BACKGROUND Commonly used cleaning brushes in the reprocessing of flexible endoscopes often cause damage within the working channels.AIM To develop a spray flushing system to achieving effective cleaning of the working...BACKGROUND Commonly used cleaning brushes in the reprocessing of flexible endoscopes often cause damage within the working channels.AIM To develop a spray flushing system to achieving effective cleaning of the working channels while minimizing damage.METHODS This prospective study included 60 used endoscopes and 60 Teflon tubes randomly divided into a control group(n=30)and an experimental group(n=30).The material of Teflon tubes was the same as that of the endoscope working channel.Endoscopes in the control group were manually cleaned using traditional cleaning brushes,while those in the experimental group were cleaned using the newly developed spray flushing system.ATP levels,cleanliness,and microbiological testing of the working channels were measured.Additionally,Teflon tubes in the control group underwent 500 passes with a cleaning brush,while those in the experimental group were subjected to the spray flushing system,and channel damage was evaluated.RESULTS The ATP levels(RLU)in the two groups were 32.5(13-66)and 26(16-40),respectively(P>0.05).Cleanliness scores were 1.5(1-2)and 1(1-2),respectively(P>0.05).Debris was found in 73.3%of the control group,which was significantly higher than 46.7%in the experimental group(P<0.05).Microbiological tests for both groups yielded negative results.Teflon tube damage in the control group was rated at 4(4-5.25),which was significantly higher than in the experimental group 4(3-4)(P<0.01).CONCLUSION The spray flushing system demonstrated superior efficacy in removing debris and resulted in less damage to the endoscope working channels compared with traditional cleaning brushes.展开更多
Aimed at the problem of stochastic routings for reprocessing operations and highly variable processing times,an open queuing network is utilized to model a typical reprocessing system.In the model,each server is subje...Aimed at the problem of stochastic routings for reprocessing operations and highly variable processing times,an open queuing network is utilized to model a typical reprocessing system.In the model,each server is subject to breakdown and has a finite buffer capacity,while repair times,breakdown times and service time follow an exponential distribution.Based on the decomposition principle and the expansion methodology,an approximation analytical algorithm is proposed to calculate the mean reprocessing time,the throughput of each server and other parameters of the processing system.Then an approach to determining the quality of disassembled parts is suggested,on the basis of which the effect of parts quality on the performance of the reprocessing system is investigated.Numerical examples show that there is a negative correlation between quality of parts and their mean reprocessing time.Furthermore,marginal reprocessing time of the parts decrease with the drop in their quality.展开更多
Due to their unique features,such as the inherent safety,simplified fuel cycle,and continuous on-line reprocessing,molten salt reactors(MSRs)are regarded as one of the six reference reactors in the Generation IV Inter...Due to their unique features,such as the inherent safety,simplified fuel cycle,and continuous on-line reprocessing,molten salt reactors(MSRs)are regarded as one of the six reference reactors in the Generation IV International Forum(GEN-IV).Molten chloride salt fast reactors(MCFRs)are a type of MSR.Compared to molten fluoride salt reactors(MFSRs),MCFRs have a higher solubility of heavy metal atoms,a harder neutron spectrum,lower accumulation of fission products(FPs),and better breeding and transmutation performance.Thus,MCFRs have been recognized as a type of MSR with great prospects for future development.However,as the most important feature for MSRs,the effect of different reprocessing modes on MCFRs must be researched in depth.As such,this study investigated the effect of different isotopes,especially FPs,on the neutronic performance of an MCFR,such as its breeding performance.Furthermore,the characteristics of the different reprocessing modes and MCFR rates were analyzed in terms of safety,radioactivity level,neutron economy,and breeding capacity.In the end,a reprocessing method suitable for MCFRs was determined through calculation and analysis,which provides a reference for the further research of MCFRs.展开更多
The purpose of this article is to review the evidence regarding transmission of infection during gastrointestinal endoscopy, factors important in endoscope reprocessing and infection control, areas to focus on to impr...The purpose of this article is to review the evidence regarding transmission of infection during gastrointestinal endoscopy, factors important in endoscope reprocessing and infection control, areas to focus on to improve compliance, and recent developments and advances in the field.展开更多
This study provides a comprehensive understanding of the polymeric properties of lignin-based non-isocyanate poly(iminehydroxyurethane)s(LNIPUs).The properties of the LNIPUs are affected by changes in the stoichiometr...This study provides a comprehensive understanding of the polymeric properties of lignin-based non-isocyanate poly(iminehydroxyurethane)s(LNIPUs).The properties of the LNIPUs are affected by changes in the stoichiometric feed ratios of the bis(6-membered cyclic carbonate)(BCC)and levulinate enzymatic hydrolysis lignin(LEHL).The results showed that the LNIPUs exhibited a short relaxation time and excellent thermal repair and degradation properties.With a change in the LEHL content in the LNIPUs to 45.53%,a relaxation time of only 9 s was achieved,and the thermal repair rate of the scratches reached 93%.Furthermore,the tensile strength of the LNIPUs decreased with an increase in the LEHL content after two hot-pressing processes,while a higher than 75% tensile strength was maintained after the second hot-pressing treatment.The LNIPUs exhibited thermoresponsive shape memory property with deformation and shape fixing at 80℃.In addition,the as-synthesized LNIPUs were soluble in ethylene glycol in the absence of any organic solvents.This work demonstrates the synthesis of LNIPUs with self-healing,reprocessing,shape memory,and degradation properties.展开更多
Objective To evaluate the application of enzyme in instrument cleaning for hospital sterile reprocessing and different factors that impact the enzyme activity.Methods Standard soil objects for instrument cleaning qual...Objective To evaluate the application of enzyme in instrument cleaning for hospital sterile reprocessing and different factors that impact the enzyme activity.Methods Standard soil objects for instrument cleaning quality evaluation,as testing coupons,were identified and used to evaluate different cleaning processes designed with varied conditions.Between testing groups using enzymatic detergent versus non-enzymatic detergent,the amount of residual protein on the testing coupons were quantified and compared at different soaking time(10min,20min,30min,45min and 60min).Then,within the enzymatic detergent group,different testing conditions were further explored by adjusting factors,in⁃cluding the soaking temperature(25°C,30°C and 45°C),use solution pH(7.0,8.0),and enzyme dosing(1/80,1/40,1/20,3/40,1/10 and 3/20 in v/v).Then,through an observational comparative study for each testing condition,the time needed to achieve a complete soil removal through visual inspection of the testing coupons was documented for analyses.Results In the test of enzymatic detergent versus non-enzymatic detergent,the non-enzymatic group did not show an obvious decline in the residual protein amount(1069μg at 10 min vs.1042μg at 60 min),whereas the enzymatic group showed significant decrease in residual protein quantity(947μg at 10 min vs.620μg at 60 min).Meanwhile,the amounts of the residual protein at different time points in the enzyme group(947μg at 10 min,864μg at 20 min,812μg at 30 min,691μg at 45 min,and 620μg at 60 min)were consistently lower than those at the same time schedule in the non-enzyme group(1069μg at 10 min,1069μg at 20 min,1067μg at 30 min,1059μg at 45 min,and 1042μg at 60 min).Furthermore,within the enzymatic group,the soaking temperature,use solution pH and enzyme dosing factors all appear to impact the enzyme activity and significantly contribute to the cleaning outcomes.Specifi⁃cally,the higher soaking temperature,higher use solution pH and higher enzyme dosing showed 58.4%,20.0%and 34.4%time reduction to completely remove the soil on the testing coupons,respectively.Conclusion Enzyme seems to play a significant role in the instrument cleaning process for hospital sterile reprocessing.The soaking temperature,cleaning use solution pH,and enzyme dosing all appear to be critical factors impacting the enzyme activity and thus the overall cleaning outcomes.In practice,cleaning process verification should be considered to ensure the optimal use conditions for enzyme cleaning performance are well-understood and consistently achieved at the facility level.展开更多
Remanufacturing is regarded as a sustainable manufacturing paradigm of energy conservation and environment protection.To improve the efficiency of the remanufacturing process,this work investigates an integrated sched...Remanufacturing is regarded as a sustainable manufacturing paradigm of energy conservation and environment protection.To improve the efficiency of the remanufacturing process,this work investigates an integrated scheduling problem for disassembly and reprocessing in a remanufacturing process,where product structures and uncertainty are taken into account.First,a stochastic programming model is developed to minimize the maximum completion time(makespan).Second,a Q-learning based hybrid meta-heuristic(Q-HMH)is specially devised.In each iteration,a Q-learning method is employed to adaptively choose a premium algorithm from four candidate ones,including genetic algorithm(GA),artificial bee colony(ABC),shuffled frog-leaping algorithm(SFLA),and simulated annealing(SA)methods.At last,simulation experiments are carried out by using sixteen instances with different scales,and three state-of-the-art algorithms in literature and an exact solver CPLEX are chosen for comparisons.By analyzing the results with the average relative percentage deviation(RPD)metric,we find that Q-HMH outperforms its rivals by 9.79%-26.76%.The results and comparisons verify the excellent competitiveness of Q-HMH for solving the concerned problems.展开更多
For the future energy system, we propose a new closed nuclear energy cycle system, which consists of an accelerator-driven external neutron source, a ceramic reactor and an extend AIROX reprocessing. The attractive fe...For the future energy system, we propose a new closed nuclear energy cycle system, which consists of an accelerator-driven external neutron source, a ceramic reactor and an extend AIROX reprocessing. The attractive features of this system are as follows. (l) The operating mode of the reactor is a combination of subcritical mode and critical mode. initially, the reactor would be driven by the accelerator external neutron source in subcritical mode. A few years later, the reactor would reach the critical mode, and then would operate for a long time. (2) Nuclear fuels, coolants, and structure materials in the ceramic reactor core are made up of ceramic with excellent thermodynamics properties and neutron performance. Therefore, the ceramic reactor has extremely inherent safety, good breeding performance and high power generation efficiency. (3) Fuel reprocessing uses an extend AIROX reprocessing, which is a simple high-temperature dry process and rarely involved in chemical process. In this reprocessing, only most of fission products are separated. Other isotopes, including uranium isotopes, transuranic nuclides and long-lived fission products, would re-enter the reactor as new fuels. Therefore, this closed nuclear energy system could be known as ADANES, short for Accelerator-Driven Advanced Nuclear Energy System, which can greatly improve the utilization rate of nuclear fuels, enhance the nuclear safety, reduce the nuclear proliferation and become a sustainable and low-carbon energy supply for thousands of years.展开更多
This paper investigates the problem of inconsistent states of radio frequency identification (RFID) tag data caused by incomplete execution of read/write operations during access to RFID tag memory. Passive RFID tag...This paper investigates the problem of inconsistent states of radio frequency identification (RFID) tag data caused by incomplete execution of read/write operations during access to RFID tag memory. Passive RFID tags require RF communication to access memory data. This study is motivated by the volatility of RF communication, where instability is caused by intermittent connections and uncertain communication. If a given tag disappears from the communication area of the reader during the reading or writing of tag data, the operation is incomplete, resulting in an inconsistent state of tag data. To avoid this inconsistency, it is necessary to ensure that any operations on tag memory are completed. In this paper, we propose an asynchronous reprocessing model for finalizing any incomplete execution of read/write operations to remove inconsistent states. The basic idea is to resume incomplete operations autonomously by detecting a tag's re-observation from any reader. To achieve this, we present a concurrency control mechanism based on continuous query processing that enables the suspended tag operations to be re-executed. The performance study shows that our model improves the number of successful operations considerably in addition to suppressing inconsistent data access completely.展开更多
Atmospheric water vapor is an essential climate variable(ECV)with extensive spatial and temporal variations.Microwave humidity observations from meteorological satellites provide important information for climate syst...Atmospheric water vapor is an essential climate variable(ECV)with extensive spatial and temporal variations.Microwave humidity observations from meteorological satellites provide important information for climate system variables,including atmospheric water vapor and precipitable water,and assimilation in numerical weather prediction(NWP)and reanalysis.As one of the payloads onboard China’s second-generation polar-orbiting operational meteorological Fengyun-3(FY-3)satellites,the Microwave Humidity Sounder(MWHS)has been continuously observing the global humidity since 2008.The reprocessing of historical FY-3 MWHS data is documented in detail in this study.After calibrating and correcting the data,the quality of the reprocessed dataset is evaluated and the improvement is shown in this study.The results suggest that MWHS observations bias is reduced to approximately 0.8 K,compared with METOP-A Microwave Humidity Sounder(MHS).The temporal variability of MWHS is highly correlated with the instrument temperature.After reprocessing,the scene temperature dependency is mitigated for all 183 GHz channels,and the consistency and stability between FY-3A/B/C are also improved.展开更多
Sea surface temperature(SST)is a crucial physical parameter in meteorology and oceanography.This study demonstrates that the influence of earth incidence angle(EIA)on the SST retrieved from the microwave radiation ima...Sea surface temperature(SST)is a crucial physical parameter in meteorology and oceanography.This study demonstrates that the influence of earth incidence angle(EIA)on the SST retrieved from the microwave radiation imager(MWRI)onboard FengYun-3(FY-3)meteorological satellites should not be ignored.Compared with algorithms that do not consider the influence of EIA in the regression,those that integrate the EIA into the regression can enhance the accuracy of SST retrievals.Subsequently,based on the recalibrated Level 1B data from the FY-3/MWRI,a long-term SST dataset was reprocessed by employing the algorithm that integrates the EIA into the regression.The reprocessed SST data,including FY-3B/MWRI SST during 2010-2019,FY-3C/MWRI SST during 2013-2019,and FY-3D/MWRI SST during 2018-2020,were compared with the in-situ SST and the SST dataset from the Operational Sea Surface Temperature and Ice Analysis(OSTIA).The results show that the FY-3/MWRI SST data were consistent with both the in-situ SST and the OSTIA SST dataset.Compared with the Copernicus Climate Change Service V2.0 SST,the absolute deviation of the reprocessed SST,with a quality flag of 50,was less than 1.5℃.The root mean square errors of the FY-3/MWRI orbital,daily,and monthly SSTs,with a quality flag of 50,were approximately 0.82℃,0.69℃,and 0.37℃,respectively.The primary discrepancies between the FY-3/MWRI SST and the OSTIA SST were found mainly in the regions of the western boundary current and the Antarctic Circumpolar Current.Overall,this reprocessed SST product is recommended for El Niño and La Niña events monitoring.展开更多
BACKGROUND Patient-ready duodenoscopes were designed with an assumed contamination rate of less than 0.4%;however,it has been reported that 5.4%of clinically used duodenoscopes remain contaminated with viable high-con...BACKGROUND Patient-ready duodenoscopes were designed with an assumed contamination rate of less than 0.4%;however,it has been reported that 5.4%of clinically used duodenoscopes remain contaminated with viable high-concern organisms despite following the manufacturer’s instructions.Visual inspection of working channels has been proposed as a quality control measure for endoscope reprocessing.There are few studies related to this issue.AIM To investigate the types,severity rate,and locations of abnormal visual inspection findings inside patient-ready duodenoscopes and their microbiological significance.METHODS Visual inspections of channels were performed in 19 patient-ready duodenoscopes using the SpyGlass visualization system in two endoscopy units of tertiary care teaching hospitals(Tri-Service General Hospital and National Taiwan University Hospital)in Taiwan.Inspections were recorded and reviewed to evaluate the presence of channel scratches,buckling,stains,debris,and fluids.These findings were used to analyze the relevance of microbiological surveillance.RESULTS Seventy-two abnormal visual inspection findings in the 19 duodenoscopes were found,including scratches(n=10,52.6%),buckling(n=15,78.9%),stains(n=14,73.7%),debris(n=14,73.7%),and fluids(n=6,31.6%).Duodenoscopes>12 mo old had a significantly higher number of abnormal visual inspection findings than those≤12 mo old(46 findings vs 26 findings,P<0.001).Multivariable regression analyses demonstrated that the bending section had a significantly higher risk of being scratched,buckled,and stained,and accumulating debris than the insertion tube.Debris and fluids showed a significant positive correlation with microbiological contamination(P<0.05).There was no significant positive Spearman’s correlation coefficient between negative bacterial cultures and debris,between that and fluids,and the concomitance of debris and fluids.This result demonstrated that the presence of fluid and debris was associated with positive cultures,but not negative cultures.Further multivariate analysis demonstrated that fluids,but not debris,is an independent factor for bacterial culture positivity.CONCLUSION In patient-ready duodenoscopes,scratches,buckling,stains,debris,and fluids inside the working channel are common,which increase the microbiological contamination susceptibility.The SpyGlass visualization system may be recommended to identify suboptimal reprocessing.展开更多
The high rate of relapse among heroin users remains a significant public concern in China. In the present study, we utilized a Motivation-Skill-Desensitization-Mental Energy (MSDE) intervention and evaluated its effec...The high rate of relapse among heroin users remains a significant public concern in China. In the present study, we utilized a Motivation-Skill-Desensitization-Mental Energy (MSDE) intervention and evaluated its effects on abstinence and mental health. Eighty-nine male heroin users in a drug rehabilitation center were enrolled in the study. The participants in the MSDE intervention group (n=46) received MSDE intervention, which included motivational interviewing, coping skills training, eye movement desensitization and reprocessing, and mindfulness-based psychotherapy. The participants in the control group (h=43) received a series of lectures on skills training. A significant increase in Contemplation Ladder score (P<0.001) and decreases in scores on the Obsessive Compulsive Drug Use Scale (P<0.001), Beck Depression Inventory (P<0.001), and Aggression Questionnaire (P=O.O33) were found immediately after intervention. Compared to the control group, the MSDE intervention group reported significantly higher abstinence rates (P=0.027) and retention rates (P<0.001) at follow-up. Overall, the MSDE intervention, which uses a combined strategy for relapse prevention, could be a promising approach for preventing relapse among heroin users in China.展开更多
To use fly ash and coal waste effectively, the current technologies for reprocessing and recycling these wastes into eco-building materials were reviewed, such as utilizing fly ash as the component of fly ash cement a...To use fly ash and coal waste effectively, the current technologies for reprocessing and recycling these wastes into eco-building materials were reviewed, such as utilizing fly ash as the component of fly ash cement and low heat cement after the processes of separation, removal of carbon remains and fine comminution, calcining coal waste into kaolin and meta-kaolin with suspension technology, and preparing clinkerless alkali-activated geopolymer materials with fly ash and meta-kaolin.展开更多
Global Positioning System data processing is affected by many non-tectonic factors, including the common-mode errors (CME) in station-position time series. The characteristics and origins of CME are still not clear,...Global Positioning System data processing is affected by many non-tectonic factors, including the common-mode errors (CME) in station-position time series. The characteristics and origins of CME are still not clear, due to uneven distribution of global GPS networks and the lack of reliable data of the position time series. In this work, data from 241 continuous GPS stations were reprocessed in a consistent way and the results were compared with those generated at Jet Propulsion Laboratory (JPL). Improvements of residual positions were obtained for many low-quality stations, especially those located in Asia and Australia.展开更多
In this study,an environmentally friendly and non-toxic route to synthesize lignin-based non-isocyanate poly(imine-hydroxyurethane)s networks was explored.Specifically,the NH_(2)-terminated polyhydroxyurethanes(NPHUs)...In this study,an environmentally friendly and non-toxic route to synthesize lignin-based non-isocyanate poly(imine-hydroxyurethane)s networks was explored.Specifically,the NH_(2)-terminated polyhydroxyurethanes(NPHUs)prepolymer was first synthesized from bis(6-membered cyclic carbonate)(BCC)and diamine via the ring-opening reaction.Subsequently,the corresponding ligninbased non-isocyanate polyurethanes(NIPUs)with tunable properties were synthesized from NPHUs and levulinate lignin derivatives containing ketone groups via the Schiff base reaction.The structural,mechanical,and thermal properties of NIPUs with different stoichiometric feed ratios of BCC and levulinate lignin were characterized by Fourier transform infrared spectroscopy(FT-IR),nuclear magnetic resonance(NMR),differential scanning calorimetry(DSC),dynamic mechanical analysis(DMA),and thermogravimetric analysis(TGA).The results indicated that the tensile strength,Young's modulus,toughness,storage modulus,glass transition temperature,and thermal stability of lignin-based NIPUs gradually increased with increasing lignin content,and the highest Young's modulus of 41.1 MPa was obtained when lignin content reached 45.53%.With good reprocessing properties,this synthetic framework of ligninbased NIPUs also provides sustainable non-isocyanate-based substitutions to traditional polyurethane networks.展开更多
Background: Seven patients at a hospital in Houston, TX, were diagnosed during a two-week period in 2009 with joint space infection of pansusceptible P. aeruginosa following arthroscopic procedures of the knee or shou...Background: Seven patients at a hospital in Houston, TX, were diagnosed during a two-week period in 2009 with joint space infection of pansusceptible P. aeruginosa following arthroscopic procedures of the knee or shoulder. Tosh et al. (2011), who investigated and published the principal report discussing this bacterial outbreak, conclude that its most likely cause was the improper reprocessing of certain reusable, physically-complex, heat-stable arthroscopic instruments used during these arthroscopic procedures. These reusable instruments reportedly remained contaminated with remnant tissue, despite diligent efforts by the hospital to clean their internal structures. This retained bioburden presumably shielded the outbreak’s strain of embedded P. aeruginosa from contact with the pressurized steam, reportedly resulting in ineffective sterilization of these arthroscopic instruments and bacterial transmission. Objectives: First, to clarify which specific sterilization methods, in addition to steam sterilization, Methodist Hospital employed to process its reusable arthroscopic instrumentation at the time of its outbreak, in 2009;second, to evaluate Tosh et al.’s (2011) conclusion that ineffective steam sterilization due to inadequate cleaning was the most likely cause of this hospital’s outbreak;third, to consider whether any other hitherto unrecognized factors could have plausibly contributed to this outbreak;and, fourth, to assess whether any additional recommendations might be warranted to prevent disease transmission following arthroscopic procedures. Methods: The medical literature was reviewed;some of the principles of quality assurance, engineering and a root-cause analysis were employed;and Tosh et al.’s (2011) findings and conclusions were reviewed and compared with those of other published reports that evaluated the risk of disease transmission associated with the steam sterilization of physically-complex, heat-stable, soiled surgical instruments. Results and Conclusion: Reports documenting outbreaks of P. aeruginosa or another vegetative bacterium associated with the steam sterilization of inadequately cleaned surgical or arthroscopic instruments are scant. This finding—coupled with a number of published studies demonstrating the effective steam sterilization of complex instruments contaminated with vegetative bacteria mixed with organic debris, or, in one published series of tests, with resistant bacterial endospores coated with hydraulic fluid—raises for discussion whether Methodist Hospital’s outbreak might have been due to one or more factors other than, or in addition to, that which Tosh et al. (2011) conclude was its most likely cause. An example of such a factor not ruled out by Tosh et al. (2011) findings would be the re-contamination of the implicated arthroscopic instruments after sterilization. The specific methods that Methodist Hospital employed at the time of its outbreak to sterilize some of its arthroscopic instrumentation remain unclear. A number of additional recommendations are provided to prevent disease transmission following arthroscopic procedures.展开更多
The corrosion behavior of a titanium-5% tantalum alloy (Ti-STa) in hot nitric acid condensate was investigated to understand aging behavior ofreprocessing equipments. On the basis of long-term immersion tests, it wa...The corrosion behavior of a titanium-5% tantalum alloy (Ti-STa) in hot nitric acid condensate was investigated to understand aging behavior ofreprocessing equipments. On the basis of long-term immersion tests, it was determined that the corrosion of Ti-STa in nitric acid condensate is accelerated with an increase in the concentration. The corrosion rate was nearly constant during the immersion test and the coupons suffered from uniform corrosion. In addition, it is important to note that the nitric acid concentration in the condensate increased on addition of metal salts to the heated nitric acid solution. The larger valence of metal ions was contributed to the increase in the concentration of nitric acid condensate. Consequently, the metal salt in the heated nitric acid solution accelerates the corrosion of Ti-STa in the condensate. Therefore, the nitric acid condensate condition should be carefully considered for the corrosion environment of titanium and its alloys.展开更多
A blending strategy of virgin and reprocessed polylactide may be postulated as an alternative to reduce the material cost at industrial level,and as a valorization route to plastic waste management of production scrap...A blending strategy of virgin and reprocessed polylactide may be postulated as an alternative to reduce the material cost at industrial level,and as a valorization route to plastic waste management of production scraps.The performance of blends prepared from virgin polylactide and polylactide mechanically reprocessed up to two cycles(PLA-V/R)was assessed in terms of thermo-oxidative stability,morphology,viscoelasticity and thermal kinetics for energetic valorization.PLA-V/R blends showed appropriate thermo-oxidative stability.The amorphous nature of polylactide was preserved after blending.The viscoelastic properties showed an increment of the mechanical blend effectiveness,which suggested the feasibility of using PLA-V/R blends under similar mechanical conditions to those of virgin PLA goods.Finally,it was shown that the energetic valorization of PLA-V/R blends would result in a more feasible process,due to the lower required activation energy,thus highlighting the advantages of the energetic demand for the process.In conclusion,PLA-V/R blends showed similar processability,service performance and valorization routes as virgin PLA and therefore could be relevant in the sustainable circular industry of bioplastics.展开更多
This study assessed the life cycle of biocomposites with antioxidants by repeated processing.The effects of antioxidants on the life cycle of wood flour/polypropylene(PP)composites were determined by analyzing their m...This study assessed the life cycle of biocomposites with antioxidants by repeated processing.The effects of antioxidants on the life cycle of wood flour/polypropylene(PP)composites were determined by analyzing their mechanical and thermal properties.The composites were repeatedly processed for seven times with pelletizing and extruding.An antioxidant,pentaerythritoltetrakys 3-(3,5-ditert-butyl-4-hydroxyphenyl)propionate,was used.The mechanical strength of the biocomposites decreased after reprocessing.Fourier transformed infrared analysis showed that thermo-oxidative aging occurred during reprocessing.The thermal performance of the resulting composites decreased because of reprocessing.Wood flour/PP has a long lifetime and antioxidants can slow the thermo-oxidative and mechanical degradation during reprocessing.展开更多
基金West China Nursing Discipline Development Special Fund Project,No.HXHL21029。
文摘BACKGROUND Commonly used cleaning brushes in the reprocessing of flexible endoscopes often cause damage within the working channels.AIM To develop a spray flushing system to achieving effective cleaning of the working channels while minimizing damage.METHODS This prospective study included 60 used endoscopes and 60 Teflon tubes randomly divided into a control group(n=30)and an experimental group(n=30).The material of Teflon tubes was the same as that of the endoscope working channel.Endoscopes in the control group were manually cleaned using traditional cleaning brushes,while those in the experimental group were cleaned using the newly developed spray flushing system.ATP levels,cleanliness,and microbiological testing of the working channels were measured.Additionally,Teflon tubes in the control group underwent 500 passes with a cleaning brush,while those in the experimental group were subjected to the spray flushing system,and channel damage was evaluated.RESULTS The ATP levels(RLU)in the two groups were 32.5(13-66)and 26(16-40),respectively(P>0.05).Cleanliness scores were 1.5(1-2)and 1(1-2),respectively(P>0.05).Debris was found in 73.3%of the control group,which was significantly higher than 46.7%in the experimental group(P<0.05).Microbiological tests for both groups yielded negative results.Teflon tube damage in the control group was rated at 4(4-5.25),which was significantly higher than in the experimental group 4(3-4)(P<0.01).CONCLUSION The spray flushing system demonstrated superior efficacy in removing debris and resulted in less damage to the endoscope working channels compared with traditional cleaning brushes.
文摘Aimed at the problem of stochastic routings for reprocessing operations and highly variable processing times,an open queuing network is utilized to model a typical reprocessing system.In the model,each server is subject to breakdown and has a finite buffer capacity,while repair times,breakdown times and service time follow an exponential distribution.Based on the decomposition principle and the expansion methodology,an approximation analytical algorithm is proposed to calculate the mean reprocessing time,the throughput of each server and other parameters of the processing system.Then an approach to determining the quality of disassembled parts is suggested,on the basis of which the effect of parts quality on the performance of the reprocessing system is investigated.Numerical examples show that there is a negative correlation between quality of parts and their mean reprocessing time.Furthermore,marginal reprocessing time of the parts decrease with the drop in their quality.
基金supported by the Chinese TMSR Strategic Pioneer Science and Technology Project (No.XDA02010000)the Frontier Science Key Program of Chinese Academy of Sciences (No.QYZDY-SSW-JSC016)the Shanghai Sailing Program (No.20YF1457600).
文摘Due to their unique features,such as the inherent safety,simplified fuel cycle,and continuous on-line reprocessing,molten salt reactors(MSRs)are regarded as one of the six reference reactors in the Generation IV International Forum(GEN-IV).Molten chloride salt fast reactors(MCFRs)are a type of MSR.Compared to molten fluoride salt reactors(MFSRs),MCFRs have a higher solubility of heavy metal atoms,a harder neutron spectrum,lower accumulation of fission products(FPs),and better breeding and transmutation performance.Thus,MCFRs have been recognized as a type of MSR with great prospects for future development.However,as the most important feature for MSRs,the effect of different reprocessing modes on MCFRs must be researched in depth.As such,this study investigated the effect of different isotopes,especially FPs,on the neutronic performance of an MCFR,such as its breeding performance.Furthermore,the characteristics of the different reprocessing modes and MCFR rates were analyzed in terms of safety,radioactivity level,neutron economy,and breeding capacity.In the end,a reprocessing method suitable for MCFRs was determined through calculation and analysis,which provides a reference for the further research of MCFRs.
文摘The purpose of this article is to review the evidence regarding transmission of infection during gastrointestinal endoscopy, factors important in endoscope reprocessing and infection control, areas to focus on to improve compliance, and recent developments and advances in the field.
基金The authors wish to express their gratitude for the grants from the National Key Research and Development Program of China(2017YFB0307903)Natural Science Foundation of China(21706154)Foundation of Key Laboratory of Pulp and Paper Science and Technology of the Ministry of Education of China(KF201916).
文摘This study provides a comprehensive understanding of the polymeric properties of lignin-based non-isocyanate poly(iminehydroxyurethane)s(LNIPUs).The properties of the LNIPUs are affected by changes in the stoichiometric feed ratios of the bis(6-membered cyclic carbonate)(BCC)and levulinate enzymatic hydrolysis lignin(LEHL).The results showed that the LNIPUs exhibited a short relaxation time and excellent thermal repair and degradation properties.With a change in the LEHL content in the LNIPUs to 45.53%,a relaxation time of only 9 s was achieved,and the thermal repair rate of the scratches reached 93%.Furthermore,the tensile strength of the LNIPUs decreased with an increase in the LEHL content after two hot-pressing processes,while a higher than 75% tensile strength was maintained after the second hot-pressing treatment.The LNIPUs exhibited thermoresponsive shape memory property with deformation and shape fixing at 80℃.In addition,the as-synthesized LNIPUs were soluble in ethylene glycol in the absence of any organic solvents.This work demonstrates the synthesis of LNIPUs with self-healing,reprocessing,shape memory,and degradation properties.
文摘Objective To evaluate the application of enzyme in instrument cleaning for hospital sterile reprocessing and different factors that impact the enzyme activity.Methods Standard soil objects for instrument cleaning quality evaluation,as testing coupons,were identified and used to evaluate different cleaning processes designed with varied conditions.Between testing groups using enzymatic detergent versus non-enzymatic detergent,the amount of residual protein on the testing coupons were quantified and compared at different soaking time(10min,20min,30min,45min and 60min).Then,within the enzymatic detergent group,different testing conditions were further explored by adjusting factors,in⁃cluding the soaking temperature(25°C,30°C and 45°C),use solution pH(7.0,8.0),and enzyme dosing(1/80,1/40,1/20,3/40,1/10 and 3/20 in v/v).Then,through an observational comparative study for each testing condition,the time needed to achieve a complete soil removal through visual inspection of the testing coupons was documented for analyses.Results In the test of enzymatic detergent versus non-enzymatic detergent,the non-enzymatic group did not show an obvious decline in the residual protein amount(1069μg at 10 min vs.1042μg at 60 min),whereas the enzymatic group showed significant decrease in residual protein quantity(947μg at 10 min vs.620μg at 60 min).Meanwhile,the amounts of the residual protein at different time points in the enzyme group(947μg at 10 min,864μg at 20 min,812μg at 30 min,691μg at 45 min,and 620μg at 60 min)were consistently lower than those at the same time schedule in the non-enzyme group(1069μg at 10 min,1069μg at 20 min,1067μg at 30 min,1059μg at 45 min,and 1042μg at 60 min).Furthermore,within the enzymatic group,the soaking temperature,use solution pH and enzyme dosing factors all appear to impact the enzyme activity and significantly contribute to the cleaning outcomes.Specifi⁃cally,the higher soaking temperature,higher use solution pH and higher enzyme dosing showed 58.4%,20.0%and 34.4%time reduction to completely remove the soil on the testing coupons,respectively.Conclusion Enzyme seems to play a significant role in the instrument cleaning process for hospital sterile reprocessing.The soaking temperature,cleaning use solution pH,and enzyme dosing all appear to be critical factors impacting the enzyme activity and thus the overall cleaning outcomes.In practice,cleaning process verification should be considered to ensure the optimal use conditions for enzyme cleaning performance are well-understood and consistently achieved at the facility level.
基金This work was in part supported by the Science and Technology Development Fund(FDCT),Macao SAR,(No.0019/2021/A)Shandong Province Outstanding Youth Innovation Team Project of Colleges and Universities(No.2020RWG011),National Natural Science Foundation of China(Nos.62173356 and 61703320)+2 种基金Natural Science Foundation of Shandong Province(No.ZR202111110025)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515011531)Zhuhai Industry-University-Research Project with Hongkong and Macao(No.ZH22017002210014PWC).
文摘Remanufacturing is regarded as a sustainable manufacturing paradigm of energy conservation and environment protection.To improve the efficiency of the remanufacturing process,this work investigates an integrated scheduling problem for disassembly and reprocessing in a remanufacturing process,where product structures and uncertainty are taken into account.First,a stochastic programming model is developed to minimize the maximum completion time(makespan).Second,a Q-learning based hybrid meta-heuristic(Q-HMH)is specially devised.In each iteration,a Q-learning method is employed to adaptively choose a premium algorithm from four candidate ones,including genetic algorithm(GA),artificial bee colony(ABC),shuffled frog-leaping algorithm(SFLA),and simulated annealing(SA)methods.At last,simulation experiments are carried out by using sixteen instances with different scales,and three state-of-the-art algorithms in literature and an exact solver CPLEX are chosen for comparisons.By analyzing the results with the average relative percentage deviation(RPD)metric,we find that Q-HMH outperforms its rivals by 9.79%-26.76%.The results and comparisons verify the excellent competitiveness of Q-HMH for solving the concerned problems.
基金supported by the"Strategic Priority Research Program"of the Chinese Academy of Sciences(Grant No.XDA03030100)the National Natural Science Foundation of China(Grant No.11605264)
文摘For the future energy system, we propose a new closed nuclear energy cycle system, which consists of an accelerator-driven external neutron source, a ceramic reactor and an extend AIROX reprocessing. The attractive features of this system are as follows. (l) The operating mode of the reactor is a combination of subcritical mode and critical mode. initially, the reactor would be driven by the accelerator external neutron source in subcritical mode. A few years later, the reactor would reach the critical mode, and then would operate for a long time. (2) Nuclear fuels, coolants, and structure materials in the ceramic reactor core are made up of ceramic with excellent thermodynamics properties and neutron performance. Therefore, the ceramic reactor has extremely inherent safety, good breeding performance and high power generation efficiency. (3) Fuel reprocessing uses an extend AIROX reprocessing, which is a simple high-temperature dry process and rarely involved in chemical process. In this reprocessing, only most of fission products are separated. Other isotopes, including uranium isotopes, transuranic nuclides and long-lived fission products, would re-enter the reactor as new fuels. Therefore, this closed nuclear energy system could be known as ADANES, short for Accelerator-Driven Advanced Nuclear Energy System, which can greatly improve the utilization rate of nuclear fuels, enhance the nuclear safety, reduce the nuclear proliferation and become a sustainable and low-carbon energy supply for thousands of years.
基金supported by the Grant of the Regional Core Research Program/Institute of Logistics Information Technology of Korean Ministry of Education, Science and Technology
文摘This paper investigates the problem of inconsistent states of radio frequency identification (RFID) tag data caused by incomplete execution of read/write operations during access to RFID tag memory. Passive RFID tags require RF communication to access memory data. This study is motivated by the volatility of RF communication, where instability is caused by intermittent connections and uncertain communication. If a given tag disappears from the communication area of the reader during the reading or writing of tag data, the operation is incomplete, resulting in an inconsistent state of tag data. To avoid this inconsistency, it is necessary to ensure that any operations on tag memory are completed. In this paper, we propose an asynchronous reprocessing model for finalizing any incomplete execution of read/write operations to remove inconsistent states. The basic idea is to resume incomplete operations autonomously by detecting a tag's re-observation from any reader. To achieve this, we present a concurrency control mechanism based on continuous query processing that enables the suspended tag operations to be re-executed. The performance study shows that our model improves the number of successful operations considerably in addition to suppressing inconsistent data access completely.
基金Supported by the National Key Research and Development Program of China(2018YFB0504900 and 2018YFB0504902)National Natural Science Foundation of China(41775020,42005105,and 41905034)。
文摘Atmospheric water vapor is an essential climate variable(ECV)with extensive spatial and temporal variations.Microwave humidity observations from meteorological satellites provide important information for climate system variables,including atmospheric water vapor and precipitable water,and assimilation in numerical weather prediction(NWP)and reanalysis.As one of the payloads onboard China’s second-generation polar-orbiting operational meteorological Fengyun-3(FY-3)satellites,the Microwave Humidity Sounder(MWHS)has been continuously observing the global humidity since 2008.The reprocessing of historical FY-3 MWHS data is documented in detail in this study.After calibrating and correcting the data,the quality of the reprocessed dataset is evaluated and the improvement is shown in this study.The results suggest that MWHS observations bias is reduced to approximately 0.8 K,compared with METOP-A Microwave Humidity Sounder(MHS).The temporal variability of MWHS is highly correlated with the instrument temperature.After reprocessing,the scene temperature dependency is mitigated for all 183 GHz channels,and the consistency and stability between FY-3A/B/C are also improved.
基金National Natural Science Foundation of China(42330602)Youth Innovation Team for“FengYun Satellite Remote Sensing Product Verification”(CMA2023QN12)。
文摘Sea surface temperature(SST)is a crucial physical parameter in meteorology and oceanography.This study demonstrates that the influence of earth incidence angle(EIA)on the SST retrieved from the microwave radiation imager(MWRI)onboard FengYun-3(FY-3)meteorological satellites should not be ignored.Compared with algorithms that do not consider the influence of EIA in the regression,those that integrate the EIA into the regression can enhance the accuracy of SST retrievals.Subsequently,based on the recalibrated Level 1B data from the FY-3/MWRI,a long-term SST dataset was reprocessed by employing the algorithm that integrates the EIA into the regression.The reprocessed SST data,including FY-3B/MWRI SST during 2010-2019,FY-3C/MWRI SST during 2013-2019,and FY-3D/MWRI SST during 2018-2020,were compared with the in-situ SST and the SST dataset from the Operational Sea Surface Temperature and Ice Analysis(OSTIA).The results show that the FY-3/MWRI SST data were consistent with both the in-situ SST and the OSTIA SST dataset.Compared with the Copernicus Climate Change Service V2.0 SST,the absolute deviation of the reprocessed SST,with a quality flag of 50,was less than 1.5℃.The root mean square errors of the FY-3/MWRI orbital,daily,and monthly SSTs,with a quality flag of 50,were approximately 0.82℃,0.69℃,and 0.37℃,respectively.The primary discrepancies between the FY-3/MWRI SST and the OSTIA SST were found mainly in the regions of the western boundary current and the Antarctic Circumpolar Current.Overall,this reprocessed SST product is recommended for El Niño and La Niña events monitoring.
基金Ministry of Defense-Medical Affairs Bureau,Tri-Service General Hospital,No.TSGH-D-109182.
文摘BACKGROUND Patient-ready duodenoscopes were designed with an assumed contamination rate of less than 0.4%;however,it has been reported that 5.4%of clinically used duodenoscopes remain contaminated with viable high-concern organisms despite following the manufacturer’s instructions.Visual inspection of working channels has been proposed as a quality control measure for endoscope reprocessing.There are few studies related to this issue.AIM To investigate the types,severity rate,and locations of abnormal visual inspection findings inside patient-ready duodenoscopes and their microbiological significance.METHODS Visual inspections of channels were performed in 19 patient-ready duodenoscopes using the SpyGlass visualization system in two endoscopy units of tertiary care teaching hospitals(Tri-Service General Hospital and National Taiwan University Hospital)in Taiwan.Inspections were recorded and reviewed to evaluate the presence of channel scratches,buckling,stains,debris,and fluids.These findings were used to analyze the relevance of microbiological surveillance.RESULTS Seventy-two abnormal visual inspection findings in the 19 duodenoscopes were found,including scratches(n=10,52.6%),buckling(n=15,78.9%),stains(n=14,73.7%),debris(n=14,73.7%),and fluids(n=6,31.6%).Duodenoscopes>12 mo old had a significantly higher number of abnormal visual inspection findings than those≤12 mo old(46 findings vs 26 findings,P<0.001).Multivariable regression analyses demonstrated that the bending section had a significantly higher risk of being scratched,buckled,and stained,and accumulating debris than the insertion tube.Debris and fluids showed a significant positive correlation with microbiological contamination(P<0.05).There was no significant positive Spearman’s correlation coefficient between negative bacterial cultures and debris,between that and fluids,and the concomitance of debris and fluids.This result demonstrated that the presence of fluid and debris was associated with positive cultures,but not negative cultures.Further multivariate analysis demonstrated that fluids,but not debris,is an independent factor for bacterial culture positivity.CONCLUSION In patient-ready duodenoscopes,scratches,buckling,stains,debris,and fluids inside the working channel are common,which increase the microbiological contamination susceptibility.The SpyGlass visualization system may be recommended to identify suboptimal reprocessing.
基金This study was funded by the National Natural Science Foundation of China (No.30872175,No.81573236).
文摘The high rate of relapse among heroin users remains a significant public concern in China. In the present study, we utilized a Motivation-Skill-Desensitization-Mental Energy (MSDE) intervention and evaluated its effects on abstinence and mental health. Eighty-nine male heroin users in a drug rehabilitation center were enrolled in the study. The participants in the MSDE intervention group (n=46) received MSDE intervention, which included motivational interviewing, coping skills training, eye movement desensitization and reprocessing, and mindfulness-based psychotherapy. The participants in the control group (h=43) received a series of lectures on skills training. A significant increase in Contemplation Ladder score (P<0.001) and decreases in scores on the Obsessive Compulsive Drug Use Scale (P<0.001), Beck Depression Inventory (P<0.001), and Aggression Questionnaire (P=O.O33) were found immediately after intervention. Compared to the control group, the MSDE intervention group reported significantly higher abstinence rates (P=0.027) and retention rates (P<0.001) at follow-up. Overall, the MSDE intervention, which uses a combined strategy for relapse prevention, could be a promising approach for preventing relapse among heroin users in China.
基金Funded by the Sciences and Technology Bureau of Yulin City (No. 2006YL100-06)
文摘To use fly ash and coal waste effectively, the current technologies for reprocessing and recycling these wastes into eco-building materials were reviewed, such as utilizing fly ash as the component of fly ash cement and low heat cement after the processes of separation, removal of carbon remains and fine comminution, calcining coal waste into kaolin and meta-kaolin with suspension technology, and preparing clinkerless alkali-activated geopolymer materials with fly ash and meta-kaolin.
基金supported by the Institute of Crustal Dynamics Fund(ZDJ2009-01)National Natural Science Foundation of China(41104001)
文摘Global Positioning System data processing is affected by many non-tectonic factors, including the common-mode errors (CME) in station-position time series. The characteristics and origins of CME are still not clear, due to uneven distribution of global GPS networks and the lack of reliable data of the position time series. In this work, data from 241 continuous GPS stations were reprocessed in a consistent way and the results were compared with those generated at Jet Propulsion Laboratory (JPL). Improvements of residual positions were obtained for many low-quality stations, especially those located in Asia and Australia.
基金the grants from the Natural Science Foundation of China(21706154)the National Key Research and Development Program of China(2017YFB0307903)+1 种基金the Foundation of Key Laboratory of Pulp and Paper Science and Technology of Ministry of Education of China(KF201916)the Natural Science Foundation of Shaanxi Province,China(2019JQ-277).
文摘In this study,an environmentally friendly and non-toxic route to synthesize lignin-based non-isocyanate poly(imine-hydroxyurethane)s networks was explored.Specifically,the NH_(2)-terminated polyhydroxyurethanes(NPHUs)prepolymer was first synthesized from bis(6-membered cyclic carbonate)(BCC)and diamine via the ring-opening reaction.Subsequently,the corresponding ligninbased non-isocyanate polyurethanes(NIPUs)with tunable properties were synthesized from NPHUs and levulinate lignin derivatives containing ketone groups via the Schiff base reaction.The structural,mechanical,and thermal properties of NIPUs with different stoichiometric feed ratios of BCC and levulinate lignin were characterized by Fourier transform infrared spectroscopy(FT-IR),nuclear magnetic resonance(NMR),differential scanning calorimetry(DSC),dynamic mechanical analysis(DMA),and thermogravimetric analysis(TGA).The results indicated that the tensile strength,Young's modulus,toughness,storage modulus,glass transition temperature,and thermal stability of lignin-based NIPUs gradually increased with increasing lignin content,and the highest Young's modulus of 41.1 MPa was obtained when lignin content reached 45.53%.With good reprocessing properties,this synthetic framework of ligninbased NIPUs also provides sustainable non-isocyanate-based substitutions to traditional polyurethane networks.
文摘Background: Seven patients at a hospital in Houston, TX, were diagnosed during a two-week period in 2009 with joint space infection of pansusceptible P. aeruginosa following arthroscopic procedures of the knee or shoulder. Tosh et al. (2011), who investigated and published the principal report discussing this bacterial outbreak, conclude that its most likely cause was the improper reprocessing of certain reusable, physically-complex, heat-stable arthroscopic instruments used during these arthroscopic procedures. These reusable instruments reportedly remained contaminated with remnant tissue, despite diligent efforts by the hospital to clean their internal structures. This retained bioburden presumably shielded the outbreak’s strain of embedded P. aeruginosa from contact with the pressurized steam, reportedly resulting in ineffective sterilization of these arthroscopic instruments and bacterial transmission. Objectives: First, to clarify which specific sterilization methods, in addition to steam sterilization, Methodist Hospital employed to process its reusable arthroscopic instrumentation at the time of its outbreak, in 2009;second, to evaluate Tosh et al.’s (2011) conclusion that ineffective steam sterilization due to inadequate cleaning was the most likely cause of this hospital’s outbreak;third, to consider whether any other hitherto unrecognized factors could have plausibly contributed to this outbreak;and, fourth, to assess whether any additional recommendations might be warranted to prevent disease transmission following arthroscopic procedures. Methods: The medical literature was reviewed;some of the principles of quality assurance, engineering and a root-cause analysis were employed;and Tosh et al.’s (2011) findings and conclusions were reviewed and compared with those of other published reports that evaluated the risk of disease transmission associated with the steam sterilization of physically-complex, heat-stable, soiled surgical instruments. Results and Conclusion: Reports documenting outbreaks of P. aeruginosa or another vegetative bacterium associated with the steam sterilization of inadequately cleaned surgical or arthroscopic instruments are scant. This finding—coupled with a number of published studies demonstrating the effective steam sterilization of complex instruments contaminated with vegetative bacteria mixed with organic debris, or, in one published series of tests, with resistant bacterial endospores coated with hydraulic fluid—raises for discussion whether Methodist Hospital’s outbreak might have been due to one or more factors other than, or in addition to, that which Tosh et al. (2011) conclude was its most likely cause. An example of such a factor not ruled out by Tosh et al. (2011) findings would be the re-contamination of the implicated arthroscopic instruments after sterilization. The specific methods that Methodist Hospital employed at the time of its outbreak to sterilize some of its arthroscopic instrumentation remain unclear. A number of additional recommendations are provided to prevent disease transmission following arthroscopic procedures.
文摘The corrosion behavior of a titanium-5% tantalum alloy (Ti-STa) in hot nitric acid condensate was investigated to understand aging behavior ofreprocessing equipments. On the basis of long-term immersion tests, it was determined that the corrosion of Ti-STa in nitric acid condensate is accelerated with an increase in the concentration. The corrosion rate was nearly constant during the immersion test and the coupons suffered from uniform corrosion. In addition, it is important to note that the nitric acid concentration in the condensate increased on addition of metal salts to the heated nitric acid solution. The larger valence of metal ions was contributed to the increase in the concentration of nitric acid condensate. Consequently, the metal salt in the heated nitric acid solution accelerates the corrosion of Ti-STa in the condensate. Therefore, the nitric acid condensate condition should be carefully considered for the corrosion environment of titanium and its alloys.
文摘A blending strategy of virgin and reprocessed polylactide may be postulated as an alternative to reduce the material cost at industrial level,and as a valorization route to plastic waste management of production scraps.The performance of blends prepared from virgin polylactide and polylactide mechanically reprocessed up to two cycles(PLA-V/R)was assessed in terms of thermo-oxidative stability,morphology,viscoelasticity and thermal kinetics for energetic valorization.PLA-V/R blends showed appropriate thermo-oxidative stability.The amorphous nature of polylactide was preserved after blending.The viscoelastic properties showed an increment of the mechanical blend effectiveness,which suggested the feasibility of using PLA-V/R blends under similar mechanical conditions to those of virgin PLA goods.Finally,it was shown that the energetic valorization of PLA-V/R blends would result in a more feasible process,due to the lower required activation energy,thus highlighting the advantages of the energetic demand for the process.In conclusion,PLA-V/R blends showed similar processability,service performance and valorization routes as virgin PLA and therefore could be relevant in the sustainable circular industry of bioplastics.
基金This work was supported by the Fundamental Research Funds for the Central Universities(Grant No.2572018BB07)the National Natural Science Foundation of China(Grant No.31670570).
文摘This study assessed the life cycle of biocomposites with antioxidants by repeated processing.The effects of antioxidants on the life cycle of wood flour/polypropylene(PP)composites were determined by analyzing their mechanical and thermal properties.The composites were repeatedly processed for seven times with pelletizing and extruding.An antioxidant,pentaerythritoltetrakys 3-(3,5-ditert-butyl-4-hydroxyphenyl)propionate,was used.The mechanical strength of the biocomposites decreased after reprocessing.Fourier transformed infrared analysis showed that thermo-oxidative aging occurred during reprocessing.The thermal performance of the resulting composites decreased because of reprocessing.Wood flour/PP has a long lifetime and antioxidants can slow the thermo-oxidative and mechanical degradation during reprocessing.