Posts Tagged ‘US National Institute of Standards and Technology’

Rice U and the US National Institute of Standards and Technology settle into armchairs, the carbon nanotube kind

Wednesday, February 6th, 2013

An armchair carbon nanotube is amongst the most desirable of carbon nanotubes. You’ll have to look carefully to see the resemblance to an armchair,

Armchair carbon nanotubes, so named for the arrangement of atoms that make their ends look like armchairs, are the most desirable among nanotube researchers for their superior electrical properties. Image by Erik Hároz [downloaded from http://news.rice.edu/2013/02/05/essential-armchair-reading-for-nanotube-researchers-2/]

Armchair carbon nanotubes, so named for the arrangement of atoms that make their ends look like armchairs, are the most desirable among nanotube researchers for their superior electrical properties. Image by Erik Hároz [downloaded from http://news.rice.edu/2013/02/05/essential-armchair-reading-for-nanotube-researchers-2/]

The Feb. 6, 2013 news item on phys.org about the armchair carbon nanotubes notes that this latest research is an early outcome from a recently announced (Oct. 2012) partnership between Rice University and the US National Institute of Standards and Technology (NIST). Trom the news item (Note: Links have been removed),

The first fruits of a cooperative venture between scientists at Rice University and the National Institute of Standards and Technology (NIST) have appeared in a paper that brings together a wealth of information for those who wish to use the unique properties of metallic carbon nanotubes.

The feature article published recently in the Royal Society of Chemistry journal Nanoscale gathers research about the separation and fundamental characteristics of armchair carbon nanotubes, which have been of particular interest to researchers trying to tune their electronic and optical properties.

The Rice University Feb. 5, 2013 news release by Mike Williams, which originated the news item, describe s the process the scientists undertook,

This paper, said Rice physicist Junichiro Kono, provides scientists a valuable resource for detailed information about metallic carbon nanotubes, especially armchair nanotubes. “Basically, we summarized all our recent findings as well as all information we could find in the literature about metallic nanotubes, along with detailed accounts of preparation methods for metal-enriched nanotube samples, to show the community just how much we now understand about these one-dimensional metals,” he said.

As part of the lengthy work, the team compiled and published tables of essential statistics, including optical properties, for a variety of metallic nanotubes. “We provide fundamental theoretical backgrounds and then show very detailed experimental results on unique properties of metallic nanotubes,” Kono said. “This paper summarizes what kind of aspects are understood, and what is not, about fundamental optical processes in nanotubes and will make it easier for researchers to identify their spectroscopic features and transition energies.”

For this of us who are less well versed on armchair carbon nanotubes and their electronic and optical properties, the news releases provides some information (Note: Links have been removed),

Nanotubes come in many flavors, depending on their chirality. Chirality is a characteristic akin to the angles at which a flat sheet of paper might align when wrapped into a tube. Cut the tube in half and the atoms at the open edge would line up in the shape of an armchair, a zigzag or some variant. Even though their raw material is identical – chicken-wire-like hexagons of carbon – the chirality makes all the difference in how nanotubes transmit electricity.

Armchairs are the most coveted because they have no band gap; electrons flow through without resistance. Cables made with armchair nanotubes have the potential to move electricity over great distances with virtually no loss. That makes them the gold standard as the basic element of armchair quantum wire. The ongoing development of this very strong, lightweight, high-capacity cable could improve further the record properties of multifunctional carbon nanotube fibers that are being developed by the group of Rice Professor Matteo Pasquali.

For the project-specific work the scientists performed (Note: Links have been removed),

The new work led by Kono and Robert Hauge, a distinguished faculty fellow in chemistry at Rice, along with scientists at NIST and Los Alamos National Laboratory, looks beyond the armchair’s established electrical properties to further detail their potential for electronic, sensing, optical and photonic devices.

“Of course, to get there, we need really good samples,” Kono said. “Many applications will rely on our ability to separate carbon nanotubes and then assemble macroscopically ordered structures consisting of single-chirality nanotubes. Nobody can do that at this point.”

When a batch of nanotubes comes out of a furnace, it’s a jumble of types. That makes detailed analysis of their characteristics — let alone their practical use — a challenge.

But techniques developed in recent years at Rice and by NIST scientist Ming Zheng to purify metallic nanotubes are beginning to change that. Rice graduate student Erik Hároz said recent experiments established “unambiguous evidence” that a process he and Kono are using called density gradient ultracentrifugation can enrich ensemble samples of armchairs. Taking things further, Zheng’s method of DNA-based ion-exchange chromatography provides very small samples of ultrapure armchair nanotubes of a single chirality.

You can read more about the work at phys.org or at Rice University using the links already provided. For those who’d like to read the research,

Fundamental optical processes in armchair carbon nanotubes by Erik H. Hároz ,  Juan G. Duque,  Xiaomin Tu ,  Ming Zheng ,  Angela R. Hight Walker ,  Robert H. Hauge ,  Stephen K. Doorn and Junichiro Kono. Nanoscale, 2013,5, 1411-1439 DOI: 10.1039/C2NR32769D First published on the web 04 Jan 2013

This article is behind a paywall of sorts.  RSC (Royal Society of Chemistry) Publishing (which publishes Nanoscale) has an open access policy but there are various options, from the RSC Publishing’s Open Access Policy webpage,

RSC Open Access statement

Open Access is the term given to making electronic versions of articles accessible to readers, without any subscription or ‘access side’ fees.

RSC supports Open Access models which seek to ensure that scholarly publishing activities operate in a long term sustainable way.

  • Our fundamental goal is to advance the chemical sciences, through the effective dissemination of high quality research content
  • We seek to maximise the dissemination of the research that we publish
  • We support any and all sustainable and fair models of access. We believe that the integrity and archiving of scholarly content must be maintained throughout
  • We support ‘Gold’* Open Access and encourage funding to be made available to support authors during any transition from reader to author side payments
  • We support the author’s ability to choose where they publish their work to the benefit of the advancement of science. We do not wish authors to be discriminated against if they are unable to pay author-side fees
  • We seek to work closely with other parties, including funders and government agencies, to achieve the above goals

RSC Publishing provides authors with the option to make their article Open Access, through payment of a fee on acceptance. Authors following the traditional route still have deposition options – details are on the ‘Deposition and Licence to Publish’ page of the website.

*There are several types of Open Access:

  • Gold Open Access: Publication costs are covered by an ‘Article Processing Fees’ being paid by authors upon acceptance. The final ‘article of record’ is made available to all, immediately, without any barriers to access
  • Green Open Access: A version of the paper (often the author’s manuscript) is made available via a subject or institutional repository. An embargo period is often involved, typically 6-24 months. No payment is made, and publishers should strive to recoup their investment through traditional sales during the embargo period
  • Delayed Open Access: The final version of the paper is made available by the publisher after an embargo period (e.g. publisher deposit the paper in PubMed after 12 months)

It would seem the option for this article is ‘Delayed Open Access’.

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Clone your carbon nanotubes

Thursday, November 15th, 2012

The Nov. 14, 2012 news release on EurekAlert highlights some work on a former nanomaterial superstar, carbon nanotubes,

Scientists and industry experts have long speculated that carbon nanotube transistors would one day replace their silicon predecessors. In 1998, Delft University built the world’s first carbon nanotube transistors – carbon nanotubes have the potential to be far smaller, faster, and consume less power than silicon transistors.

A key reason carbon nanotubes are not in your computer right now is that they are difficult to manufacture in a predictable way. Scientists have had a difficult time controlling the manufacture of nanotubes to the correct diameter, type and ultimately chirality, factors that control nanotubes’ electrical and mechanical properties.

…

Carbon nanotubes are typically grown using a chemical vapor deposition (CVD) system in which a chemical-laced gas is pumped into a chamber containing substrates with metal catalyst nanoparticles, upon which the nanotubes grow. It is generally believed that the diameters of the nanotubes are determined by the size of the catalytic metal nanoparticles. However, attempts to control the catalysts in hopes of achieving chirality-controlled nanotube growth have not been successful.

The USC [University of Southern California] team’s innovation was to jettison the catalyst and instead plant pieces of carbon nanotubes that have been separated and pre-selected based on chirality, using a nanotube separation technique developed and perfected by Zheng [Ming Zheng] and his coworkers at NIST [US National Institute of Standards and Technology]. Using those pieces as seeds, the team used chemical vapor deposition to extend the seeds to get much longer nanotubes, which were shown to have the same chirality as the seeds..

The process is referred to as “nanotube cloning.” The next steps in the research will be to carefully study the mechanism of the nanotube growth in this system, to scale up the cloning process to get large quantities of chirality-controlled nanotubes, and to use those nanotubes for electronic applications

H/T to ScienceDaily’s Nov. 14, 2012 news item for the full journal reference,

Jia Liu, Chuan Wang, Xiaomin Tu, Bilu Liu, Liang Chen, Ming Zheng, Chongwu Zhou. Chirality-controlled synthesis of single-wall carbon nanotubes using vapour-phase epitaxy. Nat. Commun., 13 Nov, 2012 DOI: 10.1038/ncomms2205

The article is behind a paywall.

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Atomic force microscopy and uncertainty

Monday, November 14th, 2011

Michael Berger at Nanowerk writes about the importance of determining uncertainty in his Nov. 11, 2011 article, A framework to evaluate the uncertainties of AFM nanomechanical measurements, on Nanowerk. It may seem oxymoronic trying to evaluate uncertainty but it’s done all the time.Take for example a political poll where they tell you how accurate it is likely to be, “19 times of 20.”  For another example, there’s also significance (p value) when analyzing statistical data. Here’s a brief description of p value from GraphPad,

Definition of a P value

Consider an experiment where you’ve measured values in two samples, and the means are different. How sure are you that the population means are different as well? There are two possibilities:

  • The populations have different means.
  • The populations have the same mean, and the difference you observed is a coincidence of random sampling.

The P value is a probability, with a value ranging from zero to one. It is the answer to this question: If the populations really have the same mean overall, what is the probability that random sampling would lead to a difference between sample means as large (or larger) than you observed?

…

Many people misunderstand what question a P value answers.

If the P value is 0.03, that means that there is a 3% chance of observing a difference as large as you observed even if the two population means are identical. It is tempting to conclude, therefore, that there is a 97% chance that the difference you observed reflects a real difference between populations and a 3% chance that the difference is due to chance. Wrong. What you can say is that random sampling from identical populations would lead to a difference smaller than you observed in 97% of experiments and larger than you observed in 3% of experiments.

You have to choose. Would you rather believe in a 3% coincidence? Or that the population means are really different?

In other words, which one has greater certainty? Getting back to nanotechnology, there’s this from Berger’s article,

“The atomic force microscope is used extensively for measuring the material properties of nanomaterials with nanometer resolution, unfortunately there is a lack of standards and uncertainty quantification in these measurements,” explain Robert Moon, an Adjunct Assistant Professor of Materials Engineering, and Arvind Raman, Professor of Mechanical Engineering, both at Purdue University. “Other fields, such as six sigma standards in industry and beam corrections in scanning electron microscopy, have developed thorough methods for quantifying the uncertainty in a given measurement, model, or system. Broadly speaking these methods can be classified as uncertainty quantification. Without applying the methods of uncertainty quantification to AFM measurements it is impossible to say if the measurements are accurate within 5% or 100%.”

Moon and Raman at Purdue’s Birck Nanotechnology Center and collaborators at the National Institute of Standards and Technology (NIST) including Drs. Jon Pratt and Gordon Shaw, have now presented a framework to ascribe uncertainty to local nanomechanical properties of any nanoparticle or surface measured with the AFM by taking into account the main uncertainty sources inherent in such measurements.

…

“Our findings demonstrate the inherently large uncertainty associated with certain types of AFM material property measurements,” Ryan Wagner, a graduate student in Raman’s group at Purdue, and the paper’s first author, tells Nanowerk. “Specifically, force-displacements measurements of elastic modulus on thin, stiff samples are very uncertainty because of poor indentation resolution. In addition, our work provides a general framework for evaluating uncertainty in force-displacement based elasticity measurements that is valid for all samples and AFMs.”

Berger’s article offers more details about the process of arriving at a framework for uncertainty and a link to the researchers’ paper.

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Fuel cells and iron veins and Ballard Power Systems

Monday, September 5th, 2011

The iron ‘veins’ are an idea from the researchers at the US National Institute of Standards and Technology (NIST) that might make fuel cells a standard piece of equipment in a car. From the August 31, 2011 news item on Nanowerk,

With a nod to biology, scientists at the National Institute of Standards and Technology (NIST) have a new approach to the problem of safely storing hydrogen in future fuel-cell-powered cars. Their idea: molecular scale “veins” of iron permeating grains of magnesium like a network of capillaries. The iron veins may transform magnesium from a promising candidate for hydrogen storage into a real-world winner (“Thermodynamics, kinetics and microstructural evolution during hydrogenation of iron-doped magnesium thin films”).

Hydrogen has been touted as a clean and efficient alternative to gasoline, but it has one big drawback: the lack of a safe, fast way to store it onboard a vehicle. According to NIST materials scientist Leo Bendersky, iron-veined magnesium could overcome this hurdle. The combination of lightweight magnesium laced with iron could rapidly absorb—and just as importantly, rapidly release—sufficient quantities of hydrogen so that grains made from the two metals could form the fuel tank for hydrogen-powered vehicles.

There are more technical details in the Nanowerk news item.

Since Ballard Power Systems, known for its fuel cell powered buses, is located in the Vancouver area (the region where I live) I was curious as the why this NIST advance is considered so wonderful. After all, fuel cells are already being used commercially. From the Ballard website page on buses,

Ballard designs and manufactures fully-integrated FC velocity®-HD6 fuel cell modules delivering 75 kW or 150 kW of power for use in the bus market. Ballard’s leading-edge fuel cell technology combined with our customer’s advanced hybrid bus system designs have demonstrated improved vehicle performance, durability and lower cost. All of which has created a path to commercialization for the fuel cell hybrid bus.

Zero-emission fuel cell-powered buses deliver economic, operational as well as environmental benefits, when compared to traditional diesel or diesel hybrid systems. Economic benefits are a direct result of increased fuel cell efficiency and reliability. And fuel cell buses emit only water vapour, eliminating air pollutants such as nitrogen oxides, sulphur oxides and particulate matter. Fuel cell buses can also significantly reduce greenhouse gas emissions on a “well-to-wheel” basis, when compared to conventional technologies.

I note Ballard has a hybrid system so perhaps the NIST researchers are working on a 100% fuel cell system? I did check one more thing while I was on the Ballard website, the technical specifications for the fuel cells used to power the buses. The weight for the smaller 75w fuel cell is 350 kg or 772 lbs. and its dimensions are 1530 x 871 x 495 mm or 50 x 34 x 12 in. With that weight and those dimensions, I imagine that’s why we haven’t been hearing about hybrid fuel cell cars. I now better understand why the NIST researchers are excited.

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2011 Scientific integrity processes: the US and Canada

Friday, August 19th, 2011

Given recent scientific misconduct  (July is science scandal month [July 25 2011] post at The Prodigal Academic blog) and a very slow news month this August,  I thought I’d take a look at scientific integrity in the US and in Canada.

First, here’s a little history. March 9, 2009 US President Barack Obama issued a Presidential Memorandum on Scientific Integrity (excerpted),

Science and the scientific process must inform and guide decisions of my Administration on a wide range of issues, including improvement of public health, protection of the environment, increased efficiency in the use of energy and other resources, mitigation of the threat of climate change, and protection of national security.

The public must be able to trust the science and scientific process informing public policy decisions.  Political officials should not suppress or alter scientific or technological findings and conclusions.  If scientific and technological information is developed and used by the Federal Government, it should ordinarily be made available to the public.  To the extent permitted by law, there should be transparency in the preparation, identification, and use of scientific and technological information in policymaking.  The selection of scientists and technology professionals for positions in the executive branch should be based on their scientific and technological knowledge, credentials, experience, and integrity.

December 17, 2010 John P. Holdren, Assistant to the President for Science and Technology and Director of the Office of Science and Technology Policy,  issued his own memorandum requesting compliance with the President’s order (from the Dec. 17, 2010 posting on The White House blog),

Today, in response to the President’s request, I am issuing a Memorandum to the Heads of Departments and Agencies that provides further guidance to Executive Branch leaders as they implement Administration policies on scientific integrity. The new memorandum describes the minimum standards expected as departments and agencies craft scientific integrity rules appropriate for their particular missions and cultures, including a clear prohibition on political interference in scientific processes and expanded assurances of transparency. It requires that department and agency heads report to me on their progress toward completing those rules within 120 days.

Here’s my edited version (I removed fluff, i.e. material along these lines: scientific integrity is of utmost importance …) of the list Holdren provided,

Foundations

  1. Ensure a culture of scientific integrity.
  2. Strengthen the actual and perceived credibility of Government research. Of particular importance are (a) ensuring that selection of candidates for scientific positions in executive branch is based primarily on their scientific and technological knowledge, credentials, experience, and integrity, (b) ensuring that data and research used to support policy decisions undergo independent peer review by qualified experts where feasibly and appropriate, and consistent with law, (c) setting clear standards governing conflicts, and (d) adopting appropriate whistleblower protections.
  3. Facilitate the free flow of scientific and technological information, consistent with privacy and classification standards. … Consistent with the Administration’s Open Government Initiative, agencies should expand and promote access to scientific and technological information by making it available  online in open formats. Where appropriate, this should include data and models underlying regulatory proposals and policy decisions.
  4. Establish principles for conveying scientific and technological information to the public. … Agencies should communicate scientific and technological findings by including a clear explication of underlying assumptions; accurate contextualization of uncertainties; and a description of the probabilities associated with optimistic and pessimistic projections, including best-case and worst-case scenarios where appropriate.

Public communication

  1. In response to media interview requests about the scientific and technological dimensions of their work, agencies will offer articulate and knowledgeable spokespersons who can, in an objective and nonpartisan fashion, describe and explain these dimension to the media and the American people.
  2. Federal scientists may speak to the media and the public about scientific and technological matters based on their official work, with appropriate coordination with their immediate supervisor and their public affairs office. In no circumstance may public affairs officers ask or direct Federal scientists to alter scientific findings.
  3. Mechanisms are in place to resolve disputes that arise from decisions to proceed or not to proceed  with proposed interviews or other public information-related activities. …

(The sections on Federal Advisory Committees and professional development were less relevant to this posting, so I haven’t included them here.)

It seems to have taken the agencies a little longer than the 120 day deadline that John Holdren gave them but all (or many of the agencies) have complied according to an August 15, 2011 posting by David J. Hanson on the Chemical & Engineering News (C&EN) website,

OSTP director John P. Holdren issued the call for the policies on May 5 in response to a 2009 Presidential memorandum (C&EN, Jan. 10, page 28). [emphasis mine] The memorandum was a response to concerns about politicization of science during the George W. Bush Administration.

The submitted integrity plans include 14 draft policies and five final policies. The final policies are from the National Aeronautics & Space Administration, the Director of National Intelligences for the intelligence agencies, and the Departments of Commerce, Justice, and Interior.

Draft integrity policies are in hand from the Departments of Agriculture, Defense, Education, Energy, Homeland Security, Health & Human Services, Labor, and Transportation and from the National Oceanic & Atmospheric Administration, National Science Foundation, Environmental Protection Agency, Social Security Administrations, OSTP, and Veterans Administration.

The drafts still under review are from the Department of State, the Agency for International Development, and the National Institute of Standards & Technology.

The dates in this posting don’t match up with what I’ve found but it’s possible that the original deadline was moved to better accommodate the various reporting agencies. In any event, David Bruggeman at his Pasco Phronesis blog has commented on this initiative in a number of posts including this August 10, 2011 posting,

… I’m happy to see something out there at all, given the paltry public response from most of the government.  Comments are open until September 6.Regrettably, the EPA [Environmental Protection Agency] policy falls into a trap that is all too common.  The support of scientific integrity is all too often narrowly assumed to simply mean that agency (or agency-funded) scientists need to behave, and there will be consequences for demonstrated bad behavior.

But there is a serious problem of interference from non-scientific agency staff that would go beyond reasonable needs for crafting the public message.

David goes on to discuss a lack of clarity in this policy and in the Dept. of the Interior’s policy.

His August 11, 2011 posting notes the OSTP claims that 19 departments/agencies have submitted draft or final policies,

… Not only does the OSTP blog post not include draft or finalized policies submitted to their office, it fails to mention any timeframe for making them publicly available.  Even more concerning, there is no mention of those policies that have been publicly released.  That is, regrettably, consistent with past practice. While the progress report notes that OSTP will create a policy for its own activities, and that OSTP is working with the Office of Management and Budget on a policy for all of the Executive Office of the President, there’s no discussion of a government-wide policy.

In the last one of his recent series, the August 12, 2011 posting focuses on a Dept. of Commerce memo (Note: The US Dept. of Commerce includes the National Oceanic and Atmospheric Administration and the National Institute of Standards and Technology),

“This memorandum confirms that DAO 219-1 [a Commerce Department order concerning scientific communications] allows scientists to engage in oral fundamental research communications (based on their official work) with the media and the public without notification or prior approval to their supervisor or to the Office of Public Affairs. [emphasis David Bruggeman] Electronic communications with the media related to fundamental research that are the equivalent of a dialogue are considered to be oral communications; thus, prior approval is not required for  scientist to engage in online discussions or email with the media about fundamental research, subject to restrictions on protected nonpublic information as set forth in 219-1.”

I find the exercise rather interesting especially in light of Margaret Munro’s July 27, 2011 article, Feds silence scientist over salmon study, for Postmedia,

Top bureaucrats in Ottawa have muzzled a leading fisheries scientist whose discovery could help explain why salmon stocks have been crashing off Canada’s West Coast, according to documents obtained by Postmedia News.

The documents show the Privy Council Office, which supports the Prime Minister’s Office, stopped Kristi Miller from talking about one of the most significant discoveries to come out of a federal fisheries lab in years.

Science, one of the world’s top research journals, published Miller’s findings in January. The journal considered the work so significant it notified “over 7,400″ journalists worldwide about Miller’s “Suffering Salmon” study.

…

The documents show major media outlets were soon lining up to speak with Miller, but the Privy Council Office said no to the interviews.

In a Twitter conversation with me, David Bruggeman did note that the Science paywall also acts as a kind of muzzle.

I was originally going to end the posting with that last paragraph but I made a discovery, quite by accident. Canada’s Tri-Agency Funding Councils opened a consultation with stakeholders on Ethics and Integrity for Institutions, Applicants, and Award Holders on August 15, 2011 which will run until September 30, 2011. (This differs somewhat from the US exercise which is solely focussed on science as practiced in various government agencies.  The equivalent in Canada would be if Stephen Harper requested scientific integrity guidelines from the Ministries of Environment, Natural Resources, Health, Industry, etc.) From the NSERC Ethics and Integrity Guidelines page,

Upcoming Consultation on the Draft Tri-Agency Framework: Responsible Conduct of Research

The Canadian Institutes of Health Research (CIHR), the Social Sciences and Humanities Research Council of Canada (SSHRC), and NSERC (the tri-agencies) continue to work on improving their policy framework for research and scholarly integrity, and financial accountability. From August 15 to September 30, 2011, the three agencies are consulting with a wide range of stakeholders in the research community on the draft consultation document, Tri-Agency Framework: Responsible Conduct of Research.

I found the answers to these two questions in the FAQs particularly interesting,

  • What are some of the new elements in this draft Framework?

The draft Framework introduces new elements, including the following:

A strengthened Tri-Agency Research Integrity Policy
The draft Framework includes a strengthened Tri-Agency Research Integrity Policy that clarifies the responsibilities of the researcher.

‘Umbrella’ approach to RCR
The draft Framework provides an overview of all applicable research policies, including those related to the ethical conduct of research involving humans and financial management, as well as research integrity. It also clarifies the roles and responsibilities of researchers, institutions and Agencies in responding to all types of alleged breaches of Agency policies, for example, misuse of funds, unethical conduct of research involving human participants or plagiarism.

A definition of a policy breach
The draft Framework clarifies what constitutes a breach of an Agency policy.

Disclosure
The draft Framework requires researchers to disclose, at the time of application, whether they have ever been found to have breached any Canadian or other research policies, regardless of the source of funds that supported the research and whether or not the findings originated in Canada or abroad.

The Agencies are currently seeking advice from privacy experts on the scope of the information to be requested.

Institutional Investigations
The Agencies currently specify that institutional investigation committee membership must exclude those in conflict of interest. The draft Framework stipulates also that an investigation committee must include at least one member external to the Institution, and that an Agency may conduct its own review or compliance audit, or require the Institution to conduct an independent review/audit.

Timeliness of investigation
Currently, it is up to institutions to set timelines for investigations. The draft Framework states that inquiry and investigation reports are to be submitted to the relevant Agency within two and seven months, respectively, following receipt of the allegation by the institution.

  • Who is being consulted?

The Agencies have targeted their consultation to individual researchers, post-secondary institutions and other eligible organizations that apply for and receive Agency funding.

As far as I can tell, there is no mention of ethical issues where the government has interfered in the dissemination of scientific information; it seems there is an assumption that almost all ethical misbehaviour is on that part of the individual researcher or a problem with an institution following policy. There is one section devoted breaches by institutions (all two paragraphs of it),

5 Breaches of Agency Policies by Institutions

In accordance with the MOU signed by the Agencies and each Institution, the Agencies require that each Institution complies with Agency policies as a condition of eligibility to apply for and administer Agency funds.

The process followed by the Agencies to address an allegation of a breach of an Agency policy by an Institution, and the recourse that the Agencies may exercise, commensurate with the severity of a confirmed breach, are outlined in the MOU.

My criticism of this is similar to the one that David Bruggeman made of the US policies in that the focus is primarily on the individual.

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Measuring nanoparticles

Wednesday, August 4th, 2010

When manufacturers claim to produce nanoparticles that are 30 nm in diameter, they are giving customers the average size of the nanoparticles being delivered. (From Nanowerk Spotlight’s Meaningful nanotechnology EHS research requires independent nanomaterial characterization)

“For example, it might be stated that a certain nanoparticle is being sold as 30 nm in diameter and, although ’30 nm’ might be close to the average diameter, there is usually a range of particle sizes that can extend from as much as small as 5 nm to as large as 300 nm.” (Vicki H. Grassian, a professor in the Department of Chemistry at the University of Iowa)

As I noted in my April 27, 2010 posting this size range could pose problems with Canada’s proposed plan/inventory/scheme. Happily, the US National Institute of Standards and Technology (NIST) has successfully measured and sorted nanoparticles with a device that operates like a coin sorter (separating pennies, dimes, nickels, and quarters). From the news item on physorg.com,

First introduced in March 2009 …, the device consists of a chamber with a cascading “staircase” of 30 nanofluidic channels ranging in depth from about 80 nanometers at the top to about 620 nanometers (slightly smaller than an average bacterium) at the bottom. Each of the many “steps” of the staircase provides another “tool” of a different size to manipulate nanoparticles in a method that is similar to how a coin sorter separates nickels, dimes and quarters.

In a new article in the journal Lab on a Chip, the NIST research team demonstrates that the device can successfully perform the first of a planned suite of nanoscale tasks—separating and measuring a mixture of spherical nanoparticles of different sizes (ranging from about 80 to 250 nanometers in diameter) dispersed in a solution.

Seems to me that is pretty exciting news. I wonder when this device will go into standard use. The usual answer to this question includes the number 5 as in 3-5 years, 5-7 years, or 5 years. In any case, the researchers are also hoping to use the technique to sort nanoparticles of different shapes as in tubes from spheres and that sort of thing.

For anyone interested in the researcher’s article the citation is,

S.M. Stavis, J. Geist and M. Gaitan. Separation and metrology of nanoparticles by nanofluidic size exclusion. Lab on a Chip, forthcoming, August 2010

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At the atto scale

Friday, July 30th, 2010

Earlier this week, a team of Canadian scientists announced that they were able to observe a chemical bond as it broke. From the news item on physorg.com,

Scientists at the National Research Council of Canada (NRC) and the University of Ottawa (uOttawa) enjoyed a bird’s eye view of a chemical bond as it breaks.

The making and breaking of chemical bonds underlie the biochemical processes of life itself. A greater understanding of the quantum processes that lead to chemical reactions may lead to new strategies in the design and control of molecules — ultimately leading to scientific breakthroughs in health care and diagnostic medicine, quantum computing, nanotechnology, environmental science and energy.

The NRC-uOttawa team, led by Dr. David Villeneuve, achieved their feat using a technique developed several years ago at NRC in which an image was obtained of a single electron orbiting a molecule. In the current experiment, which is reported in the July 29th edition of Nature, scientists injected bromine gas into a vacuum chamber. There, an ultra brief ultraviolet light pulse caused the bromine molecules to separate into their individual atoms (a bromine molecule is composed of two bromine atoms).

A few femtoseconds later, an intense infrared laser pulse caused the molecule to emit an attosecond-duration X-ray burst that contained a snapshot of the atom’s position as the molecule fell apart and revealed how the electrons rearranged themselves.

…

The interference of the x-rays emitted by the two quantum states of the molecule was used to find the location of the atoms and to watch over a period of only 200 femtoseconds as it progressed from being a molecule to being two separate atoms. The experiment reached a precision below 500 zeptoseconds in clocking the emitted x-ray bursts. [emphases mine]

I’ve highlighted the units of measurement because they fascinate me in and of themselves. (I hadn’t encountered zeptos before although I have blogged about attoseconds,  May 13, 2009 posting).

Here are official designations starting with the nanoscale and dropping down to the smallest unit to date (from the US National Institute of Standards and Technology, Technology Services, Weights and Measures page),

nano, (n), meaning 10-9
pico, (p), meaning 10-12
femto, (f), meaning 10-15
atto, (a), meaning 10-18
zepto, (z), meaning 10-21
yocto, (y), meaning 10-24

If nano is the science of small, what will the others be?

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Nanotechnology in Manitoba; petition for a National Day for Canadian Research; Word on the Street Festival

Friday, September 25th, 2009

I wasn’t expecting to find that researchers in Manitoba were working with researchers from Johns Hopkins University, two biopharmaceutical companies, Dartmouth College, and researchers from the US National Institute of Standards and Technology (NIST) to study sugar-coated nanoparticles. In fact since I don’t cover nanomedicine very often, I almost missed the item which is about how these particles might be used in cancer therapy .

From the news item on Science Daily,

In cooperation with colleagues at The Johns Hopkins University, Dartmouth College, the University of Manitoba and two biopharmaceutical companies, the NIST team has demonstrated that the particles—essentially sugar-coated bits of iron oxide, about 100 nanometers wide—are potent cancer killers because they interact with one another in ways that smaller nanoparticles do not. The interactions, thought by many bioengineers to be undesirable, actually help the larger particles heat up better when subjected to an alternating magnetic field. Because this heat destroys cancer cells, the team’s findings may help engineers design better particles and treatment methods.

Sometimes it seems to me that there is a drive to work with smaller and smaller bits of matter so this realization that the larger particle could be prove to be more effective is interesting and mildly amusing to me since I get caught up in this ‘drive to smaller and smaller’.

I recently received notice of a petition for a National Day for Canadian Research being organized by graduate students (presumably across the country).  From the notice,

Myself and others are trying to establish a National Day for Canadian Research to help support and recognize the achievements of researchers in Canada. This is a non-partisan and cost-free approach that the government should have no difficulty accepting.

For this to occur, it must be enacted by Parliament and we must petition them formally. In this effort, we have set up a website where hard copies of a petition (in either French or English) can be downloaded and signed (www.canadianresearchday.ca). In addition, an online petition can also be found at http://www.petitiononline.com/NCRD/petition.html or through the link found at www.canadianresearchday.ca. The CSBMCB has also posted our links on their advocacy website.

Signing the online petition is good but if the effort is to be successful, hard copy petitions must be signed and sent. If you want to read the full notice, you can go here to the Don’t leave Canada behind forum.

The Vancouver (Canada) edition of the Word on the Street Festival is this Sunday, Sept.27, 2009. It goes from 11 am to 5 pm and is being held in the blocks surrounding the main branch of the Vancouver Public Library (at 350 West Georgia St.). There are maps on their website as well as other information. They do advise using public transit since they do close  a few blocks to car traffic for the festival.

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