Effect Of Different Structures Research Articles

A novel hybrid battery thermal management system using TPMS structure and delayed cooling scheme

Phase change material (PCM) cooling plays an important role in battery thermal management systems (BTMS). However, PCM has been suffering from low thermal conductivity and inefficient latent heat recovery. Based on this, this study designs a hybrid BTMS combining triply periodic minimal surface (TPMS), PCM, and liquid cooling, and proposes a cooling scheme that determines the operating time of the coolant based on the battery temperature. The system aims to improve the utilization of PCM in two different ways: structural design and cooling scheme. Numerical analysis was used to compare the effects of different structures on the melting rate of PCM and to study the thermal performance of the battery module under various cooling schemes. The results show that the effective thermal conductivity of PCM/TPMS composites reaches 21 W/(m·K), which can effectively enhance the heat absorption rate of PCM. In particular, the I-graph-and-wrapped-package (IWP) structure combined with PCM is the most effective. Under the continuous cooling scheme, when the coolant flow rate is 0.04 m/s, the temperature of the battery at a 3C discharge rate can be controlled at 308.28 K, but the PCM utilization rate is only 0.25. After adopting the delayed cooling scheme, the performance of the BTMS cooling remains excellent, with the battery temperature at only 309.88 K and the liquid phase rate of PCM reaching 0.97. For the first time, the heat absorbed by passive cooling is comparable to that of active cooling in the BTMS heat absorption energy distribution, with a 73 % reduction in pumping energy consumption. Furthermore, under cycling conditions, the delayed cooling scheme still performs well, recovering all the latent heat from PCM and keeping the battery temperature below 313.15 K. In addition, it should be noted that the flow rate of the coolant should be determined by the charging rate. Additionally, the BTMS is capable of addressing the heat dissipation challenges in different ambient temperatures. This study can guide for the design of PCM in hybrid BTMS.

Long range self-transport of liquid droplets driven by electric field and roughness gradient

It is well known that roughness and charge gradients could be used for droplet self-transport. The key issue is how to synergize the two effects. The uniform density charge can form linearly increasing charge gradient on a roughness gradient surface. Under this condition, the influence on the droplet self-transport under the synergy of these two effects was obtained by statics analysis, and the driving function was presented. An energy equation was constructed to study the conditions for crossing periodic boundaries, and the problem of distance limitation on periodic surfaces due to energy dissipation was solved by converting electric potential into droplet kinetic energy. A periodic roughness gradient surface with K = 0.07 was designed and prepared via 3D printing. Water droplets can be transported over long distances and the maximum velocity increases with charge density up to 46 mm/s. Finally, the effect of different structures on the maximum charge density in the Cassie state was investigated by simulation. The biomimetic structures exhibit great compressive stability, which can increase the surface charge density of droplets in the Cassie state by 3.6 times compared to pillar structures. It can be widely used in the fields of materials science and interface chemistry, etc.

Design and analysis of hundred-meter wind turbine blade trailing edge based on finite element method (FEM)

Abstract The trailing edge region of composite wind turbine blades usually has a large deformation under wind load and the accidents caused by the damage of blade trailing edge accounts for a large proportion among blade accidents. With the development of large blade size, higher requirements are put forward for the stability of wind turbine blade trailing edge. Therefore, the trailing edge region is critical in the design of blade. A detailed study of the design and analysis for wind turbine blade trailing edge region was carried out in which the structure stability was regarded as the key. The influence of auxiliary spar cap and auxiliary spar web on the stiffness distribution and stability of the trailing edge were studied based on focus and finite element method (FEM). The respiratory effect of different structures due to deformation were analyzed and compared. The results showed that the structure of the auxiliary spar cap and auxiliary spar web can significantly increase stiffness, stability and decrease respiratory deformation at the trailing edge of blade compared to the traditional three webs structure. The structure of auxiliary spar and auxiliary spar web is the best design scheme for hundred-meter composite blade trailing edge.

A comprehensive review on the fundamental principles, innovative designs, and multidisciplinary applications of micromixers

This paper comprehensively reviews the fundamental principles, innovative designs, and multidisciplinary applications of micromixers. First, it introduces the fundamental principles of fluid mixing in micromixers, including passive and active mixing mechanisms, and the flow characteristics of fluids at the microscale. Subsequently, it focuses on the innovative design of passive micromixers, covering a variety of designs, such as obstacle structures, curved serpentine structures, groove structures, separation and recombination structures, topology optimization structures, and baffle structures, and analyzes the effects of different structures on mixing efficiency and pressure drop. In addition, it also studies the innovative design of active micromixers, including magnetic field assistance, electric field assistance, surface acoustic wave assistance, and thermal effect assistance, and analyzes the effects of different driving modes on mixing efficiency. Finally, it outlines the multidisciplinary applications of micromixers in the fields of biomedicine, chemical analysis, environmental monitoring and control, and new energy. This review aims to provide a comprehensive reference for the research and application of micromixers and promote their application in more fields.

Ti-mesh bipolar plate design and optimization for enhanced PEM electrolyzer performance in water splitting

Proton exchange membrane (PEM) electrolyzers are promising devices for hydrogen production from water splitting, but their performance and stability are still limited by various factors. This paper studies the effects of different structures on the performance of PEM electrolyzers, focusing on the working temperature, water conductivity, and the structure of bipolar plate. The results show that higher temperature and lower water conductivity enhance the electrolyzer performance, by increasing the catalyst activity and the proton transport. Moreover, a novel structure using a platinum-coated titanium mesh-based bipolar plate is proposed and tested. This structure improves the performance of the electrolyzer, by optimizing the mass transport, pressure drop, and water management in the electrolyzer. A 23-cell electrolyzer with this structure is developed and demonstrated. The electrolyzer achieves a high performance and stability, with a cell voltage of 1.742 V, a voltage efficiency of 85.0%, and a hydrogen production rate of 1.14 Nm3/h at 0.99 A/cm2. The observed cell voltage for the PEM electrolyzer is consistent with the documented range, typically spanning from 1.55 to 1.90 V at a current density of 0.99 A/cm2. This suggests that our bipolar plate design simplifies PEM electrolyzer manufacture while maintaining comparable performance to existing electrolyzers.

Research Progress on Influence of Centrifugal Blood Pump on Blood Injury

Centrifugal blood pumps drive blood flow by regulating blood flow rate, and have been widely used in clinical applications, including extracorporeal membrane oxygenation (ECMO), cardiopulmonary bypass (CPB), and extracorporeal circulation carbon dioxide removal (ECCO2R). However, because different structures and different forms of centrifugal pumps have different requirements for blood extracorporeal circulation in clinical application scenarios, blood pumps face different application conditions in clinical use. In this study, the effects of different structures of centrifugal pumps and different working conditions on blood damage are summarized for reference by relevant institutions and R&D personnel.

Effects of multilayer structure on the high-speed dry-cutting performance of AlCrBN/AlCrN multilayer coatings

To investigate the effects of different structures on the cutting performance of AlCrBN/AlCrN multilayer coatings, AlCrBN/AlCrN coatings with different multilayer structures (single layer, 10 bilayers, and 20 bilayers corresponding to T1 coating, T10 coating, and T20 coating) were synthesized using multi-arc ion plating technology. Grazing incidence X-ray diffraction (GIXRD) and transmission electron microscopy (TEM) results showed that the coatings were mainly composed of fcc-(Cr, Al) N phases located on the (111) and (200) crystal planes. All coatings exhibited a good indentation adhesion to the substrates. The hardness of the T10 coating (32.6 GPa) and T20 coating (31.2 GPa) was significantly higher than that of the T1 coating (28.0 GPa). Annealing experiments show that no phase composition evolution was revealed at 800 °C. High-speed milling tests imply that the milling life of the T10 coating (13 m) and the T20 coating (10 m) was increased by 62.5% and 25.0% compared to the T1 coating (8 m), respectively. In high-speed dry turning tests, the T10 coated tool also showed the longest lifetime (16 mins), an improvement of 23.1% over T1 or T20 coated tools (13 mins). SEM analyses of wear coated tools indicated that a multilayer structure enhanced their resistance to abrasion and adhesion wear, and led to better cutting performance, probably because of their excellent mechanical properties and thermal stability.

Simulation and Design of Optimized Three-Layer Radiation Shielding to Protect Electronic Boards of Satellite Revolving in Geostationary Earth Orbit (GEO) Orbit against Proton Beams

The safety of electronic components used in aerospace systems against cosmic rays is one of the most important requirements in their design and construction (especially satellites). In this work, by calculating the dose caused by proton beams in geostationary Earth orbit (GEO) orbit using the MCNPX Monte Carlo code and the MULLASSIS code, the effect of different structures in the protection of cosmic rays has been evaluated. A multi-layer radiation shield composed of aluminum, water and polyethylene was designed and its performance was compared with shielding made of aluminum alone. The results show that the absorbed dose by the simulated protective layers has increased by 35.3% and 44.1% for two-layer (aluminum, polyethylene) and three-layer (aluminum, water, polyethylene) protection respectively, and it is effective in the protection of electronic components. In addition to that, by replacing the multi-layer shield instead of the conventional aluminum shield, the mass reduction percentage will be 38.88 and 39.69, respectively, for the two-layer and three-layer shield compared to the aluminum shield.

Thermal performance of cavity masonry wall structures in the solar rich areas of Western China

Air cavities can effectively improve the thermal performance of building envelope. A cavity masonry wall (CMW) is a common and suitable envelope in the solar rich areas of Western China for integrating thermal insulation and heat storage. However, suitable structures for CMWs have not been obtained for different indoor and outdoor climates, which hinders the realization of near-zero energy buildings. In the present study, thermal performance was analyzed for different CMW structures to obtain the design method of the CMW structure. A mathematical model of CMWs was established and validated based on experiments. This model was used to analyze the effects of different structures for CMWs, and suitable structures were determined. Climate adaptability characteristics were analyzed for the suitable structures. Finally, the energy performance of buildings with CMWs was analyzed. A climate index for CMW structure design comprising the ratio of cooling relative to heating (RCH) was proposed to divide the outdoor climate, with winter heating when RCH ≤0.17, and winter heating and summer cooling when RCH >0.17. The suitable structures were obtained in different indoor and outdoor climates, where the closed air cavity was preferably placed on the low temperature side of the construction. The suitable structures exhibited better heat transfer attenuation delay characteristics to adapt to indoor and outdoor climates. It had a significant impact on the heating load compared with buildings with masonry walls, and a saving of above 10%. The design method of CMW structure proposed in this study can provide guidance for the application.

A structural optimized fluorescent probe for monitoring hydrogen sulfide in cells and zebrafish

In this work, we reported a fluorescent probe Fur-SH, a derivative of benzofuranone, which was used to detect H2S in living cells and zebrafish. Based on the three structural characteristics of the probe, the effects of different structural modifications on the optical properties of the fluorophore were compared. Then, the fluorophore Fur-OH was synthesized by modifying diethylamino group with benzofuranone as the main skeleton. With 2,4-dinitrofluorobenzene as the recognition group and diethylamino as the electron donor, the push–pull electron effect occurred with nitro group, which led to fluorescence quenching, and an openable fluorescent probe Fur-SH was formed. The probe Fur-SH (λex = 510 nm; λem = 570 nm) had the advantages of smaller full width at half maxima, rapid response (5 min) and wide pH window. The quantitative properties of the probe were excellent, reaching saturation at 50 equivalents of substrate. The probe Fur-SH showed high sensitivity to H2S, with LOD of 48.9 nM and LOQ of 50 nM. At present, the probe Fur-SH had been applied to fluorescence imaging of MCF-7 cells and zebrafish. By comparing the effects of different structures on the optical properties of fluorophores, this work was expected to be helpful to the development of fluorescent probes in the future.

The effect of inequality of opportunity on entrepreneurship: Evidence from China

AbstractDespite the rich literature on income inequality, its impact on entrepreneurship is inconclusive, especially regarding the effect of different structures of inequality. In this research, we endeavour to explain such a phenomenon by formalising the inequality of opportunity. Utilising micro‐level data from China, we argue that it is inequality of opportunity that is negatively correlated with people's engagement in entrepreneurship, and this conclusion is consistent under a series of robustness checks. Our heterogeneity analysis indicates that the association between inequality of opportunity and entrepreneurship is stronger for self‐employment than for bigger‐scale private companies. It is also the strongest in regions with the lowest GDP per capita, the lowest fiscal expenditures and the smallest tertiary sector. These results suggest that economic development quality, economic structure and public service are important factors that influence the correlations between inequality of opportunity (IO) and entrepreneurial activities. Finally, we seek to understand the channels through which IO may be linked to entrepreneurship. Our results find that IO may discourage engagement in entrepreneurship by depressing human capital accumulation, access to credit, social capital and risk taking.

A health equity framework to support the next generation of cancer population simulation models.

Over the past 2 decades, population simulation modeling has evolved as an effective public health tool for surveillance of cancer trends and estimation of the impact of screening and treatment strategies on incidence and mortality, including documentation of persistent cancer inequities. The goal of this research was to provide a framework to support the next generation of cancer population simulation models to identify leverage points in the cancer control continuum to accelerate achievement of equity in cancer care for minoritized populations. In our framework, systemic racism is conceptualized as the root cause of inequity and an upstream influence acting on subsequent downstream events, which ultimately exert physiological effects on cancer incidence and mortality and competing comorbidities. To date, most simulation models investigating racial inequity have used individual-level race variables. Individual-level race is a proxy for exposure to systemic racism, not a biological construct. However, single-level race variables are suboptimal proxies for the multilevel systems, policies, and practices that perpetuate inequity. We recommend that future models designed to capture relationships between systemic racism and cancer outcomes replace or extend single-level race variables with multilevel measures that capture structural, interpersonal, and internalized racism. Models should investigate actionable levers, such as changes in health care, education, and economic structures and policies to increase equity and reductions in health-care-based interpersonal racism. This integrated approach could support novel research approaches, make explicit the effects of different structures and policies, highlight data gaps in interactions between model components mirroring how factors act in the real world, inform how we collect data to model cancer equity, and generate results that could inform policy.

Transparent and Soft Crack-Resistant Bouligand Elastomers Inspired by Fish Scales.

Nature with its abundant source offers numerous inspirations for structural and engineering designs. The oriented membranes stacked with bouligand structures in the fish scales show an outstanding combination of high strength and crack resistance. Although the applications of hard biomimetic composites are reported, the structures are rarely utilized in soft materials. Inspired by the scales of various fishes, electrospun membranes are used and stacked to fabricate bouligand elastomers, including orthogonal-plywood, single-bouligand, and double-bouligand structures. The effects of different structures on the properties of elastomers are systematically investigated and possible mechanism is explained using finite element analysis (FEA). The stiffness and fatigue characteristics of these biomimetic elastomers with the above structures are improved compared with the original membranes, especially the elastomers with a single-bouligand structure, which can undergo 5000 cycles at a maximum strain of 35% without complete failure. The crack only propagates to half of the width of the elastomer with remaining strength of 50% of its original strength. Moreover, the mechanical performance can be adjusted by regulating the proportion of the components. The excellent crack-resistant properties and transparency promote its various potential applications.

Effects of different starch structures on energy metabolism in pigs

BackgroundStarch is a major component of carbohydrates and a major energy source for monogastric animals. Starch is composed of amylose and amylopectin and has different physiological functions due to its different structure. It has been shown that the energy supply efficiency of amylose is lower than that of amylopectin. However, there are few studies on the effect of starch structure on the available energy of pigs. The purpose of this study was to measure the effect of different structures of starch in the diet on the net energy (NE) of pigs using a comparative slaughter method and to establish a prediction equation to estimate the NE of starch with different structures. Fifty-six barrows (initial BW 10.18 ± 0.11 kg) were used, and they were housed and fed individually. Pigs were divided into 7 treatments, with 8 replicates for each treatment and 1 pig for each replicate. One of the treatments was randomly selected as the initial slaughter group (ISG). Pigs in the remaining treatments were assigned to 6 diets, fed with basic diet and semi-pure diets with amylose/amylopectin ratio (AR) of 3.09, 1.47, 0.25, 0.15 and 0.12, respectively. The experiment lasted for 28 d.ResultsResults showed that compared with the high amylose (AM) groups (AR 3.09 and 1.47), the high amylopectin (AP) group (AR 0.15) significantly increased the final BW, average daily weight gain and average daily feed intake of pigs (P < 0.05), but the F:G of the AM group was lower (P < 0.01). In addition, AR 0.15 and 0.12 groups have higher (P < 0.01) nutrient digestibility of dry matter, crude protein, gross energy and crude ash. Meanwhile, compared with other groups, AR 0.15 group has a higher (P < 0.05) NE intake and energy retention (RE). The regressive equation for predicting with starch structures was established as RE = 1,235.243 − 48.298AM/AP (R2 = 0.657, P = 0.05).ConclusionsIn conclusion, NE intake and RE of pigs augmented with the increase of dietary amylopectin content, indicating that diets high in amylopectin were more conducive to promoting the growth of pigs in the late conservation period.

Solute Transport across the Lymphatic Vasculature in a Soft Skin Tissue.

Convective transport of drug solutes in biological tissues is regulated by the interstitial fluid pressure, which plays a crucial role in drug absorption into the lymphatic system through the subcutaneous (SC) injection. In this paper, an approximate continuum poroelasticity model is developed to simulate the pressure evolution in the soft porous tissue during an SC injection. This poroelastic model mimics the deformation of the tissue by introducing the time variation of the interstitial fluid pressure. The advantage of this method lies in its computational time efficiency and simplicity, and it can accurately model the relaxation of pressure. The interstitial fluid pressure obtained using the proposed model is validated against both the analytical and the numerical solution of the poroelastic tissue model. The decreasing elasticity elongates the relaxation time of pressure, and the sensitivity of pressure relaxation to elasticity decreases with the hydraulic permeability, while the increasing porosity and permeability due to deformation alleviate the high pressure. An improved Kedem-Katchalsky model is developed to study solute transport across the lymphatic vessel network, including convection and diffusion in the multi-layered poroelastic tissue with a hybrid discrete-continuum vessel network embedded inside. At last, the effect of different structures of the lymphatic vessel network, such as fractal trees and Voronoi structure, on the lymphatic uptake is investigated. In this paper, we provide a novel and time-efficient computational model for solute transport across the lymphatic vasculature connecting the microscopic properties of the lymphatic vessel membrane to the macroscopic drug absorption.

Band gap characteristics of multi-functional lattice metamaterials with adjustable thermal expansion and Poisson's ratio

The current development of science and technology has put increased demands on the versatility of metamaterials. In this paper, the band gap characteristics of a lattice metamaterial that can simultaneously modulate thermal expansion and Poisson’s ratio are studied, the dispersion characteristics of elastic waves propagating in periodic lattice metamaterials are analyzed, and the effects of different structures and parameters on the band gap are discussed. The results indicate that the configuration has excellent band gap properties while satisfying the tunable coefficient thermal expansion (CTE)and Poisson’s ratio functions. Through reasonable material selection and shape design, it is expected to achieve a multi-objective win-win for specific thermal expansion properties, Poisson’s ratio, and band gap design, resulting in better tunability and versatility of the metamaterial.

Leaf-vein bionic fin configurations for enhanced thermal energy storage performance of phase change materials in smart heating and cooling systems

In the present study, we investigated the effect of different structures of a novel leaf vein bionic fin and various arrangements in the tube on the complete melting time of phase change materials (PCM) in a triplex-tube thermal energy storage (TES) system. RT82 was adopted as the phase change material. The enthalpy-porosity method was employed for this numerical study. The numerical model was validated against experimental data from a previous reference. The simulation results demonstrate that the novel fins deliver significant reductions in the duration of complete melting. Based on fin-branched vein numbers of 1, 2 and 3, increasing the fin angle from 30° to 60° can reduce the complete melting time by up to 14.3%. Additionally, adjusting the fin arrangement can save up to 6.35% of the complete melting time. The proper arrangement of the fins can improve the heat transfer performance of the PCM. The non-dimensional quantities analysis of the calculated results shows that the melting time is negatively correlated with the non-dimensional angle. As the non-dimensional parameter, fin arrangement number decreases from 1, the complete melting time corresponding to the fins of different structures first decreases and then increases for the phase change material.

New molecular structure based models for estimation of the CO2 solubility in different choline chloride-based deep eutectic solvents (DESs)

In this study, CO2 solubility in different choline chloride-based deep eutectic solvents (DESs) has been investigated using the Quantitative Structure–Property Relationship (QSPR). In this regard, the effect of different structures of the hydrogen bond donor (HBD) in choline chloride (ChCl) based deep eutectic solvents (DESs) has been studied in different temperatures and different molar ratios of ChCl as hydrogen bond acceptor (HBA) to HBD. 12 different datasets with 390 data on the CO2 solubility were chosen from the literature for the model development. Eight predictive models, which contain the pressure and one structural descriptor, have been developed at the fixed temperature (i.e. 293, 303, 313, or 323 K), and the constant molar ratio of ChCl to HBD equal to 1:3 or 1:4. Moreover, two models were also introduced, which considered the effects of pressure, temperature, and HBD structures, simultaneously in the molar ratios equal to 1:3 or 1:4. Two additional datasets were used only for the further external validation of these two models at new temperatures, pressures, and HBD structures. It was identified that CO2 solubility depends on the “EEig02d” descriptor of HBD. “EEig02d” is a molecular descriptor derived from the edge adjacency matrix of a molecule that is weighted by dipole moments. This descriptor is also related to the molar volume of the structure. The statistical evaluation of the proposed models for the unfixed and fixed temperature datasets confirmed the validity of the developed models.

Strategies for improving Chinese language proficiency based on artificial intelligence technology

Abstract In recent years, the development of artificial intelligence technology and theory has been rapid, and the application in language science has been gradually comprehensive and diversified, especially the accuracy rate of artificial intelligence for Chinese language is up to 90%. In the era of artificial intelligence, the effect of different structures and parameters of arithmetic models on Chinese language recognition varies greatly. Language science is an important research area for realizing machine-human communication, and accurate comprehension of the meaning of linguistic expressions is the key to realize communication. In this paper, we construct a speech system that is different from the traditional stable time series for the irreplaceable characteristics of artificial intelligence technology to improve Chinese language ability. A dynamic Bayesian network (DBN) is used for modeling and analysis, and a DBN construction method is investigated to import a hidden Markov model in a speech recognition system to reveal the interactions between nodes within multiple time slices. The accuracy of dynamic Bayesian networks in Chinese dialect inference algorithms is demonstrated using Matlab simulations to characterize the reliability of speech features using a speech spectrogram. It proves that artificial intelligence technology and Chinese language science are complementary and mutually reinforcing, showing a good and rapid development trend.

Effect of different structures on corrosion resistance of Mg–Zn–Ca–Cu alloys

AbstractCompared with traditional magnesium alloys, magnesium‐based metallic glasses exhibit favorable properties, making them potential materials for clinical implants. In this work, to develop magnesium‐based metallic glasses suitable for different degradation requirements, the effects of different structures of Mg–Zn–Ca–Cu alloys on their corrosion resistance were investigated. Mg66Zn29.5Ca4Cu0.5 metallic glasses were prepared by copper mold injection, and the alloys were heat treated at 90°C, 160°C, 230°C, and 270°C. The phase composition was determined by X‐ray diffraction, and electrochemical tests and hydrogen evolution experiments were carried out in a simulated liquid at 37°C. The results show that the corrosion resistance of the alloy is seriously affected by its microstructure.