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Effect of graphene and its derivatives on thermo-mechanical properties of phase change materials and its applications:a comprehensive review

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Frontiers in Energy 2022年第2期16卷 150-186页

作者： Sumit NAGAR Kamal SHARMA A.K.PANDEY v.v.TYAGI Department of Mechanical Engineering GLA UniversityMathura(U.P)-281406India Research Center for Nano-Materials and Energy Technology(RCNMET) School of Engineering and TechnologySunway University47500 Selangor Darul EhsanMalaysia School of Energy Management Shri Mata Vaishno Devi UniversityKatra 182320India

Phase change materials(PCMs)play a leading role in overcoming the growing need of advanced thermal management for the storage and release of thermal energy which is to be used for different solar ***,the effectiveness of PCMs is greatly affected by their poor thermal ***,in the present review the progress made in deploying the graphene(Gr)in PCMs in the last decade for providing the solution to the aforementioned inadequacy is presented and discussed in *** and its derivatives((Gr oxide(GO),Gr aerogel(GA)and Gr nanoplatelets(GNPs))based PCMs can improve the thermal conductivity and shape stability,which may be attributed to the extra ordinary thermo-physical properties of ***,it is expected from this review that the advantages and disadvantages of using Gr nanoparticles provide a deep insight and help the researchers in finding out the exact basic properties and finally the applications of Gr can be *** this work,Gr and its derivatives based PCMs was characterized by Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction spectroscopy(XRD),and scanning electron microscopy(SEM)by which crystal structure was known,phase was identified along with the knowledge of surface structure *** increase in the mass fraction(%)of the filler(Gr and its derivatives)led to even better thermo-physical properties and thermal *** thermal characterization was also done by differential scanning calorimetry(DSC),thermo gravimetric analysis(TGA)and thermal conductivity *** enthalpy of freezing and melting showed that Gr and its derivatives based PCMs had a very high energy storage capability as reflected in its various applications.

关键词： phase change materials(PCMs) graphene thermal conductivity characterization

Influence of the safety factor profile on the particle and heat transport in the Globus-M spherical tokamak

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Plasma Science and Technology 2019年第11期21卷 1-6页

作者： A YU TELNOvA G S KURSKIEv E O KISELEv N N BAKHAREv v K GUSEv N A KHROMOv S YU MEDvEDEv v B MIINAEv I v MIROSHNIKOv M I PATROv Yu v PETROv N v SAKHAROv A D SLADKOMEDOvA P B SHCHEGOLEv v v SOLOKHA v A TOKAREv S YU TOLSTYAKOv E A TUKHMENEvA Ioffe Institute Saint-Petersburg 194021Russia Keldysh Institute Russian Academy of SciencesMoscow 125047Russia NRC'Kurchatov Institute’ Moscow 123098Russia

The advanced tokamak scenario is a promising operation scenario for ITER and fusion neutron *** this scenario the minimum value of the safety factor in the center of the plasma exceeds *** the compact spherical tokamak Globus-M,the formation of such conditions is possible with neutral beam injection at the current ramp-up *** to the slower diffusion of current inside the plasma,a zone is formed with reduced heat and particle transport across the magnetic field,which affects the temperature and density profiles of the *** leads to the peaked density profile formation and improvement of the energy confinement *** achieve a high fraction of the bootstrap current,it is necessary to increase the plasma *** the same time,the maximum allowable pressure is limited to the normalized beta limit.

关键词： advanced tokamak mode transport analysis internal transport barriers

MgCo2-D2 and MgCoNi-D2 systems synthesized at high pressures and interaction mechanism during the HDDR processing

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Progress in Natural Science:Materials International 2017年第1期27卷 74-80页

作者： Chubin Wan v.E.Antonov R.v.Denys v.I.Kulakov v.A.Yartys University of Science and Technology Beijing Institute for Energy Technology Institute of Solid State Physics Russian Academy of Sciences HYSTORSYS AS Norwegian University of Science and Technology

MgCo2and MgNiCo crystallize with hexagonal Laves type intermetallic structures of the C14 type and do not form hydrides at ambient hydrogen pressures. However, applying high hydrogen pressures in the GPa range forces the hydrogen absorption and leads to the formation of multi-phase compositions, which contain approximately 2.5 atoms H per formula unit of MgCo2or MgNiCo and remain thermally stable under normal *** hydrogenation of MgCo2resulted in its decomposition to a ternary Mg2CoD5deuteride and metallic cobalt. Phase-structural transformations accompanying the vacuum desorption of deuterium in the temperature range of 27–500 °C were studied using in situ neutron powder diffraction. The investigation showed a complete recovery of the initial MgCo2intermetallic via a Hydrogenation-Disproportionation-Desorption-Recombination process. At 300°C, the Mg2CoD5deuteride first decomposed to elementary Mg and hexagonal Co. At 400°C, a MgCo phase was formed by interaction between Mg and Co. At the highest processing temperature of 500°C, a solid-state interaction of MgCo and Co resulted in the recovery of the initial *** interaction of MgNiCo with deuterium under the synthesis conditions of 2.8 GPa and 200 °C proceeded in a more complex way. A very stable ternary deuteride MgNi2D3was leached away while Co was separated in the form of Mg2CoD5and the remaining nickel formed a solid solution with Co with the approximate composition *** thermal desorption of deuterium from MgCo2D2.5and from MgNiCoD2.5has been studied by Thermal Desorption Spectroscopy with deuterium released into a closed volume. The observed effects nicely correlate with changes in the phase structural composition of the hydrides ***2is a new example of the hydrogen storage alloy, in which a successful HDDR processing results in the reversible formation of the initial intermetallic at much lower temperatures than in the equilibrium phase diagram of the Mg-Co system.

关键词： Intermetallics Hydrogen storage materials Neutron powder diffraction High pressure synthesis Phase-structural transformations Magnesium Cobalt Nickel

Unveiling the atomic-scale transition between light harvesting and photoprotective states in plant photosynthesis

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Science China Chemistry 2024年第5期67卷 1375-1377页

作者： Alexander v.Ruban School of Biological and Behavioural Sciences Queen Mary University of LondonLondon E14NSUK

Non-photochemical chlorophyll fluorescence quenching(NPQ) stands as a cornerstone in the realm of photosynthesis research, attracting generations of dedicated scientists in their quest to unravel its mysteries. This mechanism, crucial for safeguarding photosynthesis, plays a pivotal role in regulating light harvesting, particularly in oxygenic photosynthesis where the oxygen-evolving photosystem II (PSII)is susceptible to photodamage [1].

关键词： harvesting protective attracting

Optimizing the Pulsed Current Gas Tungsten Arc Welding Parameters

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Journal of Materials Science & Technology 2006年第6期22卷 821-825页

作者： M.Balasubramanian v.Jayabalan v. Balasubramanian Department of Production Engineering Sathyabama Institute of Science and TechnologyIndia Department of Manufacturing Engineering Anna UniversityIndia Department of Manufacturing Engineering Annamalai UniversityIndia

The selection of process parameter in the gas tungsten arc （GTA） welding of titanium alloy was presented for obtaining optimum grain size and hardness. Titanium alloy （Ti-6Al-4v） is one of the most important non-ferrous metals which offers great potential application in aerospace, biomedical and chemical industries, because of its low density （4.5 g/cm^3）, excellent corrosion resistance, high strength, attractive fracture behaviour and high melting point （1678℃）. The preferred welding process for titanium alloy is frequent GTA welding due to its comparatively easier applicability and better economy. In the case of single pass （GTA） welding of thinner section of this alloy, the pulsed current has been found beneficial due to its advantages over the conventional continuous current process. Many considerations come into the picture and one needs to carefully balance various pulse current parameters to reach an optimum combination. Four factors, five level, central composite, rotatable design matrix were used to optimize the required number of experimental conditions. Mathematical models were developed to predict the fusion zone grain size using analysis of variance （ANOvA） and regression analysis. The developed models were optimized using the traditional Hooke and Jeeve＇s algorithm. Experimental results were provided to illustrate the proposed approach.

关键词： Pulsed current Gas tungsten arc welding Titanium alloy Design of experiments ANOvA, Hooke and Jeeve's algorithm Grain size Hardness

Express Methods for Measurement of Electroconductivity of Semiconductor Layered Crystal

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Chinese Physics Letters 2015年第11期32卷 114-117页

作者： FILIPPOv v. v. vLASOv A. N. Department of Physics Lipetsk State Pedagogical University Lipetsk 398020 Russian Federation Department of Natural Sciences and Technical Disciplines the Branch in Lipetsk of Moscow State University of Technologies and Management Lipetsk 398006 Russian Federation

We describe theoretically the grounded method of measuring the conductivity of anisotropic layered semiconductor materials. The suggested method implies the use of a four-probe testing device with a linear arrangement of probes. The final expressions for identifying the electrical conductivity are presented in the form of a series of analytic functions. The suggested method is experimentally verified, and practical recommendations of how to apply it are also provided.

关键词： Express Methods for Measurement of Electroconductivity of Semiconductor Layered Crystal

Process Parameter Optimization of the Pulsed Current Argon Tungsten Arc Welding of Titanium Alloy

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Journal of Materials Science & Technology 2008年第3期24卷 423-426页

作者： M.Balasubramanian v.Jayabalan v.Balasubramanian Department of Mechanical Engineering Maamallan Institute of Technology Department of Manufacturing-Engineering Anna University Department of Manufacturing Engineering Annamalai University

The selection of process parameters for obtaining optimal tensile properties in the pulsed current gas tungsten arc welding is presented. The tensile properties include ultimate tensile strength, yield strength and notch tensile strength. All these characteristics are considered together in the selection of process parameters by modified taguchi method to analyse the effect of each welding process parameter on tensile properties. Experimental results are furnished to illustrate the approach.

关键词： Pulsing current Modified taguchi method Tensile properties

A NEW APPROACH TO SOLvE SYSTEMS OF LINEAR EQUATIONS

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Journal of Computational Mathematics 2001年第4期19卷 445-448页

作者： v á squez, Luis v á squez-Poletti, Jos é L. Universidad Complutense 西班牙 E-28040 Universidad Pontificia Comillas 西班牙 E-28015

Presents a study which proposed an iterative approach to solve systems of linear equations. Definition of two families of convergent iterative methods; Features of the iterative method; Application of the method to a ... 详细信息

关键词： Iterative method Linear systems Classical dynamics.

Effect of Multiple Martensitic Transformations on Structure of Fe-Ni Alloys

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Journal of Materials Science & Technology 2013年第3期29卷 279-282页

作者： v.Danilchenko Ie.Dzevin v.Sagaradze G.v.Kurdyumov Institute of Metal Physics NAS of UkraineKievUkraine Institute of Metal Physics Ural Division of RASEkaterinburgRussia

Effect of multiple direct and reverse martensitic transformations on fragmentation of austenitic grains in Fe-Ni alloys have been studied by X-ray diffraction and scanning electron microscopy. An ultra-fine structure was formed by fragmentation inside austenitic grains due to progressing misorientation of austenitic sub-grains during multiple γ-α-γ-martensitic phase transitions. An increase in the number of γ-α-γ-transformations increases misorientation angle between austenitic sub-grains and leads to transformation of an austenitic single crystal into a textured polycrystal. It has been shown that multiple γ-α-γ-martensitic phase transitions change the mechanism of internal stress relaxation from dislocation-based to deformation twinning.

关键词： Austenite Crystal lattice Ultra-fine structure Martensitic transformation