Effect of nitrous acid on antipyrine. II. Synthesis of fluoro-organic derivatives

Interaction of antipyrine (I) with nitrous acid in the presence of excess sodium nitrite as buffer, followed by the addition of fluoroboric acid afforded the direct and short way to synthesis of antipyrine-4′-diazonium fluoroborate (II). Pyrolysis of (II) at 165°C gave 4′-fluoroantipyrine (III). The structure of (III) was determined by IR and ¹³C NMR analyses.     

Mutual coupling between loops on layered earth using images

The problem of mutual coupling between wire loops on or above the surface of a layered lossy earth is solved by using the image theory. It is shown that the image solution, besides its simplicity, is accurate both when the wavelength inside the earth is much larger or much smaller than the distances involved. In the intermediate frequency range when these distances are comparable to the wavelength or skin depth inside the earth, accuracy of the solution is retained by the addition of a set of continuous images to complement the single image representation. Numerical examples relevant to the prediction of the depth of a subsurface layer inside the ground are given.     

Expanding Finance-Based Scheduling to Devise Overall-Optimized Project Schedules

Construction contractors often finance projects using bank credit lines that allow contractors to withdraw money up to certain credit limits. Finance-based scheduling provides schedules that ensure that the contractor’s indebtedness at any time during the construction stage does not exceed the credit limit. Generally, constricted credit limits tend to yield prolonged schedules. Provided that credit limits can be adequately relaxed, compressed schedules of compressed-duration activities can be attained. Devising a compressed schedule calls for the incorporation of time-cost trade-off (TCT) analysis to strike a balance between the decreased overhead costs and the increased direct costs of the activities. Since employing TCT analysis usually causes great fluctuations in the daily resource requirements by mixing compressed-duration activities of high resource demand with others of low resource demand, therefore, the need for resource management techniques becomes inevitable to ensure efficient utilization of resources. This note used genetic algorithms to expand finance-based scheduling to devise schedules for relaxed credit limits. A prototype system was developed and coded using VISUAL BASIC, then demonstrated using a five-activity example project. The prototype was validated by comparing the results with those obtained by using the integer programming. Expanding finance-based scheduling to handle the whole spectrum of credit limits helps devise overall-optimized schedules that consider cash, time, cost, and resources.     

Adsorption of some radionuclides from their aqueous solutions using zirconium molybdate ion exchanger

Zirconium molybdate ion exchanger prepared from equimolar amounts of sodium molybdate and zirconyl chloride was used as an effective sorbent for the absorption of some radionuclides from their aqueous solutions. The zirconium molybdate sorbent was characterized by IR spectra and X-ray diffraction. The adsorption behavior of zirconium molybdate toward Cs(I) (¹³⁴Cs), Co(II) (⁶⁰Co), Zn(II) (⁶⁵Zn), and Eu(III) (^{152, 154}Eu) ions in aqueous solutions was studied in relation to the contact time, composition of aqueous solutions, and temperature. The separation factors of the radionuclides in sorption on zirconium molybdate were determined. The efficiency of the recovery and separation of the radionuclides on zirconium molybdate was assessed. Published in Russian in Radiokhimiya, 2006, Vol. 48, No. 4, pp. 347–351. The text was submitted by the authors in English.     

Mass Spectrometry of Irradiated Linolenic Acid

Identification of the products of irradiated micelles of linolenic acid methyl ester (5×10^?2mol · dm^?3) in the presence of O₂ has been studied using GC, chemical-ionization (CI/MS) and electron-ionization (EI/MS) mass spectrometry. CI/MS showed better results than EI/MS, where 17 products have been identified by the former method. However four products only have been recognized using latter method, this due to the disappearing of the molecular ion of the relatively high molecular weight products. The products include hydrocarbons, fatty acids, hydroxy compounds, hydroperoxides and epoxides.     

Simulation of the impulse response of electrical machines

This paper presents three different methods for modeling the transient response of electrical machines. The state-space approach, the Laplace transformation technique and the realization of a new, wide-frequency range equivalent circuit of the machine terminal impedance are applied to obtain the transient response to any waveform. The introduced methods are based on the frequency response of the machine which is often seen as a black box. Both laboratory- and large-scale machines are used to investigate the effect of a variety of impulse waveforms on the transient response of the other phases and to obtain the voltage distribution along the winding of each phase. A frequency response test for the machine is applied to obtain the resonance frequencies and the rational forms for both the voltage gains and terminal impedance. Excellent agreement (error is within 3%) is found between the three methods and the experimental results for different types and ratings of electrical machines under different impulse waveforms     

Factors influencing ampacity and temperature of underground power cables

This paper presents the factors that influence ampacity and temperature rise of three-phase, single-core 33- and 500-kV XLPE underground cables (UGC) using CYMCAP software. These factors are conductor cross-sectional area, soil thermal resistivity, cable burial depth, cable separation, sheath bonding, bedding and backfill heights and thermal conductivities, nearby parallel heat source, formation of dry zone, loss tangent and segmented conductors. Results reveal that increasing the separation distance between phases gives higher ampacity, contrary to the burial depth. The rate of conductor temperature reduction due to the increase in the bedding thermal conductivity is more pronounced than that achieved by increasing backfill thermal conductivity. Furthermore, increasing the native thermal conductivity and/or the maximum conductor temperature increases the UGC ampacity and consequently increases the induced sheath voltage. Sheath losses are significant in transmission UGC where the load currents are always high. High conductor temperature and hence degradation rate is expected for UGC carrying currents of highly fluctuating loads. UGC must be derated as they age (increasing loss tangent), or when dry zones are formed around them, or when a nearby parallel heat source. Finally, it is found that the increase in the number of conductor segments nonlinearly increases the UGC ampacity.     

Synthesis, characterization and morphology of polyanthranilic acid micro- and nanostructures

Polyanthranilic acid (PANA) nanofibres, nanorods, nanospheres and microspheres were synthesized by polymerization of anthranilic acid using ammonium peroxydisulfate (APS) as oxidant without hard or soft templates. Polymerization of anthranilic acid was carried out in aqueous solutions of strong (hydrochloric) and weak (acetic) acids. The influence of synthetic parameters such as oxidant, initiator, dopant acid and its concentration, redox initiator, and reaction medium on the morphology and particle size of PANA have been investigated. PANA nanofibres and nanorods were obtained via redox polymerization of anthranilic acid initiated by FeSO₄ as redox initiator. PANA nanospheres and nanofibres were also obtained when used aromatic amines as initiators. When polymerization carried out in the solution of weak (acetic) acid the microsphere morphology obtained and the particle size increase with increasing the concentration of weak acid. PANA nanorods were obtained also by polymerization of anthranilic in ethanol-water mixture unlike interfacial polymerization of anthranilic acid (in chloroform-water) that give PANA microspheres. The morphology and particle size of PANA was studied by scanning electron microscope (SEM) and transmission electron microscope (TEM). The average diameter of nanostructures obtained ≤100 nm. The optical bandgap of microspheres and nanofibers polymeric products were determined using UV-vis spectroscopic technique and found to be 2.0 eV and 1.6 eV, respectively. The bandgap decreased with decreasing the particle size. IR spectrum confirmed the structure of PANA nanofibres (synthesized with FeSO₄ as redox initiator) in emeraldine form. The thermal stability of polymer obtained was determined by thermal gravimetric analysis (TGA). The molecular weight was determined also by gel permeation chromatography (GPC).     

Seismic interpretation for the Jurassic/Paleozoic reservoirs of QASR gas field,Shushan-Matrouh basin north Western Desert,Egypt

The QASR gas field lies in the northern part of Shushan-Matrouh Basin (northern part of the Western Desert). Jurassic (Lower Safa)/Paleozoic are a reservoir rocks, in which the gas is trapped in clastic Sandstone, depending on structural framework affecting it. The QASR field structure is one of the most complex structures in the Western Desert of Egypt. The Jurassic (Lower Safa) and Paleozoic formations are consists of sandstone, siltstone with some shale streaks, indicating shallow marine facies, its sequence may reach a maximum thickness of over 900?ft in the northeastern part of Shushan-Matrouh basin.The combination between well logs data and 3D seismic interpretation represent that the Jurassic (Lower Safa)/Paleozoic form a complex horst block, which is bounded by NE-SW trending deep-seated faults, with throws is excess of 300?ft. The migration of hydrocarbons into the QASR structure could either be laterally from source rocks that occur in the Shushan basin to the west, and vertically from the sub-basin to the north via the QASR-OZORIS bounding fault.Time and depth-structural maps of Jurassic (Lower Safa)/Paleozoic describe various structure aspects that play a vital role in the hydrocarbon potentialities and prospect identification in the area. One incipient element of exploration and development success is to detect the faults that provide structural closure and traps.Two major faults run in the NE-SW direction and configurator a manner of horst and graben blocks. In addition, NWSW trending faults cut these blocks and form a right-lateral strike-slip component of displacement. Four-way dip structural closure represents the fruitful locations for high production and new prospect wells in the QASR gas field and other similar setting elsewhere.