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.
Abstract
The Umayyad poets tried to invest all artistic tools in order to achieve a measure of creativity in their texts. The phenomenon of visual composition is breaking the familiar writing system, with the aim of increasing the number of possible connotations. The visual in the Umayyad poetry tries to replace it through expression with the visual image, and its manifestations were manifested by the multiplication of punctuation marks in the body of the poetic text and the tearing of the single poetic line by cutting it into several sentences or repetition.
Keywords: visual formation, poetic writing, Umayyad poetry, recipien
Abstract
The current research aims to identify the level of organizational relaxation among the employees of educational directorates in the Sultanate of Oman. The descriptive approach was used, as well as a questionnaire of two parts to collect data. The questionnaire consists of (15) items divided into three themes about the relaxing level. It was applied on a sample of (406) male & female employees of the educational directorates who were randomly selected. The results of the study showed that the level of organizational relaxation was low. The study results also found that there were no statistically significant differences at the level of significance (α ≤ 0.05) of the study sample in the level of org
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The experiment has been carried out in the Syrian National Commission of Biotechnology, during the growing season 2018/2019, to study the effect of abiotic stresses (salinity and osmotic stresses) on the activity of some antioxidant enzymes and biochemical traits in Catharanthus roseus. The experiment has been laid according to (CRD) with three replications. The seeds have been sterilized by NaOCl solution (0.5% v/v), then planted on MS medium. Plantlets have been moved to MS medium enriched with NAA (1 mg.L-1) and BA (2 mg.L-1). The callus has been initiated from leaves using MS medium containing NAA (1 mg L-1) and KIN (2 mg.L-1). After 60 days, callus
... Show MoreThe accuracy of the skillful performance of the front and back dimensions of badminton in volleyball, occurs through the investment of complex exercises (physical skills) in a single performance and its characteristics that give the correct movement behavior and speed to the accuracy of the performance of the strokes as well as the identification of changes in some physiological indicators of By using these compound exercises. The research problem lies: I found a weakness in the accuracy of the performance of the front and back dimensions strike and diagnosed this through the tests that it conducted on the players to identify and know the problem, and attributed this weakness to a weakness in the necessary physical and skill abilities and t
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Investment in human capital of renewable energy can be relied upon to get to achieve the goals of development is important for Iraq through the intellectual community cards creative able to innovate and develop what is so is study the effect of human investment on economic growth through the adoption of the index of national income as a function of variables independent ( human capital, physical capital) and this is built on the premise that the relationship direct correlation between economic growth and human investment, and it can measure the return on human investment, which is an incentive to increase human capital through education and the development of the economy in general have shown th
... Show MoreHigh performance liquid chromatography was applied for the separation and identification of four antharquinone derivatives, aloe emodin, emodin, chrysophanol and physcion. The separation was carried out using Eurospher 100, C18 column (4.6 mm i.d. x 250 mm, 5 µm) under the following conditions: acetonitile (solvent A) and water: acetic acid (99.9: 0.1 v/v, pH 3.5)( solvent B) as a mobile phase with isocratic elution with 30% solvent B at flow rate 0.8 ml/min. The detection wavelength was set at 254 nm. The four antharquinone derivatives were isolated from the Iraqi rhubarb, Rheum ribes root by preparative TLC, their structures were identified by 1H NMR and used as standards for HPLC analysis. The percentages of alo
... Show MoreThe research attempts to diagnose the level of the effect of human resources flexibility (employees skills flexibility, employees behaviors flexibility, and human resource practice flexibility) in the south al-rusafa directorate of a power station one of the formations and the Ministry of Electricity, and impact of a range of variables related to the performance operational, namely, (efficiency, effectiveness)recognizing the importance of the subjects studied,& because of the importance of expected results of the field under consideration,researcher selected a sample of size (121) engineers and technicians of workers in the directorate. Was my hypotheses the major search of a relationship and impact between human resources flex
... Show MoreThis study was conducted at the Poultry Research Station in Abu Ghraib, Department of Agricultural Research, Ministry of Agriculture, the experimental field during three months (Three terms for a period of four weeks), from 10 th of December 2019 to the 10 th of January 2020. The study aimed to determine the effect of using different proportions of chlorella algae in layer hen ration and its effect on the hen's productive performance and numbers of lactobacilli bacteria in the intestine. The experiment included 400 laying hens (ISA Brown) of 54 week old which were fed according to the standard requirements mentioned in the guide for this breed (ISA Brown layer management guide). The hens raised using a 3 stage cages system with five hens in
... Show Moreهدف البحث الى بيان طبيعة ارتباط والتأثير بين الضغوط التنافسية (المتغير المستقل) والتجديد الاستراتيجي (المتغير التابع) ، تم تطبيق البحث في فنادق الدرجة الممتازة في بغداد. وبلغت عدد افراد عينة البحث (99) مديراً يعملون في (6) فنادق من الدرجة (الممتازة) ببغداد، وهي (فندق الرشيد، فندق عشتار، فندق ميريديان، فندق المنصور، فندق بابل، وفندق بغداد) وتم اجراء التحليل الاحصائي باستخدام البرنامج الاحصائي AMOS وظهرت وجود تنافسي
... Show MoreThe subject of the evolution of fire insurance of the hottest topics accidents, because it falls within the commercial insurance, as its importance is reflected for being a security source and contentment of the insured person and so it is worth pointing out the importance of fire insurance in enterprises and organizations of all kinds, because of the guarantee of its assets from meridian as well as protection from the effects of the fire therefore ensure continuity in the performance of their activities