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Effect of environmental factors on the effectiveness of ammoniated bagasse in wicking oil from contaminated wetlands

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Journal of Environmental Sciences 2012年第8期24卷 1371-1377页

作者： Seungjoon Chung makram T.Suidan Albert D.Venosa Technology Development Center Samsung Engineering Co.Ltd.SuwonGyeonggi 443-823South Korea Faculty of Engineering and Architecture American University of BeirutBeirut 11072020Lebanon National Risk Management Research Laboratory U.S.Environmental Protection AgencyCincinnatiOH 45268USA

Ammoniated bagasse is a plant-derived organic sorbent that can be used for capturing oil and for supplying slow-release nutrients to oil-degrading microorganisms. We investigated the oil-wicking behavior of this sorbent under various conditions for its effectiveness in remediating oil-contaminated wetlands. Abiotic microcosms simulating a wetland environment were used to assess the influence of sand particle sizes （20x30 and 60x80 U.S. mesh）, degrees of oil saturation （25% and 75%）, water table levels （on top of the clean sand layer, oiled-sand layer, and sorbent layer）, and the presence of sorbent. Results indicated that oil wicking favors higher oil contamination, larger sand particle size, and low water coverage. Water coverage was the predominant factor limiting the effectiveness of sorbent. The most plausible explanation for this limitation was that sorbent captured more water than oil at higher water coverage.

关键词： crude oil wetlands sorbent remediation sediment

Novel continuous single-step synthesis of nitrogen-modified TiO_2 by flame spray pyrolysis for photocatalytic degradation of phenol in visible light

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Journal of Materials Science & Technology 2018年第9期34卷 1494-1502页

作者： Thirupathi Boningari Siva Nagi Reddy Inturi makram Suidan Panagiotis G.Smirniotis Chemical Engineering Program College of Engineering & Applied Science University of Cincinnati Environmental Engineering College of Engineering & Applied Science University of Cincinnati

A novel rapid and continuous process has developed for the synthesis of nitrogen-doped TiO2（N-TiO2）with flame spray pyrolysis（FSP） method. The nitrogen incorporation into TiO2 was achieved by a facile modification（addition of dilute nitric acid） in the precursor for the synthesis. The catalysts were characterized by X-ray diffraction, Raman spectroscopy, transmission electron microscopy, diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. The doping of nitrogen into the TiO2 was confirmed by X-ray photoelectron spectroscopy（XPS） and energy dispersive X-ray（EDX） spectroscopy. The UV-vis spectra of the modified catalysts（with primary N source） exhibited band-gap narrowing for 4 N-TiO2 with band gap energy of 2.89 eV, which may be due to the presence of nitrogen in TiO2 structure. The introduction of secondary N-source（urea） into TiO2 crystal lattice results in additional reduction of the band gap energy to 2.68 eV and shows a significant improvement of visible light absorption. The N-TiO2 nanoparticles modified by using secondary N-source showed significant photocatalytic activity under visible light much higher than TiO2. The higher activity is attributed to the synergetic interaction of nitrogen with the TiO2 lattice. The lowering of the band-gap energy for the flame made N-doped TiO2 materials implies that the nitrogen doping in TiO2 by aerosol method is highly effective in extending the optical response of TiO2 in the visible region. The nitrogen atomic percentage has increased monotonically（0.09%-0.15%）with the increase in primary nitrogen source（nitric acid）, and significantly boosted to 0.97% when secondary nitrogen source（urea） was introduced. The highest rate of phenol degradation was obtained for catalysts with secondary N source due to increase in N content in the catalyst.

关键词： Flame spray pyrolysis(FSP) Titania (TiO2) Visible-light-induced Liquid phase Phenol photodegradation

Performance of rotating drum biofilter for volatile organic compound removal at high organic loading rates

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Journal of Environmental Sciences 2008年第3期20卷 285-290页

作者： YANG Chunping CHEN Hong ZENG Guangming ZHU Xueqing SUIDAN makram T College of Environmental Science and Engineering Hunan University Changsha 410082 China Department of Civil and Environmental Engineering University of Cincinnati Cincinnati OH 45221-0071 USA

Uneven distribution of volatile organic compounds （VOCs） and biomass, and excess biomass accumulation in some biofilters hinder the application of biofiltration technology. An innovative multilayer rotating drum biofilter （RDB） was developed to correct these problems. The RDB was operated at an empty bed contact time （EBCT） of 30 s and a rotational rate of 1.0 r/min. Diethyl ether was chosen as the model VOC. Performance of the RDB was evaluated at organic loading rates of 32,1, 64.2, 128, and 256 g ether/（m^3·h）（16.06 g ether/（m^3·h） ≈ 1.0 kg chemical oxygen demand （COD）/（m^3·d））. The EBCT and organic loading rates were recorded on the basis of the medium volume. Results show that the ether removal efficiency decreased with an increased VOC loading rate. Ether removal efficiencies exceeding 99% were achieved without biomass control even at a high VOC loading rate of 128 g ether/（m^3·h）. However, when the VOC loading rate was increased to 256 g ether/（m^3·h）, the average removal efficiency dropped to 43%. Nutrient limitation possibly contributed to the drop in ether removal efficiency. High biomass accumulation rate was also observed in the medium at the two higher ether loading rates, and removal of the excess biomass in the media was necessary to maintain stable performance. This work showed that the RDB is effective in the removal of diethyl ether from waste gas streams even at high organic loading rates. The results might help establish criteria for designing and operating RDBs.

关键词： biofiltration organic loading rotating drum biofilter (RDB) volatile organic compound

An explicit and novel structure,lattice dynamics,and photoemission of La-doped nanocrystalline SrZrO_(3) perovskite

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Rare Metals 2021年第1期40卷 105-112页

作者： Kamilia Sedeek Nahed makram Hanan Hantour Taghreed Zaghloul Amer Shimaa Ali Said Nano-Materials Laboratory Physics DepartmentFaculty of ScienceAl-Azhar UniversityNasr CityCairo 11751Egypt Physics Department Faculty of ScienceAl-Azhar UniversityNasr CityCairo 11751Egypt

As no complete and comprehensive studies have been previously reported for La-doped nanocrystalline SrZrO_(3)(SZO),we researched herein a detailed investigation for pure and La-doped samples.A modified solid-state reaction process,including successive cycles of milling and sintering at high temperature,was followed to produce SZO and Sr_(0.9)La_(0.1)ZrO_(3)(SLZO)powdered *** analysis of X-ray diffractometer data predicts that the two samples exhibit orthorhombic structure with an increase in crystallite size by~25%for doped sample.A great reduction in Raman modes intensity(~60%)and an annihilation of several vibration modes were detected using Raman *** degree of ordering on the B-site was recorded to be higher in La-doped *** to ultraviolet-visible(UV-Vis)absorption,a decrease in the optical gap width(E_(g))from 4.40 eV to 4.21 eV was achieved by La incorporation due to the presence of additional defect states such as oxygen and Sr vacancies at the band *** process of electron-hole recombination was studied using photoluminescence(PL)*** of PL spectra yielded four emission bands:one green band,one blue band,and two violet *** intense violet emission atλ=393 nm approximately five times greater than that detected for pure SZO is realized as La^(3+)substitutes for Sr^(2+).Such property nominates SLZO for technological applications requiring highly intense violet emission,e.g.,light-emitting diodes.

关键词： Orthorhombic perovskite structure Lattice dynamics Diffused reflectance Photoluminescence Highly intense violet emission

Biodegradation of alkylates under less agitated aquifer conditions

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Journal of Environmental Sciences 2013年第8期25卷 1529-1538页

作者： Jay J. Cho makram T. Suidan Albert D. Venosa URS Corporation 7720N 16th St. Ste 100 Phoenix AZ 85020 USA Faculty of Engineering and Architecture American University of Beirut Dean's officeP.O.Box 11-0236 Riad El Solh 1107 2020 Beirut Lebanon US Environmental Protection Agency National Risk Management Research LaboratoryCincinnati OH 45268 USA

The biodegradability of three alkylates （2,3-dimethylpentane, 2,4-dimethylpentane and 2,2,4-trimethylpentane） under less agitated aquifer conditions was investigated in this study. All three alkylates biodegraded completely under these conditions regardless of the presence or absence of ethanol or benzene, toluene, ethylbenzene, and xylenes （BTEX） in the feed. In the presence of ethanol, alkylates degradation was not inhibited by ethanol. However, alkylates degraded more slowly in the presence of BTEX suggesting competitive inhibition to microbial utilization of alkylates. In the sterile controls, alkylates concentrations remained unchanged throughout the experiments.

关键词： biodegradation alkylates inhibition BTEX ethanol

Electron beam pumping improves the conversion efficiency of low-frequency photons radiated by perovskite quantum dots

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Chinese Physics B 2023年第4期32卷 754-761页

作者：杜鹏母一宁任航 Idelfonso Tafur Monroy 李彦正樊海波王帅 makram Ibrahim 梁栋 School of Physics Changchun University of Science and TechnologyChangchun 130022China Institute for Photonic Integration Eindhoven University of TechnologyEindhoven 5600 MBNetherlands Science and Technology on Low-Light-Level Night Vision Laboratory Xi’an 710018China Kunming Institute of Physics Kunming 650221China Solar and Space Research Department National Research Institute of Astronomy and Geophysics(NRIAG)Cairo 11421Egypt

This research argues that using an electron beam with high kinetic energy to pump perovskite quantum dots can significantly boost the efficiency of the low-frequency photon radiation ***,we measure the random lasing threshold and luminescence threshold of CsPbX_(3)films pumped by an electron ***,we simulate the spatial distribution of the electron beams in CsPbX_(3)*** with the above data,a low-frequency photon radiation conversion model based on the electron pumped perovskite quantum dots is *** could be a way to create a terahertz source with a high-power output or to multiply the terahertz power.

关键词： electron beam perovskite quantum dots THz

Physical Properties of SiC Nanostructure for Optoelectronics Applications

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Journal of Renewable Materials 2021年第9期9卷 1519-1530页

作者： Mayyadah H.Mohsin Najwan H.Numan Evan T.Salim makram A.Fakhri Applied Science Department University of Technology-IraqBaghdad10066Iraq Laser and Optoelectronic Engineering Department University of Technology-IraqBaghdad10066Iraq

A SiC nanofilms have been deposited and investigated on quartz and silicon substrates using pulsed laser deposition technique with the 300 pulses of Nd:YAG laser at two different laser wavelengths of 1064 nm and 532 *** structural,morphological,and optical properties of the deposited nanostructure SiC were prepared and characterized as a function of the wavelengths of the used *** structural result shows four different pecks at(111),(200),(220),and(311)planes related to Nano *** transmission result presents that the optical energy gap value for the SiC nanostructure is depended on the wavelength of the used laser and it is found about the range(3.03 eV–3.23 eV).The investigations of the SEM and AFM show that the prepared SiC Nano-films having a grain size range(36.34–48.75)nm and roughness about 4.462 to 3.062 ***/Si hetero-junction devices show an enhanced performance at 532 nm.

关键词： Pulsed Laser deposition nanostructure 4H-SiC PLD heterostructure nanofilms

Configuration Optimization of Cables in Ductbank Based on Their Ampacity

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Journal of Power and Energy Engineering 2018年第4期6卷 1-15页

作者： Bin Sun Elham makram Electrical and Computer Engineering Department Clemson University Clemson USA

Electrical power companies are using more underground cables rather than overhead lines to distribute power to their customers. In practice, cables are generally installed in some compact ductbanks. Since the cost of underground cables is very expensive, using the entire space of a ductbank is extremely important. But such usage is limited due to the overheating of cables. Overheating is generally caused by overload, which means the carrying current exceeds the ampacity of a cable. The ampacity of a cable depends on not only the material and design of a cable but also the distance between different cables. Thus the configuration of cables determines the total ampacity value and the potential use of a ductbank. In this paper, the best configuration based on ampacity is achieved for a three-row, five-column ductbank that is buried at a depth of one meter below the earth’s surface. Both balanced and unbalanced scenarios are considered, and all cables have two available types to be selected.

关键词： Configuration Optimization Underground Cables Ampacity Balanced Unbalanced

Arithmetic Reduction of Intensity or Age Models with Bathtub Failure Intensity

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Computer Technology and Application 2011年第1期2卷 15-23页

作者： makram Krit Abdelwaheb Rebai Higher Institute of Companies Administration Gafsa 2133 Tunisia

In this paper, the authors will study the estimation of maintenance efficiency in Arithmetic Reduction of Intensity （ARI） and Arithmetic Reduction of Age （ARA） models with a memory m. These models have been proposed by Doyen （2005）, the failure process is simply Non Homogeneous Poisson Process （NHPP）. Our models are defined by reformulation of ARI and ARA ones using bathtub failure intensity. This form is presented like a superposition of two NHPP and Homogeneous Poisson Process （HPP）. Moreover, the particularity of this model allows taking account of system state improvement in time course. The maintenance effect is characterized by the change induced on the failure intensity before and after failure during degradation period. To simplify study, the asymptotic properties of failure process are derived. Then, the asymptotic normality of several maintenance efficiency estimators can be proved in the case where the failure process without maintenance is known. Practically, the coverage rate of the asymptotic confidence intervals issued from those estimators is studied.

关键词： Repairable systems reliability bathtub failure intensity imperfect repair maintenance homogeneous poisson process(HPP) non homogeneous poisson process (NHPP) estimation likelihood.