Negative Sequence
Negative Sequence - Related Videos
08:19
Generating Transposon Insertion Libraries in Gram-Negative Bacteria for High-Throughput Sequencing
0 Views •
Cited by 16 •
2020
We describe a method to generate saturating transposon mutant libraries in Gram-negative bacteria and subsequent preparation of DNA amplicon libraries for high-throughput sequencing. As an example, we focus on the ESKAPE pathogen, Acinetobacter baumannii, but this protocol is amenable to a wide range of Gram-negative organisms.
08:57
Amplicon Sequencing using the Long-Read Sequencing Technologies
0 Views •
2025
This protocol was optimized for targeted deep sequencing of 18 drug-resistance regions in Mycobacterium tuberculosis using a long-read sequencing platform, followed by analysis with a tuberculosis-specific bioinformatics pipeline designed for long-read data.
01:23
Negative Regulator Molecules
0 Views •
2019
Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria. Three of the best-understood negative regulators are p53, p21, and retinoblastoma protein (Rb). The regulatory roles of each of these proteins were discovered after faulty copies were found in cells with uncontrolled replication (i.e., cancer). These...
01:23
Negative Externalities
0 Views •
2025
A negative externality occurs when an economic transaction imposes unintended costs on third parties who are not directly involved in the market transaction. These external costs are not captured in the market price. Negative Externalities and Market Failure Consider a chemical manufacturing plant that produces industrial chemicals for sale. The plant's private costs include raw materials, labor, equipment, and maintenance, which are reflected in the market price of the chemicals. However,...
00:58
Positive, Negative, and Zero Work
0 Views •
2025
Work is done on an object when energy is transferred to the object. In other words, work is done when a force acts on a body that undergoes a displacement from one position to another. By definition, the work done by a force is the integral of the force with respect to the displacement along its path. Forces can vary as a function of position, and displacements can occur along various paths between two points. The magnitude of a force multiplied by the cosine of the angle that the force makes...
FAQs
The three sequence components describe different parts of an unbalanced three-phase quantity. Positive sequence represents the forward-rotating component, while negative sequence rotates in the opposite direction. Zero sequence forms the third component used in the decomposition. Comparing these components helps engineers distinguish ordinary balanced behavior from phase imbalance and asymmetrical fault conditions.
Negative-sequence current creates a magnetic field that rotates opposite to the normal operating field in generators and motors. This reverse-rotating field can induce rotor heating and produce torque pulsations. Continued exposure may reduce equipment life, so monitoring this component gives protection systems an indication of electrically stressful operating conditions before damage becomes more severe.
Negative-sequence quantities become important when a three-phase system departs from balance, particularly during phase imbalance or an asymmetrical fault. Because the component isolates the portion associated with unequal phase behavior, engineers can use its magnitude and presence to identify abnormal operating conditions that may not be evident from balanced-system analysis alone.
Engineers begin with measured phase voltages or currents and apply symmetrical-component analysis. This mathematical decomposition separates the original three-phase quantities into positive-, negative-, and zero-sequence sets. The resulting negative-sequence value can then be evaluated alongside the other components to assess imbalance, support fault detection, and characterize the system condition.
Protection schemes monitor negative-sequence current because its reverse-rotating magnetic field can heat rotors and create torque pulsations. A measured negative-sequence condition therefore provides a protection indicator for abnormal three-phase operation. In generator and motor applications, this information supports decisions intended to limit exposure to damaging imbalance and help preserve equipment life.
Negative-sequence measurements quantify the phase-imbalance portion of a three-phase electrical condition. During power-quality assessment, engineers can compare this component with the positive- and zero-sequence results to determine whether abnormal behavior is associated with imbalance or an asymmetrical fault. The analysis also supports diagnosis of unbalanced operating conditions in engineered power systems.