Posted by TD Steiger, PhD on 2nd April 2013
One of the primary metrics by which a charitable organization is judged is the percentage of the donations that are actually delivered to those in need. In other words: overhead. At first glance this seems reasonable. After all, you would like the money you donate to go to the starving children or abused puppies or disabled vets rather than see it “wasted” on office supplies or – worse – line the pockets of administrators.
However, we don’t take this attitude when buying goods or services. When shopping for cars no one asks how much of the purchase price actually goes to buying the component parts, and how much goes to the CEO. When acting as consumers we look at the cost we pay and the benefit we receive. If the benefit is worth the cost then we happily pay it without worrying about what happens to the money after it leaves our hands.
Why do we have such a different attitude when donating to charity? And should we? What is the benefit we receive in this case?
If the benefit is simply a tax write-off or a warm fuzzy feeling then perhaps our attitude towards giving makes sense. The more puppies get rescued, the fuzzier the feeling, so low overhead is key. And the fact that there are always more puppies to rescue means we can enjoy a tax benefit in perpetuity.
But if the goal of charity is to actually solve a problem then maybe overhead isn’t the right metric at all. So argues Dan Pallotta in a talk delivered at a recent TED conference in Long Beach, California. The talk is compelling and entertaining and definitely worth a look. It is essentially a condensation of Pallotta’s books Charity Case and Uncharitable.
One of his main points is that part of what counts as “overhead” is the cost of marketing and development. In other words: the cost of growth. And by forcing charities to keep their overhead low what we are doing is ensuring that they will always remain small. Too small to actually resolve the problems they seek to address. The proper metric, he argues, is not the fraction of the money raised that goes to the cause, but rather the total amount of money that is delivered.
Pallotta is in a unique position to know whereof he speaks, having founded a for-profit fund-raising organization called Pallotta TeamWorks (PTW). After raising hundreds of millions of dollars for charitable causes PTW was driven out of business by lawsuits and the resultant negative press.
And this is where things get tricky.
From the perspective of the plaintiffs in these cases Pallotta was a charlatan who over-promised and under-delivered. But from Pallotta’s perspective he was ridden out of town on a rail by the very narrow-minded, short-sighted Puritanical views of charity that he decries in his TED talk.
So who is right?
According to Pallotta, the donations to a fund-raising event for one breast cancer charity plummeted from $71M when he ran the event to $11M after they severed ties with PTW and ran the event themselves the following year. This seems to drive home the point that overhead is irrelevant if you are delivering more money.
But clearly there has to be a limit. If you raise $1B and deliver only $1M to charity that is an indication of a problem, even though $1M is a lot of money. So where is the line and how should we draw it?
In the private sector there is (at least in principle) a check on this sort of abuse due to competition. If a company funnels too much of its profits to top Management they will be at a competitive disadvantage against a company that re-invests its profits into business development activities. And in a way it is competition of this sort that is driving overheads down in charitable organizations. Charities are competing to have the lowest overhead as a way of demonstrating their virtuousness to potential donors.
If we want charities to actually be effective at eliminating problems like poverty and homelessness then what is required is a cultural shift in the attitudes of the giving public. Instead of asking charities about their overhead, we should be asking them: What is the scope of the problem you are trying to fix, what resources are required to address a problem of that scope, and what is your plan for raising the required resources?
And Pallotta – love him or hate him – has at least begun the conversation required to effect such a shift.
Posted by Alex Ivaschenko on 30th October 2012
Optically clear sight glass compared to a non-lapped sight glass.
Looking inside a reactor chamber while the process is running can be a rich experience, literally. This type of experience goes on a resume of a progressive scientist and opens more career opportunities. This is one way of looking at the benefits of an optically clear sight glass. Another way to look at it is to recognize that the reactor under observation actually needs understanding of the process going on inside it. A better understanding of the process results in better control. Better control results in a better product, higher yields and lower production costs.
The benefits of a clear sight glass unarguably are very strong. In the picture we compare two sight glasses for optical clarity. Both sight glasses are NPT – threaded housing having glass fused to the metal. These are what is known as fused sight glasses, where the glass is melted inside the metal housing, then the glass cools down at the same time as the metal housing. The glass eventually solidifies, meaning it is no longer a liquid. The metal at that temperature is still hot as the glass continues to relax its stress post solidification. The glass is “annealing” at this temperature range. When the metal and the glass cool down to room temperature, the result is an inseparable assembly of glass and the metal. The product is mechanically very strong. The glass is literally fused to the metal and cannot be separated from it by force, only by chemically dissolving it. Mechanically, a fused sight glass is the safest type of sight glasses on the planet. They do not catastrophically break, they hold high pressures, can tolerate strong vibrational forces and large temperature swings. In every way, except one, fused sight glasses are superior to composite sight glasses, that is, assembled from discrete components.
The only potential disadvantage of a fused sight glass over a sight glass assembled from several components is the optical clarity. Potential that is, not actual. If a fused sight glass is lapped post fusing, this disadvantage goes away. By nature of melting the glass, simultaneous fusing it to metal and subsequent cooling, the glass becomes concave in the process. In other words, the glass surfaces are bowed, non-flat, lens-like, where the thickness of the glass in the center is thinner than at the walls. The glass during fusing “wets” the metal walls by capillary action and tends to creep up the wall surface. This is what makes fused glasses so strong in the first place and this “bowing” is inherent in all fused glasses if they are not post-lapped.
Post-lapped fused sight glasses are typically used in imaging systems requiring good optical clarity. Applications include in-tank camera systems, viewports for in- reactor cameras, as well as windows for a laser sensor.
Posted by Alex Ivaschenko on 16th June 2012
Sealing glass to metal creates a hermetic seal between two dissimilar materials. Choosing the proper sealing method is critical for designing sight glasses and viewports. Some of the main sealing methods are:
- - Fusing glass to metal
- - Bonding sapphire or quartz to metal with adhesives
- - Brazing sapphire or quartz to metal
- - O-ring seals
- - Metal seals, typically C-seals
Borosilicate glass is fused to a stainless steel housing.
It seems logical for the glass to flow out from the metal housing at temperature and pressure as the metal expands when hot. This is a very reasonable engineering observation. However, this does not happen because the housing is compressing the glass at its maximum yield stress. This is a very strong compression. In other words, the metal housing is under constant hoop stress and when the housing expands at temperature, there is no dimensional expansion, only relaxation of the hoop stress. Dimensionally the housing maintains the same internal diameter as when it’s cold. Only at relatively high temperature the housing completely relaxes the hoop stress and then starts to increase its I.D., and O.D.
During sight glass fabrication the glass and the metal housing, both, are heated above 950 degrees C. The glass melts inside the housing and fuses to the metal wall. The glass and the metal become inseparable, this is the effect of molecular tension of liquid glass and the roughened surface of the inner metal wall. On the cooling down cycle, the glass anneals and becomes solid, now permanently fused to the housing. At this point the temperature is still above 700 degrees C. As cooling continues, the metal now collapses onto the solid glass and develops a permanent hoop stress.
The final product thus becomes as strong as the metal. Fused sight glasses are the strongest of any kind. Assemblies with O-rings, gaskets, thick glass, are an order of magnitude weaker to rupture than fused sight glasses. These have been tested at temperate and pressure applied at the same time. The proof pressure is approximately 4X of the rated pressure at the maximum rated temperature. At room temperature these have been tested to 9,000 psi with no damage. At over 9,000 psi the glass develops cracks, but still stays in place, does not fly out. There is no sudden glass failure as with the assembled types.
Bonding glass to metal
Bonding glass to metal is a popular method for applications requiring low cost alternatives to brazing. Another advantage of organic sealing is relative elasticity. Organic bonding materials and can create a stronger seal than brazing because of forgiving CTE mismatch between crystalline window and the metal housing. Bonding materials are available meeting the FDA requirements for food applications, 3-A Standards, or high-strength requirements for high pressure and high temperature applications in downhole cameras.
Brazing sapphire or quartz into metal
Brazing sapphire or quartz into metal or other crystalline housings is designed for high temperature applications. Also, brazing quartz and sapphire into housings is used for vacuum application where clean He-leak-tight seals are required. For operating temperatures are up to 1000°C quartz or sapphire can be brazed directly into a housing made of alumina, or yttria stabilized zirconia, (YAG-stabilized zirconia). The most common sight glasses with brazed windows have a metal housing, not a crystalline housing. Typically, quartz or sapphire is metallized with Titanium and then subsequently brazed with a silver-based material into a Kovar sleeve. Then the sleeve with the brazed window is welded into a metal housing, typically Inconel 718, which retains its strength up to 700°C. An intermediate Kovar sleeve is required to accommodate a CTE mismatch between the housing and the crystalline windows materials.
Sapphire is brazed to Niobium metal.
Brazing process of sapphire into Niobium is similar to brazing quartz into Kovar. Because Niobium closely matches CTE of sapphire, the sleeve can be made thicker allowing higher operating pressures of the sight glass assembly.
O-rings sealing glass
O-rings sealing glass is a simple method widely used in sight glass designs. O-rings sandwich a glass disk and create a seal. For semiconductor or pharmaceutical applications, Viton or Kalrez materials are commonly selected materials for elastomer O-rings for temperatures up to 327°C (Kalrez) and pressures up to 2,000 psi. In plasma chambers elastomer O-rings cannot be used as these materials eventually harden in presence of strong UV light, and therefore lose their sealing ability.
C-seals are a good replacement for elastomer O-rings.
Crossection of a “C” metal seal is in the shape of the letter “C”, therefore the name. C-seals come is a external pressure or internal pressure variety, where the C facing toward the pressure is the internal pressure seal. C facing away from the center of the seal is for external pressures. For high temperatures, C-seals made of Waspalloy is the preferred choice.