Open Access Original Research Article

Experimental Investigation of Building Thermal Insulation from Agricultural By-products

Krishpersad Manohar

Current Journal of Applied Science and Technology, Page 227-239
DOI: 10.9734/BJAST/2012/1528

The thermo-physical properties of environmentally friendly biodegradable agricultural by-products, oil palm, coconut and sugarcane fiber, were investigated for use as potential building thermal insulation. Thermal conductivity measurements were conducted on 51 mm thick, 254 mm square test specimens in accordance with ASTM C518 where the apparent thermal conductivity, λ, was measured under steady-state one-dimensional test conditions with heat flow upwards. The test apparatus provided λ measurements with ±0.2% repeatability and ±0.5% reproducibility within the range 0.005 W/m.K to 0.35 W/m.K. For all three materials, experimental data at various mean test temperatures show the thermal conductivity variation with density followed the characteristic hooked shape associated with loose-fill fibrous insulation. Test results indicated that sugarcane fiber with the lowest solid fiber density of 686 kg/m3 exhibited the lowest apparent thermal conductivity of 0.04610 W/m.K and a trend of increase in solid fiber density of the material reflected an increase in the minimum λ of the fibrous batt. The minimum λ for the materials ranged between 0.04160 W/m.K to 0.05784 W/m.K over the mean temperature ranges 15.6°C to 32°C. These λ values are within the range 0.02 W/m.K to 0.06W/m.K which is normally used for thermal building insulation.

 

Open Access Original Research Article

foF2 Long Term Trends at Ouagadougou Station

Frédéric Ouattara

Current Journal of Applied Science and Technology, Page 240-253
DOI: 10.9734/BJAST/2012/1552

A trough station (Ouagadougou station) of African Equatorial Ionization Anomaly sector foF2 long term trends are carried out after the elimination of solar cycle long term variation part. For this part, foF2 is expressed as a third degree polynomial function of Rz. We analyzed diurnal, seasonal and annual foF2 long term trends during 30 years covering the period 1966-1996. Diurnal trend variation showed positive hourly trend at the morning (slope maximum value at 0400 LT: + 1.5 x 10-3 per year) and at night (slope maximum value at 2200 LT: + 0.7 x 10-3 per year). During night and morning times well correlation is observed between foF2 and Ap. The absolute maximum trend is observed at 1900 LT (+ 2.5 x 10-3 per year). Seasonal variation at 1900 LT exhibited for each season positive trend except during summer where negative trend was observed (-0.0472 per year). At equinoxes, there is no asymmetry and foF2 trend is + 0.0412 per year. Annual investigation showed that from 1966 to 1981 Ap and foF2 present the same sense variation while from 1981 to 1966 it is the reverse. At 0400 LT, between 1966 and 1981 relative foF2 presents positive trend (+5.4 x 10-3 per year) and between 1981 and 1996, it shows negative trend (- 5.3 x 10-3 per year). At 1900 LT, for the 30 years involved, relative foF2 shows strong negative trend (- 6.5x 10-3 per year).

 

Open Access Original Research Article

Extent of Highway Travel Time Differentials Resulting from Rainfall Intensities

Nordiana Mashros, Johnnie Ben-Edigbe, Raha Rahman

Current Journal of Applied Science and Technology, Page 254-265
DOI: 10.9734/BJAST/2012/1416

Travel time on a roadway segment is what most road users are concerned about. It is a useful guide for measuring road users’ perception of the quality of roadway service. Rainfall affects traffic flows by reducing drivers’ visibility and road surface friction among others. These reductions have profound impacts on travel time. The aim of the paper is to determine the impact of rainfall intensities (slight, moderate and heavy) on travel time. The impact study was carried out at locations along Terengganu East Coast Highway 5, between November 2010 and February 2011. Based on the hypothesis that rainfall intensity has effect on travel time, a ‘with-and-without rainfall impact study for both directions of a single carriageway was conducted. Volume, speed, headway, gaps and types of vehicles collected by way of automatic traffic counter continuously for three months estimated and compared. Rainfall data were collected and supplemented with data supplied by the Malaysian Hydrology Department. Results show that light and moderate rainfall will cause a travel time increase of about 0.43 and 0.54 minutes per kilometer by respectively; whereas heavy rainfall will account for travel time increase of 0.74 minutes per kilometer. It also shows that traffic kinematics and shockwave propagations at the onset of rainfall can also be called to account for travel time differentials. The paper concluded that rainfalls irrespective of their intensities have significant impact on roadway travel time.

 

Open Access Original Research Article

Baseline Measurement of Natural Radioactivity in Soil, Vegetation and Water in the Industrial District of the Federal Capital Territory (FCT) Abuja, Nigeria

A.M. Umar, M.Y. Onimisi, S.A. Jonah

Current Journal of Applied Science and Technology, Page 266-274
DOI: 10.9734/BJAST/2012/1467

Natural radioactivity in environmental samples (soil, vegetation and water) from the (Idu) industrial district of Federal Capital Territory (FCT) Abuja, Nigeria was measured by means of gamma-ray spectrometer with NaI (Tl) detector to establish a baseline data for activity concentration of 40K, 226Ra and 232Th. The highest activity concentration of 40K, 226Ra and 232Th were found in soil collected from location S2 (943.1 Bq/kg), in vegetation VC (82.3 Bq/kg) and in soil collected from location S3 (107.3 Bq/kg), respectively, where only the activity from S2 is higher than the world average of 420 Bq/kg and the highest activity concentrations of both 226Ra and 232Th from VC (82.3 Bq/kg) is above the world average of 50 Bq/kg (UNSCEAR, 2000). Results from the twelve field samples analysed also indicated that the activity concentration due to 40K in the soil samples ranked highest against the lowest value obtained for sediments in the water samples.

 

Open Access Original Research Article

Development of an Intelligent Electronic Module for Energy Management in Wind/Diesel or Photovoltaic/Diesel Hybrid Systems

Julius K. Tangka, P. Tchakoua, H. Fotsin, A. Fomethe

Current Journal of Applied Science and Technology, Page 275-295
DOI: 10.9734/BJAST/2012/1513

An intelligent electronic module for managing battery power in a wind/diesel, solar/diesel or wind/solar/diesel hybrid systems was designed, fabricated and tested. It is made of five blocks mainly a power supply unit, a battery voltage monitor, a programmable interface controller, a battery charger, and a start up monitor block. A computer program inscribed on the module permits it to perform five commands. It connects dump load 1 when battery voltage attains 15V. It connects dump load 2 when battery voltage of 15V persists for some time while dump load 1 is already connected. It starts the backup generator when battery voltage is below 10.5V with no energy from the renewable source. It is also programmed to activate battery charging when only the generator is working. Based on the logical sequence designed, the module was erected on an integrated circuit using the, Advanced Routing and Editing Software, (ARES) of Proteus Professional Laboratory. Simulations using the Isis software for all types of eminent energy hybrid system scenarios in an off grid setting revealed that the module can successfully manage energy supply in a wind/diesel, PV/diesel or wind/PV/diesel system. During field tests the module was inserted in a micro hybrid system made of a small locally made 700watts Hugh Piggott type wind turbine, a 200watts solar module and a 5kw diesel generator. The battery bank was a 2400AH battery bank capacity. The module successful communicated with the all the components connected except dump load 2 due to the fact that dump load one was enough to handle excess voltage. It was concluded that the module can successful manage energy storage and distribution in a small off grid hybrid system of wind/diesel of PV/diesel.

Open Access Review Article

The Applications of Membrane Operations in the Textile Industry: A Review

Abdulraheem Giwa, Abiodun Ogunribido

Current Journal of Applied Science and Technology, Page 296-310
DOI: 10.9734/BJAST/2012/1520

Water reuse continues to rise as demand for fresh water supplies increases worldwide. By recycling and reusing treated wastewater, communities and industries can save on the costs of clean water, ensure adequate supplies and help to preserve a diminishing natural resource. The increase in water reuse has been driven largely by innovative treatment technologies that are both cost effective and reliable in removing harmful bacteria and pathogens. Membrane technology offers several varied applications covering many aspects of the textile processing. These applications are unique because they provide a return on investment (ROI) while abating a water pollution problem. This paper presents descriptions of some of the uses membranes have in textile operations and their benefits, it also delivers a scientific and technical overview and useful information to scientists and engineers who work in this field.