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Nagmani

Tuesday, July 28, 2015

Characterization and performance study on visible active TiO2 polymorphs for solar application

The photocatalytic is a reaction which uses light to activate substances which modify the rate of chemical reaction without involving in the reaction. The photocatalytic activity is a result of the synergy of a succession of phenomena- photogeneration, separation, and participation of the charge carriers at the catalyst surface for chemical reaction. Synergistic effect of the mixed phase titania on its performance compared to the pristine phase has been investigated. 

The experiments were conducted under visible light irradiations. The characterization was done using tools X-ray diffraction (XRD) and Scanning electron microscope (SEM). 



For photocatalytic degradation test methylene blue was used as probe pollutant and it was tested under visible light. The results show that the mixed phase catalysts showed 1.6 times more activity than anatase phase of TiO2 and 7.6 times than rutile phase of TiO2. Thus the fundamental charge transfer process at different phases is important for light harvesting photocatalyst.

Gas Sensing Studies of Multifunctional Metal Oxide: Undoped/doped TiO2 Nanomaterial and Thin Films

At Bhabha Atomic Research Centre, Sensing studies were carried out at room temperature, 100°C, 150°C, 200°C and 300°C. Sensing response at150°C is over 200% at 10 ppm which is encouraging from application point of view. Fabrication of a sensor array based on TiO2 and doped- TiO2 thin films was demonstrated. TiO2 thin films were deposited on LaAl2O3 substrates by pulse laser deposition. The as-grown films were characterized by XRD. The sensor array based on TiO2 thin film can be used for identifying H2S gas both qualitatively and quantitatively by a proper control over the process parameters, namely: operating temperature and surface modifications. The maximum sensor response (S=204) at optimal temperature (150°C) was obtained for pure TiO2 epitaxial thin film . A concentration profile at 150°C was recorded for generation of data bank.
The Nb-doping in TiO2 improves the conductivity of TiO2, mainly in high temperature range where the material is mostly sensitive to gaseous species.

Further from the present work it is clear that TiO2 thin films can be operated as a H2S sensor in ppm level in the range of 1- 50 ppm. The sensor based on TiO2 found to be faster response and recovery time.
It is well established that sensor response and selectivity of metal-oxide sensors can be improved by using different strategies, such as, doping with penta-valent or tri-valent material and making composites of metal-oxides. In particular, for ppm level H2S detection it has been demonstrated that selectivity can be greatly enhanced if the sensing element consists of random p-n junctions. single chemiresistive sensor is usually tailored to detect a single gas.


By: Nagmani

Monday, July 6, 2015

CENTRAL UNIVERSITY OF JHARKHAND ADMISSION RESULTS - 2015




Admission to all the courses offered by Central University of Jharkhand, for the academic session beginning from July 2015,
is being done through the Central Universities Common Entrance Test (CUCET) - 2015.
Applicants are advised to regularly visit the website of CUCET-2015 (www.cucet2015.co.in), as well as the below mentioned link/s for latest updates :-

ADMISSIONS RESULTS

Merit list for UG/ Integrated Courses

Merit list for B.Ed Courses

Merit list for Post Graduate Courses

For more information CLICK HERE

Source : www.cuj.ac.in

Thursday, October 16, 2014

This new nuclear reactor could bring carbon-free power to 80,000 homes, and fit in the back of a truck

American aerospace and technology company Lockheed Martin has announced that they’re working on a new nuclear fusion reactor that’s 10 times smaller than any other reactor on the market. Their 100-megawatt reactor measures just 3 metres by 3 metres, which makes it compact enough to fit in the back of a truck.
Called a compact fusion reactor (CFR), researchers at Lockheed Martin say this small device will be able to power warships, spaceships, aeroplanes, and even a city filled with 80,000 homes. This means no more reliance on fossil fuels, which is significant, because according to Andrea Shalal at Reuters, it's been predicted that there will be a 40 to 50 percent increase in energy use over the next generation.
"Crucially, by being 'compact', Lockheed believes its scalable concept will also be small and practical enough for applications ranging from interplanetary spacecraft and commercial ships to city power stations," says Guy Norris at Aviation Week. "It may even revive the concept of large, nuclear-powered aircraft that virtually never require refueling - ideas of which were largely abandoned more than 50 years ago because of the dangers and complexities involved with nuclear fission reactors."
Lockheed Martin is also building this new energy source to be much safer and more efficient than current nuclear reactors, and more environmentally friendly. It runs on just 25 kg of deuterium-tritium fuel per year, which can generate nearly 10 million times more energy than the same amount of fossil fuels. 
The key to the success of this system is a new design that allows it to hold way more plasma than current systems. Tom McGuire, who is heading up the project, told Aviation Week that current nuclear reactors only have a plasma ratio of about 5 percent, and they have to be enormous just to achieve this much. The CFR, on the other hand, is predicted to increase this ratio to at least 100 percent.
The team says they’ve tested the system out in the lab already, and they’ll have a prototype up and running within five years. They predict their reactors will be operational and on the market in 10 years. 
It might sound too good to be true, and these things often are, but the fact that Lockheed Martin is one of the biggest aerospace and military companies in the world makes this a promising announcement. But not everyone is impressed. Thermonuclear plasma physicist at the University of Texas, Swadesh M. Mahajan, told James West at Mother Jones, “we know of no materials that would be able to handle anywhere near that amount of heat,” for a device as small the CFR.
And Tom Jarboe, professor of aeronautics and astronautics at the University of Washington, told Jessica Orwig at Business Insider“The nuclear engineering clearly fails to be cost effective."
We'll just have to wait and see...

Tuesday, October 14, 2014

Ultra-fast charging batteries that can be 70% recharged in just two minutes

October 13, 2014
Scientists have developed a new battery that can be recharged up to 70 per cent in only 2 minutes. The battery will also have a longer lifespan of over 20 years. Expected to be the next big thing in battery technology, this breakthrough has a wide-ranging impact on many industries, especially for electric vehicles which are currently inhibited by long recharge times of over 4 hours and the limited lifespan of batteries.
This next generation of lithium-ion batteries will enable electric vehicles to charge 20 times faster than the current technology. With it, electric vehicles will also be able to do away with frequent battery replacements. The new battery will be able to endure more than 10,000 charging cycles -- 20 times more than the current 500 cycles of today's batteries.
NTU Singapore's scientists replaced the traditional graphite used for the anode (negative pole) in lithium-ion batteries with a new gel material made from titanium dioxide, an abundant, cheap and safe material found in soil. It is commonly used as a food additive or in sunscreen lotions to absorb harmful ultraviolet rays.
Naturally found in a spherical shape, NTU Singapore developed a simple method to turn titanium dioxide particles into tiny nanotubes that are a thousand times thinner than the diameter of a human hair.
This nanostructure is what helps to speeds up the chemical reactions taking place in the new battery, allowing for superfast charging.
Invented by Associate Professor Chen Xiaodong from the School of Materials Science and Engineering at NTU Singapore, the science behind the formation of the new titanium dioxide gel was published in the latest issue of Advanced Materials, a leading international scientific journal in materials science.
NTU professor Rachid Yazami, who was the co-inventor of the lithium-graphite anode 34 years ago that is used in most lithium-ion batteries today, said Prof Chen's invention is the next big leap in battery technology.
"While the cost of lithium-ion batteries has been significantly reduced and its performance improved since Sony commercialised it in 1991, the market is fast expanding towards new applications in electric mobility and energy storage," said Prof Yazami.
"There is still room for improvement and one such key area is the power density -- how much power can be stored in a certain amount of space -- which directly relates to the fast charge ability. Ideally, the charge time for batteries in electric vehicles should be less than 15 minutes, which Prof Chen's nanostructured anode has proven to do."
Prof Yazami, who is Prof Chen's colleague at NTU Singapore, is not part of this research project and is currently developing new types of batteries for electric vehicle applications at the Energy Research Institute at NTU (ERI@N).
Commercialisation of technology
Moving forward, Prof Chen's research team will be applying for a Proof-of-Concept grant to build a large-scale battery prototype. The patented technology has already attracted interest from the industry.
The technology is currently being licensed to a company and Prof Chen expects that the new generation of fast-charging batteries will hit the market in two years' time. It holds a lot of potential in overcoming the longstanding power issues related to electro-mobility.
"With our nanotechnology, electric cars would be able to increase their range dramatically with just five minutes of charging, which is on par with the time needed to pump petrol for current cars," added Prof Chen.
"Equally important, we can now drastically cut down the waste generated by disposed batteries, since our batteries last ten times longer than the current generation of lithium-ion batteries."
The long-life of the new battery also means drivers save on the cost of a battery replacement, which could cost over USD$5,000 each.
Easy to manufacture
According to Frost & Sullivan, a leading growth-consulting firm, the global market of rechargeable lithium-ion batteries is projected to be worth US$23.4 billion in 2016.
Lithium-ion batteries usually use additives to bind the electrodes to the anode, which affects the speed in which electrons and ions can transfer in and out of the batteries.
However, Prof Chen's new cross-linked titanium dioxide nanotube-based electrodes eliminate the need for these additives and can pack more energy into the same amount of space.
"Manufacturing this new nanotube gel is very easy," Prof Chen added. "Titanium dioxide and sodium hydroxide are mixed together and stirred under a certain temperature. Battery manufacturers will find it easy to integrate our new gel into their current production processes."
This battery research project took the team of four NTU Singapore scientists three years to complete and is funded by Singapore's National Research Foundation.
Last year, Prof Yazami was awarded the Draper Prize by the National Academy of Engineering for his ground-breaking work in developing the lithium-ion battery with three other scientists.


Nanoparticles can act like liquid on the outside, crystal on the inside

October 12, 2014
A surprising phenomenon has been found in metal nanoparticles: They appear, from the outside, to be liquid droplets, wobbling and readily changing shape, while their interiors retain a perfectly stable crystal configuration.

The research team behind the finding, led by MIT professor Ju Li, says the work could have important implications for the design of components in nanotechnology, such as metal contacts for molecular electronic circuits.
The results, published in the journal Nature Materials, come from a combination of laboratory analysis and computer modeling, by an international team that included researchers in China, Japan, and Pittsburgh, as well as at MIT.
The experiments were conducted at room temperature, with particles of pure silver less than 10 nanometers across -- less than one-thousandth of the width of a human hair. But the results should apply to many different metals, says Li, senior author of the paper and the BEA Professor of Nuclear Science and Engineering.

Wednesday, October 8, 2014

Summer Research Fellowship Programme 2015 (SRPF- 2015)

Summer Research Fellowship Programme for Students and Teachers 2015

Online application process now OPEN

Instructions to applicants




A. General

1) Applications should be submitted online in the prescribed format. See link at the bottom of this page. This link is available in the website of the three Academies (www.ias.ac.in; www.insaindia.org; www.nasi.org.in).

Sunday, September 21, 2014

Solar-cell efficiency improved with new polymer devices

September 19, 2014
New light has been shed on solar power generation using devices made with polymers. Researchers identified a new polymer -- a type of large molecule that forms plastics and other familiar materials -- which improved the efficiency of solar cells. The group also determined the method by which the polymer improved the cells' efficiency. The polymer allowed electrical charges to move more easily throughout the cell, boosting the production of electricity -- a mechanism never before demonstrated in such devices.
Researchers identified a new polymer -- a type of large molecule that forms plastics and other familiar materials -- which improved the efficiency of solar cells. The group also determined the method by which the polymer improved the cells' efficiency. The polymer allowed electrical charges to move more easily throughout the cell, boosting the production of electricity -- a mechanism never before demonstrated in such devices.
"Polymer solar cells have great potential to provide low-cost, lightweight and flexible electronic devices to harvest solar energy," said Luyao Lu, graduate student in chemistry and lead author of a paper describing the result, published online last month in the journal Nature Photonics.
Solar cells made from polymers are a popular topic of research due to their appealing properties. But researchers are still struggling to efficiently generate electrical power with these materials.
"The field is rather immature -- it's in the infancy stage," said Luping Yu, professor in chemistry, fellow in the Institute for Molecular Engineering, who led the UChicago group carrying out the research.
The active regions of such solar cells are composed of a mixture of polymers that give and receive electrons to generate electrical current when exposed to light. The new polymer developed by Yu's group, called PID2, improves the efficiency of electrical power generation by 15 percent when added to a standard polymer-fullerene mixture.
"Fullerene, a small carbon molecule, is one of the standard materials used in polymer solar cells," Lu said. "Basically, in polymer solar cells we have a polymer as electron donor and fullerene as electron acceptor to allow charge separation." In their work, the UChicago-Argonne researchers added another polymer into the device, resulting in solar cells with two polymers and one fullerene.
8.2 percent efficiency
The group achieved an efficiency of 8.2 percent when an optimal amount of PID2 was added -- the highest ever for solar cells made up of two types of polymers with fullerene -- and the result implies that even higher efficiencies could be possible with further work. The group is now working to push efficiencies toward 10 percent, a benchmark necessary for polymer solar cells to be viable for commercial application.
The result was remarkable not only because of the advance in technical capabilities, Yu noted, but also because PID2 enhanced the efficiency via a new method. The standard mechanism for improving efficiency with a third polymer is by increasing the absorption of light in the device. But in addition to that effect, the team found that when PID2 was added, charges were transported more easily between polymers and throughout the cell.
In order for a current to be generated by the solar cell, electrons must be transferred from polymer to fullerene within the device. But the difference between electron energy levels for the standard polymer-fullerene is large enough that electron transfer between them is difficult. PID2 has energy levels in between the other two, and acts as an intermediary in the process.
"It's like a step," Yu said. "When it's too high, it's hard to climb up, but if you put in the middle another step then you can easily walk up."
Thanks to a collaboration with Argonne, Yu and his group were also able to study the changes in structure of the polymer blend when PID2 was added, and show that these changes likewise improved the ability of charges to move throughout the cell, further improving the efficiency. The addition of PID2 caused the polymer blend to form fibers, which improve the mobility of electrons throughout the material. The fibers serve as a pathway to allow electrons to travel to the electrodes on the sides of the solar cell.
"It's like you're generating a street and somebody that's traveling along the street can find a way to go from this end to another," Yu said.
To reveal this structure, Wei Chen of the Materials Science Division at Argonne National Laboratory and the Institute for Molecular Engineering performed X-ray scattering studies using the Advanced Photon Source at Argonne and the Advanced Light Source at Lawrence Berkeley.
"Without that it's hard to get insight about the structure," Yu said, calling the collaboration with Argonne "crucial" to the work. "That benefits us tremendously," he said.
Chen noted that "Working together, these groups represent a confluence of the best materials and the best expertise and tools to study them to achieve progress beyond what could be achieved with independent efforts.
"This knowledge will serve as a foundation from which to develop high-efficiency organic photovoltaic devices to meet the nation's future energy needs," Chen said. -- By Emily Conover

Story Source:  University of Chicago

Wednesday, August 27, 2014

Australian scientists are a step closer to converting sunlight and water into fuel

Scientists have replicated a crucial photosynthetic reaction for the first time, taking them a step closer to creating sustainable, cheap fuel from water and sunlight - just like plants do.

Plants use photosynthesis to turn water, carbon dioxide and sunlight into oxygen and the energy they need to power their systems. And for decades scientists have been trying to replicate this reaction in order to create biological systems that can produce cheap, clean hydrogen fuel.
Now, for the first time ever, scientists from the Australian National University in Canberra, Australia, have managed to modify a naturally occurring protein, and use it to capture energy from sunlight, a key step in photosynthesis. Their results have been published in BBA Bioenergetics.
“Water is abundant and so is sunlight. It is an exciting prospect to use them to create hydrogen, and do it cheaply and safely,” Kastoori Hingorani, the lead research from the ARC Centre of Excellence for Translational Photosynthesis, said in a press release.
Hydrogen has the potential to be a zero-carbon replacement for the petroleum products that we currently rely on. But up until now, we haven’t been able to find a way to create it as safely and efficiently as plants do. To replicate this step in the reaction in plants, the research team took a naturally occurring protein called ferritin, and modified it slightly. 
Ferritin is found in almost all living organisms, and it usually stores iron. But the team replaced iron with the common metal manganese, so that it closely resembled the water splitting site in photosynthesis. They also replaced another binding site with a light-sensitive pigment, Zinc Chlorin.
Once these changes had been made, the researchers shone light onto the modified ferritin and saw a clear indication of electrical charge transfer, just like the one that occurs in plants. The researchers describe this as the “electrical heartbeat” that’s the key to photosynthesis.
The researchers now need to work on using this protein to create biological, water-splitting systems. But this is an important first step.
“This is the first time we have replicated the primary capture of energy from sunlight,” Ron Pace, a co-researcher in the study, said in the press release. “It’s the beginning of a whole suite of possibilities, such as creating a highly efficient fuel, or to trapping atmospheric carbon.”
One of the most exciting things about this research is that, because this protein is powered by the Sun and does not require batteries or expensive metals, the entire process could be affordable for developing countries.
“That carbon-free cycle is essentially indefinitely sustainable. Sunlight is extraordinarily abundant, water is everywhere – the raw materials we need to make the fuel. And at the end of the usage cycle it goes back to water,” said Pace.

Monday, August 4, 2014

Scientists shine bright new light on how living things capture energy from the sun

July 31, 2014
Scientists may have uncovered a new method of exploiting the power of sunlight by focusing on a naturally occurring combination of lipids that have been strikingly conserved throughout evolution.
"We confirmed the properties of individual thylakoid galactoglycerolipid (or glycolipid) classes previously reports as HII forming lipids, but brought to light how these properties are subtly orchestrated in the matrix in which proteins are embedded, as contributing components for the elaboration of the architecture of photosynthetic membranes and its dynamics," said Juliette Jouhet, Ph.D., a researcher involved in the work from the Laboratoire de Physiologie Cellulaire and Vegetale at the Institut de Recherches en Technologies et Sciences pour le Vivant in Grenoble, France.
To make this discovery, Jouhet and colleagues analyzed biomimetic membranes reconstructed with different mixtures of natural lipids, so as to comprehend the contribution of each one of them in the observed biophysical properties. They then analyzed the membranes by neutron diffraction methods. The cohesion between membranes was analyzed by the evolution of the distance between bilayers upon hydration.
"This report helps fulfill the hope of Jimmy Stewart's character, Tony, in 'You Can't Take it with You,'" said Gerald Weissmann, M.D., Editor-in-Chief of the FASEB Journal. "Just as he once dreamt of harnessing the process by which grass derives energy from the sun, this report helps us do just that by defining the green engines in plants and higher organisms that accomplish the task."