Purpose: To use the L25 Taguchi orthogonal array for optimizing the three main solvothermal parameters that affect the synthesis of metal-organic frameworks-5 (MOF-5). Methods: The L25 Taguchi methodology was used to study various parameters that affect the degree of crystallinity (DOC) of MOF-5. The parameters comprised temperature of synthesis, duration of synthesis, and ratio of the solvent, N,N-dimethyl formamide (DMF) to reactants. For each parameter, the volume of DMF was varied while keeping the weight of reactants constant. The weights of 1,4-benzodicarboxylate (BDC) and Zn(NO3)2.6H2O used were 0.390 g and 2.166 g, respectively. For each parameter investigated, five different levels were used. The MOF-5 samples were synthesized using the solvothermal reaction method, and successful synthesis was confirmed with x-ray diffraction (XRD), microscopy, Fourier transform infrared spectroscopy (FTIR) and energy-dispersive x-ray spectroscopy (EDS). The DOC obtained via XRD served as a parameter of objective quality. Results: The optimum conditions that gave the highest DOC were synthesis temperature of 130 °C, duration of 60 h, and a vehicle volume of 50 mL, with optimum Brunauer-Emmett-Teller surface area (BET -SA) of 800 m2/g. All the three synthesis parameters significantly influenced the DOC of the synthesized MOF-5 (p < 0.05). Sub-optimal conditions resulted in distorted MOFs, products that deviated from MOF-5 specifications, or MOF-5 with low DOC. Conclusion: Based on DOC and BET-SA, the best conditions for synthesis of MOF-5 when using Taguchi OA, were temperature of 130 °C, duration of 60 h, and a DMF volume of 50 mL.
Charge transfer complex formation method has been applied for the spectrophotometric determination of erythromycin ethylsuccinate, in bulk sample and dosage form. The method was accurate, simple, rapid, inexpensive and sensitive depending on the formed charge- transfer complex between cited drug and, 2,3- Dichloro-5,6-dicyano-p- benzoquinone (DDQ) as a chromogenic reagent. The formed complex shows absorbance maxima at 587 nm against reagent blank. The calibration graph is linear in the ranges of (10 - 110) μg.mL-1 with detection limit of 0.351μg.mL-1. The results show the absence of interferences from the excipients on the determination of the drug. Therefore the proposed method has been successfully applied for the determination of eryth
... Show MoreIn this study, a one-dimensional model represented by Butler-Volmer-Monod (BVM) model was proposed to compute the anode overpotential and current density in a mediator-less MFC system. The system was fueled with various organic loadings of real field petroleum refinery oily sludge to optimize the favorable organic loading for biomass to operate the suggested system. The increase in each organic loading showed higher resistance to electrons transport to the anode represented by ohmic loss. On the contrary, both activation and mass transfer losses exhibited a noticeable decrement upon the increased organic loadings. However, current density was improved throughout all increased loads achieving a maximum current density of 5.2 A/m3
... Show MoreIn this research we study a variance component model, Which is the one of the most important models widely used in the analysis of the data, this model is one type of a multilevel models, and it is considered as linear models , there are three types of linear variance component models ,Fixed effect of linear variance component model, Random effect of linear variance component model and Mixed effect of linear variance component model . In this paper we will examine the model of mixed effect of linear variance component model with one –way random effect ,and the mixed model is a mixture of fixed effect and random effect in the same model, where it contains the parameter (μ) and treatment effect (τi ) which has
... Show MoreThe aim of the research is to identify to what extent to which Malcolm Baldrige standards of total quality are applied in the after-sales services of a private sector company for electrical appliances, from the point of view of administrative leaders, in it. To achieve this aim a questionnaire has been used to measure the degree of application of Malcolm’s seven criteria for total quality, namely: (leadership, strategic planning, focus on the customer, measurement and analysis and knowledge management, focus in human resource and operation management and results of the company’s management), the research found that the company achieved a good level of the standard from the de
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The aim of this paper is to model and optimize the fatigue life and hardness of medium carbon steel CK35 subjected to dynamic buckling. Different ranges of shot peening time (STP) and critical points of slenderness ratio which is between the long and intermediate columns, as input factors, were used to obtain their influences on the fatigue life and hardness, as main responses. Experimental measurements of shot peening time and buckling were taken and analyzed using (DESIGN EXPERT 8) experimental design software which was used for modeling and optimization purposes. Mathematical models of responses were obtained and analyzed by ANOVA variance to verify the adequacy of the models. The resul
... Show MoreSansevieriatrifasciata was studied as a potential biosorbent for chromium, copper and nickel removal in batch process from electroplating and tannery effluents. Different parameters influencing the biosorption process such as pH, contact time, and amount of biosorbent were optimized while using the 80 mm sized particles of the biosorbent. As high as 91.3 % Ni and 92.7 % Cu were removed at pH of 6 and 4.5 respectively, while optimum Cr removal of 91.34 % from electroplating and 94.6 % from tannery effluents was found at pH 6.0 and 4.0 respectively. Pseudo second order model was found to best fit the kinetic data for all the metals as evidenced by their greater R2 values. FTIR characterization of biosorbent revealed the presence of carboxyl a
... Show MoreAcidity constants at 30co and 0.125 ionic strength have been determined for the Nitrogous bases of nucleic acid; cytocine, uarcil and thymine, and found to be 3.55 x10-19 , 1.44 x10 -19 and 7.24 x10 -20 respectively. Stability constants of these bases with Thorium and uranyl ions have been determined. Results showed that metal ions Thorium and uranyl ions behave as hard acids and the nitrogenum bases behave as Hard bases according to Pearson's definition .Hardness – softness parameters for these ligands were calculated ,stability constants of complexes with metal ions could be arranged as follows :- Cytosine > Uracil > Thymine .
Samples of Oxytricha falax were collected from Tigris River by 55µ. mesh net. Culturing of O. falax were cultivated in specific conditions (DO 3-5mg/l.; W.Temp. 24±1ºC; pH: 6.8-7.5).The effect of various furfural concentration 0, 20, 40, 80,100 and 124 ppm and toluene concentration 0, 15, 30, 34.2, 34.5 and 35 ppm after two periods of treatment (24 and 48 hr.) on the physiological parameters of O. falax ciliate were observed. This study showed that the lethal concentration of furfural was 124ppm and 80ppm after 24hr. and 48hr. from treatment which killed all the individual community respectively. Furthermore the treatment of O. falax individuals with different concentrations of toluene indicated that 34.5 ppm of it caused disappearance o
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