2,204 research outputs found
Applying Strict Liability to Defective Products Litigation in West Virginia with Explanatory Emphasis upon Coal Mining Machinery Cases
Damages--Vehicle--Recovery of More Than Actual Physical Damage When the Vehicle is Partially Destroyed
Evidence--Expert Witness--Qualification of Specialist as Expert Witness in Medical Malpractice
A guide for field trips for teachers of consumer education
Thesis (Ed.M.)--Boston UniversityThe purpose of this study was to prepare a guide for field trips that would be of value to teachers of consumer
education courses at the secondary school level. The guide
is designed to be of use to teachers in planning field
trips in their own communities
Rapid rotation of micron and submicron dielectric particles measured using optical tweezers
We demonstrate the use of a laser trap (‘optical tweezers’) and back-focal-plane position detector to measure rapid rotation in aqueous solution of single particles with sizes in the vicinity of 1 μm. Two types of rotation were measured: electrorotation of polystyrene microspheres and rotation of the flagellar motor of the bacterium Vibrio alginolyticus. In both cases, speeds in excess of 1000 Hz (rev s−1) were measured. Polystyrene beads of diameter about 1 μm labelled with smaller beads were held at the centre of a microelectrode array by the optical tweezers. Electrorotation of the labelled beads was induced by applying a rotating electric field to the solution using microelectrodes. Electrorotation spectra were obtained by varying the frequency of the applied field and analysed to obtain the surface conductance of the beads. Single cells of V. alginolyticus were trapped and rotation of the polar sodium-driven flagellar motor was measured. Cells rotated more rapidly in media containing higher concentrations of Na+, and photodamage caused by the trap was considerably less when the suspending medium did not contain oxygen. The technique allows single-speed measurements to be made in less than a second and separate particles can be measured at a rate of several per minute
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