High Load Research Articles

Preparation and tribological properties study of a novel self-lubricating Alumina-based composite coating

A self-lubricating composite coating Al2O3/C was designed and sprayed via atmospheric plasma spraying (APS), in order to endow the alumina coating with certain lubricating properties under room temperature conditions. The raw feeding powders of boehmite-alumina-graphite (AlO(OH)/Al2O3/C) with particle sizes of 30–50 µm were prepared through hydroxylation treatment, physical stirring, and spray granulation process. The tribological properties of the Al2O3/C composite coating were systematically studied using a CSM friction tester. The prepared Al2O3/C composite coating exhibited fewer defects, lower coefficient of friction (COF), and slighter adhesion wear degree compared to single-component Al2O3 coating. The graphite lubrication film was discovered on both the worn surface of the composite coatings and the friction pair after friction. The existence of the graphite lubrication film decreased the COF, and the reduction extent depended on the load, with a maximum reduction of 55 %. The composite coatings presented the best tribological properties when sliding against Si3N4 balls at a higher load (5 N) because of the diverse wear mechanisms and the influence of graphite lubrication film, resulting in a reduction in the COF and wear rate by approximately 48 % and 11 times respectively. In addition, part of γ-Al2O3 in the Al2O3/C composite coating transformed into α-Al2O3 after the friction test. But the Al2O3 coating remained phase stable, with no phase change occurring before and after the friction. The transformation from the γ-Al2O3 to the α-Al2O3 phase was positive as for the tribological performance. It could reduce the COF as well as improving the thermal conductivity and mechanical properties of the coating.

The effect of the modifiable areal unit problem (MAUP) on spatial aggregation of COVID-19 wastewater surveillance data

Large wastewater-based epidemiology (WBE) projects often have wide coverage and multiple sampling sites, necessitating spatial aggregation for data reporting and interpretation. However, the outcome may be impacted by a type of statistical bias called the modifiable areal unit problem (MAUP). In this study, we examined the presence and extent of the MAUP scaling effect on a New York State COVID-19 wastewater surveillance project. Specifically, we investigated three metrics: 1) the difference in wastewater SARS-CoV-2 concentrations between sampling at city-level site (i.e., city's primary wastewater treatment plant influent stream) and at upstream sampling sites; 2) the correlation between WBE data and clinical indicators at the WWTP-level and the more aggregated county-level; and 3) the proportion of population affected by misalignment of COVID-19 community risk levels at different spatial scales. The results showed that the MAUP can have a negative impact on risk perception by masking regions with high wastewater viral load or COVID-19 community risk level. On the other hand, the MAUP improved the correlation between wastewater surveillance and clinical measures by an average of 26.02 %. This is the first study to investigate the MAUP in the context of WBE and may encourage future WBE projects to consider the implications of the MAUP when interpreting and reporting spatial data, ultimately leading to better data representativeness and accuracy.

Total carbohydrate consumption through co-fermentation of agro-industrial waste: use of wild-type bacterial isolates specialized in the conversion of C-5 sugars to high levels of lactic acid with concomitant metabolization of toxic compounds.

Value-added bioproducts are linked to the expansion of lignocellulosic biorefineries based on agro-industrial waste and local economic growth. Thus, the aim of this study was to pretreat rice hull (RH), a highly recalcitrant biomass, with saturated steam and convert it to lactic acid (LA). Strategically, the individual fractions and the blend of detoxified liquor and water-insoluble solids were used as substrate in the simultaneous saccharification and co-fermentation (SSCF) by wild-type bacteria. The microbial consortium between Pediococcus acidilactici and Acetobacter cerevisiae enabled the metabolization of all the xylose contained in the liquor, as well as the consumption of all minor sugars when using the blend. Assays resulted in the production of 106.2g L- 1 of LA. Furthermore, A. cerevisiae promoted complete degradation of 5-HMF/furfural in a short period of time. This study demonstrates the benefits provided by processes integration (SSCF/blend) employing high solids load (22% w/v), representing an innovative and economically interesting approach.

Particles made of a novel recombinant spider silk protein rAcSp2 as delivery system for peptide drugs with anti-tumor activity

The recombinant spider silk proteins (spidroins) are promising biomaterials for the use as drug delivery system (DDS) because of their non-cytotoxicity, low immunogenicity and customizable properties. However, most reported spidroin-based materials as DDS derive from the repetitive domain of dragline silk protein, limiting us to take advantage of their desirable properties for medical and industrial innovation. Here, we produced the recombinant aciniform silk protein (rAcSp2) that contains only the N-terminal domain and formulated it into nanoparticles for use as a DDS. We demonstrated that antitumor peptide drugs such as ChMAP-28 can be loaded onto rAcSp2 particles via electrostatic interaction, with a high loading capacity of up to 45 % (w/w) and nearly 100 % loading efficiency. In addition, the release of ChMAP-28 depends on the pH and ionic strength of the release buffer. In the meantime, rAcSp2 particles not only effectively reduce the toxicity of ChMAP-28 to normal cells, but also significantly enhance its anti-tumor activity. Therefore, our rAcSp2 particles are a promising novel particulate drug carrier system for the delivery of peptide drugs with anti-tumor activity.

Role of ryanodine receptor cooperativity in Ca2+-wave-mediated triggered activity in cardiomyocytes.

Ca2+ waves are known to trigger delayed after-depolarizations that can cause malignant cardiac arrhythmias. However, modelling Ca2+ waves using physiologically realistic models has remained a major challenge. Existing models with low Ca2+ sensitivity of ryanodine receptors (RyRs) necessitate large release currents, leading to an unrealistically large Ca2+ transient amplitude incompatible with the experimental observations. Consequently, current physiologically detailed models of delayed after-depolarizations resort to unrealistic cell architectures to produce Ca2+ waves with a normal Ca2+ transient amplitude. Here, we address these challenges by incorporating RyR cooperativity into a physiologically detailed model with a realistic cell architecture. We represent RyR cooperativity phenomenologically through a Hill coefficient within the sigmoid function of RyR open probability. Simulations in permeabilized myocytes with high Ca2+ sensitivity reveal that a sufficiently large Hill coefficient is required for Ca2+ wave propagation via the fire-diffuse-fire mechanism. In intact myocytes, propagating Ca2+ waves can occur only within an intermediate Hill coefficient range. Within this range, the spark rate is neither too low, enabling Ca2+ wave propagation, nor too high, allowing for the maintenance of a high sarcoplasmic reticulum load during diastole of the action potential. Moreover, this model successfully replicates other experimentally observed manifestations of Ca2+-wave-mediated triggered activity, including phase 2 and phase 3 early after-depolarizations and high-frequency voltage-Ca2+ oscillations. These oscillations feature an elevated take-off potential with depolarization mediated by the L-type Ca2+ current. The model also sheds light on the roles of luminal gating of RyRs and the mobile buffer ATP in the genesis of these arrhythmogenic phenomena. KEY POINTS: Existing mathematical models of Ca2+ waves use an excessively large Ca2+-release current or unrealistic diffusive coupling between release units. Our physiologically realistic model, using a Hill coefficient in the ryanodine receptor (RyR) gating function to represent RyR cooperativity, addresses these limitations and generates organized Ca2+ waves at Hill coefficients ranging from ∼5 to 10, as opposed to the traditional value of 2. This range of Hill coefficients gives a spark rate neither too low, thereby enabling Ca2+ wave propagation, nor too high, allowing for the maintenance of a high sarcoplasmic reticulum load during the plateau phase of the action potential. Additionally, the model generates Ca2+-wave-mediated phase 2 and phase 3 early after-depolarizations, and coupled membrane voltage with Ca2+ oscillations mediated by the L-type Ca2+ current. This study suggests that pharmacologically targeting RyR cooperativity could be a promising strategy for treating cardiac arrhythmias linked to Ca2+-wave-mediated triggered activity.

Computer Vision-Based Research on the Mechanism of Stick–Slip Vibration Suppression and Wear Reduction in Water-Lubricated Rubber Bearing by Surface Texture

Water-lubricated rubber bearings are a critical component of the propulsion systems in underwater vehicles. Particularly under conditions of low speed and high load, friction-induced vibration and wear often occur. Surface texturing technology has been proven to improve lubrication performance and reduce friction and wear; however, research on how different texture parameters affect friction-induced vibration and wear mechanisms remains insufficient. In this study, various texture patterns with different area ratios and aspect ratios were designed on the surface of water-lubricated rubber bearings. By combining these designs with an in situ observation system based on computer vision technology, the effects of texture parameters on bearing friction, vibration, and wear were thoroughly investigated. The experimental results show that surface textures play a critical role in improving hydrodynamic effects and stabilizing the lubrication film at the friction interface. Specifically, textures with a high area ratio (15%) and aspect ratio (3:1) exhibited the best vibration suppression effect, primarily due to the reduction in actual contact area. However, excessively high area ratios may lead to increased surface wear. This study concludes that a reasonable selection of texture area and aspect ratios can significantly reduce frictional force fluctuations and vibration amplitude, minimize surface wear, and extend bearing life.

Enhanced Dielectric Properties and Antibacterial Activity of Natural Rubber by Modification with Poly(Acrylic Acid-Co-Acrylamide) Incorporating Silver Nanoparticles and Titanium Dioxide.

This work aims to enhance natural rubber's dielectric properties and antibacterial activity by incorporating silver nanoparticles and titanium dioxide. Deproteinized natural rubber (DPNR) was modified through the graft copolymerization of acrylic acid and acrylamide using N', N'-Methylenebisacrylamide as a crosslinking agent, resulting in poly(acrylic acid-co-acrylamide)-modified, deproteinized natural rubber (MDPNR). This modification facilitated coordination with silver ions and interaction with titanium dioxide. Silver nanoparticles were generated under heat and pressure. Modified natural rubber composites containing silver nanoparticles and titanium dioxide (MDPNR/Ag-TiO2) were prepared. Scanning electron microscopy (SEM) revealed well-distributed silver in the modified natural rubber matrix, while agglomeration of titanium dioxide was observed at a high loading. Both MDPNR and MDPNR/Ag-TiO2 showed high thermal stability compared to DPNR. The MDPNR/Ag-TiO2 composites exhibited higher Tg and lower tan δ, indicating higher stiffness due to the restriction of chain movement compared to that in MDPNR. DPNR exhibited a low dielectric constant, enhanced by poly(acrylic acid-co-acrylamide) modification and silver nanoparticle/titanium dioxide incorporation. Incorporating 0.5 phr of AgNO3 and 2.5 phr of TiO2 in the composites increased the dielectric constant by 1.33 times compared to that of MDPNR. MDPNR showed no antibacterial activity, while the MDPNR/Ag-TiO2 composites exhibited promising antibacterial activity against Staphylococcus aureus and Escherichia coli.

Sexual Victimization Among Gay and Bisexual Emerging Adult Men: Multivariate Differences in Substance Use, Minority Stress and Relationship Characteristics

ABSTRACT This study documented between-group differences in factors associated with lifetime sexual victimization in a sample of young sexual minority men. Diverse samples of gay (N = 205, ageM = 24.33 years) and bisexual (N = 201, ageM = 23.31 years) men were recruited using the CloudResearch platform to assess recent experiences of intimate partner violence (IPV). Participants were categorized into four groups, cross-classified by dichotomous self-reports of (a) childhood sexual abuse (CSA) and (b) sexual IPV. Principal components analysis was used to reduce the number of variables associated with sexual IPV in three domains: Past-year substance use involvement, minority stress, and relationship characteristics, separately for each sample. Gay men reporting both CSA and sexual IPV reported significantly higher mean factor scores for a principal component with high loadings for recent substance use, daily discrimination, relational aggression and relational victimization, compared to other groups of gay men. Bisexual men who experienced sexual IPV reported significantly higher mean factor scores for a principal component with high loadings for five measures of minority stress, compared to counterparts with no history of sexual victimization. Adult sexual IPV among gay men reporting CSA appears to occur in conditions that include harmful substance use, daily discrimination experiences, and relationship violence. Sexual IPV among bisexual men is associated with multiple minority stressors. Our findings highlighted different patterns of risk factors for sexual IPV among sexual minority men, providing information for tailored risk reduction initiatives, including the need for trauma-informed services and specialized training for service providers.

Graphitic nanotubes confined with Ni nanocrystals: Artificial armor for ammonium polyphosphate towards fire-safe epoxy composite

With the ever-growing usages of epoxy resin (EP) in versatile aspects, its high fire hazard comes to prominence. How to improve the flame retardancy of EP at the least cost has been hotspot. In this context, we have constructed an artificial armor, namely N doped graphitic nanotubes confined with nickel nanoparticles (NGNTs@Ni), on the surface of ammonium polyphosphate (APP). Here, the ratios of NGNTs@Ni and APP are fixed at 1:9, 2:8, 3:7, acquiring the flame retardants of 1NGNTs@Ni/9APP, 2NGNTs@Ni/8APP, 3NGNTs@Ni/7APP. Compared with APP, 1NGNTs@Ni/9APP induces the superior inhibitions in heat, smoke and toxic gas releases. Concretely, the using of 15 wt% APP leads to reductions of 65.1 %, 22.8 %, 57.7 %, 40.1 % in peak heat release rate (PHRR), peak CO production rate (PCOPR), peak CO2 production rate (PCO2PR), peak smoke production rate (PSPR). By using 10 wt% 1NGNTs@Ni/9APP, the reductions in PHRR, PCOPR, PCO2PR, PSPR reach 75.6 %, 49.2 %, 70.4 %, 60.4 %. As anticipated, the high loading of APP triggers the decreases in mechanical properties while the using of modified APP results in the promotion in mechanical performances. In short, this work can provide inspirations for the facile design of APP based flame retardant, reducing its dosage and improving its flame retardation efficiency.

In-vivo stress measurements in kitesurfing and wakeboarding: implications on load control and preventive approaches - an in-vivo field study.

The trend sports kitesurfing and wakeboarding are increasingly gaining popularity. Tricks and high jumps - both in the air and over obstacles - are performed with increasing difficulty. Repeated high loads on the body, particularly when landing after a jump, can lead to overuse and acute injuries directly related to peak forces, particularly in the lower extremities.There is a lack of detailed analyses of these forces resulting from wakeboarding or kitesurfing, although such data would be relevant for the analysis of injury mechanisms and the subsequent development of prevention strategies. This study is the first of its kind in which the loads on the lower extremity during wakeboarding and kitesurfing were subjected to in-vivo measurements during various maneuvers.Six wakeboarders and 12 kitesurfers (6 with loop bindings and 6 with fixed bindings) were investigated (mean age 33.1 ± 9.9 years). Jump height, hang time, acceleration, and the maximum vertical ground reaction force of both feet during takeoff and landing were recorded by means of sensor insoles (Moticon, Germany) on the feet of the athletes and simultaneously by a height and acceleration sensor (PIQ Sport Intelligence) on the board. A statistical analysis was performed.The data showed that wakeboarders were exposed to higher loads than kitesurfers, with significant differences occurring only between wakeboarders and kitesurfers with loop bindings and between kitesurfers with loop bindings and fixed bindings. High mean forces occurred during the landing of wakeboarders (rear foot 24.24 N/kg ± 8.82; front foot 20.33 N/kg ± 5.05) compared to kitesurfers with loop bindings (rear foot 12.09 N/kg ± 5.6; front foot 12.23 N/kg ± 4.92) as well as partially in kitesurfers with fixed shoe bindings (front foot 13.61 N/kg ± 5.92). Forces during lift-off were comparable in the rear foot (wakeboarders, kitesurfers with fixed bindings, kitesurfers with loop bindings 14.17 ± 6.37 vs. 16.39 ± 4.99 vs. 14.72 ± 5.13 N/kg). Similarly, despite the higher average acceleration force of the wakeboarders (4.16 g ± 1.02), there was no statistically significant difference (p = 0.166) compared to the kitesurfers.The in-vivo forces acting on the lower extremities during wakeboarding and kitesurfing are high (highest absolute values of 3012 N and relative values of 31.71 N/Kg). In addition, fixed boot bindings allow for the generation of higher forces than strap bindings. The results of our study have important implications on load control and preventive approaches in these two sports.

Self-Exfoliated Guanidinium Covalent Organic Nanosheets as High-Capacity Curcumin Carrier.

Drug administration is commonly used to treat chronic wounds but faces challenges such as poor bioavailability, instability, and uncontrollable release. Existing drug delivery platforms are limited by chemical instability, poor functionality, complex synthesis, and toxic by-products. Presently, research efforts are focused on developing novel drug carriers to enhance drug efficacy. Guanidinium Covalent Organic Nanosheets (gCONs) offer promising alternatives due to their high porosity, surface area, loading capacity, and ability to provide controlled, sustained, and target-specific drug delivery. Herein, we successfully synthesized self-exfoliated gCONs using a Schiff base condensation reaction and embedded curcumin (CUR), a polyphenolic pleiotropic drug with antioxidant and anti-inflammatory properties, via the wet impregnation method. The BET porosimeter exhibited the filling of gCON pores with CUR. Morphological investigations revealed the formation of sheet-like structures in gCON. Culturing human dermal fibroblasts (hDFs) on gCON demonstrated cytocompatibility even at a concentration as high as 1000 µg/mL. Drug release studies demonstrated a controlled and sustained release of CUR over an extended period of 5 days, facilitated by the high loading capacity of gCON. Furthermore, the inherent antioxidant and anti-inflammatory properties of CUR were preserved after loading into the gCON, underscoring the potential of CUR-loaded gCON formulation for effective therapeutic applications. Conclusively, this study provides fundamental information relevant to the performance of gCONs as a drug delivery system and the synergistic effect of CUR and CONs addressing issues like drug bioavailability and instability.

Principal Component Analysis of Morphometric Traits of Tripura Desi Cattle

Background: In 234 cows of Tripura desi cattle from three districts, 18 different biometric traits were measured and analyzed by PCA to explain body conformation. These traits included body length, height at withers, heart girth, paunch girth etc. The native cattle in Tripura are of a smaller breed, according to the average of these several traits. Methods: Six factors that accounted for roughly 75.67% of the variation overall were found using factor analysis with promax rotation. Explaining 26.07% of the total variation, factor 1 characterized the overall body structure. The measurements of tail length, shank length, heart girth, paunch girth, circumference of horn and horn length were significantly positive with high loadings. Result: The outcome indicates that a significant decrease in the number of biometric parameters required to record in order to explain body conformation could lead to the application of principal component analysis (PCA) in breeding programmes. As a result, the study will support conservation efforts and the stabilization of this non-descript breed of cow.

Evaluating the impact of post-processing on the wear and friction properties of polyamide 6 carbon fiber composites produced by fused deposition modeling

The current research addresses the challenges encountered in polyamide 6 carbon fiber composites synthesized by fused deposition modeling. It specifically investigates issues such as inadequate interlaminar bonding and increased void content compared to conventionally manufactured composite components and as-built printed parts. The study focuses on printing pin samples via fused deposition modeling and explores various thermal post-processing methods to reduce void content while preserving dimensional accuracy. To evaluate wear and friction behavior, a pin-on-disc tester was used to test both as-built samples and samples post-heat-treated at 70 °C, 140 °C, and 210 °C. The results indicate that as the applied load increases from 5 to 20 N, both wear rates and friction coefficients increase across all speeds (1–5 m/s). Heating the samples to 70 °C and 140 °C strengthens the interlayer bonding. This significantly improves the maximum wear rates and friction coefficients compared to the as-built samples. However, samples heated to 210 °C do not show much of a change in wear rates or friction coefficients. Samples heated to 210 °C exhibit a decrease in wear rate of 16.87%, 15.82%, and 15.73% for loads ranging from 5 to 20 N, at speeds of 1, 3, and 5 m/s, respectively. This is likely due to pores sealing off and structures binding tightly. The worn surfaces were analyzed using a scanning electron microscope and measured the Shore D hardness of the samples before and after wear testing and documented the results for further analysis. In a scanning electron microscope, samples treated at 210 °C displayed smoother, less worn surfaces. Shore D hardness tests revealed a slightly higher hardness in samples heated to higher temperatures, followed by higher loads and sliding speeds in tribometer tests. This showed that the material was more stable. These post-processing methods significantly advance the development of functional composite elements for superior structural or dynamic performance.

Biotinylated platinum(IV)-conjugated graphene oxide nanoparticles for targeted chemo-photothermal combination therapy in breast cancer

Graphene oxide (GO) and GO-based nanocomposites are promising in drug delivery and photothermal therapy due to their exceptional near-infrared optical absorption and high specific surface area. In this study, we have effectively conjugated an oxaliplatin (IV) prodrug, PEGylated graphene oxide, and PEGylated biotin (PB) in a single platform for breast cancer treatment. This platform demonstrates promising prospects for targeted drug delivery and the synergistic application of photothermal-chemotherapy when exposed to NIR-laser irradiation. The resulting nanocomposite (GO(OX)PB (1/1/0.2) NPs) displayed an exceptionally large surface area, minimal particle size (195.7 nm), specific targeting capabilities, a high drug load capacity (43.56 %) and entrapment efficiency (89.48 %) and exhibit excellent photothermal conversion efficiency and photostability when exposed to NIR-laser irradiation (808 nm). The therapeutic effectiveness was assessed both in vitro and in vivo conditions employing human breast cancer cells (MCF-7), mouse mammary gland adenocarcinoma cells (4T1), and 4T1-Luc tumor-bearing mouse models. The findings demonstrated that GO(OX)PB (1/1/0.2) NPs (+L) were highly effective in causing significant cytotoxicity, G2/M phase cell cycle arrest, ROS generation, mitochondrial membrane depolarization, apoptosis, and photothermal effect. This resulted in a greater percentage of cell death compared to free OX, GO(OX)PEG (1/1/0.2) NPs (±L), and GO(OX)PB (1/1/0.2) NPs (−L). The in vivo therapeutic studies on 4T1-Luc tumor-bearing mice revealed that a combination of GO(OX)PB (1/1/0.2) NPs (+L) caused complete disappearance of the tumor, no tumor recurrence, prolonged survival, reduced lung metastasis, and mitigated nephrotoxicity. The serum and blood analysis demonstrated minimal systemic toxicity of GO(OX)PB (1/1/0.2) NPs. The developed nanoplatform, in this context, may serve as a potential nanomedicine to address conventional nephrotoxicity in breast cancer and prevent metastasis by combining chemo-photothermal therapy.

Setting Standards in Residential Aged Care: Identifying Achievable Benchmarks of Care for Long-term Aged Care Services.

Benchmarks are an important aspect of quality measurement and evaluation of long-term care services (LTCS) performance. In this study, we aimed to estimate achievable benchmarks of care (ABC©) for 12 quality indicators used to monitor quality of care in Australian LTCS and to identify LTCS characteristics associated with attaining the estimated ABC. A cross-sectional study was conducted using integrated population-based datasets from long-term care, health care, and social welfare sectors within the Registry of Senior Australians (ROSA) National Historical Cohort. All LTCS residents in 2019 were included. Twelve risk-adjusted quality indicators were examined. ABC were defined as the performance level of top-ranked LTCS, including those sequentially from rank 1 onward, until the combined number of residents included at least 10% of all residents nationally. Indicator-specific ABC for 2019 were estimated using Bayesian-adjusted performance fraction ranking. Logistic regressions estimated LCTS characteristics associated with ABC attainment. 2746 LTCS and 244,419 residents (≥65 years) between 01/01/2019 and 31/12/2019 were included. The cohort was mostly female (65%), with a median age of 86 years, and 56% had dementia. The ABC provide performance targets based on the observed levels of top-performing LTCS. The ABC for premature mortality (0.007%), weight loss hospitalisations (0.1%), pressure injuries (0.2%), delirium and dementia hospitalisations (0.3%), and medication-related adverse events (0.4%) were lower than 1% and attained by 17-59% of LTCS. The ABC for fractures (1.3%), falls (4.0%), and emergency department presentations (5.1%) were between 1-5% and attained by 7-11% of LTCS. The ABC for antipsychotic use (10.7%), chronic opioid use (23.6%), high sedative load exposure (27.4%), and antibiotic use (47.8%) were between 10-50% and met by 6-7% of LTCS. Smaller LTCS and government-owned LTCS were more likely to achieve the ABC compared to medium, larger, private, and not-for-profit LTCS. This is the first national estimation of ABC for Australian LTCS, identifying real-world examples of LTCS with relatively better national performance. The ABC are realistic goals for LTCS improvement efforts. They can be leveraged as national standards in quality monitoring reports and incentive programs. Smaller and government LTCS were generally more likely to attain ABC.

High‐Potential and Stable Organic Cathode for Rechargeable Batteries with Fast‐Charging and Wide‐Temperature Adaptability

AbstractOrganic carbonyl compounds have been recognized as promising electrodes due to multiple active sites, abundant element resources and flexible structural designability, while their practical applications are still hindered by the easy solubility and low discharge potential. Herein, a novel bipolar polymer composite (TAC) was well‐designed by grafting p‐type triphenylamine units onto n‐type anthraquinone to form an extended π‐conjugated structure and in situ growing on carbon nanotubes, which was proved not only with higher discharge potential but also effectively suppress the dissolution issues. Moreover, TAC combined the advantages of different active sites and behaved a dual‐ion storage mechanism. Benefitting from the in situ polymerization process, TAC with tube‐type core–shell structure exhibited enhanced electron transport and improved utilization of active sites, resulting in high capacity (193 mAh g−1), outstanding rate performance (fast charging within 17 s), long‐term stability (a high capacity retention of 87 % after 1000 cycles) and high mass loading (10 mg cm−2). Additionally, TAC can well adapt to the temperature change, outputting a capacity of 72 mAh g−1 at −60 °C and 165 mAh g−1 at 80 °C. Such versatile polymer structure inspires the design of high performance organic materials for rechargeable batteries to satisfy high stability and wide temperature operations.

Using phragmites australis biochar bio-augmented with actinomycetes for enhancing UASB reactor performance: A field study

Anaerobic processes are a cost-effective and sustainable method for wastewater treatment due to their lower energy demand and potential for biogas-high methane recovery. The up-flow anaerobic sludge blanket reactor system (UASB) is a commonly used technology. This study aimed to evaluate the performance of UASB reactors for handling the wash water from the buffalo shed, with a comparison of traditional UASB to UASB modified reactor by incorporation of immobilized biochar with and without bioaugmentation of a bacterial species with documented anaerobic capabilities. The investigation was conducted as a pilot project at the Suez Canal University Veterinary Experimental Farm in Ismailia, Egypt. Adding Streptomyces hydrogenans S11-immobilized Phragmites australis biochar to the USAB reactor increased removal efficiency, even at high influent loadings. The findings demonstrated that the traditional UASB reactor attained removal efficiency for COD, BOD5, TSS, TDS, color, and turbidity of 81.0 %, 75.0 %,80.0 %, 80.0 %, 70.0 %, and 70.0 % respectively, and biogas production of (0.025 mL biogas/mg COD removed).In comparison, the modified UASB reactor attained COD, BOD5, TSS, TDS, Color, and Turbidity removal efficiencies of 93.0 %, 91.5 %,90.3 %, 91.10 %, 85 %, and 80.0 %, respectively. The biogas production reached (0.037 mL biogas/mg COD removed). The removal efficiencies of the measured parameters were statistically analyzed, and this analysis indicated that the efficiency of the modified reactor was enhanced dramatically compared to the traditional system. Hence, this work demonstrates an efficient approach for treating buffalo wastewater.

Synthesis and evaluation of tribo-mechanical and corrosion properties of electroless Ni-P coating on AZ91D Mg alloy with stannate conversion underlayer

The work reports on synthesis and comprehensive evaluation of different properties of a bilayer protective coating on Mg alloy of AZ91D grade. Initially the alloy substrates were treated in stannate bath for 15, 30, 45, 60, 75 and 90 min for synthesizing an MgSnO3.3H2O layer. Electroless Ni-P was then deposited for 30 and 60 min, on the stannate layer synthesized for 60 min. A time-dependent cyclic growth behaviour was observed for stannate layers, characterized by formation and dissolution of MgSnO3.3H2O globules. The stannate coatings displayed polycrystalline structure. Hardness and scratch resistance were strongly influenced by uniformity of the coatings. While the uncoated alloy exhibited hardness of only 93 HV0.05, a remarkable improvement in hardness to 484 HV0.05 was obtained after 60 min of stannate treatment. High critical load of adhesion (Lc3) of 29 N was also obtained for the same. The stannate layers exhibited coefficient of friction (CoF) of 0.4–0.6 as compared to 0.7–0.8 for bare alloy. The wear loss also notably reduced. In tribo-test, hard and well-adherent coating restricted surface deformation under action of normal load. This in-turn, reduced mechanical engaging at interface, leading to low CoF and wear loss. The dense stannate coating also reduced corrosion rate by 19 times by hindering penetration of corrosive medium. Electroless deposition for 30 min on stannate conversion layer yielded only sporadic growth of Ni-P, which improved to a dense, uniform layer after 60 min of deposition. The Ni-P top coating aided the stannate underlayer in furthering the tribo-mechanical and corrosion characteristics.

Parts-Per-Million Level Loading Cyclometalated Ru(II)-NHC Catalyzed Selective Oxidation of Olefins to Carbonyls.

Oxidative cleavage of olefins is a useful reaction in organic synthesis. The most well-known catalytic system is the osmium based Lemieux-Johnson catalyst, which generally requires high catalyst loading and tends to suffer from rapid overoxidation to produce the acid predominantly. Hence, the development of a mild, general, and selective method toward the oxidative cleavage of alkenes to carbonyl compounds is highly desired. In this work, a highly efficient ruthenium-based catalyst for olefin oxidation has been demonstrated by employing a fused π-conjugated imidazo[1,5-a]quinoxaline (ImQx) based NHC ligand with bidentate C(carbanion) CNHC motif. Strong C-donor ligands, paired with a rigid backbone and ruthenium redox activity, provided exceptionally high catalytic activity and a long lifetime for olefin oxidation. Complex showed high catalytic activity and a long lifetime, TONs are several million. The catalyst tolerates numerous functional groups and can be applicable to challenging biomass, natural products, sugar, amino acids, and fatty acid-derived substrates. Based on kinetic studies, thermodynamic activation parameters, and DFT study, the mechanistic finding demonstrated that [3+2] cycloaddition reaction is the key step in the oxidation process. The use of the by-product NaIO3 in the catalytic efficiency has been disclosed for the first time.

Study on the effect of stress redistribution in different notched specimens of DD6 on the life of combined high and low cycle fatigue under high temperature

Under combined high and low cycle fatigue (CCF) loading, the multi-axial stress state induced by geometric discontinuities of different notch forms under the same stress amplitude can result in significant differences in fatigue performance of DD6 alloy. Therefore, it is of great importance to study the CCF behavior of Ni-base single-crystal alloy samples with differing notch geometries at the high temperatures. In order to obtain an approximate CCF lifespan, different stress amplitudes need to be applied to DD6 specimens with different notch forms. In this study, two kinds of notched DD6 plate specimens with [001] orientation were studied by CCF test at 760 °C, and the amplitudes of stresses were acquired under the same service life level. The effect of stress redistribution, in particular stress triaxiality, was evaluated on CCF lifetime of the DD6 specimens. A damage model with anisotropy considering stress triaxiality effect was suggested. The results indicated that the conventional stress–strain variables could not reflect the trend of CCF lifetime for different geometrical notched DD6 specimens, whereas the stress triaxiality at the CCF load peak could. A modified Basquin model was introduced for predicting CCF life according to the stress triaxiality at the peak loading. It can accurately and efficiently estimate the CCF life of two kinds of notched DD6 plate specimens, and the life prediction results fall within a scatter band of ±3 times of fatigue life.