fuckyeahfluiddynamics:

fuckyeahfluiddynamics:

Defrosting and deicing surfaces is an energy-intensive affair, with lots of heat lost to warming up system components rather than the ice itself. In a new study, researchers explore a faster and more efficient method that focuses on heating just the interface. They coated their working surface in a thin layer of iridium tin oxide, a conductive film used in defrosting. Then, once the surface was iced over, they applied a 100 ms pulse of heating to the film. That localized heat melted the interface, and gravity pulled away the detached ice. Compared to conventional defrosting methods, this technique requires only 1% of the energy and 0.01% of the time. If the method scales reliably to applications like airplane deicing, it would provide enormous savings in time and energy. (Image and research credit: S. Chavan et al.)

New Metamaterials for Energy Harvesting Desi…

New Metamaterials for Energy Harvesting Designed by Machine Learning

Design would enable thermophotovoltaic devices that convert waste heat to electricity.

Durham, N.C. — Electrical engineers at Duke University have harnessed the power of machine learning to design dielectric (non-metal) metamaterials that absorb and emit specific frequencies of terahertz radiation. The design technique changed what could have been more than 2000 years of calculation into 23 hours, clearing the way for the design of new, sustainable types of thermal energy harvesters and lighting.

The study was published online on September 16, 2019, in the journal Optics Express.

Metamaterials are synthetic materials composed of many individual engineered features, which together produce properties not found in nature through their structure rather than their chemistry. In this case, the terahertz metamaterial is built up from a two-by-two grid of silicon cylinders resembling a short, square Lego.

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A stretchable and flexible biofuel cell that…

A stretchable and flexible biofuel cell that runs on sweat

A unique new flexible and stretchable device, worn against the skin and capable of producing electrical energy by transforming the compounds present in sweat, was recently developed and patented by CNRS researchers from l"Université Grenoble Alpes and the University of San Diego (U.S.). This cell is already capable of continuously lighting an LED, opening new avenues for the development of wearable electronics powered by autonomous and environmentally friendly biodevices. This research was published in Advanced Functional Materials on September 25, 2019.

The potential uses for wearable electronic devices continue to increase, especially for medical and athletic monitoring. Such devices require the development of a reliable and efficient energy source that can easily be integrated into the human body. Using “biofuels” present in human organic liquids has long been a promising avenue.

Scientists from CNRS/Université Grenoble Alpes who specialize in bioelectrochemistry collaborated with an American team from the University of San Diego in California comprising experts in nanomachines, biosensors, and nanobioelectronics. Together, they developed a flexible conductive material consisting of carbon nanotubes, crosslinked polymers, and enzymes joined by stretchable connectors that are directly printed onto the material through screen-printing.

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A new way to turn heat into useful energy

A new way to turn heat into useful energy

Capturing heat that otherwise would have been lost

An international team of scientists has figured out how to capture heat and turn it into electricity.

The discovery, published last week in the journal Science Advances, could create more efficient energy generation from heat in things like car exhaust, interplanetary space probes and industrial processes.

“Because of this discovery, we should be able to make more electrical energy out of heat than we do today,” said study co-author Joseph Heremans, professor of mechanical and aerospace engineering and Ohio Eminent Scholar in Nanotechnology at The Ohio State University. “It’s something that, until now, nobody thought was possible.”

The discovery is based on tiny particles called paramagnons – bits that are not quite magnets, but that carry some magnetic flux. This is important, because magnets, when heated, lose their magnetic force and become what is called paramagnetic. A flux of magnetism – what scientists call “spins” – creates a type of energy called magnon-drag thermoelectricity, something that, until this discovery, could not be used to collect energy at room temperature.

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The blade of a wind turbine being transporte…

The blade of a wind turbine being transported through city streets. 

International Year of the Periodic Table: Lead

sci:

2019 has been declared by UNESCO as the Year
of the Periodic Table. To celebrate, we are releasing a series of blogs about
our favourite elements and their importance to the chemical industry. Today’s
blog focuses on lead and its place in the battery industry.

2019 is a critical year for the European
Battery Industry. As policymakers set priorities to decarbonise the energy
systems, whilst boosting Europe’s economic and technical performance, lead-acid
batteries have become a viable player in the battery industry. 

Increased
government action and ongoing transformations to address the environmental
situation has furthered global interest in the lead battery market, as they
remain crucial in the battle to fight against the adverse effects of climate
change. Subsequently, reliance on fuel technologies is lessening as we see a
rise in the lead battery industry which had a market share of 31% in year 2018
with an annual growth rate of 5.4%.

According to
reports by Reports and Data, the Global Lead- Acid Battery market is predicted
to reach USD 95.32 Billion by 2026. Rising demand for electric vehicles and
significant increases of this battery use in sectors including automotive,
healthcare, and power industries, are a large push behind the growth in this
market. 

Thus, expansion of these sectors and particularly the automobile
sector, means further development in this market will be underway, especially
as it is the only battery technology to meet the technical requirements for
energy storage on a large market scale. 

Lead-acid battery is a rechargeable cell,
comprising plates of lead and lead oxide, mixed in a sulfuric acid solution,
which converts chemical energy into electrical power. The oxide component in
the sulfuric acid oxidizes the lead which in turn generates electric current.

In the past, lead has fallen behind competing
technologies, such as lithium-ion batteries which captured approximately 90% of
the battery market. Although lithium-ion batteries are a strong opponent, lead
still has advantages. Lead batteries do not have same fire risks as lithium-ion
batteries and they are the most efficiently recycled commodity metal, with over
99% of lead batteries being collected and recycled in Europe and U.S. 

Researchers are trying to better understand
how to improve lead battery performance. A build-up of sulfation can limit lead
battery performance by half its potential, and by fixing this issue, unused
potential would offer even lower cost recyclable batteries. Once the chemical
interactions inside the batteries are better understood, one can start to
consider how to extend battery life. 

Tiffany Hionas is a Digital Media and Press officer at SCI. You can find more of her work here.

3-D printable 2-D materials based inks show …

3-D printable 2-D materials based inks show promise to improve energy storage devices

For the first time, a team of researchers, from the School of Materials and the National Graphene Institute at The the University of Manchester have formulated inks using the 2-D material MXene, to produce 3-D printed interdigitated electrodes.

As published in Advanced Materials, these inks have been used to 3-D print electrodes that can be used in energy storages devices such as supercapacitors.

MXene, a ‘clay-like’ two-dimensional material composed of early transition metals (such as titanium) and carbon atoms, was first developed by Drexel University. However, unlike most clays, MXene shows high electrical conductivity upon drying and is hydrophilic, allowing them to be easily dispersed in aqueous suspensions and inks.

Graphene was the world’s first two-dimensional material, more conductive than copper, many more times stronger than steel, flexible, transparent and one million times thinner than the diameter of a human hair.

Read more.

Understanding UK Carbon Dioxide Emissions

sci:

image

Since the beginning of SCI Energy Group’s blog series, new
legislation has come into place regarding emission targets. Instead of the
previous 80% reduction target, the UK must now achieve net-zero emissions by
2050. This makes significant, rapid emission reduction even more critical. This
article introduces the main sources of UK CO2 emissions across individual
sectors.

The Big Picture

In 2018, UK CO2 emissions totalled to roughly 364 million
tonnes. This was 2.4% lower than 2017 and 43.5% lower than 1990. The image
below shows how much each individual sector contributed to the total UK carbon
dioxide emissions in 2018. As can be seen, large emitting sectors include:
energy supply, transport and residential. For this reason, CO2 emission trends
from these sectors are discussed in this article.

image

Figure
1 Shows the percentage contribution toward Total UK
Greenhouse Gas Emissions per Sector (2018)

Figure: BEIS

Transport Sector

In 2018, the transport sector accounted for 1/3rd of total
UK CO2 emissions. Since 1990, there has been relatively little change in the
level of greenhouse gas emissions from this sector. Historically, transport has
been the second most-emitting sector. However, due to emission reductions in
the energy supply sector, it is now the biggest emitting sector and has been
since 2016. Emission sources include road transport, railways, domestic aviation, shipping, fishing & aircraft support vehicles.

image

The main source of emissions are petrol and diesel in road transport. 

Ultra-low emission vehicles (ULEV) can provide emission
reductions in this sector. Some examples of these include: hybrid electric,
battery electric and hydrogen fuel cell vehicles. In 2018, there were 200,000
ULEV’s on the road in the UK. In addition to this, there was a 53% increase in
ULEV vehicle registration compared to 2016. In 2018, UK government released
the ‘Road to Zero Strategy’, which seeks to see 50% of new cars to be ULEV’s by
2030 and 40% of new vans.

image

Energy Supply Sector

In the past, the energy supply sector was the biggest
emitting sector but, since 1990, this sector has reduced its greenhouse gas
emissions by 60% making it the second-biggest emitting sector. Between 2017 and
2018, this sector accounted for the largest decrease in CO2 emissions (7.2%). Emission sources included fuel combustion for electricity generation and other energy production sources, The main sources of emission are use of natural gas and coal in power plants.  

image

In 2015, the Carbon Price Floor tax changed from £9/tonne
CO2 emitted to £18/ tonne CO2 emitted. This resulted in a shift from coal to
natural gas use for power generation. There has also been a considerable
growth in low-carbon technologies for power generation. All of these have
contributed to emission reductions in this sector.

image

Figure 2 – Natural gas power plant

Residential Sector

Out of the total greenhouse gas emissions from the
residential sector, CO2 emissions account for 96%. Emissions from this sector
are heavily influenced by external temperatures. For example, colder
temperatures drive higher emissions as more heating is required.

In 2018, this sector accounted for 18% of total UK CO2
emissions. Between 2017 and 2018, there was a 2.8% increase in residential
emissions. Overall, emissions from this sector have dropped by 16% since 1990. Emission sources include fuel combustion for heating and cooking, garden machinery and aerosols. The main source of emission are natural gas for heating and cooking. 

Summary

The UK has reduced CO2 emissions by 43.5% since 1990.
However, further emission reductions are required to meet net-zero targets. The
energy supply sector has reduced emissions by 60% since 1990 but remains the
second biggest emitter. In comparison to this, emission reductions in the
residential sector are minor. Yet, they are still greater than the transport
sector, which has remained relatively static. Each of these sectors require
significant emission reduction to aid in meeting new emission targets.

Reace Edwards is a member of SCI’s Energy group and a PhD Chemical Engineering student at the University of Chester. Read more about her involvement with SCI here or watch her recent TEDx Talk here.

Regular

Ultra-thin layers of rust generate electricity from flowing water

There are many ways to generate electricity – batteries, solar panels, wind turbines, and hydroelectric dams, to name a few examples. …. And now there’s rust.

New research conducted by scientists at Caltech and Northwestern University shows that thin films of rust – iron oxide – can generate electricity when saltwater flows over them. These films represent an entirely new way of generating electricity and could be used to develop new forms of sustainable power production.

Interactions between metal compounds and saltwater often generate electricity, but this is usually the result of a chemical reaction in which one or more compounds are converted to new compounds. Reactions like these are what is at work inside batteries.

In contrast, the phenomenon discovered by Tom Miller, Caltech professor of chemistry, and Franz Geiger, Dow Professor of Chemistry at Northwestern, does not involve chemical reactions, but rather converts the kinetic energy of flowing saltwater into electricity.

The phenomenon, the electrokinetic effect, has been observed before in thin films of graphene – sheets of carbon atoms arranged in a hexagonal lattice – and it is remarkably efficient. The effect is around 30 percent efficient at converting kinetic energy into electricity. For reference, the best solar panels are only about 20 percent efficient.

Read more.

Harvesting energy from the human knee

Harvesting energy from the human knee

Researchers develop a way to power small devices by walking

Imagine powering your devices by walking. With technology recently developed by a group of researchers at the Chinese University of Hong Kong, that possibility might not be far out of reach.

The group describes the technology in Applied Physics Letters, from AIP Publishing. An energy harvester is attached to the wearer’s knee and can generate 1.6 microwatts of power while the wearer walks without any increase in effort. The energy is enough to power small electronics like health monitoring equipment and GPS devices.

“Self-powered GPS devices will attract the attention of climbers and mountaineers,” said author Wei-Hsin Liao, professor in the department of mechanical and automation engineering.

The researchers used a special smart macrofiber material, which generates energy from any sort of bending it experiences, to create a slider-crank mechanism – similar to what drives a motor. The authors chose to attach the device to the knee due to the knee joint’s large range of motion, compared to most other human joints.

Read more.

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