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Graphical abstract Highlights • Biodegradable surface sizing agent(poly-vinyl alcohol/itaconic acid/acrylamide)was synthesized via radical polymerization with MINITAB software'DOE. • PVA/IA/AM could form the hydrophobic coating layer with a spatial network structure on the surface of paper. • It not only improve the hydrophobicity of paper but also increase the paper surface strength. • The copolymer had better forming film characteristic and lower property of penetrating into the interior of paper than PVA. Abstract Biodegradable surface sizing agent(poly-vinyl alcohol/itaconic acid/acrylamide)was synthesized via radical polymerization with MINITAB software. Fourier transform infrared spectroscopy and scanning electron microscopy were used to evaluate the structure of the surface sizing agent. In the meantime, a thin layer of PVA or PVA/IA/AM was coated on the surface of paper. The strength and water resistance of paper were studied and compared. The optimization experiment condition for the surface sizing agent was determined by Design of Experiment (DOE). It indicated that PVA/IA/AM copolymer not only improve the hydrophobicity of paper but also increase the paper surface strength. It was attributed that PVA/IA/AM could form the hydrophobic coating layer with spatial network structure on the surface of paper and increase the number of hydrogen bonding between the copolymer and fiber. Furthermore, the copolymer had better forming film characteristic and lower property of penetrating into the interior of paper than PVA when they were coated on the surface of paper. [ABSTRACT FROM AUTHOR]

• Jack bean and soybean crude ureases were used for topsoil stabilization. • Organic matter in crude urease affected soil mechanical properties markedly. • Jack bean presented a greater potential in topsoil stabilization than soybean. • Optimum bean dosages were proposed at 40 g/L jack bean and 80 g/L soybean. • The cost of using crude ureases was greatly reduced compared to commercial urease. Enzyme-induced carbonate precipitation (EICP) is a prominent biogeotechnical technique for soil stabilization to address desert invasion and dust emission issues. This study investigates the bio-cementation efficacy of EICP mediated by jack bean crude urease (JCU) and soybean crude urease (SCU) on surface stabilization of aeolian sand from Tengger Desert. Topsoil properties of the EICP-treated sand including CaCO 3 , organic matter content, surface strength, and wind erosion resistance were evaluated. The urease activity of JCU was 3.4 times higher than SCU, resulting in a higher CaCO 3 content and surface strength of JCU-treated topsoil. The optimum bean dosages were observed at 40 g/L jack bean and 80 g/L soybean for achieving maximum CaCO 3 content and surface strength, respectively. EICP-treatments with excessive bean dosages would decrease the surface strength due to the interference of organic matter precipitation on effective bridging between the generated CaCO 3 crystals and the sand particles. Wind erosion resistance was evaluated under wind-sand flow condition at a wind speed of 13.8 m/s, which was positively correlated with surface strength. JCU presented an overall greater stabilization potential of topsoil than SCU. Additionally, the urease costs of EICP-treatments with JCU and SCU were reduced by about 380–1400 times compared with commercially available ureases. [ABSTRACT FROM AUTHOR]

The surface strength and pore content in electron beam melted (EBM) Ti-6Al-4V alloy play a key role in its tribological performance and fatigue life. In this study, a novel surface electropulsing treatment was applied to generate local phase transformation strengthening on the surface of EBM Ti-6Al-4V while simultaneously repairing the pores in the hardened zone. The surface microhardness was enhanced by 36 % from ∼260 HV 0.2 to ∼355 HV 0.2 when electropulsing treated for 120 ms, and keep the hardness with the prolongation of time to 240 ms. The thickness of the hardened surface increased from 1.3 mm to 1.7 mm with the increase in processing time. In addition, the hardened zone showed much fewer pores than the matrix. Mathematical simulation indicated that the high cooling rate in the treated zone was sufficient to result in a martensite transformation, and the compressive stress induced by thermal stress and electrode loading could cause deformation and furtherly improve the strength. More importantly, the combination of the large-scale compressive stress with the current crowding effect induced compression in the hardened zone is a benefit for repairing the pore. Predictably, this novel electropulsing treatment can be extended to other AM α + β Ti alloy systems and AM martensite steel systems for strengthening and pore repair. • Electropulsing was proposed to improve the surface strength of the EBM Ti alloy. • Pores in the hardened zone were repaired simultaneously. • A mathematical simulation was applied to study the temperature change. • The hardened surface showed a high thickness (≥1.3 mm). • The surface hardness could be enhanced by around 36 %. [ABSTRACT FROM AUTHOR]

In this work, a novel polymeric fluorescent brightener based on coumarin (PFBC) was synthesized, using three-step synthetic route, from 7-amino-4-methylcoumarin, coumarin monomer (FBC), Acrylamide (AM) and methacrylatoethyl trimethyl ammonium chloride (DMC). The structure of PFBC was characterized by FT-IR, 1 HNMR and GPC. PFBC was applied to paper fiber as light stabilizer, fluorescent brightener and surface sizing agent and its performances were evaluated by measuring the UV–vis, fluorescence, thermal stability, the cationic degree, surface strength and smoothness of paper, the brightness degree of paper and the PC value of paper. Results showed that PFBC had better solubility in water than that of FBC, by measuring the optical properties. Through the surface sizing experiment and UV aging experiment, PFBC not only enhanced the surface strength and smoothness of paper as a surface sizing agent, but also had better effect on anti-UV aging than that of FBC as light stabilizer and fluorescent brightener. [ABSTRACT FROM AUTHOR]

Gradient nanotwinned layers (GNTLs) with high hardness of approximately 500 HV and good thermal stability were produced in a Fe–20Mn–3Al–3Si TRIP steel by means of a high strain-rate surface mechanical grinding treatment (SMGT). The effect of the strain-rate on the plasticity-enhancing mechanisms in steels was investigated. It is found that although it primarily exhibits transformation-induced plasticity (TRIP) when cold-rolled, this steel shows twinning-induced plasticity (TWIP) during the SMGT process, illustrating that the steel may undergo a transition from TRIP to TWIP under high-strain-rate deformation. The martensite induced by deformation is thermally unstable and can easily transform back to austenite during annealing. In contrast, the deformation twins (DTs) are thermally much stable, since de-twinning, which plays a key role in the recovery of DTs, is more difficult to occur during thermal annealing. As such, undergoing the same annealing at 600 °C for 1 h, the GNTLs containing a great many of DTs maintain high hardness, whereas the cold-rolled counterpart samples containing deformation-induced martensite softens drastically. [ABSTRACT FROM AUTHOR]

Highlights: [•] TPI could provide spatial distribution of surface density/roughness of core tablet. [•] Tensile strength, friability provided no information on visible surface defect risk. [•] TPI helped in estimating tablet abrasion risk prior to film coating. [•] TPI revealed the relationship between surface strength and blending condition. [Copyright &y& Elsevier]

Abstract: In this study, we evaluate the effect of supplied oil quantity and contact bulk temperature on micro-pitting life using two-roller contact machine. To quantify the failure rate of damaged surfaces of micro-pitting occurrence, the DBR(Dark and Bright Ratio) method was effectively implemented for observing not a sudden occurrence of macro-pitting but the transition of micro-pitting growth. The failure criterion is set as 4% micro-pitting on contact surfaces, which is adopted from precedent researches. The change of surface damaged area was measured by an optical microscope and calculated by the use of dark and bright ratio of test specimen pictures taken by optical microscope. The optimum oil quantity was determined to obtain the minimum oil quantity with no change in bulk temperature despite of increasing the supplied oil quantity. In conclusion, the influence of supplied oil quantity and contact bulk temperature on micro-pitting lifetime and the surface contact strength by the S-N curves of failure rate are quantitatively reported and expressed as empirical formulas. [Copyright &y& Elsevier]

Abstract: The non-Faradaic material loss is the difference between the material loss measured by the weight loss method and the one determined by Faraday''s secondary law. Being observable in flowing corrosive electrolytes, it is promoted by increasing wall shear stress and anodic dissolution, is reduced by the increasing strength of electrode, and disappears in quiescent electrolytes or under cathodic protection. Therefore, the non-Faradaic material loss is likely a result of certain corrosion-aided mechanical damage mechanisms. A phenomenological model is proposed for the quantitative evaluation of the non-Faradaic material loss. The applicability of this model has been verified by the test data measured in both aqueous and non-aqueous electrolytes. [Copyright &y& Elsevier]

Abstract: Silicon nitride (Si3N4) has been used in various rolling contact applications in turbomachinery, automotive and power industry. It is favoured to replace conventional steel due to its low density, low friction, corrosion resistance and good performance under extreme condition. However, a major limitation of its wider application is its high material and machining cost, especially the cost associated with the finishing process. In the present study, a low cost sintered and reaction bonded silicon nitride (SRBSN) is used to study the surface machining effects on its rolling contact performance. Attempt has been made to link the surface strengths of Si3N4 derived from half-rod and C-sphere flexure strength specimens to the rolling contact lifetimes of Si3N4 rod and ball specimens. The rolling contact fatigue tests are carried out on ball-on-rod and modified four ball machines. Three types of surfaces with coarse, fine and conventional finishing conditions are examined. Flexure strength tests on half-rod and C-sphere show an increasing surface strength from specimens with coarse, fine to conventionally machined conditions. During rolling contact fatigue test of as-machined specimens, there are no failures observed on both ball-on-rod and four ball tests after 100 million stress cycles. However, there is a trend of decreasing wear volumes measured on the contact path of rods and balls with coarse, fine and conventional conditions. In four ball test, spall failures are observed on pre-crack specimens. There is a trend of increasing rolling contact fatigue lifetime from pre-cracked specimens with coarse, fine to conventional machining conditions. [Copyright &y& Elsevier]

Abstract: Silicon nitride material has been traditionally used as bearing material due to its superior performance against bearing steel. Its successful application as a bearing element has led to the development of rolling contact applications in turbomachinery and automotive industries. In the case of latter, this is especially true for the engine manufacturing industry where its excellent rolling contact performance can make significant savings on warranty cost for engine manufactures. In spite of these advantages, the remaining limitation for their broader application is the high component machining cost. Further understanding of rolling contact performance of silicon nitride in relation to its surface integrity will enable engine manufacturers to produce components that meet the design requirements while at the same time reduce the machining cost. In the present study, the relationship between the C-sphere strength of a silicon nitride and its rolling contact fatigue life is investigated. The C-sphere test is used here to compare the strengths of three batches of sintered reaction-bonded silicon nitride (SRBSN) specimens with different subsurface quality induced by variation of machining parameters. In parallel, the rolling contact fatigue (RCF) performance of those machining conditions is studied on a modified four-ball tester. The results show that the most aggressively machined specimens have the weakest C-sphere strength and the shortest RCF life. This positive relationship can give component manufacturers a valuable reference when they make selections of candidate material and finishing standards. [Copyright &y& Elsevier]

Acid fracture surface strength plays an important role in acid fracture conductivity. Previous experimental studies have proven mechanical deterioration of carbonate after acid etching. However, such conclusion drawn from cylindrical samples could not be applied into conductivity evaluation as such samples represent the rock mechanical properties of the carbonate mass rather than the fracture surface. As another representative of fracture surface strength, embedment strength has not met an agreement on the evolution pattern during acid etching. So the absence of fracture surface strength measurement data during acid etching causes a challenge to conductivity evaluation and acid fracturing optimization. In an effort to overcome this challenge, scratch test was adopted for the measurement of the fracture surface strength before and after acid etching, as scratch test could acquire the uniaxial compressive strength of asperities on the fracture surface. In an aim to study the influence of mineral composition, acid contact time and acid injection rate, acid etching experiments under different etching conditions were carried out. The scratch test results uncovered the strong heterogeneity on the limestone samples, and strength of limestone fracture surface would experience both rising and declining trend during acid etching process. Dolomite in limestone samples was responsible for the strength increase while Calcite contributed to the decrease of strength according to the X-ray diffraction experimental results. What is more, the rising Dolomite strength and the decreasing Calcite strength affected the average strength of acidized fracture inherently. As acid contact time increased, the firstly strengthened then weakened Dolomite strength and constantly decreasing Calcite strength gave rise to an average surface strength change tendency that rises in the beginning and later declines. The change tendency of surface strength clearly indicated an optimal acid contact time in acid fracturing operation. Calcite strength showed the decreasing trend and Dolomite exhibited both the rising and decreasing trend as injection rate increased, resulting in an indefinite evolution trend of average strength of acid fracture surface. • Scratch test is applied to measure the strength of acid fracture surface. • Acid fracture surface strength is the result of acid reactivity and strength differences between Calcite and Dolomite. • Why optimal acid etching time exists is demonstrated based on change trend of acid fracture surface strength. • Effects of acid etching time on acid fracture surface strength is studied. [ABSTRACT FROM AUTHOR]

Abstract: The critical elements associated with a CPF drainage medium and their associated effects on the near surface performance of vertically cast concrete slabs are the focus of this study. A range of board absorption levels, textured features and texture depth are investigated using a Taguchi orthogonal array approach. A permeable polypropylene filter layer was used in conjunction with the various drainage mediums. Statistical software was utilised to determine significant variables as a function of the near surface performance. The range of tests used to characterise the surface performance of the various drainage mediums include surface roughness, surface hardness, surface tensile strength and water absorption. Results are compared to a control sample which was cast against impermeable plywood formwork. All drainage medium permutations showed similar evidence of water/cement ratio reduction at the near surface region of the concrete slab. Surface quality was analysed using quantitative methods and showed significant improvements for all systems over the control. The results for the systems studied indicate that the features of a drainage medium are not critical to the functionality of a CPF liner to reduce the near surface w/c ratio. In fact, it is indicated that the absence of a drainage medium has the same enhancement in near surface concrete slab properties as that of a complex structure when compared to the control sample. [Copyright &y& Elsevier]

Abstract: The influence of concrete mixes and commonly used mineral additions and their effects on the near surface performance of vertically cast concrete against controlled permeable formwork (CPF) are the focus of this study. Three grades of concrete (C25, C30 and C45) and mineral additives including GGBS and PFA have been tested for surface performance in situ with CPF. The various loadings were chosen to represent the minimum and maximum levels seen in standard industry practice. The range of tests used to characterise the near surface performance include subjective assessment of surface quality, surface hardness and surface tensile strength. Permeability studies of the liners after casting indicate that no excessive embedding of fine particles occurred irrespective of constituents used. Surface quality was dramatically improved in each case and changes to surface colour through densification were quantified. Near surface performance studies indicated a significant improvement for all systems studied. [Copyright &y& Elsevier]

Abstract: Many degradation processes affecting surfaces of buildings that are part of the Cultural Heritage manifest themselves by detachment of the component particles. The most important cases are the crystallisation of salts, the formation of ice, the intrusion of living forms, and the impact of particles transported, or at any rate mobilised, by the wind. This work presents a physical analysis of the process of grain detachment at microscopic level. It is suggested here that the impact of solid particles on the surface may be used as the basis on which to construct a method to measure the mechanical strength of surfaces, also in relation to the assessment in quantitative terms of the performance of consolidants currently used in the conservation sector. The experiments showed that the approach was effective in discriminating the different parameters used in the test (diameter of impacting particles, position of surface, operational pressure of nozzle). [Copyright &y& Elsevier]

Abstract: The ability of the mixture of α-linked glucose oligomers in corn syrup to function as intrafiber components of paper is statistically assessed at the 95% confidence level for two degrees of refining (257 and 402mL CSF) of never-dried commercial softwood and hardwood/softwood pulps. Independent of the extent of refining, the replacement of the beaten fibers by corn syrup at about the 6% level does not result in a statistically significant deterioration (two-sided t-test, p =0.05) of the ISO brightness or of the tensile, tear, burst or surface strength values of the resultant papers. The economic potential of such fiber replacement is discussed. As paper additives, the mixed α-oligomers (corn syrup), glucose and lactose perform indistinguishably. [Copyright &y& Elsevier]

• Low-cost growth medium was used to cultivate Sporosarcina pasteurii prepared in deionized water and tap water. • Soil biocementation treatment was performed through surface percolation method. • Analytical-grade cementation reagents can be replaced with technical-grade cementation reagents. • Utilizing technical-grade reagents for sand biocementation resulted in 47 to 51-fold cost reduction. The use of microbially induced carbonate precipitation (MICP) to produce biocementitious material for soil stabilization has emerged in recent decades as a sustainable alternative approach to conventional methods. However, the use of standard analytical-grade reagents for various MICP studies makes this technology very expensive and unsuitable for field-scale consideration. In this present study, the feasibility of using commercially available and inexpensive technical-grade reagents for the cultivation of ureolytic bacteria and enhancement of soil stabilization was investigated. Low-cost growth media prepared in deionized water and tap water were used to cultivate Sporosarcina pasteurii as a replacement to standard laboratory-grade media. Biocement treatment was carried out on sand columns using different concentrations (0.25–1.0 M) of technical-grade and analytical-grade cementation solutions via surface percolation method. After 92 h of treatment, the columns were cured for 3 weeks at room temperature (26 ± 2 °C) before analysing their respective surface strengths, CaCO 3 content, pH of effluents and sand microscopic structures. The results indicated that the growth of bacteria in low-cost cultivation medium was similar to that observed in the standard cultivation medium. Surface strengths and CaCO 3 contents of the consolidated samples were in the ranges of 11448.00 ± 69.00–4826.00 ± 00 kPa and 5.56 ± 1.15–33.24 ± 0.59%, respectively. Overall, the obtained results of the current study encourage future MICP studies to utilize commercially available technical-grade reagents for economical MICP field-scale trials. [ABSTRACT FROM AUTHOR]