We describe a basic experiment for the undergraduate laboratory that demonstrates aspects of both the science and the art of precision electronic measurements. The essence of the experiment is to measure the resistance of a small length of brass wire to high accuracy using a simple voltage divider and a lock-in amplifier. By performing the measurement at different frequencies and different driv...

Astrophysical sources of energetic gamma rays provide the right conditions for maximal mixing between (pseudo)scalar (axion-like) particles and photons if their coupling is strong enough. This is independent of whether or not the axion interaction is standard at all energies or becomes suppressed in the extreme conditions of the stellar interior. The flux of such particles through the Earth cou...

Sabotage in Tournaments: Evidence from a Laboratory Experiment Although relative performance schemes are pervasive in organizations reliable empirical data on induced sabotage behavior is almost non-existent. We study sabotage in tournaments in a controlled laboratory experiment and are able to confirm one of the key insights from theory: effort and sabotage increase with the wage spread. Addit...

We conducted an experiment to explore the time-consistency of risk preferences in a multi-period betting game. Specifically, subjects planned their contingent betting decisions in advance then played the game dynamically later to determine whether their respective decisions matched. We found that subjects took more risk than planned in their initial bet and after losses. In addition, this incre...

Both multifractal and monofractal scaling of structure function exponents are observed in the turbulent magnetic fluctuations of the Swarthmore Spheromak Experiment plasma. Structure function and probability distribution function (PDF) analysis exhibits multifractal scaling exponents in low frequency, inertial range fluctuations of the turbulence but monofractal scaling in higher frequency, dis...

This laboratory exercise introduces students to concepts in recombinant DNA technology while accommodating a major semester project in protein purification, structure, and function in a biochemistry laboratory for junior- and senior-level undergraduate students. It is also suitable for forensic science courses focused in DNA biology and advanced high school biology classes. Students begin by ex...

We describe an undergraduate laboratory experiment on conductance steps observed to occur near integer multiples of 2e/h as nanocontacts form and break between gold wires in loose contact. This experimental arrangement was first described by Costa-Krämer et al. @Surf. Sci. 342, L1144 ~1995!#. A simple op-amp circuit in conjunction with an inexpensive storage oscilloscope suffice to observe the ...

We create an environment in which congestion forces agents to match inefficiently early. We then introduce one of two centralized clearinghouse mechanisms. One of these has been successfully used to halt this kind of unraveling in a number of labor markets, while the other has failed. When it is costly for Žrms andworkers to bemismatched comparedwith the costs of matching early, the experimenta...