#Assuring solar modules will last for decades The Energy department's National Renewable energy Laboratory (NREL) is co-leading an international push to assure the reliability of solar panelsn assurance demanded by customers, manufacturers, lenders, and utilities.
Solar photovoltaic (PV) systems affected by defective or underperforming panels is very lowust 0. 1%per year according to new data of 50,000 systems analyzed by the Energy department's National Renewable energy Laboratory (NREL).
But in the face of pressure to keep lowering prices, it is essential that quality be maintained
and assured, said Sarah Kurtz, a Research Fellow at NREL who manages the lab's PV Module Reliability Test and Evaluation Group.
The International PV Quality assurance Task force (PVQAT) was formed in 2011 to develop standards to help customers quickly assess a PV product's ability to withstand regional stresses
whether the panels are to be mounted directly on a roof or on open racks. Quality management of the manufacturing process.
Rigorous quality management will help assure that panels manufactured on one day of the month will be the same quality as those manufactured on any other day of the month.
and voltage Diodes, shading, and reverse bias. Later, task groups were formed to address snow and wind loading;
A final task group was assembled to tackle how to communicate PV quality assurance ratings to the industry, stakeholders,
and provide investors with confidence in their investments. In addition, the group aims to create guidelines for inspecting factories during module manufacturing.
Durable and reliable design is paramount Assuring solar modules will last for decades Sarah Kurtz,
also leads NREL's participation in the International PV Quality assurance Task force. The task force was formed to develop standards ore The first leg of the stool in assuring reliability is a durable design, one that holds up to its intended application,
whether that is in the deserts of the American Southwest or in a snowy mountain range. To that end, qualification tests should
But money may be saved in the long run by the manufacturer who differentiates, building a hardier module for the most difficult climates and a slimmed-down, less expensive module for milder climates.
The rating system being developed by the PVQAT, to be implemented through IEC, seeks to define tests to differentiate among three climate zonesoderate, tropical,
open-rack and close roof. That new rating system will be managed alongside the current international standards, which should hasten the process.
Data on 50,000 systems reveal they stand up to hurricanes, hail Kurtz and NREL's Dirk Jordan have analyzed data from 50,000 solar energy systems installed between 2009 and 2013 and discovered that just 0. 1%of all PV systems reported being affected by damaged or underperforming modules per year,
and less than 1%each year had hardware problems. Inverter failures and fuse failures were reported more commonly than panel failure.
Despite hurricanes hail, shading, vandalism, and hookup delays, approximately 85%of all systems each year produced 90%or more of the electricity predicted,
and the typical system produces more electricity than predicted. Year to year comparisons suggest that the degradation ratehe gradual loss of energy productions in the historical range of 0. 5%%per year.
Consistent manufacturing The second leg of the stool in the push for assuring reliability is managing manufacturing quality.
A good design isn't enough if there's slippage in the factory. It's easier to confirm that each module functions correctly at the beginning of its life than it is to control the long-term reliability.
Yet those hard-to-detect problems that occur over time can begin in the factory.
Early last year, the IEC accepted the PVQAT's proposal,"Guidelines for Increased Confidence in Module Design Qualification and Type Approval."
"This technical specification should be published sometime this year, but some manufacturers are already using it to improve their processes.
System-level inspectionsssential for lenders and insurers Assuring solar modules will last for decades Work by Namaste Solar installing PV modules on the roof of the parking structure on NREL's South Table
Mountain campus. The finished product includes 3, 632 solar modules installed on the garage roof and south facade.
Credit: Dennis Schroeder The third leg of the stool is assuring that the entire systemade up of many modules
and the electrical components needed to connect them to the grids performing as promised. Even if the modules are perfect,
Lenders and insurers want that kind of certification to know how to set rates or to determine
Wells fargo Environmental finance Banker Jon Previtali told the international gathering that 3. 7 gigawatts of utility-scale solar were installed in the United states in 2014.
"That's the equivalent of 10 nuclear plants or 10 coal fired power plants.""Assuring solar modules will last for decades The International PV Quality assurance Task force is developing a comprehensive set of standards that includes:
qualification of the design for module conditions; auditing the quality management of the manufacturing process;
and inspections ore Previtali also noted that more banks are jumping into the solar market,
and with the added competition comes diminished profits. That is why it is essential that investors,
along with everyone else in the solar industry, know with maximum assurance how long the PV systems will last and
He noted that his bank faced decisions on advancing huge sums of money to two solar projects that had eleventh-hour problems with solar panel reliability.
The bank assembled a team to set rules for fixing the problems and adjust the revenue projections based on the likelihood of lower overall energy output.
But along the way his team also learned the importance of putting every test requirement in writingnd being very specific.
It's important that the bank and the developer agree to the precise type of testot, for example,
an airplane flyover that falls far short of capturing the detailed images needed to identify a potential problem."
"All these areas I've highlighted are areas that your work influences, one way or another,
"So the work you are doing is very material.""He said that in the future when his bank has concerns about performance ratio tests,
he likely will turn to new work at NREL headed by Jordan on the methodology of calculating degradation rates."
#Lab-on-a-chip device detects cryptosporidium in as little as 10 minutes For a healthy individual, an infection of Cryptosporidium parvum may mean nothing more than a few days of bad diarrhea.
For someone with a compromised immune system, it can mean death, following an excruciating, protracted bout of watery diarrhea.
Recently, researchers at Fudan University's Institute of Biomedical sciences in Shanghai developed a lab-on-a-chip device that can rapidly diagnose cryptosporidium infections from just a finger prickotentially bringing point-of-care diagnosis to at-risk areas in rural China
in order to improve treatment outcomes. Worldwide treatment for the parasitic infection consists largely of oral rehydration
and managing symptoms until the body clears the infection, something that may take far longer for people with HIV infections.
Currently, China has more than 780,000 people living with HIV/AIDS, but there is very little data on how many of them are living with Cryptosporidium infections.
This stems from the difficulties of diagnosing an infection in the field-poor sensitivity and a short window of spore secretion both limit the viability of acid-fast staining,
a standard diagnostic assay in use today. More advanced immunoassays such as ELISA, are difficult to use broadly
because they require relatively advanced lab settings and skilled technicians. To address this need, Xunjia Cheng and Guodong Sui, both professors at Fudan University,
sought to develop a device better suited for the field. Cheng's research has involved medical protozoa and opportunistic HIV infections,
and Sui's lab focuses on microfluidics. This week in the journal Biomicrofluidics, from AIP Publishing, they describe how they developed
The microfluidic chip was designed by Autocad software and manufactured from a widely used silicon-based organic polymer known as PDMS.
pumps and columns, collectively sitting at the heart of a platform of reagent cartridges, an injection pump, a fluorescence microscope and a digital camera.
The chip itself is small-3 cm by 2 cm-and only costs about a dollar to manufacture, according to Sui.
The microfluidic device tests for the presence of the parasites'P23 antigen, a major molecular target of host antibody responses against the pathogen's infective stages.
Sui and Cheng tested their device's efficacy at diagnosing Cryptosporidium infections in 190 HIV-infected patients in Guangxi, China.
timeframe, size and the amount of training needed to operate. Future work for Sui and Cheng involves expanding the chip's sample processing capacities to include other infectious diseases
as well as increasing the device's sensitivity and specificity i
#High fidelity: Researcher finds keys to genome integrity Maintaining the stability and the correct sequence of our genetic information is vital to the accurate transmission of our genetic code.
However, in the course of replicating, our DNA frequently runs into roadblocks, arising from both internal and external sources,
that threaten the fidelity of our genetic information. The accurate processing of these roadblocks is paramount to genome integrity.
Defects in this process can lead to cancer, genetic problems and premature aging. In a research paper published in the Journal of Cell biology, Alessandro Vindigni, Ph d.,professor in the Edward A. Doisy Department of Biochemistry and Molecular biology at Saint louis University
shares a discovery that explains how cells use a process called replication fork reversal in order to deal with these roadblocks and transmit accurate genetic data.
Lesions in DNA can occur as often as 100,000 times per cell per day. They can be the result of normal metabolic activities, like free radicals,
as well as exposure to environmental factors such as UV radiation, X-rays and chemical compounds. Improper repair of DNA lesions can lead to mutations, abnormal chromosome structures,
or loss of genetic information that in turn can cause premature aging, cancer, and genetic abnormalities. Depending on the degree of genome instability
these alterations will determine whether a cell survives, goes into a growth-arrest state, or dies.
If the cell's replication machinery collides with the lesion, a strand break can occur."
"If these strands are repaired not properly, the cell may simply die, "Vindigni said.""Or, growth may be interrupted permanently."
"Or, a serious lesion may be tolerated and the cell will continue to replicate. This may or may not be a good decision,
as this can lead to cancer. It is the degree of genomic instability caused by the lesion that will determine
whether the cell will survive.""While these scenarios pose serious threats, our cells have evolved elegant mechanisms to cope,
Vindigni says. DNA replicates by unzipping its two interwoven strands and making copies of each.
As the DNA strands separate and copy, they form a"replication fork.""Sometimes, these forks run into obstacles-like the lesions described above-that block their progress.
When they do, cells often perform a maneuver called fork reversal. The newly synthesized DNA strands detach from their parental strands
"Fork reversal is a central mechanism that our replication machinery uses to deal with DNA lesions,
and collision with the lesion is prevented.""In this study, Vindigni and team have identified new enzymes that enable cells to resume replication once the DNA lesion has been repaired.
Vindigni found that DNA2, an enzyme that works both as a nuclease (an enzyme that degrades DNA)
and a helicase (an enzyme that unwinds double-stranded DNA), plays a key role in allowing reversed forks to restart.
"Vindigni hopes that his discoveries about how repair mechanisms work will teach us how to control these mechanisms.
which could improve the efficacy of existing chemotherapy drugs.""It is important to understand how fork reversal
and restart works, "Vindigni said.""If we can develop inhibitors, we can sensitize cancer cells to chemotherapeutics that are already in use,
because they often carry mutations in DNA repair genes essential for the repair of these collisions.
"In addition to the paper published in the Journal of Cell biology, the journal also published a discussion that explains Vindigni's work:
http://jcb. rupress. org/content/208/5/495. full. The study also was highlighted in Faculty of 1000,
a group of over 5000 expert scientists and clinical researchers who review and highlight top biomedical research.
Vindigni's group also contributed to a second paper that was published as back-to-back in the same issue of the Journal of Cell biology on the role of a key homologous recombination factor in the formation of reversed replication forks:
http://www. ncbi. nlm. nih. gov/pubmed/2573371 1
#Tablet for 2 waiting at an Olive Garden near you soon Olive Garden, owned by Florida's Darden Restaurants Inc,
. started using Ziosk tablets in some of its restaurants last year. The chain said Tuesday that locations using the devices have experienced faster dining times and increased tip percentages for wait staff.
It will start rolling them out at additional restaurants next month and expects the 7-inch devices to be in all of its more than 800 U s. restaurants before year's end."
"We've been focused on improving the dining experience at every touch point, and we're excited to give our guests the ability to customize their visit by leveraging the technology of Ziosk's tabletop tablets,"Dave George,
Olive Garden president, said in a statement. Tablets have made appearances in airports, where travelers can have delivered food to where they sit,
but are limited still in the traditional restaurant scene. Ziosk tablets are in use at Chili's restaurants
and are in the process of launching nationwide at Red Robin. Darden's stock fell 47 cents to $68. 13 in afternoon trading.
Explore further: Percentage of children eating fast food on a given day drop p
#Physicists tune Large hadron collider to find'sweet spot'in high-energy proton smasher As protons collide,
physicists will peer into the resulting particle showers for new discoveries about the universe, said Ryszard Stroynowski, a collaborator on one of the collider's key experiments and a professor in the Department of physics at Southern Methodist University,
Dallas."The hoopla and enthusiastic articles generated by discovery of the Higgs boson two years ago left an impression among many people that we have succeeded,
we are done, we understand everything, "said Stroynowski, who is the senior member of SMU's Large hadron collider team."
A project of CERN, the European organization for nuclear research, the 17-mile LHC tunnel big enough to ride a bicycle through straddles the border between France and Switzerland.
In 2012 it was paused for an extensive upgrade. The new upgraded and supercharged LHC restarts at almost twice the energy
and higher intensity than it was operating at previously, so it will deliver much more data."
"I think that in the LHC Run 2 we will sieve through more data than in all particle physics experiments in the world together for the past 50 years,
"Stroynowski said.""Nature would be really strange if we do not find something new.""SMU is active on the LHC's ATLAS detector experimentwithin the big LHC tunnel,
gigantic particle detectors at four interaction points along the ring record the proton collisions that are generated
With that many collisions, each detector captures collision events 40 million times each second. That's a lot of collision data, says SMU physicist Robert Kehoe, a member of the ATLAS particle detector experiment with Stroynowski and other SMU physicists.
Evaluating that much data isn't humanly possible so a computerized ATLAS hardware"trigger system"grabs the data,
makes a fast evaluation, decides if it might hold something of interest to physicists, than quickly discards
or saves it.""That gets rid of 99.999 percent of the data, "Kehoe said.""This trigger hardware system makes measurements
but they are very crude, fast and primitive.""To further pare down the data, a custom-designed software program culls even more data from each nanosecond grab,
reducing 40 million events down to 200. Two groups from SMU, one led by Kehoe, helped develop software to monitor the performance of the trigger systems'thousands of computer processors."
"The software program has to be accurate in deciding which 200 to keep. We must be very careful that it's the right 200 the 200 that might tell us more about the Higgs boson, for example.
If it's not the right 200, then we can't achieve our scientific goals."
"The ATLAS computers are part of CERN's computing center, which stores more than 30 petabytes of data from the LHC experiments every year, the equivalent of 1. 2 million Blu-ray discs.
Flood of data from ATLAS transmitted via tiny electronics designed at SMU to withstand harsh conditionsan SMU physics team also collaborates on the design,
construction and delivery of the ATLAS"readout"system an electronic system within the ATLAS trigger system that sends collision data from ATLAS to its data processing farm.
Data from the ATLAS particle detector's Liquid Argon Calorimeter is transmitted via 1 524 small fiber-optic transmitters.
A powerful and reliable workhorse, the link is one of thousands of critical components on the LHC that contributed to discovery and precision measurement of the Higgs boson.
The custom-made high-speed data transmitters were designed to withstand extremely harsh conditions low temperature and high radiation.""It's not always a smooth ride operating electronics in such a harsh environment,
"said Jingbo Ye, the physics professor who leads the SMU data-link team.""Failure of any transmitter results in the loss of a chunk of valuable data.
We're working to improve the design for future detectors because by 2017 and 2018,
the existing optical data-link design won't be able to carry all the data.""Each electrical-to-optical and optical-to-electrical signal converter transmits 1. 6 gigabytes of data per second.
Lighter and smaller than their widely used commercial counterpart, the tiny, wickedly fast transmitters have been transmitting from the Liquid Argon Calorimeter for about 10 years.
Upgraded optical data link is now in the works to accommodate beefed-up data flow A more powerful data link much smaller and faster than the current one'is in research and development now.
Slated for installation in 2017, it has the capacity to deliver 5. 2 gigabytes of data per second.
The new link's design has been even more challenging than the first Ye said. It has a smaller footprint than the first,
but handles more data, while at the same time maintaining the existing power supply and heat exchanger now in the ATLAS detector.
The link will have the highest data density in the world of any data link based on the transmitter optical subassembly TOSA, a standard industrial package,
Ye said. Fine-tuning the new, upgraded machine will take several weeksthe world's most powerful machine for smashing protons together will require some"tuning"before physicists from around the world are ready to take data,
said Stephen Sekula, a researcher on ATLAS and assistant professor of physics at SMU. The trick is to get reliable,
stable beams that can remain in collision state for 8 to 12 to 24 hours at a time,
so that the particle physicists working on the experiments, who prize stability, will be satisfied with the quality of the beam conditions being delivered to them,
Sekula said.""The LHC isn't a toaster, "he said.""We're not stamping thousands of them out of a factory every day,
there's only one of them on the planet and when you upgrade it it's a new piece of equipment with new idiosyncrasies,
so there's no guarantee it will behave as it did before.""Machine physicists at CERN must learn the nuances of the upgraded machine,
he said. The beam must be stable, so physicists on shifts in the control room can take high-quality data under stable operating conditions.
The process will take weeks, Sekula said. 10 times as many Higgs particles means a flood of data to sift for gems LHC Run 2 will collide particles at a staggering 13 teraelectronvolts (Tev),
which is 60 percent higher than any accelerator has achieved before.""On paper, Run 2 will give us four times more data than we took on Run 1,
"Sekula said.""But each of those multiples of data are actually worth more. Because not only are we going to take more collisions,
we're going to do it at a higher energy. When you do more collisions and you do them at a higher energy, the rate at
which you make Higgs bosons goes way up. We're going to get 10 times more Higgs than we did in run 1 at least."
"SMU's Maneframe supercomputer plays a key role in helping physicists from the Large hadron collider experiments.
One of the fastest academic supercomputers in the nation, it allows physicists at SMU and around the world to sift through the flood of data,
quickly analyze massive amounts of information, and deliver results to the collaborating scientists. During Run 1, the LHC delivered about 8, 500 Higgs particles a week to the scientists,
but also delivered a huge number of other kinds of particles that have to be sifted away to find the Higgs particles.
And with more Higgs, we'll have an easier time sifting the gems out of the gravel."
but some will be more important than others There are a handful of major new discoveries that could emerge from Run 2 data,
#Crystal breeding factory uncovered A breakthrough in understanding the way in which crystals develop will have a major impact for the pharmaceutical, chemical and food industries.
Lancaster University chemists in collaboration with international colleagues have uncovered a'Crystal Nuclei Breeding Factory'which, they say,
expensive business,"explains Professor Jamshed Anwar, from Lancaster University's Chemistry department.""Crystal'seeds'(very small crystals) are added to the process to act as a'template'to ensure more of the same shape
and size of crystals are produced.""""The rule of the garden isf you sow a single seed you should get a single plant.
However with crystals, a single seed causes thousands of new crystals to form, almost as if'breeding'is taking place.
How this happens has never been understood. It's been a big question and it's fundamental."
"Previous experiments to understand the issue have been inconsequential as microscopes are just not strong enough to determine what the molecules are actually doing.
Professor Anwar and his colleagues, Dr Shahzeb Khan, of Malakand University, Pakistan, and Professor Lennart Lindfors, of Astrazeneca, Sweden, have mapped out'in diagram format the actual movements made by chemical molecules on their breeding journey using computer simulations.
The simulations rely on understanding the'forces'between the atoms from which they compute what the molecules do,
rather like predicting by calculation how a billiard ball is likely to make a break. The journey involves the chemical molecules in solution forming clusters which
form new nanocrystals that are attached loosely to the seed surface. Fluids, used in the process, shear the weakly tethered new crystals from the seed crystal surface allowing the surfaces to be further available for a repeat process
and the new crystals to go on to act as seed crystals themselves.""This is a big step forward,
"adds Professor Anwar.""It means that one can intervene in the crystallisation process and actually engineer the shape,
size and type of crystals to design.""For some drugs, having the correct'handedness'is essential as you need the right key in the lock to make the drugs work.
The'seeding'methodology allows you to separate correct molecules from rogue ones and to do this efficiently."
"The breakthrough also sheds light on the longstanding question of how the distinct'handedness'of molecules of life might have arisen.
Molecules of life exist in pairs that are mirror images of each other. Life forms appear to have selected molecules of only one of these mirror images (known as handedness)
"says Professor Anwar. Current ideas are that molecules of one of the mirror images came together and led to a chance formation of a mirror crystal which, subsequently, induced massive crystallisation of the same image."
"Thanks to this study, we now know how such a single crystal seed could have amplified its effect
and given rise to thousands of new crystals of the same image,"adds Professor Anwar A
#Engineering team invents a camera that powers itself A research team led by Shree K. Nayar,
T. C. Chang Professor of Computer science at Columbia Engineering, has invented a prototype video camera that is the first to be fully self-poweredt can produce an image each second, indefinitely, of a well-lit indoor scene.
They designed a pixel that can not only measure incident light but also convert the incident light into electric power.
who directs the Computer Vision Laboratory at Columbia Engineering. He notes that in the last year alone,
Digital imaging is expected to enable many emerging fields including wearable devices, sensor networks, smart environments, personalized medicine,
although digital cameras and solar panels have different purposes-one measures light while the other converts light to power-both are constructed from essentially the same components.
At the heart of any digital camera is an image sensor, a chip with millions of pixels.
The key enabling device in a pixel is the photodiode, which produces an electric current when exposed to light.
This mechanism enables each pixel to measure the intensity of light falling on it. The same photodiode is used also in solar panels to convert incident light to electric power.
The photodiode in a camera pixel is used in the photoconductive mode while in a solar cell it is used in the photovoltaic model.
Nayar, working with research engineer Daniel Sims BS'14 and consultant Mikhail Fridberg of ADSP Consulting, used off-the-shelf components to fabricate an image sensor with 30x40 pixels.
In his prototype camera, which is housed in a 3d printed body, each pixel's photodiode is operated always in the photovoltaic mode.
The pixel design is very simple, and uses just two transistors. During each image capture cycle, the pixels are used first to record
and read out the image and then to harvest energy and charge the sensor's power supplyhe image sensor continuously toggles between image capture and power harvesting modes.
When the camera is used not to capture images, it can be used to generate power for other devices,
such as a phone or a watch. Nayar notes that the image sensor could use a rechargeable battery and charge it via its harvesting capability:"
"But we took an extreme approach to demonstrate that the sensor is indeed truly self-powered
and used just a capacitor to store the harvested energy.""""A few different designs for image sensors that can harvest energy have been proposed in the past.
However, our prototype is the first demonstration of a fully self-powered video camera, "he continues."
"And, even though we've used off-the-shelf components to demonstrate our design, our sensor architecture easily lends itself to a compact solid-state imaging chip.
We believe our results are a significant step forward in developing an entirely new generation of cameras that can function for a very long durationdeally,
foreverithout being powered externally. a
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