Fabrication and mechanical testing of a new sandwich structure with carbon fiber network core

The aim is the fabrication and mechanical testing of sandwich structures including a new core material known as fiber network sandwich materials. As fabrication norms for such a material do not exist as such, so the primary goal is to reproduce successfully fiber network sandwich specimens. Enhanced vibration testing diagnoses the quality of the fabrication process. These sandwich materials possess low structural strength as proved by the static tests (compression, bending), but the vibration test results give high damping values, making the material suitable for vibro-acoustic applications where structural strength is of secondary importance e.g., internal panelling of a helicopter

High pressure gas flow, storage, and displacement in fractured rock-Experimental setup development and application.

This paper presents the design, development, and application of a laboratory setup for the experimental investigations of gas flow and reactions in a fractured rock. The laboratory facility comprises (i) a high pressure manometric sorption apparatus, where equilibrium and kinetic phenomena of adsorption and desorption can be examined, (ii) a high pressure triaxial core flooding system where the chemical reactive transport properties or processes can be explored, and (iii) an ancillary system including pure and mixed gas supply and analysis units. Underground conditions, in terms of pore pressure, confining pressure, and temperature, can be replicated using the triaxial core flooding system developed for depths up to 2 km. Core flooding experiments can be conducted under a range of gas injection pressures up to 20 MPa and temperatures up to 338 K. Details of the design considerations and the specification for the critical measuring instruments are described. The newly developed laboratory facility has been applied to study the adsorption of N2, CH4, and CO2 relevant to applications in carbon sequestration in coal and enhanced coalbed methane recovery. Under a wide range of pressures, the flow of helium in a core sample was studied and the evolution of absolute permeability at different effective stress conditions has been investigated. A comprehensive set of high resolution data has been produced on anthracite coal samples from the South Wales coalfield, using the developed apparatus. The results of the applications provide improved insight into the high pressure flow and reaction of various gas species in the coal samples from the South Wales coalfield

Effect of some biotic factors on microbially-induced calcite precipitation in cement mortar

Sporosarcina pasteurii, a common soil bacterium has been tested for microbial treatment of cement mortar. The present study also seeks to investigate the effects of growth medium, bacterial concentration and different buffers concerning the preparation of bacterial suspensions on the compressive strength of cement mortar. Two growth media, six different suspensions and two bacterial concentrations were used in the study. The influence of growth medium on calcification efficiency of S. pasteurii was insignificant. Significant improvement in the compressive as well as the tensile strength of cement mortar was observed. Microbial mineral precipitation visualized by Scanning Electron Microscopy (SEM) shows fibrous material that increased the strength of cement mortar. Formation of thin strands of fillers observed through SEM micrographs improves the pore structure, impermeability and thus the compressive as well as the tensile strengths of the cement mortar. The type of substrate and its molarity have a significant influence on the strength of cement mortar

A comparison of flexural strengths of polymer (SBR and PVA) modified, roller compacted concrete

This brief article aims to reveal the flexural performance, including the equivalent flexural strength of PVA (Polyvinyl Alcohol) modified concrete by comparing it primarily with that of SBR (Styrene Butadiene Rubber) concrete. This data article is directly related to Karadelis and Lin [6]

On the identification of earlywood and latewood radial elastic modulus of Pinus pinaster by digital image correlation: a parametric analysis

This work addresses the reconstruction of strain gradient fields at the wood growth ring scale from full-field deformation measurements provided by digital image correlation. Moreover, the spatial distribution of the earlywood and latewood radial modulus of elasticity is assessed. Meso-scale tensile tests are carried out on Pinus pinaster Ait. Wooden specimens oriented in the radial–tangential plane under quasi-static loading conditions. A parametric analysis of the twodimensional digital image correlation extrinsic and intrinsic setting parameters is performed, in a balance between spatial resolution and resolution. It is shown that the parametric module is an effective way to quantitatively support the choice of digital image correlation parameters in the presence of the high deformation gradient fields generated by the structure–property relationships at the scale of observation. Under the assumption of a uniaxial tensile stress state, the spatial distribution of the radial elastic modulus across the growth rings is obtained. It is observed that the ratio of the radial modulus of elasticity between latewood and earlywood tissues can vary significantly as a function of the digital image correlation parameters. It is pointed out, however, that a convergence value can be systematically established. Effectively, earlywood and latewood stress–strain curves are obtained and elastic properties are determined assuming the converged digital image correlation setting parameters

Evaluation of activated high volume fly ash systems using Na2SO4, lime and quicklime in mortars with high loss on ignition fly ashes

In general, concretes made with blended Portland cement containing high volumes of fly ash provide an alternative to conventional Portland cement concrete to enable carbon footprint reduction. This study evaluates the chemical activation of four fly ashes in blends with Portland cement, by assessing their effects on hydration and compressive strength. In this study, a sieving process is used to regulate the fly ash composition, which has an effect in the chemistry and reaction of the mix. The results show the importance of the amorphous content of the fly ash with respect to achieving a high compressive strength. The effect of sodium sulfate, added as an activator, is significant in terms of compressive strength at early age for two of the fly ashes studied; in this case, the parameter used to correlate with the compressive strength evolution is the amount of portlandite consumed through pozzolanic reactions. However, sodium sulfate does not have the same effect on fly ashes with a high amount of Fe2O3, in which portlandite consumption is much lower

Application of several pretreatment technologies to a wastewater effluent of a petrochemical industry finally treated with reverse osmosis

[EN] This work studies the adequacy of different reverse osmosis (RO) pretreatments applied to different petrochemical wastewater effluents. Three effluents from a caprolactam factory were analysed: ion-exchange resin washing effluent (RWE), batch reactor washing effluent and factory outlet effluent. Coagulation–flocculation, microfiltration (MF) and ultrafiltration (UF) were tested as RO pretreatments. Various inorganic coagulants (Aluminium Chloride, Iron (III) Chloride, Aluminium Sulphate and polyaluminium chloride), commercial coagulants (Nophos and ACO) and commercial flocculants (polyacrylamide, CH-30 and active polyfloc) were tested at different dosages and stirring speeds. The highest removal of suspended solids (SS) and the lowest turbidity were obtained for the ion-exchange RWE. Two combinations of coagulants and flocculants were chosen as the most suitable conditions for the coagulation–flocculation process. The ion-exchange RWE was further treated with a combination of MF followed by UF. SS were completely removed and turbidity decreased to 0.136 NTU. The silt density index at 15 min was reduced to 6.41.The authors of this work wish to gratefully acknowledge the financial support from the Generalitat Valenciana through the programme “Ayudas para la realizacio´n de proyectos I+D para grupos de investigacio´n emergentes GV/2013”.Vincent Vela, MC.; Alvarez Blanco, S.; Lora García, J.; Carbonell Alcaina, C.; Sáez Muñoz, M. (2014). Application of several pretreatment technologies to a wastewater effluent of a petrochemical industry finally treated with reverse osmosis. Desalination and Water Treatment. 1-9. doi:10.1080/19443994.2014.939866S19Benito-Alcázar, C., Vincent-Vela, M. C., Gozálvez-Zafrilla, J. M., & Lora-García, J. (2010). Study of different pretreatments for reverse osmosis reclamation of a petrochemical secondary effluent. Journal of Hazardous Materials, 178(1-3), 883-889. doi:10.1016/j.jhazmat.2010.02.020Madaeni, S. S., & Eslamifard, M. R. (2010). Recycle unit wastewater treatment in petrochemical complex using reverse osmosis process. Journal of Hazardous Materials, 174(1-3), 404-409. doi:10.1016/j.jhazmat.2009.09.067Kim, H.-C., & Dempsey, B. A. (2008). Effects of wastewater effluent organic materials on fouling in ultrafiltration. Water Research, 42(13), 3379-3384. doi:10.1016/j.watres.2008.04.021Karabacakoğlu, B., Tezakıl, F., & Güvenç, A. (2014). Removal of hardness by electrodialysis using homogeneous and heterogeneous ion exchange membranes. Desalination and Water Treatment, 54(1), 8-14. doi:10.1080/19443994.2014.880159Gare, S. (2002). RO systems: the importance of pre-treatment. Filtration & Separation, 39(1), 22-27. doi:10.1016/s0015-1882(02)80047-7Garg, A., Mishra, I. M., & Chand, S. (2010). Effectiveness of coagulation and acid precipitation processes for the pre-treatment of diluted black liquor. Journal of Hazardous Materials, 180(1-3), 158-164. doi:10.1016/j.jhazmat.2010.04.008Verma, S., Prasad, B., & Mishra, I. M. (2010). Pretreatment of petrochemical wastewater by coagulation and flocculation and the sludge characteristics. Journal of Hazardous Materials, 178(1-3), 1055-1064. doi:10.1016/j.jhazmat.2010.02.047Garrote, J. (1995). Treatment of tannery effluents by a two step coagulation/flocculation process. Water Research, 29(11), 2605-2608. doi:10.1016/0043-1354(94)00312-uSanto, C. E., Vilar, V. J. P., Botelho, C. M. S., Bhatnagar, A., Kumar, E., & Boaventura, R. A. R. (2012). Optimization of coagulation–flocculation and flotation parameters for the treatment of a petroleum refinery effluent from a Portuguese plant. Chemical Engineering Journal, 183, 117-123. doi:10.1016/j.cej.2011.12.041Wang, J.-P., Chen, Y.-Z., Wang, Y., Yuan, S.-J., & Yu, H.-Q. (2011). Optimization of the coagulation-flocculation process for pulp mill wastewater treatment using a combination of uniform design and response surface methodology. Water Research, 45(17), 5633-5640. doi:10.1016/j.watres.2011.08.023Rossini, M., Garrido, J. G., & Galluzzo, M. (1999). Optimization of the coagulation–flocculation treatment: influence of rapid mix parameters. Water Research, 33(8), 1817-1826. doi:10.1016/s0043-1354(98)00367-4Guida, M., Mattei, M., Della Rocca, C., Melluso, G., & Meriç, S. (2007). Optimization of alum-coagulation/flocculation for COD and TSS removal from five municipal wastewater. Desalination, 211(1-3), 113-127. doi:10.1016/j.desal.2006.02.086HABERKAMP, J., RUHL, A., ERNST, M., & JEKEL, M. (2007). Impact of coagulation and adsorption on DOC fractions of secondary effluent and resulting fouling behaviour in ultrafiltration. Water Research, 41(17), 3794-3802. doi:10.1016/j.watres.2007.05.029Petrov, S., & Stoichev, P. (2002). Reagent ultrafiltration purification of water contaminated with reactive dyes. Filtration & Separation, 39(8), 35-34. doi:10.1016/s0015-1882(02)80229-4Shon, H. K., Vigneswaran, S., Ngo, H. H., & Ben Aim, R. (2005). Is semi-flocculation effective as pretreatment to ultrafiltration in wastewater treatment? Water Research, 39(1), 147-153. doi:10.1016/j.watres.2004.09.003Hatt, J. W., Germain, E., & Judd, S. J. (2011). Precoagulation-microfiltration for wastewater reuse. Water Research, 45(19), 6471-6478. doi:10.1016/j.watres.2011.09.039Dryden Aqua Ltd, Edinburgh, 2013. Available from: www.DrydenAqua.com (April 6, 2013).Sincero, A. P., & Sincero, G. A. (2002). Physical-Chemical Treatment of Water and Wastewater. doi:10.1201/978142003190