Office quality classification theoretical and empirical issues

Office quality classification literature recognises identification of office classes through division of office market rent distribution into intervals but failed to provide sound theoretical framework and comprehensive empirical approach to this method. This paper theorised that as office rental levels are a function of office quality; high quality office classes should have their mean rents greater than average market rent and mean rents of low quality classes. Also that heterogeneous nature of property coupled with lack of perfect information to market participants could result into differential evaluation of rent and quality of the same property by different market participants. The behaviour of participants normally reflects in distribution of market rent by depicting natural breaks in the distribution that could be captured by univariate data exploration. Frequency and histograms of rent distributions that were assumed to depict the behaviour of market participants were used to divide rent distribution to intervals to identify office quality classes. The results of this classification were validated by discriminant analysis. 67% and 59% accuracies were achieved for estimation and holdout subsamples respectively. This paper extended theoretical and empirical approaches in office quality classification. The proposed empirical approach could be used in future classification research

Investigation of Sewage Flows in Universiti Malaysia PAHANG’s Sewerage System

Sewerage systems have long been one of the most critical infrastructure to any development project. The study presented here is part of a research that aim to evaluate the flow characteristics in sewerage systems. Sewage flow data was collected from a sewerage catchment within Universiti Malaysia PAHANG using an area-velocity flowmeter. The data obtained were extracted using a software associated to the flowmeter and analyzed for both dry and wet periods. The results show that the peak or maximum flow for the wet period with a rainfall intensity of 2.5 mm was twice as high for the dry period. The design criterion value back-calculated for the wet period was also twice the value for the design criterion value back-calculated for the dry period. This demonstrates that rainfall has an important effect on flows in sewerage system in that it increases the flow significantly. The k value back-calculated for both dry and wet periods were lower than the criterion recommended in Malaysian Standard MS1228:1991, suggesting that the current peak flow factor equation applied by the industry is over-adequate for sewerage catchments servicing the same population equivalent as this study

Effect of Inflow and Infiltration in Sewerage System of Residential Area, Kuantan, Pahang

Inflow and infiltration is a phenomenon in sewerage systems that can have negative effects on the environment and human health if not treated properly. Collaboration has been made between Universiti Malaysia Pahang (UMP) and Indah Water Konsortium Sdn. Bhd. (IWK) where the purpose is to evaluate the amount of inflow and infiltration happening in sewerage systems of residential areas in Kuantan. For this part of the study, one sewer pipeline (MH92a–MH92b) was selected at the residential area of Bandar Putra, having a population equivalent of 1694. The method used in this research was the Flowrate method to tabulate data. ISCO 2150 and 4250 Area Velocity Flowmeters were used to measure flow rate data in the sewer pipeline, whereas ISCO 674 Rain Gauge was used to collect rainfall intensity data. Calibration of all the equipment was done at the Hydrology and Hydraulic Laboratory in UMP. The data was collected for 41 days with each measurement separated by an interval of five minutes. The result shows that the average percentage Infiltration Rate of Qpeak and Qave in this residential catchment were 10.3% and 26.5% which is higher than the value mentioned in Hammer and Hammer (2012). Inflow and infiltration is a real concern, so more study is required to determine whether revision of the infiltration rate recommended in the Malaysian Standard is needed

Image analysis of non-aqueous phase liquid migration in aggregated kaolin

Double-porosity is an important feature in soil due to its influence on the migration of fluids within the soil. Conventional ways of measuring fluid saturation involves intrusive use of equipment that may disturb the original setting of the sample being measured. The use of image analysis has overcome this problem but has rarely been applied in research concerning double-porosity soil media. The study presented in this article applies image analysis to study the migration of non-aqueous phase liquid (NAPL) in soil with double-porosoity features. In this study, the laboratory experiments were conducted in a three-dimensional rectangular acrylic model and images were acquired using the photographic technique. Immiscible NAPL was chosen as the fluid applied as it is relatively less studied in double-porosity media compared to miscible contaminants. Aggregated kaolin was used as the double-porosity soil samples. Image analysis was utilized to observe the migration of the NAPL based on migration area coverage, the optical saturation of the NAPL as well as the intensity of the NAPL during migration. The experiments were performed over a range of different moisture content contained in the aggregated soil samples and the effect of different soil moisture content on the migration of NAPL in double-porosity soil was analyzed. The experimental results showed that the rate of NAPL migration will increase as the moisture content increases. In summary, image analysis was found to be a viable method in observing and visualizing the migration of NAPL based on optical saturation, intensity, and area invaded by NAPL in double-porosity soil

Assessment of the Behaviour of Soil Structure in Double-Porosity Kaolin Media Using Light Transmission Visualization (LTV) Method

Double-porosity is a phenomenon that occurs naturally and can be found in many subsurface media such as rock aquifers, agricultural topsoils and compacted soils. These media have different pore size characteristics that result in different hydraulic properties. Two approaches were used to create the doubleporosity soil structure using kaolin clay to be tested in migration of contaminant experiments using light transmission visualization (LTV) method. Aggregated kaolin and sintered clayey spheres mixture were used as the media for the first and second test, respectively. The observation shows that the first approach is not viable for a saturated-porous medium because kaolin particles have disintegrated and turned into emulsion. In contrast, uniform kaolin particles that remain strong and solid have been produced using the second approach. In conclusion, the LTV method is viable to monitor the behaviour of fluids in porous media under different conditions

Water quality improvement features of aquaponic systems and their economic feasibility

Aquaponics is an evolving sector with significant presence in arid regions or areas that have scarce arable land. Since they are a combination of aquaculture and hydroponics, naturally the focus of such systems will be the amount and quality of the food produced. Nevertheless, aquaponic systems also contain large quantites of various microorganisms that helps with fish growth and the assimilation of nutrients by plants. In a way, they are cleaning up the water as well but this aspect of aquaponic systems is largely ignored. In this study, effluent from a sewage treatment plant was fully applied in a media bed unit aquaponic system in place of natural freshwater to investigate the capability of the system in improving the quality of the water. On top of that, economic feasibility of such a system using the benefit-cost ratio method was also studied. It was found through this study that the first 12 hours upon application of the contaminated water is when the rate of change in the parameters were greatest. The water quality parameters tested (biochemical oxygen demand, chemical oxygen demand, total suspended solids, ammonia-nitrogen, nitrate-nitrogen, phosphorous, oil & grease) showed good improvement by the end of each trial. Economic feasibility of the treated sewage effluent aquaponic system was also studied using the benefit-cost ratio and it was found that the system is able to deliver a positive net present value. In short, aquaponic systems is a feasible alternative to traditional farming and agriculture

An Evaluation of the Design Criterion For Sewerage Peak Flow Factor At Segi University Hostel

Field monitoring of the sewage flows from a sewerage catchment servicing the hostel within SEGi University was performed using an area-velocity flowmeter. The data obtained were processed through the Flowlink software and the results show that the peak flow for the monitored duration occurred at night whereas the daily peak flow occurred on a weekday. The actual per capita flow measured based on the current number of students is 35.6% higher than the design per capita flow stipulated in the Malaysian Standard MS1228:1991. On the other hand, based on the actual per capita flow and actual peak flow from the duration monitored, the actual design criterion obtained is 2.88, lower than the design criterion of 4.7 recommended in MS1228:1991. From the evaluations done, the recommended design criterion for peak flow factor by MS1228:1991 is adequate for a sewerage catchment catering to a population equivalent (PE) similar to this study

Analysis of Flow Characteristics in Sewerage System

In the present study, two parameters, the per capita flow and the design criterion, were investigated. The investigation was performed on a manhole located between the library and sports complex within Universiti Malaysia Pahang, Gambang campus (UMP Gambang) where field monitoring of sewage flows was conducted. ISCO 2150 area-velocity flowmeter was used to collect the flow data and Flowlink 5.1 software was used for data retrieval as well as display. Calibration of the flowmeter was done in the Hydraulics and Hydrology Laboratory of UMP Gambang. The study duration was from November 2014 to February 2015. Each set of data consists of sewage flow readings every 5 minutes for duration of two weeks. The same data measurement interval was applied to the rainfall data, collected through an ISCO 675 rain gauge. From the results obtained, both the parameters investigated were found to be lower than their respective values stated in the Malaysia Standard MS1228:1991. After analysis of the results, it can be concluded that the flow characteristics in the sewerage system studied is sufficient to cater to the population equivalent in the stud

Marine Oil Spillage in Malaysian Waters

Oil spill is defined as the release of liquid petroleum hydrocarbon into the environment due to anthropogenic activities (Najafi et al., 2009). Oil spills in general, whether on land or in natural water bodies, constitutes some of the worst environmental disasters known to man. However, oil spills in the marine environment are particularly destructive to nature and disruptive to humans, especially when the extent of the spillage intrudes into all three of the ‘spheres’ that make up the marine environment; the hydrosphere, biosphere and the lithosphere

Numerical Model For Napl Migration In Double-Porosity Subsurface Systems

The double-porosity concept has been successfully applied by many researchers to simulate fluid flow in oil reservoirs over the past few decades. These oil reservoirs were typically considered to be made of fractured or fissured rock, hence the usance of the double-porosity concept. Nonetheless, double-porosity may also exist in soil either through soil aggregation, or through soil features such as wormholes, cracks and root holes. These attributes in soil that cause the occurrence of double-porosity are also known as secondary porosity features and are akin to the reservoir rock fractures or fissures. In the case of groundwater contamination, the occurrence of double-porosity in soil is highly influential since immiscible fluids have been found to flow preferentially through the secondary porosity features. Ergo, a numerical model for non-aqueous phase liquids (NAPL) migration in double-porosity groundwater systems was developed. This model was modified from the conventional double-porosity model applied in the petroleum industry. The difference is that while the standard double-porosity models usually simulate the fluid flows in both continua making up the doubleporosity medium, the double-porosity model presented here focuses the modelling on the secondary porosity features in the soil, therefore making it more pertinent in the context of groundwater contamination. In the modified model, the phase saturations and relative permeabilities are expressed as functions of the capillary pressures. The resultant nonlinear governing partial differential equations are solved using numerical methods. The problem is discretized spatially using the Galerkin’s weighted-residual finite element method whereas a fully implicit scheme is used for temporal discretization. Verification of the developed model has been done against similar works in the open literature and the preferential flow of NAPL through the secondary porosity features was validated