking that we find this Neandertal/Denisovan
child among the handful of ancient individuals whose genomes
have been sequenced", adds Svante Pääbo, Director of the
Department of Evolutionary Genetics at the MPI-EVA and lead
author of the study. "Neandertals and Denisovans may not
have had many opportunities to meet. But when they did,
they must have mated frequently - much more so than we previously
Salvaged Wooden Ships And Artifacts Back To Life With 'Smart'
Nanotech - Thousands of shipwrecks litter the seafloor
all over the world, preserved in sediments and cold water.
But when one of these ships is brought up from the depths,
the wood quickly starts deteriorating. Today, scientists
report a new way to use "smart" nanocomposites to conserve
a 16th-century British warship, the Mary Rose, and its artifacts.
The new approach could help preserve other salvaged ships
by eliminating harmful acids without damaging the wooden
structures themselves. The Mary Rose sank in 1545 off the
south coast of England and remained under the seabed until
she was salvaged in 1982, along with over 19,000 artifacts
and pieces of timber. While buried in the seabed, sulfur-reducing
marine bacteria migrated into the wood of the Mary Rose
and produced hydrogen sulfide. This gas reacted with iron
ions from corroded fixtures like cannons to form iron sulfides.
Although stable in low-oxygen environments, sulfur rapidly
oxidizes in regular air in the presence of iron to form
destructive acids. Researchers' goals were to avoid acid
production by removing the free iron ions. Once raised from
the seabed, the ship was sprayed with cold water, which
stopped it from drying out and prevented further microbial
activity. The conservation team then sprayed the hull with
different types of polyethylene glycol (PEG), a common polymer
with a wide range of applications, to replace the water
in the cellular structure of the wood and strengthen its
outer layer. Scientists at the University of Glasgow are
devising a new family of tiny magnetic nanoparticles to
aid in this process, in collaboration with Schofield and
Rachel O'Reilly, Ph.D., at the University of Warwick. In
their initial step, the team used synchrotron techniques
to probe the nature of the sulfur species before turning
the PEG sprays off, and then periodically as the ship dried.
This was the first real-time experiment to closely examine
the evolution of oxidized sulfur and iron species. This
accomplishment has informed efforts to design new targeted
treatments for the removal of these harmful species from
the Mary Rose wood. The next step will be to use a nanocomposite
based on core magnetic iron oxide nanoparticles that include
agents on their surfaces that can remove the ions. The nanoparticles
can be directly applied to the porous wood structure and
guided to particular areas of the wood using external magnetic
fields, a technique previously demonstrated for drug delivery.
The nanocomposite will be encompassed in a heat-responsive
polymer that protects the nanoparticles and provides a way
to safely deliver them to and from the wood surface. A major
advantage of this approach is that it allows for the complete
removal of free iron and sulfate ions from the wood, and
these nanocomposites can be tuned by tweaking their surfaces.
Breakthrough Has Physicists Close To Cooling Down Antimatter
the first time, physicists at CERN have observed a benchmark
atomic energy transition in anithydrogen, a major step toward
cooling and manipulating the basic form of antimatter. "The
Lyman-alpha transition is the most basic, important transition
in regular hydrogen atoms, and to capture the same phenomenon
in antihydrogen opens up a new era in antimatter science,"
said Takamasa Momose, the University of British Columbia
chemist and physicist who led the development of the laser
system used to manipulate the anithydrogen. "This approach
is a gateway to cooling down antihydrogen, which will greatly
improve the precision of our measurements and allow us test
how antimatter and gravity interact, which is still a mystery."
Antimatter, annihilated on impact with matter, is notoriously
tricky to capture and work with. But its study is key to
solving one of the great mysteries of the universe: why
anti-matter, which should have existed in equal amounts
to matter at the time of the Big Bang, has all but disappeared.
"This gets us just a bit closer to answering some of these
big questions in physics," said Makoto Fujiwara, Canada's
spokesperson for CERN's ALPHA antihydrogen research collaboration,
and a physicist with TRIUMF, Canada's particle accelerator
centre. "Over the past decades, scientists have been able
to revolutionize atomic physics using optical manipulation
and laser cooling, and with this result we can begin applying
the same tools to probing the mysteries of antimatter."
The so-called Lyman-alpha transition, first seen in hydrogen
more than 100 years ago, is measured as a series of ultraviolet
emissions when a hydrogen atom's electron is prompted to
shift from a low orbital to a high orbital. Using laser
pulses lasting nano seconds, Momose, Fujiwara, Canadian
colleagues, and the international ALPHA collaboration at
CERN, were able to achieve the same transition in several
hundred antihydrogen atoms magnetically trapped in a vacuum.
Quote of the Month - “Bad times have
a scientific value. These are occasions a good learner would
not miss." - Ralph Waldo Emerson
New at the Museum:
Bones: A Visit to the Capuchin Crypt -
is a city of marvelous history, art and architecture: The
Coliseum, the Roman Forum, and Saint Peters Basilica to
name a few. However, nothing in the city rivals one site
for its macabre display: The Capuchin Crypt, where thousands
of human bones have been arranged in a morbid tableau. -
Picture of the Month - What
BIG CRUNCH -What is the Big Crunch and when will
it occur? - Madison
"Big Crunch" is one of several theories about how the universe
will end. Probably everybody is now familiar with the leading
theory about how the universe started, the so called "Big
Bang." According to the Big Bang theory, at the beginning
of the universe all matter and energy was compressed into
an infinity small point with infinite density and temperature.
Then followed a period of rapid inflation and expansion
(the Bang). Matter in the universe cooled and coalesced
into stars, planets and galaxies. The expansion continues
today as each of the local groups of galaxies, including
ours, grows further apart from each other.
many years scientists pondered what would happen at the
end of the universe. While the expansion continues, gravity
is trying to reverse the process and pull all matter back
together. Scientists figured that either gravity would be
too weak and the expansion would continue forever while
just getting slower and slower, or gravity would be strong
enough to bring all the matter and energy back together
in a "Big Crunch."
Scientists also speculated if the universe did come back
into a "Big Crunch" it might precipitate another "Big Bang"
which would create another universe. Ours, they suggested,
might be just one in an unending series of universes.
Initial measurements suggested the amount of gravity and
the speed of the expansion were very nearly balanced. This
meant that scientists had to impatiently wait for decades
until better technology was available so that more accurate
studies could be made and they could find out what the fate
of the universe was.
In one of those moments that proved that Sir Arthur Eddington
was right when he said "not only is the universe stranger
than we imagine, it is stranger than we can imagine,"
the results came back showing that the expansion wasn't
slowing at all. It was - much to the shock of almost everybody
- accelerating. Scientists have decided that the
reason for the acceleration must be something they've dubbed
"dark energy," but they have almost no idea what this energy
might be and how it works.
the expansion continues at the current rate the universe
may end in "The Big Rip." At some point about 50 billion
years in the future the expansion will become so great that
everything will be ripped apart. Galaxies will fly apart
as individual solar systems go their own way. Later stars
will lose their planets and eventually everything down to
the subatomic level will be torn asunder.
a "Big Crunch" seems unlikely due to this most recent finding,
because scientists know almost nothing about what "dark
energy" is, they can't rule out that it might suddenly reverse
and cause a rapid collapse of the universe. When this might
happen is also a mystery. If there is a Big Crunch, the
universe would end as all matter was sucked into black holes,
then the black holes were pulled together to create a single
massive black hole. Scientists have no idea whether this
singularity might lead to a new universe and a new expansion
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U.S. Nuclear Plant - On September 6th of 1954, the ground
was broken at Shippingport, Pennsylvania, for the first
U.S. full-scale atomic power reactor devoted non-military
uses. When completed the reactor at full power had a capacity
of 60 megawatts and could supply a city of 250,000 homes.
The system used a single pressurized water-type reactor
which heated steam that would drive an electrical turbine-generator.
Glimpse of Neptune - The planet Neptune is too faint
to be glimpsed with the naked eye, but this month you might
just be able to spot it using a pair of binoculars. Neptune
comes into opposition - when it is nearest the Earth - on
the 7th of September. It should be easily seen through binoculars
sitting in the constellation Aquarius over to the left of
the star Lambda Aquarii. You may need a star chart to find
this constellation if you are unfamiliar with it.
Man Bags Giant Gator - A South Florida resident
named Jim Howard hunted and killed a 1,000, 12 foot long
alligator in Lake Okeechobee, Florida, during a contest.
Howard, who works as an airline pilot, is described by his
daughter as "crazy and a badass all at the same time." After
hooking the massive gator, Howard had assistance from two
friends in bringing it in close enough to his boat that
he could dispatch it with a shotgun shell in a "bang stick"
to the head. Despite the size the gator was not the longest
ever caught. That was a 14 footer killed in 2010.
and Meep are on a well deserved vacation. In their place
we feature highlights from their past adventures.
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