Time-dependent Deterioration Research Articles

SRSF2 is essential for maintaining pancreatic beta-cell identity and regulating glucose homeostasis in mice

Diabetes is characterized by decreased beta-cell mass and islet dysfunction. The splicing factor SRSF2 plays a crucial role in cell survival, yet its impact on pancreatic beta cell survival and glucose homeostasis remains unclear. We observed that the deletion of Srsf2 specifically in beta cells led to time-dependent deterioration in glucose tolerance, impaired insulin secretion, decreased islet mass, an increased number of alpha cells, and the onset of diabetes by the age of 10 months in mice. Single-cell RNA sequencing (scRNA-seq) analyses revealed that, despite an increase in populations of unfolded protein response (UPR)-activated and undifferentiated beta cells within the SRSF2_KO group, there was a notable decrease in the expression of UPR-related and endoplasmic reticulum (ER)-related genes, accompanied by a loss of beta-cell identity. This suggests that beta cells have transitioned from an adaptive phase to a maladaptive phase in islets of 10-month-old SRSF2_KO mice. Further results demonstrated that deletion of SRSF2 caused decreased proliferation in beta cells within 3-month-old islets and Min6 cells. These findings underscore the essential role of SRSF2 in controlling beta-cell proliferation and preserving beta-cell function in mice.

The role of climate change and corrosion modeling strategy in dynamic response of pile-supported wharves

This paper explores the fragility of pile-supported wharves to environmental hazards, notably climate change and corrosion, and underscores the critical need to understand the interplay between these factors when assessing structural safety. The research advocates for comprehensive methodologies that encompass climate change effects, aging, and time-dependent deterioration in evaluating the seismic fragility functions of pile-supported wharves. An examination of aging and seismic effects is performed on a representative pile-supported wharf at designated time intervals. This study highlights the pronounced impacts of climate change and corrosion on the structural integrity of concrete and steel in marine environments. Specifically, it considers effects such as sea level rise, increased temperatures, and heightened relative humidity on pile-supported wharves. Additionally, three corrosion pitting configurations in prestressed strands with and without climate change considerations are analyzed to determine their influence on the strength and ductility of materials, limit states, and ultimately, on the fragility curves. The findings indicate that climate change significantly exacerbates the corrosion of materials in pile-supported wharves, and increases failure probability. The relative increase in corrosion rate after 50 years due to climate change is found to be 94%.

Abstract Mo112: ARA290, a small peptide non-erythropoietic Erythropoietin derivative, ameliorates heart functional deterioration in a chronic cardiac stress model

Objective: To determine whether ARA290 can prevent or delay age-related declines in cardiac function and structure in the TG AC8 heart failure model. Methods: The study consists of 9 TG AC8 + mice that were randomly assigned to treatment group (n=5) or non-treatment saline group (n=4). Both groups received intraperitoneal injections of ARA290 (100 μg/kg) or saline tri-weekly. Monthly echocardiographic assessment of heart systolic function prior to, and monthly during 7 months of treatment was performed starting at 10 months of age. Two Way ANOVA was used to analyze the data. Results: At baseline, 10 months of age, prospective treatment and non-treatment group did not exhibit any statistically significant difference in their measure of ejection fraction (EF), fractional shortening (FS), and stroke volume (SV) ( P > 0.05). ARA290 treatment preserved EF, FS, and SV, (compared to a progressive, time dependent deterioration of these systolic functions in the saline treated group). Significant interaction terms for EF ( P < 0.04), FS ( P < 0.03), and SV ( P < 0.02), and time indicated that the ARA290 effect depended upon treatment time. Conclusion: The prevention of the decline in heart systolic functional by ARA290 suggests that this small peptide derivative of EPO has therapeutic potential as a novel intervention to retard declines in cardiac function that accompany chronic heart diseases.

Inventory Optimization Model with Quadratic Demand Pattern and Non-instantaneous Deterioration Rate with Mixed Cash and Advance Payment Scheme

Objectives: To develop a mathematical model for cost minimization by examining a scenario involving a seasonal product retail market, evaluating the outcome, and providing solutions to unanswered queries of existing models are the highlights of this present work. Methods: 1. Using dynamic differential equations with initial and boundary conditions, we mathematically model a retail market scenario for perishable commodities and determine the retailer's total cost. 2. We consider a quadratic function of time to precisely describe the maintenance cost and demand function. Also, a combination of cash and advance payment schemes is implemented in our model. 3. Our model was numerically formulated using a dataset deduced from earlier research. We have included a sensitivity analysis and a numerical example with a graphical depiction of the total cost function that highlights the most and least influential factors. 4. Based on the Hessian matrix condition and the calculus derivative approach, we developed an algorithm to calculate the optimal cost. Findings: This model provides retailers with insights for effective stock management while optimizing the cost of retailing perishable commodities with non-linear demand patterns. Sensitivity analysis showed that the two factors that have the biggest impact on retailers' overall costs are non-linear demand and holding cost parameters. The smaller optimal inventory cycle time and the large value of time at which a shortage happens raise the overall cost. Additionally, because of higher demand, the time-dependent deterioration rate has the least impact on overall cost. Additionally, a three-dimensional graph of cost minimization is offered to illustrate the convexity of total cost. Novelty: Implementation of Quadratic time-dependent demand and non-linear holding costs under a mixed cash advance payment structure, along with time-dependent deterioration and partial backlog shortages. Keywords: Quadratic Demand pattern, Non­instantaneous decay rate, Cash and Advance Payment scheme, Partial Backlog Shortages

Influence of Corrosion on Lifespan of Reinforced Concrete Structures: A Comprehensive Review

Carbonation-induced corrosion is a major concern for reinforced cement concrete (RCC) structures, impacting their long-term durability and structural integrity. This review synthesizes the findings on the deterioration mechanisms in concrete structures, focusing on carbonation, chloride-induced corrosion, and time-dependent deterioration. The analysis includes discussions on predictive likelihood methods for estimating bridge reliability, the impact of environmental factors on carbonation, and standardized testing methods for assessing concrete durability. The review highlights the importance of understanding material characteristics and environmental conditions in designing durable concrete structures, emphasizing the processes of carbonation, its impact on rebar corrosion, and strategies for mitigation. Sheltered concrete carbonation resistance in metropolitan tropical climates is 10-20% lower than open exposure. SCM concretes exhibit equivalent or greater long-term carbonation resistance to OPC concretes, as evidenced by the increase in carbonation depth ( Δ xd) at ages greater than 5 years. The paper concludes with recommendations for integrating advanced modeling techniques and empirical studies to develop robust maintenance strategies and improve concrete mix designs for enhanced durability.

Evaluation of viability, developmental competence, and apoptosis-related transcripts during in vivo post-ovulatory oocyte aging in zebrafish Danio rerio (Hamilton, 1822).

Post-ovulatory aging is a time-dependent deterioration of ovulated oocytes and a major limiting factor reducing the fitness of offspring. This process may lead to the activation of cell death pathways like apoptosis in oocytes. We evaluated oocyte membrane integrity, egg developmental competency, and mRNA abundance of apoptosis-related genes by RT-qPCR. Oocytes from zebrafish Danio rerio were retained in vivo at 28.5°C for 24 h post-ovulation (HPO). Viability was assessed using trypan blue (TB) staining. The consequences of in vivo oocyte aging on the developmental competence of progeny were determined by the embryo survival at 24 h post fertilization, hatching, and larval malformation rates. The fertilization, oocyte viability, and hatching rates were 91, 97, and 65% at 0 HPO and dropped to 62, 90, and 22% at 4 HPO, respectively. The fertilizing ability was reduced to 2% at 8 HPO, while 72% of oocytes had still intact plasma membranes. Among the apoptotic genes bcl-2 (b-cell lymphoma 2), bada (bcl2-associated agonist of cell death a), cathepsin D, cathepsin Z, caspase 6a, caspase 7, caspase 8, caspase 9, apaf1, tp53 (tumor protein p53), cdk1 (cyclin-dependent kinase 1) studied, mRNA abundance of anti-apoptotic bcl-2 decreased and pro-apoptotic cathepsin D increased at 24 HPO. Furthermore, tp53 and cdk1 mRNA transcripts decreased at 24 HPO compared to 0 HPO. Thus, TB staining did not detect the loss of oocyte competency if caused by aging. TB staining, however, could be used as a simple and rapid method to evaluate the quality of zebrafish oocytes before fertilization. Taken together, our results indicate the activation of cell death pathways in the advanced stages of oocyte aging in zebrafish.

A deterministic multi-item inventory model with quadratic demand under neutrosophic and pythagorean hesitant fuzzy programming approach

In this paper, a deterministic fuzzy inventory model with quadratic demand pattern, time-dependent holding cost, and time-dependent deterioration has been created. We have taken the rate of shortage as fully backlogged. In traditional inventory model, most of the cost parameters were taken as crisp. But in real world, fuzzy cost parameters are more realistic to appear instead of crisp parameters. Due to uncertainty we have considered all the cost parameters as hexagonal fuzzy number. We have regarded all of the cost parameters as hexagonal fuzzy numbers due to uncertainty. Our primary goal is to reduce the total average cost, and for that we've covered two optimization techniques: the Pythagorean Hesitant Fuzzy Programming Approach (PHFPA) and the Neutrosophic Hesitant Fuzzy Programming approach (NHFP).Through extensive numerical experiments and sensitivity analysis, the effectiveness and practicality of the proposed model are demonstrated. Comparative studies with traditional inventory models underscore the advantages of the Neutrosophic and Pythagorean Hesitant Fuzzy Programming Approach in managing multi-item inventory systems with quadratic demand patterns, highlighting its robustness in handling uncertain and ambiguous information.

Abstract 16692: Early Life Stress Elicits Heart Failure Traits Across Generations in Mice

Introduction: Adverse childhood experiences, particularly early life stress (ELS), are associated with cardiovascular disease later in life but the underlying mechanisms remain elusive. Parental life experiences can have effects that are transmitted to the offspring suggesting a possible trans-generational transmission of ELS phenotypic traits. Hypothesis: ELS can impair cardiac function in exposed parents and their offspring. Methods: We used an ELS mouse model based on unpredictable separation of mouse pups (F1) from their mother (F0) each day for 3 hours from postnatal day 1 (PND1) to PND14 combined with dams exposure to an additional unpredictable stressor (forced swim in 18°C water for 5 minutes or 20-minute physical restraint in a tube) during separation. Control litters were raised normally. Echocardiography (Vevo 3100, Visualsonics) was performed at 6, 12 and 18 months in exposed animals (F0), their unexposed offspring (F1) and grand-offspring (F2). Both male and female mice were studied. Heart weight/tibia length was used to assess cardiac mass while Masson's Trichrome was employed to detect fibrosis. Lung congestion was assessed as lung wet/dry weight ratio. Single-cell RNA sequencing (scRNAseq) was performed in MSUS and control hearts. A 6-week environmental enrichment (EE) program (cages containing running wheels, maze) was employed to test the possible rescue of ELS effects in adult males and their offspring. Results: Male and female MSUS mice (F1) displayed a time-dependent deterioration (from 6 to 18 months) of LV hypertrophy, diastolic function, myocardial fibrosis and lung congestion when compared to controls. ScRNAseq revealed dysregulation of genes controlling inflammation and metabolism (Cav1, Fabp4) in cardiomyocyte and endothelial cell clusters. MSUS F1 and F2 females and males had diastolic dysfunction and lung congestion at 12 and 18 months (no change at 6 months). Notably, EE improved diastolic function and lung congestion in MSUS mice. Conclusions: ELS induces heritable cardiac alterations which can be rescued by EE in fathers. These results shed light on the causal role of ELS on heart failure development and potential mitigation strategies.

Quantification of time-dependent deterioration in mechanical property and ballistic performance through Cunniff Number of poly (p-phenylene terephthalamide) fibers under UV irradiation

Poly (p-phenylene terephthalamide) fibers, a crucial constituent of soft body armor, experience significant deterioration in mechanical and ballistic performance due to UV exposure. However, photo-degradation by UV radiation involves complex chemical reactions and the difficulty in estimating the extent of damage that restricts the development of the predictive aging models or kinetics in such fibrous materials. Hence in this work, the photo-degradation kinetics of poly (p-phenylene terephthalamide) or KF-fibers is quantified by correlating the degradation behavior of different properties with time, thereby assessing the useful performance span of the UV-aged (UV-KF) fibers. The experimental trends indicate three stages of deterioration of any property (modulus, extension at break, Cunniff Number and crystallinity), i.e., an exponential decline followed by an increase over a short duration and finally, a steady and continuous drop. The suitable performance period of UV-aged fibers is estimated based on the initial two stages and presented as ‘favorable property region’ or ‘FPR-zone.’ Changes in V50 ballistic limit, theoretically derived from Cunniff Number, are also estimated, which show a good agreement with the literature data. It reveals that the energy absorption capacity of UV-KF fibers corresponds to initial two years as a span of considerable ballistic protection before continuing to function at 50% of its original protection level for lower aging temperatures. Besides, the apparent activation energy for all the studied properties is correlated to the microstructural and physico-chemical aspects. It indicates that relative changes in molar mass by bond scission/rearrangement and alterations in crystallinity are proportionally related to the degree of variation in modulus and extension at break, thus affecting the wave-velocities in terms of Cunniff Number. The proposed degradation model further can be extended to determine the rate of degradation and lifetime of various ballistic materials under other environmental conditions.

Comparison of Damage Indexes for Assessing Seismic Fragility of Bearings in an Offshore Bridge

This study analyzes the applicability of different damage indexes for bearings, focusing on the time-dependent deterioration of materials and the time-dependent bond-slip behavior between steel and concrete caused by chloride erosion. First, the methodology is proposed, encompassing the time-dependent deterioration of materials, the time-dependent bond-slip behavior, the quantification of different damage indexes of the bearing, and the fragility analysis for the bearings. Next, an offshore bridge is used as an example to investigate the detailed elements of the components and the time-varying effects. Thereafter, based on incremental dynamic analysis and fragility analysis, the discussion focuses on the comparison of damage indexes for assessing the seismic fragility of bearings in an offshore bridge. This study indicates that if the relative displacement ductility ratio is adopted as the criterion, the coverage of PGA obtained by the theoretical method is 167% greater than that obtained using the empirical method, and the relative displacement ductility ratio, which incorporates the shear deformation of piers, is better aligned with the performance-based ductility design concept and offers better economy. Safety-based damage indexes are recommended for the bridge in seismic zones, while economy-based indexes can be used in favorable bridge environments.

Statistical Data Analysis for Trackway Asset Management Using Low-Level Nonconformance Rates

Well-documented conditions of the country’s subway systems suggest that the development of a management strategy for aging infrastructure is an important asset management challenge. The purpose of this work is to address this challenge by developing a statistical data analysis approach for forecasting the aging effect on the time-dependent deterioration rate of an identified trackway cluster. The infrastructure database is the New York City subway system and the trackway that supports the delivery of service. While much focus has been given to the steel rail subcomponent of the trackway, little has been done in the way of statistical analysis on the low-level nonconformances in the support structure of those rails—namely, the invert, ties, fasteners, and plates. Though detectable, these conditions pose no risk to either safety or the serviceability of that asset, yet they do provide a certain degree of awareness that an entirely intuitive lifecycle deterioration process is underway. This paper illustrates the development of a statistical data analysis methodology using available trackway data sets for forecasting the aging effect on the system performance.

Stochastic single machine scheduling with time-dependent deterioration or position-dependent learning effect

Stochastic single machine scheduling with time-dependent deterioration or position-dependent learning effect

Seismic Fragility Analysis of the Aging RC Columns under the Combined Action of Freeze–Thaw Cycles and Chloride-Induced Corrosion

The combined action of freeze–thaw cycles and chloride-induced corrosion are generally recognized as one of the main causes of the degradation of the mechanical properties and seismic performance of reinforced concrete (RC) structures in the northern frozen coastal regions. To investigate the degradation mechanisms of the seismic performance of RC columns subjected to the combined action of freeze–thaw cycles and chloride-induced corrosion, the impact of freeze–thaw cycles on the chloride diffusion coefficient of concrete was studied through concrete deterioration tests and theoretical analysis. This paper proposed a time-dependent deterioration model for RC columns, which is suitable to consider the combined action of freeze–thaw cycles and chloride-induced deterioration. The proposed deterioration model could be applied to the investigations of time-dependent seismic performance and the seismic fragility of RC columns. Based on the established deterioration model, this paper proposed a time-dependent seismic fragility analysis framework for the aging RC columns, considering the combined action of freeze–thaw cycles and chloride-induced corrosion. In addition, a representative three-span RC continuous T-shaped girder bridge that is located in the high-latitude northern frozen coastal regions of China was taken as the case study, and the time-dependent seismic fragility analysis of RC columns was conducted considering the involved uncertainties in geometric parameters, the deterioration mechanisms of the materials, and ground motions. The time-dependent seismic fragility curves of RC columns were obtained at different service time points. The results indicated that the combined action of freeze–thaw cycles and chloride-induced deterioration had a significant influence on the time-dependent seismic responses of the deteriorating RC columns. Under the combined action of freeze–thaw cycles and chloride-induced corrosion, when the RC bridge was in service for 75 years, the stirrup strength decreased by 3.88% and the cross-sectional area decreased by 30.03%. The peak stress of the confined concrete decreased by 52.1% and its peak strain increased by 12.2 times, respectively. Moreover, the time-dependent seismic fragilities of the aging RC columns under different damage states exhibited a nonlinear increase as the service life increased.

Real time vibration measurement and inverse analysis for dynamic properties of an axisymmetric masonry structure

ABSTRACT Historic buildings are public symbols, standing as sacred reminders. Many of them have been recognized as World Heritage Sites. In this study, real time vibration measurement of an important axisymmetric masonry pagoda was performed. With the measured vibration data, inverse analysis was proposed to backward determine its damping and natural period. The proposed algorithm utilizes Duhamel’s time integration method for solving the equation of motion and the Gauss-Newton algorithm to minimize the sum-of-squares error between the calculated and real-time measured accelerations of the structure. Four distant earthquake-induced vibrations were recorded and used for the analysis. The results show that the dynamic parameters determined by the proposed method agree with those obtained from the previous study adopting finite element analysis. The obtained dynamic properties of the two perpendicular directions are slightly different, indicating the non-homogenous body of the axisymmetric structure or there would be a particular damage zone. From the results, an onsite damage investigation can be specifically identified. In summary, continuous structural health monitoring and time-dependent deterioration of historic buildings are possible with real time measurement and the proposed analytical algorithm.

H2S contributed from CSE during cellular senescence suppresses inflammation and nitrosative stress

Aging involves the time-dependent deterioration of physiological functions attributed to various intracellular and extracellular factors. Cellular senescence is akin to aging and involves alteration in redox homeostasis. This is primarily marked by increased reactive oxygen/nitrogen species (ROS/RNS), inflammatory gene expression, and senescence-associated beta-galactosidase activity, all hallmarks of aging. It is proposed that gasotransmitters which include hydrogen sulfide (H2S), carbon monoxide (CO), and nitric oxide (NO), may affect redox homeostasis during senescence. H2S has been independently shown to induce DNA damage and suppress oxidative stress. While an increase in NO levels during aging is well established, the role of H2S has remained controversial. To understand the role of H2S during aging, we evaluated H2S homeostasis in non-senescent and senescent cells, using a combination of direct measurements with a fluorescent reporter dye (WSP-5) and protein sulfhydration analysis. The free intracellular H2S and total protein sulfhydration levels are high during senescence, concomitant to cystathionine gamma-lyase (CSE) expression induction. Using lentiviral shRNA-mediated expression knockdown, we identified that H2S contributed by CSE alters global gene expression, which regulates key inflammatory processes during cellular senescence. We propose that H2S decreases inflammation during cellular senescence by reducing phosphorylation of IκBα and the p65 subunit of nuclear factor kappa B (NF-κB). H2S was also found to reduce NO levels, a significant source of nitrosative stress during cellular senescence. Overall, we establish H2S as a key gasotransmitter molecule that regulates inflammatory phenotype and nitrosative stress during cellular senescence.

Abstract 137: Effect Of Chest Compression Release Velocity On Cerebral Perfusion Pressure In A Porcine Experimental Model Of Cardiac Arrest.

Background: Previous studies have shown that chest compression release velocity (CCRV) of over 400mm/s is associated with improved survival and favorable neurologic outcome after cardiac arrest. However, it is uncertain whether CCRV during CPR is related to cerebral perfusion pressure (CePP). The purpose of this study was to evaluate the association between CCRV and CePP in a porcine cardiac arrest model. Methods: After 6 minutes of untreated ventricular fibrillation, 2 cycles of basic life support (BLS) and 12 cycles of advanced cardiovascular life support (ACLS) were conducted. During ACLS phase, CCRV was accelerated from 250mm/s to 450mm/s by 50mm/s (accelerating group) or decelerated from 450mm/s to 250mm/s by 50mm/s (decelerating group). Both groups performed BLS with the self-set value of the mechanical CPR device (LUCAS 2 chest compression system, CCRV of 170mm/s). Twenty-four pigs were randomly assigned to each group. Macrovascular circulation (CePP) and microvascular circulation using laser doppler flowmetry presented as a fraction of the baseline flow (f-LDF) were measured. We excluded the last 2 cycles of ACLS phase from the analysis due to time-dependent deterioration effects of hemodynamic outcomes. Linear mixed model was used to measure the median difference in CePP and f-LDF according to CCRV. Results: A total of 24 pigs were analyzed. Decelerating group of CCRV of 400mm/s showed significantly higher CePP values compared to the group of 170mm/s. Effect of changes in CCRV on CePP, stratified by groups, are as follows (median, [95% confidence intervals]): 1. Accelerating group: CCRV of 170mm/s; reference, 250mm/s; -1.98 [-10.78 - 11.79] mmHg, 300mm/s; -1.88 [-11.15 - 12.55] mmHg, 350mm/s; -2.55 [-11.46 - 12.24], 400mm/s; -6.05 [-5.59 - 16.86], and 2. Decelerating group: CCRV of 170mm/s; reference, 250mm/s; 5.71 [-16.27 - 27.11] mmHg, 300mm/s; 6.01 [-16.28 - 27.90] mmHg, 350mm/s; 6.96 [6.36 - 47.70], 400mm/s; 26.96 [6.36 - 47.70]. However, there was no significant CCRV effects on f-LDF (Accelerating CCRV of 400mm/s; 1.54 [ -0.03 - 3.10] and decelerating CCRV of 400mm/s; -2 [-4.42 - 0.34]). Conclusion: In a VF cardiac arrest porcine study, CCRV of 400mm/s at early phase of CPR has positive effects on CePP.

Advancing Our Understanding of the Chronically Denervated Schwann Cell: A Potential Therapeutic Target?

Outcomes for patients following major peripheral nerve injury are extremely poor. Despite advanced microsurgical techniques, the recovery of function is limited by an inherently slow rate of axonal regeneration. In particular, a time-dependent deterioration in the ability of the distal stump to support axonal growth is a major determinant to the failure of reinnervation. Schwann cells (SC) are crucial in the orchestration of nerve regeneration; their plasticity permits the adoption of a repair phenotype following nerve injury. The repair SC modulates the initial immune response, directs myelin clearance, provides neurotrophic support and remodels the distal nerve. These functions are critical for regeneration; yet the repair phenotype is unstable in the setting of chronic denervation. This phenotypic instability accounts for the deteriorating regenerative support offered by the distal nerve stump. Over the past 10 years, our understanding of the cellular machinery behind this repair phenotype, in particular the role of c-Jun, has increased exponentially, creating opportunities for therapeutic intervention. This review will cover the activation of the repair phenotype in SC, the effects of chronic denervation on SC and current strategies to ‘hack’ these cellular pathways toward supporting more prolonged periods of neural regeneration.

Deteriorating dispersibility of flushable wet wipes during storage: Role of fibre swelling and ionic shielding

Wet wipes are everyday products with the purpose to be flushed down the toilet after usage and dispersed into single fibres and small fragments thereby. During wet storage, these wipes can deteriorate their dispersibility over time, characterized by the slosh box disintegration test, recently named dispersibility ageing. This effect in flushable wet wipes, usually made of long man-made cellulose fibres and short wood pulp fibres, can be reduced by using unbleached softwood kraft pulp as the short fibre component. The aim of this work is to analyse mechanisms that could contribute to dispersibility ageing. Therefore, we will discuss three mechanisms that are able to explain this effect, that occurs in cellulosic fabrics when stored in water. Swelling (1) is demonstrated to be a long-term effect, but altering swelling with pH and salt addition has no effect on dispersibility ageing, making it unlikely that swelling contributes to it. With ionic shielding (2) a mechanism has been introduced that could impact dispersibility ageing by cations leaching from the wood pulp, which was demonstrated for an unbleached softwood kraft pulp by conductivity measurements over wet storage time. These cations neutralize the negatively charged pulp fibre fibrils and restrict their possibility to entangle with each other, which could contribute to decreasing dispersibility ageing. We will discuss the mechanism of interdiffusion (3) in dispersibility ageing, although we were not able to find a method that quantifies the contribution of cellulosic polymer diffusion to the time-dependent deterioration in dispersibility.

Inventory Modeling of Demand as A Polynomial Function of Time and Time-dependent Deterioration

Inventory Modeling of Demand as A Polynomial Function of Time and Time-dependent Deterioration

Machine learning-based bridge cable damage detection under stochastic effects of corrosion and fire

This paper proposes a novel machine learning-based cable damage detection model to investigate the upper and lower bounds of bridges’ cable damage degrees under the effects of corrosion and fire. In the proposed approach, the surrogate model for bridge cable damage detection under stochastic effects of corrosion and fire was established by combining machine learning and finite-element analysis to estimate the remaining life of cables. Then the accuracy and generalization performance of three typical machine learning methods for cable damage prediction are compared, such as Back Propagation neural network(BPNN), Radial Basis Function neural network(RBFNN) and Least Square-Support Vector Machine (LS-SVM). It is conducted that LS-SVM owns better prediction accuracy for cable damage under the coupling effects of corrosion and fire than the others. Additionally, the LS-SVM surrogate model combined with stochastic analysis and time-dependent deterioration model of steel wires under corrosion and fire is used to obtain the upper and lower bounds of cable damage under coupling effect of corrosion and fire. The proposed surrogate model can assist management in diagnosing and evaluating cable damage more quickly, efficiently, and flexibly once the real-time monitoring data is obtained. In addition, the surrogate model can guide bridge maintenance in advance.