Abstract: The present invention is directed to systems and methods for producing microarrays of biological samples using an improved slide platform, vacuum manifold, and variable pin contact velocity. Slides onto which spotting pins produce the microarray of biological samples are secured on a flat slide platform using magnetic unit bars. The vacuum manifold effects optimal cleaning of the spotting pins by inducing increased air flow and turbulence. By reducing the velocity of the spotting pins before or after contact with the blot pad or the microarray slide, the morphology of biological samples deposited may be kept uniform. Similarly, low impact and separating velocities while acquiring biological materials prevent the pins from being overloaded with solution on the outside of the pin and causing sample wastage and non-uniform spotting.

Abstract: A dual wheel assembly is formed by an inner wheel (10) and an outer wheel (30) coaxially mounted on a common hub (11). The inner wheel (10) has an inner tire (13) mounted on an inner wheel rim (12). The outer wheel (30) has an outer tire (13A) mounted on an outer wheel rim (32). The wheels (13, 13A) are of the same size, but the diameter of the outer wheel rim (32) is smaller than the inner wheel rim (12), to permit the inner tire (13) to pass over the outer wheel rim (32), thereby enabling the inner tire (13) to be removed without first removing the outer wheel rim (32). Removable bead seats (37, 40) are provided between the outer wheel rim (32) and its tire (13A). These bead seats are thicker than the corresponding bead seat(s) on the inner wheel (10) to compensate for the reduced diameter of the outer wheel rim.

Abstract: A dual wheel assembly is formed by an inner wheel (10) and an outer wheel (30) coaxially mounted on a common hub (11). The inner wheel (10) has an inner tyre (13) mounted on an inner wheel rim (12). The outer wheel (30) has an outer tyre (13A) mounted on an outer wheel rim (32). The wheels (13, 13A) are of the same size, but the diameter of the outer wheel rim (32) is smaller than the inner wheel rim (12), to permit the inner tyre (13) to pass over the outer wheel rim (32), thereby enabling the inner tyre (13) to be removed without first removing the outer wheel rim (32). Removable bead seats (37, 40) are provided between the outer wheel rim (32) and its tyre (13A). These bead seats are thicker than the corresponding bead seat(s) on the inner wheel (10) to compensate for the reduced diameter of the outer wheel rim.

Abstract: Addition of water to a gas phase olefin polymerization reactor in amounts greater than 3 ppmv permits an increase in the level of condensable gas and facilitates operation of the reactor at an elevated dew point by ameliorating electrostatic phenomena in the reactor; the process inhibits sheeting.

Abstract: An improved method of bed temperature control is provided by the coordinated manipulation of the water flow rate in one or more heat exchangers and cycle gas flow rate to the reactor.

Abstract: A low-cost detector of hydrogen-containing compounds in gas or thin-film samples is disclosed. The device preferably includes an alpha particle source, an energy degrading medium, a charged particle detector (e.g. a solid state diode detector), and amplification, threshold, counting, logic, timing circuits, humidity correction apparatus, and alarm/display. The invention relies upon the use of the energy degrading foil to pass selectively certain particles. Energetic alpha particles from a radioactive source enter the sample and hydrogen nuclei, or protons, elastically scattered by alpha particles, are able to penetrate the energy degrading foil which is thick enough to stop the alpha particles. The protons are detected and a suitable output signal can be produced to provide an accurate measure of the quantity of hydrogen in the gas or thin-film sample. The hydrogen detector can be combined with a smoke detector to produce an apparatus capable of detecting both smoke and hydrogen.