Continuous Degradation Research Articles

Cyclic vinyl sulfones activate NRF2 to protect from oxidative stress-induced programmed necrosis

The NRF2 transcriptional factor is a member of cellular stress response machinery and is activated in response to oxidative stress caused either by cellular homeostasis imbalance or by environmental challenges. NRF2 levels are stringently controlled by rapid and continuous proteasomal degradation. KEAP1 is a specific NRF2 binding protein that acts as a bridge between NRF2 and the E3 ligase Cullin-3. In this study, we examine model cyclic vinyl sulfone derivatives as potential NRF2 activating probes. Previously, we and other authors have found anti-inflammatory properties of these compounds in in vivo models; however, the mechanism of action remained unknown. Here, we show that the naphthohydroquinone derivative LCB1353 efficiently stabilizes NRF2 protein levels and upregulates its target genes. At low 5–10 µM concentrations LCB1353 protects non-small cell lung cancer H1299 cells from ferroptotic death induced by cytotoxic concentrations of RSL3, reducing cell death from 90 % to 5 %. Thus, we suggest that cyclic vinyl sulfones are promising scaffolds for the design of protective molecules for conditions associated with toxic and inflammatory levels of oxidative stress.

Trichloroethylene detoxification in low-permeability soil via electrokinetic-enhanced bioremediation technology: Long-term feasibility and spatial-temporal patterns

In situ remediation of low-permeability soils contaminated with trichloroethylene (TCE) is challenging due to limited mass transfer and low bioavailability in clay soils. The electrokinetic-enhanced bioremediation (EK-BIO) system offers a promising solution by combining electrokinetics with bioremediation to address these challenges. While previous studies have demonstrated microbial succession and TCE removal, the long-term performance of dechlorination and interactions between electrode reactions and anaerobic dechlorination remain unclear. This study constructed five one-dimensional columns, each operated for a different period (28, 42, 56, 84 and 138 days) to explore spatial and temporal dechlorination patterns. Continuous TCE degradation was achieved, with 46.52 % of TCE recovery. Prolonged electrokinetic operation accelerated the first-step dehalogenation (TCE to DCE). Although Dehalococcoides was widespread at 138 days (2.30–5.74 %), oxygen exposure led to irreversible damage, necessitating secondary inoculation. The presence of aerobic bacteria (Comamonas and Pseudomonas) suggested the formation of aerobic detoxification pathways in electrode chambers. Gene expression analysis (tceA, vcrA and Dhc16S) further confirmed the loss of 2nd and 3rd step dehalogenation (DCE to ethene) over time. These findings demonstrate that secondary inoculation and alternative aerobic pathways can sustain long-term biodegradation in the EK-BIO system. This study highlights the potential of the EK-BIO system for effective remediation of TCE-contaminated low-permeability soils, supporting its field application.

Using X-ray Microscopy to Probe Failure Mechanisms in Anode-free Cells: An Industry Perspective

To meet the energy demands of future electric vehicle technologies, batteries with ever-increasing energy densities are desired. One promising technology is an anode-free lithium metal battery (AFLMB) cell, where lithium ions are deposited directly on the anode current collector, resulting in more energy dense cells relative to the current state-of-the-art lithium-ion battery cell. Nevertheless, anode-free cells are prone to early capacity degradation and cell failure. To better understand the degradation mechanisms in these devices, we present a methodology for assessing microstructural changes in battery cells that can be easily implemented within existing battery manufacturing facilities. We employed X-ray tomographic imaging and analyses on small format, AFLMB pouch cells. Anode thickness variations were characterized non-destructively by housing the pouch cells in fabricated pressurized jigs during both cycling and tomographic imaging. Additionally, we present a technique to measure cathode porosities and tortuosities at the end-of-life (EOL) with higher resolution X-ray imaging. The proposed methodology is able to accurately reproduce known microstructural behaviors in AFLMBs. At the anode, significant thickness changes are observed because of continuous electrolyte degradation and solid electrolyte interphase growth. At the cathode, large porosity changes are detected at the EOL, potentially owing to NCM (LiNixCoyMnzO2) particle cracking.

Sustained release of persulfate and ferrous sulfate encapsulated in stearic acid for continuous pyrene degradation in groundwater

Sustained release of persulfate and ferrous sulfate encapsulated in stearic acid for continuous pyrene degradation in groundwater

Origin for dark catalytic performance of sulfide-based photocatalysis: Vital role of sulfur vacancy in charge storage and release

Effective storage and release of photogenerated charge carriers is a feasible strategy to resolve the light-dependence of photocatalytic technology. Herein, a sulfur vacancy-rich (Sv) 1T@2H-MoS2/Cd0.5Zn0.5S junction is developed. The strong ability of sulfur vacancies for storage and release of photogenerated charge carriers enables the 1T@2H-MoS2/Cd0.5Zn0.5S junction to work efficiently under intermittent light. In case of stopping illumination, Sv-1T@2H-MoS2/Cd0.5Zn0.5S junction still shows catalytic activity, leading to the continuous degradation of ofloxacin in the following dark period. Under intermittent lighting, the ofloxacin removal efficiency is 91.7 %, and the energy consumption was reduced by 62 % in comparison with that under continuous visible-light irradiation. The origin for the post-illumination catalytic activity in the dark was explored, and the excitonic effects were also taken into account in 1O2 generation.

The dynamic patterns of critical ecological areas in the Yellow River Basin are driven primarily by climate factors but threatened by human activities

While the identification of critical ecological areas (CEAs) has been limited by the availability of resources, funds, and land space, these areas are central for maintaining the contributions from nature and ecosystem biodiversity. Thus, in this study, CEAs were systematically identified and classified via long-term ecosystem assessment with a multifunctionality–stability–integrity framework in the Yellow River Basin (YRB). The intensity and pathways of the driving factors of CEA dynamics were also determined by the geographical detector model (GDM) and the partial least squares structural equation model (PLS-SEM). The results revealed a gradual decrease in the proportion of CEAs in the upper and lower reaches from 2005 to 2020, in contrast with a significant increase in the middle reaches. The CEAs were distributed mainly in the Sanjiangyuan and Ziwuling regions and the Qingling, Qilian, Lvliang and Taihang Mountains. The areas with low, medium, and high levels of CEAs accounted for 12.48%, 17.73% and 12.54%, respectively, of the YRB. Moreover, climate factors, especially precipitation, were the foremost drivers influencing the dynamic patterns of CEAs. However, notably, the CEAs in the YRB experienced continuous degradation from 2005 to 2020 due to intensified human activities. Our results confirmed the important role of climate factors in determining the distribution of CEAs while underscoring the necessity of mitigating human disturbances to maintain ecosystem functions. These investigations of the dynamics and drivers of CEAs based on long-term multi-dimensional ecosystem assessments could provide useful insights for developing ecological conservation and sustainable development strategies.

Controllable fabrication of the luminescent photocatalytic material AgB/SMSO for application in cement: Optimization of doping strategies and all-weather degradation of pollutants

This paper presents an innovative luminescent photocatalytic material, Ag3PO4/BiVO4/Sr2MgSi2O7:(Eu2+, Dy3+) (AgB/SMSO), which overcomes a pivotal limitation of photocatalysts—dependence on a light source—and effectively remediates pollutants and augments cement-based composite properties. The efficient carrier separation facilitated by Ag3PO4, in conjunction with the broad spectral response of BiVO4, enables AgB/SMSO to harness the internal luminescent properties of SMSO as a persistent light source, achieving continuous degradation of pollutants, which reveals the exceptional afterglow characteristics and photocatalytic activity of AgB/SMSO. At a 1:1:40 ratio, AgB/SMSO maintained its catalytic efficacy for over 8 h in the dark (methylene blue degradation rate of 70.43%), surpassing the 3-hour limit of current luminescent photocatalysts. Furthermore, the impact of integrating AgB/SMSO with cement on early-stage cement hydration, morphology, and micromechanical properties was comprehensively assessed. Ultimately, the overall photocatalytic capability of the derived AgB/SMSO cement-based composites was evaluated through experiments, revealing the synergistic mechanisms involved. This study not only enriches the theoretical understanding of photocatalysis but also provides a robust technical foundation for the innovation of environmentally friendly building materials and the advancement of sustainable urban development.

Salt template-assisted polymer tethering strategy to achieve high dispersed cobalt single atoms/clusters on porous carbon catalysts for effective Fenton-like reactions

The exploration of the synthesis of porous carbon-supported metal nanocatalysts with high metal loading and dispersion for the development of heterogenous catalysts is important. However, this remains a challenging subject. In this paper, a salt template-assisted polymer tethering strategy was proposed to prepare Co single atom and ultrafine cluster anchored on porous carbon (Co-NPC) with a high-loading of 16.9wt%, thereby exposing high density of reaction sites. The obtained Co-NPC catalyst exhibited excellent catalytic performance for almost 100% degradation of bisphenol A (BPA) within 20min, which is much faster than the CoSA-NPC catalyst with only single atom sites and Co-NC without salt template added. Radical quenching experiments and electron paramagnetic resonance tests verified that both the nonradical oxidation pathway by 1O2, the electron transfer and radical oxidation pathway by •OH, SO4•- appeared during the degradation process. After 3 cycles, the removal rate of BPA did not decrease significantly. The fixed bed experiment revealed that Co-NPC could realize the continuous degradation of methylene blue (MB) with almost 100% degradation efficiency. This research indicated that the strategy by pyrolyzing metal coordinated polymer is a potential method for the synthesis of high metal loading catalyst at gram scale, meeting the requirement of practical applications.

Methodology for the Monitoring and Control of the Alterations Related to Biodeterioration and Physical-Chemical Processes Produced on the Paintings on the Ceiling of the Polychrome Hall at Altamira

On the surface of the Cave of Altamira’s prehistoric paintings, a series of active deterioration processes are evident, leading to significant alterations of this invaluable heritage. This study proposes a comprehensive methodology for the systematic recording and management of these alterations. To achieve this, advanced microphotogrammetric monitoring techniques are employed, allowing for the acquisition of very high-resolution images that provide objective and quantifiable data that let us determine the evolution of the alterations. By comparing these images with those from earlier campaigns, the study tracks changes. The data collected through this protocol has helped with the development of new research avenues to understand, among the many alteration processes that impact paintings, the dynamics of water and fluid mechanics affecting the conservation of Cave of Altamira. These investigations help clarify how, why, and at what rate degradation processes such as pigment migration, washing, and bacterial colonization occur. The insights gained from these techniques inform indirect conservation measures aimed at reducing the deterioration of the cave art, located both on the Polychrome ceiling and throughout the rest of the Cave of Altamira. The results underline the importance of regular monitoring and the application of precise, non-invasive techniques to protect rock art from continued degradation. This research provides a model for similar conservation initiatives at other vulnerable heritage sites.

Selecting ecological attributes for managing within environmental limits: an example of a robust science-policy process in Aotearoa New Zealand

ABSTRACT Aotearoa New Zealand is experiencing continued environmental degradation despite its regulatory settings intended to improve environmental outcomes. A lack of clear environmental limits has made it hard to protect ecological integrity and reduce pressures from the cumulative effects of human activities, even more so in a changing climate. This article outlines an evidence-informed process for selecting attributes – i.e. measurable characteristics – of ecological integrity for use by policy makers in resource management across Aotearoa New Zealand. It describes criteria developed (including urgency and importance, suitability and feasibility) to select an initial suite of attributes through engagement with partners and stakeholders and substantial review. The new attributes are intended to fill key gaps not well covered by existing legislation. Seven new attributes were identified including indigenous vegetation cover, erodible soil stabilisation, sediment mud content, sediment accretion rate, nuisance macroalgae, and saltmarsh and seagrass extent. This small number of attributes are not sufficient on their own to protect ecological integrity by managing within environmental limits, but considered a necessary first step in managing priority issues. A more holistic suite of attributes could be developed later, building from this process that can be adapted depending on the details of any future resource management system.

The Regulation of Solid Electrolyte Interphase on Composite Lithium Anodes in Solid-State Batteries.

Solid-state lithium metal batteries (SSLMBs) with solid polymer electrolyte (SPE) are highly promising for next-generation energy storage due to their enhanced safety and energy density. However, the stability of the solid electrolyte interphase (SEI) on the lithium metal/SPE interface is a major challenge, as continuous SEI degradation and regeneration during cycling lead to capacity fading. This article investigates the SEI formation on lithium anodes (l-SEI) and composite lithium anodes (c-SEI) in solid-state lithium metal batteries. The composite anodes form a uniform Li2S-rich inorganic SEI layer and a thinner organic SEI layer, effectively passivating the interface for enhanced cycling stability. Specifically, the full cells with c-SEI anodes sustain over 400 cycles at 0.5 C under a high areal capacity of 2.0 mAh cm-2. Moreover, the reversible high-loading solid-state pouch cells exhibit exceptional safety even after curling and cutting. These findings offer valuable insights into developing composite electrodes with robust SEI for solid-state polymer-based lithium metal batteries.

The Regulation of Solid Electrolyte Interphase on Composite Lithium Anodes in Solid‐State Batteries

AbstractSolid‐state lithium metal batteries (SSLMBs) with solid polymer electrolyte (SPE) are highly promising for next‐generation energy storage due to their enhanced safety and energy density. However, the stability of the solid electrolyte interphase (SEI) on the lithium metal/SPE interface is a major challenge, as continuous SEI degradation and regeneration during cycling lead to capacity fading. This article investigates the SEI formation on lithium anodes (l‐SEI) and composite lithium anodes (c‐SEI) in solid‐state lithium metal batteries. The composite anodes form a uniform Li2S‐rich inorganic SEI layer and a thinner organic SEI layer, effectively passivating the interface for enhanced cycling stability. Specifically, the full cells with c‐SEI anodes sustain over 400 cycles at 0.5 C under a high areal capacity of 2.0 mAh cm−2. Moreover, the reversible high‐loading solid‐state pouch cells exhibit exceptional safety even after curling and cutting. These findings offer valuable insights into developing composite electrodes with robust SEI for solid‐state polymer‐based lithium metal batteries.

Study on the Microscopic Pore Characteristics and Mechanisms of Disturbance Damage in Zhanjiang Formation Structural Clay

To investigate the microscopic pore evolution characteristics of Zhanjiang Formation structural clay during the disturbance process, unconfined compressive strength tests, scanning electron microscopy (SEM), and X-ray diffraction (XRD) were conducted on disturbed samples subjected to various disturbance conditions after vibrational disturbance. Based on the evolution characteristics of the microstructure, the microscopic pore characteristics of the disturbance damage of Zhanjiang Formation structural clay were examined. The results indicate the following. (1) The porosity in three-dimensional visualization images of the microstructure reconstructed by ArcGIS 10.1 increases with the disturbance degree, showing a linear growth trend. (2) The correlation analysis between macroscopic mechanics and microscopic pores shows that the unconfined compressive strength of Zhanjiang Formation structural clay is mainly affected by its porosity, with a significant linear negative correlation. Based on this, a reasonable regression model between the microscopic porosity and the unconfined compressive strength has been established. The model can rapidly estimate the unconfined compressive strength from porosity data, facilitating the assessment engineering properties of the soil. (3) The microscopic pore structure of Zhanjiang Formation structural clay exhibits prominent Menger fractal characteristics. The three-dimensional pore fractal dimension has a certain positive correlation with the disturbance degree, and can be utilized to characterize the pore structure and complexity, serving as a significant parameter for the quantitative evaluation of the pore structure characteristics of Zhanjiang Formation structural clay. Consequently, the complexity of the pore structure of the engineering soil can be evaluated by the pore fractal dimension. (4) The impact of disturbance on soil is primarily manifested in the structural changes in secondary clay minerals, transitioning from a relatively intact to a fully adjusted state. During this process, interparticle pores continuously increase, pore structure complexity increases, and interparticle cementation weakens, resulting in the continuous degradation of unconfined compressive strength. This study contributes to a deeper understanding of the disturbance damage characteristics of Zhanjiang Formation structured clays from a microscopic pore perspective, providing a theoretical basis for the engineering construction and operational maintenance in regions with Zhanjiang Formation structural clay.

Spatiotemporal Evolution and Drivers of Ecological Quality in the Tengger Desert (2001–2021)

Desert ecosystems, particularly in arid regions like the Tengger Desert, are highly sensitive to both anthropogenic activities and climate change, making the monitoring and evaluation of ecological quality critical for sustainable management and restoration efforts. This study analyses the spatiotemporal evolution of ecological quality in the Tengger Desert from 2001 to 2021 using the Remote Sensing Ecological Index (RSEI), incorporating meteorological factors (temperature, precipitation, wind speed), topographical factors (elevation, slope, relief) and anthropogenic indices (land use and land cover). The mean RSEI fluctuated between 0.1542 and 0.2906, indicating poor ecological quality, with a peak in 2008 attributed to national ecological projects. Despite initial improvements, overall ecological quality declined at a rate of 0.0008 a−1 from 2008 to 2021. Spatially, degradation was most pronounced in the central and southern areas. Due to sand-binding engineering in the Tengger Desert in 2008 and the mountain climate suitable for vegetation growth, improvements occurred in the northeast and southwest. Moran’s I and Hurst index analyses revealed significant spatial clustering of ecological quality and persistence of degradation trends, with over 49.53% of the area projected to experience further deterioration. Geodetector analysis identified land use and land use cover as the most influential factors on RSEI, especially in combination with wind speed, temperature, and precipitation, underscoring the role of both human activities and climate. The study highlights the need for sustained ecological management, particularly in areas showing continuous degradation, to prevent further ecological deterioration.

Service-life multi-hazard risk assessment of structures: framework and application

Fragility and risk assessment of civil engineering structures against various design loads and their combinations need to be conducted to evaluate structural vulnerability. This is typically done at the design stage. However, during the service (design) life, it is important to investigate the change (increase) in the risk posed to the structure on account of multiple hazards. This article discusses a holistic novel framework that considers aging effects in addition to major or minor structural damage resulting from independent hazards. The framework is illustrated for independent action of earthquake and fire hazards on reinforced concrete (RC) buildings with varied occupancies while considering continuous structural deterioration on account of chloride- and carbonation-induced corrosion over a building’s service life. The change in the structure’s performance in the fire over its service life, in terms of incident risk and the resistance period, is evaluated for a combination of environmental effects and multi-hazard effects of earthquake and fire. The results from this study indicate that there is a significant increase in the risk of post-earthquake fire if continuous structural degradation due to environmental factors and minor damage due to earthquakes is not addressed.

Synthesis and electrochemical performance Assessment of sunflower oil-based organosulfur Co-Polymers as the cathode additive for Li-S battery

Lithium-Sulfur battery (Li-S) is considered as a promising new generation battery chemistry. Nevertheless, the sulfur based battery chemistry has downsides in terms of the low electronic conductivity, polysulfide shuttle effect, and low active material utilization. Currently, there are several strategies available to suppress LiPS shuttling and thereby enhance cycle life behavior of the Li-S battery. However, there is no existing literature on the use of organosulfur-based copolymer as a cathode additive material in Li-S. Herein, we have investigated the feasibility of organosulfur copolymer synthesized using sulfur, fresh and used cooking (sunflower) oil. The developed polymers were used cathode additives. The results reveal that the copolymer developed by used cooking oil-loaded cathode (poly-S-UCO@SC) delivers high specific discharge capacity of 936mAh/g at 0.05C-rate and the copolymer developed by fresh sunflower oil loaded cathode (poly-S-SF@SC) exhibits 828mAh/g. However, the poly-S-UCO@SC exhibited poor structural stability, continuous cathode degradation and poor electrochemical performances than poly-S-SF@SC. The poly-S-SF@SC showed improved polysulfide conversion, reduced shuttle effect, reversible redox process, 66.5 % capacity retention for 40 cycles with stable cycling stability and shows much potential as a suitable cathode additive material compared to poly-S-UCO. The results demonstrate that utilization of biomass-based components in Li-S batteries may trigger new research pathways in Li-Sulfur battery science and technology.

Microenvironment modulation of Fe single atoms in porous g-C3N4 by introducing −SOx groups for enhanced photo-Fenton reactions

Heterogeneous photo-Fenton reactions based on hydrogen peroxide (H2O2) activation exhibit great potential in the treatment of organic wastewater. For developing efficient photo-Fenton catalysts, a fundamental investigation into the specific catalytic sites and the reaction mechanism is highly desired. Herein, a novel photo-Fenton catalyst (Fe1/CN-SOx) was constructed by synchronously anchoring Fe single atoms (SAs) and oxidized sulfur (−SOx) groups into porous graphitic carbon nitride (g-C3N4). The presence of trace −SOx groups altered the local configuration of g-C3N4 and optimized the coordination microenvironment of Fe SAs, thereby modulating the electronic structures of catalytic sites in favor of H2O2 activation. The cooperation between Fe SAs and the neighboring C atoms bonded with −SOx (C-SOx) enhanced the adsorption and cleavage of H2O2. The photoinduced charge carriers further accelerated Fe2+/Fe3+ redox cycles and hydroxyl radical (•OH) production, achieving an efficient photo-Fenton synergistic catalysis for continuous degradation of organic contaminants. The Fe1/CN-SOx catalyst also exhibited excellent anti-interference performance in diverse aquatic systems and good long-term stability, indicating its great potential for applications in water treatment. This study provides an in-depth insight into the optimal fabrication of single-atom active sites by modulating the local structures of support materials, aiming to enhance photo-Fenton reactions.

Transforming European Food Systems with multi-actor networks and Living Labs through the FoodSHIFT Approach.

Our current global Food System is facing extraordinary challenges in both size and severity, including a rise in unsustainable consumption behaviours, continued environmental degradation, growing food insecurity, and widening social inequalities. A Food System transformation is now both critically important and overwhelmingly complex, requiring nothing less than a complete overhaul of the entire value chain. Everyone is needed: Small Medium Enterprises (SMEs) with technological solutions, Non-Governmental Organisations (NGOs) with social innovations, researchers with novel methodologies, governments with food policy advancements, professionals with varying expertise, and last but not least, empowered and informed citizens with the ability and resources for better decision-making. Living Labs offer a holistic, place-based approach needed to facilitate multi-actor inputs on various levels, specifically Food System Living Labs (FSLLs) like the ones established as part of the FoodSHIFT 2030 Project. Nine front-runner Food System Living Labs were operationalised alongside a novel framework merging high-level interdisciplinary initiatives with a diverse set of innovative approaches towards more Sustainable Food Systems (SFS). The FoodSHIFT Approach concept was praised by external evaluators for its ground-breaking framework, and the nearly completed project has been listed as a best practice. However, positive applications alone will not ensure a cross-sector European-wide Food System transformation, and the following text offers a critical reflection coupled with experience-based solutions to further improve the FoodSHIFT Approach.

Wear mechanisms and failure analysis of a tool used in refill friction stir spot welding of AA6061-T6

Investigating tool wear in refill friction stir spot welding (RFSSW) is essential for understanding its limitations and improving its efficiency. Increasing the tool's service life is important to push the technology's readiness level and transfer the technology from the laboratory to industrial applications. In this study, the quasi-static lap shear performance of AA6061-T6 similar welded spots was investigated and tool wear was continuously monitored until tool failure at 3450 welding cycles. Furthermore, the fundamentals of the wear mechanisms in RFSSW were further elucidated. The investigation shows that it is possible to achieve steady quasi-static lap shear performance of the spot welds over advancing tool wear by adjusting the heat input to compensate for losses in frictional heat generation efficiency (related to tool profile changes by abrasion). A subsequent tool failure case analysis showed the main causes for the continuous wear degradation of the shoulder. Tool wear was driven by plastic deformation of the hot-work tool steel and subsequent break-out of tool steel ridges, introducing big hard particles into the contact region between the moving and rotating tools. In addition, the formation and detachment of Fe-Al intermetallic compounds counteract with the rotating tools and increase tool wear.

Reliability Analysis for Degradation-Shock Processes with State-Varying Degradation Patterns Using Approximate Bayesian Computation (ABC) for Parameter Estimation

The degradation of products is an integral part of their life-cycle, often following predictable trajectories. However, sudden, unexpected events, termed ’shocks’, can substantially alter these degradation paths. Shocks can significantly influence the pace of degradation, leading to accelerated system failure. Moreover, they may initiate changes in degradation patterns, transitioning from linear to non-linear or random trajectories. To address this challenge, we present a novel multi-state reliability model for competing failure processes that account for degradation-shock dependencies by considering the state-varying degradation pattern. The degradation process is divided into s-states, with each state treated according to its pattern based on the time-transform Wiener process. The reliability function is derived based on soft failure caused by continuous degradation involving the s-states, the sudden increase in degradation caused by random shocks, and hard failure due to some shock processes. Additionally, we performed a sensitivity analysis to determine which parameters have the most significant impact on product reliability. Due to the complexity of the likelihood function, we adopted the ABC method to estimate the model parameters. A simulation study and a practical application with micro-electro-mechanical systems (MEMS) degradation results are used to demonstrate the efficiency and effectiveness of the proposed approach.