Lean interfaces for integrated catchment management models: rapid development using ICMS

A move towards the development of lean, issue-focused interfaces is being explored to provide a rapid delivery mechanism to transfer catchment science to managers and custodians. This approach is a move away from development of large decision support systems which attempt to anticipate a myriad of management questions. It relies on having a modelling system which supports the rapid building and integration of catchment models, and is independent of the interface. ICMS (Interactive Component Modelling System) is a PC-based software tool which has been developed with this in mind. The kernel of the ICMS system, ICMSBuilder, provides the modeller’s view of the world, on top of which can be built any number of interfaces which provide the targetted audience’s view of the world. This paper presents an ICMS prototype to demonstrate the power and flexibility of such an approach. It describes an ICMS project - a suite of linked models which explore the relationships between hydrology, water allocation and extraction rules, and on-farm decision making; and an ICMS View - an interface for that project tailored to address specific management scenarios. Interestingly, the ability to interact with parts of the models through the View gave managers the confidence to delve into the underlying models and data, something often denied to them by traditional decision support systems

Kinematic discrimination of ataxia in horses is facilitated by blindfolding

BACKGROUND: Agreement among experienced clinicians is poor when assessing the presence and severity of ataxia, especially when signs are mild. Consequently, objective gait measurements might be beneficial for assessment of horses with neurological diseases. OBJECTIVES: To assess diagnostic criteria using motion capture to measure variability in spatial gait-characteristics and swing duration derived from ataxic and non-ataxic horses, and to assess if variability increases with blindfolding. STUDY DESIGN: Cross-sectional. METHODS: A total of 21 horses underwent measurements in a gait laboratory and live neurological grading by multiple raters. In the gait laboratory, the horses were made to walk across a runway surrounded by a 12-camera motion capture system with a sample frequency of 240 Hz. They were made to walk normally and with a blindfold in at least three trials each. Displacements of reflective markers on head, fetlock, hoof, fourth lumbar vertebra, tuber coxae and sacrum derived from three to four consecutive strides were processed and descriptive statistics, receiver operator characteristics (ROC) to determine the diagnostic sensitivity, specificity and area under the curve (AUC), and correlation between median ataxia grade and gait parameters were determined. RESULTS: For horses with a median ataxia grade ≥2, coefficient of variation for the location of maximum vertical displacement of pelvic and thoracic distal limbs generated good diagnostic yield. The hoofs of the thoracic limbs yielded an AUC of 0.81 with 64% sensitivity and 90% specificity. Blindfolding exacerbated the variation for ataxic horses compared to non-ataxic horses with the hoof marker having an AUC of 0.89 with 82% sensitivity and 90% specificity. MAIN LIMITATIONS: The low number of consecutive strides per horse obtained with motion capture could decrease diagnostic utility. CONCLUSIONS: Motion capture can objectively aid the assessment of horses with ataxia. Furthermore, blindfolding increases variation in distal pelvic limb kinematics making it a useful clinical tool

Groundwater recovery problems associated with opencast mine backfills

The research outlined in this thesis is concerned with the environmental aspects of groundwater re-establishment as a consequence of surface mining. No principal effects which have been identified as being detrimental to the restored land area are as follows; i). The vertical and horizontal displacements of backfill materials following restoration, and ii). The pollution of groundwater from contact with weathered rockfill materials. The research into settlement has attempted to classify the types of movement which may occur within a backfill mass, in particular the differential movements which are of great importance to the stability of proposed structures or surface drainage. The field results from 10 opencast mine sites are presented, 3 of which were instrumented for detailed field investigations. It has been shown that backfill movements do not necessarily show similar trends under similar conditions, and reasons for this are proposed. A variety of instrumentation schemes have been devised to examine backfill displacements, both vertically and horizontally. Permeability testing has been conducted at different horizons the backfill mass in order to locate the zones of collapse settlement due to groundwater recovery. A critical review of the instrumentation utilised in the investigations is presented, with suggestions for improvement. Investigations into groundwater pollution have been devoted to examining the qualities of groundwater flowing into British surface mines and evaluating its likely reactions with fill materials. An insight into general groundwater pollution and treatment techniques is presented together with a critical analysis of their applicability, to British conditions. An investigation into water qualities in each of the six geographical regions of the opencast mining industry of Great Britain is detailed. Finally some suggestions for future research areas are indicated

Groundwater recovery problems associated with opencast mine backfills

The research outlined in this thesis is concerned with the environmental aspects of groundwater re-establishment as a consequence of surface mining. No principal effects which have been identified as being detrimental to the restored land area are as follows; i). The vertical and horizontal displacements of backfill materials following restoration, and ii). The pollution of groundwater from contact with weathered rockfill materials. The research into settlement has attempted to classify the types of movement which may occur within a backfill mass, in particular the differential movements which are of great importance to the stability of proposed structures or surface drainage. The field results from 10 opencast mine sites are presented, 3 of which were instrumented for detailed field investigations. It has been shown that backfill movements do not necessarily show similar trends under similar conditions, and reasons for this are proposed. A variety of instrumentation schemes have been devised to examine backfill displacements, both vertically and horizontally. Permeability testing has been conducted at different horizons the backfill mass in order to locate the zones of collapse settlement due to groundwater recovery. A critical review of the instrumentation utilised in the investigations is presented, with suggestions for improvement. Investigations into groundwater pollution have been devoted to examining the qualities of groundwater flowing into British surface mines and evaluating its likely reactions with fill materials. An insight into general groundwater pollution and treatment techniques is presented together with a critical analysis of their applicability, to British conditions. An investigation into water qualities in each of the six geographical regions of the opencast mining industry of Great Britain is detailed. Finally some suggestions for future research areas are indicated

Groundwater recovery problems associated with opencast mine backfills

The research outlined in this thesis is concerned with the environmental aspects of groundwater re-establishment as a consequence of surface mining. No principal effects which have been identified as being detrimental to the restored land area are as follows; i). The vertical and horizontal displacements of backfill materials following restoration, and ii). The pollution of groundwater from contact with weathered rockfill materials. The research into settlement has attempted to classify the types of movement which may occur within a backfill mass, in particular the differential movements which are of great importance to the stability of proposed structures or surface drainage. The field results from 10 opencast mine sites are presented, 3 of which were instrumented for detailed field investigations. It has been shown that backfill movements do not necessarily show similar trends under similar conditions, and reasons for this are proposed. A variety of instrumentation schemes have been devised to examine backfill displacements, both vertically and horizontally. Permeability testing has been conducted at different horizons the backfill mass in order to locate the zones of collapse settlement due to groundwater recovery. A critical review of the instrumentation utilised in the investigations is presented, with suggestions for improvement. Investigations into groundwater pollution have been devoted to examining the qualities of groundwater flowing into British surface mines and evaluating its likely reactions with fill materials. An insight into general groundwater pollution and treatment techniques is presented together with a critical analysis of their applicability, to British conditions. An investigation into water qualities in each of the six geographical regions of the opencast mining industry of Great Britain is detailed. Finally some suggestions for future research areas are indicated

Effect of realistic vehicle seats, cushion length, and lap belt geometry on child ATD kinematics

This series of sled tests examined the effect of using real vehicle seats on child ATD performance. Cushion length was varied from production length of 450 mm to a shorter length of 350 mm. Lap belt geometry was set to rear, mid, and forward anchorage locations that span the range of allowable lap belt angles found in real vehicles. Six tests each were performed with the standard Hybrid III 6YO and 10YO ATDs. One additional test was performed using a booster seat with the 6YO. An updated version of the UMTRI seating procedure was used to position the ATDs that positions the ATD hips further forward with longer seat cushions to reflect the effect of cushion length on posture that has been measured with child volunteers. ATD kinematics were evaluated using peak head excursion, peak knee excursion, the difference between peak head and peak knee excursion, and the minimum torso angle. Shortening the seat cushion improved kinematic outcomes, particularly for the 10YO. Lap belt geometry had a greater effect on kinematics with the longer cushion length, with mid and forward belt geometries producing better kinematics than the rearward belt geometry. The worst kinematics for both ATDs occurred with the long cushion length and rearward lap belt geometry. The improvements in kinematics from shorter cushion length or more forward belt geometry are smaller than those provided by a booster seat. The results show potential benefits in occupant protection from shortening cushion length, particularly for children the size of the 10YO ATD.National Highway Traffic Safety Administrationhttp://deepblue.lib.umich.edu/bitstream/2027.42/90972/1/102859.pd

Synchrotron radiation computed tomography for experimental validation of a tensile strength model for unidirectional fibre-reinforced composites

Synchrotron radiation computed tomography has been used to analyse fibre break accumulation in unidirectional composites loaded in tension. The data are compared to model predictions. The model only slightly overestimated the composite failure strain, but predictions of fibre break density were too high, which can be mainly attributed to errors in the Weibull distribution. Both the number and percentage of interacting fibre break clusters were under-predicted by the model. This was attributed to an underestimation of stress concentrations in the model. While the experimental observations revealed mainly co-planar clusters, the model predicted mainly diffuse clusters. The experiments showed that the clusters did grow any further after their formation, while the model predicted a gradual development. Both local and dynamic stress concentrations were hypothesised to be key features for further exploration. The discrepancies identified, inform suggestions for directions advancing the state-of-the-art strength models of UD composites

The design of a controllable energy recovery device for solar powered reverse osmosis desalination with experimental validation

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 84-86).The purpose of this thesis is to design and validate a controllable energy recovery device with application to photovoltaic powered reverse osmosis (PVRO). The energy consumption of a reverse osmosis plant depends significantly on the efficiency of its energy recovery process. This work presents a concept for a controllable energy recovery process, so that a system can operate optimally based on the incoming water and power characteristics. The design presented here uses a variable nozzle and a Pelton wheel to recover energy from the high pressure concentrated brine exiting the reverse osmosis membrane. The components are designed, analytically modeled using fundamental engineering principles, and experimentally tested. The experimental data is then used to check the validity of the formulated concept models. This research encompasses the modeling and testing of a variable nozzle using a needle valve to control the flow through the nozzle, and also of a Pelton bucket, to examine the effectiveness of the momentum transfer from a high velocity jet to the Pelton wheel. This research is done to examine the feasibility of this concept for potential implementation on a full scale PVRO system. The component validation is performed to prove that the concept is effective and competitive with other options.by Elizabeth Anne Reed.S.M

Scaling analysis of electron transport through metal-semiconducting carbon nanotube interfaces: Evolution from the molecular limit to the bulk limit

We present a scaling analysis of electronic and transport properties of metal-semiconducting carbon nanotube interfaces as a function of the nanotube length within the coherent transport regime, which takes fully into account atomic-scale electronic structure and three-dimensional electrostatics of the metal-nanotube interface using a real-space Green's function based self-consistent tight-binding theory. As the first example, we examine devices formed by attaching finite-size single-wall carbon nanotubes (SWNT) to both high- and low- work function metallic electrodes through the dangling bonds at the end. We analyze the nature of Schottky barrier formation at the metal-nanotube interface by examining the electrostatics, the band lineup and the conductance of the metal-SWNT molecule-metal junction as a function of the SWNT molecule length and metal-SWNT coupling strength. We show that the confined cylindrical geometry and the atomistic nature of electronic processes across the metal-SWNT interface leads to a different physical picture of band alignment from that of the planar metal-semiconductor interface. We analyze the temperature and length dependence of the conductance of the SWNT junctions, which shows a transition from tunneling- to thermal activation-dominated transport with increasing nanotube length. The temperature dependence of the conductance is much weaker than that of the planar metal-semiconductor interface due to the finite number of conduction channels within the SWNT junctions. We find that the current-voltage characteristics of the metal-SWNT molecule-metal junctions are sensitive to models of the potential response to the applied source/drain bias voltages.Comment: Minor revision to appear in Phys. Rev. B. Color figures available in the online PRB version or upon request to: [email protected]

Various spin-polarization states beyond the maximum-density droplet: a quantum Monte Carlo study

Using variational quantum Monte Carlo method, the effect of Landau-level mixing on the lowest-energy--state diagram of small quantum dots is studied in the magnetic field range where the density of magnetic flux quanta just exceeds the density of electrons. An accurate analytical many-body wave function is constructed for various angular momentum and spin states in the lowest Landau level, and Landau-level mixing is then introduced using a Jastrow factor. The effect of higher Landau levels is shown to be significant; the transition lines are shifted considerably towards higher values of magnetic field and certain lowest-energy states vanish altogether.Comment: 4 pages, 2 figures. Submitted to Phys. Rev.