Optimization and fault diagnosis of 132 kV substation low-voltage system using electrical transient analyzer program

In this paper, a simulation and analysis of 132 kV Substation in feeds western Iraq have been presented including a short circuit (S.C) analysis. This work helps to properly control and coordinate the protection equipment used in this grid interconnection spot. This work includes power flow analysis carried out using electrical transient analyzer program (ETAP) simulator. Also, the most common types of faults are investigated for the substation buses using International Electrotechnical Commission (IEC) and the American National Standards Institute (ANSI) standards to discover the behavioral characteristics under different scenarios for the substation transformers connection to assess the range of S.C current this substitution can ride through. Finally, the results of ANSI and IEC are theoretically investigated for validity to ensure reliability and quality assurance in the case study substation

Postoperative Serum Calcium as a marker for Hypocalcemia after Thyroidectomy

Objectives: The present study aimed to determine the incidence of hypocalcemia (temporary and permanent) following total thyroidectomy and to assess whether or not its clinical and biochemical features could be used as predictive markers for postoperative hypocalcemia. Methods: A total of 144 patients who undergone a total thyroidectomy were constitutes the base of such prospective study. Serum calcium were measured in addition to details of the operation including the pathology and complications were recorded. Results: The rate of hypocalcemia was identified in 70 patients (48.61%), among them, 62 patients (43.05%) were found to developed temporary hypocalcemia and only 8 patients (5.55) identified to developed a permanent hypocalcemia. Temporary hypocalcemia was significantly more common among patient who had a toxic goiter. The mean of serum calcium levels that measured at 6 hours and 24 hours postoperatively were significantly different among study’s groups of hypocalcemia (normo-calcemia, temporary and permanent hypocalcemia). Conclusion: The serum calcium levels that measured six hours and 24 hours post thyroidectomy are useful as predictive marker for developing hypocalcemia