Abstract: Alginite has been evaluated as an efficient pollution control material. In this paper, alginite from maar Pinciná (SR) for removal of Cd2+ ions from aqueous solution was studied. The potential sorbent was characterized by X-ray fluorescence analysis (RFA) analysis, Fourier transform infrared spectral analysis (FT-IR) and specific surface area (SSA) was also determined. The sorption process was optimized from the point of initial cadmium concentration effect and effect of pH value. The Freundlich and Langmuir models were used to interpret the sorption behavior of Cd2+ ions, and the results showed that experimental data were well fitted by the Langmuir equation. Alginite maximal sorption capacity (Qmax) for Cd2+ ions calculated from Langmuir isotherm was 34 mg/g. Sorption process was significantly affected by initial pH value in the range from 4.0-7.0. Alginite is a comparable sorbent with other materials for toxic metals removal.
Abstract: L-asparagine admixture Paranitrophenol (LAPNP) single crystals were grown successfully by solution method with slow evaporation technique at room temperature. Crystals of size 12mm×5 mm×3mm have been obtained in 15 days. The grown crystals were Brown color and transparent. The solubility of the grown samples has been found out at various temperatures. The lattice parameters of the grown crystals were determined by X-ray diffraction technique. The reflection planes of the sample were confirmed by the powder X-ray diffraction study and diffraction peaks were indexed. Fourier transform infrared (FTIR) studies were used to confirm the presence of various functional groups in the crystals. UV–visible absorption spectrum was recorded to study the optical transparency of grown crystal. The nonlinear optical (NLO) property of the grown crystal was confirmed by Kurtz–Perry powder technique and a study of its second harmonic generation efficiency in comparison with potassium dihydrogen phosphate (KDP) has been made. The mechanical strength of the crystal was estimated by Vickers hardness test. The grown crystals were subjected to thermo gravimetric and differential thermal analysis (TG/DTA). The dielectric behavior of the sample was also studied
Abstract: Vibration monitoring methods of most critical equipment like main turbine and compressors always plays important role in preventive maintenance and management consideration in big industrial plants. There are a number of traditional methods like monitoring the overall vibration data from Bently Nevada panel and the time wave form (TWF) or fast Fourier transform (FFT) monitoring. Besides, Shaft centerline monitoring method developed too much in recent years. There are a number of arguments both in favor of and against this method between people who work in preventive maintenance and condition monitoring systems (vibration analysts). In this paper basic principal of Turbine compressor vibration analysis and rotor movement evaluation by shaft centerline method discussed in details through a case history. This case history is related to main turbine compressor of an olefin plant in Iran oil industry. In addition, some common mistakes that may occur by vibration analyst during the process discussed in details. It is worthy to know that, these mistakes may one of the reasons that sometimes this method seems to be not effective. Furthermore, recent patent and innovation in shaft position and movement evaluation are discussed in this paper.
Abstract: Pasta is one of the most widely consumed food products around the world. Rapid determination of the moisture content in pasta will assist food processors to provide online quality control of pasta during large scale production. Rapid Fourier transform near-infrared method (FT-NIR) was developed for determining moisture content in pasta. A calibration set of 150 samples, a validation set of 30 samples and a prediction set of 25 samples of pasta were used. The diffuse reflection spectra of different types of pastas were measured by FT-NIR analyzer in the 4,000-12,000cm-1 spectral range. Calibration and validation sets were designed for the conception and evaluation of the method adequacy in the range of moisture content 10 to 15 percent (w.b) of the pasta. The prediction models based on partial least squares (PLS) regression, were developed in the near-infrared. Conventional criteria such as the R2, the root mean square errors of cross validation (RMSECV), root mean square errors of estimation (RMSEE) as well as the number of PLS factors were considered for the selection of three pre-processing (vector normalization, minimum-maximum normalization and multiplicative scatter correction) methods. Spectra of pasta sample were treated with different mathematic pre-treatments before being used to build models between the spectral information and moisture content. The moisture content in pasta predicted by FT-NIR methods had very good correlation with their values determined via traditional methods (R2 = 0.983), which clearly indicated that FT-NIR methods could be used as an effective tool for rapid determination of moisture content in pasta. The best calibration model was developed with min-max normalization (MMN) spectral pre-processing (R2 = 0.9775). The MMN pre-processing method was found most suitable and the maximum coefficient of determination (R2) value of 0.9875 was obtained for the calibration model developed.
Abstract: Vibration analysis of screw compressors is one of the most challenging cases in preventive maintenance. This kind of equipment considered as vibration bad actor facilities in industrial plants. On line condition monitoring systems developed too much in recent years. The high frequency vibration of ball bearings, gears, male and female caused complex fast Fourier transform (FFT) and time wave form (TWF) in screw compressors. The male and female randomly are sent to balance shop for balancing operation. This kind of operation usually caused some bending in rotors during the process that could cause further machining in such equipment. This kind of machining operation increased the vibration analysis complexity beside some process characteristic abnormality like inlet and out let pressure and temperature. In this paper mechanical principal and different type of screw compressors explained. Besides, some new condition monitoring systems and techniques for screw compressors discussed. Finally, one of the common behavior of oil injected twin rotary screw compressors called hydraulic unbalance that usually occurred after machining operation of male or female and have some specific characteristics in FFT and TWF discussed in details through a case history related to Iran oil industries.
Abstract: Cavitation is one of the most well-known process faults that may occur in different industrial equipment especially centrifugal pumps. Cavitation also may happen in water pumps and turbines. Sometimes cavitation has been severe enough to wear holes in the impeller and damage the vanes to such a degree that the impeller becomes very ineffective. More commonly, the pump efficiency will decrease significantly during cavitation and continue to decrease as damage to the impeller increases. Typically, when cavitation occurs, an audible sound similar to ‘marbles’ or ‘crackling’ is reported to be emitted from the pump. In this paper, the most effective monitoring items and techniques in detecting cavitation discussed in details. Besides, some successful solutions for solving this problem for sea water vertical Centrifugal lift Pump discussed through a case history related to Iran oil industry. Furthermore, balance line modification, strainer choking and random resonance in sea water pumps discussed. In addition, a new Method for diagnosing mechanical conditions of sea water vertical Centrifugal lift Pumps introduced. This method involves disaggregating bus current by device into disaggregated currents having correspondences with operating currents in response to measured bus current. Moreover, some new patents and innovations in mechanical sea water pumping and cooling systems discussed in this paper.
Abstract: One of the most challenging times in operation of big industrial plant or utilities is the time that alert lamp of Bently Nevada connection in main board substation turn on and show the alert condition of machine. All of the maintenance groups usually make a lot of discussion with operation and together rather this alert signal is real or fake. This will be more challenging when condition monitoring vibrationdata shows 1X(X=current rotor frequency) in fast Fourier transform(FFT) and vibration phase trends show 90 degree shift between two non-contact probedirections with overall high radial amplitude amounts. In such situations, CM (condition monitoring) groups usually suspicious about unbalance in rotor. In this paper, four critical case histories related to SIEMENS V94.2 Gas Turbines in Iran power industry discussed in details. Furthermore, probe looseness and fake (unreal) trip in gas turbine power plants discussed. In addition, critical operation decision in alert condition in power plants discussed in details.
Abstract: Vibration analysis is the most important factor in preventive maintenance. Gas turbine vibration analysis is also one of the most challenging categories in most critical equipment monitoring systems. Utilities are heart of the process in big industrial plants like petrochemical zones. Vibration analysis methods and condition monitoring systems of this kind of equipment developed too much in recent years. On the other hand, too much operation condition consideration in this kind of equipment should be adjusted properly like inlet and outlet pressure and temperature for both turbine and compressor. In this paper the most important tools and hypothesis used for analyzing of gas turbine power plants discussed in details through a real case history related to an Alstom Typhoon gas turbine power plant in Iran oil industries. In addition, the basic principal of vibration behavior caused by mechanical unbalance in gas turbine rotor discussed in details.
Abstract: In this study, tapioca starch, which acts as natural polymer, was added in the blend in order to produce biodegradable product. Low density polyethylene (LDPE) and tapioca starch blends were prepared by extrusion and the test sample by injection moulding process. Ethylene vinyl acetate (EVA) acts as compatibilizer while glycerol as processing aid was added in the blend. The blends were characterized by using melt flow index (MFI), fourier transform infrared (FTIR) and the effects of water absorption to the sample. As the starch content increased, MFI of the blend was decreased. Tensile testing were conducted shows the tensile strength and elongation at break decreased while the modulus increased as the starch increased. For the biodegradation, soil burial test was conducted and the loss in weight was studied as the starch content increased. Morphology studies were conducted in order to show the distribution between LDPE and starch.
Abstract: The paper analyzes the response of buildings and industrially structures on seismic waves (low frequency mechanical vibration) generated by blasting operations. The principles of seismic analysis can be applied for different kinds of excitation such as: earthquakes, wind, explosions, random excitation from local transportation, periodic excitation from large rotating and/or machines with reciprocating motion, metal forming processes such as forging, shearing and stamping, chemical reactions, construction and earth moving work, and other strong deterministic and random energy sources caused by human activities. The article deals with the response of seismic, low frequency, mechanical vibrations generated by nearby blasting operations on a residential home. The goal was to determine the fundamental natural frequencies of the measured structure; therefore it is important to determine the resonant frequencies to design a suitable modal damping. The article also analyzes the package of seismic waves generated by blasting (Primary waves – P-waves and Secondary waves S-waves) and investigated the transfer regions. For the detection of seismic waves resulting from an explosion, the Fast Fourier Transform (FFT) and modal analysis, in the frequency domain, is used and the signal was acquired and analyzed also in the time domain. In the conclusions the measured results of seismic waves caused by blasting in a nearby quarry and its effect on a nearby structure (house) is analyzed. The response on the house, including the fundamental natural frequency and possible fatigue damage is also assessed.
Abstract: Chitosan (CH) material reinforced by bioactive glass (46S6) was fabricated. 46S6 containing 17% wt% CH was studied in vitro and in vivo. Physicochemical techniques, such as Fourier transform infrared spectroscopy (FT-IR), coupled plasma optical emission spectrometry (ICP-OES) analysis were used. The behavior of 46S6CH17 was studied by measuring the in situ pH in a SBF solution. The 46S6CH17 was implanted in the rat femoral condyl. In vitro 46S6CH17 gave an FTIR - spectrum in which three absorption bands with the maxima at 565, 603 and 1039cm-1 after 3 days of soaking in physiological solution. They are assigned to stretching vibrations of PO4^3- group in phosphate crystalline. Moreover, the pH measurement was decreased in the SBF solution. The stability of the calcium phosphate precipitation depended on the pH value. In vivo, a rise in the Ca and phosphate P ions concentrations in the implanted microenvironment was determined.
Abstract: This paper investigates the impact on operating time delay and relay maloperation when 1st,2nd and 3rd order analog antialiasing filters are used in numerical distance protection. RC filter with cut-off frequency 90 Hz is used. Simulations are carried out for different SIR (Source to line Impedance Ratio), load, fault type and fault conditions using SIMULINK, where the voltage and current signals are fed online to the developed numerical distance relay model. Matlab is used for plotting the impedance trajectory. Investigation results shows that, about 75 % of the simulated cases, numerical distance relay operating time is not increased even-though there is a time delay when higher order filters are used. Relay maloperation (selectivity) also reduces (increases) when higher order filters are used in numerical distance protection.
Abstract: Graphene-based materials were prepared by chemical reduction of covalently functionalized graphene oxide with environmentally friendly agents. Two varying stoichiometry of graphene oxide (GO) induced by using different chemical preparation conditions, further covalent functionalization of the GO materials with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride / N-hydroxysuccinimide and ascorbic acid and sodium bisulfite as reducing agents were exploited in order to obtain controllable properties of the final solution-based graphene materials. The obtained materials were characterized by thermo-gravimetric analysis, Fourier transform infrared and Raman spectroscopy and X-ray diffraction. The results showed successful functionalization of the GO materials, while a comparison of the deoxygenation efficiency of the two-type functionalized graphene oxide suspensions by the different reducing agents has been made, revealing the strong dependence of their properties on the GO structure and reducing agents.
Abstract: Magnesium borate(MB) istechnical ceramic for high heat-resisting, corrosion-resisting, super mechanical strength, superinsulation, light weight, high strength, and high coefficient of elasticity. Zinc borate (ZB) can be used as multi-functional synergistic additives with flame retardant additives in polymers. The most important properties are low solubility in water and high dehydration temperature. ZB dehydrates above 290°C and anhydrous ZB has thermal resistance about 400°C. In this study, the raw materials of ZnO, MgO and H3BO3 were used with mole ratio of 1:1:9. With the starting materials hydrothermal method was applied at a temperature of 100oC. The reaction time was determined as 30, 60, 90 and 120 minutes after some preliminary experiments. After the synthesis, the crystal structure and the morphology of the products were examined by X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). As a result, the forms of Zinc Oxide Borate Hydrate [Zn3B6O12.3.5H2O], Admontite [MgO(B2O3)3.7(H2O)] and Mcallisterite [Mg2(B6O7(OH)6)2.9(H2O)] were synthesized.
Abstract: Carbon dioxide has been well associated with greenhouse effect, and due to its corrosive nature it is an undesirable compound. A variety of physical-chemical processes are available for the removal of carbon dioxide. Previous attempts in this field have established alkanolamine group has the capability to remove carbon dioxide. So, this study combined the polymeric membrane and alkanolamine solutions to fabricate the amine polymeric membrane (APM) to remove carbon dioxide (CO2). This study entails the effect of three types of amines, monoethanolamine (MEA), diethanolamine (DEA), and methyldiethanolamine (MDEA). The effect of each alkanolamine group on the morphology and performance of polyether sulfone (PES) polymeric membranes was studied. Flat sheet membranes were fabricated by solvent evaporation method by adding polymer and different alkanolamine solutions in the N-Methyl-2-pyrrolidone (NMP) solvent. The final membranes were characterized by using Field Emission Electron Microscope (FESEM), Fourier Transform Infrared (FTIR), and Thermo-Gravimetric Analysis (TGA). The membrane separation performance was studied. The PES-DEA and PES-MDEA membrane has good ability to remove carbon dioxide.
Abstract: According to synthetic plastics obtained from petroleum cause some environmental problems. Therefore, degradable plastics become widely used and studied for replacing the synthetic plastic waste. A biopolymer of poly hydroxybutyrate-co-hydroxyvalerate (PHBV) is subgroups of a main kind of polyhydroxyalkanoates (PHAs). Naturally, PHBV is hard, brittle and low flexible while natural rubber (NR) is high elastic latex. Then, they are blended and the biodegradation of the blended PHBV and NR films were examined in soil environment. The results showed that the degradation occurs predominantly in the bulk of the samples. The order of biodegradability was shown as follows: PHBV> PHBV/NR> NR. After biodegradation, the blended films were characterized by appearance analysis such as Scanning Electron Microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC). It was found that the biodegradation mainly occurred at the polymer surface.
Abstract: In this paper, we present a non-blind technique of
adding the watermark to the Fourier spectral components of audio
signal in a way such that the modified amplitude does not exceed the
maximum amplitude spread (MAS). This MAS is due to individual
Discrete fourier transform (DFT) coefficients in that particular frame,
which is derived from the Energy Spreading function given by
Schroeder. Using this technique one can store double the information
within a given frame length i.e. overriding the watermark on the
host of equal length with least perceptual distortion. The watermark
is uniformly floating on the DFT components of original signal.
This helps in detecting any intentional manipulations done on the
watermarked audio. Also, the scheme is found robust to various signal
processing attacks like presence of multiple watermarks, Additive
white gaussian noise (AWGN) and mp3 compression.
Abstract: The use of plastic materials in agriculture causes
serious hazards to the environment. The introduction of biodegradable materials, which can be disposed directly into the soil
can be one possible solution to this problem. In the present research results of experimental tests carried out on biodegradable film
fabricated from natural waste (corn husk) are presented. The film was
characterized by Fourier transform infrared spectroscopy (FTIR),
differential scanning calorimeter (DSC), thermal gravimetric analysis
(TGA) and atomic force microscope (AFM) observation. The film is
shown to be readily degraded within 7-9 months under controlled soil
conditions, indicating a high biodegradability rate. The film
fabricated was use to produce biodegradable pot (BioPot) for
seedlings plantation. The introduction and the expanding use of
biodegradable materials represent a really promising alternative for
enhancing sustainable and environmentally friendly agricultural
activities.
Abstract: In this study, static batch fermentation was used for bacterial cellulose production in date syrup solution (Bx. 10%) at 28°C using Gluconacetobacter. xylinus (PTCC 1734). The physicochemical properties of standard Sigma CMC and the produced carboxymethyl bacterial cellulose (CMBC) were studied using FT-IR spectroscopy, X-ray diffractometry (XRD) and Scanning Electron Microscopy (SEM). According to the FT-IR spectra the bands at 1664 and 1431 cm-1 indicate that carboxylic acid groups and carboxylate groups exist on the surface. The SEM imaging of CMBC and CMC carried out in magnification of 1K. Comparing the SEM imaging obviously showed that the ribbon shape in CMC remained but the length of ribbons became shorter while that shape changed to flake shape for CMBC. Determination of the area under XRD patterns demonstrated that the crystallinity amount of CMC was more than that for CMBC (51.08% and 81.84% for CMBC and CMC, respectively).
Abstract: Magnesium wastes are produced by many industrial activities. This waste problem is becoming a future problem for the world. Magnesium borates have many advantages such as; high corrosion resistance, heat resistance, high coefficient of elasticity and can also be used in the production of material against radiation. Addition, magnesium borates have great potential in sectors
including ceramic and detergents industry and superconducting materials.
In this study, using the starting materials of waste magnesium and H3BO3 the hydrothermal method was applied at a moderate
temperature of 70oC. Several mole ratios of waste magnesium to H3BO3 are selected as; 1:2, 1:4, 1:6, 1:8, 1:10. Reaction time was determined as 1 hour. After the synthesis, X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR) techniques are applied to products. As a result the forms of mcallisterite “Mg2(B6O7(OH)6)2.9(H2O)”, admontite “MgO(B2O3)3.7(H2O)” and magnesium boron hydrate (MgO(B2O3)3.6(H2O)” are obtained.