Effects Of Deterioration Research Articles

Behavior of steel tubed rubberized geopolymer concrete columns under axial compression: Experimental study and analytical modeling

Rubberized geopolymer concrete (RuG) has become increasingly popular due to its capability of sustainable utilization of resources, but the mechanical properties of RuG could deteriorate significantly with the increase of rubber content. To mitigate the adverse effects of rubber and further promote the engineering applications of eco-friendly building materials, a new type of composite column, i.e., steel tubed rubberized geopolymer concrete (ST-RuG) columns, was proposed and tested in this paper. The influence of concrete types, rubber replacement ratios, the configurations of steel tubes, and diameter-to-thickness ratios on the compressive behavior of specimens was analyzed. The test results show that the incorporation of rubber has a deterioration effect on the strength of ST-RuG columns with a maximum degradation of 37.6%, but it can improve the ductility of specimens to a certain extent, which is slightly superior to steel tubed rubberized ordinary concrete (ST-RuO) columns. Due to the inherent brittleness of geopolymer concrete (GPC), more obvious residual behavior is detected for ST-RuG compared with ST-RuO under the same rubber replacement ratio Rf. Moreover, with the increase of Rf, the confining pressure of ST-RuG specimens gradually decreases, and a significant decreasing trend is observed for both the peak stress ratio and residual strength ratio of confined RuG. Finally, a new stress-strain model considering the effect of rubber replacement ratio is developed, and comparisons with test results reveal that the proposed model possesses satisfactory accuracy in predicting the axial stress-strain curves of steel-confined GPC and RuG.

Effects of Faraday cup deterioration on Sr and Cr isotope analyses by thermal ionization mass spectrometry.

By comparing data from an extensive set of Sr and Cr isotope measurements performed on two different thermal ionization mass spectrometers (TIMS), using three sets of Faraday cups with different usage histories, we assess the effects of Faraday cup deterioration on high-precision isotope measurements by TIMS. We find that dynamic 84Sr/86Sr and 87Sr/86Sr measurements provide stable and reproducible results over the entire 56 months of this study, regardless of which set of Faraday cups is used. By contrast, static 84Sr/86Sr and 87Sr/86Sr measurements lead to deviant results, drifts over time, and in general exhibit larger scatter. For the most part, these differences can be attributed to changing Faraday cup efficiencies. For the instruments of this study we find that the center cup is most affected, consistent with this cup often receiving the highest ion beam intensities during measurements conducted in our laboratory. For Cr isotopes, we find that the correlation between mass fractionation-corrected 53Cr/52Cr and 54Cr/52Cr ratios observed for static measurements in several prior studies also reflects different Faraday cup efficiencies. Again, the changing efficiency of predominantly the center cup can account for the observed drift and correlation in 53Cr/52Cr and 54Cr/52Cr. Multi-static Cr isotope measurements reduce this drift, but still result in a residual correlation between the two ratios, suggesting this correlation in part also reflects unaccounted mass fractionation effects.

Evolutionary Multitasking Memetic Algorithm for Distributed Hybrid Flow-Shop Scheduling Problem With Deterioration Effect

Evolutionary Multitasking Memetic Algorithm for Distributed Hybrid Flow-Shop Scheduling Problem With Deterioration Effect

The Interplay between Disordered Sleep and Alzheimer’s Disease: Exploring the Bidirectional Relationship

The debilitating neurodegenerative condition referred to as Alzheimer’s Disease (AD), results in severe cognitive deterioration, including deficits in memory, confusion, and abnormal behaviour. Sleep plays a crucial role in sustaining cognitive health, as it supports brain repair and performs memory consolidation. Complaints of consistently disrupted sleeping habits, such as reduced quality and fragmented sleep, are increasingly recognized as potential risk factors for AD. The fundamental elements of healthy sleep: its structure, oscillations and benefits- then considering how changes in sleep architecture, including alterations in REM and NREM stages, are associated with cognitive decline. Another significant concept is the finding that sleep deprivation is often correlated with increased levels of amyloid beta (Aβ) and tau proteins in the brain, which are two biomarkers of AD pathology and accumulate with disease progression. This review examines the connection between unhealthy sleep patterns during aging and AD development, emphasizing the need for continued research into how improving sleep hygiene could potentially moderate the effects of cognitive deterioration.

Assessment of Natural Background Radiation Exposure in the Federal Capital Territory of Nigeria

The detrimental effects of environmental contamination and deterioration on health are a worldwide concern and Nigerian environmental and public authorities continue to be concerned about the risk to public health. The water, the sky, construction materials and the earth's crust all release natural background radiation that contaminates the environment around us. Additionally, people are exposed to background radiation that comes from internal, cosmic, and terrestrial sources, although, the altitude determines the amount of cosmic radiation exposure, and high altitudes result in large radiation doses. Monitoring the amounts of radiation to which humans are exposed, either directly or indirectly, requires an understanding of the natural background radiation in the environment. The current study attempted to create a baseline of outdoor background radiation in FCT for exposure rate, absorbed dose rate, annual effective dose equivalent, and excess life cancer risk. The study used a very sensitive survey meter to measure the BIR. The average BIR value found in the research areas is marginally below the 0.013mRh-1 global BIR level, indicating an almost high BIR level for the FCT while the absorbed dose rates of 105.85nGy/hr was greater than the 59nGy/hr global population weighted average gamma dose rates estimate. The obtained annual effective dosage equivalent value is greater than the global average normal annual effective dosage level for outdoor environments, and the excess lifetime cancer risk values were higher than the 0.29×10-3 allowable level as reported by UNSCEAR & ICRP. Therefore, the general people and those who live in environmentally sensitive areas may experience immediate health effects from contamination and radiation levels at the current rates.

Hardness determination by a semi-automatic testing system

The hardness testing is vital for metals for testing and production quality control. Hardness testing is a fine indicator to determine the mechanical characteristics of metals. The various types of hardness testing methods include Rockwell, Vicker, Brinell, and Knoop testing methods. The most prevalent manual method to determine hardness is indentation using dead weight technology. However, the said technology is quite ancient and it has its own limitations, like the kinetic effect applying excessive load at actual, man-to-man variations, variation over the period due to deterioration and friction effects of moving parts like lever, weight block hanger, etc. increases the uncertainty of this method and eventually demands for upgradation of the technology. Further, the methods currently in use are open-loop and manually operated testers. The main drawback of all these testers is that they provide zero feedback, and so the obtained result needs to be compared to the desired result. To overcome the above-stated problem, the paper presents some novel modifications for measuring hardness using existing methods of Rockwell, Vicker, and Brinell testing. Toward this objective, the paper proposes to modify existing testers and develop a semiautomatic hardness testing system. Firstly, for Rockwell testing, the work aims to design a closed-loop system for hardness testing. The proposed system comprises of Arduino as an open microcontroller, a load cell along with servo motor, and its driver to establish the desired closed loop. The need of obtaining a more accurate result, free from human interference gives rise to a closed-loop system for hardness testing. The key aspect of the closed-loop system lies in retaining the basic structure of the metal. Unlike traditional hardness tester, during testing, the weight increases gradually, due to which the basic structure of metal is not deformed. Secondly, the paper proposes a computational methodology that would estimate the Vickers and Brinell hardness value. The proposed system comprises of a camera for gathering hardness indentation images, thereby automating the system. Further, these images are analyzed based on image processing software, and the indentation depth is obtained. The proposed work thus replaces human intervention to calculate the hardness of the material. The results obtained based on the proposed systems provide a proof of concept to address the problems of traditional Rockwell, Vicker, and Brinell testing.

Supplementation of Saussurea costus root alleviates sodium nitrite-induced hepatorenal toxicity by modulating metabolic profile, inflammation, and apoptosis.

Sodium nitrite (NaNO2) is a widely used food ingredient, although excessive concentrations can pose potential health risks. In the present study, we evaluated the deterioration effects of NaNO2 additives on hematology, metabolic profile, liver function, and kidney function of male Wistar rats. We further explored the therapeutic potential of supplementation with S. costus root ethanolic extract (SCREE) to improve NaNO2-induced hepatorenal toxicity. In this regard, 65 adult male rats were divided into eight groups; Group 1: control, Groups 2, 3, and 4 received SCREE in 200, 400, and 600mg/kg body weight, respectively, Group 5: NaNO2 (6.5mg/kg body weight), Groups 6, 7 and 8 received NaNO2 (6.5mg/kg body weight) in combination with SCREE (200, 400, and 600mg/kg body weight), respectively. Our results revealed that the NaNO2-treated group shows a significant change in deterioration in body and organ weights, hematological parameters, lipid profile, and hepatorenal dysfunction, as well as immunohistochemical and histopathological alterations. Furthermore, the NaNO2-treated group demonstrated a considerable increase in the expression of TNF-α cytokine and tumor suppressor gene P53 in the kidney and liver, while a significant reduction was detected in the anti-inflammatory cytokine IL-4 and the apoptosis suppressor gene BCL-2, compared to the control group. Interestingly, SCREE administration demonstrated the ability to significantly alleviate the toxic effects of NaNO2 and improve liver function in a dose-dependent manner, including hematological parameters, lipid profile, and modulation of histopathological architecture. Additionally, SCREE exhibited the ability to modulate the expression levels of inflammatory cytokines and apoptotic genes in the liver and kidney. The phytochemical analysis revealed a wide set of primary metabolites in SCREE, including phenolics, flavonoids, vitamins, alkaloids, saponins and tannins, while the untargeted UPLC/T-TOF-MS/MS analysis identified 183 metabolites in both positive and negative ionization modes. Together, our findings establish the potential of SCREE in mitigating the toxic effects of NaNO2 by modulating metabolic, inflammatory, and apoptosis. Together, this study underscores the promise of SCREE as a potential natural food detoxifying additive to counteract the harmful impacts of sodium nitrite.

Optimizing pricing and promotions for sustained profitability in declining markets: A Green-Centric inventory model

<abstract><p>In the face of a competitive and ever-changing business landscape, companies often grapple with the challenge of sustaining their products in declining markets. To combat this issue, effective strategies such as promotional efforts play a pivotal role in boosting demand and maintaining market position. Additionally, businesses are increasingly focusing on ecological safety and greening efforts to minimize their environmental impact while ensuring the production of environmentally friendly products. These green initiatives not only contribute to environmental sustainability but can also enhance retailer profitability. This article presents an innovative inventory model tailored for perishable products within a stochastic environment. The model integrates elements such as linear pricing, time dynamics, promotional efforts, and a demand rate that depends non-linearly on the level of greening efforts. The model also considers partial backlogging of shortages, lost sales, time-dependent product deterioration, and investments in preservation technology to mitigate deterioration effects. The primary objective is to calculate the retailer's profit function, taking into account cycle time, selling price, promotional effort, and greening effort as key variables. To address this complex problem, the article introduces an algorithm for finding feasible solutions. Furthermore, the concavity of these solutions is demonstrated through graphical analysis. A numerical example is provided to illustrate the application of the model, and sensitivity analysis is conducted to elucidate how changes in inventory parameters impact decision variables. We will also depicted the short representation of proposed study in <xref ref-type="fig" rid="Figure1">Figure 1</xref>.</p> </abstract>

Effects of Fish Skin Gelatin Hydrolysates Treated with Alcalase and Savinase on Frozen Dough and Bread Quality.

Fish skin gelatin, as a waste product of sea bream, was used to obtain fish gelatin hydrolysate (FGH) with the treatment of alcalase (alc) and savinase (sav). The functional properties of FGHs and their usage possibilities in frozen dough bread making were investigated. FGH treated with alc showed a higher emulsifying stability index (189 min), while FGH treated with sav showed greater foaming capacity (27.8%) and fat-binding capacity (1.84 mL/g). Bread doughs were produced using two FGHs (alc and sav) and their combination (FGH-alc + FGH-sav). Using FGH treated with these enzymes individually was more effective than their combination in terms of polyacrylamide gel electrophoresis (SDS-PAGE) results and bread quality (specific volume and hardness). The addition of FGH into bread dough showed no significant effect on bread dough viscoelasticity (tan δ), while the increment level of tan δ value for control dough was higher than the dough containing FGH after frozen storage (-30 °C for 30 days). The highest freezable water content (FW%) was found in control dough (33.9%) (p < 0.05). The highest specific volume was obtained for control fresh bread and bread with FGH-alc, while the lowest volume was obtained for fresh bread containing FGH-sav (p < 0.05). After frozen storage of the doughs, the bread with FGH-alc showed the highest specific volume. FGH addition caused a significant reduction in the L* (lightness) value of fresh bread samples when compared to control bread (p < 0.05). This study suggested that usage of FGH-alc in bread making decreased the deterioration effect of frozen storage in terms of the specific volume and hardness of bread.

Investigating the Mechanical Deterioration Effect of Hard Sandstone Induced by Layer Structure under Uniaxial Compression

The deterioration of the surrounding rock at the tunnel bottom is a damage mechanics issue that occurs under disturbance load. To investigate the anisotropic characteristics of mechanical behavior and the AE response mechanism of layered sandstone, uniaxial compression tests and acoustic emission (AE) monitoring were conducted. The results show that the layer structure causes remarkable anisotropic characteristics in the wave velocities. The strain characteristics and mechanical parameters of layered sandstone exhibit obvious deterioration effects. The local strain and overall strain show a synergistic feature, with the local strain path being more complex and the deformation response being extremely sensitive. The peak stress and elastic modulus both exhibit V-type distribution rules, slowly decreasing first, then rapidly decreasing, and finally increasing rapidly, with the boundary points of the layer angle being 45° and 67.50°. The peak stress and elastic modulus show a nonlinear exponential correlation with the layer angle, and the sandstone belongs to the intermediate anisotropy level. The rupture pattern shows significant anisotropic characteristics, with the failure modes including tension failure, including tension failure I and tension failure Ⅱ, shear failure, and tension–shear composite failure. The fractal dimension shows a negative correlation with the layer deterioration effect. The AE activity exhibits a phased response characteristic to the aging deformation of layer structure. The more obvious the layer deterioration effect is, the longer the AE delay is. The AE intensity of tensile failure sandstone is generally greater than that of oblique shear failure.

A Comprehensive Review of Aging Models in Lithium-Ion Batteries

Lithium-ion batteries degrade over time with usage, and it's improbable that the effects of aging-related deterioration can be entirely eradicated. The processes responsible for the aging of these batteries are intricate and varied, closely linked to a range of interacting factors such as battery types, chemical reactions, and operational circumstances. Elements like charge level, charging and discharging speed, cycles, and temperature have a direct impact on degradation, underscoring the significance of operational conditions and stressors. The challenge of battery aging presents a substantial area of research, influencing the energy and power capacity of batteries as time progresses. This piece presents a comprehensive examination of various methods for simulating battery aging and investigations carried out on this subject, with a specific emphasis on indicators employed to gauge the well-being of batteries. The objective of this review is to succinctly outline the outcomes of prediction techniques for the aging of lithium-ion batteries in diverse applications. Given the extensive array of studies focused on battery aging, a wealth of knowledge is available in this domain, and consequently, this article offers an overview of these varied approaches.

Deconvoluting the Impact of Early-Life Abuse Conditions on the Cyclic Degradation of Lithium-Ion Cells

The successful repurposing of degraded lithium-ion (Li-ion) batteries in second-life applications is a vital step towards achieving a circular economy. While reusing aged Li-cells is a promising way of mitigating their overall environmental footprint, it is crucial to anticipate their future safety and performance characteristics. Unfortunately, predicting these properties is a cumbersome task, essentially caused by limited knowledge of the interference of different degradation modes in the cells’ first life.To still enable estimating of these parameters from a current state, the present study systematically investigates the impact of abusive conditions in an early phase of the cells’ life on their subsequent degradation behavior. For this purpose, individual Li-cells are initially stressed by different measures such as overcharging, deep-discharging, plating, and deliberate combinations of the aforementioned methods. Electrochemical performance indicators are monitored during subsequent cycling of the cells which provides insights into the interdependencies of different degradation modes induced by specific stress conditions. In this manner, it is clarified whether or not the total degradation can be determined by a convolution or a superposition of individual deterioration effects and, thus, be described as a multidimensional state function.This knowledge will finally contribute to a better understanding of the performance and safety behavior of degraded Li-ion batteries which can help to successfully implement them into second-life applications.

Mechanical properties and damage modeling of unloaded marble under freezing and thawing with different temperature ranges

The seasonal freeze-thaw environment is a primary factor contributing to the deterioration of manually excavated disturbed rock masses on reservoir bank slopes in highland alpine areas. To investigate the mechanical properties and damage deterioration mechanism of excavation-unloading rock under seasonal freeze-thaw environment in cold region, the freeze-thaw cycle tests with different temperature difference levels (−10–10 °C, −15–25 °C, −20–40 °C) and different cycle times (0,10,20,30) were simulated for the triaxial unloading damaged marble. Then, the mechanical parameters of unloaded marble after freezing and thawing were obtained by uniaxial compression and triaxial compression tests, and the influence laws of temperature ranges, number of freezing and thawing cycles and confining pressure on the mechanical properties of unloaded marble were analyzed. Finally, the damage model of unloaded marble considering freeze-thaw action was established. The results show that the strength of unloaded marble is significantly weakened under the combined effect of F-T (freezing and thawing) and loading, and that the deterioration effect of the number of F-T cycles is stronger than that of the temperature ranges. The increase in the confining pressure increased the compressive strength and elastic modulus of the unloaded marble, and suppressed the damage of the unloaded marble after the freeze-thaw treatment. The porosity of the unloaded marble developed gradually and increased exponentially with the increase of the number of freeze-thaw cycles, the compressive strength and elastic modulus had a negative exponential relationship with the number of freeze-thaw cycles, and the shear strength parameter had a quadratic polynomial relationship with the number of freeze-thaw cycles. In addition, the softening mechanism of unloaded marble by natural water plays a key role in the process of freeze-thaw cycle, and the damage model considering freeze-thaw is established, and the theoretical curves are well matched with the experimental results. The outcomes of this study hold significant theoretical and engineering importance for evaluating the stability of excavated unloaded rock in highland alpine regions.

Numerical simulation method and deterioration analysis of load-bearing performance of tunnel linings containing cold joints in plain concrete

Cracking in tunnel linings is a common issue in tunnel engineering, with the main cause being construction-induced defects. As a construction-induced defect in a lining, a cold joint affects the bearing capacity of the lining, and the effect of cold joints on the bearing performance deterioration of linings remains unclear. In this study, 180 high-speed railroad tunnels built in Grade III surrounding rock areas were investigated to determine their degradation states, and the distribution of lining cracks in these tunnels was explored on the basis of different factors. Subsequently, three-point bending experiments were conducted on concrete components with different pouring interval cold joint. Based on the experimental results, a computational unit applicable to cold joint simulation was proposed, and the unit parameters were inverted. Finally, the unit was applied to establish a tunnel model with cold joints and to analyze the deterioration effect of cold joints on the bearing performance of the lining. The cracks caused by cold joints in the lining of a structure were found to extend perpendicular to the lining surface, and this can greatly affect the overall strength of the structure. It's important to consider the impact of cold joints on the lining. In order to simulate these cold joints, cohesive elements were used to calculate the maximum stress and stiffness degradation of the lining with and without cold joint elements. The results showed that there were only small differences, indicating that cohesive elements are effective for simulating cold joints. Two cracking patterns were identified, the dorsal tension misalignment model and the medial tension misalignment model, which are related to the stress state of the cold joints. It's necessary to pay attention to cold joints in the inner tensioned area of the lining and those that exceed the final setting time of concrete during pouring.

Analysis of static stiffness properties of column-architrave structures of ancient buildings under long term load-natural aging coupling

The column-architrave structures were widely used in the Yingxian wooden pagoda and pagoda has been in service for many years. Over time, it has been subjected to stress and the effects of natural aging. In order to analysis the ability of the structures to resist deformation under specific static excitation, a study of the static stiffness properties of column-architrave structures in ancient buildings considering long term load-natural aging coupling was carried out. Based on the Gerhards model, a strength degradation model has been developed for column elements and architrave elements, taking into account long-term loading and natural aging effects; By constructing a regular model and a realistic model, the deformation of the regular model under long term self weight load and the deformation of the realistic model under long term self weight load and aging are simulated by finite element model; The relationship between deformation values and static stiffness as a function of time is investigated through multiple points of the column-architrave structures, and the reliability of the proposed model is verified by extracting and comparing data from the automated real-time 3D monitoring system of the wooden pagoda. The results show that the numerical simulations of both models show that the middle of the architrave is more easily deformed than the mortise and tenon joint structures; The deformation resistance of the realistic model is lower than the deformation resistance of the regular model, and the natural aging effect has a non-negligible deterioration effect on the deformation of the column-architrave structures; For the column and architrave elements, they are likely to become unstable at 3330 AD and 3543 AD respectively, which means that after 1307 and 1520 years, the static stiffness of both elements tends to decrease with time in service, with the decrease in static stiffness of the architrave elements being less than that of the column elements.

Maternal antibiotic exposure enhances ILC2 activation in neonates via downregulation of IFN1 signaling

Microbiota have an important function in shaping and priming neonatal immunity, although the cellular and molecular mechanisms underlying these effects remain obscure. Here we report that prenatal antibiotic exposure causes significant elevation of group 2 innate lymphoid cells (ILC2s) in neonatal lungs, in both cell numbers and functionality. Downregulation of type 1 interferon signaling in ILC2s due to diminished production of microbiota-derived butyrate represents the underlying mechanism. Mice lacking butyrate receptor GPR41 (Gpr41-/-) or type 1 interferon receptor IFNAR1 (Ifnar1-/-) recapitulate the phenotype of neonatal ILC2s upon maternal antibiotic exposure. Furthermore, prenatal antibiotic exposure induces epigenetic changes in ILC2s and has a long-lasting deteriorative effect on allergic airway inflammation in adult offspring. Prenatal supplementation of butyrate ameliorates airway inflammation in adult mice born to antibiotic-exposed dams. These observations demonstrate an essential role for the microbiota in the control of type 2 innate immunity at the neonatal stage, which suggests a therapeutic window for treating asthma in early life.

Remanufacturing system scheduling of batch products with the consideration of dynamic changes in machine efficiency using an improved artificial bee colony algorithm

Remanufacturing has the ability to bring the quality and condition of the recycled product back to the level of or even better than the new product. As remanufacturing continues to receive more and more attention from industry and academia, the scheduling of remanufacturing systems (RMS) has been extensively studied. However, few studies have not only focused on the dynamic changes (deterioration and learning) in machine efficiency during RMS scheduling but also considered that the three subsystems (disassembly, reprocessing and reassembly) of RMS collaborate with each other during scheduling. Therefore, this study proposes a new RMS scheduling model of batch recycled products with the consideration of dynamic changes in machine efficiency for handling the batch recycled products. It considers not only the collaboration among the three subsystems comprehensively, but also the dynamic changes in machine efficiency, i.e., deterioration effects and learning effects, during the scheduling. To solve this model, an improved artificial bee colony algorithm with a new representation scheme and a new population generating method is proposed. The effectiveness and practicality of this algorithm are examined through simulation experiments and comparison with other baseline algorithms.

Liposomes-The 21st Century’s Drug Delivery System: Developments in the Last Two Decade

Liposomes have been thoroughly investigated and are utilized for various illnesses for the past few decades starting from its first discovery in 1961. Since then, therapeutic efficiency of liposomes is enhanced by increasing drug absorbance while fast deterioration and adverse effects are avoided or minimized. This will extend the biological halfway life. Liposomes are more attractive for usage as drug delivery carriers with all of these characteristics and versatility to modify their surface to create additional specific functionalities. In various phases of research, there are numerous new liposomal compositions that improve the therapeutic efficiency of new and old medicines used in pre-clinical and clinical studies. Current multimodal imaging advances aimed at better diagnosing and monitoring liposome therapies as diagnostic tools. Liposomes are major possibilities for medication delivery improvement. Recent researches show that the liposomes can be taken widely in cancer treatments. The primary properties of these structures include minimal toxicity, cytocompatibility, reduced clearance rates, tissue targeting and sustained drug release. Liposomes offer a variety of benefits as shown by approval of Doxil, as compared to traditional chemotherapy with free medication treatment. There are a multitude of liposomes depending on their size, lamellar number, shape and composition. Diagnostic, therapeutic, improved vaccination are covered by clinical use of these systems. Drug and gene delivery are two therapeutic aspects, where due to their unique characteristics liposomes might be beneficial. Several illnesses have been examined with respect to the participation of liposomes, with some good results. Cancer is a life-threatening disease. These structures have been examined in this respect, both in imaging and in chemotherapy. These investigations have resulted in different liposome compositions in different clinical stages. We take this great opportunity to present various surface functionalization strategies and bio-applications of liposomes developed during the last two decades covering the notable work published from 2011 to 2021 in this review. In addition, we provide opinions on the liposome industry, its commercial market and the prospective developments in the field of liposome technology. It is anticipated that this review will serve as a valuable resource, fostering interest and engagement among scientists worldwide in the field of liposome research.

Quantitative Analysis of Cu(II)-Induced Deterioration Effects on Barrier Performance of Soil-Bentonite Slurry

Quantitative Analysis of Cu(II)-Induced Deterioration Effects on Barrier Performance of Soil-Bentonite Slurry

One-way fluid structure interaction analysis of a static savonius hydrokinetic turbine under different velocity and surface roughness with different blade materials

Hydrokinetic turbines are prone to a harsh hydrodynamic environment with intricate vortical flows that elevate the probability of failure. The degradation of the blade surface caused by corrosion can impact the blade's hydrodynamic and the structural performance. This paper reports a one-way three-dimensional fluid-structure interaction simulation to analyse the performance of a static Savonius hydrokinetic turbine at varying rotor positions, with different surface roughness and water velocities, in terms of coefficients of static torque, static torque, stresses, and blade deformation. The simulations revealed that the optimum position for the highest coefficient of static torque was at 15° (Cst = 0.30) in reference to the water flow. Increasing the water velocity from 0.4 ms−1 to 0.84 ms−1 improved the turbine static torque due to an increase in the kinetic energy. However, the presence of surface roughness has deterioration effects on the static torque coefficient due to a delayed separation which causes a drag reduction. The simulation predicted no structural failure at 0.4 ms−1 and 0.84 ms−1, but varying materials exhibited varying maximum principal stress and deformation, highlighting the significance of the early development of materials selection process. The maximum von Mises stress and deformation was obtained when the turbine is resting at 45° for aluminium blade (σ = 1.05 MPa, ε = 5.6e−4 mm). The results of this study indicate suitable materials from a hydrodynamic and material perspectives for the construction of the Savonius hydrokinetic turbine, which can be implemented in the design process to potentially save cost and minimize turbine downtime.