Effect Of Saline Environment Research Articles

Effect of saline environment on the fatigue crack growth resistance of WE43 Mg alloy

New magnesium alloys have been developed to reduce the weight of engineering components without compromising the mechanical properties and corrosion resistance; however, there is a lack in the literature regarding such properties. Hence, this work focuses on studying the fatigue crack propagation of the WE43 magnesium alloy, considering the effects of air and sodium chloride environments. Fatigue results showed similar behavior for both, main and transverse, directions regarding the rolling mill process. Yet, fatigue crack rates (FCR) were higher in the sodium chloride environment than in laboratory air, which could be attributed to hydrogen embrittlement and anodic dissolution at the crack tip. Laboratory air FCR results presented a lower m value (3.63 and 1.72) than the one found for the sodium chloride environment (9.15 and 4.83), indicating a lower FCR rate variation with ΔK. Comparing FCR for saline and air conditions, at the end of Paris' region II, FCR in the saline environment was enhanced by almost two orders of magnitude (ΔK= 11 MPa.m1/2). Furthermore, fractography showed mixed intergranular and transgranular cracking in the saline environment.

Effect of Saline Environment on LCF Behavior of Inconel 718 at 550 °C

Low-cycle fatigue behavior of alloy IN718 was studied with NaCl salt coating at 550 °C in total strain-controlled mode. Fatigue life of the salt-coated specimens was found to be drastically reduced at the lowest total strain amplitude of ±0.40%; however, fatigue life was not affected at higher strain amplitudes. In general, there was cyclic softening in both the uncoated as well as salt-coated specimens. Variation of fatigue life with plastic strain amplitude followed Coffin-Manson relationship. Reduction in fatigue life from salt coating was found to be associated with early crack initiation from the roots of corrosion pits.

Effect of Sulphur on Plant Growth & Defense System Against Salinity Stress

The given investigation was undertaken to evaluate the performance of black gram (vigna mungo L.) under different salinity levels (i.e. 50mM, 100mM and 150mM NaCl) and to find out the remedial effect of two doses of S (i.e. 2mM and 4mM) against salinity stress on growth of studied crop by providing tolerance against salinity stress. The experiment was carried out in Botany department, Jinnah University for women, Nazimabad, Karachi, in controlled laboratory condition by using plate culture technique followed as completely randomized design with three replication of each treatment. The observation of given research showed that the percentages of shoot and root length and Fresh and dry seedling weights were higher in control treatment. The low (50mM NaCl) level of salinity treatment had no deleterious effects on plant vegetative growth, while at higher concentration of NaCl (100mM), all the growth parameters were drastically reduced. Both application rates of MgSO4 were found satisfactory to eliminate the negative effect of saline environment inside rhizosphere by promoting plant tolerance against stress thus support treated plants growth and development.

Effect of saline environment on mechanical properties of adhesive joints

Literature reports very few works about the effect of corrosive environments on the mechanical properties of adhesive joints. Therefore, the present study intends to contribute for a better understanding of the effect of saline solution on the mechanical properties of single-lap adhesive joints. The specimens were manufactured using Docol 1000 high strength steel plates with 1mm of thickness and Araldite® 420 A/B epoxy adhesive. The static shear strength of the joints was influenced by the exposure time in saline solutions only up to 120h, and remained, after this period, nearly constant. In terms of fatigue strength, for 105 cycles, a decrease about 25% and 39% occurred in specimens immersed during 120h in deionised water and saline solution, respectively, comparatively to the control samples.

Effect of Saline Environment on the Strength of Reinforced Concrete Beams

This paper presents the experimental results of tests carried out to investigate the influence of parameters such as w/c ratio, curing condition and surface bar coating on the shear and bending strengths of fifteen reinforced concrete beams under severe saline environmental conditions. Sodium chloride was used as an additive and an aqueous solution for chloride introduction. The effectiveness of coating the surface of reinforcing steel bar with a paint to protect it against corrosion in concrete was also evaluated. Results show that after 500 days of soaking in the chloride solution the beams undergone considerable deterioration. Significant reduction in shear and flexural strength of reinforced concrete beams due to concrete degradation and steel corrosion especially when sodium chloride was used as an additive. The results indicate that the use of paint-coated reinforcing steel bars in reinforced concrete beams can be helpful to protect the reinforcement against corrosion under saline environment. Key Words : Concrete beams, Saline environment, Water cement ratio, Shear strength.

Effect of Saline Environment on Yield and Smut Disease Severity of Different Corn Genotypes (Zea mays L.)

AbstractThe effects of saline irrigation water on growth, yield, smut index and leaf CI content were investigated under field conditions. The plants were grown in 1994 and 1995 and artificially infected with U. maydis‐ spore‐suspension at V6 and V10 leaf stages. The severity was rated on a 1–9 scale, whenever the symptotns appeared. The results showed that superior growth, greater yield performance, associated with lower smut incidence and leaf Cl contents were generally observed on Taba than its counterparts. Increasing salinity exhibited significant increases in leaf CI and induced marked inhibition on growth, yield and SI data. The salt sensitivity of corn genotypes, as revealed from the comparison of the slope of linear regression equations, was related to 1.00: 1.19;1.42 for cvs Taba, 310 and 320, respectively. The differential yield response with respect to SI data proved that smut susceptibility was inversely related to salt tolerance concept. The data of Cl‐disease interaction showed that smut reactions of highly susceptible and resistant genotypes (cvs 320 and Taba) were hardly monitored by plant Cl content, revealing that disease resistance is genetically controlled. Conversely, the progressive modifications of smut reaction, accompanied by CI accumulation in the moderately susceptible genotype 310 proved that disease resistance was environmentally conditioned by salt stress.

Control of skeletal muscle fibres and adipose cells size in the flesh of rainbow trout

The distributions of the diameters of skeletal muscle fibres and adipocytes were studied in rainbow trout. The cellularity of perivisceral adipose tissues and subcutaneous ventral and dorsal adipose tissues were characterized more specifically. In these tissues, a population of small adipocytes was distinguishable from larger adipocytes. The same was observed in white muscle. The effects of extrinsic factors (dietary lipid in two different thermal conditions) and intrinsic factors (strains in two different saline conditions, growth hormone) on the long-term response of the cellularity of both muscle and adipose tissues were studied. The effects of thermal environment were tested on fish fed the same ration and the effects of saline environment on fish fed ad libitum. The mean size of white muscle fibres was relatively unaffected by the different treatments tested: genetic origin and dietary lipid in different environmental conditions. There were significant differences in growth rate due to genetic origin and saline environment. The possible involvement of hyperplasia in response to these different factors is discussed. Growth hormone supplementation enhanced the percentage of small diameter fibres indicating a role of this hormone in the control of muscle hyperplastic growth. The mean size of adipose cells was affected only slightly by the different treatments tested. An increase in adipose cell size with aging and lipid content was observed. The percentage of small adipocytes also increased with aging. Thus, it is proposed that the development of adipose tissues, and thus fat retention, both result from the recruitment of new adipocytes and from the increase in size of existing adipocytes. The hyperplastic process contributed significantly to the differences in fat retention due to different treatments tested (strains, thermal and saline environments). When partially substituting fish oils for corn oils in the diet, a large increase in the ventral adipose cell size was seen indicating a potential negative effect of n-6 fatty acids on cell proliferation. Growth hormone treatment, on the contrary, induced a decrease in the size of perivisceral adipocytes. Thus, diet and hormonal status affect adipose cells size through two different metabolic pathways: lipogenesis and lipolysis respectively.

Control of skeletal muscle fibres and adipose cells size in the flesh of rainbow trout

The distributions of the diameters of skeletal muscle fibres and adipocytes were studied in rainbow trout. The cellularity of perivisceral adipose tissues and subcutaneous ventral and dorsal adipose tissues were characterized more specifically. In these tissues, a population of small adipocytes was distinguishable from larger adipocytes. The same was observed in white muscle. The effects of extrinsic factors (dietary lipid in two different thermal conditions) and intrinsic factors (strains in two different saline conditions, growth hormone) on the long‐term response of the cellularity of both muscle and adipose tissues were studied. The effects of thermal environment were tested on fish fed the same ration and the effects of saline environment on fish fed ad libitum. The mean size of white muscle fibres was relatively unaffected by the different treatments tested: genetic origin and dietary lipid in different environmental conditions. There were significant differences in growth rate due to genetic origin and saline environment. The possible involvement of hyperplasia in response to these different factors is discussed. Growth hormone supplementation enhanced the percentage of small diameter fibres indicating a role of this hormone in the control of muscle hyperplastic growth. The mean size of adipose cells was affected only slightly by the different treatments tested. An increase in adipose cell size with aging and lipid content was observed. The percentage of small adipocytes also increased with aging. Thus, it is proposed that the development of adipose tissues, and thus fat retention, both result from the recruitment of new adipocytes and from the increase in size of existing adipocytes. The hyperplastic process contributed significantly to the differences in fat retention due to different treatments tested (strains, thermal and saline environments). When partially substituting fish oils for corn oils in the diet, a large increase in the ventral adipose cell size was seen indicating a potential negative effect of n‐6 fatty acids on cell proliferation. Growth hormone treatment, on the contrary, induced a decrease in the size of perivisceral adipocytes. Thus, diet and hormonal status affect adipose cells size through two different metabolic pathways: lipogenesis and lipolysis respectively.