Single Contact Research Articles

A simulation study on stress-seepage characteristics of 3D rough single fracture based on fluid-structure interaction

This paper expounds on the process of deformation and seepage field change of single coarse fracture under normal stress and puts forward a numerical simulation framework based on fluid-structure coupling method to reasonably link contact deformation of fracture surface with seepage field change. The geometric model of a three-dimensional rough single fracture surface with controllable JRC is established based on the random surface generation method. The numerical test model of radiation flow of single fracture in rough rock is constructed, which is consistent with the laboratory test. Through carrying out numerical simulation tests of different JRC and normal stress conditions, this paper discusses the phenomenon and intrinsic nature of the influence of JRC on fracture seepage characteristics. The increase in eddy current intensity and eddy current area ratio is the inherent characteristics of the seepage field characteristics after JRC increases. With the rise of energy loss, the macroscopic seepage flow decreases. In addition, with the advantage of the fluid-structure interaction method, the fracture deformation characteristics under different normal stresses are reflected by the ratio of the contact area. The correlation among fracture surface deformation, velocity vector, and seepage pressure are analyzed. Finally, the cubic polynomial correlation between gap width ratio and contact area ratio is established and verified. It is of positive significance to quantify the influence of coarse single fracture contact ratio on deformation-seepage coupling characteristics under normal stress.

EFFECT OF KEROSENE MASS FLOW RATE AND AVERAGE TEMPERATURE IN DIRECT CONTACT HEAT EXCHANGER

Industrial plants are huge consumers of energy, these plants are installing heat exchangers in an effort to reduce energy consumption, and so improve operating efficiencies. Limited numbers of experimental and numerical investigations have dealt with the parameters affecting the heat transfer aspects in single phase direct contact heat exchangers which may be selected for their high thermal efficiency and minimum capital investment. In oil refineries energy from hot temperature oil streams can be recovered by transfer directly to a cheap coolant liquid in liquid-liquid direct contact heat exchangers. The heat recovered from these heat exchangers has different applications including preheating boiler feed water and preheating wash water. Heat recovery from hot temperature refinery products using direct contact heat exchanger throughout a theoretical phenomenological study is central to the theme of this paper. Kerosene-water system has been chosen. The effect of the heating fluid inlet temperature (65-97.50)°C, and mass flow rate (25 to 45) kg/s on direct contact heat exchanger design parameters and heat transfer characteristics were investigated theoretically throughout nine cases. Correlations of heat recovered from the system as well as design and operating characteristics of the heat exchanger were estimated. Increasing kerosene flow rate found to associate directly with increasing the contact surface area, number of plates, number of channels per pass and pressure drop, while when the heat exchanger is designed to operates at high kerosene inlet temperature, big heat exchangers with large areas, high number of plates and channels per pass are needed for efficient heat exchanger performance. Optimization and modeling the effect of kerosene operating variables on heat recovered was conducted using Response Surface Methodology. The results showed that an optimum heat recovery value of 6.8782 megawatt could be achieved for kerosene optimum inlet temperature (91.82°C), and mass flow rate (50.11 kg/s). Keywords: direct contact heat exchanger; kerosene and water system, kerosene mass flow rate and inlet temperature.

Predicting the corrosion-wear response of an isolated austenite phase under anodic polarization

The wear-assisted corrosion response of a super-duplex stainless-steel from a single asperity contact was obtained using atomic force microscopy (AFM). The AFM tip applied increasing loads to an isolated surface region that was polarized to two different static potentials in the passive potential region of the alloy in a 0.6 M NaCl solution. The wear-assisted corrosion response was modeled using an interfacial film growth model to obtain consistent kinetics parameters for the austenite phase response across applied loads and polarization potentials. The average response was then fit with an Arrhenius model that suggested that the stress fields from the single asperity contact induced damage in the protective oxide but also disrupted other oxide-formation processes at the oxide-electrolyte interface, thereby slowing repassivation, and allowing increasingly high corrosion currents as the stress fields increased.

Signorini-Type Problems over Non-Convex Sets for Composite Bodies Contacting by Sharp Edges of Rigid Inclusions

A new type of non-classical 2D contact problem formulated over non-convex admissible sets is proposed. Specifically, we suppose that a composite body in its undeformed state touches a wedge-shaped rigid obstacle at a single contact point. Composite bodies under investigation consist of an elastic matrix and a rigid inclusion. In this case, the displacements on the set, corresponding to a rigid inclusion, have a predetermined structure that describes possible parallel shifts and rotations of the inclusion. The rigid inclusion is located on the external boundary and has the form of a wedge. The presence of the rigid inclusion imposes a new type of non-penetration condition for certain geometrical configurations of the obstacle and the body near the contact point. The sharp-shaped edges of the obstacle effect such sets of admissible displacements that may be non-convex. For the case of a thin rigid inclusion, which is described by a curve and a volume (bulk) rigid inclusion specified in a subdomain, the energy minimization problems are formulated. The solvability of the corresponding boundary value problems is proved, based on analysis of auxiliary minimization problems formulated over convex sets. Qualitative properties of the auxiliary variational problems are revealed; in particular, we have found their equivalent differential formulations. As the most important result of this study, we provide justification for a new type of mathematical model for 2D contact problems for reinforced composite bodies.

Cost analysis of two types of fixed maxillary retainers and a removable vacuum-formed maxillary retainer: a randomized controlled trial.

SummaryBackgroundThere has been an increased interest in conducting healthcare economic evaluations. Also, orthodontic treatments have gathered focus from an economic point of view, however orthodontic research seldom examines both clinical and economic outcomes.ObjectiveTo evaluate and compare the costs of three retention methods: a bonded retainer to the maxillary four incisors, a bonded retainer to the maxillary four incisors and canines, and a removable vacuum-formed retainer (VFR) in the maxilla. The null hypothesis was that there was no difference in costs for the three types of retention methods.Trial designThree-arm, parallel group, single-centre, randomized controlled trial.Materials and methodsNinety adolescent patients, 54 girls and 36 boys, treated with fixed or removable retainers in the maxilla, were recruited to the study. The patients were randomized in blocks of 30, by an independent person, to one of three groups: bonded multistranded PentaOne (Masel Orthodontics) retainer 13-23, bonded multistranded PentaOne (Masel Orthodontics) retainer 12-22, and removable VFR. A cost analysis was made regarding chair time costs based on the costs per hour for the specialist in orthodontics, and material costs plus any eventual costs for repairs of the appliance. Changes in Little’s irregularity index and in single contact point discrepancies (CPDs) were measured on digitalized three-dimensional study casts. Data were evaluated on an intention-to-treat basis. The analysis was performed at 2 years of retention.ResultsNo statistically significant difference in costs between the maxillary fixed retainers and the VFRs was found, however, the material and emergency costs were significantly higher for the VFR compared with the bonded retainers. All three retention methods showed equally effective retention capacity, and no statistically significant differences in irregularity or CPDs of the maxillary anterior teeth in the three groups was detected.LimitationsIt was a single-centre trial, and hence less generalizable. Costs depended on local factors, and consequently, cannot be directly transferred to other settings.ConclusionsAll three retention methods can be recommended when considering costs and retention capacity.Trial registrationNCT04616755.

One-step recycling of mineral acid from concentrated gold mining wastewater by high-temperature liquid–liquid extraction

Liquid-liquid extraction (LLE) was investigated for mineral acid (H2SO4) recycling from membrane distillation (MD) concentrate treating gold mining wastewater. Five extractants (Alamine 336, Aliquat 336, Cyanex 923, TEHA, and Versatic Acid) were preferably diluted in kerosene or 1-decanol (30 vol%) in extraction experiments conducted at 60 °C. Cyanex 923 extracts the mineral acid mainly by solvation of the neutral species, whereas the mechanisms for amine-based extractants involve an ion-pair formation. An important outcome was the temperature contribution to extraction efficiency. The endothermic nature of extraction would be advantageous to acid recovery and the integration of MD with LLE considering that the MD concentrated is produced at ∼ 60 °C. If stripping is considered, Aliquat 336 (diluted in 1-decanol), Cyanex 923, and TEHA (diluted in 1-decanol) become the most appropriate organic phases for mineral acid recycling given the greater efficiency for acid recovery (>90%) after a single contact stage. The results for extraction efficiency, selectivity, stripping efficiency, and costs demonstrated that TEHA (30 vol% in 1-decanol) was the most cost-effective (US$ 0.57/kg) alternative for mineral acid recycling. It would be possible to recover 4.8 kg of mineral acid per cubic meter of MD concentrate as an acid solution (concentration: 25 mmol/L). Overall, LLE was a feasible alternative to enhance gold mining wastewater exploitation and MD concentrate management. From a broader perspective, acid recycling would imply environmental gains, economical savings given the lower requirements of neutralizing agents for mining wastewater treatment and residual sludge disposal, or additional incomes by its commercialization.

Electrical conductivity of a single parallel contact between carbon nanotubes.

Interfacial resistance plays a critical role in the transport properties of nanomaterial-based assemblies. However, understanding of them remains limited due to the difficulty of experimental approaches. Here we report in situ measurements of the electrical resistance of a single parallel contact between carbon nanotubes. By varying the contact length systematically, we derive the electrical conductivities of carbon nanotubes and interfaces. The interface between nanotubes exhibits conductivity intermediate between those of pyrolytic and single-crystal graphite. The threshold contact length between interface- and bulk-dominant electrical transport is quantitatively estimated.

Contamination assessment in metal foam flow field-based proton exchange membrane fuel cell

The relative slippage between the open-cell metal foam flow fields and other parts in a fuel cell due to vehicular and flow-induced vibrations causes fretting. The material degradation due to fretting in nickel struts contaminate the stack and is investigated using simulated experiments. The as-formed strut surfaces are rough and increases the material loss during fretting. The total wear volume associated with a single contact in 22,000 cycles is 4.66 E−04 mm3. The contamination in the stack is estimated assuming a dodecahedron unit cell geometry and neglecting the fretting corrosion. About 47 g of debris is expected to be generated when an 8 ppi nickel foam flow fields used in a 50-cell stack for 8700 hours of operation. In addition, the generated flake shaped debris (<10 μm) can obstruct the flow of gases by clogging the gas diffusion layer. The proposed contamination estimation methodology will aid in performance prediction during service.

A Clinical Study of the Impact of Soft Contact Lenses on the Progression of Myopia in Young Patients.

PurposeTo assess the impact of soft contact lenses on the progression of myopia in young patients.Patients and MethodsThe observational study included 102 patients divided into 3 groups: MFCL (multifocal contact lenses) group: 15 girls and 9 boys, aged 8–20 (nbar x n= 14.12 ± 2.863) with soft multifocal contact lenses with myopia: nbar x n = −3.12 D ± 1.776 D and mean myopia progression −0.23 ± 0.233D after 2 years; SVCL (single vision contact lenses) group: 30 girls and 5 boys, 11–20 years old (nbar x n=15.5 ± 2.24) with myopia nbar x n = −2.88 ± 2.122 D at admission and mean myopia progression −0.54 ± 0.464 D after 2 years; the spectacle (single vision glasses) group: 25 girls and 18 boys, aged 8–18 years (nbar x n = 13.65 ± 2.448) with single vision glasses with myopia: nbar x n = −1.74 ± 1.412 D at admission and mean myopia progression −0.86 ± 0.489D after 2 years. Medical history and physical examination were performed every 6, 12, 18 and 24 months. Refractive error was examined using the autorefractometry after cycloplegia.ResultsThe analysis of myopia correction after 2 years showed differences between MFCL and spectacle correction. The change in myopia progression after 2 years was statistically significant for MFCL vs SVCL and MFCL vs spectacle correction when the myopia occured before the period of intensive growth. When myopia occurred during the period of intensive growth, difference was noted for MFCL vs spectacle correction and SVCL vs spectacle correction. When myopia occurred after a period of intensive growth, no significant differences between the groups were observed.Conclusion1) Multifocal contact lenses and some single vision contact lenses (Biofinity) may be useful in the control of myopia in younger patients, slowing the progression of nearsightedness; therefore, they can be a therapeutic option in inhibiting the progression of myopia. 2) The best effects of using multifocal contact lenses occur if myopia is diagnosed before the period of intensive growth.

A CONTINUOUS SMOOTH CONTACT STIFFNESS MODEL FOR JOINT SURFACE CONSIDERING SUBSTRATE DEFORMATION

The contact stiffness of the joint surface directly affects the static and dynamic mechanical properties of the machine tool and the level of accuracy retention. In the process of elastic, elastoplastic and fully plastic contact deformation, based on the idea that asperity contact state variables have continuous and smooth characteristics, a single asperity normal contact stiffness model is established through Hermite polynomial interpolation function. Considering the effect of substrate deformation, the elastic contact substrate deformation is introduced in the three deformation stages of asperity. A continuous smooth joint surface stiffness model considering substrate deformation is established by statistical methods. The differences between GW, ZMC, KE, and Brake models are compared with the proposed model, and the influence of surface roughness on contact stiffness is revealed. The research shows that the contact stiffness and contact load obtained by considering the substrate deformation are smaller than those of ignoring the substrate deformation. The influence of substrate deformation increases rapidly as the surface roughness decreases. In addition, the contact load and surface roughness are the two main factors that affect the contact stiffness of the joint surface. The contact stiffness increases with the increase of the load or the decrease of the surface roughness.

Optical inspection of single vision soft contact lenses based on an active adaptive wavefront sensor.

We present an experimental configuration for optical inspection of single vision soft contact lenses based on an active adaptive wavefront sensor. At first, the soft lenses were immersed in a saline filled wet cell to prevent surface deformation during measurements. Thereafter, refractive powers and aberrations were accurately measured before and after correcting illumination laser beam aberrations and wet cell-induced aberrations. The results reveal that there is a significant difference between the measured aberrations and refractive powers before and after aberration compensation. Accordingly, the proposed system is recommended as an optical inspection tool for precise assessment of commercially available contact lenses.

Study on sliding friction characteristics of magnetorheological elastomer—copper pair affected by magnetic-controlled surface roughness and elastic modulus

To optimize the online friction coefficient adjustment, it is necessary to study the parameter change features of the magneto-sensitive polymer and its influence on the friction characteristics under magnetic field. A series of magnetorheological elastomers (MREs) with different initial surface roughness were prepared, and a sliding friction platform with MRE—copper block pair was built to carry out magnetic-controlled friction characteristic experiment. Results show that the sliding friction coefficient of MRE decreases with the increase of the magnetic field, but the degree of reduction is quite different under different initial surface roughness and elastic modulus. When the initial surface roughness of MRE is between 0.5 and 2.5 μm and the carbonyl iron particles volume fraction is between 10% and 15%, its magnetic-controlled friction coefficient has the largest reduced value of 22.75%. Moreover, features of elastic modulus and surface topography under magnetic field were tested and analyzed. By combining with the single peak contact model and the friction binomial law, the relationship between the surface roughness and elastic modulus of MREs and the sliding friction force is deduced, and it is proved that the friction coefficient is affected by the coupling effect of surface roughness and elastic modulus. The magnetic-controlled elastic modulus is the key factor, which determines the overall downward trend of the friction coefficient of MREs. Magnetic-controlled surface roughness also plays an important role in the adjustable range of friction coefficient, and reducing the initial surface roughness can increase the magnetic-controlled friction coefficient adjustable range.

Separation of platinum group metals from model chloride solution using phosphonium-based ionic liquid

• Liquid-liquid separation of PGMs’ from HCl medium using Cyphos IL 101 was studied. • Increasing acid and total Cl – ion concentration inhibited the extraction efficiency. • Poorly extracted Rh(III) efficiently scrubbed from organic phase in high acid solution. • Outer sphere complexation of [PtCl 6 ] 2− and [PdCl 4 ] 2− with ionic liquid was observed. • Quantitative stripping of Pt(IV) with NaSCN and Pd(II) with CH 4 N 2 S was achieved. The present study dealt with liquid–liquid separation of PGMs (Pt, Pd, and Rh) from a model chloride-based leach solution using an undiluted phosphonium-based ionic liquid, Cyphos IL 101. Based on the parametric optimization studies, 30 min equilibration of both phases at an organic-to-aqueous volume ratio of 1 showed the highest PGMs’ extraction of > 99% Pt(IV) and Pd(II), and ~ 22% Rh(III). Depending upon the HCl and total Cl − ions concentrations, species like [PtCl 6 ] 2− and [PdCl 4 ] 2− exhibited remarkable ability for ion-pairing with Cyphos IL 101 unlike the higher charge density of [RhCl 6 ] 3− which significantly lowered down to be < 5% at an aqueous feed of 0.1 mol.L −1 HCl. Thermodynamic properties with negative changes in enthalpy and entropy indicated that the PGMs’ extraction process exhibit exothermic behaviour with the formation of outer -sphere complexes in the ionic liquid phase. With the supports of experimental results and spectral analysis, the possible structure of Pt(IV)-Pd(II)-loaded ionic liquid could also be revealed. The poorly extracted Rh(III) was efficiently scrubbed by contacting with 5.0 mol.L −1 HCl solution, leaving the organic phase free from Rh(III). The selectivity in back-extraction of Pt(IV) and Pd(II) was achieved by first contacting the loaded ionic liquid with 1 × 10 −1 mol.L −1 NaSCN in two stages, which exhibiting ~ 99% efficacy of Pt(II) stripping. Subsequently, Pt(IV)-depleted organic phase was stripped with 1 × 10 −2 mol.L −1 CH 4 N 2 S that yielded > 99% Pd(II) recovery in a single contact. Results of extraction-stripping cycles that were showing similar efficiency of PGMs extractability clearly indicated the stability and reusability of ionic liquid.

Neuron-specific chromosomal megadomain organization is adaptive to recent retrotransposon expansions

Regulatory mechanisms associated with repeat-rich sequences and chromosomal conformations in mature neurons remain unexplored. Here, we map cell-type specific chromatin domain organization in adult mouse cerebral cortex and report strong enrichment of Endogenous Retrovirus 2 (ERV2) repeat sequences in the neuron-specific heterochromatic B2NeuN+ megabase-scaling subcompartment. Single molecule long-read sequencing and comparative Hi-C chromosomal contact mapping in wild-derived SPRET/EiJ (Mus spretus) and laboratory inbred C57BL/6J (Mus musculus) reveal neuronal reconfigurations tracking recent ERV2 expansions in the murine germline, with significantly higher B2NeuN+ contact frequencies at sites with ongoing insertions in Mus musculus. Neuronal ablation of the retrotransposon silencer Kmt1e/Setdb1 triggers B2NeuN+ disintegration and rewiring with open chromatin domains enriched for cellular stress response genes, along with severe neuroinflammation and proviral assembly with infiltration of dendrites . We conclude that neuronal megabase-scale chromosomal architectures include an evolutionarily adaptive heterochromatic organization which, upon perturbation, results in transcriptional dysregulation and unleashes ERV2 proviruses with strong neuronal tropism.

The contribution of plastic sink-in to the static friction of single asperity microscopic contacts

We report microscale friction experiments for diamond/metal and diamond/silica contacts under gigapascal contact pressures. Using a new nanoprobe technique that has a sufficient dynamic range of force and stiffness, we demonstrate the processes involved in the transition from purely interface sliding at the nanoscale to the situation where at least one of the sliding bodies undergoes some plastic deformation. For sliding of micrometre-sized tips on metallic substrates, additional local plastic yielding of the substrate resulting from tangential tractions causes the tip to sink into the surface, increasing the contact area in the direction of loading and resulting in a static friction coefficient higher than the kinetic during ploughing. This sink-in is largely absent in fused silica, and no friction drop is observed, along with lower friction in general. The transition from sink-in within the static friction regime to ploughing in the sliding friction regime is mediated by failure of the contact interface, indicated by a sharp increase in energy dissipation. At lower contact pressures, the elastic interfacial sliding behaviour characteristic of scanning probe or surface force apparatus experiments is recovered, bridging the gap between the exotic realm of nanotribology and plasticity-dominated macroscale friction.

Modeling metal removal from workpiece surface during centrifugal rotation processing

The modeling and analysis the removal of metal process in centrifugal rotational processing of workpiece in abrasive medium are considered in this article. The single contact interaction process between abrasive particle and the workpiece surface is researched through three-dimensional modeling taking into account dry coefficient of friction. The contact interaction problem is solved through Ansys software and Archard code programmed to analyze the data. The removal of metal from the workpiece surface is researched when changing the technological parameters: friction coefficient, machining time, speed. The dependences between metal removal from the workpiece surface and technological parameters are constructed, from which reasonable parameters can be selected when machining the workpiece, allowing to achieve high accuracy. Experimental results have been confirmed by simulation results. Through this research, essential and important data sheets will be provided for actual production and testing activities. Consequently, time and money are saved in achieving the desired surface quality.

Membrane distillation and dispersive solvent extraction in a closed-loop process for water, sulfuric acid and copper recycling from gold mining wastewater

Membrane distillation (MD) and dispersive liquid–liquid extraction (d-LLE) were integrated for gold mining wastewater beneficiation and better use of natural resources. MD presented an average permeate flux of 5.51 ± 0.14 L/m2·h, without a significant flux decay (p < 0.001), and rejection efficiencies for acid and metallic species>98.7%. Five different extractants were studied for sulfuric acid recovery from MD concentrate. Considering the extraction and stripping efficiency, tris-2-ethylhexylamine (TEHA) was the most appropriate alternative for sulfuric acid extraction, requiring 2 stages of extraction and 1 of striping to achieve a recovery>95%. The endothermic nature of acid extraction contributed to the integration of d-LLE and MD, designating a proper destination for MD concentrate, a stream often forgotten while discussing membrane separation processes for wastewater treatment. Copper was then selectively recovered from the raffinate from acid extraction (βCu/Fe = 4,274, βCu/Al = 176, and βCu/Mg = 1,262) by Lix 84-I. A single contact stage ensured that 99.3% of copper was recovered. Fourier-transform infrared spectra demonstrated that the acid extraction mechanisms involve amine salts formation, whereas copper is extracted by anion exchange processes. The economic assessment was favorable for water (US$/m3 0.23) and copper (US$/kgCu 4.25) recovery, with prices lower than currently practiced for both commodities. For sulfuric acid, the operational expenditures corresponded to US$/kgH2SO4 0.423, slightly higher than its marketable price. Overall, the integrated system could be inserted in a perspective that departs from the linear focus of raw material utilization, prioritizing recycling and reuse processes.

Forward doubly-virtual Compton scattering off an unpolarized deuteron in pionless effective field theory

We calculate the forward unpolarised doubly-virtual Compton scattering (VVCS) off the deuteron in the framework of pionless effective field theory, up to next-to-next-to-next-to-leading order (N3LO) for the longitudinal and next-to-leading order (NLO) for the transverse amplitude. The charge elastic form factor of the deuteron, obtained from the residue of the longitudinal VVCS amplitude, is used to extract the value of the single unknown two-nucleon one-photon contact coupling that enters the longitudinal amplitude at N3LO. We also study the lowest spin-independent generalised polarisabilities of the deuteron. The calculated unpolarised VVCS amplitude provides a high-precision model-independent input for a future calculation of the two-photon-exchange correction to the Lamb shift of muonic deuterium.

Multi contact-based folding method for de novo protein structure prediction.

Meta contact, which combines different contact maps into one to improve contact prediction accuracy and effectively reduce the noise from a single contact map, is a widely used method. However, protein structure prediction using meta contact cannot fully exploit the information carried by original contact maps. In this work, a multi contact-based folding method under the evolutionary algorithm framework, MultiCFold, is proposed. In MultiCFold, the thorough information of different contact maps is directly used by populations to guide protein structure folding. In addition, noncontact is considered as an effective supplement to contact information and can further assist protein folding. MultiCFold is tested on a set of 120 nonredundant proteins, and the average TM-score and average RMSD reach 0.617 and 5.815Å, respectively. Compared with the meta contact-based method, MetaCFold, average TM-score and average RMSD have a 6.62 and 8.82% improvement. In particular, the import of noncontact information increases the average TM-score by 6.30%. Furthermore, MultiCFold is compared with four state-of-the-art methods of CASP13 on the 24 FM targets, and results show that MultiCFold is significantly better than other methods after the full-atom relax procedure.

Analysis of the Wear-Assisted Corrosion of a Super-Duplex Stainless-Steel Using an Interface Film Growth Model

The wear-assisted corrosion response of a super-duplex stainless-steel alloy from a single asperity contact was measured using the contact mode of an atomic force microscope (AFM). The AFM tip, as illustrated in the figure below, applied increasing loads to an isolated surface region that was polarized to two different static potentials in a 0.6 M NaCl solution. The AFM tip was swept across the isolated, exposed, surface region of the alloy while the alloy response was measured by a potentiostat. The wear-assisted corrosion response was modeled using an interfacial film growth model (IFM) that was used to estimate kinetics parameters for the response of the alloy as a function of the applied loads and polarization potentials.The average response values from the IFM were then approximated using an Arrhenius expression that incorporated the peak applied stress and activation volume for the reaction as modifiers to the energy barrier for oxide film formation. This Arrhenius model suggested that the stress fields from the single asperity contact induced damage in the protective oxide and also disrupted other oxide-formation processes at the oxide-electrolyte interface. The induced damage and the disruption of the oxide-formation processes, as a function of the applied stress, slowed repassivation and allowed increasingly high corrosion currents as the stress fields increased.AcknowledgmentsThe U.S. Naval Research Laboratory sponsored this work under work unit 1E19 as part of its Basic Research Program. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Office of Naval Research, the U.S. Navy, the Department of Defense, or the U.S. government.Figure CaptionSchematic diagram of experimental setup of the AFM tip loading the isolated region on the super-duplex stainless-steel alloy surface while the potentiostat is used to both polarize the alloy and measure its response to the load. Figure 1