Deterioration and loss of quality of vegetable oil is a big challenge in the food industry.This study investigated the synthesis of nickel ferrite(Ni Fe_(2)_(O4))via co-precipitation method and its use for the removal...Deterioration and loss of quality of vegetable oil is a big challenge in the food industry.This study investigated the synthesis of nickel ferrite(Ni Fe_(2)_(O4))via co-precipitation method and its use for the removal of free fatty acids(FFAs)in deteriorated vegetable oil.Ni Fe2 O4 was characterized using Fourier transformed infrared spectroscopy(FTIR),X-ray diffraction(XRD),thermogravimetric(TG)analysis,Brunauer–Emm ett–Teller(BET)surface area,transmission electron microscopy(TEM),scanning electron microscopy(SEM)and energy-dispersive X-ray spectroscopy(EDX).Synthesis of Ni Fe_(2)_(O4)was confirmed by characterization,which revealed a BET surface area of 16.30 m^(2)·g^(-1)and crystallite size of 29 nm.Ni Fe_(2)_(O4)exhibited an adsorption capacity of 145.20 L·kg^(-1)towards FFAs with an 80.69%removal in a process,which obeys Langmuir isotherm and can be described by the pseudo-second-order kinetic model.The process has enthalpy(DH)of 11.251 k Jámolà1 and entropy(DS)of 0.038 k J·mol^(-1)K^(-1)with negative free energy change(DG),which suggests the process to be spontaneous and endothermic.The quantum chemical computation analysis via density functional theory further revealed the sorption mechanism of FFAs by Ni Fe_(2)_(O4)occurred via donor–acceptor interaction,which may be described by the lowest unoccupied molecular orbital(LUMO)and the highest occupied molecular orbital(HOMO).The study showed Ni Fe_(2)_(O4)to be a potential means that can remove FFAs from deteriorated vegetable oil.展开更多
This paper aims to present an effective method to partial deteriorated strength columns,and to investigate the mechanical behavior of the defect part. Five groups of 150×150 mm×mm plain square columns are ca...This paper aims to present an effective method to partial deteriorated strength columns,and to investigate the mechanical behavior of the defect part. Five groups of 150×150 mm×mm plain square columns are cast; each specimen has two different strengths,the lower strength in the middle segment and higher strength in both ends. The lower strength is to simulate the status of partial deteriorated region. Different layers of CFRP sheets have been wrapped just on the lower strength part to gain the reinforcement with CFRP sheets,and to verify the practicability of partial confinement. Specimens are subjected to monotonic axial compression until failure. Axial load,axial and transverse strains are measured to compare the different behaviors between the two parts. Experimental results show that partial confinement can significantly enhance the strength and the ductility of the deteriorated strength part,then,the load capacity of the whole column can be increased subsequently. Test data indicate that the ultimate load of the confined column is higher than that of the original column without deterioration; partial confinement on weakness is a feasible approach.展开更多
This paper considers a deteriorated multi-item economic order quantity (EOQ) problem, which has been studied in literature, but the algorithms used in the literature are limited. In this paper, we explore the optimal ...This paper considers a deteriorated multi-item economic order quantity (EOQ) problem, which has been studied in literature, but the algorithms used in the literature are limited. In this paper, we explore the optimal policy of this inventory problem by analyzing the structural properties of the model, and introduce a simple algorithm for generating the optimal solution to this problem. Numerical results are reported to show effi-cacy of the proposed method.展开更多
Different from oil and gas production,hydrate reservoirs are shallow and unconsolidated,whose mechanical properties deteriorate with hydrate decomposition.Therefore,the formations will undergo significant subsidence d...Different from oil and gas production,hydrate reservoirs are shallow and unconsolidated,whose mechanical properties deteriorate with hydrate decomposition.Therefore,the formations will undergo significant subsidence during depressurization,which will destroy the original force state of the production well.However,existing research on the stability of oil and gas production wells assumes the formation to be stable,and lacks consideration of the force exerted on the hydrate production well by formation subsidence caused by hydrate decomposition during production.To fill this gap,this paper proposes an analytical method for the dynamic evolution of the stability of hydrate production well considering the effects of hydrate decomposition.Based on the mechanical model of the production well,the basis for stability analysis has been proposed.A multi-field coupling model of the force state of the production well considering the effect of hydrate decomposition and formation subsidence is established,and a solver is developed.The analytical approach is verified by its good agreement with the results from the numerical method.A case study found that the decomposition of hydrate will increase the pulling-down force and reduce the supporting force,which is the main reason for the stability deterioration.The higher the initial hydrate saturation,the larger the reservoir thickness,and the lower the production pressure,the worse the stability or even instability.This work can provide a theoretical reference for the stability maintaining of the production well.展开更多
Here,we aimed to study the changes in proteome of golden pompano fillets during post-mortem storage.Tandem mass tags(TMT)-labeled quantitative proteomic strategy was applied to investigate the relationships between pr...Here,we aimed to study the changes in proteome of golden pompano fillets during post-mortem storage.Tandem mass tags(TMT)-labeled quantitative proteomic strategy was applied to investigate the relationships between protein changes and quality characteristics of modified atmosphere packaging(MAP)fillets during superchilling(-3°C)storage.Scanning electron microscopy was used to show that the muscle histology microstructure of fillets was damaged to varying degrees,and low-field nuclear magnetic resonance was used to find that the immobilized water and free water in the muscle of fillets changed significantly.Total sulfhydryl content,TCA-soluble peptides and Ca2+-ATPase activity also showed that the fillet protein had a deterioration by oxidation and denaturation.The Fresh(FS),MAP,and air packaging(AP)groups were set.Total of 150 proteins were identified as differential abundant proteins(DAPs)in MAP/FS,while 209 DAPs were in AP/FS group.The KEGG pathway analysis indicated that most DAPs were involved in binding proteins and protein turnover.Correlation analysis found that 52 DAPs were correlated with quality traits.Among them,8 highly correlated DAPs are expected to be used as potential quality markers for protein oxidation and water-holding capacity.These results provide a further understanding of the muscle deterioration mechanism of packaging golden pompano fillets during superchilling.展开更多
Since the advent of transcatheter aortic valve replacement(TAVR)in 2002,it has now become the default interventional strategy for symptomatic patients presenting with severe aortic stenosis,particularly in intermediat...Since the advent of transcatheter aortic valve replacement(TAVR)in 2002,it has now become the default interventional strategy for symptomatic patients presenting with severe aortic stenosis,particularly in intermediate to highsurgical risk patients.In 2019,the United States Food and Drug Administration approved TAVR in low-risk patients based on two randomized trials.However,these breakthrough trials excluded patients with certain unfavorable anatomies and odd profiles.While currently there is no randomized study of TAVR in young patients,it may be preferred by the young population given the benefits of early discharge,shorter hospital stay,and expedite recovery.Nonetheless,it is important to ruminate various factors including lifetime expectancy,risk of pacemaker implantation,and the need for future valve or coronary interventions in young cohorts before considering TAVR in these patients.Furthermore,the data on long-term durability(>10 years)of TAVR is still unknown given most of the procedures were initially performed in the high or prohibitive surgical risk population.Thus,this editorial aims to highlight the importance of considering an individualized approach in young patients with consideration of various factors including lifetime expectancy while choosing TAVR against surgical aortic valve replacement.展开更多
The main purpose of this paper is to generalize the effect of two-phased demand and variable deterioration within the EOQ (Economic Order Quantity) framework. The rate of deterioration is a linear function of time. Th...The main purpose of this paper is to generalize the effect of two-phased demand and variable deterioration within the EOQ (Economic Order Quantity) framework. The rate of deterioration is a linear function of time. The two-phased demand function states the constant function for a certain period and the quadratic function of time for the rest part of the cycle time. No shortages as well as partial backlogging are allowed to occur. The mathematical expressions are derived for determining the optimal cycle time, order quantity and total cost function. An easy-to-use working procedure is provided to calculate the above quantities. A couple of numerical examples are cited to explain the theoretical results and sensitivity analysis of some selected examples is carried out.展开更多
Objective:To explore the risk factors for the progression of renal function deterioration in patients with diabetic nephropathy(DN).Methods:The clinical data and biochemical indexes of 100 diabetic patients admitted t...Objective:To explore the risk factors for the progression of renal function deterioration in patients with diabetic nephropathy(DN).Methods:The clinical data and biochemical indexes of 100 diabetic patients admitted to our hospital from October 2021 to October 2022 were retrospectively analyzed.The patients were divided into a DN group,which consisted of 55 cases,and a nondiabetic nephropathy group(NDN),which consisted of 45 cases.The urinary microalbumin to creatinine ratio,the clinical data(gender,age,duration of the disease,and BMI),and the biochemical indexes(triglycerides[TG],low-density lipoprotein cholesterol[LDL-C],high-density lipoprotein cholesterol[HDL-C],total cholesterol[TC],glycated hemoglobin A1c[HbA1c],systolic blood pressure[SBP],diastolic blood pressure[DBP])of the two groups were compared.Subsequently,the risk factors related to the progression of renal function deterioration in DN were analyzed through multifactorial logistic regression analysis.Results:No statistically significant difference was observed in the comparison of gender,age,BMI,LDL-C,and DBP between the two groups(P>0.05).The DN group demonstrated a longer disease duration and higher SBP,TC,HDL-C,HbA1c,and TG compared to the NDN group(P<0.05).Through multifactorial logistic regression analysis,it was found that the duration of the disease,the TC,the HDL-C,the HbA1c,the TG,and the SBP were independent risk factors of the deterioration of renal function in DN patients.Conclusion:Other than conventional indicators,TC,HDL-C,HbA1c,TG,and SBP are also crucial indicators in determining the progression of renal function deterioration in DN patients.展开更多
The objective is to develop a model considering demand dependent on selling price and deterioration occurs after a certain period of time, which follows two-parameter Weibull distribution. Shortages are allowed and fu...The objective is to develop a model considering demand dependent on selling price and deterioration occurs after a certain period of time, which follows two-parameter Weibull distribution. Shortages are allowed and fully backlogged. Fuzzy optimal solution is obtained by considering hexagonal fuzzy numbers and for defuzzification Graded Mean Integration Representation Method. A numerical example is provided for the illustration of crisp and fuzzy, both models. To observe the effect of changes in parameters, sensitivity analysis is carried out.展开更多
We consider the preventive maintenance of a production system that is deteriorated by random shocks and the production process itself. The degree of deterioration is modeled by discrete and finite states. Shocks arriv...We consider the preventive maintenance of a production system that is deteriorated by random shocks and the production process itself. The degree of deterioration is modeled by discrete and finite states. Shocks arrive according to a Poisson process and deteriorate the system by random amounts. The system may deteriorate whenever it produces an item. The system is continuously monitored and repaired if the system state is at or above a predetermined level for maintenance. We analyze the lifetime, product quantity, average cost, and average profit considering revenue from the product and cost due to setup, operation, and repair. Assuming a structure of system parameters and costs, using numerical examples, we investigate the impact of production and shock arrivals on the average profit and the optimal maintenance level that maximizes the average profit. The proposed model is applicable to manufacturing tasks in which machines wear due to production, for example, press processes, milling, turning, punching, and drilling.展开更多
To reveal the deterioration mechanism and service life of concrete durability in the western saline soil area,the indoor accelerated test of the concrete specimen was simulated in the coupled environment of salt erosi...To reveal the deterioration mechanism and service life of concrete durability in the western saline soil area,the indoor accelerated test of the concrete specimen was simulated in the coupled environment of salt erosion and dry-wet cycles in the west saline soil area of China.The deterioration mechanism of concrete durability was revealed through the relative dynamic elastic modulus,relative quality evaluation parameters,SEM,and XRD evaluation indexes.Random Wiener distribution function was used for modeling life prediction.The results show that the relative dynamic elastic modulus evaluation parameter as an evaluation index of concrete durability under various environmental coupling effects is more reliable than the relative quality,there were holes and cracks in the concrete,and needle-like and layered crystals grow from the internal cracks.The corrosion products include ettringite,gypsum and other expansive crystals and non-gelling Mg(OH)_(2);the expansion stress caused by physical,chemical reaction,and temperature change under the action of drywet cycle aggravates the formation and development of cracks.The random Wiener distribution function can describe the degradation process of concrete specimen durability,and the established concrete reliability function can intuitively reflect the service life of concrete specimens.展开更多
Under the periodic rise and fall of the water level in the Three Gorges Reservoir in China,the rock mass in the ebb and flow zone of the slope is always in a state of a dry-wet cycle.In order to explore the influence ...Under the periodic rise and fall of the water level in the Three Gorges Reservoir in China,the rock mass in the ebb and flow zone of the slope is always in a state of a dry-wet cycle.In order to explore the influence of dry-wet cycle on mechanical properties of jointed sandstone,the triaxial and uniaxial compression tests of dry-wet cycle of jointed sandstone were carried out.For the experiment,four groups of samples with different numbers of joints were set up,and the jointed rock samples were subjected to 20 dry-wet cycles.Using both the triaxial compression test and the Mohr-Coulomb(M-C)rock fracture criterion,the strength envelope of the sandstone samples was fitted,and their strength degradation was further analyzed and studied.The results show that:(1)The peak intensity and elastic modulus of the sandstone samples decrease with increased number of dry-wet cycles.(2)The total deterioration of mechanical properties of intact rock samples is bigger than that of jointed sandstone samples as the number of dry-wet cycles increases.(3)With the increase of confining pressure,the peak intensity of intact sandstone samples increases much more than that of jointed sandstone samples,which indicates that joints and their numbers have obvious influence.(4)Joints and their numbers play an important role in guiding the damage effects of sandstone samples,which weaken the damage caused by dry-wet cycles.Therefore,the envelope of the M-C strength criterion of intact sandstone samples moves more than that of jointed sandstone samples.展开更多
Recent studies for computer vision and deep learning-based,post-earthquake inspections on RC structures mainly perform well for specific tasks,while the trained models must be fine-tuned and re-trained when facing new...Recent studies for computer vision and deep learning-based,post-earthquake inspections on RC structures mainly perform well for specific tasks,while the trained models must be fine-tuned and re-trained when facing new tasks and datasets,which is inevitably time-consuming.This study proposes a multi-task learning approach that simultaneously accomplishes the semantic segmentation of seven-type structural components,three-type seismic damage,and four-type deterioration states.The proposed method contains a CNN-based encoder-decoder backbone subnetwork with skip-connection modules and a multi-head,task-specific recognition subnetwork.The backbone subnetwork is designed to extract multi-level features of post-earthquake RC structures.The multi-head,task-specific recognition subnetwork consists of three individual self-attention pipelines,each of which utilizes extracted multi-level features from the backbone network as a mutual guidance for the individual segmentation task.A synthetical loss function is designed with real-time adaptive coefficients to balance multi-task losses and focus on the most unstably fluctuating one.Ablation experiments and comparative studies are further conducted to demonstrate their effectiveness and necessity.The results show that the proposed method can simultaneously recognize different structural components,seismic damage,and deterioration states,and that the overall performance of the three-task learning models gains general improvement when compared to all single-task and dual-task models.展开更多
In this paper,the effects of different mineral admixtures and sulfate solution types on the appearance,mass change rate,relative dynamic elastic modulus,and corrosion resistance coefficient of concrete were systematic...In this paper,the effects of different mineral admixtures and sulfate solution types on the appearance,mass change rate,relative dynamic elastic modulus,and corrosion resistance coefficient of concrete were systematically studied.X-ray Diffraction(XRD),Mercury Intrusion Porosimetry(MIP),Scanning Electron Microscopy(SEM),and X-ray Computed Tomography(X-CT)were used to explore and analyze the changes in the microstructure and the corrosion products of concrete in the sulfate solution.The results show that the existence of magnesium ions accelerates concrete deterioration.There is a critical dosage of fly ash for magnesium sulfate resistance of concrete.The magnesium sulfate resistance of concrete is improved when the fly ash content is less than 20%.Slag can significantly improve the corrosion resistance of concrete to magnesium sulfate.The diffusion of sulfate ions into concrete is a gradual process.In the early stages of corrosion,sulfate ion content in the concrete immersed in the magnesium sulfate solution is slightly less than that of the concrete immersed in the sodium sulfate solution.However,in the later stage of corrosion,the sulfate ion content in the concrete immersed in the magnesium sulfate solution is significantly higher than that of the concrete immersed in the sodium sulfate solution.展开更多
As a kind of green concrete,the mechanical properties and durability of cemented gangue backfill material(CGBM)will be affected if they are in acid mine water with sulfate ions in the long term.To improve the performa...As a kind of green concrete,the mechanical properties and durability of cemented gangue backfill material(CGBM)will be affected if they are in acid mine water with sulfate ions in the long term.To improve the performance of CGBM in acid mine water with sulfate ions,CGBM specimens with different doses of barium hydroxide were immersed in sulfuric acid solutions of different concentrations for 270 days.The changes of mass,ultrasonic pulse velocity(UPV)and compressive strength of the specimens at different ages were analyzed.Scanning electron microscopy(SEM)and X-ray diffraction(XRD)were used to analyze the microstructure and composition of the specimens.The results show that incorporation of barium hydroxide into CGBM specimen can promote the formation of barium sulfate precipitation and inhibit the generation of corrosion products such as ettringite.Meanwhile,barium sulfate precipitation blocks the pore channel invaded by sulfuric acid solution,delaying the progress of corrosion reaction and making the interior of CGBM specimen more complete.And the specimen with 2.0 kg/m^(3)barium hydroxide was more effective in improving performance.This study provides a basis for the ratio design of CGBM in acid mine water with sulfate ions.展开更多
Currently,energy conservation draws wide attention in industrial manufacturing systems.In recent years,many studies have aimed at saving energy consumption in the process of manufacturing and scheduling is regarded as...Currently,energy conservation draws wide attention in industrial manufacturing systems.In recent years,many studies have aimed at saving energy consumption in the process of manufacturing and scheduling is regarded as an effective approach.This paper puts forwards a multi-objective stochastic parallel machine scheduling problem with the consideration of deteriorating and learning effects.In it,the real processing time of jobs is calculated by using their processing speed and normal processing time.To describe this problem in a mathematical way,amultiobjective stochastic programming model aiming at realizing makespan and energy consumption minimization is formulated.Furthermore,we develop a multi-objective multi-verse optimization combined with a stochastic simulation method to deal with it.In this approach,the multi-verse optimization is adopted to find favorable solutions from the huge solution domain,while the stochastic simulation method is employed to assess them.By conducting comparison experiments on test problems,it can be verified that the developed approach has better performance in coping with the considered problem,compared to two classic multi-objective evolutionary algorithms.展开更多
Cassava (Manihot esculenta Crantz) is the third largest source of calories in tropical countries and the sixth most important food crop in the World. However, the short shelf life of its storage roots after harvest du...Cassava (Manihot esculenta Crantz) is the third largest source of calories in tropical countries and the sixth most important food crop in the World. However, the short shelf life of its storage roots after harvest due to a rapid post-harvest physiological deterioration (PPD) makes the roots to be considered as a risky product to market. The objectives of this work were to investigate the influence of two harvest periods on cassava agronomic parameters and their physiological response to PPD. Three cassava cultivars 96/1414, I070593 and LMR were selected for the experiment and harvested at 10 and 12 months after planting (MAP). The response to PPD was assessed during storage at 0, 3, 8 and 15 days after harvest (DAH). Total proteins content, soluble sugars and starch, total polyphenols compounds, polyphenoloxidase and peroxidase activities were recorded during storage. Results showed large variation among the parameters at the two harvest periods across the cultivars. High number of tubers was recorded in all the cultivars at 12 MAP and a significant increase in storage roots length was observed in 96/1414 and LMR from 10 MAP to 12 MAP (25 ± 5.1 to 41.3 ± 5.9 and 22.6 ± 3.3 to 27.9 ± 4.8) respectively. A reduction of about 49% of tubers weight was observed in I070593 from 10 to 12 MAP while an increase of about 36% and 11% were recorded in LMR and 96/1414 respectively. Tubers from I070593 showed less susceptibility to PPD when harvested at 10 MAP compared to those from LMR and 96/1414 where less susceptibility to PPD were recorded at 12 MAP. An increase in soluble sugars content, total proteins content and peroxidase activity subsequently to a decrease in starch content were recorded during storage from 8 to 15 days after harvest especially at 10 MAP in I070593 and at 12 MAP in LMR and 96/1414. High content of total phenolic compounds and less activity of polyphenol oxidase were correlated to PPD susceptibility. This work opens a new insight issue of the consideration of the appropriate harvest time of the cultivars as a tool to better control the onset of postharvest physiological deterioration.展开更多
Background: Prune belly syndrome (PBS) is a congenital anomaly that consists of a triad of abdominal wall defect, bilateral cryptorchidism, and urinary tract dilation. The disease is of varying severity. This study ai...Background: Prune belly syndrome (PBS) is a congenital anomaly that consists of a triad of abdominal wall defect, bilateral cryptorchidism, and urinary tract dilation. The disease is of varying severity. This study aims to highlight the challenges and peculiarities in the management of PBS in a resource-poor setting. Materials and Methods: This is a ten-year retrospective study conducted at the University of Port Harcourt Teaching Hospital. Ethical approval for the study was sought and gotten from the hospital’s ethical committee. The information gotten included history, duration of symptoms, examination findings, age of the patient, category of disease, and intraoperative findings. The data from the folders were collected and evaluated. Frequencies, percentages, the mean and standard deviation were used to summarize the data as appropriate. Results: Fifteen patients were included in the study. The hospital incidence of PBS was 112/100,000, twelve males and three females. The age range was from 1 day to 15 years, mean age was 14 months ± 2.3 months. Most patients presented between 3 months and 2 years and 11 months. Twelve patients had category three PBS and five patients had associated anomalies. Eleven male patients died after 5 years of follow-up from progressive renal deterioration. The female patient fared better than the males. Conclusion: PBS is rare, most patients with the condition present late. The most common cause of mortality was progressive renal deterioration.展开更多
Bridges serve as essential parts of transportation infrastructure,facilitating the movement of people and goods across rivers,valleys,and other obstacles.However,they are also susceptible to a wide range of natural ha...Bridges serve as essential parts of transportation infrastructure,facilitating the movement of people and goods across rivers,valleys,and other obstacles.However,they are also susceptible to a wide range of natural hazards,including floods,earthquakes,and landslides,which can damage or even collapse these structures,leading to severe economic and human losses.A risk index has been developed to address this issue,which quantifies the likelihood and severity of natural hazards occurring in a specific location.The application of risk indices for natural hazards in bridge management involves a data collection process and mathematical modelling.The data collection process gathers information on bridges’location,condition,and vulnerability,while mathematical modelling uses the data to assess the risk of natural hazards.Overall,risk indices provide a quantitative measure of the vulnerability of bridges to natural hazards and help to prioritize maintenance and repair activities.Mitigation measures are then evaluated and implemented based on the risk assessment results.By using this tool,the UBMS research group has developed an algorithm for risk assessment which will be essential in the decision-making process,specifically focused on enhancing Fund Optimization,Deterioration Modelling,and Risk Analysis.These developments effectively fulfill the primary objectives associated with addressing and mitigating hazards.This development also helps bridge managers understand the potential threats posed by natural hazards and allocate resources more efficiently to ensure the safety and longevity of critical transportation infrastructure.展开更多
The study is based on the analysis of the design and operational path conducted by the architect Gio Ponti on ceramic materials between the late 1920s and the early 1970s,with particular attention to applications in t...The study is based on the analysis of the design and operational path conducted by the architect Gio Ponti on ceramic materials between the late 1920s and the early 1970s,with particular attention to applications in the Milanese context.Milan represents the main laboratory for experimenting with the figurative,plastic and chromatic potential of modern ceramic surfaces.The analysis of archival documentation preserved at the CSAC Archive in Parma,the Gio Ponti Archives in Milan and the Archivio Progetti at the Iuav University of Venice allows for a deeper understanding of the design path at different scales,from the design of specific lines of ceramics for industry,to their application in buildings.The second part of the analysis is aimed at tracing the conservation problems of ceramic surfaces,with the aim of highlighting both the cultural and technical aspects that are affecting the conservation of this heritage.Connected to the latter aspect is a focus on the principal deterioration phenomena of modern ceramic surfaces related to different types of substrates,providing in-depth knowledge that opens up new strategies for their conservation.展开更多
文摘Deterioration and loss of quality of vegetable oil is a big challenge in the food industry.This study investigated the synthesis of nickel ferrite(Ni Fe_(2)_(O4))via co-precipitation method and its use for the removal of free fatty acids(FFAs)in deteriorated vegetable oil.Ni Fe2 O4 was characterized using Fourier transformed infrared spectroscopy(FTIR),X-ray diffraction(XRD),thermogravimetric(TG)analysis,Brunauer–Emm ett–Teller(BET)surface area,transmission electron microscopy(TEM),scanning electron microscopy(SEM)and energy-dispersive X-ray spectroscopy(EDX).Synthesis of Ni Fe_(2)_(O4)was confirmed by characterization,which revealed a BET surface area of 16.30 m^(2)·g^(-1)and crystallite size of 29 nm.Ni Fe_(2)_(O4)exhibited an adsorption capacity of 145.20 L·kg^(-1)towards FFAs with an 80.69%removal in a process,which obeys Langmuir isotherm and can be described by the pseudo-second-order kinetic model.The process has enthalpy(DH)of 11.251 k Jámolà1 and entropy(DS)of 0.038 k J·mol^(-1)K^(-1)with negative free energy change(DG),which suggests the process to be spontaneous and endothermic.The quantum chemical computation analysis via density functional theory further revealed the sorption mechanism of FFAs by Ni Fe_(2)_(O4)occurred via donor–acceptor interaction,which may be described by the lowest unoccupied molecular orbital(LUMO)and the highest occupied molecular orbital(HOMO).The study showed Ni Fe_(2)_(O4)to be a potential means that can remove FFAs from deteriorated vegetable oil.
文摘This paper aims to present an effective method to partial deteriorated strength columns,and to investigate the mechanical behavior of the defect part. Five groups of 150×150 mm×mm plain square columns are cast; each specimen has two different strengths,the lower strength in the middle segment and higher strength in both ends. The lower strength is to simulate the status of partial deteriorated region. Different layers of CFRP sheets have been wrapped just on the lower strength part to gain the reinforcement with CFRP sheets,and to verify the practicability of partial confinement. Specimens are subjected to monotonic axial compression until failure. Axial load,axial and transverse strains are measured to compare the different behaviors between the two parts. Experimental results show that partial confinement can significantly enhance the strength and the ductility of the deteriorated strength part,then,the load capacity of the whole column can be increased subsequently. Test data indicate that the ultimate load of the confined column is higher than that of the original column without deterioration; partial confinement on weakness is a feasible approach.
文摘This paper considers a deteriorated multi-item economic order quantity (EOQ) problem, which has been studied in literature, but the algorithms used in the literature are limited. In this paper, we explore the optimal policy of this inventory problem by analyzing the structural properties of the model, and introduce a simple algorithm for generating the optimal solution to this problem. Numerical results are reported to show effi-cacy of the proposed method.
基金financially supported by the National Natural Science Foundation of China(Grant No.51890914)。
文摘Different from oil and gas production,hydrate reservoirs are shallow and unconsolidated,whose mechanical properties deteriorate with hydrate decomposition.Therefore,the formations will undergo significant subsidence during depressurization,which will destroy the original force state of the production well.However,existing research on the stability of oil and gas production wells assumes the formation to be stable,and lacks consideration of the force exerted on the hydrate production well by formation subsidence caused by hydrate decomposition during production.To fill this gap,this paper proposes an analytical method for the dynamic evolution of the stability of hydrate production well considering the effects of hydrate decomposition.Based on the mechanical model of the production well,the basis for stability analysis has been proposed.A multi-field coupling model of the force state of the production well considering the effect of hydrate decomposition and formation subsidence is established,and a solver is developed.The analytical approach is verified by its good agreement with the results from the numerical method.A case study found that the decomposition of hydrate will increase the pulling-down force and reduce the supporting force,which is the main reason for the stability deterioration.The higher the initial hydrate saturation,the larger the reservoir thickness,and the lower the production pressure,the worse the stability or even instability.This work can provide a theoretical reference for the stability maintaining of the production well.
基金supported by Central Public-Interest Scientific Institution Basal Research Fund,CAFS(2023TD74,2023TD78)the Earmarked Fund for CARS-47(CARS-47)+2 种基金Guangdong Provincial Science and Technology Plan Project(2023B0202010015)Central Public-Interest Scientific Institution Basal Research Fund,CAFS(Sanya Yazhou Bay Science and Technology City(SKJC-2020-02-013))Special Funds for Promoting Economic Development in Guangdong Province(For Modern Fishery)(YueNong 2019B14).
文摘Here,we aimed to study the changes in proteome of golden pompano fillets during post-mortem storage.Tandem mass tags(TMT)-labeled quantitative proteomic strategy was applied to investigate the relationships between protein changes and quality characteristics of modified atmosphere packaging(MAP)fillets during superchilling(-3°C)storage.Scanning electron microscopy was used to show that the muscle histology microstructure of fillets was damaged to varying degrees,and low-field nuclear magnetic resonance was used to find that the immobilized water and free water in the muscle of fillets changed significantly.Total sulfhydryl content,TCA-soluble peptides and Ca2+-ATPase activity also showed that the fillet protein had a deterioration by oxidation and denaturation.The Fresh(FS),MAP,and air packaging(AP)groups were set.Total of 150 proteins were identified as differential abundant proteins(DAPs)in MAP/FS,while 209 DAPs were in AP/FS group.The KEGG pathway analysis indicated that most DAPs were involved in binding proteins and protein turnover.Correlation analysis found that 52 DAPs were correlated with quality traits.Among them,8 highly correlated DAPs are expected to be used as potential quality markers for protein oxidation and water-holding capacity.These results provide a further understanding of the muscle deterioration mechanism of packaging golden pompano fillets during superchilling.
文摘Since the advent of transcatheter aortic valve replacement(TAVR)in 2002,it has now become the default interventional strategy for symptomatic patients presenting with severe aortic stenosis,particularly in intermediate to highsurgical risk patients.In 2019,the United States Food and Drug Administration approved TAVR in low-risk patients based on two randomized trials.However,these breakthrough trials excluded patients with certain unfavorable anatomies and odd profiles.While currently there is no randomized study of TAVR in young patients,it may be preferred by the young population given the benefits of early discharge,shorter hospital stay,and expedite recovery.Nonetheless,it is important to ruminate various factors including lifetime expectancy,risk of pacemaker implantation,and the need for future valve or coronary interventions in young cohorts before considering TAVR in these patients.Furthermore,the data on long-term durability(>10 years)of TAVR is still unknown given most of the procedures were initially performed in the high or prohibitive surgical risk population.Thus,this editorial aims to highlight the importance of considering an individualized approach in young patients with consideration of various factors including lifetime expectancy while choosing TAVR against surgical aortic valve replacement.
文摘The main purpose of this paper is to generalize the effect of two-phased demand and variable deterioration within the EOQ (Economic Order Quantity) framework. The rate of deterioration is a linear function of time. The two-phased demand function states the constant function for a certain period and the quadratic function of time for the rest part of the cycle time. No shortages as well as partial backlogging are allowed to occur. The mathematical expressions are derived for determining the optimal cycle time, order quantity and total cost function. An easy-to-use working procedure is provided to calculate the above quantities. A couple of numerical examples are cited to explain the theoretical results and sensitivity analysis of some selected examples is carried out.
文摘Objective:To explore the risk factors for the progression of renal function deterioration in patients with diabetic nephropathy(DN).Methods:The clinical data and biochemical indexes of 100 diabetic patients admitted to our hospital from October 2021 to October 2022 were retrospectively analyzed.The patients were divided into a DN group,which consisted of 55 cases,and a nondiabetic nephropathy group(NDN),which consisted of 45 cases.The urinary microalbumin to creatinine ratio,the clinical data(gender,age,duration of the disease,and BMI),and the biochemical indexes(triglycerides[TG],low-density lipoprotein cholesterol[LDL-C],high-density lipoprotein cholesterol[HDL-C],total cholesterol[TC],glycated hemoglobin A1c[HbA1c],systolic blood pressure[SBP],diastolic blood pressure[DBP])of the two groups were compared.Subsequently,the risk factors related to the progression of renal function deterioration in DN were analyzed through multifactorial logistic regression analysis.Results:No statistically significant difference was observed in the comparison of gender,age,BMI,LDL-C,and DBP between the two groups(P>0.05).The DN group demonstrated a longer disease duration and higher SBP,TC,HDL-C,HbA1c,and TG compared to the NDN group(P<0.05).Through multifactorial logistic regression analysis,it was found that the duration of the disease,the TC,the HDL-C,the HbA1c,the TG,and the SBP were independent risk factors of the deterioration of renal function in DN patients.Conclusion:Other than conventional indicators,TC,HDL-C,HbA1c,TG,and SBP are also crucial indicators in determining the progression of renal function deterioration in DN patients.
文摘The objective is to develop a model considering demand dependent on selling price and deterioration occurs after a certain period of time, which follows two-parameter Weibull distribution. Shortages are allowed and fully backlogged. Fuzzy optimal solution is obtained by considering hexagonal fuzzy numbers and for defuzzification Graded Mean Integration Representation Method. A numerical example is provided for the illustration of crisp and fuzzy, both models. To observe the effect of changes in parameters, sensitivity analysis is carried out.
基金supported by the 2010 Hannam University Research Fund
文摘We consider the preventive maintenance of a production system that is deteriorated by random shocks and the production process itself. The degree of deterioration is modeled by discrete and finite states. Shocks arrive according to a Poisson process and deteriorate the system by random amounts. The system may deteriorate whenever it produces an item. The system is continuously monitored and repaired if the system state is at or above a predetermined level for maintenance. We analyze the lifetime, product quantity, average cost, and average profit considering revenue from the product and cost due to setup, operation, and repair. Assuming a structure of system parameters and costs, using numerical examples, we investigate the impact of production and shock arrivals on the average profit and the optimal maintenance level that maximizes the average profit. The proposed model is applicable to manufacturing tasks in which machines wear due to production, for example, press processes, milling, turning, punching, and drilling.
基金Funded by National Natural Science Foundation of China(NSFC)(Nos.52178216,51868044)。
文摘To reveal the deterioration mechanism and service life of concrete durability in the western saline soil area,the indoor accelerated test of the concrete specimen was simulated in the coupled environment of salt erosion and dry-wet cycles in the west saline soil area of China.The deterioration mechanism of concrete durability was revealed through the relative dynamic elastic modulus,relative quality evaluation parameters,SEM,and XRD evaluation indexes.Random Wiener distribution function was used for modeling life prediction.The results show that the relative dynamic elastic modulus evaluation parameter as an evaluation index of concrete durability under various environmental coupling effects is more reliable than the relative quality,there were holes and cracks in the concrete,and needle-like and layered crystals grow from the internal cracks.The corrosion products include ettringite,gypsum and other expansive crystals and non-gelling Mg(OH)_(2);the expansion stress caused by physical,chemical reaction,and temperature change under the action of drywet cycle aggravates the formation and development of cracks.The random Wiener distribution function can describe the degradation process of concrete specimen durability,and the established concrete reliability function can intuitively reflect the service life of concrete specimens.
基金financially supported by the National Natural Science Foundation of China(No.5197806)Graduate Research and Innovation Foundation of Chongqing,China(No.CYS21027)。
文摘Under the periodic rise and fall of the water level in the Three Gorges Reservoir in China,the rock mass in the ebb and flow zone of the slope is always in a state of a dry-wet cycle.In order to explore the influence of dry-wet cycle on mechanical properties of jointed sandstone,the triaxial and uniaxial compression tests of dry-wet cycle of jointed sandstone were carried out.For the experiment,four groups of samples with different numbers of joints were set up,and the jointed rock samples were subjected to 20 dry-wet cycles.Using both the triaxial compression test and the Mohr-Coulomb(M-C)rock fracture criterion,the strength envelope of the sandstone samples was fitted,and their strength degradation was further analyzed and studied.The results show that:(1)The peak intensity and elastic modulus of the sandstone samples decrease with increased number of dry-wet cycles.(2)The total deterioration of mechanical properties of intact rock samples is bigger than that of jointed sandstone samples as the number of dry-wet cycles increases.(3)With the increase of confining pressure,the peak intensity of intact sandstone samples increases much more than that of jointed sandstone samples,which indicates that joints and their numbers have obvious influence.(4)Joints and their numbers play an important role in guiding the damage effects of sandstone samples,which weaken the damage caused by dry-wet cycles.Therefore,the envelope of the M-C strength criterion of intact sandstone samples moves more than that of jointed sandstone samples.
基金National Key R&D Program of China under Grant No.2019YFC1511005the National Natural Science Foundation of China under Grant Nos.51921006,52192661 and 52008138+2 种基金the China Postdoctoral Science Foundation under Grant Nos.BX20190102 and 2019M661286the Heilongjiang Natural Science Foundation under Grant No.LH2022E070the Heilongjiang Province Postdoctoral Science Foundation under Grant Nos.LBH-TZ2016 and LBH-Z19064。
文摘Recent studies for computer vision and deep learning-based,post-earthquake inspections on RC structures mainly perform well for specific tasks,while the trained models must be fine-tuned and re-trained when facing new tasks and datasets,which is inevitably time-consuming.This study proposes a multi-task learning approach that simultaneously accomplishes the semantic segmentation of seven-type structural components,three-type seismic damage,and four-type deterioration states.The proposed method contains a CNN-based encoder-decoder backbone subnetwork with skip-connection modules and a multi-head,task-specific recognition subnetwork.The backbone subnetwork is designed to extract multi-level features of post-earthquake RC structures.The multi-head,task-specific recognition subnetwork consists of three individual self-attention pipelines,each of which utilizes extracted multi-level features from the backbone network as a mutual guidance for the individual segmentation task.A synthetical loss function is designed with real-time adaptive coefficients to balance multi-task losses and focus on the most unstably fluctuating one.Ablation experiments and comparative studies are further conducted to demonstrate their effectiveness and necessity.The results show that the proposed method can simultaneously recognize different structural components,seismic damage,and deterioration states,and that the overall performance of the three-task learning models gains general improvement when compared to all single-task and dual-task models.
基金supported by“the National Natural Science Foundation of China(Grant No.52008146)”“the Research Fund of Henan Key Laboratory of Materials on Deep-Earth Engineering(Grant No.MDE2020-01,Henan Polytechnic University)”+1 种基金“the Fundamental Research Funds for the Central Universities of China(Grant Nos.JZ2021HGTB0089,JZ2020HGQA0205)”“State Key Laboratory of High Performance Civil Engineering Materials(2021CEM003)”.
文摘In this paper,the effects of different mineral admixtures and sulfate solution types on the appearance,mass change rate,relative dynamic elastic modulus,and corrosion resistance coefficient of concrete were systematically studied.X-ray Diffraction(XRD),Mercury Intrusion Porosimetry(MIP),Scanning Electron Microscopy(SEM),and X-ray Computed Tomography(X-CT)were used to explore and analyze the changes in the microstructure and the corrosion products of concrete in the sulfate solution.The results show that the existence of magnesium ions accelerates concrete deterioration.There is a critical dosage of fly ash for magnesium sulfate resistance of concrete.The magnesium sulfate resistance of concrete is improved when the fly ash content is less than 20%.Slag can significantly improve the corrosion resistance of concrete to magnesium sulfate.The diffusion of sulfate ions into concrete is a gradual process.In the early stages of corrosion,sulfate ion content in the concrete immersed in the magnesium sulfate solution is slightly less than that of the concrete immersed in the sodium sulfate solution.However,in the later stage of corrosion,the sulfate ion content in the concrete immersed in the magnesium sulfate solution is significantly higher than that of the concrete immersed in the sodium sulfate solution.
基金sponsored by the National Natural Science Foundation of China(Grant No.51974192)the Distinguished Youth Funds of National Natural Science Foundation of China(Grant No.51925402)Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering Project(2021SX-TD001).
文摘As a kind of green concrete,the mechanical properties and durability of cemented gangue backfill material(CGBM)will be affected if they are in acid mine water with sulfate ions in the long term.To improve the performance of CGBM in acid mine water with sulfate ions,CGBM specimens with different doses of barium hydroxide were immersed in sulfuric acid solutions of different concentrations for 270 days.The changes of mass,ultrasonic pulse velocity(UPV)and compressive strength of the specimens at different ages were analyzed.Scanning electron microscopy(SEM)and X-ray diffraction(XRD)were used to analyze the microstructure and composition of the specimens.The results show that incorporation of barium hydroxide into CGBM specimen can promote the formation of barium sulfate precipitation and inhibit the generation of corrosion products such as ettringite.Meanwhile,barium sulfate precipitation blocks the pore channel invaded by sulfuric acid solution,delaying the progress of corrosion reaction and making the interior of CGBM specimen more complete.And the specimen with 2.0 kg/m^(3)barium hydroxide was more effective in improving performance.This study provides a basis for the ratio design of CGBM in acid mine water with sulfate ions.
文摘Currently,energy conservation draws wide attention in industrial manufacturing systems.In recent years,many studies have aimed at saving energy consumption in the process of manufacturing and scheduling is regarded as an effective approach.This paper puts forwards a multi-objective stochastic parallel machine scheduling problem with the consideration of deteriorating and learning effects.In it,the real processing time of jobs is calculated by using their processing speed and normal processing time.To describe this problem in a mathematical way,amultiobjective stochastic programming model aiming at realizing makespan and energy consumption minimization is formulated.Furthermore,we develop a multi-objective multi-verse optimization combined with a stochastic simulation method to deal with it.In this approach,the multi-verse optimization is adopted to find favorable solutions from the huge solution domain,while the stochastic simulation method is employed to assess them.By conducting comparison experiments on test problems,it can be verified that the developed approach has better performance in coping with the considered problem,compared to two classic multi-objective evolutionary algorithms.
文摘Cassava (Manihot esculenta Crantz) is the third largest source of calories in tropical countries and the sixth most important food crop in the World. However, the short shelf life of its storage roots after harvest due to a rapid post-harvest physiological deterioration (PPD) makes the roots to be considered as a risky product to market. The objectives of this work were to investigate the influence of two harvest periods on cassava agronomic parameters and their physiological response to PPD. Three cassava cultivars 96/1414, I070593 and LMR were selected for the experiment and harvested at 10 and 12 months after planting (MAP). The response to PPD was assessed during storage at 0, 3, 8 and 15 days after harvest (DAH). Total proteins content, soluble sugars and starch, total polyphenols compounds, polyphenoloxidase and peroxidase activities were recorded during storage. Results showed large variation among the parameters at the two harvest periods across the cultivars. High number of tubers was recorded in all the cultivars at 12 MAP and a significant increase in storage roots length was observed in 96/1414 and LMR from 10 MAP to 12 MAP (25 ± 5.1 to 41.3 ± 5.9 and 22.6 ± 3.3 to 27.9 ± 4.8) respectively. A reduction of about 49% of tubers weight was observed in I070593 from 10 to 12 MAP while an increase of about 36% and 11% were recorded in LMR and 96/1414 respectively. Tubers from I070593 showed less susceptibility to PPD when harvested at 10 MAP compared to those from LMR and 96/1414 where less susceptibility to PPD were recorded at 12 MAP. An increase in soluble sugars content, total proteins content and peroxidase activity subsequently to a decrease in starch content were recorded during storage from 8 to 15 days after harvest especially at 10 MAP in I070593 and at 12 MAP in LMR and 96/1414. High content of total phenolic compounds and less activity of polyphenol oxidase were correlated to PPD susceptibility. This work opens a new insight issue of the consideration of the appropriate harvest time of the cultivars as a tool to better control the onset of postharvest physiological deterioration.
文摘Background: Prune belly syndrome (PBS) is a congenital anomaly that consists of a triad of abdominal wall defect, bilateral cryptorchidism, and urinary tract dilation. The disease is of varying severity. This study aims to highlight the challenges and peculiarities in the management of PBS in a resource-poor setting. Materials and Methods: This is a ten-year retrospective study conducted at the University of Port Harcourt Teaching Hospital. Ethical approval for the study was sought and gotten from the hospital’s ethical committee. The information gotten included history, duration of symptoms, examination findings, age of the patient, category of disease, and intraoperative findings. The data from the folders were collected and evaluated. Frequencies, percentages, the mean and standard deviation were used to summarize the data as appropriate. Results: Fifteen patients were included in the study. The hospital incidence of PBS was 112/100,000, twelve males and three females. The age range was from 1 day to 15 years, mean age was 14 months ± 2.3 months. Most patients presented between 3 months and 2 years and 11 months. Twelve patients had category three PBS and five patients had associated anomalies. Eleven male patients died after 5 years of follow-up from progressive renal deterioration. The female patient fared better than the males. Conclusion: PBS is rare, most patients with the condition present late. The most common cause of mortality was progressive renal deterioration.
文摘Bridges serve as essential parts of transportation infrastructure,facilitating the movement of people and goods across rivers,valleys,and other obstacles.However,they are also susceptible to a wide range of natural hazards,including floods,earthquakes,and landslides,which can damage or even collapse these structures,leading to severe economic and human losses.A risk index has been developed to address this issue,which quantifies the likelihood and severity of natural hazards occurring in a specific location.The application of risk indices for natural hazards in bridge management involves a data collection process and mathematical modelling.The data collection process gathers information on bridges’location,condition,and vulnerability,while mathematical modelling uses the data to assess the risk of natural hazards.Overall,risk indices provide a quantitative measure of the vulnerability of bridges to natural hazards and help to prioritize maintenance and repair activities.Mitigation measures are then evaluated and implemented based on the risk assessment results.By using this tool,the UBMS research group has developed an algorithm for risk assessment which will be essential in the decision-making process,specifically focused on enhancing Fund Optimization,Deterioration Modelling,and Risk Analysis.These developments effectively fulfill the primary objectives associated with addressing and mitigating hazards.This development also helps bridge managers understand the potential threats posed by natural hazards and allocate resources more efficiently to ensure the safety and longevity of critical transportation infrastructure.
文摘The study is based on the analysis of the design and operational path conducted by the architect Gio Ponti on ceramic materials between the late 1920s and the early 1970s,with particular attention to applications in the Milanese context.Milan represents the main laboratory for experimenting with the figurative,plastic and chromatic potential of modern ceramic surfaces.The analysis of archival documentation preserved at the CSAC Archive in Parma,the Gio Ponti Archives in Milan and the Archivio Progetti at the Iuav University of Venice allows for a deeper understanding of the design path at different scales,from the design of specific lines of ceramics for industry,to their application in buildings.The second part of the analysis is aimed at tracing the conservation problems of ceramic surfaces,with the aim of highlighting both the cultural and technical aspects that are affecting the conservation of this heritage.Connected to the latter aspect is a focus on the principal deterioration phenomena of modern ceramic surfaces related to different types of substrates,providing in-depth knowledge that opens up new strategies for their conservation.