A hydraulic analysis of shock wave generation mechanism on flat spillway chutes through physical modeling

Shock waves are generated downstream of spillways during flood operations, which have adverse effects on spillway operations. This paper presents the physical model study of shock waves at the Mohmand Dam Spillway project, Pakistan. In this study, hydraulic analysis of shock waves was carried out to investigate its generation mechanism. Different experiments were performed to analyze the rooster tail on a flat spillway chute and to examine the factors affecting the characteristics of the rooster tail. The study results show that shock wave height is influenced by spillway chute slope, pier shape, and flow depth. Moreover, the height of the shock wave can be minimized by installing a semi-elliptical pier on the tail part of the main pier. Further modifications in the geometry of the extended tail part of the pier are recommended for the elimination of the shock wave. Based on observed data collected from the model study, an empirical equation was developed to estimate the shock wave height generated on the flat slope spillway chutes (5◦ to 10◦ )

Antagonistic potential of bacterial isolates associated with entomopathogenic nematodes against tomato wilt caused by Fusarium oxysporum f.sp., Lycopersici under greenhouse conditions

Three concentrations of Xenorhabdus nematophila and Xenorhabdus spp., (4x10(5,) 4x10(6,) 4x10(7) cells/ml) were evaluated in the laboratory and in pot experiments to test their antagonistic effects on Fusarium oxysporum f.sp., lycopersici. All concentrations effectively inhibited its growth on agar plates. In soil under greenhouse conditions treatments with each bacterium at 4x10(7) cells/ml reduced the disease incidence of tomato by up to 40.38 and 47.54% respectively and there were significant increases of plant biomass by 198 and 211% respectively. The rhizosphere population of Fusarium oxysporum f.sp., lycopersici was reduced by 97%. The Xenorhabdus spp., was comparatively more effective than X. nematophila

COPPER ORE FLOTATION PARAMETERS OPTIMIZATION USING STATISTICAL TECHNIQUES

Mathematical simulation has been used in mineral processing system design, optimization and control for more than 30 years. Presently a new set of simulation tools based on the physics of the underlying processes were developed. Because these models provide accurate micro scale simulations of equipment and process behavior, these high-fidelity simulation (HFS) tools are deemed to constitute a radical innovation of great importance to the mineral processing industry.This research study deals with the development of a mathematical model based on the parameters processes developed both at laboratory and pilot scale of North Waziristan copper ore. In the mathematical model the effect of four process parameters (parameters are denoted by X1, X2. X3 and X4) will be tested individually on grade (YG) (enrichment) of copper in the final product of North Waziristan. When the value of NaPX is 200 gm/ton, pH is 11.5, Na2S is 22 gm/ton and the value of NaCN is 58 gm/ton

ASSESSMENT OF GROUND WATER QUALITY FOR IRRIGATION IN THE LACHI AREA OF DISTRICT KOHAT

Ground water samples from different tube wells and dug wells at different locations in Lachi area of district Kohat were collected for chemical analysis. The objective was to check their quality for irrigation prior to their use. The EC values of the selected water samples ranged from 0.73 to 11.37 dSm-1 with an average of 3.54 dSm-1, the SAR values ranged from 1.18 to 26.00 with an average of 7.98 and the RSC values ranged from 0 to 3.9 meql-1 with an average of 0.79 meql-1. Based on EC, SAR and RSC cumulatively, 44% of the water samples were found suitable for growing nearly all types of crops without reduction in yield, 10% of samples have marginal quality and 46% have hazardous nature. Based on EC and SAR, only 3% data point is in C2S1 class (medium salinity), 50% samples are in C3S1 class (high salinity), 28% samples are in C4S1 class (very high salinity), and 19% are in C4S3 class (extremely high salinity). The variation between the salinity classes is due to the existence of the saline stream in the area with electrical conductivity of about 13 dSm-1 i.e. area closed to the stream have high salinity and the salinity gradually advancing to the surrounding areas due to the unscientific ground water exploitation

IMMUNIZED AUTONOMOUS MULTI-ROBOT COOPERATION FOR MULTI OBJECTS TRANSPORTATION

This paper investigates an approach for coordination among multiple robots for the transportation of multiple objects to a specific location. In this paper, we propose an Artificial Immune System based dynamic task allocation to a group of autonomous and heterogeneous mobile robots. In our work, the system will autonomously select the appropriate number of capable robots required to cooperatively transport number of objects to a goal location. The environment is considered as dynamic and unknown, and there is no centralized knowledge available to the robots, hence the frame work is fully distributed and decentralized. The communication, coordination and cooperation strategies are inspired by Jerne's Idiotypic Network Theory and the structure of an antibody in a human immune system. The developed methodology of multi-robot cooperation is verified through computer simulation

A Hydraulic Analysis of Shock Wave Generation Mechanism on Flat Spillway Chutes through Physical Modeling

Shock waves are generated downstream of spillways during flood operations, which have adverse effects on spillway operations. This paper presents the physical model study of shock waves at the Mohmand Dam Spillway project, Pakistan. In this study, hydraulic analysis of shock waves was carried out to investigate its generation mechanism. Different experiments were performed to analyze the rooster tail on a flat spillway chute and to examine the factors affecting the characteristics of the rooster tail. The study results show that shock wave height is influenced by spillway chute slope, pier shape, and flow depth. Moreover, the height of the shock wave can be minimized by installing a semi-elliptical pier on the tail part of the main pier. Further modifications in the geometry of the extended tail part of the pier are recommended for the elimination of the shock wave. Based on observed data collected from the model study, an empirical equation was developed to estimate the shock wave height generated on the flat slope spillway chutes (5° to 10°)