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Today high speed protection of power system elements is necessary and realizable. This paper introduces time-domain protection techniques for transmission lines using voltage and current signals in Cartesian coordinates. Three techniques are proposed using this approach for line protection. Direction of fault is obtained using change in angle between Cartesian planes of voltage and current. In the second application on unit protection scheme, internal and external faults in transmission lines are discriminated using dot product of the normals to both end current planes. Fault type identification is obtained using the angle between incremental changes in currents in Cartesian coordinates. The output of each protection function using the new concept is derived in a quarter-cycle. The performance of each of the proposed techniques is tested for load variation, high resistance fault, different fault types, power swing, fault inception angles and signal with noise. Further, the proposed techniques are evaluated using field data from a 400 kV double circuit line. [ABSTRACT FROM AUTHOR]

Hydatid cyst disease of the spine is rare, and only a few are reported in the scientific literature. This infection is caused by the larvae of Echinococcus granulosus cestode. The presentation is usually late because the patient remains asymptomatic for a longer duration after the infection. The initial form of treatment is always surgical in a symptomatic patient for excision of the diseased tissue. A 35-year-old male presented in the outpatient department with a chief complaint of mid-back pain and intermittent history of fever following his back surgery for 4 years. The patient has taken presumptive treatment for tuberculosis before presenting it to us. Radiological investigations dictate the presence of hydatid cyst in the D4 vertebra. Intact cysts were excised with perioperative albendazole coverage. The patient was mobilized on postoperative day-1 with Taylor's brace, and the brace was continued for 6 weeks. The patient was followed up at regular intervals for 1 year, and no recurrence was found. Hydatid cyst disease in the spine is a rare disease but associated with high morbidity despite significant advances in diagnostic imaging techniques and surgical treatment. For a provisional diagnosis, magnetic resonance imaging is the investigation of choice. Surgical decompression is the main stray of treatment along with antihelminthic therapy. A close follow-up is required after the initial treatment to find the recurrence at the earliest. [ABSTRACT FROM AUTHOR]