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1.
Saravanan Vanal Krishnan Muthumanickam Muthukaruppan Ambalam Ragavendran Venkatesan Jeyanthinath Mayandi Vishnukanthan Venkatachalapathy 《Ceramics International》2021,47(17):23693-23701
Ceramic Matrix Composites (CMCs) have many interesting properties, mainly light weight, cost efficiency, low density, high compressive strength, high hardness and durability. Hence, they emerged as a boon to the development of personnel armors in the past. The current work aims to review various new methodologies adapted for the reinforcement of Alumina (Al2O3) CMCs in recent times, including some of the interesting results obtained with respect to mechanical properties, suitability of the synthesized composites for armor applications, and the upcoming reinforcement trends. Finally, studies related to reinforcement in Al2O3 CMCs, specifically towards armor applications have been consolidated to arrive at some of the important inferences for concluding reasonably. 相似文献
2.
Mani Balamurugan Hui‐Yun Jeong Venkata Surya Kumar Choutipalli Jung Sug Hong Hongmin Seo Natarajan Saravanan Jun Ho Jang Kang‐Gyu Lee Yoon Ho Lee Sang Won Im Venkatesan Subramanian Sun Hee Kim Ki Tae Nam 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(25)
The electrochemical reduction of carbon dioxide (CO2) to hydrocarbons is a challenging task because of the issues in controlling the efficiency and selectivity of the products. Among the various transition metals, copper has attracted attention as it yields more reduced and C2 products even while using mononuclear copper center as catalysts. In addition, it is found that reversible formation of copper nanoparticle acts as the real catalytically active site for the conversion of CO2 to reduced products. Here, it is demonstrated that the dinuclear molecular copper complex immobilized over graphitized mesoporous carbon can act as catalysts for the conversion of CO2 to hydrocarbons (methane and ethylene) up to 60%. Interestingly, high selectivity toward C2 product (40% faradaic efficiency) is achieved by a molecular complex based hybrid material from CO2 in 0.1 m KCl. In addition, the role of local pH, porous structure, and carbon support in limiting the mass transport to achieve the highly reduced products is demonstrated. Although the spectroscopic analysis of the catalysts exhibits molecular nature of the complex after 2 h bulk electrolysis, morphological study reveals that the newly generated copper cluster is the real active site during the catalytic reactions. 相似文献
3.
4.
EV Chandrasekaran RK Jain RD Larsen K Wlasichuk KL Matta 《Canadian Metallurgical Quarterly》1996,35(27):8914-8924
The assembly of complex structures bearing the H determinant was examined by characterizing the specificities of a cloned blood group H gene-specified alpha 1,2-L-fucosyltransferase (FT) toward a variety of sulfated, sialylated, or fucosylated Gal beta 1,3/4GlcNAc beta- or Gal beta 1,3GalNAc alpha-based acceptor structures. (a) As compared to the basic type 2, Gal beta 1,4GlcNAc beta-(K(m) = 1.67 mM), the basic type 1 was 137% active (K(m) = 0.83 mM). (b) On C-6 sulfation of Gal, type 1 became 142.1% active and type 2 became 223.0% active (K(m) = 0.45 mM). (c) On C-6 sulfation of GlcNAc, type 2 showed 33.7% activity. (d) On C-3 or C-4 fucosylation of GlcNAc, both types 1 and 2 lost activity. (e) Type 1 showed 70.8% and 5.8% activity, respectively, on C-6 and C-4 O-methylation of GlcNAc. (f) Type 1 retained 18.8% activity on alpha 2,6-sialylation of GlcNAc. (g) Terminal type 1 or 2 of extended chain had lower activity. (h) With Gal in place of GlcNAc in type 1, the activity became 43.2%. (i) Compounds with terminal alpha 1,3-linked Gal were inactive. (j) Gal beta 1,3GalNAc alpha- (the T-hapten) was approximately 0.4-fold as active as Gal beta 1,4GlcNAc beta-. (k) C-6 sulfation of Gal on the T-hapten did not affect the acceptor activity. (l) C-6 sulfation of GalNAc decreased the activity to 70%, whereas on C-6 sulfation of both Gal and GalNAc the T-hapten lost the acceptor ability. (m) C-6 sialylation of GalNAc also led to inactivity. (n) beta 1,6 branching from GalNAc of the T-hapten by a GlcNAc residue or by units such as Gal beta 1, 4GlcNAc-, Gal beta 1,4(Fuc alpha 1,3)GlcNAc-, or 3-sulfoGal beta 1,4GlcNAc- resulted in 111.9%, 282.8%, 48.3%, and 75.3% activities, respectively. (o) The enhancement of enzyme affinity by a sulfo group on C-6 of Gal was demonstrated by an increase (approximately 5-fold) in the K(m) for Gal beta 1,4GlcNAc beta 1,6(Gal beta 1,3)GalNAc alpha-O-Bn in presence of 6-sulfoGal beta 1,- 4GlcNAc beta-O-Me (3.0 mM). (p) Among the two sites in Gal beta 1, 4GlcNAc beta 1,6(Gal beta 1,3) GalNAc alpha-O-Bn, the enzyme had a higher affinity ( > 3-fold) for the Gal linked to GlcNAc. (q) With respect to Gal beta 1,- 3GlcNAc beta-O-Bn (3.0 mM), fetuin triantennary asialo glycopeptide (2.4 mM), bovine IgG diantennary glycopeptide (2.8 mM), asialo Cowper's gland mucin (0.06 mM), and the acrylamide copolymers (0.125 mM each) containing Gal beta 1,3GlcNAc beta-, Gal beta 1,3(6-sulfo)GlcNAc beta-, Gal beta 1,3GalNAc alpha-, Gal beta 1,3Gal beta-, or Gal alpha 1,3Gal beta- units were 153.6%, 43.0%, 6.2%, 52.5%, 94.9%, 14.7%, 23.6%, and 15.6% active, respectively. (r) Fucosylation by alpha 1,2-L-FT of the galactosyl residue which occurs on the antennary structure of the bovine IgG glycopeptide was adversely affected by the presence of an alpha 1,6-L-fucosyl residue located on the distant glucosaminyl residue that is directly attached to the asparagine of the protein backbone. This became evident from the 4-fold activity of alpha 1,2-L-FT toward bovine IgG glycopeptide after approximately 5% removal of alpha 1,6-linked Fuo. 相似文献
5.
U V Varadaraju G V Subba Rao K D Chandrasekaran A Baradarajan K Krishnaiah Mukesh Agarwala V S Achutharaman P Venugopal K A Padmanabhan L S Vaidyanathan G Rangarajan 《Bulletin of Materials Science》1989,12(1):63-80
The oxygen-deficient phase of the highT
c superconductor, YBa2Cu3O7, was oxygen-enriched using the fluidization technique to give good superconducting properties. The normal method of oxygen
treatment at 900°C for 24 h and at 600°C for 24 h has been reduced to just one treatment at 600°C for 12 h by the fluidization
technique to achieve almost the same strength of superconducting signal for the YBa2Cu3O7 powder, which establishes the attractiveness of the latter route for the large-scale preparation of superconducting material.
The particle sizes were in the range 0–90, 90–180 and 180–420 μm. The fluidized particles were crystalline with orthorhombic
distortion.T
c
onset
, estimated using the a.c. magnetic susceptibility method, was 91·3 K. The volume fraction of superconducting material in
the product was 83·7–85·3%, one of the highest values reported so far for YBa2Cu3O7. 相似文献
6.
It is well known that low levels of light element impurities, such as oxygen and nitrogen, can significantly modify phase
equilibria in conventional titanium alloys. However, although the role of nitrogen and oxygen as alpha stabilizers is well
established, little quantitative work exists in ternary and higher order systems. Moreover the effect of such elements on
equilibria with phases other than cx-and P-Ti is often unknown. The problems in measuring light elements at the microscopic
level adds to the difficulty of establishing partitioning, and old axioms are often transferred to new alloys with little
evidence that they are applicable. As part of a current program on titanium alloys, phase diagram modeling has been performed
for a variety of titanium alloys with additions of oxygen and nitrogen. This paper presents results for the system Ti-Al-V-O-(N,C)
with particular reference to the O additions to the commercially important alloy Ti-6A1-4V.
This paper was presented at the International Phase Diagram Prediction Symposium sponsored by the ASM/MSD Thermodynamics and
Phase Equilibria Committee at Materials Week, October 21–23,1991, in Cincinnati, OH. The symposium was organized by John Morral,
University of Connecticut, and Philip Nash, Illinois Institute of Technology. 相似文献
7.
Characterization of surface micromachined metallic microneedles 总被引:1,自引:0,他引:1
The purpose of the paper is to provide quantitative characterization of metallic microneedles. Mechanical and fluid flow experiments were performed to evaluate the buckling force, the penetration force, and the pressure versus flow rate characteristics of the microneedles. The microneedle design variations characterized included varying the shaft lengths, varying the tip taper angles/geometries, and the inclusion of micromechanical barbs. The penetration force was found to range from 7.8 gF for a microneedle of shaft length 500 /spl mu/m, to 9.4 gF for a length of 1500 /spl mu/m, both with a tip taper angle of 30/spl deg/. Microneedles with a linear tip taper angle of 30/spl deg/ penetrated 95 +% of the time without failure. The microneedles with a 15/spl deg/ and 20/spl deg/ linear tip taper penetrated 10% and 25% of the time, respectively. The buckling force was found to be 98.4 gF for a 500 /spl mu/m long microneedle shaft, 72.3 gF for a needle of shaft length 1000 /spl mu/m, and 51.6 gF for a 1500 /spl mu/m long shaft. The results demonstrate that the penetration force was 7.9% of the buckling force for 500 /spl mu/m long shafts, 11.6% for a 1000 /spl mu/m long shaft, and 18.2% for a 1500 /spl mu/m long microneedle shafts. The microneedle fluid flow characteristics were studied. An inlet pressure of 49.0 Pa was required for a flow rate of 1000 /spl mu/L/h and 243.0 Pa for a flow rate of 4000 /spl mu/L/h using air as the fluid medium. For water, an average pressure of 30.0 kPa was required for a flow rate of 1000 /spl mu/L/h and 106.0 kPa for a flow rate of 4000 /spl mu/L/h. 相似文献
8.
Iyer Srikrishna Velmurugan T. Gandomi A. H. Noor Mohammed V. Saravanan K. Nandakumar S. 《Neural computing & applications》2021,33(11):5897-5915
Neural Computing and Applications - A multi-robot-based fault detection system for railway tracks is proposed to eliminate manual human visual inspection. A hardware prototype is designed to... 相似文献
9.
C. Christopher ColumbusAuthor Vitae K. Chandrasekaran Author VitaeSishaj P. Simon Author Vitae 《Applied Soft Computing》2012,12(1):145-160
This paper proposes a nodal ant colony optimization (NACO) technique to solve profit based unit commitment problem (PBUCP). Generation companies (GENCOs) in a competitive restructured power market, schedule their generators with an objective to maximize their own profit without any regard for system social benefit. Power and reserve prices become important factors in decision process. Ant colony optimization that mimics the behavior of ants foraging activities is suitably implemented to search the UCP search space. Here a search space consisting of optimal combination of binary nodes for unit ON/OFF status is represented for the movement of the ants to maintain good exploration and exploitation search capabilities. The proposed model help GENCOs to make decisions on the quantity of power and reserve that must be put up for sale in the markets and also to schedule generators in order to receive the maximum profit. The effectiveness of the proposed technique for PBUCP is validated on 10 and 36 generating unit systems available in the literature. NACO yields an increase of profit, greater than 1.5%, in comparison with the basic ACO, Muller method and hybrid LR-GA. 相似文献
10.
G. Van Tendeloo M. Chandrasekaran F. C. Lovey 《Metallurgical and Materials Transactions A》1986,17(12):2153-2161
β Cu-Zn-Al samples with different surface orientations have been examined by electron microscopy and diffraction. The nature
of the modulated microstructure or tweed and the accompanying diffuse streaking has been studied. Tweed in samples without
surface martensite is confirmed to be a subsurface phenomenon, and the diffuse streaking is attributed to both dynamic and
static {110}
displacement waves. The image contrast in samples with surface martensite is shown to be determined essentially by the surface
martensite features and probably tweed in the surface martensite. Possible reasons for the observed tweed are discussed.
Formerly at Division Metales, Centro Atómico Bariloche, Argentina. 相似文献