The urgent need to mitigate climate change impacts and achieve net zero emissions has led to extensive research on carbon dioxide(CO_(2))-capture *** study focuses on the kinetics of CO_(2)capture using solid adsorben...
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The urgent need to mitigate climate change impacts and achieve net zero emissions has led to extensive research on carbon dioxide(CO_(2))-capture *** study focuses on the kinetics of CO_(2)capture using solid adsorbents specifically through thermal gravimetric analysis(TGA).The research explores the principles behind TGA and its application in analyzing adsorbent performance and the significance of kinetics in optimizing CO_(2)-capture *** adsorbents have gained significant attention due to their potential for efficient and cost-effective CO_(2)***,three different types of adsorbents,namely calcium-,tin-,and zirconium-based ones(quicklime:CaO,potassium stannate:K_(2)SnO_(3),and sodium zirconate:Na_(2)ZrO_(3)),in adsorbing high-temperature carbon dioxide were investigated;their quality and performance by various factors such as price,stability,non-toxicity,and efficiency are *** diffusion models and geometrical contraction models were the best-fitted models to explain the kinetic of these solid adsorbents for high-temperature CO_(2)sorption;it means the morphology is important for solid adsorbent *** minimum energy needed to start a reaction for K_(2)SnO_(3),Na_(2)ZrO_(3),and CaO,is 73.55,84.33,and 86.23 kJ·mol^(-1),respectively;with the lowest value being for potassium *** high-temperature CO_(2)adsorption performance of various solid adsorbents in regard with the rate of reaction followed the order of K_(2)SnO_(3)>CaO>>Na_(2)ZrO_(3),based on experiments and kinetic studies.
This paper proposes new quasi-periodic orbits around Earth–Moon collinear libration points using solar *** including the time-varying sail orientation in the linearized equations of motion for the circular restricted...
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This paper proposes new quasi-periodic orbits around Earth–Moon collinear libration points using solar *** including the time-varying sail orientation in the linearized equations of motion for the circular restricted three-body problem(CR3BP),four types of quasi-periodic orbits(two types around L1 and two types around L2)were *** them,one type of orbit around L2 realizes a considerably small geometry variation while ensuring visibility from the Earth if(and only if)the sail acceleration due to solar radiation pressure is approximately of a certain magnitude,which is much smaller than that assumed in several previous *** means that only small solar sails can remain in the vicinity of L2 for a long time without propellant *** orbits designed in the linearized CR3BP can be translated into nonlinear CR3BP and high-fidelity ephemeris models without losing geometrical *** this study,new quasi-periodic orbits are formulated,and their characteristics are ***,their extendibility to higher-fidelity dynamic models was verified using numerical examples.
Recently,intelligent fault diagnosis methods have been employed in the condition monitoring of rotating *** them,graph neural networks are emerging as a new feature extraction tool that can mine the relationship chara...
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Recently,intelligent fault diagnosis methods have been employed in the condition monitoring of rotating *** them,graph neural networks are emerging as a new feature extraction tool that can mine the relationship characteristics between ***,many existing graph construction methods suffer from structural redundancy or missing node relationships,thus limiting the diagnosis accuracy of the models in *** this paper,an adaptive adjustment k-nearest neighbor graph-driven dynamic-weighted graph attention network(AAKNN-DWGAT)is proposed to address this ***,time-domain signals are transformed into frequency-domain features by using fast Fourier ***,a frequency similarity evaluation method based on dynamic frequency warping is proposed,which enables the conversion of distance measurements into a frequency similarity matrix(FSM).Then,an adaptive edge construction operation is conducted on the basis of FSM,whereby the effective domain is captured for each node using an adaptive edge adjustment method,generating an AAKNN graph(AAKNNG).Next,the constructed AAKNNG is fed into a dynamic-weighted graph attention network(DWGAT)to extract the fault features of nodes layer by *** particular,the proposed DWGAT employs a dynamic-weighted strategy that can update the edge weight periodically using high-level output features,thereby eliminating the adverse impacts caused by noisy ***,the model outputs fault diagnosis results through a softmax *** case studies verified the effectiveness and the superiority of the proposed method compared with other graph neural networks and graph construction methods.
Two or more elements with different physical and chemical characteristics make up the composite material. The composite may be prepared using a variety of methods, but stir casting is a popular choice since it is easy...
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This study introduces a new rotary draw bending method that utilizes a variable curvature bending die. Unlike traditional methods that bend tubes with a fixed radius, this method gradually deforms the tube from a larg...
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Friction rolling additive manufacturing(FRAM)is a solid-state additive manufacturing technology that plasticizes the feed and deposits a material using frictional heat generated by the tool *** ther-mal efficiency of ...
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Friction rolling additive manufacturing(FRAM)is a solid-state additive manufacturing technology that plasticizes the feed and deposits a material using frictional heat generated by the tool *** ther-mal efficiency of FRAM,which depends only on friction to generate heat,is low,and the thermal-accumulation effect of the deposition process must be *** FRAM heat-balance-control method that combines plasma-arc preheating and instant water cooling(PC-FRAM)is devised in this study,and a temperature field featuring rapidly increasing and decreasing temperature is constructed around the tool ***,2195-T87 Al-Li alloy is used as the feed material,and the effects of heating and cooling rates on the microstructure and mechanical properties are *** results show that water cooling significantly improves heat accumulation during the deposition *** cooling rate increases by 11.7 times,and the high-temperature residence time decreases by more than 50％.The grain size of the PC-FRAM sample is the smallest,i.e.,3.77±1.03 μm,its dislocation density is the highest,and the number density of precipitates is the highest,the size of precipitates is the smallest,which shows the best precipitation-strengthening *** hardness test results are consistent with the precipitation *** ultimate tensile strength,yield strength and elongation of the PC-FRAM samples are the highest(351±15.6 MPa,251.3±15.8 MPa and 16.25％±1.25％,respectively)among the samples *** preheating and water-cooling-assisted deposition simultaneously increases the tensile strength and elongation of the deposited *** combination of preheating and instant cooling improves the deposition efficiency of FRAM and weakens the thermal-softening effect.
In this research paper,a solar air heater with triangular fins has been experimentally analysed and ***,an experimental set-up of a solar air heater having triangular fins has been developed at the location of 28.10&#...
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In this research paper,a solar air heater with triangular fins has been experimentally analysed and ***,an experimental set-up of a solar air heater having triangular fins has been developed at the location of 28.10°N,78.23°*** heat transfer rate through fins and fins efficiency has been determined by the Finite Difference Method model *** experimental data and modeled data of response parameters have been optimized in MINITAB-17 software by the Response Surface Methodology *** creating the response surface design,three input parameters have been selected namely solar intensity,Reynolds number,and fin base-to-height *** range of solar intensity,Reynolds number,and fin base-to-height ratio is 600 to 1000W/m^(2),4000 to 6000,and 0.4 to 0.8 *** response surface design has been analyzed by calculating the outlet temperature,friction factor,Nusselt number,fin efficiency,thermal performance factor,and exergy *** optimum settings of input parameters:solar intensity is 1000 W/m^(2);Reynolds number is 4969.7,and the fin base to height ratio is 0.6060,on which these response:namely outlet temperature of 92.531℃,friction factor of 0.2350,Nusselt number of 127.761,thermal efficiency of 50.836%,thermal performance factor of 1.4947,and exergy efficiency of 8.762%.
In conveying concentrated liquid-solid mixtures in pipelines oriented horizontally,gravitational settling promotes a concentration-rich layer of solids at the pipe invert that degrades the wall due to sliding(abrading...
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In conveying concentrated liquid-solid mixtures in pipelines oriented horizontally,gravitational settling promotes a concentration-rich layer of solids at the pipe invert that degrades the wall due to sliding(abrading)action against the *** current study investigates near-wall flow field characteristics and then obtains flow and geometry conditions using a response surface methodology(RSM)that minimizes the maximum sliding frictional power developed in the vicinity of a 90° horizontal bend for transporting a dense solid-liquid *** liquid-solid flow field is mathematically modeled with a Eulerian-Eulerian approach using the realizable κ-ε model with standard wall functions for turbulence *** effect of several operating parameters such as solid concentration,mixture velocity,particle sizes,pipe diameters,and bend ratios on the near-wall flow field in the bend reveals useful insight relevant to the bend wall degradation by solid particles.A reduction of 28％in the maximum sliding frictional power is achieved with the optimized flow conditions within the operating range *** novel approach could be utilized in an apriori estimation of the erosion in bends for any particle-pipe wall material combination in the hydro transport of dense solids.
Automobiles are the inevitable mode of ***,increasing fuel prices and carbon dioxide emissions are posing a serious threat to automobile users and the ***,the development of new lightweight materials has been a key ar...
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Automobiles are the inevitable mode of ***,increasing fuel prices and carbon dioxide emissions are posing a serious threat to automobile users and the ***,the development of new lightweight materials has been a key area of ***-based commercial alloys(AZ and ZK series alloys)are the lightest among all structural ***,there is still a question about the replacement of Aluminum-based alloys due to HCP crystal *** this connection,Mg-Al-Ca-Mn(AXM)Mg alloy can be a choice as an alternative to the existing Mg-based commercial alloys for structural *** contains(Al,Mg)_(2)Ca,Al_(2)Ca,Mg_(2)Ca,and Al_(8)Mn_(5)as the secondary phases,contributing to the microstructural refinement and property ***,the formation of those precipitates depends on the amount of Al,Ca,and Mn,especially,the Ca/Al *** addition,the secondary processes influence the grain refinement and property enhancement of texture ***,this review article focuses on elaborating on the significance of the Ca/Al ratio for the precipitate formation,secondary process,and texture *** co-segregation behavior of other micro-alloying elements like Cerium,Lanthanum,and Zinc in AXM Mg alloy systems has also been discussed for property enhancement.
In the present work, an attempt has been made to develop the composite specimen using natural fibres. Natural fibres are the by-product of animals or plants considered waste and disposed into the sea or landfill. The ...
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