Abstract: A centrifuge for continuously separating the various constituents of blood or other biological fluids includes a rotating bowl having high-G and low-G walls. An inwardly directed ramped surface on the high-G wall interacts with an interface region between the separated fluid constituents to provide an optically detectable indication of the position of the interface between the high-G and low-G walls. An optical sensor sensing each passage of the ramped surface past a point develops a changing signal indicative of the interface position. Signal processing circuitry responsive to the signal measures such signal parameters as peak amplitude, signal area and signal shape. By so monitoring these signal parameters, a better indication of actual interface position between the high-G and low-G walls can be obtained. This, in turn, results in better control over centrifuge operation and improved separation of the desired fluid components.

Abstract: The invention relates to a copolyester, having (a) a repeat unit of a dicarboxylic acid component, having from 80 to 100 mole % terephthalic acid or the corresponding ester thereof, and from 0 to 20 mole % of a modifying aromatic dicarboxylic acid having less than or equal to 20 carbon atoms or the corresponding ester thereof, wherein the total mole % of dicarboxylic acid component is equal to 100 mole %; and (b) a repeat unit of a glycol component, having from 5 to 85 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol, ethylene glycol of from 15 to 95 mole %, and at least 1 mole % of a modifying glycol having from 3 to 16 carbon atoms, wherein the total mole % of glycol component is equal to 100 mole %. The invention also relates to a method of making the copolyester described above. The invention also relates to articles made from the copolyesters described above. The invention further relates to a method of determining the melt strength and sag of a polyester.

Abstract: A blend of polycarbonates of dihydroxydiphenyl cycloalkanes and optionally 4,4'-isopropylidenediphenol with polyesters from terephthalic acid, isophthalic acid, ethylene glycol and 2,2,4,4-tetramethyl-1,3-cyclobutanediol, having the advantage of being colorless and providing an unexpected amount of impact strength, hardness and heat resistence. The polymer blends are especially suitable for the manufacture of clear molded articles, fibers, sheeting, and film.

Abstract: The invention relates to a copolyester, having (a) a repeat unit of a dicarboxylic acid component, having from 80 to 100 mole % terephthalic acid or the corresponding ester thereof, and from 0 to 20 mole % of a modifying aromatic dicarboxylic acid having less than or equal to 20 carbon atoms or the corresponding ester thereof, wherein the total mole % of dicarboxylic acid component is equal to 100 mole %; and (b) a repeat unit of a glycol component, having from 5 to 85 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol, ethylene glycol of from 15 to 95 mole %, and at least 1 mole % of a modifying glycol having from 3 to 16 carbon atoms, wherein the total mole % of glycol component is equal to 100 mole %. The invention also relates to a method of making the copolyester described above. The invention also relates to articles made from the copolyesters described above. The invention further relates to a method of determining the melt strength and sag of a polyester.

Abstract: The invention relates to a copolyester containing (a) a dicarboxylic acid component having from about 80 to 100 mole % terephthalic acid or the ester thereof; less than or equal to 20 mole % of an aromatic dicarboxylic acid having up to 20 carbon atoms or the ester thereof; and less than or equal to 10 mole % of an aliphatic dicarboxylic acid or an ester thereof having up to 16 carbon atoms; and (b) a glycol component having from about 25 to 85 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol, from about 15 to 75 mole % ethylene glycol; and less than or equal to 10 mole % of a diol having 3 to 16 carbon atoms, wherein the total mole % of the dicarboxylic acid component is 100 mole % and the total mole % of the glycol component is 100 mole %. The invention further relates to a process for preparing the above-identified copolyester.

Abstract: Disclosed are clear blends comprising:(A) from 1 to 99 percent by weight of a polycarbonate comprising a diol component comprising from 5 to 100 mol percent units of a diphenol or mixture of diphenols having the formula ##STR1## (B) from 1 to 99 percent by weight of a polyester comprising (a) a dicarboxylic acid component comprising from 80 to 100 mol percent 1,4-cyclohexane-dicarboxylic acid units; and from 0 to about 20 mol percent modifying dicarboxylic acid units having from 2 to 20 carbons, and(b) a glycol component comprising from 10 to 75 mol percent 2,2,4,4-tetramethyl-1,3-cyclobutanediol units, from 25 to 90 mol percent 1,4-cyclohexanedimethanol units, and from 0 to 10 mol percent modifying glycol units having 2 to 16 carbons,wherein the total units of said polyester is equal to 200 mol percent; wherein said blend is clear and the total weight percent of said polycarbonate (A) and said polyester (B) is equal to 100 weight percent.

Abstract: A digital control device and method are provided for controlling functions such as volume and tuning for an electronic radio in response to a digital rotary switch. The apparatus includes a digital switch movable to a plurality of positions and which has a plurality of digital outputs to represent the positions. Control increments corresponding to an amount of rotation and rate of rotation of the switch are stored in a memory. The rotary switch output is periodically sampled to determine when switch movement occurs and to further determine the direction of switch rotation based on a sequence of the plurality of digital outputs. The rate of rotation of the rotary switch is then determined from counting changes in position of the switch over a sampling time A control increment is looked up in the memory that corresponds to the determined rate. The control increment is then used to change a digital output signal for controlling the electronic device.

Abstract: Disclosed are melt-processable wholly aromatic polyesters prepared from terephthalic acid, 2,6-naphthalenedicarboxylic acid, and hydroquinone.