Increase In Capacity Research Articles

Environmental performance and trends of the world's semiconductor foundry industry

AbstractThe semiconductor foundry industry faces the challenge of reducing its high environmental impact, mainly due to its energy‐ and water‐intensive processes and significant generation of waste. To date, no other study has focused on the assessment of the environmental performance and related historical trends of this industry as a whole. Methodologically, the first step was to analyze and process a large quantity of economic, production, and environmental data, available in the Corporate Social Responsibility reports of a companies’ sample, highly representative of the entire world's foundry industry (about 70% of the global revenue of the related sector). It was thus possible to calculate, using a common manufacturing index (MI) and after appropriate data processing, some key performance indicators, along a significant decade (2012–2021), marked by deep political, economic, and health crises. Some of the main findings of this study are that, over this 10‐year period, the increases in technological capacity (patents), wafer production, and revenue (400%, 183%, and 172%, respectively) are matched by a significant increase in hazardous waste generation per MI (20%; 239% in absolute value) and a much larger increase in general waste generation per MI (135%; 568% in absolute value). The indicators of energy, water, and revenue per MI are substantially unchanged. A substantial decrease occurs in GHG1&2 emissions per MI (−32%), mainly due to significant investments in renewable energy sources. The findings of this research could help and guide upcoming sustainability policy decisions and encourage business‐to‐business collaboration and the adoption of better environmental production practices.

Experimental and numerical characterization of screw elements used in twin-screw extrusion

Hot melt extrusion by a co-rotating twin screw extruder is an important process in the pharmaceutical industry. Especially for quality by design aspects, a comprehensive process understanding is indispensable. The performance of conveying elements was determined as critical process parameter, and therefore an experimental and numerical framework was developed to analyze and compare variations. A test rig capable of measuring volume flow, pressure and torque with high accuracy and precision was designed and built. The 3D simulation was performed using computational fluid dynamics (CFD). A stationary model with impulse transmission and an apparent motion of the screws was applied. The experimental data were fitted to the model of Pawlowski, and parameters for the pressure (A1, A2) and power characteristics (B1, B2) were determined. Good agreement between experimental data and the model was observed. The simulation was significantly faster compared to common methods, and the results were consistent with the literature. Systematic investigations of a native and worn screw were performed with CFD resulting in a transport capacity increase and a pressure build up decrease for all tested screw elements. An experimental and simulation setup was generated to assess the performance of co-rotating twin screw elements. The experiments provided high-quality data, and the simulations exhibited high flexibility with low computational effort.

Effects of Ellagic Acid Supplementation on Antioxidant Status and Symptom Improvement in Patients with Major Depressive Disorder: A Double-blind Randomized Clinical Trial

Background: Depression is one of the most common mood disorders and a major public health concern. Ellagic acid (EA), a type of polyphenol, acts as a strong hydrogen bond network as an electron receptor, enabling it to participate in various reactions. Objectives: Major depression is a critical medical condition that has emerged as a public health issue due to its high incidence, mortality, and suicide rates. One significant factor in the pathogenesis of depression is oxidative stress. This study aimed to evaluate the effects of ellagic acid supplementation on antioxidant status and symptom improvement in patients with major depressive disorder, considering the antioxidant capabilities of ellagic acid. Methods: A total of 40 patients diagnosed with major depressive disorder based on DSM-V criteria were assessed using the Beck Depression and Hamilton Depression Questionnaires. The dietary and caloric intake of the patients were monitored. Additionally, height and weight were measured, and patients with similar age, gender, and weight were matched. The individuals were randomly assigned to either the intervention group or the placebo group using a randomization table. The intervention group received a daily dose of 200 mg of ellagic acid in capsule form. The placebo group received a daily dose of one capsule containing 200 mg of wheat flour, identical in appearance to the intervention substance. The study period lasted for 8 weeks. Venous blood samples were collected before and after the study from all 40 individuals, and after serum separation, oxidative stress markers (malondialdehyde and total antioxidant capacity). were measured using a specific kit and ELISA method. Results: The study results showed a significant reduction in depression scores in the ellagic acid group during the study (P: 0.001)., with these alterations being significant when compared to the placebo group. In the ellagic acid group, a significant increase in total antioxidant capacity (P: 0.027). and a significant decrease in malondialdehyde levels (P: 0.014). were observed at the end of the study, and these changes were significant compared to the placebo group. In contrast, significant changes in total antioxidant capacity and malondialdehyde levels were not observed in the placebo group. Conclusions: The current study indicates that ellagic acid intervention may have a favorable effect on depression in patients with major depressive disorder. This is achieved by reducing BDI scores and serum levels of MDA, as well as increasing serum levels of TAC in these patients compared to the placebo group. However, further investigation is necessary to explore the mechanisms underlying the different alterations of ellagic acid in depression.

Optimal coordination of overcurrent relays in microgrids using meta-heuristic algorithms NSGA-II and harmony search

The emergence of distributed generation from renewable energy sources has led to the adoption microgrids as an alternative energy solution. However, implementing microgrids presents challenges, particularly in coordinating relay protection, due to factors like distributed generation sources, bidirectional power flow, variable short-circuit levels, and changes in network behavior. Although overcurrent relays (OCR) are frequently utilized in microgrid protection, a more adaptable strategy is needed as grid architectures transition from radial to non-radial. This paper proposes a new method to optimize the coordination of OCRs in microgrids by adjusting parameters like time multiplier settings (TMS), plug settings (PS), and characteristic curve selection. The study utilizes meta-heuristic techniques such as the harmony search algorithm (HSA) and the non-dominated sorting genetic algorithm-II (NSAGA-II) for optimal coordination. Simulations on a microgrid and bus test system demonstrate the effectiveness of the proposed approach in enhancing protection indicators like sensitivity, speed, selectivity, and reliability in microgrid operations. The results also indicate that the computation time of HSA is less than NSGA-II, but with an increase in DGs capacity, there is a continuous tendency to reduce the relay operation time.

Spatial variation in genomic signatures of local adaptation during the cane toad invasion of Australia.

Adaptive evolution can facilitate species' range expansions across environmentally heterogeneous landscapes. However, serial founder effects can limit the efficacy of selection, and the evolution of increased dispersal during range expansions may result in gene flow swamping local adaptation. Here, we study how genetic drift, gene flow and selection interact during the cane toad's (Rhinella marina) invasion across the heterogeneous landscape of Australia. Following its introduction in 1935, the cane toad colonised eastern Australia and established several stable range edges. The ongoing, more rapid range expansion in north-central Australia has occurred concomitant with an evolved increase in dispersal capacity. Using reduced representation genomic data of Australian cane toads from the expansion front and from two areas of their established range, we test the hypothesis that high gene flow constrains local adaptation at the expansion front relative to established areas. Genetic analyses indicate the three study areas are genetically distinct but show similar levels of allelic richness, heterozygosity and inbreeding. Markedly higher gene flow or recency of colonisation at the expansion front have likely hindered local adaptation at the time of sampling, as indicated by reduced slopes of genetic-environment associations (GEAs) estimated using a novel application of geographically weighted regression that accounts for allele surfing; GEA slopes are significantly steeper in established parts of the range. Our work bolsters evidence supporting adaptation of invasive species post-introduction and adds novel evidence for differing strengths of evolutionary forces among geographic areas with different invasion histories.

Impact of Intermittent Fasting and Dietary Restriction on Redox State, Energetic Metabolism, and Liver Injury in Common Bile Duct Ligation Model.

The aim of this work was to test whether we can treat cholestasis with dietary approaches applied after the onset of the disease. The effects of intermittent fasting and dietary restriction on liver damage caused by common bile duct ligation (BDL) in rats were studied, with particular attention paid to changes in the activity of enzymes of energy metabolism and antioxidant protection. Morphological changes in liver tissue and serum markers of liver damage were assessed in rats with BDL kept for one month on ad libitum diet, intermittent fasting, or 35% dietary restriction. We studied parameters of glucose metabolism (activity of glycolysis and gluconeogenesis enzymes), TCA cycle, and indicators of oxidative stress and redox status of the liver tissue. Dietary restriction resulted in an increase in gluconeogenesis activity, antioxidant capacity, and autophagy activation. When implemented after BDL, none of the dietary restriction protocols reduced the level of oxidative stress, detrimental morphological and biochemical alterations, or the fibrosis progression. Thus, under severe damage and oxidative stress developing in cholestasis, dietary restrictions are not hepatoprotective and can only be used in a pre-treatment mode.

Manajemen Koperasi Gema Nusa Gerakan Pemuda Ansor Kecamatan Cilongok Kabupaten Banyumas Tahun 2023

The aim of this research is to analyze the management of the Gema Nusa Cooperative in an effort to improve the welfare of its members and support local socio-religious organizations. The research method used is a qualitative approach with a case study design. Data collection was conducted through interviews, observations, and documentation studies. Data analysis includes three data processing flows, namely data reduction, data presentation, and conclusion drawing. Data validation uses data triangulation, which is a data collection technique that combines various existing data and sources. The results show that Gema Nusa Cooperative has implemented management functions quite well, but still has some weaknesses in terms of strategic planning and supervision. Therefore, Gema Nusa Cooperative needs to develop a comprehensive organizational strategic planning, develop an effective and efficient organizational structure, and apply the principles of good cooperative governance that includes a performance monitoring and evaluation system, performance feedback, and responsive and collaborative problem solving. Collectively, with the increase in management capacity, it is expected that Gema Nusa Cooperative can be more optimal in improving the welfare of its members.

Unraveling the intercorrelation between pseudo-graphitic phase and Li+/Na+ migration behavior in semicoke-based carbon anodes

Microstructural engineering is regarded as a promising option for fabricating high-performance carbon anodes. Hence, a facile solvothermal-assisted low-temperature calcination strategy was employed to modulate the microstructure of semicoke-derived carbon anodes. Owing to the effective pseudo-graphite phase modulation, the modified carbon anode exhibited a significant increase in capacity, cycling stability and ion kinetics in both lithium-ion batteries and sodium-ion batteries. Kinetic analysis and in-situ X-ray diffraction confirmed the “adsorption and intercalation” energy storage mechanism of the obtained carbon electrodes. In addition, by investigating the energy storage mechanism, we found that increasing the pseudo-graphite phase proportion played different roles in lithium and sodium ions storage. For lithium-ion storage, the pseudo-graphitic phase preferentially promotes lithium-ion transport kinetics. Conversely, during sodium-ion storage, this particular structure markedly augments the embedding capacity of sodium. Theoretical calculations demonstrate that different patterns of variation in the activation energy with the carbon layer spacing of lithium/sodium intercalation compounds lead to differences in performance enhancement. This study not only offers a low-cost approach for preparing carbon anodes enriched with a pseudo-graphitic phase, but also provides new insight into the discrepancy between lithium ion and sodium ion storage.

Ultra-efficient peroxymonosulfate utilization and trichloroethylene degradation in heterogeneous catalytic system guided by sheet-like Cu2MnO4 nanoparticles: The role of Cu(III)–O species and free radicals

Synthesizing cubic spinel Cu2MnO4 with nanosheet structure (SCMO) aimed to construct a “non-radical-mediated radical-oxidative reaction”, for increasing PMS utilization efficiency, and solving the defects of SO4•− and •OH through indirect PMS activation by electron transfer process. Compared with box-like Cu2MnO4 (11.1%, 0.0035 min−1) and ordinary Cu2MnO4 nanoparticles (21.3%, 0.0070 min−1), SCMO/PMS showed excellent trichloroethylene removal (98.8%, 0.1577 min−1). The pivotal role of Cu(III) was determined based on EPR analysis, quenching experiments, chemical probe experiments, hydrogen temperature-programmed reduction and Raman spectroscopy analysis, in-situ FTIR and Raman analyses. In brief, the interaction between PMS and SCMO could produce surface-bonded reactive complexes and the subsequent breaking of O–O bond in the sub-stable structure allowed the conversion of Cu(II) to Cu(III), which in turn facilitates the generation of •OH and SO4•−. The density functional theory (DFT) calculations provided supporting evidence for the electron donor role of SCMO and the increase of the electron acceptance capacity of PMS. SCMO/PMS system showed good resistance and degradation efficiency to complex composition and combined pollutants in actually contaminated groundwater, respectively. However, the coexistence of high concentrations of arsenic could significantly affect SCMO performance due to their adsorption on –OH groups, which still need in-depth study.

Theoretical prediction on Irida-graphene monolayer as promising anode material for lithium-ion batteries

With the growing interest in energy storage technologies, the demand for alternative rechargeable batteries has become increasingly urgent. We evaluate the feasibility of a two-dimensional (2D) material, Irida-graphene (IG) monolayer, as an anode for lithium-ion batteries (LIBs) through first-principles calculations. IG monolayer, after Li adsorption, exhibits metallic property, suggesting the good electrical conductivity. Additionally, in comparison with IG bilayer, IG monolayer possesses low diffusion barriers (0.19–0.24 eV), high theoretical capacity (1115.8mA h/g), and low average open circuit voltage (0.317 V). Furthermore, under the influence of solvent effects, the adsorption performance becomes even more stable, and the theoretical capacity increases. These intriguing findings make IG monolayer great potentials for the anode of LIBs.

Unraveling Mechanism for Microstructure Engineering toward High-Capacity Nickel-Rich Cathode Materials.

Microstructural engineering on nickel-rich layered oxide (NRLO) cathode materials is considered a promising approach to increase both the capacity and lifespan of lithium-ion batteries by introducing high valence-state elements. However, rational regulation on NRLO microstructures based on a deep understanding of its capacity enhancement mechanism remains challenging. Herein for the first time, it is demonstrated that an increase of 14mAhg-1 in reversible capacity at the first cycle can be achieved via tailoring the micro and nano structure of NRLO through introducing tungsten. Aberration-corrected scanning transmission electron microscopy (STEM) characterization reveals that the formation of a modified microstructure featured as coherent spinel twin boundaries. Theoretical modeling and electrochemical investigations further demonstrate that the capacity increase mechanism is related to such coherent spinel twin boundaries, which can lower the Li+ diffusion barrier and thus allow more Li+ to participate in deeper phase transitions. Meanwhile, the surface and grain boundaries of NRLOs are found to be modified by generating a dense and uniform LiWxOy phase, which further extends its cycle life by reducing side reactions with electrolytes. This work enables a comprehensive understanding of the capacity-increased mechanism and endows the remarkable potential of microstructural engineering for capacity- and lifespan-increased NRLOs.

Lactate promotes fatty acid oxidation by the tricarboxylic acid cycle and mitochondrial respiration in muscles of obese mice.

Lower oxidative capacity in skeletal muscles (SKMs) is a prevailing cause of metabolic diseases. Exercise not only enhances the fatty acid oxidation (FAO) capacity of SKMs but also increases lactate levels. Given that lactate may contribute to tricarboxylic acid cycle (TCA) flux and impact monocarboxylate transporter 1 in the SKMs, we hypothesize that lactate can influence glucose and fatty acid (FA) metabolism. To test this hypothesis, we investigated the mechanism underlying lactate-driven FAO regulation in the SKM of mice with diet-induced obesity (DIO). Lactate was administered to DIO mice immediately after exercise for over 3 wk. We found that increased lactate levels enhanced energy expenditure mediated by fat metabolism during exercise recovery and decreased triglyceride levels in DIO mice SKMs. To determine the lactate-specific effects without exercise, we administered lactate to mice on a high-fat diet (HFD) for 8 wk. Similar to our exercise conditions, lactate increased FAO, TCA cycle activity, and mitochondrial respiration in the SKMs of HFD-fed mice. In addition, under sufficient FA conditions, lactate increased uncoupling protein-3 abundance via the NADH-NAD+ shuttle. Conversely, ATP synthase abundance decreased in the SKMs of HFD mice. Taken together, our results suggest that lactate amplifies the adaptive increase in FAO capacity mediated by the TCA cycle and mitochondrial respiration in SKMs under sufficient FA abundance.NEW & NOTEWORTHY Lactate administration post-exercise promotes triglyceride content loss in skeletal muscles (SKMs) and reduced body weight. Lactate enhances fatty acid oxidation in the SKMs of high-fat diet (HFD)-fed mice due to enhanced mitochondrial oxygen consumption. In addition, lactate restores the malate-aspartate shuttle, which is reduced by a HFD, and activates the tricarboxylic acid cycle (TCA) cycle in SKMs. Interestingly, supraphysiological lactate facilitates uncoupling protein-3 expression through NADH/NAD+, which is enhanced under high-fat levels in SKMs.

Об элементных фундаментах опор высоковольтных линий

Purpose: to substantiate the possibility of using the foundations of supports of high-voltage lines in the form of dispersed horizontal elements combined into a single structure for the perception of alternating loads. To determine by experimental and computational methods the effect of the mutual displacement of elements in the form of an increase in the bearing capacity of foundations and a decrease in their deformations under the influence of pressing and pulling loads. To show the possibility of replacing slab foundations of supports of high-voltage lines with structures made of prefabricated elements to reduce the volume and weight of products transported from the factory. Methods: application of the moire photogrammetric method to assess the development of soil compaction zones and angular deformations of the soil base in a tray with a glass wall under models of slab and elemental foundations. Using the method of boundary integral equations to obtain the dependence of precipitation on the step of elements for flexible and rigid foundations. Results: the effect of mutual influence of foundation elements during their convergence and dispersal in the form of a change in the stress-strain state in their base is illustrated. Differences in the depths of the distribution of compaction zones and areas of development of angular deformations are revealed. Quantitative data on the precipitation of slab and elemental foundations and the influence of the depth of the roof of the solid underlying layer on them have been obtained. Graphical dependences of the relationship of sediment elements with the distance (step) between them are presented. The effect of the division of the foundation on the rate of extinction of marginal tangential stresses in the base is shown. An illustration is made of an increase in the volume and surface area of the bulging body of the elemental foundation, which leads to an increase in its bearing capacity compared to the slab one when calculating for pulling out. Practical importance: the effectiveness of the use of an element foundation in comparison with the paid option in reducing the parameters of the stress-strain state of the base and facilitating logistical tasks during construction is shown. The experimental and computational methods used can be recommended for further refinement of the parameters of the elemental foundations.

Capacity design assessment of composite reduced web section (RWS) connections

A gap in current design approaches demands explicitly introducing a capacity design approach when designing steel-concrete composite reduced web section (RWS) connections. This paper addresses this gap by presenting test-validated finite element models and parametric investigations, focusing on the presence and absence of composite action over the web opening, the diameter, and the end-distance of the web opening. Additionally, the first-ever comprehensive experimental and numerical database from the literature on bare steel and composite RWS connections is compiled and thoroughly analysed to develop the capacity design assessment for such connections. Both parametric investigations and the database highlight the significance of the capacity design ratio between the connected components in achieving a desirable ductile mechanism. This is crucial, as evidenced by the results: a 15 % increase in the connection's moment capacity led to an average 21 % difference in dissipated energy, favouring the web opening with a diameter of 50do over 80do, in RWS connections with the presence of composite action. The results show that proper consideration of the capacity design approach in designing RWS connections ensures a stable yield mechanism is developed, resulting in the redistribution of global action and capping deformation demands on non-ductile elements. This enhances connections' rotational capacity and ductility by forming the Vierendeel mechanism. Lastly, the paper presents a detailing recommendation for employing RWS connections in both existing and new structures for seismic purposes.

In-hospital areas with distinct maintenance and staff/patient traffic have specific microbiome profiles, functions, and resistomes.

Effective measures to combat antibiotic resistances and healthcare-associated infections are urgently needed, including optimization of microbial control. However, previous studies have indicated that stringent control can lead to an increase in the resistance capacities of microbiomes on surfaces. This study adds to previous knowledge by focusing on the conditions in a single hospital, resolving the microbiomes and their resistomes in three different confinement levels (CL): operating room, patient-related areas, and non-patient-related areas. We were able to identify stable key taxa; profiled the capacities of taxa, functions, and antimicrobial resistances (AMR); and reconstruct genomes and plasmids in each CL. Our results show that the most restrictive CL indeed had the highest functional diversity, but that resistances were mostly encoded on chromosomes, indicating a lower possibility of resistance spread. However, clever strategies are still required to strike a balance between microbial control and selective pressures in environments where patients need protection.

Low complexity equalization in coherent optical communication based on Fermat number transform.

In order to reduce the power consumption of digital signal processing (DSP) in a coherent optical communication system, a low complexity equalization scheme in DSP flow of a 400 Gb/s DP-16QAM system has been proposed. This scheme is based on Fermat number transform (FNT), which sequentially performs static equalization (SE) and dynamic equalization (DE) in the transform domain. For different distances, the proposed scheme finds the optimal solution under the condition that transform length and data bit width are mutually restricted under different transmission distances while achieving low complexity and optimal performance. The experimental results show that the adopted transform-domain equalization (TrDE) scheme has much lower computational complexity than the traditional frequency-domain equalization (FDE) and time-domain equalization (TDE) nearly without any performance loss. In the 80, 160, and 240 km scenarios, the number of multiplier is reduced by more than 72%, and the advantage becomes more obvious as the transmission capacity increases.

Synthesis and application of mesoporous MIL-88A for enhanced lipase immobilization and high value oil conversion

MIL-88A, a metal–organic framework (MOF), has significant promise for lipase immobilization due to its robust acid and water tolerance coupled with cost-effectiveness. Nonetheless, enhancing the dimensional compatibility of carrier with lipase and substrate is imperative for its broader application. In this study, we innovatively synthesized mesoporous MIL-88A (Meso-MIL-88A) with a fairly wide pore distribution around 10 nm using a soft-template method followed by a citrate dissociation strategy. The adsorption isotherm of Meso-MIL-88A conformed to the Langmuir model, exhibiting a notable increase in the adsorption capacity of lipase ET 2.0 compared to common MIL-88A (C-MIL-88A), attributed to the augmented external specific surface area (59 to 19 m2/g). Moreover, the immobilized lipase on Meso-MIL-88A showcased superior specific activity and enzyme activity recovery in contrast to C-MIL-88A, owing to enhanced structural preservation of lipase protein and reduced mass transfer resistance. Greater stability towards pH and temperature and better dynamic performance of immobilized lipase compared to free lipases exhibited the great advantages of Meso-MIL-88A as immobilized carrier. Notably, in the synthesis of phosphatidyl DHA (docosahexaenoic acid), immobilized CalB (Candida antarctica lipase B) on Meso-MIL-88A exhibited a 41.89 % incorporation of DHA into PC (phosphatidylcholine) within 48 h and an 82.60 % recovery after five batches of use. SEM observations confirmed the sustained integrity of the immobilized lipase structure post-recycling, underscoring the good stability of Meso-MIL-88A in the catalysis system. This study unveils the substantial potential of Meso-MIL-88A in lipase immobilization and offers a facile approach to tailoring the pore size of MOFs for practical application system.

The impact of electrical stimulation at the back-shu acupoint with an extrinsic diaphragmatic pacing mode on respiratory function and extubation success rate in tracheostomized stroke patients: An observational study.

To observe of the effect of electrical stimulation at the back-shu acupoint with extrinsic diaphragmatic pacing (EDP) mode on respiratory function and extubation success rate in tracheostomized stroke patients. A total of 200 patients who underwent tracheostomy after a stroke from January 2022 to February 2023 were included in this study. They were divided into 2 groups based on whether electroacupuncture was used: the EDP + electroacupuncture group and the EDP group. We assessed the differences in cough reflex scores and clinical lung infection scores between the 2 groups, and measured levels of blood gas analysis indicators, diaphragmatic function, lung function, maximum inspiratory pressure, and maximum expiratory pressure in both groups. The total effective rate in the EDP + electroacupuncture group was 91.00% (91/100), which was higher than the EDP group's 80.00% (80/100) (P < .05). After treatment, both groups showed a decrease in clinical lung infection scores and cough reflex scores compared to before treatment, with the EDP + electroacupuncture group having lower scores than the EDP group (P < .05). After treatment, the pH value, arterial oxygen pressure, and oxygenation index all increased compared to before treatment, with the EDP + electroacupuncture group showing higher values than the EDP group (P < .05). After treatment, both groups showed a decrease in arterial carbon dioxide pressure compared to before treatment, with the EDP + electroacupuncture group having lower PaCO2 levels than the EDP group (P < .05). After treatment, both groups showed an increase in forced vital capacity as a percentage of predicted value (FVC%), diaphragm thickness, diaphragm mobility, maximum inspiratory pressure, maximum expiratory pressure, forced expiratory volume in the first second as a percentage of predicted value (FEV1%), and diaphragm contraction speed compared to before treatment. Additionally, the EDP + electroacupuncture group had higher values in these parameters compared to the EDP group (P < .05). The EDP + electroacupuncture group had a shorter average extubation time and a higher extubation success rate compared to the EDP group (P < .05). The combination of EDP mode and electroacupuncture at the back-shu acupoint appears to be effective in improving lung function and diaphragmatic function in tracheostomized stroke patients. It also leads to a shorter extubation time and higher extubation success rates.

Bond Shear Tests to Evaluate Different CFRP Shear Strengthening Strategies for I-Shaped Concrete Cross-Sections.

I-shaped concrete girders are widely used in precast bridge and roof construction, making them a common structural component in existing infrastructure. Despite well-established strengthening techniques using various innovative materials, such as externally bonded carbon fibre reinforced polymer (CFRP) reinforcement, the shear strengthening of an I-shaped concrete girder is not straightforward. Several research studies have shown that externally bonded CFRP reinforcement might exhibit early debonding at the concave corners of the I-shape, resulting in a marginal increase in shear capacity. This research study aims to assess the performance of two different CFRP shear strengthening strategies for I-shaped concrete cross-sections. In the first strategy, CFRP was bonded along the I-shape of the cross-section with the provision of additional anchorage. In the second strategy, the I-shape was transformed into a rectangular shape by using in-fill blocks over which the CFRP was bonded in a U-configuration. In addition to the strengthening strategies, the investigated parameters included two different materials for the in-fill blocks (conventional and aerated concrete) and two different anchoring schemes (bolted steel plate anchor and CFRP spike anchor). To avoid testing on large-scale girders, a new test methodology has been implemented on concrete I-sections. The test results demonstrate the feasibility of comparing different shear strengthening configurations dedicated to I-sections. Among other findings, the results showed that the local transformation of the I-shape to an equivalent rectangular shape could be a viable solution, resulting in shear strength enhancement of 12% to 53% without and with the anchorages, respectively.

Enhanced performance of graphene-incorporated electrodes for solid-state lithium-sulfur batteries through facilitated ionic diffusion pathways

Significant progress has been achieved in advancing all-solid-state lithium-sulfur batteries through the development of sulfide solid electrolytes. Nonetheless, a challenge lies in creating a percolated ion–electron conduction path with intimate contact between charge carriers throughout the cathode which is crucial for enhancing overall efficiency and addressing issues related to slow kinetics and impedance during battery operation. This study introduces a framework elucidating how the integration of graphene enhances electrode performance by refining ionic diffusion pathways. An idealized ionic diffusion pathway characterized by a continuous ionic network, facilitating minimum diffusion distances, is proposed. Through a parametric study substituting portions of ionic and electronic conductive agents with graphene, the impact on total ionic and electronic conductivity of positive electrodes was comprehended. The findings underscore the critical role of optimum graphene content, which fills the gaps between ionic conductive materials and creates the shortest diffusion paths for ions and electrons. While incorporating graphene into cathode electrodes is not novel, it is noteworthy that graphene, as a mixed ion–electron conductive material, significantly enhances ion mobility due to its 2D structure, addressing a crucial aspect of cathode performance. Upon achieving optimum composite formulation, empirical findings demonstrate substantial performance improvement, including a 17.7% increase in initial capacity and a remarkable 21% enhancement in capacity retention compared to electrodes without graphene.