Mixing Index Research Articles

Constructal design of passive micromixers with multiple obstacles via computational fluid dynamics

Passive micromixers have applications mainly in the chemical, pharmaceutical, and materials industries. Two or more fluids mix while flowing through microchannels in these devices. Due to the small dimensions and low flow rates, the flow is essentially laminar, and mixing takes place mainly by mass diffusion. One way to increase the mixing rate in micromixers is the addition of obstacles that increase the advective effects. This work aimed to introduce high-performance designs of passive micromixers with multiple obstacles. These designs were obtained by combining the Constructal Design method with the Response Surface Optimization method and Computational Fluid Dynamics (CFD). The micromixers were Y-shaped tubes with grooves and circular obstacles in cells that repeated along the device. From the first design inspired by a high-performance design from the literature, the evolutionary design of the system was achieved by increasing the number of obstacles and finding the best configuration for each evolution level (number of obstacles per cell, from three to seven). The effects on mixing percentage, pressure difference, and mixing energy cost (MEC) of obstacles’ vertical and horizontal distances were investigated with CFD simulations. Increasing the number of obstacles made it possible to increase the mixture percentage of the micromixer. At the same time, the total pressure drop rises faster than the mixing percentage. However, analyzing the pressure locally, it was shown that the lower the number of obstacles, the greater the local pressure drop, which could cause flow obstructions. The vertical distance of the obstacles had a more significant impact on the mixing than their horizontal distance. Both vertical and horizontal distances had a substantial effect on the pressure drop. As the number of obstacles increased, the effect of the horizontal distance became weaker as its variation was limited. The three-obstacles design presented a MEC equal to 2.47 and a mixing percentage equal to 67.12% mixing index. The latest design evolution (i.e., seven obstacles) achieved the best mixing percentage, 70.30%, with MEC equal to 2.97. By modifying the degrees of freedom, it was possible to understand and propose a path to the evolutionary design of the system to increase its performance while still using simple designs.

Baseline Characteristics and Outcomes for People With and Without COVID-19 Diagnoses Receiving Inpatient Rehabilitation Care Across the US in 2020-2021

ObjectiveTo assess sociodemographic, medical complexity, and outcomes of persons receiving care at inpatient rehabilitation facilities (IRFs) with and without a diagnosis of COVID-19. DesignA retrospective cohort study using electronic medical record (EMR) data from 138 IRFs across 34 states and Puerto Rico. SettingN/A. ParticipantsIRF EMR data for 212,663 patients discharged between 04/01/2020 and 05/31/2021 (N=212,663), of which 16,199 (COVID-19 group) had a primary or secondary COVID-19 diagnosis based upon ICD codes set (ICD-10 codes U07.1, B94.8, Z86.19, Z86.16). Main Outcome MeasuresFour categories: (a) sociodemographic, (b) medical complexity, (c) process, that is, standard IRF processes, and clinical outcomes (collected routinely as part of administrative reporting), and (d) functional outcomes. Patients with missing functional data associated with short/incomplete stays (n=623) were excluded from analysis of functional outcomes category only. Standard descriptive analysis techniques were employed for comparing categorical and continuous variables between groups. ResultsStatistically significant differences were noted between the COVID-19 group and non-COVID groups for race (26.0% vs 19.7% non-minority, P<.001), Case Mix Index (1.49 vs 1.46, P<.001), Center for Medicare and Medicaid Services 60% rule qualification (79.0% vs 73.4%, P<.001), time to onset (24.3 vs 18.0 days, P<.001), length of stay (14.2 vs 12.9 days, P<.001), and discharge disposition (to community: 75.3% vs 81%, P<.001; to acute care facility: 15.6% vs 10.8%, P<.001). The COVID-19 group had higher frequency of respiratory and cardiovascular disease, diabetes, encephalopathy, morbid obesity, and critical illness neuropathy and myopathy. Clinically insignificant differences were noted for age, sex, depression, and cognitive assessment. Ability to participate and functional outcomes were comparable between the groups. ConclusionThere are significant differences between the COVID-19 and non-COVID group in some sociodemographic, medical complexity, process and clinical outcomes, but not in functional outcomes. The ability to participate in the IRF-required intensity of therapy services along with attainment of comparable levels of functional outcomes supports the benefit of IRFs for persons with COVID-19.

Urban feature shadow extraction based on high-resolution satellite remote sensing images

With the continuous increase in the resolution of high-resolution remote sensing satellite images, shadows have increasingly impacted feature target recognition and classification in images, urban reconstruction, and image interpretation. Although various shadow detection methods exist for different features, undetected small shadowed areas, misclassified dark areas, and highlighted non-shadowed areas remain. Moreover, it is still difficult to distinguish waters from shadowed regions owing to their similar characteristics. To further solve these problems, we propose a novel mixed shadow detection index (MSDI) for extracting urban feature shadows, using the original information of the first principal component that contains the differences between most of the different objects in the image, as well as the difference features in the shadowed areas and water bodies. We evaluated the effectiveness and robustness of our method by conducting comparison experiments using Gaofen-1, Gaofen-2, and WorldView-3 images from different scenes, times, and acquisition locations. Through visual analysis and data analysis of our method, we found that the method achieved excellent shadow detection results, with an average total accuracy 94% for shadow detection. The proposed shadow detection algorithm could accurately recognize waters, and it could also accurately recognize easily missed small shadowed areas and easily confused non-shadowed areas.

Demystifying the decadal shift in the extent of groundwater in the coastal aquifers of Gujarat, India: A case of reduced extent but increased magnitude of seawater intrusion

Catastrophic increase in urbanisation and industrialisation along the coastal region leads to increased stress on groundwater reservoirs worldwide. As a growing economy, India faces extreme water crises due to rising water demand and escalating salinisation, specifically in the coastal districts. Therefore, this study shows the implication of a comprehensive modelling approach to assess the spatiotemporal changes in hydrogeochemical processes in the coastal aquifer of the Surat district. Using a multi-model assessment approach, the present study focuses on the decadal evolution in groundwater quality of the coastal aquifers of Surat, Gujarat. Fifty-one groundwater samples were collected for 2008, 2012, and 2018 to assess the spatio-temporal shift in groundwater quality. Piper diagram revealed a shift of hydrogeochemical facies from Mg2+-HCO3− type to Ca2+-Mg2+-Cl− type, indicating the increased salinisation over a decade. The result suggests that rock-water interaction, seawater intrusion mechanism, and anthropogenic activities (intensive agricultural activities and improper waste management) govern the hydrogeochemical processes in the coastal aquifer. A shift of dominance of carbonate weathering to silicate weathering with the dissolution of calcite, dolomite, and gypsum, changing the hydrogeochemistry, was observed over the last decades. This shift leads to the increasing hardness of groundwater. The enrichment of nutrients in groundwater during 2018 (NO3− = 2 to 85 mg. L−1) compared to 2008 (NO3− = 1 to 36 mg.L−1) indicates the increasing imprints of agricultural fertilizer application and human organic waste through sewage contamination on the coastal aquifer. The seawater mixing index model demonstrates that extent of seawater intrusion reduced in 2018 compared to 2012, but the magnitude increased near the coastal talukas (SMI =9.5). The present study helps to understand the increasing anthropogenic activities over a decade leading to increased salinisation and groundwater contamination in the aquifer system. This work can help local stakeholders, water resource managers, and the state government manage the groundwater resources and the future potential threat of aquifer contamination.

Paediatric clinical decision support: Evaluation of a best practice alert for red blood cell transfusion.

Providing red blood cell (RBC) transfusion to paediatric patients with a haemoglobin (Hb) level of <7 g/dL is the current best practice, but it is often difficult to ensure appropriateness of RBC transfusion on a health system level. Electronic health record (EHR) clinical decision support systems have been shown to be effective in encouraging providers to transfuse at appropriate Hb thresholds. We present our experience with an interruptive best practice alert (BPA) at a paediatric healthcare system. An interruptive BPA requiring physician response was implemented in our EHR (Epic Systems Corp., Verona, WI, USA) in 2018 based on Hb thresholds for inpatients. The threshold was initially <8 g/dL and later changed to <7 g/dL in 2019. We assessed total activations, number of RBC transfusions and hospital metrics through 2022 compared to the 2 years prior to implementation. The BPA activated 6956 times over 4 years, slightly less than 5/day, and the success rate, with no RBC transfusions within 24 h of order attempt, was 14.5% (1012/6956). There was a downward trend in the number of total RBC transfusions and RBC transfusions per admission after implementation, non-significant (p = 0.41 and p = >0.99). The annual case mix index was similar over the years evaluated. The estimated cost savings based on acquisition costs for RBC units were 213,822 USD or about $51,891 per year. BPA implementation led to sustained change in RBC transfusion towards best practice, and there were long-term savings in RBC expenditure.

Numerical simulation and structural recombination of microchannel micromixer for excellent mixing performance

A facile continuous flow micromixer with a novel internal structure is developed to improve the mixing effect through computational fluid dynamics (CFD) simulation. Meanwhile, an authentic transparent micromixer was prepared following the mathematical model of the micromixer, and reliability of the simulation was verified by result comparison of fluid mixing performance. Moreover, several internal structures were designed and their mixing effect was calculated. Using velocity inlet and pressure outlet, ignoring the change of energy during the mixing process, it is shown that the structure of the micro-mixer has a positive effect on the mixing effect at Re < 1200. In the cubic structure, the fluid is dominated by molecular diffusion, the increase of concavity and convexity structure makes the fluid produce spiral flow, and the fluid separates and recombines many times in the mixed structure, the convective mixing process is superior to the molecular diffusion process and the mixing effect is improved. Furthermore, it was astonished that the addition of cubic structure inside convex-concave structures (a recombination structure), improve the mixing index as well as reducing the flow resistance by increasing fluid-to-fluid interface area.

Relationship between Racial Diversity in Medical Staff and Hospital Operational Efficiency: An Empirical Study of 3870 U.S. Hospitals.

Demand for foreign nurses and medical staff is rapidly increasing due to the severe labor shortage in U.S. hospitals triggered by the COVID-19 pandemic. However, empirical studies on the effect of the racial diversity of medical staff on hospital operations are still lacking. This research gap is thus investigated based on the foreign medical staff working in 3870 U.S. hospitals. Results show that workforce racial diversity has a significantly positive relationship with hospital operational efficiency regarding occupancy rate, manpower productivity, capacity productivity, and case mix index. Notably, this study empirically supports that increasing the ratio of foreign nurses positively affects the overall operational efficiency of hospitals. In addition, the study results also indicate that the hospital location, size, ownership, and teaching status act as significant control variables for the relationship between racial diversity and hospital efficiency. These results imply that hospitals with these specific operating conditions need to pay more attention to racial diversity in the workplace, as they are structurally more sensitive to the relationship between racial diversity and operational efficiency. In short, the findings of this study suggest that hospital efficiency can be operationally improved by implementing workforce ethnic diversity. For this reason, hospital stakeholders and healthcare policymakers are expected to benefit from this study's findings. Above all, the results of this study imply that if an organization adapts to extreme external environmental changes (e.g., the COVID-19 pandemic) through appropriate organizational restructuring (i.e., expanding the workforce racial diversity by hiring foreign medical staff), the organization can gain a competitive advantage, a claim that is supported by contingency theory. Further, investors are increasingly interested in ESG, especially companies that embody ethical and socially conscious workplaces, including a diverse and inclusive workforce. Thereby, seeking racial diversity in the workforce is now seen as a fundamental benchmark for organizational behavior that predicts successful ESG business practices, a claim that is supported by stakeholder theory. Therefore, in conclusion, the findings of this study suggest that workforce racial diversity is no longer an optional consideration but should be considered as one of the essential determinants of competitive advantage in organizations, particularly in the healthcare sector.

Machine learning-augmented fluid dynamics simulations for micromixer educational module.

Micromixers play an imperative role in chemical and biomedical systems. Designing compact micromixers for laminar flows owning a low Reynolds number is more challenging than flows with higher turbulence. Machine learning models can enable the optimization of the designs and capabilities of microfluidic systems by receiving input from a training library and producing algorithms that can predict the outcomes prior to the fabrication process to minimize development cost and time. Here, an educational interactive microfluidic module is developed to enable the design of compact and efficient micromixers at low Reynolds regimes for Newtonian and non-Newtonian fluids. The optimization of Newtonian fluids designs was based on a machine learning model, which was trained by simulating and calculating the mixing index of 1890 different micromixer designs. This approach utilized a combination of six design parameters and the results as an input data set to a two-layer deep neural network with 100 nodes in each hidden layer. A trained model was achieved with R2 = 0.9543 that can be used to predict the mixing index and find the optimal parameters needed to design micromixers. Non-Newtonian fluid cases were also optimized using 56700 simulated designs with eight varying input parameters, reduced to 1890 designs, and then trained using the same deep neural network used for Newtonian fluids to obtain R2 = 0.9063. The framework was subsequently used as an interactive educational module, demonstrating a well-structured integration of technology-based modules such as using artificial intelligence in the engineering curriculum, which can highly contribute to engineering education.

Application of split and recombine microchannel for microfluidic applications: a review

Microfluidic mixing is used in micro-scale systems to combine numerous samples quickly but thoroughly. These devices promote sample mixing primarily by improving the diffusion result among the fluxes of several species. In general, there are two types of microfluidic mixing methods: active (which employs an external power force to disturb the specimen genus) and passive (which uses specifically designed microchannel to-pologies to increase the area of contact as well as contact period of the sample species). This review research uses a comprehensive survey under the microfluidic micromixer (active and passive micromixer). Along with a study of hybrid active and passive micro-mixers, the use of microfluidic is also thoroughly examined. Based on this analysis, we were able to compare the mixing indexes of active and passive mixers, with active achieving a maximum mixing index of 0.73 and passive achieving a maximum mixing index of 0.97. At the end of this review, readers will have a better knowledge of microfluid-ics and its applications in the real world.

How daily activities and built environment affect health? A latent segmentation-based random parameter logit modeling approach

Transport studies have recently started focusing on the link between activity participation and general health. This study explores the relationship between general health and travel activities, physical activity, and built environment attributes. Individuals’ self-rated health is considered a general health indicator. Using data from the Impacts of Bicycle Infrastructure in Mid-sized Cities (IBIMS) survey of Kelowna, British Columbia, Canada, this study develops a latent segmentation-based random parameter logit (LSRPL) model. The motivation for adopting the LSRPL model is to capture multi-dimensional heterogeneity by allocating individuals into discrete latent segments (inter-segment heterogeneity) and then allowing a continuous distribution of the parameters within the segments (intra-segment heterogeneity). The model is estimated for two segments where segment one includes younger suburban dwellers; segment two includes older urban dwellers. The model results confirm the effect of travel, physical activity, and built environment on general health revealing multi-dimensional heterogeneity. In the case of inter-segment heterogeneity, results confirm that a higher share of travel duration using a car reduces the likelihood of excellent health in segment one. In contrast, a positive relationship is found in segment two. Whereas, for intra-segment heterogeneity results reveal that, a higher commute duration is found to be negatively associated with good health in segment two. However, this variable shows higher heterogeneity in mean for land use mix index, which indicates that urban areas coupled with higher land use mix increase the propensity towards good health. These findings will assist in developing transportation policies and investment decisions to build healthier cities.

Numerical study of the influence of geometry and flow on the mixing process of non-Newtonian fluids in micromixers

This article is designed for the study of the mixing of non-Newtonian fluids using a kenics micromixer. The governing equations are solved numerically using a CFD code. The species transport model was chosen to characterize the mixing. The flow regime is laminar. The generalized Reynolds number ranges from 0.1 to 120. The CMC solutions supplied to the power law model are used in the simulations as a non-Newtonian fluid. The mixing efficiency was assessed by calculating the mixing index MI. Two geometric configurations of T-type and Y-type micromixers are investigated, and their hydrodynamic mixing performance is compared. The results of the numerical simulations show that the proposed micro kenics have the best mixing index which exceeds 0.98 for all values of (n) and Reg less than or equal to 25 considered in this study. This micromixer had real potential to improve mixing performance because the kinematic properties are totally chaotic. Finally, this micromixer is suitable for use in microfluidic systems that demand rapid mixing while maintaining low Reynolds numbers.

Performance Investigation of Micromixer with Spiral Pattern on the Cylindrical Chamber Side Wall.

In this paper, a sequence of passive micromixers with spiral patterns on the side wall of cylindrical chambers are designed, optimized, prepared and tested. The simulation studies show that the vortex magnitude and continuity in the mixing chamber are the most important factors to determine mixing performance, while the inlet position and structural parameters are secondary influences on their performance. According to the above principles, the performance of a micromixer with a continuous sidewall spiral finally wins out. The total mixing length is only 14 mm, but when Re = 5, the mixing index can reach 99.81%. The multi-view visual tests of these mixer chips prepared by 3D printing are consistent with the simulation results. This paper provides a new idea for optimizing the micromixer with spiral patterns on the side wall and the problems of floor area and pressure loss are significantly improved compared to the conventional spiral structure.

Long term trends at a comprehensive cancer center during the COVID-19 pandemic.

As the ongoing public health crisis from Coronavirus Disease 2019 (COVID-19) pandemic puts strains on current models of cancer care, many health care centers had to adapt to minimize the risk of exposure and infection. The effects of the COVID-19 pandemic in a comprehensive cancer center were determined. To measure the impact of the COVID-19 pandemic on care delivery at a comprehensive cancer center. The number of on-site and telehealth visits (TH) were obtained from scheduling software. Multiple factors including total visits, telehealth visits, screenings for cancer diagnosis, and cancer treatments were tracked from 2 years before the pandemic onset through 2022. The length of stay (LOS) and Case Mix Index (CMI) were calculated using hospital database. In the third quarter of FY 2020, telehealth visits (TH) represented a fifth of total patient encounters. Cancer treatments, such as chemotherapy, radiation therapy, and surgery, decreased during the pandemic with number of surgeries being most affected (23% decrease in 2020 compared to the previous fiscal year). The average length of stay (LOS) was also longer with less discharges per given time during the pandemic. The increased LOS was related to increased severity of patient illnesses since CMI was higher. Screening mammograms decreased to a nadir of 58% in 2021 as compared to those screened in pre-pandemic fiscal years. The COVID-19 pandemic impacted many aspects of care, such as treatment and screenings. Many of these factors had to be postponed due to the fear of acquiring COVID-19 and access to care. The findings presented implicate that the delays and changes in cancer care during the pandemic resulted in less screening and treatment of more advanced disease.

Electrochemical performance optimization of NMC811 through the structure design of its precursor

This paper presents a study on the effect of the precursor structure on NMC811 electrochemical properties. The influence of different parameters, such as morphology and crystallinity of the precursor, Ni0.8Mn0.1Co0.1(OH)2, on the final electrochemical performance of NMC811 are analyzed. To ensure a correct and fast mixing of the precursor reactants and prepare the Ni0.8Co0.1Mn0.1(OH)2, a novel approach is used employing a micromixer, thus enabling the collection of the precipitated metal hydroxide within a few seconds after its precipitation. Then the precursor is calcinated together with a Li source to obtain the NMC811 cathode material. When analyzing the aging time of the precursor, between collection and calcination, it is observed that the primary particles of the precursor grow and become more crystalline, adopting a lamellar shape, while the secondary particles turn more compact, when increasing the aging time. The NMC materials synthesized from the aged precursors have smoother primary particles, exposing clearer crystalline planes. This change in morphology is also evidenced in the crystalline structure where an increase in the aging time produces better layered materials with a lower cation mixing index. The well-ordered structure impacts the electrochemical characteristics; indeed, the aged precursor produces NMC with higher specific capacity, better cyclability and lower capacity fade.

Waste valorization in fluidized bed reactor: Statistical assessment of particle segregation in binary mixtures of sand and Tetra Pak residues

The fluidized bed reactor is an alternative for aluminum recovery and waste valorization of polyolefins from the polyethylene/aluminum composite (LDPE/Al). The sand is typically added as an inert particle into the fluidized bed to enhance heat and mass transfer. Such addition, however, can lead to particle segregation and compromise the reactor start-up. As a research novelty, this paper uses a 33-factorial experimental design with three central points to assess particle concentration uniformity in a fluidized bed composed of LDPE/Al and sand mixtures. A statistical procedure permits an evaluation of the factors effect of the LDPE/Al mass fraction (XC% w/w), the air velocity ratio (V/Vmf), and the diameter ratio of LDPE/Al and sand (dC/dS) on the bed mixing index (IM). Results show that only the dC/dS and V/Vmf ratio affects the IM. Data analysis reveals that fluidized beds reach axial particle uniformity with 0.67 dC/dS, 10 % V/Vmf, and 15% wt. LDPE/Al composite. The statistical model developed accurately predicts the IM, with an error of less than 15%. Such results allow applying a fluidized bed for waste-derived fuels, aluminum recovery from carton packaging wastes, and energy saving of 0.745 MWh per each ton of recovered carton package annually.

Biodiesel Preparation without a Cosolvent in an Opposite-Side Micro-Fixed-Bed Reactor

In the process of preparing biodiesel using microreactors, cosolvents and homogeneous catalysts are generally used, which adds to the separation cost. Hence, this study explored the use of an opposite-side feed micro-fixed-bed reactor with an inner diameter of 2 mm to produce biodiesel by the transesterification of soybean oil and methanol without any cosolvent, in which a fixed solid base acted as catalyst and obstacles. A biodiesel yield of 99.4% was achieved when the methanol-to-oil molar ratio was 12, the temperature was 70 °C, and the residence time was 8.05 min. A mixing study was conducted for this microreactor through computational fluid dynamics (CFD) simulations. The results showed that the best mixing index could reach 0.94 within 25 mm (length). Then, the transesterification kinetics in this reactor were found to be consistent with the proposed pseudo-homogeneous secondary reaction model. With the kinetics data and mixed-model, the biodiesel yield could be predicted. The simulated results were consistent with the experimental data.

Acoustofluidic control of chemical concentration within picoliter droplets in a disposable microfluidic chip

We propose an acoustofluidic method to dynamically control the chemical concentration (CC) within picoliter-scale droplets at high-throughput production exceeding 2000 drops per second. Co-flowing laminar streams of two fluids were rapidly mixed via acoustic streaming flow-induced micro-vortices, and the mixing index was precisely controlled by modulating the wave amplitude. The mixed aqueous sample was fed into a T-junction as a dispersed phase with a continuous phase oil to produce droplets. We conducted numerical and experimental analysis on the flow mixing in terms of the flow rate and wave amplitude. We produced the droplets with tunable CCs with higher than 100-fold enhancement and the droplet libraries with varying inter-droplet chemical concentration (CCD) gradients. The temporal stability and dynamic controllability of the CCD were also verified by the experiments. We demonstrated the applicability of the proposed method by generating doxorubicin-loaded droplets with tunable CCs. The proposed device includes a disposable microfluidic chip to enable the reusable transducer on the piezoelectric substrate, leading to improved flexibility and functionality. We expect that the proposed method to produce droplet libraries with desired CCs is promising for various droplet microfluidic applications including high-through drug screening and discovery, combinatorial biochemistry, and synthesis of functionalized hydrogels.

The financial impact of the COVID-19 pandemic on sleeve gastrectomy at a major academic institution.

The COVID-19- pandemic significantly impacted metabolic and bariatric surgery (MBS) practices due to large-scale surgery cancellations along with staff and supply shortages. We analyzed sleeve gastrectomy (SG) hospital-level financial metrics before and after the COVID-19 pandemic. Hospital cost-accounting software (MicroStrategy, Tysons, VA) was reviewed for revenues, costs, and profits per SG at an academic hospital (2017-2022). Actual figures were obtained, not insurance charge estimates or hospital projections. Fixed costs were obtained through surgery-specific allocation of inpatient hospital and operating-room costs. Direct variable costs were analyzed with sub-components including: (1) labor and benefits, (2) implants, (3) drug costs, and 4) medical/surgical supplies. The pre-COVID-19 period (10/2017-2/2020) and post-COVID-19 period (5/2020-9/2022) financial metrics were compared with student's t-test. Data from 3/2020 to 4/2020 were excluded due to COVID-19-related changes. A total of 739 SG patients were included. Average length of stay (LOS), Center for Medicaid and Medicare Case Mix Index (CMI), and percentage of patients with commercial insurance were similar pre vs. post-COVID-19 (p > 0.05). There were more SG performed per quarter pre-COVID-19 than post-COVID-19 (36 vs. 22; p = 0.0056). Pre-COVID-19 and post-COVID-19 financial metrics per SG differed significantly for, respectively, revenues ($19,134 vs. $20,983) total variable cost ($9457 vs. $11,235), total fixed cost ($2036 vs. $4018), total profit ($7571 vs. $5442), and labor and benefits cost ($2535 vs. $3734; p < 0.05). The post-COVID-19 period was characterized by significantly increased SG fixed cost (i.e., building maintenance, equipment, overhead) and labor costs (increased contract labor), resulting in precipitous profit decline that crosses the break-even in calendar year quarter (CQ) 3, 2022. Potential solutions include minimizing contract labor cost and decreasing LOS.

Design of proton exchange membranes with high durability for fuel cells: From the perspective of machine learning

Proton exchange membranes (PEMs)（） with high chemical durability have been generally researched in recent years. Free radical scavengers such as ceria can significantly suppress the chemical degradation of proton exchange membranes when added to proton exchange membranes. However, proton conductivity may decline in the presence of ceria. Thus, a trade-off between performance and durability in ceria-containing membranes emerges. To address this challenge, we developed a novel machine learning methodology called SPARK (Smart Prediction of Advanced Research on PEMs using Knowledge-based machine learning) to quickly predict the performance and durability of proton exchange membranes in fuel cell applications with high precision. Moreover, with the definition of the mixed index, the performance and durability were coupled, and the trade-off of performance and durability could be easily made. The SPARK methodology not only streamlines the design process for ceria-containing proton exchange membranes but also has broader implications for the development of other proton exchange membrane systems.

Application of an Improved Link Prediction Algorithm Based on Complex Network in Industrial Structure Adjustment

For a healthy industrial structure (IS) and stable economic development in China, this study proposes an improved link prediction algorithm (LP) based on complex networks. The algorithm calculates the similarity by constructing a mixed similarity index. A regional IS network model is built in the study, and the direction of IS adjustment is calculated with the mixed similarity indicators. In this study, the prediction accuracy of the proposed improved LP algorithm in the real network dataset is up to 0.944, which is significantly higher than that of the other algorithms. In the reality of IS optimization, industries of high similarity could be obtained through similarity algorithms, and reasonable coordinated development strategies are proposed. In addition, the simulated IS adjustment strategy in this study shows that it is highly sustainable in development, which is reflected in its lower carbon emissions. The optimization of IS adjustment could be achieved through IS network model and the improved LP algorithm. This study provides valuable suggestions for China’s regional industrial structure adjustment.