Kick it into 4WD with Sphero Nubby covers. Turn your Sphero into the ultimate off-road robot in the color of your choice. Not only do Nubby covers give you a strategic advantage navigating gravel, water, and concrete courses, they also protect against scratches and scuffs. Game on.

Sphero Nubby covers work with all Sphero versions.

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• Shields your Sphero against the elements
• Provides unbeatable traction for all types of terrain
• Available in three unique colors: Sphero Blue, Cyber Yellow, and Adventure Orange

- See more at: http://store.gosphero.com/products/nubby-cover-1#sthash.53HN3vya.dpuf

Infographic – Toys your Dad played with as a kid.

Solar Simulator from a well known company

A solar simulator is a device that provides illumination approximating natural sunlight. The purpose of the solar simulator is to provide a controllable indoor test facility under laboratory conditions, used for the testing of solar cells, sun screen, plastics, and other materials and devices. The basic idea of a solar cell is to convert light energy into electrical energy. The energy of light is transmitted by photons, small packets or quanta of light. Electrical energy is stored in electromagnetic fields, which in turn can make a current of electrons flow. Thus a solar cell converts light, a flow of photons, to electric current, a flow of electrons.

When photons are absorbed by matter in the solar cell, their energy excites electrons higher energy states where the electrons can move more freely. The perhaps most well-known example of this is the photoelectric effect, where photons give electrons in a metal enough energy to escape the surface. In an ordinary material, if the electrons are not given enough energy to escape, they would soon relax back to their ground states. In a solar cell however, the way it is put together prevents this from happening. The electrons are instead forced to one side of the solar cell, where the build-up of negative charge makes a current flow through an external circuit. The current ends up at the other side (or terminal) of the solar cell, where the electrons once again enter the ground state, as they have lost energy in the external circuit

Vickers hardness

Hardness is the property of a material that enables it to resist plastic deformation, usually by penetration. However, the term hardness may also refer to resistance to bending, scratching, abrasion or cutting.

The Vickers hardness test was developed in 1921 by Robert L. Smith and George E. Sandland at Vickers Ltd as an alternative to the Brinell method to measure the hardness of materials.^[1] The Vickers test is often easier to use than other hardness tests since the required calculations are independent of the size of the indenter, and the indenter can be used for all materials irrespective of hardness. The basic principle, as with all common measures of hardness, is to observe the questioned material's ability to resist plastic deformation from a standard source. The Vickers test can be used for all metals and has one of the widest scales among hardness tests. The unit of hardness given by the test is known as the Vickers Pyramid Number (HV) or Diamond Pyramid Hardness (DPH). The hardness number can be converted into units of Pascal’s, but should not be confused with a pressure, which also has units of Pascal’s. The hardness number is determined by the load over the surface area of the indentation and not the area normal to the force, and is therefore not a pressure.[1]

It is the standard method for measuring the hardness of metals, particularly those with extremely hard surfaces: the surface is subjected to a standard pressure for a standard length of time by means of a pyramid-shaped diamond. The diagonal of the resulting indention is measured under a microscope and the Vickers Hardness value read from a conversion table. 

Vickers hardness is a measure of the hardness of a material, calculated from the size of an impression produced under load by a pyramid-shaped diamond indenter. 

A method of determining the hardness of steel whereby a diamond pyramid is pressed into the polished surface of the specimen and the diagonals of the impression are measured with a microscope fitted with micrometer eye piece. The rate of application and duration are automatically controlled and the load can be varied. Two types of indenters are generally used for the Vickers test family, a square base pyramid shaped diamond for testing in a Vickers hardness tester and a narrow rhombus shaped indenter for a Knoop hardness test
 

2.  WORKING PRINCIPLE

The Vickers hardness test method consists of indenting the test material with a diamond indenter, in the form of a right pyramid with a square base and an angle of 136 degrees between opposite faces subjected to a load of 1 to 100 kg. The full load is normally applied for 10 to 15 seconds. The two diagonals of the indentation left in the surface of the material after removal of the load are measured using a microscope and their average calculated. The area of the sloping surface of the indentation is calculated. The Vickers hardness is the quotient obtained by dividing the kgf load by the square mm area of indentation
 

The Vickers hardness test operates on similar principles to the Brinell test, the major difference being the use of a square based pyramidal diamond indenter rather than a hardened steel ball. Also, unlike the Brinell test, the depth of the impression does not affect the accuracy of the reading so the P/D2 ratio is not important. The diamond does not deform at high loads so the results on very hard materials are more reliable. The load may range from 1 to 120kgf and is applied for between 10 and 15 seconds.         
As illustrated in the figure, two diagonals, d1 and d2, are measured, averaged and the surface area calculated then divided into the load applied. As the hardness may be reported as Vickers Hardness number (VHN), Diamond Pyramid Number (DPN) or, most commonly, Hv xx where 'xx' represents the load used during the test [2].

F= Load in kgf.

d = Arithmetic mean of the two diagonals, d1 and d2 in mm

HV = Vickers hardness

The Vickers hardness number, reported as HV, is the ratio of the force applied to the indenter (kgf) to the surface area (mm²) of the indentation. When the mean diagonal of the indentation has been determined the Vickers hardness may be calculated from the formula, but is more convenient to use conversion tables. The Vickers hardness should be reported like 800 HV/10, which means a Vickers hardness of 800, was obtained using a 10 kg force. Several different loading settings give practically identical hardness numbers on uniform material, which is much better than the arbitrary changing of scale with the other hardness testing methods. The advantages of the Vickers hardness test are that extremely accurate readings can be taken, and just one type of indenter is used for all types of metals and surface treatments. Although thoroughly adaptable and very precise for testing the softest and hardest of materials, under varying loads, the Vickers machine is a floor standing unit that is more expensive than the Brinell or Rockwell machines.

 There is now a trend towards reporting Vickers hardness in SI units (MPa or GPA) particularly in academic papers. Unfortunately, this can cause confusion. Vickers (e.g. HV/30) value should normally be expressed as a number only (without the unit’s kgf/mm2). Rigorous application of SI is a problem. Most Vickers hardness testing machines use forces of 1, 2, 5, 10, 30, 50 and 100 kgf and tables for calculating HV. SI would involve reporting force in Newton’s (compare 700 HV/30 to HV/294 N = 6.87 GPa) which is practically meaningless and messy to engineers and technicians. To convert Vickers hardness number the force applied needs converting from kgf to Newton’s and the area needs converting form mm2to m2 to give results in Pascal’s using the formula above [2].

 To convert HV to MPa multiply by 9.807

To convert HV to GPA multiply by 0.009807

XRD MACHINE

Powder X-ray Diffraction (XRD) is one of the primary techniques used by mineralogists and solid state chemists to examine the physico-chemical make-up of unknown solids. This data is represented in a collection of single-phase X-ray powder diffraction patterns for the three most intense D values in the form of tables of interplanar spacing (D), relative intensities (I/I_o), and mineral name.

X-ray powder diffraction (XRD) is a rapid analytical technique primarily used for phase identification of a crystalline material and can provide information on unit cell dimensions. The analyzed material is finely ground, homogenized, and average bulk composition is determined.

Max von Laue, in 1912, discovered that crystalline substances act as three-dimensional diffraction gratings for X-ray wavelengths similar to the spacing of planes in a crystal lattice. X-ray diffraction is now a common technique for the study of crystal structures and atomic spacing.

X-ray diffraction is based on constructive interference of monochromatic X-rays and a crystalline sample. These X-rays are generated by a cathode ray tube, filtered to produce monochromatic radiation, collimated to concentrate, and directed toward the sample. The interaction of the incident rays with the sample produces constructive interference (and a diffracted ray) when conditions satisfy Bragg's Law (nλ=2d sin θ). This law relates the wavelength of electromagnetic radiation to the diffraction angle and the lattice spacing in a crystalline sample. These diffracted X-rays are then detected, processed and counted. By scanning the sample through a range of 2θangles, all possible diffraction directions of the lattice should be attained due to the random orientation of the powdered material. Conversion of the diffraction peaks to d-spacings allows identification of the mineral because each mineral has a set of unique d-spacings. Typically, this is achieved by comparison of d-spacings with standard reference patterns.

All diffraction methods are based on generation of X-rays in an X-ray tube. These X-rays are directed at the sample, and the diffracted rays are collected. A key component of all diffraction is the angle between the incident and diffracted rays. Powder and single crystal diffraction vary in instrumentation beyond this.

TRANSMISSION ELECTRON MICROSCOPE (TEM)

Transmission electron microscopy is a powerful tool to investigate crystallographic defects down to the nanoscale, and is a critical technique to study irradiated materials. The JEOL 100CXII, a 100kV TEM with a lattice resolution of 0.2 nm, is dedicated for microstructure observations on high-dose neutron-irradiated specimens. The work focuses on defect structure and microstructure evaluations. The examinations help understand various degradation mechanisms related to neutron irradiation

WHAT IS SINGLE-CRYSTAL X-RAY DIFFRACTION?

Single-crystal X-ray Diffraction is a non-destructive analytical technique which provides detailed information about the internal lattice of crystalline substances, including unit cell dimensions, bond-lengths, bond-angles, and details of site-ordering. Directly related is single-crystal refinement, where the data generated from the X-ray analysis is interpreted and refined to obtain the crystal structure. The most common experimental method of obtaining a detailed structure of a molecule, that allows resolution of individual atoms, single crystal X-ray diffraction (SXRD) is performed by analyzing the pattern of X-rays diffracted by an ordered array of many identical molecules (single crystal). Many pure compounds, from small molecules to organometallic complexes, proteins, and polymers, solidify into crystals under the proper conditions. When solidifying into the crystalline state, these individual molecules typically adapt one of only a few possible 3D orientations. When a monochromatic X-ray beam is passed through a single crystal, the radiation interacts with the electrons in the atoms, resulting in scattering of the radiation to produce a unique image pattern. Multiple images are recorded, with an area X-ray detector, as the crystal is rotated in the X-ray beam. Computationally intensive analysis of a set images results in a solution for the 3D structure of the molecule.

US considers blocking Chinese nationals from hacking conferences

Following its decision to charge five Chinese officials for allegedly stealing trade secrets, the US is apparently ready take further action. Reuters reports that the US government may impose visa restrictions on Chinese computer experts, stopping them from attending the high-profile Def Con and Black Hat hacking conferences in August. Black Hat currently has three Chinese speakers lined up to present, while Def Con has none on its roster. The move is said to be part of a "broader effort to curb Chinese cyber espionage," after cybercriminals were said to have infiltrated six American private-sector companies to help give Chinese state-owned firms a competitive advantage. Organizers of both events, which include the founder of Def Con and Black Hat Jeff Moss, were unaware of the government's plans, but Moss did note on Twitter that such actions would not help build a "positive community." While an official block has yet to be imposed, stopping Chinese nationals already in the country from attending could prove difficult: Def Con's privacy-conscious setup requires attendees to pay using only cash and they never have to share their name.

Bringing the Rubik's Cube to the next generation of problem solvers

As a designer, it's always humbling when you encounter a perfect piece of design. Good design attracts our attention with its beauty, doesn’t need a user manual, is universally understood by anyone in the world, and is simple without sacrificing functionality. 

In 1974, the world gave us one such piece of perfect design—the Rubik's Cube. Budapest-based educator and inventor Ernő Rubik created the puzzle originally to help his students better understand spatial geometry. Released to the public in the 1980s, it quickly became an international obsession, bigger than hairspray and breakdancing combined. But the Rubik’s Cube is more than just a toy; it’s a puzzle waiting to be solved and a question waiting to be answered. Over the past 40 years, the cube has puzzled, frustrated, and fascinated so many of us, and has helped spark an interest in math and problem solving in millions of kids. That’s part of why so many of us at Google love the cube, and why we're so excited to celebrate its 40th birthday this year. 

As everyone knows (right??), there are 519 quintillion permutations for the Rubik’s cube, so May 19 seemed like a fine day to celebrate its 40th anniversary. To kick things off, we’re using some of our favorite web technologies (HTML5 and Three.js among others) to bring the cube to the world in the form of one of our most technically ambitious doodles yet. You can twist and turn it by dragging along its sides, but with full respect to all the speedcubers out there, we’ve included keyboard shortcuts:

Using the same technology that’s behind the doodle, we built Chrome Cube Lab, a series of Chrome Experiments by designers and technologists that reinterpret Rubik’s puzzle with the full power of the web. Create your own music with experiments 808Cube and SynthCube; make a custom, shareable cube of your own photos and GIFs with ImageCube; or send a scrambly message with the Type Cube. You can visit some of these experiments at the Liberty Science Center’s Beyond Rubik’s Cube exhibition, and if you'd like to explore the cube even further, consider borrowing the cube’s source code to build an experiment of your own.

We hope you enjoy getting to know the cube from a few new angles.

Google+ Stories and Movies: memories made easier

A suitcase full of dirty clothes. A sad-looking house plant. And 437 photos and videos on your phone, tablet and camera. This is the typically messy scene after a vacation. And although we can’t do your laundry (thanks but no thanks), or run your errands (well, maybe a few), we’d still like to help. Enter Google+ Stories, which can automatically weave your photos, videos and the places you visited into a beautiful travelogue.

No more sifting through photos for your best shots, racking your brain for the sights you saw, or letting your videos collect virtual dust. We’ll just gift you a story after you get home. This way you can relive your favorite moments, share them with others, and remember why you traveled in the first place.

Stories will be available this week on Android and the web, with iOS coming soon. In the meantime you can browse my story below (click to start), or explore a few others by paraglider Tom de Dorlodot, DJ Steve Aoki and Allrecipes photographer Angela Sackett.

When it’s less about travel, and more about today's events (like a birthday party, or baby’s first steps), Google+ Movies can produce a highlight reel of your photos and videos automatically—including effects, transitions and a soundtrack. Today we’re bringing Movies to Android, iOS and the web, so lots more people will receive these video vignettes.