Journal articles on the topic 'Constrained thermal expansion'
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1
Ho, S., and Z. Suo. "Tunneling Cracks in Constrained Layers." Journal of Applied Mechanics 60, no. 4 (December 1, 1993): 890–94. http://dx.doi.org/10.1115/1.2900998.
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A thin, brittle layer bonded between tougher substrates is susceptible to cracking under residual and applied stresses. Such a crack initiates from an equi-axed flaw, confined by the substrates, tunneling in the brittle layer. Although tunneling is a three-dimensional process, the energy release rate at the front of a steady-state tunnel can be computed using plane strain fields. Several technically important problems are analyzed, including tunnels in adhesive joints, shear fracture, and kinked tunnels in a reaction product layer. The concept is finally applied to microcracking in brittle matrix composites caused by thermal expansion mismatch.
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Sahu, Chinmay, V. Kirubakaran, TK Radhakrishnan, and N. Sivakumaran. "Explicit model predictive control of split-type air conditioning system." Transactions of the Institute of Measurement and Control 39, no. 5 (December 16, 2015): 754–62. http://dx.doi.org/10.1177/0142331215619976.
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Domestic air conditioners are a major source of energy consumption. In this study, utilizing real-time data from a public domain, a cascaded hardware in loop approach to the control of room temperature is considered. An inner loop to control the supply air temperature by adjusting the electronic expansion valve using a second-order plus delay time model is proposed. The room temperature control is considered the outer loop. A simplified lumped parameter representation of the thermal dynamics of the building is modelled in MATLAB using ordinary differential equations. A constrained multi parametric model predictive controller (mpMPC) is designed for both the control loops. The constraints include safety limits on the superheat and manipulation rates for the inner loop and a rate constraint on the reference signal in the outer loop. Model uncertainties like ambient temperature and thermal load variations (representing an office space) are considered for hardware in the loop testing of the proposed strategy. From performance analysis, using power spent and thermal comfort quantization, it is observed that the mpMPC scheme outperforms traditional control strategies.
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Wang, Lucai, Yanli Wang, Xiaohong You, and Fang Wang. "Foaming Behavior and Pore Structure Evolution of Foamed Aluminum under the Extrusion Constraint." Advances in Materials Science and Engineering 2020 (December 22, 2020): 1–10. http://dx.doi.org/10.1155/2020/3948378.
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This study evaluates foaming behavior and pore structure evolution of aluminum foam by cross-sectional image processing, which was prepared by the powder compact melting (PCM) method under the constraint. The results revealed that the heating time and the heating rate are the key factors affecting the foaming behavior and pore structure of aluminum foam. The thermal decomposition of the foaming agent and aluminum melting behavior affect the foam expansion under different heating times and heating rates. The evolution of the pore structure during the foaming process includes pore formation, small-sized spherical pores, large-sized spherical pores, polygonal pores, merging, and collapse. Due to the limitation of the pipe wall, the maximum expansion height and porosity are constrained, and the macrostructure of aluminum foam is improved.
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Wendt, David, Emil Bozin, Joerg Neuefeind, Katharine Page, Wei Ku, Limin Wang, Brent Fultz, Alexei V. Tkachenko, and Igor A. Zaliznyak. "Entropic elasticity and negative thermal expansion in a simple cubic crystal." Science Advances 5, no. 11 (November 2019): eaay2748. http://dx.doi.org/10.1126/sciadv.aay2748.
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While most solids expand when heated, some materials show the opposite behavior: negative thermal expansion (NTE). In polymers and biomolecules, NTE originates from the entropic elasticity of an ideal, freely jointed chain. The origin of NTE in solids has been widely believed to be different. Our neutron scattering study of a simple cubic NTE material, ScF3, overturns this consensus. We observe that the correlation in the positions of the neighboring fluorine atoms rapidly fades on warming, indicating an uncorrelated thermal motion constrained by the rigid Sc-F bonds. This leads us to a quantitative theory of NTE in terms of entropic elasticity of a floppy network crystal, which is in remarkable agreement with experimental results. We thus reveal the formidable universality of the NTE phenomenon in soft and hard matter.
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Nowok, J. W., J. P. Kay, and R. J. Kulas. "Thermal expansion and high-temperature phase transformation of the yttrium silicate Y2SiO5." Journal of Materials Research 16, no. 8 (August 2001): 2251–55. http://dx.doi.org/10.1557/jmr.2001.0309.
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The linear thermal-expansion coefficients of yttrium silicate Y2SiO5, [Y2(SiO4)O] were measured in the temperature range from 20 to 1400 °C using x-ray diffraction. The anomalous behavior of thermal expansion was observed above Tc = 850 °C and was attributed to the displacive phase transformation. The transformation was reversible and resulted from the local order °C the compositional disorder and local fluctuation in the elastic free energy constrained a secondary transformation related to the polymorphic twin transformation. This created an additional peak in x-ray diffraction patterns at 2 's intensity. The characteristic of phase transformation both on heating and on cooling of the sample was also investigated using the differential thermal analysis method. The thermogravimetric technique did not indicate on a change of weight at Tc.
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Li, Hui Fang, Cai Fu Qian, and Xiao Dong Yu. "Thermal Stress Analysis of a Tubesheet with a Welding Clad." Advanced Materials Research 201-203 (February 2011): 302–7. http://dx.doi.org/10.4028/www.scientific.net/amr.201-203.302.
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In this paper, numerical simulation was carried out for the tube bundle of a slurry oil steam generator with concentration on the thermal stresses at the tubesheet with or without a welding clad on the tubesheet surface. It is found that as having a larger heat expansion coefficient, thermal expansion of the welding clad is constrained and most areas are in compressive state. But the tensile stresses in the clad are also notable especially at the interface and could break the clad if added by the tensile stresses produced by pressure loadings. Presence of the welding clad causes significant tensile stresses in the base tubesheet. It is possible that the maximum tensile stress comprised by the thermal tensile stress and pressure induced tensile stress will exceed the tensile strength of the material and cause initiation of cracks in the tubesheet.
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Solanki, Prem K., and Yoed Rabin. "Perspective: Temperature-Dependent Density And Thermal Expansion Of Cryoprotective Agents." Cryoletters 43, no. 1 (January 1, 2022): 1–9. http://dx.doi.org/10.54680/fr22110110112.
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Density is a key thermophysical property, affecting the response of materials to temperature changes in different ways, consistent with the phase of state. In fluids, temperature variation across the domain leads to colder areas being heavier than warmer areas, where buoyancy effects drive fluid flow and thereby increase heat transfer. This phenomenon is known as natural heat convection, which in general is a more efficient heat transfer mechanism than heat conduction in the absence of flow. In solids, where the material is locked in place, colder areas tend to contract while warmer areas tend to expand, leading the material to deform. When this deformation is constrained by the geometry of the domain and/or its container, mechanical stresses develop. This phenomenon is known as thermomechanical stress (or thermal stress), which can lead to structural damage such as fractures. The picture becomes even more complex during vitrification (or glass formation), where the material gradually changes from liquid to an amorphous solid over a significant temperature range. There, due to temperature variation across the domain, fluid mechanics and solid mechanics effects may coexist. It follows that characterization of the density as a function of temperature is crucial for the analyses of thermal, fluid, and mechanical effects during cryopreservation, with the goals of protocol planning, optimization, and preserving structural integrity. For this purpose, the current study focuses on the density of the material and its companion property of thermal expansion. Specifically, this paper reviews literature data on thermal expansion of cryoprotective agents (CPAs), discusses the mathematical relationship between thermal expansion and density, and presents new calculated density data. This study focuses on the CPA cocktails DP6, VS55, M22, and their key ingredients at various concentrations, including DMSO, propylene glycol, and formamide. Data for DP6 combined with a selection of synthetic ice modulators (SIMs) are further presented.
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REPETTO, CARLOS E., and OSCAR P. ZANDRON. "PERTURBATIVE EXPANSION FOR THE t-J MODEL CONSTRUCTED FROM THE GENERATORS OF THE SUPERSYMMETRIC HUBBARD ALGEBRA." International Journal of Modern Physics B 23, no. 14 (June 10, 2009): 3159–77. http://dx.doi.org/10.1142/s0217979209052856.
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By using the Hubbard [Formula: see text]-operators as field variables along with the supersymmetric version of the Faddeev–Jackiw symplectic formalism, a family of first-order constrained Lagrangians for the t-J model is found. In order to satisfy the Hubbard [Formula: see text]-operator commutation rules satisfying the graded algebra spl(2,1), the number and kind of constraints that must be included in a classical first-order Lagrangian formalism for this model are presented. The model is also analyzed via path-integral formalism, where the correlation-generating functional and the effective Lagrangian are constructed. In this context, the introduction of a proper ghost field is needed to render the model renormalizable. The perturbative Lagrangian formalism is developed and it is shown how propagators and vertices can be renormalized to each order. In particular, the renormalized ferromagnetic magnon propagator arising in the present formalism is discussed. As an example, the thermal softening of the magnon frequency is computed.
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Rajak, Neeraj K., Neha Kondedan, Husna Jan, Muhammed Dilshah U, S. D. Navya, Aswathy Kaipamangalath, Manoj Ramavarma, Chandrahas Bansal, and Deepshikha Jaiswal-Nagar. "Setup of high resolution thermal expansion measurements in closed cycle cryostats using capacitive dilatometers." Journal of Physics Communications 5, no. 12 (December 1, 2021): 125004. http://dx.doi.org/10.1088/2399-6528/ac3a44.
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Abstract We present high resolution thermal expansion measurement data obtained with high relative sensitivity of ΔL/L = 10−9 and accuracy of ± 2 % using closed cycle refrigerators employing two different dilatometers. Experimental details of the set-up utilizing the multi-function probe integrated with the cold head of two kinds of closed cycle refrigerators, namely, pulse tube and Gifford-McMahon cryocoolers, has been described in detail. The design consists of decoupling the bottom sample puck and taking connections from the top of the multi-function probe to mitigate the vibrational noise arising from the cold heads, using which smooth and high quality thermal expansion data could be obtained. It was found that dilatometer#2 performs a better noise mitigation than dilatometer#1 due to the constrained movement of the spring in dilatometer#2. This was confirmed by finite element method simulations that were performed for understanding the spring movement in each dilatometer using which the effect of different forces/pressures and vibrations on the displacement of the spring was studied. Linear thermal expansion coefficient α obtained using both dilatometers was evaluated using derivative of a polynomial fit. The resultant α obtained using dilatometer#2 and either of the closed cycle cryostats on standard metals silver and aluminium showed excellent match with published values obtained using wet cryostats. Finally, thermal expansion measurements is reported on single crystals of two high temperature superconductors YBa2Cu3−x Al x O6+δ and Bi2Sr2CaCu2O8+x along the c-axis with very good match found with published data obtained earlier using wet liquid helium based cryostats.
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Staroszczyk, Ryszard. "On maximum forces exerted by floating ice on a structure due to constrained thermal expansion of ice." Marine Structures 75 (January 2021): 102884. http://dx.doi.org/10.1016/j.marstruc.2020.102884.
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Santos, Júlio Cesar, Antunes Andre Da Silva, Afonso Paulo Monteiro Pinheiro, Leonardo Kyo Kabayama, Odair Doná Rigo, and Jorge Otubo. "Preliminary Results of Stress Recovery of Constrained NiTi SMA Wire for Aerospace Applications." Materials Science Forum 643 (March 2010): 15–18. http://dx.doi.org/10.4028/www.scientific.net/msf.643.15.
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The rocket propellant ignition system uses electro-explosive device actuated by wire electrode. Those wires are usually made by Fe-Ni based alloy with controlled thermal expansion inserted into a ceramic feed-through and are connected to thin resistive wire which is heated through the passage of an electrical current for propellant ignition. The contact between ceramic feed-through and wires should be reliable since sometimes it could fail. A novel alternative process is to use SMA wires taking into account the shape recovery effect constraining the wire inside the feed-through. The recovery stress of 326 MPa for 4% pre-strain should be enough to constrain the wire inside the feed-trough avoiding the gas leakage.
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Xia, Qi, and Tielin Shi. "Multiphysics Topology Optimization of Thermal Actuators by Using the Level Set-Based Multiple-Type Boundary Method." International Journal of Computational Methods 17, no. 08 (June 20, 2019): 1950044. http://dx.doi.org/10.1142/s0219876219500440.
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Thermal actuators use thermal expansion and contraction of an elastic body to produce motion at its output port. In the present study, a thermal actuator comprises an elastic body and heating/cooling devices. Such devices have a thin-layer shape and are installed on the surface of the elastic body. The design optimization of thermal actuator is a multiphysics problem, including both heat conduction and elastic deformation. The design variables include multiple types of boundaries, i.e., the temperature boundary (high temperature and low temperature) and the free boundary. In order to solve such a multiphysics optimization problem involving multiple types of boundaries, the level set-based multiple-type boundary method is employed. In the analysis for the shape derivative of the temperature boundary, the constrained variational principle is employed to explicitly include the temperature boundary condition into the weak form of heat conduction equation. Numerical examples in two dimensions are investigated.
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Aiello, Luigi, Ilie Hanzu, Gregor Gstrein, Eduard Ewert, Christian Ellersdorfer, and Wolfgang Sinz. "Analysis and Investigation of Thermal Runaway Propagation for a Mechanically Constrained Lithium-Ion Pouch Cell Module." Batteries 7, no. 3 (July 19, 2021): 49. http://dx.doi.org/10.3390/batteries7030049.
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In this paper, tests and analysis of thermal runaway propagation for commercial modules consisting of four 41 Ah Li-ion pouch cells are presented. Module samples were tested at 100% state-of-charge and mechanically constrained between two steel plates to provide thermal and mechanical contact between the parts. Voltage and temperature of each cell were monitored during the whole experiment. The triggering of the exothermal reactions was obtained by overheating one cell of the stack with a flat steel heater. In preliminary studies, the melting temperature of the separator was measured (from an extracted sample) with differential scanning calorimetry and thermogravimetric analysis techniques, revealing a tri-layers separator with two melting points (≈135 °C and ≈170 °C). The tests on module level revealed 8 distinct phases observed and analyzed in the respective temperature ranges, including smoking, venting, sparkling, and massive, short circuit condition. The triggering temperature of the cells resulted to be close to the melting temperature of the separator obtained in preliminary tests, confirming that the violent exothermal reactions of thermal runaway are caused by the internal separator failure. Postmortem inspections of the modules revealed the internal electrical failure path in one cell and the propagation of the internal short circuit in its active material volume, suggesting that the expansion of the electrolyte plays a role in the short circuit propagation at the single cell level. The complete thermal runaway propagation process was repeated on 5 modules and ended on average 60 s after the first thermal runaway triggered cell reached a top temperature of 1100 °C.
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Adak, Debabrata. "A new approach of estimating the galactic thermal dust and synchrotron polarized emission template in the microwave bands." Monthly Notices of the Royal Astronomical Society 507, no. 3 (August 20, 2021): 4618–37. http://dx.doi.org/10.1093/mnras/stab2392.
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ABSTRACT The Internal Linear Combination (ILC) method has been extensively used to extract the cosmic microwave background (CMB) anisotropy map from foreground contaminated multifrequency maps. However, the performance of simple ILC is limited and can be significantly improved by heavily constraint equations, dubbed constrained ILC (cILC). The standard ILC and cILC work on spin-0 fields. Recently, a generalised version of ILC has been developed, named polarization ILC (PILC), in which Q ± iU at multiple frequencies are combined using complex coefficients to estimate Stokes Q and U maps. A statistical moment expansion method has recently been developed for high-precision modelling of the galactic foregrounds. This paper develops a semiblind component separation method combining the moment approach of foreground modelling with a generalised version of the PILC method for heavily constraint equations. The algorithm is developed in pixel space over a spin-2 field. We demonstrate the performance of the method on three sets of absolutely calibrated simulated maps at WMAP and Planck frequencies with varying foreground models. We apply this component separation technique in simultaneous estimation of Stokes Q and U maps of the thermal dust at 353 GHz and synchrotron at 30 GHz. We also recover both dust and synchrotron maps at 100 and 143 GHz, where separating two components is challenging.
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Phu, Phan Huu, Nguyen Ngoc Viet, Nguyen Minh Ngoc, Vu Ngoc Hung, and Chu Duc Trinh. "Simulation and optimization of a silicon-polymer bimorph microgripper." Vietnam Journal of Mechanics 34, no. 4 (November 30, 2012): 247–59. http://dx.doi.org/10.15625/0866-7136/34/4/2339.
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This paper presents an electro-thermally bimorph microgripper based on silicon-polymer laterally stacked structures and a method to optimized the fabricated device. The actuated displacement is enhanced due to the polymer constraint effect. Both the thermal expansion and apparent Young’s modulus of the constrained polymer blocks are significantly improved, compared with the no constraint one. The device consists of a serpentine-shape deep silicon structure with a thin film aluminum heater on the top and filling polymer in the trenches among the vertical silicon parts. The fabricated bimorph microgripper can operate in four modes and generates a large motion up to 15 μm. The simulated results are met the fabricated measurements. An optimized structure is proposed for decreasing the working temperature, power consumption but increasing the output displacement. The simulated results are showed that the output displacement is increased up to 550% and temperature profile improved considerably. This electro-thermally silicon-polymer opened and closed microgripper can be used in micro-robotics, micro-assembly, minimally invasive surgery, living cells surgery.
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Anaz Khan, Muhammed, Annakodi Vivek Anand, Muthukannan Duraiselvam, Koppula Srinivas Rao, Ramachandra Arvind Singh, and Subramanian Jayalakshmi. "Thermal Shock Resistance and Thermal Insulation Capability of Laser-Glazed Functionally Graded Lanthanum Magnesium Hexaluminate/Yttria-Stabilised Zirconia Thermal Barrier Coating." Materials 14, no. 14 (July 10, 2021): 3865. http://dx.doi.org/10.3390/ma14143865.
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In this work, functionally graded lanthanum magnesium hexaluminate (LaMgAl11O19)/yttria-stabilised zirconia (YSZ) thermal barrier coating (FG-TBC), in as-sprayed and laser-glazed conditions, were investigated for their thermal shock resistance and thermal insulation properties. Results were compared with those of a dual-layered coating of LaMgAl11O19 and YSZ (DC-TBC). Thermal shock tests at 1100 °C revealed that the as-sprayed FG-TBC had improved thermal stability, i.e., higher cycle lifetime than the as-sprayed DC-TBC due to its gradient architecture, which minimised stress concentration across its thickness. In contrast, DC-TBC spalled at the interface due to the difference in the coefficient of thermal expansion between the LaMgAl11O19 and YSZ layers. Laser glazing improved cycle lifetimes of both the types of coatings. Microstructural changes, mainly the formation of segmentation cracks in the laser-glazed surfaces, provided strain tolerance during thermal cycles. Infrared rapid heating of the coatings up to 1000 °C showed that the laser-glazed FG-TBC had better thermal insulation capability, as interlamellar pores entrapped gas and constrained heat transfer across its thickness. From the investigation, it is inferred that (i) FG-TBC has better thermal shock resistance and thermal insulation capability than DC-TBC and (ii) laser glazing can significantly enhance the overall thermal performance of the coatings. Laser-glazed FG-TBC provides the best heat management, and has good potential for applications that require effective heat management, such as in gas turbines.
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Faizal, Mohammed, Abdelmalek Bouazza, John S. McCartney, and Chris Haberfield. "Axial and radial thermal responses of energy pile under six storey residential building." Canadian Geotechnical Journal 56, no. 7 (July 2019): 1019–33. http://dx.doi.org/10.1139/cgj-2018-0246.
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The axial and radial thermal responses of a cast-in-place energy pile, 10 m long and 0.6 m in diameter, installed in unsaturated sand under a six storey building are examined during a heating–cooling cycle. The instrumentation in the pile was configured to compare radial and axial thermal responses at the same elevations and to evaluate the temperature and axial thermal stress distribution across the cross-sectional area of the pile. The magnitudes of the axial thermal strains were more constrained than the radial thermal strains at all depths, leading to the development of axial and radial thermal stresses of up to –4.5 and –0.015 MPa, respectively, for a change in average pile temperature of 24.1 °C. The magnitudes of the radial thermal stresses with changes in pile temperature were significantly lower than the axial thermal stresses at all depths of the pile, indicating that the radial thermal expansion had negligible effects on the development of axial thermal strains and stresses. The temperature distribution over the cross section of the pile showed low variations at all depths, indicating that it would be justified to consider a uniform temperature distribution at least in piles of similar dimensions and with even heat exchanger layouts.
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Kristanti, Risky Ayu, Wilawan Khanitchaidecha, Gaurav Taludar, Peter Karácsony, Linh Thi Thuy Cao, Tse-Wei Chen, Noura M. Darwish, and Bandar M. AlMunqedhi. "A Review on Thermal Desorption Treatment for Soil Contamination." Tropical Aquatic and Soil Pollution 2, no. 1 (April 16, 2022): 45–58. http://dx.doi.org/10.53623/tasp.v2i1.68.
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Soil contamination is a major issue that must be prioritized, as food safety is mostly determined by soil quality. Soil quality has deteriorated significantly across the world with the continued expansion of industrial growth, urbanization, and agricultural activities. Soil contamination has become a growing issue and a barrier that must be addressed if we are concerned about re-establishing a healthy ecosystem. The activity is mostly driven by human activities, which include the use of pesticides, chlorinated organic pollutants, herbicides, inorganic fertilizers, industrial pollution, solid waste, and urban activities. While many methods have been developed to remediate significant pollutants generated by these activities, their degree of application may be constrained or inappropriate for a specific location. Parameters such as treatment duration, safety, and efficacy of soil/pollutant treatment all play a part in selecting the best appropriate technique. These technologies have been classified into three broad categories: physical, chemical, and bioremediation. This review shows and talks about thermal desorption (TD), which is a common way to clean up polluted soil.
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Heggy, Essam, Elizabeth M. Palmer, Alain Hérique, Wlodek Kofman, and M. Ramy El-Maarry. "Post-rendezvous radar properties of comet 67P/CG from the Rosetta Mission: understanding future Earth-based radar observations and the dynamical evolution of comets." Monthly Notices of the Royal Astronomical Society 489, no. 2 (August 12, 2019): 1667–83. http://dx.doi.org/10.1093/mnras/stz2174.
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ABSTRACT Radar observations provide crucial insights into the formation and dynamical evolution of comets. This ability is constrained by our knowledge of the dielectric and textural properties of these small-bodies. Using several observations by Rosetta as well as results from the Earth-based Arecibo radio telescope, we provide an updated and comprehensive dielectric and roughness description of Comet 67P/CG, which can provide new constraints on the radar properties of other nuclei. Furthermore, contrary to previous assumptions of cometary surfaces being dielectrically homogeneous and smooth, we find that cometary surfaces are dielectrically heterogeneous ( εr′≈1.6–3.2), and are rough at X- and S-band frequencies, which are widely used in characterization of small-bodies. We also investigate the lack of signal broadening in CONSERT observations through the comet head. Our results suggest that primordial building blocks in the subsurface are either absent, smaller than the radar wavelength, or have a weak dielectric contrast (Δ εr′). To constrain this ambiguity, we use optical albedo measurements by the OSIRIS camera of the freshly exposed subsurface after the Aswan cliff collapse. We find that the hypothetical subsurface blocks should have |Δ εr′|≳0.15, setting an upper limit of ∼ 1 m on the size of 67P/CG's primordial building blocks if they exist. Our analysis is consistent with a purely thermal origin for the ∼ 3 m surface bumps on pit walls and cliff-faces, hypothesized to be high-centred polygons formed from fracturing of the sintered shallow ice-bearing subsurface due to seasonal thermal expansion and contraction. Potential changes in 67P/CG's radar reflectivity at these at X- and S-bands can be associated with large-scale structural changes of the nucleus rather than small-scale textural ones. Monitoring changes in 67P/CG's radar properties during repeated close-approaches via Earth-based observations can constrain the dynamical evolution of its cometary nucleus.
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Wu, Frank F. H. "Analytical Solutions of Stresses in a Cylindrical Plate Due to Polynomial Radial Temperature Distributions." Journal of Electronic Packaging 115, no. 2 (June 1, 1993): 214–18. http://dx.doi.org/10.1115/1.2909320.
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Thermal stress is a significant contributor to a component’s failure during manufacturing processes. In the electronic industry, for example, it is very common that components experience an extensive number of nonuniform, local heating cycles throughout its life time. In order to promote reliability, components are put through burn-in which creates a very nonuniform temperature distribution. In order to reduce cost, reworkability is considered to be a necessary option for the manufacturing processes to achieve high yield; these rework processes usually require localized heating. In addition, due to certain functionality requirements, materials with different coefficients of thermal expansion are cast together. The thermal mismatch caused by nonuniform temperature and/or different coefficients of thermal expansion will create thermal stress which could result in the cracking of the components. The fracture often initiates on the interface between the different materials or at the free edge of the surface. To make the problems mathematically tractable, the problems here are simplified as linear thermo-elastic and axisymmetric. It is concluded that the displacement distribution is one order higher than the temperature distribution if the temperature is a polynominal function of the radial distance from the center of a disk. The solutions also show the effect of the edge boundary conditions on the stress level; namely a certain degree of constrained edge support will reduce the tensile stress around the edge of the plate. This will reduce the failure rate of the plate, particularly for a brittle material. Finally, a numerical finite element solution for a square plate with a localized heating source is given to demonstrate the applications of the analytical solutions to fixture design during the process development.
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MacKay, J. Ross. "Thermally induced movements in ice-wedge polygons, western arctic coast: a long-term study." Géographie physique et Quaternaire 54, no. 1 (October 2, 2002): 41–68. http://dx.doi.org/10.7202/004846ar.
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AbstractThermally induced seasonal movements of the active layer and subjacent permafrost have been measured in numerous ice-wedge polygons that have varied in age, type, crack frequency, and topographic location. The field observations show that, in winter, thermal contraction, which is inward, is constrained or vanishes at the polygon centres but, in summer, thermal expansion, which is outward, is unconstrained at the ice-wedge troughs. Therefore, there tends to be a small net summer transport of the active layer, to varying depths, into the ice-wedge troughs. The movement has been observed in all polygons studied. The slow net transport of material into the ice-wedge troughs has implications for: permafrost aggradation and the growth of syngenetic wedges in some troughs; the palaeoclimatic reconstruction of some ice- wedge casts; and the interpretation of polygon stratigraphy based upon the assumption that the polygon material has accumulatedin situ.
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Saitou, Kazuhiro. "Built to be Reclaimed." Mechanical Engineering 133, no. 09 (September 1, 2011): 52–54. http://dx.doi.org/10.1115/1.2011-sep-5.
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This article elaborates a new design approach that aims at designing products with built-in disassembly means to be activated at the end of a product’s life. Two projects explored in this area are the design of a new class of joints that can be detached by the application of localized heat, and the design of assemblies that can disintegrate via a domino-like process triggered by the removal of one or only a few fasteners. The detachable joints (heat-reversible locator-snap systems) allow easy, non-destructive, and clean detaching of product enclosures. They consist of locators and snaps molded on the internal surfaces of thin-walled product enclosures. During disassembly, thermal expansion of the enclosure walls constrained by locators and the temperature gradient along the wall thickness are exploited to realize the deformation required to release the snaps. In self-disintegrating assemblies, the relative motions of components are constrained by the locators integral to the components, in such a way that the removal of one or few fasteners would cause the self-disintegration of the assembly in a desired sequence.
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Azmi, K., M. N. Derman, A. M. Mustafa Al Bakri, and A. V. Sandu. "Cu-SiCp Composites as Advanced Electronic Packaging Materials." Key Engineering Materials 594-595 (December 2013): 852–56. http://dx.doi.org/10.4028/www.scientific.net/kem.594-595.852.
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The demand for advanced thermal management materials such as silicon carbide particles reinforced copper matrix (Cu-SiCp) composites is increasing due to the stringent design requirement in the electronic packaging industries. High interest on Cu-SiCp composites is highlighted by the high thermal conductivity and low coefficient of thermal expansion (CTE) properties. However, the thermal properties of the Cu-SiCp composites are constrained by the bonding between the copper matrix and the silicon carbide particles (SiCp) reinforcement. In the powder metallurgical (PM) methodology in particular, the bonding between the two constituents is weak, thus demoting the thermal properties of the Cu-SiCp composites. In order to improve the interface bonding, the SiCp were copper coated via electroless coating process. Based on the experimental results and findings, a continuous copper deposition on the SiCp was obtained via the electroless plating process. The copper film was found to be high in purity and homogeneously deposited on the SiCp surfaces. The CTE values of the Cu-Coated Cu-SiCp composites were found significantly lower than those of the non-Coated Cu-SiCp composites and were in agreement with Kernels model which accounts for both the shear and isostatic stresses developed in the component phases.
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Foster, P., G. Abdelal, and A. Murphy. "Modelling of mechanical failure due to constrained thermal expansion at the lightning arc attachment point in carbon fibre epoxy composite material." Engineering Failure Analysis 94 (December 2018): 364–78. http://dx.doi.org/10.1016/j.engfailanal.2018.08.003.
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Morishige, M. "The thermal structure of subduction zones predicted by plate cooling models with variable thermal properties." Geophysical Journal International 229, no. 3 (January 7, 2022): 1490–502. http://dx.doi.org/10.1093/gji/ggac008.
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SUMMARY Previous modelling studies have investigated the effects of experimentally constrained thermal properties (i.e. thermal conductivity, specific heat and the thermal expansion coefficient) on the thermal structure of subduction zones. However, these studies have not carefully considered whether the assumed thermal structure of the slab before subduction is consistent with geophysical observations. This study investigates the effects of thermal properties on the thermal structure of the Tohoku subduction zone, northeast Japan, by using the slab temperature at the trench determined from plate cooling models. Three types of thermal properties were tested: constant, temperature-dependent and temperature- and lithology-dependent types. For each case, the parameters for the plate cooling models were inferred based on the observed surface heat flow and seafloor depth using Bayes’ theorem. It was found that the predicted temperature and location of phase boundaries in the slab, which are possibly related to intermediate-depth earthquakes, are similar for the three cases. This suggests that, in the Tohoku subduction zone, constant thermal properties can be used in modelling to examine phenomena related to slab dehydration. The depth uncertainties for isotherms in the oceanic plate and slab increase with temperature, and are about ±10 and ±20 km for the 600 and 1200 °C isotherms, respectively. When this uncertainty is considered, the location of the serpentinite-out boundary matches that of the lower plane of double seismic zone, suggesting that dehydration may be important in triggering intermediate-depth seismicity. However, the large uncertainty makes it difficult to discuss in detail the origins of intraplate earthquakes, the lithosphere–asthenosphere boundary, and the lower boundary of the slab in terms of temperature.
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Nauels, Alexander, Malte Meinshausen, Matthias Mengel, Katja Lorbacher, and Tom M. L. Wigley. "Synthesizing long-term sea level rise projections – the MAGICC sea level model v2.0." Geoscientific Model Development 10, no. 6 (June 30, 2017): 2495–524. http://dx.doi.org/10.5194/gmd-10-2495-2017.
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Abstract. Sea level rise (SLR) is one of the major impacts of global warming; it will threaten coastal populations, infrastructure, and ecosystems around the globe in coming centuries. Well-constrained sea level projections are needed to estimate future losses from SLR and benefits of climate protection and adaptation. Process-based models that are designed to resolve the underlying physics of individual sea level drivers form the basis for state-of-the-art sea level projections. However, associated computational costs allow for only a small number of simulations based on selected scenarios that often vary for different sea level components. This approach does not sufficiently support sea level impact science and climate policy analysis, which require a sea level projection methodology that is flexible with regard to the climate scenario yet comprehensive and bound by the physical constraints provided by process-based models. To fill this gap, we present a sea level model that emulates global-mean long-term process-based model projections for all major sea level components. Thermal expansion estimates are calculated with the hemispheric upwelling-diffusion ocean component of the simple carbon-cycle climate model MAGICC, which has been updated and calibrated against CMIP5 ocean temperature profiles and thermal expansion data. Global glacier contributions are estimated based on a parameterization constrained by transient and equilibrium process-based projections. Sea level contribution estimates for Greenland and Antarctic ice sheets are derived from surface mass balance and solid ice discharge parameterizations reproducing current output from ice-sheet models. The land water storage component replicates recent hydrological modeling results. For 2100, we project 0.35 to 0.56 m (66 % range) total SLR based on the RCP2.6 scenario, 0.45 to 0.67 m for RCP4.5, 0.46 to 0.71 m for RCP6.0, and 0.65 to 0.97 m for RCP8.5. These projections lie within the range of the latest IPCC SLR estimates. SLR projections for 2300 yield median responses of 1.02 m for RCP2.6, 1.76 m for RCP4.5, 2.38 m for RCP6.0, and 4.73 m for RCP8.5. The MAGICC sea level model provides a flexible and efficient platform for the analysis of major scenario, model, and climate uncertainties underlying long-term SLR projections. It can be used as a tool to directly investigate the SLR implications of different mitigation pathways and may also serve as input for regional SLR assessments via component-wise sea level pattern scaling.
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Hyndman, R. D. "The consequences of Canadian Cordillera thermal regime in recent tectonics and elevation: a reviewThis article is one of a series of papers published in this Special Issue on the theme Lithoprobe — parameters, processes, and the evolution of a continent.Geological Survey of Canada Contribution 20090195." Canadian Journal of Earth Sciences 47, no. 5 (May 2010): 621–32. http://dx.doi.org/10.1139/e10-016.
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The crust and upper mantle thermal regime of the Canadian Cordillera and its tectonic consequences were an important part of the Cordillera Lithoprobe program and related studies. This article provides a review, first of the thermal constraints, and then of consequences in high surface elevation and current tectonics. Cordillera and adjacent craton temperatures are well constrained by geothermal heat flow, mantle tomography velocities, upper mantle xenoliths, and the effective elastic thickness, Te. Cordillera temperatures are very high and laterally uniform, explained by small scale convection beneath a thin lithosphere, 800–900 °C at the Moho, contrasted to 400–500 °C for the craton. The high temperatures provide an explanation for why the Cordillera has high elevation in spite of a generally thin crust, ∼33 km, in contrast to low elevation and thicker crust, 40–45 km, for the craton. The Cordillera is supported ∼1600 m by lithosphere thermal expansion. In the Cordillera only the upper crust has significant strength; Te ∼ 15 km, in contrast to over 60 km for the craton. The Cordillera is tectonically active because the lithosphere is sufficiently weak to be deformed by plate boundary and gravitational forces; the craton is too strong. The Canadian Cordillera results have led to new understandings of processes in backarcs globally. High backarc temperatures and weak lithospheres explain the tectonic activity over long geological times of mobile belts that make up about 20% of continents. They also have led to a new understanding of collision orogenic heat in terms of incorporation of already hot backarcs.
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Stacer, R. G., E. D. von Meerwall, and F. N. Kelley. "Time-Dependent Tearing of Carbon Black-Filled and Strain Crystallizing Vulcanizates." Rubber Chemistry and Technology 58, no. 5 (November 1, 1985): 913–23. http://dx.doi.org/10.5254/1.3536103.
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Abstract 1. Unstable tearing can be minimized and tear-tip diameter held reasonably constant for carbon black-filled and strain-crystallizing vulcanizates using a constrained trouser tear testpiece first suggested by Gent and Henry. In the absence of these complicating features, the tear energy has been shown to be thermo-rheologically simple, readily lending itself to time-temperature superposition over a broad range of temperatures and rates. 2. Shift factors used to superpose tear energy data at different temperatures for both filled and unfilled SBR also superposed small deformation stress-relaxation data. This result did not hold for the NR formulations tested, indicating that the temperature dependency of the principal viscoelastic process is different for these properties. Evidence of this was observed in the thermal expansion coefficient, a, derived from the WLF coefficients, which increased by a factor of 10 for tear energy data. It is concluded that even with the tear path constrained, strain-induced crystallization still occurs near the tear tip for the NR formulations. 3. Temperature-reduced tear energy master curves for both filled and unfilled vulcanizates showed the same general tear behavior when referenced to Tg. At high rates or low temperatures, the master curves coincide, approaching a characteristic tear energy of approximately 50 kJ/m2, regardless of formulation. Only at lower rates did the different nature of the rubbers become apparent. All the master curves showed evidence of a tear energy plateau between −15 and −10 decades in rate, with the NR compounds showing the lowest slopes in this region. 4. Addition of filler increases the tear energy by approximately 20–40% over most of the master curves. This supports a previous conclusion of Gent and Henry that the major effect of reinforcing filler is to dissipate energy over a larger volume of material without significantly increasing inherent strength. Addition of filler also tended to mask the plateau in the tear energy master curve and decrease both the free volume at Tg and the thermal expansion coefficient of the material.
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Torabi, Mohsen, Hessameddin Yaghoobi, Andrea Colantoni, Paolo Biondi, and Karem Boubaker. "Analysis of Radiative Radial Fin with Temperature-Dependent Thermal Conductivity Using Nonlinear Differential Transformation Methods." Chinese Journal of Engineering 2013 (October 28, 2013): 1–12. http://dx.doi.org/10.1155/2013/470696.
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Radiative radial fin with temperature-dependent thermal conductivity is analyzed. The calculations are carried out by using differential transformation method (DTM), which is a seminumerical-analytical solution technique that can be applied to various types of differential equations, as well as the Boubaker polynomials expansion scheme (BPES). By using DTM, the nonlinear constrained governing equations are reduced to recurrence relations and related boundary conditions are transformed into a set of algebraic equations. The principle of differential transformation is briefly introduced and then applied to the aforementioned equations. Solutions are subsequently obtained by a process of inverse transformation. The current results are then compared with previously obtained results using variational iteration method (VIM), Adomian decomposition method (ADM), homotopy analysis method (HAM), and numerical solution (NS) in order to verify the accuracy of the proposed method. The findings reveal that both BPES and DTM can achieve suitable results in predicting the solution of such problems. After these verifications, we analyze fin efficiency and the effects of some physically applicable parameters in this problem such as radiation-conduction fin parameter, radiation sink temperature, heat generation, and thermal conductivity parameters.
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Vivet, Damien, Jordi Vilà-Valls, Gaël Pages, and Eric Chaumette. "Robust Filter-Based Visual Navigation Solution with Miscalibrated Bi-Monocular or Stereo Cameras." Remote Sensing 14, no. 6 (March 18, 2022): 1470. http://dx.doi.org/10.3390/rs14061470.
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This work addressed the problem of miscalibration or decalibration of mobile stereo/bi-monocular camera setups. We especially focused on the context of autonomous vehicles. In real-world conditions, any optical system is subject to various mechanical stresses, caused by vibration, rough handling, collisions, or even thermal expansion. Such mechanical stresses change the stereo pair geometry, and as a consequence, the pre-calculated epipolar geometry or any geometric-based approach is no longer valid. The standard method, which consists of estimating the calibration online, fails in such harsh conditions. The proposed method was based on a robust linearly constrained state estimation technique able to mitigate the model mismatch without estimating the model parameters. Therefore, our solution was able to mitigate the errors with negligible use of additional computing resources. We propose to use a linearly constrained extended Kalman filter for a stereo-based visual odometry or simultaneous localization and mapping approach. Simulations confirmed that the method kept the system (and objects of the map) localized in real-time even with huge miscalibration errors and parameter variations. The results confirmed that the method was robust to a miscalibration of all the extrinsic calibration parameters even when the standard online calibration procedure failed.
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Shane, Phil, and Anna Sandiford. "Paleovegetation of marine isotope stages 4 and 3 in Northern New Zealand and the age of the widespread Rotoehu tephra." Quaternary Research 59, no. 3 (May 2003): 420–29. http://dx.doi.org/10.1016/s0033-5894(03)00044-9.
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AbstractPaleolake sediment, constrained by tephrochronology, from Onepoto basin volcanic crater in Auckland, Northern New Zealand (36° 48′S), provides one of the few uninterrupted records of paleovegetation for marine oxygen isotope stages (MIS) 4 and 3 (76,000–26,000 yr B.P.) in the region. This period was characterized by cool temperate conifer-hardwood forest that lacked some of the warmer taxa typical of the Holocene. The period 64,400–60,500 yr B.P. was marked by opening of forest canopy and expansion of small trees and shrubs, and correlates to the thermal minima of MIS 4. However, the landscape was never as open as the forest-shrubland mosaic of the MIS 2. The beginning of MIS 3 (60,500–50,500 yr B.P.) was marked by the dramatic expansion and then decline of conifer-hardwood forest dominated by Dacrydium cupressinum, a species that prefers wetter conditions. This forest was succeeded by the typically montane Nothofagus at 50,500 yr B.P., corresponding to a thermal decline. Thus, MIS 3 began with an abrupt change to moist cool conditions that lasted about 5000 yr, followed by gradual cooling and dryer conditions. This supports some interpretations from other parts of the southwest Pacific region, that MIS 3 was a period of increased precipitation. The widespread and stratigraphically important Rotoehu tephra, erupted from Okataina Volcanic Centre, has been variously dated at 45,000–65,000 yr B.P. At Onepoto, sedimentation rate and paleovegetation reconstruction imply an age of c. 44,300 yr B.P. The tephra provides a correlation horizon in the marine and terrestrial realms during a period (MIS 3) difficult to date by radiometric methods.
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Stevanato, Nicolò, Matteo V. Rocco, Matteo Giuliani, Andrea Castelletti, and Emanuela Colombo. "Advancing the representation of reservoir hydropower in energy systems modelling: The case of Zambesi River Basin." PLOS ONE 16, no. 12 (December 2, 2021): e0259876. http://dx.doi.org/10.1371/journal.pone.0259876.
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In state-of-the-art energy systems modelling, reservoir hydropower is represented as any other thermal power plant: energy production is constrained by the plant’s installed capacity and a capacity factor calibrated on the energy produced in previous years. Natural water resource variability across different temporal scales and the subsequent filtering effect of water storage mass balances are not accounted for, leading to biased optimal power dispatch strategies. In this work, we aim at introducing a novelty in the field by advancing the representation of reservoir hydropower generation in energy systems modelling by explicitly including the most relevant hydrological constraints, such as time-dependent water availability, hydraulic head, evaporation losses, and cascade releases. This advanced characterization is implemented in an open-source energy modelling framework. The improved model is then demonstrated on the Zambezi River Basin in the South Africa Power Pool. The basin has an estimated hydropower potential of 20,000 megawatts (MW) of which about 5,000 MW has been already developed. Results show a better alignment of electricity production with observed data, with a reduction of estimated hydropower production up to 35% with respect to the baseline Calliope implementation. These improvements are useful to support hydropower management and planning capacity expansion in countries richly endowed with water resource or that are already strongly relying on hydropower for electricity production.
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Klinger, Dane H., Simon A. Levin, and James R. Watson. "The growth of finfish in global open-ocean aquaculture under climate change." Proceedings of the Royal Society B: Biological Sciences 284, no. 1864 (October 4, 2017): 20170834. http://dx.doi.org/10.1098/rspb.2017.0834.
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Aquaculture production is projected to expand from land-based operations to the open ocean as demand for seafood grows and competition increases for inputs to land-based aquaculture, such as freshwater and suitable land. In contrast to land-based production, open-ocean aquaculture is constrained by oceanographic factors, such as current speeds and seawater temperature, which are dynamic in time and space, and cannot easily be controlled. As such, the potential for offshore aquaculture to increase seafood production is tied to the physical state of the oceans. We employ a novel spatial model to estimate the potential of open-ocean finfish aquaculture globally, given physical, biological and technological constraints. Finfish growth potential for three common aquaculture species representing different thermal guilds—Atlantic salmon (Salmo salar), gilthead seabream (Sparus aurata) and cobia (Rachycentron canadum)—is compared across species and regions and with climate change, based on outputs of a high-resolution global climate model. Globally, there are ample areas that are physically suitable for fish growth and potential expansion of the nascent aquaculture industry. The effects of climate change are heterogeneous across species and regions, but areas with existing aquaculture industries are likely to see increases in growth rates. In areas where climate change results in reduced growth rates, adaptation measures, such as selective breeding, can probably offset potential production losses.
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Ye, Zhilin, Dawei Fan, Bo Li, Qizhe Tang, Jingui Xu, Dongzhou Zhang, and Wenge Zhou. "Thermal equation of state of the main minerals of eclogite: Constraining the density evolution of eclogite during the delamination process in Tibet." Solid Earth 13, no. 3 (March 30, 2022): 745–59. http://dx.doi.org/10.5194/se-13-745-2022.
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Abstract. Tibet, which is characterized by collisional orogens, has undergone the process of delamination or convective removal. The lower crust and mantle lithosphere appear to have been removed through delamination during orogenic development. Numerical and analog experiments demonstrate that the metamorphic eclogitized oceanic subduction slab or lower crust may promote gravitational instability due to increased density. The eclogitized oceanic subduction slab or crustal root is believed to be denser than the underlying mantle and tends to sink. However, the density of eclogite under high-pressure and high-temperature conditions as well as density differences from the surrounding mantle are not preciously constrained. Here, we offer new insights into the derivation of eclogite density with a single experiment to constrain delamination in Tibet. Using in situ synchrotron X-ray diffraction combined with a diamond anvil cell, experiments focused on minerals (garnet, omphacite, and epidote) of eclogite are conducted under simultaneous high-pressure and high-temperature conditions, which avoids systematic errors. Fitting the pressure–temperature–volume data with the third-order Birch–Murnaghan equation of state, the thermal equation of state (EoS) parameters, including the bulk modulus (KT0), its pressure derivative (KT0′), and the thermal expansion coefficient (α0), are derived. The densities of rock-forming minerals and eclogite are modeled along with the geotherms of two types of delamination. The delamination processes of subduction slab break-off and the removal of the eclogitized lower crust in Tibet are discussed. The Tibetan eclogite, which contains 40 vol %–60 vol % garnet and 44 %–70 % eclogitization, can promote the delamination of slab break-off in Tibet. Our results indicate that eclogite is a major controlling factor in the initiation of delamination. A high abundance of garnet, a high Fe content, and a high degree of eclogitization are more conducive to instigating the delamination.
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Wilson, Maurice L., John C. Raymond, Susan T. Lepri, Roberto Lionello, Nicholas A. Murphy, Katharine K. Reeves, and Chengcai Shen. "Constraining the CME Core Heating and Energy Budget with SOHO/UVCS." Astrophysical Journal 927, no. 1 (March 1, 2022): 27. http://dx.doi.org/10.3847/1538-4357/ac4d35.
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Abstract We describe the energy budget of a coronal mass ejection (CME) observed on 1999 May 17 with the Ultraviolet Coronagraph Spectrometer (UVCS). We constrain the physical properties of the CME’s core material as a function of height along the corona by using the spectra taken by the single-slit coronagraph spectrometer at heliocentric distances of 2.6 and 3.1 solar radii. We use plasma diagnostics from intensity ratios, such as the O vi doublet lines, to determine the velocity, density, temperature, and nonequilibrium ionization states. We find that the CME core’s velocity is approximately 250 km s−1, and its cumulative heating energy is comparable to its kinetic energy for all of the plasma heating parameterizations that we investigated. Therefore, the CME’s unknown heating mechanisms have the energy to significantly affect the CME’s eruption and evolution. To understand which parameters might influence the unknown heating mechanism, we constrain our model heating rates with the observed data and compare them to the rate of heating generated within a similar CME that was constructed by the MAS code’s 3D MHD simulation. The rate of heating from the simulated CME agrees with our observationally constrained heating rates when we assume a quadratic power law to describe a self-similar CME expansion. Furthermore, the heating rates agree when we apply a heating parameterization that accounts for the CME flux rope’s magnetic energy being converted directly into thermal energy. This UVCS analysis serves as a case study for the importance of multislit coronagraph spectrometers for CME studies.
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Gu, X. J., Ji Hong Zhu, W. H. Zhang, and J. S. Li. "The Topology Optimization Design for the Stereolithography Based Investment Casting Pattern." Materials Science Forum 697-698 (September 2011): 604–7. http://dx.doi.org/10.4028/www.scientific.net/msf.697-698.604.
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The purpose of this paper is to introduce the topology optimization method into the lattice style design for the rapid casting SL patterns. During the burnout procedure of the SL resin pattern, the thermal expansion will lead to the crack of the ceramic shell and fail the investment casting. Therefore, the SL patterns are always designed hollowed and some lattice styles are used to fill the cavity to solve the problem. In this paper, we propose to carry out the structural design by assigning the inner part of the SL pattern as the design domain where the material distribution is optimized with topology optimization. The idea is 1) to save the cost of the resin material, 2) to solve the crack problem of the ceramic shell and 3) to maintain certain stiffness for the pattern itself. As a result, we choose to minimize the thermal stress in the ceramic shell as the design objective with the stiffness and material cost of the SL pattern constrained to certain values. The topology optimization is implemented with different definitions of design domain in this paper. Various optimal results are obtained numerically. By comparing the optimal design with the existing lattice style, the newly obtained designs have shown better performances in reducing the stress in ceramic shell and maintaining the stiffness of the SL pattern.
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Ngernchuklin, Piyalak, Arjin Boonruang, Chalearmchai Jeerapan, Pracha Laoauyporn, Sittichai Kanchanasutha, and Jung Ho Ryu. "Electromechanical Displacement of Soft/Hard PZT Bi-Layer Composite Actuator." Key Engineering Materials 659 (August 2015): 96–101. http://dx.doi.org/10.4028/www.scientific.net/kem.659.96.
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PZTs can be classified into two types, i.e., soft and hard PZTs, which are categorized by the piezoelectric and ferroelectric properties such as coercive field, piezoelectric strain, mechanical quality factor etc. It is known that the combination effect of the soft/hard PZT composites can generate large strain/actuation compared to monolithic PZT ceramics. In this study, soft and hard PZT powders were co-pressed into bi-layer disks with various ratios between soft and hard PZT powders, ranging from 0:100~100:0 vol. % (with 10 % increments) and then they were co-sintered. Due to the difference in the planar shrinkage of the two layers and thermal expansion coefficient mismatch, dome-shaped bi-layer composites with various dome heights were obtained. It was shown that the constrained layer either soft PZT or hard PZT affected various properties including the dome geometry, the strain-E-field response, and the displacement hysteresis loop. The electromechanical properties and actuation performance of such bi-layer composite actuators have been investigated and compared to the soft and hard PZT single layer counterparts.
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Roberts, D. I., R. H. Ryder, and R. Viswanathan. "Performance of Dissimilar Welds in Service." Journal of Pressure Vessel Technology 107, no. 3 (August 1, 1985): 247–54. http://dx.doi.org/10.1115/1.3264443.
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Dissimilar metal welds (DMWs) between austenitic and ferritic steel tubing and piping are commonly employed in high-temperature applications in energy conversion systems. Differences in coefficient of thermal expansion between the two types of steel induce thermal stresses at the welds and local metallurgical changes near the low alloy steel/weld metal interface due to prolonged service at an elevated temperature. These phenomena, together with the differences in creep behavior of the materials joined, render the DMWs more prone to failure than welds between similar steels. This has been reflected in relatively high failure rates in DMWs in certain service applications (e.g., in utility power plant boiler tubing). Typically these welds fail by low ductility cracking in the low alloy steel at, or very close to, the fusion line. A project, sponsored by the Electric Power Research Institute (EPRI) and managed by the Metal Properties Council (MPC), has made significant headway over the last three years in understanding the failure modes and causes involved and in developing methods to assess residual life of DMWs. Welds from service in superheaters and reheater tubes and from laboratory simulation tests were examined to establish metallurgical characteristics and failure modes. Three failure modes were identified: (i) Prior austenite grain boundary cracking in the ferritic steel, one or two grains away from the fusion line; this mode was mainly observed in DMWs made with stainless steel filler metal. (ii) Cracking along the weld interface, which occurred in DMWs made with nickel-base filler metal. (iii) Propagation of cracks initiating from oxide notches formed at the weld outside surface; this mode occurred mainly in thin-walled tubes. Creep damage induced by steady and cyclic loading was found to be the predominant mechanism for damage and failure; therefore a dependence of damage on loading levels and service temperature was established. It was also determined that failure susceptibility in DMWs made with nickel-base filler was strongly influenced by the type of microstructure that formed at the low alloy steel/weld metal interface. The technique developed for estimating the condition and remaining life of DMWs in service involves detailed assessment of loading histories to which the welds are subjected, along with the use of empirical quantitative relationships established from both laboratory and service data. The methodology assumes that damage results from the combined effects of self damage (caused by thermal cycling of materials of different expansion coefficients) and service loadings, including both primary loads (e.g., pressure and deadweight) and secondary, or cyclic, loads due to the constrained thermal expansion of the system as a whole. The technique, Prediction Of Damage In Service (designated PODIS), has been found to adequately predict levels of damage in stainless-based DMWs in service. It is currently being developed further to embrace nickel-based DMWs.
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Ng, C. W. W., C. Shi, A. Gunawan, L. Laloui, and H. L. Liu. "Centrifuge modelling of heating effects on energy pile performance in saturated sand." Canadian Geotechnical Journal 52, no. 8 (August 2015): 1045–57. http://dx.doi.org/10.1139/cgj-2014-0301.
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The operation of energy piles in summer can expel excess heat of the buildings into the ground by the use of a heat pump. Despite having been implemented for decades, the design of energy piles still relies heavily on empiricism, as there is limited understanding about heating effects on pile capacity. A series of centrifuge model tests on aluminum energy piles in medium dense saturated sand is reported in this study to investigate heating effects on the settlement patterns as well as capacities of single piles. In total, four in-flight pile load tests under three different temperatures, namely 22, 37, and 52 °C, and different loading sequences were carried out. Variations of pile capacity were interpreted with the help of a nonlinear elastic analysis. The test results show that after heating at zero applied axial load, toe resistance of the pile was mobilized as a result of constrained downward thermal expansion of the pile. Heating to a higher temperature caused the neutral plane to shift towards the pile toe due to a larger degree of mobilization of end-bearing resistance. It is also found that for a pile under a maintained working load, the pile head heaved initially by 1.4%D (D, pile diameter) when the temperature increased by 30 °C, but it gradually settled to 0.8%D after 4 months of continuous heating at the constant temperature. The post-pile settlement is believed to be caused by thermal contraction of sand. Subsequent pile load tests show that pile capacities increased by 13% and 30% with incremental temperatures of 15 and 30 °C, respectively. With an increasing temperature, shaft resistance increased but at a reducing rate. At a higher elevated temperature, toe resistance increased more rapidly than shaft resistance due to a larger downward expansion of the pile. For simplicity, earth pressure coefficients with values of 1.1K0 and 1.3K0 were found to be suitable for estimating the capacities of aluminum model piles with temperature increments of 15 and 30 °C, respectively.
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Speck, J. S., J. Steinbeck, and M. S. Dresselhaus. "Microstructural studies of laser irradiated graphite surfaces." Journal of Materials Research 5, no. 5 (May 1990): 980–88. http://dx.doi.org/10.1557/jmr.1990.0980.
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The structure of pulsed laser irradiated graphite surfaces has been elucidated. The pulse fluences range up to 4 J cm−2 with durations no longer than 30 ns. The region exterior to the irradiated spot is littered with ∼0.1 μm diameter carbon spheroids. The boundary region is characterized by both spheroids and torn layers 1–5 μm. in lateral extent. The central region displays carbon spheroids and surface upheavals. The carbon spheroids are attributed to hydrodynamic sputtering of carbon. The surface upheavals and torn carbon layers are attributed to constrained thermal expansion and contraction of the irradiated region. It is estimated that a nearly instantaneous 1000°C temperature change is necessary to cause the observed surface deformation. Pulse fluences in excess of 0.8 J cm−2 cause a thin layer of carbon to melt. This is proven by the fact that the irradiated layer in the solid phase has a turbostratic structure. Electron diffraction experiments and dark-field imaging experiments show that the basal plane grain size of the resolidified material varies from ∼20 Å at the melt threshold to ∼100 Å for samples irradiated with 4.0 J cm−2.
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Gumennik, Alexander, Etgar C. Levy, Benjamin Grena, Chong Hou, Michael Rein, Ayman F. Abouraddy, John D. Joannopoulos, and Yoel Fink. "Confined in-fiber solidification and structural control of silicon and silicon−germanium microparticles." Proceedings of the National Academy of Sciences 114, no. 28 (June 22, 2017): 7240–45. http://dx.doi.org/10.1073/pnas.1707778114.
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Crystallization of microdroplets of molten alloys could, in principle, present a number of possible morphological outcomes, depending on the symmetry of the propagating solidification front and its velocity, such as axial or spherically symmetric species segregation. However, because of thermal or constitutional supercooling, resulting droplets often only display dendritic morphologies. Here we report on the crystallization of alloyed droplets of controlled micrometer dimensions comprising silicon and germanium, leading to a number of surprising outcomes. We first produce an array of silicon−germanium particles embedded in silica, through capillary breakup of an alloy-core silica-cladding fiber. Heating and subsequent controlled cooling of individual particles with a two-wavelength laser setup allows us to realize two different morphologies, the first being a silicon−germanium compositionally segregated Janus particle oriented with respect to the illumination axis and the second being a sphere made of dendrites of germanium in silicon. Gigapascal-level compressive stresses are measured within pure silicon solidified in silica as a direct consequence of volume-constrained solidification of a material undergoing anomalous expansion. The ability to generate microspheres with controlled morphology and unusual stresses could pave the way toward advanced integrated in-fiber electronic or optoelectronic devices.
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Samyn, P., W. Van Paepegem, J. S. Leendertz, A. Gerber, L. Van Schepdael, J. Degrieck, and P. De Baets. "Large-Scale Evaluation of Constrained Bearing Elements Made of Thermosetting Polyester Resin and Polyester Fabric Reinforcement." Journal of Tribology 128, no. 4 (June 14, 2006): 681–96. http://dx.doi.org/10.1115/1.2345413.
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Polymer composites are increasingly used as sliding materials for high-loaded bearings, however, their tribological characteristics are most commonly determined from small-scale laboratory tests. The static strength and dynamic coefficients of friction for polyester/polyester composite elements are presently studied on large-scale test equipment for determination of its bearing capacity and failure mechanisms under overload conditions. Original test samples have a diameter of 250 mm and thickness of 40 mm, corresponding to the practical implementation in the sliding surfaces of a ball-joint, and are tested at various scales for simulation of edge effects and repeatability of test results. Static tests reveal complete elastic recovery after loading to 120 MPa, plastic deformation after loading at 150 MPa and overload at 200 MPa. This makes present composite favorable for use under high loads, compared to, e.g., glass-fibre reinforced materials. Sliding tests indicate stick-slip for pure bulk composites and more stable sliding when PTFE lubricants are added. Dynamic overload occurs above 120 MPa due to an expansion of the nonconstrained top surface. A molybdenum-disulphide coating on the steel counterface is an effective lubricant for lower dynamic friction, as it favorably impregnates the composite sliding surface, while it is not effective at high loads as the coating is removed after sliding and high initial static friction is observed. Also a zinc phosphate thermoplastic coating cannot be applied to the counterface as it adheres strongly to the composite surface with consequently high initial friction and coating wear. Most stable sliding is observed against steel counterfaces, with progressive formation of a lubricating transfer film at higher loads due to exposure of PTFE lubricant. Composite wear mechanisms are mainly governed by thermal degradation of the thermosetting matrix (max. 162°C) with shear and particle detachment by the brittle nature of polyester rather than plastic deformation. The formation of a sliding film protects against fiber failure up to 150 MPa, while overload results in interlaminar shear, debonding, and ductile fiber pull-out.
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Al-Badour, Fadi, N. Merah, A. N. Shuaib, and A. Bazoune. "Experimental and Finite Element Modeling of Friction Stir Seal Welding of Tube-Tubesheet Joint." Advanced Materials Research 445 (January 2012): 771–76. http://dx.doi.org/10.4028/www.scientific.net/amr.445.771.
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Tube-tubesheet joints are critical in some applications, where contact between shell and tube side fluids is not tolerable. To ensure joint tightness, standards (ASME and TEMA) recommend performing a combination of rolling-or expansion of tube-tubesheet and seal welding. Available techniques for seal welding are based on fusion welding that sometimes results in a number of defects such as cracking and porosity formation, and such defects may take a newly fabricated heat exchanger out of service. In this work, friction stir welding (FSW) was used for tube-tubesheet seal joint and simulated using a 3D thermo-mechanical finite element model (FEM). The model was analyzed using a commercial finite element (FE) package. The model included the thermal effect of the tool workpiece interaction along with axial load, ignoring the metal flow around the tool. The material model took into account temperature dependency of thermal and mechanical properties. The model objectives were to evaluate the temperature distribution and residual stress in the workpiece resulting from the thermal cycle and axial load during welding for various process parameters, and to study how residual stresses in adjacent roller expanded tubes are affected during welding. The FE results show that the maximum temperature at the welding zone does not exceed the solidus temperature (except at high tool rotational speeds); the process can thus be classified as cold working. Moreover, adjacent tubes temperature does not exceed the annealing temperature. An experimental setup was designed and manufactured to show the feasibility of the process in this constrained size joints and to validate the numerical results. A test cell and a special FSW tool were designed and manufactured for this purpose. Many tests were performed with welding quality depending on process parameters.
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Remazeilles, Mathieu, and Jens Chluba. "Mapping the relativistic electron gas temperature across the sky." Monthly Notices of the Royal Astronomical Society 494, no. 4 (May 4, 2020): 5734–50. http://dx.doi.org/10.1093/mnras/staa1135.
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ABSTRACT With increasing sensitivity, angular resolution, and frequency coverage, future cosmic microwave background (CMB) experiments like PICO will allow us to access new information about galaxy clusters through the relativistic thermal Sunyaev–Zeldovich (SZ) effect. We will be able to map the temperature of relativistic electrons across the entire sky, going well beyond a simple detection of the relativistic SZ effect by cluster stacking methods that currently define the state-of-the-art. Here, we propose a new map-based approach utilizing SZ-temperature moment expansion and constrained-ILC methods to extract electron gas temperature maps from foreground-obscured CMB data. This delivers a new independent map-based observable, the electron temperature power spectrum $T_{\rm e}^{yy}(\ell)$, which can be used to constrain cosmology in addition to the Compton-y power spectrum $C_\ell ^{yy}(\ell)$ . We find that PICO has the required sensitivity, resolution, and frequency coverage to accurately map the electron gas temperature of galaxy clusters across the full sky, covering a broad range of angular scales. Frequency coverage at $\nu \gtrsim 300\, {\rm GHz}$ plays an important role for extracting the relativistic SZ effect in the presence of foregrounds. For Coma, PICO will allow us to directly reconstruct the electron temperature profile using the relativistic SZ effect. Coma’s average electron temperature will be measured to 10σ significance after foreground removal using PICO. Low angular resolution CMB experiment like LiteBIRD could achieve 2σ to 3σ measurement of the electron temperature of this largest cluster. Our analysis highlights a new spectroscopic window into the thermodynamic properties of galaxy clusters and the diffuse electron gas at large angular scales.
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Xue, Gaopeng, Masaya Toda, Xinghui Li, Bing Li, and Takahito Ono. "Demonstration of Heterogeneous Structure for Fabricating a Comb-Drive Actuator for Cryogenic Applications." Micromachines 13, no. 8 (August 11, 2022): 1287. http://dx.doi.org/10.3390/mi13081287.
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This study presents an experimental demonstration of the motion characteristics of a comb-drive actuator fabricated from heterogeneous structure and applied for cryogenic environments. Here, a silicon wafer is anodically bonded onto a glass substrate, which is considered to be a conventional heterogeneous structure and is commonly adopted for fabricating comb-drive actuators owing to the low-cost fabrication. The displacement sensor, also with comb-finger configuration, is utilized to monitor the motion characteristics in real time at low temperatures. The irregular motions, including displacement fluctuation and lateral sticking, are observed at specific low temperatures. This can be attributed to the different thermal expansion coefficients of two materials in the heterogeneous structure, further leading to structural deformation at low temperatures. The support spring in a comb-drive actuator is apt to be deformed because of suspended flexible structures, which affect the stiffness of the support spring and generate irregular yield behavior. The irregular yield behavior at low temperatures can be constrained by enhancing the stiffness of the support spring. Finally, we reveal that there are limited applications of the heterogeneous-structure-based comb-drive actuator in cryogenic environments, and simultaneously point out that the material substrate of silicon on the insulator is replaceable based on the homogeneous structure with a thin SiO2 layer.
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Torres-Dias, Abraao Cefas, Anthony Impellizzeri, Emmanuel Picheau, Laure Noé, Alain Pénicaud, Christopher Ewels, and Marc Monthioux. "Asymmetrical Cross-Sectional Buckling in Arc-Prepared Multiwall Carbon Nanotubes Revealed by Iodine Filling." C 8, no. 1 (January 27, 2022): 10. http://dx.doi.org/10.3390/c8010010.
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We report the intercalation of iodine chains in highly crystalline arc-discharge multiwalled carbon nanotubes (MWCNTs), not in the central cavity but instead between the concentric graphene shells. High-resolution transmission electron microscopy demonstrated that the intercalation was asymmetric with respect to the longitudinal axis of the nanotubes. This filling is explained through the existence of asymmetric intershell channels which formed as the tubes shrank upon cooling after growth. Shrinkage occurred because the geometrically constrained equilibrium intershell spacing was higher at growth than room temperature, due to the highly anisotropic coefficient of thermal expansion of graphite (or graphene stacks). Computational modelling supported the formation of such cavities and explained why they all formed on the same side of the tubes. The graphene shells were forced to bend outward, thereby opening aligned intergraphene nanocavities, and subsequently allowing the intercalation with iodine once the tube ends were opened by oxidative treatment. These observations are specific to catalyst-free processes because catalytic processes use too low temperatures, but they are generally applicable in geometrically closed carbon structures grown at high temperatures and so should be present in all arc-grown MWCNTs. They are likely to explain multiple observations in the literature of asymmetric interlayer spacings in multiple-shell graphenic carbon structures.
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Afferrante, L., M. Ciavarella, and J. R. Barber. "Sliding thermoelastodynamic instability." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 462, no. 2071 (March 6, 2006): 2161–76. http://dx.doi.org/10.1098/rspa.2006.1676.
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Numerous mechanisms can give rise to instabilities and vibrations in sliding systems. These can generally be characterized as either elastodynamic (e.g. ‘brake squeal’) or thermoelastic. The time-scales of these processes differ considerably, so it is usual to neglect coupling between them, i.e. to neglect thermal effects in elastodynamic analyses and to use the quasi-static approximation in thermoelastic analyses. In the present paper, we consider the potential coupling between them in the simplest possible context—a thermoelastodynamic layer sliding against a rigid plane and constrained to one-dimensional displacements. The results show that although the coupling is extremely weak, it has a destabilizing effect on the natural elastodynamic vibration of the layer at arbitrarily low sliding speeds. A numerical solution of the transient equations below the quasi-static critical speed shows that an initial disturbance grows exponentially until periods of separation develop, after which the system approaches asymptotically to a steady state involving periods of contact and separation alternating at the lowest natural frequency of the elastodynamic system. With increasing sliding speed, the proportion of the cycle spent in contact is reduced and the maximum contact pressure increases. It is important to note that neither a quasi-static thermoelastic analysis, nor an elastodynamic analysis neglecting thermal expansion would predict instability in this speed range. Similar instabilities due to thermoelastodynamic coupling are almost certain to occur in more complex practical sliding systems such as brakes and clutches, implying the need for the incorporation of these effects in commercial analysis software. The proposed mechanism might also provide an explanation of reported experimental observations of vibrations normal to the contact interface during frictional sliding.
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Turney, Chris S. M., Christopher J. Fogwill, Nicholas R. Golledge, Nicholas P. McKay, Erik van Sebille, Richard T. Jones, David Etheridge, et al. "Early Last Interglacial ocean warming drove substantial ice mass loss from Antarctica." Proceedings of the National Academy of Sciences 117, no. 8 (February 11, 2020): 3996–4006. http://dx.doi.org/10.1073/pnas.1902469117.
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The future response of the Antarctic ice sheet to rising temperatures remains highly uncertain. A useful period for assessing the sensitivity of Antarctica to warming is the Last Interglacial (LIG) (129 to 116 ky), which experienced warmer polar temperatures and higher global mean sea level (GMSL) (+6 to 9 m) relative to present day. LIG sea level cannot be fully explained by Greenland Ice Sheet melt (∼2 m), ocean thermal expansion, and melting mountain glaciers (∼1 m), suggesting substantial Antarctic mass loss was initiated by warming of Southern Ocean waters, resulting from a weakening Atlantic meridional overturning circulation in response to North Atlantic surface freshening. Here, we report a blue-ice record of ice sheet and environmental change from the Weddell Sea Embayment at the periphery of the marine-based West Antarctic Ice Sheet (WAIS), which is underlain by major methane hydrate reserves. Constrained by a widespread volcanic horizon and supported by ancient microbial DNA analyses, we provide evidence for substantial mass loss across the Weddell Sea Embayment during the LIG, most likely driven by ocean warming and associated with destabilization of subglacial hydrates. Ice sheet modeling supports this interpretation and suggests that millennial-scale warming of the Southern Ocean could have triggered a multimeter rise in global sea levels. Our data indicate that Antarctica is highly vulnerable to projected increases in ocean temperatures and may drive ice–climate feedbacks that further amplify warming.
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Zhang, Youshui, Xiaoqin Wang, Heiko Balzter, Bingwen Qiu, and Jingyuan Cheng. "Directional and Zonal Analysis of Urban Thermal Environmental Change in Fuzhou as an Indicator of Urban Landscape Transformation." Remote Sensing 11, no. 23 (November 27, 2019): 2810. http://dx.doi.org/10.3390/rs11232810.
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Urban expansion results in landscape pattern changes and associated changes in land surface temperature (LST) intensity. Spatial patterns of urban LST are affected by urban landscape pattern changes and seasonal variations. Instead of using LST change data, this study analysed the variation of LST aggregation which was evaluated by hotspot analysis to measure the spatial dependence for each LST pixel, indicating the relative magnitudes of the LST values in the neighbourhood of the LST pixel and the area proportion of the hotspot area to gain new insights into the thermal effects of increasing impervious surface area (ISA) caused by urbanization in Fuzhou, China. The spatio-temporal relationship between urban landscape patterns, hotspot locations reflecting urban land cover change in space and the thermal environment were analysed in different sectors. The linear spectral unmixing method of fully constrained least squares (FCLS) was used to unmix the bi-temporal Landsat TM/OLI imagery to derive subpixel ISA and the accuracy of the percent ISA was assessed. Then, a minimum change threshold was chosen to remove random noise, and the change of ISA between 2000 and 2016 was analysed. The urban area was divided into three circular consecutive urban zones in the cardinal directions from the city centre and each circular zone was further divided into eight segments; thus, a total of 24 spatial sectors were derived. The LST aggregation was analysed in different directions and urban segments and hotspot density was further calculated based on area proportion of hotspot areas in each sector. Finally, variations of mean normalized LST (NLST), area proportion of ISA, area proportion of ISA with high LST, and area proportion of hotspot area were quantified for all sectors for 2000 and 2016. The four levels of hotspot density were classified for all urban sectors by proportional ranges of 0%–25%, 25%–50%, 50%–75% and 75%–100% for low-, medium-, sub-high, and high density, and the spatial dynamics of hotspot density between the two dates showed that urbanization mainly dominated in sectors south–southeast 2 (SSE2), south–southwest 2 (SSW2), west–southwest 2 (WSW2), west–northwest 2 (WNW2), north–southwest 2 (NSW2), south–southeast 3 (SSE3) and south–southwest 3 (SSW3). This paper suggests a methodology for characterizing the urban thermal environment and a scientific basis for sustainable urban development.
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Kaiser, Trent M. V., Victor Y. B. Yung, and Russ M. Bacon. "Cyclic Mechanical and Fatigue Properties for Oil-Country-Tubular-Goods Materials." SPE Journal 13, no. 04 (December 1, 2008): 480–86. http://dx.doi.org/10.2118/97775-pa.
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Summary This paper describes differences between actual material behavior and idealizations used for modeling purposes and discusses some of the implications for interpreting model predictions. Much of the design for well structures subjected to high-amplitude cyclic loading is based on material assumptions that extrapolate strength properties from uniaxial, tensile tests to conditions where multiaxial, cyclic stresses are imposed. This paper presents results from cyclic testing on a common oil-country-tubular-goods (OCTG) material and demonstrates differences between the physical behavior measured under cyclic loading conditions and theoretical behavior extrapolated by numerical modeling. Modeling theories for plastic deformation are discussed with their limitations and relevance in a cyclic-loading environment. The implications of these limitations for design choices in thermal wells also are discussed with example applications of cyclic material behavior and fatigue-life prediction. Material fatigue properties for the high-amplitude, low-cycle application of thermal operations have not been investigated in much depth previously, particularly for OCTG. Along with characterizing cyclic mechanical properties, the tests discussed here also assessed the low-cycle fatigue properties of the sample OCTG steel. The consistent fatigue measurements, combined with analysis results using representative cyclic mechanical properties, can provide a basis for estimating fatigue life. Depending on analysis-model assumptions, substantial variation in predicted fatigue life can occur; therefore, exact fatigue-life predictions are not anticipated. The primary value in such modeling is in evaluating the relative effectiveness of mitigation options for extending well life. Introduction Most thermal enhanced-oil-recovery (EOR) wells in western Canada operate using either the cyclic-steam-stimulation (CSS) or the steam-assisted-gravity-drainage (SAGD) method. In both methods, operational factors result in thermal cycles being imposed on the well structures, particularly in the intermediate casing (Placido et al. 1997). Thermal expansion is constrained by the formation and cement in CSS and SAGD wells, producing loads that exceed the yield strength of the tubulars when the well is heated. Localization mechanisms also might amplify the strain magnitude, imposing additional plastic fatigue load at discrete locations along the well structure. Thermal-well casing designs have evolved during more than 30 years of operating experience, and much of the computer modeling that describes casing performance is based on measured uniaxial tensile material properties that are extrapolated to multidimensional cyclic behavior through engineering models. Cyclic material-properties data are sparse, particularly in the temperature regime common in thermal-recovery wells. Furthermore, plastic fatigue-life information for materials commonly used in well construction is difficult to obtain. Such information, however, is required to make reliable predictions of certain deformation mechanisms and the associated fatigue life for wells exposed to cyclic, thermally imposed loading. A test program for characterizing cyclic material properties was implemented to evaluate both cyclic mechanical properties and low-cycle fatigue life. Test-result consistency indicates a reliable material characterization that can be applied in constitutive analysis models and component-life assessments. The observed cyclic-stress-strain material behavior also demonstrates different characteristics from those predicted through engineering models using uniaxial monotonic material properties for input. This has important implications for thermal-well design and operations.