摘要:
Novel polyethylene copolymer compositions prepared with a homogeneous catalyst system are characterized by having a unique high molecular weight, low comonomer (high density) fraction. These heterogeneous/homogeneous compositions may be prepared using a solution polymerization process in which the polymerization reactor contains a gradient in temperature, catalyst concentration or monomer concentration. The heterogeneous/homogeneous compositions of this invention are easily processed into films having excellent tear strengths and low hexane extractables.
摘要:
The cycle time for a rotomolding process is improved through the use of a molding material comprising a blend of at least two polyethylenes having narrow molecular weight distributions and homogeneous comonomer distributions. Alternatively, the molding temperature may be reduced to conserve energy and reduce energy costs. The polyethylene blend also has a narrow molecular weight distribution of less than 3 and a density of from 0.930 to 0.950 g/cc. Rotomolded parts prepared from the blend composition have excellent impact resistance and are also resistant to warpage. A preferred process employs a blend composition which contains a blend component having a higher molecular weight and a lower density than another blend component—this blend may be used to prepare rotomolded parts with warpage resistance and improved environmental stress crack resistance (ESCR). A highly preferred process uses a blend composition which further contains aminor amount (from 0.5 to 10 weight %) of a third ethylene blend component which has a higher molecular weight and density—this highly preferred composition may be used to prepare rotomolded parts having warpage resistance, very good ESCR and comparatively high modulus (or stiffness).
摘要:
Novel polyethylene copolymer compositions prepared with a homogeneous catalyst system are characterized by having a unique high molecular weight, low comonomer (high density) fraction. These heterogeneous/homogeneous compositions may be prepared using a solution polymerization process in which the polymerization reactor contains a gradient in temperature, catalyst concentration or monomer concentration. The heterogeneous/homogeneous compositions of this invention are easily processed into films having excellent tear strengths and low hexane extractables.
摘要:
The present disclosure provides for selectively enabling a primary communication channel upon receipt of enablement instructions received via a secondary communication channel. In some embodiments, a first intelligent electronic device (IED) may be connected to a second IED via a primary communication channel. In various embodiments, the primary communication channel may be selectively and/or temporarily enabled by transmitting an enablement instruction via a secondary communication channel. The secondary communication channel may be relatively more secure than the primary communication channel. In some embodiments, the secondary communication channel may also connect the first and second IEDs. Accordingly, the first IED may transmit an enablement instruction to the second IED in order to temporarily enable communication via the primary communication channel between the first and second IEDs.
摘要:
A method and apparatus are provided for processing a nucleic acid. The apparatus includes a disposable self-contained processing module that contains the nucleic acid and substantially all of the fluids to effect a nanoparticle hybridization test, a pump coupled to the processing module, a valving system disposed between the pump and processing module and a control system coupled to the pump and valving system causing the processing fluids to interact with the nucleic acid to effect a sandwich hybridization test using nanoparticles.
摘要:
A method is provided for preparing a test sample for detecting a predetermined target nucleic acid. The method includes the steps of providing a test probe comprising an oligonucleotide attached to a nanoparticle and providing a hybridization unit containing the test sample and the test probe, wherein said hybridization unit further includes a target sample substrate and a distribution manifold coupled to a first side of the substrate. The method further includes the steps of clamping a processing fluids manifold to the distribution manifold of the hybridization unit, denaturing the test sample and preparing the test sample for detecting the predetermined target nucleic acid by pumping a plurality of processing fluids between the processing fluids source manifold and distribution manifold to hybridize the test probe and predetermined target nucleic acid to the target sample substrate, to wash the hybridized sample and to amplify a detectable parameter of the hybridized sample.
摘要:
Adaptive circuits and methods for reducing vibration-induced bias errors in inertial sensors are disclosed. An adaptive circuit for reducing vibration or shock induced errors in an inertial sensor having a proof mass and sense electrode may include a sense bias voltage source, a charge amplifier, a means for detecting and/or anticipating an external vibration or shock on the inertial sensor, and a means for selectively dampening the proof masses and/or adjusting the gain sensitivity of the charge amplifier in response to an external vibration or shock on the inertial sensor. A dampening resistive element may be provided to dampen the proof mass motion in response to an external vibration or shock on the inertial sensor. Alternatively, or in addition, the gain sensitivity of the rate signal outputted by the charge amplifier can be adjusted in response to an external vibration or shock on the inertial sensor. During operation, the dampening and/or gain sensitivity can be adjusted to prevent signal saturation or clipping from occurring in the sense electronics, allowing the inertial sensor to continue functioning during periods of vibration or shock.
摘要:
The cycle time for a rotomolding process is improved through the use of a molding material comprising a blend of at least two polyethylenes having narrow molecular weight distributions and homogeneous comonomer distributions. Alternatively, the molding temperature may be reduced to conserve energy and reduce energy costs. The polyethylene blend also has a narrow molecular weight distribution of less than 3 and a density of from 0.930 to 0.950 g/cc. Rotomolded parts prepared from the blend composition have excellent impact resistance and are also resistant to warpage. A preferred process employs a blend composition which contains a blend component having a higher molecular weight and a lower density than another blend component—this blend may be used to prepare rotomolded parts with warpage resistance and improved environmental stress crack resistance (ESCR). A highly preferred process uses a blend composition which further contains a minor amount (from 0.5 to 10 weight %) of a third ethylene blend component which has a higher molecular weight and density—this highly preferred composition may be used to prepare rotomolded parts having warpage resistance, very good ESCR and comparatively high modulus (or stiffness).
摘要:
Devices and methods for reducing quadrature motion in a MEMS-type gyroscope are disclosed. A MEMS-type gyroscope in accordance with an illustrative embodiment of the present invention can include one or more proof masses configured to oscillate in a drive plane above a sense electrode for measuring Coriolis forces exerted on the one or more proof masses resulting from motion of the gyroscope about an input axis. One or more quad steering voltage members can be positioned adjacent each of the one or more proof masses and activated to electrostatically attract the proof masses toward the sense electrodes to reduce quadrature motion of the proof masses. A levitation force can be induced in certain embodiments to further reduce quadrature motion of the proof masses, if desired.
摘要:
Methods of fabricating thinned comb MEMS devices are disclosed. A comb drive device in accordance with an illustrative embodiment of the present invention can include a number of interdigitated comb fingers some of which have a reduced thickness along at least a portion of their length relative to other comb fingers.