Full steam ahead for new Tuas mega port


The Tuas Terminal will be developed in four phases over 30 years, with Phase 1 scheduled to be completed by the early 2020s.ST GRAPHICS


Project proceeding as planned despite industry downturn


Karamjit KaurSenior Aviation Correspondent 

Works are in full swing at the future Tuas port, with reclamation ongoing for two out of four phases of the development and more than 3km of caisson already installed to form the wharf.


The caisson, which sits on a foundation on the seabed, is a 28m-high concrete watertight structure - about the height of a 10-storey Housing Board block. Using caissons to build the wharf structure is faster than traditional methods like piling.




In all, 8.6km of caisson will have to be constructed under Phase 1 of the Tuas port project, which aims to grow the Singapore port, amid competition from other regional and global ports.


The new Tuas port - which will be twice the size of Ang Mo Kio town - will be opened progressively from 2021. When fully completed by 2040, it will be able to handle up to 65 million twenty-foot equivalent units of cargo a year, more than double what the port handled last year.


Work on the port, which will eventually house current operations at Pasir Panjang, Tanjong Pagar, Keppel and Brani container terminals, is proceeding as planned despite the current industry downturn.


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http://www.straitstimes.com/singapore/full-steam-ahead-for-new-tuas-mega-port

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Construction & Installation of 1st Caisson at Tuas Terminal Port Phase 1:Video



A behind-the-scene look at the construction and installation of the 1st caisson at the Tuas Terminal Port Phase 1 development. Coordinating Minister for Infrastructure and Minister for Transport Khaw Boon Wan marked the initiation ceremony on April 29, 2016 by launching the first caisson.


In total, 222 such caissons will form the permanent wharf structure.


With each caisson 28 metres tall and equivalent to the height of a 10-storey HDB block, the caissons designed for Tuas Terminal Phase 1 are one of the largest in the world. Find out more at http://ow.ly/4nlK38  SOURCE: VesselFinder



The Tuas Terminal development - a testament to Singapore’s commitment to retain its lead as a global maritime nation and to invest in port infrastructure - entered Phase 1 of its construction yesterday. When completed, the 21 deep-water berths under Phase 1 will be able to handle 20 million Twenty-Foot Equivalent Units (TEUs) per annum. The entire mega-terminal will have a total capacity of up to 65 million TEUs.


“The Tuas Terminal is a centrepiece of Singapore’s ‘Next Generation Port Vision’ and demonstrates our strong commitment to strengthening and sustaining our leadership position as a global hub port and international maritime centre. Additionally, we hope that complex projects of this scale can inspire the next generation of engineers to join the profession and help shape our future.” said the Maritime and Port Authority of Singapore (MPA) Chief Executive, Andrew Tan.


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Araco founder: precast concrete can reduce construction waste


Rahim Banizaman Lari is the founder and 

managing director of Araco. 


by Fatima De La Cerna on Jun 8, 2017 

The construction industry in the UAE can reduce the amount of waste produced on sites if it used precast concrete in projects.


Rahim Banizaman Lari, the founder and managing director of Araco, said that although precast concrete is more environmentally friendly than traditional construction materials, like wood or cement, it remains underutilised in the country.


Speaking with Construction Week, he said: "Precast concrete [...] is a solution to the problem of waste created during construction. And yet, it's barely used, with more than 70% of the buildings here in Dubai still built using conventional construction methods and materials."




Offering an explanation of why this is the case, he pointed out that consultants don't have the required budget to hire in-house engineers who specialise in precast concrete. He added: "Araco now has a separate designer who specialises in using precast concrete, but most consultants don't have the capacity."


To find out Lari's idea on how to address the problem, read Construction Week's exclusive interview with Araco's chief, in issue 657, published on 27 May, 2017

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Decommissioning Nuclear Facilities

(Updated 31 May 2017)


Robotic systems for safe nuclear  decommissioning of nuclear facilities source Machining News

edited by kcontents


 

To date, over 110 commercial power reactors, 48 experimental or prototype reactors, over 250 research reactors and a number of fuel cycle facilities have been retired from operation. Some of these have been fully dismantled.


Most parts of a nuclear power plant do not become radioactive, or are contaminated at only very low levels. Most of the metal can be recycled.


Proven techniques and equipment are available to dismantle nuclear facilities safely and these have now been well demonstrated in several parts of the world.


Decommissioning costs for nuclear power plants, including disposal of associated wastes, are high relative to other industrial plants but are reducing, and contribute only a small fraction of the total cost of electricity generation.





All power plants, coal, gas and nuclear, have a finite life beyond which it is not economically feasible to operate them. Generally speaking, early nuclear plants were designed for a life of about 30 years, though with refurbishment, some have proved capable of continuing well beyond this. Newer plants are designed for a 40 to 60 year operating life. At the end of the life of any power plant, it needs to be decommissioned, cleaned up and demolished so that the site is made available for other uses.


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Trump reveals US$1 trillion infrastructure vision


source Business Insider




Written by Thomas Allen - 05 Jun 2017

In his latest budget request, President Trump followed through with one of his main campaign promises by putting forward his much-anticipated spending proposal that includes a new section intended to provide an infrastructure plan that would support US$1 trillion of private and public infrastructure investment.


The rebuilding plan would inject US$200 billion into transport projects over the next ten years, with the goal of creating US$1 trillion worth of overall investment.


According to the document, the administration would reach its spending target through a combination of new federal funding, incentives for private sector investment and expedited projects that supposedly would not have happened without the administration’s involvement.


The proposal is underpinned by four key approaches – leveraging private sector investment, ensuring federal dollars are targeted at transformative projects, shifting more services and underused capital assets to the private sector, and giving states and localities greater flexibility.


A fact sheet from the White House said the current environmental review and permitting process was “fragmented, inefficient and unpredictable”. As a result, the plan intends to eliminate or reform such regulations, which are believed to slow down projects.




Other proposals included in the infrastructure initiative include the expansion of the Transportation Infrastructure Finance and Innovation Act (TIFIA) program to US$1 billion every year, the reduction of tolling restrictions on existing interstate highways, the encouragement of programs that explore innovative ways to reduce traffic, and the lifting of a US$15 billion cap on Private Activity Bonds.


The White House also wants to create a mandatory revolving fund to help finance federally owned civilian capital assets and establish partnership grants for federal assets.

source khl

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Brazil’s nuclear power program undone by corruption


angra 3 nuclear power plant site. source Power Engineering Magazine 

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The future of Brazil’s partially-built Angra-3 reactor is uncertain in the wake of a wide-ranging corruption scandal that has engulfed the country. Angra-3 was conceived in controversy in 1975 and it may die in controversy.


The turnkey Angra-1 reactor was built by Westinghouse from 1971 to 1982. Angra-1 suffered continuing problems with its steam supply system and its load factor was only 25% over its first 15 years, but since 1999 it has performed "much better" according to the World Nuclear Association.1


Then came the hugely controversial "deal of the century" between Germany and Brazil for the supply of eight reactors, a suite of nuclear fuel cycle facilities and oodles of technology transfer despite Brazil’s obvious interest in nuclear weapons. Academic Matthew Bunn explains:2


"In 1975, Brazil and Germany agreed on a nuclear "deal of the century" in which Germany was to provide several reactors and a complete nuclear fuel cycle, including both an enrichment plant and a reprocessing facility, under international safeguards. (The deal was later drastically scaled back, due to delays, economic constraints, and U.S. pressure.)

"At about the same time, Brazil launched a secret, unsafeguarded "parallel program" run by the military, divided into segments run by different services, with the Navy pursuing centrifuge enrichment (ultimately successfully establishing an enrichment facility), and the Army pursuing plutonium production.


"Personnel trained in the safeguarded program with Germany were transferred to the weapons program, and technologies from the safeguarded program are believed to have been used in both the unsafeguarded enrichment facility and a small plutonium separation facility. The weapons program was cancelled under a later civilian government, and following the Brazil-Argentina rapprochement, all of Brazil’s nuclear facilities are now under safeguards."


Under the Germany/Brazil agreement, the Angra 2 and 3 pressurized water reactors were to be built immediately, with equipment from Kraftwerk Union (KWU). Work began on Angra-2 in 1976 but was suspended due to a lack of finances and lower than expected growth in electricity demand. Work resumed in 1995 and the reactor came online in 2000. Three years earlier, Eletronuclear was formed as a subsidiary of state energy utility Eletrobrás and assumed responsibility for construction and operation of nuclear power plants.


The ex-president of Eletronuclear in Brazil, Othon Luiz 

Pinheiro da Silva, photo by Marcello Casal Jr/Agência 

Brasil.

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Angra-3

The development of Angra-3 ‒ a Siemens/KWU pressurized water reactor, identical to Angra-2 ‒ began in 1984 but was halted in 1986 before full construction began. In 2006, the government announced plans to complete Angra-3 and also to build four more reactors beginning in 2015. In 2008, Eletronuclear signed an agreement with Areva for work on Angra-3. In mid-2010, the National Nuclear Energy Commission granted a construction licence and work began on Angra-3 after a 24-year hiatus. In November 2013, a contract was awarded to Areva in line with the 2008 agreement.


And then the Angra-3 project began to fall apart ... again. Funding was a problem. Areva said in April 2015 that progress on the project was "dependent on the securing of project financing by the customer".3 Areva announced in June 2015 that it had reduced its activities at Angra-3 due to delays in securing financing for the remainder of the project.4,5


In August 2015, four Brazilian construction companies stopped work on Angra-3 due to non-payment of millions of dollars from Eletronuclear, and in the context of an escalating bribery corruption scandal engulfing the construction companies as well as Eletronuclear, Eletrobrás, politicians and political parties.6,7

The following month, Eletrobrás suspended work on Angra-3 pending an internal corruption inquiry. Eletronuclear CEO Pedro José Diniz de Figueiredo ‒ newly appointed after the July 2015 arrest of former CEO Othon Luiz Pinheiro da Silva in connection with the corruption scandal ‒ said all building contracts for the project had been frozen for 90 days.8




Over a year later and the Angra-3 project remains frozen. Figueiredo said in April 2016 that several issues needed to be resolved: completion of the internal corruption investigation; setting a new budget for the project, cancelling contracts suspected of being fraudulent and conducting a new tender process, and renegotiating funding for the project.9


When construction began in 2010, commissioning of Angra-3 was expected in late 2015.1 Now, Eletrobrás and Eletronuclear hope to commission the reactor in 2021.10 But that timeline assumes that work will resume, and that it will resume in 2017, and both assumptions are doubtful. According to the World Nuclear Association, the timeline for completion of Angra-3 is "indefinite, maybe 2022"; in other words, it may never be completed.1

Construction of Angra-3 is about two-thirds complete according to Eletronuclear.9 But more funding is required to complete the project. According to powertechnology.com, an additional US$1.8 billion is required in addition to a government loan previously secured.11 In December 2016, Eletronuclear executives will visit China in an attempt to secure new investors to complete Angra-3.12 China might be interested in supporting Angra-3 if it opens up options for the deployment of Chinese reactor technology in Brazil (as with Chinese funding for Hinkley Point C in the UK). But it is doubtful whether new reactors will be built in Brazil in the foreseeable future.


Eletrobrás and its subsidiary Eletronuclear are in no position to be covering the funding shortfall for Angra-3. In November 2015, Eletrobrás booked a 3.39 billion reais (US$980 million) impairment charge on Angra-3.13 In the same month, Eletrobrás announced that it would cut 13,000 jobs over the next two years, around 30% of the utility’s staff.10


Then Eletrobrás reported its biggest ever annual loss: a net loss of 14.4 billion reais (US$4.1 billion) in 2015. Economic consulting firm BNamericas reported that the largest write-down was 5 billion reais (US$1.44 bn) for Angra-3.14


The estimated cost of Angra-3 has increased significantly. According to BNamericas, in the late 2000s the estimated cost was US$5.4 billion whereas the latest estimate is 121% greater at US$12 billion.15 According to the World Nuclear Association, the estimated cost in 2010 was US$6 billion and it is now US$7.6 billion.1 Cost increases have arisen due to exchange rate fluctuations, inflation and additional works required to satisfy environmental concerns.15 Eletronuclear reportedly estimates additional losses of US$1.7 million per day if the reactor is not operational by the end of 2018.7


Corruption and crisis

Angra-3 featured in the ’Most Controversial Projects 2015’ list compiled by RepRisk, a business intelligence provider specializing in environmental, social, and governance risk analytics.16 Angra-3 was listed at number five in RepRisk’s top 10. The award citation read:


"Repeated allegations of corruption have led to the inclusion of Brazil’s third nuclear power plant, the Angra 3 Nuclear Reactor, in the MCP 2015 report. ... [I]n May 2015, Eletrobras found itself embroiled in a corruption scandal, when it was alleged that Edison Lobao, Brazil’s former Minister for Mines and Energy, had received BRL 1 million (USD 250,000) to help the construction company, UTC Participacoes, win a contract for the Angra 3 Nuclear Plant.


"It was then revealed that the CEO of Eletronuclear had accepted bribes from construction companies involved in the Angra 3 project and in July 2015, he was arrested for allegedly receiving BRL 4.5 million (USD 1.1 million) in kickbacks between 2009 and 2014 from Andrade Gutierrez and Engevix Engenharia (Engevix). A senior energy executive of Andrade Gutierrez was also arrested. Investigators then began to probe the Angramon consortium, charged with constructing Angra 3 ...


"Later in July [2015], hundreds of shareholders of Eletrobras filed charges against the company in New York, claiming that the firm had known about the corruption at Eletronuclear and had hidden the fact for more than a year. One month later, Eletrobras and some of its executives were sued in a class-action lawsuit in a US District Court for violating the US Securities Exchange Act and for providing materially false statements related to the awarding of USD multibillion construction projects, including the Angra 3 Nuclear Reactor.




"In November 2015, the Brazilian Administrative Council for Economic Defense (CADE) launched an investigation into a group of construction companies, including UTC Engenharia, EBE, Construtora Andrade Gutierrez, Construtora Norberto Odebrecht, Construtora Queiroz Galvao, Camargo Correa, and Techint, on suspicions that they had formed a BRL 3 billion (USD 775.3 million) cartel to rig the bidding for the Angra 3 Nuclear Reactor. According to CADE, the cartel was known as the "big group," which held meetings to agree on the prices and winners of each construction tender.


"In December 2015, Brazil’s Federal Criminal Court ratified the charges brought by the Federal Ministry of Public Prosecution against Eletronuclear and former executives of Andrade Gutierrez for corruption related to the Angra 3 Nuclear Reactor. The CEO of Eletronuclear, a shareholder of Engevix, and the former president of Andrade Gutierrez Energia were placed under house arrest."


Eletronuclear CEO Othon Luiz Pinheiro da Silva, considered the father of Brazil’s nuclear program, was arrested in July 2015. In the same month, Luiz Pinguelli Rosa, a nuclear physicist and Eletrobrás’ chief executive from 2003‒2005, said: "The arrest is a tragedy for the industry. The industry was already in crisis, but now the corruption concerns are bound to delay Angra 3 further and cause costs to rise even more."17


The drama has continued this year. In August 2016, Silva was sentenced to 43 years in prison for colluding with executives at Brazilian construction companies to set up an over-billing and kick-back operation for Angra-3.18,20 Investigators alleged Silva skimmed up to 30 million reais (US$8.6 m) from Angra-3 engineering and construction contracts.19


The judge said in his ruling: "The elements of the court findings permit the conclusion that the corruption scheme was structured before, during and after the tenders for Eletronuclear’s construction of Angra 3 and consisted in the payment of bribes to public servants and agents" by the construction and engineering companies.18

In addition to Silva, 12 other people, including Silva’s daughter, were sentenced in August 2016 for their involvement in the embezzlement of public funds.20


In July 2016, prosecutors announced that Eletronuclear CEO Pedro Figueredo had been suspended from his duties for allegedly colluding with Silva and interfering with the company’s internal investigations.19 In the same month, 19 people were arrested for allegedly paying bribes to senior executives of Eletronuclear.22 In return for bribes, Eletronuclear executives allegedly let construction companies inflate the cost of contracts for Angra-3, and politicians and political parties were also beneficiaries of the corruption.22


In May 2016, Brazil’s second biggest contractor, Andrade Gutierrez, agreed to a plea deal and will pay one billion reais (US$288 million) to settle the matter. The company was involved in corrupt dealings in connection with Angra-3 and other projects.21


A future for nuclear power in Brazil?

Angra 1 and 2 provided Brazil with 13.9 terawatt-hours or 2.8% of its electricity in 2015, down from a maximum of 4.3% in 2001.23


In addition to Angra 1‒3, plans for an additional 4‒8 reactors have been discussed. However, as the World Nuclear Association notes, "funding is likely to be a problem".1 Claudio Salles, president of Instituto Acende, a Brazilian energy-research group, said in mid-2015: "These [nuclear] plants take 10−15 years to build and as time goes on they become less viable."17


Plans to expand renewable energy have better prospects. The World Nuclear Association states that power from existing nuclear plants at about US$75/MWh is about 1.5 times more expensive than hydropower, and power from Angra-3 is expected to be slightly over twice as expensive as hydro.1


Hydro generates about three-quarters of Brazil’s electricity. Plans are in train to add around 40 gigawatts (GW) of new hydro capacity by 2035, primarily from small- to medium-sized run-of-the-river plants which generally have a small impact on the environment and indigenous tribes when compared to some large hydro projects.24

Brazil’s Ministry of Mines and Energy says that wind power will make up over 30% of new capacity in the next 11 years, and that at least 25 GW of new wind power capacity will be added by 2035.24


Modest increases of solar and biomass (primarily leftovers from other production processes, such as bagasse from sugarcane processing) are planned. Brazil plans to shut down its coal-fired power plants (2.5 GW) by 2030, and no new permits for coal-fired plants will be granted.24


In mid-2015, Brazil announced its intention to increase the share of non-hydro renewable electricity sources to 20% by 2030.25

Jim Green ‒ Nuclear Monitor editor

http://www.ciranda.net/Brazil-s-nuclear-power-program?lang=pt_br

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  DSME launches first icebreaking LNG ship in Russia


Putin source chosun biz

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Daewoo Shipbuilding & Marine Engineering’s shipbuilding technology has launched the world’s first ice-breaking liquefied natural gas carrier in St. Petersburg, Russia.


(DSME)


Russia’s President Vladimir Putin, South Korea’s Ambassador to Russia Park Dae-bong and DSME CEO Jung Sung-leep attended a naming ceremony for the country’s new carrier Saturday. The world’s first ice-breaking LNG carrier was named Christophe de Margerie, after the former chief executive of French oil company Total who was killed in an airplane accident in Moscow in 2014.


Following the completion of successful test trials in March, the vessel is slated to be used as part of the country’s Yamal Project, a liquefied natural gas project located in the northernmost Yamal peninsula in Siberia, producing 16.5 million tons of LNG per year.


DSME received an order for 15 icebreaking LNG carriers from companies in Russia, Japan and Canada for roughly $14.8 billion at $320 million per ship. The remaining 14 carriers are being constructed at the Okpo shipyard in Geoje, South Gyeongsang Province and are expected to be delivered by the first half of 2020.


By Julie Jackson (juliejackson@heraldcorp.com)

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China just switched on the world's largest floating solar power plant


The 40MW floating solar power plant at Huainan, China, is the world's largest Image: Sungrow Power Supply




It wasn’t too long ago that China had a reputation as a coal-guzzling, smog-blanketed polluter. But that is changing - and fast.


Today, China invests more each year in wind, hydro and solar power than any other country on earth. This week it further underlined its role as the global leader in renewable energy by switching on the world’s largest floating solar power plant.


The facility is located in the city of Huainan, in China’s eastern Anhui province. It has a capacity of 40 megawatts (MW), enough to power a small town. And in a stroke of pleasing symbolism, the plant floats over a flooded former coal-mining region.



Floating solar arrays have been in use for a little over a decade. They have several advantages; they don’t take up any valuable space on land, and the cooling effect of the water on which the panels float makes them more efficient. They can also help to mitigate the evaporation of water for drinking or irrigation by intercepting sunlight before it hits a reservoir’s surface.


But while the technology is well-established, the Huainan plant represents a giant step forwards in scale. Previously, the largest floating solar array was a 6.3MW plant located in the UK. That will be overshadowed by a plant in Japan, due to come online next year, that will produce 13.7MW - still a long way behind China’s new facility.




As well as accelerating its investment in renewables, China has also been putting the brakes on its fossil fuel consumption. In January this year, the country's energy regulator brought a stop to more than 100 coal-fired power plants under construction across the country, with a combined output of 100 gigawatts (GW).


China's renewable energy trajectory can be viewed in counterpoint to that of the US. Last night, President Donald Trump fulfilled a promise he made on his election campaign: to withdraw from the 2015 Paris Climate Agreement.


In response, China and the EU have issued a joint statement reaffirming their commitment to the Paris Agreement and announcing their intention to ramp up efforts on reducing global carbon emissions. Without the US in the accord, it will leave a superpower-shaped hole in global climate-change leadership - one that China seems willing and able to fill.

https://www.weforum.org/agenda/2017/06/china-worlds-largest-floating-solar-power


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Oman's Duqm earmarks $1bln a year for infra development


Construction workers are seen at the site of the Abdali Project in Amman June 24, 2010. REUTERS/Muhammad Hamed IMAGE ONLY FOR ILLUSTRATIVE PURPOSE


REUTERS/Muhammad Hamed

29 May 2017

Muscat: Oman’s Special Economic Zone Authority at Duqm (Sezad) plans to invest $1 billion per year for developing infrastructure at the free zone and adjoining areas, in a bid to attract both foreign and local investments.


These investments are for building the remaining infrastructure work at the port, a liquid berth, a fisheries harbour, main roads, power transmission and distribution lines and water pipelines, Lee Chee Khian, chief executive officer of Sezad, told Times of Oman. “We need to build roads and utility facilities,” he added. 


Duqm refinery development. source Oman Observer

edited by kcontents


As many as $5 billion has so far been invested in developing infrastructure facilities at Duqm. It (the infrastructure development) will take a considerable amount of time, and the pace of development will depend on the demand for land from the private sector. The planned investment for developing infrastructure is for a long period, ranging from 30 to 50 years.




Power transmission lines

Duqm Authority will also invest in power transmission lines for supplying electricity to the proposed Ras Al Markaz crude storage facility, which is part of the refinery project, and is being built 60 kms from Duqm port.


Duqm Authority is also investing heavily in a major fisheries harbour, which is being built by Galfar Engineering and Contracting Company, and an integrated fish processing zone.


Galfar Engineering and Contracting Company had been awarded a contract to build the fishing harbor in August last year, at a contract value of OMR60.69 million. The scope of the work includes building marine and road-related works at the fishing harbour.


According to earlier reports, the proposed fishing harbour will accommodate not only Omani fleets, but also fleets from other countries passing through the Indian Ocean, and more than 60 processing plants and related facilities will be built in a large area at the back of the Duqm fishing harbour.


The proposed integrated fisheries hub at Duqm will be the largest facility of its kind in the wider Gulf region. Spread over an area of eight square kilometres, the hub will be anchored by a commercial fishery harbour that will be the largest of its kind in Oman. The multi-purpose port can accommodate fishing fleets, ferries and coast guards.


In the port, there will be facilities, such as a fish market, an auction hall, administrative buildings, workshops, some stores for fishermen, cafeterias and coffee shops.




The fully-fledged fishery industries complex project will include a research centre, a training centre, an international standards and quality assurance centre, as well as modern handling and cold storage facilities.


The government will invest in the infrastructure and other utilities and will prepare the required land on a lease basis for investors, with the aim of creating a fisheries hub in the region.


The proposed areas for private sector investment in the fisheries sector include value addition in fisheries products, certified fish seed breeding facilities, a fish feed industry and a fishing gear and equipment industry.

© Times of Oman 2017

https://www.zawya.com/mena/en/story/Omans_Duqm_earmarks_1bln_a_year_for_infra_development-ZAWYA20170529041731/

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LIGO detects gravitational waves for third time

June 1, 2017


Gravitational waves detected a third time

This image shows a numerical simulation of a binary black hole merger with masses and spins consistent with the third and most recent LIGO observation, named GW170104. The strength of the gravitational wave is indicated by elevation as well …more


The Laser Interferometer Gravitational-wave Observatory (LIGO) has made a third detection of gravitational waves, ripples in space and time, demonstrating that a new window in astronomy has been firmly opened. As was the case with the first two detections, the waves were generated when two black holes collided to form a larger black hole.


The newfound black hole, formed by the merger, has a mass about 49 times that of our sun. This fills in a gap between the masses of the two merged black holes detected previously by LIGO, with solar masses of 62 (first detection) and 21 (second detection).


"We have further confirmation of the existence of stellar-mass black holes that are larger than 20 solar masses—these are objects we didn't know existed before LIGO detected them," says MIT's David Shoemaker, the newly elected spokesperson for the LIGO Scientific Collaboration (LSC), a body of more than 1,000 international scientists who perform LIGO research together with the European-based Virgo Collaboration. "It is remarkable that humans can put together a story, and test it, for such strange and extreme events that took place billions of years ago and billions of light-years distant from us. The entire LIGO and Virgo scientific collaborations worked to put all these pieces together."


An international team of researchers has made a third detection of gravitational waves, ripples in space and time, in a discovery that provides new insights into the mysterious nature of black holes and, potentially, dark matter. Credit: LSC/OzGrav


The new detection occurred during LIGO's current observing run, which began November 30, 2016, and will continue through the summer. LIGO is an international collaboration with members around the globe. Its observations are carried out by twin detectors—one in Hanford, Washington, and the other in Livingston, Louisiana—operated by Caltech and MIT with funding from the National Science Foundation (NSF).


LIGO made the first-ever direct observation of gravitational waves in September 2015 during its first observing run since undergoing major upgrades in a program called Advanced LIGO. The second detection was made in December 2015. The third detection, called GW170104 and made on January 4, 2017, is described in a new paper accepted for publication in the journal Physical Review Letters.


In all three cases, each of the twin detectors of LIGO detected gravitational waves from the tremendously energetic mergers of black hole pairs. These are collisions that produce more power than is radiated as light by all the stars and galaxies in the universe at any given time. The recent detection appears to be the farthest yet, with the black holes located about 3 billion light-years away. (The black holes in the first and second detections are located 1.3 and 1.4 billion light-years away, respectively.)




The newest observation also provides clues about the directions in which the black holes are spinning. As pairs of black holes spiral around each other, they also spin on their own axes—like a pair of ice skaters spinning individually while also circling around each other. Sometimes black holes spin in the same overall orbital direction as the pair is moving—what astronomers refer to as aligned spins—and sometimes they spin in the opposite direction of the orbital motion. What's more, black holes can also be tilted away from the orbital plane. Essentially, black holes can spin in any direction.


The new LIGO data cannot determine if the recently observed black holes were tilted but they imply that at least one of the black holes may have been non-aligned compared to the overall orbital motion. More observations with LIGO are needed to say anything definitive about the spins of binary black holes, but these early data offer clues about how these pairs may form.


"This is the first time that we have evidence that the black holes may not be aligned, giving us just a tiny hint that binary black holes may form in dense stellar clusters," says Bangalore Sathyaprakash of Penn State and Cardiff University, one of the editors of the new paper, which is authored by the entire LSC and Virgo Collaborations.

There are two primary models to explain how binary pairs of black holes can be formed. The first model proposes that the black holes are born together: they form when each star in a pair of stars explodes, and then, because the original stars were spinning in alignment, the black holes likely remain aligned.


In the other model, the black holes come together later in life within crowded stellar clusters. The black holes pair up after they sink to the center of a star cluster. In this scenario, the black holes can spin in any direction relative to their orbital motion. Because LIGO sees some evidence that the GW170104 black holes are non-aligned, the data slightly favor this dense stellar cluster theory.


"We're starting to gather real statistics on binary black hole systems," says Keita Kawabe of Caltech, also an editor of the paper, who is based at the LIGO Hanford Observatory. "That's interesting because some models of black hole binary formation are somewhat favored over the others even now and, in the future, we can further narrow this down."


The study also once again puts Albert Einstein's theories to the test. For example, the researchers looked for an effect called dispersion, which occurs when light waves in a physical medium such as glass travel at different speeds depending on their wavelength; this is how a prism creates a rainbow. Einstein's general theory of relativity forbids dispersion from happening in gravitational waves as they propagate from their source to Earth. LIGO did not find evidence for this effect.


"It looks like Einstein was right—even for this new event, which is about two times farther away than our first detection," says Laura Cadonati of Georgia Tech and the Deputy Spokesperson of the LSC. "We can see no deviation from the predictions of general relativity, and this greater distance helps us to make that statement with more confidence."


"The LIGO instruments have reached impressive sensitivities," notes Jo van den Brand, the Virgo Collaboration spokesperson, a physicist at the Dutch National Institute for Subatomic Physics (Nikhef) and professor at VU University in Amsterdam. "We expect that by this summer Virgo, the European interferometer, will expand the network of detectors, helping us to better localize the signals."


The LIGO-Virgo team is continuing to search the latest LIGO data for signs of space-time ripples from the far reaches of the cosmos. They are also working on technical upgrades for LIGO's next run, scheduled to begin in late 2018, during which the detectors' sensitivity will be improved.




"With the third confirmed detection of gravitational waves from the collision of two black holes, LIGO is establishing itself as a powerful observatory for revealing the dark side of the universe," says David Reitze of Caltech, executive director of the LIGO Laboratory. "While LIGO is uniquely suited to observing these types of events, we hope to see other types of astrophysical events soon, such as the violent collision of two neutron stars."

https://phys.org/news/2017-06-gravitational-insight-black-holes.html


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