Abstract: A method of making a belt-creped absorbent cellulosic sheet includes compactively dewatering a papermaking furnish to form a nascent web having an apparently random distribution of papermaking fiber, applying the nascent web having the apparently random fiber distribution to a translating transfer surface that is moving at a transfer surface speed, belt-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a patterned creping belt, the belt-creping step occurring under pressure of at least 20 pounds per linear inch in a belt creping nip defined between the transfer surface and the creping belt. The belt is traveling at a belt speed that is slower than the speed of the transfer surface. The web is creped from the transfer surface and redistributed on the creping belt.

Abstract: A method of making a fabric-creped absorbent cellulosic sheet includes forming a nascent web from a papermaking furnish, the nascent web having a generally random distribution of papermaking fiber, transferring the nascent web having the generally random distribution of papermaking fiber to a translating transfer surface that is moving at a transfer surface speed, drying the web, to a consistency of from about 30 to about 60 percent, including compactively dewatering the web prior to or concurrently with transfer of the web to the transfer surface, fabric-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a creping fabric with a patterned creping surface, the fabric-creping step occurring under pressure in a fabric creping nip defined between the transfer surface and the creping fabric, the web being creped from the transfer surface and redistributed on the creping fabric.

Abstract: A method of making a fabric-creped absorbent cellulosic sheet includes compactively dewatering a papermaking furnish to form a nascent web having an apparently random distribution of papermaking fiber, applying the nascent web having the apparently random fiber distribution to a translating transfer surface that is moving at a transfer surface speed, and fabric-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a patterned creping fabric, the fabric-creping step occurring under pressure in a fabric creping nip defined between the transfer surface and the creping fabric, the web being creped from the transfer surface and wherein the creping fabric is adapted to contact the transfer surface and applies pressure to the web against the transfer surface such that the fibers of the web are redistributed on the creping fabric to form a web with a drawable reticulum.

Abstract: An absorbent sheet of cellulosic fibers includes a mixture of hardwood fibers and softwood fibers arranged in a reticulum having (i) a plurality of pileated fiber enriched regions of a relatively high local basis weight each extending a distance in the cross-machine direction (CD) of the sheet and interconnected by way of (ii) a plurality of lower local basis weight linking regions that each extend a distance in the machine direction (MD) of the sheet and whose fiber orientation is biased along the direction between pileated regions interconnected thereby. The relative basis weight, degree of pileation, hardwood to softwood ratio, fiber length distribution, fiber orientation, and geometry of the reticulum are controlled such that the sheet exhibits a percent CD stretch that is at least about 2.75 times the machine direction to cross-machine direction (MD/CD) dry tensile ratio of the sheet.

Abstract: An absorbent cellulosic sheet having a variable local basis weight includes a papermaking-fiber reticulum provided with (a) a plurality of elongated densified regions of compressed papermaking fibers, the densified regions being oriented generally along the machine direction (MD) of the sheet and having a relatively low local basis weight, as well as leading and trailing edges at their longitudinal extremities, and (b) a plurality of fiber-enriched, pileated regions connected with the plurality of elongated densified regions, the pileated regions having (i) a relatively high local basis weight and (ii) a plurality of cross-machine direction (CD) extending crests having concamerated CD profiles such that the extending crests of the pileated regions are arcuate and extend around the leading and trailing edges of the plurality of elongated densified regions.

Abstract: A bi-directional DC to DC power converter includes two DC sources, two inductors respectively connected to the two DC sources, a first switch and a second switch respectively connected to the two inductors, two capacitors respectively connected to the two switches, and a third switch connected between the two inductors. The first, second and third switches are respectively connected reversely with a diode in parallel. When the third switch is alternately turned on and off and the first and second switches are always turned off, the power converter operates as a boost power converter and electric energy flows from the two DC sources to the two capacitors. When the third switch is always turned off and the first and second switches are synchronously turned on or off, the power converter operates as a buck power converter and electric energy flows from the two capacitors to the two DC sources.

Abstract: Kitchen roll toweling having surprising softness, absorbency and bulk is formed from a furnish comprising long cellulosic fiber having: (i) average weight-weighted fiber length of at least 2.5 mm; coarseness at least 15.5 mg/100 mm; and a Canadian Standard freeness of at least 600 ml combined with (ii) short cellulosic fiber having an average weight-weighted fiber length of at most 1.9 mm having a Canadian Standard freeness of at least 500 ml in a weight ratio of short fiber to long fiber of at least 0.25 to 1.0 to form a nascent web having a consistency in the range from about 10% to about 35% which is rush transferred from one fabric to another at a speed differential of at least about 15%; and creping the web from a Yankee dryer while controlling the real crepe to at most 3% and thereafter converting the web to form a two ply product having a basis weight of at least 29 lb/rm and caliper of at least 220 mils/8 sheets.

Abstract: A UPS system includes one or more UPS units with identical or different capacities. A control circuit, used to control a DC/AC inverter of the UPS unit, includes a voltage feedback control circuit and a current feedforward control circuit. The voltage feedback control circuit is used to control the amplitude and the waveform of load voltage. The current feedforward control circuit is used to operate the DC/AC inverter of the UPS unit as a virtual fundamental resistor and a virtual harmonic resistor which are serially connected to an output terminal of the DC/AC inverter such that each UPS unit can be distributed to provide an output current according to the capacity ratio of the UPS system.

Abstract: An estimation method for residual discharging time of batteries includes the steps of: providing a set of battery-discharge-current intervals and a set of battery-discharge equations, setting discharge time of each battery-discharge-current intervals zero; detecting a discharge current, voltage and time of batteries; judging whether the discharge current exceeding all of the battery-discharge-current intervals; selecting one of the battery-discharge-current intervals and the associated battery-discharge equation according to the detected discharge current; calculating an estimation of residual discharging time; accumulating and recording the discharge time; judging whether the discharge voltage being lower than a predetermined value and calculating an estimation error of the residual discharging time; adjusting parameters of the battery-discharge equation for reducing the estimation error of the residual discharging time if the estimation error is greater than a predetermined error value.

Abstract: A three-leg power converter apparatus including first, second and third input/output ports, a three-leg bridge converter, a filter circuit, a decoupling circuit and a controller is presented. The three-leg bridge converter has three single-leg circuits, two DC terminals connecting to two terminals of the first input/output port, and three mid-terminals with each of them being formed by a middle point of one of the three single-leg circuits. The controller connects to the three-leg bridge converter for controlling an input or output current passing through each DC terminal and mid-terminal. The filter circuit connects between two of the mid-terminals and the second input/output port. The decoupling circuit has two terminals connecting to the second input/output port and another terminal connecting to a terminal of the third input/output port, with the third input/output port having another terminal connecting to the other mid-terminal that dose not connect with the filter circuit.

Abstract: A ripple voltage suppression apparatus includes a DC/DC converter and a control circuit. The DC/DC converter has a power electronic switch. The control circuit has a voltage detector detecting a DC output voltage of the DC/DC converter, a ripple voltage suppression circuit receiving the detected DC output voltage to generate an AC control signal for controlling an AC component of a duty ratio of the power electronic switch, an output voltage regulation circuit receiving the detected DC output voltage to generate a DC control signal for controlling an DC component of a duty ratio, an adder adding the AC and DC control signals to form a combined control signal, and a PWM circuit converting the combined control signal into a PWM signal to control the power electronic switch. Only the DC output voltage of the DC/DC converter has to be detected for the control circuit.

Abstract: The present invention relates to the creation of toweling with surprisingly high absorbency using a furnish comprising a major proportion of recycle furnish when the furnish is creped from a Yankee dryer coated with a creping adhesive comprising polyvinyl alcohol and an epichlorohydrin crosslinked polyamide creping adhesive at a consistency corresponding to a sheet temperature (immediately prior to the creping blade) of between 225° F. and 255° F. (107° C. and 124° C.), preferably ranging from about 230° F. (110° C.) up to about 250° F. (121° C.).

Abstract: An absorbent cellulosic sheet having variable local basis weight includes a papermaking-fiber reticulum provided with (i) a plurality of cross-machine direction (CD) extending, fiber-enriched pileated regions of relatively high local basis weight interconnected by (ii) a plurality of elongated densified regions of compressed papermaking fibers. The elongated densified regions have relatively low local basis weight and are generally oriented along the machine direction (MD) of the sheet and have an MD/CD aspect ratio of at least 1.5. The products are most preferably prepared by way of a compactive dewatering/wet crepe process.

Abstract: An improved method of controlling build-up of adhesive coating on a Yankee drying cylinder preferably includes intermittently: (a) increasing the add-on rate of resinous adhesive to the drying cylinder substantially above the steady-state add-on rate; (b) segregating the absorbent sheet product produced while the add-on rate of resinous adhesive to the drying cylinder is elevated above the steady-state add-on rate from absorbent sheet product accumulated during steady-state operation; and (c) while the add-on rate of resinous adhesive to the drying cylinder is increased above the steady-state add-on rate, stripping at least a portion of the adhesive coating from the drying cylinder with a cleaning doctor.

Abstract: An islanding detection apparatus for a distributed generation power system and a detection method therefor operates a power converter to act as a virtual capacitor or inductor at a frequency close to but unequal to that of a utility power system under abnormal condition of the utility power system. When power failure occurs in the utility power system, only the distributed generation power system supplies power to a load so that a load voltage has been changed in at least one of amplitude and frequency which can be immediately detected islanding phenomenon.

Abstract: An absorbent cellulosic sheet having variable local basis weight includes a papermaking-fiber reticulum provided with (i) a plurality of cross-machine direction (CD) extending, fiber-enriched pileated regions of relatively high local basis weight interconnected by (ii) a plurality of elongated densified regions of compressed papermaking fibers. The elongated densified regions have relatively low local basis weight and are generally oriented along the machine direction (MD) of the sheet and have an MD/CD aspect ratio of at least 1.5. The products are most preferably prepared by way of a compactive dewatering/wet crepe process.

Abstract: An active power filter includes an energy storage capacitor, an inverter, a filtering circuit and a controller. The inverter is controlled to act as a virtual resister at a fundamental frequency for compensating for the power loss of the active power filter, to act as a virtual capacitor at a fundamental frequency for compensating for a fundamental reactive power of the load, and/or to generate a harmonic current for suppressing the harmonic currents of specific orders of the load.

Abstract: A three-leg power converter apparatus including first, second and third input/output ports, a three-leg bridge converter, a filter circuit, a decoupling circuit and a controller is presented. The three-leg bridge converter has three single-leg circuits, two DC terminals connecting to two terminals of the first input/output port, and three mid-terminals with each of them being formed by a middle point of one of the three single-leg circuits. The controller connects to the three-leg bridge converter for controlling an input or output current passing through each DC terminal and mid-terminal. The filter circuit connects between two of the mid-terminals and the second input/output port. The decoupling circuit has two terminals connecting to the second input/output port and another terminal connecting to a terminal of the third input/output port, with the third input/output port having another terminal connecting to the other mid-terminal that dose not connect with the filter circuit.

Abstract: An improved creping adhesive is prepared by first reacting a dibasic carboxylic acid, or its ester, half-ester, or anhydride derivative, with a polyalkylene polyamine, preferably in aqueous solution, under conditions suitable to produce a water soluble polyamide. The water-soluble polyamide is then reacted with an epihalohydrin until substantially fully cross-linked, and stabilized by acidification with phosphoric acid at the end of the polymerization reaction to form a water-soluble poly(aminoamide)-epihalohydrin creping adhesive that is re-wetable and facilitates water spray removal of buildup so as to lengthen the life of the creping blades, with attendant significant decrease in downtime and maintenance.

Abstract: A bidirectional active power conditioner includes a DC side, a bidirectional DC/DC power converter, a DC/AC inverter and an AC side. The DC side electrically connects with a DC source while the AC side electrically connects with a load and an AC source. The bidirectional DC/DC power converter is controlled via high-frequency pulse width modulation (PWM) switching so as to generate a predetermined DC voltage or DC current while the DC/AC inverter is controlled to convert the predetermined DC voltage or DC current into a predetermined AC voltage or AC current.