Modelling of material removal due to sliding wear caused by bulk material

A convex pattern surface has been proposed and optimized to reduce sliding wear of bulk handling equipment by adjusting the flow behaviour of bulk material. This study aims at modelling the surface deformation of the convex pattern sample to investigate how effectively the sample reduces sliding wear. Archard wear model and a deformable...

Pin-on-Disc Modelling with Mesh Deformation Using Discrete Element Method

The pin-on-disc test is a standard sliding wear test used to analyse sliding properties, including wear contour and wear volume. In this study, long-term laboratory test performance is compared with a short-term numerical model. A discrete element method (DEM) approach combined with an Archard wear model and a deformable geometry technique is...

Extending Attitude Estimation Capability for Agile Precision Target Tracking NanoSats: Hardware Characterisation, Configuration Selection, and Gyro-Stellar based Unscented Calibration Filter Synthesis

Though NanoSats are becoming increasingly capable of featuring active payloads, and acquiring inertial data at arcsec level precision; the payload operational duty-cycle largely remains limited by its data downlink capabilities. NanoSat laser communication terminal (LCT) promises 1 Gbps data downlink capabilities. However, LEO to ground free...

The Influence of Rainfall and Catchment Critical Scales on Urban Hydrological Response Sensitivity

Interactions between spatial and temporal variability of rainfall and catchment characteristics strongly influence hydrological response. In urban areas, where runoff generation is fast due to high imperviousness degree, it is especially relevant to capture the high spatiotemporal rainfall variability. Significant progress has been made in...

Using the GOCE star trackers for validating the calibration of its accelerometers

A method for validating the calibration parameters of the six accelerometers on board the Gravity field and steady-state Ocean Circulation Explorer (GOCE) from star tracker observations that was originally tested by an end-to-end simulation, has been updated and applied to real data from GOCE. It is shown that the method provides estimates of...

Rescaling of incorrect source strength using Marchenko Redatuming

The iterative Marchenko scheme is a recent development in the field of Geophysics and a way to retrieve Green's functions at any point in the subsurface, called a focal point. To achieve this, only the reflection response measured at the Earth's surface and an estimation of the first arrival at the focal point are required. If the amplitude of...

GOCE gradiometer: Estimation of biases and scale factors of all six individual accelerometers by precise orbit determination

A method has been implemented and tested for estimating bias and scale factor parameters for all six individual accelerometers that will fly on-board of GOCE and together form the so-called gradiometer. The method is based on inclusion of the individual accelerometer observations in precise orbit determinations, opposed to the baseline method...

Exploring the possibilities for star-tracker assisted calibration of the six individual GOCE accelerometers

A method has been developed and tested for estimating calibration parameters for the six accelerometers on board the Gravity field and steady-state Ocean Circulation Explorer (GOCE) from star tracker observations. These six accelerometers are part of the gradiometer, which is the prime instrument on board GOCE. It will be shown that by taking...