总被引：1，自引：0，他引：1  

D. Senthilkumar  I. Rajendran  M. Pellizzari 《Journal of Materials Processing Technology》2011,211(3):396-401

The present research work studies the effect of cryogenic treatment on the residual stress state in 4140 steel. Two kinds of cryogenic treatment, namely shallow (SCT, −80 °C × 5 h) and deep cryogenic treatment (DCT, −196 °C × 24 h) were carried out between quenching and tempering in conventional heat treatment process. The results evidenced an increase in the compressive residual stress in steel are subjected to cryogenic treatment before tempering. X-ray diffractometry revealed that residual stresses are relieved during tempering, according to the redistribution of carbon in martensite and the precipitation of transition carbides. While conventional heat treatment (CHT) and shallow cryogenic treatment (SCT) promote a tensile state of residual stress, DCT shows a compressive residual stress.  相似文献   

    

Jihye Yong;Yu Kyung Lee;Hansol Park;Senthilkumar Muthu;Juhwan Shin;Dong Ryeol Whang;Bong-Gi Kim;Dong Wook Chang;Hui Joon Park; 《Advanced functional materials》2024,34(14):2312505

Interfacial engineering in organic–inorganic hybrid perovskite solar cells (PSCs) has attracted significant attention, aiming to achieve high-performing and highly stable devices. Here, newly designed organic small molecules based on quinoxaline and triphenylamine for inverted type wide-bandgap PSCs are introduced, with the objective of enhancing the interfacial properties between perovskite and NiOx hole transport layer (HTL). The incorporation of an organic interlayer effectively reduces the energy level offset between the HTL and wide-bandgap perovskite, while passivating defects within the perovskite layer. It leads to improved charge extraction and minimized non-radiative recombination at the interface. Furthermore, the enhanced interfacial characteristics and hydrophobicity contribute to the improvement of perovskite film quality, resulting in larger grain size and higher crystallinity. As a result, the power conversion efficiency (PCE) of the PSC is enhanced from 18.9% to 20.1% with the incorporation of the IQTPAFlu interlayer, accompanied by an increase in Voc to ≈1.3 V, achieving a significantly low Voc deficit of 0.46 V. And the IQTPAFlu-based devices demonstrate stable and consistent performance over 500 h, with ≈91% of their initial PCE retained. The highly stable wide-bandgap PSCs, characterized by high Voc and PCEs, hold great promise as potential candidates for tandem solar cells.  相似文献   

    

M. Divya  Arun Krishna Vellore Sripathibabu  Senthilkumar Rajendran 《Structural Concrete》2023,24(4):5197-5214

The longitudinal shear forces are transferred through mechanical shear connectors at the steel beams and concrete slab intersection in composite beams. The shear connectors can be directly welded to the hot rolled steel beam, which is difficult in thin, cold-formed steel beams. Thus, a cold-formed double-channel shear connector is proposed, and its suitability is investigated in this study. The double channel shear connector is a channel shaped shear connector formed from a flat plat and it is mounted on the flange of steel beam in pairs. The finite element model of the experimental Pushout test assembly was developed with the equivalent numerical constraints and interaction commands in a finite element software (ABAQUS). The developed models were fed with initial imperfection, load slip response, and material nonlinearity to achieve the proper experiment simulation. Initially, the developed models were validated against nine experimental test data reported by authors in the previous study. The parametric study was conducted to assess the behavior of cold-formed channel shear connectors. The key parameters adopted in this study are the length of the shear connector, the grade of concrete and the grade and thickness of the steel connector. Three common failure patterns were witnessed among 107 numerical models. In this study, the factors influencing the control of failure patterns are presented, along with the factors influencing the shear connector's ultimate capacity.  相似文献   

    

S. Senthilkumar  V. Samuthira Pandi  T. Sripriya  N. Pragadish 《Concurrency and Computation》2023,35(8):e7629

Recustomize finite impulse response (RFIR) filter is designed to achieve lesser power consume, cost, area, and higher speed of system operation. This is used to remove the noises from the image and signal. Previously, several filters were designed for removing noises, but that filters consume more area, power, cost, and delay and did not provide accurate results and the error rate was increased. To overcome these issues, this work is proposed. In this work, the Recustomize finite impulse response (RFIR) filter is designed using truncation-based scalable rounding approximate multiplier (TOSAM) and error reduced carry prediction approximate adder (ERCPAA) for image processing application. Here, TOSAM-ERCPAA is used to speed up the filter design with less area and less power consumption. The proposed ERCPAA adder is divided into three blocks, such as carry prediction logic, approximate full adder cells array, constant truncation along error lessening logic, which can reduce the power and area. The proposed RFIR- TOSAM-ERCPAA filter is designed and executed in Verilog programming language and the simulation is done in Xilinx ISE 14.5 design tools.  相似文献   

    

Periasamy Vijay  Moses O. Tad  Zongping Shao 《国际能源研究杂志》2019,43(7):2478-2500

A 2‐stage model validation strategy for the previously developed solid oxide fuel cell model using the data from custom‐designed experiments is presented. The strategy is based on the identification of model structural and parametric errors. In the preliminary validation, the causes that can result in the voltage error during changing temperature and fuel flow rate conditions are analysed. It is identified that the convection heat transfer process contributes significantly towards the cell performance in a temperature controlled test environment. Rectification of this error results in the reduction of the maximum voltage error from 14% to 0.5%. Graphical methods for data visualisation are utilised to examine goodness of fit of the model. Input sensitivity analysis reveals that the air flow rate has negligible influence on the output quantities of current density, fuel utilisation, and cell temperature owing to temperature‐controlled conditions of the test. Parameter sensitivity analysis through the elementary effects method reveals that most of the electrochemical parameters in general and the activation energies in particular have dominant effects on the considered system outputs. Model validation is carried out through a classical statistical method of hypothesis testing by using the parameter uncertainty information obtained through nonlinear least squares fitting. The efficacy of the model validation strategy is demonstrated through the model acceptance with 8% maximum error in cell current.  相似文献   

  总被引：1，自引：0，他引：1  

Shahin Hosseini  Periasamy Vijay  Khaliq Ahmed  Moses O. Tadé  Vishnu Pareek  Ranjeet Utikar 《国际能源研究杂志》2017,41(11):1563-1578

A dynamic tank in series reactor model of a direct internally reforming solid oxide fuel cell is presented and validated using experimental data as well as a computational fluid dynamics (CFD) model for the spatial profiles. The effect of the flow distribution pattern at the inlet manifold on the cell performance is studied with this model. The tank in series reactor model provides a reasonable understanding of the spatio‐temporal distribution of the key parameters at a much lesser computational cost when compared to CFD methods. The predicted V–I curves agree well with the experimental data at different inlet flows and temperatures, with a difference of less than ±1.5%. In addition, comparison of the steady‐state results with two‐dimensional contours from a CFD model demonstrates the success of the adopted approach of adjusting the flow distribution pattern at the inlet boundaries of different continuous stirred tank reactor compartments. The spatial variation of the temperature of the PEN structure is captured along with the distributions of the current density and the anode activation over‐potential that strongly related to the temperature as well as the species molar fractions. It is found that, under the influence of the flow distribution pattern and reaction rates, the dynamic responses to step changes in voltage (from 0.819 to 0.84 V), fuel flow (15%) and temperature changes (30 °C), on anode side and on cathode side, highly depend on the spatial locations in the cell. In general, the inlet points attain steady state rapidly compared to other regions. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

    

A Saravana Kumaar  A Senthilkumar  T Sornakumar  S.S Saravanakumar  V.P Arthanariesewaran 《Journal of Natural Fibers》2019,16(2):175-184

This article presents the characteristics of Carica papaya fibers (CPFs) extracted from the bark of the perennial papaya plant. Detailed chemical compositions of CPFs such as cellulose, lignin, ash, moisture, and wax contents were established and determined by using standard methods. Further, chemical groups, crystalline structure, surface roughness, and thermal stability of CPFs were examined using Fourier transform infrared analysis, X-ray diffraction, atomic force microscope, and thermogravimetric analysis, respectively. The physico-chemical properties of CPFs, crystallinity index (56.34%), cellulose content (38.71 wt. %), hemicellulose (11.8%), and density (943 kg/m³) were compared to those properties of other natural fibers. The results suggest that the biodegradable CPFs can be used as a potential reinforcemnet in the polymer matrix composite structure.  相似文献   

    

Saravanakumar Kannivel  Kailashbalan Periasamy  Arumugam Vellayaraj 《Polymer Composites》2019,40(6):2441-2451

In this research work, the low‐velocity impact behavior and post impact performance of carbon/epoxy laminates modified with milled glass fibers was investigated. Unidirectional (UD) and Cross‐ply (CP) carbon/epoxy laminates were incorporated with milled glass fibers by 5 wt% of epoxy. Low‐velocity impact test was performed at impact velocity of 3, 3.5, 4, 4.5, and 5 m/s, respectively and the results were correlated with the baseline samples without filler. The filler loaded samples exhibited higher peak force, lesser deformation, and lower damage degree than the baseline samples. The milled glass fibers in the interlaminar zone restricts the delamination crack propagation resulting in reduced impact damage area and also promotes additional energy dissipation mechanism including filler debonding/pullout. Furthermore, the CP filler‐loaded samples show higher residual load‐bearing capacity for impact velocities 3, 3.5, and 4 m/s, respectively. Although the unidirectional filler‐loaded samples showed better load bearing capacity for impact velocities beyond 4 m/s. POLYM. COMPOS., 40:2441–2451, 2019. © 2018 Society of Plastics Engineers  相似文献   

    

Senthilkumar Pachiyappan  Dawn Shanmuganatham Selvanantham  Sree Samanvitha Kuppa  Saipriya Chandrasekaran  Antony Vincent Samrot 《IET nanobiotechnology / IET》2019,13(4):416

In this study, polyhydroxybutyrate (PHB) nanoparticles were synthesised following nanoprecipitation method having different solvents and surfactant (Tween 80) concentrations. In this study, PHB nanoparticles were encapsulated with curcumin and subjected for sustained curcumin delivery. Both the curcumin loaded and unloaded PHB nanoparticles were characterised using FTIR, SEM, and AFM. Sizes of the particles were found to be between 60 and 300 nm. The drug encapsulation efficiency and in vitro drug release of the nanoparticles were analysed. Antibacterial activity and anticancer activity were also evaluated. The LC₅₀ values of most of the nanoparticles were found to be between 10 and 20 µg/100 µl, anticancer activity of curcumin loaded PHB nanoparticles were further confirmed by AO/PI staining and mitochondrial depolarisation assay.Inspec keywords: encapsulation, cancer, scanning electron microscopy, nanoparticles, surfactants, drugs, nanofabrication, antibacterial activity, biomedical materials, drug delivery systems, polymers, nanomedicine, Fourier transform infrared spectra, precipitation (physical chemistry), atomic force microscopy, particle sizeOther keywords: surfactant‐mediated synthesis, polyhydroxybutyrate nanoparticles, sustained drug delivery, surfactant concentrations, PHB nanoparticles, sustained curcumin delivery, drug encapsulation efficiency, anticancer activity, in vitro drug release, nanoprecipitation method, Tween 80, FTIR spectra, SEM, AFM, particle sizes, antibacterial activity, AO‐PI staining, mitochondrial depolarisation assay  相似文献   

    

Wilfred Ruban Savariraj  Narendra Babu Ravindran  Porteen Kannan  Raja Paramasivam  TMA Senthilkumar  Peria Kumarasamy  Veluru Appa Rao 《Journal of Food Safety》2019,39(1)

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