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  • richardmitnick 3:29 pm on May 25, 2017 Permalink | Reply
    Tags: , , , Chemistry, Fertilizer research, Nitrogen fixation   

    From Caltech: “Nitrogen Fixation Research Could Shed Light on Biological Mystery” 

    Caltech Logo

    Caltech

    05/25/2017

    Emily Velasco
    626-395-6487
    evelasco@caltech.edu

    1
    Fertilizer is applied to an agricultural field. Credit: Credit: SoilScience.info (CC BY 2.0)

    New Process Could Make Fertilizer Production More Sustainable

    Inspired by a natural process found in certain bacteria, a team of Caltech researchers is inching closer to a new method for producing fertilizer that could some day hold benefits for farmers—particularly in the developing world—while also shedding light on a biological mystery.

    Fertilizers are chemical sources of nutrients that are otherwise lacking in soil. Most commonly, fertilizers supply the element nitrogen, which is essential for all living things, as it is a fundamental building block of DNA, RNA, and proteins. Nitrogen gas is very abundant on Earth, making up 78 percent of our atmosphere. However, most organisms cannot use nitrogen in its gaseous form.

    To make nitrogen usable, it must be “fixed”—turned into a form that can enter the food chain as a nutrient. There are two primary ways that can happen, one natural and one synthetic.

    Nitrogen fixation occurs naturally due to the action of microbes that live in nodules on plant roots. These organisms convert nitrogen into ammonia through specialized enzymes called nitrogenases. The ammonia these nitrogen-fixing organisms create fertilizes plants that can then be consumed by animals, including humans. In a 2008 paper appearing in the journal Nature Geoscience, a team of researchers estimated that naturally fixed nitrogen provides food for roughly half of the people living on the planet.

    The other half of the world’s food supply is sustained through artificial nitrogen fixation and the primary method for doing this is the Haber-Bosch process, an industrial-scale reaction developed in Germany over 100 years ago. In the process, hydrogen and nitrogen gases are combined in large reaction vessels, under intense pressure and heat in the presence of a solid-state iron catalyst, to form ammonia.

    “The gases are pressurized up to many hundreds of atmospheres and heated up to several hundred degrees Celsius,” says Caltech’s Ben Matson, a graduate student in the lab of Jonas C. Peters, Bren Professor of Chemistry and director of the Resnick Sustainability Institute. ” With the iron catalyst used in the industrial process, these extreme conditions are required to produce ammonia at suitable rates.”

    In a recent paper appearing in ACS Central Science, Matson, Peters, and their colleagues describe a new way of fixing nitrogen that’s inspired by how microbes do it.

    Nitrogenases consist of seven iron atoms surrounded by a protein skeleton. The structure of one of these nitrogenase enzymes was first solved by Caltech’s Douglas Rees, the Roscoe Gilkey Dickinson Professor of Chemistry. The researchers in Peters’ lab have developed something similar to a bacterial nitrogenase, albeit much simpler—a molecular scaffolding that surrounds a single iron atom.

    The molecular scaffolding was first developed in 2013 and, although the initial design showed promise in fixing nitrogen, it was unstable and inefficient. The researchers have improved its efficiency and stability by tweaking the chemical bath in which the fixation reaction occurs, and by chilling it to approximately the temperature of dry ice (-78 degrees Celsius). Under these conditions, the reaction converts 72 percent of starting material into ammonia, a big improvement over the initial method, which only converted 40 percent of the starting material into ammonia and required more energy input to do so.

    Matson, Peters, and colleagues say their work holds the potential for two major benefits:

    • Ease of production: Because the technology being developed does not require high temperatures or pressures, there is no need for the large-scale industrial infrastructure required for the Haber-Bosch process. This means it might some day be possible to fix nitrogen in smaller facilities located closer to where crops are grown.

    “Our work could help to inspire new technologies for fertilizer production,” says Trevor del Castillo, a Caltech graduate student and co-author of the paper. “While this type of a technology is unlikely to displace the Haber-Bosch process in the foreseeable future, it could be highly impactful in places that that don’t have a very stable energy grid, but have access to abundant renewable energy, such as the developing world. There’s definitely room for new technology development here, some sort of ‘on demand’ solar-, hydroelectric-, or wind-powered process.”

    • Understanding natural nitrogen fixation: The nitrogenase enzyme is complicated and finicky, not working if the ambient conditions are not right, which makes it difficult to study. The new catalyst, on the other hand, is relatively simple. The team believes that their catalyst is performing fixation in a conceptually similar way as the enzyme, and that its relative simplicity will make it possible to study fixation reactions in the lab using modern spectroscopic techniques.

    “One fascinating thing is that we really don’t know, on a molecular level, how the nitrogenase enzyme in these bacteria actually turns nitrogen into ammonia. It’s a large unanswered question,” says graduate student Matthew Chalkley, also a co-author on the paper.

    Peters says their research into this catalyst has already given them a deeper understanding of what is happening during a nitrogen-fixing reaction.

    “An advantage of our synthetic iron nitrogenase system is that we can study it in great detail,” he says. “Indeed, in addition to significantly improving the efficiency of this new catalyst for nitrogen fixation, we have made great progress in understanding, at the atomic level, the critical bond-breaking and making-steps that lead to ammonia synthesis from nitrogen.”

    If processes of this type can be further refined and their efficiency increased, Peters adds, they may have applications outside of fertilizer production as well.

    “If this can be achieved, distributed solar-powered ammonia synthesis can become a reality. And not just as a fertilizer source, but also as an alternative, sustainable, and storable chemical fuel,” he says.

    See the full article here .

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    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus

     
  • richardmitnick 11:56 am on May 25, 2017 Permalink | Reply
    Tags: , Chemistry, Chiral nonlinear spectroscopy, , ,   

    From Cornell: “Water forms ‘spine of hydration’ around DNA, group finds” 

    Cornell Bloc

    Cornell University

    May 24, 2017
    Tom Fleischman
    tjf85@cornell.edu

    Story Contacts
    Cornell Chronicle
    Tom Fleischman
    607-255-9735
    tjf85@cornell.edu

    Media Contact
    Daryl Lovell
    607-254-4799
    dal296@cornell.edu

    1
    An illustration of what chiral nonlinear spectroscopy reveals: that DNA is surrounded by a chiral water super-structure, forming a “spine of hydration.” Poul Petersen/Provided

    Water is the Earth’s most abundant natural resource, but it’s also something of a mystery due to its unique solvation characteristics – that is, how things dissolve in it.

    “It’s uniquely adapted to biology, and vice versa,” said Poul Petersen, assistant professor of chemistry and chemical biology. “It’s super-flexible. It dissipates energy and mediates interactions, and that’s becoming more recognized in biological systems.”

    How water relates to and interacts with those systems – like DNA, the building block of all living things – is of critical importance, and Petersen’s group has used a relatively new form of spectroscopy to observe a previously unknown characteristic of water.

    “DNA’s chiral spine of hydration,” published May 24 in the American Chemical Society journal Central Science, reports the first observation of a chiral water superstructure surrounding a biomolecule. In this case, the water structure follows the iconic helical structure of DNA, which itself is chiral, meaning it is not superimposable on its mirror image. Chirality is a key factor in biology, because most biomolecules and pharmaceuticals are chiral.

    “If you want to understand reactivity and biology, then it’s not just water on its own,” Petersen said. “You want to understand water around stuff, and how it interacts with the stuff. And particularly with biology, you want to understand how it behaves around biological material – like protein and DNA.”

    Water plays a major role in DNA’s structure and function, and its hydration shell has been the subject of much study. Molecular dynamics simulations have shown a broad range of behaviors of the water structure in DNA’s minor groove, the area where the backbones of the helical strand are close together.

    The group’s work employed chiral sum frequency generation spectroscopy (SFG), a technique Petersen detailed in a 2015 paper in the Journal of Physical Chemistry. SFG is a nonlinear optical method in which two photon beams – one infrared and one visible – interact with the sample, producing an SFG beam containing the sum of the two beams’ frequencies, or energies. In this case, the sample was a strand of DNA linked to a silicon-coated prism.

    More manipulation of the beams and calculation proved the existence of a chiral water superstructure surrounding DNA.

    In addition to the novelty of observing a chiral water structure template by a biomolecule, chiral SFG provides a direct way to examine water in biology.

    “The techniques we have developed provide a new avenue to study DNA hydration, as well as other supramolecular chiral structures,” Petersen said.

    The group admits that their finding’s biological relevance is unclear, but Petersen thinks the ability to directly examine water and its behavior within biological systems is important.

    “Certainly, chemical engineers who are designing biomimetic systems and looking at biology and trying to find applications such as water filtration would care about this,” he said.

    Another application, Petersen said, could be in creating better anti-biofouling materials, which are resistant to the accumulation of microorganisms, algae and the like on wetted surfaces.

    Collaborators included M. Luke McDermott, Ph.D. ’17; Heather Vanselous, a doctoral student in chemistry and chemical biology and a member of the Petersen Group; and Steven Corcelli, professor of chemistry and biochemistry at the University of Notre Dame.

    This work was supported by grants from the National Science Foundation and the Arnold and Mable Beckman Foundation, and made use of the Cornell Center for Materials Research, an NSF Materials Research Science and Engineering Center.

    See the full article here .

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    Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

    Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

    On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

     
  • richardmitnick 10:49 am on May 25, 2017 Permalink | Reply
    Tags: , , , , Chemistry, Education: Combine and conquer, , ,   

    From Nature- “Education: Combine and conquer” 

    Nature Mag
    Nature

    25 May 2017
    Amber Dance

    1
    Nature

    Completing two graduate degrees can offer great flexibility.

    In 2009, veterinary ophthalmologist Ron Ofri took a call about a flock of sheep in northern Israel. Some of the lambs were day-blind: they wandered easily at night, but stood motionless when the Sun rose.

    Ofri, a researcher at the Hebrew University of Jerusalem who has a PhD and a doctorate in veterinary medicine (DVM), examined the sheep. Then he swapped his clinician’s hat for his research one, assessing the sheep’s retinal function and genome using techniques that he had learnt in graduate school. He and his colleagues then determined that some sheep carry a mutation in the same gene that causes human day-blindness. They successfully tested a gene therapy in sheep, and expect to soon launch human trials.

    The combination of a clinical and a research focus has been enormously beneficial, Ofri says. “One enriches the other.”

    Ofri is one of a small group of PhD scientists who have augmented their research training with a professional degree or a master’s in another topic — public health, for example, or physical therapy (see ‘Mix and match’). Data from the US National Science Foundation show that fewer than 1% of the 261,581 people who were awarded a PhD between 2011 and 2015 also earned a Doctor of Medicine (MD) degree. Even fewer combined a PhD with a dental degree.

    Obtaining multiple advanced degrees can open career doors and position scientists to act as a bridge between two fields of expertise. A downside, however, is that they can take a long time to complete — seven years or more, in some cases. The degrees are usually done sequentially, but some programmes make it possible to do them concurrently. The costs vary: during a PhD, tuition and stipends are usually covered by an adviser’s grant or other sources.

    But for professional degrees, students tend to pay their own way or have to apply for partial or full fellowships. Combination programmes can help to lower the costs, because they may fully or partially subsidize the clinical training. Furthermore, government schemes will often waive the repayment of loans for those who go on to perform clinical research.

    Whatever the route, people who successfully complete multiple advanced degrees tend to have clear goals for how they will apply the skills from each, and have the ability to rapidly switch back and forth between the two roles, as Ofri did in his sheep project.

    But it’s not the right course for everyone, says Tim Church, chief medical officer at ACAP Health, a consultancy firm in Dallas, Texas, who has an MD and a PhD. Those mulling over this route, he says, should carefully consider their interest in research and whether the dual degree will lead to a better job. The degrees ended up being a great choice for him, but the cost may not be worth the sacrifices for everyone.

    Bridge builders

    For many, the clinical component comes first. In Europe, for example, people wanting to become dentists generally spend five or six years in training directly after finishing secondary school, says Paulo Melo, a PhD dentist at the University of Porto in Portugal and chair of the working group on education and professional qualifications at the Council of European Dentists. They can then train in a speciality such as oral surgery, or pursue a research master’s or PhD. The number of people who go on to do the research component varies widely by nation and research field, he says.

    Liz Kay, founding dean of the Peninsula Dental School at Plymouth University, UK, has earned a clinical degree in dentistry, a Master of Public Health (MPH) and a PhD in clinical decision-making. Now, she runs a master’s of business administration programme for health-care workers. She spends one day a week in the clinic and teaches, researches and writes. “I’ve always tried to wedge open all my options,” Kay says.

    In the United States, dentistry students typically cannot enrol for a clinical degree, such as a Doctor of Dental Surgery (DDS), until they have done an undergraduate degree. And some universities offer the professional degrees together with a PhD.

    Box 1: Mix and match

    Degrees that can enhance a PhD include, but are not limited to, these programmes.

    MD A Doctor of Medicine often leads to work in academia, with most hours devoted to research, and some to clinical care.
    MBA A Master of Business Administration can help scientists to turn their research into start-up companies or to ascend in industry (see Nature 533, 569–570; 2016).
    JD A Juris Doctor degree allows scientists to apply their technical expertise in patent law (see Nature 423 666–667; 2003).
    DVM Graduates with a Doctor of Veterinary Medicine can perform translational research in academia and are highly sought after by pharmaceutical companies.
    DDS Many PhD graduates who have a Doctor of Dental Surgery stay in academia, teaching and performing research.
    MPH A Master of Public Health teaches rigorous statistics that enable researchers to work in areas such as epidemiology.
    DPT A Doctor of Physical Therapy helps PhD graduates to work in an academic post and to do research that informs clinical practice.
    PharmD A Doctor of Pharmacy with a PhD could work at a university or contribute to research or drug development in industry.
    DNP A Doctor of Nursing Practice prepares PhD graduates to perform research in nursing science and to teach in nursing schools.
    MSCI A Master of Science in Clinical Investigation produces a greater understanding of clinical research and opens up careers in clinical trials.
    MPP A Master of Public Policy sets graduates up to work in academia, government or research firms, analysing and developing child, family and educational policies.
    A.D.

    Professors who train students in such dual-degree programmes say that there’s a need for graduates who can change gear with ease. Michael Atchison, director of the veterinary–PhD programme at the University of Pennsylvania School of Veterinary Medicine in Philadelphia, says that his graduates are particularly desirable to pharmaceutical companies, which often struggle to find people who can adapt molecular and cellular data for use in an entire organism, he says.

    According to a 2013 report by the US National Academy of Sciences (NAS), about one-quarter of the veterinary surgeons in contract research organizations hold PhDs, and they work mostly in safety research. In animal-health companies, about one-third hold PhDs, and they work mainly in clinical research and development. According to a 2007 NAS questionnaire, 24 of 170, or 37%, of company job adverts for full-time vets sought candidates with a PhD and a veterinary degree.

    The NAS report estimated that an average of 83 North American vets enrolled in a PhD programme each year between 2007 and 2011. Further education is a popular option for vets in Europe. A 2015 survey by the Federation of Veterinarians of Europe found that 21% of veterinary-degree recipients earn a PhD or master’s as well.

    The dual degree may be a requirement for some jobs. Daisuke Ito says that applicants for his job as a medical-science liaison at Bristol-Myers Squibb in Fukuoka, Japan, were required to have both a PhD and an MD or veterinary-medicine degree. Liaisons use their scientific expertise throughout the drug-development process, and maintain relationships between the company and academic physicians.

    In 2014, Emory School of Medicine partnered up with the Georgia Institute of Technology in Atlanta to offer a combined PhD and doctor of physical therapy (DPT) scheme. They, too, expect that the graduates will fill a niche, not least because one-fifth of the US population has a disability, according to the US Centers for Disease Control and Prevention. “There’s a growing recognition about the need for robust rehabilitation science and researchers,” says programme director Edelle Field-Fote.

    Hiring committees may feel that having a PhD shows that a candidate has proven their ability to complete a complex project, says veterinary microbiologist Patrick Butaye of Ross University in Basseterre, West Indies. Butaye earned his veterinary degree at the University of Ghent in Belgium, where the six-year programme includes both undergraduate and graduate course work. He then got a PhD from the university, and now holds an associate appointment there.

    The system is similar in South Korea, says Jong Hyuk Kim, a cancer researcher at the University of Minnesota in Minneapolis. Kim wanted to know more about the diseases he’d been trained to treat during his six-year veterinary programme at Konkuk University in Seoul. So, in his final semester, he took some pathology courses that would count for credit in a PhD programme, and enrolled in that PhD course immediately after completing his veterinary degree. He estimates that about 10% of his classmates did so, too. Both Butaye and Kim note that their PhDs made it easier for them to find work abroad.

    Most countries allow people to work for two advanced degrees sequentially, but truly dual programmes seem to be concentrated in the United States. Yet even there, they are rare. About 120 US universities offer MD–PhD programmes, 15 have vet–PhD courses and around a dozen have PhD–DDS combinations.

    3
    Ron Ofri is often called on to assess eye infections at the Tisch Family Zoological Gardens in Jerusalem. Ron Ofri

    Dual programmes appeal most to students with a strong educational drive and clear goals. Osefame Ewaleifoh, for instance, was interested in combining tightly focused neurovirology questions with a wide view of public health. That brought him to the PhD–MPH programme at the Driskill Graduate Program in the Life Sciences at Northwestern University Feinberg School of Medicine in Chicago, Illinois. In his PhD lab, he studies the brain’s protections against viral invasion; in his public-health work, he’s implementing education for refugees to improve long-term health outcomes.

    Of course, joint programmes can be costly. At the University of Buffalo in New York, Erik Hefti is the first student to embark on a combined PhD–doctor of pharmacy course. He took out loans for his pharmacy degree. Now doing the PhD component, he works nights in a hospital pharmacy so that he can pay off those loans before they accumulate too much interest.

    For those who pay their own way through a professional course, the addition of a PhD can help to cut down on the debt. Church says that he owed nearly US$300,000 — mostly from the MD — by the time he’d finished medical school, a PhD and an MPH course. But because he went on to perform clinical research, government programmes helped Church to pay it off within ten years.

    Choose your adventure

    Even if a university doesn’t offer a specific dual programme, students may be able to design their own, says Steven Anderson, associate director for the Driskill programme, which now allows PhD students to pursue an MPH or a Master of Science in Clinical Investigation (MSCI), after a few students did so on their own.

    Eric Skaar was the first PhD student to do this. He was interested in molecular epidemiology, and hoped that the master’s would position him for jobs investigating disease outbreaks. At first, the university wasn’t eager to let him enrol in the MPH, which at the time was meant only for medical students. But by promising that it would enhance his PhD, not distract from it, he found faculty support.

    Skaar set rules with himself and his PhD adviser — that he’d be a research student until evening, when he attended his public-health classes. He aligned his two courses with a PhD dissertation on how the bacterium that causes gonorrhoea evades the immune system, and a public-health thesis on the epidemiology of the sexually transmitted infection. He never did become an outbreak investigator, but is now director of the division of molecular pathogenesis at Vanderbilt University School of Medicine in Nashville, Tennessee. Thanks to the MPH, he can approach his work on hospital infections with an epidemiological background.

    Students who want to create an ad hoc joint degree should be prepared to hack through plenty of bureaucratic red tape, warns Anderson. Particularly if the degrees are administered by different schools within an institution, basic issues such as tuition and class registration can be tricky. In fact, he’s not sure what form Driskill’s MPH option will take in the future, because he’s working out how to manage the tuition.

    Balancing act

    The multiple-degree path is mentally tricky, too. Ofri notes that people in his clinic don’t understand why he spends so much time in the lab, and his students wonder why he’s always in the clinic. It’s near-impossible to maintain a perfect 50–50 split, says Jaime Modiano, a graduate of the Penn vet–PhD course and now director of the Animal Cancer Care and Research Program at the University of Minnesota in Minneapolis and in St Paul. He decided to forego taking the veterinary board exam, opting for a research postdoc instead.

    Butaye made a similar decision: he researches antibiotic resistance in microbes. But he appreciates the veterinary degree for giving him the flexibility to work in multiple species.

    The balancing act is especially challenging for students during dual-degree programmes. “You have to be able to manage these two very different things you’re doing at the same time,” says Modiano.

    In veterinary classes, he had to memorize and integrate masses of information, then apply it immediately to treat animals. In research, he had to find the information himself and integrate it to spur future discoveries. “People who are successful are highly adaptable,” he says.

    See the full article here .

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    Nature is a weekly international journal publishing the finest peer-reviewed research in all fields of science and technology on the basis of its originality, importance, interdisciplinary interest, timeliness, accessibility, elegance and surprising conclusions. Nature also provides rapid, authoritative, insightful and arresting news and interpretation of topical and coming trends affecting science, scientists and the wider public.

     
  • richardmitnick 8:43 pm on May 21, 2017 Permalink | Reply
    Tags: , , , Chemistry, , , NanoFab, ,   

    From NIST: “Nanocollaboration Leads to Big Things” 

    NIST

    May 12, 2017 [Nothing like being timely getting into social media.]

    Ben Stein
    benjamin.stein@nist.gov
    (301) 975-2763

    1
    Entrance to NIST’s Advanced Measurement Laboratory in Gaithersburg, Maryland. Credit: Photo Courtesy HDR Architecture, Inc./Steve Hall Copyright Hedrich Blessing

    Roche Sequencing Solutions engineer Juraj Topolancik was looking for a way to decode DNA from cancer patients in a matter of minutes.

    Rajesh Krishnamurthy, a researcher with the startup company 3i Diagnostics, needed help in fabricating a key component of a device that rapidly identifies infection-causing bacteria.

    Ranbir Singh, an engineer with GeneSiC Semiconductor Inc., in Dulles, Virginia, sought to construct and analyze a semiconductor chip that transmits voltages large enough to power electric cars and spacecraft.

    These researchers all credit the NanoFab, located at the Center for Nanoscale Science and Technology (CNST) on the Gaithersburg, Maryland campus of the National Institute of Standards and Technology (NIST). The NanoFab provides cutting-edge nanotechnology capabilities for NIST scientists that is also accessible to outside users, with supplying the state-of-art tools, know-how and dependability to realize their goals.


    Learn more about the CNST NanoFab, where scientists from government, academia and industry can use commercial, state-of-the-art tools at economical rates, and get help from dedicated, full-time technical support staff. Voices: David Baldwin (Great Ball of Light, Inc.), Elisa Williams (Scientific & Biomedical Microsystems), George Coles (Johns Hopkins Applied Physics Laboratory) and William Osborn (NIST).

    When Krishnamurthy, whose company is based in Germantown, Maryland, needed an infrared filter for the bacteria-identifying chip, proximity was but one factor in reaching out to the NanoFab.

    “Even more important was the level of expertise you have here,” he says. “The attention to detail and the trust we have in the staff is so important—we didn’t have to worry if they would do a good job, which gives us tremendous peace of mind,” Krishnamurthy notes.

    The NanoFab also aided his project in another, unexpected way. Krishnamurthy had initially thought that the design for his company’s device would require a costly, highly customized silicon chip. But in reviewing design plans with engineers at the NanoFab, “they came up with a very creative way” to use a more standard, less expensive silicon wafer that would achieve the same goals, he notes.

    “The impact in the short term is that we didn’t have to pay as much [to build and test] the device at the NanoFab, which matters quite a bit because we’re a start-up company,” says Krishnamurthy. “In the long run, this will be a huge factor in [enabling us to mass produce] the device, keeping our costs low because, thanks to the input from the NanoFab, the source material is not a custom material.”

    Singh came to the NanoFab with a different mission. His company is developing a gallium nitride semiconductor device durable enough to transmit hundreds to thousands of volts without deteriorating. He relies on the NanoFab’s metal deposition tools and high-resolution lithography instruments to finish building and assess the properties of the device.

    2
    Semiconductor device, fabricated with the help of the NanoFab, designed to transmit high voltages.
    Credit: GeneSiC Semiconductor Inc.

    “Not only is there a wide diversity of tools, but within each task there are multiple technologies,” Singh adds.

    For instance, he notes, technologies offered at the NanoFab for depositing exquisitely thin and highly uniform layers of metal—which Singh found crucial for making reliable electrical contacts—include both evaporation and sputtering, he says.

    The wide range of metals available for deposition at the NanoFab, uncommon at other nanotech facilities, was another draw.

    “We needed different metals compared to those commonly used on silicon wafers and the NanoFab provided those materials,” notes Singh.

    Topolancik, the Roche Sequencing Solutions engineer, needed high precision etching and deposition tools to fabricate a device that may ultimately improve cancer treatment. His company‘s plan to rapidly sequence DNA from cancer patients could quickly determine if potential anti-cancer drugs and those already in use are producing the genetic mutations necessary to fight cancer.

    “We want to know if the drug is working, and if not, to stop using it and change the treatment,” says Topolancik.

    In the standard method to sequence the double-stranded DNA molecule, a strand is peeled off and resynthesized, base by base, with each base—cytosine, adenine, guanine and thymine—tagged with a different fluorescent label.

    “It’s a very accurate but slow method,” says Topolancik.

    Instead of peeling apart the molecule, Topolancik is devising a method to read DNA directly, a much faster process. Borrowing a technique from the magnetic recording industry, he sandwiches the DNA between two electrodes separated by a gap just nanometers in width.

    3

    Illustration of experiment to directly identify the base pairs of a DNA strand (denoted by A, C, T, G in graph). Tunneling current flows through DNA placed between two closely spaced electrodes. Different bases allow different amounts of current to flow, revealing the components of the DNA molecule.
    Credit: J. Topolancik/Roche Sequencing Solutions

    According to quantum theory, if the gap is small enough, electrons will spontaneously “tunnel” from one electrode to the other. In Topolancik’s setup, the tunneling electrons must pass through the DNA in order to reach the other electrode.

    The strength of the tunneling current identifies the bases of the DNA trapped between the electrodes. It’s an extremely rapid process, but for the technique to work reliably, the electrodes and the gap between them must be fabricated with extraordinarily high precision.

    That’s where the NanoFab comes in. To deposit layers of different metals just nanometers in thickness on a wafer, Topolancik relies on the NanoFab’s ion beam deposition tool. And to etch a pattern in those ultrathin, supersmooth layers without disturbing them—a final step in fabricating the electrodes—requires the NanoFab’s ion etching instrument.

    “These are specialty tools that are not usually accessible in academic facilities, but here [at the NanoFab] you have full, 24/7 access to them,” says Topolancik. “And if a tool goes down, it gets fixed right away,” he adds. “People here care about you, they want you to succeed because that’s the mission of the NanoFab.” As a result, he notes, “I can get done here in two weeks what would take half a year any place else.”


    Take a 360-degree walking tour of the CNST NanoFab in this video!

    See the full article here.

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    NIST Campus, Gaitherberg, MD, USA

    NIST Mission, Vision, Core Competencies, and Core Values

    NIST’s mission

    To promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life.
    NIST’s vision

    NIST will be the world’s leader in creating critical measurement solutions and promoting equitable standards. Our efforts stimulate innovation, foster industrial competitiveness, and improve the quality of life.
    NIST’s core competencies

    Measurement science
    Rigorous traceability
    Development and use of standards

    NIST’s core values

    NIST is an organization with strong values, reflected both in our history and our current work. NIST leadership and staff will uphold these values to ensure a high performing environment that is safe and respectful of all.

    Perseverance: We take the long view, planning the future with scientific knowledge and imagination to ensure continued impact and relevance for our stakeholders.
    Integrity: We are ethical, honest, independent, and provide an objective perspective.
    Inclusivity: We work collaboratively to harness the diversity of people and ideas, both inside and outside of NIST, to attain the best solutions to multidisciplinary challenges.
    Excellence: We apply rigor and critical thinking to achieve world-class results and continuous improvement in everything we do.

     
  • richardmitnick 3:32 pm on May 20, 2017 Permalink | Reply
    Tags: , , , , Biology [et al] needs more staff scientists, Chemistry, ,   

    From Nature: “Biology needs more staff scientists” 

    Nature Mag
    Nature

    16 May 2017
    Steven Hyman

    Independent professionals advance science in ways faculty-run labs cannot, and such positions keep talented people in research, argues Steven Hyman.

    1
    Staff scientist Stacey Gabriel co-authored 25 of the most highly cited papers worldwide in 2015. Maria Nemchuk/Broad Inst.

    [I have to ask, I do a Women in STEM series, why are the women I see always so good looking. This cannot be normal. No uglies, no fatties, that just does not compute.]

    Most research institutions are essentially collections of independent laboratories, each run by principal investigators who head a team of trainees. This scheme has ancient roots and a track record of success. But it is not the only way to do science. Indeed, for much of modern biomedical research, the traditional organization has become limiting.

    A different model is thriving at the Broad Institute of MIT and Harvard in Cambridge, Massachusetts, where I work.


    Broad Institute Campus

    In the 1990s, the Whitehead Institute for Biomedical Research, a self-governing organization in Cambridge affiliated with the Massachusetts Institute of Technology (MIT), became the academic leader in the Human Genome Project. This meant inventing and applying methods to generate highly accurate DNA sequences, characterize errors precisely and analyse the outpouring of data. These project types do not fit neatly into individual doctoral theses. Hence, the institute created a central role for staff scientists — individuals charged with accomplishing large, creative and ambitious projects, including inventing the means to do so. These non-faculty scientists work alongside faculty members and their teams in collaborative groups.

    When leaders from the Whitehead helped to launch the Broad Institute in 2004, they continued this model. Today, our work at the Broad would be unthinkable without professional staff scientists — biologists, chemists, data scientists, statisticians and engineers. These researchers are not pursuing a tenured academic post and do not supervise graduate students, but do cooperate on and lead projects that could not be accomplished by a single academic laboratory.

    Physics long ago saw the need to expand into different organizational models. The Manhattan Project, which during the Second World War harnessed nuclear energy for the atomic bomb, was not powered by graduate students. Europe’s particle-physics laboratory, CERN, does not operate as atomized labs with each investigator pursuing his or her own questions.

    LHC

    CERN/LHC Map

    CERN LHC Tunnel

    CERN LHC particles

    And the Jet Propulsion Laboratory at the California Institute of Technology in Pasadena relies on professional scientists to get spacecraft to Mars.


    NASA JPL-Caltech Campus

    A different tack

    In biology, many institutes in addition to the Broad are experimenting with new organizational principles. The Mechanobiology Institute in Singapore pushes its scientists to use tools from other disciplines by discouraging individual laboratories from owning expensive equipment unless it is shared by all. The Howard Hughes Medical Institute’s Janelia Research Campus in Ashburn, Virginia, the Salk Institute of Biological Sciences in La Jolla, California, and the Allen Institute for Brain Science in Seattle, Washington, effectively mix the work of faculty members and staff scientists. Disease-advocacy organizations, such as the ALS Therapy Development Institute in Cambridge, do their own research without any faculty members at all.

    Each of these institutes has a unique mandate, and many are fortunate in having deep resources. They also had to be willing to break with tradition and overcome cultural barriers.

    At famed research facilities of yore, such as Bell Labs and IBM Laboratories, the title ‘staff scientist’ was a badge of honour. Yet to some biologists the term suggests a permanent postdoc or senior technician — someone with no opportunities for advancement who works solely in a supervisor’s laboratory, or who runs a core facility providing straightforward services. That characterization sells short the potential of professional scientists.

    The approximately 430 staff scientists at the Broad Institute develop cutting-edge computational methods, invent and incorporate new processes into research pipelines and pilot and optimize methodologies. They also transform initial hits from drug screens into promising chemical compounds and advance techniques to analyse huge data sets. In summary, they chart the path to answering complex scientific questions.

    Although the work of staff scientists at the Broad Institute is sometimes covered by charging fees to its other labs, our faculty members would never just drop samples off with a billing code and wait for data to be delivered. Instead, they sit down with staff scientists to discuss whether there is an interesting collaboration to be had and to seek advice on project design. Indeed, staff scientists often initiate collaborations.

    Naturally, tensions still arise. They can play out in many ways, from concerns over how fees are structured, to questions about authorship. Resolving these requires effort, and it is a task that will never definitively be finished.

    In my view, however, the staff-scientist model is a win for all involved. Complex scientific projects advance more surely and swiftly, and faculty members can address questions that would otherwise be out of reach. This model empowers non-faculty scientists to make independent, creative contributions, such as pioneering new algorithms or advancing technologies. There is still much to do, however. We are working to ensure that staff scientists can continue to advance their careers, mentor others and help to guide the scientific direction of the institute.

    As the traditional barriers break down, science benefits. Technologies that originate in a faculty member’s lab sometimes attract more collaborations than one laboratory could sustain. Platforms run by staff scientists can incorporate, disseminate and advance these technologies to capture more of their potential. For example, the Broad Institute’s Genetic Perturbation Platform, run by physical chemist David Root, has honed high-throughput methods for RNA interference and CRISPR screens so that they can be used across the genome in diverse biological contexts. Staff scientists make the faculty more productive through expert support, creativity, added capacity and even mentoring in such matters as the best use of new technologies. The reverse is also true: faculty members help staff scientists to gain impact.

    Our staff scientists regularly win scientific prizes and are invited to give keynote lectures. They apply for grants as both collaborators and independent investigators, and publish regularly. Since 2011, staff scientists have led 36% of all the federal grants awarded for research projects at the Broad Institute (see ‘Staff-led grants’). One of our staff scientists, genomicist Stacey Gabriel, topped Thomson Reuters’ citation analysis of the World’s Most Influential Scientific Minds in 2016. She co-authored 25 of the most highly cited papers in 2015 — a fact that illustrates both how collaborative the Broad is and how central genome-analysis technologies are to answering key biological questions.

    3
    Source: Broad Inst.

    At the Broad Institute’s Stanley Center for Psychiatric Research, which I direct, staff scientists built and operate HAIL, a powerful open-source tool for analysis of massive genetics data sets. By decreasing computational time, HAIL has made many tasks 10 times faster, and some 100 times faster. Staff scientist Joshua Levin has developed and perfected RNA-sequencing methods used by many colleagues to analyse models of autism spectrum disorders and much else. Nick Patterson, a mathematician and computational biologist at the Stanley Center, began his career by cracking codes for the British government during the cold war. Today, he uses DNA to trace past migrations of entire civilizations, helps to solve difficult computational problems and is a highly valued support for many biologists.

    Irrational resistance

    Why haven’t more research institutions expanded the roles of staff scientists? One reason is that they can be hard to pay for, especially by conventional means. Some funding agencies look askance at supporting this class of professionals; after all, graduate students and postdocs are paid much less. In my years leading the US National Institute of Mental Health, I encountered people in funding bodies across the world who saw a rising ratio of staff to faculty members or of staff to students as evidence of fat in the system.

    That said, there are signs of flexibility. In 2015, the US National Cancer Institute began awarding ‘research specialist’ grants — a limited, tentative effort designed in part to provide opportunities for staff scientists. Sceptical funders should remember that trainees often take years to become productive. More importantly, institutions’ misuse of graduates and postdocs as cheap labour is coming under increasing criticism (see, for example, B. Alberts et al. Proc. Natl Acad. Sci. USA 111, 5773–5777; 2014).

    Faculty resistance is also a factor. I served as Harvard University’s provost (or chief academic officer) for a decade. Several years in, I launched discussions aimed at expanding roles for staff scientists. Several faculty members worried openly about competition for space and other scarce resources, especially if staff scientists were awarded grants but had no teaching responsibilities. Many recoiled from any trappings of corporatism or from changes that felt like an encroachment on their decision-making. Some were explicitly concerned about a loss of access and control, and were not aware of the degree to which staff scientists’ technological expertise and cross-disciplinary training could help to answer their research questions.

    Institutional leaders can mitigate these concerns by ensuring that staff positions match the shared goals of the faculty — for scientific output, education and training. They must explain how staff-scientist positions create synergies rather than silos. Above all, hiring plans must be developed collaboratively with faculty members, not by administrators alone.

    The Broad Institute attracts world-class scientists, as both faculty members and staff. Its appeal has much to do with how staff scientists enable access to advanced technology, and a collaborative culture that makes possible large-scale projects rarely found in academia. The Broad is unusual — all faculty members also have appointments at Harvard University, MIT or Harvard-affiliated hospitals. The institute has also benefited from generous philanthropy from individuals and foundations that share our values and believe in our scientific mission.

    Although traditional academic labs have been and continue to be very productive, research institutions should look critically and creatively at their staffing. Creating a structure like that of the Broad Institute would be challenging in a conventional university. Still, I believe any institution that is near an academic health centre or that has significant needs for advanced technology could benefit from and sustain the careers of staff scientists. If adopted judiciously, these positions would enable institutions to take on projects of unprecedented scope and scale. It would also create a much-needed set of highly rewarding jobs for the rising crop of talented researchers, particularly people who love science and technology but who do not want to pursue increasingly scarce faculty positions.

    A scientific organization should be moulded to the needs of science, rather than constrained by organizational traditions.

    See the full article here .

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  • richardmitnick 3:26 pm on May 19, 2017 Permalink | Reply
    Tags: , Chemistry, Chemists Are One Step Closer to Manipulating All Matter, Controlling a single molecule’s behavior, David Wineland, , ,   

    From WIRED: “Chemists Are One Step Closer to Manipulating All Matter” 

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    WIRED

    Date of Publication: 05.11.17.
    05.11.17
    Nick Stockton

    1
    Getty Images

    For all their periodic tables, styrofoam ball-and-pencil models, and mouth-garbling vocabulary, chemists really don’t know jack about molecules.

    Part of the problem is they can’t really control what molecules do. Molecules spin, vibrate, and trade electrons, all of which affect the way they react with other molecules. Of course, scientists know enough about those scaled-up reactions to do things like make concrete, refine gasoline, and brew beer. But if you’re trying to use individual molecules as tools, or manipulate them so precisely that you can snap them together like Lego pieces, you need better control. Scientists aren’t all the way there yet, but recently scientists at the National Institute of Standards and Technology solved an early challenge: controlling a single molecule’s behavior.

    At the very basic level, controlling a molecule would let scientists learn more about it. “This is a long-standing problem,” says Dietrich Leibfried, a physicist with NIST’s Ion Storage Group in Boulder, Colorado. “Everything around us is made out of molecules, but it’s hard to precisely find out about them.” And that would have practical applications. For instance, NIST keeps tables of molecular properties that astrophysicists consult when they’re reading the spectral signatures of faraway stars and exoplanets. Filling in those blanks would support predictions of whether some exoplanet can support life. With enough control, scientists won’t just get a better look at molecules—they’ll manipulate matter.

    But for now, they are still experimenting. Scientists know how to control atoms using cold vacuum and lasers—so at NIST, scientists’ limited molecular control builds on that knowledge. Their research, published yesterday in Nature, describes their experiment: They begin with a vacuum chamber, a 3-inch box containing a tiny electrode, which itself holds a single positively charged calcium atomic ion. Then come the molecules: Ionized hydrogen gas, which the scientists leak into the vacuum chamber until a single H2 reacts with the calcium atom.

    Now the ionized atom and the ionized molecule are trapped together. But they’re repelled by their positive charges, and the force of the repulsion sends them vibrating—like two magnets when you bring them close. They’re also spinning, like a lopsided barbell hurled into the air.

    So the scientists set out to freeze the pair in place, again calling on their skills of atomic control. First they fire a low-energy laser at the calcium atom, cooling it and stopping its motion—and because it’s coupled to the hydrogen molecule, the hydrogen stops vibrating as well. That’s the easy part. The calcium-hydride is still rotating. “That rotation, the spinning along the horizontal or vertical plane, is the hardest thing to control,” says Leibfried. Imagine trying to stick Legos together if they were spinning independently. Leibfried and his group do know how to stop, and even alter the spinning. They figured that out last year using lasers tuned to specific frequencies.

    All that rigamarole is worthless if you don’t know which way the molecule is pointing, though. And if you want to check in on the molecule—by firing another laser—you set it into random motion once again. So instead the NIST scientists fire a teeny tiny laser at the calcium atom, causing it to wiggle. Because it is connected to the hydrogen molecule, it picks up on the molecule’s state. And Leibfried and his team can “read” that state by examining the way the laser’s light scatters when it encounters the calcium atom. The whole intricate choreography between them lasts about a millisecond, and at the end they can see if the molecule behaved as it was directed.

    So what’s the point of all that? If you can control with certainty the orientation of a molecule, it’s one step closer to sticking them together exactly how you want—no more tossing compounds in a beaker and praying for the right kind of bubbles. Or, to return to the Lego analogy, you can understand—and manipulate—how molecules stick together.

    This discovery builds off work done by Leibfried’s mentor, Nobel winner David Wineland, who did the foundational atomic control work behind atomic clocks based on single trapped ions. But unlike atomic clocks—which changed the scale at which scientists could measure time, and led to breakthroughs like GPS—this process isn’t ready to revolutionize chemistry just yet. Scientists need to fine-tune their control, and have yet to proof the concept on molecules besides hydrogen. Having just one molecule would be like trying to build a city from Legos using only 2×4 bricks.

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  • richardmitnick 4:22 pm on May 3, 2017 Permalink | Reply
    Tags: , Chemistry, LBNL FIONA,   

    From LBNL: “FIONA to Take on the Periodic Table’s Heavyweights” 

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    Berkeley Lab

    May 3, 2017
    Glenn Roberts Jr
    geroberts@lbl.gov
    (510) 486-5582

    1
    Berkeley Lab Scientists Jackie Gates, left, and Kenneth Gregorich work on FIONA, a new device at the Lab’s 88-Inch Cyclotron. FIONA is designed to precisely measure the mass number of the periodic table’s superheavy elements, and could also be useful for other types of explorations of superheavy elements. (Credit: Marilyn Chung/Berkeley Lab)

    A new tool at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) will be taking on some of the periodic table’s latest heavyweight champions to see how their masses measure up to predictions.

    Dubbed FIONA, the device is designed to measure the mass numbers of individual atoms of superheavy elements, which have higher masses than uranium.

    “Once we have determined those mass numbers, we will use FIONA to learn about the shape and structure of heavy nuclei, guide the search for new elements, and to give us better measurements for nuclear fission and related processes in nuclear physics and nuclear chemistry research,” said Kenneth Gregorich, a senior scientist in Berkeley Lab’s Nuclear Science Division who has been involved in building and testing FIONA.

    2
    Jackie Gates, a Berkeley Lab staff scientist, points to a branching region of the periodic table that is populated by isotopes of superheavy elements. (Credit: Marilyn Chung/Berkeley Lab)

    FIONA’s full name is “For the Identification Of Nuclide A.” The “A” is a scientific symbol representing the mass number—the sum of protons, which are positively charged, and neutrons, which do not have an electric charge— in the nucleus of an atom. The proton count, also known as the atomic number, is unique for each element and is the basis for the arrangement of elements in the periodic table.

    FIONA builds on a long history of expertise in heavy element discoveries and nuclear physics research at Berkeley Lab. The Lab’s scientists have been involved in the discovery of 16 elements and also various forms of elements, known as isotopes, which have different numbers of neutrons.


    VIDEO: Chemistry World magazine visited Berkeley Lab’s 88-Inch Cyclotron to discuss how superheavy elements are made and studied. (Credit: © Chemistry World)

    Nuclear physicists have used the known masses of radioactive decay “daughter atoms” as a framework for determining the masses for these heavier “parent” elements.

    Previous experiments have also helped to home in on the masses of some of the superheavy elements. But determining the mass number of some of the heaviest elements has remained out of reach because it is challenging to produce isolated atoms and to measure them before they rapidly decay.

    FIONA’s measurements are expected to provide a better fundamental understanding of the makeup of these manufactured superheavy atomic nuclei.

    “We will be exploring the limits of nuclear stability, answering basic questions such as how many protons you can put in a nucleus,” Gregorich said.

    A holy grail in this field is to reach the so-called “island of stability,” an as-yet unexplored realm in the chart of nuclei where human-made isotopes are theorized to be long-lived.

    “We will perhaps be probing the edge of this ‘island’ — informing theories that predict such things so they can be refined,” Gregorich said.

    FIONA was installed in November 2016 at Berkeley Lab’s 88-Inch Cyclotron, which produces intense particle beams for nuclear physics experiments and to test the radiation-hardness of computer chips for use in satellites, and has since undergone a range of tests to prepare it for a first round of experiments this summer. FIONA is an enhancement to a long-running machine called the Berkeley Gas-filled Separator (BGS) that separates atoms of superheavy elements from other types of charged particles.

    4
    Jeffrey Kwarsick, a graduate student, works on the installation of FIONA at Berkeley Lab’s 88-Inch Cyclotron. (Credit: Marilyn Chung/Berkeley Lab)

    The separator’s job is to separate the heavy elements of interest from the beam and other unwanted reaction products,” Gregorich said, and FIONA is designed to move the desired atoms away from this “noisy” environment and to quickly measure them within about 10 thousandths of a second.

    This is important because the human-made superheavy elements discovered so far have very short half-lives, in some cases decaying down to lighter elements on scales measured in thousandths of a second.

    FIONA components include a new shielding wall that is designed to reduce background noise from other charged particles, a specialized trapping mechanism for atoms, and a sensitive silicon-based detector array that can measure the energy, position, and timing of the decay of radioactive atoms.

    Several components of FIONA were constructed under contract with Argonne National Laboratory, and the mass analyzer was designed and built at Berkeley Lab.

    “The design for FIONA is practical, flexible, and unique,” Gregorich said. “We were looking at different ways to perform mass separation, and everything else was either more expensive or more difficult.”

    6
    A view of FIONA’s detector components. (Credit: Marilyn Chung/Berkeley Lab)

    The initial beams that will be produced at the 88-Inch Cyclotron for the early FIONA experiments will use an isotope of calcium that is accelerated to strike a target containing a heavy element—typically human-made americium, which is heavier than plutonium. This bombardment fuses some of the atomic nuclei to produce even heavier atoms.

    Jackie Gates, a staff scientist in the Nuclear Science Division and a leader of the FIONA team, said, “Some other devices have a much higher mass resolution but a lower efficiency—FIONA will have the highest efficiency.” This higher efficiency means that FIONA can isolate and measure more atoms of a specific superheavy element in a given time than comparable devices.

    Even so, the creation of the heaviest atoms yet discovered is challenging: Of all the particles pouring through the separator, perhaps one in a quintillion (one followed by 18 zeros) reaching the experiment will form a superheavy element of interest.

    That translates into the production of possibly one atom of interest per day, and several detections will be needed to determine the mass number, Gates said.

    After separation in the Berkeley Gas-filled Separator, atoms of interest are trapped, bunched, and cooled in a device known as a radiofrequency quadrupole trap.

    They are then sent through the FIONA mass separator, which contains crossed electric and magnetic fields. In the separator, the ions take on a looping trajectory, sending them to the detector with positions determined by their mass-to-charge ratio. The position in the detector at which the superheavy element radioactive decay is detected gives the mass number.

    7
    A view of FIONA in Cave 2 at Berkeley Lab’s 88-Inch Cyclotron. (Credit: Marilyn Chung/Berkeley Lab)

    FIONA’s commissioning should wrap up this spring, Gates said, and one of the headline experiments for the new device will be to study decay processes associated with element 115, recently named moscovium (its periodic table symbol is “Mc”).

    “The Berkeley Gas-filled Separator gave us 20 years of science,” Gates said, “and now we are looking at extending this another 10 to 20 years with FIONA.”

    This work is supported by the Department of Energy’s Office of Nuclear Physics.

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  • richardmitnick 9:19 am on April 10, 2017 Permalink | Reply
    Tags: , Chemistry, , Nanoporous materials, , , , Stanford scientist’s new approach may accelerate design of high-power batteries, Storing electricity, Supercapacitors   

    From Stanford: “Stanford scientist’s new approach may accelerate design of high-power batteries” 

    Stanford University Name
    Stanford University

    April 6, 2017
    Danielle Torrent Tucker

    1
    Electric vehicles plug in to charging stations. New research may accelerate discovery of materials used in electrical storage devices, such as car batteries. (Image credit: Shutterstock)

    In work published this week in Applied Physics Letters, the researchers describe a mathematical model for designing new materials for storing electricity. The model could be a huge benefit to chemists and materials scientists, who traditionally rely on trial and error to create new materials for batteries and capacitors. Advancing new materials for energy storage is an important step toward reducing carbon emissions in the transportation and electricity sectors.

    “The potential here is that you could build batteries that last much longer and make them much smaller,” said study co-author Daniel Tartakovsky, a professor in the School of Earth, Energy & Environmental Sciences. “If you could engineer a material with a far superior storage capacity than what we have today, then you could dramatically improve the performance of batteries.”

    Lowering a barrier

    One of the primary obstacles to transitioning from fossil fuels to renewables is the ability to store energy for later use, such as during hours when the sun is not shining in the case of solar power. Demand for cheap, efficient storage has increased as more companies turn to renewable energy sources, which offer significant public health benefits.

    Tartakovsky hopes the new materials developed through this model will improve supercapacitors, a type of next-generation energy storage that could replace rechargeable batteries in high-tech devices like cellphones and electric vehicles. Supercapacitors combine the best of what is currently available for energy storage – batteries, which hold a lot of energy but charge slowly, and capacitors, which charge quickly but hold little energy. The materials must be able to withstand both high power and high energy to avoid breaking, exploding or catching fire.

    “Current batteries and other storage devices are a major bottleneck for transition to clean energy,” Tartakovsky said. “There are many people working on this, but this is a new approach to looking at the problem.”

    The types of materials widely used to develop energy storage, known as nanoporous materials, look solid to the human eye but contain microscopic holes that give them unique properties. Developing new, possibly better nanoporous materials has, until now, been a matter of trial and error – arranging minuscule grains of silica of different sizes in a mold, filling the mold with a solid substance and then dissolving the grains to create a material containing many small holes. The method requires extensive planning, labor, experimentation and modifications, without guaranteeing the end result will be the best possible option.

    “We developed a model that would allow materials chemists to know what to expect in terms of performance if the grains are arranged in a certain way, without going through these experiments,” Tartakovsky said. “This framework also shows that if you arrange your grains like the model suggests, then you will get the maximum performance.”

    Beyond energy

    Energy is just one industry that makes use of nanoporous materials, and Tartakovsky said he hopes this model will be applicable in other areas, as well.

    “This particular application is for electrical storage, but you could also use it for desalination, or any membrane purification,” he said. “The framework allows you to handle different chemistry, so you could apply it to any porous materials that you design.”

    Tartakovsky’s mathematical modeling research spans neuroscience, urban development, medicine and more. As an Earth scientist and professor of energy resources engineering, he is an expert in the flow and transport of porous media, knowledge that is often underutilized across disciplines, he said. Tartakovsky’s interest in optimizing battery design stemmed from collaboration with a materials engineering team at the University of Nagasaki in Japan.

    “This Japanese collaborator of mine had never thought of talking to hydrologists,” Tartakovsky said. “It’s not obvious unless you do equations – if you do equations, then you understand that these are similar problems.”

    The lead author of the study, “Optimal design of nanoporous materials for electrochemical devices,” is Xuan Zhang, Tartakovsky’s former PhD student at the University of California, San Diego. The research was supported by the Defense Advanced Research Projects Agency and the National Science Foundation.

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  • richardmitnick 10:54 am on March 27, 2017 Permalink | Reply
    Tags: , Chemistry, , , Power factor,   

    From Rutgers: “How Graphene Could Cool Smartphone, Computer and Other Electronics Chips” 

    Rutgers University
    Rutgers University

    March 27, 2017
    Todd B. Bates

    1
    Graphene, a one-atom-thick layer of graphite, consists of carbon atoms arranged in a honeycomb lattice. Photo: OliveTree/Shutterstock

    Rutgers scientists lead research that discovers potential advance for the electronics industry.

    With graphene, Rutgers researchers have discovered a powerful way to cool tiny chips – key components of electronic devices with billions of transistors apiece.

    “You can fit graphene, a very thin, two-dimensional material that can be miniaturized, to cool a hot spot that creates heating problems in your chip, said Eva Y. Andrei, Board of Governors professor of physics in the Department of Physics and Astronomy. “This solution doesn’t have moving parts and it’s quite efficient for cooling.”

    The shrinking of electronic components and the excessive heat generated by their increasing power has heightened the need for chip-cooling solutions, according to a Rutgers-led study published recently in Proceedings of the National Academy of Sciences. Using graphene combined with a boron nitride crystal substrate, the researchers demonstrated a more powerful and efficient cooling mechanism.

    “We’ve achieved a power factor that is about two times higher than in previous thermoelectric coolers,” said Andrei, who works in the School of Arts and Sciences.

    The power factor refers to the effectiveness of active cooling. That’s when an electrical current carries heat away, as shown in this study, while passive cooling is when heat diffuses naturally.

    Graphene has major upsides. It’s a one-atom-thick layer of graphite, which is the flaky stuff inside a pencil. The thinnest flakes, graphene, consist of carbon atoms arranged in a honeycomb lattice that looks like chicken wire, Andrei said. It conducts electricity better than copper, is 100 times stronger than steel and quickly diffuses heat.

    The graphene is placed on devices made of boron nitride, which is extremely flat and smooth as a skating rink, she said. Silicon dioxide – the traditional base for chips – hinders performance because it scatters electrons that can carry heat away.

    In a tiny computer or smartphone chip, billions of transistors generate lots of heat, and that’s a big problem, Andrei said. High temperatures hamper the performance of transistors – electronic devices that control the flow of power and can amplify signals – so they need cooling.

    Current methods include little fans in computers, but the fans are becoming less efficient and break down, she said. Water is also used for cooling, but that bulky method is complicated and prone to leaks that can fry computers.

    “In a refrigerator, you have compression that does the cooling and you circulate a liquid,” Andrei said. “But this involves moving parts and one method of cooling without moving parts is called thermoelectric cooling.”

    Think of thermoelectric cooling in terms of the water in a bathtub. If the tub has hot water and you turn on the cold water, it takes a long time for the cold water below the faucet to diffuse in the tub. This is passive cooling because molecules slowly diffuse in bathwater and become diluted, Andrei said. But if you use your hands to push the water from the cold end to the hot, the cooling process – also known as convection or active cooling – will be much faster.

    The same process takes place in computer and smartphone chips, she said. You can connect a piece of wire, such as copper, to a hot chip and heat is carried away passively, just like in a bathtub.

    Now imagine a piece of metal with hot and cold ends. The metal’s atoms and electrons zip around the hot end and are sluggish at the cold end, Andrei said. Her research team, in effect, applied voltage to the metal, sending a current from the hot end to the cold end. Similar to the case of active cooling in the bathtub example, the current spurred the electrons to carry away the heat much more efficiently than via passive cooling. Graphene is actually superior in both its passive and active cooling capability. The combination of the two makes graphene an excellent cooler.

    “The electronics industry is moving towards this kind of cooling,” Andrei said. “There’s a very big research push to incorporate these kinds of coolers. There is a good chance that the graphene cooler is going to win out. Other materials out there are much more expensive, they’re not as thin and they don’t have such a high power factor.”

    The study’s lead author is Junxi Duan, a Rutgers physics post-doctoral fellow. Other authors include Xiaoming Wang, a Rutgers mechanical engineering post-doctoral fellow; Xinyuan Lai, a Rutgers physics undergraduate student; Guohong Li, a Rutgers physics research associate; Kenji Watanabe and Takashi Taniguchi of the National Institute for Materials Science in Tsukuba, Japan; Mona Zebarjadi, a former Rutgers mechanical engineering professor who is now at the University of Virginia; and Andrei. Zebarjadi conducted a previous study on electronic cooling using thermoelectric devices.

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  • richardmitnick 4:35 pm on March 17, 2017 Permalink | Reply
    Tags: , Chemistry, , , Scientists make microscopes from droplets, Tunable microlenses   

    From MIT: “Scientists make microscopes from droplets” 

    MIT News

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    MIT News

    March 10, 2017
    Jennifer Chu

    1
    Researchers at MIT have devised tiny “microlenses” from complex liquid droplets, such as these pictured here, that are comparable in size to the width of a human hair. Courtesy of the researchers

    With chemistry and light, researchers can tune the focus of tiny beads of liquid.

    Liquid droplets are natural magnifiers. Look inside a single drop of water, and you are likely to see a reflection of the world around you, close up and distended as you’d see in a crystal ball.

    Researchers at MIT have now devised tiny “microlenses” from complex liquid droplets comparable in size to the width of a human hair. They report the advance this week in the journal Nature Communications.

    Each droplet consists of an emulsion, or combination of two liquids, one encapsulated in the other, similar to a bead of oil within a drop of water. Even in their simple form, these droplets can magnify and produce images of surrounding objects. But now the researchers can also reconfigure the properties of each droplet to adjust the way they filter and scatter light, similar to adjusting the focus on a microscope.

    The scientists used a combination of chemistry and light to precisely shape the curvature of the interface between the internal bead and the surrounding droplet. This interface acts as a kind of internal lens, comparable to the compounded lens elements in microscopes.

    “We have shown fluids are very versatile optically,” says Mathias Kolle, the Brit and Alex d’Arbeloff Career Development Assistant Professor in MIT’s Department of Mechanical Engineering. “We can create complex geometries that form lenses, and these lenses can be tuned optically. When you have a tunable microlens, you can dream up all sorts of applications.”

    For instance, Kolle says, tunable microlenses might be used as liquid pixels in a three-dimensional display, directing light to precisely determined angles and projecting images that change depending on the angle from which they are observed. He also envisions pocket-sized microscopes that could take a sample of blood and pass it over an array of tiny droplets. The droplets would capture images from varying perspectives that could be used to recover a three-dimensional image of individual blood cells.

    “We hope that we can use the imaging capacity of lenses on the microscale combined with the dynamically adjustable optical characteristics of complex fluid-based microlenses to do imaging in a way people have not done yet,” Kolle says.

    Kolle’s MIT co-authors are graduate student and lead author Sara Nagelberg, former postdoc Lauren Zarzar, junior Natalie Nicolas, former postdoc Julia Kalow, research affiliate Vishnu Sresht, professor of chemical engineering Daniel Blankschtein, professor of mechanical engineering George Barbastathis, and John D. MacArthur Professor of Chemistry Timothy Swager. Moritz Kreysing and Kaushikaram Subramanian of the Max Planck Institute of Molecular Cell Biology and Genetics are also co-authors.

    Shaping a curve

    The group’s work builds on research by Swager’s team, which in 2015 reported a new way to make and reconfigure complex emulsions. In particular, the team developed a simple technique to make and control the size and configuration of double emulsions, such as water that was suspended in oil, then suspended again in water. Kolle and his colleagues used the same techniques to make their liquid lenses.

    They first chose two transparent fluids, one with a higher refractive index (a property that relates to the speed at which light travels through a medium), and the other with a lower refractive index. The contrast between the two refractive indices can contribute to a droplet’s focusing power. The researchers poured the fluids into a vial, heated them to a temperature at which the fluids would mix, then added a water-surfactant solution. When the liquids were mixed rapidly, tiny emulsion droplets formed. As the mixture cooled, the fluids in each of the droplets separated, resulting in droplets within droplets.

    To manipulate the droplets’ optical properties, the researchers added certain concentrations and ratios of various surfactants — chemical compounds that lower the interfacial tension between two liquids. In this case, one of the surfactants the team chose was a light-sensitive molecule. When exposed to ultraviolet light this molecule changes its shape, which modifies the tension at the droplet-water interfaces and the droplet’s focusing power. This effect can be reversed by exposure to blue light.

    “We can change focal length, for example, and we can decide where an image is picked up from, or where a laser beam focuses to,” Kolle says. “In terms of light guiding, propagation, and tailoring of light flow, it’s really a good tool.”

    Optics on the horizon

    Kolle and his colleagues tested the properties of the microlenses through a number of experiments, including one in which they poured droplets into a shallow plate, placed under a stencil, or “photomask,” with a cutout of a smiley face. When they turned on an overhead UV lamp, the light filtered through the holes in the photomask, activating the surfactants in the droplets underneath. Those droplets, in turn, switched from their original, flat interface, to a more curved one, which strongly scattered light, thereby generating a dark pattern in the plate that resembled the photomask’s smiley face.

    The researchers also describe their idea for how the microlenses might be used as pocket-sized microscopes. They propose forming a microfluidic device with a layer of microlenses, each of which could capture an image of a tiny object flowing past, such as a blood cell. Each image would be captured from a different perspective, ultimately allowing recovery of information about the object’s three-dimensional shape.

    “The whole system could be the size of your phone or wallet,” Kolle says. “If you put some electronics around it, you have a microscope where you can flow blood cells or other cells through and visualize them in 3-D.”

    He also envisions screens, layered with microlenses, that are designed to refract light into specific directions.

    “Can we project information to one part of a crowd and different information to another part of crowd in a stadium?” Kolle says. “These kinds of optics are challenging, but possible.”

    This research was supported, in part, by the National Science Foundation, the Natural Sciences and Engineering Research Council of Canada, and the Max Planck Society.

    See the full article here .

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