Electrochemical capacitance of iron oxide nanotube (Fe-NT): effect of annealing atmospheres.

The effect of annealing atmosphere on the supercapacitance behavior of iron oxide nanotube (Fe-NT) electrodes has been explored and reported here. Iron oxide nanotubes were synthesized on a pure iron substrate through an electrochemical anodization process in an ethylene glycol solution containing 3% H2O and 0.5 wt.% NH4F. Subsequently, the annealing of the nanotubes was carried out at 500 °C for 2 h in various gas atmospheres such as air, oxygen (O2), nitrogen (N2), and argon (Ar). The morphology and crystal phases evolved after the annealing processes were examined via field emission scanning electron microscopy, x-ray diffraction, Raman spectroscopy, and x-ray photoelectron spectroscopy. The electrochemical capacitance properties of the annealed Fe-NT electrodes were evaluated by conducting cyclic voltammetry (CV), galvanostatic charge-discharge, and electrochemical impedance spectroscopy tests in the Li2SO4 electrolyte. Based on these experiments, it was found that the capacitance of the Fe-NT electrodes annealed in air and O2 atmospheres shows mixed behavior comprising both the electric double layer and pseudocapacitance. However, annealing in N2 and Ar environments resulted in well-defined redox peaks in the CV profiles of the Fe-NT electrodes, which are therefore attributed to the relatively higher pseudonature of the capacitance in these electrodes. Based on the galvanostatic charge-discharge studies, the specific capacitance achieved in the Fe-NT electrode after annealing in Ar was about 300 mF cm(-2), which was about twice the value obtained for N2-annealed Fe-NTs and three times higher than those annealed in air and O2. The experiments also demonstrated excellent cycle stability for the Fe-NT electrodes with 83%-85% capacitance retention, even after many charge-discharge cycles, irrespective of the gas atmospheres used during annealing. The increase in the specific capacitance was discussed in terms of increased oxygen vacancies as a result of the enhanced transformation of the hematite (α-Fe2O3) phase to the magnetite (Fe3O4) phase for the electrodes annealed in the N2 and Ar atmospheres.

Theoretical and experimental study of sensing triacetone triperoxide (TATP) explosive through nanostructured TiO2 substrate.

The present study focuses on understanding of the principle of interaction of explosive molecule triacetonetriperoxide (TATP) with metal sensitized TiO2 nanotube composite material through theoretical modeling. This effort has also been extended in developing a laboratory scale sensor set up to detect TATP based on comprehensive computational modeling outcome and subsequent experimentation. Sensing mechanism depends on the nature of metal, where the TATP interaction with metal functionalized TiO2 prompts a change in conductivity of the sensor platform. Therefore, a metal with higher affinity towards TATP would enhance the conductance, thereby promoting the efficiency of the sensor platform. DFT methodology has been used to identify metal with high affinity to TATP. It was found that Co(2+) metal ion shows significantly higher affinity towards TATP, selected from an array of metal ions with different valency, from monovalent to tetravalent. The preliminary experimental data also suggests that Co(2+) ion detects TATP by inducing a change in conductivity of the sensor substrate.

Self-Ordered Titanium Dioxide Nanotube Arrays: Anodic Synthesis and Their Photo/Electro-Catalytic Applications.

Metal oxide nanotubes have become a widely investigated material, more specifically, self-organized titania nanotube arrays synthesized by electrochemical anodization. As a highly investigated material with a wide gamut of applications, the majority of published literature focuses on the solar-based applications of this material. The scope of this review summarizes some of the recent advances made using metal oxide nanotube arrays formed via anodization in solar-based applications. A general methodology for theoretical modeling of titania surfaces in solar applications is also presented.

Endometrial stromal nodule with smooth muscle differentiation.

Uterine tumors composed of a prominent component of smooth muscle and endometrial stroma (so-called stromomyoma) are distinctly uncommon. This article describes the morphological features of one such tumor discovered as an incidental finding in a hysterectomy specimen of a 49-year-old lady with a clinical diagnosis of dysfunctional uterine bleeding. Morphological and immunohistochemical (IHC) evaluation were performed and a final diagnosis of endometrial stromal nodule with smooth muscle differentiation was rendered.

Paratesticular myxoid liposarcoma: a case report.

Liposarcoma of the paratesticular region is a rare malignant soft tissue neoplasm. Out of all the possible sites of liposarcoma, the incidence in spermatic cord is rare, accounting for only 5% of these neoplasms. Among the various subtypes of liposarcoma described in the paratesticular region, myxoid variant of liposarcoma is seen very rarely. One such case is we ported here for its rarity and also to draw attention to the fact that, early diagnosis and complete excision carry better prognostic value.