Abstract:
Die Erfindung betrifft einen Matrix-Umrichter (MU), der mit einem ersten und einem zweiten mehrphasigen Wechselspannungsnetz (N1, N2) verbunden ist. Mit dem ersten Wechselspannungsnetz (N1) sind jeweils erste induktive Schaltungselemente (Su1, Sv1, Sw1) und mit dem zweiten Wechselspannungsnetz (N2) jeweils zweite induktive Schaltungselemente (Su2, Sv2, Sw2) verbunden. Eine Schaltmatrix (MA) verbindet die von dem ers- ten Wechselspannungsnetz (N1) abgewandten Enden (Eu1, Ev1, Ew1) der ersten induktiven Schaltungselemente (Su1, Sv1, Sw1) mit den von dem zweiten Wechselspannungsnetz (N2) abgewandten Enden (Eu2, Ev2, Ew2) der zweiten induktiven Schaltungselemente (Su2, Sv2, Sw2), wobei die Schaltmatrix (MA) aus steuerbaren Umrichtereinheiten (Uu1, Uv1, Uw1; Uu2, Uv2, Uw2) besteht. Mit Steuereingängen der steuerbaren Umrichtereinheiten (Uu1, Uv1, Uw1; Uu2, Uv2, Uw2) ist eine Regelanordnung (R) verbunden, wobei die Regelanordnung (R) mit Strom- und Spannungsmessöβen des ersten und des zweiten Wechselspannungsnetzes (N1, N2) beaufschlagt ist. Um einen solchen Matrix-Umrichter (MU) kostengünstig herstellen zu können, sind bei einem Matrix-Umrichter MU) mit mit jeweils einer zwischen den von dem ersten Wechselspannungsnetz (N1) abgewandten Enden (u1, Ev1, Ew1) der ersten induktiven Schaltungselemente (Slu1, Sv1, Sw1) und Erdpotential (M) angeordneten ersten Umrichtereinheit (Uu1, Uv1, Uw1) in einer Ausführung als steuerbare Wechselspannungsquelle und jeweils einer zwischen die von dem ersten Wechselspannungsnetz (N1) abgewandten Enden (Eu1, Ev1, Ew1) der ersten induktiven Schaltungselemente (Su1, Sv1, Sw1) und die von dem zweiten Wechselspannungsnetz (N2) abgewandten Enden (u2, Ev2, Ew2) der zweiten induktiven Schaltungselemente (Su2, Sv2, Sw2) angeschlossenen zweiten Umrichtereinheit (Uu1, Uv1, Uw1) in einer Ausführung als steuerbare Wechselspannungsquelle die Umrichtereinheiten (Uu1, Uv1, Uw1; Uu2, Uv2, Uw2) mittels der Regelanordnung (R) derart gesteuert, dass die dem Matrix- Umrichter (MU) zuflieβende elektrische Leistung gleich der aus dem Matrix-Umrichter (MU) abflieβenden elektrischen Leistung ist. Die Erfindung betrifft auch ein Verfahren zum Erzeugen einer Wechselspannung mittels eines Matrix-Umrichters (MU).
Abstract:
The present invention generally relates to devices, systems, and methods for acquiring and/or dispensing a sample without introducing a gas into a microfludic system, such as a liquid bridge system. An exemplary embodiment provides a sampling device including an outer sheath; a plurality of tubes within the sheath, in which at least one of the tubes acquires a sample, and at least one tubes expels a fluid that is immiscible with the sample, in which the at least one tube that acquires the sample is extendable beyond a distal end of the sheath and retractable to within the sheath; and a valve connected to a distal portion of the sheath, in which the valve opens when the tube extends beyond the distal end and closes when the tube retracts to within the sheath.
Abstract:
The invention provides a lubricating composition containing (a) an oil of lubricating viscosity, (b) a phosphite having at least one hydrocarbyl group that has 4 or more carbon atoms, and (c) a compound derived from a hydroxy-carboxylic acid. The invention further relates to the use of the lubricating composition in an internal combustion engine.
Abstract:
The invention provides a method of lubricating an aluminium-alloy surface of an internal combustion engine comprising supplying to the aluminium-alloy surface a lubricating composition comprising an oil of lubricating viscosity and an alkali or alkaline earth metal phenate detergent. The phenate disclosed herein may further provide antiwear performance on the aluminium-alloy surface.
Abstract:
Oxidative degradation may be reduced in a lubricant composition which contains an oil of lubricating viscosity and at least about 1 percent by weight of a C1-C3 alkyl ester of a carboxylic acid of about 12 to about 24 carbon atoms, by including within the lubricant composition a sulfonate detergent in an amount sufficient to provide at least about 0.2 percent by weight sulfonate soap to the lubricant composition, wherein the weight ratio of sulfonate soap to phenate soap in the lubricant composition is at least about 0.35:1.
Abstract:
The present invention generally relates to devices, systems, and methods for acquiring and/or dispensing a sample without introducing a gas into a microfluidic system, such as a liquid bridge system. An exemplary embodiment provides a sampling device including: a sampling member for acquiring or dispensing a sample; and a supply of a fluid that is immiscible with the sample; in which the device is configured to provide a continuous flow of immiscible fluid enveloping the sampling member.
Abstract:
A readily burstable slide fastener A readily burstable slide fastener (1) for an inflatable device, such as a lifejacket (101'), comprises a first stringer (3), a second stringer (5) and a slider (19) slidably mounted on the second stringer (5). At a weakened region (23) along the slide fastener (1) coupling elements (15) are omitted from each of the stringers (3, 5) so that when a bursting force is applied to this region (23) the coupling elements (15) adjacent thereto are disengaged. Coupling elements (15) are omitted from the top of the first stringer (3) so that when the slider (19) is at the top of the coupling elements (15) of the second stringer (5), the first stringer (3) can disengage from the slider (19). When the slide fastener (1) is fitted to an inflatable lifejacket (101'), the stringers (3, 5) are separated completely when the lifejacket (101') is inflated.
Abstract:
The invention provides methods of conducting a nucleic acid reaction, including methods for performing digital PCR using a "droplet-in-oil" technology. In the methods, the starting sampled is segmented at least partially into a set of sample droplets each containing on average about one or fewer copies of a target nucleic acid. The droplets are passed in a continuous flow of immiscible carrier fluid through a channel that passes through a thermal cycler, whereby the target is amplified. In one implementation, the droplets are about 350 nl each and the number of positively amplified droplets is counted at the near-saturation point.
Abstract:
The invention provides a lubricating composition containing an oil of lubricating viscosity and a calcium-containing detergent with a soap content of 0.06 wt % to 1.6 wt % of the lubricating composition. The lubricating composition is suitable for lubricating an internal combustion engine.