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White Graphene Shows Promise for Unlimited Hydrogen Storage

Rice University engineers have zeroed in on the optimal architecture for storing hydrogen in "white graphene" nanomaterials, using a design resembling a skyscraper with "floors" of boron nitride sitting one atop another and held precisely 5.2 angstroms apart by boron nitride pillars.

Stephen Hawking Dies at 76, Cosmos Pauses to Welcome Its Brightest Star

Stephen Hawking died in the early hours of March 14 at age 76. His insights helped shape modern cosmology and he is widely credited with inspiring millions worldwide to look to the stars and challenge conventional thought. "He was a great scientist and an extraordinary man whose work and legacy...

Wunderkind Material is Both Superconductor and Insulator

Physicists at MIT and Harvard University report that graphene can exhibit a curious electronic property, behaving both as an insulator—where electrons are completely blocked from flowing—and as a superconductor—where electrical current can stream through without resistance.

Book Review: Thermodynamic Properties of Cryogenic Fluids

An accurate knowledge of the thermodynamic properties of fluids is one of the cornerstones of cryogenic engineering. These properties, which vary greatly with temperature and pressure, drive refrigeration cycle design, safety analysis and overall cryogenic system design. Having access to these properties and knowing the accuracy of their values is...

Superconducting Magnet Sets 32-T World Record

The National High Magnetic Field Laboratory (CSA CSM) chalked up another world record in December when a new superconducting magnet at the facility reached a magnetic field of 32 teslas, a third stronger than the previous record and more than 3,000 times stronger than a common refrigerator magnet.

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Regenerators

Regenerators or regenerative heat exchangers are a key component of cryocoolers such as pulse tube cryocoolers (Cold Facts, August 2014). Regenerator performance greatly affects the coefficient of performance of cryocoolers. Improvements in regenerator design and, in particular, regenerator materials have been an important factor in the improvement of the performance...

Pulse Tube Cryocoolers

The development of pulse tube cryocoolers has been a significant topic of research and development over the past 20 or so years. Pulse tube cryocoolers have a number of advantages over other types of cryocoolers and are now available commercially. In order to understand pulse tube cryocoolers, it’s best to...

Thermal Expansion

Thermal expansion refers to the change in size (length or volume) that a material undergoes as its temperature changes. In cryogenic systems this effect can be quite large and must be allowed for in the design. In isotropic materials, which include most engineering materials, the thermal expansion is the same...

Cryogenic Electronics

Randall Kirschman, consulting physicist, Mountain View, California ExtElect@gmail.com Cryogenic electronics—the operation of electronic devices, circuits, and systems at cryogenic temperatures—has been a valuable technology for decades. Cryogenic electronics (also referred to as low-temperature electronics, or cold electronics) can be based on semiconductive devices, on superconductive devices, or on a combination...

Particle Physics: High Energy Physics

Cryogenics and High-Energy Physics 1. From symmetry magazine: http://www.symmetrymagazine.org/cms/?pid=1000627: Cryogenics is the study of how materials behave at temperatures near absolute zero. In high-energy particle accelerators, such frigid temperatures reduce the electrical resistance of wires in superconducting magnets, increasing the magnet strength and allowing faster particle acceleration. The same holds...

HTS Degaussing Systems

From the Spring 2009 issue of Cold Facts (Volume 25, Number 2): Thanks to a joint project by the US Navy and a number of industry partners, high temperature superconducting (HTS) technology is now at the heart of an advanced degaussing system aboard the USS Higgins at the naval station...

Magnetic Resonance Imaging

From http://www.superconductors.org: An area where superconductors can perform a life-saving function is in the field of biomagnetism. Doctors need a non-invasive means of determining what’s going on inside the human body. By impinging a strong superconductor-derived magnetic field into the body, hydrogen atoms that exist in the body’s water and...

An Issue of Pressure and Flow Rate in a Supply Tank

Please help solve this problem: A supply tank requires a vaporizer to generate sufficient pressure to pump stored fluid up into a vehicle or tank. The available head is limited as the tank level falls and it is important to minimize the system pressure drop to maintain the desired flow...

Using MLI on VJ Line Joints or Cryo Storage Tanks

When installing Multi Layer Insulation (MLI) blankets on VJ line joints or cryo storage tanks should they be wrapped and tied down tight or loose? These are usually pre-cut to size. Also should they have an access hole at the point of where the molecular sieve is installed to help...