Sharif Digital Repository

Food rich in antioxidants plays an essential role in the prevention of diseases and plum is an example of these food .Our objective in this research was to determine the amount of variation in total phenolic compound present in plum fruits, so that it can be utilized in breeding programs to enhance the health benefits.Total phenolic content of the fruits, which were determined in 7 genotypes by using 4 solvents (water , methanol , ethanol , acetone) to extract phenolic compound, ranged from 178 to 497 mg/100 gr for methanol, from 306 to 407.33 mg/100 gr for ethanol , from 300 to 392 mg/100 gr for acetone and from 193 to 281.25 mg/100 gr for water. The results show that the methanol... 

Phenolic foam are common among the polymeric foams, they can be prepared from resole resin, it is possible to apply an external thermal reservoir to achieve curing and expansion simultaneously, or use an acid as curing agent, without external heating, and utilize heat of curing reaction for expansion of foaming mixture. Because of economic aspect of view and ease of processing the latter method is preferable. However, the existing problem is that the resole resin must be so active to react with acid curing agent and produce suitable heat. Also,physical properties of resin such as viscosity have a great importance to the efficiency of resin in foam processing.In the present work, resole... 

This project surveys bioregeneration of granular activated carbons contaminated with phenolic compounds. To carry out this survey, the procedure of phenol absorption on the surface of activated carbon was studied and their adsorption isotherms were calculated. In the first step, newly activated carbon was contaminated with phenol solution and optimum amount of carbon in phenol elimination was 0.5g. Then, the effect of time contact on phenol elimination was studied and eventually 1 hour of time contact was determined as the equilibrium time of phenol adsorption. In the second step, kinetics of adsorption of phenol and different stages of adsorption were studied. The results of this study... 

Many industries such as olive oil mills, petroleum refineries, petrochemical plants and oil field operations generate saline wastewaters containing phenol. The aerobic moving bed biofilm reactor (MBBR) was investigated in this work in order to assess its performance for the degradation and chemical oxygen demand (COD) removal of phenol as the sole substrate from saline wastewater. The effect of inlet concentration of phenol (200–1200mg/L), hydraulic retention time (8–24 h), inlet concentration of salt (10-70gr/L), organic shock loading, hydraulic shock loading and salt shock loading were evaluated on the performance of two 10-liter MBBR seeded with mixed culture of active biomass... 

Nowadays , application of enzymes as biocatalysts in wastewater treatment processes is increasing. It is economically important to reuse enzymes and increase their stability in these types of processes. Therefore, was immobilization of enzymes and using them in wastewater treatment have a great importance.In this project, Horseradish peroxidase enzyme, whose effect on phenol removal reactions in other studies has been proven before, was immobilized on the alginate-coated magnetic nanoparticles, to investigate the effect of immobilization on the stability and function of this enzyme for phenol removal. The enzyme was immobilized at the temperature of 25 ° C and pH = 8, according to the data... 

In this study different kinds of solid phase microextraction fibers based on sol-gel technology were employed for extraction and pre-concentration of phenol in occupational air and oxadiargyl in plant and environmental samples. In the first work, a SPME method followed by on-fiber derivatization and gas chromatography-mass spectrometry detection (GC-MS) was developed for the analysis of phenol in the air. The application and feasibility of three different sol-gel based SPME fibers with different polarities, polar and non-polar poly (dimethylsiloxane) (PDMS) and polyethylene glycol (PEG), have been studied. Influential parameters such as fiber coating type, type of derivatization reagent,... 

In the recent decade, composites have been used in safety system of automobiles due to important characteristics such as high wear resistant and durability, low weight and also low noise pollution, stable friction coefficient, availability and low cost. In recent years, composites have attracted the attention of brake pads manufacturers because of their appropriate thermal and mechanical properties. Fibers play an important role in these material. Carbon fiber due to its features such as high strength, acceptable module, proper heat transfer coefficient and excellent resistant against thermal degradation has been considered by the experts but there is not any comprehensive research on... 

In this research, the capability of an aerobic moving bed biofilm reactor (MBBR) for removal of phenol from Arak refinery dilute wastewater has been investigated. A cubical MBBR with approximate capacity of 10 liters was filled with Kaldnes-K1 biocarriers at filling ratio at 50 percent. Moreover, The MBBR which filled with actual refinery wastewater, combined with Flocculation and Coagulation in order to removing more COD, turbidity and TSS and also reaching to criterion that water can be used by cooling tower. The effects of Phenol concentration (10-100 mgl-1), COD concentration (50-500 mgl-1), Hydraulic Retention Time (HRT) (4-12 h) and Phenol shocks on the performance of MBBR were... 

Recently nanodiamond has drawn a vast attention of researchers due to exceptional mechanical properties. However, nanodiamond tendency to aggregation in polymer matrix restricts its reinforcement properties. In this research, novolac phenolic resin nanocomposites reinforced by nanodiamond were prepared by solution blending method and their mechanical properties were investigated. In order to prevent nanodiamond aggregation, ultrasonic treatment was used and nanodiamond surface was modified with acid and amine functional groups. FTIR and TGA were performed in order to investigate nanodiamond surface and confirmation of existence of acid carboxylic and oleylamine (OLA) groups. Produced... 

In this research the effects of addition of clay in phenolic glass fiber reinforced composite has been investigated. Layered clay/phenolic nanocomposite resin systems were first prepared with 0.5, 1.5 and 2.5 wt% of Cloisite Na+ (CN) and Cloisite 30B (CB). After that the suspension was hold in an ultrasonic bath for 30 min in order to enhance nanodispersion of the clay platelet within the resin. The phenolic/clay solution was used to impregnate the glass fabric using the solvent impregnation method. After suspension for 2 days in the room with natural condition, the impregnated fabrics were pre-cured at 135 ˚C in an oven for 3.5 min to obtain B-stage prepregs. Seven layers of prepregs (150... 

The research on the automotive brake composite materials is very extensive due to its complex formulation and the used of diverse variety of materials. While various research activities has been applied in this research group, but there are many unknown areas. This subject with the arrival of new materials, especially nanometer materials, has received increasing attention. In this study, the effect of alumina nanoparticles on the performance of automotive brake friction materials were examined. Generally, alumina (as micro particles) used as the abrasive material for many years in the formulation of composite brake pads. But, the effect of alumina on the nanometer scale hasn't been examined... 

The most common type of polymer based composite friction materials are usually in vehicles as the brake pads are used and must characteristics such as high wear resistance, low weight, durability, low noise and stable friction coefficient. Polymer matrix, in addition to providing other material suitable for storage, the final properties, including mechanical properties, heat, friction and wear is also effective. Thermoset resin polymer matrixes (usually phenolic resin) are used in the brake pads which used for automotive and in some cases, rubber particles as powder formulations may be entered, in order to achieve good properties of rubber and resin simultaneously. Nanofillers because of... 

In this project an enzymatic peroxidase biosensor based on two naono structured material 1-Polyaniline nananofibers 2-Polyethylene glycol-Poly citric acid copolymer was studied for phenol detection.Polyaniline nanofibers and poly ethylene glycol-poly citric acid copolymer were synthetized by chemical polymerization.Electrochemical behaviors of these biosensors were studied using cyclic voltammetry (CV) and amperometric techniques. The amperometric response of the coated electrodes is highly stable with 92% of the initial activity remaining after 5 determinations. These phenol biosensors show an oxidation peak at 0.55V. The amperometric response for phenol biosensor based on Polyaniline... 

Various composite friction materials containing 40 vol.% organic binder (phenolic resin plus styrene-butadiene-rubber (SBR)) with varying phenolic-resin/SBR ratio were prepared. The content of phenolic resin in each composite was indicated by the resin value (RV) index ranging between 0-100%. The composites with RVs greater than 50% form resin-based friction materials in which the primary binder is the phenolic resin. For RVs less than 50%, the composites become the rubber-based materials where the primary binder is the SBR. The analysis of mechanical properties exhibited that the conformability of the composites increases upon incorporation of SBR. The frictional analysis revealed that type... 

Application of fuel cells as one of the new and clean energy generators at recent years is many interesting for governments. In many cases hydrogen gas is fuel of these cells. One of the problems at this field is issue of hydrogen storage with a safety and ecconemical way. Usually storage of hydrogen be done with several different ways : Composite tank, Liquid hydrogen, Metal hydride , Chemical hydride, carbon nanotube and etc. Use of polymers that have ability of adsorption is one of topics that is attended at these years , because of their low density and easy process ability and low explosion risk and economical aspect . So at this research we try to identify polymers that have... 

The aim of this study is numerical simulation of progerasive failure in conical structures that manufactured by tape-winding proceses in various temperatures. For this purpose, flat laminates by tape-winding proceses firstly manufactured using carbon/phenolic prepreg tape. Then tensile, compression, shear and thermal expansion coefficient specimens are cut from these laminates. Tensile and compression test are done on these specemens in fiber and matrix directions in temperature range 23-200℃ and stress-strain and stress-time curves are achavied. Using these curves tensile elastic modulus in fiber and matrix directions and Poisson's ratio are obtained in room temperature. Also tensile and... 

An antioxidant is a molecule capable of preventing the oxidation of other molecules and neutralizing free radicals. Free radicals are the root cause for many human diseases.Rice bran is one of the most important co-products in the rice milling.In this research antioxidant activity of two Iranian rice bran varieties Fajr and Tarem, extracted by three different solvents (methanol, ethanol and ethyl acetate),determined at different time of extraction by measurement of total phenolic content, free radical scavenging, inhabitation of linoleic acid peroxidation and reducing power. The methanolic extract of Fajr rice bran produced strong results in antioxidant activity. The amount of Total... 

The purpose of this project is the synthesis and characterization of a group of phenolic amino acidic derivatives that are studied in both solid phases as well as their solutions. For this, new phenol derivatives of serin and isoleucine amino acids were synthesized and characterized by 1H NMR , 13C NMR, IR spectroscopy as well as elemental analysis. These ligands were utilized to prepare LSF perovskite membrane. According to their XRD patterns, it was concluded that the powdered precursor prepared by serin derivative has shown better qualification and less intermediate phase in the synthesized perovskite membrane similar to the sample prepared by applying EDTA. Furthermore, in the previous... 

Inorganic membranes are a group of compounds which are used in gas separations such as isolating of oxygen from air and/or in petrochemical process like OCM, POM. These days, a variety of research is being conducted to synthesize these membranes from perovskite structures with formulation of ABO3. These compounds have various production procedures and various final perovskite compounds. The purpose of this project is to synthesis and identification of a group of phenolic amino acidic derivatives as new chelating agents, and their use in synthesis of perovskite membranes. For this, novel phenol derivatives of glycine, alanine, β- alanine and leucine amino acids were synthesized and... 

In this study, through explaining a micromechanical model of progressive damage, failure in a composite conical structure under mechanical and thermal loads with 36 layers of carbon/phenolic material have been studied. To this end, first, mechanical behaviors of composite layers in micro and macro scale and their properties via fiber and matrix characterizations are discussed. In the following, selection of a proper RVE along with different types of boundary conditions on RVE are discussed. Then stress reinforcement coefficients in order to convert the mechanical and thermal stresses from macro to micro scale for carbon / phenolic material are extracted through defining appropriate RVE for...