This is surely an obscure topic, which pretty much only engineers care about, but here goes: The (NIST, a government agency) develops the (REFPROP) which calculates fluid properties for many industrial chemicals. Calculating such properties is critical for all sorts of engineering calculations. NIST charges $200 for this program, which seems very strange to me. If NIST came to the conclusion that such a product has significant enough positive externalities that the government should develop it (which seems relatively plausible to me), why do they charge money for it? Since software has a marginal production cost of zero, shouldn’t NIST’s goal be for people to use it as much as possible?

If it were free, students could use it and other developers could use it in their own programs, making it a lot more useful. Starting and ending time worksheets. NIST also seems to charge for a lot of other software it creates. I am not sure on their exact reasoning for charging for the software, but it is not too abnormal for government agencies to charge nominal fees to recoup the costs of various services, eg Drivers Licensing. While the marginal cost of the software is near zero, there is a substantial, and re-occuring fixed cost from development/support that needs to be recouped. 200$ does seem kind of steep, but I wonder what their over-all volume is, and how that cost would compare to privately developed software of that kind? For my field in EE most software packages cost 10,000$ per license on the low end, up to 50,000$ on the high end. I don’t know enough about fluids to estimate the actual cost of development for software like this, but it would stand to reason that a private company would produce a less expensive version if it were possible to be done profitably.

I also wonder about the legality of the government selling software. I was under the impression that any works produced by the government are in the public domain. I am not a lawyer, and copyright law is very complicated, but based on this:, it would seem that the work would be in the public domain unless it was created by a contractor(in which case it would be property of the contractor), or NIST is an exempt agency(they are not listed as such). BTW, Eric Lemmon is one of the developers for REFProp.

He mentions above that there is a student version available for teachers, students, researcher, and really anyone. This allows anyone to have (some) access to the libraries. This way students can learn but anyone that will be designing, manufacturing, or profiting from the software can help recoup some of the software development costs. Also, $200 is a tiny amount for the product, similar thermodynamic flash libraries can cost $5,000 to $50,000 (HYSYS, VGMSim, Design II, Multiflash, VGMSim). Our company bought the program and Mr. Lemmon was kind enough to respond to some questions I had emailed.

WTT User's Guide Speed of Sound (Liquid) REFPROP Model for Where appropriate, this web application obtains thermophysical property recommendations using REFPROP. REFPROP is an acronym for REFerence fluid PROPerties. This program, developed by the National Institute of Standards and Technology (NIST), provides tables and plots of the thermodynamic and transport properties of industrially important fluids and their mixtures with an emphasis on refrigerants and hydrocarbons, especially natural gas systems. REFPROP is based on the most accurate pure fluid and mixture models currently available. Naruto ninja heroes 3 for laptop cso. It implements three models for the thermodynamic properties of pure fluids: equations of state explicit in Helmholtz energy, the modified Benedict-Webb-Rubin equation of state, and an extended corresponding states (ECS) model. By using an equation of state to represent thermodynamic properties, a wide range of fluid properties are guarenteed to display thermodynamic consistency.