摘要:
A binder composition in aqueous solution, suitable for use in the production of foundry sand moulds and cores is obtained by mixing an alkali metal silicate, glycosylated polyhydric alcohols produced by acid catalyzed condensation of a carbohydrate having a reducing group and an alcohol having two or more hydroxyl groups, and optionally an oxyanion salt such as a borate.
摘要:
A binder composition for producing articles of bonded particulate material such as foundry moulds or cores comprises an alkaline aqueous solution of a resol phenol-aldehyde resin and an oxyanion capable of forming a stable complex with the resin the amount of alkali present in the solution being sufficient to substantially prevent stable complex formation. Bonded articles are produced from mixtures of particulate material and the binder composition by passing carbon dioxide gas through the formed articles whereby the oxyanion forms a stable complex with the resin and the resin is cured. The oxyanion may be for example borate, stannate or aluminate.
摘要:
A binder composition for producing articles of bonded particulate material such as foundry moulds or cones comprises an alkaline aqueous solution of a resol phenol-aldehyde resin and an oxyanion capable of forming a stable complex with the resin the amount of alkali present in the solution being sufficient to substantially prevent stable complex formation. Bonded articles are produced from mixtures of particulate material and the binder composition by passing carbon dioxide gas through the formed articles whereby the oxyanion forms a stable complex with the resin and the resin is cured. The oxyanion may be for example borate, stannate or aluminate.
摘要:
An integrated fault and personnel protection system and method for a multi-thread converter in a wind turbine power system is provided. The structure and method provide for system optimization, as well as, arc flash protection. Fault sensing with means of removing power applied to the converter minimizes the energy available to produce an arc flash event. Sensing and disconnects devices for the protections are provided close to the source of energy to protect more of the system. Converter controls detect, identify and isolate faults selecting the best combinations of the novel specific fault isolation devices. Components are distributed into separate physical to enhance protection.
摘要:
A method for operating an electrical machine includes coupling the electrical machine to an electric power system such that the electric power system is configured to transmit at least one phase of electric power to and from the electrical machine. The method also includes configuring the electrical machine such that the electrical machine remains electrically connected to the electric power system during and subsequent to a voltage amplitude of the electric power system operating outside of a predetermined range for an undetermined period of time.
摘要:
A system and method determine the parameters of a field of a DC motor. The method comprises obtaining parameters of the DC motor; and performing an iterative processing loop, the iterative processing loop being performed n times. The iterative processing loop includes regulating field current based on the parameters of the DC motor, and calculating a field resistance from a field voltage and the field current measured during the regulating of the field current; operating in a closed loop mode to determine a first field firing angle and a second field firing angle; operating in an open loop mode to determine a first time constant and a second time constant based on applying the first field firing angle and the second field firing angle; and determining at least one parameter of the field of the DC motor based on the first time constant, the second time constant, and the calculated field resistance.
摘要:
A process for the modification, solubilization and/or hydrolysis of a glycosidically linked carbohydrate having reducing groups using a mixture comprising water, an inorganic acid and a halide of lithium, magnesium or calcium. The process is particularly useful for converting cellulose (derived for example from waste-paper, wood or sawdust) or starch to glucose. When cellulose is the starting material the preferred halide is a lithium halide. When starch is the starting material a magnesium halide is preferred.
摘要:
A process for the treatment of a mixture comprising one or more sugars and oxyanions to separate a sugar or a sugar mixture therefrom wherein the ion-containing mixture is treated with an ion-exchange resin. The process may comprise treatment of the ion-containing mixture with a cationic exchange resin having thereon monovalent counterions or a mixture of divalent counterions and hydrogen ions or with first a cationic exchange resin having thereon hydrogen ions and then second with an anionic exchange resin having thereon monovalent or divalent counterions. The process is very useful in the production of fructose-containing syrups.
摘要:
An integrated fault and personnel protection system and method for a multi-thread converter in a wind turbine power system is provided. The structure and method provide for system optimization, as well as, arc flash protection. Fault sensing with means of removing power applied to the converter minimizes the energy available to produce an arc flash event. Sensing and disconnects devices for the protections are provided close to the source of energy to protect more of the system. Converter controls detect, identify and isolate faults selecting the best combinations of the novel specific fault isolation devices. Components are distributed into separate physical to enhance protection.
摘要:
A process for the modification, solubilization and/or hydrolysis of a glycosidically linked carbohydrate having reducing groups using a mixture comprising water, an inorganic acid and a halide of lithium, magnesium or calcium. The process is particularly useful for converting cellulose (derived for example from waste-paper, wood or sawdust) or starch to glucose. When cellulose is the starting material the preferred halide is a lithium halide. When starch is the starting material a magnesium halide is preferred.