Thin sections are 30 µm (0.03 mm) thick slices of rock, minerals, concrete, mortar, or other materials that are mounted to a glass microscope slide with epoxy and topped with a glass coverslip. They are typically analysed by geologists and petrographers by using a petrographic microscope (sometimes referred to as a polarizing light microscope). Petrographic microscopes allow experienced analysts to investigate the sample in great detail to collect data regarding the sample mineralogy, overall texture, individual mineral texture, microstructures present, and much more. In the case of rocks and minerals, a geologic history can be interpreted by the data collected via petrographic examination. With regard to concrete, it allows for deformation mechanisms to be identified and for many other issues to be investigated.
How exactly are standard thin sections made? First, a sample is cut to fit on a standard petrographic microscope slide (typically 27 x 46 mm). Once cut, one side of sample is lapped (semi-polished) to create a flat, smooth surface. The flat smooth surface is then mounted to an etched microscope slide with epoxy. Once the epoxy has set, the sample is prepped with a thin sectioning system. These systems have two components: a saw blade and a grinding wheel. The glass slide with the mounted sample is held to a vacuum chuck by a vacuum pump. The chuck with the sample is safely guided into the saw blade, cutting it to a thickness of <1 mm. After cutting, the sample is moved to the grinding wheel side of the system. The sample is rocked back and forth along the grinding wheel, and a micrometre is used to measure how much of the sample has been ground away. When the thickness of the sample is near 30 µm, the sample is removed from the system and ground by hand to reach a final thickness of 30 µm (thinner than human hair). A coverslip is applied to the finished section with epoxy to fill in imperfections in the slide and to protect the sample from scratches and other damage.
With regard to a geologic investigation or a structural evaluation of concrete, the devil is in the details. Petrographic examination of thin sections pertaining to those investigations or evaluations allows for those details to be documented and evaluated in a way that no other technique can match.
Finished Slide: 30 µm thickness
Plane-Polarized Light: Field of view from left to right is approximately 2mm
Crossed-Polarized Light: Field of view from left to right is approximately 2mm
For more information on how we can assist you with thin sectioning or petrographic examination, please contact our Specialist Geologist/Petrographer Dan Cukierski or Rick Hughes on +61 8 9225 5810.
We are hanging up our lab coats and dusting off those tuxes and gowns ready to attend 2017 Telstra Business Awards at Crown on Friday, 7th July 2017.
The team would love to see a short message of support from you on the big screen at the event. Send us your message today at telstrabusinessawards.com/mos“.
Follow us on the night as we post photos on our Instagram and Facebook
Wish us luck!
Capturing the Art Behind the Science
I like to think a lot of what we do at Microanalysis has an element of artistic flare. The images we capture on the SEM and Solarius are often quite beautiful. We recently invited the highly experienced and exceptionally talented Andrew Tyndall to come and photograph our scientists at work. His work has encapsulated the art behind the science. We look forward to sharing some of these images with you over the next few months.
Check out Andy’s website and Facebook page for more of his incredible work.
Payment Times and Practices Inquiry
Microanalysis has always taken a very strong stance in relation to our payment terms. Respecting the importance of our cash flow, has been at the forefront of our business model and will continue to be. The trend for the larger multi-nationals asking for increased payment terms, some as large as 90+ days, has had a ripple effect across many small businesses. We have consistently remained vigilant on this issue, keeping our standard prices only applicable to approved clients who agree to our payments terms of 30 days from date of invoice. We have found many of our clients respect our payment terms and we benefit from a mutually beneficial working relationship.
For many small businesses however, this has become a huge issue. Small businesses constitute 97% 1 of businesses within WA and are vital to our economy. Establishing a framework that supports and encourages a healthy cash flow for these businesses is critical. As result the Australian Small Business and Family Enterprise Ombudsman (ASBFEO), in partnership with the Small Business Commissioners in New South Wales, Victoria, South Australia and Western Australia, and in association with the Council of Small Business Australia (COSBOA) and the Australian Institute of Credit Management (AICM), recently conducted an inquiry to examine payment times and practices in Australia.2
Their terms of reference were:
The practice of corporations setting payment terms particularly for small businesses;
Trends in payment terms and late payment with emphasis on commercial dealings between small business with large corporations;
The effects and impacts that long payment times have on small businesses; and
Potential regulatory and market-based responses available including recent developments such as unfair contracts legislation.
For the full Payment Times and Practices Inquiry Report, click here.
In short there have been 10 recommendations to the Australian Government following this inquiry, to assist small businesses. Of particular note is recommendation 8 & 9:
Recommendation 8: The Australian Government to introduce legislation for larger businesses to publicly disclose all of their payment times and practices and performance against those terms. Larger businesses being the top 100 listed on the ASX and multinationals.
Recommendation 9: Australian Government to introduce legislation which sets a maximum payment time for business to business transactions. Certain industries may need terms greater than the maximum which can be agreed providing they are not grossly unfair to one party. Where a longer term is called into dispute it will be considered an unfair contract term 3.
A recent analysis of average annual payments from over 300 clients this financial year has seen a healthy 28 days average for payment from date of invoice. We do have some outliers, companies that we will continue to work with to bring in line with our standard terms. Overall, we are extremely pleased with the positive financial relationships we have developed with our clients and suppliers. Spending less time chasing overdue invoices leaves us with the time to do what we do best, analyse your samples, and enables us to continue to provide affordable scientific analysis to all for many years to come.
Thank you Paula McLay for writing this fabulous account of April’s RACI WA Event at Microanalysis. We thoroughly enjoyed hosting this event.
The evening of Tuesday April 18 was clear and cool: a perfect day for a RACI Members Monthly Meeting. This was a special event – a laboratory tour of Microanalysis. And as our President says, who doesn’t like to see how another lab does it? So, the RACI members (and non-members) gathered in the carpark in front of the building as the light slowly faded from the sky. The laboratory is situated in East Perth, and across the prettily landscaped road was a row of swanky apartments/town houses – not the scruffy industrial look many chemists are used to. Over the bowls of chips, the drinks and the sizzling sausages the 25 or so attendees mingled with the Microanalysis staff and chatted. What a diverse bunch: highly respected chemists enjoying retirement, chemists from a number of industries and laboratories, recent retirees, chemistry students in their undergraduate years – even a 3 year old mini chemist! After 30 minutes or so of eating/drinking/gossiping networking, Alistair Day, the host for the day (and Chair of the RACI WA Analytical Group), divided the mingling mob in two, sending the first half into the lab while the other gobbled sausages networked.
The laboratory retained strong traces of the property group that had previously inhabited the premises. A big kitchenette with heaps of comfy leather chairs. Big open plan office. Huge spherical white woven light fittings in the lab spaces (which staff wanted to decorate as Deathstars) and more carpet than you expect in laboratory work areas. A green and white wall of healthy green plants in fresh white pots separated the reception and office areas from the laboratory areas. The lab was clearly divided into wet sample handling areas, preparation areas with a huge bench to provide plenty of space, neat little side rooms containing the twin scanning electron microscopes and a big room with lots of other analytical equipment (various types of microscopes, X-ray diffraction equipment, laser surface scanners and other cool bits of kit we didn’t have time to play with).
The twenty or so staff at Microanalysis are involved in materials analysis – a nice catch-all phrase for all sorts of testing of materials. They measure asbestos and respirable crystalline silica for occupation exposure monitoring. They do particle characterisation, including size, shape, morphology and density. There is forensic analysis (including of gunshot residue). Mineralogy and petrography are undertaken and there was some interesting discussion of the examination of concrete to look at cracking and possible failure. Microanalysis undertake dangerous goods testing – these days if you ship it or fly it you need to know how corrosive/nasty “it” is and Microanalysis can find out. Think little metal plates soaking in “it” and lasers reading how deep each corroded pit is (or isn’t). Microanalysis is one of those classic labs where you can send some of that goop that came out of a pipe, ended up in a filter, or otherwise appeared unexpectedly – and they can hopefully tell you what it is. That takes some skill and is a very useful service.
After half the attendees had their look around the lab, the groups switched over so everyone could have their share of laboratory examination and drinking with a sausage-in-a-bun in the other hand. In due course, all were re-united in the carpark for further vigorous discussion. Eventually the sausages were eaten, the drinks packed away and talkative groups dispersed into the night.
The RACI wishes to thanks the staff of Microanalysis for their hospitality and the opportunity to familiarise chemists with the laboratory, techniques, equipment and services. Thanks also to Alistair and the Analytical Group for organising the visit.
