A cabbage leaf like nanostructure of a NiS@ZnS composite on Ni foam with excellent electrochemical performance for supercapacitors.

In the present study, a NiS@ZnS composite nanostructure was synthesized on a nickel foam substrate by a facile chemical bath deposition (CBD) method. The prepared composites were analyzed by X-ray photoelectron spectroscopy, high resolution transmission electron microscopy, and field emission scanning electron microscopy. The electrochemical performance of the supercapacitor (SC) electrodes was examined by cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The NiS@ZnS composite exhibited a cabbage leaf like nanostructure and showed outstanding electrochemical performance in SCs with a specific capacitance of 1533.0 F g-1 at a current density of 7.5 A g-1, good cycling stability with 97.9% retention over 3000 cycles, greater energy density, and excellent rate capability compared to the bare NiS (1279.83 F g-1) and ZnS (616.66 F g-1)-based electrodes in SCs. The facile, novel synthesis method, outstanding performance, well defined surface morphology, synergetic effect and low cost make the NiS@ZnS composite an ideal electrode material for electrochemical energy storage devices.

NiMoO4@NiWO4 honeycombs as a high performance electrode material for supercapacitor applications.

In this study, we report a facile two-step fabrication of honeycomb-like NiMoO4@NiWO4 nanocomposites on Ni foam as the electrode for high-performance supercapacitor applications. Structural characterization and compositional analysis of the as-prepared NiMoO4@NiWO4 nanocomposites was performed using scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, cyclic voltammetry, galvanostatic charge-discharge cycling, and electrochemical impedance spectroscopy. The electrochemical properties of the as-synthesized NiMoO4@NiWO4 nanocomposites were studied in a 3 M KOH electrolyte solution for application as electrode material of supercapacitors. A maximum specific capacitance of 1290 F g-1 was achieved for NiMoO4@NiWO4 at a current density of 2 A g-1. This electrode exhibits excellent long cycle-life stability with 93.1% specific capacitance retention after 3000 cycles at a current density of 6 A g-1. Our studies indicate that the as-synthesized NiMoO4@NiWO4 nanocomposites could be a promising candidate as the electrode material in high-performance electrochemical energy storage applications.

Influence of solvents in the preparation of cobalt sulfide for supercapacitors.

In this study, cobalt sulfide (CoS) electrodes are synthesized using various solvents such as water, ethanol and a combination of the two via a facile chemical bath deposition method on Ni foam. The crystalline nature, chemical states and surface morphology of the prepared CoS nanoparticles are characterized using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and transition electron microscopy. The electrochemical properties of CoS electrodes are also evaluated using cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. When used as an electrode for a supercapacitor, CoS prepared with ethanol as a solvent exhibits a capacitance of 41.36 F g-1 at 1.5 A g-1, which is significantly better than that prepared using water and water/ethanol-based solvents (31.66 and 18.94 F g-1 at 1.5 A g-1, respectively). This superior capacitance is attributed to the ideal surface morphology of the solvent, which allows for easy diffusion of electrolyte ions into the inner region of the electrode. High electrical conduction enables a high rate capability. These results suggest that CoS nanoparticles are highly promising for energy storage applications as well as photocatalysis, electrocatalysis, water splitting and solar cells, among others. These results show that CoS is a promising positive electrode material for practical supercapacitors.

A strategy to enhance the efficiency of dye-sensitized solar cells by the highly efficient TiO2/ZnS photoanode.

In dye-sensitized solar cells (DSSCs), the TiO2 photoanode film plays an important role in increasing the power conversion efficiency. In this work, TiO2 nanoparticles were first coated on fluorine-doped tin oxide by the doctor-blade method, and then a thin film of zinc sulfide (ZnS) was successfully fabricated on the surface of the TiO2 nanoparticles using the successive ionic layer adsorption and reaction method. The performance of the DSSCs was examined in detail using a cobalt sulfide counter electrode and I(-)/I3(-) electrolyte. X-ray diffraction and energy dispersive X-ray spectroscopy measurements were used to find the composition of the films. Characterization with electrochemical impedance spectroscopy indicated that the recombination rate decreased drastically during the electron transportation. The DSSCs based on ZnS coated TiO2 photoanode achieved a power conversion efficiency of 5.90% under 1 sunlight illumination, which is higher than that of the bare TiO2 photoanode (4.43%). This suggests that the promising ZnS-coated TiO2 nanoparticles accumulate a large number of photo-injected electrons in the conduction band of the photoanode and the N719 dye lowers the recombination of photo-injected electrons with the redox electrolyte.

"Question of the Day": Impact on learning and retention.

Background Studying regularly has been a known method for better memory and long term retention of a subject. Getting students to study on a regular basis has been tried in many ways and its impact is increased if they understand the importance and value the efficiency of it. Objectives With large number of students, it would be a time consuming process to follow one on one interactions or study sessions. Hence, we introduced a new strategy, the "Question of the Day", which is interesting, challenging and most of all; it has produced positive influence on the examination performance of the students who performed this task. Main objective of this study was to make students answer questions related to the topics taught every day. Method Regular studying and updating the subject knowledge was provided through Question of the Day (Annexure-1). The students were given the questions on a regular basis during dissection classes and were asked to document the answers for those questions. Result The students who worked on the "Question of the Day" scored significantly higher in the exams than those who did not. The results of the opinion survey clearly indicated that this exercise was liked by most of the students. Conclusion "Question of the day" did have a positive influence on the student's performance. Most of the students felt that this exercise had a positive impact on their study methods, interaction with peers and teachers, retention and recollection of the knowledge.

An Unusual Venous Plexus on Psoas Major Muscle Connecting the Inferior Mesenteric and Testicular Veins

Knowledge of communication between parietal abdominal veins, testicular vein and mesenteric veins is important for Surgeons, Urologists and Radiologists. These communications can result in varicocele or hemorrhoids and may lead to low success rate in hemorrhoid and varicocele surgeries. During routine dissection classes, we observed an unusual large venous plexus on the left psoas major muscle. The venous plexus was unilateral and was formed by many anastomotic venous channels on the psoas fascia and communicated with the left testicular and inferior mesenteric veins. The testicular and inferior mesenteric veins were significantly enlarged below the level of communication with the venous plexus.

Uncommon Peritoneal Anomaly of Spleen Associated with the Unusual Relationship of Spleen with the Left Lobe of the Liver

Though congenital anomalies of the spleen are quite common, the peritoneal anomalies of the spleen are very rare. In the present case, we observed two unusual phrenico-splenic ligaments connecting the spleen to the diaphragm. Apart from this, the left lobe of the liver was elongated and was related to the diaphragmatic surface of the spleen. The splenic artery had a straight course to the spleen, indicating the possible restricted movements of the spleen. Knowledge of such unusual relation of spleen is essentially important for the surgeons as the elongated left lobe of the liver might get ruptured in addition to the spleen in the fractures of the left 9th, 10th and 11th ribs. Awareness of the straight course of the splenic artery is also of importance to Radiologists performing arterial splenoportography.

Abnormal Intraparotid Termination of Facial Vein and Its Clinical Importance

Facial vein is the main vein of the face. Though its origin is constant, it frequently shows variations in its termination. We report a rare type of variation of facial vein. The right facial vein coursed transversely across the masseter, superficial to the parotid duct and entered into the substance of the parotid gland, at its anterior border. Deep dissection of the gland revealed the abnormal termination of facial vein into the superficial temporal vein. The transverse facial vein drained into the facial vein. The superficial temporal vein after receiving the facial vein continued as retromandibular vein. Knowledge of this anomalous course and termination of facial vein may be important for the surgeons doing parotid, maxillofacial and plastic surgeries.