Synthesis of Reprocessable Lignin-based Non-isocyanate Poly(imine-hydroxyurethane)s Networks

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.

Investigation on UV-curing Reprocessable Thermosets Bearing Hindered Urea Bonds and Their Composites with Modified Zinc Oxide Nanoparticles

In this study,a series of hindered urea bond(HUB)containing polyurethane-urea methacrylate prepolymers and a none HUB containing polyurethane methacrylate prepolymer were prepared using isobornyl methacrylate as the reactive diluent via one-pot procedure.The prepolymers were characterized fully by various techniques.Then,their thermosets were fabricated via UV curing in presence of a photo initiator,and their mechanical property and thermal behavior were investigated and compared.Different from the none HUB containing thermoset,the HUB containing thermosets(defined as PUT)could be recycled and reprocessed by hot press under relatively mild conditions with high recovery ratio of mechanical property.Furthermore,zinc oxide(ZnO)nanoparticles were modified with 3-(trimethoxysilyl)propyl methacrylate and the modified ZnO(defined as ZnO-TPM)was dispersed and polymerized into PUT matrix to prepare their nanocomposites.The influence of ZnO-TPM on the mechanical performance of the composites was evaluated,which indicated that the Young’s modulus and tensile strength increased gradually to the maximum values at ZnO-TPM content of 1 wt%and then decreased.The composites also displayed good reprocessability with improved recovery ratio compared to the pure PUT sample.In addition,the composite materials exhibited strong UV absorption capacity,implying their potential application in the circumstance where UV-shielding was required.

Catalyst-free and Reprocessable Aromatic Polydithiourethanes

The incorporation of dynamic covalent bonds into thermosets facilitates the reprocessing of polymer networks,thereby meeting the sustainable requirements for polymer recycling.However,the mechanical properties of many materials often decline significantly upon reprocessing due to side reactions caused by harsh processing conditions.In this work,we find that the aromatic dithiocarbamate bond can undergo dissociation under mild conditions without the need for a catalyst,enabling the efficient reprocessing of the corresponding polydithiourethane.As a consequence,the mechanical properties of the polydithiourethane can be largely preserved after reprocessing.The discovery of this dynamic chemistry is anticipated to broaden the potential for material design in dynamic covalent polymer networks.

Efficacy of spray flushing in the reprocessing of flexible endoscopes:A randomized controlled trial

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.

Influences of Earth Incidence Angle on FY-3/MWRI SST Retrieval and Evaluation of Reprocessed SST

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.

Effect of reprocessing on neutrons of a molten chloride salt fast reactor

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.

A novel reprocessable chloroprene rubber based on dynamic disulfide metathesis

For sustainable application of chloroprene rubber(CR),a new technology is developed by the vulcanization of CR using 2,2'-dithiodipyridine(DPD)as a cross-linking agent with the repro-cessing performance owing to disulfde metathesis.When DPD was incorporated into CR vulcanization,the Menschutkin reac-tion between allyl chloride group and pyridine group occurred with a maximum exothermic peak at 184°C.The number of effective cross-linking bond at o.5 phr DPD vulcanizate was higher than that at high DPD content.This vulcanizate showed high tensile strength(11.12 MPa)and elongation at break(1253±120%)owing to the exchangeable disulfide bond in the system.Under the catalysis of triphenylphosphine,the metathesis of disulfide compound was improved obviously,which endowed CR/DPD vulcanizates with good recyclability performance.Disulfide cross-linkage maintains its stability at low temperature,thus ensuring the mechanical stability of CR/DPD vulcanizate under the ambient conditions.Vulcanization and reprocessing of CR/DPD vulcanizate can be conducted with common industrial rubber processing equipment.Such reprocessable chloroprene rubber could have potential appli-cation in CR industry,also serve to significantly improve envir-onmental sustainability.

Effect of quality uncertainty of parts on performance of reprocessing system in remanufacturing environment

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.

Current issues in endoscope reprocessing and infection control during gastrointestinal endoscopy

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.

Abstinence Following a Motivation-Skill-Desensitization-Mental Energy Intervention for Heroin Dependence: A Three-year Follow-up Result of a Randomized Controlled Trial

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.

SpyGlass application for duodenoscope working channel inspection: Impact on the microbiological surveillance

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.

The Future Resources for Eco-building Materials:Ⅱ. Fly Ash and Coal Waste

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.

Data-processing induced GPS-positioning error

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.

Synthesis of Lignin-based Nonisocyanate Poly(imine-hydroxyurethane)s Networks.Part II:Self-healing,Reprocessing,and Degradation

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.

Other Possible Causes of a Well-Publicized Outbreak of <i>Pseudomonas aeruginosa</i>Following Arthroscopy in Texas

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.

Suitability of Blends from Virgin and Reprocessed Polylactide: Performance and Energy Valorization Kinet

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.

Effect of an antioxidant on the life cycle of wood flour/polypropylene composites

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.

Corrosion Behavior of a Titanium Alloy in Hot Nitric Acid Condensate

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.

Future Resources for Eco-building Materials:I. Metallurgical Slag

In order to make an effectivily recycle use of iron and steel slags that are main industrial wastes generated in Chinese metallurgical industry, the current technologies for reprocessing and recycling these wastes into eco-building materials were reviewed, such as preparing cement-steel slag blended cement with steel slag after metal recovery, using the fine powder of blast furnace slag （BFS） for manufacturing slag cement and high performance concrete. A further research on using these available resources more efficiently were discussed.

Scenarios for Sustainable Management of a Solid Release from a Hydrometallurgical Zinc Treatment in the Democratic Republic of Congo

The treatment of zinc ores at the UZK(Kolwezi Zinc Factory),in the DRC(Democratic Republic of Congo),has generated a deposit of solid releases rich in recoverable metals,but presented an environmental risk given the conditions of its storage.The results of chemical analyses by X-ray fluorescence have shown the presence of base metals recoverable in significant proportions in these releases,which contain on average 17%zinc and 3.5%copper.In addition,X-ray diffraction analyses have identified the main minerals:franklinite,willemite and sphalerite.The environmental risks are real,because the results of the availability tests for leaching have revealed significant zinc and copper extraction rates for a liquid to solid ratio of 100 and those of landfill compliances show that although under European Directive 2003/33/EC,these discharges are dangerous and must be treated under conditions which respect the environment.Following an environmental risk assessment,two scenarios for reprocessing these discharges are envisaged and will be compared from a technical,economic and environmental point of view,including their feasibility in the context of the DRC.The two processes would be on the one hand a hot acid attack in two or three stages and on the other hand a mixed digestion-roasting treatment followed by leaching with water.