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•Two chitosan derivatives (CS-1 and CS-2) were developed as eco-friendly inhibitors.•Both CS-1 and CS-2 act as mixed-type inhibitors for mild steel in acidic solution.•Their ...adsorption on mild steel surface follows the Langmuir adsorption isotherm.•CS-2 exhibit much higher inhibition effect than those reported chitosan inhibitors.•The theoretical calculations reveal the adsorption mechanism of CS-1 and CS-2.
Chitosan is a promising biopolymer to be used as environmentally friendly materials for corrosion protection. In this work, two novel chitosan derivatives (CS-1 and CS-2) were synthesized as eco-friendly inhibitors and their inhibitive performances for the corrosion of Q235 mild steel in 1 M HCl solution were evaluated by electrochemical measurements and surface characterization. It is found that the inhibition efficiency of CS-2 reaches 98.0 % with the concentration of 150 mg/L, which is much higher than those already reported chitosan derivatives. The relationship between the structures and high inhibition effect of the developed chitosan derivatives is revealed by theoretical calculations.
A solution culture experiment was conducted to investigate the effect of silicate on the yield and arsenate uptake by rice. Rice seedlings (Oryza sativa L. cv. Weiyou 77) were cultured in modified ...Hoagland nutrient solution containing three arsenate levels (0, 0.5 and 1.0 mg L⁻¹ As) and four silicate levels (0, 14, 28 and 56 mg L⁻¹ Si). Addition of Si significantly increased shoot dry weight (P = 0.001) but had little effect on root dry weight (P = 0.43). Addition of As had no significant effect on shoot dry weight (P = 0.43) but significantly increased root dry weight (P = 0.01). Silicon concentrations in shoots and roots increased proportionally to increasing amounts of externally supplied Si (P < 0.001). The presence of As in the nutrient solution had little effect on shoot Si concentration (P = 0.16) but significantly decreased root Si concentration (P = 0.005). Increasing external Si concentration significantly decreased shoot and root As concentrations and total As uptake by rice seedlings (P < 0.001). In addition, Si significantly decreased shoot P concentration and shoot P uptake (P < 0.001). The data clearly demonstrate a beneficial effect of Si on the growth of rice seedlings. Addition of Si to the growth medium also inhibited the uptake of arsenate and phosphate by the rice seedlings.
•The corrosion of N80 carbon steel in supercritical CO2 oilfield produced water was studied.•A pyrimidine derivative (DABTP) was developed as a high efficiency inhibitor.•A network structure of ...adsorbed DABTP molecules may be formed by hydrogen bonds.•Fluid flow leads to a decline in the corrosion inhibition performance of DABTP.•DABTP may desorb from the steel surface by the drag relating to fluid flow.
A pyrimidine derivative, 4,6-diamino-2-(benzylthio)pyrimidine (DABTP), was developed as an inhibitor for the corrosion of N80 carbon steel in supercritical CO2 containing oilfield produced water under static and dynamic conditions. Its inhibition effect and mechanism were investigated by electrochemical tests, quantum chemical calculations, and molecular dynamics simulations. DABTP exhibits high inhibition efficiency, with a decrease under dynamic conditions. A network structure of the adsorbed DABTP molecules may be formed by hydrogen bonds, which enhances the adsorption stability of DABTP. The adsorbed DABTP molecules may desorb from the steel surface due to the dragging action of flowing H2O molecules through hydrogen bonding.
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In the view of environmental protection and sustainable development, the application of green effective inhibitors for metal corrosion in industry field is of great significance. In ...this work, two thiourea functionalized glucosamine derivatives, 5-hydroxy-1-phenyl-4-(1,2,3,4-tetrahydroxybutyl)imidazolidine-2-thione (GA-1) and 1-phenyl-3-(2,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-3-yl)thiourea (GA-2), were synthesized as eco-friendly corrosion inhibitors for mild steel (MS) in 1 M HCl solution, and their inhibition performance were evaluated by electrochemical tests and surface analyses. The electrochemical tests and surface analyses indicate that both GA-1 and GA-2 have high inhibition performance. Especially for GA-2, the inhibition efficiency reaches 97.7% with a concentration of 0.64 mM. Theoretical calculations were also conducted to elucidate the adsorption mechanism of GA-1 and GA-2 on MS surface.
► The coatings exhibit higher hardness and E–C resistance than 304 stainless steel. ► E–C rate increases with flow velocity, particle size and sand content. ► E–C rate depends on amorphous phase ...contents, porosities and hardness. ► E–C process is mechanically dominated and attack arises from coatings defects. ► The coatings may be good candidates to solve E–C problems of marine pumps.
Corrosion and slurry erosion–corrosion (E–C) behaviour of FeCrMoMnWBCSi amorphous metallic coatings (AMCs) compared with 304 stainless steel was investigated by static electrochemical measurements and weight loss tests under rotating conditions in simulated seawater. E–C rates of the AMCs increased with flow velocity, particle size, sand content and NaCl concentration. The AMCs are preferentially attacked at coating defects. The superior E–C resistance of AMCs can be attributed to the high micro-hardness, alloying elements and amorphous microstructure. The AMCs with better slurry E–C resistance may be good candidates to solve the E–C problems of marine pumps in sand-containing seawater.
•The evolution of corrosion products of carbon steel in supercritical CO2 environment was determined.•The effects of corrosion products on the inhibition performance of pyrimidine derivative (DABTP) ...were studied.•The presence of corrosion products (Fe3C, FeCO3) reduces the inhibition effect of DABTP.•The adsorption mechanisms of DABTP on bare steel and corrosion products were explored by theoretical calculations.
The effect of corrosion products on the inhibition effect of pyrimidine derivative inhibitor (DABTP) for the corrosion of N80 carbon steel in supercritical CO2 oilfield produced water was studied by electrochemical measurements, surface characterization, and theoretical calculations. It is found that DABTP exhibits high inhibition performance for bare carbon steel, while the formation of corrosion products (Fe3C, FeCO3) after pre-corrosion reduces the inhibition effect of DABTP. Theoretical calculations indicate that DABTP preferentially adsorb on FeCO3 film instead of Fe surface, which results in the reduction of inhibition effect of DABTP after FeCO3 film formed on the carbon steel surface.
The effects of adding CeO2 nanoparticles on the formation and growth of interfacial intermetallic compounds (IMCs) between Sn-0.3Ag-0.7Cu-xCeO2 (x = 0, 0.05, 0.1, 0.15, 0.2, 0.3 wt%) (SAC0307-xCeO2) ...solders and Cu substrates during reflow soldering were investigated. Scanning electron microscopy (SEM) was used to observe the microstructural evolution of the solder joints and measure the thickness and grain size of the intermetallic layers. The results show that the thicknesses and grain sizes of the IMCs decrease with CeO2 nanoparticle addition to the SAC0307 solder and that these parameters decrease significantly at a particle concentration of approximately 0.15 wt%. At higher concentrations, the thicknesses and grain sizes of the IMCs increase slightly. The growth exponents for the IMC layers and grains are determined by curve fitting to study the growth kinetics of the IMCs during reflow soldering. The results reveal that the growth exponents of the IMC layers range from 0.335 to 0.374 and those of the IMC grains range from 0.302 to 0.318, thus suggesting that the growth of the IMCs is controlled by the combined kinetic processes of atomic interdiffusion, interfacial reactions, and grain ripening. These data also show that among the tested solders, the SAC0307–0.15CeO2 solder joint has the smallest growth rate and exhibits the most significant effects in IMC growth suppression and grain size refinement. Based on the theories of heterogeneous nucleation and adsorption, a mechanism for reducing the IMC growth rate by the addition of CeO2 nanoparticles to the SAC0307 solder is proposed.
•The formation and growth of IMC between SAC0307-xCeO2 and Cu were studied.•Addition of small amounts nano-CeO2 particles can suppress the growth of IMC layer.•SAC0307-0.15CeO2 solder joint has the smallest growth rate.•Nano-CeO2 particles can act as a grain refiner in the IMC formation and growth.•The growth of the IMC layer is controlled through combined kinetics process.
Cell deformability is an important biomarker which can be used to distinguish between healthy and diseased cells. In this study, microfluidics is used to probe the biorheological behaviour of breast ...cancer cells in an attempt to develop a method to distinguish between non-malignant and malignant cells. A microfabricated fluidic channel design consisting of a straight channel and two reservoirs was used to study the biorheological behaviour of benign breast epithelial cells (MCF-10A) and non-metastatic tumor breast cells (MCF-7). Quantitative parameters such as entry time (time taken for the cell to squeeze into the microchannel) and transit velocity (speed of the cell flowing through the microchannel) were defined and measured from these studies. Our results demonstrated that a simple microfluidic device can be used to distinguish the difference in stiffness between benign and cancerous breast cells. This work lays the foundation for the development of potential microfluidic devices which can subsequently be used in the detection of cancer cells.
In this work, a water chemistry model was developed by combining the activity coefficient-fugacity coefficient type solubility model and species equilibrium model to determine the mutual solubilities ...of CO2 and H2O, and the corresponding species concentrations in the CO2-mixed salts-H2O system (mainly contains Na+, Ca2+, Mg2+, K+, Cl-, and SO42-) with the temperature range of 15–250 °C, the pressure range of 1–600 bar and the salt molality range of 0–6 mol/kg. The computed solubilities of CO2 and H2O, and pH values show a good agreement with the experimental data in the literature, which indicates the high accuracy and accessibility of this water chemistry model. Based on this accurate water chemistry model, a comprehensive mechanistic model was established to predict the corrosion of carbon steel in supercritical CO2-containing formation water based on finite element method. The modeling corrosion rate agrees well with the measured corrosion rate.
•A water chemistry model was developed in the CO2-mixed salts-H2O system at different pressures and temperatures.•The modeling solubilities of CO2 and H2O, and pH value agree well with the experimental data in the literature.•A mechanistic model was established to predict the corrosion of carbon steel in supercritical CO2 environment.•The modeling corrosion rate is in good agreement with the measured corrosion rate.
•Population growth and climate change pose challenges to the sustainability of poultry farming.•Locally adapted local breeds are important sources of genes for environmental adaptability.•Differences ...in adaptability selection between chicken breeds can be exploited.•Genes and pathways related to local adaptation were identified.•This study may help to better understand the genetic basis of environmental adaptability.
Population growth and climate change pose challenges to the sustainability of poultry farming. The emphasis on high-yield traits in commercialized breeds has led to a decline in their adaptability. Chicken varieties adapted to the local environment, possessing traits that facilitate adaptation to climate change, such as disease resistance and tolerance to extreme weather conditions, can improve hybridization outcomes. In this study, we conducted an analysis of the population structure and genetic diversity of 110 chickens representing indigenous breeds from southern China and two different commercial breeds. Further, we performed comparative population genomics, utilizing nucleotide diversity and fixation statistics, to characterize genomic features of natural selection and to identify unique genetic traits and potential selection markers developed by indigenous breeds after adapting to the local environment. Results based on genetic diversity and population structure analyses showed that indigenous varieties exhibited high levels of genetic diversity. Commercial breeds that have been indigenously bred demonstrated higher levels of genetic diversity than those that have not, and breeds with different selection practices displayed significant differences in genetic structure. Additionally, we further searched for potential genomic regions in native chicken ecotypes, uncovering several candidate genes related to ecological adaptations affecting local breeds, such as IKBKB, S1PR1, TSHR, IL1RAPL1 and AMY2A, which are involved in disease resistance, heat tolerance, immune regulation and behavioral traits. This work provides important insights into the genomic characterization of ecotypes of native chicken in southern China. The identification of candidate genes associated with traits such as disease resistance, heat tolerance, immunomodulation, and behavioral traits is a significant outcome. These candidate genes may contribute to the understanding of the molecular basis of the adaptation of the southern native chicken to the local environment. It is recommended that these genes be integrated into chicken breeding programs to enhance sustainable agriculture and promote effective conservation and utilization strategies.
