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Human hair chips away at a razor’s edge, engineers say

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human hair chips away at a razors edge engineers say

A shaving razor that doesn’t blunt could be on the horizon after scientists discover human hair can ‘chip’ metal blades, despite being 50 times softer than steel.

In shaving experiments, engineers closely studied shaving in ultra-fine detail with an electron microscope to see how a razor blade can be damaged as it cuts human hair.

Despite hair’s relative softness in comparison to the strength of steel, the edge of the blade dulls quickly after a few short shaves. 

Defects in the steel’s microscopic structure combined with the angle of a shave can chip the blade even with a single stroke, researchers reveal. 

The study suggests ways for current blade technology to be improved, thereby lengthening the lifetimes of commercial disposable razors and kitchen knives. 

Engineers at MIT have studied the simple act of shaving up close, observing how a razor blade can be damaged as it cuts human hair -- a material that is 50 times softer than the blade itself

Engineers at MIT have studied the simple act of shaving up close, observing how a razor blade can be damaged as it cuts human hair -- a material that is 50 times softer than the blade itself

Engineers at MIT have studied the simple act of shaving up close, observing how a razor blade can be damaged as it cuts human hair — a material that is 50 times softer than the blade itself 

A single strand of hair can cause the edge of a blade to chip under specific conditions, the engineers say. 

Once this initial crack forms, the blade is vulnerable to further chipping, and as more cracks accumulate around the initial chip, the razor’s edge can quickly dull. 

‘Our main goal was to understand a problem that more or less everyone is aware of – why blades become useless when they interact with much softer material,’ said study author C. Cem Tasan at the Massachusetts Institute of Technology (MIT). 

‘We found the main ingredients of failure, which enabled us to determine a new processing path to make blades that can last longer.’

How steel loses it edge upon cutting significantly softer materials like hair, despite being more than 50 times harder, had been poorly understood. 

Razors, scalpels and knives are commonly made from stainless steel, which is honed to give a a razor-sharp edge and coated with even harder materials such as diamond-like carbon to increase its lifespan. 

Metal under a scanning electron microscope. The researchers have filed a provisional patent on a process to manipulate steel to make longer-lasting blades

Metal under a scanning electron microscope. The researchers have filed a provisional patent on a process to manipulate steel to make longer-lasting blades

Metal under a scanning electron microscope. The researchers have filed a provisional patent on a process to manipulate steel to make longer-lasting blades

However, knives require regular sharpening and razors are routinely replaced, even when they’ve been cutting materials far softer than the blades themselves.   

Researchers explored the microstructure of metals in order to design new materials with better damage-resistance. 

‘We are metallurgists and want to learn what governs the deformation of metals, so that we can make better metals,’ Tasan said. 

‘In this case, it was intriguing that, if you cut something very soft, like human hair, with something very hard, like steel, the hard material would fail.’  

Tasan’s colleague, MIT graduate student Gianluca Roscioli, first carried out some initial shaving experiments.

He used martensitic stainless-steel blades, which are typical of standard commercial disposable safety razor cartridges. 

WHAT IS A SCANNING ELECTRON MICROSCOPE (SEM)?

Scanning electron microscope (SEM) uses a focused beam of high-energy electrons to generate a variety of signals at the surface of solid specimens. 

The signals reveal information about the sample including texture, chemical composition, crystalline structure and orientation of materials in a sample. 

Areas ranging from approximately 1 cm to 5 microns in width can be imaged in a scanning mode using conventional SEM techniques.  

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Martensitic stainless steel is a type of alloy that can be hardened and tempered, such as with heat treatment. 

Generally, blade material is heterogeneous (made of two or more constituents) carbide-rich stainless steel, with a high chromium content used to form carbides and make the steel stainless.  

Using the disposable razors on his own face, Roscioli took images of the razor’s edge with a scanning electron microscope (SEM) to track how the blade wore down after every shave. 

While the experiments revealed little wear in terms of a rounding-out of the blade, he noticed chips forming along certain regions of the razor’s edge.  

‘This created another mystery – we saw chipping, but didn’t see chipping everywhere, only in certain locations,’ Tasan said. 

‘And we wanted to understand, under what conditions does this chipping take place, and what are the ingredients of failure?’

Roscioli then built a small, mechanical apparatus to carry out more controlled shaving experiments, consisting of a movable stage with two clamps on either side – one to hold a razor blade and the other to anchor strands of hair.  

The apparatus is designed to fit inside a scanning electron microscope, where Roscioli was able to take high-resolution images of both the hair and the blade as he carried out multiple cutting experiments. 

He used his own hair, as well as hair sampled from several of his labmates, representing ‘a wide range of hair diameters’.

He used blades from commercial razors, which he set at various angles and cutting depths to mimic the act of shaving. 

Roscioli observed the same mechanism by which hair damaged a blade – and just as in the initial shaving experiments, hair caused the blade’s edge to chip, but only in certain spots. 

After analysing the SEM images, he found chips did not occur when the hair was cut perpendicular to the blade, and when the hair was free to bend, chips were more likely to occur.

These chips most commonly formed in places where the blade edge met the sides of the hair strands. 

In yet another stage of experiments, the team ran computational simulations in which they modelled a steel blade cutting through a single hair. 

Using martensitic stainless-steel blades - those typical of standard commercial disposable safety razor cartridges - and human hair, Gianluca Roscioli and colleagues performed a series of cutting experiments and ­in situ­ electron microscopy to observe the evolution of blade wear

Using martensitic stainless-steel blades - those typical of standard commercial disposable safety razor cartridges - and human hair, Gianluca Roscioli and colleagues performed a series of cutting experiments and ­in situ­ electron microscopy to observe the evolution of blade wear

Using martensitic stainless-steel blades – those typical of standard commercial disposable safety razor cartridges – and human hair, Gianluca Roscioli and colleagues performed a series of cutting experiments and ­in situ­ electron microscopy to observe the evolution of blade wear

As they simulated each hair shave, they altered certain conditions, such as the cutting angle, the direction of the force applied in cutting and the composition of the blade’s steel.

Simulations predicted failure under three conditions – when the blade approached the hair at an angle, when the blade’s steel was heterogeneous in composition (made of two or more constituents) and when the edge of a hair strand met the blade at a weak point in its structure.  

The problem with the razors was defined as ‘stress intensification’, in which the effect of a stress applied to a material is intensified if the material’s structure has micro-cracks. 

Once an initial micro-crack forms, the material’s heterogeneous structure enabled these cracks to easily grow to chips. 

The findings also apply to the sharpness of a kitchen knife’s blade – for instance, when slicing vegetables, a chef might consider cutting straight down, rather than at an angle.     

‘Our simulations explain how heterogeneity in a material can increase the stress on that material, so that a crack can grow, even though the stress is imposed by a soft material like hair,’ said Tasan.

The researchers have filed a patent on a process to manipulate steel into a more homogenous form, in order to make longer-lasting, more chip-resistant blades.

When slicing vegetables, a chef might consider cutting straight down, rather than at an angle, to preserve a knife's sharpness

When slicing vegetables, a chef might consider cutting straight down, rather than at an angle, to preserve a knife's sharpness

When slicing vegetables, a chef might consider cutting straight down, rather than at an angle, to preserve a knife’s sharpness

When designing longer-lasting, more chip-resistant blades, manufacturers might consider making knives from more homogenous materials at the cutting edge, such as with nanostructured alloys. 

‘The basic idea is to reduce this heterogeneity, while we keep the high hardness,’ Roscioli said.

‘We’ve learned how to make better blades, and now we want to do it.’ 

The study has been published in the journal Science

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Twitter goes down for more than an hour leaving thousands of users unable to access the platform

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twitter goes down for more than an hour leaving thousands of users unable to access the platform

More than 50,000 Twitter users were unable to access the website and app versions of the social media platform Thursday morning due to a worldwide outage.

Down Detector showed the outage started around 9:30am ET and was plaguing parts of the US, Europe and Asia.

Many users were met with an ‘error message’ when logging in, along with a blank news feed that only reads ‘try again’ and disabled features – all of which hindered their ability to share tweets. 

The peak of the outage hit around 10am ET, but much of the service was restored around 10:45am ET – some Twitter users may still be experiencing issues. 

More than 50,000 Twitter users were unable to access the website and app versions of the social media platform Thursday morning due to a worldwide outage. Down Detector showed the outage started around 9:30am ET and was plaguing parts of the US, Europe and Asia

More than 50,000 Twitter users were unable to access the website and app versions of the social media platform Thursday morning due to a worldwide outage. Down Detector showed the outage started around 9:30am ET and was plaguing parts of the US, Europe and Asia

More than 50,000 Twitter users were unable to access the website and app versions of the social media platform Thursday morning due to a worldwide outage. Down Detector showed the outage started around 9:30am ET and was plaguing parts of the US, Europe and Asia 

Typically when one social media site experiences an outage, users flock to Twitter to share their frustrations or ask if anyone else is having problems.

But when Twitter went down, the world may be in a frenzy.

DailyMail.com has reached out to Twitter for comment and has yet to receive a response. 

Down Detector, a platform that monitors website and online service outages, is one of the only places the public can go to check on the outage when Twitter is down. 

The outage appeared around 9:30am and is located in the US, the UK and Japan - other countries in Europe, Asia and South American are also reporting issues

The outage appeared around 9:30am and is located in the US, the UK and Japan - other countries in Europe, Asia and South American are also reporting issues

The outage appeared around 9:30am and is located in the US, the UK and Japan – other countries in Europe, Asia and South American are also reporting issues

Many users were met with an 'error message' when logging in, along with a blank news feed that only reads 'try again' and disabled features - all of which hindered their ability to share tweets

Many users were met with an 'error message' when logging in, along with a blank news feed that only reads 'try again' and disabled features - all of which hindered their ability to share tweets

Many users were met with an ‘error message’ when logging in, along with a blank news feed that only reads ‘try again’ and disabled features – all of which hindered their ability to share tweets 

The majority of the outage was plaguing the website, but users reported issues with the iOS and Android apps. 

Down Detector’s outage map showed a number of major cities in the US as red, including Seattle, San Francisco, Washington  DC and New York City.

Twitter also went down in Japan, parts of India and Indonesia, along with countries in Europe.

Users shared their frustrations on Down Detector about Twitter going down so early in the day.

Users have shared their frustrations on Down Detector about Twitter going down so early in the day. One user joke that without the site, all they can do is look at the wall

Users have shared their frustrations on Down Detector about Twitter going down so early in the day. One user joke that without the site, all they can do is look at the wall

Users have shared their frustrations on Down Detector about Twitter going down so early in the day. One user joke that without the site, all they can do is look at the wall

Another took this time to take a dig at liberals: 'I hope they fix it by 11:30AM when all the white liberals start rolling out of bed... they have some very important hashtags to tweet out today to save all the helpless minorities they are trying to rescue'

Another took this time to take a dig at liberals: 'I hope they fix it by 11:30AM when all the white liberals start rolling out of bed... they have some very important hashtags to tweet out today to save all the helpless minorities they are trying to rescue'

Another took this time to take a dig at liberals: ‘I hope they fix it by 11:30AM when all the white liberals start rolling out of bed… they have some very important hashtags to tweet out today to save all the helpless minorities they are trying to rescue’

One user joked that without the site, all they can do is look at the wall.

Another took this time to take a dig at liberals: ‘I hope they fix it by 11:30AM when all the white liberals start rolling out of bed… they have some very important hashtags to tweet out today to save all the helpless minorities they are trying to rescue.’

The peak of the outage was around 10am ET, but service was coming back shortly after, with reports decreasing about 45 minutes later.

This post first appeared on dailymail.co.uk

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Twitter is DOWN! Thousands of users across the world are unable to access the social media platform

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twitter is down thousands of users across the world are unable to access the social media platform

 If you are having issues with Twitter, you are not the only one – more than 40,000 users across the world are experiencing problems with the social media platform.

The social media site is experiencing an outage that seems to be hitting the website and apps on both iOS and Android.

The outage appeared around 9:30am and is located in the US, the UK and Japan – other countries in Europe, Asia and South American are also reporting issues.

Many users have been met with an ‘error message’ when logging in, along with a blank news feed. 

If you are having issues with Twitter, you are not the only one. The social media site is experiencing an outage that seems to be hitting the website and apps on both iOS and Android

If you are having issues with Twitter, you are not the only one. The social media site is experiencing an outage that seems to be hitting the website and apps on both iOS and Android

Typically when one social media site experiences an outage, users flock to Twitter to share their frustrations or ask if anyone else is having problems.

But with Twitter down, the world may be in a frenzy.

Down Detector, a platform that monitors website and online service outages, is one of the only places the public can go to check on the outage.

The outage report shows more than 48,000 people have reported issues with Twitter, which started flowing in around 9:30am ET.

The outage appeared around 9:30am and is located in the US, the UK and Japan - other countries in Europe, Asia and South American are also reporting issues. Many users have been met with an 'error message' when logging in, along with a blank news feed

The outage appeared around 9:30am and is located in the US, the UK and Japan – other countries in Europe, Asia and South American are also reporting issues. Many users have been met with an ‘error message’ when logging in, along with a blank news feed

Approximately 49 percent are experiencing issues with the website, 35 percent noted problems with Twitter on an iOS devices and 15 percent on the Android app.

Down Detector’s outage map shows a number of major cities in the US as red, including Seattle, San Francisco, Washington  DC and New York City.

Twitter has also gone down in Japan, parts of India and Indonesia.

This post first appeared on dailymail.co.uk

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Nuclear fusion reactor could be producing electricity within a decade 

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nuclear fusion reactor could be producing electricity within a decade

A tennis court-sized nuclear fusion reactor being developed in the US could be producing electricity within a decade, backers claim.  

The SPARC nuclear fusion reactor, a joint project involving Massachusetts Institute of Technology, is expected to begin construction on June 21 next year and take three or four years until completion.

It is hoped that SPARC will demonstrate energy gain from fusion for the first time in history by 2025, and be producing fusion energy to generate electricity to power nearby cities within 10 years. 

Nuclear fusion power works by colliding heavy hydrogen atoms to form helium, releasing vast amounts of energy, mimicking the process that occurs naturally in the centre of stars like our Sun. 

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SPARC, which is on track to begin construction in 2021 and demonstrate net energy gain from fusion for the first time in history by 2025. Pictured, artists' impression of the reactor with a human for scale

SPARC, which is on track to begin construction in 2021 and demonstrate net energy gain from fusion for the first time in history by 2025. Pictured, artists’ impression of the reactor with a human for scale

Fusion could eventually combat climate change by replacing energy sources that emit greenhouse gases, such as coal and gas. 

Fusion also provides cheap, clean and safe energy without radioactive waste, or the risk of meltdown. 

SPARC will pave the way for the first commercially viable fusion power plant, called ARC. 

MIT said limitations imposed by the Covid-19 pandemic have only slightly slowed progress on SPARC and researchers are back in the labs under new operating guidelines. 

‘The work is progressing smoothly and on track,’ said MIT, which is working with Cambridge, Massachusetts-based company Commonwealth Fusion Systems (CFS) on SPARC. 

A fusion power plant could provide clean, carbon-free energy with an essentially unlimited fuel supply. From the point of view of electrical power generation, the fusion device is just another heat source that could be used in a conventional thermal conversion cycle.

A fusion power plant could provide clean, carbon-free energy with an essentially unlimited fuel supply. From the point of view of electrical power generation, the fusion device is just another heat source that could be used in a conventional thermal conversion cycle. 

‘No unexpected impediments or surprises have shown up, and the remaining challenges appear to be manageable,’ it said in a statement.  

SPARC is set to be the first experimental device ever to achieve a ‘burning plasma’ – a self-sustaining fusion reaction in which different isotopes of the element hydrogen fuse together to form helium, without the need for any further input of energy. 

When deuterium and tritium nuclei – which can be found in hydrogen – fuse, they form a helium nucleus, a neutron and a lot of energy.

This is done by heating the fuel to temperatures in excess of 270,000,000°F (150,000,000°C) and forming a hot plasma – a gaseous soup of subatomic particles – held in place by magnets.

The strong magnetic fields are used to keep the plasma away from the reactor’s walls, so that it doesn’t cool down and lose its energy potential.

Fusion power works by colliding heavy hydrogen atoms to form helium - releasing vast amounts of energy in the process, as occurs naturally in the centre of stars

Fusion power works by colliding heavy hydrogen atoms to form helium – releasing vast amounts of energy in the process, as occurs naturally in the centre of stars

These fields are produced by superconducting coils surrounding the vessel and by an electrical current driven through the plasma.    

Information gathered from the behaviour of burning plasma is ‘crucial’ for developing the next step – a working prototype of a practical, power-generating power plant, the SPARC team said. 

Once this is up and running, key information can be gained that will help pave the way to commercial, power-producing fusion devices. 

Fuel running these devices – the hydrogen isotopes deuterium and tritium – can be made available in virtually limitless supplies. 

Work on the first stage of the SPARC project is the development of the superconducting magnets that would allow smaller fusion systems to be built. 

Fusion power plants are set to reduce greenhouse gas emissions from the power-generation sector, which is one of the major sources of these emissions globally.    

SPARC is designed to achieve what is called a Q factor – a key parameter denoting the efficiency of a fusion plasma – of at least two.

This essentially means that twice as much fusion energy is produced as the amount of energy pumped in to generate the reaction. 

Fusion joins two light elements (with a low atomic mass number), forming a heavier element, to generate energy. Pictured, artist's illustration (stock image)

Fusion joins two light elements (with a low atomic mass number), forming a heavier element, to generate energy. Pictured, artist’s illustration (stock image)

If realised, SPARC would be the first time a fusion plasma of any kind has produced more energy than it consumed. 

Computer calculations and simulation tools show SPARC could actually achieve a Q ratio of 10 or more, MIT claims.

A series of papers authored by 47 researchers from 12 institutions have been published in Journal of Plasma Physics summarising progress on SPARC. 

Together, the papers outline the theoretical and empirical physics basis for the new fusion system before it starts construction next year. 

‘The MIT group is pursuing a very compelling approach to fusion energy,’ said Chris Hegna, a professor of engineering physics at the University of Wisconsin at Madison, who was not connected to this work. 

‘They realised the emergence of high-temperature superconducting technology enables a high magnetic field approach to producing net energy gain from a magnetic confinement system. 

Pictured, one of two 800-tonne vacuum vessel assembly tools, as captured by the artist Luca Zanier, involved in the construction of the much larger ITER Tokamak reactor now being built in France

Pictured, one of two 800-tonne vacuum vessel assembly tools, as captured by the artist Luca Zanier, involved in the construction of the much larger ITER Tokamak reactor now being built in France

‘This work is a potential game-changer for the international fusion program​.’ 

The SPARC design would achieve fusion performance comparable to that expected in the much larger ITER Tokamak now being built in France. 

The Provence-based ITER project is expected to begin delivering power in 2035 – several years later than SPARC if all goes to plan for the US team. 

‘We’re really focused on how you can get to fusion power as quickly as possible,’ CFS CEO Bob Mumgaard told the New York Times.

SPARC would be far smaller than ITER – about the size of a tennis court, compared with a soccer field, Mumgaard said. 

High power in a small size is made possible by advances in superconducting magnets that allow for a much stronger magnetic field to confine the hot plasma, MIT said. 

DIFFERENCE BETWEEN NUCLEAR FUSION AND NUCLEAR FISSION 

 Both are nuclear processes, in that they involve nuclear forces to change the nucleus of atoms.

Fusion joins two light elements (with a low atomic mass number), forming a heavier element.

For fusion to occur, hydrogen atoms are placed under high heat and pressure until they fuse together.

Meanwhile, fission splits a heavy element (with a high atomic mass number) into fragments.

In both cases, energy is freed because the mass of the remaining nucleus is smaller than the mass of the reacting nuclei.

The reason why opposite processes release energy can be understood by examining the binding energy per nucleon curve. Both fusion and fission reactions shift the size of the reactant nuclei towards higher bounded nuclei.

Source: International Atomic Energy Agency  

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