Sci-Afric Journal of Scientific Issues, Research and Essays

8

Authors: Iman M. El Husseiny, *Mohamed H. Mona, Amal I. Seif and Mohamed T. Yassin.

Quantitative knowledge on the use of aquatic insects as bioindicators has not been elucidated in Egypt. Given these concerns, the goal of the present study is to use aquatic insect communities as biotic indices for evaluating water quality in some Egyptian fresh water streams. The study was carried out for a period of one year during summer and autumn 2010 and winter and spring 2011. Sampling was done using kicking and dipping method to collect the aquatic insects. Insects were identified up to the family level. Several metrics were used to analyze the aquatic insect data. Physic-chemical parameters of water samples were analyzed using standard methods. A total of 438 aquatic insect individuals (representing 19 families from 7 orders), 535 (20 insect families from 7 orders) and 241 (13 families from 6 orders) were recorded from El-Kassed, Rasheed and Kafr el Zayat streams. According to total taxa richness for Ephemeroptera, Plecoptera and Trichoptera (SEPT) -biotic index, the situation of water quality in the three water bodies was moderate impact; however it was "Good" according to Stroud water research center (SWRC). The SEPT is the most suitable biotic index for calculating water bio-class in Egyptian streams. Margalef's water quality index values were less than 3, indicating that the water quality of the three streams was impacted. Various anthropogenic activities were showing their impacts on the water quality of Egyptian streams. This study, as elsewhere, shows that aquatic insect communities could be good indicators of water quality and should be used as bioindicators of water quality of fresh water streams in Egypt.

12

Authors: Amin Tamale Kiggundu

Large cities across the globe are today facing a pervasive problem of air pollution. Also according to the 2014 World Health Organisation Report, in 2012 about 3.7million premature deaths occurred across the globe due to exposure to particulate matter of 10 microns or less in diameter (PM10). The purpose of this study is to assess the capabilities and gaps in urban air quality management in Uganda as well as propose strategies for curbing air pollution in various local towns and cities. To achieve its objectives, the study applied face to face interviews targeting key informants such as the environmental experts, urbanisation researchers as well as officials from the lead agencies such as the National Environment Management Authority (NEMA). Existing literature on urban air pollution was also reviewed. Results show that rapid motorisation, continued dependence on fossil fuels, open waste burning, biomass burning for domestic use, industrialisation, bush fires and urbanisation are the key causes of air pollution in Uganda. Among the key gaps identified are: incomplete and fragmented legislation on air quality management, lack of emission inventory, lack of restrictions on the age of imported vehicles, lack of stations for air quality monitoring, lack of air quality strategic plans for both local and central governments, lack of a specific legislation on clean air programme as well as lack of a clear strategy to promote cleaner fuels. Recognised also is that the existing environmental laws have not been adequately enforced due to institutional fragility. Various stakeholders such as the mass media are also rarely involved in local air quality management programmes. To reduce air pollution and improve urban air quality in Uganda, it is critical that a more feasible strategy is adopted to promote mass transit and non-motorised transport, increase access to electricity among households, introduce bye laws to regulate open waste burning, establish fully equipped laboratories to test and analyse samples, strengthen local research and training capacity on air pollution, promote regional and international collaboration on air pollution, introduce more fuel efficient vehicles, introduce regular and periodic vehicle inspection as well as carry out campaigns to raise public awareness about air pollution. Recommended also is the introduction of cleaner fuels such as liquefied petroleum gas, compressed natural gas, unleaded gasoline and ethanol. It is further critical that the institutional capacity required to monitor air quality is established and strengthened through training and providing necessary equipment.

15

Authors: Antonio Marcilla, M Isabel Beltrán, Amparo Gómez-Siurana*, Isabel Martínez-Castellanos and Deseada Berenguer

The effect of the weight of tobacco per cigarette (WTC) on the mainstream smoke of reference (R) and commercial (F) cigarettes and the effect of the addition of an SBA-15 catalyst has been studied. The yield of total particulated matter (TPM) obtained from the reference tobacco, with and without catalyst, is decreased as WTC increases, but the results for the commercial cigarettes show a maximum for TPM and CO at the medium WTC value. The highest yields of the different chemical families of compounds appearing in TPM extracted from filters (TPM-F) from F and R cigarettes, and in TPM from the traps after filters (TPM-T) from R, have been obtained at the intermediate WTC, whereas for TPM-F from reference cigarette + catalyst (RC) and TMP-T from F and RC, a decreasing trend as WTC increases is observed. Interesting reductions have been obtained in the presence of catalyst, especially for the carbonyls group in TPM-F and for aromatics in TPM-T.

4

Authors: Mirela Costianu

As Mark Twain said, prophecies are always difficult to make, that's why nobody can say precisely how much oil there is in the world and which is yet to be discovered, for how long will last the oil we already know about and where it is, how much will we be able to exploit what we have and what is there to discover, for how long will the oil last, for how long we will need it, if we already went beyond the maximum peak of production and discoveries etc. We can only analyze the data we have, make calculations, predictions and assumptions on the basis of what has been in the past, and what it is in the present, to hope or, on the contrary, to prepare ourselves for the worst. But we can't know for certain. So we try in the following to do it, without claiming that we know the sure answer to the question that is on the lips of all humanity. Further can be found: an analysis on the oil reserves in the world, starting from the reserves discovered and put into service (as they were declared), reserves discovered and unexploited yet, reserves proven, but still undiscovered and forecasts, by the experts in the field with regard to future discoveries.

4

Authors: Olatunji Peter FOLORUNSO

One of the key aspects of flood mitigation in open channel flow is the appropriate evaluation of flow resistance within the channel system. The flow resistance in open channel expresses the effects that the physical features have on its flow characteristics. In this work, the hydraulic resistance of an idealized partly vegetated open channel is measured and quantified. The channel bed roughness was realized with grass and gravel beds, alternately placed at the right and left side of the flume to form an elongated checkerboard. The stage-discharge curve shows a breakpoint where there is a slight change between the lower discharge and high discharge. At low discharge, the stage rises fast, causing an increase in gradient, and approximately linear at higher discharge. The overall Manning’s n value is found to be 0.025 which shows an average value of Manning’s roughness coefficient n selected for both grass and gravel bed for the channel. The friction factor consistently decreased with increase in discharge. The grass vegetation bed exerts more friction on the flow, and the friction for gravel bed tending towards constant value as the flow depth increases. Minimal value of f is obtained for highest flow depth and the maximum hydraulic resistance found closed to the channel bed. The stage-discharge curve provides a mean of comparison with the theoretical Manning’s model to independently reveal the retarding effects of the grass and gravel roughness respectively. The work will be relevant to hydraulic engineers involved in river restoration and flood control programmes