The Effect of Temperature on the Destruction of Salmonellas in Activated Sludge

The effect of temperature on the survival of salmonellas in activated sludge was examined. The results showed that the Salmonella destruction rates increased in line with increasing temperature of the mixed liquor from 5° to 25°C, whereas at 30°C the rate declined markedly. This is most probably due to inactivation of ciliate protozoa at the higher temperature resulting in increased survival of the pathogens. The slow reduction in the number of salmonellas at 30°C may be the result of nutrient starvation, in addition to other possible mechanisms such as the lytic action of bacterial viruses

The occurrence of antibiotic resistant Salmonellas in sewage and the effect of primary sedimentation on their numbers

The widespread use of antibiotics has led to the occurrence of resistant strains of bacteria in sewage and in the aquatic environment. This study has shown that there is no significant change in the proportion of antibiotic-resistant and antibiotic sensitive salmonellas during sedimentation of sewage and hence these organisms must have acquil·ed resistance during the initial use of the antibiotic and not during sewage treatment. Primary sedimentation alone can remove more than 80% of the total salmonellas present in raw sewage but negligible reductions will occur if the process is not optimised. The best way of controlling the release of antibiotic resistant salmonellas into the environment is to control the prescription and use of antibiotics

A Study of the Bacterial Population Fluctuations During Poultry Processing

The microbial assessment of skin-washed water samples taken from 39 poultry carcasses and the wash water from a poultry processing unit revealed cumulative increases z"n the number of microflora at each stage of processing. A comparison of the bacterial population densities on the skin at the' start and at the end of processing showed that the levels of E. coli and coli forms increased by 231.1% and 263.1% respectively whereas the Salmonella concentrations decreased by about 9%. A positive correlation was obtained between the occurrence of bacterz"a and parameters such as wash water pH and temperature, and suspended solids concentration. An examination of the storage tank effluent which was used to store the poultry carcasses pri"or to packaging showed that E. coli and Salmonella were able to thrive in the liquid. During the 4 h incubation period, the levels of both organisms decined rapidly during the initial half hour, but quickly became adapted and multipUed z"n the subsequent hours. The implications of both, the field and laboratory studies are discussed with a view of reducing the level of contamination during processing

A Study of the Problems Related to the Testing of Smoke Emission From Diesel Powered Vehicles in Malaysia

This study was carried out to examine the smoke emission level from diesel powered vehicles plying Malaysian roads and the problems related to the enforcement of the Motor Vehicles (Smoke and Gas Emission) Rules 1977. The results show that approximately 35% of the lorries examined had excessive smoke emission compared to 33% for taxis, 16% for buses and mini buses, and 13% for cars. Further examination£on of the data did not show any relationship between the degree of smoke emission and parameters such as age and maintainance of the vehicle, or duration since the last mandatory inspect£on by the RTD. A study of the past records of enforcement carnage out by the DOE showed that an average of only 52. 7% of the planned exercises were actually carnage out during 1979 to 1983. This was due to various reasons including manpower and budget problems, equipment, transportation, and weather. The selection of suitable sites for curb-side enforcement is nearly always hampered by the need to select locations which would not cause severe traffic problems and hence did not necessarily match the traffic flow. The main problem faced by the RTD is the lack of space to carry out inspection of the motor vehicles. The results also give a strong indication that some drivers of diesel vehicle may adopt underhand tactics such as tempenng with the engine parts or adding volatile additives into the fuel tanks to achieve short term reductions for smoke emission during the RTD tests

ISLAMIC MUTUAL FUNDS PROMOTIONAL ACTIVITIES: NORMAL APPROXIMATION OF BINOMIAL DISTRIBUTION AND TYPE I ERROR

The paper applies normal approximation procedure to binomial probability distribution. A sample of 392 respondents are surveyed whether they agree or not agree that promotional activities determined the level of awareness of benefits of Islamic mutual funds. The paper hypothesizes the population mean µ of success effects of promotional activities at 68%, and attempts to reduce Type I error - the probability of rejecting null hypothesis when it is true

Managing potential health risks associated with drinking water supplies: some issues and approaches

More than 90% of Malaysia's water supplies are derived from surface water sources. Long-term monitoring programs and research data indicate that many river systems are moderately to grossly polluted by domestic and industrial wastes. Properly planned, long-term, interdisciplinary studies are needed to assess the health implications of the country's social and industrial development and the associated impacts on the quality of drinking water supplies. New areas of potential risks need to be properly evaluated and the multiple barrier concept in providing safe water supplies needs to be properly coordinated, instituted and continuously monitored

GDC-UTP System Studies

The power system analysis studies serve as the basis for ensuring reliability, improving system performance and power quality, reducing operating costs, and providing a reliable supply power during system operation. Thus, this paper presents a case study for designing power supply system for a plant which will include load flow study, short circuit study and protection relay study. The studies mentioned will be conducted through simulation by using DIG SILENT Power Factory Software. This study will focus in island system which is Gas District Cooling (GDC) in Universiti Teknologi PETRONAS (UTP). The load flow study will be emphasized on loading and voltage. The short circuit study will be emphasized on fault current for three phase, line to line, line to ground and line to line to ground. Finally, the protections relay study is to know the correct Time Multiplier Setting (TMS) to make the relay operate coordinately. The purpose of this study to understand the importance of system study analysis in plant, study and performed the analysis simulation for designing a power system and finally to familiarize with software which is DIGSilent Power Factory. The system study should be done in Universiti Teknologi PETRONAS because of total blackout and increasing in load every year. The method that used to do this study such as gathering data, model the system in software and analysis the data. The simulation base on four scenarios for load flow study and short circuit study and one scenario for protection relay study. The result that obtained from this study is for load flow study, the voltage deviation with the limit base on PETRONAS Technical Standard (PTS). For short circuit study, the current faults that obtained from the study will not damage the buses. For protection relay study, some breaker has been suggested to have new Time Multiplier Setting (TMS) during overcurrent and cannot manage to do the earthfault due to limitation on software

Efficient computation of Islamic yield and forward rates in sukuk market of Malaysia

The dynamic yield rates prevailing in the bond market determines the bond portfolio values as the yield rate is negatively correlated with the bond value. Due to economic conditions principal in the country the yield rate sometimes goes up which cause the bond portfolio values to go down. This value loss is to be contained by risk management, which requires accurate yield and forward rates. The future yield rates are determined by term structure methods and published for almost 30 years. The English published are not at regular intervals. They have a lot of gaps this gap stops to be filled to get yield rates at regular intervals of every six months. The interpolation technique and spline methods were applied to get the missing yield rates. These methods produce larger errors which cause miscalculation of expected losses, defeating the objective of risk management. In this article to overcome this problem, we apply Nelson Siegel Svensson (NSS) method to compute the missing yield rates by minimizing the errors through non-linear optimization. We take the sukuk yield rates provided by the Bank Negara Malaysia and apply Microsoft Excel salver function and compute all yield rates once in every six months. These computed NSS regular yield rates are applied to get forward rates. These forward rates are essential to compute value at risk accurately. Once the value at risk is quantified accurately it is easier to hedge the portfolio value so as to avoid the value at risk. We prove that forward rate computed for 2021 and 2022 are converging well with the yield rates given by Bank Negara. The method we explain will be useful for asset managers and also the portfolio risk managers.

A Study of the Air Quality in Underground Car Parks with Emphasis on Carbon Monoxide and Airborne Lead

The concentrations of carbon monoxide and airborne lead in three enclosed underground car parks in Kuala Lumpur were measured simultaneously with traffic flow for a period of three months. The measurements were taken at a height of 1. 5 m from the ground for a duration of8 - 13 hours. A large variation in the airborne lead levels was observed which ranged from 1.75 to 23.9 J1g/m 3 in relation to traffic flow. The mean carbon monoxide concentration ranged from 23.2 to 65.2 ppm. The mean concentration of both pollutants at all the three sites was found to exceed the proposed Malaysian Air Quality Standard of 0.7 J1g/m 3 for lead and 9 ppm (8 hours average) for carbon monoxide. A positive correlation was observed between traffic flow and carbon monoxide as well as lead at the locations studied