No description available.

A physically-based, distributed sediment yield component has been developed for the SHE hydrological modelling system. This new component models the hillslope processes of soil detachment by raindrop impact, leaf drip impact and overland flow, and transport by overland flow. If the eroded soil reaches a river system it is routed downstream along with any inobilised river bed material. Deposition on land or in a river is simulated and the river bed material size distribution is continuously updated with allowance for armour layer development. The equation developed for soil detachment by raindrop and leaf drip impact was successfully tested using data from a field plot with a range of soybean canopy covers and rainfall intensities. The soil detachment coefficient in this equation was determined for a range of soil types and showed a variation consistent with that which may be expected from a consideration of the physics of a soils resistance to detachment. At present two soil detachment coefficients need calibration. In order to investigate the variation in these coefficient values, as well as to test the component, various applications were carried out. The hilislope sub-component was applied to rainfall simulator plots with a variety of surface conditions. Two sets of calibration parameters, distinguishable on a physical basis according to the degree of soil disturbance, were found to be appropriate for all the plots. To investigate scale effects, parameters calibrated at the rainfall simulator plot scale were transferred to a 1-ha rangeland sub-catchment. With no further calibration, the catchmerit response for four events was poorly simulated for both water and sediment. However, with reasonable variations in the antecedent soil moisture content but no variation in plot calibrated sediment parameters, the sediment yield for two of the four events could be successfully simulated. These applications suggest that parameter transfer is feasible if the sediment yield characteristics at the different scales are similar. Further applications of the hilislope sub-component were carried out for two small agricultural catchments. The sediment response could be simulated to at least the same accuracy as achieved by two existing distributed soil erosion models. The channel sub-component was applied to the East Fork River, Wyoming. Although the complex sediment storage/supply effects could not be reproduced completely, the simulated response was nevertheless of similar accuracy to that achieved by two existing alluvial river models. The new component is considered to be a valuable contribution to sediment yield modelling as a physically-based approach is used for both the hilislope and channel phases of the catchinent sediment system, within the framework of an advanced hydrological modelling system.

after vibration endurance testing involves manual inspection only after the test is completed. An adaptable, reliable and low cost real time monitoring and diagnostic system that would interrupt the testing operation at the first onset of a failure is desired. This thesis describes accelerometer based, microphone (single and dualmicrophone) based and acoustic emission sensor based monitoring systems for automotive light assembly failure detection during endurance testing. Preliminary results from accelerometer based and dual-microphone based diagnostic systems show that significant differences between healthy and faulty fog light assemblies can be detected. Based on these initial testing results, subsequent testing and data analysis were conducted for accelerometer based and dual microphone based systems. Four data analysis methods have been used: (1) Averaging signals in the time domain, (2) FFT of time domain waveforms over a specified time, (3) Averaging frequency spectra, and (4) Statistical methods for time domain signals. Individual frequency spectra (from FFT) and the average of multiple frequency spectra have shown potential to distinguish between signals from faulty and healthy light assemblies. Statistical measures, such as, Arithmetic mean (μ) and Kurtosis (K) can also be used to differentiate healthy and faulty light assemblies. In general, this work has shown the good potential to develop methods for adaptable, reliable and low cost real time monitoring and diagnostic systems that would interrupt the testing operation at the first onset of a failure. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2007-09-28 16:13:47.511

The ACPD method is probably the most versatile of all the commercially available NDE techniques. However as applications of such systems increase so does the awareness of serious limitations in present ACPD knowledge. In particular high local crack and notch tip strains can have a marked effect on ACPD response leading to substantial errors in estimates of crackdepth and growth rates. In the present study an investigation has been undertaken into the influence of elastic/plastic notch tip strain on the response of ACPD crack monitoring systems. Experimental work has been undertaken to produce data on the ACPD response observed in two magnetically contrasting materials (EN1A mild steel, NE8 aluminium alloy) using a series of V and U notched bend specimens. An extensive elastic/plastic finite element analysis was conducted to accurately determine the different notch tip strain fields for both materials. A fundamental study was also undertaken into the influence of strain on the electrical resistivity and relative magnetic permeability, the two material parameters governing the ACPD response. The information obtained from the investigations together with results from the FE analysis has made it possible to understand and quantify the influence of elastic/plastic deformation on ACPD response. An electric field model has been successfully developed to explain and predict the effect of increasing strain on the ACPD response in materials where the skin effect is strong. Results have also shown the inapplicability of the compensation method of crack monitoring when levels of plasticity are appreciable and an alternative method has been proposed.

The gas turbine engine has a wide range of applications, these include industrial and aerospace applications on locomotive, ferry, compressor and power generation, and the most popular application will be for the air transportation. The application for air transportation including military and commercial aircraft is highly sensitive to safety concerns. The engine health monitoring system plays a major role for addressing this concern, a good engine monitoring system will not only to provide immediate and correct information to the engine user but also provide useful information for managing the maintenance activities. Without a reliable performance diagnosis module involved, there will be not possible to build a good health monitoring system. There are many methodologies had been proposed and studied during past three decades, and yet still struggling to search for some good techniques to handle instrumentation errors. In order to develop a reliable engine performance diagnosis technique, a fully understanding and proper handling of the instrumentation is essential. A engine performance fault pattern matching method has been proposed and developed in this study, two fault libraries contains a complete defined set of 51963 faults was created by using a newly serviced fighter engine component data. This pattern matching system had been verified by different approaches, such as compares with linear and nonlinear diagnosis results and compares with performance sensitivity analysis results by using LTF program engine data. The outcomes from the verications indicate an encouraging result for further exploring this method. In conclusion, this research has not only propose a feasible performance diagnosis techniques, but also developed and verified through different kind of approaches for this techniques. In addition to that, by proper manipulating the created fault library, a possible new tool for analyzing the application of instruments' implementation was discovered. The author believes there will be more to study by using this created fault pattern library. For instance, this fault pattern library can be treated as a very good initial training sets for neural networking to develop a neural diagnosis technique. This study has put a new milestone for further exploring gas turbine diagnosis technique by using fault pattern related methods.

An investigation has been completed to determine the feasibility of using vibration measurement to develop an online tool wear monitoring system.Conventionaltransducers and FFT signal analysers have been used as the starting point for data collection and analysis. Additional software has been developed in order to obtain additional and enhanced analysis using statistical data such as percentile analysis and 4th statistical moments. The signal analysers have been interfaced with an IBM compatible PC to allow efficient data collection and analysis. • The measurement of surface finish via the use of centre line average has been selected as the primary indicator of tool wear. An experimental programme has been completed which examines the relationship between vibration measurement and surface finish during turning operations. This has provided sufficient general rules and guidelines to enable the method to be extended to other processes. It also provides information from which commonly occurring faults such as looseness of the tool holder, changes in material properties and swarf presence in the toolholder can be identified. Tests have been completed using cast iron, ENS and EN3 steels. An expert system has been developed. It has been demonstrated that sufficient data can be collected during the setting-up stage or commissioning part of a machining process from which, using the expert system, reliable tool wear monitoring can be achieved for all subsequent tests. In addition to predicting'the surface for all stages of tool life, the system can identify common faults such as looseness of the toolholder, the presence of swarf in the toolholder and changes in material properties. This system has been evaluated in relation to the available data, the present expectation of quality assesment required from the machine operation and relative to available commercial monitors. The system offers significant improvements.

No description available.

Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2011 / The purpose of this thesis was to design and develop a measurement system that would allow accurate measurement of individual cell voltages in a series cell stack. The system was initially proposed to be used in conjunction with an active cell balancer. This would allow for the efficient equalising of cells as well as provide detailed information on the cell stack and how the stack operates over time. Having a system that measures voltages accurately, with which the active cell balancer can be controlled would allow for peak cell lifetime and performance. Current battery management systems are large, complex and inefficient and a new way of battery management had to be investigated. To accurately measure individual cells in a series stack, the high common mode voltage must be negated. Different techniques that are currently used to create galvanic isolation were reviewed; circuits were designed and were simulated to find the most suitable design. The traditional methods used to create galvanic isolation did not provide adequate results. The methods were too inefficient and not accurate enough to be used. The methods that had the required accuracy were too complicated to connect in a useable system. This led to the investigation of integrated circuits created to measure voltages in large cell stacks. An integrated circuit from Linear Technology was chosen and a system was built. A system was thus designed that fulfilled the most desirable design specifications while delivering excellent results. The system allowed accurate, individual voltages to be measured in the presence of high common mode voltages. Accuracies and measurement time were well below the required system specification. Power consumption was high, but different component choice will lower power consumption to within specification. Excellent results were obtained overall with most, although not all results well below the design specifications. By including current measurements, as well as other technologies such as wireless communication, USB connectivity and a better data processor, this system will be at the forefront of current battery management technology.

International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / The Vehicle Monitoring System based on GPRS is a system using GPRS network to transmit data, including location data, time data and so on .It has many advantages compared with those systems based on other communication modes. The key of the system lies in how to build up the connection with exterior data network. In this paper, the constitution of the system is introduced, and the course of building up connection with exterior data network is described in detail.

The report is focused on the implementation of a data acquisition system that will be used for measuring different parameters which are needed in solar panel behavior analysis. To accomplish the DAQ system a DAQ board has been designed and implemented. This DAQ board acquires measured climatic parameters that affect the PV module behavior and voltage and current of a PV module. The DAQ board may take measurements of multiple analog and digital signals that come from various sensors including solar radiation, temperature, wind sensors and other measurement devices. The DAQ board may also output analog signals for controlling other devices. The DAQ board is the basic part of the DAQ system and several of them can be connected via a single communication bus (RS485). A unique slave ID can be assigned to each DAQ board on the communication bus, which allows the control of all boards via a GUI application installed on a master computer. Therefore, the DAQ system can be used for monitoring a PV module installation as well as logging the measured data in a data storage server. This report outlines the details of the DAQ system design which are helpful in utilizing or upgrading this system. These details also include programming of DAQ board and implementation of MODBUS communication protocol within the DAQ system.