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Background: Medical students undergo tremendous stress during their undergraduate course, maybe because of staying in the hostel, economic reasons, important course, the vast amount of information and skills that need to be acquired, expectations of family members, and competition. Objective: To study stress, alcohol use, ways of coping stress, and perceived social support in medical students in comparison with non-medical (engineering) students. Materials and methods: A cross-sectional study was conducted in a medical and an engineering colleges at Kuppam, Andhra Pradesh, India from November 2012 to August 2013. One hundred and fifty medical and 150 engineering students were selected after randomised sampling and were administered Perceived Stress Scale, Alcohol Use Disorders Identification Test, Multidimensional Perceived Social Support Scale, and Ways of Coping Questionnaire to assess psychological distress. Results: Medical students (72%) perceived more stress (moderate and high) compared to engineering students (56.7%), (p

Herein, we have explored performance of layered LiNi1/3Co1/3Mn1/3O2 (NCM111) cathode material for Li ion battery applications, prepared by different preparation strategies namely co-precipitated mixed hydroxide and solid state high temperature approach combined with high-temperature calcination. The effect of crystal structure and morphology of the obtained materials were characterized by means of X-ray diffraction and scanning electron microscopy. X-ray analysis reveals that the observed lattice parameter ratio c/a is greater than 4.89 for materials with different approaches, which indicates the formation of hexagonal layered α-NaFeO2 structure. The electrochemical properties of the materials were thoroughly characterized by means of charge–discharge experiments and electrochemical impedance spectroscopy. The direct solid state synthesized NCM111 material exhibits a low retention and discharge capacity of 60 mAh g−1 at the end of 50 cycles with high irreversible capacity during cycling. The present studies have shown that the importance of material synthesis route and its sintering process, prepared at 900 °C for 8 h results low cation mixing between Li and metal ions layer in NCM111 lattice compared to other sintered samples, resulting in superior electrochemical performance. The reversible capacity of 175 mAh g−1 is noticed at C/10 rate within the voltage window of 2.5–4.4 V for 900 °C treated sample. Even at C/3 rate, a stable high reversible capacity of 145 mAh g−1 is obtained with high capacity retention of 95%. The Rietveld and EIS spectroscopic analysis conforms the existence stable layered structure and electrode, interface for NCM11 approached through co-precipitation. [ABSTRACT FROM AUTHOR]

A new type of three-dimensional (3D) oxy-phosphate materials are explored for the application of Li and Na batteries. The molybdenum tungsten oxy phosphate, MoWO3(PO4)2, was synthesized by solid-state method and evaluated for Li/Na insertion/de-insertion electrode material for the first time. The cell at charged state (vs. Li+/Li) showed a discharge capacity of 786 mAh g−1 within the voltage window of 0.3 V with amorphization of crystalline MoWO3(PO4)2 as observed from ex-situ powder XRD analysis. The structural integrity was revealed in this material, even with nearly more than 5 Li+ ions into the lattice, leading to the discharge capacity of 250 mAh g−1. The reversible charge/discharge behavior with insertion/de-insertion of 2.4 Li+ ions in the voltage range of 1.65 − 3.5 V resulted in 110 and 95 mAh g−1 at C/10 and C/5 rates, respectively. On the other hand, poor cycling performance was noticed for Na ion insertion and desertion, with a discharge capacity of 250 mAh/g within the voltage range of 0.3 − 3.5 V (vs. Na+/Na). [ABSTRACT FROM AUTHOR]