November 30, 2010

Human issues in the Deepwater Horizon blowout

An Interim Report on causes of the Deepwater Horizon oil rig blowout and ways to prevent such events by the committee for the analysis of causes of the Deepwater Horizon explosion, fire, and oil spill by the National Academy of Engineering; National Research Council mentions the following:
"1.The incident at the Macondo well and Deepwater Horizon MODU was precipitated by the decision to proceed to temporary abandonment of the exploratory well despite indications from several repeated tests of well integrity [the test type known as a negative (pressure) test] that the cementing processes following the installation of a long-string production casing failed to provide an effective barrier to hydrocarbon flow (Sections II and III).
2. The impact of the decision to proceed to temporary abandonment was compounded by delays in recognizing that hydrocarbons were flowing into the well and riser and by a failure to take timely and aggressive well-control actions. Furthermore, failures and/or limitations of the BOP, when it was actuated, inhibited its effectiveness in controlling the well (Sections III and IV).
3. The failures and missed indications of hazard were not isolated events during the preparation of the Macondo well for temporary abandonment. Numerous decisions to proceed toward abandonment despite indications of hazard, such as the results of repeated negative-pressure tests, suggest an insufficient consideration of risk and a lack of operating discipline. The decisions also raise questions about the adequacy of operating knowledge on the part of key personnel. The net effect of these decisions was to reduce the available margins of safety that take into account complexities of the hydrocarbon reservoirs and well geology discovered through drilling and the subsequent changes in the execution of the well plan (Section VI).
4. Other decisions noted by the committee that may have contributed to the Macondo well accident are as follows:
• Changing key supervisory personnel on the Deepwater Horizon MODU just prior to critical temporary abandonment procedures (Section VI);
• Attempting to cement the multiple hydrocarbon and brine zones encountered in the deepest part of the well in a single operational step, despite the fact that these zones had markedly different fluid pressures (because of the different fluid pressures, there was only a small difference between the cement density needed to prevent inflow into the well from the high-pressure formations and the cement density at which an undesirable hydraulic fracture might be created in a low pressure zone) (Section II);
• Choosing to use a long-string production casing in a deep, high-pressure well with multiple hydrocarbon zones instead of using a cement liner over the uncased section of the well (Section II);
• Deciding that only six centralizers would be needed to maintain an adequate annulus for cementing between the casing and the formation rock, even though modeling results suggested that many more centralizers would have been needed (Section II);
• Limiting bottoms-up circulation of drilling mud prior to cementing, which increased the possibility of cement contamination by debris in the well (Section II);
• Not running a bond log after cementing to assess cement integrity in the well, despite the anomalous results of repeated negative-pressure tests (Section II);
• Not incorporating a float shoe at the bottom of the casing as an additional barrier
to hydrocarbon flow (Section II); and
• Proceeding with removal of drilling mud from the well without installing the
lockdown sleeve on the production casing wellhead seals to ensure the seals could not be shifted by pressure buildup under the seals (Section II).
5. Available evidence suggests there were insufficient checks and balances for decisions involving both the schedule to complete well abandonment procedures and considerations for well safety (Section VI).
6. The decisions mentioned above were not identified or corrected by the operating management processes and procedures of BP or those of their contractors or by the oversight processes employed by the Minerals Management Service (MMS) or other regulators (Sections VI and VII).
7. Currently, there are conflicting views among experts familiar with the incident regarding the type and volume of cement used to prepare the well for abandonment.There are also conflicting views on the adequacy of the time provided for the cement to cure. These factors could have had a material impact on the integrity of the well (Section II).
8. The BOP did not control—or recapture control of—the well once it was realized that hydrocarbons were flowing into the well. Also, both the emergency disconnect system designed to separate the lower marine riser from the rest of the BOP and automatic sequencers controlling the shear ram and disconnect failed to operate (Section IV).
9. Given the large quantity of gas released onto the MODU and the limited wind conditions, ignition was most likely. However, the committee will be looking into reports (such as testimony provided at the MBI hearings) that various alarms and safety systems on the Deepwater Horizon MODU failed to operate as intended, potentially affecting the time available for personnel to evacuate (Section V).
10. The various failures mentioned in this report indicate the lack of a suitable approach for anticipating and managing the inherent risks, uncertainties, and dangers associated with deepwater drilling operations and a failure to learn from previous near misses(Section VI).
11. Of particular concern is an apparent lack of a systems approach that would integrate the multiplicity of factors potentially affecting the safety of the well, monitor the overall margins of safety, and assess the various decisions from perspectives of well integrity and safety. The “safety case” strategy required for drilling operations in the North Sea and elsewhere is one example of such a systems approach (Section VII)
Read the full report in this link.

November 28, 2010

Static electricity and explosives

An article in the Times of India mentions the following about the recent blast in the cordite factory at Ooty:"factory staff suggest that mere "human vibrations" are enough to trigger a calamity in the highly explosive environment of the dough making unit....At the 13 by 13 feet at the incorporation unit where the blast occurred, earth plates and poles have been positioned for the workers to release their "vibrations" after they perform every small task."
Apparently the "human vibrations" they are talking about is nothing but static electricity. A static discharge spark can readily detonate primary explosives. From the article, all measures to avoid static electricity generation were reportedly taken. It will be good if the investigation team shares reasons on what caused the accident without breaching confidentiality as it is a defense unit.
Read the Times of India article in this link.

Safety Integrity Levels - Hip or Hype?

Yesterday I attended a seminar on "Safety Integrity - Life cycle approach", organised by ISA at IIT, Madras.The IEC 61508 and 61511 standards were discussed. Having interacted with many users, I think the problem with the safety integrity approach lies somewhere between hip and hype. When I mean hip, many users think that just be implementing a SIL 3 capable system, everything will be hunky dory. Not so! It requires a lot of operations and maintenance inputs throughout the life cycle of the system to ensure that it maintains its reliability. While instrument manufacturers often tend to go overboard to sell their ides to the client and engineering, procurement and construction companies also tend to recommend such systems to their clients, ultimately it is the the client who has to decide what level of risk is he prepared to take and whether existing instruments will be sufficient, without going in for a detailed SIL study. Unfortunately many clients do not have the technical support requires to make such decisions and rely on the designer. I go back to the analogy I had given in my earlier posts - We had operated a pneumatic controlled ammonia plant (no DCS, no smart transmitters, no fieldbus, no HART) quite successfully in the eighties for over a decade without an instrument failure that caused a spurious trip or fail dangerous undetected state. The answer to the question whether safety integrity is Hip or Hype lies in the understanding of risks by the client and is solely based on his decision. So the answer lies inbetween!!

November 26, 2010

Blast in cordite factory

Its ironical that my last blog was about a blast in a test tube. Today there is news about a massive explosion in the cordite factory in Ooty, that killed at least 5 people.A news report mentions that "An intermediary process of mixing dough (a nitrocellulose-nitroglycerine paste) was in progress when the explosion occurred. It brought down a part of the building".
Read the articles in these links":

November 25, 2010

A test tube explosion!

An accident at a school lab in the US indicates the dangers of chemicals. A news article mentions the following: "It was a simple science experiment designed to create a small combustion in a glass container and teach high schoolers about chemical reactions.A mixture of three chemicals -- potassium chlorate, manganese dioxide and glycerin -- and a dash of sugar heated over a Bunsen burner in a test tube were supposed to cause a pop and a puff of smoke, demonstrating an exothermic reaction to a class of Grade 11 students at F.J. Brennan Catholic high school.But something went wrong Tuesday morning. The test tube exploded, launching shards of glass across the science lab and injuring teacher Steve Pellarin and three students.No one was seriously hurt, but Pellarin sustained cuts to his face and hands. The students had minor lacerations, and no one sustained any chemical burns, said Windsor-Essex Catholic District School Board spokeswoman Jill Braido".
Read the article in this link.
Wikepedia mentions the following:
"Potassium chlorate is often used in high school and college laboratories to generate oxygen gas[citation needed]; it is a far cheaper source than a pressurized or cryogenic oxygen tank. Potassium chlorate will readily decompose if heated in contact with a catalyst, typically manganese (IV) dioxide (MnO2). Thus, it may be simply placed in a test tube and heated over a burner. If the test tube is equipped with a one-holed stopper and hose, warm oxygen can be drawn off. The reaction is as follows:
2KClO3(s) + heat → 3O2(g) + 2KCl(s)
The safe performance of this reaction requires very pure reagents and careful temperature control. Molten potassium chlorate is an extremely powerful oxidizer and will spontaneously react with many common materials. Explosions have resulted from liquid chlorates spattering into the latex or PVC tubes of oxygen generators, as well as from contact between chlorates and hydrocarbon sealing greases. Impurities in potassium chlorate itself can also cause problems. When working with a new batch of potassium chlorate, it is advisable to take a small sample (~ 1 gram) and heat it strongly on an open glass plate. Contamination may cause this small quantity to explode, indicating that the chlorate should be discarded".
For folks operating chemical reactors in the industry, know what you are dealing with!

Trapped inside a pipe for 80 hours

A Chinese worker in an offshore platform was reportedly trapped inside a pipe when he was inside it doing some work. The pipe apparently collapsed due to water pressure and the worker was trapped for 80 hours before he was rescued.Read the article in this link.

H2S the deadly killer

A news report mentions that 3 people were killed when H2S gas leaked out probably form a burst pipeline in an refinery in Israel. The accident occurred when maintenance work was going on. The report mentions that "An initial investigation points to a technical malfunction in a pipe to a unit that burns off the waste gas from the refining process".
Now every "technical" malfunction is caused by a "human" malfunction. I have observed many incident reports which do not want to discuss the human issue at all. Its like the saying "we are like that only"!!!
Read the report in this link.

November 23, 2010

Fire in chemical factory at Vadodara

A news report mentions that a major fire broke out at a chemical factory in Vadodara, killing one. The company manufactures industrial solvents which are highly flammable substance.The video accompanying the news item depicts the company entrance mentioning it is an ISO 9001,ISO 14001 and OHSAS 18001 certified company. Is there a lesosn to learn from this?? See the video in this link.
Read another article on the blast in this link

Ammonia leak at Navi Mumbai

Ammonia is used in many cold storages across the country.I have been reading regular reports of ammonia leaks from such facilities in the USA and it is really alarming. Now a newspaper report mentions about a ammonia leak incident in a cold storage facility in Navi Mumbai, India which caused 10 people to be hospitalized. In India, ammonia is manufactured in many large scale ammonia plants in the private as well as public sector. As part of their Corporate Social Responsibility initiatives, these organizations should train the small scale cold storage owners on the hazards of ammonia and its safe handling and maintenance procedures. Read the news article in this link.
Read another article on the accident in this link.

November 22, 2010

Accident in Chemical factory in China

The Hindustan Times has reported an accident in a chemical plant in China where three people were killed. The article mentions "The factory produced an array of chemicals ranging from common food additives to compounds used in making plastics and paper, according to the company website.
Two of the injured were in serious condition, the report said. In China, considered one of the world's most dangerous places to work, an average of 187 people were killed in work-related accidents on each day in the first half of this year, the government has said'.

Another article mentions that PVC was produced in the plant.While details of the accident are not known, the production of PVC deals with polymerization reactions that must be controlled carefully to avoid the chance of an accident. I have seen plants where batch operations of critical reactions are carried out manually. As experience levels in the chemical industry are coming down drastically, managements must periodically re assess their risk.
Read the article in this link.

November 20, 2010

Lessons in Process Safety Management from aviation incidents

Two air accidents that I have been tracking closely is the Air India express Mangalore air plane crash and the Qantas Airbus superjumbo incident in Singapore. Details of the CVR recordings from India express crash now reveal that the pilot had slept for 90 minutes during the flight and was suffering from “sleep inertia” when he was attempting to land. How many of you consider your poor shift crew in this light? When I was working in shifts, I have experienced this sleep inertia even though I had slept well during the day.
A news article about the Qantas Superjumbo Rolls Royce engine incident it was a “worst case scenario” when one of its four engines exploded. The article reports that the crew were inundated with 50 error messages. However for the pilots, luck was on their side, there was no fire, and they managed to land the plane safely.
''It could have been much, much worse,'' says Richard Woodward, a Qantas A380 captain and a vice-president of the Australian and International Pilots Association. ''It could probably be termed a one-in-100 million event with bits and pieces going everywhere.''
Smith, a two-time chairman of Australia's aviation watchdog, says it was lucky QF32 did not become a repeat of the Concorde crash in 2000.
Smith says that the public has come to expect the impossible - aircraft being fail-safe. ''It is almost like people believe that flying in the air is perfectly safe. Even the most disciplined person can make an error - it is the same with design.''
''One of the things in aviation safety is 'hindsight bias'. It is so easy after an accident to say they should have known,'' says Thomas Anthony, the director of aviation safety at the University of Southern California.
''It is part of the problem of new engines and new aeroplanes. Change is a frequent precondition to error,'' Anthony says. ''When you are changing things you really do need to have a very robust change management process to identify potential problems.''

The above accidents had direct parallels to process safety. Learn lessons from them!
Read the articles in these links
Air India Express Crash
Qantas Superjumbo incident
PS: I have a deep interest in aviation safety as my Dad was a pilot and I have spent many days in the cockpit with him when I was young!

November 19, 2010

The familiar technical and safety failures

An article mentions the following about the BP oil rig disaster:
"A sorry catalogue of technical, safety and regulatory failures all contributed to the Deepwater Horizon oil spill in the Gulf of Mexico, according to an interim independent report commissioned by the US Department of the Interior and published today.
The oil spill began on 20 April when an uncontrolled release of oil and gas from an underwater well caused an explosion that engulfed the Deepwater Horizon rig, killing 11 crewmen on board. The leak continued until 15 July, releasing about 5 million barrels of oil into the Gulf, the largest accidental marine oil spill in history.
The report highlights a number of failures that led to the accident. It says the well had not been properly sealed with cement and that this allowed oil and gas to escape.
The "pivotal moment" came when workers carried out several pressure tests to check the integrity of the well but ignored the signs that something was wrong, said Paul Bommer, a petroleum engineer at the University of Texas at Austin and a member of the panel of experts that produced the report.
The report says the panel has not yet had time to work out why the blowout preventer, a giant valve on the seafloor which should have stopped the flow of oil as a measure of last resort, failed to activate".

Always, technical as well as safety failures occur for an incident to happen. Just by implementing management systems does not mean you can prevent an incident. Today, there is also a lot of talk about behavior based safety management systems, but as I have mentioned earlier, I am not a fan of this. It needs constant 24X7 safety oriented behaviour by top management, be it budget allocation, decision making, manpower allocation, gauging technical competency to manage cost cutting etc to ensure process safety is managed well.
Read the full article in this link.

November 18, 2010

Do not ignore the warnings!

A news article mentions the following "BP and its contractors missed and ignored warning signs prior to the massive oil well blowout in the Gulf of Mexico, showing an "insufficient consideration of risk" and raising questions about the know-how of key personnel, a group of technical experts concluded.
In a 28-page report released late Tuesday, an independent panel convened by the National Academy of Engineering said the companies failed to learn from "near misses" and neither BP, its contractors nor federal regulators caught or corrected flawed decisions that contributed to the blowout.
Donald Winter, a professor of engineering practice at the University of Michigan and chair of the 15-member study committee, said in a statement that plugging of the well to seal it off for future oil and gas production continued "despite several indications of potential hazard."

No major accident happens without adequate warning. There will be enough signals that some thing disastrous is about to happen. Do not be risk blind. Read the full article in this link.

November 16, 2010

Explosion during hot work

A news article mentions that a company was fined 20,000 pounds for a hot work accident.The article mentions the following:
"David Lightfoot, 58, was carrying out welding work on a large container at Indorama Polymers (Workington) Ltd’s site in Siddick. The container housed 380 tonnes of the explosive powder, Terephthalic acid.
The company was prosecuted by the Health and Safety Executive (HSE) following an investigation into the cause of the explosion. Workington Magistrates' Court heard that, on 29 October 2008, Mr Lightfoot was welding a metal component around a two and a half inch diameter hole that had been sealed with a temporary bung, when he was suddenly engulfed by a fireball.
Mr Lightfoot, from Cockermouth, had been welding for around 20 seconds before finding himself surrounded by flames that forced him down to his hands and knees. He and another worker jumped ten feet to the ground to escape the flames but Mr Lightfoot was left with severe burns to his head, face, arms and hands.
The HSE investigation concluded the bung had fallen out, allowing around 15 grams of the explosive powder to escape, which was then ignited by the welding flame, creating the fireball".

Read the full article in this link.

November 14, 2010

Two fatalties in a Year at Dupont facilities

Dupont has an excellent safety record and is renowned for their safety management systems. This year they had two fatalities in their facilities - one on January 23 due to phosgene hose leak and another due to an explosion when hot work was in progress in a tank on November 9. I was wondering why these accidents have taken place in a company that has an enviable track record of safety. I got this article about details of a Dupont investigation. Read it in this link.
I wish the CSB brings out clearly what went wrong in these two incidents so that it will be a lesson for all of us.

November 12, 2010

Furnace explosion - take care of refractory lining

A news article mentions about a metal furnace explosion due to a liner failure causing severe burns to two persons. The article mentions the following:
"A Pennsylvania jury awarded $12.7 million to two men who were severely burned when a metal melting furnace exploded in 2003. The furnace explosion occurred when the liner failed, allowing molten metal to come into contact with a copper coil filled with ethylene-glycol and water. The resulting reaction caused the furnace to explode and spew hot liquid metal across the workplace".
Take care of your refractory lining in furnaces. In my earlier days as shift in charge in an ammonia plant, flames suddenly came out of a reformer furnace due to fallen refractory. It happened all of a sudden and the flames were close to naphtha fuel lines for the burners!We had to scramble to take action and avoid a catastrophe.
Read the article in this link

November 11, 2010

Process safety in the 21st Century

Having spent 30 years in the chemical industry, I am trying to hazard a guess on the direction of process safety in the 21st century:
1.The human being will become more and more the focus in process safety. Technical competency of individuals is fast decreasing and job hopping means that process safety knowledge is fragmented in an organisation.
2.Plants are becoming more and more hi tech with control systems and instruments with wireless technology and “smart” technology while the human being is becoming “unsmarter”.
3.As organisation become larger and larger, the management of process safety is getting lost somewhere in between the layers of communication. While leading process safety indicators are good in highlighting problem areas, the focus on these indicators is also human dependent and with directors on boards of companies changing, this focus gets shifted from time to time.
4.There will be Low frequency High Potential accidents happening in large organisations. The BP case is just a teaser. Even in organisations that manage their process safety closely, one slip is enough.Managing to avoid this “slip” will become tougher and tougher in this “flat world”.
5.Fortunately or unfortunately we are in an age of rapid technology change. Plant operators should be careful to select the technologies they need and more importantly to “deselect” the technologies they do not need. One mans bread may be the other man’s burnt toast!
6.To become more and more competitive, organizations are cutting costs. While there is nothing wrong in cutting costs, I see a drastic decrease in in-house competency to assess the technical issues while cutting costs.
7.There will be a number of security issues with chemical plants as control technologies change.
8.Competency of people is becoming a major issue. Simulator training of plant operators may become a legal requirement soon in many countries!

I do not want to bore you with this monologue, but how do we avoid this? Top management must continually have a feel of what is going on at the ground level. There is no better solution that the old fashioned way of walking the talk by periodically meeting people at ground zero and observing what their problems are! I’m signing off…..!

November 10, 2010

Culture of complacency and process safety

A news article quotes the co-chairman of the Presidential commission for investigating what went wrong in the BP oil rig disaster in the Gulf of Mexico as follows:
The commission's co-chairman William K. Reilly opened the day saying that a "suite of bad decisions" revealed "a culture of complacency" at BP as well as its main contractors Transocean and Halliburton. He concluded the day saying that the deepwater drilling disaster was the result of systemic problems, not isolated ones.
Read the full article in this link

Explosion in chemical storage tank during hot work

I had just posted the dangers of hot work a couple of posts back and now there is news of an explosion in a chemical storage tank when welding was going on that killed one contract worker. The accident happened at the Dupont plant in upstate New York. Read the article in this link.
Update: The tank reportedly was empty but earlier contained vinyl fluoride as per this news article.

November 9, 2010

Disappearing control rooms and process safety

I read an interesting article about the future of control rooms which basically says that in the future, there will not be any central control rooms in chemical plants, but operators moving about using wireless devices to communicate with the control system. While I appreciate that technology must be used for the benefit of mankind, I wonder whether we are opening new frontiers in process safety. As technology envelops us, I feel that the technology swamped human being is beginning to loose his trouble shooting and thinking capabilities. The future process safety issue will be fighting against the syndrome "I rather believe an instrument than use my brain!".
Read the article in this link

November 8, 2010

Explosion and fire in UK factory & Oil Godown in Chennai

Thanks to Abhay Gujar for sending the following news:
An explosion at a Stiller’s toiletries factory in Newton Aycliffe, County Durham that was followed by a large fire. Cause of the fire is not known.See the youtube video in this link.

A rocket firecracker was the source of ignition of a fire in an oil Godown in Chennai, India. The astray firecracker was part of the Diwali festival celebrations! There are many oil storage facilities in India which are very close to populated areas and there is every chance of an accidental source of ignition. Read more of the fire in this link.

November 7, 2010

The Dangers of Hot Work

The Department of Labour has published booklet on hot work from which I have taken these incidents:
"An engineer was killed when a 6000-litre tank exploded when he lit a welding torch to repair a seam in the tank. The tank was moved 30 metres in the explosion, and an observer who was standing 2 metres away was thrown to the ground by the blast. The tank had been flushed with water for three days prior to the explosion but this did not remove all the explosive substances.
• A worker was attempting to remove the lid of a 200-litre container that had previously contained lacquer thinners. The drum, which had both bungs in place when the worker applied heat to the lid, hit the roof of the building 6 metres up. The worker received bruising to his hand.
• While removing a cleaning bung from a 70-litre stainless steel boat fuel tank, a worker passed a heated soldering iron over the bung hole. The petrol fumes ignited, throwing the worker on the floor.
• A worker, who had a few moments spare time, began cutting a 200-litre drum to makes a barbecue. He was unaware of the contents of the drum, which exploded when the torch began the cut. He received minor injuries in the incident.
• A worker passed a gas torch to his colleague over the open lid of a bitumen tank, causing an explosion. The worker, who was on top of the tank, received 10% burns to his face and left hand and his leg was broken in three places. The worker on the other side of the tank escaped injury.
• A welding contractor was attempting to fit a tap into a 5000 litre tank. A cut had been started in one end of the tank when it exploded. The tank was turned around and
flipped over. The opposite end of the tank was blown approximately 42 metres, soaring over a stand of trees 12 metres high and landing in a vacant section. The contractor received cracked ribs, a dislocated shoulder, injuries to his collar bone and severe bruising all oyer the body.
There has been no let-up in accidents and many more examples could be given. Remember, all accidents of this type are potentially fatal. Don’t let it happen to you!"

See the booklet in this link(pdf file)

November 6, 2010

Detecting the spark that causes fires and explosions

An article mentions that German scientists developed a new method to prevent explosions due to electrical sparks.
"In most cases, a spectacular accident must first occur in order to make the public aware of a problem that lurks continually in many areas of industry: the danger of explosions due to electrical sparks. The simplest method to prevent such explosions is called "Intrinsic Safety". The intention thereby is to prevent ignitable sparks from even being created. Up to now, this has only been possible with small devices having a power of up to approx. 2 Watts - thus, above all, in process measuring and control technique.
A new concept that has been developed at the Physikalisch-Technische Bundesanstalt (PTB) in cooperation with industrial partners, increases this limit now up to 50 Watts and thus makes application possible in many more technical fields. The technology which is already being marketed under the name "Power-i"/DART and which is to be launched as an international IEC standard, promises the industry great cost savings".
"For a long time now, end users and manufacturers have wanted a considerably higher active power while at the same time keeping all the positive characteristics of Intrinsic Safety. And this is exactly what the new "Power-i"/DART technology offers. DART here stands for "Dynamic Arc Recognition and Termination".
"Power-i is different from previous concepts", states Udo Gerlach, the project leader at PTB. "The principle of an emergency shutdown is just as simple as it is effective." The safety-related validated, intelligent monitoring system recognizes a spark already while it is forming and then shuts down the system in a controlled and quick manner, before the spark can even become ignitable. "Thus, complex, expensive constructural safety measures can now be replaced with the new technology".

Read the full article in this link.

November 5, 2010

November 4, 2010

A+B=**** Hazards of incompatibility

An article mentions the following:
"Last month, an unsuspecting contractor was delivering chemicals to a water treatment plant in Andover, Minn., when he accidentally poured fluorine into a chlorine tank. A chemical reaction was triggered, releasing hazardous fumes and causing the facility to be evacuated. Luckily, the worker only sustained minor injuries and the plant was back in operation just a few hours later, but more serious, and perhaps deadly, consequences could have easily resulted from this simple mistake".
See the full article in this link.