Statistical Modelling of Ultrasonic Pulse Velocity of Fly Ash Based Geopolymer mortar using response surface methodology

The fly ash based geopolymer has emerged as a capable and sustainable binder material in construction industry. Ultrasonic pulse velocity (UPV) method is a non-destructive technique for investigating the mechanical performance of concrete. Experimental investigation was performed for studying the effect of NaOH Molarity, Na2SiO3/NaOH and curing temperature on the ultrasonic pulse velocity of geopolymer mortar. Experiments were designed based on central composite design (CCD) technique of response surface methodology (RSM). Statistical model was developed and statistically validated and found significant as the difference between adjustable R-squared and predicted R-squared less than 0.2. Finally, the optimized mix proportion was assessed for maximized value of UPV. Experimental validation on the optimized mix reveals the close agreement between experimental and predicted values of UPV with significance level of more than 95%. The proposed technique improves the yield, the reliability of the product and the processes

N′-[(E)-1-(5-Chloro-2-hy­droxy­phen­yl)ethyl­idene]pyridine-3-carbohydrazide monohydrate

In the title compound, C14H12ClN3O2·H2O, the benzene ring and the pyridine rings are oriented at a dihedral angle of 57.73 (12)° and an intra­molecular O—H⋯N hydrogen bond generates an S(6) ring. In the crystal, the water mol­ecule forms O—H⋯O and O—H⋯N hydrogen bonds to the organic mol­ecule, leading to chains containing R 4 4(16) loops. In addition, weak aromatic π–π stacking inter­actions between the centroids of pyridine rings [at distance of 3.864 (2) and 4.013 (2) Å] and C—H⋯π inter­actions occur

N′-[(E)-(1-Methyl-1H-pyrrol-2-yl)methyl­idene]benzohydrazide

In the title compound, C13H13N3O, the phenyl and pyrrole rings are inclined at 47.45 (8)°. In the crystal, inter­molecular N—H⋯O and C—H⋯O hydrogen bonds form R 2 1(6) ring motifs. Mol­ecules connected through these hydrogen bonds are arranged into polymeric chains extending along the c axis

Humanism and mental health of married female Patients with systemic lupus erythematosus.

Autoimmune diseases exert adverse impact on the psychological, social and physical well-being of the individuals who suffer from such diseases. Systemic lupus erythematosus is one of chronic illnesses that disturb the all areas of life especially psychosocial perspective of life. In such conditions, belief and view of patients about their own self is necessary to prognosis of their health. Studies suggest that humanism is one of those protective factors that can lead risky health towards better life

Statistical modeling and mix design optimization of fly ash based engineered geopolymer composite using response surface methodology

© 2018. This version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Fly ash-based geopolymer binders have been identified as one of the alternatives to the Ordinary Portland Cement (OPC), which qualify the criteria of green construction material. In the process of enhancement of the properties of geopolymer; engineered geopolymer composite (EGC) is a recent development that is classified as the high-performance fiber reinforced geopolymer matrix. The philosophy of the development of EGC is to achieve high compressive strength and ductility. In this paper, statistical models are developed to predict the mechanical and post-cracking properties of EGC using Response Surface Methodology (RSM). In this regard, effects of three principal variables; molarity of sodium hydroxide, sodium silicate to sodium hydroxide ratio, and curing temperature on the properties of fresh and hardened EGC (setting time, compressive strength, elastic modulus, flexural strength, flexural toughness, ductility index, tensile strength, tensile first crack strength and tensile strain capacity) were investigated. All models are found significant because, and the difference between predicted R2 and adjustable R2 was found less than 0.2. The optimized mixture proportion was assessed using multi-objective optimization technique as discussed in the RSM literature. Finally, an experimental program was performed to validate the optimized mixture proportion. The predicted and experimental results were found in a close agreement because the variation between the predicted and the experimental results was obtained less than 5%. The proposed method can be performed for any objective value of the EGC property with desirability almost equal to one, improving the yield, the reliability of the product and the processes.Peer ReviewedPostprint (author's final draft

N′-[(E)-(1-Methyl-1H-pyrrol-2-yl)methyl­idene]pyridine-4-carbohydrazide

In the title compound, C12H12N4O, the pyridine and pyrrole rings are inclined at an angle of 29.22 (8)° and an intra­molecular C—H⋯N inter­action geneates an S(6) ring. In the crystal, mol­ecules are linked by N—H⋯N hydrogen bonds, forming (010) C(7) chains. The chains are cross-linked by weak C—H⋯O inter­actions, which generate R 2 2(18) ring motifs within an infinite sheet. Finally, two C—H⋯π inter­actions are present, where the C—H groups are from the pyridine ring and π is the pyrrole ring

[5-(2-Fur­yl)-6-nitro-1,2,3,5,6,7-hexa­hydro­imidazo[1,2-a]pyridin-8-yl](phen­yl)methanone

In the title compound, C18H17N3O4, the furyl and phenyl rings are inclined at almost right angles [85.77 (7) and 63.25 (7)°, respectively] to the central imidazo[1,2-a]pyridinyl unit. The structure displays both inter- and intra­molecular N—H⋯O hydrogen bonding

Courses beyond borders: A case study of MOOC platform Coursera

Purpose: The study assesses the participation of different institutions in online learning environment of Coursera. Collaborative efforts, involvement of instructors and the mode of course instruction were also looked at. Design/Methodology: Data were harvested from the official website of Coursera. Through its various features, information pertaining to courses being offered, subject categorization, institutions and instructors involved was collected, tabulated and analyzed. Findings: As of February 2016, 138 institutions from 28 countries offered 1765 coursers through Coursera with the aid of 1903 instructors. Institutions were mainly from high economic zone countries. Nearly 59 percent courses were from USA based institutions and at institutional level University of Pennsylvania (USA) offered a maximum of 84 courses. Collaboration at institutional level was observed in 32 courses with instructors from different institutions, within & outside the same country. 25 percent courses were related to Business and 33 percent courses provided flexibility (on-demand) to people to learn and enrich their skills at their own pace. Implications: Further research needs to be done to evaluate the efficacy of such platforms and explore best practices to reframe the position of traditional universities. Originality/Value: The study is first of its kind to assess online learning environment with respect to participation of institutions to offer various courses and involvement of instructors from all over the globe to make such a courseware a success

N′-[(E)-(4-Bromo-2-thienyl)methyl­ene]isonicotinohydrazide

In title compound, C11H8BrN3OS, the dihedral angle between the two aromatic rings is 27.61 (14)° and the Br atom is disordered over two sites with an occupancy ratio of 0.804 (2):0.196 (2). In the crystal, the mol­ecules are linked by N—H⋯O, C—H⋯O and C—H⋯N inter­actions, resulting in chains

Synthesis, characterization and antimicrobial studies of imine derivatives of amoxicillin

Some novel imine derivatives (1-14) of a broad spectrum antibiotic amoxicillin were prepared by condensation with different carbonyl compounds. The amoxicillin imine derivatives were characterized using elemental analysis and spectroscopic techniques such as FT-IR and 1H NMR. The prepared imine derivatives were evaluated for antimicrobial activities against some pathogens using disc diffusion method. The results of present studies demonstrate enhanced antimicrobial activity of the novel imine derivatives of amoxicillin as compared to the parent drug