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Biofilm reactors, known for utilizing biofilm formation for cell immobilization, offer enhanced biomass concentration and operational stability over traditional planktonic systems. However, the dense nature of biofilms poses challenges for substrate accessibility to cells and the efficient release of products, making mass transfer efficiency a critical issue in these systems. Recent advancements have unveiled the intricate, heterogeneous architecture of biofilms, contradicting the earlier view of them as uniform, porous structures with consistent mass transfer properties. In this review, we explore six biofilm reactor configurations and their potential combinations, emphasizing how the spatial arrangement of biofilms within reactors influences mass transfer efficiency and overall reactor performance. Furthermore, we discuss how to apply artificial intelligence in processing biofilm measurement data and predicting reactor performance. This review highlights the role of biofilm reactors in environmental and energy sectors, paving the way for future innovations in biofilm-based technologies and their broader applications.

The Proton Exchange Membrane (PEM) water electrolyzer is considered one of the promising energy storing means for harnessing variable renewable energy sources to produce hydrogen. Understanding the internal fluid dynamics, which are often challenging to directly observe experimentally, has prompted the use of numerical models to investigate two-phase flow within PEM water electrolyzers. In this study, we provide a comprehensive review of prior research focusing on two-phase modeling of PEM electrolyzers, encompassing both components at mesoscopic scales and the full electrolyzer at the macroscopic level. We delve into the specifics of various modeling approaches for two-phase flow at different scales and summarize and discuss the current state of the art in the field. Presently, two-phase models for the full electrolyzer predominantly employ a macroscopic homogeneous assumption. However, mesoscopic and microscopic models capable of tracking phase interfaces are limited to components. Challenges persist in integrating various modeling scales into a comprehensive electrolyzer model, particularly in coupling two-phase flow between the channels and porous media. Future efforts should focus on developing multi-scale models and simulating two-phase flow under fluctuating input conditions. Additionally, given the structural similarities between PEM water electrolyzers and PEM fuel cells, we compare and discuss differences in two-phase modeling between the two technologies. This work offers the insights for researchers in the field of modeling of PEM water electrolyzers and even fuel cells.

Abstract Background HIV-tuberculosis (HIV-TB) co-infection is a significant public health concern worldwide. TB delay, consisting of patient delay, diagnostic delay, treatment delay, increases the risk of adverse anti-TB treatment (ATT) outcomes. Except for individual level variables, differences in regional levels have been shown to impact the ATT outcomes. However, few studies appropriately considered possible individual and regional level confounding variables. In this study, we aimed to assess the association of TB delay on treatment outcomes in HIV-TB co-infected patients in Liangshan Yi Autonomous Prefecture (Liangshan Prefecture) of China, using a causal inference framework while taking into account individual and regional level factors. Methods We conducted a study to analyze data from 2068 patients with HIV-TB co-infection in Liangshan Prefecture from 2019 to 2022. To address potential confounding bias, we used a causal directed acyclic graph (DAG) to select appropriate confounding variables. Further, we controlled for these confounders through multilevel propensity score and inverse probability weighting (IPW). Results The successful rate of ATT for patients with HIV-TB co-infection in Liangshan Prefecture was 91.2%. Total delay (OR = 1.411, 95% CI: 1.015, 1.962), diagnostic delay (OR = 1.778, 95% CI: 1.261, 2.508), treatment delay (OR = 1.749, 95% CI: 1.146, 2.668) and health system delay (OR = 1.480 95% CI: (1.035, 2.118) were identified as risk factors for successful ATT outcome. Sensitivity analysis demonstrated the robustness of these findings. Conclusions HIV-TB co-infection prevention and control policy in Liangshan Prefecture should prioritize early treatment for diagnosed HIV-TB co-infected patients. It is urgent to improve the health system in Liangshan Prefecture to reduce delays in diagnosis and treatment.

Background: Hypertension and diabetes are major components of non-communicable diseases (NCDs), with a substantial number of patients residing in underdeveloped areas. Limited medical resources in these areas often results in underreporting of disease prevalence, masking the true extent of diseases. Taking the underdeveloped Liangshan Yi Autonomous Prefecture in China as an example, this study aimed to correct the underreported prevalence of hypertension and type 2 diabetes so as to provide inspiration for the allocation of medical resources in such areas. Methods: Assuming the true number of patients in each area follows a Poisson distribution, we applied a Compound Poisson Model based on Clustering of Data Quality (CPM-CDQ) to estimate the potential true prevalence of hypertension and diabetes, as well as the registration rate of existing patients. Specifically, a hierarchical clustering approach was utilized to group the counties based on the data quality, and then the registration rate of the cluster with the best data quality was used as a priori information for the model. The model parameters were estimated by the maximum likelihood method. Sensitivity analyses were performed to test the robustness of the model. Results: The estimated prevalence of hypertension in the entire Liangshan Prefecture from 2018 to 2020 ranged from 24.59 % to 25.28 %, and for diabetes, it ranged from 4.95 % to 8.42 %. The registration rates for hypertension and diabetes were 14.10 % to 24.59 % and 15.98 % to 29.12 %, respectively. Additionally, the accuracy of clustering the counties with the best data quality had a significant impact on the performance of the model. Conclusion: Liangshan Prefecture is experiencing a significant high prevalence of hypertension and diabetes, accompanied by a concerningly low registration rate. The CPM-CDQ proved useful for assessing underreporting risks and facilitating targeted interventions for NCDs control and prevention, particularly in underdeveloped areas.

The performance degradation is a crucial factor affecting the commercialization of proton exchange membrane electrolyzer. However, it is difficult to establish a mechanism model incorporating all degradation categories due to their different time and spatial scales. In this paper, the data-driven method is employed to predict the electrolyzer voltage variation over time based on a convolutional neural network-long short term memory (CNN-LSTM) model. First, two datasets including constant operation for 1140 h and start-stop load for 660 h are collected from the durability tests. Second, the data-driven models are trained through the experimental data and the model hyper-parameters are optimized. Finally, the electrolyzer degradation in the next few hundred hours is predicted, and the prediction accuracy is compared with other time-series algorithms. The results show that the model can predict the degradation precisely on both datasets, with the R2 higher than 0.98. Compared to conventional models, the algorithm shows better fitting characteristic to the experimental data, especially as the prediction time increases. For constant and start-stop operations, the electrolyzers degradate by 4.5 % and 2.5 % respectively after 1000 h. The proposed method shows great potential for real-time monitoring in the electrolyzer system.

To improve the prediction accuracy of chaotic time series and reconstruct a more reasonable phase space structure of the prediction network, we propose a convolutional neural network (CNN)-long short-term memory (LSTM) prediction model based on the incremental attention mechanism. Firstly, a traversal search is conducted through the traversal layer for finite parameters in the phase space. Then, an incremental attention layer is utilized for parameter judgment based on the dimension weight criteria (DWC). The phase space parameters that best meet DWC are selected and fed into the input layer. Finally, the constructed CNN-LSTM network extracts spatiotemporal features and provides the final prediction results. The model is verified using Logistic, Lorenz, and sunspot chaotic time series, and the performance is compared from the two dimensions of prediction accuracy and network phase space structure. Additionally, the CNN-LSTM network based on incremental attention is compared with LSTM, CNN, recurrent neural network (RNN), and support vector regression (SVR) for prediction accuracy. The experiment results indicate that the proposed composite network model possesses enhanced capability in extracting temporal features and achieves higher prediction accuracy. Also, the algorithm to estimate the phase space parameter is compared with the traditional CAO, false nearest neighbor, and C–C, three typical methods for determining the chaotic phase space parameters. The experiments reveal that the phase space parameter estimation algorithm based on the incremental attention mechanism is superior in prediction accuracy compared with the traditional phase space reconstruction method in five networks, including CNN-LSTM, LSTM, CNN, RNN, and SVR.

China’s coal-fired power plants emit over 5.7 billion tons of CO2 annually. To realize the dual carbon goals in time, it is necessary to reduce the carbon emissions of coal-fired power plants. Microalgae carbon fixation can efficiently absorb CO2 through photosynthesis and convert it into biomass, which is a highly promising technology for carbon reduction in coal-fired power plants. Light guide tubes can flexibly change the light distribution in a photobioreactor, while optical fibers can transmit light centrally with low light loss. Therefore, a microalgae photobioreactor with an optical fiber/light guide tube is proposed to expand the light-receiving area of the microalgae suspension, increase the light-harvesting of microalgal cells, and promote carbon fixation via microalgae photosynthesis. The optical simulation software was used to trace the propagation of light in the optical fiber/light guide tube, and the light intensity distribution of the tube wall was obtained. Microalgae cultivation experiments were conducted in various photobioreactors and under different input light energy conditions. The change trends of biomass yield, carbon sequestration rate, and chlorophyll content were obtained, and the impact of built-in optical fiber /light guide tubes on carbon fixation via microalgae was investigated. Results indicated that the light intensity emitted from the optical fiber terminal decreased precipitously from 30 mm to 140 mm along the side of the light guide tube. Additionally, the tube exhibited a concentrated light-emitting range. Adding a conical reflector to reflect the transmitted light at the tube bottom and designing a stepped optical fiber to emit input light from different steps can optimize the light-emitting effect of the light guide tube and make the light distribution in the microalgae photobioreactor more uniform, so that the microalgal cells far away from the light source area can receive the light energy to photosynthesize and fix carbon. At a light input of 3.3 W/L, the minimum light intensity on the side surface of the light guide comprising a two-stage stepped optical fiber and conical reflector was 47 μmol/(m2·s). The average light intensity was 64 μmol/(m2·s), representing a 2.6-fold increase compared to the light guide tube lacking both the optical fiber and any enhancements beyond its top section. After seven days of cultivation, the microalgae concentration in the stepped fiber photobioreactor (SF-PBR) could reach 1.9 g/L, which was 46.2% higher than that of the photobioreactor inserted with flat-end fiber optic light guide (FF-PBR) and 111.1% higher than that of the photobioreactor with only top-fed light (LG-PBR). When the light input was escalated to 5.0 W/L, a high microalgae concentration of 2.8 g/L was achieved at 7 d. Meanwhile, the average carbon sequestration rate of 608.3 mg/(L·d) was obtained, exhibiting 1.9-fold augmentation compared to the control LG-PBR.

Traumatic brain injury is a serious medical condition that can be attributed to falls, motor vehicle accidents, sports injuries and acts of violence, causing a series of neural injuries and neuropsychiatric symptoms. However, limited accessibility to the injury sites, complicated histological and anatomical structure, intricate cellular and extracellular milieu, lack of regenerative capacity in the native cells, vast variety of damage routes, and the insufficient time available for treatment have restricted the widespread application of several therapeutic methods in cases of central nervous system injury. Tissue engineering and regenerative medicine have emerged as innovative approaches in the field of nerve regeneration. By combining biomaterials, stem cells, and growth factors, these approaches have provided a platform for developing effective treatments for neural injuries, which can offer the potential to restore neural function, improve patient outcomes, and reduce the need for drugs and invasive surgical procedures. Biomaterials have shown advantages in promoting neural development, inhibiting glial scar formation, and providing a suitable biomimetic neural microenvironment, which makes their application promising in the field of neural regeneration. For instance, bioactive scaffolds loaded with stem cells can provide a biocompatible and biodegradable milieu. Furthermore, stem cells-derived exosomes combine the advantages of stem cells, avoid the risk of immune rejection, cooperate with biomaterials to enhance their biological functions, and exert stable functions, thereby inducing angiogenesis and neural regeneration in patients with traumatic brain injury and promoting the recovery of brain function. Unfortunately, biomaterials have shown positive effects in the laboratory, but when similar materials are used in clinical studies of human central nervous system regeneration, their efficacy is unsatisfactory. Here, we review the characteristics and properties of various bioactive materials, followed by the introduction of applications based on biochemistry and cell molecules, and discuss the emerging role of biomaterials in promoting neural regeneration. Further, we summarize the adaptive biomaterials infused with exosomes produced from stem cells and stem cells themselves for the treatment of traumatic brain injury. Finally, we present the main limitations of biomaterials for the treatment of traumatic brain injury and offer insights into their future potential.

Macrophages play a central role in immunological responses to metallic species associated with the localized corrosion of metallic implants, and mediating in peri-implant inflammations. Herein, the pathways of localized corrosion-macrophage interactions were systematically investigated on 316L stainless steel (SS) implant metals. Electrochemical monitoring under macrophage-mediated inflammatory conditions showed a decreased pitting corrosion resistance of 316L SSs in the presence of RAW264.7 cells as the cells would disrupt biomolecule adsorbed layer on the metal surface. The pitting potentials were furtherly decreased when the RAW264.7 cells were induced to the M1 pro-inflammatory phenotype by the addition of lipopolysaccharide (LPS), and pitting corrosion preferentially initiated at the peripheries of macrophages. The overproduction of aggressive ROS under inflammatory conditions would accelerate the localized corrosion of 316L SS around macrophages. Under pitting corrosion condition, the viability and pro-inflammatory polarization of RAW264.7 cells were region-dependent, lower viability and more remarkable morphology transformation of macrophages in the pitting corrosion region than the pitting-free region. The pitting corrosion of 316L SS induced high expression of CD86, TNF-α, IL-6 and high level of intracellular ROS in macrophages. Uneven release of metallic species (Fe2+, Cr3+, Ni2+, etc) and uneven distribution of surface overpotential stimulated macrophage inflammatory responses near the corrosion pits. A synergetic effect of localized corrosion and macrophages was revealed, which could furtherly promote localized corrosion of 316L SS and macrophage inflammatory reactions. Our results provided direct evidence of corrosion-macrophage interaction in metallic implants and disclosed the pathways of this mutual stimulation effect.

Centrifugal granulation is one key step to enable waste heat recovery from the molten slag in the iron and steel industry. Yet, it remains unknown about the granulation characteristics of molten slag with different chemical compositions, especially at high throughput. In this work, we provided an experimental study on centrifugal granulation with four types of molten slags. The stage-specific centrifugal granulation was recorded and analyzed at first. Both effects of atomizer configuration and chemical compositions on granulation were investigated in detail. The cup-type atomizer favors film-mode disintegration and possesses better anti-adhesion capacity although the final granule size was not strongly affected by the atomizer configuration. Most importantly, centrifugal granulation has been demonstrated with appreciable adaptability to composition-specific blast furnace (BF) slag with binary basicity of 0.9–1.3. The present study not only sheds light on the modest effect of the chemical composition of molten slag on centrifugal granulation characteristics, but also gains credit for the adaptivity of CGATER.

Hawthorn fruits of different varieties have varied nutritional composition, sensory properties etc., thus required for different processing for product development. Due to the limitations of traditional analytical methods of time-consuming, destructive sample preparation, and high cost ect., non-destructive techniques for variety identification are needed which would benefit for large scale production of foods with hawthorn fruits. In this study, a total of 240 hawthorn fruit samples from four different varieties were subjected for near-infrared spectroscopy analysis and the collected spectral data were pre-processed by different algorithms. In order to achieve non-destructive identification of hawthorn varieties, natural language processing (NLP) model was applied for data analysis, including long short-term memory (LSTM), gated recurrent unit (GRU) neural network, logistic regression, native Bayes, decision trees, and k-nearest neighbors. The results showed that the two deep learning models both had the best discrimination effect on the spectral preprocessed by principal component analysis (PCA) with the accuracy of the validation set and test set reached 99.46%±0.00% and 100%±0.00%. While, the logistic regression model showed excellent discrimination ability for hawthorn fruit spectra but poor discrimination ability for the difference of second order (D2) pretreatment spectra (accuracy of 96.65% in the validation set and 89.58% in the test set). The naive Bayes model also showed excellent discrimination effect on the spectra processed by PCA, and the accuracy of the validation set was 95.65%, and the accuracy of the test set was 95.83%. Results gained in this study confirmed the feasibility of applying NLP to the near-infrared non-destructive identification of hawthorn fruits.

Intensification of biofuel production processes could play a critical role in boosting the economic and environmental features of the whole process. A novel bionic flow-induced peristaltic reactor with a high conversion rate is constructed to realize efficient biofuel production from high-concentration high-viscosity fluids. It is experimentally verified through biodiesel production from soybean oil. Experimental results show that the conversion efficiency is up to 89.9% at 10 s in the peristaltic reactor, which is 38.4% higher than that in the rigid tube reactor. Furthermore, a three-dimensional peristaltic model is conducted to understand the mechanism of heat and mass transfer enhancement. The simulation results show that an increase in peristaltic amplitude strengthens the mixing of the bionic peristaltic reactor by 92.5-100.8%. The temperature distribution in the bionic peristaltic reactor is more uniform than in the traditional rigid tube reactor. The results demonstrate that the conversion rate of soybean oil in the bionic flow-induced peristaltic reactor is 528.82% min-1, which is 17-60 times higher than other intensified reactors operating in either continuous or batch modes.

Abstract Background Improvement of health literacy constitutes a cornerstone to improving public health. However, the overall health literacy of Liangshan Yi Autonomous Prefecture (Liangshan Prefecture) in the southwest Sichuan Province of China has kept extremely low for a long time. How to improve health literacy of the Yi nationality residents is key to be urgently solved. Notably, Family Branch System is a distinctive patrilineal bloodline organization of Yi nationality, which plays an important role in the daily life of Yi nationality. Meanwhile, Contracted Family Doctor Services is conducted in Liangshan Prefecture. Therefore, this study proposes an intervention model of health education based on Family Branch System and Contracted Family Doctor Services, which is a Family-based Improvement for Health Literacy among the Yi nationality (FAMILY) in Liangshan, when improving traditional Innovative Care for Chronic Conditions Framework (ICCC) framework. Methods An open cohort stepped wedge cluster randomized trial design is used to implement health literacy education interventions including project preparation, core group building, promotion within family branch and competition between family branches while using Contracted Family Doctor Services as control measure. The study will be conducted among Yi nationality residents in Meigu County and Yanyuan County, with health literacy level of residents as the primary outcome. Finally, mixed-effects model and causal inference method will be used to evaluate intervention effect. Discussion This study highlights family, using the unique Family Branch System and Contracted Family Doctor Services in Liangshan Prefecture to design intervention among improved ICCC framework, and combines the mixed-effects model with complier average causal effects (CACE) to estimate the intervention effect under non-compliance for the first time. Besides, other key technologies to be adopted include construction of electronic questionnaire quality control system, with quality control based on artificial intelligence. This trial contributes to exploring an effective way to improve health literacy of Yi nationality residents in Liangshan Prefecture, which will provide reference for other areas, especially poor areas, to improve residents’ health literacy. Trial registration ISRCTN11299863 on June 1, 2022; https://www.isrctn.com/ .

Located in the hilly and mountainous central area of the national ecological security strategic pattern (described as “two ecological barriers and three green belts”), southern Jiangxi is an important ecological barrier in southeast China and a pilot area for the national mountains-rivers-forests-farmlands-lakes-grasslands restoration projects. In recent years, the rapid economic development of the southern Jiangxi region and the rapid changes in land use, agricultural intensification, and population urbanization have severely tested this ecosystem on which people depend for their survival. Currently, studies of ecosystems and their interactions from a single spatial perspective have sprung up, but only a few studies have comprehensively analyzed different spatial scales to facilitate the sustainable development of regional ecosystems. Multi-scale studies should be carried out to quantitatively understand the relationship between ecosystem services (ESs) and socio-natural drivers, in an attempt to find a suitable scale to assess regional ESs or to achieve complementary advantages by combining multi-scales so as to conduct hierarchical management of ESs. Therefore, to better understand the interplay between ESs and to achieve the goals of sustainable development, we quantitatively analyzed the evolutionary patterns, trade-offs, and synergies of ESs. In our analysis, we also looked at bundling ESs and their drivers for seven ecosystem services at the township and watershed scales for 2000–2020 in southern Jiangxi. Crop production, meat production, water yield, carbon storage, soil retention, habitat quality, and forest recreation services were specifically quantified, and redundancy analysis was used to explore the influence degree of precipitation, temperature, elevation, slope, GDP, and population density on ESs. The results showed that most ESs have increased in southern Jiangxi, indicating spatial and temporal heterogeneity. The scale effect of trade-off and synergy showed that the spatial variation was similar, but the amplitude of variation was different. Compared with the watershed scale, the overall bundle of ESs in southern Jiangxi is better identified and clustered at the township scale. In addition, Cluster 4 at the township scale and Cluster 3 at the watershed scale can comprehensively identify high-value areas of ecosystem services in the study area. The rapid growth of GDP and population density caused by rapid urbanization were the main driving factors of the difference in ESs between the two scales in southern Jiangxi. Our results provide recommendations for governance and restoration of regional ecosystem services and support for conducting a comprehensive analysis of spatio-temporal evolutionary mechanisms and interactions of ecosystem services at different scales.

Abstract Background It is of great challenge to raise the public coronavirus disease 2019 (COVID-19) related health literacy (CRHL) in impoverished regions due to the limits of poor infrastructure, large proportion of vulnerable groups, etc. However, those limits cannot be solved in the short term. Therefore, this study chose Liangshan Yi Autonomous Prefecture, one of the poorest areas in China, as a pilot, to reveal the quantitative relationships among different dimensions under the COVID-19 health education framework, clarify the key points for health promotion, and provide specific suggestions for COVID-19 health education strategy in impoverished regions. Methods A cross-sectional questionnaire survey was conducted in five regions of Liangshan Yi Autonomous Prefecture in 2020. There were 2,100 individuals sampled by multi-stage method. This survey mainly measured the four dimensions: CRHL, COVID-19 related tense psychological reactions (CRTPR), COVID-19 related information report acquisition (CRIRA), and general health literacy (GHL). The multivariate logistic regression was used to explore the influence of demographic characteristics on each dimension. Furthermore, to quantify the relationships among different dimensions, this study employed the structural equation model (SEM), and analyzed the mediating effects of CRHL and CRIRA as well as the moderating effects of regional characteristic variables. Results The CRHL played an important role in promoting COVID-19 health education, reaching 52.5% in Liangshan Yi Autonomous Prefecture. The GHL (β = 0.336) and age (β = 0.136) had statistically positive impacts on CRHL. The CRHL affected CRTPR negatively (β = − 0.198) and CRIRA positively (β = 0.052). The CRHL played significant mediating roles among the four dimensions (P

Abstract Background Continuous surveillance of death can measure health status of the population, reflect social development of a region, thus promote health service development in the region and improve the health level of local residents. Liangshan Yi Autonomous Prefecture was a poverty-stricken region in Sichuan province, China. While at the end of 2020, as the announcement of its last seven former severely impoverished counties had shaken off poverty, Liangshan declared victory against poverty. Since it is well known that the mortality and cause of death structure will undergo some undesirable changes as the economy develops, this study aimed to reveal the distribution of deaths, as well as analyze the latest mortality and death causes distribution characteristics in Liangshan in 2020, so as to provide references for the decision-making on health policies and the distribution of health resources in global poverty-stricken areas. Methods Liangshan carried out the investigation on underreporting deaths among population in its 11 counties in 2018, and combined with the partially available data from underreporting deaths investigation data in 2020 and the field experience, we have estimated the underreporting rates of death in 2020 using capture-recapture (CRC) method. The crude mortality rate, age-standardized mortality rate, proportion and rank of the death causes, potential years of life lost (PYLL), average years of life lost (AYLL), potential years of life lost rate (PYLLR), standardized potential years of life lost (SPYLL), premature mortality from non-communicable diseases (premature NCD mortality), life expectancy and cause-eliminated life expectancy were estimated and corrected. Results In 2020, Liangshan reported a total of 16,850 deaths, with a crude mortality rate of 608.75/100,000 and an age-standardized mortality rate of 633.50/100,000. Male mortality was higher than female mortality, while 0-year-old mortality of men was lower than women’s. The former severely impoverished counties’ age-standardized mortality and 0-year-old mortality were higher than those of the non-impoverished counties. The main cause of death spectrum was noncommunicable diseases (NCDs), and the premature NCD mortality of four major NCDs were 14.26% for the overall population, 19.16% for men and 9.27% for women. In the overall population, the top five death causes were heart diseases (112.07/100,000), respiratory diseases (105.85/100,000), cerebrovascular diseases (87.03/100,000), malignant tumors (73.92/100,000) and injury (43.89/100,000). Injury (64,216.78 person years), malignant tumors (41,478.33 person years) and heart diseases (29,647.83 person years) had the greatest burden on residents in Liangshan, and at the same time, the burden of most death causes on men were greater than those on women. The life expectancy was 76.25 years for overall population, 72.92 years for men and 80.17 years for women, respectively, all higher than the global level (73.3, 70.8 and 75.9 years). Conclusions Taking Liangshan in China as an example, this study analyzed the latest death situation in poverty-stricken areas, and proposed suggestions on the formulation of health policies in other poverty-stricken areas both at home and abroad.

The porous liquid (PLs) is a new material containing both permanent porosity of porous materials and liquid fluidity of solvent at room temperature, which has shown a great potential in gas separation. In this study, a novel type ? porous liquids were prepared using 2-methylimidazole zinc salt (ZIF-8) modified by tetraethylenepentamine (TEPA) as the main units and 1-Ethyl-3-methylimidazolium Bis(trifluoro-methanesulfonyl)-imide ([EMlm][NTf2]) as the sterically hindered solvent. The effect of amine loading on the CO2 absorption performance of PLs was investigated. When amine load was 30 wt%, 30TEPA@ZIF-8 not only had the pore structure inside but also effectively increased the CO2 absorption capacity of PLs. When the effect of different parameters on CO2 absorption capacity was investigated, it was found that the optimal adsorption temperature was 60 °C, and the optimal concentration of the main units was7.5 wt%. After five cycles, the absorbent's cycle efficiency and desorption efficiency were more than 98 %. All the results indicate that the prepared PLs in this paper had an application potential in CO2 capture.

This article presents an evaluation of the performance of a membrane-less organic-based flow battery using low-cost active materials, zinc and benzoquinone, which was scaled up to 1600 cm2, resulting in one of the largest of its type reported in the literature. The charge–discharge cycling of the battery was compared at different sizes and current densities, and its performance was evaluated under various mass transport and operating conditions. The results showed that the round-trip coulombic and voltage efficiencies were over 90% and 85%, respectively, for the laboratory-scale (1 cm2 electrode) cell, but these performances tended to deteriorate with the scaled-up (1600 cm2 electrode) cell due to inadequate mass transfer and sediment coverage of quinone, as well as the formation of a passivation film on the zinc anode. Despite this, the scaled-up batteries exhibited high coulombic and voltage efficiencies of up to 99% and 68.5%, respectively, at a current density of 10 mA cm−2. The capital cost of this system is also estimated to be several times lower than those of commercially available all-vanadium flow batteries and zinc bromide flow batteries for demand charge management applications.

Zinc-based hybrid-flow batteries are considered as a promising alternative to conventional electrochemical energy-storage systems for medium- to large-scale applications due to their high energy densities, safety, and abundance. However, the performance of these batteries has been limited by issues such as dendritic growth and passivation of zinc anodes during charge–discharge cycling. To address this challenge, a variety of two- and three-dimensional zinc anodes have been investigated. While two-dimensional zinc anodes have been extensively studied, there has been limited investigation into three-dimensional zinc anodes for hybrid-flow batteries. This study highlights the potential of three-dimensional zinc anodes to mitigate overpotentials and improve the mass transport of active species to promote negative electrode reactions. The performance of a membraneless flow battery based on low-cost zinc and organic quinone was herein evaluated using experimental and numerical approaches. Specifically, the use of zinc fiber was shown to yield an average coulombic efficiency of approximately 90% and an average voltage efficiency of approximately 82% over the course of 100 cycles at a current density of 30 mA cm−2. These results indicate the viability of using zinc fiber anodes to improve the performance of existing hybrid-flow batteries.

Abstract Flexibly and precisely manipulating 3D droplet transportation is a fundamental challenge for broad implications in diagnostics, drug delivery, bioengineering, etc. Herein, a light method is developed for manipulating a droplet to make it behave like a submarine. This light method enables flexible 3D transportation, stable suspension, and floating of a droplet, which can be freely altered. It is demonstrated that the localized photothermal effect induced thermocapillary flow in the water droplet/oil phase is responsible for energizing and manipulating the droplet. With such remarkable motility, the light‐fueled submarine‐like droplet successfully realizes various functions such as the acid‐base detection, particle capture and transportation, and target crystal collection, dissolution and transportation. It is demonstrated that the light‐fueled submarine‐like droplet shows promising perspective for long‐sought precise droplet manipulation in various applications.

Electricity use in residential sector accounts for almost a quarter of the total. Occupant’s indoor activities will highly affect the electricity use pattern. This paper presents a cooperative heuristic optimization algorithm for residential schedules of controllable appliances considering user’s indoor activities. First of all, Markov Chains are employed to model occupant’s behaviors, in which transition matrices are generated by using American Time Use Survey data. Then, engineering models of electric appliances are established and electricity consumption is able to be simulated by corresponding people’s activities to common electricity usage. Finally, a cooperative PSO algorithm is employed to find optimal schedules for these appliances. Experiments are conducted. The results indicate that peak loads can be shaved, electricity bills can be decreased by 3.1%, and a reduction of 5.9% of total power can be reached by optimizing high-resolution residential demand.

The two-step photosynthetic biogas upgrading process, which combines CO2 capture by carbonate solution and carbonate regeneration by using aquatic microbial oxygenic photoautotrophs (i.e., cyanobacteria, algae, and diatoms), may provide a potential alternative to the commercial routes used for gaseous biofuel upgrading. Such a process not only provides a green and low energy intensive biogas upgrading pathway but also converts CO2 in biogas into high value biomass. To improve the upgrading performance, the effects of light intensity and NaHCO3 concentration on the growth and the HCO3- transformation characteristics of halophilic and alkaliphilic Spirulina platensis were investigated in this study. Experimental results showed that the light attenuation of S. platensis culture was significant. Increasing light intensity up to 210 μmol m-2 s-1 effectively improved the S. platensis growth and photosynthetic pigment accumulation. S. platensis could grow in the range of 0.05 to 0.6 M NaHCO3, and a maximum biomass concentration of 1.46 g L-1 was achieved under an optimal growth condition of 0.1 M NaHCO3, which was 65.9% higher than at 0.05 M NaHCO3. Moreover, the bicarbonate utilization efficiency reached 42.0%. Finally, in a case study, a biogas stream at a flow rate of 800 m3 h-1 could generate biomass up to 344 kg h-1, corresponding an energy value of 5591 MJ h-1.

Abstract Background The outbreak of coronavirus disease 2019 (COVID-19) had spread worldwide. Although the world has intensively focused on the epidemic center during this period of time, it is imperative to emphasize that more attention should also be paid to some impoverished areas in China since they are more vulnerable to disease outbreak due to their weak health service capacities. Therefore, this study took Liangshan Yi Autonomous Prefecture as an example to analyze the COVID-19 epidemic in the impoverished area, evaluate the control effect and explore future control strategies. Methods In this study, we collected information including age, gender, nationality, occupation, and address of all COVID-19 cases reported from 25 January 2020 to 23 April 2020 in Liangshan Prefecture from the Nationwide Notifiable Infectious Diseases Reporting Information System (NIDRIS), which were used under license and not publicly available. Additionally, we retrieved other information of cases through epidemiological investigation reports reviewing. Data were analyzed using the software Excel 2010 and SPSS 17.0. The geographic distribution of cases was mapped using ArcGIS10.2. Results By 23 April 2020, a total of 13 COVID-19 cases and two asymptomatic SARS-CoV-2 carriers were reported in Liangshan, in three family clusters. Among the cases, eight cases had a history of sojourning in Hubei Province (61.54%), of which six were related to Wuhan. Cases aged under 44 years accounted for 61.54%, with no child case. The delay of patients’ hospital visiting, and the low degree of cooperation in epidemiological investigation are problems. Conclusions During the study period, Liangshan was well under control. This was mainly contributed to strict preventive strategies aimed at local culture, inter-sectoral coordination and highly degree of public cooperation. Besides, some possible environmentally and culturally preventive factors (e.g., rapid air flow and family concept) would affect disease prevention and control. In the next step, the health education about COVID-19 should be strengthened and carried out according to the special culture of ethnic minorities to enhance public awareness of timely medical treatment.

A model of investment casting of a titanium alloy gearbox based on the ProCAST software was established in this work, and the simulated result was used to optimize the casting process. The flow and temperature field of casting were simulated based on an actual pouring process. Casting defects and the solidification process were analyzed. The results show that the defects can be predicted by the simulation result exactly, and the simulated temperature field is in accordance with the actual process. Shrinkage and porosity are observably alleviated by remodelling the casting mould. The casting temperature field and solidification simulation results show that the casting defects arise from hot spots and heat accumulation. The temperature-time curve of different representative location nodes of casting further confirms the defect simulation results. In addition, the use of low-cost alloy elements reduces raw material costs. Compared with TC4 alloy, the mechanical properties of the casting remain unchanged.

Aluminum fumarate metal organic frameworks (AlFu MOFs) pellet was successfully prepared with outstanding porous structure and its CO2 adsorption performance was investigated. As the binder mass increased, the pellet mechanical strength rose while the CO2 adsorption capacity reduced. The chosen AlFu pellet with 2.5wt% carboxymethyl cellulose sodium (CMC) binder retained the micro-morphology characteristics with a specific surface area of 726.06 m2/g and micropore volume of 0.33 cm3/g. The adsorption performance of CO2 by the pellets was studied at different partial pressures and temperatures. The results showed that the adsorption capacity of CO2 in AlFu pellet was increased with lower adsorption temperature and higher CO2 partial pressure, the maximum adsorption amount was 1.26 mmol/g at 35 °C and 1.0 bar. The CO2 adsorption kinetics and the limiting factors for adsorption rate were analyzed. Compared with pseudo-second order model the pseudo-first order kinetic model can better describe the CO2 physical adsorption behavior of AlFu pellet. The rate-limiting kinetic analysis revealed that the CO2 adsorption rate was determined by film diffusion and intra-particle diffusion rather than inter-particle diffusion.

The condensation of moist air is a common process in industry and increase its heat transfer coefficient is of great importance for improving energy efficiency. This study used 3-D finned tube to enhance moist air condensation, and the condensation process was calculated through numerical method aligned with Diffusion Layer model and Eulerian Wall Film model. The total heat transfer, sensible heat transfer and latent heat transfer during the condensation process were discussed. The results indicated that 3-D finned tube increased heat transfer amount and the condensation was mainly on fin surface. Besides, the influence of 3-D fin height was also obtained. The results indicated that the increase of fin height in circumferential direction can increase heat transfer in the tail of tube, and sensible heat transfer process was more sensitive to the area increment.

Estimation of the viscosity of microalgae slurry is the premise for the design of industrial reactors in microalgal biofuel production. To accurately predict the viscosity of microalgae slurry (Chlorella pyrenoidosa), an artificial neural network (ANN) model is designed in this study. In the ANN model, the mass fraction of microalgal cell, shear rate, temperature, and retention time during the hydrothermal hydrolysis process are used as the input variables, and the viscosity of microalgae slurry is obtained as the output variable. Comparisons show that the ANN model is in excellent agreement with the experimental data. The mean square error (MSE), Mean Absolute Error (MAE), and goodness of fit (R2) are 0.725, 0.484 and 0.991, respectively. The results provide a proof-of-concept for using ANN models to estimate the viscosity of microalgae slurry. In particular, the developed ANN model can accurately predict the viscosity of microalgae slurry in a hydrothermal hydrolysis process, which cannot be accurately predicted by a standard curve fitting method.

Abstract Background Wheat straw, the most abundant lignocellulosic biomass in China, is rich in cellulose that can be hydrolyzed and then converted into biofuels, such as bioethanol and biohydrogen. However, the accessibility of cellulose and the enzyme activity are greatly reduced in the presence of lignin. This significantly increases the enzyme cost in the saccharification, which hampers industrial production of lignocellulosic biofuels. In this study, a laccase treatment system mediated by 1-hydroxybenzotriazole was employed to modify and degrade lignin to enhance subsequent enzymatic saccharification of wheat straw. A kinetic model considering enzyme adsorption on lignin was proposed to estimate the saccharification performance. Results Fourier transform infrared spectroscopy (FTIR) analyses showed that the peak intensity of lignin structure characteristics significantly changed after laccase-mediated system (LMS) treatment. 2D-nuclear magnetic resonance (NMR) analyses indicated that the aromatic ether bonds were cleaved and that guaiacyl (G) was oxidized after LMS treatment. X-ray diffraction (XRD) analyses suggested that the crystallinity of lignocellulose increased due to the partial degradation of lignin. As a result, the nonproductive adsorption of the enzyme on lignin was reduced by 28%, while the reducing sugar yield increased by 26%. A semi-empirical kinetic model was used to estimate the reducing sugar yield, the initial hydrolysis rate (K M ) and deactivation rate coefficient (α) of LMS-pretreated wheat straw were 0.157 (h−1) and 0.214 (h−1), respectively. The model showed high accuracy (predicting error

Soil potential nitrification rate (PNR) and diversity of ammonia-oxidizing microbes were investigated in spiked soils with Cu and Sulfadiazine (SDZ). An obvious decrease of PNR was observed with the increase of Cu and SDZ concentrations in the soil. Real-time fluorescence quota PCR result showed that AOA and AOB were slightly stimulated at the gene level in both contaminated soils. Sequential analysis indicated that 200 mg kg−1 Cu could improve AOA diversity but reduce AOB diversity, but 5 mg kg−1 SDZ caused a decrease of both AOA and AOB diversity. Microbial community’s analysis also found that 200 mg kg−1 Cu and 5 mg kg−1 SDZ had different influence on the populations of AOA and AOB. It could be concluded that Cu and SDZ might have a different ecological effect mechanism on soil potential nitrification and ammonia-oxidizing microbial communities.

To investigate responses difference of soil potential nitrification rates (PNR) to heavy metals and antibiotics, batch toxicity experiments of Cu and sulfadiazine (SDZ) were conducted in four typical soils which were collected from different locations of China. Toxic differences of Cu and SDZ to soil PNR were evaluated based on their values of EC20 and EC50 calculated with logistic model. It was found that soil nitrification was a good indicator of Cu contamination in soils except for paddy soil. For SDZ, their ECX values were significantly higher than its concentration level (0.002 ~ 0.760 mg·kg-1) in soils. Thus, it was concluded that soil nitrification might be more sensitive to Cu than SDZ in field soil. The further Pearson correlation analysis indicated that the response of soil PNR to Cu and SDZ contamination were significantly related with soil PNR0 and pH.

Summary: Bioelectrochemical systems (BESs) can fulfill the demand for renewable energy and wastewater treatment but still face significant challenges to improve their overall performance. Core efforts have been made to enhance the bioelectrode performance, yet, previous approaches are fragmented and have limited applicability, unable to flexibly adjust physicochemical and structural properties of electrodes for specific requirements in various applications. Here, we propose a facile electrode design strategy that integrates three-dimensional printing technology and functionalized modular electrode materials. A customized graphene-based electrode with hierarchical pores and functionalized components (i.e., ferric ions and magnetite nanoparticles) was fabricated. Owing to efficient mass and electron transfer, a high volumetric current density of 10,608 ± 1,036 A/m3 was achieved, the highest volumetric current density with pure Geobacter sulfurreducens to date. This strategy can be readily applied to existing BESs (e.g., microbial fuel cells and microbial electrosynthesis) and provide a feasibility for practical application.

The bending capacity of concrete-encased underground electrical duct banks has been the subject of considerable investigation using the load-structure method; however, the role of high-density polyethylene (HDPE) conduits and the thresholds of electrical duct banks has not been fully scrutinized. This study examines the bending behaviors of electrical duct banks subjected to monotonic vertical loading in a soil box using an advanced monitoring device to measure the conduit diameter change. An analysis of the experiment shows the effective role of HDPE conduits in improving the bending capacity of electrical duct banks. The results suggest 5% and 7.5% as the deformation rate thresholds with respect to the ultimate states of serviceability and bearing capacity, respectively. The threshold of the longitudinal curvature radius is determined to be 18000 m. Finally, the evolution trends of the stress and deformation rates of HDPE conduits are recommended for the monitoring indexes and control standards of electrical duct banks.

White-rot fungi is capable of producing extracellular enzymes that degrade lignin structure and facilitate biofuel production from lignocellulosic biomass wastes. However, fungal monocultures are constrained by low activities of the lignin-degrading enzyme system, leading to poor treatment efficiency and a long duration, which are not advantageous for large-scale applications. To improve enzyme production and enhance lignin degradation, a novel coculture system was proposed using the white-rot fungi Phanerochaete chrysosporium and Irpex lacteus CD2. The degradation efficiency of the alkali lignin by the fungal coculture was 26.4%, which was higher than that of the fungal monocultures. It was due to the production of lignin degrading enzymes was promoted in the liquid medium. Scanning electron microscopy, Fourier transform infrared, thermogravimetric and mercury porosimeter analyses results revealed that the alkali lignin treated with the fungal coculture had the largest porosity, and the degree of destruction of the alkali lignin structure by the fungal coculture was higher than that of the fungal monocultures. Meanwhile, the nonproductive adsorption of enzymes on alkali lignin was significantly reduced by 61.0% when the biomass was treated with the fungal coculture. As a result, the nonproductive adsorption was remarkably reduced, while it significantly improved the cellulase catalysis efficiency. These results demonstrated the synergistic effects of the fungal coculture for biomass treatment and provided a new approach for increasing lignin degradation while improving enzymatic catalysis and biofuel production through fungal coculture.

The vertical three-dimensional finned tube is one kind of strengthened tubes that effectively enhance heat transfer. In this paper, the characteristics of heat transfer on the exterior enhanced surface of a vertical 3-D finned tube were studied under natural convection conditions. The effects of varied fin height, fin width, axial fin pitch and circular fin pitch on Nusselt (Nu) number were presented. The results showed that the natural convective heat transfer performance of vertical 3-D finned tube was much better than that of a smooth tube. Under the study range, Nu number of the vertical 3-D finned tube was 2.83-2.97 times greater than that of the smooth tube. With the increase of fin height and the decrease of axial fin pitch, Nu number is increased, but the change of fin width and circular fin pitch has a little influence on the Nu number. Finally, the empirical correlation of air side free convection heat transfer was proposed for vertical 3-D finned tube, the predicted values of Nu number in agreement with the experimental values within the error of ± 11.3 %.

A high-performance anion exchange membrane (AEM) is critical for the development of alkaline fuel cell. In this work, AEMs with an interpenetrating polymer network (IPN) are synthesized. An electron microscope clearly reveals a highly efficient “ion channel” network, which is constructed with a small amount of cation exchange groups. This specially designed ion channel leads to extraordinary hydroxide conductivity (e.g., 257.8 mS cm-1 at 80 °C) of IPN AEMs at moderate ion exchange capacity (IEC=1.75 mmol g−1), as well as excellent long-term alkaline stability at harsh condition which showed that 81% of original conductivity can be retained after a long time for 1248 hours. Moreover, a remarkable peak power density of 1.20 W cm-2 (0.1 MPa backpressure) with nonprecious metal (FeNx-CNTs) as oxygen reduction reaction (ORR) catalyst in a fuel cell test was achieved. This work offers a general strategy to prepare high-performance AEMs based on IPN structure design.

Poor performance in the condensers in power plants and chemical plants is due to the fact that condensed water is deposited on the heat transfer pipes. The dynamics of condensed water droplets forming on the surface of heat transfer pipes have a significant effect on the heat transfer efficiency of heat exchangers. In the present study, a numerical approach using a coupled level-set and volume of fluid (CLSVOF) method was adopted to investigate the impact of water droplets on cylindrical pipes. The numerical model was verified by an experiment, and both sets of results showed qualitative and quantitative agreements. The effects of the surface wettability, impact velocity and relative size of the droplet to the pipe on the droplet impact dynamics are systematically investigated. Moreover, the regularities of the contact area between the liquid and the pipe during the impacting process as well as the volume of residual liquid remaining on the pipe post-impact are also analyzed; these two parameters are the key factors which affect the heat transfer efficiency of heat transfer pipes, and they cannot be acquired very accurately using experiments.

A novel anhydrous colloidal suspension was synthesized experimentally for CO2 absorption by dispersing hollow silica nanospheres (HSNs) modified by diethylenetriamine (DETA) in 2-[2-(dimethylamine) ethoxy] ethanol (DMEE) in this work. The physicochemical properties of HSNs synthesized were studied, and HSNs presented uniformed sphere-like morphology and microporous structures dominated by micropores. The CO2 absorption performance of DETA-HSNs/DMEE with different DETA loading contents (0 - 60 wt%) was investigated. A high DETA loading content can promote effectively the CO2 absorption capacity, and 60 wt%DETA-HSNs/DMEE had a highest absorption capacity of 1.0630 ± 0.0849 mmol/g. But more DETA resulted into a greater resistance of CO2 transfer in the late stage of absorption, and extend the absorption time. Moreover, pseudo-second-order model could be more successful to predict the CO2 absorption process in the colloidal suspensions studied.

Three dimensional pin fin tube is an effective heat transfer element. It has been widely used in industry process. However, condensation heat transfer characteristic of moist air outside it has not been experimentally studied. The wettability of tube surface has an important effect on this process. In this study, experiments were carried out, in which moist air condensing outside three dimensional pin fin tube with different wettability. Smooth tube is also tested to make comparison. Effects of steam mole fraction, moist air temperature, and wall subcooling are analysed in detail. Super-hydrophobic surface is obtained using oxidation and self-assembling monolayer method. The results show that heat transfer coefficient increases with the increase of steam mole fraction, wall subcooling and the decrease of moist air temperature. Heat transfer coefficient ranges from 55 to 2,035 W/m2K within the study of this paper, and hydrophilic three dimensional finned tube can achieve 2 times heat transfer coefficient compared with smooth tube and superhydrophobic three dimensional pin fin tube.

Background Owing to the high growth rate, high protein and carbohydrate contents, and an ability to grow autotrophically, microalgal biomass is regarded as a promising feedstock for fermentative hydrogen production. However, the rigid cell wall of microalgae impedes efficient hydrolysis of the biomass, resulting in low availability of assimilable nutrients and, consequently, low hydrogen production. Therefore, pretreatment of the biomass is necessary in order to achieve higher hydrogen yield (HY). In the present study, acid-thermal pretreatment of Chlorella sp. biomass was investigated. Conditions for the pretreatment, as well as those for hydrogen production from the pretreated biomass, were optimized. Acid pretreatment was also conducted for comparison. Results Under optimum conditions (0.75% (v/v) H2SO4, 160 °C, 30 min, and 40 g-biomass/L), acid-thermal pretreatment yielded 151.8 mg-reducing-sugar/g-biomass. This was around 15 times that obtained from the acid pretreatment under optimum conditions (4% (v/v) H2SO4, 150 min, and 40 g-biomass/L). Fermentation of the acid-thermal pretreated biomass gave 1,079 mL-H2/L, with a HY of 54.0 mL-H2/g-volatile-solids (VS), while only 394 mL/L and 26.3 mL-H2/g-VS were obtained from the acid-pretreated biomass. Conclusions Acid-thermal pretreatment was effective in solubilizing the biomass of Chlorella sp. Heat exerted synergistic effect with acid to release nutrients from the biomass. Satisfactory HY obtained with the acid-thermal pretreated biomass demonstrates that this pretreatment method was effective, and that it should be implemented to achieve high HY.

Dandelion seeds (DSs) have the advantages of high nitrogen content, low cost and easy availability and thus are ideal carbon precursors for fabricating carbon nanomaterials. Herein, this paper prepared a carbon nanosheet material by one-step carbonizing DSs with KOH activation (self-doped-nitrogen porous carbon nanosheets (N-CNS)) and without KOH activation (unactivated self-doped-nitrogen porous carbon nanosheets (N-UA-CNS)), which could dope nitrogen atoms directly into carbon materials without additional processes. Scanning electron microscopy(SEM) images and X-ray diffraction(XRD) patterns both showed that N-CNS was of macro-porous structure, and beneficial for microorganisms’ growth. The Brunauer Emmett Teller(BET) surface area of N-CNS was 2107.5 m2 g−1, which was much higher than that of N-UA-CNS. After carbon clothes were modified by the obtained materials, the internal resistance of both N-CNS-modified carbon cloth (N-CNS-CC) and N-UA-CNS-modified carbon cloth (N-UA-CNS-CC) was greatly reduced and was found to be only 2.7 Ω and 4.0 Ω, respectively which are all significantly smaller than that of blank carbon cloth (65.1 Ω). These electrodes were assembled in microbial fuel cells (MFCs) as anode, and the operation experiments showed that the N-CNS modification shortened start-up time, improved output stability and increased maximum output voltage significantly. The maximum power density of N-CNS-CC MFC was 1122.41 mW m−2 which was 1.3 times of that of N-UA-CNS-CC MFC and 1.6 times of that of CC MFC. The results demonstrated that N-CNS was an ideal modification material for fabricating MFC anodes with simple preparation process and low cost.

It is urgent to reduce CO2 emissions for minimizing the consequences of the greenhouse effect and carbon capture material is one of the key factors for CO2 capture technology. In this work, colloidal suspension were prepared as sorbents by dispersing porous silica nanospheres modified by polyethylenimine (PEI-PSNs) in dimethyaminoethoxyethanol (DMEE). Porous silica nanospheres (PSNs) synthesized via an emulsion method had high surface area (874.58 m2/g) and uniform morphology. The absorption of CO2 was studied over a wide range of CO2 pressure (0-200 kPa), temperature (25-55 °C) and PEI-PSNs concentration (0-50 wt%). Compared to DMEE and PSNs/DMEE, PEI-PSNs/DMEE have much more CO2 absorption capacity, resulting from that DMEE could improve reaction of amino and CO2. It was also found that the absorption amount increased firstly and then decreased with PEI-PSNs concentration increasing and the maximum absorption capacity was 1.056 mmol/g at 30 wt% PEI-PSMs at 25 °C and 150 kPa. The regeneration efficiencies of the solutions at 80 °C were higher than 92 % in 5 absorption-desorption circles. The novel sorbents showed an advantage of a higher regeneration efficiency at relatively lower temperature and had great energy-saving potential.

Chemical absorption with monoethanolamine (MEA) is the most common technology used in the CO2 removal unit for a power plant. However，the application is hindered by its high energy consumption for absorbent regeneration. In this study, a rate-based model of the typical MEA-based CO2 capture process was built for a power plant with Aspen Plus software. The thermodynamic model of ENRTL-RK was adopted. Temperature fields and the flow rates changes of components in absorber and stripper were obtained. And process analysis using the equilibrium stage model was performed to investigate the effects of operation parameters (CO2 loading in lean solution and stripper pressure) on the regeneration energy consumption. With heat pump technology adopted to assist lean solution regeneration, two processes were proposed and the reboiler duties decreased to 2.77 GJ/t CO2 and 2.38 GJ/t CO2, respectively, owing to the recovery of latent heat and part of sensible heat. Moreover, condenser duties were reduced obviously.

In this work, the control of the droplet generation by a focused infrared (IR) laser with a wavelength of 1550 nm was studied, in which the liquid water and the oil with the surfactant of Span 80 were employed as the disperse and continuous phases, respectively. The characteristics of the droplet generation controlled by the laser was explored under various flow rates, laser powers and spot positions and the comparison between the cases with/without the laser was also performed. The results showed that when the laser was focused on the region away from the outlet of the liquid water inflow channel, the droplet shedding was blocked due to the IR laser heating induced thermocapillary flow, leading to the increase of the droplet volume and the cycle time of the droplet generation as compared to the case without the laser. Decreasing the continuous phase flow rate led to the increase of the droplet volume, cycle time of the droplet generation and the volume increase ratio, while increasing the disperse phase flow rate led to the increase of the droplet volume and the decrease of the cycle time and volume increase ratio. For a given flow rate ratio between the continuous and disperse phases, the increase of the flow rates decreased the volume increase ratio. In addition, it is also found that the droplet volume, the cycle time and the volume increase ratio all increased with the laser power. When the laser was focused at the inlet of the downstream channel, the droplet volume, the cycle time and the volume increase ratio were the largest. Moving the laser spot to the downstream or upstream led to the decrease of them. When the laser was focused on the outlet of the liquid water inflow channel, the generated droplet volume and cycle time of the droplet generation were even lower than the case without the laser because of the lowered viscosity. This works provides a comprehensive understanding of the characteristics of the droplet generation controlled by the laser, which is beneficial to promote the application of this optical method in the droplet based microfluidics.

Yi people make up about 50% of the population in Liangshan Prefecture, Sichuan Province, China, but accounted for 88.07% of new HIV cases in the prefecture from 2011 to 2013. This study evaluated HIV prevalence in pregnant women of Liangshan Prefecture using HIV sentinel surveillance (HSS) data over the period of 2009 to 2015.Xichang, Zhaojue County, and Butuo County were selected as HSS sites. We investigated the temporal trends in HIV prevalence in these areas, and the association between demographic and behavioral characteristics and risk of HIV infection.Data on a total of 2797 pregnant women in Xichang and 3983 pregnant women in Zhaojue and Butuo was collected for the period 2009 to 2015. There was a fluctuating HIV prevalence among pregnant women of Xichang, with a rate of 0.75% in 2015 (χ2trend = 2.27, P = 0.13). HIV prevalence among pregnant women of Zhaojue and Butuo was consistently high, varying between 3.4% (9/267, 2011) and 10.3% (82/796, 2012) over the period of 2010 to 2015 (χ2trend = 0.12, P = 0.73). In Xichang, we found that Yi ethnicity (OR = 11.37, 95% CI = 2.92-44.25) and a husband who used drugs (OR = 32.13, 95% CI = 5.33-193.67) were significantly associated with HIV risk in pregnant women. For Zhaojue and Butuo, we observed that pregnant women had a higher risk of HIV infection when they were over 30 years old (OR = 1.72, 95% CI = 1.17-2.52), when they had a higher number of previous births, when their husbands had a history of migrating for work (OR = 1.56, 95% CI = 1.16-2.08), and when they had a history of other sexually transmitted infections (OR = 2.19, 95% CI = 1.16-2.08). Compared to those with a primary school education or below, pregnant women with a secondary or high school education level had a lower risk of HIV infection (OR = 0.28, 95% CI = 0.09-0.89).Our results indicate that there is a serious HIV epidemic among pregnant Yi women, especially for those with less education, more past births, or a husband with a history of out-migrating for work or STD infection.

Simultaneous saccharification and fermentation (SSF) and pre-hydrolysis with SSF (PSSF) were used to produce hydrogen from the biomass of Chlorella sp. SSF was conducted using an enzyme mixture consisting of 80 filter paper unit (FPU) g-biomass−1 of cellulase, 92 U g-biomass−1 of amylase, and 120 U g-biomass−1 of glucoamylase at 35 °C for 108 h. This yielded 170 mL-H2 g-volatile-solids−1 (VS), with a productivity of 1.6 mL-H2 g-VS−1 h−1. Pre-hydrolyzing the biomass at 50 °C for 12 h resulted in the production of 1.8 g/L of reducing sugars, leading to a hydrogen yield (HY) of 172 mL-H2 g-VS−1. Using PSSF, the fermentation time was shortened by 36 h in which a productivity of 2.4 mL-H2 g-VS−1 h−1 was attained. To the best of our knowledge, the present study is the first report on the use of SSF and PSSF for hydrogen production from microalgal biomass, and the HY obtained in the study is by far the highest yield reported. Our results indicate that PSSF is a promising process for hydrogen production from microalgal biomass.

Lignocellulosic materials are commonly used in bio-H2 productionfor the sustainable energy resource development asthey are abundant, cheap, renewable and highly biodegradable.In the process of the bio-H2 production, the pretreated lignocellulosicmaterials are firstly converted to monosaccharidesby enzymolysis and then to H2 by fermentation. Since thestructures of lignocellulosic materials are rather complex, thehydrolysates vary with the used materials. Even using the samelignocellulosic materials, the hydrolysates also change withdifferent pretreatment methods. It has been shown that the appropriatehydrolysate compositions can dramatically improvethe biological activities and bio-H2 production performances.Over the past decades, hydrolysis with respect to differentlignocellulosic materials and pretreatments has been widelyinvestigated. Besides, effects of the hydrolysates on the biohydrogenyields have also been examined. In this review, recentstudies on hydrolysis as well as their effects on the biohydrogenproduction performance are summarized. [BMBReports 2013; 46(5): 244-251]

Cellulose insulation polymer is an important component of oil-paper insulation, which is widely used in power transformer. The weight of the cellulose insulation polymer materials is as high as tens of tons in the larger converter transformer. Excellent performance of oil-paper insulation is very important for ensuring the safe operation of larger converter transformer. An effective way to improve the insulation and the physicochemical property of the oil impregnated insulation pressboard/paper is currently a popular research topic. In this paper, the polytetrafluoroethylene (PTFE) functional film was coated on the cellulose insulation pressboard by radio frequency (RF) magnetron sputtering to improve its breakdown voltage and the hydrophobicity properties. X-ray photoelectron spectroscopy (XPS) results show that the nano-structure PTFE functional film was successfully fabricated on the cellulose insulation pressboard surface. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) present that the nanoscale size PTFE particles were attached to the pressboard surface and it exists in the amorphous form. Atomic force microscopy (AFM) shows that the sputtered pressboard surface is still rough. The rough PTFE functional film and the reduction of the hydrophilic hydroxyl of the surface due to the shielding effect of PTFE improve the breakdown and the hydrophobicity properties of the cellulose insulation pressboard obviously. This paper provides an innovative way to improve the performance of the cellulose insulation polymer.

Space charge has close relation with the trap distribution in the insulation material. The phenomenon of charges trapping and detrapping has attracted significant attention in recent years. Space charge and trap parameters are effective parameters for assessing the ageing condition of the insulation material qualitatively. In this paper, a new method for calculating trap distribution based on the double exponential fitting analysis of charge decay process and its application on characterizing the trap distribution of oil impregnated insulation paper was investigated. When compared with the common first order exponential fitting analysis method, the improved dual-level trap method could obtain the energy level range and density of both shallow traps and deep traps, simultaneously. Space charge decay process analysis of the insulation paper immersed with new oil and aged oil shows that the improved trap distribution calculation method can distinguish the physical defects and chemical defects. The trap density shows an increasing trend with the oil ageing, especially for the deep traps mainly related to chemical defects. The greater the energy could be filled by the traps, the larger amount of charges could be trapped, especially under higher electric field strength. The deep trap energy level and trap density could be used to characterize ageing. When one evaluates the ageing condition of oil-paper insulation using trap distribution parameters, the influence of oil performance should not be ignored.

Cellulose insulation polymer (paper/pressboard) has been widely used in high voltage direct current (HVDC) transformers. One of the most challenging issues in the insulation material used for HVDC equipment is the space charge accumulation. Effective ways to suppress the space charge injection/accumulation in insulation material is currently a popular research topic. In this study, an aluminium oxide functional film was deposited on a cellulose insulation pressboard surface using reactive radio frequency (RF) magnetron sputtering. The sputtered thin film was characterized by the scanning electron microscopy/energy dispersive spectrometer (SEM/EDS), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The influence of the deposited functional film on the dielectric properties and the space charge injection/accumulation behaviour was investigated. A preliminary exploration of the space charge suppression effect is discussed. SEM/EDS, XPS, and XRD results show that the nano-structured Al2O3 film with amorphous phase was successfully fabricated onto the fibre surface. The cellulose insulation pressboard surface sputtered by Al2O3 film has lower permittivity, conductivity, and dissipation factor values in the lower frequency (

An experimental study was carried out to investigate the effects of inlet pressure, sample thickness, initial sample temperature, and temperature sensor location on the surface heat flux, surface temperature, and surface ultrafast cooling rate using stainless steel samples of diameter 27 mm and thickness (mm) 8.5, 13, 17.5, and 22, respectively. Inlet pressure was varied from 0.2 MPa to 1.8 MPa, while sample initial temperature varied from 600°C to 900°C. Beck’s sequential function specification method was utilized to estimate surface heat flux and surface temperature. Inlet pressure has a positive effect on surface heat flux (SHF) within a critical value of pressure. Thickness of the sample affects the maximum achieved SHF negatively. Surface heat flux as high as 0.4024 MW/m2 was estimated for a thickness of 8.5 mm. Insulation effects of vapor film become apparent in the sample initial temperature range of 900°C causing reduction in surface heat flux and cooling rate of the sample. A sensor location near to quenched surface is found to be a better choice to visualize the effects of spray parameters on surface heat flux and surface temperature. Cooling rate showed a profound increase for an inlet pressure of 0.8 MPa.