Abstract: A safety system for a building has an earthquake detector circuit for detecting ground accelerations exceeding a threshold acceleration/frequency curve dividing safe and hazardous ground accelerations throughout a predetermined frequency range. The earthquake detector includes an accelerometer for measuring linear acceleration along an axis, and for generating an acceleration signal indicative of a magnitude of the measured acceleration. A filter circuit produces a filtered acceleration signal from the acceleration signal. The gain/frequency characteristic of the filter circuit is a reflection of the threshold acceleration/frequency curve, such that ground accelerations falling on the threshold acceleration/frequency curve yield a filtered acceleration signal having a substantially constant value throughout the frequency range.
Abstract: A compact digital imaging microscope includes a stage for holding a specimen, a lens assembly for collecting a beam of light transmitted through the specimen, and an adjustable beamsplitter assembly for splitting the beam between an eyepiece for viewing an image of the specimen and a CCD image detector to provide both a digital and an analog signal representing an image of the specimen. The use of a lens positioned along an optical path between the lens assembly and the image detector allows the image detector to be integrated compactly within the microscope and also allows the image detector to capture an image whose viewable area is roughly the same as that viewable through the eyepiece. Furthermore, all electrical connections (other than output and power supply connections which are located at the base of the microscope) are internalized within the microscope.
Type:
Grant
Filed:
March 29, 2001
Date of Patent:
August 27, 2002
Inventors:
Chak Sing Richard Yeung, Shao Hua Dai, Qian Xiao
Abstract: A method of developing and maturing somatic embryos in a growth environment, which method comprises manipulating the water availability of the growth environment using a physical means of control. The invention also provides a growth environment for maturing somatic embryos, wherein the water potential of the embryogenic tissue is manipulated to optimize somatic embryo development and maturation. The invention further relates to a somatic embryo matured by the method of the invention. In the invention, a physical means of control is used to affect the water potential of the embryogenic tissue and developing somatic embryos growth medium, rather than a chemical means such as the introduction of PEG, to stimulate the maturation of the embryos. The physical means may be operated, for example, by separating the somatic embryos from the growth medium by a porous support, or by introducing a gelling agent (e.g. gellan gum) into the growth medium in larger than normal quantities.
Type:
Grant
Filed:
August 17, 1998
Date of Patent:
March 13, 2001
Assignee:
Cellfor Inc.
Inventors:
Krystyna Klimaszewska, Benjamin C. S. Sutton, Daniel R. Polonenko, David R. Cyr, Thomas F. Stodola
Abstract: The invention is a load voltage and power control and supply system for the supply of power to a load for which, over particular periods of time, usually on a daily basis, it is desired to reduce power. The invention has particular application to street lighting systems in which, for a period of several hours during the night (when traffic is minimal and many people are asleep), the luminaires of the lighting system can operate at reduced power. The power control system is able to act as a voltage stabilizer as well as a controlled power reduction system. The power control system may operate the bank of spaced luminaires from a single control location. Moderately reduced power (say a 30% reduction in power) supplied to luminaires does not noticeably diminish the adequacy of the illumination provided. Further, the power control system reduces power in stepwise decrements each of which reduces power by a small amount insufficient to diminish noticeably the ambient illumination.