Microminiature gas chromatographic column

Techniques commonly used for fabrication of integrated circuits are utilized to produce long capillary tubes for microminiature chromatographs. Method involves bonding of flat silicon plate to top of spirally grooved silicon chip to close groove and form capillary column

Recent Applications of the Simple Hydrocarbon Cyclooctatetrene as a Starting Material for Complex Molecule Synthesis

Cyclooctatetraene [COT], a simple non-aromatic cyclic polyene, is capable of undergoing a variety of oxidation and cycloaddition reactions to afford polycyclic structures. In addition, complexation of COT or the cycloaddition products with transition metals facilitates bond formation. Recent developments in the reactivity of COT and application to the synthesis of naturally occurring and non-naturally occurring compounds is reviewed

Nondispersive infrared analyzer for specific gases in complex mixtures

Analyzer identifies and measures particular diatomic or polyatomic gases in complex gas mixtures. Mixing of absorption effects on light energy passing through gases to photodetector produces a signal component that is related to the absorption caused by reference-gas component in unknown gas mixture

The two components of the SO(3)-character space of the fundamental group of a closed surface of genus 2

We use geometric techniques to explicitly find the topological structure of the space of SO(3)-representations of the fundamental group of a closed surface of genus 2 quotient by the conjugation action by SO(3). There are two components of the space. We will describe the topology of both components and describe the corresponding SU(2)-character spaces by parametrizing them by spherical triangles. There is the sixteen to one branch-covering for each component, and the branch locus is a union of 2-spheres or 2-tori. Along the way, we also describe the topology of both spaces. We will later relate this result to future work into higher-genus cases and the SL(3,R)-representations

Gas chromatograph injection system

An injection system for a gas chromatograph is described which uses a small injector chamber (available in various configurations). The sample is placed in the chamber while the chamber is not under pressure and is not heated, and there is no chance of leakage caused by either pressure or heat. It is injected into the apparatus by changing the position of a valve and heating the chamber, and is volatilized and swept by a carrier gas into the analysis apparatus

Reactivity of acyclic (pentadienyl)iron(1+) cations: Synthetic studies directed toward the frondosins

A short, 4-step route to the scaffold of frondosin A and B is reported. The [1-methoxycarbonyl-5-(2′,5′-dimethoxyphenyl)pentadienyl]Fe(CO)3+ cation was prepared in two steps from (methyl 6-oxo-2,4-hexadienoate)Fe(CO)3. Reaction of this cation with isopropenyl Grignard or cyclohexenyllithium reagents affords (2-alkenyl-5-aryl-1-methoxycarbonyl-3-pentene-1,5-diyl)Fe(CO)3 along with other addition products. Oxidative decomplexation of these (pentenediyl)iron complexes, utilizing CuCl2, affords 6-aryl-3-methoxycarbonyl-1,4-cycloheptadienes via the presumed intermediacy of a cis-divinylcyclopropane

Dual mode laser velocimeter

Described is a laser Doppler velocimeter (LDV) which is capable of operating with a small focus diameter for analyzing fluid flows at low velocity with high spatial resolution, or with a larger focus diameter to measure fluid flows at higher velocities accurately. More particularly, this is an LDV in which a simple reversal of a lens pair will allow it to operate in the two focus diameter modes

A cusp electron gun for millimeter wave gyrodevices

The experimental results of a thermionic cusp electron gun, to drive millimeter and submillimeter wave harmonic gyrodevices, are reported in this paper. Using a "smooth" magnetic field reversal formed by two coils this gun generated an annular-shaped, axis-encircling electron beam with 1.5 A current, and an adjustable velocity ratio alpha of up to 1.56 at a beam voltage of 40 kV. The beam cross-sectional shape and transported beam current were measured by a witness plate technique and Faraday cup, respectively. These measured results were found to be in excellent agreement with the simulated results using the three-dimensional code MAGIC