Loading Rate Research Articles

Multi-objective optimization of distributed green infrastructure for effective stormwater management in space-constrained highly urbanized areas

Green infrastructure (GI) is essential for stormwater management, but its implementation in highly urbanized areas is challenging due to the limited space available for GI retrofitting. There is a lack of comprehensive evaluations that assess the spatial adaptability, functionality, and cost-benefit of various GI measures, and optimize their placement to achieve the maximum reduction rate of total runoff (RTR) and reduction rate of pollution load (RPL) while minimizing life cycle cost (LCC) in space-constrained highly urbanized areas (SCHUA). To address this issue, a novel concept of infiltration, retention, and storage integrated GI (IRS-GI) for SCHUA was proposed, and a framework coupling the Storm Water Management Model (SWMM) with multi-objective optimization algorithms was developed to determine the optimal IRS-GI layout, focusing on the objectives of RTR, RPL, and LCC. The impacts of different GI type, size, and location, rainfall return periods, and algorithms (NSGA-II and NSGA-III) were then examined. The results showed that IRS-GI could achieve satisfactory RTR and RPL results while single-type GI may struggle to meet requirements. Optimization outcomes were significantly influenced by rainfall return periods, with cost-benefit decreasing as return periods increasing. Besides, the optimization results of NSGA-II and NSGA-III showed differences, and the comprehensive Pareto frontier obtained by reapplying non-dominated sorting could achieve more comprehensive results for determining the optimal IRS-GI configuration. Under the urban drainage design standard, the optimal IRS-GI layout, covering 32.97 % of the green spaces, 38.57 % of the rooftop, and 60.98 % of the ordinary roads and squares, respectively, could achieve a RTR of 50.09 %, RPL of 57.00 %, and LCC of 0.79 × 108 CNY/yr. Additionally, the optimal configuration suggested that a higher proportion of GI downstream of drainage system may contribute to better cost-benefit, emphasizing the need for location-specific GI solutions. This research offers valuable insights for optimizing GI in SCHUA, advancing sustainable urban stormwater management.

Performance of single PN/A reactor under wide fluctuation of nitrogen load.

Partial nitritation-anammox (PN/A) is a cost-effective technology in high ammonia-nitrogen wastewater treatment. However, PN/A is prone to instability as the ammonia-nitrogen sharply fluctuates. In this study, a packed bed reactor is employed to construct a single-stage PN/A system to investigate the operational characteristics and explore the denitrification mechanism. The effluent NH4+-N concentration, ammonia nitrogen removal rate (ARE), and total nitrogen removal rate (TNR) could be sustained at about 60mg/L, 80%, and over 70%, respectively, when the influent nitrogen load rate (NLR) is changed from 0.733 to 0.879kg-N/m3/day. Both ARE and TNR are decreased when NLR continues increasing to 1.026kg-N/m3/day. The influent NLR decreases from 0.879 to 0.147kg-N/m3/day, and ARE and TNR reached 98% and 85.4%, respectively. Therefore, the denitrification effect of the reactor could be recovered, and the excellent nitrogen removal capacity could be obtained within a wide range of influent NLR. Moreover, the high-throughput sequencing and metagenomic testing indicate that the Proteobacteria and Planctomycetes that the PN/A functional strains (i.e., ammonia-oxidizing bacteria (AOB) and anammox bacteria (AnAOB)) account for 38.8% in the sludge. The relative abundance of Nitrospira containing the nitrite-oxidizing bacteria (NOB) has dropped to 0.01%, and the functional gene nxr of the nitrite oxidation process is also inhibited. The relative expression of the functional gene is dominated by the short-range nitritation and anammox oxidation, which demonstrates that the nitrogen removal is mainly dominated by nitritation-anammox.

Fatigue mechanical properties and Kaiser effect characteristics of the saturated weakly cemented sandstone under different loading rate conditions

Weakly cemented sandstone (WCS) is a unique rock type widely distributed on the surface. Environmental factors such as groundwater and stress variations easily influence its fatigue mechanical properties and fracture characteristics. To design and evaluate the long-term stability of surrounding rock support in tunnel excavation and underground resource mining projects, investigating the fatigue mechanical properties and acoustic emission (AE) response characteristics of saturated WCS under different loading rates is of great practical and theoretical significance. This study employed experimental techniques such as X-ray diffraction (XRD), nuclear magnetic resonance (NMR), and natural water absorption tests to investigate the mineral composition, pore size, and connectivity characteristics of WCS. The multi-level cyclic loading-unloading tests (MCLU) combined with the AE system were conducted on dry and saturated WCS specimens at different loading rates. The results reveal that the deformation modulus of these specimens initially increases and then decreases under cyclic loading conditions. Water significantly influences the fatigue strength and deformation resistance of sandstone. As the loading rate increases, the range of RA values broadens, accompanied by a marked increase in the number of AE signals with high RA values. Saturated sandstone specimens are more prone to developing macroscopic shear fracture surfaces. Water has a more substantial effect on the stress distribution ranges corresponding to the response of the Kaiser effect in WCS than loading rates. The capacity of the Kaiser effect to indicate the extent of rock damage is intricately linked to the progression of internal micro-cracks. When internal damage surpasses the critical value of the Kaiser effect memory damage, the accelerated propagation of shear cracks becomes pivotal in the internal damage of the sandstone. It seems that the presence of water within the interior of the rock may facilitate the dissolution of K-feldspar in WCS, which could result in the formation of kaolinite, which will be further transformed into illite. The hydration expansion of illite may further exacerbate the deterioration effect of the mechanical properties of WCS.

An experimental study of fracture mechanism and morphology of granite specimens under various dynamic loading rates

Numerous studies have shown that dynamic fracture toughness (DFT) of rock is dependent on loading rate. This paper quantitatively studied the effect of loading rate on DFT from perspective of mesoscopic fracture morphology. First, notched semi-circle bend (NSCB) and short-core-in-compression (SCC) samples of granite were prepared for dynamic mode I and mode II fracture tests. Then, the DFT values of NSCB and SCC specimens at various loading rates were calculated and analyzed. After that, mesoscopic morphologies of failure surfaces of NSCB and SCC specimens under various loading rates were obtained by scanning electron microscope (SEM). The fracture morphology features of specimens were quantitatively characterized by a method combining deep learning and SEM images. The analytical results suggested that as loading rates rose, the increase in the percentage of mesoscopic fracture morphology caused by shear stress (MFM-S) on the fractured surface was the primary reason for the increase of DFT. When dynamic loading varied from 40 to 120 GPa m1/2 s−1, there was a linear relationship between the DFT and the proportion of MFM-S. Additionally, with an increasing loading rate, the proportion of MFM-S on the fracture surface of NSCB specimens varied slightly more, which can explain why the dependence of DFT on loading rate in NSCB specimens was somewhat more obvious than in SCC specimens.

Preparation and in vitro evaluation of pH and glutathione dual-responsive drug delivery system based on sodium carboxymethyl cellulose

Stimuli-responsive drug delivery systems based on sodium carboxymethyl cellulose (NaCMC) for drug release encounter inherent challenges. In this research, a novel pH and glutathione (GSH) dual-responsive system, CPT-S-S-NaCMC@ZIF-8/SP-PEG, was constructed. Firstly, the prodrug CPT-S-S-OH was synthesized and combined with NaCMC to form GSH-responsive micelles CPT-S-S-NaCMC, significantly enhancing the drug loading and grafting rates to 63.79 % and 91.99 %, respectively. Subsequently, zinc ions and dimethylimidazole can be assembled into porous materials (ZIF-8) on the surface of the micelles. This system exhibits dual pH-GSH responsiveness and effectively reduces the drug release from 84.76 % to 28.71 % at pH = 7.4. Moreover, incorporating pH-responsive spiropyran (SP)-modified polyethylene glycol (PEG) can reduce drug leakage to 16.09 % at pH = 7.4 and exhibit good fluorescence intensity at 722 nm.

Crashworthiness design of additively manufactured lattice-reinforced sandwich tube

A body-centered cubic lattice reinforced sandwich tube structure is designed, and the specimens are prepared using Selective laser melting (SLM) technology with integrated printing and split assembly. The effects of inner and outer wall thickness, loading rate and interaction on the deformation pattern and crashworthiness of the structures were investigated through experiments and numerical simulations. The results indicate that when subjected to axial compression, the integrated printed lattice reinforced sandwich tube (IPLT) forms more folds, and its specific energy absorption increases by 17.61% in comparison to the split assembly lattice filled sandwich tube (SALT). Under transverse compression, the integrated printed lattice reinforced sandwich tube showed no separation of the lattice from the thin-walled tube, and the specific energy absorption increased by 103.78% compared with the split assembly structure. It is noteworthy that the specific energy absorption of the designed reinforced sandwich tube under axial compression (transverse compression) increased by 294.83% (1233.95%) compared with the outer thin-walled tubes. This paper provides new ideas for the production of energy-absorbing components that are light-weight and have good crashworthiness.

Fabrication of ZMF@PS composite microspheres as T2 contrast agents with enhanced contrast performance and magnetic properties

The impacts of nanoplastics on the environment and organisms are gradually increasing, using MRI to detect the metabolic pathways of nanoplastics has low sensitivity and requires magnetic particles for enhanced visualization. In this study, we used Mn0.6Zn0.4Fe2O4 nanoparticles as magnetic particles and coated them with polystyrene to afford polystyrene composite microspheres (ZMF@PS) with enhanced contrast performance. The effects of the polymerization parameters on the morphology and loading rate of the magnetic ZMF@PS composite microspheres were investigated. In addition, the effect of the magnetic contrast agent (ZMF particles) on the magnetic properties of the ZMF@PS composite microspheres was examined. The results show that when MAA and KPS quantities are 1 mL and 0.02 g, respectively, ZMF was uniformly distributed in the ZMF@PS composite microspheres exhibiting a good coating effect, with an average microsphere size of only 151.09 nm. Regarding the contrast performance, an increase in the ZMF content increased the loading rate, saturation magnetization intensity, and relaxation rate of the ZMF@PS composite microspheres.

Treatment of gaseous toluene in an anoxic hybrid bioreactor: Optimization using response surface methodology

This study focuses on treating gaseous toluene emissions from chemical and petrochemical industries using an anoxic hybrid bioreactor (AnHBR) and optimizing the process using response surface methodology (RSM). By varying the gas flow rate (0.05–0.25 LPM) of toluene, the gas residence time (GRT) within the AnHBR ranged from 0.53 to 2.67 h, resulting in an inlet loading rate (ILR) between 0.36 to 14.33 g/m3 h. Simultaneously, the hydraulic retention time (HRT) of the liquid feed was varied from 24 to 72 h in the AnHBR. The operating parameters were varied to determine the optimal combination to achieve the maximum toluene removal, which remained above 96% throughout the operation. At the optimized combinations (flow rate: 0.15 LPM, GRT: 0.89 h, and HRT: 48 h) in AnHBR, toluene removal reached ∼99%, with end products generated consisting of 1.8% CO2 and 92.9% N2 gas. Metagenomics analysis revealed a dominance of toluene degraders (∼38%), highlighting their potential to degrade toluene in the AnHBR. The RSM enhanced toluene treatment in the AnHBR, demonstrating robustness in handling high pollutant loads and its potential for industrial applications.

Preparation of metal-modified carbon-based catalyst and experimental study on catalytic pyrolysis of distillers dried grains with solubles

Distillers dried grains with solubles (DDGS) offer high calorific value, suited for catalytic rapid pyrolysis for energy and chemical applications, yet tar and coke formation during bio-oil upgrading necessitates exploration of cost-effective, durable biocarbon-based catalysts for tar removal. In this study, a carbon-based catalyst was prepared by metal modification of alkaline biochar for catalytic pyrolysis with Distillers dried grains with solubles (DDGS) biomass. Brunauer–Emmet–Teller (BET), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) were used to characterized the morphology and microstructure of the metal-modified carbon-based catalysts. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was used to analysis the pyrolysis-gas of catalytic pyrolysis. Furthermore, the effects of the loading and metal mass ratio of carbon-based monometallic catalysts (Fe and Co) and carbon-based bimetallic catalysts (Fe-Co) on the distribution of the DDGS pyrolysis products were further investigated. The results showed that the 8 wt% of loading rate of bimetallic catalyst significantly reduced the oxygenated compounds but increased the aromatic hydrocarbons. Compared with pyrolysis without catalyst, when the catalyst was 2Fe6Co (mass ratio of Fe/Co 1:3), the hydrocarbons increased from 36.42 % to 44.53 %, the oxygen-containing compounds decreased from 60.36 % to 52.35 %, and the aromatics increased significantly from 0.73 % to 25.37 %. This study provides a new route of increasing the aromatic hydrocarbon content of catalytic pyrolysis to offer theoretical basis for carbon-based catalysts of biomass conversion.

Efficient partial denitrification-anammox process enabled by a novel denitrifier with truncated nitrite reduction pathway

Partial denitrification coupled with anaerobic ammonium oxidation (PD-anammox) is a promising technology for cost-effective nitrogen removal from wastewater. Nitrite availability is crucial to anammox performance but often limited by the slow partial denitrification process. Here we report an efficient PD-anammox system driven by the novel denitrifier Bacillus velezensis C1–3 with truncated nitrite reduction pathway. Whole-genome sequencing analysis revealed that the lack of nitrite reductase genes nirS/nirK and norBC in strain C1–3 enabled nitrite accumulation without the need for precise control of carbon dosage. By coupling it with anammox sludge, over 79 % total nitrogen (TN) removal was stably achieved, under a TN loading rate of 660 mg/L/d and a carbon/nitrogen ratio below 1.0. Mechanism explorations indicate that the niche differentiation of C1–3 and anammox bacteria facilitated their mutualism while avoiding nitrite competition. This study demonstrates a novel strategy for establishing efficient PD-anammox process by harnessing the unique metabolic deficiency of denitrifiers, shedding light on the development of stable and sustainable biological nitrogen removal technologies with minimal carbon footprint.

Integrated treatment of black wastewater using sedimentation, constructed wetland, and nanoparticles coagulation

ABSTRACT The aim of the present investigation was to achieve an efficient treatment for black wastewater for non-restricted reuse. The treatment included sedimentation followed by horizontal flow constructed wetland (HF-CW), and finally chemical coagulation using magnetite (Fe3O4) nanoparticles. For the wetland, the average organic loading rate (OLR) was 42.83 biochemical oxygen demand (BOD)/m2day and 71.30 g chemical oxygen demand (COD)/m2 day, while average surface loading rate was 0.185 m3/m2 day. The obtained results revealed that removal percentage of COD, BOD, and total suspended solids (TSS) by sedimentation followed by processing through wetlands was 80.3, 81.6, and 80%, which corresponds to 76, 42.56, and 54 mg/l, respectively. When magnetite nanoparticles were added to the HF-CW effluent at the optimum dose of 25 mg/l in combination with 10 mg/l FeCl3, the overall removal rate increased to reach 95.9, 99.1, 99.17, 92.3, 94.3, 94.3, and 91.3% for turbidity, COD, BOD, TSS, phosphate (PO4), total nitrogen (TN), and sulfide, respectively. The corresponding residual concentrations were 5 NTU, 8, 5, 18 according to table 3, 0.07, 1, and 1.04 mg/l, respectively. According to the national and international regulations, the present final treated effluent can be safely reused as a non-restricted source for agriculture purposes. The overall results revealed that the implemented study is simple, efficient, reliable, and economical, particularly for remote areas, according to the non-restricted reuse requirements.

Bimetallic Ni‐Co Supported on Nitrogen‐Doped Carbon Nanotubes For Prox Reaction

AbstractHydrogen is a key component for a successful energy transition on a large scale since it boasts remarkable energy efficiency. Currently, H2 is mainly obtained through steam reforming of natural gas or hydrocarbons and low‐carbon alcohols but contains approximately 2 % CO, a contaminant detrimental to H2 fuel cells. Herein, an N‐doped carbon nanotube was prepared via the soft nitriding method to support nickel and cobalt for the PROX‐CO as the main reaction for hydrogen purification. The most efficient condition was achieved when the reaction temperature reached 250 °C and the Ni and Co loading rate was 7.5 %. In this situation, the CO2 selectivity reached almost 33 %, and CO conversion was 61 %. Regarding CO conversion among bimetallic catalysts at 250 °C a minimal variation occurred and the catalyst 10Ni/N‐CNTs slightly outperformed (64.4 %). The effect of N‐doping on the carbon nanotube's structure was also revealed. Nitrogen atoms incorporated into the lattice of carbon nanotubes impart an electron‐donor character. Consequently, Co oxide reduction to the metallic phase occurred at significantly lower temperatures compared to other supports such as SiO2, Al2O3, and graphene. For the bimetallic catalysts, the strong metal‐support interaction facilitated obtaining different oxide and metallic phases at milder temperatures.

Effect of displacement loading rate on dynamic mechanical characteristics of fault stick-slip under constant normal stiffness conditions

The role of the displacement loading rate in fault activation and evolution is of utmost importance, yet most existing studies have primarily focused on its effect under constant normal load (CNL) conditions. However, in reality, the rock mass surrounding the earthquake source at the deep part of the fault provides normal stiffness conditions. Therefore, the influence of the displacement loading rate on the dynamic mechanical characteristics of fault stick-slip under constant normal stiffness (CNS) conditions remains uncertain. To bridge this research gap, we conducted an experimental investigation on simulated faults in granite under constant normal stiffness (CNS) conditions. Our analysis focused on the influence of the displacement loading rate on the spatial and temporal evolution of local stresses along the fault and the size of the fault nucleation zone. The findings revealed the following: Under the CNS condition, the equivalent shear stress is larger compared to the CNL condition, while the shear stress drop is smaller. The recovery of normal stress under CNS conditions depends more on the displacement loading rate. The nucleation location of the fault is influenced by the normal boundary conditions, with a larger nucleation zone observed in the CNS condition than in the CNL condition. In the early stage of friction, the local stress and stress drop of the fault exhibit a positive correlation with the displacement loading rate, whereas in the later stage, they display a negative correlation. Moreover, at the same location, the order of local stress drop rates for the fault is v3 > v1 > v2, where v1 represents the local normal stress drop rate, v2 represents the local shear stress drop rate and v3 represents the local friction coefficient drop rate. These research results contribute to a further understanding of the deep fault-slip mechanical behavior.

Amphiphilic diblock copolymers of polyisobutylene-b-poly(2-ethyl-2-oxazoline) via cationic polymerization

A series of amphiphilic polyisobutylene-b-poly (2-ethyl-2-oxazoline) (PIB-b-PEOX) diblock copolymer/Ag nanoparticle composites were successfully in-situ synthesized via cationic ring-opening polymerization of 2-ethyl-2-oxazoline (EOX) with high initiation efficiency by using allyl bromide end functionalized polyisobutylene (PIB-allylBr) as a macroinitiator and AgClO4 as a coinitiator. The microphase separation formed in the resulting PIB-b-PEOX diblock copolymers due to the thermodynamic imcompability of hydrophilic PEOX segments and hydrophobic PIB segments. The micromorphology of phase separation is dependent on the copolymer composition, in which sea-island micromorphology formed for PIB118-b-PEOX80 and bicontinuous phase micromorphology formed for PIB118-b-PEOX97. The micelles with nano-scale size in the range of 15–80 nm and having high drug loading rate of ca. 48.9 % can be formed by self-assembly of the amphiphilic diblock copolymers in n-hexane. The drug cumulative release rate can be increased with an increase in the proportion of PEOX segments, due to the strong interaction between ibuprofen and the PEOX segments. The hydrophilicity of the PIB-b-PEOX diblock copolymer surfaces can be improved after ethanol vapor induction. The PIB-b-PEOX diblock copolymers behave biocompatibility and good anti-protein adsorption property. The amphiphilic PIB-b-PEOX diblock copolymer/Ag nanoparticle composites exhibit high antibacterial efficiency for Gram-negative bacterium (E. coli) and Gram-positive bacterium (S. aureus). To the best of our knowledge, this is the first example of PIB-b-PEOX diblock copolymer/Ag nanoparticle (6.4 ± 2.6 nm) composites synthesized in-situ with good biocompatibility, anti-protein adsorption, and antibacterial properties, which would have potential applications for drug delivery and anti-protein coating in biomedical areas.

A multistage biogas slurry reflux and spray anaerobic digestion reactor for high solid anaerobic digestion: Performance and application evaluation

In this study, a new vertical plug-flow continuous dry anaerobic digestion reactor equipped with a spray percolation system was designed for rice straw and cow manure in dry AD. The findings indicated that the methane yield was 290.63 ± 19.16 mL/g VS when the optimal spray time (9 times/d) was used in batch AD. In addition, the results of continuous experiments under optimal spray time conditions showed that the volumetric methane production rate of the system was 1.55 L/(L·d) when the organic loading rate was 20 g VS/(L·d). In addition, hydrolysis and acidification steps were enhanced. This study demonstrated the potential of the new reactor for stable operation of high OLR dry AD. Digestate is already used as a substitute for synthetic fertilizers precisely because of the environmental benefits associated with its agronomic use.

Leading Through Noise: Operating Room Noise Challenges for Staff and Leadership Techniques to Ensure Optimal Operational Performance.

Noise and distractions in the operating room (OR) critically impact surgical performance and patient outcomes, particularly in high-stakes environments such as trauma surgery. While historical hospital environments prioritized quiet to facilitate recovery and reduce stress, contemporary ORs, especially those handling trauma cases, face increasing noise challenges due to advanced surgical instruments, alarms, and staff conversations, often surpassing federal exposure limits. This review investigates OR noise sources, including staff activities and equipment, analyzing their effects on cognitive load, communication, and error rates among healthcare workers. It identifies high-risk scenarios and vulnerable groups, highlighting the necessity for targeted interventions. Key strategies include implementing strict noise control policies, using noise-reducing materials in OR design, and educating staff on noise impacts. Additionally, structured communication protocols and continuous monitoring systems are advocated to enhance operational efficiency and safety. Surgeon leadership is pivotal in balancing assertiveness and empathy to maintain a productive team dynamic. Furthermore, surgeons significantly boost OR efficiency and safety by adopting these protocols, promoting inclusive team dynamics, and applying noise-reduction strategies. These practices safeguard patient care and foster a more collaborative work atmosphere, aligning all team efforts toward optimal patient outcomes. This holistic approach emphasizes the need for continuous improvement and adaptability in surgical practices to meet modern healthcare demands, particularly in trauma surgery's fast-paced, unpredictable realm. Collectively, these measures can enhance patient safety and improve conditions for surgical teams, providing a framework for quieter, more focused OR environments that ultimately elevate surgical outcomes and healthcare quality.

Improving organic and nutrient removal efficiencies in seafood processing wastewater using anaerobic membrane bioreactor (AnMBR) integrates with anoxic/oxic (AO) processes

Wastewater from seafood processing is a significant source of pollution, containing many harmful organic and inorganic compounds such as proteins, lipids, carbohydrates, nitrogen and phosphorus. This study investigated the enhancement of organic and nutrient removal efficiencies in seafood processing wastewater by integrating an Anaerobic Membrane Bioreactor (AnMBR) with an anoxic/oxic (AO) processes. A pilot-scale system was constructed with a capacity of 0.5 m3/day directly at the factory operated continuously, featuring an AnMBR process with a 24-hour hydraulic retention time (HRT) and an AO process with HRT values and internal recycle changes. The AnMBR system exhibited consistent and high-performance biochemical oxygen demand (COD) elimination, approximately 80 ± 5 %. However, this system demonstrated low-efficiency removal of total nitrogen (TN) at about 20 ± 5 %, and total phosphorus (TP) 15 ± 5 %, under organic loading rates (OLR) of 0.6 to 1.3 kg-COD/(L·d). The AO process was then continually employed to improve the treatment efficacy (at HRT, 5 h in the anoxic phase, and 8.3 h in the oxic phase, at a recycling rate of 300 %) resulting in the final post-treatment concentrations of COD 27–41 mg/L (removal 98.3 ± 0.3 %), TN 12–25 mg/L (90 ± 2 %), and TP 18 ± 2 mg/L (35 ± 5 %). The performance of the integrated AnMBR-AO system met the established Vietnamese discharge standards for seafood processing wastewater, as outlined in QCVN 11-MT: 2015/BTNMT.

Response of food waste anaerobic digestion to the dimensions of micron-biochar under 30 g VS/L organic loading rate: Focus on gas production and microbial community structure

Biochar modification is an effective approach to enhance its ability to promote anaerobic digestion (AD). Focusing on the physical properties of biochar, the impact of different particle sizes of biochar on AD of food waste (FW) at high organic loading rate (OLR) was investigated. Four biochar with different sizes (40–200 mesh) were prepared and used in AD systems at OLR 30 g VS/L. The research results found that biochar with a volume particle size of 102 μm (RBC-P140) had top-performance in promoting cumulative methane production, increasing by 13.20% compared to the control group. The analysis results of the variety in volatile acids and alkalinity in the system did not show a correlation with the size of biochar, but small size has the potential to improve the environmental tolerance of the system to high acidity. Microbial community analysis showed that the abundance of aceticlastic methanogen and the composition of zoogloea were optimized through relatively small-sized biochar. Through revealing the effect of biochar particle size on AD system at high OLR, this work provided theoretical guidance for regulating fermentation systems using biochar.

Rate‐dependent mechanical properties and acoustic emission characteristic of recycled aggregate concrete under four‐point bending

AbstractThe application of recycled aggregate is crucial for waste concrete recycling, while the loading rate significantly influences the fracture behavior of recycled aggregate concrete. Herein, we investigate the effect of loading rate on the flexural and fracture behaviors of recycled aggregate concrete, along with associated acoustic emission characteristics. Results show that the flexural strength and energy absorption capacity maximum increase by 15.18% and 38.39%, respectively, as the loading rate rises. As the loading rate increases from 0.05 to 1 mm/min, peak frequency is primarily clustered in 0 ~ 75 kHz and 75 ~ 225 kHz and tends to be dense, while the b value decreases by 19.28%, 23.30%, and 30.17%, respectively. Additionally, the proportion of shear failure also decreases, which relates to the high energy release rate. Further, the multifractal spectrum α − f(α) resembles a quadratic distribution, with both multifractal intensity ∆f and spectrum width ∆α showing a downward trend as the loading rate rises.

Evaluating Gait with Force Sensing Insoles 6 Months after Anterior Cruciate Ligament Reconstruction: An Autograft Comparison.

Aberrant knee mechanics during gait 6 months after anterior cruciate ligament reconstruction (ACLR) are associated with markers of knee cartilage degeneration. The purpose of this study was to compare loading during walking gait in QT, bone-patellar tendon-bone (BPTB), and hamstring tendon (HT) autograft patients 6 months post-ACLR using loadsol single sensor insoles, and to evaluate associations between loading and patient reported outcomes. 72 patients (13-40 years) who underwent unilateral, primary ACLR with BPTB, QT, or HT autograft completed treadmill gait assessment, the International Knee Documentation Committee (IKDC) survey and the ACL-Return to Sport after Injury (ACL-RSI) survey 6 ± 1 months post-ACLR. Ground reaction forces were collected using loadsols. Limb symmetry indices (LSI) for peak impact force (PIF), loading response instantaneous loading rate (ILR), and loading response average loading rate (ALR) were compared between groups using separate ANCOVAs. Survey scores were compared between groups using one-way ANOVAs. The relationships between IKDC, ACL-RSI, and LSIs were compared using Pearson's product moment correlation coefficients. There were no significant differences between graft sources for LSI in PIF, ILR, ALR, nor impulse. Patient-reported knee function was significantly different between graft source groups with the BPTB group reporting the highest IKDC scores; however, there was no significant difference between groups for ACL-RSI score. There were no significant associations between IKDC score, ACL-RSI score, and biomechanical symmetry among any of the graft source groups. Autograft type does not influence PIF, ILR, ALR, or impulse during walking 6 months post-ACLR. Limb symmetry during gait is not strongly associated with patient reported outcomes regardless of graft source. Loadsols appear to be a suitable tool for use in the clinical rehabilitation setting.