摘要:
A method for obtaining redispersible powders of a copolymer having a dynamic glass transition temperature, T.sub.max, below 150.degree. C., by spray drying an aqueous dispersion thereof having a minimum film forming temperature, MFT, using an inlet temperature T.sub.i and an outlet temperature T.sub.o such that MFT
摘要:
What are disclosed are methods for dispersing a powdered salt-forming synthetic resin in water in the presence of an agent forming a salt with said resin, methods for coating pharmaceutical dosage forms with a dispersion made by such a method, and powdered mixtures of a salt forming resin and salt forming agent for dispersion in water.
摘要:
Coating materials for pharmaceutical dosage forms contain, besides the conventional liquid or solid additives for pharmaceutical coatings, a binder comprising a synthetic polymer, prepared by emulsion polymerization, having 5 to 100% by weight of units derived from monomers of the formula ##STR1## wherein R.sub.1 is a hydrogen atom or a lower alkyl group, R.sub.2 is an alkylene or aralkylene group having at least 3 carbon atoms in the chain between the amino nitrogen and the ester oxygen atom of which at least one is tertiary or quaternary, and R.sub.3 and R.sub.4 are lower alkyl radicals or together with the amino-nitrogen atom form a heteroaliphatic ring, and, optionally, additional comonomer units.
摘要:
A time-release laminar pharmaceutical composition, comprised of rolled or folded layers of a polymer film, that contain a pharmaceutically active substance, in which the outer surface area of the polymer film which contains the active substance, and which is accessible to the digestive juices, amounts to at most 25% of the entire surface area in the rolled or folded state, and the rolled or folded layers adhere to one another in such a way that the laminar form of medication maintains its rolled or folded form for a period of at least one hour in the release test according to USP 23, Method A, apparatus 2, at 37° C. and 50 rpm, in artificial gastric juice, and at least 30% of the active substance contained in it is released in the rolled or folded state.
摘要:
The invention relates to aqueous dispersions containing A. C.sub.6-22 carboxylic acids and/or resinic acids and B. C.sub.6-22 oxoalcohols alkoxylated with 2 to less than 6 mol C.sub.2-4 alkylene oxides for deinking printed wastepaper.
摘要:
A unity gain amplifier of the diamond follower type provides the combination of negligible input offset voltage, high slew rate, and high bandwidth by providing first and second opposite polarity current mirror circuits which respond to currents flowing through first and second input transistors to boost current available to charge parasitic capacitances during fast rise times and fast fall times of an input pulse. The rapid charging and discharging of the parasitic capacitances eliminates degradation in the rise and fall times of an output pulse produced by the unity gain amplifier. The gains of the first and second current mirror circuits have values that result in critically damped high frequency response of the unity gain amplifier in response to high speed transistions of the input signal. Darlington output stages are used to avoid frequency response peaking due to current gain rolloff of the output transistors at high currents and high frequencies. The unity gain amplifier is used in high performance operational transconductance amplifier.
摘要:
A unity gain amplifier of the Diamond follower type provides the combination of negligible input offset voltage, high slew rate, and high bandwidth by providing first and second opposite polarity current mirror circuits which respond to currents flowing through first and second input transistors to boost current available to charge parasitic capacitances during fast rise times and fast fall times of an input pulse. The rapid charging and discharging of the parasitic capacitances eliminates degradation in the rise and fall times of an output pulse produced by the unity gain amplifier.
摘要:
To eliminate or suppress amplifier noise in amplifiers (6, 7) connected to a semiconductor light sensor, for example of a charge coupled type, in which the noise introduced by the amplifiers has a frequency spectrum which is low with respect to the clock frequency of operation of the sensor, the minimum value signal from the light sensor, as amplified, is determined; the maximum value of the signal, as amplified, is determined; and a reference is derived based on the minimum value, for example by clamping the minimum value, or utilizing the minimum value as a dynamic reference for subtraction from the maximum value, to thereby eliminate the effect of low-frequency shift of signals due to low-frequency noise of the amplifiers; various circuits may be used, such as clamping circuits (FIG. 3), threshold or non-additive mixing circuits (FIGS. 4, 5) coupled to a subtraction stage (24), band-pass filtering and envelope demodulation (FIG. 6: 28, 29, 30) or synchronous demodulation (FIG. 7: 34, 35) using the scanning clock frequency (36, 37) for synchronous demodulation, coupled with frequency limiting the output to, for example, one-half clock frequency in a low-pass filter (39).
摘要:
For reduction of the relative noise amplitude a modulator or chopper stage is provided in front of the input of a video preamplifier and at the preamplifier output balanced demodulators are provided with a subtraction circuit combining their outputs. Preferably the carrier wave used for chopping or modulation is applied to the demodulators for synchronous demodulation, with a phase shifter if necessary in the carrier supplied to the demodulators for compensation of the signal propogation time through the preamplifier.
摘要:
Signals are picked off from semiconductor image or line sensors in clock pulse intervals corresponding to successive picture elements (in order to improve the signal-to-noise ratio, an amplifier with a high input resistance is used, the charge of the output capacitance of the sensor produced at the instant of the last clock pulse is substantially maintained during a first part of the clock interval, so that the full amplitude can be picked off after transients have died down and thereafter, in a second part of the clock pulse interval, the charge is drained away.