Changes that lightning inspires in rock quantified
- Date:
- April 26, 2017
- Source:
- University of Pennsylvania
- Summary:
- New research has identified the minimum temperature of a bolt of lightning as it strikes rock. The study discovered that, based on the crystalline material in the sample, the minimum temperature at which the fulgurite formed was roughly 1,700 degrees Celsius.
FULL STORY
The study examined a rock fulgurite -- a thin
layer of glass that forms when lightning strikes a rock's surface. The
sample was collected from northern Italy's Mount Mottarone.
Credit: Reto Gieré
Benjamin Franklin, founder of the University
of Pennsylvania, is believed to have experimented with lightning's
powerful properties using a kite and key, likely coming close to
electrocuting himself in the process.
In a new set of experiments at Penn, researchers have probed the
power of lightning in a less risky but much more technologically
advanced fashion.
Chiara Elmi, a postdoctoral researcher in Penn's Department of Earth and Environmental Science in the School of Arts & Sciences, led the work, which used a suite of techniques to examine a fulgurite, a thin layer of glass that forms on the surface of rock when lightning hits it. Among other findings, the study discovered that, based on the crystalline material in the sample, the minimum temperature at which the fulgurite formed was roughly 1,700 degrees Celsius.
"People have been using morphological and chemical approaches to study rock fulgurites, but this was the first time a rock fulgurite was classified from a mineralogical point of view," Elmi said. "I was able to adapt an approach that I've used before to study the effects of meteorite impact in rocks and sediments to analyze a tiny amount of material in order to understand the phase transitions that occur when a lightning hits a rock."
Elmi collaborated on the work with senior author Reto Gieré, professor and chair of the Department of Earth and Environmental Science, along with the department's Jiangzhi Chen, a postdoctoral researcher, and David Goldsby, an associate professor.
Their paper will be published in the journal American Mineralogist.
In a study published last year, Gieré characterized a rock fulgurite found in southern France, finding that the lightning bolt that hit it transformed the layer of rock beneath the fulgurite on the atomic level, producing tell-tale structures called shock lamellae.
The team wanted to pursue a different line of study in the new work.
"In this case," Gieré said, "we instead wanted to study the glass layer in more detail to find out what the minerals present could tell us about the temperature of lightning."
To do so, Elmi performed an X-ray diffraction analysis, which collects information about the way that X-rays interact with crystalline materials to infer the mineral content of a given sample. The challenge in this instance, however, was that a typical X-ray diffraction analysis requires roughly a gram of material, and the quantity of the 10-micrometer thick fulgurite was not nearly that substantial.
To adapt the technique for a smaller quantity of sample, Elmi put the material in a narrow, rotating capillary tube and adjusted the diffraction optics to align, concentrate and direct the X-ray beam toward the sample. The analysis of the fulgurite revealed the presence of glass as well as cristobalite, a mineral with the same chemical composition of quartz but possessing a distinct crystal structure. Cristobalite only forms at very high temperature, and the glass indicated that the top layer of granite melted during the lightning strike. Elmi's analysis enabled her to quantify the glass and the residual minerals in a rock fulgurite for the first time.
"These two signatures indicate a system that received a shock of high temperature," Elmi said. "This analysis also indicates the minimal temperature you have to create the glass because cristobalite forms around 1,700 Celsius, so you know that this temperature was achieved when the lightning hit the rock."
The measured temperature of lightning in the air is in fact much higher -- measured at around 30,000 degrees Celsius -- but this analysis indicates that the rock itself was raised from ambient temperatures to at least 1,700 Celsius.
The team performed additional analyses on the fulgurite sample. They found organic material in the sample, indicating that the lightning burned lichen or moss growing on the surface of the rock and then trapped it inside the material.
"This is an extremely fast event," Gieré said. "The rock heats up very quickly and also cools down very quickly. That traps gases in the glass and some of these gases were formed by the combustion of organic material."
In future studies, the team hopes to develop a complete model of what happens to rocks during a lightning strike, incorporating chemical, physical, biological and mineralogical observations. They note that people like Franklin who experience near-misses with lightning are lucky indeed.
"It's amazing that a bolt of lightning can turn granite molten and completely change its structure, yet some people survive lightning strikes," said Gieré.
Chiara Elmi, a postdoctoral researcher in Penn's Department of Earth and Environmental Science in the School of Arts & Sciences, led the work, which used a suite of techniques to examine a fulgurite, a thin layer of glass that forms on the surface of rock when lightning hits it. Among other findings, the study discovered that, based on the crystalline material in the sample, the minimum temperature at which the fulgurite formed was roughly 1,700 degrees Celsius.
"People have been using morphological and chemical approaches to study rock fulgurites, but this was the first time a rock fulgurite was classified from a mineralogical point of view," Elmi said. "I was able to adapt an approach that I've used before to study the effects of meteorite impact in rocks and sediments to analyze a tiny amount of material in order to understand the phase transitions that occur when a lightning hits a rock."
Elmi collaborated on the work with senior author Reto Gieré, professor and chair of the Department of Earth and Environmental Science, along with the department's Jiangzhi Chen, a postdoctoral researcher, and David Goldsby, an associate professor.
Their paper will be published in the journal American Mineralogist.
In a study published last year, Gieré characterized a rock fulgurite found in southern France, finding that the lightning bolt that hit it transformed the layer of rock beneath the fulgurite on the atomic level, producing tell-tale structures called shock lamellae.
The team wanted to pursue a different line of study in the new work.
"In this case," Gieré said, "we instead wanted to study the glass layer in more detail to find out what the minerals present could tell us about the temperature of lightning."
To do so, Elmi performed an X-ray diffraction analysis, which collects information about the way that X-rays interact with crystalline materials to infer the mineral content of a given sample. The challenge in this instance, however, was that a typical X-ray diffraction analysis requires roughly a gram of material, and the quantity of the 10-micrometer thick fulgurite was not nearly that substantial.
To adapt the technique for a smaller quantity of sample, Elmi put the material in a narrow, rotating capillary tube and adjusted the diffraction optics to align, concentrate and direct the X-ray beam toward the sample. The analysis of the fulgurite revealed the presence of glass as well as cristobalite, a mineral with the same chemical composition of quartz but possessing a distinct crystal structure. Cristobalite only forms at very high temperature, and the glass indicated that the top layer of granite melted during the lightning strike. Elmi's analysis enabled her to quantify the glass and the residual minerals in a rock fulgurite for the first time.
"These two signatures indicate a system that received a shock of high temperature," Elmi said. "This analysis also indicates the minimal temperature you have to create the glass because cristobalite forms around 1,700 Celsius, so you know that this temperature was achieved when the lightning hit the rock."
The measured temperature of lightning in the air is in fact much higher -- measured at around 30,000 degrees Celsius -- but this analysis indicates that the rock itself was raised from ambient temperatures to at least 1,700 Celsius.
The team performed additional analyses on the fulgurite sample. They found organic material in the sample, indicating that the lightning burned lichen or moss growing on the surface of the rock and then trapped it inside the material.
"This is an extremely fast event," Gieré said. "The rock heats up very quickly and also cools down very quickly. That traps gases in the glass and some of these gases were formed by the combustion of organic material."
In future studies, the team hopes to develop a complete model of what happens to rocks during a lightning strike, incorporating chemical, physical, biological and mineralogical observations. They note that people like Franklin who experience near-misses with lightning are lucky indeed.
"It's amazing that a bolt of lightning can turn granite molten and completely change its structure, yet some people survive lightning strikes," said Gieré.
Story Source:
Materials provided by University of Pennsylvania. Note: Content may be edited for style and length.
Materials provided by University of Pennsylvania. Note: Content may be edited for style and length.
Making batteries from waste glass bottles
Researchers are turning glass bottles into high performance lithium-ion batteries for electric vehicles and personal electronics
- Date:
- April 19, 2017
- Source:
- University of California - Riverside
- Summary:
- Researchers have used waste glass bottles and a low-cost chemical process to create nanosilicon anodes for high-performance lithium-ion batteries. The batteries will extend the range of electric vehicles and plug-in hybrid electric vehicles, and provide more power with fewer charges to personal electronics like cell phones and laptops.
Waste glass bottles are turned into nanosilicon anodes using a low cost chemical process.
Credit: UC Riverside
Researchers at the University of California,
Riverside's Bourns College of Engineering have used waste glass bottles
and a low-cost chemical process to create nanosilicon anodes for
high-performance lithium-ion batteries. The batteries will extend the
range of electric vehicles and plug-in hybrid electric vehicles, and
provide more power with fewer charges to personal electronics like cell
phones and laptops.
Titled "Silicon Derived from Glass Bottles as Anode Materials for
Lithium Ion Full Cell Batteries," an article describing the research was
published in the Nature journal Scientific Reports. Cengiz Ozkan, professor of mechanical engineering, and Mihri Ozkan, professor of electrical engineering, led the project.
Even with today's recycling programs, billions of glass bottles end up in landfills every year, prompting the researchers to ask whether silicon dioxide in waste beverage bottles could provide high purity silicon nanoparticles for lithium-ion batteries.
Silicon anodes can store up to 10 times more energy than conventional graphite anodes, but expansion and shrinkage during charge and discharge make them unstable. Downsizing silicon to the nanoscale has been shown to reduce this problem, and by combining an abundant and relatively pure form of silicon dioxide and a low-cost chemical reaction, the researchers created lithium-ion half-cell batteries that store almost four times more energy than conventional graphite anodes.
To create the anodes, the team used a three-step process that involved crushing and grinding the glass bottles into a fine white power, a magnesiothermic reduction to transform the silicon dioxide into nanostructured silicon, and coating the silicon nanoparticles with carbon to improve their stability and energy storage properties.
As expected, coin cell batteries made using the glass bottle-based silicon anodes greatly outperformed traditional batteries in laboratory tests. Carbon-coated glass derived-silicon (gSi@C) electrodes demonstrated excellent electrochemical performance with a capacity of ~1420 mAh/g at C/2 rate after 400 cycles.
Changling Li, a graduate student in materials science and engineering and lead author on the paper, said one glass bottle provides enough nanosilicon for hundreds of coin cell batteries or three-five pouch cell batteries.
"We started with a waste product that was headed for the landfill and created batteries that stored more energy, charged faster, and were more stable than commercial coin cell batteries. Hence, we have very promising candidates for next-generation lithium-ion batteries," Li said.
This research is the latest in a series of projects led by Mihri and Cengiz Ozkan to create lithium-ion battery anodes from environmentally friendly materials. Previous research has focused on developing and testing anodes from portabella mushrooms, sand, and diatomaceous (fossil-rich) earth.
Even with today's recycling programs, billions of glass bottles end up in landfills every year, prompting the researchers to ask whether silicon dioxide in waste beverage bottles could provide high purity silicon nanoparticles for lithium-ion batteries.
Silicon anodes can store up to 10 times more energy than conventional graphite anodes, but expansion and shrinkage during charge and discharge make them unstable. Downsizing silicon to the nanoscale has been shown to reduce this problem, and by combining an abundant and relatively pure form of silicon dioxide and a low-cost chemical reaction, the researchers created lithium-ion half-cell batteries that store almost four times more energy than conventional graphite anodes.
To create the anodes, the team used a three-step process that involved crushing and grinding the glass bottles into a fine white power, a magnesiothermic reduction to transform the silicon dioxide into nanostructured silicon, and coating the silicon nanoparticles with carbon to improve their stability and energy storage properties.
As expected, coin cell batteries made using the glass bottle-based silicon anodes greatly outperformed traditional batteries in laboratory tests. Carbon-coated glass derived-silicon (gSi@C) electrodes demonstrated excellent electrochemical performance with a capacity of ~1420 mAh/g at C/2 rate after 400 cycles.
Changling Li, a graduate student in materials science and engineering and lead author on the paper, said one glass bottle provides enough nanosilicon for hundreds of coin cell batteries or three-five pouch cell batteries.
"We started with a waste product that was headed for the landfill and created batteries that stored more energy, charged faster, and were more stable than commercial coin cell batteries. Hence, we have very promising candidates for next-generation lithium-ion batteries," Li said.
This research is the latest in a series of projects led by Mihri and Cengiz Ozkan to create lithium-ion battery anodes from environmentally friendly materials. Previous research has focused on developing and testing anodes from portabella mushrooms, sand, and diatomaceous (fossil-rich) earth.
Story Source:
Materials provided by University of California - Riverside. Original written by Sarah Nightingale. Note: Content may be edited for style and length.
Materials provided by University of California - Riverside. Original written by Sarah Nightingale. Note: Content may be edited for style and length.
Can you explain about aloy ? Thanks
BalasHapusAlloy is a mixture of two or more metals, metals and non-metals that form materials with new properties. These alloys have been discovered and developed since hundreds or even thousands of years ago from different cultures.
HapusIn the past the use of alloys was limited to the manufacture of sharp weapons and household appliances. But now the use of alloys is very broad and specific.
One of the most popular examples of alloys is steel material. Steel is a mixture of two elements, namely iron, some other metals and carbon. Copper (Cu) and Tin (Tin / Sn) when mixed will form alloys that we know by the name of bronze
Komentar ini telah dihapus oleh pengarang.
BalasHapusIs there any other example besides the example in the above article
BalasHapusBesides using used bottles. There are other simple materials to make the battery.
HapusHow to make a battery from a salt solution kitchen
It turns out that salt can be a power source like a battery. The trick is to prepare salt, water, container, copper plate, iron plate or aluminum, cables, led and solder lamps along with tin. Then dissolve the salt into the water and then stir. Then put it in the container. Next dip the iron or aluminum plate and the copper plate into a container containing the salts of these two plates serves as positive electrodes and negative electrodes but in dipping these two electrodes should not touch. The next step is to solder the two electrodes with the cable and then solder also the other end of the cable with the led light, the end of the cable from the copper plate will be a positive electrode while the iron or aluminum plate will be a negative electrode. After soldered observe and watch the led light, the led lamp lights up only by using salt solution.
How to make a battery using lemon.
The trick is also the same as the above was just when using lemon orange both electrodes were plugged into lemon.
Why a bottle of glass can be used as a battery?
BalasHapusSilicon dioxide in waste beverage bottles can provide high purity silicon nanoparticles for lithium-ion batteries.
HapusSilicon anodes can store energy up to 10 times more than conventional graphite anodes, but expansion and shrinkage during charging and discharging make it unstable.