Category Archives: CounterCurrent

Schneier on Security

3 Replies

Over at CNN.com there is an excellent post by the security expert Bruce Schneier. Finally, somebody has spoken what must be said. Schneier, by the way, was the one who invented the Blowfish encryption algorithm.

“Security theater” refers to security measures that make people feel more secure without doing anything to actually improve their security. An example: the photo ID checks that have sprung up in office buildings. No one has ever explained why verifying that someone has a photo ID provides any actual security, but it looks like security to have a uniformed guard-for-hire looking at ID cards …

Despite fearful rhetoric to the contrary, terrorism is not a transcendent threat. A terrorist attack cannot possibly destroy a country’s way of life; it’s only our reaction to that attack that can do that kind of damage. The more we undermine our own laws, the more we convert our buildings into fortresses, the more we reduce the freedoms and liberties at the foundation of our societies, the more we’re doing the terrorists’ job for them. –Bruce Schneier

My take on Schneier’s thesis is that the public, i.e., the teeming masses, must not allow the many arms of government to further tighten its grip on our liberties. Liberties once taken are hard to recover. The combination of media sensationalism, advanced information gathering, and authoritarian reflex is driving the USA into a permanent security state. A mature and thinking public must buffer the exaggerations and sensationalism that is broadcast into our homes every minute of every day.

Counterterrorism is also hard, especially when we’re psychologically prone to muck it up. Since 9/11, we’ve embarked on strategies of defending specific targets against specific tactics, overreacting to every terrorist video, stoking fear, demonizing ethnic groups, and treating the terrorists as if they were legitimate military opponents who could actually destroy a country or a way of life — all of this plays into the hands of terrorists. –Bruce Schneier

By closely following the exploits of a handful of radicals as though they could bring down our civilization, we legitimize their efforts as being worthy of our sustained attention. These are low frequency high visibility events.  Unfortunately, lingering and repeated gawking at sensational events against a constant buzz of soaring narrative is what television does best.

PETN in his BVD’s

3 Replies

History will record an underwear bomber and a shoe bomber. Luckily for the passengers of one transatlantic flight, the anonymous martyr on board was incompetent. Like the shoe bomber before him, this murderous buffoon failed to plan for a reliable means of triggering his bomb.

PETN, or pentaerythritoltetranitrate, was found to be the explosive agent used in the attempted inflight bombing of  Northwest Flight 253. This is a relatively common and powerful explosive in the category of aliphatic nitrate esters. It is a colorless powder that can be used in mixed and cast explosives or as the pure material. Like many detonable materials, it does not need to be placed in confinement to produce an explosion. PETN becomes unstable above 71 C, a fact that limits its suitability for some applications. My references do not clarify what is meant by unstable, but the material could be prone to chemical degradation above this temperature which would adversely affect its quality.

Other aliphatic nitrate esters include nitroglycerin, BTTN or 1,2,4-butanetriol trinitrate, EGDN or ethylene glycol dinitrate, and PETRIN, the trinitrate analog of PETN. A nitrate ester has a C-O-NO2 linkage and differs from aliphatic or aromatic nitro compounds which have C-NO2 linkages instead.

Nitrate esters are made from an alcohol or polyol and nitric acid. Nitro aromatics like TNT are made by acid catalyzed nitration of reasonably electron rich aromatic compounds like toluene or phenolics. The oxygen in the C-O-NO2 ester linkage confers some extra measure of instability to the molecule.

PETN is commonly used in Primacord, an explosive cord comprised of a PETN core inside a thin fabric or plastic sleeve. Primacord can be used as a blasting agent itself or it can be used as a fuse or delay line to trigger other explosives from a central point.

PETN is an explosive with a high brisance value. That is, it produces a shock that has a shattering effect on materials. In fact, brisance is quantified by the “sand test” which measures the production of fines from the shattering of 200 g of 30 mesh Ottawa sand. After the test, the sand is re-screened and the finer material that later passes through the screen is weighed. The greater the mass of fines, the greater the brisance.

Explosive         Sand Crush (g)   Heat of Explosion (cal/g) 
Black powder         8                                    684
Lead Azide            19                                  367
Comp C-4             55.7                            1590
TNT                      48                                1080
RDX                  60.2                        1280
Nitroglycerin         51.5                           1600
AN                               nil                                346
Picric Acid              48.5                           1000
PETN                         62.7                            1385
Source:  Cooper & Kurowski, Introduction to the Technology of Explosives, 1996, Wiley-VCH, p76-77. ISBN 0-471-18635-X

Pentolite is a composition prepared from a 50/50 blend of trinitrotoluene (TNT) and PETN with wax as a bonding agent and plasticizer. There are many blends of explosive materials. The composition is adjusted for the application.

The job of an explosive is to do PV work on objects. It does this by generating an abrupt pulse of heat and a large number of small gas molecules like N2 and CO2. The detonation velocity of PETN is ~ 8 km/s, so that a relatively small number of PETN molecules in a small volume are converted rapidly into a larger number of  gas phase molecules, all seeking to occupy the molar volume of 22.4 L/mol. 

The prompt generation of many moles of hot, small molecules results in the expansion of decomposition gases which forcefully press against the surroundings. The gases resulting from the 8 km/s detonation wave in the bulk solid explosive expand and compress the nearby air into a shock front that expands approximately spherically. As it does this the gases cool and the shock dissipates.

Explosive Power is a measure of an explosives ability to do work. Explosive power = Q x V,  Q = heat of explosion and V = volume of gas generated. The Power Index of a material is the ratio of explosive power to that of picric acid times 100 %. The power index of PETN is 167, TNT is 119, and RDX is 169.

CT scan abuses. Who is actually in charge of the use of X-rays?

7 Replies

The latest news  about CT scan abuse and the subsequent excessive radiation exposure to the public is very disturbing. A recent issue of the Archives of Internal Medicine features 2 articles describing their findings in regard to the use and possible misuse of CT x-rays. There is no point in my regurgitating the details of the two articles. The reader can study the articles without my noisy input.

What I would like to point out is that this is a case of faulty administrative control over the exposure of patients to hazardous energy. Who is the gatekeeper for access to a CT scan-  the primary care doc or a consulting radiologist? If it is the primary care doc, is he/she up to speed on the exposure/dose details? Does the primary care doc know the dose and variability in radiation exposure for a given workup? Does the dose vary with the model of CT scanner? How much resolution is really necessary, anyway? Does half the dose give half the resolution, or is there some other law relating transmitted energy to resolution?

Maybe the gatekeeper should be the radiologist. The radiologist should be able to calculate a radiation dose and speak knowledgeably about the details of the risk. But should the radiologist be in a position to second guess the primary care doc? Does anybody provide feedback to the primary care doc as to the wisdom of a given CT scan? Doesn’t sound like that would work very well.

So, who is really the gatekeeper in regard to the merits of any given CT scan given to the patient? But more importantly, how the hell can it transpire that radiation exposures are far higher than anybody apparently realized??? Radiation technology and radiation biology are mature sciences now. And presumably, radiologists are trained to pay attention to these kinds of details.

Where the HELL were the radiologists when these instances of excessive exposure were accumulating?? Isn’t that why we train them … to provide expertise in the use of ionizing radiation in medicine??  Were they busy? Did they have something else to do besides monitoring the use of radiation on actual patients?

Could it be that people in the CT business are more captivated by the industrial light and magic of imagery and special effects rather than the grubby details of dosimetry?

Heads on a Stick

4 Replies

As one of those poindexters who actually likes to watch Book TV on C-SPAN-2, I blundered into an interview of Naomi Prins. The host was Senator Bernie Sanders (I-VT). Prins is presently a Senior Fellow at Demos and has had careers at Goldman Sachs and Bear Stearns.

Prins has a good deal of interesting insight into how securities are engineered from subprime loans and stamped with ratings. What stands out is how artificial securities are as an asset. It’s like putting a step ladder on a canoe. The view is good, but evenually you’re going to get wet.

Securities are synthesized from dung and straw, drenched in investment sauce, and then nestled in decorative tins by white gloved MBA castrati to afford a “product”. Naturally, banks and ratings agencies assure us that the rating on the security is meaningful. After all, who is more sober and conservative than a banker?

Perhaps investment banking as it is now practiced should be regarded as a pathological condition- a form of predatory, sociopathic behavior worthy of a psychiatric profile? Investment banking is a profession dedicated to the proposition that the mere repackaging and skimming of the wealth of others is the desired outcome. It is a bubble industry specializing in puffery and deception.

My libertarian friends assure me that the free market place is the most natural and efficient form of economic intercourse. Of course, the problem is that there isn’t a substantially free market anywhere. We have regulated markets because some people invariably game the system at the expense of others, resulting in a convulsive discharge of legislation.

One could take a Darwinistic view and say that the victims of investment shenanigans are to blame for being greedy and uninformed. There is truth in caveat emptor, but one of the reasons we have civilization is to buffer out the harshness of life. How do you protect the greedy and uninformed from the greedy and deceitful? It is the eternal problem.

The most despicable part of the 2008-9 financial collapse is the lack of accountability on the part of the skunks who invented and promulgated the unstable investment devices.  Their heads should be impaled on sticks and planted in the financial districts for all to see. Figuratively, I suppose.

Thanksgiving Tofurky

4 Replies

This year we tried Tofurky along with turkey for the thanksgiving meal. While my expectations were low, I have to admit that the Tofurky wasn’t quite as nasty as I had imagined. It is a seitan/soy product textured to resemble meat. Truthfully, in texture it resembles a firm bologna or salami lunchmeat. The package recommends that it be sliced thinly.

One plate holds a Tofurky. Can you tell which one it is?

Buried in mashed potatoes and real turkey gravy, the Tofurky was moderately edible. It is hard to say just how thankful the pilgrims might have been if Squanto had brought Tofurky to the feast. I’ll wager that the soiree would have gone badly.

Placer Gold Mining in the Wilderness

3 Replies

I recently had the occasion to sit and talk to an independent gold miner. This fellow had spend many seasons in the Yukon doing placer mining and had a few useful things to say about it.

In my friends experience the Alaskan placer mining season is very short- just 100 days or 2400 hours per year.  In that time you have to get your operation in place and process enough gravel and sediment through the sluices or centrifuge to isolate enough gold to make the process profitable. Sluicing and centrifugation are just forms of classification and your system must be able to separate gold particles in a manner consistant with the particle size range prevalent in the claim.

It is not uncommon for gold to be heavily represented in the 400 mesh range, or ca 0.037 mm particle size. In the old days, miners recovered fine particulate gold using amalgamation. Some large operations like Ashanti Gold in Cripple Creek use cyanide heap leaching to isolate the fines.

Sluicing operations in Alaska require considerable cash input and preparation. Sluicing generates considerable suspended solid and turbidity in the streams and the EPA, BLM, and wildlife agencies will have to be satisfied that the environmental impact is understood and minimized. Permitting is therefore a major hurdle for potential sluicing operations beyond the small scale.

My friend said that continuous centrifugation was necessary to capture the 400 mesh gold fines in the district he worked. As the capital equipment requirements increase, the volume of sediment to be classified must be scaled up to bring a satisfactory return on investment. Manpower and ancillary equipment requirements increase correspondingly. Soon you have a camp to maintain, payroll, and a crew to feed. In remote locations, air cargo transport is necessary to bring in the machinery and supplies. There is no Home Depot down the road to supply duct tape. Just like on a trip to Mars, you have to anticipate all needs and haul it in ahead of time.

A modest mining effort soon becomes a large logistics and financing problem. It’s a wonder that anybody still does this kind of thing. But, yet, they do.

Hamthrax

Leave a reply

So, the slang name for the H1N1 swine flu is “hamthrax”. Pretty funny. I suppose it could be called spamthrax as well.

As a kid I lived for a time in an Iowa town that had a Hormel Spam processing plant. During the winter in particular, the town of Fort Dodge, Iowa, would smell like cooked Spam. Ft Dodge sits atop the Des Moines River valley. During the cold months the valley would fill to the brim with the odor of Spam. It was an odd experience to drive into town and be overwhelmed by the smell of potted spiced meat.

Ft Dodge was (is) also known for the vast gypsum deposit that sits underneath the area. The word was that hair from the hogs at Hormel was blended with the gypsum to add strength to the sheetrock that was produced. I don’t know if this is true, but it made a great story for countless toe-headed farm kids who drove by the gypsum plant and pondered how they got the hair from the hogs and into the wallboard.

Mole Day Thoughts on Lab Life

6 Replies

I have come to the realization that, after a career of avoiding it, I really dig physical organic chemistry. While I do have the synthetikkers love for developing a synthesis, I really enjoy taking the rare opportunity to do a focused study on a single transformation or compound.  It is a stylized form of play that any developmental psychologist would recognize. Discovery is about learning, just like play, and many of the exploratory behaviors observed in play apply just as well to discovery (well, except for hitting and crying).

One way a scientist learns is by doing a search for boundary conditions. Where or how in parameter space does a thing change? What is the best solvent for the desired outcome? What effect does stoichiometry have? Does dry, inert atmosphere really make a difference? What are the best leaving groups? Yes, it’s just research. But there is more.

In order to claim that you have expertise with a substance or process, you must have an understanding of how a process or substance behaves under a variety of conditions. If faced with a product that is off spec and the prospect of having to rework or remake, it is very helpful to understand what conditions lead to the off-normal outcome. Either the chemist sleuths each upset for a cause, or the chemist goes in the lab and purposely exposes the process to off-normal parameters and analyzes the outcome, or both. After a while, patterns begin to arise and trends become apparent. This is play.

Seems bloody obvious. But in a production environment the opportunity to explore  parameter space is often not possible. Favor almost always finds the more practical, though short term, fixes. Production managers are not always chosen for their focus on the long term. They are short term oriented- a necessary predilection for timely delivery of product on a tight timeline.

Part of a good process development program is a study of how the process behaves in various upset conditions. This is important for understanding the thermal safety issues, but it also is a good time to take snapshots of how the composition of the process system behaves when it is out of whack.  A reaction profile under conditions of reagent mischarges or off-temperature can give many clues as to the operating window of the process. It can also tell you something about the best way to do an in-process check and define flags for particular types of upsets.

Many companies do this, but a good many find a way to gloss over such work.

Balloon Boy Still Missing

1 Reply

So the breaking news in my neighborhood is that the Colorado Balloon Boy’s craft has landed, but the 6 year-old boy is missing. The balloon lifted off from a residence in Ft Collins and landed near Prospect reservoir, a few miles NE of Denver International Airport. He drifted at least 50 miles. Reportedly, the basket that was affixed to the balloon was not present at the landing site.

I can only say that as a former six year-old boy, I might not have been able to resist climbing into the balloon either.