Explore further The new system is more complex than a chain and gears and consists of a rope and pulley on each side of the bike. The rotation of the pedals forces arms at each side to swing forward and backward on its shaft. When moving forward, the arm pulls the driving wire that is wound around a drum on the rear wheel, forcing the wheel to rotate. The arms at each side alternate so that when one is moving forward the other is moving backward. The new system has 19 “gear” positions and the transmission ratio can be changed at any time by turning a shifting knob on the right handle grip. This moves the pulley shafts up and down along a traction path on an eccentric disc, which has 19 notches to adjust the height of the pulleys and distance between the center of rotation and the shaft. The gears can be changed even if the bicycle is stationary, but gear change speed increases with the speed of the bicycle. 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. The traditional bicycle has a chain and gears on one side, which the designers from bicycle manufacturer Schwinn Csepel Zrt say has led to a lot of problems, although they do not say exactly what those problems are. They say most are unnoticeable problems until you’ve actually ridden a symmetrical system. One problem that the new design does remove is soiling clothes with the grease or oil on the chain, since the pulley system is dry. Citation: Introducing Stringbike: the bike with no chain (w/ Video) (2010, September 22) retrieved 18 August 2019 from https://phys.org/news/2010-09-stringbike-bike-chain-video.html Another advantage of the system is that the ropes can be attached in different positions on the two sides of the bicycle, which means it can compensate if one of the rider’s legs is weaker than the other. The designers also say the lifetime of components will be longer than for conventional bicycles because chains are more susceptible to wear and abrasion, and the number of components is reduced. (PhysOrg.com) — Hungarian bicycle designers have unveiled their new Stringbike in Padova, Italy. The design replaces the traditional chain with a symmetrical rope and pulley system, which they say is more efficient, makes for a more comfortable ride, and provides improved maneuverability around winding streets. The drive system will be able to be replaced with different size parts and different shaped eccentric discs for specialized purposes such as racing or touring. The rear wheel can be removed in only a few seconds without affecting the drive system. The driving rope is a special high density polyethylene (HDPE) product with high stability over extended periods, and which is resistant to mud, water, dirt, sand, and humidity. © 2010 PhysOrg.com More information: www.stringbike.com/ Gyrowheel to keep new bike riders upright (w/ Video)
Citation: Newly identified self-cloning lizard found in Vietnam (2010, November 11) retrieved 18 August 2019 from https://phys.org/news/2010-11-newly-self-cloning-lizard-vietnam.html (PhysOrg.com) — Scientists have just discovered that a small lizard, long known as a restaurant food item in southeastern Vietnam, is an all-female species that reproduces through “cloning” itself. © 2010 PhysOrg.com Image credit: L. Lee Grismer. Scientists discover four new gecko species 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. The lizard, Leiolepis ngovantrii, was found by Ngo Van Tri from the Vietnam Academy of Science and Technology and classified by L. Lee Grismer, a herpetologist from La Sierra University in Riverside, California. The species was previously unknown to science, even though it has been eaten in the Mekong Delta region as long as anyone can remember.Ngo first found the lizard at a restaurant in Ba Ria-Vung Tau Province, where live specimens were being kept in a tank. Ngo noticed all the individuals looked identical, and sent photographs to his colleague Grismer and his PhD student son Jesse. The Grismers identified the lizard as probably belonging to the Leiolepis genus, but in this genus males and females have different coloration, and the photographs showed only males. This made them suspect the new species consisted only of females.The Grismers flew to Ho Chi Minh City and telephoned the restaurant to ask them to keep the lizards alive until they could get there eight hours later. By the time they arrived the “crazy guy” restaurant owner had got drunk and sold them all, but the scientists found more specimens at other restaurants, and were aided by local school children to find more in the wild. They found nearly 70 of the lizards altogether, and all were females.The findings, published in the journal ZOOTAXA, also identified unique rows of enlarged scales on its forelimbs and bone layers (lamellae) under their toes. Grismer said the species, which lives in a transition zone between coastal sand dunes and scrub, may be a hybrid of two related species of maternal and paternal lizards that thrive in the separate habitats.Genetic testing of mitochondrial DNA has identified the maternal species as L. guttata, but the paternal species is not yet known. (Mitochondrial DNA is passed down only through females.)The newly described species is not the only one that reproduces through cloning, since around one percent of lizard species reproduce with no contribution from males, by a process known as parthenogenesis (from the Greek for virgin birth). In this process the ovum contains a full complement of chromosomes and develops into an embryo without being fertilized. Parthenogenesis also occurs, but rarely, in fish and invertebrates, especially insects such as aphids, and has been artificially induced in mice and other species.The Leiolepis ngovantrii species is not rare in the area in which it was found, but some herpetologists such as Charles Cole of the American Museum of Natural History in New York, think as a hybrid species it may be more prone to extinction because of the reduced genetic variation from one generation to the next. Cole said unisexual species do not generally survive as long as other species of lizards, but they can be healthier in the short term. More information: ZOOTAXA paper (PDF): www.mapress.com/zootaxa/2010/f/z02433p061f.pdf Explore further
Explore further © 2010 PhysOrg.com Citation: Solar panels released in an array of colors (2011, June 7) retrieved 18 August 2019 from https://phys.org/news/2011-06-solar-panels-array.html One Canadian-based solar technology company is looking to change that view. Qsolar has announced the creation of the Kristal and Kristal Rainbow range of semi-transparent and colored semi-transparent solar panels. These lines come in a variety of colors, including red, green, brown and blue as well as in a few different patterns. The panels do not have frames attached to them, because the panels are rigid.At first, this may seem like it is simply a vanity, putting a new skin on a green technology, but these semi-transparent have a chance to go places that standard solar panels are simply not used, making them an option for buildings that do not have the space to support a standard solar panel set up. Some potential places these new panels could be installed include windows and the glass spaces of atrium roofs. This makes them optimal for building with limited roof space, due to either building design issues or the fact that other equipment has previously been placed on the roof. The panels are already available for purchase by the public. Information on pricing is on a case-by-case basis, and interested consumers should contact the company to find out what the system would cost to be installed in their building. Willis Tower goes solar (PhysOrg.com) — Solar panels are, for the most part, large black panels, made of squares, but what if it does not have to be that way. What if users could get all of the benefits of solar panels without making their roofs look like the side of a Manhattan skyscraper? 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.
More information: Hierarchical multiscale structure– property relationships of the Red-bellied Woodpecker (Melanerpes carolinus) beak. N. Lee et al. Journal of the Royal Society Interface, 2014. rsif.royalsocietypublishing.or … .1098/rsif.2014.0274 (Phys.org) —A team of researchers at Mississippi State University has found that the beaks of woodpeckers are constructed in such a way as to help dissipate energy. In their paper published in Journal of the Royal Society Interface, the team describes their work in analyzing the beaks of several red-bellied woodpeckers and how they found that it has three layers that all help to absorb shocks as the bird pecks away at trees looking for insects inside. Most everyone knows that woodpeckers bang away at trees (or sometimes other structures) with their beaks to create holes that allow them access to insects hidden inside. Prior research has shown that woodpeckers have a variety of features throughout their heads that help absorb shock, preventing the birds from suffering brain or other damage as they hunt for their prey. In this new effort, the researchers sought to learn if there was anything special about their beaks that might also help soften the internal blow as the birds hammer away at a tree, between one and three hundred times a minute.Close inspection revealed that the beak’s outer or rhamphotheca layer was made of a keratin sheath, which was, like most birds, arranged in a scale pattern, with defined edges between each scale. There was one major difference however, the scale edges, which are not straight but follow a zig-zag course (and have been nick-named sutures because they resemble those used in surgery), were much more wiggly than other pecking birds, such as chickens. This, the researchers noted, would help deflect compressing forces as the beak hit the wood. They found that the scales were also thinner and more elongated than other pecking birds as well, which appears to allow for more sliding of scales over one another during pecking, serving as a shock-absorber.The researchers also found that the middle “foam” layer of the bird’s beak, was more porous than other pecking birds, which would of course allow for directing the energy from impacts into other parts of the birds head that are better able to handle the abuse.Taken as a whole, it appears a woodpecker’s beak offers a first line of defense against head damage when pecking, dissipating energy where possible and directing the rest to where it will do the least damage. © 2014 Phys.org Journal information: Journal of the Royal Society Interface A male Red-bellied Woodpecker (Melanerpes carolinus). Credit: Ken Thomas/public domain Explore further Mechanical properties and microstructure of cranial and beak bones of the woodpecker and the lark Citation: Study reveals shock-absorbing ability of woodpecker beaks (2014, May 7) retrieved 18 August 2019 from https://phys.org/news/2014-05-reveals-shock-absorbing-ability-woodpecker-beaks.html 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.
It’s been a pretty busy week for technology development also: A Dutch company launched new-generation urban wind turbines—they’re a lot quieter than conventional turbines and take up much less space. And, a team at MIT has announced a new breed of solar cells: Quantum-dot photovoltaics set a new record for efficiency in such devices—another step toward a new generation of cells that last a lot longer and can be manufactured under ordinary temperatures.In the biological sciences, a study shows environmental influences may cause autism in some cases—a finding that could help explain why it is that babies born to older mothers have an increased risk of developing the disorder. Another team is reporting a breakthrough that shows how DNA is ‘edited’ to correct genetic diseases. It’s a step forward in understanding how enzymes impact genes to prevent genetic diseases, and maybe leading to a way to improve the process.In otherworldly news, a pair of researchers suggest black holes at center of galaxies might instead be wormholes. It may sound a bit far-fetched, but a new addition to a telescope in Chili could prove them right or wrong, in just a couple of years. Also, researchers working with NASA’s Swift satellite report a cosmic explosion spotted in neighboring galaxy. They’re not sure what happened, but suspect it was two neutrons stars colliding.And finally, food for thought: Does porn affect the brain? Scientists urge more study. Preliminary research indicates heavy users have less grey matter. But was porn the cause, or was it a condition that led to the behavior? More research will have to be done to find out. In the meantime, the team at Max Planck Institute isn’t making any recommendations. Artistic impression of quantum teleportation of a spin state between two distant diamonds. Research team claims to have accurately ‘teleported’ quantum information ten feet Explore further © 2014 Phys.org 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. (Phys.org) —It’s been a remarkable week for physics work—first a research team claims to have accurately ‘teleported’ quantum information ten feet, and report that they did so with 100 percent accuracy. If the claims turn out to be true, this could mark the beginning of real-world quantum computers or networks. Equally exciting, researchers at Lawrence Berkeley National Laboratory’s have found that combining lasers could shrink particle accelerators from kilometers to meters. Imagine the cost savings—such a development would allow more scientists access to such research, perhaps opening the door to a flood of new discoveries. And imagine also, a space-based experiment that could test gravity’s effects on quantum entanglement—and in so doing, make inroads toward creating a unifying theory between the theory of relativity and quantum theory. Citation: Best of Last Week – quantum information accurately transfered, better wind turbines and study of porn’s impact on brain (2014, June 2) retrieved 18 August 2019 from https://phys.org/news/2014-06-week-quantum-accurately-turbines-porn.html