Engineers Forum

Annoyingly tiny fridges may not be restricted to hotels or dorm rooms much longer. A new study proposes a way to construct the smallest refrigerator yet, based on just a few particles and capable of cooling to near absolute zero.

The study, which will appear in an upcoming issue of Physical Review Letters, pushes the limits of how small a cooling device can get and still remain functional.

“When thermodynamics was first invented, it was applied to big, steam engine sorts of things,” says physicist Tony Short of the University of Cambridge in England, who was not involved in the study. “The fact that you can bring the ideas all the way down to individual quantum systems of tiny dimensions and the same basic ideas still work is quite nice.”

Study coauthors Noah Linden, Sandu Popescu and Paul Skrzypczyk, all of the University of Bristol in England, propose a cooling scheme that relies on three linked qubits — particles that can exist in one of two states. Two of these qubits make up the refrigerator and would be held in two different heat baths: one very hot and one near room temperature. The third qubit is the object to be cooled. Because these qubits share a quantum connection, they can influence one another. So, as the hottest qubit absorbs energy from its toasty bath, it triggers the tepid qubit to siphon energy off the third qubit, cooling it. This extra energy dissipates off the second qubit in the same way the coil at the back of a refrigerator in the kitchen emits heat.

In their calculations, the physicists found that as the bath of the hottest qubit got hotter, the cooling ability of the fridge got better. And in principle, as long as the heat bath stays hot, the system can run forever. “Once you set it up, it just sits there, gently cooling away,” Linden says.

Other small systems have been created, but this is the first that doesn’t rely on external mechanisms, such as sophisticated lasers. “The whole guts of the fridge, it’s all accounted for and not hidden in some macroscopic object which is really doing the work,” Linden says.

Linden and his team also propose an even smaller system, in which a single particle with three distinct levels of quantum information, called a qutrit, acts as the refrigerator. “We believe this is the smallest possible thing you can call a fridge,” Linden says.

Physicist Nicolas Gisin of the University of Geneva says the new study is “extremely elegant. It opens a totally new avenue for interesting questions, combining thermodynamics and quantum information science in a very original way.”

The researchers plan to collaborate with other groups to settle on an exact blueprint for the minifridge and to build it. In the future, a tiny fridge might be used to slow or speed up reactions between proteins in cells by cooling precise parts, or to keep delicate components in quantum computers frigid.

A particularly fascinating question is whether such fridges might already exist in nature, Gisin says. For instance, a sun-drenched plant could have molecules with one end sitting directly in a natural thermal bath, allowing a tiny refrigerator to cool the other end.

Linden and his colleagues also find that idea exciting, but he’s careful to point out that so far, it’s just an idea. “We don’t want to claim that we know of a place where this happens,” he says. “But it would be great if someone came up with a molecule and said, ‘Look at this. Doesn’t it have the characteristics you need?’ We’d be really, really happy if that happened.”

Source: http://www.sciencenews.org/view/generic/id/62734/title/Very_tiny%2C_very_cool

A news has published on http://www.nce.co.uk which describes that ” 500,000 engineering and manufacturing workers will be needed in the coming eight years to satisfy demand in the transport, construction, aerospace and defence industries, according to EngineeringUK.”

If this is true and guessed right then engineers who are redundant or getting job seekers allowance should be happy that their tough time is going to end. The news in detail is as following:

“A new report highlights barriers to achieving the figure, which include an increasingly sparse pool of talent, a decline in engineering lecturers and fewer students studying for manufacturing and engineering degrees.
EngineeringUK predicts more than 350,000 skilled workers will be needed in the transport sector alone by 2017.
The construction industry will look to recruit almost 400,000, while 1,000 new apprentices and graduates will be required every year until 2025 to replace nuclear workers.
Chief executive of EngineeringUK, Paul Jackson, said: “We are calling for Government, business and education providers to work together to develop a clear road map for the UK engineering sector.
“Tax breaks and other regulatory incentives for small and medium-sized enterprises will play a significant part, but what really matters is a long-term strategy, detailing all major infrastructure projects for the foreseeable future and inspiring UK engineering with the confidence it needs to invest in new skills and technologies.
“Without the coherence and stability a clear roadmap will bring, the UK will not only miss out on the high-level manufacturing skills it needs to get the economy back on track but could also lose ground to other countries in many highly-competitive global markets.”

This is a mathematical challenge, and it’s been said that:

* If you’re an engineer, you should be able to solve any engineering problem in one minute;
* if you’re an architect, in two hours;
* if you’re a doctor, in five hours;
* if you’re an accountant, in three months and
* If you’re a lawyer or an economist or a General , probably never.

These facts show that every person is expert in his field and have a command of resolution. If you appoint a person on wrong position under political pressure or special policy, you should expect that actual problem will never solve.