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The dissolution–ionization–diffusion–deposition (DIDD) model was used for developing a corrosion–resistant stainless steel (SS) by the means of alloying and the guidelines for the process were proposed. The novel HP–13Cr–Cu SS was designed to resist corrosion in H 2 S–containing geothermal environment. The results indicated that the preferential deposition of CuS promoted the heterogeneous nucleation rate of Cr 2 O 3 , FeCr 2 O 3 , and FeS, which formed denser corrosion product layer. As a result, this alloy exhibited a low corrosion rate and a high sulfide stress cracking (SSC) resistance. The results were consistent with the theoretical calculation conducted by the DIDD model. • The DIDD model established the bridge between thermodynamics and kinetics of electrochemical corrosion. • The guidelines for designing corrosion–resistance stainless steel were proposed by means of micro–alloying. • A novel HP–13Cr–Cu SS was designed based on the DIDD model to resistant the H 2 S corrosion. • The testing results verified HP–13Cr–Cu SS gained the low corrosion rate and high SSC resistance. [ABSTRACT FROM AUTHOR]

The dissolution-ionization-diffusion-deposition (DIDD) model is corrected by a cathodic process with the feature of complex equilibrium and deposition competition. CO 2 /H 2 S corrosion of steel is taken as an example to better understand whether the main factor controlling the corrosion is CO 2 , H 2 S or both. The preliminary assessment reveals that when the rate of nuclei is less than 10 % of the total, the corrosion is controlled by only one factor. Furthermore, the calculated results also have a good agreement with morphology and weight loss experiments. This study makes a significant contribution to promoting the application of DIDD model. • The DIDD model is corrected with a complex cathodic process and deposition competition. • When the FeCO 3 nuclei rate is less than 10 %, the corrosion is controlled by H 2 S. • When the FeS nuclei rate is less than 10 %, corrosion is controlled by CO 2 , otherwise controlled by both. • Taking CO 2 /H 2 S corrosion of 20 steel as an example to validate the corrected model. [ABSTRACT FROM AUTHOR]

• The effect of temperature and CO 2 pressure on the stress corrosion cracking of HP-13Cr stainless steel was proposed. • The stress and strain concentration in pitting area was studied by finite element analysis. • A pitting-to-cracking model has been built to elucidating the initiation of stress corrosion cracking. • A "HTHP-SCC electrochemical system" was developed to conduct the electrochemistry measurement under applied stress. The stress corrosion cracking of HP-13Cr stainless steel in the geothermal environment was studied by experimental measurements and modeling calculations. The stress corrosion cracking susceptibility of HP-13Cr stainless steel increases with both temperature and CO 2 pressure, and shows a synergistic effect greater than the temperature or CO 2 pressure does singly. The fracture morphologies presented quasi-cleavage fracture characteristic in the geothermal environment. The stress corrosion cracking mechanism is dominated by the anodic process. The critical stress intensity factor for stress corrosion cracking was measured and the pitting-to-cracking process was clarified by a mechanism model. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe 3 O 4 @AP-Au NPs reduced spermatogenic cells apoptotic indexes and prostate weight gain. • Fe 3 O 4 @AP-Au NPs improved the sperm percentage with total motility, normal morphology, and progressive motility and Johnsen's and Miller's criteria. • The particles are almost homo-morphic and are sized between 30 and 50 nm. In the current years, conjugated bio-nanomaterials involving magnetic core are interested as promising platform in modern generation biological composites for the treatment of several types of inflammations such as epididymo-orchitis. In this regard, we described a novel Au NPs supported apple pectin (AP) modified magnetic Fe 3 O 4 nanoparticles as a novel nano-biocomposite (Fe 3 O 4 @AP-Au NPs). The post-synthetically modified biogenic material was analyzed in details over a number of physicochemical methods like, Fourier transformed infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), elemental mapping, X-ray diffraction (XRD) and inductively coupled plasma-optical emission spectroscopy (ICP-OES). In the in vivo part, we divided 80 Wistar rats into five following groups (n = 16 per group): a. Control-intact group, b. Vehicle group, c. Fe 3 O 4 @AP-Au NPs group, d. epididymo-orchitis group, and e. epididymo-orchitis/ Fe 3 O 4 @AP-Au NPs group. We assessed relative sex organs weight, body weight, germ cell apoptosis, Johnson's criteria, sperm parameters, and germ cell layers number. Acute epididymo-orchitis raised the prostate relative weight and seminal vesicles and apoptotic indexes of spermatogenic cells, also decreased the quality of sperm such as sperm concentration, normal sperm percentage, and total motility and Johnsen's and Miller's scores. Fe 3 O 4 @AP-Au NPs group reduced spermatogenic cells apoptotic indexes and prostate weight gain and improved the sperm percentage with total motility, normal morphology, and progressive motility and Johnsen's and Miller's criteria. [ABSTRACT FROM AUTHOR]