Sharif Digital Repository

Asphaltene precipitation and deposition are sources of a number of problems for petroleum industry. Thus, solving the problem of precipitation and deposition is very important. In order to measure deposition level, study of other asphaltene flocculation is vital; since there is a time interval between precipitation and deposition. Use of chemical inhibitors is one of the best methods for prevention of asphaltene precipitation that could postpone precipitation point and prevent formation of huge flocculations. In this study, effects of asphaltene flocculation size on deposition with or without using inhibitors were investigated. In this regard, QCM was used for measuring the amount of... 

In this study, the effect of green coffee extract powder, as a green corrosion inhibitor of steel in a concrete simulation environment was investigated. In this study, the green coffee extract was obtained by the Maceration method and its performance was investigated by weight loss method, electrochemical methods including Polarization, Electrochemical Impedance Spectroscopy. Scanning Electron Microscopy images were also used to visualize the corroded areas. The results of the polarization test showed that 450 mg/lit of coffee extract powder at 25 °C has the corrosion inhibiting efficiency of about 82% and the corrosion rate of the bare sample reduced from 6 to 1.16 mpy. The dosage of 550... 

Many experimental and theoretical studies have suggested that zinc binding to Aβ could promote amyloid-β aggregation and reactive oxygen species (ROS) production induced by AD disease. Therefore, the introduction of multifunctional drugs capable of chelating zinc metal ion and inhibiting Aβ aggregation is a promising strategy in the development of AD treatment. In present study molecular docking and molecular dynamics (MD) simulations were used to evaluate the efficacy of two new bifunctional peptide drug, composed of two different domains: C-terminal hydrophobic region of Aβ and Zn2+ chelator region. To evaluate the multifunctionality of the ligands, a comprehensive set of MD simulations up... 

SHP2 has been reported as a critical non-receptor phosphatase enzyme that plays crucial roles in numerous disorders like cancer. The previous studies on this enzyme showed that inhibiting the action of the enzyme comes as a way of controlling enzyme activity. SHP099 was discovered as an Allosteric inhibitor of the enzyme with the most inhibitory effect among all of the studied compounds. In this study we aimed to design novel dipeptide-and sugar-based inhibitors for the allosteric binding site of this enzyme with in-silico studies including docking, molecular dynamic simulation, and free binding energy analysis. Our novel designed drugs possess enough binding properties, low toxicity, and... 

Quartz crystal microbalance (QCM) is a piezoelectric sensor used to measure the mass of adsorbent deposition at the nanoscale on the surface, real-time and non-destructively. The QCM technique has recently gained extensive attention in the chemical and oil industries and other research fields such as medicine and nanotechnology due to its various applications in the advanced sciences. This technique provides comprehensive insights to scientists in the field of phase equilibrium of low-solubility and solid-liquid interactions. Therefore, many attempts have been made to investigate the interaction phenomenon mechanistically using QCM.Scale formation can have many adverse effects, and... 

This project aims to design a drug to fight leukemia and some autoimmune diseases having few side effects. These drugs are composed of natural sugar and amino acid structures. Among the various treatments available, drug structures as inhibitors of enzymes involved in cancer-related cellular processes is an important treatment. Methotrexate is one of the most widely used anticancer drugs in the last half-century and treats leukemia and many autoimmune diseases such as psoriasis. It is a derivative of folic acid (vitamin B9) and one of the drugs with specific properties. It is an anti-folate whose anti-metabolic effects can help kill cancer cells. One of the problems with using this drug to... 

In this study, MOF / PAN hybrid nanoparticles have been used as active anti-corrosion inhibitors for the first time. At first, UIO-66, PANI, and hybrid nanoparticles were synthesized based on different weight percentages of UIO-66. Their functional groups, crystal structure, nanoparticle morphology, porosity structure, stability and thermal performance were investigated using FT-IR, XRD, FE-SEM, BET, and TGA analyses, respectively. The type of nanoparticle structure formation was investigated by TEM images. The particle size distribution along with their surface charge was determined using DLS analysis. Inhibitory properties of nanoparticles were evaluated by TOEFL polarization method and... 

The present work focuses on the sustainable development of an intelligent self-healing anticorrosion coating using nanocontainers based on the aluminium oxide nanostructure-pomegranate peel extract-Ce3+ (Ce-PPE@Cat). The Ce-PPE@Cat nanopigment was introduced into the epoxy film (Ep) to achieve a smart barrier/ self-healing anti-corrosive property. To this end, a couple of characterization tests, including FT-IR, TGA, and, BET have been carried out to investigate the Ce-PPE@Cat nanopigment structure/composition. The effectiveness of the anti-corrosion performance of the established coatings was confirmed by EIS, FE-SEM, and accelerated salt spray test. Furthermore, EIS studies revealed that... 

In this research, a coating was created on the steel surface using the network structure of zeolite imidazolate-8 (ZIF-8) and its effect on the corrosion behavior of steel was investigated. Then, the effect of two coupling agents, mercaptopropyltriethoxysilane (MPTES) and aminopropyltriethoxysilane (APTES) on the coating and its anti-corrosion properties was investigated. Then, in order to make a hydrophobic coating, the substrate was first coated with ZIF-8 and then a combination of silica nanoparticles plus hexamethyldisilazane (HMDS) and polymethylhydrogensiloxane (PMHS) was added to the initial solution and then coating was done. As a result of this process, the contact angle of water... 

Cyclin-dependent kinases 2 (CDK2) are one of the important proteins in cell cycle regulation and progression. In many human cancer cells, the activity of CDK2 kinases and their related subunits are deregulated, leading to tumor formation. Therefore, inhibition of this enzyme as an attractive therapeutic target can cause cancer cell death in glioblastoma and diffuse large B-cell lymphoma. Using new pharmaceutical structures based on sugar and amino acids is a new approach due to its greater efficacy and fewer side effects than old drugs. In this research, according to the structure of Flavopiridol as one of the CDK2 inhibitors, the active site of CDK2, and the structure of ATP molecule, 50... 

Cellulose nanocrystals as a reinforcement in polymer nanocomposites are part of current research for reasons such as source renewable, biocompatibility, nanoscale dimensions, high specific surface area, and surface chemistry. This research used cellulose nanocrystals as a corrosion inhibitor carrier in epoxy-based composite with 1% by weight. In order to load the corrosion inhibitor, firstly, cellulose nanocrystals were surface modified by aniline so that they can spread well in the hydrophobic epoxy matrix. Different corrosion inhibitors were tested for adsorption on the surface of cellulose nanocrystals modified with polyaniline, but finally the acidic agent of phosphoric acid showed... 

In this research, it has been tried to use alumina and magnesia nanoparticles to hydroxyapatite nano powder, a three-component coating, with corrosion resistance, adhesion and desirable biocompatibility on the 316 stainless steel substrate, by electrophoretic method. It should be applied at 3 voltages of 10, 30 and 50 volts and for 3 minutes. TEA was used as a dispersing agent and ethanol as a solvent to prepare the suspension. Alumina nano powder was added to nanohydroxyapat in two amounts of 10 and 20% by weight and 20% was optimized as the amount, and magnesia nano powder was added to the composition in three amounts of 1, 3 and 5% by weight, which was 3% by weight of the results Was... 

This project aims to design a novel structure that can inhibit the activitvation of the c-Met enzyme using amino acids and sugars building blocks. The c-Met enzyme is a receptor tyrosine kinase that plays a significant role in several biological activities such as cell proliferation, survival, and invasion. Abnormal activity of the enzyme is linked to the progression of various types of cancer, including breast, lung, liver, and stomach cancer. The proposed sugar amino acid conjugate structures is expected to increase stability amino acids and dipeptides in the physiological environment, improve membrane permeability via active transport mechanism, and reduce toxicity and side effects by... 

Since the beginning of oil, gas and gas condensate production, the prediction of the formation of mineral scales in different operating conditions has been a serious challenge. Mineral scale are solid particles that are separated from the free water in the reservoir due to changes in the production conditions in terms of temperature and pressure or the fluid composition of the production fluid of reservoir, and there is a possibility of their deposing on the wall of the well column and in the production system, where The way of production from reservoirs faces serious risks. free water, which is permanently entering the pipeline, contains all kinds of salts in the structure of the fluid... 

In this research project, the aim was to investigate the potential of olive leaf extract as an eco-friendly inhibitor for enhancing the corrosion resistance of reinforcing steel in simulated geopolymer concrete pore solution (GCP) containing chloride ions. The inhibitory effects of olive leaf extract were evaluated using various electrochemical techniques as well as scanning electron microscopy. The main phenolic compounds present in olive leaf extract were identified using high performance liquid chromatography (HPLC). Moreover, the elements and chemical bonds present in the surface passive film of the steel bar immersed in the olive leaf inhibiting system were characterized using...