I recently had an inquiry for an explosion proof refrigerator. A client wanted to store a potentially explosive chemical in a refrigerator. I decided to do some research on what “Explosion Proof” really means. I discussed this with several suppliers of flammable materials and explosion proof refrigerators and freezers. Here is what I have learned:
Explosion proof refrigerators are designed for use in areas which may have explosive or flammable gases in the atmosphere – Hazardous Locations. The compressors in the refrigerators are isolated and will produce no external sparks which might ignite explosive or flammable fumes.
Flammable material storage refrigerators are designed for storing flammable products. The compressors in these refrigerators are isolated from the interior of the refrigerator and there is nothing inside the refrigerator to generate a spark which might ignite any flammable fumes inside.
In my discussion of my client’s request the suppliers recommended a flammable materials refrigerator for storing his sample. These types of refrigerators are not designed to contain an explosion should one occur, they are only designed not to create an explosion in their normal operation. I don’t know of a storage refrigerator or freezer which is designed to contain an explosion.
Recently I have seen discussions and questions about the analytical method of standard addition. Standard addition can apply to any analytical method which has a linear signal or response vs. concentration of the analyte; for example absorbance in spectroscopy or peak area in chromatography. Standard addition is used when the matrix effects of a sample changes the response in a linear manner by changing the slope of the standard curve y= mx+b; m would change as a result of the sample matrix. Standard addition will not work where matrix effect contributes to baseline response – b. If b is affected a sample matrix blank would have to be subtracted from all values to use the standard addition method.
In the graph above is a response of analyte concentration to absorbance. The lower regression line is the response of the analyte as a standard curve. The upper regression line is the standard addition in a sample matrix. The slope of the two lines is different due to matrix effects. If the sample analyte within the matrix with signal of 0.09 is compared to the standard curve a concentration of 8.9 ppm would be the result. Using the standard addition line the concentration of the sample is the absolute value as the regression line crosses the X axis: (-)7.1 ppm.
Standard addition can be used in a quality control setting using only one standard if the method has been verified to be linear in the sample matrix and it has been verified there is no enhancement of the baseline (blank) signal based on matrix effects. The level of standard to be added should be at least 2x the level of analyte expected in the sample* – as long as the resulting signal is within the linear range. The standard must be added to each sample for reliable results. The volume must either be kept constant or the change in volume must be considered in calculating the concentration of the standard.
*Thompson, Michael, ed. “Standard Additions: Myth and Reality.” Amc Technical Briefs 1 Mar. 2009. Print.
Microscopy is a definitely skill worth learning; but when you must capture images for reports, or show images to your students, you would rather dispense with complicated set ups. Finally, there is a cell imaging system able to eliminate the challenges and complexities of microscopy – without compromising performance. Enter the EVOS Cell Imaging System. Whether you’re capturing images for publications, teaching, or research, the EVOS system was designed to allow users to focus on their data rather than the operation of the microscope.
Built to perform a variety of routine and specialty applications, EVOS Imaging Systems can handle everything from cell cultures to complex protein analysis. The proprietary LED light cube technology minimizes photobleaching and offers over 50,000 hours of LED illumination, along with adjustable intensity.
There are five Cell Imaging Systems to choose from:
EVOS XL Core - Bright-field and phase contrast with 4 position objective turret.
- EVOS XL – Bright-field and phase contrast with 5 position objective turret.
- EVOS FLoid - Fluorescence channels: DAPI (blue), FITC (green), and Texas Red (red)
- EVOS FL - Simultaneously accommodates up to 4 fluorescent light cubes. Proprietary LED light cubes include: DAPI, TagBFP, CFG, DFP YFP, RFP, Texas Red, Cy5, Cy5.5, Cy7. Custom cubes are available.
- EVOS FL Auto - Automated X-Y scanning stage; interchangeable vessel holders available. Optional onstage incubator also available
Interested? Learn more about the entire EVOS Cell Imaging System Lineup at EVOS Cell Imaging Systems
So, unless you’ve been living in a cave for the last year, you could not of helped to hear about the future of delivery and surveillance that we will be in our lives in the near future. Actually, I guess this is already happening. And for those of you, like my wife, (sorry honey), who aren’t really sure what a “Drone” is, we’re talking about those small, unmanned aircraft. And why have I brought up this topic you may ask? When you think about it, there is a lot of controversy behind it. From a guy’s perspective, they’re cool toys. Expensive, but cool.
Now, I’m not really addressing the ones being used by the armed forces. Undoubtedly, they help to save lives of our troops in an effecient way. I’m sure there’s an argument behind this statement as well.
I was thinking more about the role that retailers like Amazon are taking. For me personally, I feel this is great concept. Logistically can this really happen? I mean, are flying package drones going to collide with themselves or worse, aircraft?
An Amazon photo showing a test of package delivery by drone(Photo: Amazon)
This seems to be something taken right out of the cartoon, The Jetsons, that we use to watch on Saturday mornings. And bottom line, do we really need delivery within the hour?
I welcome your feed back.
Teaching our children to have grit. No, this has nothing to do with our kids playing out in the sand and mud. I happen to hear this very interesting story on NPR (National Public Radio). At first I had visions of the old movie “True Grit” with John Wayne
(photo courtesy of IMDbPro)
Well, it ends up that I was on target. There’s a movement in several of our school systems that have created programs for kids, to basically teach them to deal with rejection, failure and to “pull themselves up by their bootstraps”.
I personally understand the concept as relating to my own kids. We all want to see our children succeed in their studies, careers and life, in general, but if we always “baby” them, how are they supposed to deal with stress and adversity in their adult lives? So, does Teaching Kids To Get ‘Gritty’ Help Them Get Ahead? Again we’re defining grit as persistence, determination and resilience.
According to NPR, even the Obama administration is now on the “grit” bandwagon. A 2013 report from the Department of Education states that kids are learning to “do school,” but aren’t learning the skills they need in life.
The other side of the coin are those who feel this is just another fad in education that will soon “burn itself out”.
I welcome your feedback on this very interesting topic.
Picture of baby Garrett and His Mother Natalie Peterson, courtesy of NPR.
On my way to work this morning, I was Listening to this incredible story on NPR about Garrett, who was born with a defective windpipe. Apparently, Garrett was born with a defective windpipe. The condition, is called, tracheomalacia. In Garrett’s case, his left trachea is so weak that it takes very little for his trachea to collapse, causing him to stop breathing.
Garrett’s parents were able to connect with Dr. Glenn Green fromt he University of Michigan. Scott Hollister, a biomedical engineer, runs the University’s 3-D Printer, was able to create a splints to hold open little Garrett’s windpipe.
Pictured right is a model of Garrett’s trachea, along with splints similar to those used in the operation. Picture provided by Juliet Fuller/University of Michigan Health System.
Doctors were able to make a replica of Garrett’s windpipe from a CT scan. The comparrison was made of a tent that one might use to go camping, that keeps falling down. The splints were able to keep Garrett’s windpipe open. A frustrating part of the story was that the device did not have FDA approval. Hats off to Doctor Green and Scott Hollister for convincing the FDA to issue an emergency waiver.
Long story short, little Garrett has responded very well to the surgery. He is still on a ventilator but his prognosis for a healthy future is very promising.
Wondering if anyone else happen to hear the story. It made me think of all the babies who probably did not survive in the past. It made me think how wonderful and cool technology can be.
From Thermo Scientific
Perhaps all your lab needs is deionized water. Or you would like to use DI water as feed water for further purification. There are cartridge deionizers which are simple to install and require little maintenance.
Ion exchange in water treatment removes monovalent ions from water such as Na+, K+, and Cl−; divalent ions such as Ca2+ and Mg2+; and other polyvalent inorganic ions such as SO42− and PO43−. These ions contribute to the conductivity of water and the removal of these ions is necessary to produce the resistivity necessary for ASTM type II and type I water.Ion exchange resins are tiny synthetic beads which have hydrogen ions (H+) and hydroxyl ions (OH−) on their surfaces. As the water passes across these beads the H+ is exchanged with the positive ions in the feed water and the OH− is exchanged with the negative ions in the feed water. The replaced OH− and H+ combine to produce H2O while the larger ions are bound to the resin beads.
From Thermo Scientific
Cation exchange resins remove the positively charged ions and anion exchange resins remove the negatively charged ions. Eventually all the binding sites on the resin are filled and the resin has to be regenerated or replaced. In the case of a home water softening system the cation exchange resin can be regeneratedby passing a concentrated salt solution through the resin. Laboratory water purification systems use a mixed bed ion exchange cartridge where both cation and anion exchange resins are present so regeneration is not practical and the cartridge must be replaced.
Mixed bed ion exchange is very efficient at removing dissolved inorganic ions and produces water with >18 MΩ⋅cm resistivity. To produce Type II or type I water ion exchange must be used with other water purification technologies. Ion exchange does not remove particles or colloids (filtration), it does not remove organics (distillation/reverse osmosis), and pyrogens or bacteria (reverse osmosis/ultrafiltration).
Professional Weather Stations for use in schools, labs and industrial applications. This instrument is designed to monitor conditions, forecast weather, and check environmental air parameters. The unit displays temperature, humidity, dew point, barometric pressure/pressure trend, weather forecast, wind direction/speed, wind chill, rainfall amount, and clock/calendar. The model displayed on the left has a serial data output which permits linking to a computer for storing all information. Stored data can then be placed into a permanent weather database for generating analysis, and studying weather trends.
A complimentary instrument in the study and monitoring of Meteorology is the Anemometer/Thermometer which measures air velocity and temperature. Readings are updated instantaneously and has a memory function which will recall the highest and lowest readings.
OpticsPlanet offers these and similar tools which prove to be beneficial for use in both the laboratory and classroom environment. Though I’m sure the novice hobbyist would also find them both educational and entertaining.
Please feel free to contact any of our knowledgeable staff for additional information or for assistance in selecting the best weather station for your needs.
Where do you start for a laboratory water treatment system? Especially if you have a small laboratory. Initial water treatment in the lab could start with a water pre-filter to remove particulates followed by a reverse osmosis system. This is a simple way to have Type III water which is suitable for many of your laboratory procedures. RO water can also be feed water for Type I ultra purification systems. Reverse Osmosis removes >94% of dissolved ions and >99% of suspended solids, bacteria and pyrogens. Reverse osmosis produces Type III water ready for further purification to Type II or Type I water. The amount of contaminants removed depends greatly on the feed water for the RO system.
Osmosis is the tendency of water molecules to move across a semi-permeable membrane from the purer side of the membrane to the less pure side; this is how cells exchange water and nutrients. Osmotic pressure is the pressure of the water molecules on the membrane from the purer side. In reverse osmosis pressure is applied – greater than osmotic pressure – to the less pure side of the membrane forcing water across the membrane and leaving behind most of the inorganic ions and other contaminants.
Particulates, dissolved organics, and Chlorine are damaging to reverse osmosis membranes and many RO units have a pre-filter and an activated carbon filter. Reverse osmosis has a slower flow rate than other water treatment technologies so it is necessary to store the RO water in a tank. A pump may also be necessary to provide the required flow rate from the RO tank to subsequent water treatment units.
RO is a good first step in a water polishing system; the quality of RO water protects polishing systems such as deionizing cartridges. RO water quality is sufficient for many routine laboratory needs.
The right tool for the right job! Test Tube Brushes seem to be one of those items you don’t really think about until you need it. I recently received orders from several labs. In each case, the tech ran out or had used the last remaining brush they had, beyond the life of the bristle. Needless to say, I end up placing some rush orders, which prompted me to create this blog as a friendly reminder to those of you who haven’t checked your stock of brushes in a while.
Standard lengths range from 8″ to 13″ with brush diameters from 3/4″ (1.9 cm) to 1-3/8″ (3.5 cm). Though there are longer and wider brushes available, including beaker and centrifuge brushes, which I’ll address in a future blog. Choice of bristle’s are nylon and natural and most come in packs of 10, which should keep you going for awhile.
Again, these brushes are ideal for cleaning test tubes and narrow mouth glassware. Rounded tuft at tip facilitates cleaning and protects the glassware.
The brush pictured to the right is an example of a test tube brush that has a Tufted End.