6,249 research outputs found

    Studying the Dynamical Properties of 20 Nearby Galaxy Clusters

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    Using SDSS-DR7, we construct a sample of 42382 galaxies with redshifts in the region of 20 galaxy clusters. Using two successive iterative methods, the adaptive kernel method and the spherical infall model, we obtained 3396 galaxies as members belonging to the studied sample. The 2D projected map for the distribution of the clusters members is introduced using the 2D adaptive kernel method to get the clusters centers. The cumulative surface number density profile for each cluster is fitted well with the generalized King model. The core radii of the clusters' sample are found to vary from 0.18 Mpc \mbox{h}^{-1} (A1459) to 0.47 Mpc \mbox{h}^{-1} (A2670) with mean value of 0.295 Mpc \mbox{h}^{-1}. The infall velocity profile is determined using two different models, Yahil approximation and Praton model. Yahil approximation is matched with the distribution of galaxies only in the outskirts (infall regions) of many clusters of the sample, while it is not matched with the distribution within the inner core of the clusters. Both Yahil approximation and Praton model are matched together in the infall region for about 9 clusters in the sample but they are completely unmatched for the clusters characterized by high central density. For these cluster, Yahil approximation is not matched with the distribution of galaxies, while Praton model can describe well the infall pattern of such clusters.Comment: 16 pages, 8 figure

    Mixture characteristics of buton rock asphalt

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    The huge deposit of Buton Rock Asphalt (BRA) in Lawele of Buton Island, Indonesia, has not been utilized optimally. The less optimal usage was due to lack of knowledge on its characteristics. It is expected that there will be a shortage in petroleum bitumen, due to high price or limited sources of petroleum in the future. In this research, the bitumen used was penetration grade 80 /100 as control. Numerous bitumen tests were conducted in the laboratory to investigate the characteristic of BRA bitumen such as the penetration, softening point, and viscosity test. Only one aggregate gradation was considered under this investigation. An attempt was made to evaluate the mixture characteristics of BRA. The optimum bitumen content by using the Superpave mix design method were 6% , 6%, 6.5%, 7% for petroleum bitumen, BRA bitumen, 10% BRA granular and 15% BRA granular, respectively. Then by using Universal Testing Machine (UTM), the samples were tested for performance tests which were Indirect Tensile Stiffness Modulus Test and Dynamic Creep Test. The samples were tested at different temperatures of 30˚C, 40˚C, 50˚C using the Indirect Tensile Stiffness Modulus Test. Similarly, the samples were tested at 45˚C using Dynamic Creep Test. It was observed that the effectiveness of using BRA as granular showed better performance in the asphalt mixture. From the results, the use of 15% BRA granular showed the highest stiffness modulus and the highest permanent deformation resistance when compared with 10% of BRA granular and BRA bitumen. In addition, the use of 15% BRA granular showed the highest creep resistance

    A framework for IoT-enabled environment aware traffic management

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    Vehicular traffic has increased across all over the world especially in urban areas due to many reasons including the reduction in the cost of vehicles, degradation of the quality of public transport services and increased wealth of people. The traffic congestion created by these vehicles causes many problems. Increased environment pollution is one of the most serious negative effects of traffic congestion. Noxious gases and fine particles emitted by vehicles affect people in different ways depending on their age and present health conditions. Professionals and policy makers have devised schemes for better managing traffic in congested areas. These schemes suffer from many shortcomings including the inability to adapt to dynamic changes of traffic patterns. With the development of technology, new applications like Google maps help drivers to select less congested routes. But, the identification of the best route takes only the present traffic condition on different road segments presently. In this paper the authors propose a system that helps drivers select routes based on the present and expected environment pollution levels at critical points in a given area

    STR-827: SHEAR STRENGTH OF CIRCULAR CONCRETE BEAMS REINFORCED WITH GFRP BARS

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    This paper presents the results of an investigation of the shear strength and behavior of three circular concrete beams reinforced with glass-FRP (GFRP) bars and spirals. The beams, which measured 3,000 mm in length by 500 mm in diameter, were tested under four-point bending. The test parameters included the GFRP-spiral-reinforcement ratio (different spiral spacings [150 and 200 mm] and spiral diameters [13 and 15 mm]). As designed, the beams failed in shear due to GFRP-spiral rupture. The test results indicated that the higher the GFRP spiral reinforcement ratio, the higher the enhancement of the shear strength due to the confinement, which controls shear cracks and improves aggregate interlocking

    Some biological aspects of four marine fish species in Iraqi marine waters, northwest Arabian Gulf

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    The study described some biological characteristics of four commercially important fish species in Iraqi marine waters including Planiliza klunzengeri, P. subviridis, Acanthopagrus arabicus and Otolithes ruber from February 2020 to January 2021. The length and weight of individual fish caught were measured. The length-weight relationships were W= 0.027L2.715 for P. klunzengeri,  W= 0.034L2.670 for P. subviridis,  W= 0.030L2.867 for A. arabicus and W= 0.023L2.755 for O. ruber, and all species indicated negative allometric growth. The lower values of the relative condition factor (Kn) were found at the mid-lengths of P. klunzingeri and P. subviridis, and the large individuals for A. arabicus and O. ruber. Scales were used for age determination and measurements, and the back-calculated lengths-at-ages were calculated using the body proportional formula. Asymptotic total lengths (L∞) estimated were 29.6, 32.8, 44.9 and 70.6 cm for P. klunzengeri, P. subviridis, A. arabicus and O. ruber, respectively. These results could assist in fisheries management for the sustainable exploitation of these commercially important species in Iraqi marine waters

    SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL STUDY OF MANNICH BASES AND THEIR COPPER (II) COMPLEXES

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    Objective: The present study is focused on the synthesis of novel Mannich bases and their metal complexes, and to characterize them by physical, chemical and biological methods. Mannich bases, 2-(piperazin-1-yl(thiophen-2-yl)methyl)hydrazinecarboxamide (PTMHC), 2-(piperazin-1-yl(thiophen-2-yl)methyl)hydrazinecarbothioamide (PTMHCT), and 2-((4-methylpiperazin-1-yl)(thiophen-2-yl)methyl)hydrazinecarboxamide (MPTMHC) and 2-((4-methylpiperazin-1-yl)(thiophen-2-yl)methyl)hydrazinecarbothioamide (MPTMHCT), were prepared by Mannich condensation method.Methods: The compounds and complexes were prepared by known literature methods. Characterizations were carried out through physical methods such as elemental analyses, melting point and TLC. IR, 1H NMR, [13]C NMR and Mass spectral studies were carried out to characterize the ligands. The methods like EPR, magnetic susceptibility measurements, conductance measurements and thermal analysis were carried out for complexes besides the UV-Vis and IR spectral studies. Anti-cancer activity of synthesized ligands was performed using human lung and colon cancer cell lines.Results: Eight compounds have been prepared and characterized. Four among the eight compounds were used as ligands for the preparation of metal complexes. The results of physical and chemical methods show all the complexes act as bidentate ligands. The coordination with the metal ion takes place through N, S and O atoms. The results of molar conductivity and magnetic susceptibility measurements reveal the electrolytic and non-electrolytic nature of the metal complexes. EPR and TG-DTA studies also support the other spectral data.Conclusions: Copper (II) complexes of PTMHC, PTMHCT, MPTMHC, and MPTMHCT were prepared and their structures were determined. The anti-cancer activity of the synthesized ligands and their complexes was evaluated. The synthesized novel ligands of Mannich bases can serve as a potential anti-cancer agent.Â

    Embryoid induction and plantlet regeneration from leaf segments of sugarcane (Saccharum officinarum L.)

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         Sugarcane (Saccharum officinarum L.) is an economically important crop in Sudan for domestic consumption and export. It is the first and essential source for production of high purity sugar. Tissue culture techniques can be used for in vitro conservation of sugarcane (Taylor and Dukic, 1993) and mass propagation of elite cultivars of crop species. Moreover, it was used for production of pathogen-free planting material from infected mother plants. Variability induced in vitro can furnish a base for improvement of vegetatively propagated crops including sugarcane. Different tissue culture techniques were applied successfully to sugarcane propagation and plant regeneration through organogenesis of shoot meristem (Nadar and Heinz, 1977; Ho and Vasil, 1983a), cell suspension cultures (Ho and Vasil, 1983b, Aftab et al., 1996) and protoplast cultures ( Liu, 1994). Cell suspen - Sion cultures were also used for cytological, pathological (Peros and Lombard, 1992), biochemical and physiological investigations of sugarcane (Heinz et al., 1977).      This study was initiated, during 1998-2000, to investigate the effect of 2,4-D on induction of embryogenic callus from leaf explants of sugarcane and regeneration of somatic embryos on different concen-trations of Murashige and Skoog (1962) medium (MS)

    Chilled Water Storage Feasibility with District Cooling Chiller in Tropical Environment

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    The difficulties of efficiently operating a chiller cooling system are manifest in the high-energy consumption under partial-cooling loads. The performance of a chiller cooling system declines when operating away from the optimal design conditions, which is typically 75% of chiller capacity. One pathway has been found to overcome this problem using multiple smaller chillers within the same chiller plant, accompanied by a smart control system that is designed and constructed based on the cooling demand profile. Thermal energy storage integration with chiller cooling system is proposed to shave the cooling peak demand. This can be achieved by storing chilled water during the lower electricity-tariff period by the thermal energy storage system, which will then be discharged during the higher tariff-rate, thus, aiming for sustainable operating cost. The present paper studies the feasibility of sensible thermal energy storage to be integrated with two chillers, of 30-ton capacity each, under hot-and-humid climates. A computational model validated with experimental results is developed for three chiller cooling system case scenarios. The smart control scenario, as well as the thermal energy storage scenario results, showed great potential for energy and electricity cost saving. In addition, the carbon dioxide emissions reduction is calculated based on the amount of energy saving
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