Academic literature on the topic 'Outdoor aging test'

In order to further study the aging properties of high temperature vulcanization (HTV) silicone rubber for composite insulator in the high-altitude region, tests of outdoor electric aging and ultraviolet accelerated aging have been carried out in the paper. The contact angles test, scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR) were used to study the microscopic physical properties of samples after the aging tests. SEM observed that the surface flatness of samples declined, holes and particles increased on the sample surface, a large number of fillers exposed. The results of FTIR showed that Si-C bonds in the side chain in Si-O backbones were broken by ultraviolet radiation and methyl groups were oxidized, a small amount of fire retardant (Al2O3•3H2O) were decomposed, hydrophilic groups increased, all which have happened on the HTV silicone rubber after both the aging tests under the same ultraviolet radiation. The differences between the aging properties of two kinds of tests are that the aging extent of samples after outdoor electric aging was severer than that in ultraviolet accelerated aging, and the surface hydrophobicity of it after outdoor electric aging increased compared to ultraviolet accelerated aging. The aging of HTV silicone rubber for composite insulator is mainly caused by strong ultraviolet radiation in high-altitude region.

The photodegradation behavior of a straight asphalt was investigated using a new method "photodegradation test of asphalt binder using pressed thin film samples". Although the photodegradation caused by outdoor exposure is limited to the near surface, the results confirmed that the degree of degradation during 1 to 2 months is more severe than that by the pressure aging vessel (PAV) test, which is designed to simulate the degradation that will occur in the asphalt pavement over 5 to 10 service years.Key words: asphalt binder, aging, photodegradation, thin film, DSR, FTIR.

To estimate the photo-oxidation aging performance of PVC-coated membrane material in atmospheric conditions under tensile stresses, the relationship between physical and mechanical properties under accelerated weathering test and outdoor weathering test is studied with the same cumulative UV radiation energy. And then, both tensile strength and whiteness index were measured and compared to characterize the property change of membrane material after aging under four different tensile stresses (0%, 5%, 10% and 20% of the breaking strength), respectively. In addition, FTIR spectrometry was applied to characterize the chemical components of the samples under different weathering conditions, and the carbonyl index was extracted. The results show that there were significant differences of tensile strength and carbonyl index between two kinds of aging conditions, whereas with the increasing tensile stresses, the whiteness index represented a consistent increasing deviation of accelerated weathering from the outdoor weathering. However, the relationship have been built between both whiteness index and tensile strength retention of accelerated weathering and those of outdoor weathering conditions after a Schwarzschild’s modification. Therefore, the service lifespan of PVC-coated membrane materials can be evaluated by accelerated weathering tests under tensile stresses.

Walking on complex surface conditions in outdoor environments is important for active aging. This study aimed at examining whether fall prevention exercise integrated with an outdoor multisurface terrain compared with indoor solid ground was more beneficial for older adults. Twenty-two older nursing home residents were randomly assigned to outdoor multisurface terrain (n = 11, 79.5 ± 2.1 years) or indoor solid ground (n = 11, 78.8 ± 5.2 years) groups. Training occurred five times per week (30 min) for 3 weeks. The following performance test outcomes were measured: 10 m walk test (10 mWT), multisurface terrain walk test (MTWT), 2 min walk test (2 MWT), timed up and go test (TUGT), single-leg standing test with eyes open (SLSTEO), single-leg standing test with eyes closed (SLSTEC), and closed cycles test (CCT). Compared with baseline, the outdoor multisurface terrain training significantly improved performance in all tests (p < 0.01). The improvements of the outdoor multisurface terrain group after intervention were significantly higher than those of the indoor solid group in the 10 mWT (p = 0.049), MTWT (p = 0.02), and 2 MWT (p = 0.000). Exercise combined with outdoor multisurface terrain training may be an efficacious approach and a feasible environmental intervention for fall prevention in older adults.

A Texas Department of Transportation study performed by the Texas Transportation Institute was undertaken with a goal of providing methods to assure the quality of cold-applied, asphalt-stabilized maintenance mixtures. Test procedures and acceptance criteria were developed for hot-mix, cold-laid asphalt concrete patching mixtures. Two specific objectives were to develop a test procedure to simulate approximately six months of stockpile-aging and a test procedure to quantify workability of maintenance mixtures. The protocol developed is designed to estimate the relative ability of a maintenance mixture to retain adequate workability after outdoor stockpile storage. This protocol could be useful as part of a specification to promote quality. Two test procedures were evaluated regarding their potential to quantify the workability of maintenance mixtures: a triaxial test and an unconfined compression test. Test results indicated that both procedures provide a relatively good measure of workability before and after aging. Two laboratory aging procedures were evaluated for their ability to predict workability of a stockpiled maintenance mixture after six months of field aging. Procedure A appeared to provide a reasonable approximation of six months of field aging.

Composite insulators are widely used in power systems because of their advantages of light weight, good pollution resistance, and high mechanical strength. With the increasingly serious environmental pollution problem, especially in winter at high latitudes, composite insulators are easily affected by fog, bird droppings, algae, and icing. Long-term exposure to the outdoor insulator surface will cause aging, which will then pose ae potential safety hazard to the stable operation of insulators. Therefore, the self-cleaning, anti-icing, and aging test technologies of composite insulators are particularly important. This paper introduces the research progress and current situation of self-cleaning, anti-icing surface preparation, and aging test technology of composite insulators, and looks forward to the future development of composite insulators.

Two types of polyurea coatings based on polyaspartic esters (PAE) (PAE-F1 and PAE-F2) were exposed in salt fog environments and outdoor for different time periods. The aging behaviors of two types of coatings were evaluated by using electronic tensile testing machine, glossmeter and Fourier transform infrared spectroscopy (FTIR). The results showed that the salt fog had a significant effect on the gloss loss, hydrogen-bonded urea carbonyl in PAE-F1 and PAE-F2 were 77.1% and 74.9% respectively by the results obtained from FTIR analysis. The index of gloss loss, strength change rate and elongation at break change rate of PAE-F1 and PAE-F2 coatings kept well exposed in outdoor and salt fog environment after 350 days. All test results indicated that PAE coating has excellent aging resistance; PAE-F1 with higher degree of hydrogen bond was more orderly structural and better aging resistant than PAE-F2 coating.

Glubam is a kind of environmentally friendly and energy efficient composite material in civil engineering developed in recent years. But the mechanical performance after subjected aging under the outdoor conditions is a blank of research field. In this paper, a new artificial accelerated aging test method and equipment for glubam have been presented by authors. The basic material performance, including deformation changing, tensile properties, compressive properties, bending properties and internal bonding strength, are tested according to the equivalent aging duration of 120 days, 240 days, 480 days and 960 days. The failure mode of specimens shows that delamination of glubam caused by dry wet circulation is the main reason for mechanical properties degradation. All test results present monotone decreasing trend and the internal bonding strength is the most sensitive to aging duration. Aging influence factor β, internal bonding correlation coefficient η and internal correlation coefficient θ can be used to evaluate aging performance of glubam, but the accuracy of evaluation results need further research.

Outdoor bronzes exposed to the environment form naturally a layer called patina, which may be able to protect the metallic substrate. However, since the last century, with the appearance of acid rains, a strong change in the nature and properties of the copper based patinas occurred [1]. Studies and general observations have established that bronze corrosion patinas created by acid rain are not only disfiguring in terms of loss of detail and homogeneity, but are also unstable [2]. The unstable patina is partially leached away by rainwater. This leaching is represented by green streaking on bronze monuments [3]. Because of the instability of the patina, conservation techniques are usually required. On a bronze object exposed to the outdoor environment, there are different actions of the rainfall and other atmospheric agents as a function of the monument shape. In fact, we recognize sheltered and unsheltered areas as regards exposure to rainwater [4]. As a consequence of these different actions, two main patina types are formed on monuments exposed to the outdoor environment. These patinas have different electrochemical, morphological and compositional characteristics [1]. In the case of sheltered areas, the patina contains mainly copper products, stratified above a layer strongly enriched in insoluble Sn oxides, located at the interface with the uncorroded metal. Moreover, different colors of the patina result from the exposure geometry. The surface color may be pale green for unsheltered areas, and green and mat black for sheltered areas [4]. Thus, in real outdoor bronze monuments, the corrosion behavior is strongly influenced by the exposure geometry. This must be taken into account when designing conservation procedures, since the patina is in most cases the support on which corrosion inhibitors are applied. Presently, for protecting outdoor bronzes against atmospheric corrosion, inhibitors and protective treatments are used. BTA and its derivatives, which are the most common inhibitors used for copper and its alloy, were found to be toxic for the environment and human health [5, 6]. Moreover, it has been demonstrated that BTA is efficient when applied on bare copper but not as efficient when applied on bare bronze [7]. Thus it was necessary to find alternative compounds. Silane-based inhibitors (already successfully tested on copper and other metallic substrates [8]), were taken into consideration as a non-toxic, environmentally friendly alternative to BTA derivatives for bronze protection. The purpose of this thesis was based on the assessment of the efficiency of a selected compound, to protect the bronze against corrosion, which is the 3-mercapto-propyl-trimethoxy-silane (PropS-SH). It was selected thanks to the collaboration with the Corrosion Studies Centre “Aldo Daccò” at the Università di Ferrara. Since previous studies [9, 10, 11] demonstrated that the addition of nanoparticles to silane-based inhibitors leads to an increase of the protective efficiency, we also wanted to evaluate the influence of the addition of CeO2, La2O3, TiO2 nanoparticles on the protective efficiency of 3-mercapto-propyl-trimethoxy-silane, applied on pre-patinated bronze surfaces. This study is the first section of the thesis. Since restorers have to work on patinated bronzes and not on bare metal (except for contemporary art), it is important to be able to recreate the patina, under laboratory conditions, either in sheltered or unsheltered conditions to test the coating and to obtain reliable results. Therefore, at the University of Bologna, different devices have been designed to simulate the real outdoor conditions and to create a patina which is representative of real application conditions of inhibitor or protective treatments. In particular, accelerated ageing devices by wet & dry (simulating the action of stagnant rain in sheltered areas [12]) and by dropping (simulating the leaching action of the rain in unsheltered areas [1]) tests were used. In the present work, we used the dropping test as a method to produce pre-patinated bronze surfaces for the application of a candidate inhibitor as well as for evaluating its protective efficiency on aged bronze (unsheltered areas). In this thesis, gilded bronzes were also studied. When they are exposed to the outside environment, a corrosion phenomenon appears which is due to the electrochemical couple gold/copper where copper is the anode. In the presence of an electrolyte, this phenomenon results in the formation of corrosion products than will cause a blistering of the gold (or a break-up and loss of the film in some cases). Moreover, because of the diffusion of the copper salts to the surface, aggregates and a greenish film will be formed on the surface of the sample [13]. By coating gilded samples with PropS-SH and PropS-SH containing nano-particles and carrying out accelerated ageing by the dropping test, a discussion is possible on the effectiveness of this coating, either with nano-particles or not, against the corrosion process. This part is the section 2 of this thesis. Finally, a discussion about laser treatment aiming at the assessment of reversibility/re-applicability of the PropS-SH coating can be found in section 3 of this thesis. Because the protective layer loses its efficiency with time, it is necessary to find a way of removing the silane layer, before applying a new one on the “bare” patina. One request is to minimize the damages that a laser treatment would create on the patina. Therefore, different laser fluences (energy/surface) were applied on the sample surface during the treatment process in order to find the best range of fluence. In particular, we made a characterization of surfaces before and after removal of PropS-SH (applied on a naturally patinated surface, and subsequently aged by natural exposure) with laser methods. The laser removal treatment was done by the CNR Institute of Applied Physics “Nello Carrara” of Sesto Fiorentino in Florence. In all the three sections of the thesis, a range of non-destructive spectroscopic methods (Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS), μ-Raman spectroscopy, X-Ray diffractometry (XRD)) were used for characterizing the corroded surfaces. AAS (Atomic Absorption Spectroscopy) was used to analyze the ageing solutions from the dropping test in sections 1 and 2.

Abstract This article presents a general overview of outdoor weather aging factors, their effects on the performance of polymeric materials, and the accelerated test methods that can be used to investigate those effects. These test methods are used to characterize material performance when subjected to specific, often controlled, and well-defined factors. The article also presents an overview of instrumental weathering types that simulate outdoor stress factors.

Background: A growing but contrasting evidence relates air pollution to cognitive decline. The role of cerebrovascular diseases in amplifying this risk is unclear. Objectives: 1) Investigate the association between long-term exposure to air pollution and cognitive decline; 2) Test whether cerebrovascular diseases amplify this association. Methods: We examined 2,253 participants of the Swedish National study on Aging and Care in Kungsholmen (SNAC-K). One major air pollutant (particulate matter ≤2.5 μm, PM2.5) was assessed yearly from 1990, using dispersion models for outdoor levels at residential addresses. The speed of cognitive decline (Mini-Mental State Examination, MMSE) was estimated as the rate of MMSE decline (linear mixed models) and further dichotomized into the upper (25% fastest cognitive decline), versus the three lower quartiles. The cognitive scores were used to calculate the odds of fast cognitive decline per levels of PM2.5 using regression models and considering linear and restricted cubic splines of 10 years exposure before the baseline. The potential modifier effect of cerebrovascular diseases was tested by adding an interaction term in the model. Results: We observed an inverted U-shape relationship between PM2.5 and cognitive decline. The multi-adjusted piecewise regression model showed an increased OR of fast cognitive decline of 81%(95%CI = 1.2–3.2) per interquartile range difference up to mean PM2.5 level (8.6 μg/m3) for individuals older than 80. Above such level we observed no further risk increase (OR = 0.89;95%CI = 0.74–1.06). The presence of cerebrovascular diseases further increased such risk by 6%. Conclusion: Low to mean PM2.5 levels were associated with higher risk of accelerated cognitive decline. Cerebrovascular diseases further amplified such risk.

This paper presents the ASTM WK22010 proposed standard on testing of photovoltaic modules. It aims to become a general framework that defines objective parameters regarding output production and lifecycle of modules and includes: - quantifying the PV module performance decay from the global effects of extended outdoor weather exposure and induced fatigue stress; - determine the mechanical resistance of modules to weathering from exposure to real outdoor or artificially created conditions, including extreme weather events; - determine the mechanical resistance and decay of optical characteristics of glasses from exposure to real outdoor or artificially created conditions, including extreme weather events; - determine the effective output production of modules and the resulting decay, during the expected module lifetime in real operating conditions and/or predefined artificial weather conditions; in order to predict performance in different real weather conditions from test result parameters.

Knowing that healthy aging lifestyles are connected to mobility and independence, the researchers wanted to examine how industrial design could be utilized to support this demographic. This research examined the traction performance of key footwear styles, to make recommendations on how to improve outsole design, to reduce the risk of outdoor falling. Falls are the leading cause of death and disability for the aging population. A footwear traction test method adapted from ASTM F2333-04 was used to collect data from six footwear styles with four common outdoor walking surfaces (wet and dry) and foot contact directions (normal and shuffle). The data determined that although the footwear tested were marketed for traction and safety, they greatly decreased performance in wet conditions and performed inconsistently across all flooring surfaces and outsole contact directions. Results from the work determined that better care with outsole design could improve footwear performance for aging users and potentially reduce the risk of injury for this growing demographic.

Real-time leak monitoring of pipelines is a need that is growing with the aging of the assets and the rise of the population living in their close proximity. While traditional deployment of external monitoring solutions on legacy assets may require extensive construction and trenching on the pipeline right-of-way, a new class of self-powered and wirelessly communicating devices provides an intriguing alternative. These devices are installed on the right-of-way with no need for mechanical excavation and allow continuous monitoring of a pipeline over long distances. Their low-power requirement makes it possible to operate the monitoring system continuously on battery power and their wireless communication is established through a self-forming network. These attributes make real-time monitoring possible without requiring any wiring to be deployed on the right-of way. The devices take advantage of the pipe’s characteristics that guide the acoustic waves generated by the leak along the pipeline to detect leaks. These characteristics make the detection possible even from a device that is not in close proximity of the leak. Since device spacing is a key parameter in the cost of monitoring with the leak detection system, it is important to understand the parameters that govern the propagation of leak sound on pipelines. Testing was performed for this purpose to validate the ability of these novel acoustic sensors in an outdoor test facility under a variety of leak conditions. This testing evaluated the propagation of acoustic waves emanating from small leaks on a buried pipe. This was achieved by pressurizing the pipeline to different levels of pressure and inducing leaks through various orifice sizes. The acoustic disturbances induced by these leaks were measured by sensors deployed at various stations on the pipe. The results of this testing demonstrated the ability of such an approach to be used for detecting very small disturbances in soil from an offset position caused by leaking liquids.

Abstract The latest dope-free configuration combines an electrodeposited zinc-nickel (ZnNi) plating, which provides anti-galling and most of anticorrosion properties, and an organic topcoat which provides lubrication through its low friction coefficient. This dry lubrication constitutes an alternative to storage and running dope meanwhile it improves running performances, reduces operational costs on the yard and rig and avoids dope discharge to the environment. Since the technology is "rig-ready", it must withstand the different risks of degradation occurring along its whole lifecycle. The present study aims at assessing the robustness towards ageing along storage on yards, transportation to the rig and or service life in well conditions. The performances of the different layers were checked stepwise, first assessing the ZnNi plating alone, and then considering the additional protection brought by thermoset topcoat. Regarding atmospheric corrosion, the characterization path involved both accelerated laboratory tests (such as the VDA 233-102 cyclic corrosion test) and outdoor exposures, under plastic protectors and after their removal, in different climates: temperate, desertic and tropical. The specimens were inspected regarding at: (i) efficiency of cathodic protection provided by the metallic coating; (ii) paint blistering, (iii) propagation of corrosion from a scribe down to substrate. Regarding rig operations, some examples of rig-return were reported and the compatibility with completion fluids, encountered in case of misrun and subsequent pull-out of the column, was checked though immersion in alkaline brines. In respect to the service in simulated well conditions, the resistance to Stress Corrosion Cracking (SCC) in brines were carried out to complete the former autoclave tests to assess resistance of carbon and stainless steel to well conditions. Both the ZnNi plating and the bi-layer system revealed lifetimes in storage conditions ranging from 3 to more than 5 years before any sign of significant degradation such as red rust, paint blistering or disbonding. According to cyclic corrosion tests results, higher lifetimes could be even expected thanks to the additional anticorrosion protection of the topcoat. Regarding exposure to completion fluids, the bilayer coating was shown to withstand 3000h exposure with no more than scarce rust indications. These results testify of the technology robustness from storage on yards to rig operations. In the multiple service conditions in wells, it was shown that the corrosion and cracking resistance of the substrate was not deteriorated by the plating presence, but instead improved in the multiple assessed well service conditions. The present communication updates the results of atmospheric corrosion compared to the former one [1] and it details new results after rig-return and regarding the risks of cracking.