Studying the in vitro corrosion response of nanostructured TaN coatings in Hank's physiological solution

The goal of this research is to determine the effect of N₂ pressure to argon pressure on the microstructural analysis and corrosion behavior of nanostructured TaN deposited coatings using a reactive DC-magnetron sputtering (RDCMS) technique. The samples coated microstructure was studied by the X-ray diffraction (XRD) and scanning electron microscope (SEM), and elemental distribution was studied using energy-dispersive X-ray spectroscopy (EDS). To investigate the corrosion behavior of nanostructured TaN coatings, the potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) tests were performed in Hank's physiological solution. The results of different tests revealed that the coating with a content of 17.6% P_N2/P_Ar consisted of hexagonal and orthorhombic TaN phases and had denser microstructure and free pores. This coating showed superior corrosion behavior in comparison to the other ones. Also, the corrosion resistance of this coating raised by increasing the time of immersion from 48 to 168 h.     

Optimization of Dynamic Interfacial Tension for Crude Oil–Brine System in the Presence of Nonionic Surfactants

In this study, interfacial tension (IFT) is measured between brine and crude oil (a sample of heavy oil from an Iranian oil reservoir) in the presence of two nonionic surfactants, KEPS 80 (Tween 80) and Behamid D, at different concentrations in order to optimize the concentrations of the surfactants. The surface response method is used to design the IFT measurement experiments. The experimental design and optimization is performed using the IFT as an objective function and temperature, concentration, and time as independent variables. In addition to the IFT measurement, various experiments such as stability tests of the surfactants in NaCl brine solutions, adsorption experiments on the carbonated rock surface, and phase behavior tests are performed to investigate the behavior of KEPS 80 and Behamid D in the enhanced oil recovery process. At the end, a model using the response surface statistical technique is designed for optimization of the concentrations of the surfactants, and a surfactant molecular migration mechanism is used for explanation of the dynamic IFT variation versus time. In the case of IFT experiments, the effect of surfactant concentration (at 1000, 3000, and 5000 ppm) on the dynamic IFT is investigated. The experiments are performed at four temperatures (25, 40, 50, and 67°C). The results show that the oil–brine IFT values can be reduced to about 4 mN m⁻¹ in the presence of Behamid D and to about 1 mN m⁻¹ in the presence of KEPS 80 at low concentrations.     

Activation of Autophagy by Low-Dose Silica Nanoparticles Enhances Testosterone Secretion in Leydig Cells

Silica nanoparticles (SNPs) can cause abnormal spermatogenesis in male reproductive toxicity. However, the toxicity and toxicological mechanisms of SNPs in testosterone synthesis and secretion in Leydig cells are not well known. Therefore, this study aimed to determine the effect and molecular mechanism of low doses of SNPs in testosterone production in Leydig cells. For this, mouse primary Leydig cells (PLCs) were exposed to 100 nm Stöber nonporous spherical SNPs. We observed significant accumulation of SNPs in the cytoplasm of PLCs via transmission electron microscopy (TEM). CCK-8 and flow cytometry assays confirmed that low doses (50 and 100 μg/mL) of SNPs had no significant effect on cell viability and apoptosis, whereas high doses (more than 200 μg/mL) decreased cell viability and increased cell apoptosis in PLCs. Monodansylcadaverine (MDC) staining showed that SNPs caused the significant accumulation of autophagosomes in the cytoplasm of PLCs. SNPs activated autophagy by upregulating microtubule-associated protein light chain 3 (LC3-II) and BCL-2-interacting protein (BECLIN-1) levels, in addition to downregulating sequestosome 1 (SQSTM1/P62) level at low doses. In addition, low doses of SNPs enhanced testosterone secretion and increased steroidogenic acute regulatory protein (StAR) expression. SNPs combined with rapamycin (RAP), an autophagy activator, enhanced testosterone production and increased StAR expression, whereas SNPs combined with 3-methyladenine (3-MA) and chloroquine (CQ), autophagy inhibitors, had an opposite effect. Furthermore, BECLIN-1 depletion inhibited testosterone production and StAR expression. Altogether, our results demonstrate that low doses of SNPs enhanced testosterone secretion via the activation of autophagy in PLCs.     

On the probability of facing random breakdowns: a measure of networks’ vulnerability

In this paper, we study the vulnerability of networks in the case of random removal of individual nodes. To achieve this goal, a network reliability measure, the probability of messages facing malfunctions, has been proposed. The benefit of this measure is its capability of applying in a wide range of graphs. Moreover, it is well suited to human activities and foraging patterns of some sorts of animals, as they try to make an alternative path in the case of facing failures. We examine the most prominent communication networks such as meshes and tori; further, CAN, Chord, Petersen, PRU, and Hypergrid, which are well suited for P2P networks, have been investigated. In order to gain a better understanding of the studied networks’ vulnerability and easier evaluation of the proposed measure, an ant colony-based communication protocol has been presented. Experimental results verify the correctness of the proposed measure.     

ANFIS modeling of carbon dioxide capture from gas stream emissions in the petrochemical production units

Amino acid salt, especially sodium glycinate, was known as a new class of environment-friendly solution that is now being studied as a favorable alternative to amines. In the present collaboration, the Adaptive Network-based Fuzzy Inference System (ANFIS) was employed to estimate CO₂ loading capacity in the presence of aqueous sodium glycinate solution under broad ranges of temperature and pressure. The outcomes of suggested ANFIS model indicated their brilliant agreement with corresponding experimental values. The calculated values of mean relative error and R-squared were 2.93 and 0.988, respectively. Our suggested model can be of huge value for process engineers to have a simple and accurate tool in order to have rapid estimations of CO₂ solubility as a function of temperature, pressure, and mass composition of sodium glycinate solution.     

Optimal design of support parameters for minimum force transmissibility of a flexible rotor based on H∞ and H2 optimization methods

Rotating machinery support design with the aim of reducing the force transmitted to the foundation has significant importance regarding the various applications of this machinery. This article presents H_∞ and H₂ methods for calculating the optimum support flexibility and damping of flexible rotors to minimize force transmissibility in the vicinity of the rotor’s first critical speed. First, the governing equations for the Jeffcott rotor model mounted on flexible supports are derived and the optimal parameters for the supports are analytically achieved by H_∞ and H₂ optimization procedures. The proposed approach of the tuned damper support system is similar to that designed for dynamic vibration absorber optimization. The main objective of the H_∞ optimization is to minimize the force transmitted based on fixed-point theory and the mean square transmissibility of flexible rotor is minimized in the H₂ optimization design as analytical formulae. It is proven by numerical solution that the system optimization design can effectively minimize the force transmitted to the foundation. Comparison of two optimization than with H_∞.     

Comparison of blood lipid-lowering effects of olive oil and other plant oils: A systematic review and meta‐analysis of 27 randomized placebo‐controlled clinical trials

Objective: We aim to report a systematic review and meta-analysis of randomized controlled trials (RCTs) on effects of olive oil consumption compared with other plant oils on blood lipids.

Methods: PubMed, web of science, Scopus, ProQuest, and Embase were systematically searched until September 2017, with no age, language and design restrictions. Weighed mean difference (WMD) and 95% confidence interval (CI) were expressed as effect size. Sensitivity analyses and pre specified subgroup was conducted to evaluate potential heterogeneity. Meta-regression analyses were performed to investigate association between blood lipid-lowering effects of olive oil and duration of treatment.

Results: Twenty-seven trials, comprising 1089 participants met the eligibility criteria. Results of this study showed that compared to other plant oils, high-density lipoprotein level increased significantly more for OO (1.37 mg/dl: 95% CI: 0.4, 2.36). Also OO consumption reduced total cholesterol (TC) (6.27 mg/dl, 95% CI: 2.8, 10.6), Low-density lipoprotein (LDL-c) (4.2 mg/dl, 95% CI: 1.4, 7.01), and triglyceride (TG) (4.31 mg/dl, 95% CI: 0.5, 8.12) significantly less than other plant oils. There were no significant effects on Apo lipoprotein A1 and Apo lipoprotein B.

Conclusion: This meta-analysis suggested that OO consumption decreased serum TC, LDL-c, and TG less but increased HDL-c more than other plant oils.     

Texture development and microstructure evolution in metastable austenitic steel processed by accumulative roll bonding and subsequent annealing

In this paper, microstructure and texture development in a Fe–24Ni–0.3C metastable austenitic steel processed by accumulative roll bonding (ARB) and subsequent annealing was studied. Microstructural observations and crystallographic analysis were carried out by FE-SEM/EBSD. The results showed that elongated ultrafine-grained austenite having 300 nm in thickness surrounded by high angle boundaries was obtained after 6 cycles of the ARB process. It was found that 1-cycle ARB-processed specimen exhibited Copper ({112} 〈111〉) component as main texture, while by increasing the number of ARB cycles, it deviated to S component ({123} 〈634〉) at 2 cycles or Brass component ({110} 〈112〉) at 6-cycle. Annealing of 6-cycle ARB-processed specimen at 873 K for 1.8 ks resulted in the formation of an austenite with mean grain size of 2.5 µm having strong Cube recrystallization texture ({100} 〈001〉).     

Rapid response concentration-controlled desorption of activated carbon to dampen concentration fluctuations

Fluctuations in concentration of organic vapors in gas streams that are treated by devices such as biofilters or oxidizers make it challenging to remove the vapors from the gas streams in an efficient and economic manner. Combining adsorption with concentration-controlled desorption provides an active buffer between the source of vapors and the control device for better control of concentration and flow rate of the gas stream that is treated by the secondary control device, hence further enhancing the performance or reducing the size of the devices. Activated carbon fiber cloth is used with microwave swing adsorption to remove methyl ethyl ketone (MEK) from air streams and then provide a readily controllable feed stream of that vapor in air at a specified concentration and gas flow rate with steady-state tracking desorption. MEK was captured with >99.8% efficiency during the adsorption cycle. The MEK concentration during the regeneration cycle was readily controlled at concentration set-points between 170 and 5000 ppmv, within relative standard deviations of 1.8 and 4.9%, respectively, and at 20% of the gas flow rate that was treated during the adsorption cycle. Such capability of the system allows the secondary control device to be optimized for select constant concentrations and low gas flow rates that is not possible without such pretreatment.