Abstract: This disclosure describes a system for tracking removal or placement of items at inventory locations with a materials handling facility. In some instances, a user may remove an item from an inventory location and the inventory management system may detect that removal and update a user item list associated with the user to include an item identifier representative of the removed item. Likewise, if the user places an item at an inventory location, the inventory management system may detect that placement and update the user item list to remove an item identifier representative of the placed item.

Abstract: An automatic detection method and apparatus for a rotor initial position angle of a double-fed machine (2). The method comprises the following steps: giving a reference voltage angle ?given, and combining with a given reference voltage amplitude Vref to generate a reference voltage vector; converting the reference voltage vector into a driving signal by space vector width modulation SVPWM to drive a rotor side PWM converter (5) to generate an alternating current voltage signal and apply it to a rotor winding of the double-fed machine (2); obtaining a rotor mechanical angle n*?rotor of the double-fed machine (2); obtaining a stator voltage vector angle ?1; and subtracting the rotor mechanical angle n*?rotor and the given reference voltage angle ?given from the stator voltage vector angle ?1 to obtain the rotor initial position angle ?initial; wherein n is the number of pole pairs of the double-fed machine (2).

Abstract: An ionic liquid piezoelectric gas sensor for the detection of polar and nonpolar organic vapors. The gas sensor can operate at high temperatures with a fast linear response which is also reversible. At high temperatures, the frequency change (?f) versus concentration (C) curve mirrors the Henry's gas law, such that the concentration of a gas sample in liquid solvent is proportional to the concentration or partial pressure of the sample in gas phase. The gas sensor can be used for quantitative analysis of gas vapors and determination of Henry constants.

Abstract: This invention describes a one pot, single-step process for the preparation of halide-free hydrophobic salts comprising polyalkylated imidazolium cations and various anions in accordance with the following structure, where R1 and R3 represent the either the same or different alkyl groups, and R2, R4, and R5 represent either hydrogen atoms, or the same or different alkyl group substituents; X represents a polyatomic anion that is the conjugate base of an acid.

Abstract: This invention describes a one pot, single-step process for the preparation of halide-free hydrophobic salts comprising polyalkylated imidazolium cations and various anions in accordance with the following structure, where R1 and R3 represent the either the same or different alkyl groups, and R2, R4, and R5 represent either hydrogen atoms, or the same or different alkyl group substituents; X represents a polyatomic anion that is the conjugate base of an acid.