Presence Of Rust Research Articles

Efecto Bioprotector de Micorrizas Arbusculares en la Reducción de Roya (Hemileia vastatrix) en la Región San Martín

La roya es un problema generalizado que ha afectado a diferentes países de América Latina, generando pérdidas económicas en los productores cafetaleros. Se evaluó el efecto de los hongos micorrízicos arbusculares (HMA), sobre la presencia de roya (Hemileia vastatrix) en plantas de café. Se empleó un Diseño Completamente al Azar con dos factores: fuentes de inóculo HMA e Inoculación de roya, incluyendo tratamiento testigos (absoluto e infestado); se usó como sustrato tierra agrícola y arena (2:1); se inoculó plantas de café con 1 500 esporas de HMA procedente de Rioja, Lamas, Dorado y Huallaga, posteriormente se inóculo con esporas de roya; se evaluaron altura de planta, área foliar, biomasa seca y aérea, incidencia, severidad, colonización micorrízica y longitud de micelio extraradical. Los resultados mostraron que los tratamientos inoculados con HMA presentaron mejoras incrementos en morfología, micorrización y menor incidencia y severidad a roya.

Influence of operating factors on the efficiency of the vehicle brake system

The main system responsible for the safety of the car is its braking system. The efficiency of the braking system is assessed by several parameters, the main of which is the maximum braking force, which is generated in the braking mechanisms, usually it is disc or drum types of brakes. The analysis of peculiarities of designs of existing types of brakes of cars is carried out, advantages and disadvantages of each of them, characteristics of application and maintenance are substantiated. The main factors that have a significant impact on the efficiency of the car's brake system have been identified. It was carried out the research of the influence of the main operational factors on the efficiency of the car's brake system: the pressure in the car's tires, contamination, and friction pairs of the brake mechanisms. The method of conducting experimental test lane and road researches of influence of the chosen factors on indicators of braking efficiency of the car is developed. Test lane experimental studies were performed using the Bosch BSA 4340 brake test equipment, graphs of changes in the braking efficiency of each of the car's wheels based on the researches were built, depending first on the change in tire pressure, then on the presence of rust, grit, and grime and level of wear of mechanisms. The quantity of the maximum braking force of the car depending on three quantities of pressure in tires of wheels was identified: the pressure recommended by the factory of 0,18 MPa, the lowered and increased pressures 0.15 and 0.25 MPa respectively. The influence of motor oil caught in the brake mechanism or treatment with special pastes on the value of the maximum braking force is also determined. The influence of the state of the brake discs and pads on the braking efficiency of the car was also investigated, the braking indicators were measured before and after the replacement of the brake disc and pads. On the basis of the conducted test line and road researches, conclusions are made and practical recommendations on prevention of reduction of brake efficiency of the car in the conditions of operation are offered.

Study on the Bond‐Slip Performance of CFSSTs Based on Push‐Out Tests

To study the interfacial bond‐slip performance of concrete‐filled square steel tubes (CFSSTs), taking the core concrete strength, slenderness ratio, and width‐to‐thickness ratio as the influencing factors; 9 specimens were designed with 3 factors and 3 levels for the orthogonal test method. In addition, different from the above 9 specimens, one specimen without rust removal was designed for the purpose of comparison. Based on the bond stress distribution and deformation coordination relationships between the specimens during the push‐out tests, a theoretical formula for calculating the relative slip of a CFSST was deduced. The results show that with the increase of load, the relative slip at the loading ends was earlier than that at the free ends of the specimens; the interfacial bond failure and relative slip gradually developed from the two ends towards the centre of the specimens; the increase of the bond stress in the middle part was faster than that at the ends of the specimens. The order of these factors from main to secondary is the presence of rust in the inner wall of the square steel tube, the slenderness ratio, the core concrete strength, and the width‐to‐thickness ratio.

One new genus, two new species and two new records of Eriophyidae from Vietnam (Acari: Eriophyoidea)

ABSTRACTTo date, only three eriophyoid species have been reported from Vietnam. In this article, we described and illustrated a new genus, two new species and two new records of eriophyoid mites from Vietnam. One species is Dorsisulcatus hsienmus gen. nov. & sp. nov., which infests Burretiodendron hsienmu W.Y. Chun & F.C. How (Malvaceae). The mite seems to be vagrant and no visible symptoms were observed on the leaf surfaces. The other mite species is Shevtchenkella longitubercula sp. nov., which resides on the undersurface of Dimocarpus longan Lour. (Sapindaceae) leaves. The presence of numerous mites did not produce visible symptoms nor the presence of rust on the leaf undersurface. Furthermore, Neometaculus catappiae Huang and Tegonotus evodiae Wei were recorded in Vietnam for the first time.http://zoobank.org/urn:lsid:zoobank.org:pub:A088EBF8-D98B-47F5-8B6E-36406C143FEC

Fault detection in heavy duty wheels by advanced vibration processing techniques and lumped parameter modeling

Heavy duty wheels are used in applications such as automatic vehicles and are mainly composed of a polyurethane tread glued to a cast iron hub. In the manufacturing process, the adhesive application between tread and hub is a critical assembly phase, since it is completely made by an operator and a contamination of the bond area may happen. Furthermore, the presence of rust on the hub surface can contribute to worsen the adherence interface, reducing the operating life. In this scenario, a quality control procedure for fault detection to be used at the end of the manufacturing process has been developed. This procedure is based on vibration processing techniques and takes advantages of the results of a lumped parameter model. Indicators based on cyclostationarity can be considered as key parameters to be adopted in a monitoring test station at the end of the production line due to their not deterministic characteristics.

Ferrugem em Plumeria spp. (Apocynaceae) em Mato Grosso do Sul

<p>O jasmim-manga (Plumeria spp.) é uma planta muito utilizada na ornamentação urbana, principalmente por sua rusticidade, fácil manejo e exuberância de suas flores. Folhas de Plumeria spp. foram coletadas no município de Dourados, MS, com sintomas e sinais típicos da presença de ferrugem: uredinias pulverulentas de coloração amarelada na face abaxial e manchas cloróticas e necróticas, na face adaxial das folhas, culminando algumas vezes com abscisão foliar. O presente trabalho tem por objetivo registrar a ocorrência da doença no Estado de Mato Grosso do Sul. Observações microscópicas e mensurações de urediniosporos e teliosporos confirmaram a presença do fungo Coleosporium plumeriae infectando essas plantas.</p>

Avaliação da solução de pulsing com ácido giberélico na vida de vaso de Heliconia bihai

<p>O jasmim-manga (Plumeria spp.) é uma planta muito utilizada na ornamentação urbana, principalmente por sua rusticidade, fácil manejo e exuberância de suas flores. Folhas de Plumeria spp. foram coletadas no município de Dourados, MS, com sintomas e sinais típicos da presença de ferrugem: uredinias pulverulentas de coloração amarelada na face abaxial e manchas cloróticas e necróticas, na face adaxial das folhas, culminando algumas vezes com abscisão foliar. O presente trabalho tem por objetivo registrar a ocorrência da doença no Estado de Mato Grosso do Sul. Observações microscópicas e mensurações de urediniosporos e teliosporos confirmaram a presença do fungo Coleosporium plumeriae infectando essas plantas.</p>

Polychlorinated dibenzo-p-dioxins and dibenzofurans formed from sucralose at high temperatures

Sucralose is a widely-used artificial high-intensity sweetener. Although doubts have been raised about the safety of sucralose by several researchers, it can still be found in a broad range of foods and beverages worldwide, including in baked goods. Sucralose may decompose at high temperatures, and participate in chlorination reactions, generating highly toxic compounds. Here, we demonstrate that heating sucralose at high temperatures in stainless steel or other metal utensils in the presence of rust (Al2O3, Fe2O3, and CuO) produces polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). PCDD/Fs were found in smoke generated during the heating of sucralose and in the residues after heating. CuO enhanced the PCDD/F yield in comparison with Al2O3 and Fe2O3.

Study of Rust Effect on the Corrosion Behavior of Reinforcement Steel Using Impedance Spectroscopy

Most studies on corrosion of steel reinforcement in concrete are conducted on steel samples with polished surface (free of all oxides) in order to reproduce the same experimental conditions. However, before embedding in concrete, the steel bars are often covered with natural oxides (rust), which are formed during exposure to the atmosphere. The presence of this rust may affect the electrochemical behavior of steel rebar in concrete. In order to understand the effect of rust on the corrosion behavior of reinforcement steel, potentiodynamic and electrochemical impedance spectroscopy (EIS) tests were carried out in a simulated concrete pore solution using steel samples with two different surface conditions: polished and rusted samples. The obtained results have shown that the presence of rust on the steel bar has a negative effect on its corrosion behavior, with or without the presence of chlorides. This detrimental effect can be explained by the fact that the rust provokes a decrease of the electrolyte resistance at the metal-concrete interface and reduces the repassivating ability. In addition, the rust layer acts as a barrier against the hydroxyl ion diffusion, which prevents the realkalinization phenomenon.

Effect of propylene glycol monomethyl ether and rust impurities on TS-1 deactivation in propylene epoxidation

The properties of TS-1 catalyst in continuous reaction of propylene epoxidation, as well as the effects of by-product propylene glycol monomethyl ether (PGME) on catalytic performance, was investigated in a low-pressure fixed bed reactor with chemical pure methanol as solvent. As the rust could be doped from the pipings and solvent containers, its impact on catalyst deactivation was then studied by using industrial-grade methanol. Finally the catalyst before and after deactivation was contrastively characterized by means of micro-structure analysis, TPD and TPR. The results showed that self-developed TS-1 catalyst performed well in the reaction, and the by-product propylene glycol monomethyl ether would not depress the catalytic activity in 80h. The presence of rust could not only block active sites leading to partial loss of activity, but also increase the surface acidity, which would induce side reactions and decrease the selectivity of propylene oxide.

Study of the evolution of a semi‐open cooling circuit

Purpose – The evolution of a semi‐open cooling circuit of a nuclear reactor was monitored over a two year period. The work aims to provide orientation elements for preventive procedures against localised corrosion.Design/methodology/approach – The water of the circuit was analysed in stagnation and in circulation, at various sampling points. The rust was analysed by neutron diffraction and the surface quality of the steel was checked by microscopic observations.Findings – The obtained results did not confirm the presence of rust in iron compounds supported by chlorine, such as the Akaganeite, β‐FeOOH. In addition, chemical analysis of water showed that, after two years, the increase of chlorine concentration and water conductivity remained weak. Moreover, the pH was maintained within values favourable rather to the passivation of the steel.Practical implications – It was deduced through this work that the dosing of the circuit with chlorine was not sufficient that it should require an annual replacement o...

Breeding for Resistance to Soybean Rust.

Soybean rust occurs in all major soybean-growing regions of the world including the North American mainland. Soybean rust, caused by Phakopsora pachyrhizi, is the most destructive foliar disease of soybean, and yield losses of over 50% are common when environmental conditions are conducive for disease development. Heavily infected plants defoliate and mature more rapidly than plants not infected with rust. P. pachyrhizi has a broad host range and can infect many other legumes including some native to Australia. A number of physiological races of the fungus have been reported on these native legumes from Australia and on soybean. In addition, four single genes for rust resistance were previously identified in four different soybean plant introductions. These sources of resistance also have been reported to be susceptible in some field locations and when challenged with certain isolates of P. pachyrhizi. Partial resistance, expressed as reduced pustule number and increased length of latent period, has also been reported but has not been widely used in breeding programs. Yield stability has been used in the past and compares percentage of yields in fungicide and nonfungicide plots. Cultivars or lines with a higher percentage of yield have greater yield stability in the presence of rust. Although soybean rust only recently was found in the continental United States, a proactive project to evaluate the USDA soybean germ plasm collection for rust resistance was initiated in 2002 at the Fort Detrick plant biocontainment facility and at six international locations. Part of this project is to discover soybean lines with greater yield stability, and additional single and partial resistance. To help minimize the impact of soybean rust, the first line of defense will be fungicides, with host resistance and yield stability augmenting the long-term management of soybean rust.

Effect of variable amounts of rust at the steel/paint interface on the behaviour of anticorrosive paint systems

This paper analyses the effect of the presence of rust at the metal/paint interface on the behaviour of different paint systems used for protecting the structural steel exposed to the atmosphere. The paint systems were applied as films of variable thickness over rusted steel surfaces cleaned to different grades of surface preparation (Sa3, Sa2(1/2), Sa2 and St2). Pre-rusting of steel was carried out in a clean (uncontaminated) rural atmosphere. Atmospheric exposure tests were conducted for 14 years at three Spanish test sites of different atmospheric corrosivity. Exposed specimens were evaluated for rusting and blistering, as well as for delamination of the paint system on both sides of a scribe made in the paint film. The results reveal that in some cases the presence of rust has a negligible influence on the durability of the paint system applied. Those systems including a zinc-rich (ethyl silicate) primer were found to provide the most effective protection against corrosion under all types of conditions tested.

Biological control of Senecio vulgaris in carrots (Daucus carota) with the rust fungus Puccinia lagenophorae

Senecio vulgaris is a troublesome weed in horticulture that is tolerant or resistant to a range of herbicides, and is therefore a candidate for biological control. The rust fungus Puccinia lagenophorae is a potential control agent, but being biotrophic, it is not suitable for use as a mycoherbicide. We tested the effects of induced rust epidemics on S. vulgaris, and investigated the resulting shading dynamics within this system. We sowed carrots at 267 seeds m−2 on five farms in western Switzerland in plots either with or without S. vulgaris seeds (also at 267 seeds m−2, within crop rows), and with or without strong sources of rust spore (four inoculum sources placed every 2 m along crop beds). Plots with S. vulgaris and no inoculum source produced low total carrot yields (18% of yield from S. vulgaris-free plots), whereas plots with S. vulgaris plus rust inoculum sources produced 48% of the yield from S. vulgaris-free plots. There were, however, no significant differences in several commercially important yield parameters such as the number of first grade carrots between S. vulgaris-free plots and those with S. vulgaris plus inoculum sources. Carrots grown with S. vulgaris were smaller and had skewed size distributions compared with the weed-free controls, but adding rust inoculum reduced this effect. This reduced size variability and reduced weed competition have important economic benefits to farmers. Carrots had longer leaves when grown with S. vulgaris, suggesting that carrots and S. vulgaris competed for light. Percent ground cover and height of S. vulgaris relative to carrots was reduced by the presence of rust, and these effects were most obvious one month after placing inoculum sources in the field. Our results are encouraging, even with artificially high weed competition, but further research is needed before this paradigm can be proposed for practical applications.

The Effects of Rust and Anthracnose on the Photosynthetic Competence of Diseased Bean Leaves

ABSTRACT The effects of rust (caused by Uromyces appendiculatus) and anthracnose (caused by Colletotrichum lindemuthianum) and their interaction on the photosynthetic rates of healthy and diseased bean (Phaseolus vulgaris) leaves were determined by gas-exchange analysis, in plants with each disease, grown under controlled conditions. The equation P(x)/P(0) = (1 - x)() was used to relate relative photosynthetic rate (P(x)/P(0)) to proportional disease severity (x), where beta represents the ratio between virtual and visual lesion. The beta values obtained for rust were near one, indicating that the effect of the pathogen on the remaining green leaf area was minimal. The high values of beta obtained for anthracnose (8.46 and 12.18) indicated that the photosynthesis in the green area beyond the necrotic symptoms of anthracnose was severely impaired. The impact of anthracnose on bean leaf photosynthesis should be considered in assessments of the proportion of healthy tissue in diseased leaves. The accurate assessment of the healthy portion of the leaf could improve the use of concepts such as healthy leaf area duration and healthy leaf area absorption, which are valuable predictors of crop yield. The equation used to analyze the interaction between rust and anthracnose on the same leaf was P(z) = P(0) (1 - x)(x) x (1 - y)(y), where P(z) is the relative photosynthetic rate of any given leaf, P(0) is the maximum relative photosynthetic rate, x is anthracnose severity, y is rust severity, betax is the beta value for anthracnose in the presence of rust, and betay is the beta value for rust in the presence of anthracnose. From the resulting response surface, no interaction of the two diseases was observed. Dark respiration rate increased on diseased leaves compared with control leaves. The remaining green leaf area of leaves with both diseases was not a good source to estimate net photosynthetic rate because the effect of anthracnose extended far beyond the visual lesions, whereas the effect of rust on photosynthesis was essentially limited to the pustule plus halo.

The infection of pyrola (Pyrola asarifolia; Pyrolaceae) by spruce cone rust (Chrysomyxa pirolata; Uredinales): Morphological correlates in the host and consequences for spore dispersal

Sexual spores (i.e., basidiospores) of the spruce cone rust (Chrysomyxa pirolata; Uredinales) produced on leaves of a small perennial herb, the common pink wintergreen (Pyrola asarifolia; Pyrolaceae), must travel from the forest floor to the forest canopy, where they infect the female cones of white spruce (Picea glauca; Pinaceae). Asexual spores (i.e., urediniospores) must move among pyrola plants on the forest floor. Spore transmission is complicated by relatively calm wind conditions within the forest, and the short critical period during which the cones of white spruce can be infected. Here, we document a correlation between the orientation of leaves in the pyrola and presence of rust pustules on the leaf’s ventral surface. We experimentally address the consequences to spore dispersal of this change in leaf position and presence of pustules. Transmission of rust spores can increase with higher leaf angles in two ways: (i) by raising the pustules further above the ground surface, thereby increasing the probability that wind will carry spores further (confirmed in experiment 1), or (ii) by increasing the probability that flying insects will alight on the pustules (confirmed in experiments 2 and 3), and either carry asexual spores (i.e., urediniospores) to other pyrola plants, or carry basidiospores to spruce cones. Vertical orientation increased insect attraction to both real and artificial leaves. Presence of rust increased insect attraction to natural leaves, an effect that could not be mimicked with coloured artificial leaves. Colour alone cannot explain attraction of insects (confirmed in experiments 2 and 3). We infer that both wind and flying insects, as potential agents of spore dispersal, are the likely targets of the rust’s alteration of the orientation and structure of the ventral surface of leaves of its pyrola host.

Influence of corrosion on prestress strands

Corrosion on prestress strands affects their mechanical properties as well as the coefficient of friction in the surface strand/duct. In previous research on prestress beams, the authors have observed different coefficients of friction depending on the surface condition of the strands and wires used in investigation. Some of the strands used for the experiments were stored for some months in the laboratory and gained some rust on the surface. This was enough to influence the coefficient of friction in a noticeable manner. To study the influence of corrosion on the mechanical properties of prestress strands several samples were stored under different environmental conditions to produce various levels of corrosion. These samples were tested afterwards to determine the influence of corrosion on fatigue properties and the coefficient of friction. Apart from the coefficient of friction, light rust decreases none of the other studied mechanical properties of the strands and may even increase the bond characteristics. The presence of rust does not necessarily mean that the strands should be rejected. The work described in this paper was conducted to investigate the level of rust that could be considered acceptable and how corrosion influences some mechanical properties of prestressing strands.Key words: reinforced concrete, prestressed concrete, prestressed beams and girders, structural design, structural members, corrosion, fatigue, losses.

Microwave Detection of Rust Under Paint and Composite Laminates

Accurate, reliable, and early detection of rust/corrosion under paint and laminate composites in many industrial and military applications is of great concern and interest. Although there are several methods for detecting rust under paint, they all have their respective limitations. Microwave nondestructive and noncontact inspection techniques are well suited for the early and reliable detection of rust under various paints and composite laminates. In this paper, the potential of utilizing open-ended rectangular waveguide sensors for detecting rust under paint and laminate composites is investigated theoretically and experimentally. An electromagnetic model describing the interaction of microwave signals radiating from an open-ended rectangular waveguide with a stratified dielectric structure is used to model the presence of rust under paint and a composite laminate coating. For the experimental investigations, we used a rusted steel specimen that was painted over by common spray paint to as much as ten coats of paint. These experiments are conducted at 24 and 10 GHz. The issue of detecting rust unambiguously while a certain paint thickness variation may exist is also addressed.

The use of host resistance in disease management of rust in common bean

Bean rust, caused by Uramyces appendiculatus, is one of the major diseases in dry and snap bean production world-wide. Numerous advancements in disease management have been made to reduce rust losses. Host resistance is an important component of rust management. However, durability of disease resistance has often been short due to the use of single genes for resistance interacting with extremely high virulence diversity of the bean rust fungus. The challenge to increase durability of resistance has led to strategies such as gene pyramiding of race-specific resistance, selection and use of partial resistance, and investigation and discovery of leaf morphological features that may slow the rust epidemic. Germplasm with multiple sources of rust resistance has been developed in specific bean seed classes and released for public and commercial use in intensive production systems such as those in the United States. However, progress to develop rust resistant germplasm for the subsistence agriculture of Latin America and Africa where intercropping and mixed cultivars dominate the production system has been slow. Incorporation of high yielding, disease-resistant components as partial replacement in farmer's mixtures has the potential to reduce severity in the crop and increase yield in the presence of rust. This strategy would not erode the genetic diversity that is historically known to enhance resistance durability and for many years has given stability in production in the subsistent agriculture systems.

Experience with, and problems relating to, bottom bearings of electricity meters

The paper first outlines the results obtained over a period of 10 years with oiled sapphire-steel bearings on a single type of meter used by a large supply undertaking, and describes tests carried out on new and worn pivots and jewels with various lubricants and abrasives. The results indicate that oil greately increases the life of a bearing, but that, even when oiled or greasy jewels are used, the presence of rust or debris is the major cause of wear and consequent errors in the reading of the meter.A series of wear tests on various pivot materials, both oiled and dry, is next described. The results show that materials of all hardnesses give comparatively good results when oiled. No conclusive evidence is obtained of the validity of Stott's theory that oxygen is set free from sapphire under the influence of the large cohesive forces which operate in meter bearings.The cause of surface cracking in sapphire jewels is then investigated, by means of a device which initiates impacts at the rate of 18 per minute between the pivot and the jewel of a meter bearing.Finally, an account is given of apparatus designed for the rotational testing of meter bearings in air and inert atmospheres, providing special facilities for the microscopical examination of jewels. The results of tests in nitrogen, argon, neon, hydrogen, and a vacuum, are discussed, and it is concluded that further experimental work is necessary in order to confirm or disprove the sapphire-oxygen theory.