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Mitigating Carbon Emissions:A Comprehensive Analysis of Transitioning to Hydrogen-Powered Plants in Japan’s Energy Landscape Post-Fukushima
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作者 Nugroho Agung Pambudi Andrew Chapman +2 位作者 Alfan Sarifudin Desita Kamila Ulfa Iksan Riva Nanda 《Energy Engineering》 EI 2024年第5期1143-1159,共17页
One of the impacts of the Fukushima disaster was the shutdown of all nuclear power plants in Japan,reaching zero production in 2015.In response,the country started importing more fossil energy including coal,oil,and n... One of the impacts of the Fukushima disaster was the shutdown of all nuclear power plants in Japan,reaching zero production in 2015.In response,the country started importing more fossil energy including coal,oil,and natural gas to fill the energy gap.However,this led to a significant increase in carbon emissions,hindering the efforts to reduce its carbon footprint.In the current situation,Japan is actively working to balance its energy requirements with environmental considerations,including the utilization of hydrogen fuel.Therefore,this paper aims to explore the feasibility and implications of using hydrogen power plants as a means to reduce emissions,and this analysis will be conducted using the energy modeling of the MARKAL-TIMES Japan framework.The hydrogen scenario(HS)is assumed with the extensive integration of hydrogen into the power generation sector,supported by a hydrogen import scheme.Additionally,this scenario will be compared with the Business as Usual(BAU)scenario.The results showed that the generation capacities of the BAU and HS scenarios have significantly different primary energy supplies.The BAU scenario is highly dependent on fossil fuels,while the HS scenario integrates hydrogen contribution along with an increase in renewable energy,reaching a peak contribution of 2,160 PJ in 2050.In the HS scenario,the target of reducing CO2 emissions by 80%is achieved through significant hydrogen penetration.By 2050,the total CO2 emissions are estimated to be 939 million tons for the BAU scenario and 261 million tons for the Hydrogen scenario.In addition,the contribution of hydrogen to electricity generation is expected to be 153 TWh,smaller than PV and wind power. 展开更多
关键词 Business as usual(BAU)scenario hydrogen scenario CO2 emissions power generation sector
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Effect of PEG Incorporation on Physicochemical and in vitro Degradation of PLLA/PDLLA Blends:Application in Biodegradable Implants
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作者 Mochamad Chalid Gifrandy Gustiraharjo +3 位作者 Azizah Intan Pangesty Alyssa Adyandra Yudan Whulanza Sugeng Supriadi 《Journal of Renewable Materials》 EI 2023年第7期3043-3056,共14页
Polyethylene glycol(PEG)was added at different concentrations to the blend of poly(L-lactic acid)(PLLA)and poly(D,L-lactic acid)(PDLLA)to tailor the properties.The differential scanning calorimetry(DSC)measurement sho... Polyethylene glycol(PEG)was added at different concentrations to the blend of poly(L-lactic acid)(PLLA)and poly(D,L-lactic acid)(PDLLA)to tailor the properties.The differential scanning calorimetry(DSC)measurement showed that all blends were miscible due to shifting a single glass transition temperature into a lower temperature for increasing PEG content.The DSC,FTIR,and XRD results implied the crystallinity enhancement for PEG content until 8 wt%,then decreased at 12 wt%PEG.The XRD result indicated the homo crystalline phase formation in all blends and no stereocomplex crystal.The in vitro degradation study indicated that PEG content is proportional to the degradation rate.The highest weight loss after 28 days was achieved at 12 wt%PEG.The FTIR analysis showed a structural evolution overview during hydrolytic degradation,viz.increasing and decreasing crystallinity during 14 days for the blend without and with PEG,respectively.In conclusion,the PEG addition increased crystallinity and degradation rate of the PLLA/PDLLA mixture,but PEG higher amounts led to a decrease in crystallinity,and the weight loss was intensified.This can be useful for tuning PLA-based biomaterials with the desired physicochemical properties and appropriate degradation rates for applications in drug delivery/tissue engineering. 展开更多
关键词 PLLA PDLLA PEG CRYSTALLINITY degradation
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The Mechanical and Electronic Properties of Ternary Rare-Earth Hexaboride LaxNd8-xB6 (x = 0, 1, 7, 8) Materials
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作者 Cengiz Bozada 《Modeling and Numerical Simulation of Material Science》 2022年第1期1-11,共11页
We have carried out density functional theory to study the lattice constants and electronic properties of LaB<sub>6</sub>, NdB<sub>6</sub>, Nd-doped LaB<sub>6</sub>, and La-doped Nd... We have carried out density functional theory to study the lattice constants and electronic properties of LaB<sub>6</sub>, NdB<sub>6</sub>, Nd-doped LaB<sub>6</sub>, and La-doped NdB<sub>6</sub>. The lattice constant, intra-octahedral bond, inter-octahedral boron bond, and positional parameter (z) were calculated for LaB<sub>6</sub>, La<sub>7</sub>Nd<sub>1</sub>B<sub>6</sub>, La<sub>1</sub>Nd<sub>7</sub>B<sub>6</sub>, and NdB<sub>6</sub>. Our results show that the doped Nd increases the lattice constant of La<sub>7</sub>Nd<sub>1</sub>B<sub>6</sub>. Likewise, La-doping leads to an increase in the lattice constant of the La<sub>1</sub>Nd<sub>7</sub>B<sub>6</sub>. The PDOSs of LaB<sub>6</sub>, B of LaB<sub>6</sub>, La<sub>7</sub>Nd<sub>1</sub>B<sub>6</sub>, B of La<sub>7</sub>Nd<sub>1</sub>B<sub>6</sub>, La<sub>1</sub>Nd<sub>7</sub>B<sub>6</sub>, B of La<sub>1</sub>Nd<sub>7</sub>B<sub>6</sub>, NdB<sub>6</sub>, and B of NdB<sub>6</sub> were calculated. La d-electron bands cross the Fermi energy, showing classical conductor behavior. The charge density results indicate that light and dark colors show high and low-intensity zones, respectively. La<sub>1</sub>Nd<sub>7</sub>B<sub>6</sub> has a low-density region and LaB<sub>6</sub> has a high-density region. The LaB<sub>6</sub> midpoint has strong charge density peaks. Weak peaks are also observed for La<sub>1</sub>Nd<sub>7</sub>B<sub>6</sub>. Thus, ternary REB<sub>6</sub> has good potential for many applications. This article reports an investigation of the electronic features and structural parameters of binary and ternary hexaborides. 展开更多
关键词 Rare-Earth Hexaboride Lattice Constant PDOS Charge Density
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Electrochemical characterization of Ni-Co and Ni-Co-Fe for oxidation of methyl alcohol fuel with high energetic catalytic surface 被引量:4
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作者 Subir Paul Sk Naimuddin Asmita Ghosh 《燃料化学学报》 EI CAS CSCD 北大核心 2014年第1期87-95,共9页
Non Pt based metals and alloys as electrode materials for methyl alcohol fuel cells have been investigated w ith an aim of finding high electrocatalytic surface property for the faster electrode reactions.Electrodes w... Non Pt based metals and alloys as electrode materials for methyl alcohol fuel cells have been investigated w ith an aim of finding high electrocatalytic surface property for the faster electrode reactions.Electrodes w ere fabricated by electrodeposition on pure Al foil,from an electrolyte of Ni,Co,Fe salts.The optimum condition of electrodeposition w ere found out by a series of experiments,varying the chemistry of the electrolyte,pH valve,temperature,current and cell potential.Polarization study of the coated Ni-Co or Ni-CoFe alloy on pure Al w as found to exhibit high exchange current density,indicating an improved electro catalytic surface w ith faster charge-discharge reactions at anode and cathode and low overvoltage.Electrochemical impedance studies on coated and uncoated surface clearly show ed that the polarization resistance and impedance w ere decreased by Ni-Co or Ni-Co-Fe coating.X-ray diffraction(XRD),energy dispersive X-ray spectroscopy(EDX)and atomic absorption spectroscopy(AAS)studies confirmed the presence of alloying elements and constituents of the alloy.The morphology of the deposits from scanning electron microscope(SEM)images indicated that the electrode surface w as a three dimensional space w hich increased the effective surface area for the electrode reactions to take place. 展开更多
关键词 ELECTRODEPOSITION Ni-Co alloy ELECTROCATALYTIC exchange current density impedance X-ray diffraction(XRD) scanning electron microscope(SEM)
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Behavior of fluxed lime iron oxide pellets in hot metal bath during melting and refining 被引量:3
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作者 J. Pal S. Ghorai +3 位作者 M. C. Goswami D. Ghosh D. Bandyopadhyay S. Ghosh 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2013年第4期329-337,共9页
Lump lime as a fiux material in a basic oxygen furnace (BOF) often creates problems in operation due to its high melting point, poor dissolution property, hygroscopic nature, and fines generation tendency. To allevi... Lump lime as a fiux material in a basic oxygen furnace (BOF) often creates problems in operation due to its high melting point, poor dissolution property, hygroscopic nature, and fines generation tendency. To alleviate these problems, fluxed lime iron oxide pellets (FLIP) containing 30% CaO were developed in this study using waste iron oxide fines and lime. The suitable handling strengths of the pellet (crushing strength: 300 N; drop strength: 130 times) of FLIP were developed by treating with CO2 or industrial waste gas at room temperature, while no separate binders were used. When the pellet was added into hot metal bath (carbon-containing molten iron), it was decomposed, melted, and transformed to produce low melting oxidizing slag, because it is a combination of main CaO and Fe2O3. This slag is suitable for facilitating P and C removal in refining. Furthermore, the pellet enhances waste utilization and use of CO2 in waste gas. In this article, emphasis is given on studying the behavior of these pellets in hot metal bath during melting and refining along with thermodynamics and kinetics analysis. The observed behaviors of the pellet in hot metal bath confirm that it is suitable and beneficial for use in BOF and replaces lump lime. 展开更多
关键词 ore pellets LIME dissolution MELTING REFINING basic oxygen converters
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Electrochemical characterization of MnO_2 as electrocatalytic energy material for fuel cell electrode
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作者 Subir Paul Asmita Ghosh 《燃料化学学报》 EI CAS CSCD 北大核心 2015年第3期344-351,共8页
Development of inexpensive non Pt based high electrocatalytic energy materials is the need of the hour for fuel cell electrode to produce clean alternative green energy from synthesized bio alcohol using biomass. MnO ... Development of inexpensive non Pt based high electrocatalytic energy materials is the need of the hour for fuel cell electrode to produce clean alternative green energy from synthesized bio alcohol using biomass. MnO 2,electro synthesized at different current density is found to be well performed electrocatalytic material,comparable to Pt,with higher current density,very lowovervoltage for the electrochemical oxidation of methanol. From EIS study,the polarization resistance of the coated MnO 2is found to be much lowand electrical double layer capacitance is high,the effect increases with increase in current density of electro deposition. XRD,EDX and AAS analysis confirm the M nO 2deposition. The morphology of SEM images exhibits an enhanced 3D effective substrate area,for electro oxidation of the fuel. A fewnano structured grains of the deposited M nO 2is also observed at higher current density. The fact supports that a high energetic inexpensive electro catalytic material has been found for fuel cell electrode to synthesis renewable energy from methanol fuel. 展开更多
关键词 electro catalytic energy material fuel cell impedance polarization electro coating
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Comparative Studies on Synthesis and Characterization of Titania and Iron Oxide Doped Magnesia from Indian Salem Magnesite
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作者 Sukriti Manna Tamoghna Chakrabarti 《Journal of Materials Science and Chemical Engineering》 2016年第7期67-76,共10页
Sintering, densification, and characterization of Salem Magnesite with Titania (TiO<sub>2</sub>) and Iron Oxide (Fe<sub>2</sub>O<sub>3</sub>) addition have been carried out in this ... Sintering, densification, and characterization of Salem Magnesite with Titania (TiO<sub>2</sub>) and Iron Oxide (Fe<sub>2</sub>O<sub>3</sub>) addition have been carried out in this work. Salem Magnesite samples with 2 wt.% TiO<sub>2</sub> and Fe<sub>2</sub>O<sub>3</sub> addition have been sintered in the temperature range of 1550?C - 1650?C. The sintered sample has been characterized in terms of physico-chemical properties like bulk density, apparent porosity, specific gravity and structural properties by X-ray diffraction and scanning electron microscope (SEM). Salem magnesite samples with 2 wt.% TiO<sub>2</sub> and Fe<sub>2</sub>O<sub>3</sub> addition have been densified to the specific gravity of 3.75 and 3.41 g/cc respectively after sintering at 1650?C and 2 h. The presence of Calcium Titanate (CaTiO3) phase at the grain boundary has been observed in the case of TiO<sub>2</sub> addition. For Iron Oxide addition, precipitation of “Y” shaped magnesium ferrite spinel has been observed inside the grains. Finally, TiO2 addition in Salem Magnesite shows better densification compared to both as received Salem Magnesite and Salem Magnesite with Fe<sub>2</sub>O<sub>3</sub> addition. 展开更多
关键词 SINTERING Additive MAGNESITE DENSIFICATION
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Mechanical Properties of Epoxy Composite Materials Produced with Different Ceramic Powders
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作者 Yelda Akcin Ergün 《Journal of Materials Science and Chemical Engineering》 2019年第12期1-8,共8页
In this study, production and mechanical properties of polymer composite materials obtained by using Al2O3, SiO2, MgO and TiO2 hard ceramic fillers were studied. Epoxy resin was used as the matrix material, and four d... In this study, production and mechanical properties of polymer composite materials obtained by using Al2O3, SiO2, MgO and TiO2 hard ceramic fillers were studied. Epoxy resin was used as the matrix material, and four different ceramic powders were mechanically mixed into the resin at 3% and 5% as reinforcement. The mechanical properties of the polymer composite materials were then characterized. For this purpose, flexural modulus and flexural strength of composite materials were determined by using three point bending test and impact toughness of the materials were determined by Charpy impact test. In addition, the hardness values of the samples were determined by Shore D hardness test. 展开更多
关键词 Polymer Composite EPOXY Ceramic Powders Mechanical Properties
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Microbial leaching of chromite overburden from Sukinda mines,Orissa,India using Aspergillus niger 被引量:1
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作者 Supratim Biswas Saikat Samanta +2 位作者 Rajib Dey Siddhartha Mukherjee Pataki C.Banerjee 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2013年第8期705-712,共8页
Leaching of nickel and cobalt from two physical grades (S1, 125-190 μm, coarser and S3, 53-75 μm, finer) of chromite overburden was achieved by treating the overburden (2% pulp density) with 21-d culture filtrat... Leaching of nickel and cobalt from two physical grades (S1, 125-190 μm, coarser and S3, 53-75 μm, finer) of chromite overburden was achieved by treating the overburden (2% pulp density) with 21-d culture filtrate of an Aspergillus niger strain grown in sucrose medium. Metal dissolution increases with ore roasting at 600℃ and decreasing particle size due to the alteration of microstructural properties involving the conversion of goethite to hematite and the increase in surface area and porosity as evident from X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (DT- TGA), and field emission scanning electron microscopy (FESEM). About 65% Ni and 59% Co were recovered from the roasted S3 ore employing bioleaching against 26.87% Ni and 31.3% Co using an equivalent amount of synthetic oxalic acid under identical conditions. The results suggest that other fungal metabolites in the culture filtrate played a positive role in the bioleaching process, making it an efficient green approach in Ni and Co recovery from lateritic chromite overburden. 展开更多
关键词 nickeliferous laterite BIOLEACHING Aspergillus niger CHROMITE nickel metallurgy cobalt metallurgy
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Influence of cryogenic treatment on the wear characteristics of 100Cr6 bearing steel
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作者 R.Sri Siva D.Mohan Lal +1 位作者 P.Kesavan Nair M.Arockia Jaswin 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2014年第1期46-51,共6页
A series of reciprocating wear tests were performed on the deep cryogenically treated and conventionally heat-treated samples of 100Cr6 bearing steel to study the wear resistance. The worn surfaces as well as the wear... A series of reciprocating wear tests were performed on the deep cryogenically treated and conventionally heat-treated samples of 100Cr6 bearing steel to study the wear resistance. The worn surfaces as well as the wear debris were analyzed by scanning electron microscopy. The improvement in wear resistance of the deep cryogenically treated samples ranges from 49% to 52%. This significant improvement in wear resistance can be attributed to finer carbide precipitation in the tempered martensitie matrix and the transformation of retained aus- tenite into martensite. X-ray diffraction analysis shows that the volume fraction of retained austenite in the conventionally heat-treated samples is 14% and that of the deep cryogenically treated samples is only 3%. 展开更多
关键词 bearing steel cryogenic treatment wear resistance carbides MARTENSITE
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Study on Corrosion Behavior of Pearlitic Rail Steel
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作者 S. Samal A. Bhattaacharyya S.K. Mitra 《Journal of Minerals and Materials Characterization and Engineering》 2011年第7期573-581,共9页
The present study is an attempt to find out the effect of environmental corrosion on the commonly used pearlitic rail steel. The cases of corrosion of rail under Indian environment have been studied. It has been found... The present study is an attempt to find out the effect of environmental corrosion on the commonly used pearlitic rail steel. The cases of corrosion of rail under Indian environment have been studied. It has been found that in marine environment both the yield strength and tensile strength decreases with increasing corrosion rate. In acidic environment yield strength increased with increasing corrosion rate, although the tensile strength decreases with increasing corrosion rate. 展开更多
关键词 ATMOSPHERIC CORROSION MARINE ENVIRONMENT quasi-cleavage FRACTURE peralitic steel.
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Effect of Bitumen on the Mechanical Properties of Medium Carbon Steel
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作者 Abdulmumin Akoredeley Alabi Peter Bitrus Madakson +1 位作者 Danjuma Saleh Yawas Terver Ause 《Journal of Minerals and Materials Characterization and Engineering》 2013年第4期131-137,共7页
The effect of austempering of 0.45% carbon steel in hot bitumen on the hardness, impact strength, tensile properties and microstructure were investigated. The hardness values, impact strengths and tensile strengths of... The effect of austempering of 0.45% carbon steel in hot bitumen on the hardness, impact strength, tensile properties and microstructure were investigated. The hardness values, impact strengths and tensile strengths of the austempered samples increased almost linearly from the austempering time of 1 hour to 3 hours after which they all dropped. At the austempering time of 3 hours the maximum values of hardness, impact strength and tensile strength of 496.2HV, 149J and 706.2 N/mm2respectively were attained. These values are 24.5%, 4.9% and 25.8% higher than the hardness values, impact strength and tensile strength respectively of the as-received steel. The high impact strength and tensile strength recorded despite the high hardness value was probably due to the formation of bainite structure and the diffusion of carbon from the bitumen into the steel samples. 展开更多
关键词 BITUMEN AUSTEMPERING MECHANICAL Properties TENSILE STRENGTH IMPACT STRENGTH
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A Novel Layered Double Hydroxide and Dodecyl Alcohol Assisted PCM Composite with High Latent Heat Storage Capacity and Thermal Conductivity
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作者 AL-AHMED Amir SARI Ahmet +7 位作者 KHAN Firoz AL-RASHEIDI Masoud Hekimoğlu Gökhan AFZAAL Mohammad A.ALSULAMI Ahmed DAFALLA Hatim SALHI Billel A.ALSULAIMAN Fahad 《Journal of Thermal Science》 SCIE EI CAS CSCD 2024年第2期537-547,共11页
Dodecyl alcohol(DDA) is a promising solid-liquid phase change material(PCM) due to its favorable latent heat storage(LHS) characteristics.However,the leakage issue of PCM in a melted state during the heating period an... Dodecyl alcohol(DDA) is a promising solid-liquid phase change material(PCM) due to its favorable latent heat storage(LHS) characteristics.However,the leakage issue of PCM in a melted state during the heating period and low thermal conductivity restricts its utilization potential in thermal energy storage(TES) practices.Within the same context,the present work aims to overcome the leakage issue and improve the thermal conductivity of the DDA.With this in mind,a novel leak-proof layered double hydroxide(LDH)/DDA composite PCM is proposed through a solution-based impregnation method.The leak-proof impregnation ratio of the DDA impregnated within the cavities of the synthesized Al/Fe-LDH was determined to be 60%.Detailed morphological,physicochemical,and thermal properties of the fabricated composite were studied by scanning electron microscopy(SEM),Fourier transforms infrared(FTIR) spectroscopy,X-ray diffraction(XRD)spectroscopy,differential scanning calorimetry(DSC),thermalgravimetric analysis(TGA),and thermal cycling study.The results show that the LDH/DDA composite has a suitable phase change temperature(about 20℃) for passive solar thermal management of building envelopes.This composite PCM showed high LHS enthalpy(about136 J/g),good thermal stability,and cycling LHS reliability.It also showed nearly 152% higher thermal conductivity compared to that of pure DDA,ultimately reducing the melting and solidification time of the pure DDA by 44.9% and 45.5%,respectively. 展开更多
关键词 dodecyl alcohol layered double hydroxide composite PCM thermal conductivity thermal energy storage(TES)
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印度东部钛磁铁矿的氧化行为和相分析(英文) 被引量:1
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作者 Saikat SAMANTA Siddhartha MUKHERJEE Rajib DEY 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第9期2976-2985,共10页
钛磁铁矿是一种复杂的共生矿石,含有钛铁矿、磁铁矿、铁铝尖晶石和镁铁铝尖晶石等矿物。对从印度东部采集到的钛磁铁矿石进行XRD、WDXRF、SEM和M?ssbauer谱分析。在氧气气氛下,通过TG-DTA分析对矿石的氧化行为进行研究。随后,在氧气和... 钛磁铁矿是一种复杂的共生矿石,含有钛铁矿、磁铁矿、铁铝尖晶石和镁铁铝尖晶石等矿物。对从印度东部采集到的钛磁铁矿石进行XRD、WDXRF、SEM和M?ssbauer谱分析。在氧气气氛下,通过TG-DTA分析对矿石的氧化行为进行研究。随后,在氧气和空气气氛下,将样品在不同温度下(873-1473 K)保温不同时间,进行等温氧化实验。观察到在较低的温度下钛铁矿相转变为赤铁矿、氧化钛,而在较高的温度下转变为钛酸亚铁相。将氧化后的矿样与焦炭混合压制成圆柱形球团,在1473 K下进行直接还原,成功地实现了将磁铁矿铁转变为氧化铁和二氧化钛的相变。 展开更多
关键词 钛磁铁矿 热分析 相分析 氧化 还原
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冷却倾斜板铸造、再加热和触变锻造AA7075铝合金(英文) 被引量:1
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作者 Kerem Altug GULER Alptekin KISASOZ +1 位作者 Gokhan OZER Ahmet KARAASLAN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第11期2237-2244,共8页
冷却倾斜板铸造已成功应用于生产非枝晶组织铝合金的铸造中。为了研究半固态铸造对AA7075铝合金显微组织的影响,用冷却倾斜板浇铸法制备具有非枝晶组织的AA7075铸锭,并对其进行再加热和触变锻造。对铸件进行金相观察、图像分析、扫描电... 冷却倾斜板铸造已成功应用于生产非枝晶组织铝合金的铸造中。为了研究半固态铸造对AA7075铝合金显微组织的影响,用冷却倾斜板浇铸法制备具有非枝晶组织的AA7075铸锭,并对其进行再加热和触变锻造。对铸件进行金相观察、图像分析、扫描电镜和能谱分析。组织分析结果显示,材料的晶粒尺寸和球形度较好。在再加热过程中,晶粒可能突然变粗。冷却倾斜板铸造采用30°和60°倾斜角,采用60°倾斜角的结果更好。此外,短时再加热和半固态锻造致使固态晶粒中微量元素析出。 展开更多
关键词 半固态合金 冷却倾斜板铸造 触变锻造 AA7075合金
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Modeling and computation by artificial neural network of fracture toughness of low alloy steel to study the effect of alloy composition 被引量:1
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作者 Subir Paul Shibasish Bhattacharjee 《International Journal of Modeling, Simulation, and Scientific Computing》 EI 2018年第6期43-56,共14页
The unpredictable structure failures of carbon steel and low alloy steel leading to accidents may be caused by the propagation of a flaw or crack already present in the structure.Fracture toughness which describes the... The unpredictable structure failures of carbon steel and low alloy steel leading to accidents may be caused by the propagation of a flaw or crack already present in the structure.Fracture toughness which describes the ability of a material containing a crack to resist fracture is one of the most important material properties for design applications of metallic structures.Since this material property is influenced by several parameters,namely material chemistry,heat treatment,morphology of structure,it requires millions of experiments to be conducted to understand and predict it.So,mathematical modeling is one of the solutions to find the effect of these parameters and design future alloys.Stress–intensity factor(KIC)is a quantitative parameter of fracture toughness determining a maximum value of stress which may be applied to a specimen containing a crack(notch)of a certain length.An artificial neural network(ANN)model was developed using over 100 sets of data to study the effect of alloying elements on fracture toughness,KIC for the low alloy steel.20%of data was used for training,60%to develop predictive model and rest of the 20%for validation.The model can predict the fracture toughness of unknown new data close to 80%accuracy which is good enough for statistical modeling.The details of program code with ANN modeling steps have been explained.Prediction of fracture toughness by the model with variation of alloy composition as well as yield stress gives interesting and important information which may help in designing alloy which will resist crack propagation in a structure and hence enhance the life of structure to fail. 展开更多
关键词 Stress-intensity factor fracture toughness low alloy steel alloying elements ANN modeling prediction
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HIGH DIELECTRIC CONSTANT COMPOSITE BASED ON CHLOROPHYLL A ENTRAPPED NANOPOROUS SILICA GEL
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作者 J.S.MANNA M.K.MITRA +1 位作者 S.MUKHERJEE G.C.DAS 《Journal of Advanced Dielectrics》 CAS 2012年第3期64-72,共9页
Chlorophyll a(naturally occurring Mg porphyrene)has been entrapped in nano/porous silica gel using sol-gel method at room temperature,producing a stable composite.HR TEM observationreveals regular nanoscale[around 15-... Chlorophyll a(naturally occurring Mg porphyrene)has been entrapped in nano/porous silica gel using sol-gel method at room temperature,producing a stable composite.HR TEM observationreveals regular nanoscale[around 15-20 nm diameter]distribution of aggregated polycrystalinechlorophylla within porous silica matrix.UV-vis study also corroborates the presence of variousaggregated chlorophyll a species within the system.Low field measurement shows almost 400times enhancement of dielectric constant(1700)with incorporation of only 0.125 mg/ml of chlorophyll and the loss is 0.5 at room temperature at 100 Hz.The dielectric constant of the composite reaches 2500 as chlorophyll concentration becomes 1 mg/ml.Observed strong space charge response to the external field and strong frequency dispersion of the dielectric properties ofthe composite can be attributed to the long-range electron delocalization[nomadic polarization]in chlorophyl a aggregates.The electric modulus(M*)formalism used in this study enabled us todistinguish and separate various relaxation processes.It is found that with increasing chlorophyll concentration D.C.relaxation time decreases exponentially at room temperature.It is shown that observed relaxations do not perfectly follow the Debye response in high frequency region due toheterogeneous distribution of chlorophyll aggregates.The low values of room temperature acti-vation energy calculated from Arrhenius plot reveal that polaronic hopping phenomena is absent at grain-interfacial region due to low thermal energy. 展开更多
关键词 Nanoporous silica gel chlorophyll a DIELECTRIC dipole relaxation activation energy
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