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.
This study has applied the theoretical framework of conceptual metaphor theory to the analysis of the source and target domains of metaphors that are used in two English nineteenth century sonnets, both written by contemporaneous female poets. The quantitative and qualitative results of the textual analysis have clearly revealed that Elizabeth Barrett Browning’s sonnet 23 centres around the conceptual mapping of the journey of love and life with that of possession. In contrast, Christina Rossetti’s sonnet Remember tackles the central conceptual mapping of death as a journey in relation to its further experiential connections. In addition, the application of conceptual metaphor theory in identifying the frequencies and densities of metap
... Show MoreAsthma is a condition characterized by bronchial spasms, inflammation, and mucous hypersecretion which leads to difficulties in respiration. Asthmatic patients are usually presented with recurrent attacks of coughing, wheezing, and shortness of breath which could be life-threatening. More than three million cases of asthma in the United States are diagnosed annually. Resveratrol, a polyphenolic stilbene, is known to be useful in controlling asthmatic attacks via different molecular mechanisms within the lung epithelium and infiltrating immune cells. However, few studies mentioned the effect of resveratrol on the microbiome in ovalbumin-induced asthma mouse model. In this study, we ind
In spite of the disappearing of a clear uniform textbook for teaching ESP at different departments and different colleges in both scientific and humanistic studies, the practitioners at those departments and colleges have to teach translation as one of the important requirements to pass the English language exam. The lack of defined translation activities is a noticeable problem therefore; the problem of teaching translation is diagnosed in that the students lack the ability to comprehend the text in English language and other translation knowledge and skills.
The study aims to suggest a translation strategy and then find out the effect of the translation strategy on ESP learners’ achievement in translation. A sample of 50 stud
... Show MoreThe current study has sought to identify the levels of the compound thinking among secondary school students basing and relying on the opinions of Lipman who sees that the compound thinking consists of creative thinking and critical thinking, In accordance with this point of view, researchers have resorted to build scale of the critical thinking in its final form of (28) item additionally to the adoption of Torrance for the creative thinking which was translated by sayed. Khairallah in 1981 after confirming psychometric Properties Of both scales and then collect scores of both scales and be the final score represented the level of the compound thinking that has been shown by the results of secondary school students they have no skill of
... Show MoreThe research paper aims to highlight the impact of electronic governance in improving the quality of auditing through accounting disclosure and how to make use out of it in resolving many of the problems by economic units in general and in particular the financial problems in particular. It focuses on the most important financial information of the loss of confidence and credibility in the financial information of the economic units, This study has been carried out through the use and application of many of the principles and rules contained in the electronic governance, The most important Which is the accounting disclosure, and hence the dimensions of accounting for electronic governance through the achievement of ac
... Show MoreThere is no doubt that Jane Austen is one of the most studied authors of the late 18th and early 19th centuries. Her female characters have been extensively studied and they seem to have aroused much interest as manifestations of the conduct of their time. Her heroines have realized that there were many mistakes in the rules of conduct that controlled and restricted their behaviors. Thus, they have found no fault in correcting these mistakes, by behaving naturally without acting. Elizabeth Bennet the heroine of Pride and Prejudice and Marianne Dashwood of Sense and Sensibility are the chosen examples of that kind of women.
This study deals with an important area in the field of linguistics, namely person deixis.
The study aims at: (1) Describing the notion of deixis, its importance, and its place in the field
of linguistics, (2) Presenting a detailed illustration of person deixis, and (3) Conducting an
analysis of person deixis in one of Synge‟s plays Riders to The Sea according to Levinson‟s
model. The most important aim of these three is the third one (the analysis). To achieve this
aim, the researcher depends on Levinson‟s (1983) descriptive approach. According to the
descriptive approach of deixis, the category of person deixis can be defined as the encoding of
the participant roles in the speech situation. This encoding is r