316 research outputs found

    Hydrodynamics and Kinetics of Phenols Removal from Industrial Wastewater in a Trickle Bed Reactor (Part I: Hydrodynamic Study)

    Get PDF
    An experimental investigation of the hydrodynamic parameters in a trickle bed reactor is presented. The operating conditions are selected for the operating system to be at trickle flow regime. The effects of the two-phase flow rates, reactor pressure and temperature on the pressure drop, external liquid holdup and liquid axial dispersion are discussed. Pressure drop was measured using differential pressure transducer, while liquid holdup and axial dispersion were estimated using RTD technique with a reactive dye as a tracer. The results confirmed that pressure drop is proportional to flow rate of fluids and operating pressure while it is inversely proportional to temperature. Liquid flow rate has a proportional effect on liquid holdup and axial dispersion while gas flow rate and temperature presented a different image. A comparison between the results of present work and that of literature is presented and discussed. Empirical correlations for pressure drop, liquid holdup and axial dispersion with operating conditions are developed with correlation coefficient of 98.4 to 99.7 %

    Impact of channelized flow on temperature distribution and fluid flow in restless calderas:Insight from Campi Flegrei caldera, Italy

    Get PDF
    Magmatic hydrothermal systems develop by the imposition of a magmatically derived heat flux upon a shallow groundwater system. As such their dynamics can be intermittently perturbed by changing conditions within the associated magmatic system. Understanding the nature of the coupling between the magmatic and groundwater systems is thus key to discriminating geophysical signals of magmatic unrest from purely hydrothermal ones.Using a series of numerical groundwater models run with TOUGH2, we simulate the coupled groundwater–magmatic system at Campi Flegrei caldera, with particular emphasis on the impact of permeability developed within local fault systems and the dynamics of the system during magmatic unrest. Simulation results suggest that faults can play an important role in controlling the dynamics of recharge and heat transport within the shallow hydrothermal reservoir. Results specifically highlight that contrasts in permeability between faults and surrounding rock impact local temperature gradients, with faults either acting as preferential routes for recharge or discharge of groundwater, depending on fault/caldera fill permeability contrast and the vertical extent of the fault. Simulations of magmatic unrest with a step-wise increase in basal heat flux suggest that periodic geophysical and chemical signals may stem from the interaction between the development of gas at depth and the recharge–discharge dynamics of the reservoir. These results highlight the potential for the dynamics of magmatic–hydrothermal systems to be significantly impacted by the presence and nature of local fault systems. Where dynamic groundwater systems are involved, it is thus important to understand the impact of such geological elements when interpreting monitoring data such as ground deformation, seismicity and gas emissions

    Numerical Analysis of Torsional Reinforcement of Concrete Beams in Unconventional by ANSYS Software

    Get PDF
    In this study, a finite element analysis is conducted to study the behaviour of RC beams with different configurations of transverse reinforcement under torsion. These configurations of stirrups are traditional closed stirrups, circular spiral stirrups, and inclined rectangular spiral stirrups. The numerical torsional load values are compared with the experimental torsional load values from previous research. The numerical analysis determined by the ANSYS software shows a reasonable agreement with the experimental torsional load values. The numerical results demonstrate that the use of continuous rectangular spiral stirrups improved the torsional response compared to using another type of beam stirrup. Thus, numerical results show that continuous spiral stirrups are effective at increasing torsional capacity. It is also noted that the behaviour of these beams with continuous spiral stirrups is better than the behaviour of the beams with traditional stirrups. The beams with helical reinforcement, which are TB2, TB3, and TB4 spiral reinforcements, greatly enhanced the toughness. The equivalent stresses are 13.709, 13.728, 14.72, and 15.894 MPa, while the equivalent elastic strains are 0.00421, 0.00377, 0.00347, and 0.00539 mm/mm for the beams TB2, TB3, and TB4, respectively. The beam TB4 had the highest stress and strain value, so its strength improved its ductility properties. As a result, the stirrups' configurations enabled the detection of beam failure mechanisms by improving torsional behaviour when compared to the beam's traditional stirrups. As a result, this research adds more knowledge to the literature on the most effective spiral stirrups for transverse reinforcement to improve the torsional behaviour of beams. Doi: 10.28991/CEJ-2023-09-01-04 Full Text: PD

    Some Immunologic Evaluations of Toxoplasmosis in Iraqi Aborted Females

    Get PDF
    Forty-eight aborted women (Iraqi Arab Muslims) at the first trimester with a serological evidence of toxoplasmosis were investigated. Two age- and ethnic-matched control groups were included: 40 aborted women due to accidental events (Control I), and 40 unmarried (virgin) women (Control II). The subjects were evaluated for the following parameters: HLA-class I antigens (A, B and Cw), blood groups, total and differential counts of leukocytes, lymphocyte subpopulations (CD3+, CD4+ and CD20+ cells), phagocytosis of heat-killed yeast (phagocytic index and NBT index), and total serum levels of immunoglobulins (IgA, IgG and IgM) and complement components (C3 and C4). The HLA-A2 and -Cw8 antigens were significantly increased in the patients, while A3 antigen was significantly decreased. Blood group phenotypes in patients and controls also showed significant variations. The total and differential counts of leukocytes showed no significant differences between patients and controls, with the exception of lymphocytes, which showed a significant decreased count in the patients compared to control II. However, the lymphocyte subpopulations showed a significant increased percentage in patients. The phagocytic index was approximated in patients and controls, while NBT index was significantly decreased. Total serum level of IgG was significantly increased in the patients, while IgA, IgM, C3 and C4 levels did not maintain such variation

    Enhancing Wireless Sensor Networks Routing Protocols based on Cross Layer Interaction

    Get PDF
    Wireless sensor networks aim to develop a smart city based on sensing environment. The routing protocols of wireless sensor networks is important to transfer the data in smart cities since sensor nodes have limited power and transmission range. The aim of this research is to enhance wireless sensor networks routing protocols based on proposed cross-layer interaction between physical layer and network layer also a proposed routing table information of wireless sensor nodes is developed to consider the transmission power of neighbor’s nodes to determine the next hop. Cross-layer interaction provides a useful information and effective adaptation for WSN routing protocols. As a result, the proposed routing protocol shows an improvement in network performance when number of intermediate nodes are minimized

    The Effect Of Constraint Length And Interleaver On The Performance Of Turbo Code

    Get PDF
    This paper presents a class derived from convolutional code called turbo code. Theperformance of turbo code is investigated through examining the effect of different constraintlength, the effect of changing rate, and the effect of interleaver on the performance of turbocode with presence burst errors.The performance of turbo code is investigates through computer simulation, by usingMATLAB program.The simulation encoder is composed of two identical RSC component encoder with parallelconcatenated, separated by interleaver.The turbo code simulation results are showngraphically for different constraint length, in hard and soft decision. Also the simulationresults are shown for case with interleaver and without interleaver

    The Impact of Crumb-Rubber on the Mechanical Characteristics of Modified Asphalt Mixture

    Get PDF
    By following up on the effect of rubber, which has recently been widely used as a direct additive to the asphalt binder or to the concrete mix as a percentage of the weight of the aggregate. The success of the effect of this type of admixture on improving the modified asphalt binder in addition to the modified concrete mix has been investigated. As it was noted the importance of following the asphalt properties due to the increasing use of crumb rubber modifiers in asphalt mixtures, there is a more position to check their rheological and physical properties comprehensively. In general, the performance of the asphalt rubber binder is affected by the rubber crumb content and mixing conditions. This research used 40/50 asphalt grade and Crumb Rubber additives with contents (5, 10, 15, and 20%). The main objectives of this study were to investigate the physical and rheological properties of rubber-modified asphalt binder and mixture. These purposes were achieved by testing HMA samples using the Marshall test approach to determine (Marshall stability and flow and void properties) and measuring the retained Marshall stability and DSR and Viscosity test. Sample testing showed that when recycled rubber was used as modifiers for asphalt mixes, the mixture became more stable, had a higher bulk specific gravity, and had less flow value and air voids. This infers that using recycled rubber can enhance the rutting resistance of bituminous mix

    The effect of Chaetomium globosum and organic fertilizer on the sweet pepper varieties growth and yield under the greenhouse conditions

    Get PDF
    This experiment was conducted at horticulture college (USAMV Bucharest) during the summer season of the year 2017 to investigate the growth and yield of sweet pepper varieties (Dinamica f1, Abadia f1 and Abadia f1-grafted on emperador) planted under the greenhouse as influenced by Dix 10 n (organic fertilizer) with dose (300 g/m2 dix 10n) and soil contaminated with Chaetomium globosum fungus. The results of the experiment demonstrated that the highest plant height between the varieties were represented by Dinamica recorded 69.66cm while the maximum plant height between the interaction treatments recorded with (Dinamica + (D+CG), Dinamica + CG and Abadia G+ CG evaluated (89.66, 87.66, 84.00 cm) respectively. While the highest percentage of aerial plant dry matter represented by the interaction treatments of Dinamica + (D + CG) and Abadia G + (D + CG) which reached to (18.56 and 18.53 %) respectively. While the minimum effect for percentage of root dry matter obtained (15.20 and 16.20 %) for control treatment of (Abadia and Abadia G) respectively. The highest yield of plant (Dinamica + (D + CG), Abadia G (D + CG) and Abadia (D + CG)) were recorded lowest yield per plant were (1367.66, 1363.00 and 1325.66 g) respectively. The highest chlorophyll content in leaves were (135.30 and 117.53 µmol m-2) in Abadia G (D + CG) and Abadia G + CG respectively. The minimum photosynthesis value was 7.36 µmol m-2 s-1 in Abadia G (D + CG). The maximum of highest N-NO3 was in Dinamica + (D+CG) treatment which reached to 90.13 ppm, while the highest PO4 level was observed in Abadia + D treatment which recorded 198.87 ppm and the highest level of K was in Abadia G + CG which reached to 4066.66 ppm

    Geochronology, geochemistry and geodynamics of the Cabo de Gata volcanic zone, Southeastern Spain

    Get PDF
    © 2014 Societa Geologica Italiana, Roma. New 40Ar/39Ar ages and major and trace element geochemistry of the middle-late Miocene Cabo de Gata volcanic complex, southeast Spain, indicate that the volcanic activity of the Cabo de Gata volcanic zone developed over a short period through several pulses of geochemically and isotopically different parental magmas. The oldest volcanic rocks exposed in the Cabo de Gata volcanic zone are the shoshonite and high-K calc-Alkaline rocks of Bujo group, which cry - stallised from a parental magma transitional from calc-Alkaline to alkaline potassic generated through large degrees of partial melting, and then affected by a minor contribution from metasomatised veins and a larger one from the surrounding mantle wedge, in comparison to ultrapotassic melts. Subsequent partial melting of the mantle source produced typical calc-Alkaline parental magmas belonging to the Rodalquilar and Agua Amarga groups. Sr-Nd-Pb isotope and incompatible trace element distributions of Cabo de Gata rocks are in agreement with a mantle-wedge source affected by a two-fold metasomatism. The data suggested that mild potassic to sub-Alkaline subduction-related parental magmas (i.e., high-K calc-Alkaline and calc-Alkaline) were generated in the Cabo de Gata sector within a mantle wedge metasomatised by a fluid-dominated agent. In contrast, the enrichment in K2O of shoshonitic to ultrapotassic magmas was achieved through recycling of subducted sediments through melts that enriched the mantle wedge in K and related elements. Such a scenario can be easily reconciled with a geodynamic setting at the edge of a destructive plate margin with the subducted slab responsible for the recycling of sediments within the mantle wedge.Geochemical, petrographic and analytical work were supported by the Italian MIUR through Cofin_2004 (grants #2004040502_001 and 2004040502_002), Cofin_2008 (grants #2008HMHYFP_002 and 2008HMHYFP_004) and Cofin_2010-2011 (grants #2010TT22SC_001, 2010TT22SC_005 and 2010TT22SC_006; 2010TT22SC_003) projects, to Sandro Conticelli and Massimo Mattei, respectively. Further financial support for geochronological analyses was provided by Spanish projects CGL2009-06968-E, CGL2005-03511/BTE and HI2006-0073 to Carles C. Soriano.Peer Reviewe

    Enhancing Bitumen Properties through Worm Mix Asphalt Additives: A Study on Physical and Rheological Characteristics

    Get PDF
    This study aimed to determine how various concentrations of warm mix asphalt (WMA) additives can affect the rheological and physical characteristics of asphalt cement. Bitumen was modified by the chemical additive PAWMA® with an addition ratio of (0.2, 0.4, and 0.6), while the organic additives, Sasobit® and Kaowax®, were added at concentrations of (2, 4, and 6%) by the weight of bitumen. Bitumen hardness, softness, temperature susceptibility, viscosity, and elastic behavior have all been measured using a variety of physical and rheological tests, such as the penetration degree, softening point, penetration index, rotational viscosity, and dynamic shear rheology. This study showed that bitumen physical and rheological properties were affected differently according to the type and percentage of the WMA additive employed. The PAWMA additive, for instance, raised the bitumen penetration while Sasobit® and Kaowax® decreased the bitumen penetration degree. The inverse occurred for the softening point values. All WMA additives lowered bitumen viscosity values. Results from a dynamic shear rheometer (DSR) showed that the rutting index value (G*/Sin) rose, indicating improved rutting resistance
    • …
    corecore