Salt ions, in contrast, are larger than water molecules and cannot cross the membrane. The porous membrane allows osmosis,
The membrane allowed rapid transport of water through the membrane and rejected nearly 100 percent of the salt ions, e g.,
including irradiation with electrons and ions, but none of them worked. So far, the oxygen plasma approach worked the best,
The results have now been published in Physical Review Letters("Direct Photonic Coupling of a Semiconductor Quantum dot and a Trapped Ion".
In contrast, charged atoms, called ions, have an excellent memory: They can store quantum information for many minutes.
therefore both of these components, qdots and ions, to work together as a team. Experts speak of a hybrid system,
"We used the photon to excite an ion, "explains Prof. Dr. Michael Khl from the Institute of Physics at the University of Bonn."
"Conscientious ions To do so, the researchers connected a thin glass fiber to the qdot. They transported the photon via the fiber to the ion many meters away.
The fiberoptic networks used in telecommunications operate very similarly. To make the transfer of information as efficient as possible,
they had trapped the ion between two mirrors. The mirrors bounced the photon back and forth like a ping pong ball,
until it was absorbed by the ion.""By shooting it with a laser beam, we were able to read out the ion that was excited in this way,
"explains Prof. Khl.""In the process, we were able to measure the direction of polarization of the previously absorbed photon".
"In a sense then, the state of the qdot can be preserved in the ion theoretically this can be done for many minutes.
and charged atoms (ions) play a key role in the temperature sensitivity of both living plant cells and the dry cyberwood.
and the ions can move about more freely, "explains Di Giacomo. As a result, the material conducts electricity better when temperature increases.
In ongoing work, they are now further developing it such that it functions without plant cells, essentially with only pectin and ions.
"This novel material significantly enhanced catalytic activity for the oxygen reduction reaction--the splitting of an O2 molecule into two oxygen ions--that is critical to fuel cells and potentially other electrochemical applications.
#Quick, easy and early diagnosis with rare earth ions Lack of oxygen in cells is an indicator of diseases as serious as cerebral haemorrhages, stroke and cancer.
Control voltages that shift oxygen ions and vacancies switch the bits between ones and zeroes.
the researchers found the tantalum oxide gradually loses oxygen ions, changing from an oxygen-rich, nanoporous semiconductor at the top to oxygen-poor at the bottom.
These are"holes"in atomic arrays where oxygen ions should exist, but don't. The voltage-controlled movement of oxygen vacancies shifts the boundary from the tantalum/tantalum oxide interface to the tantalum oxide/graphene interface."
Third, the flow of current draws oxygen ions from the tantalum oxide nanopores and stabilizes them.
These negatively charged ions produce an electric field that effectively serves as a diode to hinder error-causing crosstalk.
replacing up to 25 percent of the lanthanum ions in the host material with strontium ions, offers considerable promise.
or ion channels, each of which is a portal for specific ions. Ion channels are typically about 1 nanometer wide;
by maintaining the right balance of ions, they keep cells healthy and stable. Now researchers at MIT have created tiny pores in single sheets of graphene that have an array of preferences and characteristics similar to those of ion channels in living cells.
which scientists have studied ever ion flow. Each is also uniquely selective, preferring to transport certain ions over others through the graphene layer. hat we see is that there is a lot of diversity in the transport properties of these pores,
which means there is a lot of potential to tailor these pores to different applications or selectivities, says Rohit Karnik, an associate professor of mechanical engineering at MIT.
detecting ions of mercury, potassium, or fluoride in solution. Such ion-selective membranes may also be useful in mining:
In the future, it may be possible to make graphene nanopores capable of sifting out trace amounts of gold ions from other metal ions, like silver and aluminum.
Karnik and former graduate student Tarun Jain, along with Benjamin Rasera, Ricardo Guerrero, Michael Boutilier, and Sean Oern from MIT and Juan-carlos Idrobo from Oak ridge National Laboratory, publish their results today in the journal Nature Nanotechnology("Heterogeneous sub-continuum ionic transport in statistically isolated graphene nanopores").
which are slightly smaller than the ions that flow through them. hen nanopores get smaller than the hydrated size of the ion,
In particular, hydrated ions, or ions in solution, are surrounded by a shell of water molecules that stick to the ion,
depending on its electrical charge. Whether a hydrated ion can squeeze through a given ion channel depends on that channel size and configuration at the atomic scale.
Karnik reasoned that graphene would be a suitable material in which to create artificial ion channels:
The group reasoned that any ions flowing through the two-layer setup would have passed likely first through a single graphene pore,
The group measured flows of five different salt ions through several graphene sheet setups by applying a voltage and measuring the current flowing through the pores.
and from ion to ion, with some pores remaining stable, while others swung back and forth in conductance an indication that the pores were diverse in their preferences for allowing certain ions through. he picture that emerges is that each pore is different
and that the pores are dynamic, Karnik says. ach pore starts developing its own personality.
which scientists have studied ion flow. With the model, the group calculated the effect of various factors on pore behavior,
Knowing this, researchers may one day be able to tailor pores at the nanoscale to create ion-specific membranes for applications such as environmental sensing and trace metal mining. t kind of a new frontier in membrane technologies,
it is only through a fundamental understanding of ion transport that the overall anticipated behaviors of bulk graphene membranes can be drawn.
by showing that potassium can work with graphite in a potassium-ion battery-a discovery that could pose a challenge and sustainable alternative to the widely-used lithium-ion battery.
Lithium-ion batteries are ubiquitous in devices all over the world, ranging from cell phones to laptop computers and electric cars.
A potassium-ion battery has been shown to be possible. And the last time this possibility was explored was
"The Journal of the American Chemical Society published the findings from this discovery("Carbon Electrodes for K-Ion Batteries),
as the charge carrier whose ions migrate into the graphite and create an electrical current.
Right now, batteries based on this approach don't have performance that equals those of lithium-ion batteries,
"It's safe to say that the energy density of a potassium-ion battery may never exceed that of lithium-ion batteries,
when it comes to water and ions. These insights are intriguing on their own, but when the scientists examined the structure of the nanosheetsbackbone,
#New way to store information uses ions to save data and electrons to read data Scientists from Kiel University
and the Ruhr Universität Bochum (RUB) have developed a new way to store information that uses ions to save data
It consists of two metallic electrodes that are separated by a so-called solid ion conductor usually a transition metal oxide.
as well as ions within the layer between being displaced. The advantage is that cells that are constructed in this way are easy to produce
The scientists achieve a long storage time by setting the ion density in the cells precisely via the voltage applied."
"Electrons are roughly 1000 times lighter than ions and so they move much more easily under the influence of an external voltage.
whereby in our component, the ions are immovable for extremely low voltages, while the electrons remain mobile
the researchers built an ion conductor, which was only a few nanometres (a millionth of a millimetre) thin to utilise quantum-mechanical effects for the flow through the storage cells."
ions are moved within the storage cell at voltages above one volt, and electrons, on the other hand, at voltages far below one volt.
This way, ions can be used specifically for storing and electrons specifically for reading data. The researchers also reported that their research had another very interesting element.
theoretical work indicates that boron-doped graphene could lead to improved lithium-ion batteries and field-effect transistors, the authors report t
ACS) Today, lithium-ion batteries are the storage technology of choice for many applications, from electric cars to smartphones.
For example, Tesla, the maker of luxury electric cars, is ambitiously expanding its lithium-ion technology to fill that niche
Maksym V. Kovalenko and colleagues wanted to develop an affordable alternative to lithium-ion. The researchers started with magnesium as the batterys safe
Testing showed that the resulting devices energy density was close to that of lithium-ion batteries. It could get an additional two-to threefold boost with further development of magnesium electrolytes.
made entirely of positively or negatively charged ions. Because the material is liquid at room temperature, it is safer and simpler to take it into space than a plasma or gas.
Applying an electric field can send these ions streaming away from the satellite at high speeds
Would the ions left behind corrode the spacecraft? Would the spacecraft itself remain neutrally charged,
or would the positive ions left behind pull the negative ions back in, cancelling out the thrust?
rather than having it fly around the lab. One thruster emitted positive ions and the other negative ones, keeping the Cubesat neutrally charged.
will we be able to deplete all the ions from this ionic liquid? Lozano says. ut we were able to get every single ion out.
The tank was completely dry. This is the most exciting test we have run so far.
#Aluminum-Ion Batteries Are Flexible, Fast-Charging, And Won't Catch on Fire Almost all of the electronic devices that we carry around with us all day now rely on one key,
the lithium-ion battery. A mainstay of rechargeable power for the last couple decades, this battery technology has gotten only minor refinements.
compromise a lithium-ion battery and you'll likely see some sparks or flame, but the materials in this new battery are all non-reactive.
000 you'd likely get out of a Li-ion battery--aluminum-ion's woes aren't all behind it.
The voltage provided by an aluminum-ion battery is only about half of that what you'd get from a lithium-ion cell.
And, as Ars Technica points out the overall power density--the amount of juice you can store in a battery vis-a-vis its size--more closely resembles the large lead-acid battery you'd find in your car.
So aluminum-ion batteries still aren't quite ready for primetime, but you can bet that electronics manufacturers, makers of electric cars,
Meanwhile, researchers are working to enhance the performance of lithium-ion batteries using materials like carbon nanotubes,
Should scientists be able to increase the power and energy density of aluminum-ion batteries its speed of charging, lack of volatility,
the most notable kinds of electric engines include ion thrusters, which propel rockets by accelerating ions.
Such an engine is currently being used on the Dawn mission to the dwarf planet Ceres. However,
ions effectively dance within the glass and hit the electrochromic material to achieve tint-controlled windows.
a postdoctoral researcher in Zia's lab. Cueff started with an emitter made of erbium ions,
This change in reflectivity, in turn, switches how nearby erbium ions emit light. As the VO2 changes phase, the erbium emissions go from being generated mostly by magnetic dipole transitions (the rotational torque push
which is ten times that of a lithium-ion battery. Such a high energy density would be comparable to that of gasoline
In the lithium-ion (Li-ion) batteries we use in our laptops and smartphones, the negative electrode is made of graphite (a form of carbon),
The action of the battery depends on the movement of lithium ions between the electrodes. Li-ion batteries are light
but their capacity deteriorates with age, and their relatively low energy densities mean that they need to be recharged frequently.
Over the past decade, researchers have been developing various alternatives to Li-ion batteries, and lithium-air batteries are considered the ultimate in next-generation energy storage, because of their extremely high energy density.
whereas 0. 2 V is closer to that of a Li-ion battery, and equates to an energy efficiency of 93%.
these channels act like a doorman to regulate the entry of calcium ions in the nerve cells.
"It has also been known for a long time that following transient severe brain injury and prior to an initial spontaneous epileptic seizure, the concentration of free zinc ions increases in the hippocampus.
If the number of zinc ions increases following transient severe brain damage, these ions dock in greater numbers onto a switch, the so-called metal-regulatory transcription factor 1 (MTF1.
#This transparent lithium-ion battery charges itself with sunlight Researchers in Japan have invented a rechargeable lithium-ion battery that can charge itself using sunlight-no solar cell required.
of which are used commonly in rechargeable lithium-ion batteries. For the prototype that was put on display in Tokyo last month,
another possibility for the technology is self-charging smartphone screens made from transparent lithium-ion batteries.
#Researchers create lithium-air battery that could be 10x more powerful than lithium-ion A new lithium-air battery created by researchers at the University of Cambridge points the way to the ultimate battery packs of the future,
The idea of a lithium-air or lithium-oxygen battery isn't new scientists have known for a while that these types of batteries can hold up to 10 times the charge of today's lithium-ion packs (imagine not having to charge your phone for a whole week.
With the use of lithium ions as dopant, researchers found it offered significant electronic conductivity
Yanliang Liang, a research associate at UH and first author on the paper, said researchers aren't trying to compete directly with conventional lithium-ion batteries."
cheaper and more powerful and durable than lithium-ion batteries common in mobile phones and laptops and increasingly used in hybrid and electric cars.
The batteries can have three times the energy density of lithium-ion batteries, but have been sluggish. To counter that problem,
In its cellular membrane, the bacterium had a previously unknown type of ion transporter. The protein,
Integrating these ion transporters into the neuronal membrane makes it possible to alter their state of charge using light impulses
and each of these proteins was only permeable to certain ions. KR2 transports positively charged sodium ions out of the cell,
which is a feature that so far had been missing in the toolkit of optogenetics. However, until now neither the exact atomic structure nor the ion transport mechanism had been known--which is an important prerequisite for utilizing KR2
and adapting it for specific applications. This challenge awakened the interest of a team of structural biologists headed by Prof.
A feature of KR2, that the scientists were interested particularly in was the unusual structure of the inward facing ion-uptake cavity,
"We hypothesized that this structure could act as a kind of filter causing the selectivity of KR2 for sodium ions,
"In neurons, transporting potassium ions from the cell is the natural mechanism of deactivation. Normally, an activated neuron will release them through passive potassium channels in the membrane.
, it has attached negative ions to its surface. It thus attracts small positively charged molecules whether these are ions or drugs.
When an electrical current is applied to it, the flow of electrons generated projects the molecules of interest toward the target area.
#Better battery imaging paves way for renewable energy future"Iron fluoride has the potential to triple the amount of energy a conventional lithium-ion battery can store,
which use aluminum as the key material for the lithium-ion battery's negative electrode,
Most present lithium-ion batteries--the most widely used form of rechargeable batteries--use anodes made of graphite, a form of carbon.
As a result, previous attempts to develop an aluminum electrode for lithium-ion batteries had failed.
a better conductor of electrons and lithium ions when it is very thin. Aluminum powders were placed in sulfuric acid saturated with titanium oxysulfate.
"which shows that small ions can get through the shell. The particles are treated then to get the final aluminum-titania (ATO) yolk-shell particles.
while allowing lithium ions and electrons to get in and out. The result is an electrode that gives more than three times the capacity of graphite (1. 2 Ah/g) at a normal charging rate
while still allowing the ions to flow seamlessly to complete the electrical circuit in the cell.
the researchers etched micrometer scale pillars into a silicon surface using photolithography and deep reactive-ion etching,
This biotechnology method could also have similar applications to other low-concentration ions in solution.
with the added complication that seawater also contains various metal ions at high concentrations, making separating the uranium extremely complex.
thermally stable protein called Super Uranyl-binding Protein (SUP) binds uranyl tightly (Kd of 7. 4 femtomolar) and with high selectivity(>10,000-fold selectivity over other metal ions.
They direct a broad beam of noble gas ions onto a gallium arsenide wafer, which, for example, is used in producing high-speed and high-frequency transistors, photocells or light-emitting diodes."
"One could compare ion bombardment with sand blasting. This means that the ions mill off the surface of the target.
There, the desired nanostructures are created all by themselves, "explains Dr. Facsko. The finely chiselled and regular structure is reminiscent of sand dunes,
Ion Bombardment at Elevated Temperature At room temperature, however, the ion beam destroys the crystal structure of the gallium arsenide and thus its semiconducting properties.
Dr. Facsko's group at the HZDR's Ion beam Center therefore uses the opportunity to heat the sample during ion bombardment.
The colliding ions not only shift the atoms they hit, but also knock individual atoms entirely out of the crystal structure.
Because we use particularly low energy ions--under 1 kilovolt, -which can be generated using simple methods,
or ion channels, each of which is a portal for specific ions. Ion channels are typically about 1 nanometer wide;
by maintaining the right balance of ions, they keep cells healthy and stable. Now researchers at MIT have created tiny pores in single sheets of graphene that have an array of preferences and characteristics similar to those of ion channels in living cells.
which scientists have studied ever ion flow. Each is also uniquely selective, preferring to transport certain ions over others through the graphene layer."
"What we see is that there is a lot of diversity in the transport properties of these pores,
detecting ions of mercury, potassium, or fluoride in solution. Such ion-selective membranes may also be useful in mining:
In the future, it may be possible to make graphene nanopores capable of sifting out trace amounts of gold ions from other metal ions, like silver and aluminum.
Karnik and former graduate student Tarun Jain, along with Benjamin Rasera, Ricardo Guerrero, Michael Boutilier, and Sean O'Hern from MIT and Juan-carlos Idrobo from Oak ridge National Laboratory, publish their results in the journal Nature Nanotechnology.
which are slightly smaller than the ions that flow through them.""When nanopores get smaller than the hydrated size of the ion,
then you start to see interesting behavior emerge, "Jain says. In particular, hydrated ions, or ions in solution, are surrounded by a shell of water molecules that stick to the ion,
depending on its electrical charge. Whether a hydrated ion can squeeze through a given ion channel depends on that channel's size and configuration at the atomic scale.
Karnik reasoned that graphene would be a suitable material in which to create artificial ion channels:
A sheet of graphene is an ultrathin lattice of carbon atoms that is one atom thick, so pores in graphene are defined at the atomic scale.
The group reasoned that any ions flowing through the two-layer setup would have passed likely first through a single graphene pore,
The group measured flows of five different salt ions through several graphene sheet setups by applying a voltage and measuring the current flowing through the pores.
and from ion to ion, with some pores remaining stable, while others swung back and forth in conductance--an indication that the pores were diverse in their preferences for allowing certain ions through."
"The picture that emerges is that each pore is different and that the pores are dynamic,
which scientists have studied ion flow. With the model, the group calculated the effect of various factors on pore behavior,
Knowing this, researchers may one day be able to tailor pores at the nanoscale to create ion-specific membranes for applications such as environmental sensing and trace metal mining."
VRAC is regulated a volume anion channel that allows negatively charged ions (anions) and amino acids into the cell and back out again.
In the future, these infections will be prevented thanks to a new plasma implant coating that kills pathogens using silver ions.
and during that time they continuously release small quantities of antimicrobial silver ions, which kill bacteria.
and the outermost layer releases the ions. This is beneficial because it prevents direct contact between the tissue and the silver particles,
This allows the silver ions to penetrate the outermost plasma polymer layer over a set period of time deemed necessary to properly integrate the implant.
no more silver ions are released, thus avoiding any long-term toxic effects. In trials using finished implants and titanium test samples
absorb silver ions and, as a result, end up dying. t UVA Dankovich and her colleagues started to test their filter pages in Limpopo province in South africa in 2013.
#Computer-Designed Rocker Protein Worlds First To Biomimic Ion Transport For the first time, scientists recreated the biological function of substrate transportation across the cell membranes by computationally designing a transporter protein.
was shown to transport ions across the membrane, a process crucial to cell and organismal survival in various functions,
designed so that zinc ions and protons can flow in a controlled way across the lipid-membrane barrier around the cell-like vesicle.
and to form two special pockets for binding zinc ions and protons along the cavity within the bundle.
One conformation opens up the pocket near one side of the membrane to grab zinc ions or protons.
Once the zinc ion binds to the pocket Rocker changes its shape to close off the pocket,
This allows the ions from the closed pocket to travel to the second pocket before being released to the outside of the membrane.
The catch is that Rocker can have both pockets bind the ions at the same time, nor permit the cavity to open all the way through the membrane at one time
because this would leak down the ion concentration levels important for keeping cells intact and healthy.
Also, Rocker reconstituted in membrane vesicles was tested to show that it really pushed zinc ions from one side of the membrane to the other,
But if you could transport something into the cell such as a toxic ion or small molecule that could be quite interesting,
Early success stories The Electrolyte Genome first major scientific findinghat magnesium electrolytes are very prone to forming ion pairs,
it has attached negative ions to its surface. It thus attracts small positively charged molecules, whether these are ions or drugs.
When an electrical current is applied to it the flow of electrons generated projects the molecules of interest toward the target area.
#Discovery unlocks ion conductor that is 100 times faster than all the others A research group at the Technical University of Denmark (DTU),
Department of energy Conversion and storage (DTU Energy) has discovered a new way to stabilize an ion conducting material with a 100 times faster ion conductivity than all previous known ion conductors. he new
the current is transported by oxygen ions. There has been enormous interest over the years to use this material in application however;
which exhibit the highest ionic conductivity and was discovered by L. G. Sillén (1916-1970)( Mineralogist,
with the hope that this discovery opens brand new possibilities for usingd-Bismuth as an ion conductor. e have used very advanced fabrication
What we know is that they have gained a new way to access the best ion conductor available.
hings like yttria or lutecia and and dope them with rare earth ions. NRL has transitioned both types of laser materials and applications to industry.
introducing certain types of ions or pushing ions out of the cells to alter electrical activity.
But without a feedback loop, scientists could only assume that the optical signals were having the effects desired
the researchers etched micrometer scale pillars into a silicon surface using photolithography and deep reactive-ion etching,
They have created a new type of lithium-ion battery anode using portabella mushrooms, which are inexpensive, environmentally friendly and easy to produce.
The current industry standard for rechargeable lithium-ion battery anodes is synthetic graphite, which comes with a high cost of manufacturing
Hierarchically Porous Carbon Anodes for Li-ion Batteries, published on Sept. 29 in the journal Nature Scientific Reports.
This paper involving mushrooms is published just over a year after the Ozkan labs developed a lithium-ion battery anode based on nanosilicon via beach sand as the natural raw material.
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