Probability Of Damage Research Articles

Lipid Peroxidation and Detection of Pro-Inflammatory Variables in Rheumatoid Arthritis- A Comprehensive Analysis of Malondialdehyde and Isoprostanes in Synovial Fluids and SERA

Background: Rheumatoid arthritis (RA) is a chronic autoimmune disease marked by systemic inflammation and joint destruction produced mostly by oxidative stress and lipid peroxidation. Analyzing markers for these processes is critical to understanding the etiology of RA. Objectives: The goal of this study is to assess the importance of the lipid peroxidation indicators malondialdehyde (MDA) and isoprostanes in RA synovial fluids and sera in indicating oxidative stress, as well as their potential diagnostic use. Methodology: We carried up cross-sectional analytical study with 60 participants, evenly divided between RA patients and healthy controls of the same age and gender. Malondialdehyde levels were measured spectrophotometrically using the thiobarbituric acid reactive substances (TBARS) method, and isoprostanes were quantified using commercially available ELISA kits. The samples were obtained at the Arif Clinical and Diagnostic Centre and examined in the biochemical labs of Rashid Latif Hospital in Lahore. Results: The study found that RA patients had significantly higher levels of MDA and isoprostanes in their serum (MDA: 1.95±0.094 µmol/ml; Isoprostanes: 12.26±5.26 pg/ml) and synovial fluid (MDA: 3.26±0.65 µmol/ml; Isoprostanes: 34.26±4.26 pg/ml) compared to controls (MDA: 0.95±0.019 µmol/ml; Synovial Fluid MDA: 0.019±0.0016). Conclusion: Elevated levels of MDA and isoprostanes in RA patients highlight their significance as oxidative stress indicators, representing the continuous inflammatory process and probable joint damage in RA. These findings lend credence to the diagnostic and prognostic value of lipid peroxidation products in the treatment of RA.

Time-dependent reliability analysis for structures under multilevel loads based on fatigue damage theory

This paper proposes an efficient method to evaluate the time-dependent fatigue reliability of structures under complex multilevel loads using a finite set of fatigue test data obtained under single-level loading conditions. The method preserves the simplicity of linear damage accumulation theory while considering the interactions among multiple load levels and the influence of load sequence on reliability. Leveraging the linear damage rule, a cumulative damage probability model was established under single-level constant amplitude loading. This model incorporates a fatigue life degradation function to characterize the cumulative damage effect of load cycles and corrects the fatigue reliability curve under single-level constant amplitude loading. By employing the principle of fatigue damage equivalence, the method determines the damage equivalence at the load switching point using the damage curve method, enabling the conversion of equivalent reliability under multilevel loads. The proposed method was validated by combining the test data obtained under three working conditions, including two-level loads loading, load blocks loading, and changing loads loading. The results demonstrate that the proposed method can accurately and efficiently evaluate the time-dependent fatigue reliability under different types of multilevel loads, using only a limited set of fatigue life data under single constant amplitude loads.

A cloud model target damage effectiveness assessment algorithm based on spatio-temporal sequence finite multilayer fragments dispersion

To solve the problem of target damage assessment when fragments attack target under uncertain projectile and target intersection in an air defense intercept, this paper proposes a method for calculating target damage probability leveraging spatio-temporal finite multilayer fragments distribution and the target damage assessment algorithm based on cloud model theory. Drawing on the spatial dispersion characteristics of fragments of projectile proximity explosion, we divide into a finite number of fragments distribution planes based on the time series in space, set up a fragment layer dispersion model grounded in the time series and intersection criterion for determining the effective penetration of each layer of fragments into the target. Building on the precondition that the multilayer fragments of the time series effectively assail the target, we also establish the damage criterion of the perforation and penetration damage and deduce the damage probability calculation model. Taking the damage probability of the fragment layer in the spatio-temporal sequence to the target as the input state variable, we introduce cloud model theory to research the target damage assessment method. Combining the equivalent simulation experiment, the scientific and rational nature of the proposed method were validated through quantitative calculations and comparative analysis.

Sensitivity analysis of attack helicopter combat indicators based on machine learning

This paper focuses on sensitivity analysis in the design of Attack helicopter combat indicators, and combines the advantages of machine learning to propose a combat effectiveness oriented sensitivity analysis method for Attack helicopter combat indicators. Firstly, the steps of sensitivity analysis of Attack helicopter combat indicators based on machine learning are introduced. Secondly, through operational scenarios, constructing indicator systems, collecting relevant data, evaluating effectiveness, and using machine learning algorithms for modelling and training, the sensitivity assessment of the damage probability of Attack helicopter to ground armoured weapons can be achieved. This paper is able to provide reference for the sensitivity analysis of weapon equipment system effectiveness, and provide more scientific and reasonable support for the research and application of helicopters in combat systems.

Does transanal endomicrosurgery affects the results of “salvage mesorectumectomy” for patients with early rectal cancer? Systematic review and meta-analysis

Aim. Our systematic review and meta-analysis aimed to compare studies with primary mesorectumectomy (pME) and “salvage mesorectumectomy” (sME) after transanal endomicrosurgery for patients with early rectal cancer.Materials and methods. We selected publications from 1 January 1999 to 1 April 2023. A total of 7 studies were included after screening. Following indicators were compared: quality of mesorectum, frequency of abdominoperineal resection, frequency of local recurrence and distant metastases, mortality, morbidity, time of surgery, post-operative stay, frequency of involvement of circular resection margin. Statistical data was processed using ReviewManager 5.3.Results. Statistically significant differences were observed in probability of intraoperative damaging of mesorectal fascia (Odds Ratio (OR) 0.42; 95 % Confidence Interval (CI) 0.24–0.72, р = 0.002). There were also a trend towards decreasing of number of sphincter-preserving operations after transanal endomicrosurgery (TEM) (OR 1.84; 95 % CI 0.96–3.52, р = 0,06). Other indicators didn’t reach statistical significance when compared.Conclusion. sTME is a safe procedure and comparable with pME. However, previous TEM is considered a risk factor for damaging of mesorectum, intraoperative perforation and abdominoperineal resection.

Monte Carlo analysis of masonry structures under tsunami action: Reliability of lognormal fragility curves and overall uncertainty prediction

Tsunami vulnerability of coastal buildings has gained more and more interest in recent years, in the consciousness of what losses may be caused. The improvement of the available approaches for the quantitative estimation of the probability of building damage and for defining possible strategies for risk mitigation is an actual goal. In this framework, several authors have provided empirical fragility curves based on field surveys after tsunamis. Nevertheless, a predictive approach based on analytical fragility curves, which can be extended to many classes of buildings, is essential for the scopes of civil protection and risk mitigation. In this paper, an approach for the construction of fragility curves, proposed for masonry structures under tsunami waves, is discussed and refined in the part regarding the assignment of the uncertainties. Further, an assessment of the reliability of the lognormal fragility distribution is carried out based on a Monte Carlo simulation applied to 4 classes of buildings. Here, it is shown that Monte Carlo analysis allows a direct evaluation of the uncertainties without the need to resort to ambiguous regression analyses and rules of combination of the uncertainties of demand and capacity based on the regression analysis results or other uncertainty estimation approaches.

Seismic capacity models for earth dams and their use in developing fragility curves

This article develops seismic capacity models for earth dams and demonstrates how the proposed seismic capacity models may be used to develop seismic fragility curves that predict the probability of damage as a function of ground shaking intensity. Developing earth dam fragility curves requires two major components: (1) a seismic capacity model that predicts the probability of a damage state given the relative settlement (RS) and (2) an engineering demand model that predicts the RS as a function of ground motion intensity. While seismic demand models for earth dams have been studied by various researchers, there is a scarcity of seismic capacity models. This article focuses first on developing seismic capacity relationships using a dataset of earthquake case histories of dam performance. Different from previously developed relationships, only the damage description for each dam is used when assigning the damage state, which results in statistical variability in the capacity relationship between the damage state and RS. The fragility curve development is demonstrated by combining the seismic capacity relationships with a seismic demand model for RS derived from nonlinear, dynamic finite element analyses for a 20-m generic dam geometry subjected to a suite of earthquake motions from the NGA-West2 database.

Uncertain damage identification methods based on residual force vector under the influence of measurement noise

This paper proposes probabilistic and interval methods, grounded in the residual force vector technique, to quantify measurement uncertainties and effectively integrate them into the identification process. In the probabilistic method, the measurement noise is assumed to be a zero-mean normal distribution, while the stiffness parameters of structural elements are assumed to follow a normal distribution, represented by mean values and standard deviations. In the interval method, the measurement noise is modelled as interval numbers, and the interval perturbation technique is employed to derive interval bounds for elemental stiffness parameters. A two-step model updating strategy is implemented, separately addressing pristine and damaged structures, to mitigate modeling errors. By using the results of probabilistic damage identification, a novel damage index termed damage expectation capable of capturing both the extent and probability of damage is introduced. Furthermore, an interval damage index is introduced to quantify the damage based on interval damage identification results. The impact of noise levels on the statistical properties of uncertain damage indices is also investigated. Numerical examples reveal that deterministic indexes exhibit a monotonic increase in average values with increasing noise levels. Particularly, as noise levels rise, the standard deviation of the combination index initially surpasses the deterministic damage index but eventually diminishes. Through the proposed methodology, structural damage can be identified even in the presence of uncertainties. The efficacy of the proposed damage identification technique is also validated by experimental data.

Evaluating and strengthening low-rise reinforced concrete buildings constructed in Nepal

In Nepal, the reinforced concrete (RC) frame system is commonly used to construct low-rise buildings. In last three decades, a significant number of such buildings were proportioned and constructed in accordance with Nepal National Building Code NBC 205:1994 and NBC 205:2012—also known as the Mandatory Rule of Thumb (MRT). In the aftermath of 2015 Gorkha Earthquake (Mw 7.8) which resulted in large scale social and economic losses, the efforts to formulate improved seismic design provisions led to the development of NBC 105:2020. Considering that MRT-designed low-rise RC frame buildings still constitute a significant part of existing building stock, this study is aimed to conduct a comparative seismic performance evaluation of several case study structures under a comprehensive set of ground motions. Using the nonlinear analysis and seismic fragility assessment of four low-rise RC frame buildings (designed using all three code versions), it is shown that the structural performance and seismic losses can be significantly reduced by following NBC 105:2020 provisions. Several retrofitting solutions are also explored to improve the seismic performance of buildings designed using MRT. It is shown that the concrete or steel jacketing of RC columns can significantly increase the lateral strength and energy dissipation, and reduce the damage probability of such buildings. Lastly, based on the developed results, a machine learning approach is employed to correlate the peak ground acceleration with structural drifts for convenient practical applications.

Investigating the seismic performance and developing the fragility curves of self-centering steel frames with augmented nonlinear viscous damping: A numerical simulation

This paper focuses on investigating the seismic performance of post-tensioned steel frames equipped with nonlinear viscous dampers. The aim is to increase the ductility and seismic energy dissipation capacity of these structures. Finite element (FE) models were created using the Abaqus software and validated against reference experimental data under cyclic loading. Two types of post-tensioned moment-resisting frames (PT-Frames) were developed: a conventional PT-Frame and a PT-Frame with two pairs of nonlinear viscous dampers acting as knee braces (each brace pair, contains two dampers connected in parallel, thus there are 4 dampers used in total). Various analyses, including modal analysis, cyclic loading, and incremental dynamic analysis (IDA), were conducted using earthquake records mentioned in FEMA P-695. Fragility curves were plotted based on the IDA results. The findings indicate that the augmented nonlinear viscous damping significantly increases the natural fundamental period of vibration in PT-Frames (133 % increase observed). It also enhances the absorption and dissipation of input seismic energy (800 % increase in cumulative dissipated seismic energy observed). Moreover, it reduces the probability of damage exceeding the damage index value for different performance levels (collapse prevention, life safety, and immediate occupancy) by average values of 115 %, 61.72 %, and 25.126 %, respectively. These improvements help mitigate damage to the structural components.

Seismic Damage Probability Assessment of Existing Reinforced Concrete School Buildings in Afghanistan

Existing Reinforced Concrete School buildings with low earthquake resistance may suffer structural failure or severe damage in a catastrophic seismic event. Ascertaining earthquake resistance in existing school buildings is vital to confirming the safety of students, teachers, and all school members. Reinforced concrete (RC) has been used significantly for numerous years as the primary material due to its easy access and low cost-effectiveness in construction. The current research focused on analyzing the existing RC school buildings designed and constructed in various regions of Afghanistan over the last three decades. Seismic fragility curves, which are generated from incremental dynamic analysis (IDA), have been used to evaluate the damage probability of RC school buildings against earthquake ground motions. In this investigation, 34 RC school buildings were selected from an extensive database and subsequently classified as either A-type or B-type based on specific criteria, including design details and construction year. Following this classification, an assessment of the seismic damage probability for these buildings was conducted using probabilistic models based on IDA curves. The results indicate that A-type school buildings with newer construction are less prone to damage compared to B-type school buildings, showing improved resilience. Especially the B-type buildings in seismic Zone-I are found to be highly vulnerable under the maximum considered earthquake scenarios.

Design and experimental study on rheological behavior and sealing performance of shear sensitive fluids to control lost circulation during drilling

Loss circulation is considered as a time-consuming, costly, and challenging issue while drilling or cementing jobs, which ought to be treated and resolved promptly. The choice of a treatment that quickly plugs the loss zone and helps to restore the circulation is critical. Cross-linkable polymer gels play a significant role in mitigating drilling fluid loss, but controlling the gelation time and pumpability are the main challenges of these gels. This research aims to evaluate a novel smart fluid that has high flexibility in design. The shear sensitive fluid (SSF) is an oil-based fluid containing a polymer, gelation agents, and multi-crosslinkers. After passing through the drilling bit, the SSF is crosslinked with time to produce a high strength gel. The designed shear sensitive fluid is one of the possible solutions for severe loss circulation.The overall purpose of this research was to scrutinize the gelation behavior and SSF performance as a smart lost circulation treatment, which was followed in two sections including experimental analysis and empirical modeling. The effect of various factors including the type of crosslinker, shear rate, emulsifier concentration, temperature, shear history, salinity, etc. on the performance of the formed gels was studied. Furthermore, the maximum sealing pressure of formed gels in the highly permeable porous medium and fractured core as well as the probability of formation damage was evaluated.In order to determine the correlations required to predict the ultimate gelation time of SSF, the response surface methodology was utilized according to the central composite design. The considerable values of correlation coefficients (R2 = 0.91) prove the validity of estimated models for the fit enough responses with the experimental data. For the designed SSFs, depending on the operating conditions, the appropriate gelation time can be adjusted by emulsifier concentration and shear rate values. Also, the minimum gelation time and the highest crosslinking rate occur approximately at the shear rate of 45,000 1/s. At high shear rates, the effect of temperature on the functionality of the formed gels decreases, which is due to the high rate of crosslinking. Based on dynamic sealing pressure tests, the SSFs have a high potential in mitigation of lost circulation during drilling. The maximum sealing pressure was measured above 1000 psi in highly permeable porous medium and up to 600 psi in fractured core, which indicate the high strength of the formed gels against drilling fluid pressure. The designed SSFs could be easily removed from reservoir by 15 vol% hydrochloric acid, indicating the non-damaging properties of the formed gels.

Probabilistic risk assessment for reinforced concrete frame structures subject to mainshock‐aftershock sequences

AbstractRecent earthquakes have highlighted that aftershocks can considerably increase the structural demand and seismic risk of engineering structures. This study presents a probabilistic approach to assess the seismic risk of reinforced concrete (RC) frame structures subjected to mainshock‐aftershock sequences. In this approach, a predictive fragility method is used to evaluate the probabilities of structural damage under sequential excitations. The Bayes theorem is employed to generate posterior distributions of unknown model parameters. Then, a practical seismic hazard assessment method is used to conduct mainshock‐aftershock hazard analysis. The Copula technique is employed to develop a joint distribution model of the mainshock and aftershock intensity measures. Finally, the seismic risk is evaluated using the classical risk integration equation with the mainshock‐aftershock fragilities and hazard surfaces. Confidence bounds for fragilities and seismic risks are also obtained to account for the uncertainties of model parameters caused by aftershocks. The proposed approach is demonstrated by considering a seismic‐designed RC frame building. It can be concluded that aftershocks can significantly increase the seismic risk throughout the entire structural service life. The additional uncertainties caused by aftershocks result in wider confidence bounds for seismic risk.

Understanding the multi-source uncertainties effect on the seismic performance assessment of deeply hydraulic tunnels based on the generalized PDEM

One crucial element of a seismic performance evaluation approach is to appropriately account for the stochastic characteristics of SGMs and the uncertainty associated with material properties. Furthermore, the incidence angle of seismic waves may be influenced by topographic and geological factors, leading to uncertainty and randomness. This variability in incident angles has the potential to cause unforeseen structural damage. However, the current seismic design code of underground structures has commonly assumed the vertical or horizontal seismic input method in underground engineering. From the uncertain point of view, the multi-source uncertainties that incorporate the nonstationary SMGs, seismic input angles, and material parameters utilized to conduct the seismic performance assessment of HTs remain a challenge in current seismic design and performance evaluation. To overcome this challenge, the Generalized F-discrepancy method, the generalized PDEM, and the equivalent extreme-value event are introduced to conduct stochastic dynamic analysis and develop the appropriate fragility curves of HTs considering the multi-source uncertainties. The results demonstrate that the probability of damage of the HT obtained by multi-source uncertainties is significantly different in analyzing the single uncertain and two uncertainties. Moreover, it can be concluded that the multi-source uncertainties can cause more seismic demand than the single uncertain and two uncertainties under different earthquake intensity levels for the HT. In light of this, it is strongly suggested that seismic design and performance assessment of HTs take into account the relevant aspects, such as the input angles, the random features of seismic waves, and the material parameters.

Exploring the association between serum phosphate levels and mortality in patients hospitalized with infectious diseases: a nationwide study.

The purpose of this study was to examine associations of serum phosphate levels with mortality, target organ damage and length of hospital stay in adults with infectious diseases hospitalized outside of the intensive care unit. This nationwide retrospective cohort study comprised patients admitted with infections, to medical and surgical departments in eight tertiary hospitals during 2001-2020. The main exposure variable was the first serum phosphate levels at admission (up to 1 week). The analysis included multivariable logistic regression models and quantile regression. Of 126,088 patients (49% males, mean age: 69.3 years), 24,809 (19.7%) had decreased phosphate levels, 92,730 (73.5%) normal phosphate levels, and 8,549 (6.8%) elevated phosphate levels on admission. Overall- and in-hospital mortality rates were highest among those with hyperphosphatemia (74.5 and 16.4%, respectively), followed by those with normophosphatemia (57.0 and 6.6%), and lastly the hypophosphatemia group (48.7 and 5.6%); p < 0.001 for all. After adjusting for confounders, the lowest predicted mortality rate was observed in the normophosphatemia group. In the multivariable model, hyperphosphatemia conferred a higher probability of target organ damage (OR [95% CI]: 2.43 [2.06-2.86]), while moderate hypophosphatemia conferred a lower probability (OR [95% CI]: 0.73 [0.65-0.82]), compared to normal phosphate levels and extreme hypophosphatemia showed a non-significant association (OR [95% CI]: 0.87 [0.57-1.28]). The associations were independent of renal failure. In a multivariable model, hyperphosphatemia was associated with a slight increase of 0.33 days in length of stay compared to normal phosphate levels. A J-shaped relation was found between phosphate levels and prognosis in patients hospitalized with infectious diseases, regardless of their renal function.

Intrusive luxation in primary dentition: clinical report

Intrusive dislocation is the most frequent type of traumatic injury in the primary dentition, characterized by displacement of the tooth into the alveolus. Intrusions require a thorough physical examination, radiographs of diagnostic value, and follow-up of the case, since the prognosis is unfavorable, mainly due to the probability of damage to the permanent tooth germ. This work aims to report a clinical case of intrusive dislocation in the primary dentition, from diagnosis to follow-up. This is a male patient, 3 years old, who attended the Emergency of the Children’s Specialty Clinic – State University of Londrina (UEL) due to dento-alveolar trauma in the antero-superior region that occurred three days ago. On clinical examination, tooth 61 had grade II intrusion (one-third of the crown visible), and tooth 62 had grade I intrusion, with more than one-third of the crown visible. Radiographically, a buccal inclination was observed, with no fracture of the bone plate. Thus, we opted for conservative treatment, waiting for the spontaneous re-eruption of the teeth involved. Furthermore, parents were informed about the possible consequences of this type of trauma and the need for clinical and radiographic follow-up consultations. After eight months of follow-up, the teeth erupted satisfactorily. It is extremely important to establish a protocol for observation and control of the traumatized tooth, observing signs and symptoms of the tissues involved in the trauma to reduce sequelae in both dentitions.

Fragility assessment of sea-crossing cable-stayed bridge subjected to multi-hazard action via TKC and R-vine copula

Seismic fragility analysis methods commonly used for assessing structural components and systems have certain limitations. This paper introduces a new semi-parametric approach for structural component fragility analysis, the TKC method. This method is based on log-transformed kernel density estimation (log-TKDE) and copula functions, which establish the joint probability distribution (JPD) of a structural response value (d) and a disaster-inducing factor strength parameter (α) using log-TKDE and match the marginal cumulative distributions (MCDs) of d and a via bivariate copula functions. A novel method for evaluating structural system fragility is also proposed based on the R-vine copula function. This approach accounts for the intricate correlations among different components, providing a precise estimation of the multidimensional JPD. The reliability and accuracy of the proposed methods are demonstrated through a seismic fragility analysis of a sea-crossing cable-stayed bridge under earthquake load. Furthermore, a multi-hazard fragility analysis of bridge components and systems is conducted considering hazards such as earthquake, wind, and wave loads. A comparison is made with the seismic fragility of bridges subjected to earthquake loads alone. The results show that the median and 95% confidence of the damage probability of structural components calculated by the TKC method and Monte Carlo simulation (MCS) closely match, which validates the proposed method. The TKC method is also more accurate and computationally efficient than the MCS method with the same Bootstrap sample size and confidence level (95%). The proposed structural system fragility assessment method based on the R-vine copula accounts for complex correlations between components and yields more accurate results than the first-order boundary method. Load spectrum characteristics, structural component characteristics, and other factors cause the multi-hazard fragility of bridge components and systems to differ substantially from their seismic fragility. The difference rate of system damage probability can reach 28.82%. In evaluating the anti-disaster performance of sea-crossing bridges, it is necessary to incorporate the marine environmental load and consider the dynamic response coupling effect of the bridge excited by seafloor ground motions with extreme wind and wave loads. This approach can guide the optimization of bridge designs and facilitate multi-hazard fragility analysis in accordance with real damage probabilities.

Impact of Consumer Subsidy Considering Subsidy Threshold on New Energy Vehicle Firms and Environmental Benefits

This paper investigates a competitive market consisting of two new energy vehicle (NEV) firms with a technology gap and consumers with green preferences. By employing a Hotelling model, we obtain the equilibrium outcomes of two competing firms without and with segmented consumer subsidy (SCS) following Nash game theory. We further explore the incentive effect, effective scope of SCS policy and the impacts of subsidy threshold and technology improvement on it, which fills the gap in the literature and provides managerial insights. We find that SCS can only play a role when the threshold is intermediate, and the government can expand the effective scope of subsidies by cultivating consumers’ green preferences and strengthening the intensity of subsidies. Moreover, the government can change the competitiveness and green level gap of two firms through the threshold. When threshold is small (large), increasing it can narrow (expand) the green level gap between two firms but widen (narrow) the market gap. We also find that implementing an SCS policy has a positive impact on environmental benefits and technological improvement is more likely to cause environmental damage. However, the government can effectively decrease the degree and probability of damage by raising the subsidy threshold and reducing the subsidy amount.

A Pushover analysis approach considering structural and loading uncertainties for seismic performance assessment

This paper proposes an approach for evaluating the seismic performance of buildings. By considering the uncertainties in material and geometrical properties of the structural elements as well as those related to the seismic loading, this method aims to delimit the performance zone of the structure rather than focusing on a single performance point commonly used in pushover analysis. This zone makes it possible to identify the probable levels of performance of the building linked to uncertainties and to indicate the most severe level of damage. Reasoning by performance points leads to an answer that gives a single state of damage. The performance zone is defined by capacity curves and response spectrum representing the mean values plus and minus standard deviation obtained by Monte Carlo simulations. These simulations consider the stiffnesses of the structural elements, the natural periods, and the damping ratio of the response spectrum as random variables. The application of the procedure to a case of a building made it possible to identify the upper limit of damage corresponding to the most unfavourable scenario of uncertainties, as well as the situation of the response value of the studied structure in the performance zone, indicating a less critical level of damage (minor damage) to the building. The calculation of the performance point revealed a level of damage oscillating between Immediate Occupancy (IO) and Life Safety (LS). Considering the uncertainties in the material and geometric properties of the structural elements as well as those linked to the response spectrum, the probable extreme damage state is between the LS and CP levels (severe damage).

Mechanical Damage Caused by Compression and Its Effects on Storage Quality of Mandarin.

Mandarin is vulnerable to a range of external loads during processing and shipping, which can cause interior mechanical damage that can happen right away or over time and cause serious rotting when kept in storage. In this study, mandarin was treated to a certain quantity of compression load that did not result in a noticeable rupture of the peel. The interior pulp structure of mandarin was examined for damage prior to peel damage using CT scanning and image reconstruction. An image segmentation method based on mask processing was then used to calculate the pulp damage rate. We examined the variations in physiological activities and internal components between the test group that underwent compression load and the control group that did not undergo this type of stress during storage. The aim was to investigate the factors that contributed to the faster decay of mandarin following mechanical damage. Regression analysis was also used to establish a quantifiable relationship between the amount of compression deformation and the rates of damage and decay of mandarin during storage. The findings demonstrated that mandarin pulp exhibited visible mechanical damage when compression deformation exceeded 8 mm. This led to the disruption of physiological processes like respiration and polysaccharide breakdown, which in turn decreased the hardness of the fruit and sped up its rotting. This study identifies the critical range of compression deformation that leads to the beginning of pulp damage in mandarins. Additionally, it clarifies the quality deterioration mechanism of mandarins that have been subjected to compression damage during the storage period. Therefore, in practical production, various methods of picking, sorting, and collecting mandarins can be optimized to control the amount of compression deformation within a suitable range. This will reduce the probability of pulp damage. According to the study's conclusions, storage conditions can be optimized to regulate the physiological activities of mandarins in a targeted manner. This can minimize the probability of fruit decay and reduce economic losses.