Monday, September 29, 2014

Nostalgia: $3 Bookstore in Lake Park Georgia

Three weeks back I had to drive down to Jacksonville Florida for a customer engagement. On the way back I stopped at the $3 and under Book Store in Lake Park Georgia. It's just north of the Florida/Georgia state line just off of the exit on I-75.

How could I resist this siren's beckoning call?  I love books, and I'm cheap!  Cheap books are a Panacea!  So. (grinning sheepishly) ... I bought a few books!

The best part of this was the overwhelming nostalgia when I walked in the store. As I came through the door I realized I'd been there once before.  It was dozens of years ago on the last vacation I took with my parents.  I can still remember the book I bought too.  It was "The Robot Builder's Bonanza".  This was a favorite, and  I still have it.

This stop made my trip.  +1, 5 Stars, Thumbs-Up!

Thursday, September 25, 2014

Book I Read:The Hot Zone: The Terrifying True Story of the Origins of the Ebola Virus by Richard Preston

The other book I read this week was The Hot Zone: The Terrifying True Story of the Origins of the Ebola Virus by Richard Preston.

This tells the story of the only known outbreak of the Ebola virus in the United States.  It occurred at a monkey quarantine facility in Reston Virginia in 1989.  The outbreak was managed by the CDC and USAMARIID, the Army's Biological Laboratory.  This book does an excellent job of discussing in layman's terms what we know about Ebola, Marbug, and Filovirii in general.  It also talks through the way that the incident response was handled at the Reston facility.  The latter is quite frightening. 

The funniest part of the book is when the doctors enter the Monkey facility in full level 4 biological protective gear, and come face-to-face with the animal handlers in street clothes.  The handlers suddenly realize the gravity of the situation and flee.  I cannot help but giggle at the imagined look of stunned panic they must have had when seeing space-suited Doctors coming in through the airlock.

The book has a couple of terrifying parts.  Ebola is a scary disease.  Understanding that, I can't believe that two medically trained professionals at USAMARIID would choose to conceal their exposure instead of voluntarily submitting to quarantine.  That is grossly irresponsible.  The other scary part is the monkey-facility-company's refusal to take the infection seriously.  I suspect this was largely because ebola wasn't in the public consciousness then.  People didn't know how serious it could be.  I wonder how this would be handled differently today, in our post-9/11 world.

Long story short, America dodged a bullet with this incident.  If this had been one of the "bad" strains of ebola, like Ebola Zaire, we could have lost huge swaths of population around DC before the outbreak was controlled.  This wouldn't have been an extinction event, but it would have changed the world.

An interesting thought occurred to me while reading the history of ebola.  A commonality of two index patients of separate, non-US, outbreaks was found.  Both were infected after visiting a specific cave that was made when ancient volcanic ashfall engulfed a prehistoric forest.  One of the behaviors of the virus is that it forms crystalline brick-like structures during the amplification state before it ruptures the cell walls.  I'm curious if the scientists on the cave expedition ever thought to attempt to culture any samples of the rocks in the cave walls.  It would be incredible if a virus had managed to survive for eons in the rock of the cave and this seems stunningly unlikely, but ...?

I'm doubly curious about this as the infection appeared to start in the fingertips of the second patient, a Danish boy.  I'm triply curious, as this virus is known to disappear for years, and then come creeping back out of the jungle again.  Occam's razor suggests that it probably has an animal host during these time gaps, but a rock > bat > human or rock > elephant > human transmission vector would be scientifically fascinating.

(No, I'm not going to kick off an expedition for this.  Ebola, or any other hemorrhagic disease, is firmly in the not-my-cup-of-tea category.)

This author has another book that's just come out.  I understand it is about bioterrorism and smallpox. For non-fiction, his books read like an action novel, and I'm definitely going to try to find a copy today.

Wednesday, September 24, 2014

Book I Read: Isaac's Army: A Story of Courage and Survival in Nazi-Occupied Poland

I just finished reading Isaac's Army: A Story of Courage and Survival in Nazi-Occupied Poland.

This book was hard to read.  The story is a painful one. This book tells the story of a number of Polish Jewish families in Warsaw Poland during World War Two.  It tells the story of those that fled Poland, those that hid, those that fought, and many that died.

I started this book relatively ignorant of this part of history.  I understood that there had been a Jewish uprising against the Nazis in the Warsaw Ghetto from reading "Unintended Consequences".  What I didn't understand was what the ghetto truly was.  This book changed that, irreparably.

In reading this book I found myself waiting and hoping for the moment of heroic triumph where the huddled masses unite and crush their Nazi oppressors.  I kept hoping for the drone of legions of American bombers to fly over and put an end to the death trains and Auschwitz-bound rail cars.

The best part of this book almost reaches this crescendo.  The chapter where the resistance defends the ghetto from the SS and Wehrmacht is thrilling.  After the murder of tens of thousands, the relief of fighting back was overwhelming.  Then the resistance collapses, and it is heartbreaking.

The worst part of the book is the hopelessness.  The author does a remarkable job of placing you in the mind of the people.  This makes you feel it, viscerally, when you hear that your hometown had been destroyed, with everyone man/woman/child/gentile/jew killed and buried in shllow mass graves.

As I said previously, this was exceptionally hard to read.  The darkness of the story still lingers with me, punctuated with the sad knowledge that this is not fiction.

Wednesday, September 10, 2014

(Audio)Book I Read: Impact by Douglas Preston

This week I had to drive from Nashville Tennessee to Jacksonville Florida and back in 3 days.  20 hours in the car.  That is a very long time.

To pass the time I listened to the BBC Audiobook version of "Impact " by Douglas Preston.

This book is hard to categorize.  The plotline is like the love child of a science fiction novel and a spy/action novel.  The best comparison I could make is that it's like the Jack du Brul/Phillip Mercer books without the immortal hypermasculine testosterone exudate action hero protagonist.  I enjoyed the book a great deal.  If you like the Mercer Books, then give it a try.  On the science side, most of the science bits were plausible.  It didn't get in the way of the story at all.  It also pointed me down the path of learning about strangelets.  That's a bonus.

Minor point of annoyance with the AudioBook format.  There is no end-of-CD designation.  You're driving around listening and then the CD starts over.  Minor irritation, not bad.

Verdict: I will look for more from this Author.  Would read again. -Ellie

Monday, September 8, 2014

Update: HobbyKing T-45 Goshawk R/C initial flight test results

Monday we went out for our first flight test on the Hobbyking T-45 Goshawk.

I have several notes.

1. Verify that the Battery compartment is glued in securely.  We found that it was not in pre-flight checks.  We pulled it out, scraped off the glue, and epoxied it back in permanently.

2. The stock configuration Ailerons and Elevator do not have sufficient throw for acceptable flight.  We used an Xacto knife to slot out a portion of the hinges and this helped significantly.

3. My choice of hole for the elevator servo arm position was wrong.  You need maximum control of the elevator for this aircraft, so use the very last hole.  I also had to cut a small amount (<5mm) of foam for clearance for the aileron and elevator control rods to keep them from rubbing.

4. The plastic Y-shaped tail linkage can come apart in flight, resulting in loss of elevator control.  Preempt this by gluing the metal control linkages into the white plastic clip.

5. Flight time is ~4 minutes with the recommended 2200mA battery.

6. The plane is FAST. :)

The good news is that we were able to successfully land and recover the undamaged aircraft, even with the crippled elevator.  That's fantastic.  The bad news is our charger isn't working properly and we're waiting on a new Li-Po charger before our next flight.  I'll post again when we get it back in the air.

One last bit.  I seemed to have annoyed at least one person over at Hobbyking with my comments.  I'm sorry for that.  My goal with this series is to give an honest description of the product, warts and all.  Also I want to help you skip the trial-and-error of setting up this plane.  If I've failed in either those objectives, I apologize.


Sunday, September 7, 2014

Book I Read: Enemy Combatant: My Imprisonment at Guantanamo, Bagram, and Kandahar by Moazzam Begg

Today I finished reading "Enemy Combatant: My Imprisonment at Guantanamo, Bagram, and Kandahar" by Moazzam Begg.

I am deeply conflicted by what I read.

To talk about this book I first have to establish my position.  I am a realist.  Terrorists on Islamic Jihad attacked the World Trade Center 1993 and 2001.  They attacked the USS Cole.  They attacked the Pentagon.  All conspiracy theories aside, there is a nontrivial threat to America from radical Islamic Jihad.  Not all Terrorists are Muslim.  Not all Muslims are Terrorists.

Mr. Begg is a Englishman of Pakistani descent holding dual citizenship between England and Pakistan.  In this book he describes his youth, including membership and exploits in a gang.  He describes combating anti-Paki racism growing up, and becoming progressively more religious over time.  He describes running an islamic Bookstore and strong ties to the Muslim community.  He describes involvement in donations and aid work for Muslims in Bosnia, Chechnya, and Afghanistan.  He describes his visits to multiple war zones including to a militant training camp in the Afghan mountains.  He also describes his decision to move his family to Afghanistan to be in an Islamic state. 

Mr. Begg and his family fled Afghanistan to Pakistan after the start of the US invasion.  His home was raided.  He was pulled from his bed and imprisoned for three years as an enemy combatant in the War on Terror.  The majority of this book deals with the conditions and events of his three year imprisonment in Afghanistan and Cuba.  It also describes his eventual transfer to Scotland yard in 2005 and release.

I cannot honestly say if Mr. Begg is a terrorist.  He might be or he may not.  Suspicion is not sufficient.  I have no evidence beyond his own words and his wiki-leaked Guantanamo file and am unable to make a judgement on his guilt or innocence with the evidence provided.

It is not in question that Mr. Begg was isolated, tortured, imprisoned, and interrogated in a foreign land.  He was not plucked from a battlefield, but from his bed far from any fighting.  He spent years with no legal representation.  He spent years in social isolation.  He was never given the opportunity to confront his accusers, present a defense, or have the evidence against him heard by a nonmilitary judge.  These facts alone are sufficient information to judge my Country's actions. 

I am ashamed of my country.  My America is party to the Geneva and Hague Conventions.  My America does not snatch a man from his bed and imprison him for years without trial.  My America does not resort to torture.  My America was built on the rule of law, even in wartime.  My America certainly does not operate a Cuban gulag worthy of Pyongyang.

Sometimes it feels like I don't live in my America anymore.

The beacon of light is the handful of soldiers in the book that recognized their actions were wrong; they saw the America they swore to defend was not the America of dog cages and orange jumpsuits.  This handful of honest men and women gives me hope that all is not lost.

I recommend this book.  Patriotism is not a starry-eyed white washed flag and national anthem.  It requires honesty in judging your leaders and actions.  This book made me understand our failures in a completely new way.  I am a better American because of this book.

I welcome your comments and opinions.  Please let me know what you think.

Warning Labels: Vacuum Sealer

I choose to believe that every warning label has some backstory that justifies its existence.  Today I found a mason jar adapter for my vacuum sealer at Goodwill.  It had this warning.

Do not apply the hose or lid sealer to any part of
the body while vacuum pump is in operation.

I'm certain the backstory to that is a fascinating one. :)


Saturday, September 6, 2014

"The Last Question" by Isaac Asimov

This morning I  read a fantastic short story by Isaac Asimov, The Last Question. This is a very quick read, just a few minutes, and worth it.

Friday, September 5, 2014

Blog Changes

I've taken some constructive criticism on this blog and made a few changes.  To the right you now have a Tag Cloud, list of my most popular posts, search box, and a list of my current projects.  The Blogger bar is gone, and I've put up a crudely drawn logo.  The logo is temporary, I've asked a chap over on Fiverr to make something slightly less amateurish to go there.

Writing is easy.  Presentation is hard.  :/

Please comment, positive or negative, if you see something that needsd changing or have suggestions.  I want this to be as much fun for you to read as it is for me to write.


Monday, September 1, 2014

ScienceMadness: Construction of an inexpensive adjustable speed magnetic stirrer

This is an old piece that I wrote and posted to the ScienceMadness discussion forums back in July of 2013.  If you prefer, the original thread is here.  I rather like this writing style.  I was attempting to copy the feel of a proper scientific paper.

Construction of an inexpensive adjustable speed magnetic stirrer

This paper describes the construction of an inexpensive adjustable speed magnetic stirrer for use with a non-ferrous hotplate or oil bath. Design decisions, Pitfalls, Schematics of the speed controller, and a bill of materials are included.

Action Shot:

A rectangular magnet is attached to the top of an inexpensive double ball-bearing CPU fan. The fan is driven by a PWM motor speed controller and powered by a 500 mW wall-wart power supply. JB-Weld adhesive is used to secure the magnet, and great care was taken to balance the assembly. A square of non-skid padding is attached to the bottom of the stirrer to prevent it from vibrating off the workbench.

Design Decisions and Pitfalls:
This fan was specifically selected for its dual ball-bearing construction. The unit was originally constructed with a junk-drawer sleeve-bearing fan. This unit failed very quickly.

The chosen fan is nominally rated for 3,000 rotations per minute. This speed would make the finished device unusable, sending both the stir bar and solutions flying across the lab. A simple potentiometer was attempted for speed control, but the stirrer would not rotate at any speed with the potentiometer connected.

Failing the simple speed control option, the second option was to use an Arduino to output a PWM signal to a simple motor driver circuit. The following circuit was built and tested on a breadboard.

Figure: Schematic of the dead-simple motor driver circuit.

To drive the circuit, the Arduino AnalogWrite function was used. See Permanently dedicating an Arduino microcontroller to this project violates the “Low-Cost” objective of this project. Additionally, the movers broke my Arduino touch screen shield. :( A third option, a dedicated PWM generator, was designed, tested, and built. 

Figure: A low-cost PWM DM motor speed control circuit

An Altoids tin was selected as a project enclosure. This was lined with duct-tape to prevent shorting out the controller. Any container of suitable size would suffice, but the likelihood of exposure to heat and chemical spills suggests the use of a metal enclosure.

Cyanoacrylate “Super-Glue” adhesive was tried as the adhesive for the fan-to-drive-magnet junction. This failed repeatedly during testing. The first failure was at approximately 75% speed, impacting the wall behind the workbench. After reattaching, the magnet snapped off when the stirrer was accidentally dropped onto a wooden workbench. Hot-Glue was discarded as an option due to heat and chemical compatibility. Roughing the surface of the drive magnet and fan with 80-grit sandpaper and securing the magnet with JB-Weld adhesive provided a satisfactory solution.

The magnet must be centered very carefully on the fan to prevent excessive vibration. This is a painstaking process, and the JB-Weld allows plenty of time to make final adjustments. Before applying the adhesive, use a stir-bar to verify the magnet’s polarity. Improper orientation will cause the stir-bar to stand on end.

Figure: Magnet Placement Polarity Failure Indication

An attempt to use two magnets for greater magnetic flux was made, but this was too much load on the fan bearings. It would not rotate at low speeds.

The author has assumed there is a fuse built-in to the wall-wart power supply. This is a foolish and unsafe assumption, and a discrete fuse will be added.

The author’s electronics skills are very limited, and skill in drawing schematics even more so. Those attempting construction of this project are strongly recommended to breadboard the circuits before construction.

Bill of Materials:
Note: Radio-Shack part numbers are included in parenthesis below, but other vendors may be significantly less expensive. Excluding the Fan, Magnet, and 12V power brick, all of the electronic components to breadboard this project are included in the Radio Shack “Electronics Learning Lab” Kit.
  • Inland brand “80mm Performance Fan”. (Micro-Center $2.99) 
  • Magnet Source 3/8” x 7/8” x 1 7/8“ Permanent Ceramic Magnet ( CB60N) 
  • JB-Weld Adhesive (Home Depot) 
  • 12 volt 500 mA wall-wart power supply (#273-357) 
  • NE555 timer IC (#276-1723) 
  • 1 NPN Transistor (#276-1617) 
  • 3 1N4001 Diodes (# 276-1653) 
  • 2 0.1uF Ceramic capacitors (#55047557) 
  • 1 0.01uF Ceramic capacitor (#55047551) 
  • 1 10K Ohm resistor (#271-306 assortment Pack) 
  • 1 1K Ohm resistor (Included in above assortment) 

To permanently construct the motor controller off the breadboard, the following additional components are required.
  • Altoids tin or other project enclosure 
  • Printed circuit board or perfboard (#276-148) 
  • 100K ohm potentiometer (#271-092) 
  • SPST toggle switch (#275-324) 
  • Solder, soldering iron, & hookup wire. 
  • Non-Slip drawer liner for “feet” (Source unknown) 

Suggestions for Future Work:
A motor is a series of electromagnets energized in such a way to make a magnetic rotor rotate. It seems Rube-Goldberg-ian to physically attach this apparatus to a magnet for the purposes of rotating a third magnet. A more efficient design would use a number of electromagnet coils turned on and off in the correct sequence cause the stir bar to rotate. This apparatus could be physically constructed in a relatively inert substance like glass or ceramic to make a silent and vibration free stir-plate or stir-hockey-puck. It may be possible to adapt a stepper-motor controller IC for the difficult work of generating the correct polarity, sequence, and timing for this apparatus. To the author’s dismay, a patent search found an example of this idea in patent 3554497 and a number of similar products on the market.

A larger drive current could be used safely by limiting the PWM duty cycle. This would allow significantly higher starting and low-speed torque.

A humming sound can be heard when the device is in use, particularly at low speeds. Increasing the frequency of the PWM drive to > 20kHz should shift this humming sound out of the range of human hearing. With the addition of another drive transistor, a second fan/magnet could be added to agitate large solutions or an oil bath.

Simple PWM DC Motor Driver Circuit 

NE555 PWM Motor Controller Circuit

Homemade Show: 2$ Magnetic Stirrer Tutorial

Bonus Material (Not on SM):
Completed Magnetic Stirrer External Shot

Completed Magnetic Stirrer Internal Shot

How not to breadboard  (USE SHORTER WIRES!)