The recent development by Casio of the hand-held ClassPad 300 device raises a number of important questions for the design of mathematical learning experiences for students. This paper provides a brief description of the ClassPad 300 and its mathematical capabilities, followed by a description of the idea of an eActivity, well provided for in the operating system of the device. As their name su...

Insiders trade not only because they have private information about their companies but also because of other exogenous reasons. Therefore, it is important to control for exogenous trading needs in empirical studies regarding insider trading. Lee (1997) shows that insider trading is not closely related to the long-term performance of primary seasoned equity offering firms. This paper examines w...

Data from the Visual and Infrared Mapping Spectrometer (VIMS) on Cassini during its flyby of the Moon in 1999 show a broad absorption at 3 micrometers due to adsorbed water and near 2.8 micrometers attributed to hydroxyl in the sunlit surface on the Moon. The amounts of water indicated in the spectra depend on the type of mixing and the grain sizes in the rocks and soils but could be 10 to 1000...

A high-gain harmonic-generation free-electron laser is demonstrated. Our approach uses a laser-seeded free-electron laser to produce amplified, longitudinally coherent, Fourier transform-limited output at a harmonic of the seed laser. A seed carbon dioxide laser at a wavelength of 10.6 micrometers produced saturated, amplified free-etectron laser output at the second-harmonic wavelength, 5.3 mi...

A simple method to fabricate circular microchannels in polydimethylsiloxane (PDMS) is presented and used for facil single cell trapping at low vacuums. A coating of liquid PDMS is applied on the walls of square microchannels, to give them a circular cross section. Diameters ranging from few micrometers to few hundreds of micrometers were achieved. Different coating conditions were systematicall...

We report the generation of up to 0.7 mW of narrow-linewidth (<60-MHz) radiation at 3.3 micrometers by difference frequency mixing of a Nd:YAG-seeded 1.6-W Yb fiber amplifier and a 1.5-micrometers diode-laser-seeded 0.6-W Er/Yb fiber amplifier in periodically poled LiNbO3. A conversion efficiency of 0.09%/W (0.47 mWW-2 cm-1) was achieved. A room-air CH4 spectrum acquired with a compact 80-m mul...

The novel SiO2 net-like nanobelts have been successfully fabricated on Au-coated Si substrates by a simple thermal evaporation of CdS powder. The as-synthesized SiO2 nanostructures were characterized by using scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive spectroscopy (EDS), respectively. The as-grown SiO2 net-like nanobelts are rather uniformly...