摘要:
Method for determining the size concentration, the particle size and the particle size distribution of natural and/or synthetic sizes in a paper stock by staining a sample of the particles (Ti) of the size with a fluorescent dye, light being radiated into the sample of fluorescent or fluorescently stained particles and scattered light and/or fluorescent light from the sample being recorded and evaluated, and use of this method for determining the particle size distribution of reactive size particles in the paper stock or in the white water of paper machines during papermaking.
摘要:
A method is disclosed of controlling a switched mode converter comprising a switch and for providing power to device having a load, comprising: in response to the load exceeding a first threshold, operating in a first mode, being a CCM; in response to the load exceeding a second threshold and not exceeding the first threshold, operating in second mode, being a BCM without valley skipping wherein the switching frequency increases with decreasing load; in response to the load exceeding a third threshold and not exceeding the second threshold, operating in a third mode, being a BCM with valley skipping, wherein the switching frequency depends on the load and the number of valleys skipped and is between a fixed upper and a lower switching frequency limit; and in response to the load not exceeding the third threshold, operating in a fourth mode, being a BCM with valley skipping, wherein the switching frequency depends on at least the load, and is between an upper and a lower switching frequency limit wherein the upper switching frequency limit decreases with decreasing load. A switched mode converter controlled by such a method is also disclosed.
摘要:
A power conversion controller for controlling the operation of a switch in a power conversion circuit, wherein the power conversion controller is configured to operate the switch according to: a variable frequency mode of operation for switching frequencies greater than a minimum threshold value; and a fixed frequency mode of operation at a switching frequency equal to the minimum threshold value.
摘要:
Consistent with an example embodiment, a circuit comprises a power factor correction stage having a DC input, a ground input, a DC output and a ground output. The circuit further includes a capacitor; a diode; and a discharge circuit. A first terminal of the diode is connected to an input of the power factor correction stage, a second terminal of the diode is connected to the first plate of the capacitor; and the second plate of the capacitor is connected to the other input of the PFC stage. The discharge circuit is connected to the capacitor and is configured to discharge the capacitor such that it contributes to the output of the PFC stage when the level of a signal at the input of the PFC stage falls below a threshold value.
摘要:
Aqueous alkyl ketene dimer dispersions which comprise at least 15% by weight of an alkyl ketene dimer and at least one water-soluble cationic starch, aluminum sulfate and at least one condensate of naphthalenesulfonic acid and formaldehyde or lignin sulfonic acid or in each case salts thereof, the dispersions comprising, based in each case on alkyl ketene dimer, from 2 to 50% by weight of aluminum sulfate, and in which the dispersions additionally comprise from 0.1 to 5% by weight of a saturated carboxylic acid having 1 to 10 carbon atoms, benzenesulfonic acid, p-toluenesulfonic acid and/or a mineral acid at an aluminum sulfate content of from 2 to 15% by weight, and the use of the dispersions as engine size and surface size for paper and paper products.
摘要:
A method for reorganizing performance quantity data in a segment of a non-volatile memory. The method encompasses the tasks or operations of generating a cohesive data block at an address space of a working memory, of performance quantity data from a first segment of the non-volatile memory and/or from the working memory, and of copying the data block to a predefined address space of the first or a second segment of the non-volatile memory in a block write operation, the performance quantity data of the data block in essence being written to the predefined address space simultaneously in the block write process.
摘要:
A drainage arrangement for a tailgate of a motor vehicle body has water outflow spouts in the inner panel of the tailgate. The water outflow spouts are arranged correspondingly to water outflow openings in a rear part or a rear-end trim panel of the body behind a vehicle license plate as viewed in relation to the direction of travel.
摘要:
A drainage arrangement for a tailgate of a motor vehicle body has water outflow spouts in the inner panel of the tailgate. The water outflow spouts are arranged correspondingly to water outflow openings in a rear part or a rear-end trim panel of the body behind a vehicle licence plate as viewed in relation to the direction of travel.
摘要:
The invention relates to a process in which a compound R1COOR3 (I) is made by a transesterification reaction of an ester compound R1COOR2 (II) with an alcohol R3OH (III) in the presence of a transesterification catalyst, wherein R1 is H or C1-4 alkyl or CH2═CR4—; R2 is C1-4 alkyl; R3 is selected from the group consisting of alkyl having at least 4 carbon atoms, cycloalkyl having at least 5 carbon atoms, aryl, aralkyl, alkaryl and amino alkyl; and R4 is —H or —C1-4 alkyl, wherein alcohol R2OH (IV) is formed as a byproduct and in which said byproduct (IV) is removed by distillation in the presence of an entrainer, in which the entrainer is a compound that suppresses the formation of an azeotrope between compound (II) and byproduct (IV). The process can be useful in the preparation of esters such as dimethyl amino ethyl(meth)acrylate. The invention also provides a method of separating alcohols and esters. In a further form of the invention a process of preparing esters by a transesterification process is provided in which the transesterification catalyst is homogenous.
摘要翻译:本发明涉及在酯交换催化剂存在下,通过酯化合物R1COOR2(II)与醇R3OH(Ⅲ)的酯交换反应制备化合物R1COOR3(Ⅰ)的方法,其中R1是H或C1- 4烷基或CH2-CR4-; R2是C1-4烷基; R 3选自具有至少4个碳原子的烷基,具有至少5个碳原子的环烷基,芳基,芳烷基,烷芳基和氨基烷基; R4是-H或-C1-4烷基,其中醇R2OH(Ⅳ)作为副产物形成,其中所述副产物(Ⅳ)在夹带剂存在下通过蒸馏除去,其中夹带剂是一种化合物, 抑制化合物(II)和副产物(IV)之间的共沸物的形成。 该方法可用于制备酯如二甲基氨基乙基(甲基)丙烯酸酯。 本发明还提供了分离醇和酯的方法。 在本发明的另一种形式中,提供了通过酯交换方法制备酯的方法,其中酯交换催化剂是均匀的。
摘要:
Aqueous alkenylsuccinic anhydride-containing polymer dispersions which are obtainable by miniemulsion polymerization of hydrophobic monoethylenically unsaturated monomers in the presence of alkenylsuccinic anhydrides, processes for the preparation of such polymer dispersions by polymerizing hydrophobic monomers by a miniemulsion polymerization method in the presence of at least one alkenylsuccinic anhydride and, if appropriate, an alkyldiketene, and use of the resulting aqueous alkenylsuccinic anhydride-containing polymer dispersions as engine and surface sizes for paper and for imparting water repellency to leather, natural and/or synthetic fibers and textiles.