Effect of sulphuric acid on concrete with iron ore tailings

Researches into the uses of waste materials are increasingly being explored to meet up society’s needs and global protection for sustainable, safe and economic development. This paper assessed concrete with iron ore tailings (IOT) exposed to dilute sulphuric acid. Iron ore tailings are the materials left-over after separating the valuable fraction from the uneconomic fraction of an ore. To study the effect of sulphuric acid, concrete of 100 mm cube with a different mix ratios containing IOT were prepared and cured for 28 days in water. The cubes were later immersed into dilute sulphuric acid at a concentration of 5%. The compressive strength of concrete at 7, 28 and 90 days of water curing were determined. Mass loss and strength reduction due to sulphuric effect were evaluated at 7, 28 and 90 days respectively. XRD microstructure of concrete specimens was analysed. Test results indicated that the IOT could be used in concrete as sand replacement since the concrete with IOT has similar trend in compressive strength loss and mass loss to sulphuric acid attack compared to control specimen. The mineralogical crystal failure patterns due to the sulphuric acid in terms X-ray diffraction analysis are the same for control and IOT concrete

Comparing the effects of oil palm kernel shell and cockle shell on properties of pervious concrete pavement

Nowadays, pervious concrete pavement is one of the best materials used in construction industry as a top layer of permeable pavement system to control the storm water at source. In addition, increasing production of waste materials, increased the interest in utilising the waste materials for environmental and technical benefits. Therefore, this paper compared the effect of using two different sizes of oil palm kernel shell (OPKS) and cockleshell (CS) as partial replacement of natural coarse aggregate on properties of pervious concrete pavement. Thirteen mixtures were made, in which 6.30-mm natural gravel was replaced with 0, 25, 50 and 75% of 6.30-mm and 4.75-mm of both shells. The relationships between the properties of pervious concrete mixtures was also determined. The replacement of OPKS and CS as the natural aggregate decreased the compressive strength, while the angular shape of both shells caused higher void content and permeability as compared to those of control pervious concrete. On the other hand, pervious concrete containing CS showed better properties than those of incorporating OPKS. Apart from that, strong relationships between density, void content, permeability, compressive strength values indicated that they can be used as a pervious concrete quality control tests for prediction of properties of pervious concrete pavement before placement in the field

Evaluation Of Wind Turbine Potentiality At Windy Sites In Malaysia.

Wind speed data in Malaysia has been Used, which was recorded hourly from years 1995 t 2002 at three meteorological stations, Mersing, Cameron Highland (Peninsular Malaysia) and Pulau Labuan ( Sabah state). The wind speed distribution and wind power were evaluated to provide spatial mean information of wind energy potential

Experiment study of using parallel plate sensor for the detection of conductive material

Gold is the yellow precious metal that has been used in many applications likes medicine, electronics, jewelry, investment and others. Thus, gold is one of the commodities which has high demand in the global market. In other to secure the purity of gold and to protect the retailer and consumer from fraud, the detection of gold is very important in the industry. There are many techniques have been used to detect the purity of gold material and those techniques must consider a several factors such as non-destructive, inexpensive, precise, simple and widely accepted by the jewelry industries. Electrical capacitance tomography (ECT) is the most mature non-destructive technique among various tomography. The advantages of ECT are non-radioactive, non-intrusive, high imaging speed and low cost. This paper introduces the ECT using the square sensor. The aim of his paper this to present a new method of verifying the conductive materials using a parallel plate sensor which adopted from the ECT system

Stochastic Generation Of Hourly Wind Speed Time Series.

In the present study hourly wind speed data of Kuala Terengganu in Peninsular Malaysia are simulated by using transition matrix approach of Markovian process. The wind speed time series is divided into various states based on certain criteria

Engineering properties of high volume biomass waste mortar

This paper represents the effects of using waste generated from palm oil industries like ash, shell and fibre on the engineering properties of mortar. Palm Oil Fuel Ash (POFA) was used as cement replacement up to 60% and Oil Palm Kernel Shell (OPKS) as sand replacement in mortar mixture. The Oil Palm Fibre was added to increase the strengthening performance of mortar. The method used to find the water binder ratio was by trial and error method with 1:3 ratio of cement to sand. The cubes size of 70mm x 70mm x 70mm, beams size of 40mm x 40mm x 160mm, and cylinders size of 70mm diameter and 150mm height, were cast and tested for compressive strength, flexural strength and splitting tensile strengths of mortar. Samples were cured in water before testing it at 7, 28, and 60 days. Also, the water absorption of mortar was tested at the age of 28 days. The results showed that oil palm fibre provided more advantages and increase the strength properties especially in the flexural and tensile strength. The addition of Oil Palm Kernel Shell reduced the density of mortar and it can be used for lightweight application. The test results also showed that as the POFA ratio increased, the compressive strength of mortar decreased. However, as OPKS ratio increased, the density was found to be decreased. The mix proportions using 60% POFA and 20% OPKS was considered as the optimum mix design. The mortar showed optimum strength at 9% with the addition of fibre

Autoregressive Integrated Moving Average Model(Arima)For Forecasting Wind Speed.

For proper planning and efficient utilization of wind energy, wind speed predictions are important. In the present study the hourly wind speed data from 1995 to 2001 at three meteorological stations at a height of 14 m above the ground level have been analysed for fitting autoregressive integrated moving average (ARIMA) models

Classification of the quantum deformation of the superalgebra GL(1∣1)GL(1|1)

We present a classification of the possible quantum deformations of the supergroup $GL(1|1)$ and its Lie superalgebra $gl(1|1)$. In each case, the (super)commutation relations and the Hopf structures are explicitly computed. For each $R$ matrix, one finds two inequivalent coproducts whether one chooses an unbraided or a braided framework while the corresponding structures are isomorphic as algebras. In the braided case, one recovers the classical algebra $gl(1|1)$ for suitable limits of the deformation parameters but this is no longer true in the unbraided case.Comment: 23p LaTeX2e Document - packages amsfonts,subeqn - misprints and errors corrected, one section adde

Geometric View of Measurement Errors

The slope of the best fit line from minimizing the sum of the squared oblique errors is the root of a polynomial of degree four. This geometric view of measurement errors is used to give insight into the performance of various slope estimators for the measurement error model including an adjusted fourth moment estimator introduced by Gillard and Iles (2005) to remove the jump discontinuity in the estimator of Copas (1972). The polynomial of degree four is associated with a minimun deviation estimator. A simulation study compares these estimators showing improvement in bias and mean squared error

Characterization of a sodium dodecyl sulphate-degrading Pseudomonas sp. strain DRY15 from Antarctic soil

A bacterium capable of biodegrading surfactant sodium dodecyl sulphate (SDS) was isolated from Antarctic soil. The isolate was tentatively identified as Pseudomonas sp. strain DRY15 based on carbon utilization profiles using Biolog GN plates and partial 16S rDNA molecular phylogeny. Growth characteristic studies showed that the bacterium grew optimally at 10 degrees C, 7.25 pH, 1 g l(-1) SDS as a sole carbon source and 2 g l(-1) ammonium sulphate as nitrogen source. Growth was completely inhibited at 5 g l(-1) SDS. At a tolerable initial concentration of 2 g l(-1), approximately 90% of SDS was degraded after an incubation period of eight days. The best growth kinetic model to fit experimental data was the Haldane model of substrate inhibition with a correlation coefficient value of 0.97. The maximum growth rate was 0.372 hr(-1) while the saturation constant or half velocity constant (Ks) and inhibition constant (Ki), were 0.094% and 11.212 % SDS, respectively. Other detergent tested as carbon sources at 1 g l(-1) was Tergitol NP9, Tergitol 15S9, Witconol 2301 (methyl oleate), sodium dodecylbenzene sulfonate (SDBS), benzethonium chloride, and benzalkonium chloride showed Tergitol NP9, Tergitol 15S9, Witconol 2301 and the anionic SDBS supported growth with the highest growth exhibited by SDBS.Fil: Halmi, M. I. E.. University of Putra; MalasiaFil: Hussin, W. S. W.. University of Putra; MalasiaFil: Aqlima, A.. University of Putra; MalasiaFil: Syed, M. A.. University of Putra; MalasiaFil: Ruberto, Lucas Adolfo Mauro. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: MacCormack, Walter P.. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Yukor, M. Y.. University of Putra; Malasi