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71.
Porous Hollow‐Structured LaNiO3 Stabilized N,S‐Codoped Graphene as an Active Electrocatalyst for Oxygen Reduction Reaction 下载免费PDF全文
Tran Duy Thanh Nguyen Dinh Chuong Jayaraman Balamurugan Hoa Van Hien Nam Hoon Kim Joong Hee Lee 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(39)
A nanohybrid based on porous and hollow interior structured LaNiO3 stabilized nitrogen and sulfur codoped graphene (LaNiO3/N,S‐Gr) is successfully synthesized for the first time. Such a nanohybrid as an electrocatalyst shows high catalytic activity for oxygen reduction reaction (ORR) in O2‐saturated 0.1 m KOH media. In addition, it demonstrates a comparable catalytic activity, longer working stability, and much better alcohol tolerance compared with commercial Pt/C behavior in same experiment condition. The obtained results are attributed to synergistic effects from the enhanced electrocatalytic active sites on the rich pore channels of porous hollow‐structured LaNiO3 spheres and heteroatom doped efficiency on graphene structure. In addition, N,S‐Gr can meritoriously stabilize monodispersion of the LaNiO3 spheres, and act as medium bridging for high electrical conductivity, thereby providing large active surface area for O2 adsorption, accelerating reduction reaction, and improving electrochemical stability. Such a hybrid opens an interesting class of highly efficient non‐Pt catalysts for ORR in alkaline media. 相似文献
72.
Synthetic Arabinomannan Heptasaccharide Glycolipids Inhibit Biofilm Growth and Augment Isoniazid Effects in Mycobacterium smegmatis 下载免费PDF全文
Dr. Krishnagopal Maiti Dr. Kirtimaan Syal Prof. Dipankar Chatterji Prof. Narayanaswamy Jayaraman 《Chembiochem : a European journal of chemical biology》2017,18(19):1959-1970
Biofilm formation, involving attachment to an adherent surface, is a critical survival strategy of mycobacterial colonies in hostile environmental conditions. Here we report the synthesis of heptasaccharide glycolipids based on mannopyranoside units anchored on to a branched arabinofuranoside core. Two types of glycolipids—2,3‐branched and 2,5‐branched—were synthesized and evaluated for their efficacies in inhibiting biofilm growth by the non‐pathogenic mycobacterium variant Mycobacterium smegmatis. Biofilm formation was inhibited at a minimum biofilm growth inhibition concentration (MBIC) of 100 μg mL?1 in the case of the 2,5‐branched heptasaccharide glycolipid. Further, we were able to ascertain that a combination of the drug isoniazid with the branched heptasaccharide glycolipid (50 μg mL?1) potentiates the drug, making it three times more effective, with an improved MBIC of 30 μg mL?1. These studies establish that synthetic glycolipids not only act as inhibitors of biofilm growth, but also provide a synergistic effect when combined with significantly lowered concentrations of isoniazid to disrupt the biofilm structures of the mycobacteria. 相似文献
73.
Ramakrishnan Santhosh K. Jayaraman Dinesh Grauman Kristen 《International Journal of Computer Vision》2021,129(5):1616-1649
International Journal of Computer Vision - Embodied computer vision considers perception for robots in novel, unstructured environments. Of particular importance is the embodied visual exploration... 相似文献
74.
A. Jayaraman E. J. Herbst M. Ikawa 《Journal of the American Oil Chemists' Society》1968,45(10):700-702
The “paper disc plate” method of antibiotic assay usingBacillus megaterium spores was tested for the assay of aflatoxins and related compounds. Significant inhibitions were obtained in the range of
1–4 μg/disc for aflatoxin B1 and 4–8 μg/disc for aflatoxin G1. Dicumarol was the most active of the compounds tested and inhibited at 0.1–1.0 μg/disc. Compounds were also tested using
nine-day-old chick embryos. It was found that embryos incubated in egg cartons were much more sensitive to toxins than eggs
incubated on cotton padding or in a commercial egg incubator. The LD100 of aflatoxin B1 to carton-incubated embryos was 0.01 μg, while to embryos from the commercial incubator the LD100 was >5.0 μg. The results of the two bioassay procedures did not correlate completely with each other.
Presented at the AOCS-AACC joint meeting in Washington, D.C., 1968. 相似文献
75.
Woodfiber–polypropylene and woodfiber–waste polyethylene composites have been produced by injection molding and by hot pressing the thermoplastic between woodfiber mats. The stress relaxation under constant strain in these composites has been studied at 25, 50, and 80°C. The results have been compared with similar experiments performed on neat thermoplastics. It is interesting to note that the presence of woodfibers as reinforcement in the composites restricts the stress relaxation, but their effectiveness decrease with the increase in ambient temperature. Composites made by hot pressing the woodfiber mat and the thermoplastic are found to exhibit a lesser amount of relaxation than those made by injection molding the same combination. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 401–407, 2006 相似文献
76.
V. Kamalakar K. Raghunath S. V.B. Rao A. Jayaraman 《International journal of remote sensing》2013,34(21):7474-7486
We used a combination of simultaneous measurements made with Rayleigh lidar and O2 airglow monitoring to improve lidar investigation capability to cover a higher altitude range. We fed in instantaneous O2 airglow temperatures rather than model values at the peak altitude for a subsequent integration method of temperature retrieval using Rayleigh lidar backscattered signals. Using this method, errors in the lidar temperature estimates converge at higher altitudes indicating better altitude coverage compared with regular methods where model temperatures are used rather than real-time measurements. This improvement enables the measurement of short-term waves at upper mesospheric altitudes (~90 km). Using two case studies, we show that above 60 km the amplitude of a few short-term waves drastically increases while some of the short-term waves show either damping or saturation. We claim that by using such combined measurements, significant and cost-effective progress can be made in the understanding of short-term wave processes that are important for coupling across different atmospheric regions. 相似文献
77.
M. Haridass M. Jayaraman 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2018,40(16):1910-1918
India is mainly an agricultural country. For irrigation, the farmers are primarily dependent on diesel engines which run on immaculate diesel. In order to reduce the consumption of diesel, oxygenated fuel additives seem to be a good proposition. In this connection, biodiesel is one of the best choices and this study is an attempt in that direction. Of the various non-edible vegetable oils available for making biodiesel, Mahua oil (Madhuca Indica) is preferred since it is widely available across the country. The problem with biodiesel is the higher emission of oxides of nitrogen (NOx). NOx emissions can be controlled with Ad-Blue (Urea) solution. Fortunately, for the irrigation sector, it may be considered as a blessing in disguise since, Urea which is used to control the NOx emissions is used as a fertilizer. In this work an experimental study has been carried out to assess the suitability of selective catalytic reduction (SCR) technique in reducing NOx. To arrive at accurate results, property characterization has been carried out for various blends. Tests were conducted on a multi-cylinder water cooled diesel engine at 2400 rpm. For loading an eddy current dynamometer was used. The injection nozzle opening pressure (NOP) was set to 220 bar with constant static injection timing (SIT) of 18° before top dead center (bTDC). This study presents the results at full load, employing SCR technique. The results were compared with conventional engine results under same operating condition where no reduction technique was employed. It was found that there was a significant reduction in NOx (around 3.91%) when the engine was operated with 25% biodiesel, thereby saving 25% diesel. This study establishes that SCR technique with 25% biodiesel addition as a viable option without any modification in the engine and without any compromise on the engine performance. Therefore, this option can be considered as sustainable one in agricultural operation. 相似文献
78.
Lisa M. Hall Arthi Jayaraman Kenneth S. Schweizer 《Current Opinion in Solid State & Materials Science》2010,14(2):38-48
Significant progress towards the development of microscopic predictive theories of the equilibrium structure, polymer-mediated interactions, and phase behavior of polymer nanocomposites has been made recently based on liquid state integral equation, density functional, and self-consistent mean field approaches. The basics of these three theoretical frameworks are summarized, and selected highlights of their recent applications discussed for spherical, nonspherical, and polymer-grafted nanoparticles dissolved in athermal and adsorbing concentrated solutions and homopolymer melts. The role of nanoparticle size, volume fraction, and interfacial cohesive interactions is emphasized, especially with regards to their influence on filler dispersion and spatial ordering via entropic depletion attraction, polymer adsorption-mediated steric stabilization, and local bridging of nanoparticles. Some of the many remaining theoretical challenges and open fundamental questions are summarized. 相似文献
79.
Remanufacturing requires that used products (cores) be obtained from the enduser at the end of their current life cycle so that the value-added may be recovered and the products returned to functional use again. The acquisition of cores to be remanufactured in such recoverable manufacturing systems is a complex set of activities that requires careful coordination to avoid the uncontrolled accumulation of core inventory, or unacceptable levels of customer service. The authors report on current industry practice via an extensive survey of North American remanufacturing firms. The authors propose a formal framework for Product Acquisition Management (PrAM) to coordinate, monitor, and provide an interface between reverse logistics and production planning and control activities. Finally, a series of managerial guidelines for the organization of PrAM activities is proposed. We conclude that managers should take actions that consistently reduce the variance inherent in a remanufacturing environment. 相似文献
80.
Sustainable Synthesis of Co@NC Core Shell Nanostructures from Metal Organic Frameworks via Mechanochemical Coordination Self‐Assembly: An Efficient Electrocatalyst for Oxygen Reduction Reaction 下载免费PDF全文
Shaik Gouse Peera Jayaraman Balamurugan Nam Hoon Kim Joong Hee Lee 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(19)
Herein, a new type of cobalt encapsulated nitrogen‐doped carbon (Co@NC) nanostructure employing ZnxCo1?x(C3H4N2) metal–organic framework (MOF) as precursor is developed, by a simple, ecofriendly, solvent‐free approach that utilizes a mechanochemical coordination self‐assembly strategy. Possible evolution of ZnxCo1?x(C3H4N2) MOF structures and their conversion to Co@NC nanostructures is established from an X‐ray diffraction technique and transmission electron microscopy analysis, which reveal that MOF‐derived Co@NC core–shell nanostructures are well ordered and highly crystalline in nature. Co@NC–MOF core–shell nanostructures show excellent catalytic activity for the oxygen reduction reaction (ORR), with onset potential of 0.97 V and half‐wave potential of 0.88 V versus relative hydrogen electrode in alkaline electrolyte, and excellent durability with zero degradation after 5000 potential cycles; whereas under similar experimental conditions, the commonly utilized Pt/C electrocatalyst degrades. The Co@NC–MOF electrocatalyst also shows excellent tolerance to methanol, unlike the Pt/C electrocatalyst. X‐ray photoelectron spectroscopy (XPS) analysis shows the presence of ORR active pyridinic‐N and graphitic‐N species, along with CoNx? Cy and Co? Nx ORR active (M–N–C) sites. Enhanced electron transfer kinetics from nitrogen‐doped carbon shell to core Co nanoparticles, the existence of M–N–C active sites, and protective NC shells are responsible for high ORR activity and durability of the Co@NC–MOF electrocatalyst. 相似文献