Novel conducting lithium ferrite/chitosan nanocomposite: Synthesis, characterization, magnetic and dielectric properties

Manish Srivastava,Jay Singh,Rajneesh K. Mishra,Manish K. Singh,Animesh K. Ojha,Madhu Yashpal,Srivastava Sudhanshu 한국물리학회 2014 Current Applied Physics Vol.14 No.7

A study on Lithium ferrite/chitosan nanocomposite (LFCN), easily moldable into arbitrary shapes, as the conducting polymer and ferromagnetic characteristics is presented. The composite material is produced in the presence of Li0.5Cr0.1Fe2.4O4 and Li0.5Co0.1Fe2.4O4 nanoparticle by ex-situ polymerizations process. Various characterizations techniques have been used to explore the characteristic of the synthesized products. The frequency dependent dielectric properties and electrical conductivity of all the samples have been measured through complex impedance plot in the frequency range of 1 kHze6 MHz at room temperature. It was observed that in case of (LFCN), fluctuation in value of (ε 0) and (ε 00) is ceased over the frequency range of 4 Mz which can be attributed to the steady storage and dissipation of energy in the nanocomposite system. Moreover, it is also observed that electrical conductivity of (LFCN) increases with frequency and its value was found to be (0.032e0.048) (ohm-cm)1 in frequency range of 1 kHze6 MHz. Due to its low cost, a simple synthesis process and high flexibility, the proposed LFCN may find applications in various types of electronic components.

Recent advances in graphene and its metal-oxide hybrid nanostructures for lithium-ion batteries

Srivastava, Manish,Singh, Jay,Kuila, Tapas,Layek, Rama K.,Kim, Nam Hoon,Lee, Joong Hee The Royal Society of Chemistry 2015 Nanoscale Vol.7 No.11

<P>Today, one of the major challenges is to provide green and powerful energy sources for a cleaner environment. Rechargeable lithium-ion batteries (LIBs) are promising candidates for energy storage devices, and have attracted considerable attention due to their high energy density, rapid response, and relatively low self-discharge rate. The performance of LIBs greatly depends on the electrode materials; therefore, attention has been focused on designing a variety of electrode materials. Graphene is a two-dimensional carbon nanostructure, which has a high specific surface area and high electrical conductivity. Thus, various studies have been performed to design graphene-based electrode materials by exploiting these properties. Metal-oxide nanoparticles anchored on graphene surfaces in a hybrid form have been used to increase the efficiency of electrode materials. This review highlights the recent progress in graphene and graphene-based metal-oxide hybrids for use as electrode materials in LIBs. In particular, emphasis has been placed on the synthesis methods, structural properties, and synergetic effects of metal-oxide/graphene hybrids towards producing enhanced electrochemical response. The use of hybrid materials has shown significant improvement in the performance of electrodes.</P>

Characterizations of in situ grown ceria nanoparticles on reduced graphene oxide as a catalyst for the electrooxidation of hydrazine

Srivastava, Manish,Das, Ashok Kumar,Khanra, Partha,Uddin, Md. Elias,Kim, Nam Hoon,Lee, Joong Hee The Royal Society of Chemistry 2013 Journal of materials chemistry. A, Materials for e Vol.1 No.34

Implications of Site‐specific Mass Absorption Cross‐section (MAC) to Black Carbon Observations at a High‐altitude Site in the Central Himalaya

Priyanka Srivastava,Manish Naja,T. R. Seshadri,Hema Joshi,U. C. Dumka,Mukunda M. Gogoi,S. Suresh Babu 한국기상학회 2022 Asia-Pacific Journal of Atmospheric Sciences Vol.58 No.1

Accurate estimation of black carbon (BC) from the widely used optical attenuation technique is important for the reliable assessment of their climatic impact. The optical instruments use Mass Absorption Cross-section (MAC) for converting light attenuation records to BC mass concentrations and Aethalometer is a widely used optical instrument for BC estimation. Several studies have shown large variability inMAC values. It is thus necessary to examine the accuracy and consistency ofMAC values obtained using Aethalometer over distinct geographic locations and seasons. In the present study, MAC values are derived using simultaneous observations (2014–2017) from an EC-OC analyzer and an Aethalometer (AE-42) over a high altitude central Himalayan site at Nainital (29.4oN, 79.5oE, 1958 a.m.s.l). The observations reveal that the annual mean value of MAC (5.03 ± 0.03 m2g− 1 at 880nm) is significantly lower than the constant value used by the manufacturer (16.6 m2g− 1 at 880nm). The estimated MAC values also showed significant seasonal variation, spanning over a range from 3.7 to 6.6 m2g− 1. It is found that the seasonal variability of elemental carbon (EC), air mass variation and meteorological parameters play an important role in the changes in MAC values over this region. Multi-wavelength determination of MAC shows the contribution of absorption by species other than EC at shorter wavelengths.MAC does not show a clear diurnal variation, unlike EC and absorption coefficient. The slope of EC vs. corrected equivalent black carbon (eBC) showed a significant improvement during all seasons when compared with uncorrected eBC. This lends credibility to the fact that the use of site-specific MAC leads to more reliable estimates of eBC over the central Himalayan region. It is found that, instead of using the site specific MAC value, had we used the one supplied by the instrument, we would have underestimated the radiative forcing by about 7.8Wm− 2 which amounts to a reduction by 24 %.

Impact of Post Hardening Mechanism on Self-Healing Assessment of AA2014 Nitinol-Based Smart Composites

Vaibhav Srivastava,Manish Gupta 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.8

Exploring the self-healing capability in a metallic system, an experimental study was carried out for AA2014 and Nitinolbased smart composites material. The damage produced through the fexural test was healed by thermal heat treatmentthrough compositional healing. The objective of this work is to enhance the recovery in self-healing assessment throughdiferent hardening processes. Strengthening model (solution hardening and age hardening) as a strength enhancement isemployed on the healed samples (i.e. after heat treatment) to evaluate its efect and impact on diferent healing assessments. Further, XRD analysis was performed to explain how the developed residual stress in the microstructure is responsible inafecting the healing characteristics after each heat treatment processes. The obtained result show about 81.66% recovery incrack depth, 23.92% recovery in ductility, 84.3% recovery in crack width and 27.8% recovery in fexural strength after ageing.

Development of a Unique Mouse Intervertebral Disc Degeneration Model Using a Simple Novel Tool

Baldia Manish,Mani Sunithi,Walter Noel,Kumar Sanjay,Srivastava Alok,Prabhu Krishna 대한척추외과학회 2021 Asian Spine Journal Vol.15 No.4

Study Design: Animal case control study.Purpose: To create a simple, reproducible disc degeneration model for mouse coccygeal vertebrae. Overview of Literature: Back pain due to disc degeneration is probably the most common problem encountered in neurosurgical practice. An easily reproducible animal model for disc degeneration will help in understanding its pathophysiology, and serve as a platform for examining various therapeutic options.Methods: A total of 18 mice were divided into injured (n=12) and non-injured (n=6) groups. The disc height index (DHI%) at coccygeal 4–5 level was measured by computed tomography (CT) scan for all mice. Coccygeal 4–5 discs of the injury group were injured using a 32G needle fixed to a novel tool and confirmed by CT. The non-injury group underwent no procedure. DHI% was measured by CT at 2-, 4-, and 6-week post-injury, and all mice tails were sectioned for histopathology grading of disc degeneration at the respective time intervals.Results: The injured group showed significant variation in DHI% at 2, 4, and 6 weeks, whereas there was no change in the noninjured group. Histopathologic evaluation with Safranin O stain showed a worsening of the disc degeneration score at 2, 4, and 6 weeks in the injured group, but in the non-injured group there was no change. Percutaneous needle injury technique with our novel tool provided 100% accuracy and uniform degeneration.Conclusions: A simple, easily reproducible mouse model for disc degeneration was created using a simple, cost-effective, novel tool and technique, its advantage being high precision and user friendly.

Recent Advances for Fabricating Smart Electromagnetic Interference Shielding Textile: A Comprehensive Review

Sarika Verma,Manish Dhangar,Sriparna Paul,Kamna Chaturvedi,Mohammed Akram Khan,Avanish Kumar Srivastava 대한금속·재료학회 2022 ELECTRONIC MATERIALS LETTERS Vol.18 No.4

A sharp elevation in the generation of electromagnetic interference (EMI) is observed, directly proportional to the increasein digital and electronic appliances. With the high growing population and enhancement in the number of electrical devicesused in personal, industrial and medical sites, the issues arising due to EMI are also at their peak. EM wave interference isknown to cause malfunctioning of the nearby electronic devices, destroying the signals and affecting human health, causingnausea, headaches, neural deformities etc. To avoid the harmful effect of these interferences, the personnel in its vicinity needa shielding material, protecting them from the ill effects of the electromagnetic waves. In this review article, EMI shieldingtextiles are being focused upon. Cotton, spandex, PET, PAN, silk fabric, etc., are modified through various methods andtechniques like drop-casting, layer-by-layer electrostatic self-assembly, click chemistry, and inkjet printing to perform thefunction of shielding of EM waves. These smart, flexible, hydrophobic and light weighing fabrics can be revolutionary indiminishing the deteriorating effects of EM waves in the human body. Surface modified having high electrical conductivitiesand EMI SE of up to and beyond 90 dB in various frequency ranges have been reported, providing promising and alternativepersonal protective equipment for electromagnetic interference shielding.

Highly Efficient Bienzyme Functionalized Biocompatible Nanostructured Nickel Ferrite–Chitosan Nanocomposite Platform for Biomedical Application

Singh, Jay,Roychoudhury, Appan,Srivastava, Manish,Chaudhary, Vidhi,Prasanna, Radha,Lee, Dong Won,Lee, Seung Hee,Malhotra, B. D. American Chemical Society 2013 JOURNAL OF PHYSICAL CHEMISTRY C - Vol.117 No.16

<P>A new hybrid nanocomposite based on hydrothermally synthesized nanostructured NiFe<SUB>2</SUB>O<SUB>4</SUB> (<I>n</I>-NiFe<SUB>2</SUB>O<SUB>4</SUB>) and chitosan (CH) has been explored for bienzyme (cholesterol esterase (ChEt) and cholesterol oxidase (ChOx)) immobilization for application as total cholesterol biosensor. Results of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), Raman spectroscopy (RS) and vibrating sample magnetometer (VSM) studies demonstrate that the ChEt–ChOx/<I>n</I>-NiFe<SUB>2</SUB>O<SUB>4</SUB>–CH composite film is successfully synthesized. The obtained ChEt–ChOx/<I>n</I>-NiFe<SUB>2</SUB>O<SUB>4</SUB>–CH nanocomposite film shows large specific area, high conductivity, good biocompatibility, fast redox properties and improved antimicrobial activity. The fabricated ChEt–ChOx/<I>n</I>-NiFe<SUB>2</SUB>O<SUB>4</SUB>–CH/ITO bioelectrode exhibits largely improved amperometric biosensing performance, i.e., good linearity (5–400 mg/dL), low detection limit (24.46 mg/dL cm<SUP>–2</SUP>), high sensitivity of 1.73 μA/(mg/dL cm<SUP>–2</SUP>), fast response time of 15s, reproducibility of more than 15 times, shelf life of about 90 days and low Michaelis–Menten constant (<I>K</I><SUB><I>m</I></SUB>) value as 7.05 mg/dL (0.1825 mM). Furthermore, this modified bioelectrode has been utilized for estimation of total cholesterol in human serum samples. This efficient strategy provides new insight into the design of novel flexible electrodes for a wide range of applications in biosensing, bioelectronics, and clinical applications.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2013/jpccck.2013.117.issue-16/jp312698g/production/images/medium/jp-2012-12698g_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp312698g'>ACS Electronic Supporting Info</A></P>

COVID-19 Rapid Antigen Test: Role in Screening Prior to Gastrointestinal Endoscopy

Ashok Dalal,Ujjwal Sonika,Manish Kumar,Roshan George,Ajay Kumar,Siddharth Srivastava,Sanjeev Sachdeva,Barjesh Chander Sharma 대한소화기내시경학회 2021 Clinical Endoscopy Vol.54 No.4

Background/Aims: The severe acute respiratory syndrome coronavirus 2 pandemic has affected the gastrointestinal (GI) endoscopyunits globally owing to the risk of transmission. We present our data on the use of rapid antigen test (RAT) as a screening tool priorto endoscopy to prevent the transmission of coronavirus disease (COVID-19). Methods: This study was a retrospective analysis of patients who underwent any GI endoscopic procedure from July 2020 to October2020 at a tertiary referral center in New Delhi, India. All patients underwent screening for COVID-19 using RAT, and endoscopywas performed only when the RAT was negative. The data are presented as numbers and percentages. Results: A total of 3,002 endoscopic procedures were performed during the study period. Only one endoscopic procedure wasperformed in a COVID-19 positive patient. A total of 53 healthcare workers were involved in conducting these procedures. Only2 healthcare workers (3.8%) were diagnosed COVID-19 positive, presumably due to community-acquired infection, during thisperiod. Conclusions: The COVID-19 RAT is easily usable as a simple screening tool prior to GI endoscopy during the COVID-19 pandemic.

Structural, magnetic and optical properties of diluted magnetic semiconductor (DMS) phase of Ni modified CuO nanoparticles

Kumar Arvind,Kumar Manish,Chandra Sati Prakash,Srivastava Manish Kumar,Ghosh Surajit,Kumar Shiv 한국물리학회 2021 Current Applied Physics Vol.32 No.-

Control on the size of copper oxide (CuO) in the nano range is a highly motivating approach to study its multifunctional nature. The present investigation reports a sol-gel derived Ni doped CuO nanoparticles (Cu1- xNixO). Rietveld refinement of the XRD spectra confirms the formation of single monoclinic phase of Cu1-xNixO nanoparticles having crystallite size within the range of 19–21 nm. Raman spectra show the presence of characteristics Raman active modes and vibrational bands in the Cu1-xNixO samples that corroborate the monoclinic phase of the samples as revealed by refinement of XRD data. The estimated band gap of pure CuO is found to be ~1.43 eV, which decreases with the increase of dopant concentration into CuO matrix. This result is in line with estimated crystallite size. Magnetization curves confirm the weak ferromagnetic nature of Cu1-xNixO nanoparticles which reveal the DMS phase. This weak magnetic nature may be induced in the samples due to the exchange interaction between the localized magnetic d-spins of Ni ions and carriers (holes or electrons) from the valence band of pristine CuO lattice. Replacement of Cu+2 by Ni+2 ions into the host CuO lattice induces the magnetization. The quantified value of squareness ratio (S < 0.5) confirms the inter-grain magnetic interactions in the Cu1-xNixO nanoparticles which is also the reason of weak induced magnetization.