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In current years, the growth of high-k dielectric thin films with reduced charge density and leakage current has drawn tremendous attention for microelectronic devices. Ta2O5 thin film is deposited on p-type silicon substrate using radio frequency sputtering deposition technique for high-k dielectric applications. The as-deposited films undergo post-deposition annealing treatment at temperatures ranging from 600 °C to 900 °C for 1 h in air ambient. X-ray diffraction analysis revealed the formation of a polycrystalline orthorhombic β – Ta2O5 structure in the annealed films. The RMS roughness of the film is found to be increased from 2.3 nm to 3.7 nm with the increase in annealing temperature to 900 °C. Metal–oxide–semiconductor (Al/Ta2O5/p-Si) structures are fabricated using thermal evaporation for electrical characterizations. The capacitance-voltage (at 1 MHz) of this structure is measured for the sweep voltage from − 4 V to + 4 V. The oxide charge density and interface charge density of the film have been calculated from the C-V curve and found to decrease with the increase in annealing temperature. The highest dielectric constant value of 24.5 at 1 MHz is found for film annealed at 800 °C. The leakage current is measured from the current-voltage measurement and found to be minimum for the film annealed at 800 °C. [ABSTRACT FROM AUTHOR]

A set D of vertices in a graph G is a dominating set of G if every vertex outside D is adjacent in G to some vertex in D. A set D of vertices in G is a semitotal dominating set of G if D is a dominating set of G and every vertex in D is within distance 2 from another vertex of D. Given a graph G and a positive integer k, the semitotal domination problem is to decide whether G has a semitotal dominating set of cardinality at most k. The semitotal domination problem is known to be NP-complete for chordal graphs and bipartite graphs as shown in [M.A. Henning and A. Pandey, Algorithmic aspects of semitotal domination in graphs, Theoret. Comput. Sci. 766 (2019) 46–57]. In this paper, we present a linear time algorithm to compute a minimum semitotal dominating set in block graphs. On the other hand, we show that the semitotal domination problem remains NP-complete for undirected path graphs.

Lalit Agarwal,1 Deepti Pradhan,1 Nisha Agrawal,2 Ichhya Joshi,1 Archana Kumari,1 Anamika Kushwaha1 1Biratnagar Eye Hospital, Biratnagar, Nepal; 2Taparia Eye Care, Biratnagar, NepalCorrespondence: Deepti PradhanBiratnagar Eye Hospital, Rani, Biratnagar, NepalTel +977 9808119112Email deeptiprdhn@gmail.comPurpose: To report an uncommon case of intraoperative ocular decompression retinopathy (ODR).Case report: A 48-year-old man presented with decreased vision and pain in the left eye (LE) for 10 days following trauma with a bamboo stick. He had visual acuity of counting finger close to face in the same eye, along with corneal edema, dilated pupil and posteriorly dislocated lens. Intraocular pressure (IOP) was 42 mm of mercury (Hg). He underwent 23-gauge pars plana vitrectomy with removal of the dislocated lens. Towards the end of otherwise uneventful surgery, blot hemorrhages appeared over the posterior pole and equator. The following day, his vision was counting finger close to face and IOP was 16 mm of Hg. Fundus examination revealed large blotches of hemorrhages at different levels of the retina, later confirmed by optical coherence tomography. Disc hyperfluorescence and blocked fluorescence corresponding to blot hemorrhages were seen on fundus fluorescein angiography. Blood investigations to rule out blood dyscrasias were within normal limits.Conclusion: Ocular decompression retinopathy, though not common, has been reported to occur following various types of surgeries, especially if associated with preoperatively raised IOP. The event can also occur intraoperatively and the preoperative control of IOP is of paramount importance in the prevention of ODR.Keywords: pars plana vitrectomy, intraoperative complication, preoperative raised intraocular pressure, retinal hemorrhages, decompression retinopathy