2182 research outputs found
Sort by
On Suprememum of a set in A Dedikind Complete Topological Space
Get PDFThe supremum for a set in a multi-dimensional, Dedikind complete topological space is defined. The example is given to illustrate that the condition of Dedilind complete is necessary for the existence of supremum
The Effect of Sodium Hydroxide Solutions with Different Ph on the Corrosion Of Iron Alloy (C1010) In Industrial Water
Get PDF The effect of increasing pH value in the corrosion of iron alloy type (C1010) was studied in the presence of different pH solutions of sodium hydroxide dissolved in industrial water at 35ËšC and it was found that the corrosion rate of iron alloy was less at pH of 9.5 . This result was proved by measuring some thermodynamic parameters such as corrosion current and covered surface area that pertain to corrosion using weight loss electrical (Tafel plot ) methods . Also the effect of temperature on the rate of corrosion at ( 25ËšC , 35ËšC and 45ËšC ) at different pH was studied and it was found that the rate of corrosion is increased with increasing the temperature at the same pH
Thermal decomposition of 3,6-diphenyl-1,2,4,5-tetroxane in nitromethane solution
Get PDFThe thermal decomposition reaction of benzaldehyde diperoxide (DFT; 0.001 mol L-1) in nitromethane solution studied in the temperature range of 130.0-166.0 °C, follows a first-order kinetic law up to at least 60% DFT conversion. The organic products observed were benzaldheyde and benzoic acid. A stepwise mechanism of decomposition was proposed where the first step is the homolytic unimolecular rupture of the O-O bond. The activation enthalpy and activation entropy for DFT in nitromethane were calculated (DH# = 106.3 ± 1.0 kJ mol-1 and DS# = -58.6 ± 1.1 J mol-1K-1) and compared with those obtained in other solvents to evaluate the solvent effect
Effect of UV Irradiation on The Structure and Optical Properties of PVA/Cucl2
Get PDFThe morphology and optical properties of doped PVA with Copper Chloride, CuCl2 have been investigated. The morphology of doped samples has been examined using both atomic force microscope (AFM) and scanning electron microscope (SEM) to investigate the effect of CuCl2 on the structure of PVA. X-ray diffraction showed that the crystallinity of PVA is increased with increasing CuCl2 ratio. In addition, FTIR spectra showed that, some absorbance bands such as bands of OH groups have been affected due to CuCl2 ratio and UV irradiation. On the other hand, the effect of CuCl2 ratio and UV irradiation on UV spectra of all samples has been carried out in the range from 200 to 800 nm. It is observed that, PVA is characterized by two absorbance bands at 278 and 313 nm. The values of absorbance edge, Urbach energy and the direct energy gap of all samples have been calculated
Effect of Gamma Irradiation on Structural, Morphological and Optical Properties of p-quaterphenyl Thin Films
Get PDFPara-quaterphenyl thin films were deposited onto glass and quartz substrates by thermal evaporation method. p-quaterphenyl thin films wereexposed to gamma radiation of Cobat-60 radioactive source at room temperature with a dose of 50 kGy to study the effect of ?-irradiation onthe structure and the surface morphology as well as the optical properties of the prepared films. The crystalline structure and the surface morphology of the as-deposited and ?-irradiated films were examined using the X-ray diffraction and the field emission scanning electron microscope. The optical constants (n & k) of the as-deposited and ?-irradiated films were obtained using the transmittance and reflectance measurements, in the wavelength range starting from 250 up to 2500 nm. The analysis of the absorption coefficient data revealed an allowed direct transition with optical band gap of 2.2 eV for the as-deposited films, which decreased to 2.06 eV after exposing film to gamma irradiation. It was observed that the Urbach energy values change inversely with the values of the optical band gap. The dispersion of the refractive index was interpreted using the single oscillator model. The nonlinear absorption coefficient spectra for the as-deposited and ?-irradiated p-quaterphenyl thin films were obtained using the linear refractive index
Physical Mathematics and The Fine-Structure Constant
Get PDFResearch into ancient physical structures, some having been known as the seven wonders of the ancient world, inspired new developments in the early history of mathematics. At the other end of this spectrum of inquiry the research is concerned with the minimum of observations from physical data as exemplified by Eddington's Principle. Current discussions of the interplay between physics and mathematics revive some of this early history of mathematics and offer insight into the fine-structure constant. Arthur Eddington's work leads to a new calculation of the inverse fine-structure constant giving the same approximate value as ancient geometry combined with the golden ratio structure of the hydrogen atom. The hyperbolic function suggested by Alfred Landé leads to another result, involving the Laplace limit of Kepler's equation, with the same approximate value and related to the aforementioned results. The accuracy of these results are consistent with the standard reference. Relationships between the four fundamental coupling constants are also found
Annual Reviewer Acknowledgement
No full textThe editorial team of the journal would like to thank the reviewers for their work in referring manuscripts during 2018
Direct Spectrophotometric Determination of Cefuroxime Axetil in Pure Form and Pharmaceutical Dosage Forms.
Get PDFA simple, direct and cost-effective spectrophotometric method for determination of cefuroxime axetil (CRXA) in pure and tablet dosage forms was applied. This method is based on formation of ion-pair complex ([CRXA]:[BTB]) between CRXA and bromothymol blue (BTB) in chloroform. Beer’s law in the optimum experimental conditions using [CRXA]:[BTB] complex is valid within a concentration range of 2.00-50.00 ?M (1.021–25.524 ?g.mL-1). The developed method is applied for the determination of CRXA in pure and its commercial tablets without any interference from excipients with average assay of 96.8 to 101.6% and the results are in good agreement with those obtained by the HPLC reference method. Associated drugs (sulbactam and linesolid) with cefuroxime axetil are considered to be interfere, while metronidazole can be considered as non-interfere
Adsorption Of No3--N And Po43--P in Aqueous Solution Using Granular Activated Charcoal (Gac)
Get PDFIn this study, adsorption of NO3- -N and PO43--P on granular activated charcoal (GAC) was investigated depending on pH, agitation time, GAC dosage, adsorption capacity and adsorption isotherms by employing batch adsorption type. The GAC was characterized by thermogravimetric analysis (TG-DTA), scanning electron micrograph coupled with energy-dispersive X-ray spectroscopy (SEM-EDX) and BET surface area analyzer. The GAC exhibited nearly similar adsorption equilibrium time. Both NO3--N and PO43—P appeared to approach equilibrium after approximately 4 h of agitation time. In the adsorption equilibrium, the removal efficiencies of NO3- -N and PO43--P were found to be 14.6-66.0 % and 52.4-99.0 %, respectively. The adsorption data for NO3--N and PO43--P was correlated to Freundlich and Langmuir isotherm model and the equilibrium data was fitted well to the Langmuir isotherm model due to their higher correlation coefficient (R2) value. The Langmuir adsorption capacity was 1.54 and 2.56 mg g-1 for NO3--N and PO43--P, respectively, which suggests that the GAC is a good adsorbent for removal of NO3--N and PO43—P from water
Anion Recognition Via polarized –N-H Fragments
Get PDFHydrogen bonding interaction and or proton transfer assets of synthetic molecules in presence of anionic species is pretty fascinating in the field of supramolecular analytical chemistry. Not only amide or urea based derivatives have appeared in the highlights, rather from last few decades, polarized free amine fragments (-NH2) have been brought under the study with prompt signaling. In this report, I will be focusing on the basic aspects which trigger free amine group to decode rapid anion recognition not only under organic media, but also under aqueous conditions in diverse environments