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Removal of copper from copper-contaminated river water and aqueous solutions using Methylobacterium extorquens modified Erzurum clayey soil

Abstract

The objective of this study was to investigate the possibility of using natural and bacteria-modified Erzurum clayey soil with Methylobacterium extorquens as an alternative to high cost commercial adsorbent materials for the removal of copper from aqueous solution. The copper concentrations in the samples of the polluted river water and CuCl2 solutions treated by the natural and bacteria-modified Erzurum clayey soil (ECS) have been determined by spectrophotometric method. Firstly, the surface of ECS was modified with M. extorquens and surface functionality was increased. Then, the adsorption of Cu (II) from solution phases was studied with respect to varying metal concentration, pH, and temperature and agitation time. The maximum adsorption of Cu (II) for natural and bacteria-modified Erzurum clayey soil was observed at pH: 5.0. At different copper concentrations, copper adsorption analysis was performed on 1 g using clay soil or modified clay soil. Maximum adsorption of Cu (II) was obtained as 45.7 and 48.1 mg g-1 at initial concentration (50 mg/50 mL) and optimal conditions by natural and bacteria-modified clay soil, respectively. The copper concentration was decreased in the substantial amount of the leachates solutions of natural and bacteria-modified clay soil. Langmuir and Freundlich isotherms were used to describe the adsorption behavior of Cu (II) ions. The results showed that modified clay soil had a high level of adsorption capacity for copper ion. The various thermodynamic parameters such as ΔG°, ΔH° and ΔS° were analyzed to observe the nature of adsorption. The structural properties of the natural and bacteria-modified-ECS have been characterized by SEM, FTIR and XRD techniques. Consequently, it was concluded that the bacteria-modified clay soil could be successfully used for the removal of the copper ions from the aqueous solutions.

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Synthesis, characterization and photovoltaic properties of Mn-doped Sb2S3 thin film

Abstract

Synthesis and characterization of Mn-doped Sb2S3 thin films (TFs) prepared by chemical bath deposition (CBD) at room temperature have been documented and their structural, optical, morphological, magnetic and photovoltaic properties have been examined for the first time. Their structural properties reveal that the Mn-doped Sb2S3 TF has an orthorhombic phase structure of Sb2S3, and that the grain size of the Mn-doped Sb2S3 TF (72.9 nm) becomes larger than that of undoped Sb2S3 TF (69.3 nm). It has been observed that Mn content causes the Sb2S3 TF band gap to decrease. This situation clearly correlates with band tailing due to the impurities that are involved. The morphological properties have revealed that the shape of the Mn-doped Sb2S3 TF is more uniform than the shape of its undoped counterpart. The study on its magnetic properties has demonstrated that the Mn-doped Sb2S3 TF exhibits paramagnetic behavior. Its paramagnetic Curie-Weiss temperature was found to be -4.1 K. This result suggests that there is an anti-ferromagnetic interaction between Mn moments in the Mn-doped Sb2S3 TF. Incident photon to electron conversion efficiency (IPCE) and J-V measurements were also carried out for the Mn-doped Sb2S3 TF for the first time. The results have indicated that the Mn-doped Sb2S3 TF can be utilized as a sensitizer to improve the performance of solar cells. Another important observation on the photovoltaic properties of Mn-doped Sb2S3 TF is that the spectral response range is wider than that of undoped Sb2S3 TF. Our study suggests that the introduction of dopant could serve as an effective means of improving the device performance of solar cells.

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Production Method that Leads to TiO2 Nanofibrous Structure Usable in Food Packaging

References HE, F. – MA, F. – LI, J. – LI. T. – LI. G. 2014. Effect of calcination temperature on the structural properties and photocatalytic activities of solvothermal synthesized TiO 2 hollow nanoparticles. In Ceramics International, vol. 40, 2014, no. 5, pp. 6441–6446. ŠEVČÍK, L. – LEPŠÍK, P. – PETRŮ, M. – MAŠÍN, I. – MARTONKA, R. 2014. Modern method of construction design. In Book of Proceedings of 54 th International Conference of Machine Departments. Liberec : Technical University of Liberec, 2014. pp. 509–516. ISBN 978

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Layered Sodium Disilicates as Precursors of Mesoporous Silicas. Part II: Hydration of δ-Na2Si2O5 and α-Na2Si2O5

Layered Sodium Disilicates as Precursors of Mesoporous Silicas. Part II: Hydration of δ-Na2Si2O5 and α-Na2Si2O5

Reaction of δ-Na2Si2O5 and α-Na2Si2O5 with water at ambient conditions has been studied. The first substrate produced kanemite, the other a crystalline solid, assumed to be the layered hydrated α phase of yet unknown structure. Important differences have been observed in the kinetics of δ-Na2Si2O5 and α-Na2Si2O5 reactions with water, the phase transformation of the latter being distinctly slower. The observed different rates of hydration were associated with the different structural properties of the disilicates investigated. Hydrated δ-Na2Si2O5 and α-Na2Si2O5 possess, respectively, the platy and the needle-like morphology. Hydrated α-Na2Si2O5 contains less interlayer water, which is considered the reason for basal spacing being lower than that of kanemite. The interlayer water trapped between the layers of hydrated α-Na2Si2O5 is more strongly bound than that in kanemite.

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Performance of watermelon (Citrullus lanatus L.) in response to organic and NPK fertilizers

Abstract

The soil of North-Central Nigeria is home to many plant products that are used as industrial raw materials, and after processing their waste are often left in drainage channels, which ultimately find their way into rivers and streams where they pollute these water bodies, and sometimes some of these materials are burnt, which further aggravates global warming. In addition, the soil of the region is characterized by low organic matter content because of annual bush burnings, which reduce the low humus content of soils. Watermelon requires a fertile soil, which is high in organic matter content, while infertile soils yield an increased production of male flowers at the expense of female flowers, which results in low fruit set. Therefore, a study was carried out at the University of Ilorin Teaching and Research Farm, Ilorin, North-Central Nigeria, during the rainy seasons of 2013 and 2014 to assess the effect of different organic materials on the growth and yield of watermelon. The factors imposed were a control, NPK fertilizer and five organic materials (neem seed cake (NSC), jatropha seed cake (JSC), poultry manure (PM), compost manure (CM), and cow dung (CD)). The experiment was a randomized complete block design (RCBD) replicated thrice. Data collected on soil physico-chemical properties were: organic matter content, soil pH, organic carbon, total N, P, K, Ca, and Mg, bulk density (BD), micro porosity (MIP), macro porosity (MAP), and saturated hydraulic conductivity (KS). Plant parameters evaluated include growth (vine length and number of leaves) and yield (number of fruits per plant, fruit weight per plant, and yield ha−1). Results indicated that the organic matter content increased after the first year’s cropping and declined at the end of the study. The amended plots showed significantly higher values (P < 0.05) with respect to most soil physical properties (MIP), (MAP), and (KS), except the BD, where the values were lower. The bulk density particularly deteriorated on soils that were not organically amended. In addition, the soil chemical properties examined increased following the first year’s cropping, and thereafter declined at the end of the second-year cropping season. The response of watermelon showed that the two years’ yield data ranged between 334 and 402 t/ha, 306 and 390 t/ha, and 38.25 and 59.20 t/ha for NPK, poultry manure, and control treatments respectively. From the results, it was observed that the organic amendments were environmentally more friendly compared to the inorganic amendment (NPK fertilizer) in terms of positive effects on soil structural properties.

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On existence of nonassociative LA-ring

References [1] GAP - Groups, Algorithms and Programming. Version 4.4.12. 2008. http://www.gap-system.org [2] McCune W. Prover9 and MACE4. http://www.cs.unm.edu/mccune/mace4/ [3] Shah M, Ali A. Some structural properties of AG-group. Int. Math. Fo­rum, 2011, 6(34): 1661-1667 [4] Shah M, Gretton C, Sorge V. Enumerating AG-groups with an introduc­tion to Samarandache AG-groups. Int. Math. Forum 2011, 6(62): 3079­3086 [5] Shah M, Shah T. Some basic properties of LA-rings. Int. Math

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Application of the Drazin inverse to the analysis of descriptor fractional discrete-time linear systems with regular pencils

References Bru, R. , Coll, C., Romero-Vivo S. and Sanchez, E. (2003). Some problems about structural properties of positive descriptor systems, in L. Benvenuti, A. Santis and L. Farina (Eds.), Positive Systems , Lecture Notes in Control and Information Sciences, Vol. 294, Springer, Berlin, pp. 233-240. Bru, R., Coll, C. and Sanchez, E. (2000). About positively discrete-time singular systems, in N.E. Mastorakis (Ed.) System and Control: Theory and Applications , Electrical and Computer Engineering Series, World

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Analysis of the descriptor Roesser model with the use of the Drazin inverse

References Bru, R., Coll, C., Romero-Vivo, S. and Sanchez, E. (2003). Some problems about structural properties of positive descriptor systems, in L. Benvenuti, A. de Santis and L. Farina (Eds.), Positive Systems, Lecture Notes in Control and Information Sciences, Vol. 294, Springer, Berlin, pp. 233-240. Bru, R., Coll, C. and Sanchez, E. (2000). About positively discrete-time singular systems, in M.E. Mastorakis (Ed.), System and Control: Theory and Applications, World Scientific and Engineering Society, Athens, pp. 44

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Morphology and mechanical properties of polyamide 12 (PA12)/poly(vinylidene fluoride) (PVDF) blends

References Zdrazilowa, N., Hausnerova, B., Kitano, T. & Saha, P. (2004). The role of various modifiers in the compatibilisation of PP/PET blends — rheological and structural properties. Polimery (Warsaw) 49, 819-827. Janik, J., Lenart, S., Królikowski, W. & Penczek, P. (2004) Polymer blends PET/PE-LD and PET/PP with a new compatibilizer. Polimery (Warsaw) 49, 432-439. Bryan, E. & Ray, S. (2009) Polymers a propertity database , CRC Press, Roca Baton

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3-Paths in Graphs with Bounded Average Degree

-paths in normal plane maps, Discrete Math. 313 (2013) 2702-2711. doi:10.1016/j.disc.2013.08.018 [5] O.V. Borodin, A.V. Kostochka, J. Nešetřil, A. Raspaud and E. Sopena, On the maximum average degree and the oriented chromatic number of a graph, Discrete Math. 206 (1999) 77-89. doi:10.1016/S0012-365X(98)00393-8 [6] D.W. Cranston and D.B.West, A guide to the discharging method, arXiv: 1306.4434 [math.CO] 19 Jun 2013. [7] S. Jendrol′, A structural property of convex 3-polytopes, Geom. Dedicata 68 (1997) 91-99. doi:10.1023/A

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