Mehran University Research Journal of Engineering and Technology

6

Authors: Abbasi H., Baloch M.A., Memon A.G.

During recent decades the large scale deterioration of forests and natural resources is an eye opener. The degradation of forests and other natural resources has affected the ecology, environment, health and economy. The ecological problems with living organisms such as animals and plants and environmental problems such as increase in temperature and carbon dioxide, these factors have contributed to change in regional climate, health problems such as skin, eye diseases and sunstroke and economic problems such as loss of income to rural population and resources which depend on forests such as livestock. Therefore, it was necessary to carry out land cover/use research focusing on the monitoring and management of the present and past state of forests cover and other related objects using RS (Remote Sensing) technologies. The RS is a way of mapping and monitoring the changes taking place in forests cover and other objects on a continuing basis. Sukkur and Shikarpur riverine forests are vanishing quickly due to the construction of barrages /dams on upper streams to produce hydroelectricity and irrigation installations which reduce the discharge of fresh water into the downstream Indus basin. Moreover, anthropogenic activities, livestock population, increased grazing, load and illegal tree cutting have contributed to this. The riverine forests are turning into barren land and most of the land is used for agriculture. These uncontrolled changes contribute to climate change and global warming. These changes are difficult to monitor and control without using RS technology. Assessment of deforestation of the Sukkur and Shikarpur to find temporal changes in the forests cover from April, 1979 to April, 2009 is presented in this paper. The integrated classes such as water body, grass/agriculture land, dry/barren land and forest cover maps show the temporal changes taking place in the forests cover for the last 30 years period. RS has been employed in the present study to assess deforestation. The results show significant changes in sub-tropical forests cover, the overall forests cover in April, 1979 was 22.67%, April, 1992 17.38%, April, 1998 12.28%, April, 2000 6.15%, April, 2006 7.51%, and April, 2009 5.97%. The overall change observed in forest area is 25.07%.

6

Authors: Qadir A., Memon Z.A., Shah F.

Granular materials are found every where despite they are poorly understood at microscopic level. The main hindrance is how to connect the microscopic properties with the macroscopic behavior and propose a rigorous unified theory. One method is to test the existing theoretical models in various configurations. In this connection we have performed experiments in different configurations of granules in a silo to determine the validity of the Janssen model under such arrangements. Two and four layered structures of different bead diameters are prepared. The effective mass at the bottom of the container in such cases have been measured. Moreover, the investigation of layered structures reveals that such configurations also follow well the Janssen model. An interesting percolation phenomenon was observed when smaller beads were stacked on larger ones, despite the model remained valid. Furthermore, it is demonstrated that Janssen law holds for larger bead diameters.

8

Authors: Hashmani A.A., Mahar M.A., Khanzada T.J.S.

This paper deals with the decentralized hierarchical PSS (Power System Stabilizer) controller design to achieve a better damping of specific inter-area oscillations. The two-level decentralized hierarchical structure consists of two PSS controllers. The first level controller is a local PSS controller for each generator to damp local mode in the area where controller is located. This controller uses only local signals as input signals. The local signal comes from the generator at which the controller is located. The secondary level controller is a multivariable decentralized global PSS controller to damp inter-area modes. This controller uses selected suitable wide area PMU (Phasor Measurement Units) signals as inputs. The PMU or global signals are taken from network locations where the oscillations are well observable. The global controller uses only those global input signals in which the assigned single inter-area mode is most observable and is located at a generator that is most effective in controlling the assigned mode. The global controller works mainly in a frequency band given by the natural frequency of the assigned mode. The effectiveness of the resulting hierarchical controller is demonstrated through simulation studies conducted on a test power system.

8

Authors: Memon R.A., Uqaili M.A., Hashmani A.A.

This paper investigated the impact of velocity variation in wide streets. The building AR (Aspect Ratio) (Street-canyon-width-to-building-height i.e. W/H) has been calculated by varying the width of street canyon. The k-? turbulence model was applied to ideal street canyons of aspect ratio 0.5, 0.75 and 1.0 while the wind speed was varied from 0.5 to 4.0 m/s. The street canyon aspect ratio 1.0 was obtained by increasing the width of the street two times (i.e. W=1) as much as for AR0.5 (i.e. W=0.5). However, different results obtained from AR1 were compared with AR0.5 to analyze the impact of wide streets. Results show that the temperatures reduce with an increase in ambient wind speed. However, the impact of ambient wind speed was comparatively higher in narrow street canyons since temperature reduced by over 1.4 K with an increase of 3.5 m/s in ambient wind speed. On the other hand, in the case of AR1.0 the area weighted average temperature reduced by 1.3 K with an increase of 3.5 m/s in ambient wind speed. It is found that removing heat from narrower street canyons is comparatively difficult. Results show that the temperatures within the target street canyon of AR0.5 with ambient wind speed of 0.5 m/s were around 0.71 K higher than that in AR1.

10

Authors: Memon.A, Abro Q.M.M., Mugheri F.

Construction industry plays an important role in the development of any country. The development of construction industry depends on the quality of construction products and projects. Quality is one of the critical factors in the success of construction projects in Pakistan. Improvement in the quality of construction projects is linked with quality management in the project life cycle. Although quality management at every stage of project life cycle is important but the quality management at the design and construction stage contributes significantly on final quality outcome of construction projects. This paper therefore highlights the importance of quality management in the design and construction phase. It presents the findings of two major cities in Pakistan and suggests some proactive measures for the improvement of quality in the design and execution phase of construction projects.

12

Authors: Naveed N., Jaffar M.A., Shaikh F.K.

The breast cancer detection and diagnosis is a critical and complex procedure that demands high degree of accuracy. In computer aided diagnostic systems, the breast cancer detection is a two stage procedure. First, to classify the malignant and benign mammograms, while in second stage, the type of abnormality is detected. In this paper, we have developed a novel architecture to enhance the classification of malignant and benign mammograms using multi-classification of malignant mammograms into six abnormality classes. DWT (Discrete Wavelet Transformation) features are extracted from preprocessed images and passed through different classifiers. To improve accuracy, results generated by various classifiers are ensembled. The genetic algorithm is used to find optimal weights rather than assigning weights to the results of classifiers on the basis of heuristics. The mammograms declared as malignant by ensemble classifiers are divided into six classes. The ensemble classifiers are further used for multiclassification using one-against-all technique for classification. The output of all ensemble classifiers is combined by product, median and mean rule. It has been observed that the accuracy of classification of abnormalities is more than 97% in case of mean rule. The Mammographic Image Analysis Society dataset is used for experimentation.

12

Authors: Ejaz N., Hashmi H.N., Ghumman A.R.

In this research various parameters for surface water quality degradation in Pakistan were investigated. Ravi River was selected as a case study to highlight the main issues, concerned with untreated wastewater. This paper represents that the mixing of effluent in huge quantity without any treatment in Ravi is a serious threat to the environment. Surface water quality parameters like, BOD5 (Biochemical Oxygen Demand), DO (Dissolved Oxygen), COD (Chemical Oxygen Demand), suspended solids, phosphorus, chloride, sodium, total kjeldahls nitrogen, nitrate, nitrite, oil & grease and total coliforms were tested on fourteen selected sampling stations for a period of three years. During this assessment, the samples were collected from the field and tested in the laboratory using standard methods. The effluent characteristics of Lahore city were also analyzed from the main city outfall sewers and compared with NEQS (National Environmental Quality Standards of Pakistan). Unfortunately selected parameters are at least four times above the allowable standards. This investigation shows that the environmental condition of Ravi is becoming worse day by day and the river is acting almost a wastewater carrier. Increased rate of pollutants in the river may be more dangerous and may create serious threats to groundwater quality and local environment in near future. Water quality and other environmental conditions in this river can only be improved by proper wastewater treatment plant, environmental management and powerful environmental legislation.