Here are essays and other writings of mine:

Rational Enlightenment Essays

No Will - Published by Joel Stevens on October 1, 2014

This essay discusses Sam Harris Free Will as well as its implications to compassion.

You Are Not Your Feelings - Published by Joel Stevens on December 25, 2015

This essay discusses the temporary nature of feelings.

Scoping - Published by Joel Stevens on October 1, 2014

This essay provides a framework for generating an appropriate or "right" response to any action.  It later extends the idea to any action that is undertaken.

Financial Essays

Measuring Returns - Published by Joel Stevens on January 5, 2017

This essay discusses various methods of calculating returns--simple rate of return, time weighted rate of return, and internal rate of return. In particular, the essay shows how each return is calculated, discusses common uses of those returns, and provides illustrative examples.

Cost of Leverage - Published by Joel Stevens on October 11, 2016

This essay relates to the "Cost of Leverage" of various different leveraged vehicles for investing in common shares, such as using margin or purchasing calls or warrants. Additionally, the essay explores the relationship of Cost of Leverage as the degree to which the call or put is in or out of the money.

Price and Returns - Published by Joel Stevens on December 31, 2016

This essay relates to the relationship between price and returns. In particular, the essay explores how returns develop over different holding periods, underlying value growth, and prices paid relative to that underlying value.

Why Hold Cash? - Published by Joel Stevens on November 15, 2014

This essay relates to determining if and how much cash should be held in a portfolio to produce superior long-term results. In particular, the essay is devoted to determining whether or not it makes sense to hold cash when compelling investment opportunities still exist, e.g., in order to take advantage of an upcoming downturn, based on valuation metrics, etc.

The Hurdle for Active Investors - Published by Joel Stevens on March 24, 2014

Building on "Holding Period, Taxes, and Required Performance", this essay focuses on determining how much an active investment must outperform a passive investment, such as an index fund, over the same investment period under various situations. Initially, the essay determines appropriate scenarios for comparing the active investment to the passive investment, based on a history of returns and dividend yields from 1871 to 2013. After determining these scenarios, a representative set of variables, including annualized gains, turnover, investment period, dividend yield, and tax rate, are modeled in order to determine the hurdle for the active investor.

Holding Period, Taxes, and Required Performance - Published by Joel Stevens on September 22, 2013

This essay focuses on the impact of taxes on pre-tax returns over various holding periods, from less than a year to 20 years. Initially, the essay shows the required pre-tax returns required to generate 10, 12, 15, and 20 percent after-tax returns for holding periods from 1 year to 20 years. After some discussion of this relationship, the essay then turns to holding periods of less than a year, and similarly calculates required pre-tax returns to generate 10, 12, 15, and 20 percent after-tax returns at different tax rates from 20% to 39.6%.

Know Your Graph - Published by Joel Stevens on April 2, 2012, Reformatted October 25, 2013

This essay provides a framework for understanding risk at its fundamental level. Instead of measuring risk via beta or volatility, as is the current common practice, risk should be understood as the probability of loss. Even further, since there are many possible future outcomes, results cannot be easily used to evaluate the risk undertaken to achieve those results. As an example, if one were to play Russian Roulette with 5 bullets in a 6-bullet chamber and happened to not die, the result of not-dying certainly does not indicate that there wasn't significant risk in playing the game. In this case, the risk was obviously 5/6 or 83.3% even though the outcome was positive. The essay then applies this process to evaluating the investment results of individuals or managers.

Scientific Papers

Sidewall Amino-Functionalization of Single-Walled Carbon Nanotubes through Fluorination and Subsequent Reactions with Terminal Diamines  - Nano Letters, 2003 - Joel L. Stevens, Aaron Y. Huang, Haiqing Peng, Ivana W. Chiang, Valery N. Khabashesku, and John L. Margrave - Department of Chemistry, Rice Quantum Institute and Center for Nanoscale Science and Technology, Rice University, Houston, Texas

Single-walled carbon nanotubes (SWNTs) with the N-alkylidene amino groups covalently attached to their side walls have been prepared starting from colloidal solutions of fluorinated SWNTs (fluoronanotubes) in terminal alkylidene diamines followed by heating at 70−170 °C. On the basis of data from thermal gravimetric and energy-dispersive X-ray analyses, the degree of SWNT functionalization achieved was estimated to be as high as 1 in 8 to 12 sidewall carbons. The demonstrated new C−N functionalization method provides a synthetic tool for binding amino acids, DNA, and polymer matrices to the side walls of the SWNTs as well as yields sidewall amino-functionalized nanotube precursors for the preparation of nylon−SWNT polymer materials.

Regiocontrolled [3+2] Quinone-Nitrile Oxide Entry to Type II Polyketide Building Blocks - Tetrahedron Letters, 2003 - Joel L. Stevens, Thomas D. Welton, Jay P. Deville, and Victor Behar - Department of Chemistry, Rice University, Houston, Texas

Bromine substituents on naphthoquinones effectively activate and orient the [3+2] dipolar cycloaddition reaction with nitrile oxides to generate regiodefined type II polyketide building blocks.

Nucleophilic Partners in the Tandem Conjugate Addition-Dieckmann Condensation Reaction: 1. synthesis of 1,2,3-trisubstituted naphthalenes. - Journal of Organic Chemistry, 2004 - Aaron D. Martinez, Jay P. Deville, Joel L. Stevens, and Victor Behar - Department of Chemistry, Rice University, Houston, Texas

The scope and limitations of the tandem conjugate addition-Dieckmann condensation for the construction of 1,2,3-trisubstituted naphthalenes is defined. Viable nucleophilic partners in this methodology include organocuprates, active methylenes, and a variety of heteroatom initiators.

DNA Computation - Joel L. Stevens

This is my paper from my high school science fair project. It summarizes three years of work related to using DNA to solve NP-complete problems, such as the subset sum and bin packing problems. I was awarded "Best in Biochemistry" at the Intel International Science Fair for this work in 2008. Here's a link to the awards.  Funnily enough, my paper did not win any awards because the judges indicated that "there was no way this could have been written by a high school student" and "it must have been done by his parents", despite the fact that my parents were an elementary school teacher and a high school english teacher.


Sidewall Functionalization of Single-Wall Carbon Nanotubes through C-N Bond Forming Substitutions of Fluoronanotubes  -  - U.S. Patent Number 7,452,519 - Khabashesku; Valery N. (Houston, TX), Margrave, legal representative; Mary Lou (Bellaire, TX), Stevens; Joel L. (Houston, TX), Derrien; Gaelle Armelle (Montpellier, FR), Margrave; John L. (Bellaire, TX)

The present invention is directed toward a method of sidewall-functionalizing single-walled carbon nanotubes (SWNTs) through C--N bond forming substitution reactions with fluorinated SWNTs (fluoronanotubes), and to the sidewall-functionalized SWNTs comprising C--N bonds between carbons of the SWNT sidewall and nitrogens of the functionalizing groups made by these methods. Furthermore, when diamine species are utilized as reactants, novel materials like crosslinked SWNTs and "nanotube-nylons" can be generated. In some embodiments, SWNTs with functional groups covalently attached to their side walls through C--N bonds are prepared by either the direct interaction of fluoronanotubes with terminal alkylidene diamines or diethanolamine, or by a two-step procedure involving consecutive treatments with Li.sub.3N in diglyme and RCl (R=H, n-butyl, benzyl) reagents. Evidence for sidewall attachment of amine-derived groups has been provided by Raman, FTIR, and UV-vis-NIR spectra, SEM/EDAX and TEM data, and thermal degradation studies. The demonstrated new C--N functionalization methods offer a wide range of further SWNT derivatizations, including their covalent binding to aminoacids, DNA, and polymer matrixes.