Using Fungi to Fix Bridges

Small Cracks in Aging Concrete Can Lead to Costly Repairs
By Rachel Flores

January 8, 2018 -- America’s crumbling infrastructure has been a topic of ongoing discussion in political debates and campaign rallies. The problem of aging bridges and increasingly dangerous roads is one that has been well documented and there seems to be a consensus from both democrats and republicans that something must be done.

However, spending on infrastructure improvement has continually gone down. The New York Times reported in 2016, based on a report for the Bureau of Economic Analysis, that “in the 1950s and ’60s, federal, state and local governments were spending twice as much on the nation’s public infrastructure, relative to the size of the economy, as they are today.”

The hesitancy to invest in America’s infrastructure may come from a number of sources, but the fact remains that most want something to be done before the consequences are too severe.

Binghamton University assistant professor Congrui Jin has been working on this problem since 2013, and recently published her paper “Interactions of fungi with concrete: significant importance for bio-based self-healing concrete” in the academic journal Construction & Building Materials.

This research is the first application of fungi for self-healing concrete, a low-cost, pollution-free and sustainable approach.

Why is infrastructure crumbling?

Jin’s studies have looked specifically at concrete and found that the problem stems from the smallest of cracks in the concrete.

“Without proper treatment, cracks tend to progress further and eventually require costly repair,” said Jin. “If micro-cracks expand and reach the steel reinforcement, not only the concrete will be attacked, but also the reinforcement will be corroded, as it is exposed to water, oxygen, possibly CO2 and chlorides, leading to structural failure.”

These cracks can cause huge and sometimes unseen problems for infrastructure. One potentially critical example is the case of nuclear power plants that may use concrete for radiation shielding.

What can be done?

While remaking a structure would replace the aging concrete, this would only be a short-term fix until more cracks again spring up. Jin wanted to see if there was a way to fix the concrete permanently.

“This idea was originally inspired by the miraculous ability of the human body to heal itself of cuts, bruises and broken bones,” said Jin. “For the damaged skins and tissues, the host will take in nutrients that can produce new substitutes to heal the damaged parts.”

Jin worked with associate professor Ning Zhang from Rutgers University, and professor Guangwen Zhou and associate professor David Davies from Binghamton University with support from the Research Foundation for the State University of New York’s Sustainable Community Transdisciplinary Area of Excellence Program. Together, the team set out to find a way to heal concrete.

The team found an unusual answer, a fungus called Trichoderma reesei.

When this fungus is mixed with concrete, it originally lies dormant — until the first crack appears.

“The fungal spores, together with nutrients, will be placed into the concrete matrix during the mixing process. When cracking occurs, water and oxygen will find their way in. With enough water and oxygen, the dormant fungal spores will germinate, grow and precipitate calcium carbonate to heal the cracks,” explained Jin.

“When the cracks are completely filled and ultimately no more water or oxygen can enter inside, the fungi will again form spores. As the environmental conditions become favorable in later stages, the spores could be wakened again.”

The research is still in fairly early stages with the biggest issue being the survivability of the fungus within the harsh environment of concrete. However, Jin is hopeful that with further adjustments the Trichoderma reesei will be able to effectively fill the cracks.

“There are still significant challenges to bring an efficient self-healing product to the concrete market. In my opinion, further investigation in alternative microorganisms such as fungi and yeasts for the application of self-healing concrete becomes of great potential importance,” said Jin.

           https://www.binghamton.edu/news/story/938/using-fungi-to-fix-bridges

Vanishing European Forests

Europe’s Lost Forests – Study Shows
Coverage Has Halved over Six Millennia
Academics in Sweden, Germany, France, Estonia and Switzerland sought to establish how the nature of Europe’s forests has changed over 11,000 years
By Alan Williams, University of Plymouth

January 15, 2018 -- More than half of Europe’s forests have disappeared over the past 6,000 years thanks to increasing demand for agricultural land and the use of wood as a source of fuel, new research led by the University of Plymouth suggests.

Using pollen analysis from more than 1,000 sites, scientists showed that more than two thirds of central and northern Europe would once have been covered by trees.

Today, that is down to around a third, although in more western and coastal regions, including the UK and Republic of Ireland, the decline has been far greater with forest coverage in some areas dropping below 10 per cent.

However, those downward trends have begun to reverse, through the discovery of new types of fuel and building techniques, but also through ecological initiatives such as the ongoing National Forest project and the new Northern Forest, announced by the UK Government in January 2018.

The study is published in Nature’s Scientific Reports and lead author Neil Roberts, Professor of Physical Geography at the University of Plymouth, said:

“Most countries go through a forest transition and the UK and Ireland reached their forest minimum around 200 years ago. Other countries in Europe have yet to reach that point, and some parts of Scandinavia – where there is not such a reliance on agriculture – are still predominantly forest. But generally, forest loss has been a dominant feature of Europe’s landscape ecology in the second half of the current interglacial, with consequences for carbon cycling, ecosystem functioning and biodiversity.”

The research, which also involved academics in Sweden, Germany, France, Estonia and Switzerland, sought to establish precisely how the nature of Europe’s forests has changed over the past 11,000 years.

It combined three different methods of analysing pollen data, taken from the European Pollen Database, and showed that forest coverage actually increased from around 60 per cent 11,000 years ago up to as much as 80 per cent 6,000 years ago.

However, the introduction of modern farming practices during the Neolithic period sparked a gradual decline which accelerated towards the end of the Bronze Age and has largely continued until the present day.

Professor Roberts said this was one of the more surprising elements of the research because while forest clearance might be assumed to be a relatively recent phenomena, 20 per cent of Britain’s forests had actually gone by the end of the Bronze Age 3,000 years ago. He added:

“Around 8,000 years ago, a squirrel could have swung tree to tree from Lisbon to Moscow without touching the ground. Some may see that loss as a negative but some of our most valued habitats have come about through forests being opened up to create grass and heathland. Up until around 1940, a lot of traditional farming practices were also wildlife friendly and created habitats many of our most loved creatures. This data could then potentially be used to understand how future forestry initiatives might also influence habitat change.”

The full study – Europe’s lost forests: a pollen-based synthesis for the last 11,000 years – can be viewed in Scientific Reports doi: 10.1038/s41598-017-18646-7.

https://www.plymouth.ac.uk/news/europes-lost-forests-study-shows-coverage-has-halved-over-six-millennia

The Ugly Duckling Parable

"The Ugly Duckling" (Danish: Den grimme ælling) is a literary fairy tale by Danish poet and author Hans Christian Andersen (1805–1875). The story tells of a homely little bird born in a barnyard who suffers abuse from the others around him until, much to his delight (and to the surprise of others), he matures into a beautiful swan, the most beautiful bird of all. The story is beloved around the world as a tale about personal transformation for the better. “The Ugly Duckling” was first published 11 November 1843, with three other tales by Andersen in Copenhagen, Denmark to great critical acclaim. The tale has been adapted to various media including opera, musical, and animated film. The tale is completely Andersen's invention and owes no debt to fairy tales or folklore.

                                                        Ugly Duckling illustration

                                                            by Wilhelm Pedersen

Plot Summary

When the tale begins, a mother [duck's eggs hatch. One of the little birds is perceived by the other birds and animals on the farm as a homely little creature and suffers much verbal and physical abuse from them. He wanders sadly from the barnyard and lives with wild ducks and geese until hunters slaughter the flocks. He finds a home with an old woman, but her cat and hen tease and taunt him mercilessly and once again he sets off alone.

The duckling sees a flock of migrating wild swans. He is delighted and excited, but he cannot join them, for he is too young and cannot fly. Winter arrives. A farmer finds and carries the freezing little duckling home, but the foundling is frightened by the farmer’s noisy children and flees the house. He spends a miserable winter alone in the outdoors, mostly hiding in a cave on the lake that partly freezes over. When spring arrives a flock of swans descends on the now thawing lake.

The ugly duckling, now having fully grown and matured, unable to endure a life of solitude and hardship any more and decides to throw himself at the flock of swans deciding that it is better to be killed by such beautiful birds than to live a life of ugliness and misery. He is shocked when the swans welcome and accept him, only to realize by looking at his reflection in the water that he has grown into one of them. The flock takes to the air, and the now beautiful swan spreads his gorgeous large wings and takes flight with the rest of his new kind family.

Commentaries and Criticism

In reviewing Hans Christian Andersen: A New Life by biographer Jens Andersen, British journalist Anne Chisholm writes “Andersen himself was a tall, ugly boy with a big nose and big feet, and when he grew up with a beautiful singing voice and a passion for the theater he was cruelly teased and mocked by other children". The ugly duckling is the child of a swan whose egg accidentally rolled into a duck's nest.

Speculation suggests that Andersen was the illegitimate son of Prince Christian Frederik (later King Christian VIII of Denmark), and found this out some time before he wrote the book, and then that being a swan in the story was a metaphor not just for inner beauty and talent but also for secret royal lineage.

Bruno Bettelheim observes in The Uses of Enchantment that the Ugly Duckling is not confronted with the tasks, tests, or trials of the typical fairy tale hero. “No need to accomplish anything is expressed in “The Ugly Duckling”. Things are simply fated and unfold accordingly, whether or not the hero takes some action.” In conjunction with Bettelheim’s assessment, Maria Tatar notes in ’’The Annotated Hans Christian Andersen’’ that Andersen suggests the Ugly Duckling‘s superiority resides in the fact that he is of a breed different from the barnyard rabble, and that dignity and worth, moral and aesthetic superiority are determined by nature rather than accomplishment.

According to Carole Rosen, the story was inspired in part by Andersen's friend Jenny Lind.

https://en.wikipedia.org/wiki/The_Ugly_Duckling

Improved Schrodinger Equation

Quantum Leap: Novel Computational Approach Launches
New Paradigm in Electronic Structure Theory

Michigan State University – January 12, 2018 -- A group of Michigan State University researchers specializing in quantum calculations has proposed a radically new computational approach to solving the complex many-particle Schrödinger equation, which holds the key to explaining the motion of electrons in atoms and molecules.

By understanding the details of this motion, one can determine the amount of energy needed to transform reactants into products in a chemical reaction, or the color of light absorbed by a molecule, and ultimately accelerate the design of new drugs and materials, better catalysts and more efficient energy sources.

The work, led by Piotr Piecuch, university distinguished professor in the Department of Chemistry and adjunct professor in the Department of Physics and Astronomy in the College of Natural Science, was published recently in  Physical Review Letters. Also involved in the work are fourth-year graduate student J. Emiliano Deustua and senior postdoctoral associate Jun Shen. The group provides details for a new way of obtaining highly accurate electronic energies by merging the deterministic coupled-cluster approaches and stochastic sampling using probability concepts.

“Instead of insisting on a single philosophy when solving the electronic Schrödinger equation, which has historically been either deterministic or stochastic, we have chosen a third way,” Piecuch said. “As one of the reviewers noted, the essence of it is remarkably simple: use the stochastic approach to determine what is important and the deterministic approach to determine the important, while correcting for the information missed by stochastic sampling.”

Solving the Schrödinger equation for the many-electron wave function has been a key challenge in quantum chemistry for decades. Anything other than a one-electron problem, such as a hydrogen atom, requires resorting to numerical methods, converted into sophisticated computer programs, such as those developed by Piecuch and his group. The main difficulty has been the intrinsic complexity of the electronic motion, which quantum chemists and physicists call “electron correlation.”

The new idea is to use the stochastic methods to identify the leading wave function components and the deterministic coupled-cluster computations, combined with suitable energy corrections, to provide the missing information. The merging of deterministic and stochastic approaches as a general method of solving the many-particle Schrödinger equation may also impact other areas, such as nuclear physics.

“In the case of nuclei, instead of being concerned with electrons, one would use our new approach to solve the Schrödinger equation for protons and neutrons,” Piecuch said. “The mathematical and computational issues are similar. Just like chemists want to understand the electronic structure of a molecule, nuclear physicists want to unravel the structure of the atomic nucleus. Once again, solving the many-particle Schrödinger equation holds the key.”

http://msutoday.msu.edu/news/2018/quantum-leap-novel-computational-approach-launches-new-paradigm-in-electronic-structure-theory/

Wilson "Snowflake" Bentley

Wilson Alwyn "Snowflake" Bentley (February 9, 1865 – December 23, 1931) is one of the first known photographers of snowflakes. He perfected a process of catching flakes on black velvet in such a way that their images could be captured before they either melted or sublimated.

                                                   Snowflake photos by Bentley, c. 1902 

Kenneth G. Libbrecht notes that the techniques used by Bentley to photograph snowflakes are essentially the same as used today, and that while the quality of his photographs reflects the technical limitations of the equipment of the era, "he did it so well that hardly anybody bothered to photograph snowflakes for almost 100 years". The broadest collection of Bentley's photographs is held by the Jericho Historical Society in his home town, Jericho, Vermont.

Bentley donated his collection of original glass-plate photomicrographs of snow crystals to the Buffalo Museum of Science. A portion of this collection has been digitized and organized into a digital library.

Biography of Bentley

Bentley was born on February 9, 1865, in Jericho, Vermont. He first became interested in snow crystals as a teenager on his family farm. He tried to draw what he saw through an old microscope given to him by his mother when he was fifteen. The snowflakes were too complex to record before they melted, so he attached a bellows camera to a compound microscope and, after much experimentation, photographed his first snowflake on January 15, 1885.

He would capture more than 5,000 images of crystals in his lifetime. Each crystal was caught on a blackboard and transferred rapidly to a microscope slide. Even at subzero temperatures, snowflakes are ephemeral because they sublime [pass directly from a solid state to a gaseous state without melting into a liquid].

Bentley poetically described snowflakes as "tiny miracles of beauty" and snow crystals as "ice flowers." Despite these poetic descriptions, Bentley brought a highly objective eye to his work, similar to the German photographer Karl Blossfeldt (1865–1932), who photographed seeds, seed pods, and foliage.

In collaboration with George Henry Perkins, professor of natural history at the University of Vermont, Bentley published an article in which he argued that no two snowflakes were alike. This concept caught the public imagination and he published other articles in magazines, including National Geographic, Nature, Popular Science, and Scientific American. His photographs have been requested by academic institutions worldwide.

In 1931 Bentley worked with William J. Humphreys of the U.S. Weather Bureau to publish Snow Crystals, a monograph illustrated with 2,500 photographs. His other publications include the entry on "snow" in the fourteenth edition of Encyclopædia Britannica.

Bentley also photographed all forms of ice and natural water formations including clouds and fog. He was the first American to record raindrop sizes, and was one of the first cloud physicists.

He died of pneumonia at his farm on December 23, 1931, after walking home six miles in a blizzard. Bentley was memorialized in the naming of a science center in his memory at Johnson State College in Johnson, Vermont. His book Snow Crystals was published by McGraw-Hill shortly before his death, and is still in print today. Bentley's lifelong home is listed on the National Register of Historic Places.

                            https://en.wikipedia.org/wiki/Wilson_Bentley

False Missile Alert in Hawaii

On January 13, 2018, a false missile alert was issued via the Emergency Alert System and Commercial Mobile Alert System over television, radio, and cellphones in the U.S. state of Hawaii. The alert stated that there was a ballistic missile threat to Hawaii, advised residents to seek shelter, and stated "this is not a drill". The message was sent at 8:07 a.m. HST. Almost 40 minutes later, a second message was sent describing the first as a "false alarm". State officials later blamed a button pushed in error during a shift change at the Hawaii Emergency Management Agency for the false first message.

Governor David Ige publicly apologized for the erroneous alert, which caused panic and disruptions throughout the state. The U.S. Federal Communications Commission and the Hawaii House of Representatives immediately announced investigations into the incident.

Background

Escalating tensions between North Korea and the U.S. government, including threats by both countries that they could use nuclear weapons against one another, prompted a heightened state of readiness in Hawaii. The state is believed to be within range of North Korea's missile capability; a missile launched from North Korea would leave Hawaii residents 12 to 20 minutes to prepare once the alarm sounds. North Korean newspaper Rodong Sinmun claimed in July 2017 that North Korea possessed the capability to strike either Hawaii or the U.S. state of Alaska. The threat from North Korea was the topic of a conference at the Hawaii State Capitol on January 12, the day before the false alert was sent.

In December 2017, a nuclear threat siren was tested in Hawaii for the first time in more than 30 years. Vern Miyagi, administrator of the Hawaii Emergency Management Agency, explained that state leaders "couldn’t ignore these constant threats and missile tests from North Korea" and felt the need to prepare residents for the possibility of an attack. Officials also outlined what would happen if an emergency alert were sent: a push alert to smartphones and a message interrupting television and radio broadcasts.

Earlier in January 2018, U.S. Federal Communications Commission chairman Ajit Pai said the commission planned to vote to overhaul the wireless emergency alert system. Recode reported that Pai's proposed reforms were intended to narrow down the number of people who received alerts, confining emergency notifications to a more specific geographic area, to prevent mass panic and reduce incidences of people switching off their device's ability to receive emergency alerts.

Incident

People in Hawaii reported seeing the alert at about 8:07 a.m. HST on their smartphones. Many screenshots of the push alert were shared on social media platforms, such as Twitter. The alert read, in all capital letters:

"BALLISTIC MISSILE THREAT INBOUND TO HAWAII. SEEK IMMEDIATE SHELTER. THIS IS NOT A DRILL."

Local television broadcasts, including a college basketball game between Florida and Ole Miss being shown on CBS and a Premier League match between Tottenham Hotspur and Everton on NBC, were also interrupted by a similar alert message. The alert message on television broadcasts took the form of both an audio message and a scrolling banner. It stated in part:

"If you are outdoors, seek immediate shelter in a building. Remain indoors well away from windows. If you are driving, pull safely to the side of the road and seek shelter in a nearby building or lie on the floor. We will announce when the threat has ended."

An alert message also interrupted radio broadcasts in the state. In Lihue, a resident reported hearing a message on the radio advising of "an incoming missile warning for the islands of Kauai and Hawaii".

Vern Miyagi, the administrator of the Hawaii Emergency Management Agency, later said the alert had been inadvertently triggered by an agency employee during a shift change. He said the emergency message was sent after the employee, whose name was not released, clicked the wrong button while running a test of the state's ballistic missile preparations and then clicked through a second screen, which had been intended as a safeguard, to confirm.

State Response

By 8:10 a.m. HST, officials later said, Hawaii National Guard Adjutant General Arthur "Joe" Logan had contacted U.S. Pacific Command and confirmed there had been no missile launch. At that time, the Honolulu Police Department was notified that the alert had been a false alarm. Officials used the State Warning Point system at 8:13 a.m. to cancel the alert, preventing it from being sent out to any phones that had not already received it, such as those that were switched off or did not have reception.

Official messages refuting the emergency alert were not sent out until 8:20 a.m., according to the timeline released by officials after the incident. Hawaii Emergency Management Agency accounts on Facebook and Twitter posted messages at that time urging people to disregard the erroneous alert. Governor David Ige retweeted the HEMA message on Twitter and posted a similar message on Facebook minutes later to notify followers that the alert had been canceled. An email from the state was also sent about 25 minutes after the first alert advising that it was not correct.

Second alert

At 8:45 a.m. HST, 38 minutes after the initial alert was sent to smartphones in Hawaii, a second emergency alert was sent. The message described the first message as a "false alarm" and stated:

"There is no missile threat or danger to the State of Hawaii."

The second alert was sent "well after everyone from Hawaii’s congressional delegation to the U.S. Pacific Command had assured the world on Twitter that it was a false alarm", Pacific Business News remarked.

Governor David Ige explained at a news conference that afternoon that officials "had to initiate a manual process" and obtain authorization from the Federal Emergency Management Agency in order to send the second alert, because there was no automated way to cancel the first alert. Those procedures accounted for the delay more than 30 minutes after officials had confirmed internally that the alert was inaccurate, according to officials.

Impact and Related Panicking

During the 38 minutes between the first and second alerts, Hawaii's siren warning system — which had been tested as part of a missile preparedness exercise the previous month for the first time since the Cold War — was not activated. Little to no activity was reported at military bases in the state. Some commercial flights were reportedly delayed for a short time, although the Hawaii Department of Transportation said there were no widespread impacts at the state's airports and harbors.

Disruptions were reported across the state. Honolulu Civil Beat reported that motorists parked inside the Interstate H-3 tunnel on the island of Oahu for shelter. Hawaii News Now reported that alarms sounded at Aloha Gymfest, an international gymnastics meet in Kailua, sending hundreds of people running for cover. Officials at the Sony Open PGA Tour golf tournament on Oahu ordered an evacuation of the media center, while staff members sought cover in the kitchen and players' locker room. Tourists at Kualoa Ranch in Kaneohe were reportedly taken up to a concrete bunker in the mountains by staff and told to shelter in place there. Congresswoman Colleen Hanabusa later said her husband had been driving on a Honolulu-area freeway and saw cars speeding at up to 100 miles per hour (160 km/h) after the alert was sent out. Many Hawaii residents and visitors sought shelter or rushed through emergency preparations where they were. Others observed that there were no sirens, or that there was no immediate coverage on televisions or local radio.

The incident also created a strain on Hawaii's telephone system. Civil Defense offices in Hawaii were inundated with calls from frightened residents asking for advice or more information, the New Zealand Herald reported. Many calls to 9-1-1 would not go through. Many wireless data services were likewise initially jammed, leaving many unable to access the Internet to confirm whether the alarm was real. Some residents called friends or family members to say goodbye.

Responses to the Alert

Twitter posts and screenshots of text messages shared on social media in the immediate wake of the first alert conveyed confusion, alarm, and fear among those who received the warning.

Federal officials:  Members of Hawaii's congressional delegation also took to Twitter to dispel the false alarm. Congresswoman Tulsi Gabbard tweeted at 8:19 a.m. HST, about 12 minutes after the initial alert was sent, stating in all capitals that the message was a "false alarm" and that she had confirmed with officials that there was no incoming ballistic missile toward Hawaii. Congresswoman Colleen Hanabusa, a 2018 candidate for governor, later tweeted that the "panic and fear created by this false alarm was very dangerous". Hanabusa panned the delay between the two emergency alerts, suggesting it should not have taken 38 minutes for the second message to be sent. Senator Mazie Hirono tweeted that officials "need to get to the bottom of what happened and make sure it never happens again". In his own tweets, Senator Brian Schatz described the false alarm as "totally inexcusable", adding,

"The whole state was terrified. There needs to be tough and quick accountability and a fixed process."

Commander David Benham, a spokesman for U.S. Pacific Command, confirmed to media that there was no imminent missile threat to Hawaii. A spokesman for North American Aerospace Defense Command (NORAD) stated that "NORAD did not see anything that indicated any sort of threat to Hawaii" and said NORAD and U.S. Northern Command were still verifying what had happened. A White House official said the alert had been part of "a state exercise" and President Donald Trump was briefed on the situation. Trump ordered National Security Advisor H.R. McMaster to take charge of the administration's response to the incident.

Ajit Pai, chairman of the U.S. Federal Communications Commission, announced the commission would launch a full investigation into the false alert.

Gabbard stated in an interview after the second emergency alert was sent that the incident was "a taste of the stark reality of what we face here of a potential nuclear strike on Hawaii", referring to the possibility of a North Korean attack

State officials:  Honolulu Mayor Kirk Caldwell also tweeted that the message had been a false alarm, saying the message had been sent in error, before the second alert was sent out by the Hawaii Emergency Management Agency.

Hawaii Emergency Management Agency administrator Vern Miyagi took responsibility for the incident. Miyagi described the initial warning as a "mistake", saying it "should have been caught" before the alert was sent out. A Hawaii Emergency Management Agency spokesman initially said the agency was running a drill at the time, although he noted that standard drills do not involve the sending of an emergency alert. He said the incident was being investigated but initial indications suggested it was "a technical issue". HEMA officials, including Miyagi, said there was no evidence that the agency's systems had been hacked to send the false emergency message.

Miyagi apologized for the false alert, as did Governor David Ige, who called the incident "unfortunate and regrettable". They said officials would review the state's procedures to prevent it from happening again. Ige said:

"I know first-hand how today's false alarm affected all of us here in Hawaii, and I am sorry for the pain and confusion it caused. I, too, am extremely upset about this and am doing everything I can do to immediately improve our emergency management systems, procedures and staffing."

Hawaii Senate Majority Leader J. Kalani English said he was "outraged" by the error, which caused unnecessary "panic and pandemonium" throughout the state. Hawaii House of Representatives Speaker Scott K. Saiki announced the House would investigate the incident:

"This system we have been told to rely upon failed and failed miserably today. I am deeply troubled by this misstep that could have had dire consequences. Measures must be taken to avoid further incidents that caused wholesale alarm and chaos today. Clearly, government agencies are not prepared and lack the capacity to deal with emergency situations. Apparently, the wrong button was pushed and it took over 30 minutes for a correction to be announced. Parents and children panicked during those 30 minutes. The Hawaii House of Representatives will immediately investigate what happened and there be consequences. This cannot happen again."

The deputy adjutant of the Hawaii National Guard said that notwithstanding the erroneous alert, people should continue to follow instructions and take shelter if another alert is sent in the future.

Aftermath

State officials held a news conference in the afternoon of January 13 to address the incident. Hawaii Emergency Management Agency head Vern Miyagi said the agency had suspended tests while assessing what had happened. He also announced it had immediately changed its procedures to require two people, instead of just one, to send out both test alerts and actual alerts. The agency also moved quickly to implement a cancellation command that officials said can be triggered within seconds of an erroneous alert being sent out, which it reportedly lacked before the January 13 incident.

A formal report is expected to be issued later in the month.

                          https://en.wikipedia.org/wiki/Hawaii_missile_alert

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See also

On February 1, 2005, the Emergency Alert System was activated in portions of Connecticut calling for the immediate evacuation of the entire state. The activation was in error. Later studies showed that residents did not evacuate, and that the most common response was to 'change the channel' or seek other confirmation.  More details at:

https://en.wikipedia.org/wiki/Emergency_Alert_System_misactivation_of_2005

Six Types of Solenoid

A solenoid (from the French solénoïde, derived in turn from the Greek solen ("pipe, channel") and eidos ("form, shape")) is a coil wound into a tightly packed helix. The term was invented by French physicist André-Marie Ampère to designate a helical coil.

                                                             Illustration of a Solenoid
In physics, the term refers to a coil whose length is substantially greater than its diameter, often wrapped around a metallic core, which produces a uniform magnetic field in a volume of space (where some experiment might be carried out) when an electric current is passed through it. A solenoid is a type of electromagnet when the purpose is to generate a controlled magnetic field. If the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet. Not all electromagnets and inductors are solenoids; for example, the first electromagnet, invented in 1824, had a horseshoe rather than a cylindrical solenoid shape.

In engineering, the term may also refer to a variety of transducer devices that convert energy into linear motion. The term is also often used to refer to a solenoid valve, which is an integrated device containing an electromechanical solenoid which actuates either a pneumatic or hydraulic valve, or a solenoid switch, which is a specific type of relay that internally uses an electromechanical solenoid to operate an electrical switch; for example, an automobile starter solenoid, or a linear solenoid, which is an electromechanical solenoid. Solenoid bolts, a type of electronic-mechanical locking mechanism, also exist.

Applications

Electromechanical solenoid

Electromechanical solenoids consist of an electromagnetically inductive coil, wound around a movable steel or iron slug (termed the armature). The coil is shaped such that the armature can be moved in and out of the center, altering the coil's inductance and thereby becoming an electromagnet. The armature is used to provide a mechanical force to some mechanism (such as controlling a pneumatic valve). Although typically weak over anything but very short distances, solenoids may be controlled directly by a controller circuit, and thus have very quick reaction times.

The force applied to the armature is proportional to the change in inductance of the coil with respect to the change in position of the armature, and the current flowing through the coil (see Faraday's law of induction). The force applied to the armature will always move the armature in a direction that increases the coil's inductance.

Electromechanical solenoids are commonly seen in electronic paintball markers, pinball machines, dot matrix printers and fuel injectors. Some residential doorbells use electromechanical solenoids to hit metal chime bars.

Proportional Solenoid - Included in this category of solenoids are the uniquely designed magnetic circuits that effect analog positioning of the solenoid plunger or armature as a function of coil current. These solenoids, whether axial or rotary, employ a flux carrying geometry that both produces a high starting force (torque), and has a section that quickly begins to saturate magnetically. The resulting force (torque) profile as the solenoid progresses through its operational stroke is nearly flat or descends from a high to a lower value. The solenoid can be useful for positioning, stopping mid-stroke, or for low velocity actuation; especially in a closed loop control system. A uni-directional solenoid would actuate against an opposing force or a dual solenoid system would be self cycling. The proportional concept is more fully described in SAE publication 860759 (1986).

Rotary Solenoid

The rotary solenoid is an electromechanical device used to rotate a ratcheting mechanism when power is applied. These were used in the 1950s for rotary snap-switch automation in electromechanical controls. Repeated actuation of the rotary solenoid advances the snap-switch forward one position. Two rotary actuators on opposite ends of the rotary snap-switch shaft, can advance or reverse the switch position.

The rotary solenoid has a similar appearance to a linear solenoid, except that the core is mounted in the center of a large flat disk, with two or three inclined grooves cut into the underside of the disk. These grooves align with slots on the solenoid body, with ball bearings in the grooves.

When the solenoid is activated, the core is drawn into the coil, and the disk rotates on the ball bearings in the grooves as it moves towards the coil body. When power is removed, a spring on the disk rotates it back to its starting position, also pulling the core out of the coil.

The rotary solenoid was invented in 1944 by George H. Leland, of Dayton, Ohio, to provide a more reliable and shock/vibration tolerant release mechanism for air-dropped bombs. Previously used linear (axial) solenoids were prone to inadvertent releases. U.S. Patent number 2,496,880 describes the electromagnet and inclined raceways that are the basis of the invention. Leland's engineer, Earl W. Kerman, was instrumental in developing a compatible bomb release shackle that incorporated the rotary solenoid. Bomb shackles of this type are found in a B-29 aircraft fuselage on display at the National Museum of the USAF in Dayton, Ohio. Solenoids of this variety continue to be used in countless modern applications, and are still manufactured under Leland's original brand "Ledex", now owned by Johnson Electric.

Rotary Voice Coil

A rotary voice coil is a rotational version of a solenoid. Typically the fixed magnet is on the outside, and the coil part moves in an arc controlled by the current flow through the coils. Rotary voice coils are widely employed in devices such as disk drives. The working part of a moving coil meter is also a type of rotary voice coil that pivots around the pointer axis, a hairspring is usually used to provide a weak nearly linear restoring force.

Pneumatic Solenoid Valve

A pneumatic solenoid valve is a switch for routing air to any pneumatic device, usually an actuator, allowing a relatively small signal to control a large device. It is also the interface between electronic controllers and pneumatic systems.

Hydraulic Solenoid Valve

Hydraulic solenoid valves are in general similar to pneumatic solenoid valves except that they control the flow of hydraulic fluid (oil), often at around 3000 psi (210 bar, 21 MPa, 21 MN/m²). Hydraulic machinery uses solenoids to control the flow of oil to rams or actuators. Solenoid-controlled valves are often used in irrigation systems, where a relatively weak solenoid opens and closes a small pilot valve, which in turn activates the main valve by applying fluid pressure to a piston or diaphragm that is mechanically coupled to the main valve. Solenoids are also in everyday household items such as washing machines to control the flow and amount of water into the drum.

Transmission solenoids control fluid flow through an automatic transmission and are typically installed in the transmission valve body.

Automobile Starter Solenoid

In a car or truck, the starter solenoid is part of an automobile starting system. The starter solenoid receives a large electric current from the car battery and a small electric current from the ignition switch. When the ignition switch is turned on (i.e. when the key is turned to start the car), the small electric current forces the starter solenoid to close a pair of heavy contacts, thus relaying the large electric current to the starter motor.

Starter solenoids can also be built into the starter itself, often visible on the outside of the starter. If a starter solenoid receives insufficient power from the battery, it will fail to start the motor, and may produce a rapid 'clicking' or 'clacking' sound. This can be caused by a low or dead battery, by corroded or loose connections in the cable, or by a broken or damaged positive (red) cable from the battery. Any of these will result in some power to the solenoid, but not enough to hold the heavy contacts closed, so the starter motor itself never spins, and the engine doesn't start.

                                https://en.wikipedia.org/wiki/Solenoid