29 research outputs found
Application of cis-1,3,4,6-Tetranitrooctahydroimidazo-[4,5d] Imidazole (BCHMX) in EPX-1 Explosive
cis-1,3,4,6-Tetranitrooctahydroimidazo-[4,5 d]imidazole (BCHMX) has been studied as explosive filler to replace pentaerythritol tetra-nitrate (PETN) inEPX1 explosive. BCHMX with different particle sizes was bonded by thermoplastic binder plasticised by dibutyl phthalate to obtain BCHMX-EPX. Heat of combustion was measured. Impact energy and friction force of initiation were determined. Velocity of detonation was measured, while the detonation characteristics were calculated by thermodynamic code named EXPLO 5. For comparison, the detonation characteristics of some commercial plastic explosives such asEPX-1, SEMTEXÂ 10 and FORMEX P1were also studied. It was concluded that BCHMX-EPX has the highest detonation characteristics of all the studied plastic explosives and its sensitivity is in the same level of the studied traditional plastic explosives. BCHMX-EPX has the highest decomposition temperature of all the studied samples. The mutual relationship obtained from the experimental and calculated results indicates the compatibility of the calculated results with the experimental measurements
Various characteristics of Ni and PtâAl2O3 nanocatalysts prepared by microwave method to be applied in some petrochemical processes
AbstractAlumina-supported metal nanocatalysts were prepared via the microwave method, by loading nano Ni particles (at 1, 3 and 5wt%) or nano Pt particles (at 0.3, 0.6 and 0.9wt%). Structural and adsorption features of the nano catalysts were revealed through XRD, DSC-DTA, TEM, H2-chemisorption and N2-physisorption. N2-adsorptionâdesorption isotherms of type IV were related typically to mesoporous materials with H2 class of hysteresis loops characterizing ink bottle type of pores. The well dispersed nano-sized metal particles were evidenced in the studied catalytic systems, exhibiting marked thermal stability up to 800°C. The catalytic performances of different catalyst samples were assessed during cyclohexane, normal hexane and ethanol conversions, using the micro-catalytic pulse technique at different operating conditions. The 5% NiâÎłâAl2O3 sample was found to be the most active in dehydration of ethanol to produce ethylene, as well as in n-hexane cracking. However, the 1% NiâAl2O3 sample showed the highest dehydrogenation activity for selective production of benzene from cyclohexane. On the other hand, the 0.9% PtâÎłâAl2O3 sample exhibited the highest activity in the dehydration of ethanol and in the dehydrogenation of cyclohexane. The 0.3% PtâÎłâAl2O3 sample was the most active in the dehydrocyclization of normal hexane, as compared to the other catalyst samples under study
Use of SiO2 - TiO2 Nanocomposite as Photocatalyst for the Removal of Trichlorophenol: A Kinetic Study and Numerical Evaluation
A series of silica-titania nanocomposite materials with different silicaâtitania ratios was prepared in presence of a novel ethoxylated sulphanilamide of molecular weight 1053 by the sol-gel method. Several characterisation techniques were adopted such as thermal analysis (differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA)), N2-adsorption-desorption, X-ray diffraction (XRD), Fourier transform infrared (FTIR), and transmission electron microscopy (TEM) connected with energy dispersive spectroscopy (EDS). The surface acidity was investigated by pyridine adsorption using FTIR spectroscopy. The photocatalytic activity and the adsorptive ability of the composites were evaluated based on the photodegradation of 2, 4, 6- trichlorophenol (TCP) under UV irradiation with a wavelength of 254 nm. The maximum TCP adsorption onto the composites was measured in darkness. The results showed that there was no adsorption of TCP on pure SiO2. The 10% TiO2-SiO2 catalyst showed the highest rate of TCP removal among the synthesised composites. The removal % reached to 87 % after 90 min irradiation time. This activity was caused by the large surface area and pore volume as well as the formation of a mesoporous structure, as evidenced from the pore size distribution curve. Finally, the numerical evaluation of the photodegradation of TCP was conducted. Keywords: Nanocomposite, Ethoxylated sulphanilamide, Photocatalytic degradation, UV irradiation, 2,4,6-TCP, Numerical evaluation
Response of Matured Tissue Cultured Bartemoda and SakkotiDate Palms to Spraying Vitamins K, A& B
Abstract: This study was carried out during 2013 and 2014 seasons to test the beneficial effects of using vitamins K, B, A each at 50 ppm on yield and fruit quality of matured tissue cultured Sakkoti and Bartemoda date palms grown under Aswan conditions. The palms were sprayed four times at the first week of Feb April, June and August. Single and combined applications of vitamins K, A , B each at 50 ppm materially caused an obvious promotion on all vegetative growth characters, chlorophylls a & b , total chlorophylls, total carotenoids, total carbohydrates %, nutrients , flowering , fruit setting %, yield and fruit quality in both cvs. over the check treatment. The best vitamin in this respect was vitamin B followed by vitamin A and K. The studied vitamin treatments had pronounced effect on advancing harvesting date in both date palms cvs. Treating matured tissue cultured Sakkoti and Bartemoda date palms grown under Aswan conditions four times with a mixture of vitamins K, A, B each at 50 ppm proved to be very effective in improving yield and fruit quality
Synthesis of a novel Ce(iii)/melamine coordination polymer and its application for corrosion protection of AA2024 in NaCl solution
ABSTRACT: We present the synthesis of a new cerium(III)âmelamine coordination polymer (CMCP) by a mixedsolvothermal method and its characterization. Characterization techniques included Raman, Fourier Transformation Infra-Red (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM), in which the change in the electronic environment and the crystallinity were tracked. The characterization results confirm the coordination of cerium(III) with melamine through âNHâ groups, instead of the N atoms of the triazine ring, for which we propose a mechanism of interaction. In addition, Biovia Materials Studio package was applied to determine and investigate the molecular structure of the CMCP. All simulations were done using COMPASS force-field theory and atom-based method for summation of electrostatic and van de Waals forces. The application of the CMCP for the corrosion inhibition of AA2024 in 3.5% NaCl solution was tested using the potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results point out that the presence of cerium as cerium(III) in the CMCP structure plays the fundamental role of inhibition, whereby the inhibition mechanism occurs by cathodic oxidation of Ce(III) to Ce(IV) and cyclic reduction of Ce(IV) to Ce(III) by melamine part of CMCP
A scale invariant object detector: An implementation for license plate detection
In this paper we present a new method for 2D object detection. This method uses the Hough transform as a robust platform for edge detection and extends it in the scale space. This extension enables the Hough transform to detect the scale changes within an image. The method starts with a linear scale-space representation of the image. At each level of this space edges are extracted through a normalized derivative function and accumulated in the Hough space. Higher features are mapped from the Hough space into the spatial space and then tagged with a normalized descriptor. The feature with the maximum descriptor over scale is then selected as the object of interest The new approach is applied to the classical problem of the license plate detection. This problem is characterized by a unique solution that can be easily verified by the human observation.Mohamed Gubara and David Sute
Effect of foliar application of Sida compound fertilizer on growth, yield, and fruit chemical composition of "Early Superior" grapevine
Facile solvothermal synthesis of a MIL-47(V) metalâorganic framework for a high-performance Epoxy/MOF coating with improved anticorrosion properties
The vanadium-based metalâorganic framework MIL-47 distinguishes itself among other MOFs for its distinctive structure and unique properties (e.g., flexible structure, high thermal stability, and high surface area). The synthesis of MIL-47 has been reported from various metal precursors, including vanadium(iii) chloride (VCl(3)) as a rich source of metal ions. Attempts have been made to include other starting materials, a step forward towards large-scale production. Synthesis from various solid materials is encouraged, seeking an economic and greener approach. In this study, vanadium pentoxide (V(2)O(5)), a readily abundant low-cost and thermodynamically stable metal source, was used to synthesize the MIL-47(V) framework via a facile solvothermal route. This precursor provides a controllable rate of metal ion production depending on the applied reaction conditions. In our method, the synthesis took place at a low temperature and reaction time (180 °C for 20 h, instead of 220 °C for 72 h), yielding MIL-47 microrods. Moreover, among its unique properties, the metal centers of MIL-47 oxidize under the influence of thermal or chemical treatments, preserving the framework structure. This unusual character is not commonly witnessed in comparable MOF structures. This property can be leveraged in anti-corrosion applications, whereby a redox reaction would sacrifice the framework components, protecting the metal in contact. However, the chemical stability of MIL-47 is doubted against a corrosive medium. Thus, an epoxy coating with 10 wt% MOF loading was incorporated in our investigation to extend the aluminum alloy (AA2024) surface protection for prolonged exposure duration. The uniformity of distribution of the prepared MOF within the epoxy matrix was confirmed using SEM/EDX. Electrochemical impedance spectroscopy (EIS) was used to evaluate the corrosion performance of the coated samples. The results showed that the inclusion of V-MOF offers extended corrosion prevention, over 60 days, for the AA2024 alloy against artificial seawater. The neat epoxy coating could not prevent the corrosion of AA2024 over two weeks of immersion, whereby pitting corrosion was clearly observed. The V-MOF could induce a series of redox reactions leading to the precipitation of vanadium on the cathodic sites of metal surfaces
Corrosion protection mechanism of CeâŽâș/organic inhibitor for AA2024 in 3.5% NaCl
Cerium is a rare earth element that has been widely proposed for the corrosion protection of aluminium alloys (AA). Both cerium salts, Ce(3+) and Ce(4+), have been used in combination with other compounds to offer synergistic inhibition, however, the inhibitive corrosion mechanism when using Ce(4+) with organic compounds is still not clear. In this study, the synergistic inhibition effect of Ce(4+) and melamine (M) on the corrosion of aluminium alloy 2024 (AA2024) in 3.5% NaCl solution was investigated. Potentiodynamic Polarization (PDP) and Electrochemical Impedance Spectroscopy (EIS) techniques were used to study the synergistic effect of different Ce(4+)/M ratios on the corrosion behaviour of AA2024. The PDP study showed that a combination of 50% Ce(4+) and 50% M leads to the lowest corrosion rates, both acting as cathodic inhibitors. Both PDP and EIS results indicated that M or Ce(4+) in isolation did not offer effective corrosion protection, while the combination of M and Ce(4+) significantly enhances the corrosion protection with a synergism parameter equal to 3.5. SEM and EDX observations confirm the findings from the electrochemical techniques. XPS was used to investigate the mechanism of protection, revealing that the reduction of Ce(4+) to Ce(3+) occurs during protection of AA2024. A new mechanism of corrosion synergistic inhibition by Ce(4+) and organic compounds is postulated where the role of the organic compounds is to enhance the reduction of Ce(4+)