South African inventions

first_imgMediaClubSouthAfrica.com reporter The dolos, a South African invention in which interlocking blocks of concrete are used to protect seawalls and preserve beaches from erosion, at the Coega deep-water port.(Image copyright Coega)Where would you expect to find the inventor of the CAT scan, the makers of the “speed gun” used in cricket ovals the world over, or the world’s first oil-from-coal refinery?There’s a wide range of innovative and entrepreneurial activity in South Africa, backed up by a number of organisations that provide support for budding inventors and innovators.Q20CAT scanOil from coalHeart transplantSpeed gunKreepy KraulyAPS therapyPratley PuttyDolosseQ20, a multi-purpose lubricant The product was developed back in 1950 in Pinetown, KwaZulu-Natal, by a Mr Robertson, who reportedly had come up with an effective water repellent that kept rust at bay, eased squeaky door hinges, and made it easy to release rusted or seized nuts and bolts.Apparently Robertson did not know what to call it but he told his neighbour that it certainly had 20 answers to 20 questions, and the name Q20 stuck.Today the product, and others in the range, is used widely in South African offices, workshops and homes, and has set the standard for all subsequent similar products from around the world. It is also sold in the US and UK/Europe.According to Q20 manufacturing company Triton-Leo, the secret to the wonder substance’s efficiency is that unlike oil, it is heavier than water. Once Q20 is sprayed on water, it sinks to the bottom, where it acts as a water displacer and lubricant on the problem area.Triton-LeoCAT scanThe computed axial tomography scan, or CAT scan, was developed at Tufts University in the UK by South African physicist Allan Cormack and Godfrey Hounsfield of EMI Laboratories. Their achievement secured them the 1979 Nobel Prize in Physiology or Medicine.Cormack’s interest in the problem of X-ray imaging of soft tissues or layers of tissue of differing densities was first aroused when he took up the part-time position of physicist for a hospital radiology department.The two-dimensional representations of conventional X-ray plates were often unable to distinguish between such tissues. More information could be gained if X-rays of the body were taken from several different directions, but conventional X-ray techniques made this procedure problematic.In the early 1960s Cormack showed how details of a flat section of soft tissues could be calculated from measurements of the attenuation of X-rays passing through it from many different angles.He thus provided the mathematical technique for the CAT scan, in which an X-ray source and electronic detectors are rotated about the body and the resulting data is analysed by a computer to produce a sharp map of the tissues within a cross-section of the body.Nobel e-Museum: Allan CormackOil from coalSasol is the world’s first – and largest – oil-from-coal refinery. It is situated in Sasolburg in South Africa and provides 40% of the country’s fuel.The history of Sasol began in 1927 when a White Paper was tabled in Parliament to investigate the establishment of a South African oil-from-coal industry.It was realised then that, because South Africa did not have crude oil reserves, the country’s balance of payments had to be protected against increasing crude oil imports. After many years of research and international negotiations, the South African Coal Oil and Gas Corporation was formed in 1950.Major milestones include the first automotive fuel (1955), the construction of the National Petroleum Refiners of South Africa (1967), the establishment in 1990 of its first international marketing company, Sasol Chemicals Europe, and a joint venture agreement signed with Uzbekneftegaz in 2009 to establish a gas-to-liquids venture in Uzbekistan.Sasol has developed world-leading technology for the conversion of low-grade coal into value-added synfuels and chemicals.SasolHeart transplantThe world’s first heart transplant was performed by Dr Christiaan Barnard in Cape Town on 3 December 1967.Barnard was born in the town of Beaufort West in 1922. The seeds of his future career were sown when one of his patients delivered a baby boy with a heart defect which could not be remedied. The baby died, causing him to think deeply about the need for remedial surgery and the replacement of heart valves.A turning point came when Barnard was offered a chance to work in Minneapolis in the US under Professor Wagensteen, a great teacher of experimental surgery. The heart-lung machine was perfected, and this turned out to be the gateway to cardiac surgery.The idea of transplanting occurred to Barnard. If it was possible with kidneys, why not the heart? After more years of study in the US, he returned to South Africa with a parting gift from Prof Wagensteen – a heart-lung machine.Groote Schuur hospital was waiting his return in 1958 to start the first heart unit to perform a cardiac bypass operation.After performing the first successful kidney transplant on Edith Black, in October 1967 Barnard informed Professor Val Schrire, who had built up the cardiac clinic: “Everything is ready for a heart transplant. We have the team and we know how to do it.”In November 1967, Schrire called Barnard and told him that there was a suitable patient for a heart transplant. Louis Washkansky was suffering from heart failure and was prepared to take the chance. The rest is history.Barnard passed away in Cyprus, Greece on 2 September 2001 from an acute asthma attack.Speed gunThe South African-made speed gun, developed by Somerset West inventor Henri Johnson, was formally launched at The Oval in England during the 1999 Cricket World Cup.In 1992 Johnson, an engineer witha background in sonar and radar, invented the Speedball which was manufactured by South African firm Electronic Development House. The device accurately measures the speed and angles of speeding objects such as cricket and tennis balls.Generally referred to as a “speed gun”, Johnson’s gizmo is sold in cricketing countries and in the US and Europe. It has also been adapted for other ball sports such as tennis and golf. Johnson has since moved his company to Orlando, Florida, to better keep up with world trends.Kreepy KraulyThe swimming pool vacuum cleaner was invented by Ferdinand Chauvier, a hydraulics engineer who came to South Africa from the Belgian Congo in 1951.Chauvier quickly realised that there was a huge market for taking the hassle out of cleaning swimming pools, and went about inventing a machine that would do the job automatically, efficiently powered by the ordinary operation of the pool’s filter.But it wasn’t until 1974 that the first Kreepy Krauly was born in Chauvier’s Springs home.He died in 1985, but Kreepy Kraulys continue to keep thousands of pools clean in South Africa and the world over.APS therapyGervan Lubbe was flicking through an American medical journal one day when he stumbled across an article about pain relief. After reading all he could on the topic, he wondered whether it would be possible to electronically stimulate the body’s natural nerve impulses to relieve pain.Lubbe, had always had a keen interest in medicine, but never thought he was clever enough to be a doctor. So in his spare time he studied human anatomy and physiology until he thought he knew enough about the causes of arthritic pain. Then he set out inventing a device that would alleviate the problem.After building the first prototypes and obtaining approval from the health department and the Food and Drug Administration in the United States, Lubbe formed the company Tech Pulse in 1993 to produce, market and distribute the Action Potential Stimulation device.Today, Lubbe’s devices are sold in 41 countries, including the US, Europe and the Middle East. In South Africa alone, over 40 000 people use the little machines to relieve pain.APS TherapyPratley PuttyPratley’s famous glue is the only South African invention that has been to the moon. In 1969 the putty was used to hold bits of the Apollo XI mission’s Eagle landing craft together.Krugersdorp engineer George Montague Pratley invented his famous sticky stuff in the 1960s while looking for a glue that would hold components in an electrical box.Pratley died in 1983 and today the company is run by his son, Kim. Hundreds of tons of Pratley putty have been exported all over the world, and the company has diversified into other products.PratleyDolosseDolosse are large, unusually shaped concrete blocks weighing up to 20 tons. The structures are designed to break up wave action and protect harbour walls and coastal installations.Designed by Eric Merrifield and first installed in East London harbour, they are now used all over the world.The Coega Project, comprising an industrial development complex and deepwater port 20 kilometres east of the city of Port Elizabeth, recently made history with the casting of the biggest dolosse on the African continent.A layer of 25 000 30-ton dolosse has been laid on the two breakwaters for the deep-water harbour of Ngqura.According to Deon Retief, the partner responsible for the Nqura breakwater design at Prestedge Retief Dresner Wijnberg, the dolosse comprise the top layer of the main breakwater which, at 2.5 kilometres long, is the “largest by far” in Africa.Q20 extract by Emily van Rijswijck. Other information taken from Great South African Inventions by Mike Bruton, published by Cambridge University Press in their Indigenous Knowledge Library series. ISBN 978 0 521 74663 2.Useful linksAcademy of Science of South AfricaCouncil for GeoscienceCouncil for Scientific and Industrial ResearchDepartment of Science and TechnologyInnovation FundInnovation HubNational Advisory Council on InnovationNational Research FoundationNational Science and Technology Forum AwardsNational Science and Technology ForumPublic Understanding of BiotechnologySABS Designs InstituteSouth African Aids Vaccine InitiativeSouth African Biodiversity Information FacilitySouth African Bureau of StandardsSouthern African Large TelescopeSquare Kilometre Array South AfricaTechnology Top 100last_img read more

Ohio Ag Weather and Forecast — June 26, 2018

first_imgShare Facebook Twitter Google + LinkedIn Pinterest  We squeeze out another mostly dry day across Ohio today, with sunshine and pleasant temperatures. Moisture is moving east, though ,coming out of Illinois this morning and it will take all day to spread across Indiana. This will put scattered rain showers into western and NW Ohio overnight tonight. The moisture then spreads across the rest of the state through tomorrow and into the early part of Thursday.  Rain and thunderstorm action should trigger .25”-1.5” of rain over 100% of the state. There are very good chances of strong thunderstorms and a threat of severe weather. We will need those to see precipitation totals get up toward the higher end of the range.We dry down Thursday midday and will stay dry for the following 4 days in a row. That means we have sunny and dry weather in the forecast for Friday through Sunday. Temps will build to slightly above normal levels but will not be overly hot.Scattered showers and thunderstorms develop overnight Sunday night into Monday, starting in NW Ohio and then spreading east and sagging south. This will bring rains to the entire state for the period from Sunday overnight through Tuesday midday. Rain totals will be from a quarter to three quarters of an inch with coverage at 80% of the state. Clouds break later Tuesday, but only for a short time.For the Independence Day holiday on the 4th, we are going to have to increase our rain chances this morning. It looks like the minor front we had been looking for on the 5th has decided to speed up slightly and arrive for the 4th. Moisture totals are not impressive, perhaps a few hundredths to a tenth or two, but we can’t say we stay completely dry either. So, just be away of the minor action.We are then dry for the 5th through the 8th.Changes in the extended 11-16 day window means we are looking at our front there to shift back to the 9th, allowing for .1”-.5” to develop over the eastern corn belt, and coverage will be around 70%. A strong high still will try to develop by the end of the 16-day window, and that would promote a dry stretch into mid-month.Temperatures today will stay below normal, but tomorrow through the rest of the 10-day period, we will be a bit above normal. There is not significant heat, as we mentioned above, but we think that highs will average about 2-4 degrees above normal for this time of year as we flip the calendar into July and go through the holiday weekend.Our general sentiment is unchanged this morning. We still think this pattern still brings timely moisture, but just not as much of it the farther out we go. At right is an updated map of cumulative 10-day rains for the region.last_img read more

Aussie Police Say Apple Maps May Be Dangerous To Your Health

first_imgdan rowinski Tags:#maps Everyone knows the first version of Apple’s iOS map application was a piece of work, but life-threatening?Lots of people are upset with Apple for replacing Google’s all-but-bulletproof mapping app with its own, disastrous Maps application back in September. Locations are mislabeled, directions are absurd, towns are shown where no town has existed. It has been frustrating for many people, but few using iOS Maps have said it is really life threatening. Until now.Screen grab from Victoria policePolice in Victoria, Australia, have fielded several distress calls from motorists following Maps only to become lost in Murray Sunset National Park. The park is located in southeastern Australia where can temperatures can reach 114 degrees (46 degrees Celsius). Motorists using Maps to get Mildura, Australia, located on the northeast border of the park. Their iPhones and iPads instead placed Mildura in the middle of Murray Sunset, miles from anything. Police say motorists insufficiently prepared to survive being lost in the sprawling park could find themselves in very real danger.In a statement, the Victoria police department said travelers should rely on other maps until the problem is fixed. Department officials said they’ve contacted Apple with their concerns. This is not the first time that a government has been upset with Maps. Irish officials were perplexed when the app moved Dublin Airport — a major facility — to a rural estate named “Airfield.” They called it “dangerously misleading.” That gaffe was fixed (but political hystrionics aside, it is extremely rare for pilots anywhere to use a smartphone for navigation). Screen grab from Victoria police. Notations by the auhor.Top photo courtesy Shutterstock. Role of Mobile App Analytics In-App Engagement What it Takes to Build a Highly Secure FinTech …center_img Why IoT Apps are Eating Device Interfaces Related Posts The Rise and Rise of Mobile Payment Technologylast_img read more

CNET Book Club Infinite Detail asks what if the internet dies

first_img Culture Share your voice CNET Book Club Tim Maughan (right) and Scott Stein (left) at the podcast studio. CNET Cast your mind forward, five, 10, 30 years. What will the future of the ultra-connected smart city be like? Glad you asked, because Infinite Detail is as good an exploration of the promises and fears of the next decade as you’re likely to read.Tim Maughan, a journalist for Vice/Motherboard, New Scientist and the BBC, joins us on the podcast to discuss his novel Infinite Detail. We talk about what scares him about smart cities, the possibilities and pitfalls of augmented reality, and a lot more.Subscribe: CNET RSS | iTunes | FeedBurner | Google Play | TuneIn | Stitcher See Infinite Detail on Amazon9780374175412Infinite Detail. Tim Maughan/FSG Set in both a creepily frictionless New York City of the deep-surveillance near-future and a rebellious anti-surveillance community in Bristol, UK called The Croft, Infinite Detail also jumps back and forth in time. Half of the book takes place in a near future fully immersed in AR smartglasses and information-collecting infrastructures. The other half lives in an even farther-off future where the internet as we know it, and much of the global infrastructure, has collapsed.I won’t spoil anything else in between, but the politically-charged book follows the spirit of Cory Doctorow’s 2017 novel, Walkaway, and in some ways, Station 11 by Emily St. John Mandel: It’s both pre- and post-apocalyptic, and yet also oddly optimistic. I swear. About CNET Book Club The Book Club is hosted by a pair of self-proclaimed book experts: Dan Ackerman (author of the nonfiction video game history book The Tetris Effect), and Scott Stein, a playwright and screenwriter. We’ll be announcing our next Book Club selection soon, so send us your suggestions and keep an eye out for updates on Twitter at @danackerman and @jetscott. Previous episodes Borne by Jeff VanderMeerWalkaway by Cory DoctorowArtemis by Andy WeirDown the River Unto the Sea by Walter MosleyTen Arguments for Deleting Your Social Media Accounts Right Now by Jaron LanierCNET Book Club: Holiday 2018 gift guide specialTeam Human by Douglas RushkoffGiraffes on Horseback Salad by Josh Frank, Manuela Pertega, and Tim Heidecker Subscribe to CNET Book Club: CNET RSS | iTunes | FeedBurner | Google Play | TuneIn | Stitcher 0 Tags Post a commentlast_img read more

Its official Salman Khan thrilled to romance Alia Bhatt in Sanjay Leela

first_imgSalman Khan, Alia Bhatt and Sanjay Leela BhansaliCollage of photos taken from Twitter and FacebookBollywood superstar Salman Khan and actress Alia Bhatt have confirmed the news that they will be seen together in Sanjay Leela Bhansali’s upcoming Bollywood movie titled Inshallah.Sanjay Leela Bhansali had earlier worked with Salman Khan in movies like Khamoshi: The Musical (1996) and Hum Dil De Chuke Sanam (1999). Of late, it was rumoured that they will come back together after 20 years. The filmmaker took to his Twitter account to put all the rumour mills to rest.Bhansali Productions tweeted, “Finally all speculations and wait end as 2019 brings together #SLB, @BeingSalmanKhan and @aliaa08 in his next film, #Inshallah. Wishing that this entire journey be filled with a lot of love and Inshallah, the team is blessed with hope and faith♥️ @SKFilmsOfficial @prerna982″Salman Khan took to his Twitter account to share his excitement over teaming up with Alia Bhatt in Sanjay Leela Bhansali. The B-Town superstar tweeted, “It’s been 20 years but I am glad Sanjay and I are finally back in his next film, Inshallah. Looking forward to work with Alia and inshallah we will all be blessed on this journey. #Inshallah #SLB @aliaa08 @bhansali_produc @SKFilmsOfficial”Alia Bhatt has worked with most of the popular Bollywood actors. This is for the first time she will be working with Sanjay Leela Bhansali. The actress tweeted, “I was 9 when I first walked into Sanjay Leela Bhansali’s office, all nervous and hoping and praying that I would be in his next film. It’s been a long wait.”Later, Alia Bhatt added, “Dream with your eyes wide open they say & I did. Sanjay Sir and Salman Khan are magical together & I can’t wait to join them on this beautiful journey called “Inshallah” ❤ #Inshallah #SLB @BeingSalmanKhan @bhansali_produc @SKFilmsOfficial @prerna982.”last_img read more

7 MPs quit Labour Party over Brexit antiSemitism

first_imgFormer Labour party MPs, (From Left) Ann Coffey, Angela Smith, Chris Leslie, Chuka Umunna, Mike Gapes, Luciana Berger, and Gavin Shuker pose for a photograph following a press conference in London on 18 February 2019, where they announced their resignation from the Labour Party, and the formation of a new independent group of MPs. Seven MPs from Britain`s opposition Labour Party on Monday announced they were breaking away in protest at the party leadership`s support for Brexit and its failure to stamp out anti-Semitism. Speaking at a hastily arranged press conference in London, the seven attacked party chief Jeremy Corbyn for leading the party to the far left and said they would sit as an independent group in parliament. Photo: AFPSeven MPs from Britain’s opposition Labour Party announced on Monday they were breaking away in protest at the party leadership’s support for Brexit and its failure to stamp out anti-Semitism.Speaking at a hastily arranged press conference in London, the seven attacked party chief Jeremy Corbyn for leading the party to the far left and said they would sit as an independent group in parliament.The group included Chuka Umunna, who has led a cross-party campaign for a second referendum on Brexit and was once seen as a potential Labour leader.”If you want an alternative please help us build it,” Umunna said.”Politics is broken. It doesn’t have to be this way.”Corbyn said he was “disappointed” by the MPs’ decision.”Now more than ever is the time to bring people together to build a better future for us all,” he said.Another MP, Luciana Berger, who has been the victim of anti-Semitic abuse for years, said: “This has been a very difficult, painful but necessary decision.”Berger said the party had become “institutionally anti-Semitic”, adding: “I have become embarrassed and ashamed to represent the Labour Party.”I am leaving behind a culture of bullying, bigotry and intimidation,” she said.MP Mike Gapes said: “I am furious that the Labour leadership is complicit in facilitating Brexit”.His colleague Chris Leslie, said he was leaving because of “Labour’s betrayal on Europe”.last_img

UPDATE Franken Reiterates He Wont Resign I Know That Ive Let A

first_imgUpdated at 1:53 p.m. ETSen. Al Franken said Monday he would not resign from office after allegations of sexual harassment have been leveled against him.“I know that I’ve let a lot of people down,” Franken said, noting that he was looking forward to getting back to work. “My colleagues, my staff, my supporters and everyone who has counted on me to be a champion for women. To all of you, I just want to again say I am sorry. I know there are no magic words I can say to regain your trust.”He said the process will take time and “that starts with going back to work today.”The Minnesota Democrat spoke to reporters on Capitol Hill for the first time since multiple women have accused him of inappropriate sexual conduct, ranging from forcible kissing to unwanted touching. He took a few questions, reiterated that he would not resign and expressed remorse and regret.“I’ve been trying to take responsibility by apologizing,” Franken said. He added, “I’m going to be accountable” and “cooperate completely with the ethics investigation.”Franken’s conduct has been referred to the Senate Ethics Committee. The committee could recommend anywhere from a reprimand to censure to expulsion, but the full Senate would have to act on that.Leeanne Tweeden, a radio host in Los Angeles and former model, toured with Franken as part of the USO. She recalled Franken forcibly kissing her during sketches and rehearsals. A photo taken aboard a cargo plane also shows Franken touching Tweeden’s breasts over a flak jacket while she was asleep. Looking over his shoulder, Franken smirks at the camera.Franken said he didn’t remember his time with Tweeden the same way, but noted, “I feel that you have to respect women’s experience. I apologized to her, and I meant it. And I was very grateful that she accepted it.”Women have also accused Franken of touching their buttocks while taking photos in Minnesota. Franken said he does not remember specific instances in which that happened, but he did not deny that it did.“One is too many,” Franken said. He added that it was disrespectful and he is sorry he hurt them.“I am tremendously sorry. I am going to have to be much more conscious, much more careful, much more sensitive that this will not happen again going forward. It’s going to take a lot more time for me to earn people’s trust.”He repeated later, “I am tremendously sorry. … I am embarrassed. I feel ashamed.”Franken’s comments echo what he told Minnesota Public Radio News in an interview over the weekend: “I’m going to go forward. I’m going to take responsibility. I’m going to be held accountable, and I’m going to try to be productive in the way I speak about this.”Democrats have been aiming for the moral high ground on sexual harassment, especially ahead of a Dec. 12 Senate special election in Alabama. Republican Roy Moore there has been accused of sexual misconduct and assault against teenage girls 40 years ago. Sharelast_img read more

Enhanced strength and ductility in a highentropy alloy via ordered oxygen complexes

first_img Deformation mode. a) STEM image of the TiZrHfNb base HEA at 8% tensile strain (the yellow arrows indicate the coplanar dislocation arrays). b) STEM image of O-2 HEA at 8% tensile strain (the red arrows indicate the dipolar walls). c) STEM image of N-2 HEA at 8% tensile strain (the yellow arrows indicate the planar slip bands). Typical planar slip is observed in the base HEA and in the nitrogen-doped alloy variant N-2 HEA. However, wavy slip dominates deformation of the oxygen doped variant O-2 HEA, suggesting that oxygen addition leads to a plastic deformation mode dominated by wavy slip. The beam direction in a and c is [011] while that in b is [001]. d) Dislocation spacing of the TiZrHfNb base HEA and of the interstitially doped variants O-2 and N-2 HEAs probed during in situ TEM tensile experiments. The white arrows represent the dislocation spacing. The average dislocation spacing in the O-2 HEA is much smaller than that in the base HEA and in the N-2 HEA. The error bars are standard deviations of the mean. Credit: Nature, doi: 10.1038/s41586-018-0685-y Journal information: Nature To understand the underlying mechanism of this anomalous, interstitial solid-solution strengthening effect observed with oxygen doped materials, nanostructures of materials were investigated at the atomic scale. For this, the scientists first used synchrotron high-energy X-ray diffraction (XRD) patterns of the base HEA compared with the two alloy variants of O-2 and N-2 HEA. The results showed that addition of either nitrogen or oxygen to the base HEA did not change its single-phase body-centered cubic (b.c.c) structure. This observation was confirmed by electron back-scattering diffraction mapping. In the scanning transmission electron microscope high-angle annular dark field micrograph (STEM-HAADF) images of the O-2 HEA; light atoms were represented in dark contrast, while heavy atoms were imaged bright. Mechanical properties. a) Room-temperature tensile stress–strain curves for the as-cast TiZrHfNb (denoted as base alloy), (TiZrHfNb)98O2 (denoted as O-2) and (TiZrHfNb)98N2 (denoted as N-2) HEAs. σy is the yield strength (squares), σUTS is the ultimate strength (diamonds) and ε is the elongation (circles). The inset shows the corresponding strain hardening response (dσ/dε). A higher work-hardening rate is observed for the O-2 HEA variant (TiZrHfNb)98O2 compared to the base HEA TiZrHfNb and the N-2 HEA (TiZrHfNb)98N2. b) Changes in strength and ductility observed for the HEAs introduced here, relative to several types of established high-performance alloys. The reference systems are Ti6Al4V, β-Ti alloys, niobium, vanadium, interstitial free steel and 316 austenitic stainless steels. The alloys’ interstitial oxygen or nitrogen content is indicated for comparison. Credit: Nature, doi: https://doi.org/10.1038/s41586-018-0685-y Schematic diagram illustrating the mechanism of plastic deformation in the cubic structure of the oxygen-rich high-entropy alloy (HEA). a) In the oxygen-high entropy alloys, the ordered oxygen complexes (OOCs) acted on dislocations in mechanical strain studies. b) During the initial stages of plastic deformation, the planar slip still prevailed. c) Once the dislocations encountered severely distorted interstitial-enriched OOCs, cross-slip is promoted due to their strong pinning effects. d) This results in massive dislocation multiplications. e) More and more dislocations are pinned by OOCs, and dipolar walls emerged as the strain increased to promote work hardening of the material, eventually leading to higher ductility. Credit: Nature, doi: https://doi.org/10.1038/s41586-018-0685-y Researchers present new strategy for extending ductility in a single-phase alloy Engineering strong, tough (damage-tolerant) materials traditionally requires striking a compromise between hardness and ductility. In the new study, oxygen complexes were structurally ordered in nanoscale regions within the HEA characterized by oxygen, zirconium and titanium (O, Zr, Ti)-rich atomic complexes. Formation of these complexes was promoted by chemical short-range ordering among matrix elements within the HEAs. In face-centered cubic HEAs, carbon was reported to improve strength and ductility by lowering stacking fault energy and increasing lattice friction stress. By contrast, ordered interstitial complexes described by Lei et al. mediated a strain-harvesting mechanism with potential for specific use in Ti, Zr, and Hf (Hafnium)-containing alloys. Interstitial elements are usually highly undesirable in such metal alloys due to their embrittlement effects and since tuning the stacking fault energy and exploitation of thermal transfer had not previously led to property enhancement in other alloys. The novel study results therefore provided insight to the role of interstitial solid solutions and the associated mechanisms of strengthening metallic materials. The work is now published in Nature. Explore further Citation: Enhanced strength and ductility in a high-entropy alloy via ordered oxygen complexes (2018, November 27) retrieved 18 August 2019 from https://phys.org/news/2018-11-strength-ductility-high-entropy-alloy-oxygen.html Oxygen is an abundant element that can form undesired impurities or ceramic phases in metallic materials, while doping the element on metal can render substrates brittle. During interactions with metallic alloys, oxygen takes a state between oxide particles and frequently occurring random interstitials to form ordered oxygen complexes. In a new study, materials scientists Zhinfeng Lei and co-workers observed that unlike in traditional interstitial strengthening, such ordered interstitial complexes could form high-entropy alloys (HEAs) with unprecedented enhancement in strength and ductility in compositionally complex solid solutions. When the scientists doped a model TiZrHfNb HEA with 2.0 atomic percent (2 at%) oxygen, they observed substantially enhanced tensile strength and ductility, breaking a longstanding conflict on strength and ductility trade-off. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.center_img Statistical analysis of STEM-HAADF and corresponding annular bright field (ABF) images conducted thereafter demonstrated that oxygen preferred interstitial positions adjacent to light-atom-rich lattice sites. Such preference was not observed in the N-2 HEA. In accordance with the solid-solution strengthening model proposed by Fleischer, the calculations for O-2 and N-2 HEAs confirmed their hardening mechanisms were of interstitial nature. Yet, unlike traditional interstitial strengthening that embrittled alloys, the presence of oxygen simultaneously increased both strength and ductility in the b.c.c TiZrHfNb HEA. The key question posed by the substructure analysis is why the addition of interstitial oxygen greatly enhanced the alloy’s work hardening capacity and ductility, compared to nitrogen-containing complexes. During plastic deformation, dislocations are typically stored and arranged in ordered patterns in metal alloys. To study such dislocation patterns in more detail, the researchers conducted high-resolution aberration-corrected STEM characterization of pre-strained specimens. At the nanoscale, oxygen-containing complexes severely distorted the local lattice, causing a large strain field around them. During deformation, the ordered oxygen complexes (OOCs) interacted with dislocations as revealed by STEM images. To further illuminate the intrinsic mechanisms at the atomic scale, the scientists conducted aberration-corrected STEM. At this point, they observed that the intrinsic features of OOCs in the O-2 HEA alloy variant enabled high work hardening due to dipolar walls that emerged with increasing stress that eventually led to higher ductility in the oxygen doped materials. Such complex-dislocation dynamics were not observed for the N-2 HEA, leading to comparatively modest ductility as a result. More information: Zhifeng Lei et al. Enhanced strength and ductility in a high-entropy alloy via ordered oxygen complexes, Nature (2018). DOI: 10.1038/s41586-018-0685-y Robert O. Ritchie. The conflicts between strength and toughness, Nature Materials (2011). DOI: 10.1038/nmat3115 Zhiming Li et al. Metastable high-entropy dual-phase alloys overcome the strength–ductility trade-off, Nature (2016). DOI: 10.1038/nature17981 Microscopic structure. a, b) Synchrotron high-energy XRD and the corresponding electron back-scattering diffraction patterns of the as-cast equiatomic TiZrHfNb and the interstitially doped solid-solution HEAs. All the as-cast HEAs have single b.c.c. lattice structure. c–e) STEM-HAADF images for the [011] b.c.c. crystal axis with differently adjusted contrast to reveal the existence of chemical short-range ordering in the O-2 HEA (TiZrHfNb)98O2, and the corresponding STEM-ABF image that reveals the ordered oxygen complexes (OOCs). Red squares represent the Zr/Ti-rich regions and yellow squares indicate the Hf/Nb-rich regions. The inset in e is an enlarged view of the OOCs, with the white arrows indicating the positions of the oxygen atom columns. f) Atom probe tomography three-dimensional reconstruction from the analysis of a specimen from the O-2 HEA. The threshold for the iso-composition surface is 3.0 at% O, highlighting the presence of OOCs. g) O composition profile as a function of the distance to the interface for a selection of particles (left axis) and evolution of the composition of the main constituents relative to their respective matrix composition (right axis). The inset shows a close-up of one such OOC, along with the {011} atomic plane imaged within the reconstruction. Ni is the number of the ith atom, while Ci and Ci, matrix are the concentrations of the ith atom in the OOCs and in the matrix, respectively. Credit: Nature, doi: https://doi.org/10.1038/s41586-018-0685-y In the study, the researchers investigated the base alloy TiZrHfNb and its optimally oxygen-doped variant (TiZrHfNb)98O2 (denoted as O-2 HEA here on) for comparison, alongside an interstitial variant with 2.0 atomic percent nitrogen (TiZrHfNb)98N2, hitherto referred as N-2 HEA. Mechanical properties of the three types of HEAs were observed using tensile stress-strain curves. A strong strengthening effect was observed for both oxygen- and nitrogen-doped HEAs. As expected from conventional interstitial strengthening, the ductility of the N-2 HEA reduced. Addition of 0.2 at% (atomic percent) oxygen to the base HEA (TiZrHfNb) improved its strength and ductility. A substantial work-hardening effect was observed for O-2 HEA compared to base-HEA and N-2 HEA, to impart an unexpected increase in ductility to the oxygen doped material. The addition of more than 3.0 at% oxygen, however, led to deterioration of the observed mechanical properties. The findings by Lei et al. showed that the strength-ductility conflict could be overcome for a class of metal alloys (HEAs), while demonstrating a completely new type of strain-hardening mechanism based on ordered interstitial complexes. The resulting high strain-hardening reserve led to increased strength and ductility. By itself, the base HEA (TiZrHfNb) is not suited for use in high-temperature applications due to oxidation problems. Alloying with antioxidant elements such as Al, Si and Cr could improve resistance to oxidation with HEAs – as also previously seen in HEA designs. The authors recommend application of such ordered interstitial strengthening mechanisms to a wider range of other alloy material classes for improved strength-ductility and strain-hardening during the development of advanced materials. Dislocation movements during deformation of the O-2 HEA. Credit: Nature, doi: 10.1038/s41586-018-0685-y © 2018 Science X Network The observations revealed regions of light atoms (Ti, Zr-rich) and regions rich in heavy atoms (Nb, Hf-rich) in the O-2 HEA. Similar zones also appeared in STEM images of the base and N-2 HEAs to confirm chemical short-range ordering among the metallic matrix elements as an inherent feature of HEAs. During deformation in any one of the three alloys, no phase transformation occurred. Ex-situ transmission electron microscopy (TEM) and in-situ mechanical testing confirmed that deformation of the three alloys occurred similarly via the process of dislocation glide. , Nature Materialslast_img read more

Migraine can up heart diseases in women

first_imgThe findings showed that women with migraine have a higher risk of stroke or heart attacks than those without the condition. “Our analysis suggests that migraine should be considered  to be an important risk marker for cardiovascular disease, particularly in women,” said lead researcher Tobias Kurth, Head of the Institute of Public Health (IPH) at Charite – Universitatsmedizin Berlin, a teaching hospital in Germany.Their findings are based on an analysis of data collected as part of the US-based Nurses’ Health Study II. A team of researchers analysed data from more than 115,500 women enrolled in the Nurses’ Health Study II. The participants were aged between 25 and 42 years at baseline and free from cardiovascular disease and, of them, 17,531 reported a physician’s diagnosis of migraine.  Also Read – ‘Playing Jojo was emotionally exhausting’Between 1989 and 2011, cardiovascular events were observed in 1,329 of these women; 223 died as a result.“The risk of developing cardiovascular events was shown to be 50 per cent higher in women with a diagnosis of migraine,” Kurth said.“When compared to women unaffected by the condition, the risk of developing a heart attack was 39 per cent higher for women with migraine, the risk of having a stroke 62 per cent higher, and that of developing angina 73 per cent higher,” Kurth explained.last_img read more

Gettin Hitched

first_img Opinions expressed by Entrepreneur contributors are their own. December 1, 2006 Free Workshop | August 28: Get Better Engagement and Build Trust With Customers Now Enroll Now for Free This hands-on workshop will give you the tools to authentically connect with an increasingly skeptical online audience. 5 min read I don’t know about you, but I can’t wait for one of our nation’s last great monopolies to be subjected to free market competition. Internet protocol TV is what will finally give cable TV a real race for your money, and 2007 is the year it begins in earnest.I want my FiOS TV or DAVE.TV! I want multiple PCs connected to multiple TVs at Chez Hogan simultaneously playing news and different HBO content on my PCs, as well as PC videos, spread-sheets and e-mail on my TVs. I want to pause, play back or skip ahead in live TV programs. And before business trips, I want to use Google to fetch Gilligan’s Island episodes for my laptop.Unfortunately, this vision hasn’t come into sharp focus yet, and IPTV hasn’t reached my neighborhood. But triple-play IPTV bundles (broadband, voice and video) are available to millions of folks in communities large and small, from Boston to Pottawatomie, Oklahoma, to Beaumont, California. A potentially fruitful aspect of these deployments is a new connection between your PC network and entertainment constellation. For example, subscribe to Verizon’s FiOS triple play, and the tech installs a wireless router connected to a TV set-top box/digital video recorder that’s actually a 160GB server. It can save 120 hours of video and let you view different videos, live programming, or photos from a PC on three separate TVs.That’s just a first wobbly step toward converged PC/entertainment networks, which Parks Associates predicts will be found in 30 million American homes by 2010. Not all will include IPTV. There are thorny digital rights and regulatory issues to work out before IP becomes the lingua franca between PCs and TVs. But we’ve passed some important milestones, including super-fast internet access for a critical mass of consumers; PCs and handhelds with enough graphics and computing power to deliver quality video and audio; and big, high-resolution TV/PC flat panels available at commodity prices.More than 5 million people worldwide already subscribe to IPTV version 1.0, reports iSuppli. That number will triple in 2007. By 2010, there should be 63 million IPTV subscribers worldwide, says iSuppli vice president Mark Kirstein, about 13 million of them in the U.S.That’s not most of the viewing public by any means. But IPTV doesn’t have to supplant cable to dampen subscription rates and up the TV ante. It just has to be a viable alternative.Telecom Tuning InIronically, the main proponents of IPTV are the same telcos who’ve had their own monopolies undermined by cable competitors. AT&T and Verizon are committing billions to a last-mile fiber-optic build-out-in part to defend their best markets against cable phone offerings. But video is also the richest vein in the triple play and a brand-new way for even century-old ruraltelcos to serve less populated areas.”It’s amazing how quickly Verizon picked up 25 percent to 30 percent market share in some communities,” muses Kirstein, considering those customers were wrested from cable. Initially, IPTV providers will break in by highlighting multiscreen viewing, expanded DVR and more interactivity for prices comparable to cable. But eight separate studies have found double-digit cuts in cable rates when IPTV comes to town.The speed of deployment will depend on the outcome of a regulatory tug-o-war being fought in state houses and city councils nationwide. TV isn’t just any old free market where technology will win out. As many as 30,000 separate regulatory bodies have to give their blessing and receive their tribute.Besides expanded functionality, New TV ushers in expanded video on demand. Initially, it will be mostly the same content traditional cable pro-viders offer, says Kirstein. But cable is contractually bound to an Old TV establishment that’s conflicted about its digital rights and how many copies of what should be allowed on what platforms. The growth opportunity is not in the same mass-market content–it’s in channels narrowly focused on a particular sport, hobby, music genre or religion, says Kirstein, or foreign-language channels direct from overseas.The BBQ channel on DAVE.TV might not be your cup of sauce. But, as the MySpace/YouTube phenomenon demonstrates, there are millions of wannabe moviemakers out there. They’ll need hardware, software and services that iSuppli projects will constitute a $4.5 billion TV spinoff by 2010. And like blogs or podcasts, VOD offers a low-budget way for entrepreneurs to reach self-selecting, highly motivated customer sets.Imagine marketing to a very defined audience and supporting them with click-to-call URLs and how-to videos. The hallmarks of New TV will be more choice, more flexibility and much more interactivity between you and your customers.It won’t be your father’s TV.IPTV GuideA sampling of nationwide IPTV services:Akimbo: A $180 player and $10 a month bring an eclectic mix of 10,000 vids to your TV.AT&T U-verse: A wireless router hooked up to a set-top network lets three TVs display or record 80 hours of different traditional channels simultaneously.DAVE.TV: This content-sharing community proves anyone with a camera-phone can make movies.ITVN: A $100 player (free with a 12-month subscription at $10 per month) accesses a half-dozen reasonably priced channel packages.Verizon FiOS TV: Like AT&T U-verse, but you can record 120 hours of video and transfer PC pics and music to your TVs.Mike Hoganis Entrepreneur’s technology editor.last_img read more