Retrotechtacular: Films Used to Be Recorded on Film

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We’re sure that this title makes some readers itch because there are still a number of well-respected directors who insist on shooting with film rather than digital, but the subject of this week’s Retrotechtacular shows a portion of the movie industry that has surely been relegated to life-support in the past few decades. Photo finishing, once the stronghold of chemical processes used by all to develop their photographs, has become virtually non-existent. This is the story of how film and photo finishing drove cinema for much of its life.

The reels seen above are negative and positive film. The negative film goes in the camera and captures the images. After developing and fixing the negative film, the process is repeated. Light shines through the fixed negative in order to expose a fresh reel of film. That film is finished and fixed to create the reel which can be used in a projector. This simple process is covered near the beginning of the clip found below. The 1940 presentation moves on to discuss the in-depth chemistry techniques used in the process. But you’re really in for a treat starting about half-way through when the old manual methods are shown, which have been replaced by the “modern laboratory”. We love those huge analog dials! The video concludes by showing the true industrialization of the film developing process.

We’re running out of Retrotechtacular topics. If you know of something that might be worth a feature please send in a tip!

[Read more...]

Machine Learning Used to Create an HIV Vaccine

hiv-vaccine-microspheres

When we think of machine learning it’s usually in the context of robotics—giving an algorithm a large set of input data in order to train it for a certain task like navigation or understanding your handwriting. But it turns out you can also train a nasty virus to go to sleep and never wake up again. That’s exactly what the Immunity Project has been doing. They believe that they have a viable HIV vaccine and are trying to raise about $25 million to begin human testing.

The vaccine hacks the Human Immunodeficiency Virus itself, forcing it to mutate into a dormant form that will not attack its human carrier. It sounds so simple, but a lot of existing knowledge and procedures, as well as new technology, went into getting this far. Last week we spoke with [Reid Rubsamen, M.D.] about the process, which began by collecting blood samples from a wide range of “Controllers“. Controllers are people who carry HIV but manage to suppress the virus’s progression to AIDS. How do you find these people? That’s another story which Scientific American covered (PDF); the short answer is that thanks to the work of [Bruce D. Walker, M.D.] there was already a database of Controllers available.

The information accumulated by [Walker] then underwent a data crunching exercise. The data set was so enormous that a novel approach was adopted. For the laymen this is described as a spam filter: using computers to look at large sets of email to develop a complex process for sifting real messages out of the noise. The task at hand is to look at the genotype of a Controller and compare it with the epitope— a short chain of proteins—in the virus they carry. The power of machine learning managed to whittle down all the data to a list of the  first six epitopes that have the desired dormant-mutation property. The vaccine consists of a cocktail of these epitopes. It does, however, require some clever delivery tactics to reach the parts of the world where it’s most needed. The vaccine must not require refrigeration nor any special skills to administer.

The vaccine’s production uses existing methods to synthesize the amino acid peptides, which are the epitopes themselves. The packaging, however, is a new concept. [Dr. Rubsamen's] company, Flow Parma, Inc., is using microspheres to encapsulate the vaccine, which render it shelf-stable and allow it to be administered through a nasal spray. Learn more about the technology behind the production of microspheres from this white paper (PDF).

If the vaccine (which will be produced without profit) passes clinical trials, it could see mass distribution as early as 2017.

The $25M we mentioned earlier is a tall hill to climb, but think of the reward if the vaccine is successful. You can donate directly to help reach this goal. If you’re planning on giving gift cards this year, you can purchase them for many different retailers through Gyft, who is donating 100% of December proceeds to the project.

Boil Off Some White Gas in the Back Yard

Gas-still

[S Heath] is a Coleman lantern collector. Coleman lanterns can run from a variety of fuels, however they seem to run best with white gas, or Coleman fuel. Store bought Coleman fuel can cost upwards of $10USD/gallon. To keep the prices down, [S Heath] has created a still in his back yard to purify pump gas. We just want to take a second to say that this is not only one of those hacks that we wouldn’t want you to try at home, it’s also one that we wouldn’t try at home ourselves. Heating gasoline up past 120 degrees Celsius in a (mostly) closed container sounds like a recipe for disaster. [S Heath] has pulled it off though.

The still is a relatively standard setup. An electric hot plate is used to heat a metal tank. A column filled with broken glass (increased surface area for reflux) rises out of the tank. The vaporized liquid that does make it to the top of the column travels through a condenser – a pipe cooled with a water jacket. The purified gas then drips out for collection. The heart the system is a PID controller. A K-type thermocouple enters the still at the top of the reflux column. This thermocouple gives feedback to a PID controller at the Still’s control panel. The controller keeps the system at a set temperature, ensuring consistent operation. From 4000 mL of ethanol free pump gas, [S Heath] was able to generate 3100 mL of purified gas, and 500 mL of useless “dregs”. The missing 400 mL is mostly butane dissolved in the pump gas, which is expelled as fumes during the distillation process.

[Read more...]

The “Melt-O-Matic” – A Digital Melting Point Apparatus

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A common technique in organic chemistry is to determine the melting point of a specimen. While commercial options exist, [kymyst] decided to build one with similar (or better) functionality, and managed to keep it under $100. The basis of his rig is a 60W soldering iron. He simply replaced the normal soldering tip with an aluminum heating block that holds the capillary tubes and temperature probe. Two small fans are used to quickly cool the heating block, allowing fairly quick measurement times. It should be noted that building a project like this one will mean working with wires that carry 220V (or 115V, depending on your country). Please use proper precautions.

In case organic chemistry is on your list of ‘to learns’, [kymyst] included a nice writeup of the determination of melting points. It’s a great primer for those interested in learning more.

Using this setup, [kymyst] gets readings of ±0.1 °C. He mentions the possibility of adding a webcam for determining melting point automatically, something that would make this system competitive with much more expensive hardware.

The last time we saw one of these it used a hot glue gun as the heating element.

Crafting A Liquid Crystal Display

gif Throughout the 1960s, the management at RCA thought LCD displays were too difficult to commercialize and sent their engineers and researchers involved in LCDs off into the hinterlands. After watching [Ben Krasnow]‘s efforts to build a liquid crystal display, we can easily see why the suits thought what they did. It’s an amazing engineering feat.

Before building his own version of an LCD (seen above in action), he goes through the mechanics of how LCDs operate. Light enters the display, goes through a polarizer, and is twisted by a liquid crystal material. The first successful LCDs used two types of liquid crystals – chiral and nematic. By combining these two types of molecules in the right proportion, the display can ‘twist’ the polarized light exactly 90 degrees so it is blocked by the second piece of polarizing film in the display.

Besides getting the right crystals and engineering processes, another major hurdle for the development of LCDs displays is transparent electrically conductive traces. [Ben], along with every other LCD manufacturer, uses a thin layer of indium tin oxide, or ITO. By embedding these clear electrodes in the display, segments can be built up, like the seven segment displays of a calculator or a bunch of tiny dots as found in a TV or computer monitor.

In the end, [Ben] was able to build an extremely simple single-segment LCD display out of a pair of microscope slides. It does modulate light, just barely. With a lot of work it could be made in to a calculator type display but for now it’s an awesome demonstration of how LCDs actually work. [Read more...]

Salvaging Gold From Old Electronics

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If you’re hoarding old electronics like us, there’s a good probability you have a decent amount of gold sitting around in cardboard boxes and storage containers. Everything from old PCI cards, IC pins, and even printers have a non-negligible amount of precious metals in them, but how do you actually process those parts and recover that gold? [Josehf] has a great tutorial for gold recovery up on Instructables for the process that netted him an ounce of gold for three months’ work.

After cutting up a few circuit boards to remove the precious gold-bearing parts, [Josehf] threw these parts into a mixture of muriatic acid and hydrogen peroxide. After a week, the acid darkened and the gold slowly flaked off into dust. This gold dust was separated from the acid by passing it through a coffee filter and readied for melting into a single nugget.

Gold melts at 1064 ˚C, much hotter than what can be obtained by a simple propane torch. This melting point can be reduced by the addition of borax, allowing the simplest tools – a propane torch and a terra cotta crucible – to produce a small gold nugget.

For three months of collecting, stripping, and dissolving electronic parts, [Josehf] netted 576.5 grains of gold, or at current prices, about $1500 worth of the best conductor available. Not too bad, but not something we’d use as a retirement plan.

Thanks [Matthias] for sending this in.

Heirloom Chemistry Set

heirloom chemistry  set

We try not to share too many crowd funding projects, but when a tipster sent us to this Heirloom Chemistry Set we knew some would-be chemistry hackers might just want to see it!

[John Farrell Kuhns] runs a small science store with his wife in Kansas City called the H.M.S. Beagle, where young scientists (and adults!) can buy professional lab supplies, equipment, and the resources to study all things from chemistry to physics!

It all started when [John] was a child in the 1950’s and he received the classic Gilbert Chemistry Set as a Christmas present, which help set him on the course of becoming a professional research chemist. Now, wanting to share his love of chemistry with his children, he realized there just isn’t the same kind of chemistry sets available commercially!

Since the opening of his store he has made many custom chemistry sets very similar to the originals, but these were almost all one-off’s and very time consuming to make. So recently he decided to try making a set that he can produce in fair numbers to meet the demand, and so he started this Kickstarter to help it get off the ground. It’s already surpassed its goal by two times!

We wish we had one when we were growing up!

[Thanks Jeremy!]

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