Spectroscopic Analysis of the Kinetics of Host-Guest Chemistry Abstract

Host-guest chemistry refers to the chemistry in which a host and a guest molecule come together to form an inclusion complex. These complexes are utilized in numerous fields, including pharmaceuticals, agriculture, and cosmetics. This study focuses on the kinetic and thermodynamic behavior of a guest molecule, Brooker\u27s merocyanine, in β-cyclodextrin and its different derivatives (the hosts) at a fundamental level in an attempt to increase stability of the complexes. UV-Vis spectroscopy was used to study the kinetic stability of Brooker\u27s merocyanine\u27s unique, energy dependent isomerization pathway inside the cavity of the host molecule in solution. It was found that when the guest molecule is in acidic conditions, it will isomerize more quickly from the trans form to the cis form when inside the cavity compared to solution; also, the cyclodextrin derivatives showed minimal differences on the rate of isomerization. Under basic conditions, it is well known that the guest molecule will isomerize from the cis form to the trans form with a required input of energy in solution; however, we found that no additional UV energy is needed for isomerization in complex. Fluorescence spectroscopy was used to study the thermodynamic stability of this system to determine how well the Brooker\u27s merocyanine interacts with different cyclodextrin derivatives

Cogeneration: A Successful Response to the Energy Crisis?

This article examines the concept of cogeneration, a term for the simultaneous production of both electricity and other useful energy in a single facility by a cascading use of heat energy. It analyzes the rise of cogeneration through the lens of the Public Utility Regulatory Policies Act of 1978 ( PURPA ), enacted by Congress to improve the distribution of electric energy and encourage the conservation of resources, as well as the efforts of the Federal Energy Regulatory Commission ( FERC ) to encourage cogeneration. This article discusses a number of the issues raised and left unresolved by this federal policy of encouraging the development of cogeneration energy sources. It describes the attraction of cogeneration in an era of rising energy costs, and then goes on to discuss the legislative and administrative responses to the prospect of expanded cogeneration. Finally, it explores the impact of cogeneration on utilities, as well as the efects of the policy on regulatory control of utilities

The Efficiency of Self-Regulated Payments Systems: Learning From the Suffolk System

This paper analyzes the operation of the Suffolk System, an interbank note-clearing network operating throughout New England from the 1820s through the 1850s. Banks made markets in each other's notes at par, which allowed New England to avoid discounting of bank notes in trade. Privately enforced regu- lations prevented free riding in the form of excessive risk taking. Observers of the Suffolk System have been divided. Some emphasized the stability and effi these arrangements. Others argued that the arrangements were motivated by rent-seeking on the part of Boston banks, and were primarily coervice and exploitative. In the neighboring Mid-Atlantic states, regulations limited the potential for developing a regional clearing system centered in New York City on the model of the Suffolk System. This difference makes it possible to compare the performance of banks across regulatory regimes to judge the relative merits of the sanguine and jaundiced views of the Suffolk System. Evidence supports the sanguine view. New England's banks were able to issue more notes and these notes traded at uniform and low discount rates compared to those of other banks. An examination of the balance sheets and stock returns of Boston and New York City banks indicates that the stock market perceived that bank lending produced less risk for bank debt holders in Boston than in New York. The benefits of the system extended outside of Boston. Peripheral New England banks displayed high propensities to issue notes, and wer able to maintain low specie reserves. Boston banks did not show high profit rates or high ratios of market-to-book values of equity; thus there is no evidence that Boston banks extracted rents from their control of the payments system.

Transient Pressure Test Article Test Program

The Transient Pressure Test Article (TPTA) test program is being conducted at a new test facility located in the East Test Area at the National Aeronautics and Space Administration's (NASA's) Marshall Space Flight Center (MSFC) in Huntsville, Alabama. This facility, along with the special test equipment (STE) required for facility support, was constructed specifically to test and verify the sealing capability of the Redesigned Solid Rocket Motor (RSRM) field, igniter, and nozzle joints. The test article consists of full scale RSRM hardware loaded with inert propellant and assembled in a short stack configuration. The TPTA is pressurized by igniting a propellant cartridge capable of inducing a pressure rise rate which stimulates the ignition transient that occurs during launch. Dynamic loads are applied during the pressure cycle to simulate external tank attach (ETA) strut loads present on the ETA ring. Sealing ability of the redesigned joints is evaluated under joint movement conditions produced by these combined loads since joint sealing ability depends on seal resilience velocity being greater than gap opening velocity. Also, maximum flight dynamic loads are applied to the test article which is either pressurized to 600 psia using gaseous nitrogen (GN2) or applied to the test article as the pressure decays inside the test article on the down cycle after the ignition transient cycle. This new test facility is examined with respect to its capabilities. In addition, both the topic of test effectiveness versus space vehicle flight performance and new aerospace test techniques, as well as a comparison between the old SRM design and the RSRM are presented

Lee-Yang Property and Gaussian multiplicative chaos

The Lee-Yang property of certain moment generating functions having only pure imaginary zeros is valid for Ising type models with one-component spins and XY models with two-component spins. Villain models and complex Gaussian multiplicative chaos are two-component systems analogous to XY models and related to Gaussian free fields. Although the Lee-Yang property is known to be valid generally in the first case, we show that is not so in the second. Our proof is based on two theorems of general interest relating the Lee-Yang property to distribution tail behavior.Comment: We changed the title to emphasize Gaussian multiplicative chaos. Theorem 11, giving criteria for when some zeros are not purely imaginary, has been considerably strengthened. This yields a correspondingly improved result for continuum complex Gaussian multiplicative chaos in Proposition 1