Effect Of NaCl Solutions Research Articles

Fractional calculus-based creep model of HFRP double lap joint subjected to NaCl solution

Epoxy adhesion is one of the major joint technologies of FRP (Fiber Reinforced Polymer) and its long-term performance has been proven a key to its practical engineering application. In this paper, the effect of NaCl solution on the creep deformation of HFRP (Hybrid Fiber Reinforced Polymer) double lap joints is studied. To simplify the creep behavior capturing process, a fractional calculus-based creep model with a concise mathematical expression and a few fitting parameters is proposed, eliminating the need for complex series-parallel spring-dashpot combinations. The fitting results show excellent agreement with the test data, indicating the effectiveness of the proposed model. Creep leads to obvious redistribution of stress and strain of the adhesive lap joint. Stress and strain concentration can be effectively reduced by increasing the thickness of adhesive or using fillet.

The influence of NaCl salt stress on the yield and quality of the essential oil from two varieties of rose-scented geranium (Pelargonium graveleons L’Hér.)

The pot experiment was carried out in greenhouse conditions by using two popular varieties viz., CIM-Pawan and CIM-Bio-G-171 of rose-scented geranium to know the effect of NaCl solution on the morphological traits, essential oil content, chemical composition, and yield. The plants were exposed to varying levels of NaCl solutions viz., 0, 50, 100, 150, and 200 mM. Normally, the geranium essential oil is rich in isomenthone, geraniol, citronellol, linalool, geranyl formate, citronellyl formate, and 10-epi-γ-Eudesmol. However, the quality of geranium oil is determined by the ratio of geraniol and citronellol (approximately 1:1). The plants were treated with different concentrations of NaCl viz., 100, 150, and 200 mM, and different morphological, oil content, and oil quality parameters were measured. The analysis of variance of morphological, as well as oil content and constituents showed significant variations in both varieties. As results indicated that some components trend in the positive direction and some in the negative direction. Isomenthone and citronellyl formate contents were increased, whereas, geraniol and linalool contents were reduced significantly as the concentration of salt increased in both the varieties. Citronellol and geranyl formate contents were not affected by different salt concentrations. All the Morphological traits were affected and decreased at the varied level of salt concentrations. A higher concentration of NaCl reduced the leaf length, leaf width, and herb yield in both varieties. However, the oil content reduction started even at 50 mM salt concertation, however, the reduction was more in 100, 150, and 200 mM NaCl concentrations. In general, based on the present experimental results, the morphological, quality parameters of the geranium crop were affected even with the NaCl concentration of more than 50 mM. Irrigation of NaCl-containing water (soil salinity or water salinity) may provide ways to alter the concentration of essential oil, compositions and yield, and yield-related characters in rose-scented geranium. This study showed that soil salinity might modulate the biosynthesis of essential oil constituents in rose-scented geranium.

Effect of NaCl Solution and Simulated Concrete Pore Solution Environment on the Efficiency of Steel Bar Energized Corrosion.

As the main problem of the durability deterioration of concrete structures, the corrosion of steel bars is usually made by the method of electrified corrosion with a short cycle and low cost. However, there is a big difference between the actual corrosion depth and the theoretical corrosion depth after the reinforcement is electrified. In this paper, through the accelerated corrosion test of steel bars, the change law and influence factors of corrosion efficiency of steel bars in concrete simulated pore solution and NaCl solution are studied. The test results show that the corrosion efficiency of reinforcement in the NaCl solution is higher than that in the concrete simulated pore solution, and the corrosion efficiency in the NaCl solution changes in two stages with the corrosion degree of reinforcement. The corrosion efficiency of concrete in the simulated pore solution decreases with the increase of corrosion degree of reinforcement, which is more significant than that in the NaCl solution. Under the same conditions, the corrosion efficiency is higher in the chloride ion solution with high concentration, and the influence of chloride ion concentration change in the simulated pore solution of concrete on the corrosion efficiency is more significant. The corrosion efficiency of reinforcement under low current density is higher than that under high current density.

Fatigue life prediction of pre-corroded AZ31 magnesium alloy based on surface topology

This research explored the corrosion effect of NaCl solution on the surface quality of AZ31 magnesium alloy. Cubic-shaped specimens were immersed in standard 3.5% NaCl solution for 1, 2, 3, and 4 hours. The size of corrosion pits, fatigue crack propagation area, and surface topology were characterized. Fatigue tests were carried out on pre-corroded AZ31 specimens under different stress amplitudes. The correlation between the corrosion time and the virtual crack size was obtained. The virtual crack size is a new parameter that can relate the corrosion to the fatigue life. A new model was proposed to map the surface topology on the virtual crack size of pre-corroded AZ31 magnesium alloy. The fatigue life of 1-4-hour pre-corroded AZ31 specimens could be predicted accurately by this new model. The Levenberg-Marquardt and curve-fitting methods were used to obtain the constant parameters. The relative error between the crack size corresponding to the immersion time and the virtual crack size calculated by the proposed model was less than 1%.

Experimental study on fracture properties of CFRP-to-concrete interface subject to salt water

The mechanical property degradation of bonding interface between FRP (fiber reinforced polymer) and concrete has an adverse effect on the performance of FRP strengthened concrete structures. In order to increase the durability database and have a better understanding of the degradation mechanism, the effect of NaCl solution on CFRP (carbon fiber reinforced polymer)-to-concrete interface under mode I and mode II loading is studied by using pulling test and wedge driving test method, respectively. The relationship between salt water content and fracture energy release rate of CFRP-to-concrete interface is studied. Because the interfacial salt water content cannot be measured directly, a finite element simulation is established based on salt water uptake tests of component materials. The results show that both mode I and mode II fracture energy release rate of CFRP-to-concrete interface decrease nonlinearly with salt water content, and the change of failure mode from debonding within the concrete layer to cohesive failure along the interface is also observed.

Oedometric compression and thermal volume behavior of compacted Gaomiaozi bentonite saturated with salt solution

Saline solution has considerable influence on the thermo-hydro-mechanical behavior of compacted bentonite. In this study, the effects of NaCl solution on the swelling deformation, oedometric compression, and thermal volume behavior of compacted Gaomiaozi bentonite were investigated. Results show that compressibility of the specimens decreases with increasing NaCl concentration of the presaturation solution. At an overconsolidation ratio OCR=1 with a vertical pressure σv=0.1 MPa and at OCR=3 with σv=0.1 MPa, the specimens exhibited contraction during heating below the transition temperature, followed by dilation. A larger vertical pressure led to a higher transition temperature (at which the thermal strain turns from contraction to dilation). However, the specimens exhibited only thermal dilation at OCR=10 with σv=0.1 MPa and at OCR=2 with σv=0.5MPa. Additionally, for a given vertical pressure and presaturation solution, the specimens with a higher OCR exhibited a larger irreversible dilation after a thermal cycle. Moreover, the influence of the presaturation solution on the thermal volume change is non-monotonic. A dilute solution (NaCl solution of 0.1 mol/L) and high salinity solution (NaCl solution of 1.0 mol/L) markedly promote the thermal expansion. These experimental trends can be attributed to the fact that attenuation of the diffused double layer repulsion and electrostatic interaction as well as the reduction of the free water at high saline conditions harden the soil.

Analytical Study of the Effect of NaCl Solution on Fatigue Resistance of Rotating Shafts

Dynamic shafts subjecting to salty rain water, especially in places with no rain water drainage networks, is undesirable because this media causes corrosion of the parts of shaft that increases as increasing of shaft immersion in a salty media (NaCl) also, increasing of concentration which in turns reducing number of operation runs. Increasing salt concentration from 3% to 6% NaCl results in decreasing of operation runs from 25600 to 17100 runs. Also, increasing salt concentration leads to raise the effect of alternating stress that makes strain hardening factor drop to 0.45 and ratio of dynamic shear stress to static one raise to 2.44 that affects shaft metal performance to resist fatigue. Samples were also, treated by oxy acetylene surface hardening and were cooled by immersion in oil then immersion in 6% NaCl salty solution, the results showed that number of operation runs before failure had increased up to 71022, the effect of alternating stress had decreased down to 6100 N/m2, surface strain hardening factor had increased up to , also ratio of dynamic shear stress to static one had decreased down to 0.839. This is a good indicator of the effectiveness of surface hardening process of shaft parts that subject to salty rain water during maintenance operations.

Effects of NaCl solution on the swelling and shrinkage behavior of compacted bentonite under one-dimensional conditions

Because of its low hydraulic conductivity, high swelling capacity, and good adsorption properties, Gaomiaozi (GMZ) bentonite has been proposed as a suitable buffer/backfill material for construction of artificial barriers in deep geological repositories for high-level nuclear waste (HLW) disposal in China. By varying the concentration of NaCl solution and total suction, the swelling and shrinkage characteristics of compacted GMZ bentonite were studied under one-dimensional conditions. Results show that the swelling strain of compacted GMZ bentonite decreases as the concentration of NaCl solution increases under one-dimensional conditions. During drying with suction control by vapor phase technique, the density increases with suction. Simultaneously, the sample saturated with salt solution has a larger void ratio than that of the sample saturated with distilled water under the same suction. The void ratio and water content of the samples decrease with increasing suction. For a given suction, the sample saturated with salt solution has a higher degree of saturation than the sample saturated with distilled water. With the obtained water content (w), void ratio (e), and the degree of saturation (Sr), soil-water retention curves (SWRCs) were calculated for samples initially hydrated with different concentrations of NaCl solution. The SWRCs reveal that the sample with salt solution has higher water retention capacity than the sample with distilled water. A modified SWRC equation was proposed to account for the effect of NaCl solutions on the drying process of compacted GMZ bentonite under one-dimensional conditions. The results confirm that the modified SWRC equation can effectively describe the SWRCs of compacted GMZ bentonite considering the effects of NaCl solutions.

Effects of NaCl Solution on the Physicochemical Changes of ‘Surimi’ from Anchovies (Clupeonella spp.) During the Frozen Storage

Aims: In this study, the effect of washing process on shelf-life of surimi of Clupeonella spp. with cold-water, solution of 1.5 and 3 percent strength was investigated. Study Design: Data collected were analyzed by one-way analysis of variance (ANOVA). Place and Duration of Study: Costal line of Caspian sea near the Bandar Anzali, Gillan province of Iran. Methodology: A total of 100 kg fish were captured in the Caspian sea near the Bandar Anzali coast. The data collected from the surimi during the storage time. Results: The shelf-life of surimi was investigated by measuring total volatile baseOriginal Research Article British Journal of Applied Science & Technology, 4(4): 693-704, 2014 694 nitrogen (TVB-N), peroxide value, total count of bacteria and sensory test for 80 days. The results showed the changes of TVB-N for control, 1.5% and 3% NaCl solution were 35, 20 and 19 mg N 100g, respectively. On day 80, the total plate counts in control, samples washing with 1.5% and 3% NaCl solution were 9.4, 7.5 and 7.3 log CFU/g, respectively and the level was slightly higher than the permissible limit after 60 days. Conclusion: Based on the present results, washing with 1.5 and 3% NaCl solution treatment on Anchovies (Clupeonella spp.) leads to a retention of the good quality characteristics for longer and an extension of the shelf life during frozen storage.

Improvement in Wear and Corrosive Wear Resistance of Ti6Al4V Alloy by Double Glow Plasma Surface Alloying with W-Mo and W-Mo-N

W-Mo and W-Mo-N surface-modified layers on Ti6Al4V alloy were obtained using a double glow plasma surface alloying technique. The morphology, microstructure, and chemical composition distribution of the modified layers were analyzed by scanning electron microscope, Xray diffraction, and glow discharge optical emission spectrometry. The hardness and toughness of the modified layers were measured using a micro-hardness tester, and dynamic repeating press equipment. The wear resistance in ambient air and the corrosive wear resistance in NaCl solution were evaluated using a ball-on-disk wear tester. The results show that W-Mo and W-Mo-N surface modified layers are composed of the alloying layers which vary in composition and phase form along the depth. A microhardness gradient was observed in the modified-surface layers. The surface hardness of the W-Mo-N and W-Mo modified layers was 25.3 and 14.2 GPa, which is seven-fold and 3.9-fold harder than the Ti6Al4V substrate, respectively. W-Mo and W-Mo-N surface-modified layers significantly improved the wear and corrosion resistance of Ti6Al4V. It seems that the wear resistance of W-Mo and W-Mo-N surface-modified layers in NaCl solution is better than that in ambient air owing to the strong lubricating effect of NaCl solution and the excellent corrosion resistance of the modified layers.

Equilibrium conditions for CO 2 hydrate in porous medium

Experimental phase equilibrium conditions data for carbon dioxide (CO 2) hydrate in porous medium with the presence of sodium chloride (NaCl) solution were investigated in this study. The experimental data were generated using graphic-method in presence of solutions contained (0, 0.2, 0.4, 0.6, and 0.8) mol/L NaCl. The results indicated the increase of NaCl concentration caused the enhancement in the equilibrium pressure of CO 2 hydrate as the pore size and the temperature were kept the same. Effects of NaCl solutions on CO 2 hydrate equilibrium conditions could be neglected when the temperature is lower than ice point. An improved model was used to predict CO 2 hydrate equilibrium conditions, and the predictions showed good agreement with experimental measurements.

The effect of NaCl solution with different concentration on the resuscitation of hemorrhagic shock

To observe the clinical results of different concentration NaCl solution in hemorrhagic shock resuscitation. The 75 cases with hemorrhagic shock were divided into five groups by means of random number table. Treat the cases with 0.9% (control group), 3%, 4.5%, 6% and 7.5% NaCl solution, respectively. Observe the changes of BP, HR, blood gas, renal function, electrolyte concentration of plasma, before and after treatment. After transfusion, compared with groups of 0.9% NS, the mean BP of patients in other four groups rise more quickly but only the group of 4.5% can last 30 minutes (P < 0.05), and K(+) of plasma in groups of 6%, 7.5% NS decline more obviously (P < 0.05), the group of 4.5% maintain the best lever. The mean BP of patients rise quickly and continue for a long time, in the group of 4.5%. Meanwhile the internal environment of the body maintain relatively stable in the group of 4.5%.

Effect of NaCl solution as pore water on the residual shear strength and index properties of soil from mudstone areas

NaCl solution has significant effect on the residual shear strength of soil from mudstone areas. Soil samples were collected from the intact rock (unsheared zone) and sliding surface (sheared zone) of five mudstone landslide areas. Mixtures of distilled water and the intact rock possessed higher electric conductivity than those of distilled water and the sliding surface soil. When these samples were leached with distilled water for five times, they showed a substantial decrease in the electric conductivity. The residual shear strength varies according to the NaCl concentration in the pore water. Ring shear tests were also carried out in the commercial standard clays as bentonite and kaoline to understand the shear strength characteristics of the mudstone soils. When bentonite was treated with NaCl solution as pore water, it showed about three times increase in residual shear strength and decrease to one quarter in liquid limit. The effect of NaCl solution as pore water in kaoline was comparatively low. The residual shear strength of soil from mudstone area also increased when it was treated with NaCl solution as pore water. The result of the X-ray diffraction analysis showed that the proportion of smectite is higher than that of kaolinite in the residual soil from mudstone. These smectite minerals were found to be highly sensitive to NaCl solution. Because of the sensitive changing character of smectite minerals to NaCl solution, soil samples with NaCl rich water showed lower value in consistency limits and higher value in the residual shear strength compared to soil samples with distilled water. The findings suggest that the residual shear strength and index properties should be considered as variable properties as a result of the change in the pore water. Such properties are useful to understand frequent re-activation of the landslide occurring in the mudstone areas.