Repair of Second-Generation Recycled Fine Aggregate of Waste Concrete from Freeze-Thaw Environment by Carbonation Treatment

The reuse of waste recycled concrete from harsh environments has become a research hotspot in the field of construction.This study investigated the repair effect of carbonation treatment on second-generation recycled fine aggregate(SRFA)obtained from recycled fine aggregate concrete(RFAC)subjected to freeze-thaw(FT)cycles.Before and after carbonation,the properties of SRFA were evaluated.Carbonated second-generation recycled fine aggregate(CSRFA)at five substitution rates(0%,25%,50%,75%,100%)to replace SRFA was used to prepare carbonated second-generation recycled fine aggregate concrete(CSRFAC).The water absorption,porosity and mechanical properties of CSRFAC were tested,and its frost-resisting durability was evaluated.The results showed after carbonation treatment,the physical properties of SRFA was improved and met the requirements of II aggregate.The micro-hardness of the interfacial transition zone and attached mortar in CSRFA was 50.5%and 31.2%higher than that in SRFA,respectively.With the increase of CSRFA replacement rate,the water absorption and porosity of CSRFAC gradually decreased,and the mechanical properties and frost resistance of CSRFAC were gradually improved.Carbonation treatment effectively repairs the damage of SRFA caused by FT cycles and improves its application potential.

First Cycle Effect of Polycrystalline CuZnAl Shape Memory Alloy during Thermal-Mechanical Cycling

The thermal-mechanical (T-M) cycles at constant strain of a polycrystalline CuZnAl alloy have been studied in the. present work. In-situ optical microscopic observations have been made to reveal the features of the phase transitions during T-M cycling. The variation of stress-temperature (S-T) curves and electrical resistance-temperature (R-T) curves accompanying with T-M cycling have been measured by tensile test and electrical resistance measurements. It has been found that the polycrystalline CuZnAl alloy shows apparent morphology changes and properties variations in the first cycle during T-M cycling which is called the first cycle effect in the present work. The stable transformation procedure in the T-M cycle is: martensiteparent phase +residual acicular martensite. This residual martensite possesses the character of stress-induced martensite.

Effect of thermal-cooling cycle treatment on thermal expansion behavior of particulate reinforced aluminum matrix composites

Two micron SiC particles with angular and spherical shape and the sub-micron Al2O3 particles with spherical shape were introduced to reinforce 6061 aluminium by squeeze casting technology. Microstructures and effect of thermal-cooling cycle treatment （TCCT） on the thermal expansion behaviors of three composites were investigated. The results show that the composites are free of porosity and SiC/Al2O3 particles are distributed uniformly. Inflections at about 300℃ are observed in coefficient of thermal expansion （CTE） versus temperature curves of two SiCp/Al composites, and this characteristic is not affected by TCCT. The TCCT has significant effect on thermal expansion behavior of SiCp/Al composites and CTE of them after 3 cycles is lower than that of 1 or 5 cycles. However, no inflection is observed in Al2O3p/Al composite, while TCCT has effect on CTE of Al2O3p/Al composite. These results should be due to different relaxation behavior of internal stress in three composites.

Life cycle assessment for waste acid treatment in zinc smelting

Lift cycle assessment(LCA)methodology was applied to evaluating and comparing two waste acid disposal processes in zinc smelting.The results indicate that environmental impacts of gas−liquid vulcanization technologies are human toxicity,abiotic depletion potential,and global warming risk,which are mainly caused in neutralizing−evaporating−crystallization unit and electrodialysis unit.As for traditional lime neutralization method,vulcanization unit is the main factor.In this regard,the total environmental impact of traditional lime neutralization method is much higher than that of gas−liquid vulcanization technologies.Furthermore,the sensitive analysis shows that electricity and sodium sulfide(60%)are sensitive factors in two waste acid disposal technologies.In addition,the total cost of disposing a functional unit waste acid in traditional lime neutralization process is nearly 27 times that of the gas−liquid vulcanization waste acid disposal technologies.

Fatigue behaviour of coke drum materials under thermal-mechanical cyclic loading

Coke drums are vertical pressure vessels used in the delayed coking process in petroleum refineries. Significant temperature variation during the delayed coking process causes damage in cracking. There were some studies on coke drums in the form of bulging and the fatigue life estimation for the coke drums, but most of them were based on strain-fatigue life curves at constant temperatures, which do not consider simultaneous cyclic temperature and mechanical loading conditions. In this study, a fatigue testing system is successfully devel- oped to allow performing thermal-mechanical fatigue （TMF） test similar to the coke drum loading condition. Two commonly used base and one clad materials of coke drums are then experimentally investigated. In addition, a comparative study between isothermal and TMF lives of these materials is conducted. The experimental findings lead to better understanding of the damage mechanisms occurring in coke drums and more accurate prediction of fatigue life of coke drum materials.

Low cycle fatigue improvement of powder metallurgy titanium alloy through thermomechanical treatment

A low-cost β type Ti-1.5Fe-6.8Mo-4.8Al-1.2Nd (mass fraction, %)(T12LCC) alloy was produced by blended elemental powder metallurgy(P/M) method and subsequent thermomechanical treatment. Low cycle fatigue(LCF) behavior of P/M T12LCC alloy before and after thermomechanical treatment was studied. The results show that the LCF resistance of P/M titanium alloy is significantly enhanced through the thermomechanical treatment. The mechanisms for the improvement of LCF behavior are attributed to the elimination of residual pores, the microstructure refining and homogenization.

Influence of Ageing Heat Treatment on the High Cycle Fatigue of an 8090 Al-Li Alloy

Fatigue lives for the smooth and notched specimens of 8090 Al-Li alloy jn the different ageing conditions have been studied. For the smooth samples of 8090 alloy the artificial ageing results in an increase in fatigue life in comparison with natural ageing. On the contrary, the notched specimens of 8090 alloy in the naturally aged condition show higher fatigue life than in the peak-aged. The exposure to either the peak-aged or naturally aged leads to superior fatigue properties of Al-Li alloy to the traditional high strength aluminum alloys of 7075 and 2024, especially in the latter aged condition. In all ageing conditions, i,e. naturally, under-, peak- and over-aged, the peak-aged 8090 alloy displays the highest fatigue life and the over-aged material has a minimum value at the same stress amplitude. The difference in fatigue life is mainly attributable to the size and distribution of strengthening precipitates as well as the wide of precipitate free zones (PFZ's) along grain boundaries.

Effect of heat treatment on high-cycle fatigue behavior of Mg-Zn-Y-Zr alloy

High-cycle fatigue (HCF) behavior of as-forged-T5 Mg-Zn-Y-Zr wrought alloy with stress-ratio R=-1 at ambient environment was presented. The relationship between the maximum stress and the number of cycles to failure was constructed. The results show that the fatigue strength at 107 cycles of the as-forged alloy in T5 state is higher than that of the alloy in T4 state. However, in T6 state, the fatigue strength at 107 cycles is higher than those of the alloys in both T5 and T4 states.

Integrated strategies for chemotherapy cycles in nasopharyngeal carcinoma patients: Real-world data from two epidemic centers guiding decision-making

objective:Two cycles of induction chemotherapy(IC)followed by 2 cycles of platinum-based concurrent chemoradiotherapy(CCRT)(2IC+2CCRT)for locoregionally advanced nasopharyngeal carcinoma(LA-NPC)is widely adopted but not evidence-confirmed.This study aimed to determine the clinical value of 2IC+2CCRT regarding efficacy,toxicity and cost-effectiveness.Methods:This real-world study from two epidemic centers used propensity score matching(PSM)and inverse probability of treatment weighting(IPTW)analyses.The enrolled patients were divided into three groups based on treatment modality:Group A(2IC+2CCRT),Group B(3IC+2CCRT or 2IC+3CCRT)and Group C(3IC+3CCRT).Long-term survival,acute toxicities and cost-effectiveness were compared among the groups.We developed a prognostic model dividing the population into high-and low-risk cohorts,and survivals including overall survival(OS),progression-free survival(PFS),distant metastasis-free survival(DMFS)and locoregional relapse-free survival(LRRFS)were compared among the three groups according to certain risk stratifications.Results:Of 4,042 patients,1,175 were enrolled,with 660,419,and 96 included in Groups A,B and C,respectively.Five-year survivals were similar among the three groups after PSM and confirmed by IPTW.Grade 3-4 neutropenia and leukocytopenia were significantly higher in Groups C and B than in Group A(52.1%vs.41.5%vs.25.2%;41.7%vs.32.7%vs.25.0%)as were grade 3-4 nausea/vomiting and oral mucositis(29.2%vs.15.0%vs.6.1%;32.3%vs.25.3%vs.18.0%).Cost-effective analysis suggested that 2IC+2CCRT was the least expensive,while the health benefits were similar to those of the other groups.Further exploration showed that 2IC+2CCRT tended to be associated with a shorter PFS in high-risk patients,while 3IC+3CCRT potentially contributed to poor PFS in low-risk individuals,mainly reflected by LRRFS.Conclusions:In LA-NPC patients,2IC+2CCRT was the optimal choice regarding efficacy,toxicity and costeffectiveness;however,2IC+2CCRT and 3IC+3CCRT probably shortened LRRFS in high-and low-risk populations,respectively.

Effect of Thermal-cold Cycling Treatment on Mechanical Properties and Microstructure of 6061 Aluminum Alloy

The influence of thermal-cold cycling treatment on mechanical properties and microstructure of 6061 aluminum alloy was investigated by means of tensile test, optical microscopy(OM), X-ray diffraction(XRD) and transmission electron microscopy(TEM). The cryogenic treatment mechanism of the alloys was discussed. The results show that thermal-cold cycling treatment is beneficial since it produces a large number of dislocations and accelerates the ageing process of the alloy and yields the finer dispersed β" precipitates in the matrix. This variation of microstructural changes leads to more favorable mechanical properties than the other investigated states, while grain boundary precipitation is coarse and distributed discontinuously along grain boundaries, with a lower precipitation free zone(PEZ) on the both sides of precipitated phase. As a result, the tensile strength, elongation and conductivity of 6061 aluminum alloy after thermal-cold cycling treatment are 373.37 MPa, 17.2% and 28.2 MS/m, respectively. Compared with conventional T6 temper, the mechanical properties are improved significantly.

Effect of Thermal Cycling Treatment on Microyield Behavior of Al_2O_3p/Al Composite

An aluminum alloy (6061) matrix composite reinforced with 35% (vol.) Al 2O 3 particles was fabricated by squeeze casting method. The Al 2O 3 particles were spherical. The microyield behavior of the composite and the effect of different thermal cycling treatment on the microyield behaviors of the composite were studied. Based on TEM and HREM observation of microstructure, the mechanism of microyield behavior in the Al 2O 3p/6061 composite was analyzed. The results indicate that the microyield behavior of the Al 2O 3p/6061 composite can be described by Brown Lukens theory, which was used satisfactorily for aluminum alloys and other light alloys, and is affected greatly by the different thermal cycling treatment. The more the cycles of thermal cycling treatment, the higher to microyield strength at small strains. Thermal cycling treatment affects mainly the thermal mismatch stress and the density of movable dislocations in the matrix.

The choice of a neoadjuvant chemotherapy cycle for breast cancer has significance in clinical practice: results from a population-based, real world study

Objective:Neoadjuvant chemotherapy(NAC)is currently used in both early stage and locally advanced breast cancers.The survival benefits of standard vs.non-standard NAC cycles are still unclear.This study aimed to investigate the relationship between NAC cycles and survival based on real world data.Methods:We identified patients diagnosed with invasive primary breast cancers who underwent NAC followed by surgery.Patients who received at least 4 NAC cycles were defined as having received standard cycles,while patients who received less than 4 NAC cycles were defined as having received non-standard cycles.Kaplan-Meier curves and Cox proportional hazard models were used to estimate the disease-free survival(DFS)and overall survival(OS).Results:Of the 1,024 included patients,700 patients received standard NAC cycles and 324 patients received non-standard NAC cycles.The DFS estimates were 87.1%and 81.0%(P=0.007)and the OS estimates were 90.0%and 82.6%(P=0.001)in the standard and non-standard groups,respectively.Using multivariate analyses,patients treated with standard NAC cycles showed significant survival benefits in both DFS[hazard ratio(HR):0.62,95%confidence interval(CI):0.44–0.88]and OS(HR:0.54,95%CI:0.37–0.79).Using stratified analyses,standard NAC cycles were associated with improved DFS(HR:0.59,95%CI:0.36–0.96)and OS(HR:0.49,95%CI:0.28–0.86)in the HER2 positive group.Similar DFS(HR:0.50,95%CI:0.25–0.98)and OS(HR:0.45,95%CI:0.22–0.91)benefits were shown for the triple negative group.Conclusions:Standard NAC cycles were associated with a significant survival benefit,especially in patients with HER2 positive or triple negative breast cancer.

Effects of the number of neoadjuvant therapy cycles on clinical outcomes, safety, and survival in patients with metastatic colorectal cancer undergoing metastasectomy

The controversial outcomes in patients with metastatic colorectal cancer(mCRC)highlight the need for developing effective systemic neoadjuvant treatment strategies to improve clinical results.The optimal treatment cycles in patients with mCRC for metastasectomy remain undefined.This retrospective study compared the efficacy,safety,and survival of cycles of neoadjuvant chemotherapy/targeted therapy for such patients.Sixty-four patients with mCRC who received neoadjuvant chemotherapy/targeted therapy following metastasectomy were enrolled between January 2018 and April 2022.Twenty-eight patients received 6 cycles of chemotherapy/targeted therapy,whereas 36 patients received≥7 cycles(median,13;range,7–20).Clinical outcomes,including response,progression-free survival(PFS),overall survival(OS),and adverse events,were compared between these two groups.Of the 64 patients,47(73.4%)were included in the response group,and 17(26.6%)were included in the nonresponse group.The analysis revealed chemotherapy/targeted therapy cycle and pretreatment serum carcinoembryonic antigen(CEA)level as independent predictors of the response as well as overall survival and chemotherapy/targeted therapy cycle as an independent predictor of progression(all p<0.05).Furthermore,our results revealed shorter operation time,lower estimated operative blood loss,higher response rate,lower progression rate,and higher survival rate in≥7 cycles of chemotherapy/targeted therapy group(all p<0.05),but no statistical differences in adverse events were observed between the two groups(all p>0.05).The median OS and PFS were 48 months(95%CI,40.855–55.145)and 28 months(95%CI,18.952–37.48)in the≥7-cycle group and 24 months(95%CI,22.038–25.962)and 13 months(95%CI,11.674–14.326)in the 6-cycle group,respectively(both p<0.001).The oncological outcomes in the≥7-cycle group were significantly better than those in the 6-cycle group,without significant increases in adverse events.However,prospective randomized trials are mandatory to confirm the potential advantages of cycle numbers of neoadjuvant chemotherapy/targeted therapy.

Carbon Footprint of Recycling Service in Waste Treatment: Used Beverage Cans and Waste Papers

There are very few studies of the Carbon Footprint of Products (CFPs) in the service sector (e.g. transport and waste treatment) in comparison with those of industrial products and farm products. In this study, the CFPs of the recycling services of used beverage cans (aluminum and steel) and waste papers (cardboard, magazine and newspaper) in waste treatment were estimated as a first trial model of the service sector. Regarding the CFPs of whole life cycle of the recycling services, the amounts of CO2-equivalent (CO2e) greenhouse gas (GHG) emissions from the collection and transportation process were the largest in all recycling cases. The reason that the collection and transportation process emits the largest amounts of GHG emissions is that the collection vehicles (trucks) consume the large amounts of diesel fuel. Regarding the CFPs of the capital equipment, the amounts of GHG emissions from the capital equipment were the second largest in all recycling cases. It was found that the percentages of amounts of GHG emissions from the capital equipment in the recycling services were larger than those of industrial products and farm products.

Effect of thermo-mechanical treatment on microstructure and mechanical properties of wire-arc additively manufactured Al-Cu alloy

Wire-arc additive manufacture(WAAM)has great potential for manufacturing of Al-Cu components.However,inferior mechanical properties of WAAM deposited material restrict its industrial application.Inter-layer cold rolling and thermo-mechanical heat treatment(T8)with pre-stretching deformation between solution and aging treatment were adopted in this study.Their effects on hardness,mechanical properties and microstructure were analyzed and compared to the conventional heat treatment(T6).The results show that cold rolling increases the hardness and strengths,which further increase with T8 treatment.The ultimate tensile strength(UTS)of 513 MPa and yield stress(YS)of 413 MPa can be obtained in the inter-layer cold-rolled sample with T8 treatment,which is much higher than that in the as-deposited samples.The cold-rolled samples show higher elongation than that of as-deposited ones due to significant elimination of porosity in cold rolling;while both the T6 and T8 treatments decrease the elongation.The cold rolling and pre-stretching deformation both contribute to the formation of dense and dispersive precipitatedθ′phases,which inhibits the dislocation movement and enhances the strengths;as a result,T8 treatment shows better strengthening effect than the T6 treatment.The strengthening mechanism was analyzed and it was mainly related to work hardening and precipitation strengthening.

Effects of Heat Treatment and Thermal Cycling on Martensitic Transformation Behavior of Ni_(59)Al_(11)Mn_(30) High Temperature Shape Memory Alloy

A reversible martensitic transformation (MT) takes place during cooling and heating in the solution quenched and the solution quenched plus aged Ni59AlHMn30 alloy The MT temperature increases with increasing solution temperature. The excellent MT characteristics can be obtained from a process of lOOCTC solution quenched plus 400 °C aged. Follow this process, the MT start temperature (Ms) and the reverse MT finish temperature (Af) are 469*C and 548"C, respectively. The martensitic stabilization effect in the solution quenched and aged Ni59AlnMn3o alloy is observed as an increase in the Af temperature of the first reverse MT during thermal cycles. This stabilization effect vanishes from the second thermal cycle. Thermal cycling can enhance the stability of the reversible MT. The microstructure of the quenched NisgAlnMnjo alloy consists of martensite (M) and gamma phase. The volume fraction of gamma phase is about 40%. The substructure of M and gamma phase is twins and dislocations, respectively. The hardness of M is higher than that of gamma phase. After aging treatment the basic phases of alloy do not change, but the hardness of the phases increases.

电化学治疗对宫颈癌细胞系细胞周期及CDK、cyclin表达的影响

目的:探讨不同电化学治疗剂量对肿瘤细胞生长周期的影响、细胞周期变化特点及对宫颈癌细胞系CDK和cyclin表达的影响。方法:用体外实验方法,用不同电化学剂量处理宫颈癌细胞系后分别用流式细胞仪和RT-PCR测定细胞周期分布及细胞CDK和cyclin mRNA的表达。结果:(1)不同电化学治疗剂量组合作用后S期细胞所占比例均低于空白组,差异有统计学意义(P<0.01),但G1细胞所占比例均高于空白组,差异有统计学意义(P<0.01)。G2期细胞所占比例与空白对照的差异无统计学意义(P>0.05);(2)(5V,10C)、(10V,10C)处理组cyclin D1表达阴性;(5V,5C)、(10V,5C)处理组cyclinD1表达阳性。各电化学剂量处理组CDK4、CDK1、cyclin B1表达均阳性;(3)不同电化学治疗剂量组合作用后各基因表达与G2期比例无明显相关,但cyclinD1基因表达与G1期呈负相关,与S期呈正相关。CDK1基因表达与G1期呈正相关,与S期呈负相关。结论:电化学治疗能通过调节肿瘤细胞CDK和cyclin基因的表达影响其细胞周期各时相的分布。

Influence of laser treatment on the fatigue of notched bar

Fatigue cutting is a new approach for separating material. Man-made fatigue can be realized by applying a rotating bending load to a notched bar. To better utilize the new method, laser treatment is adopted in this study. After laser radiation at the notch root, the fatigue cycle of the bar drops dramatically. Based on the experimental result, we draw the conclusion that the fatigue of the bar is influenced by the shape of the hardened area. A hardened area that has a small axial dimension and a relatively large radial dimension facilitates the fatigue. The desirable hardened area can be obtained by controlling the laser treatment parameters.

The significance of resource recycling for coking wastewater treatment:based on environmental and economic life cycle assessment

The sustainability of the coking industry is supported by reasonable production profit and environmental quality requirements.The traditional measures substantially increased the related costs for enterprises to reach standards.This paper aims to develop a comprehensive cost combined environmental impact assessment method that is necessary for the analysis of wastewater treatment systems.Typical three coking wastewater treatment processes in China were evaluated.Results showed that eutrophication dominantly contributed to the overall environmental effect.Improving effluent quality could significantly reduce the total environmental impact.In terms of an economic perspective,the price of raw materials was the main factor that affected the operating cost of comprehensive treatment.Based on subsystem analysis,the pretreatment stage accounted for the majority of environmental and cost burdens,respectively reaching 64%-78%and 64%-86%.Optimizing the pretreatment process by enhancing the efficiency of high concentration raw material recovery and substituting toxic raw materials for extractant could reduce the environmental impact and economic cost by 43.8%and 57%,respectively,which was an effective way to improve the potential performance of coking wastewater treatment plants(WWTPs).

Enhancing the CO_(2) methanation activity of Ni/CeO_(2) via activation treatment-determined metal-support interaction

The metal-support interaction is of critical importance to enhance the catalytic activity and selectivity.However,it is still challenging to construct an appropriate interaction starting from the catalyst fabrication and/or activation.We herein established low-temperature treatment of Ni^(2+)ions impregnated on ceria in reductive atmosphere and reduction-oxidation cycles as effective approachs to regulate the metal-support interaction and raise the catalytic performance in the CO_(2)methanation.The proposed construction approach yielded Ni/Ce O_(2)that displayed highly dispersed Ni nanoparticles in contact with Ce O_(2)(111)and(100)facet,higher density of surface oxygen vacancies and larger amounts of weak basic sites relative to the reference samples,which increased the capacity for H2 and CO_(2)adsorption/activation.The interaction resulted in appreciably(2-3 fold)higher activity in the CO_(2)methanation with maintaining almost full selectivity to CH4 and high stability.Coverage of Ni surface by Ce O_(2)-x thin layer as a typical structure of strong metal-support interaction resulting from high-temperature reduction,can be alleviated via reduction-oxidation cycles.We also demonstrate the activation treatment-determined metalsupport interaction effect can generally extend to(Ti O_(2)and Zr O_(2))supported Ni catalysts.