Heavy Construction News – Drones provide new perspective on job sites

Heavy Construction News

April 19, 2017 by Jacob Stoller

Photo provided by John Flemming, president, Ocean Contractors.

When PCL Construction needed to assess the condition of an Edmonton rooftop in mid-winter, they chose an alternative approach. “Instead of sending somebody up there to walk on the roof in icy conditions, we flew a UAV (unmanned aerial vehicle) over the roof and sent the video to the consultant,” says Mirra Maheden, senior virtual construction specialist for PCL. The video provided the necessary overview, and also allowed the consultant to zoom in on various details in order to complete the assessment.

UAV or drone adoption is one of the fastest growing uses of technology in construction, and inspecting icy rooftops is only one of many emerging applications leading to safer jobsites, better dissemination of information, and in some cases, precise measurement.

“We started looking into this about two years ago, and we’ve been using UAVs on project sites for about a year now,” says Sonny Shem, virtual construction manager for PCL. “It’s gone from discussing what we could do with drones, to actually getting out there and flying and capturing data.” PCL currently has a dozen pilots trained to fly drones effectively and in accordance with legal requirements.

The most common application, says Maheden, is relatively straightforward – progress videos, typically updated on a weekly basis, that give stakeholders a “big picture” view of how a job is progressing. “Videos allow managers to see the progress of the site from an aerial view, so they can assess which areas are progressing or lagging and compare that with their planning schedule. They can also send the video to clients, or prospective clients or tenants.”

Flight videos taken on drone flights are also used to identify hazards on jobsites, and to provide documentation for compliance with environmental regulations. “EllisDon does a lot of projects with local governments, and there are guidelines for maintaining clean jobsites and handling materials in an environmentally friendly way,” says Stantton Pallister, geomatics manager at Alberta-based PME Inc., a heavy civil contractor owned by EllisDon. “Drones allow us to keep a clear photographic record of the site.”

While providing viewers with an aerial perspective is the most common use for drones, it is not the only one. “Different kinds of cameras and devices can be attached to the drone for different applications,” says Pallister. “For example, when a building is complete, we can fly a drone around it with a thermal imaging camera, and look for heat leaks.” Other technologies include magnetic imaging, laser imaging, and GPS data.

Perhaps the most powerful application is the use of drone-collected data in virtual 3D models of construction projects. This provides a common view of the site for people throughout the organization, and allows supervisors, constructions managers, and senior managers to discuss projects from the same vantage point. “The 3D models that are generated from our drone flights provide a perspective that amazes many of our customers, compared to what they are used to looking at,” says Pallister.

Drones can also be used for measurement purposes. One of the most advanced applications comes from mining: the use of drones in early stages of a project to create and update accurate geographic models, allowing contractors to measure quantities of earth, gravel, and other aggregates.

“At PME, one of the ways we get paid, is for how much earthworks material is moved at a jobsite, so we developed a process where we can use the drone to measure volumetric quantities of earthwork stockpiles on jobsites,” says Pallister. “We measure accurately to the cubic metre, and provide that to the construction team for progress billing.” The method, Pallister points out, is superior to traditional methods, such as counting truckloads. “We’re more accurate, and this adds up to substantial savings.”

Assessing the options

Thanks to the introduction of drones to the consumer market, prices have plummeted in the past three years, giving contractors a range of choices. “We’re using everything from prosumer UAV to commercial devices – it depends on the application,” says Shen. “If we’re just taking a quick video, we might use a prosumer type drone. If we’re actually mapping the terrain, we’ll need a higher end drone with a better sensor and a better camera system.”

Collecting the data, however, is only the beginning. Captured data is typically stored in the drone on memory cards, and are then uploaded to the cloud, where it is either made available as video, or processed in formats suitable for BIM programs and other 3D apps. Integration, always a challenge, is particularly daunting given the file sizes, which ranges from 4 – 6 GB from a typical flight.

For organizations that aren’t interested in purchasing or learning to operate drones, there are companies like Menlo Park, Calif.-based technology provider Kespry, which offers an all-inclusive, end-to-end solution. Clients pay a subscription fee for a complete package, which includes access to fully-equipped drones, data collection tools, and cloud-based processing facilities that allow the data to be delivered to construction applications in 30 file formats. Kespry’s software flies the drones based on defined missions, so there is no need to train pilots.

“We take care of all the steps for contractors that need to collect accurate, reliable data, but don’t want to be in the drone business,” says David Shearer, vice-president marketing for Kespry. In addition to AEC (Architecture, Engineering, Construction), the company provides solutions for aggregates and mining, and the property claims insurance industry in Canada.

One of the key requirements for drone use is keeping compliant with regulations. UAVs were unregulated in Canada until fairly recently, but are now considered aircraft and are covered under the Canadian Aviation Regulations (CAR). Restrictions include allowable flying altitudes, maintaining visual contact with the drone, and avoidance of no-fly zones such as populated areas and airports.

The regulations are extensive, and operators at the very least need to become thoroughly familiar with them, and in many cases, apply for a Special Flight Operations Certificate (SFOC). “We have seen the regulations get very complicated,” says Shem. Organizations may be required to carry special liability insurance as well.

Looking ahead

The rapid expansion of drone use in construction is not slowing down. PCL is working on expanding its capabilities for developing 3D point clouds for bringing data into its 3D modeling systems. “We’re just scratching the surface of where this can go,” says Maheden.

Pallister’s team is working on incorporating GIS data in their mapping operations. For example, PME plans to fly drones in built-up urban areas to identify and locate terrain features such as lamp posts, fire hydrants, mail boxes, and power lines – all of which are currently captured through ground observation. The information will then be shared with municipalities for urban planning, or to estimating teams. “When we’re looking at job pursuits or pre-construction work, we’ll be able to be more predictive for our planning and our costing,” says Pallister. “We’ll know what the ground features look like before we begin the project.”

Progress, however, isn’t just about improving the technology – contractors have much to gain from applying technologies that already exist. “It’s important that this is used in a wider perspective,” says Shem. “When you’re on a construction site, you don’t actually get to see the whole progress that’s taking place. We can show a progress video to a project manager that’s been on a site for two years, and they tell us they’ve never seen the project from that perspective.”

“When we share these videos with the trades on a project, they get to see things they don’t normally see,” says Maheden. “That helps them become more engaged and thus take pride in their own work, and helps us enhance the teamwork on site.”

Article from —-> http://www.on-sitemag.com/features/drones-provide-new-perspectives-jobsites/

Save

Originally posted 2017-04-25 23:47:19. Republished by Blog Post Promoter

Music Hot Hits – Listen to your Favorite music now


Music Hot Hits – Stream free music – with our Massive Music Search Engine – Playlists for everybody – Download your favorite artists and bands today
http://www.musichothits.com/

Brothers and sisters, if someone is caught in a sin, you who live by the Spirit should restore that person gently. But watch yourselves, or you also may be tempted.




Originally posted 2017-04-14 22:38:10. Republished by Blog Post Promoter

Taylor Swift | Music Weekly News


Date of Birth 13 December 1989, Reading, Pennsylvania, USA
Birth Name Taylor Alison Swift
Nicknames T-Swizzle
Tay
Tay-Tay
Height 5′ 10″ (1.78 m)
Taylor Swift

Taylor Alison Swift is a multi-Grammy award-winning American singer/songwriter who, in 2010 at the age of 20, became the youngest artist in history to win the Grammy Award for Album of the Year. In 2011 Swift was named Billboard’s Woman of the Year. She also has been named the American Music Awards Artist of the Year, as well as the Entertainer of the Year for both the Country Music Association and the Academy of Country Music, among many other accolades. As of this writing, she is also the top-selling digital artist in music history.
http://musicweeklynews.com/taylor-swift/

Do not be deceived: God cannot be mocked. A man reaps what he sows.




Originally posted 2017-04-04 21:58:25. Republished by Blog Post Promoter

Spokane, Wa Construction | Call 1 888 260 7525


Welcome Spokane Copenhaver Construction Inc. is a family owned and operated company. Established in 1992 we have continued to adapt and expand to meet the needs of our customers. From rock crushing to ready mix concrete, site prep to road construct…
http://copenhaverconstructioninc.com/spokane-wa-construction-call-1-888-260-7525/

And without faith it is impossible to please God, because anyone who comes to him must believe that he exists and that he rewards those who earnestly seek him.




Originally posted 2017-03-26 21:51:31. Republished by Blog Post Promoter

Blake Shelton | Music Hot Hits


Blake Tollison Shelton (born June 18, 1976) is an American country music artist. In 2001, he made his debut with the single “Austin”. Released as the lead-off single from his self-titled debut album, “Austin” went on to spend five weeks at Number One on the Billboard Hot Country Songs charts. This song was the first single from his gold-certified debut album, which also produced two more Top 20 hits. Although the album was released on Giant Records Nashville, Shelton was transferred to Warner Bros. Records Nashville after Giant closed in late 2001. His second and third albums, 2003’s The Dreamer (his first for Warner Bros. proper) and 2004’s Blake Shelton’s Barn & Grill, were each certified gold as well. Shelton’s fourth album, Pure BS, was issued in 2007, and re-issued in 2008 with a cover of Michael Bublé’s pop hit “Home” as one of the bonus tracks. This cover was also that album’s third single. A fifth album, Startin’ Fires, was released in November 2008.
http://www.musichothits.com/artist/Blake%20Shelton

He has saved us and called us to a holy life—not because of anything we have done but because of his own purpose and grace. This grace was given us in Christ Jesus before the beginning of time.




Originally posted 2017-04-10 21:06:23. Republished by Blog Post Promoter

Washington Sand and Gravel Companies | Call 1 888 260 7525


Welcome Washington Copenhaver Construction specializes in crushed rock, topsoil, landscape rock, pea gravel, and sand. We supply sand and gravel throughout the washington area. Copenhaver Construction Inc. is a family owned and operated company. Established in 1992 we have continued to adapt and expand to meet the needs of our customers. From rock crushing to […]
http://copenhaverconstructioninc.com/washington-sand-gravel-1888-260-7525/

The angel said to the women, “Do not be afraid, for I know that you are looking for Jesus, who was crucified. He is not here; he has risen, just as he said. Come and see the place where he lay.”




Originally posted 2017-03-30 21:00:07. Republished by Blog Post Promoter

Rock Crushing

Grand Coulee Rock Crushing

The Metso 4265 Gyratory Crusher

Crusher

A crusher is a machine designed to reduce large rocks into smaller rocks, gravel, or rock dust.

Crushers may be used to reduce the size, or change the form, of waste materials so they can be more easily disposed of or recycled, or to reduce the size of a solid mix of raw materials (as in rock ore), so that pieces of different composition can be differentiated. Crushing is the process of transferring a force amplified by mechanical advantage through a material made of molecules that bond together more strongly, and resist deformation more, than those in the material being crushed do. Crushing devices hold material between two parallel or tangent solid surfaces, and apply sufficient force to bring the surfaces together to generate enough energy within the material being crushed so that its molecules separate from (fracturing), or change alignment in relation to (deformation), each other. The earliest crushers were hand-held stones, where the weight of the stone provided a boost to muscle power, used against a stone anvil. Querns and mortars are types of these crushing devices.

 

 

 

Rock Crushing

Rock Crushing

Rock Crushing

Rock Crushing

Rock Crushing

 

 

Save

Save

Originally posted 2017-04-27 20:28:00. Republished by Blog Post Promoter

How to prepare for a clean install of Windows 10 Creators Update | News


With the public release of the Creators Update for Windows 10 arriving Tuesday, April 11, it’s time to start prepping for that “feature update” (aka version 1703). There are several steps that you can and should take to get your machines ready.

Let’s begin with a discussion of upgrade versus clean install of this new major Windows 10 release and an overview of the pros and cons for each approach.
Clean install versus upgrade install

The fastest and easiest way to move up to the Creators Update is to simply let Windows Update handle it. That is, you’ll be offered the Creators Update through Windows Update sometime after the release goes public, when you accept the offer, the update will download itself and get installed on your PC(s).
http://www.cio.com/article/3188037/windows/how-to-prepare-for-a-clean-install-of-windows-10-creators-update.html

I can do all this through him who gives me strength.




Originally posted 2017-04-06 20:19:47. Republished by Blog Post Promoter

Caterpillar Accounting issues, What does Jim Cramer say


Jim Cramer knows there is scrutiny over Caterpillar’s accounting practices, but still considers the stock a buy. Here’s why.
http://video.cnbc.com/gallery/?video=3000600365

Dishonest money dwindles away, but whoever gathers money little by little makes it grow.




Originally posted 2017-03-29 19:40:36. Republished by Blog Post Promoter

Packed ENR FutureTech Event Builds Optimism | 2017-06-07 – News

Heavy Construction Photos



A sold-out audience of construction professionals, venture capitalists and technologists at ENR’s recent FutureTech conference in San Francisco were repeatedly warned that the construction industry still is plagued by inefficiency and a lack of technology adoption, but they also were shown many hopeful signs of change, including several examples of the advantages gained from new levels of sharing and managing data.

In order to counter the effects of a shrinking workforce while meeting growing demands for connected, sustainable buildings, construction professionals must learn to capitalize on the troves of data accumulated from digital processes and increase the adoption of building information modeling and design and project collaboration, the presenters stressed.

More Shared Data, Better Outcomes

Design-build-operate project delivery is improving as a result of forced collaboration, observed Jose Luis Blanco Alvarez, a McKinsey & Co. partner, in an opening-day keynote on May 30. Better data storage and analysis and better contract models, such as shared-risk integrated project delivery, are driving beneficial BIM adoption and better, more efficient building projects, he said. 

Speaking about recent Dodge Data & Analytics studies on construction risk patterns, Dodge Vice President Cliff Brewis said the results affirm the benefits of collaboration, suggesting that the most consistent differentiator between “excellent” and “typical” construction projects is the level of participation during design by multiple disciplinary stakeholders. He said 42% of the “excellent” projects also had high participation in design by all stakeholders.

Attendees were given examples of how  big data and machine learning are giving rise to real-time project indicators that can be visualized and measured to spur corrective action in a way that would not have been possible just a few years ago. Better data is being mined, analyzed and used for predictions as well as lessons learned. Visualization and predictive analytics were two of the transformative technologies that kept cropping up in presentations throughout the three-day conference.

Automation and Drones

Thai Nguyen, director of virtual design and construction at Hensel Phelps, delivered a presentation that described how his firm used photogrammetry from indoor-flying drones and laser-scanning by autonomous robotic crawlers to validate 700,000 3D model files during a massive upgrade to a chip fabrication facility.

Validating the fast-paced and complex installation work to spot installation errors and address them quickly required constant updating, clash detection and coordination of 80,000 models. The team updated as many as 250 models a day using data from the 200,000 scans, completed in two years. The scans totaled 16 terabytes of data. Nguyen says processing that much data was made possible because of emerging services for automated scanning, quality control and productivity reporting, provided by Doxel, whose co-founder and CEO, Saurabh Ladha, shared the presentation.

Jobsites are becoming more connected, with general contractors testing systems for real-time tracking of people, equipment, tools and building materials, the speakers noted. Rosendin Electric showcased a robust implementation of its RFID-based system for tool inventory control on a national scale.

Mortenson Construction and tool vendor DeWalt presented a field test of a WiFi mesh-network system of ruggedized wireless nodes. Also at FutureTech, DeWalt announced that it is developing the pilot program into a jobsite WiFi product line, which will be released in Q4. The system promises seamless, plug-and-play, high-bandwidth wireless coverage on jobsites, enabling the kind of “always connected” environment many of the innovations discussed at the conference will require. Later this year, DeWalt also plans to launch an “internet of things” sensor and asset-management platform.

What To Do With All That Data?

Chris Mayer, executive vice president and chief information officer at Boston-based Suffolk Construction, explained how his company is preparing to open a network of facilities, called SmartLabs, to support Suffolk’s digital transformation by helping to develop and institutionalize consistent virtual design and construction standards as well as learning and development programs for the company. The ideas that graduate from the labs will get formal pilot programs on Suffolk jobsites.

“We want to determine how to use the right mechanism at the right time and create standards for where, how and when we communicate,” Mayer said.

One of the pitfalls that presenters lamented was “garbage in, garbage out” data that can plague even the smallest construction project and bog down, rather than enhance, collaboration and efficient delivery. “Models converted incompletely to 2D plans do not enhance collaboration or understanding, so why use them?” asked Hitesh Dewan, operations and technology manager at Milpitas, Calif.’s XL Construction. Dewan also demonstrated how rapidly proliferating inexpensive 360º pocket cameras are helping him to connect his projects with owners and other stakeholders with quickly captured and easily shared imagery.

EarthCam, a job-cam service provider that exhibited at the show, announced a new product based on 360º imagery to capture, tag and integrate such images in project data-management systems. The company also announced an integration of the new product into PlanGrid’s field productivity platform.

Trimble showcased its Building Points model-management system and how it can be used with Microsoft’s HoloLens headsets to plan and validate material and equipment placement via mixed reality. Owner buy-in was a key metric.

Mark Dinius, technology manager at Satterfield and Pontikus Construction, demonstrated a sophisticated reality capture and analysis solution that uses a handheld 3D-imaging scanner and processor to create a point-cloud scan to compare with the design model the work in place on a small site having tight steel-frame placement demands. Dinius described the experience of trying to convince major subcontractors to work with such technology as “heartbreaking.”

The World Economic Forum, an organization dedicated to propelling industry efficiency worldwide, recently released “Shaping the Construction Industry,” a report on what governments must do to enhance safety and productivity in their construction sectors. Michael Buehler, head of infrastructure and urban development for WEF, said $1.2 billion in infrastructure investment could be unlocked if countries would simply agree to project approval timelines and deadlines. Buehler implored construction companies to use standardized products that feed into a robust and well-sourced supply chain with uniform specifications for bids to solve the age-old productivity problem on U.S. and international project sites.

By Jeff Yoders, with Jeff Rubenstone, Scott Blair, Aileen Cho and Tom Sawyer in San Francisco



Source link

I give them eternal life, and they shall never perish; no one will snatch them out of my hand. My Father, who has given them to me, is greater than all; no one can snatch them out of my Father’s hand. I and the Father are one.

Heavy Construction News – Scientists discover a 2-D magnet — ScienceDaily

Heavy Construction Photos


Magnetic materials form the basis of technologies that play increasingly pivotal roles in our lives today, including sensing and hard-disk data storage. But as our innovative dreams conjure wishes for ever-smaller and faster devices, researchers are seeking new magnetic materials that are more compact, more efficient and can be controlled using precise, reliable methods.

A team led by the University of Washington and the Massachusetts Institute of Technology has for the first time discovered magnetism in the 2-D world of monolayers, or materials that are formed by a single atomic layer. The findings, published June 8 in the journal Nature, demonstrate that magnetic properties can exist even in the 2-D realm — opening a world of potential applications.

“What we have discovered here is an isolated 2-D material with intrinsic magnetism, and the magnetism in the system is highly robust,” said Xiaodong Xu, a UW professor of physics and of materials science and engineering, and member of the UW’s Clean Energy Institute. “We envision that new information technologies may emerge based on these new 2-D magnets.”

Xu and MIT physics professor Pablo Jarillo-Herrero led the international team of scientists who proved that the material — chromium triiodide, or CrI3 — has magnetic properties in its monolayer form.

Other groups, including co-author Michael McGuire at the Oak Ridge National Laboratory, had previously shown that CrI3 — in its multilayered, 3-D, bulk crystal form — is ferromagnetic. In ferromagnetic materials, the “spins” of constituent electrons, analogous to tiny, subatomic magnets, align in the same direction even without an external magnetic field.

But no 3-D magnetic substance had previously retained its magnetic properties when thinned down to a single atomic sheet. In fact, monolayer materials can demonstrate unique properties not seen in their multilayered, 3-D forms.

“You simply cannot accurately predict what the electric, magnetic, physical or chemical properties of a 2-D monolayer crystal will be based on the behavior of its 3-D bulk counterpart,” said co-lead author and UW doctoral student Bevin Huang.

Atoms within monolayer materials are considered “functionally” two-dimensional because the electrons can only travel within the atomic sheet, like pieces on a chessboard.

To discover the properties of CrI3 in its 2-D form, the team used Scotch tape to shave a monolayer of CrI3 off the larger, 3-D crystal form.

“Using Scotch tape to exfoliate a monolayer from its 3-D bulk crystal is surprisingly effective,” said co-lead author and UW doctoral student Genevieve Clark. “This simple, low-cost technique was first used to obtain graphene, the 2-D form of graphite, and has been used successfully since then with other materials.”

In ferromagnetic materials, the aligned spins of electrons leave a telltale signature when a beam of polarized light is reflected off the material’s surface. The researchers detected this signature in CrI3 using a special type of microscopy. It is the first definitive sign of intrinsic ferromagnetism in an isolated monolayer.

Surprisingly, in CrI3 flakes that are two layers thick, the optical signature disappeared. This indicates that the electron spins are oppositely aligned to one another, a term known as anti-ferromagnetic ordering.

Ferromagnetism returned in three-layer CrI3. The scientists will need to conduct further studies to understand why CrI3 displayed these remarkable layer-dependent magnetic phases. But to Xu, these are just some of the truly unique properties revealed by combining monolayers.

“2-D monolayers alone offer exciting opportunities to study the drastic and precise electrical control of magnetic properties, which has been a challenge to realize using their 3-D bulk crystals,” said Xu. “But an even greater opportunity can arise when you stack monolayers with different physical properties together. There, you can get even more exotic phenomena not seen in the monolayer alone or in the 3-D bulk crystal.”

Much of Xu’s research centers on creating heterostructures, which are stacks of two different ultrathin materials. At the interface between the two materials, his team searches for new physical phenomena or new functions to allow potential applications in computing and information technologies.

In a related advance, Xu’s research group, UW electrical engineering and physics professor Kai-Mei Fu led a team of colleagues published a paper May 31 in Science Advances showing that an ultrathin form of CrI3, when stacked with a monolayer of tungsten diselenide, creates a ultraclean “heterostructure” interface with unique and unexpected photonic and magnetic properties.

“Heterostructures hold the greatest promise of realizing new applications in computing, database storage, communications and other applications we cannot even fathom yet,” said Xu.

Xu and his team would next like to investigate the magnetic properties unique to 2-D magnets and heterostructures that contain a CrI3 monolayer or bilayer.



Source link

Dear friends, since God so loved us, we also ought to love one another.

Disney Goes Metal on New Cover Compilation #MusicNews


The phrase “Disney music” often conjures up images of doe-eyed princesses belting out Broadway ballads. But a new album comprised of classic tracks from the House of Mouse re-imagined with power metal vocals, crushing guitars and breakneck drumming is looking to upend that stereotype.
Related
See Ozzy Osbourne Record Metal Voiceover for Disney Cartoon

Rock legend, wife Sharon cameo in upcoming episode of ‘The 7D,’ which co-stars daughter Kelly

Metal Disney was released in Japan last year and became a hit, climbing to number three in the Amazon rock/metal charts and number two on the Kids charts. Disney has released the album stateside today, March 31st.

The well-respected heavy metal musicians that comprise the “D-Metal Stars” include Obsession vocalist Mike Vescera, who’s previously worked with Yngwie Malmsteen, and former Ozzy Osbourne bassist Rudy Sarzo. The band is rounded out by fellow Obsession guitarist John Bruno and drummer BJ Zampa, who’s played with Dokken, among
http://www.rollingstone.com/music/news/inside-disneys-attempt-to-go-metal-on-new-covers-compilation-w472108

Originally posted 2017-04-01 17:12:20. Republished by Blog Post Promoter

Heavy Construction News – John Deere


John Deere   Deere & Company John Deere World Headquarters in Moline, Illinois Type Public Traded as NYSE: DE S&P 500 Component Industry Heavy equipment Founded Grand Detour, Illinois (1837; 180 years ago) Founder John Deere Headquarters Moline, Illinois, United States Area served Worldwide Key people Samuel R. Allen (CEO and President) Products Agriculture, Construction, Forestry, Consumer & … Continue reading “Heavy Construction News – John Deere”
http://copenhaverconstructioninc.com/2017/04/18/heavy-construction-news-john-deere/

May he give you the desire of your heart and make all your plans succeed.

Save

Save

Originally posted 2017-04-18 16:41:29. Republished by Blog Post Promoter

Heavy Construction News – Spin effects in solution-based nanocrystals — ScienceDaily

Heavy Construction Photos


Wet-chemically produced nanocrystals are becoming more and more powerful. They are already used in the background lighting of the latest generation of flat panel displays. In the future they will be used increasingly as active elements, which produce higher color brilliance. They are also used in other fields of application, e.g., for medical diagnosis and treatment. Now a research group around Dr. Christian Klinke from the University of Hamburg has succeeded in substantiating electronic spin effects in such nanoplatelets. In this way, more cost-effective and more powerful transistors and computer chips with lower power consumption are conceivable in the future. The two-dimensional materials are also advantageous since they can be produced inexpensively and on a large scale in a chemical laboratory and are nevertheless of the highest quality, as shown now.

The group around Dr. Christian Klinke focuses on the synthesis and characterization of two-dimensional semiconductor nanocrystals. The nanoplatelets are adjustable in their structure, but also in their optical and electrical properties (by quantum mechanical effects). This makes them interesting for application in solar cells and computer circuits.

In contrast to classical devices which work based on the electron motion, spintronic components function based on the spin orientation of electrons. When light passes through special optical elements, it can become circularly polarized, i. e. the light receives a torque. By the illumination with circular-polarized light, it is possible to align electrical charges with respect to their spin (torque) in semiconductor materials and to convert them into an electrical current without applying a voltage. Investigations on the generated current provide information about spin-dependent properties of the crystal.

The researchers have now succeeded in demonstrating this so-called Rashba effect in two-dimensional lead sulfide nanoplatelets. It is particularly interesting since this effect is normally not observed due to the high crystal symmetry of the nanoplatelets. Only by the influence of an effective electric field the symmetry is broken and a current can be measured. By varying the layer thickness of the nanoplatelets, the character of the light used, and the intensity of the electric fields, the effect could be controlled. This allows the conditions to be adapted specifically to the targeted applications, which enables the external manipulation of the electron spin. The experimental observations were supported with simulations of the electronic structure of the materials by the group of Prof. Carmen Herrmann at the University of Hamburg.

“The findings are particularly valuable as it was demonstrated for the first time that basic effects of electric spin transport are also possible in wet-chemically generated nanomaterials,” says Christian Klinke. “This raises hope that also other interesting phenomena can be observed in these materials, which will contribute to improving our understanding of their properties.” These new insights, which are described in detail in the journal Nature Communications, make a decisive contribution to our knowledge on opto-electronic properties of tailor-made nanostructures. They serve as a foundation for the further investigation of useful two-dimensional systems and their application in the field of regenerative energies, information technology, and catalysis.

Nanotechnology is a key technology of the 21st century. Materials with a size of only a few nanometers (one millionth of a millimeter) have particular optical, magnetic, electrical and photoelectric properties. They can be used in efficient light-emitting diodes, solar cells, novel sensors, photodetectors, flexible transistors, and efficient computer chips as well as in biological and medical fields. The understanding of the opto-electrical properties of nanostructures and their precise control allows the use in semiconductor electronics at the interface to optical and electromagnetic systems, which can lead to novel high-performance and energy-saving processors.

Story Source:

Materials provided by University of Hamburg. Note: Content may be edited for style and length.



Source link

But many who are first will be last, and many who are last will be first.

The Largest Excavator in the world – Heavy Construction News

Heavy Construction News

 

Biggest excavator in the world

Bagger 288

Bagger 288 (Excavator 288), built by the German company Krupp for the energy and mining firm Rheinbraun, is a bucket-wheel excavator or mobile strip mining machine.

The Bagger 288 bucket-wheel excavator

When its construction was completed in 1978, Bagger 288 superseded Big Muskie as the heaviest land vehicle in the world, at 13,500 tons. It took five years to design and manufacture, and five years to assemble with total cost reaching $100 million. In 1995, it was itself superseded by the slightly heavier Bagger 293 (14,200 tons). NASA’s Crawler-Transporter still remains the largest self-powered land vehicle in the world, since bucket-wheel excavators are powered by an external power source, and the Overburden Conveyor Bridge F60s hold the title of largest land vehicle of any type by physical dimensions.

If your brother or sister sins, go and point out their fault, just between the two of you. If they listen to you, you have won them over.

 

Objective

The Bagger 288 was built for the job of removing overburden before coal mining at the Hambach stripmine in Germany. It can excavate 240,000 tons of coal or 23,240,000 cubic metres of overburden daily[3] – the equivalent of a football field (soccer) dug to 30 m (98 ft) deep. The coal produced in one day fills 2400 coal wagons. The excavator is up to 220 m (721 ft) long (slightly shorter than Baggers 287 and 293) and approximately 96 m (315 ft) high. The Bagger’s operation requires 16.56 megawatts of externally supplied electricity.[4] It can travel 2 to 10 m (6.6 to 32.8 ft) per minute (0.1 to 0.6 km/h). The chassis of the main section is 46 m (151 ft) wide and sits on 3 rows of 4 caterpillar track assemblies, each 3.8 m (12 ft) wide. The large surface area of the tracks means the ground pressure of the Bagger 288 is very small (1.71 bar or 24.8 psi); this allows the excavator to travel over gravel, earth and even grass without leaving a significant track. It has a minimum turning radius of approximately 100 metres, and can climb a maximum gradient of 1:18 (5° incline).

The excavating head itself is 21.6 m (70 ft 10 in) in diameter and has 18 buckets each holding 6.6 cubic metres (8.6 cu yd) of overburden.

By February 2001, the excavator had completely exposed the coal source at the Tagebau Hambach mine and was no longer needed there. In three weeks it made a 22-kilometre (14 mi) trip to the Tagebau Garzweiler, traveling across Autobahn 61, the river Erft, a railroad line, and several roads. The move cost nearly 15 million German marks and required a team of seventy workers. Rivers were crossed by placing large steel pipes for the water to flow through and providing a smooth surface over the pipes with rocks and gravel. Special grass was seeded to smooth its passage over valuable terrain. Moving Bagger 288 in one piece was more economical than disassembling the excavator and moving it piece by piece.

The Bagger 288 is one of a group of similar sized and built vehicles, such as Bagger 281 (built in 1958), Bagger 285 (1975), Bagger 287 (1976), Bagger 293 (1995), etc.

 

Save

Save

Save

Originally posted 2017-05-03 16:12:02. Republished by Blog Post Promoter