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1.
Fish Shellfish Immunol ; 119: 31-41, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34487828

RESUMO

The present study focuses on the immunity and growth of Penaeus indicus fed with varying protein levels (25%, 30%, and 35%) in a biofloc based rearing system. A 120 days growth trial was carried out using juvenile Penaeus indicus (0.71 ± 0.01) with dietary protein level, 25% (LP), 30% (MP), and 35% (HP), and a control diet-fed with 35% acted as control group resulting in 4 treatments each with four replicates and were randomly assigned 16 tank units (7500 L each). A combination of different carbon sources (molasses, wheat flour, and rice bran in 2:1:1 ratio), yeast and a probiotic (Bacillus sp.) consortium were used for the development of biofloc. At the end of the trial, the growth parameters of shrimps viz., initial weight, feed conversion ratio (FCR), and daily growth coefficient (DGC) were computed. The results indicated that shrimp fed with medium (30%) protein (MP) diet recorded significantly (P < 0.05) improved growth performance compared to high protein fed group (35%) and low protein (25%) fed group (LP) in a biofloc system and control group (35%). The immunological parameters such as hemagglutination activity (HA) assay, serum protein, lysozyme, phenol oxidase (PO), and inhibition of superoxide dismutase (SOD) activity were observed in serum, plasma, and hemocyte lysate supernatant (HLS). The HA activity, PO activity in plasma was found to be higher in high protein fed animals, whereas medium protein resulted in enhanced PO activity in serum. Similarly, lysozyme and SOD were inhibited well in high protein fed animals compared to the low protein fed group. The vital immune genes's mRNA profiling showed a potential rise in the expressional pattern in MP and HP treatments compared to LP and control. BGBP (beta-1,3-glucan binding protein) and hemocyanin mRNA transcript levels were highly upregulated in the HP (5 fold) and moderately expressed in MP (2 fold) and LP (1-2 fold). The transcripts of peroxinectin, antimicrobial peptides like crustin showed significant upregulation in HP followed by in MP and LP and control. Likewise, other immune genes, such as SOD, prophenoloxidase (proPO), showed a similar trend in a marginal way, indicating immunomodulation in the biofloc groups. This study suggested that biofloc with high protein (35%) supplementation can substantially enhance the immune response of shrimps, although medium protein level (30%) is optimum for improving the survival, growth, and in turn economic return in Indian white shrimp.

2.
Rev Sci Tech ; 40(2): 431-438, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34542104

RESUMO

Climate change due to increasing greenhouse gas (GHG) emissions is one of the most pressing issues facing society on a global scale. The growth of GHG emissions between 2000 and 2010 was higher than in each of the previous three decades, and each of the past four decades has been successively warmer than any preceding decades since 1850. Continued GHG emissions will cause further warming and changes in the climate system. Climate change affects livestock production in multiple ways, both directly and indirectly. Many of the impacts on the livestock sector result from increasing frequency and magnitude of weather and climate extremes such as droughts, flash floods, untimely rains, frost, hail and severe storms. This article describes some of the most vulnerable disaster communities in Asia, Africa, Australia, Europe and South America. It then describes the importance of meteorological information provided by national Meteorological and Hydrological Services to help Veterinary Services support sustainable management of livestock in vulnerable pastoral communities.


Assuntos
Desastres , Gases de Efeito Estufa , Animais , Mudança Climática , Secas , Efeito Estufa , Gado
3.
J Nanosci Nanotechnol ; 21(11): 5707-5713, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-33980384

RESUMO

In the present work, pure nanocrystalline monoclinic Zirconia (ZrO2) has been successfully synthesized and optimized by the modified co-precipitation method. The concentration of raw material has been optimized with the fixed amount of precipitation agent (Potassium hydroxide KOH). The thermal history of the precursor has been examined through TG/DTA analysis. All the samples are subjected to study the structure, fingerprints of the molecular vibrations, and morphology analyses. The representative sample has been analyzed through Transmission Electron Microscope (TEM) and X-ray Photo Electron Spectroscopy (XPS) analyses. The as-prepared sample exhibits the better crystallinity and surface morphology with lesser particle size (190 nm) when the raw material concentration is 0.2 M. The as-prepared ZrO2 filler (0, 3, 6, 9, and 12 wt.%) is spread through the enhanced polymer electrolyte P(S-MMA) (27 Wt.%)-LiClO4 (8 wt.%)-EC + PC (1;1 of 65 wt.%) complex system via solution casting method. The as-synthesized electrolyte films are examined via complex impedance analysis. P(S-MMA) (27 wt.%)-LiCIO4 (8 wt.%)-EC + PC (1 ;1 of 65 wt.%)-6 wt.% of ZrO2 shows the high ionic conductivity 2.35 × 10-3 Scm-1. Temperature-dependent ionic conductivity studies obey the non-linear behavior. The enhanced ZrO2 has been expected to enhance the other electrochemical properties of the lithium secondary battery.

4.
J Food Sci Technol ; 58(4): 1247-1261, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33746253

RESUMO

Antimicrobial resistance (AMR) pattern and virulence genes of extended-spectrum beta-lactamase (ESBL) producing Escherichia coli from foods of animal origin were evaluated. Based on combination disc method and ESBL E test, 42 of the 213 E. coli isolates were confirmed as ESBL producers where a high presence was observed in raw foods (60.62%), environmental samples (46.73%) and ready to eat foods (42.99%) of which 31(26.49%), 3(6.97%) and 7(15.21%) samples harbored ESBL E. coli, respectively. Higher contamination rates were observed in samples collected from meat vendors (54.36%), milk vendors (48.88%) and egg vendors (45.20%) of which 16.1%, 11.11% and 2.05%, respectively were ESBL E. coli. Among the 42 ESBL isolates, 85.71% (36/42) were multidrug-resistant. On polymerase chain reaction (PCR) analysis, expression of beta-lactamase genes viz., blaCTXM was noted in 69.04% (29/42) ESBL isolates, blaTEM in 66.66% (28/42) and blaOXA-1 in 19.04% (8/42) isolates, while blaSHV was not detected in any of the isolates. Other AMR genes viz., blaAmpC, sul1, sul2, tet(A), tet(B), catI, dhfrI, aac(3)-IIa(aacC2), aph(3')-Ia(aphA1), qnrB, qnrS were detected by PCR in 39, 28, 29, 3, 9, 5, 17, 11, 6, 6 and 33 isolates, respectively. None of the isolates harbored chloramphenicol (floR) and plasmid-mediated quinolone resistance (PMQR) (qnrA) genes. However, 21 isolates were positive for class I integron (int1), 5 for EPEC (eae) and 9 for ETEC (lt) while none were carrying bfp or stII genes. All ESBL producing isolates formed a single group when subjected to enterobacterial repetitive intergenic consensus (ERIC PCR) genotyping. The presence of multidrug-resistant ESBL E. coli in street foods of animal origin raises the issues of food safety and public health.

5.
J Minim Access Surg ; 17(4): 495-501, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33605926

RESUMO

Background: Human cadaver is ideal for learning and acquiring new surgical skills. While cadavers preserved using Thiel's embalming method are commonly used for training in laparoscopic surgery, it is a cumbersome technique. We report our experience of using Genelyn®-embalmed cadavers for training in advanced laparoscopic gastrointestinal procedures. Materials and Methods: A cross-sectional satisfaction survey corresponding to level 1 of the Kirkpatrick model for training evaluation was performed among 19 participants of advanced laparoscopy surgical skills training workshop, in December 2019, using Genelyn®-embalmed cadavers. Visual, haptic and tactile characteristics of the organs and tissues were assessed along with overall satisfaction of the workshop using Likert scale. Results: Five Genelyn®-embalmed cadavers were used for the workshop. All the 19 participants perceived that the cadavers were odourless and allowed adequate insufflation for laparoscopic procedures. Most of the participants(n=16, 84%) agreed that the appearance and tactile fidelity of the solid organs, luminal structures and tissues in Genelyn®-embalmed cadavers were similar to that of a live patient. There was a strong agreement among participants that the workshop will help improve the laparoscopic skills(median Likert score-4). Conclusion: The participants of the surgical skill training workshop felt that the Genelyn®-embalmed cadavers were ideal for use in practicing advanced laparoscopic procedures.

6.
Sci Adv ; 6(44)2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33127685

RESUMO

Hyperspectral microscopy is an imaging technique that provides spectroscopic information with high spatial resolution. When applied in the relevant wavelength region, such as in the infrared (IR), it can reveal a rich spectral fingerprint across different regions of a sample. Challenges associated with low efficiency and high cost of IR light sources and detector arrays have limited its broad adoption. Here, we introduce a new approach to IR hyperspectral microscopy, where the IR spectral map is obtained with off-the-shelf components built for visible light. The method is based on the nonlinear interference of correlated photons generated via parametric down-conversion. In this proof-of-concept we demonstrate the chemical mapping of a patterned sample, where different areas have distinctive IR spectroscopic fingerprints. The method provides a wide field of view, fast readout, and negligible heat delivered to the sample, which opens prospects for its further development for applications in material and biological studies.

7.
Anat Cell Biol ; 53(2): 194-200, 2020 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-32647087

RESUMO

Major depression belongs to mood disorders and characterized by worthlessness, no interest or happiness in any activity; lasting for atleast two weeks. Etio-pathological changes of major depression include oxidative stress leading to free radical synthesis which causes damage to carbohydrates, proteins, lipids and nucleic acids. Nucleic acid damage can be identified by either single or double strand breaks and for quantitative estimation of the same, neutral or alkaline comet assay is performed. Fluoxetine is the drug of choice for treatment of major depression having antioxidant function. In the current study eighty drug naïve major depression patients were recruited and comet parameters namely total comet length, head diameter and tail length were measured before starting the treatment and after completion of eight week fluoxetine therapy. The levels of comet parameters were higher in females than males suggesting higher prevalence of major depression among females. On categorizing into three age groups, the numbers of major depression patients belonging to 18-30 year age group were higher than 31-40 and 41-50 year age groups. All the parameters of deoxyribonucleic acid damage were reduced after eight week of fluoxetine therapy indicating that fluoxetine has anti-oxidant action along with its antidepressant properties, which cause reversal of oxidative stress induced damage occurring during major depression.

8.
J Phys Condens Matter ; 32(36): 365304, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32375126

RESUMO

Periodically driven systems exhibit resonance when the difference between an excited state energy and the ground state energy is an integer multiple of ℏ times the driving frequency. On the other hand, when a superconducting phase difference is maintained between two superconductors, subgap states appear which carry a Josephson current. A driven Josephson junction therefore opens up an interesting avenue where the excitations due to applied driving affect the current flowing from one superconductor to the other. Motivated by this, we study charge transport in a superconductor-normal metal-superconductor junction where oscillating potentials are applied to the normal metal region. We find that for small amplitudes of the oscillating potential, driving at one site reverses the direction of current at the superconducting phase differences when difference between the subgap eigenenergies of the undriven Hamiltonian is integer multiple of ℏ times the driving frequency. For larger amplitudes of oscillating potential, driving at one site exhibits richer features. We show that even when the two superconductors are maintained at same superconducting phase, a current can be driven by applying oscillating potentials to two sites in the normal metal differing by a phase. We find that when there is a nonzero Josephson current in the undriven system, the local peaks and valleys in current of the system driven with an amplitude of oscillating potential smaller than the superconducting gap indicates sharp excitations in the system. In the adiabatic limit, we find that charge transferred in one time period diverges as a powerlaw with pumping frequency when a Josephson current flows in the undriven system. Our calculations are exact and can be applied to finite systems. We discuss possible experimental setups where our predictions can be tested.

9.
Fish Shellfish Immunol ; 98: 477-487, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31945485

RESUMO

Effect of bio-augmentation of Bacillus spp in biofloc on growth, survival and immunity in Indian white shrimp Penaeus indicus was evaluated. Nine Bacillus strains were isolated and screened individually as well as in the form of a consortia. To maintain a C:N ratio of 12:1 a blend of carbohydrate sources was used. Bio-augmentation with bacterial consortium and Virgibacillus sp. produced improved growth and immunity. Shrimp survival ranged from 80 to 95% among treatments. Production was higher (35%) in the biofloc tanks with an average body weight (ABW) of 10.89 ± 1.2 g. On evaluating the immune responses, it was found that trypsin significantly (P < 0.05) enhanced Prophenoloxidase (PO) activity in Lysinibacillus, Bacillus cereus, Bacillus licheniformis and Bacillus subtilis bio-augmented groups. Laminarin induced PO activity was observed in groups supplemented with Oceanobacillus sp., Bacillus sp.and Bacillus megaterium. The lysozyme (LZ) activity was significantly (P < 0.05) higher in B. cereus and Microbial Consortia (MC), while other treatments were less effective. Total hemocyte count (THC) significantly (P < 0.05) increased in all treatment groups compared to the control. Hyaline hemocyte (HH) count was significantly (P < 0.05) higher in the control group (14.43%). Semi granular hemocytes (SGH) was higher in groups treated with Lysinibacillus, Bacillus sp., B. licheniformis and B. subtilis. The granular hemocyte (GH) count was significantly (P < 0.05) higher in Virgibacillus sp., B. cereus, B.megaterium and Oceanobacillus sp. The biofloc alone (BF), treated and augmented with B. megaterium significantly (P < 0.05) increased phagocytic activity. Highly significant phagocytic index (PI) was observed in bio-augmented groups, BF and MC. The relative expression levels of immune genes were found to be significantly up-regulated in shrimps grown in bio-augmented groups. Enhanced immunological parameters implies that bio-augmentation of biofloc with Bacillus spp. improved immunity in shrimps. Hence, bio-augmentation of probiotics in biofloc may be useful in improving culture conditions to produce P. indicus.


Assuntos
Aquicultura/métodos , Bactérias/classificação , Penaeidae/fisiologia , Criação de Animais Domésticos , Animais , Penaeidae/imunologia , Organismos Livres de Patógenos Específicos
10.
Indian J Crit Care Med ; 23(10): 462-466, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31749555

RESUMO

Intensive care unit (ICU) healthcare professionals work under a stressful environment which can lead to burnout syndrome. We conducted this study to evaluate the prevalence of stress and burnout syndrome among doctors and other healthcare professionals in ICU. We also evaluated the individual contributing factors for stress and burnout syndrome among these ICU healthcare workers. The cross-sectional survey was conducted among the healthcare professionals (doctors, nurses, clinical pharmacists, respiratory therapists and physiotherapists) in the ICUs of multispecialty hospital in south India. The survey was conducted using well-accepted tools which included job satisfaction scale, perceived stress scale and Maslach burnout inventory-human service survey. Overall, 204 healthcare professionals completed the survey. The prevalence of high burnout in our study was 80% which included 6% (n = 12) of doctors and 69% (n = 140) of nurses. Our study showed statistically significant correlation between level of job satisfaction and the level of burnout. There was a significant correlation between the level of stress and the emotional exhaustion and depersonalization domains of Maslach burnout inventory. Critical care societies and institutional committees should step forward to draft policies and benchmarks to curb the causes of stress, reduce burnout and to increase the job satisfaction. How to cite this article: Lakshmikanthcharan S, Sivakumar MN, Hisham M. Stress and Burnout among Intensive Care Unit Healthcare Professionals in an Indian Tertiary Care Hospital. Indian J Crit Care Med 2019;23(10):462-466.

11.
J Vector Borne Dis ; 56(2): 105-110, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31397385

RESUMO

Background & objectives: Japanese encephalitis (JE) is a mosquitoe-borne viral zoonotic disease and globally around three billion people are at the risk of disease. The occurrence of JE cases has shown a rising trend during last decade in India. Pig is the amplifying host for JE virus and serves as a suitable sentinel model for the prediction of disease outbreak in humans. The development of a diagnostic test that is suitable for surveillance of JE in pigs is the need of the hour. The existing tests require elaborate laboratory facilities which make their application in rural settings difficult. Therefore, realizing the need for a rapid test, efforts were made to standardize a latex agglutination test (LAT) for serodiagnosis of JE in pigs. Methods: Standardization of LAT by physical adsorption of recombinant NS1 (non-structural) protein of JE virus onto latex beads was done by altering six different variables, namely the antigen concentration, sensitization condition, surface blocking agent, blocking condition, particle concentration and reaction time. The standardized latex-protein complex was used for screening 246 pig serum samples under optimal conditions. Results: The test was standardized with a diagnostic sensitivity and specificity of 82.24 and 87.83%, respectively. Screening of 246 field pig serum samples using standardized LAT showed a seropositivity of 50.4%. The results were available within 5 min after addition of test serum sample to the sensitized beads. Interpretation & conclusion: The findings of the study highlight the potential of LAT as a rapid on-site assay for JE diagnosis in pigs which would aid in predicting JE outbreaks in humans.


Assuntos
Anticorpos Antivirais/sangue , Encefalite Japonesa/imunologia , Testes de Fixação do Látex/normas , Proteínas não Estruturais Virais/genética , Zoonoses/diagnóstico , Animais , Vírus da Encefalite Japonesa (Espécie)/imunologia , Índia , Testes de Fixação do Látex/veterinária , Proteínas Recombinantes/imunologia , Sensibilidade e Especificidade , Suínos , Proteínas não Estruturais Virais/imunologia , Zoonoses/imunologia , Zoonoses/virologia
12.
J Food Sci Technol ; 56(3): 1116-1126, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30956291

RESUMO

Street foods are one of the important sources of foodborne infections and Staphylococcus aureus is an important infectious agent transmitted through various sources including street foods. The methicillin-resistant S. aureus (MRSA) are of public health significance, hence the study was taken to assess the street foods as a source of MRSA, for which 430 street vended foods of animal origin (meat, milk, eggs and their products) and associated environmental samples were processed for isolation and characterization. A total of 52 (12.1%) S. aureus were isolated and resistant was observed to oxacillin (36.5%), cefoxitin (25%) and penicillin G (82.7%) by disc diffusion test. On genotypic screening, mecA and blaZ have detected in 17.3% and 69.2% isolates, respectively. The virulence typing identified nuc, coa, clfA, spA, FnbA and enterotoxin A (sea) genes in 100%, 96.2%, 30.8%, 55.8, 50% and 7.7% isolates, respectively. Genetic diversity among the isolates was observed by enterobacterial repetitive intergenic consensus PCR with a D value of 0.77. The presence of virulent MRSA in street vended foods trigger the public health concern and emphasis to educate the consumers and street food vendors about quality and safety of such foods.

13.
Indian J Crit Care Med ; 23(12): 594-603, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31988554

RESUMO

Background and aim: Intensive-care practices and settings differ for India in comparison to other countries. While guidelines are available to direct the use of enteral nutrition (EN), there are no recommendations specific to nutritional management of EN in dysglycemic patients, specific to patients in Indian critical care settings. Advisory board meetings were arranged to develop the practice guidelines specific to the Indian context, for the use of EN in dysglycemic critically ill patients and to overcome challenges in this field. Materials and methods: Two advisory board meetings were organized to review various existing guidelines, meta-analyses, randomized controlled trials (RCTs), controlled trials and review articles, for their contextual relevance and strength. Three rounds of Delphi voting were done to arrive at consensus on certain recommendations. A systematic grading of practice guidelines by the advisory board was done based on strength of the consensus voting and reviewed supporting evidences. Results: Based on the literature review, the recommendations for developing the practice guidelines were made as per the grading criteria agreed upon by the advisory board. The recommendations were to address challenges regarding prediction and assessment of dysglycemia (DG), acceptable glycemic targets in such settings, general nutritional aspects pertaining to DG nutrition, and nutrition in various superspecialty cases in critical care settings, where DG is commonly encountered. Conclusion: This paper summarizes the optimum EN practices for managing DG in critically ill patients. The practical solutions to overcome the challenges in this field are presented as practice guidelines at the end of each section. These guidelines are expected to provide guidance for EN management in dysglycemic critically ill patients. These guidelines also outline the model glycemic control task force and its roles in nutrition care as well as an intensive care unit DG nutrition protocol. How to cite this article: Mehta Y, Mithal A, Kulkarni A, Reddy BR, Sharma J, Dixit S, et al. Practice Guidelines for Enteral Nutrition Management in Dysglycemic Critically Ill Patients: A Relook for Indian Scenario. Indian J Crit Care Med 2019;23(12):594-603.

14.
Artigo em Inglês | MEDLINE | ID: mdl-30070783

RESUMO

Ambidexterity is the state of being equally adept in the use of both the left and right hands. It is advantageous in surgeons, but the degree of ambidexterity found among them varies greatly. It is a very desirable attribute in laparoscopic surgery. It provides the surgeon with additional options for performing critical surgical steps when positioning and space are constrained, as is often the case in cardiac surgery and even more so in minimally invasive cardiac surgery. Mentoring for ambidexterity training can be initiated as early as during medical school.  In this tutorial we demonstrate ambidextrous surgical techniques such as the 'all in one hand' technique of using two forceps in one hand, Gilbert's technique of left internal mammary harvest, and a proximal anastomosis technique in aortocoronary bypass.


Assuntos
Procedimentos Cirúrgicos Cardíacos/métodos , Lateralidade Funcional , Cardiopatias/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Cirurgiões , Procedimentos Cirúrgicos Cardíacos/educação , Humanos
15.
Indian J Crit Care Med ; 22(4): 263-273, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29743765

RESUMO

Background and Aim: Intensive-care practices and settings may differ for India in comparison to other countries. While international guidelines are available to direct the use of enteral nutrition (EN), there are no recommendations specific to Indian settings. Advisory board meetings were arranged to develop the practice guidelines specific to Indian context, for the use of EN in critically ill patients and to overcome challenges in this field. Methods: Various existing guidelines, meta-analyses, randomized controlled trials, controlled trials, and review articles were reviewed for their contextual relevance and strength. A systematic grading of practice guidelines by advisory board was done based on strength of the supporting evidence. Wherever Indian studies were not available, references were taken from the international guidelines. Results: Based on the literature review, the recommendations for developing the practice guidelines were made as per the grading criteria agreed upon by the advisory board. The recommendations were to address challenges regarding EN versus parenteral nutrition; nutrition screening and assessment; nutrition in hemodynamically unstable; route of nutrition; tube feeding and challenges; tolerance; optimum calorie-protein requirements; selection of appropriate enteral feeding formula; micronutrients and immune-nutrients; standard nutrition in hepatic, renal, and respiratory diseases and documentation of nutrition practices. Conclusion: This paper summarizes the optimum nutrition practices for critically ill patients. The possible solutions to overcome the challenges in this field are presented as practice guidelines at the end of each section. These guidelines are expected to provide guidance in critical care settings regarding appropriate critical-care nutrition practices and to set up Intensive Care Unit nutrition protocols.

16.
J Nanosci Nanotechnol ; 18(1): 121-126, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29768823

RESUMO

A sulfur-Polyacrylonitrile (PAN)-acetylene black (AB) composite was synthesized via thermal treatment processes. The as-prepared ternary composite was characterized by expending transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and electrochemical investigations. The improved electrochemical performance can be attributed to the formation of PAN layer, which can keep a tight contact between carbon and sulfur which leads to improve the conductivity. Moreover, the PAN can also act as a flexible cushion to accommodate volume changes of sulfur cathode as well as a barrier to trap soluble polysulfide intermediates during the charge-discharge process. The PAN-S-AB composite exhibits discharge capacity of 620 mAh/g even after 50 cycles with appreciable sustainability. Therefore, the resulting PAN/S/AB composite exhibited as a desirable cathode material for Li-S battery with great performance.

17.
J Nanosci Nanotechnol ; 18(1): 127-131, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29768824

RESUMO

Lithium-Sulfur (Li-S) batteries have been achieved great attention in recent years owing to its high theoretical capacity (1675 mAh/g) and energy density (2600 Wh/kg). PEG embedded MnO2/Sulfur composite was prepared via solid state reaction method. The composite was characterized by Transmission electron microscopy, scanning electron microscopy and X-ray diffractometer. MnO2 effectively suppress the diffusion of polysulfides and add a mechanical strength to the electrode. PEG binds the MnO2 and S, resulting in the minimization of active material loss and improves the electrochemical performance in lithium sulfur batteries. The PEG/MnO2/Sulfur composite exhibits discharge capacity of 647 mAh/g even after 30 cycles with appreciable sustainability. Therefore, the resulting PEG/MnO2/Sulfur composite exhibited as a desirable cathode material for Li-S battery.

18.
J Nanosci Nanotechnol ; 18(1): 215-222, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29768833

RESUMO

The present study emphases on the effect of toting of TiO2 filler on the electrochemical enactment of polymer electrolyte containing PVdF-co-HFP(30) + SEt3TFSI(10) + EC/PC(60) + TiO2(x) wt% (Poly (vinylidene fluoride-co-hexafluoropropylene + Triethylsulfoniumbis(trifluoromethylsulfonyl)imide + Ethylene carbonate/Propylene carbonate (1:1 ratio) + Titanium dioxide) for lithium battery applications. Composite electrolytes with different weight percentages of TiO2 were prepared and characterized by different surface analytical, thermal and electrochemical techniques. With gradual increase of the amount of TiO2 upto 6 wt%, broadening of the prominent peak has been noted, suggesting a decrease in the degree of crystallinity upon the addition of TiO2, as revealed by X-ray diffraction (XRD). Raman and FT-IR studies confirm the presence of various functional groups, present in the matrix. The electrolyte with TiO2 (6 wt%) has maximum stability of 460 °C, as confirmed by thermal analysis. Conductivity of the composite polymer electrolytes increases upto 6 wt% of TiO2 (3.42 × 10-3 S/cm at 303 K) and further addition, causes a dip down in conductivity, indicating an improvement in the ionic conductivity and thermal stability with the incorporation of TiO2 filler. Surface morphologic images show the presence of surface and cavity in the polymer matrix, filled with the filler uniformly. Voltammetric studies confirm the electrochemical stability of films upto 4.62 V. Coin cell containing Li anode and LiFePO4 cathode along with polymer electrolyte/6 wt% TiO2 filler, delivers a first discharge capacity of 145 mAh/g with the working voltage of 3.4 V.

19.
J Nanosci Nanotechnol ; 18(1): 296-300, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29768843

RESUMO

In this study, we first focus on effects of PVA surfactant on Li2Fe0.5Mn0.5SiO4/C by using X-ray diffraction, Fourier transform infrared spectroscopy, micro Raman analysis, scanning electron microscope, transmission electron microscope and magnetization measurements. XRD result reveals the formation of new phase (Li2Fe0.5Mn0.5SiO4/C), as a result of embedded carbon, intensity of the peaks was also suppressed. Intensity domination of G-band in micro Raman analysis affirmed that the establishment of graphene formation which was yielded from decomposition of organic materials of both PVA and acetate. Confirmation of Si-O and Si-C bond in the as-prepared material was made by FTIR analyses. A well uniform spherical shaped morphology was observed in both SEM and TEM images. In addition, the TEM picture further demonstrates Li2Fe0.5Mn0.5SiO4/C with average particle size of about 20 nm by PVA introducing.

20.
J Nanosci Nanotechnol ; 18(1): 368-373, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29768855

RESUMO

The crystalline Zirconium oxide (ZrO2) nano particles were synthesized using optimized content of Zirconium nitrate (Zr(NO3)2·3H2O) with varying KOH concentration (0.5, 1 and 1.5 M) by co-precipitation method. The thermal history of the precursor was carefully analyzed through Thermogravimetric (TG/DTA) measurement. The as prepared samples were characterized to ensure structural, functional, morphological, compositional, chemical composition and band gap by X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Laser Raman, scanning electron microscopy (SEM), High resolution Transverse Electron Microscopy (HR-TEM), X-ray photo electron spectroscopy (XPS), EDX, Photo luminescence spectroscopy (PL). The monoclinic structure with space group P21/c has been confirmed from XRD (JCPDS 89-9066). The Zr-O stretching vibration and Zr-O2-Zr bending vibrations were confirmed through FTIR analysis. The well dispersed particles with spherical morphology were confirmed through SEM and TEM analysis. The oxidation states of Zr, O and C were confirmed through XPS analysis. The oxygen vacancies and band gap of the particles were investigated through PL analysis.

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