Salt Sprays Research Articles

Impact of marine atmospheric corrosion on the thermophysical properties of building coatings

Coastal structures are subjected to substantial thermal and solar loads, as well as relentless erosion from salt sprays originating from the ocean. This erosion poses a significant threat to the integrity of the surface coatings. However, the examination of the impact of salt spray on coatings from a heat-transfer perspective is limited. The objective of this study is to quantitatively evaluate the influence of ocean salt spray on the thermal properties of building coatings by investigating the modifications in surface thermal properties and heat transfer performance. Specifically, water-based polyurethane coatings, water-based acrylic coatings, and solvent-based coatings was subjected to corrosion through indoor accelerated aging tests and wind tunnel experiments. After a 30-day expose to ultraviolet ageing and salt spray corrosion, noticeable discoloration, and a substantial reduction in surface glossiness of up to 84 % are observed in the coating samples. The change in reflectance ratio before and after corrosion was measured using a spectrophotometer, indicating a maximum reduction of 9.4 %. To analyse the variations in the dynamic heat transfer performance of the samples before and after corrosion, this study employed the heat balance equation and conducted dynamic wind tunnel tests. The corrosion process appears to increase heat transfer along the coating's surface, evident from the consistent elevation in heat transfer capacity coefficients (CHTC) of the specimens after corrosion. Notably, these increases, particularly pronounced during nighttime, reveal substantial and consistent gaps in coefficients, reaching values of up to 10 W/m2 (WP1), 12.5 W/m2 (WA1), and 10 W/m2 (S2), respectively.

Comparison of Mechanical Properties of Ductile/Brittle Epoxy Resin BFRP-AL Joints under Different Immersion Solutions.

The bonding properties of BFRP composites have been demonstrated in previous studies, satisfying the strength and durability criteria. In this paper, a further in-depth study is carried out to bond Basalt Fibre Reinforced Polymer (BFRP) to Aluminum Alloy 5052 using two bonding agents, Aralite® 2012 and Aralite® 2015, respectively. The salt sprays under 80 °C, 3.5% NaCl environment; 80 °C, 5% NaCl environment; and pure water environment are also considered for comparison. Experimental results show that joints created with Araldite® 2012 adhesives show higher average breaking strength (10.66 MPa at 720 h) and better ductility in a 5% NaCl environment. While the Araldite® 2015 adhesive joint exhibits a combination of tear failure and interface failure, along with thin-layer cohesion failure. In the SEM images of the two adhesive joints' failure, fiber pullout due to tension and damage at the interface between fiber and resin is apparent. To validate the experimental outcomes, water absorption testing, DSC, TGA-DTG, and FTIR experiments were conducted on dog-bone-shaped adhesive specimens to elucidate the results.

Self-incompatibility: a pollination control mechanism in plants

Mode of pollination is very important in plant breeding because it determines the genetic constitution, nature of gene action, ease in pollination control and stability of varieties after release. There are several mechanisms that promote cross pollination, among these self-incompatibility (SI) is of special significance as it is used in hybrid seed production. SI is defined as the prevention of fusion of fertile (functional) male and female gametes of the same plant (Gowers, 1989). SI is a system where self-recognition and rejection is the rule that prevents inbreeding depression. Bateman (1952) classified self-incompatibility based on the interaction between pollen grains and pistil as complementary and oppositional system. Lewis (1954) has classified SI into homomorphic and heteromorphic systems. Homomorphic SI is again subdivided into gametophytic (determined by the genotype of gametes) and sporophytic (determined by the genotype of the plant) systems. Molecular studies after 1980’s revealed that at least two genes within S-locus control the SI, among these one unit function as male and the other as female determinant. In Brassicaceae family, the determinant gene encodes a pollen ligand and its stigmatic receptor kinase and their interaction induces incompatible signaling within the stigma papilla cells. In the Solanaceae, Rosaceae, and Scrophulariaceae, the female determinant is ribonuclease and F-box protein, suggesting the involvement of RNA degradation and protein degradation within the system. In the Papaveraceae, the female determinant induces Ca 2+ dependent signaling network that ultimately results in the death of incompatible pollen (Takayama and Isogai, 2005). Genes controlling the SI is multiallelic in nature and number of alleles varies depending upon the crop. Number of alleles reported are five in Theobroma cacao (Knight and Rogers, 1953), 30 in Brassica campestris (Singh, 2012), 32 alleles in Raphanussativus (Karron et al ., 1989). SI is commercially exploited for the production hybrid seeds. Pusa Hybrid-2, Snow Queen and Snow King hybrids of cauliflower, BRH-5, H-44 of cabbage and CCRP8 to CCRP15 (Minimol et al ., 2015a) of cocoa are some of the examples. Kucera et al . (2006) has compared the quality between SI and male sterility hybrids in cauliflower and it was found that SI hybrids are superior in their performance. Minimol et al . (2015b) emphasized the importance of polyclonal garden in cocoa for production of F 1 hybrid seeds by utilizing the self-incompatibility. Rego and Rego (2013) evaluated the efficiency of three methods of overcoming self-incompatibility in passion fruit and found fruit set of 16.67 and 10 per cent in bud and double pollination, respectively. The main limitations in exploiting SI is the maintenance of inbreds, however, it can be overcome by some temporary methods such as bud pollination, salt sprays and irradiation methods.

The Effect of Protective Coatings using L-5A Type toward Corrosion Rate on Mild Steel Grade a Material (Case Study in Indonesia Warship)

The Indonesian Navy requires warship as the main component of defense. It most of the material used are plates. There are several materials or materials that are vulnerable when exposed to corrosive attack on the marine environment. The aim of this paper is to determine the influence of coating, characteristics and compounds corrosion mild steel material A grade toward corrosion rate in seawater environment. Characteristics and corrosion compounds, used salt spray, immersion corrosion method, and X-ray method for analyzing corrosion compounds. The result of salt spray method showed highest corrosion rate (average 7,228 mpy for 20 days). The result of highest without coating showed corrosion rate (average 52,781 mpy for 20 days). The immersion test method with painting has the highest corrosion rate (average 1,892 mpy for 10 days). The highest unpainted corrosion rate (average 4,608 mpy for 20 days) after identified using x-ray obtained analysis and element that cause corrosion. In salt sprays produce corrosion product that is Fe (CO3).

Understanding the Mechanism of Salt Tolerance in Pandanus odorifer L.

Pandanus odorifer L. belongs to Pandanaceae grows in the wild, mainly in semi-natural vegetation throughout the tropical and subtropical Pacific in littoral habitats, where it prevails against drought, strong winds, and salt sprays. To investigate the mechanism of salt stress tolerance in P. odorifer, the leaves from natural populations growing in the coastal region (SW) and those maintained under fresh water conditions (FW) were compared and analyzed for the common osmolytes proline, glycine betaine and γ-aminobutyric acid (GABA). The proline contents in both FW (13 µmol/g) and SW (12.7 µmol/g) plants were found nearly equal. The glycine betaine in FW plants was 0.745 µmol/g and in SW plants, it was 1.71 µmol/g and the amount of GABA in SW plants was ~60 and ~15 µmol/g in FW plants. Thus, among the three metabolites, GABA contents were found significantly higher, hence, the key enzymes responsible for GABA biosynthesis; glutamate decarboxylase (GAD EC 4.1.1.15), succinic semialdehyde dehydrogenase (SSADH EC 1.2.2.16) and betaine aldehyde dehydrogenase 2 (BADH2 EC 1.2.1.8) were studied with respect to their activity and expression levels in FW and SW plants. Relative expression of GAD was higher in both FW as well as in SW plants of P. odorifer. The highest activity and expression level of GAD under both the conditions suggests that probable pathway for GABA synthesis in P. odorifer is via GABA shunt.

Effect of Air-Borne Salinity on the Growth and Appearance of the Tropical Perennial Strandline Plant, Commelina erecta subsp. maritima (C.V. Morton) C.V. Morton

<p>Selection of salt spray tolerant plants with good physical appearance is of concern to ornamental growers in coastal communities. <em>Commelina erecta</em> subsp. <em>maritima</em> (C.V. Morton) C.V. Morton is a seashore plant that is widely distributed along the coast of West Africa. Therefore, the effect of salt spray was examined on the plant in a greenhouse experiment to determine its responses to various levels of air-borne salinity and to have an insight in the ecophysiological adaptations underlying these responses. It was also aimed to determine if varying levels of salt spray differentially damaged the plant. Filtered seawater was used to spray potted plants at: two sprays per week (2SS), four sprays per week (4SS) or six sprays per week (6SS) while in the control treatment (CSS), plants were sprayed with deionized water. Plants sprayed with seawater did not differ significantly (p > 0.05) in percentage necrotic leaf area compared to the control. All the plants survived but growth was inhibited by salt spray. Salt spray caused a significant (p < 0.05) reduction in leaf size and total chlorophyll content. Salt was accumulated in the shoot of salt-sprayed plants which led to ion toxicity. Salt sprays led to reduction in amount of essential nutrients in plant parts. <em>C</em>.<em> </em><em>erecta </em>subsp. <em>maritima</em> adjusted osmotically to salt stress and increased stem succulence for ion dilution. The growth of the plant was negatively affected by salt sprays but it showed no significant necrotic damage, hence it is suitable for use as a landscaping plant in coastal beaches.</p>

Ageing of silicone rubber insulators in coastal and inland tropical environment

This paper presents investigations on the performance of 33 kV silicone rubber insulators characterized by different creepage lengths, which aimed to find out whether the insulators could permanently work when electrically stressed beyond the recommended limits in polluted and clean tropical environments. The study was performed under natural field and laboratory conditions. The insulators tested included eight types of silicone rubber composite insulators, one type of hybrid silicone-ceramic insulator and one semi-conducting glazed porcelain insulator, while ordinary porcelain and glass insulators were used as reference. During the field investigation, two sets of the insulators were separately installed and energized in coastal and inland parts of Sri Lanka, being by that exposed to marine and clean tropical environments. Their performances were periodically evaluated by visual inspections and measurements of hydrophobicity class. After five years of field exposure, the insulator performances were evaluated in laboratory by measurements of leakage currents under clean fog conditions and of wet flashover voltage. A third set of the insulators was aged in laboratory for 1000 hours inside a salt fog chamber where the insulators were continuously energized and daily sprayed with salt solution for eight hours and left to rest for remaining 16 hours. This treatment represented conditions similar as those in the field i.e. insulators exposed to salt sprays during monsoons. The insulator performances were investigated by measurements of leakage currents and classifying their patterns into different categories, i.e. capacitive, resistive, non-linear, discharge and strong discharge types, by means of fast Fourier transform and short time Fourier transform analyses. It was found that the long-term field exposure yielded weaker insulator deterioration than the salt fog chamber ageing, which indicated for a possibility to increase the electric stress on silicone rubber insulators to levels higher than the ones used today on glass and porcelain counterparts.

Cell-Membrane Damage and Element Leaching in Transplanted Parmelia sulcata Lichen Related to Ambient SO2, Temperature, and Precipitation

Measurements were performed in lichen (Parmelia sulcata) transplants, to gain insight into the lichen vitality as possibly affected by both element deposition or lichen element content and further ambient atmospheric conditions (temperature, precipitation, SO2 levels). The electrical conductivity of rinsing solutions was used to assess cell-membrane damage in Parmelia sulcata in an experiment, which ran from August 2001 until August 2002. Element contents of the solutions and lichens were determined by inductively coupled plasma-optical emission spectrometry and by k0-instrumental neutron activation analysis, respectively. Factor analysis (MCATTFA) was used to determine grouping of elements of similar origin and/ or behavior. All in all, the data indicate that, apartfrom lichen Na and Cl levels, and for temperature and precipitation, no clear relationships with conductivity could be observed. Conductivity was mostly related to released Na, Cl, K, Mg, and Cs. On the basis of concentrations, Na, Cl, and K could be considered as largely determining the conductivity. The data suggest a different origin for K than that for Na and Cl: the latter two are most probably due to effects from sea salt sprays. Parmelia sulcata was sensitive enough to reflect appreciable ambient rises in air SO2 and resistant enough to recover afterward. MCATTFA on selected elements (K, Sc, Cu, V, As, and Sb) indicated the absence of any comparability between K and V, As and Sb, suggesting differences in origin and/or chemico-physical occurrence. Generally speaking, the present data suggest that the comparability of lichen vitality in large geographical areas may be limited and governed by the area's variability in temperature and precipitation rather than by variability in metal deposition rates. The leaching data on all elements and element groups, however, strongly suggest that wet deposition may also severely affect lichen elemental levels. This latter observation means that comparing outcomes for time or spatial series of lichen samples should be accompanied by a comparably careful monitoring of (preceding) ambient conditions.

Saltwater spray as an agent of natural selection: no evidence of local adaptation within a coastal population of Triplasis purpurea (Poaceae)

An ability to tolerate airborne saltwater spray is critical for plant populations in coastal environments. The opportunity for continued microevolution for improved salt tolerance can exist if there is variation in the response of genetic families to saltwater spray. Our objective was to determine whether or not there was differentiation among subpopulations near (15 m) and far (80 m) from shore and among families within subpopulations in relation to the effects of salt spray on life history traits in a population of the dunegrass Triplasis purpurea. In this annual, most seeds are matured in cleistogamous spikelets on axillary, leaf-sheath enclosed panicles and show poor dispersal capacity. Plants were reared in the greenhouse from seeds of 13 and 11 families from the near and far subpopulations, respectively. Fifty percent of plants in a family were subjected to 6 seawater sprays/wk, resulting in weekly salt deposition of 213 μg/cm(2); the others were sprayed with distilled water. Data were recorded on life span, tiller numbers, root and shoot dry mass, and seed production. There was no effect of subpopulation on any measured trait and, hence, no evidence for local adaptation to salt spray. Final tiller numbers, but not dry mass or seed production, were reduced by salt spray. However, for most traits there were significant family (within subpopulation) effects, indicating genetic substructuring. Life span and mean seed mass showed a significant family by treatment interaction, indicating genetic variation in phenotypic responses to salt spray. Life span and mean seed mass were reduced by salt spray in some, but not all, families. Path analysis revealed that an increase in life span or tiller number indirectly increased seed production via direct effects on vegetative mass. For this relatively salt-tolerant T. purpurea population on the south shore of Staten Island, New York, USA, salt sprays may not be a significant agent of natural selection. However, there are pronounced phenotypic differences among inbred family groups and opportunity for genetic substructuring within these subpopulations. Variable effects of salt spray among families could result in microevolutionary changes in life span and mean seed mass, both of which impact annual fitness in this dunegrass.

Black Turfgrass Ataenius Larval Control With Bifenthrin, 1995

Abstract Seven treatments were applied to a golf course fairway in Dover, NH, for BTA larval control. Plots were 7 X 7 ft, replicated 4 times, in a RCB design. Treatments were applied 3 Jul and rated 21 Jul by removing 2 ft2 of sod and counting live larvae and pupae. Granules were applied with a salt shaker and sprays with a CO2 boom sprayer, 8004 nozzles, at 40 PSI, in 1.74 gal water per 10002. Conditions at the time of treatment were: air temperature, 63.8°F; wind, 2 mph; sky, clear, soil temperature, 1 inch, 69.0°F; thatch depth, 0.6 inch; soil pH, 5.8; slope, 3%; soil texture, silt loam, sand 46%, silt 47%, clay 7%; soil organic matter, 8.1%; soil moisture, 31.24%; post treatment precipitation, 0.2 inch immediately.

Japanese Beetle Larval Control With Bifentrhin and B.T. Var. Japonica, 1995

Abstract Thirteen treatments were applied to a golf course fairway in Ossippee, NH for Japanese Beetle control, Plots were 7 X 7 ft, replicated 4 times, in a RCB design. Treatments were applied 15 Aug and rated 24 Sep. Granules were applied with a salt shaker and sprays with a CO2 boom sprayer, 8004 nozzles, at 40 PSI, in 2 gal water per 1000 ft2. Plots were rated by counting the number of live larvae in 2 ft2. Pretreatment density was 18.8 larvae per ft2. Larvae were 91% second and 9% third instar. Conditions at the time of treatment were: air temperature, 69.8°F; wind, 2 mph; sky, cloudy, light showers; soil temperature, 1 inch; 76.6°F; thatch depth, 0.5 inch; soil pH, 5.6; slope, 2%; soil texture, sandy loam; sand 58%, silt 23%, clay 19%; soil organic matter, 6.4%; soil moisture, 13.6%; post treatment precipitation, 0.2 inch immediately, irrigation every other day.

Effets des contraintes (vents et embruns) sur la composition et la structure de la végétation des pentes drainées de l'île de la Possession (archipel Crozet, subantarctique)

A study of the vegetation communities along two transects on the well drained slope of the Possession Island (subantarctic island, Indian Ocean) was carried out. The aim of this study was to investigate the structure of the vegetation under permanent pressure from gales and salt sprays and where there was no major perturbation. In the areas protected from gales, a Blechnum pennamarina community dominates. This fern hinders the vegetation dynamics in two ways : (i) by forming a very dense canopy that prevents sunlight from reaching shorter plants (passive competition) and (ii) by the accumulation of thick litter resulting from dead fronds. This community thus acts as the "inhibition" model of Connell and Slatyer. In areas exposed to gales and salt spray, B. pennamarina partly or completley disappears. The soil surface is consequently covered with several bryophytes and Azorella selago that form a mosaic on the soil surface. The vegetation dynamics end at this stage, despite the ability of B. pennamarina to colonize moss litter. The bryophyte community probably represent a stational climax stage acting as a "facilitation" model to B. pennamarina in an area protected from gales. It has therefore been concluded that the fernbrake community constitutes the optimal vegetation development on the well drained slopes of the Possession Island. Key words: climatic pressure, community ecology, bryophytes, Blechnum pennamarina, transect.

Magnetic Properties of Fe-Si-Ru Sputtered Films

The authors studied Fe-Si magnetic thin films with Ru added formed on glass substrates by RF sputtering. Addition of Ru tended to lower the saturation magnetic flux density, but the rate of decrease was smaller than for transition metals such as Cr. The permeability and coercive force remained unaffected. Polarization curve measurements and tests using salt sprays indicated that films with Ru added were more resistant to corrosion. Fe-Si-Ru alloys were obtained with a saturation flux density of about 1.7 T, a permeability of about 500 and a corrosive resistance comparable to that of Ni-Fe alloys.

Field Desiccation of Millets

The efficacy of common salt, Gramoxone and Regione sprays as pre-harvest desiccants on bajra (Pennisetum typhoides L.) and sorghum (Sorghum vulgare Pars) was studied. Appreciable grain moisture reduction (7.5 to 21.5%) in sorghum had occurred when pre- harvest desiccants were sprayed at different stages of maturity. Moisture reduction in boot leaf and stem was not to this extent. Gramoxone at 0.10% (a.i) was more effective than the other desiccants tried. Moisture reduction was more pronounced in 48 hr than in 24 hr of spraying. The late tillering habit and uneven maturity in rainted bajra make it difficult to adopt pre-harvest desiccation.

Tree Stress from Salts and Herbicides

Trees are damaged from both salts used in deicing highways and herbicides used for weed control. Aerial salt sprays lifted by traffic are more damaging to trees than soil accumulations. Salt injury can be reduced by applying antidesiccants, constructing physical barriers, leaching soils, incorporating activated charcoal and planting high and away from salt spray and runoff. The most damaging pre-emergence herbicides include simazine and dichlobenil while dicamba, 2,4-D and related compounds are the most harmful post-emergence chemicals. Prevent injury from herbicides by proper chemical selection, application at desired rate, with accurately calibrated equipment on a day when drift is minimized. Avoid soil residues, treating susceptible cultivars and treating under plant stress conditions. Activated charcoal can be used to detoxify many herbicides in the soil.

Effect of chemical amendments and foliar application on lentil wilt

Mn and Zn salt amendments in soil, presoaking of seeds in Mn and Zn salt solutions, foliar application of Mn and Zn salt sprays has been tried in order to control the lentil wilt pathogen. Best disease control was obtained at 80 ppm of Mn and Zn salt amendments. Presoaking the seeds also considerably reduced the disease. Foliar sprays of Zn and Mn salts were also equally effective in controlling the disease. From the point of view of practical agriculture it can be suggested that presoaking the seeds of lentil with Zn and Mn salts at 80 ppm concentration can form a very good and effective

Photometric investigations of the behaviour of chromium additives in premixed H 2 + O 2 + N 2 flames

The chemistry of a flame gas + metal additive system which may contain particles of involatile metal oxide has been studied photometrically, and the results interpreted in detail for the first time. The principal experiments discussed concern H 2 + O 2 + N 2 flames into which traces (10 -6 to 10 -8 mole fraction of the total flame gases) of either gaseous chromium carbonyl or aqueous chromium salt sprays are introduced. In the temperature-range examined (1800 to 2700 K), for both types of additive the gaseous phase results are interpreted in terms of the presence in comparable proportion of four species, Cr, CrO, CrO 2 and HCrO 3 which interact in the balanced reactions Cr + OH ⇌ CrO + H, CrO + OH ⇌ CrO 2 + H, CrO 2 + H 2 O ⇌ HCrO 3 + H, or their equivalents. The species HCrO 3 , which has not been reported before, was found by a Second-Third law procedure to have an atomization energy of 1940 ± 40 kJ mol -1 . The equilibrium constant of Cr + 3H 2 O ⇌ HCrO 3 + 2H 2 + H at 2300 K is 0.050 ± 0.008. In addition to the gas phase constituents (which alone cause the behaviour of chromium in flames to be the most complex of that of any metal studied to date) further features arise from the usual presence of solid material. In the case of salt spray additives, solid is detected even under conditions of thermodynamic instability although in such circumstances it is only a minor constituent. In the burned gases, there is no evidence for significant change in particle size or for significant interaction between solid and gaseous chromium-containing constituents in the available time scale—up to 10 ms. These ‘inert’ particles do, however, participate in the spin destruction processes Cr 2 O 3 (s) + H + H (or OH) → Cr 2 O 3 (s) + H 2 (or H 2 O) in which the rate-determining step is the rate at which the radicals strike the particle surface. The ‘hot’ particles thereby produced behave as approximately grey body emitters with temperatures which may be up to 500 K above that of the ambient flame gases. Significant catalysis of radical recombination is caused by amounts of additive as low as 1/10 6 of the total burned gases. The preferred explanation of this striking effect involves a homogeneous route in which oxygenated chromium species participate.

The Response to Epsom Salt Sprays of Mature Apple Trees of Three Varieties on Two Contrasting Rootstocks

SummaryMature trees of Beauty of Bath, Tydeman’s Late Orange and Laxton’s Superb on M.VII rootstock, growing under commercial-type conditions, were severely deficient in magnesium as shown by leaf analysis and typical symptoms. Five sprays yearly of 2% Epsom salt (MgSO4.7H2 O) raised the concentration of magnesium in the leaves and largely eliminated symptoms: the concentrations of calcium and, to a lesser extent, of potassium in leaves were reduced. Over six years, there was little effect of Epsom salt on growth as measured, but crop weight was increased by 19–39% according to variety: this was largely, but not entirely, due to increase in fruit set. The proportion of fruit that dropped was decreased for Beauty of Bath and for Tydeman’s Late Orange sprayed with Epsom salt and the weight per 100 fruits of the late varieties Tydeman’s Late Orange and Laxton’s Superb was increased. Untreated trees on M.II rootstock, in contrast to those on M.VII, showed almost no foliar symptoms of magnesium deficiency, made more growth and produced larger crops; the concentrations of magnesium and calcium in the leaves were higher whereas potassium was usually lower. Epsom salt sprays did not increase growth or cropping; indeed, there was a tendency for sprays to reduce the crop weight of Beauty of Bath on M.II, indicating that they should not be used indiscriminately.Epsom salt foliar sprays increased the “available” magnesium in the soil to a level considered to be medium—high; this effect was mainly shown in the top 6 in. of soil and gradually diminished to the 18–24 in. zone. Nevertheless, in the year following the termination of treatments, the proportion of foliage affected in Laxton’s Superb on M.VII, previously sprayed with Epsom salt, was almost as great as that of untreated trees and the concentration of magnesium in the leaves was as low. It appeared that magnesium in the soil did not reach the leaves.The increase in “available” magnesium due to sprays was greater in soil carrying trees on M.II than M.VII, a result probably due to the extra quantity of spray required for these larger trees.