SnP₃/Carbon Nanocomposite as an Anode Material for Potassium-Ion Batteries

Verma, Rakesh,Didwal, Pravin N.,Ki, Hyeong-Seo,Cao, Guozhong,Park, Chan-Jin American Chemical Society 2019 ACS APPLIED MATERIALS & INTERFACES Vol.11 No.30

<P>New anode materials with large capacity and long cyclability for next-generation potassium-ion batteries (PIBs) are required. PIBs are in the initial stage of investigation and only a few anode materials have been explored. In this study, for the first time, an SnP<SUB>3</SUB>/C nanocomposite with superior cyclability and rate performance was evaluated as an anode for PIBs. The SnP<SUB>3</SUB>/C nanocomposite was synthesized by a facile and cost-effective high-energy ball-milling technique. The SnP<SUB>3</SUB>/C electrode delivered a first reversible capacity of 410 mAh g<SUP>-1</SUP> and maintained 408 mAh g<SUP>-1</SUP> after 50 cycles at a specific current of 50 mA g<SUP>-1</SUP>. After 80 cycles at a high specific current of 500 mA g<SUP>-1</SUP>, a high capacity of 225 mAh g<SUP>-1</SUP> remained. From a crystallographic analysis, it was suggested that the SnP<SUB>3</SUB>/C nanocomposite underwent a sequential and reversible conversion and alloying reactions. The excellent cycling stability and rate capability of the SnP<SUB>3</SUB>/C electrode were attributed to the nanosized SnP<SUB>3</SUB> particles and carbon buffer layer, which supplied channels for the migration of K-ions and mitigated the stress induced by a large volume change during potassiation/depotassiation. In addition, a full cell composed of the SnP<SUB>3</SUB>/C nanocomposite anode and potassium Prussian blue cathode exhibited a reversible capacity of 305 mAh g<SUP>-1</SUP> at a specific current of 30 mA g<SUP>-1</SUP> and retained 71.7% of the original capacity after 30 cycles. These results are important for understanding the electrochemical process of the SnP<SUB>3</SUB>/C nanocomposite and using the SnP<SUB>3</SUB>/C as an anode for PIBs.</P> [FIG OMISSION]</BR>

Ternary lithium molybdenum oxide, Li₂Mo₄O₁₃: A new potential anode material for high-performance rechargeable lithium-ion batteries

Verma, Rakesh,Park, Chan-Jin,Kothandaraman, R.,Varadaraju, U.V. Pergamon Press 2017 Electrochimica Acta Vol. No.

<P><B>Abstract</B></P> <P>The need to identify lithium ion battery anodes consisting of new materials that display high energy density and good cycling stability has interested the research on reversible so-called conversion reaction between lithium and molybdenum oxides such as ternary metal oxide (Li<SUB>2</SUB>Mo<SUB>4</SUB>O<SUB>13</SUB>). Polycrystalline Li<SUB>2</SUB>Mo<SUB>4</SUB>O<SUB>13</SUB> was synthesized by conventional solid-state reaction route and explored as new potential anode material for secondary lithium ion battery applications <I>vs.</I> Li<SUP>+</SUP>/Li in half-cell mode. The electrochemical performance of the Li<SUB>2</SUB>Mo<SUB>4</SUB>O<SUB>13</SUB> electrode was studied by cyclic voltammograms and galvanostatic discharge-charge cycling under different rates. In the working voltage between 2.5 V and 0.1 V, Li<SUB>2</SUB>Mo<SUB>4</SUB>O<SUB>13</SUB> shows a high first charge capacity of 1062 mAh g<SUP>−1</SUP> at current rate of C/10 (24 Li react with 10 h) and a superior rate capability with capacity retention of 1008, 842, 713 and 640 mAh g<SUP>−1</SUP> under current rates of C/10, C/5, C/3 and C/2 (24Li react with in 2 h), respectively. Further, the cycling performance was evaluated at C/3 rate (424 mA g<SUP>−1</SUP>) and after 100 cycles a reversible capacity of 550 mAh g<SUP>−1</SUP> was obtained with columbic efficiency of ∼100%. Ex-situ XRD studies confirmed that the electrochemical reaction involves insertion of 5Li/f.u <I>vs.</I> Li<SUP>+</SUP>/Li during discharge to 1.3 V and the crystal structure was retained when charged to 2.5 V. Below 0.8 V, conversion reaction occurs leading to amorphization of the phase. When discharged to 0.1 V, Mo<SUP>+6</SUP> is reduced to Mo<SUP>0</SUP> state on the basis of the conversion reaction.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A ternary lithium molybdenum oxide (Li<SUB>2</SUB>Mo<SUB>4</SUB>O<SUB>13</SUB>) is explored as anode for lithium ion battery for the first time. </LI> <LI> Li<SUB>2</SUB>Mo<SUB>4</SUB>O<SUB>13</SUB> phase shows excellent electrochemical performance possibly due to the apriori presence of the active ions in the lattice. </LI> <LI> Li<SUB>2</SUB>Mo<SUB>4</SUB>O<SUB>13</SUB> shows high capacity, excellent rate capability and cycling. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Effect of dentin roughening and type of composite material on the restoration of non-carious cervical lesions: an in vivo study with 18 months of follow-up

Verma Sanjana,Singla Rakesh,Gill Gurdeep Singh,Jain Namita 대한치과보존학회 2023 Restorative Dentistry & Endodontics Vol.48 No.4

Objectives The purpose of this study was to evaluate the impact of dentin roughening and the type of composite resin used (either bulk-fill flowable or nanohybrid) on the restoration of non-carious cervical lesions (NCCLs) with an 18-month follow-up period. Materials and Methods This prospective split-mouth study included 36 patients, each with a minimum of 4 NCCLs. For each patient, 4 types of restorations were performed: unroughened dentin with nanohybrid composite, unroughened dentin with bulk-fill flowable composite, roughened dentin with nanohybrid composite, and roughened dentin with bulk-fill flowable composite. A universal bonding agent (Tetric N Bond Universal) was applied in self-etch mode for all groups. The restorations were subsequently evaluated at 6, 12, and 18 months in accordance with the criteria set by the FDI World Dental Federation. Inferential statistics were computed using the Friedman test, with the level of statistical significance established at 0.05. Results The 4 groups exhibited no significant differences in relation to fracture and retention, marginal staining, marginal adaptation, postoperative hypersensitivity, or the recurrence of caries at any follow-up point. Conclusions Within the limitations of the present study, over an 18-month follow-up period, no significant difference was present in the clinical performance of bulk-fill flowable and nanohybrid composite restorations of non-carious cervical lesions. This held true regardless of whether dentin roughening was performed.

Quitline Activity in Rajasthan, India

Gupta, Rakesh,Verma, Vinit,Mathur, Pankaj Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.no.sup2

Quitline activity in Rajasthan, India is a voluntary activity of Rajasthan Cancer Foundation (RCF) since April 2013. To kick-off, it took the benefit of the State Government- PIRAMAL SWASTHYA (PS)1 collaborative 104 Health Information Helpline that existed already in public-private partnership. It is a reactive quitline that helps callers through the counselors and nursing staff trained specifically through the weekly sessions held by the first author, the RCF resource on quitline. Besides structuring of the scripts for primary intervention and follow-ups after 1 week, 1 month, 6 months and a year, he also monitors calls, advices and coordinates with the supervisors to manage and analyze the data base, and reports to the PS lead at the Jaipur Center on overall performance and to plan strategic communication with the State Government on its outcomes. The quitline has limitations of its informal existence through a voluntary effort of RCF, no specific resource allocation, suboptimal data management, minimal awareness in the masses due to poor IEC (Information, Education and Communication; except its efforts made by RCF in last 1 year through the government-run State TV and City Radio) and staff shortage and its attrition due to lack of plan for career advancement. Despite these challenges in the year 2013, the quit line has registered a quit rate (for complete abstinence) of 19.93% amongst 1525 callers. The quit rate were 58.01% (304/ 524) among the responders at the 3rd follow-up at 18 months (in September 2014)2. In view of an increase in quit rate by 5- 9 times over the prevailing quit rate in the former ever daily users [both smokers and the users of smokeless tobacco (SLT)], efforts are being made by RCF in concurrence with PS to have this cost-effective model established formally with optimal resource allocation in collaboration with willing agencies (the State and Central Governments and the International Quitline Agencies) and its replication in 4 more states where PS is collaborating with the respective state governments similarly (Assam, Chhattisgarh, Jharkhand and Karnataka).

Synthesis of 3-dimensional interconnected porous Na₃V₂(PO₄)₃@C composite as a high-performance dual electrode for Na-ion batteries

Didwal, Pravin N.,Verma, Rakesh,Min, Chan-Woo,Park, Chan-Jin Elsevier 2019 Journal of Power Sources Vol.413 No.-

<P><B>Abstract</B></P> <P>Three-dimensional (3-D) interconnected porous Na<SUB>3</SUB>V<SUB>2</SUB>(PO<SUB>4</SUB>)<SUB>3</SUB> coated with carbon (NVP@C) is synthesised by a simple modified sol-gel method. When 15 wt% glucose is used as the carbon precursor, the obtained NVP@C15 composite exhibits excellent electrochemical performance as a cathode as well as an anode for sodium-ion batteries (SIBs). As a cathode, the NVP@C15 electrode delivers a high capacity of 116.9 mAh g<SUP>−1</SUP> at a rate of 1 C, which is close to its theoretical capacity. Even at a high rate of 20C, the NVP@C15 electrode exhibits an initial reversible capacity of 99.2 mAh g<SUP>−1</SUP> and a capacity retention of 77% after 6000 cycles. As an anode, the NVP@C15 delivers an initial reversible capacity of 85.8 mAh g<SUP>−1</SUP> at a rate of 1C. At higher rates of 10 and 20C, a remarkably good cyclability, with a capacity retention of 76% over 4000 cycles and 62% over 5000 cycles, respectively, is achieved. Furthermore, the full cell, composed of two symmetric NVP@C15 electrodes, exhibits an initial reversible capacity of 73 mAh g<SUP>−1</SUP> at a rate of 1C. In addition, capacity retentions of 88% after 100 cycles and 61% after 500 cycles are obtained at rates of 1C and 5C, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> 3-D interconnected porous Na<SUB>3</SUB>V<SUB>2</SUB>(PO<SUB>4</SUB>)<SUB>3</SUB>@C was synthesised by modified sol-gel method. </LI> <LI> 3-D interconnected porous structure provides easy diffusion pathways for Na ions. </LI> <LI> The uniform carbon coating on Na<SUB>3</SUB>V<SUB>2</SUB>(PO<SUB>4</SUB>)<SUB>3</SUB>@C provides better electronic conductivity. </LI> <LI> Na<SUB>3</SUB>V<SUB>2</SUB>(PO<SUB>4</SUB>)<SUB>3</SUB>@C can be used as an anode and a cathode for sodium-ion batteries. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Nitric Oxide Metabolite Concentration in Cerebrospinal Fluid: Useful as a Prognostic Marker?

Saurabh Singh,Jyoti Prakash,Rakesh Singh,Ashish Verma,Hemant Bansal 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.5

Study Design: Prospective study. Purpose: To establish the significance of cerebrospinal fluid (CSF) nitric oxide metabolite (NOx) concentration in acute spinal cord injury (SCI) patients to assess the neurological severity and prognosis. Overview of Literature: Quantitative analysis of specific biomarkers in CSF will assess neurological severity more accurately and permit the formulation of a more precise management plan. Methods: Forty SCI patients represented the cases and 20 lower limb injury patients were the controls. NOx concentration in CSF was measured at week 1, 2, and 4 by Griess method. Magnetic resonance imaging (MRI, T2-weighted) done in each case to measure cord edema and neurological severity was assessed using the Frankel classification. Results: CSF NOx concentration peaked at week 2 and declined to normal by week 4. The concentration remained normal in controls. Mean NOx concentration was directly proportional to the severity of acute SCI as correlated with cord edema seen in MRI and neurological severity assessed. Conclusions: CSF NOx concentration can be considered a specific quantitative biomarker in acute stage of SCI to predict the severity and prognosis of SCI patients.

Parkinson’s Disease: The Emerging Role of Gut Dysbiosis, Antibiotics, Probiotics, and Fecal Microbiota Transplantation

Sudhir K Dutta,Sandeep Verma,Vardhmaan Jain,Balarama K Surapaneni,Rakesh Vinayek,Laila Phillips,Padmanabhan P Nair 대한소화기 기능성질환∙운동학회 2019 Journal of Neurogastroenterology and Motility (JNM Vol.25 No.3

2 decades evidence has emerged to suggest that inflammation-derived oxidative damage and cytokine induced toxicity may play asignificant role in the neuronal damage associated with Parkinson’s disease (PD). Presence of pro-inflammatory cytokines and T cellinfiltration has been observed in the brain parenchyma of patients with PD. Furthermore, evidence for inflammatory changes hasbeen reported in the enteric nervous system, the vagus nerve branches and glial cells. The presence of α-synuclein deposits in thepost-mortem brain biopsy in patients with PD has further substantiated the role of inflammation in PD. It has been suggested thatthe α-synuclein misfolding might begin in the gut and spread “prion like” via the vagus nerve into lower brainstem and ultimately tothe midbrain; this is known as the Braak hypothesis. It is noteworthy that the presence of gastrointestinal symptoms (constipation,dysphagia, and hypersalivation), altered gut microbiota and leaky gut have been observed in PD patients several years prior to theclinical onset of the disease. These clinical observations have been supported by in vitro studies in mice as well, demonstrating the roleof genetic (α-synuclein overexpression) and environmental (gut dysbiosis) factors in the pathogenesis of PD. The restoration of the gutmicrobiome in patients with PD may alter the clinical progression of PD and this alteration can be accomplished by carefully designedstudies using customized probiotics and fecal microbiota transplantation.

연소해석 가속화를 위한 솔루션 기반 적응형 메쉬 기술 개발

전상태(Sangtae Jeon),Sourabh Shrivastava,Ishan Verma,Rakesh Yadav,Pravin Nakod 한국연소학회 2022 KOSCOSYMPOSIUM논문집 Vol.2022 No.11

For systems where flame travel over time, accurate flame tracking plays a critical role in predicting the combustion characteristics of the system. Flame tracking with 3D computational fluid dynamics is a prerequisite for fine mesh resolution depending on the flame front. Solution-based mesh adaptation approach has been extensively studied by various research groups to maintain proper mesh resolutions generating the fine mesh needed in critical areas while maintaining the overall mesh count at an appropriate level.

Objective Comparison of Benefits Derived From Contralateral Routing of Signal Hearing Aid and Bone Conduction Device in Noisy Surroundings in Patients With Single-Sided Deafness

Sikka Kapil,Yogal Rijendra,Thakar Alok,Kumar Rakesh,Chaudhary Tanvi,Bhartiya Mao,Verma Hitesh,Sharma Sonam,Singh Chirom Amit 대한청각학회 2022 Journal of Audiology & Otology Vol.26 No.4

Background and Objectives: Single-sided deafness (SSD) leads to non-participation of the diseased ear in generating adequate auditory input, which results in poor speech discrimination in noisy surroundings. The present study objectively compared the audiological benefits rendered by contralateral routing of signal (CROS) hearing aid and bone conduction device (BCD) in patients with SSD >70 dB HL using the modified hearing in noise test (HINT).Materials and Methods: Patients with SSD >70 dB HL in poor and clinically normal hearing in the better ear were enrolled. Patients aged <18 or >70 years, with a history of neurological insult or ear infection in the last 3 months, mental retardation, psychiatric or developmental disorders, and diabetes were excluded. Modified HINT was performed with the affected ear unaided, aided with CROS hearing aid, and with BCD, generating three groups. Noise signal was presented at a fixed intensity of 65 dB at the neutral position in the center and speech signal was presented to either ear sequentially. The test was repeated with the speech signal fixed at the neutral position and the noise signal presented to either ear.Results: BCD led to a better signal-to-noise ratio (SNR) than CROS hearing aid in all situations except when noise was centralized and speech was presented to the affected ear.Conclusions: A benefit was observed when auditory rehabilitation was used for the affected ear as demonstrated by better SNR scores. The results showed that BCD performed better than CROS hearing aid.

Effect of an organic additive in the electrolyte on suppressing the growth of Li dendrites in Li metal-based batteries

Ho, Van-Chuong,Ngo, Duc Tung,Le, Hang T.T.,Verma, Rakesh,Kim, Hee-Sang,Park, Choong-Nyeon,Park, Chan-Jin Elsevier 2018 ELECTROCHIMICA ACTA Vol.279 No.-

<P><B>Abstract</B></P> <P>Lithium metal has attracted much attention as an anode material for high-performance batteries owing to its high specific capacity and electrode potential. However, the Li metal electrode could suffer from the dendritic growth of Li during the cell operation due to the high reactivity of Li with organic electrolytes. To address this issue, we propose the use of thiourea as an electrolyte additive for Li metal-based batteries. The thiourea additive in LiTFSI/TEGDME electrolyte allowed the formation of a stable and uniform solid electrolyte interface layer on the Li electrode, thereby aiding the suppression of dendritic growth of Li and further electrolyte decomposition. Accordingly, a Li symmetric cell containing the thiourea additive exhibited six-times longer cycle life than a cell without the additive. Further, the electrolyte additive was also successfully employed in a Li-O<SUB>2</SUB> cell to improve its cyclability.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Thiourea is explored as an electrolyte additive for lithium metal-based batteries for the first time. </LI> <LI> Growth of lithium dendrites is controlled by varying the concentration of thiourea additive in the electrolyte. </LI> <LI> Thiourea additive, decomposition of the liquid electrolyte involving LiTFSI salt is suppressed during the discharge-charge. </LI> <LI> The Li-O<SUB>2</SUB> battery employing the liquid electrolyte containing the thiourea additive exhibits good cyclability. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>