Miracle-dz/UniFAR-FTUs huggingface dataset:
The Effects of a Parametric Variation of the Rim Seal Geometry on the Interaction Between Hub Leakage and Mainstream Flows in High Pressure Turbines

The objective of this work was to assess and understand the effects of a parametric variation performed on a typical overlapping rim seal geometry. The datum geometry has been the focus of a detailed experimental investigation employing a large-scale linear cascade subjected to a range of the mass flow rates and swirl velocities of the leakage air. The parametric variations described in this paper were examined using validated computational fluid dynamics (CFD). As a part of the parametric studies, both the axial and the radial seal clearance between the rotor fin (angel wing) and stator platform were varied as well as the length of the overlap between stator and rotor platforms. In addition, the effects of forward and backward facing annulus steps were also investigated. It has been found that a backward-facing annulus step was detrimental for all conditions considered, while a forward-facing step offered improvements for smaller step heights and/or lower leakage fractions. Tightening of the seal clearances closer to the annulus line improved the sealing effectiveness but often at the expense of increased losses. On the other hand, increasing the overlap length led to improvements in the sealing effectiveness with very small effects on the overall losses. Moving the rim seal away from the blade-leading edges reduced the pressure asymmetry at the rim seal and increased the flow uniformity of the leakage air. However, this led to an increased cross-passage flow (more negative skew) and higher losses at all but lowest leakage fractions. The results presented in this paper highlight the fact that there may not be an optimum rim seal solution that would offer an improvement for the full range of leakage fractions and that, for different rim sealing flows, there may be a different optimum geometry. In addition, rotor disk movements in radial and axial directions at various off-design conditions should be considered as a part of the design process. Based on the presented results, it may be of a benefit to the turbine designer to consider rotor disk designs that would be more biased towards the upstream and outward disk movements, which would result in tightening of the seal clearances and avoidance of a backward-facing annulus step.
Exploring the Proximity of Ground-Motion Models Using High-Dimensional Visualization Techniques

Logic trees have become a popular tool to capture epistemic uncertainties in seismic hazard analysis. They are commonly used by assigning weights to models on a purely descriptive basis (nominal scale). This invites the creation of unintended inconsistencies regarding the weights on the corresponding hazard curves. On the other hand, for human experts it is difficult to confidently express degrees-of-beliefs in particular numerical values. Here we demonstrate for ground-motion models how the model and the value-based perspectives can be partially reconciled by using high-dimensional information-visualization techniques. For this purpose we use Sammon's (1969) mapping and self-organizing mapping to project ground-motion models onto a two-dimensional map (an ordered metric set). Here they can be evaluated jointly according to their proximity in predicting similar ground motions, potentially making the assignment of logic tree weights consistent with their ground motion characteristics without having to abandon the model-based perspective.
Theoretical and experimental study of roller-compacted concrete strength

Roller-compacted concrete (RCC) is presented as an evolutionary technology for a large diversity of applications: dams, roads, parking areas. The present work considers a road application and uses some materials of local quarries. The development of compressive and tensile strengths of RCC with the specification of a low cement content is discussed. The current study treats the characterisation of different granular constituents based on local materials quarries, the formulation of various granular mixtures, by the compressive packing model ‘Rene-LCPC’, and the simulation by theoretical models developed by Feret, de Larrard and Tondat for the evaluation of compressive and tensile strengths. Compression and Brazilian tensile (by splitting) tests were performed on the cylindrical specimens type ‘16/32 cm’, prepared according to the National French Project Method ‘BaCaRa’. A comparison was therefore made between the experimental and the theoretical model results, showing a good agreement between both.
Cement hydration based model to predict the mechanical properties of precast concrete

An adiabatic temperature rise (ATR) test was used to determine the degree of cement hydration in concrete. In the experiments, emphasis was placed on the influences of water to cementitious material ratio (w/b) and aggregate content on the ATR and the development of degree of cement hydration. A total of nine concrete mixtures with three w/b ratios (0·30, 0·43, 0·62) and three aggregate contents (50%, 60%, 70% by volume) were used in the tests. The experimental results show that, for a given aggregate content, the lower the w/b ratio, the higher the temperature rise. For a given w/b ratio, the higher the aggregate content, the lower the temperature rise. The effects of temperature and age on the hydration process of cement may be taken into consideration by the equivalent age concept. For the same equivalent age, the degree of cement hydration is a function of w/b ratio only, regardless of the aggregate content. The advance of degree of cement hydration with equivalent age can be described as an initially.
Transit Incentive Program for Transit-Dependent Riders

Five years ago, several transportation agencies in Los Angeles County began discussions on developing a process to reevaluate the existing bus service delivery system, including the opportunity for public involvement and participation. As a result, the concept of a thorough restructuring study was developed. Restructuring studies are closely related to other activities focused on the bus system. In March 1996, the Metropolitan Transportation Authority (MTA) board approved a broad-based bus system improvement plan that tied together many of the ongoing service improvements with proposed plans and programs to provide a 2- to 5-year set of goals to improve bus service in Los Angeles. It is in this context that the MTA and the Los Angeles Department of Transportation commissioned a special work effort as part of the Central/East/Northeast restructuring study to examine options for a transit incentive program for transit-dependent riders. The transitory nature of transit dependency has gained increased awareness in recent years, but development of effective strategies has lagged behind as transit agencies have targeted discretionary travelers as the largest pool of potential riders. The approach taken is to identify and describe rider-incentive programs implemented at other transit agencies that target or can be applied to the transit-dependent population, to consider public input about incentives and rewards that would be attractive to these riders, and to note key neighborhoods in the study area where there are significant numbers of households without automobiles. The objectives are to develop options for a pilot incentive program and to define the type of area appropriate for a focused demonstration-type project. The application of ideas as part of the consent decree negotiated by the Los Angeles County MTA is summarized.
Congress papers from the Planning Institute of Australia 2011 National Congress

Abstract The following five papers were presented and peer reviewed for the PIA National Congress in Hobart in March 2011. These papers have been included because the editors feel theyare important and should be available to a broad audience. However please note that theydid not go through the academic peer review process for Australian Planner.
Neutron radiation effects in high electron mobility transistors [AlGaAs/GaAs]

The effect of fast neutron radiation has been investigated in High Electron Mobility Transistors (HEMT's). Devices with different layer structures have been employed for the better understanding of failure mechanism sources. The deep traps introduced by neutron irradiation in the AlGaAs donor layer have been, for the first time, studied. The application of charge control model allowed the determination of buffer layer degradation and the theoretical estimation of the shift of the threshold voltage.
F-VEP and alpha-suppressed EEG-physiological evidence of inner-light perception during zen meditation

This paper firstly reports the visual response to the inner light (a form of qi) and the outside stimulus during Zen meditation. It has been reported literally that inner light perception is the common experience for prayers or Zen-meditation practitioners. In this paper, we propose a method to quantify the EEG (electroencephalograph) and F-VEP (flash visual evoked potential) that characterize this experience. Based on wavelet analysis, we derived a set of parameters that effectively signify the alpha-suppressed EEG pattern. Furthermore, this paper presents our new results of analyzing the F-VEP data, mainly the peak amplitude. The observation of little variation in amplitude during Zen meditation reflects a more stable visual perceptive system during Zen meditation that is contrary to the visual response of the control subjects under eye-closed relaxation.
Design and finite element analysis of weighted-stiffness microelectromechanical digital-to-analogue converters

A microelectromechanical digital-to-analogue converter (DAC) based on the weighted-stiffness (WS) principle analogous to a weighted-resistor DAC for use in electronic circuits is proposed. To convert the digital voltage input to the analogue displacement, the stiffness of the vertical beams is employed as the scale factor. Finite element analysis and design optimisation are performed. Simulation shows that the error for the proposed DAC is less than 0.001 /spl mu/m.
Deformation and Failure in Wet Clay Soil: Part 2, Soil Bin Experiments

Abstract Tests of soil cutting by wide tines were conducted in wet clay soil. Force-displacement curves were obtained and the soil deformation patterns were observed and analysed with the help of a painted grid. The tine experiment showed that the soil deformation pattern depended on the tool rake angle (the angle between the tine face and the horizontal soil surface). For small rake angles, soil deformed in a narrow zone leading up from the tool tip and there were tensile cracks near the tool tip. For bigger rake angles, soil in front of the tool failed by distortion with small shear lines and big soil-soil slip lines. For rake angles equal to or bigger than 90° an elliptical wedge formed. Passive earth pressure theory did not describe the deformations observed in these wet clay soil conditions.
Linear Programming Method for Investigating the Disposal Histories and Locations of Pollutant Sources in an Aquifer

A linear programming based methodology has been used to identify the unknown sources of groundwater pollution. A source identification model is demonstrated and evaluated using hypothetical groundwater systems for a steady state case and a transient case. The concept of linear super-position is employed to find waste disposal rates at disposal sites from concentrations at measurement wells. In the steady state case, the identification model finds the unknown location and magnitude of leaks in a pipe among the probable leak locations. Contamination data are obtained from sparsely located wells. Subsequently, the transient case source identification problem is tested for unsteady case of flow and transport with several disposal periods in the aquifer. The model results show that in the steady state case problem with perturbed data, the pipe leak is identified within 1% of the true flux value when the maximum error tolerance is set to 15%. In the transient case, a large number of measurements of concentration data spread over time and space are necessary to satisfactorily identify possible unknown sources of groundwater pollution. The injection rate values were found with a relative error of 13 to 32% and a normalized error of 17% when the disposal locations were known. The results re- main unchanged after entering a dummy source to the unknown potential sources. Ignoring a measurement well location changes the identification results to a normalized error value of 21%. The linear programming model can be very useful in source identification with available measurement and aquifer parameters.
Rodent control strategy in animal farms (izzab) in Qatar

Abstract The aim of this study is to develop a control program for rodents in animal farms (izzab) in Qatar. The preliminary baseline survey for rodent-infested izzab revealed that 1506 izzab out of 1814 were infested (83%). The overall percentage reduction in the rodent-infested izzab after 6 months of the control programme (June to December 2009) was 77%. Towards the end of the control programme, a special strategy was adopted to control rodents in 327 izzab in which rodents activity was still observed. A 75% reduction was attained in these izzab at the end of the control programme. The overall reduction in the infested izzab was 94% at the end of the control programme. The most predominant rodent species found in izzab is the Norway rat Rattus norvegicus, making burrows inside and outside Izzab buildings. Less incidences were noted for the House mouse Mus musculus associated with izzab buildings.
A review and comparative study of the investigations on micro heat pipes

A review of recent investigations on micro heat pipes of various geometrical designs, fabrication methods, operational environments and applications is presented, along with a comparative analysis of the performance of various designs, based on quantitative design parameters and performance indicators. A comprehensive report of the salient features of these investigations has been presented in a tabular form, in order to provide a quick reference of the state‐of‐the‐art of micro heat pipe research. Both theoretical and experimental investigations have been included in this review, with special attention given to some of the new concepts and proposed designs for micro heat pipes, currently under development. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of Procurement Practices on Performances of Public Organizations (The Case of Essera Woreda in Dawro Zone South West Ethiopia)

The main objective of the study was to explain the effect of public procurement practices on performances of the organization. Procurement practices on such as procurement planning, procurement method, procurement transparency, competency of procuring staff, and contract management are independent variables in the study and the performance of the organization was dependent variable. The study used explanatory research design. The sampling technique used both probability and non-probability. The total target population of the study was 410.Among the total population 203 were scientifically selected as sample size. The data sources used in the study was primary data source. Primary data source used for data collection was questionnaires. Data were analysed by inferential statistical method. The study achieved 96% response rate since 195 questionnaires were filled and returned out of 203 questioners distributed. Statistical package for social science (SPSS 21 version) software used to data entry. Inferential analysis used was Pearson correlation and multiple linear regression model. The findings of the study showed that procurement planning, procurement methods, procurement transparency, staff competency and contract management had significance effect on the performances of the organizations. Finally, the researcher recommended that public organizations should efficiently manage procurement practices to achieve effectively.
Laboratory Experiments on Electroosmotic Dewatering of Vegetable Sludge and Mine Tailings

ABSTRACT Vegetable wastes in the food industry are costly lo handle because of their high moisture content. while mill plant tailings in the mining industry contain large quantities of ultralines which are difficult io dewater.This paper describes the results of small scale electmosmotic dewatering (EOD) and combined field dewatering (CFD) measurements with model vegetable sludges and mine tailings.
Theory of imperfect waveguides: the effect of wall impedance

Wave propagation in waveguides whose walls exhibit an arbitrary but small surface impedance is studied. It is shown that, although in the case of circular waveguides all E-and H-modes are stable, in the case of rectangular waveguides all E-modes and higher-order H-modes are unstable, leaving only H modes that can propagate without change of form. General formulae are derived from which the propagation coefficients of imperfect waveguides can be calculated, and for imperfect cavities an expression for the bandwidth and resonant frequency is obtained.
Development of an Experimentally Validated Analytical Model for Modular Bridge Expansion Joint Behavior

Modular bridge expansion joints (MBEJ) are large-capacity systems placed between two superstructure segments designed to provide safe joint crossing based on anticipated bridge movements. Locations of discontinuity in bridges are often recognized as weak links and therefore characterizing the behavior of expansion systems installed at deck joints under various excitations is critical to support the forecasting of bridge functionality. This paper presents the development of an analytical model representative of a common modular bridge expansion joint including its critical components, such as friction elements, equidistant devices, support bars, and center beams. The model is then validated through full-scale experimental testing of the joint. The results of this study offer a predictive model for the longitudinal motion of bridge joints excited through anticipated service or extreme events, which can be used to help determine local and global failure within the joint and make inferences as to how a bridge system could be affected. Such models provide a key step toward aiding design efforts, enabling more accurate specification of MBEJs, and supporting functionality-based risk assessment for bridges.
Experimental Investigation and Numerical Analysis of Surface Charge Decay on Acrylic and Glass Epoxy Multilayer Materials in Air

To establish an optimal lightning protection method for power distribution lines, factors such as the mechanism behind lightning surges as well as power distribution network and insulation level of power distribution lines should be taken into consideration. This study experimentally clariﬁes the voltage-time (V-t) characteristics of currently used 6.6-kV power distribution insulators having higher lightning impulse withstand voltage (LIWV) by considering the di ﬀ erences in polarity and the presence or absence of slurry. Furthermore, in this paper we propose approximation formulas based on the sparkover model for calculating the ﬂashover charac- teristics of 6.6-kV power distribution insulators, which can contribute to insulation coordination throughout the power distribution system. This paper investigates a switching overvoltage due to the induc-tive current interruption. 2 shows operation conditions of load switches and simulation results. A circuit analysis method of a line-to-ground voltage of a solar when the structure for the panel is struck by a is a test circuit of a with its power lines. At ﬁrst, the overvoltage is calculated by of a Finite Di ﬀ Time (FDTD) which is one of numerical electromagnetic analysis and can take into account the complex conﬁguration of a solar The result indicates that the dielectrics of the solar can be by some capacitors. measured and calculated overvoltages by an FDTD program and by the Electro-Magnetic Transients Program (EMTP) considering a current distribution of a lightning current ﬂowing
Field surveys of the effect of lamp spectrum on the perception of safety and comfort at night

Public lighting improves visibility and provides orientation. It also contributes to the perception of comfort and safety of people outside after dark. At present, highpressure sodium lamps are widely used in street lighting. This is in part due to their high efficacy and relatively long lifetime (≥16 000 hours). Their use, however, comes at the expense of good colour rendering. Recently developed ceramic metal halide lamps provide many of the advantages of HPS in addition to white light and better rendering of colours. In this paper, results of research conducted in three European countries on the effect of lamp spectrum on face recognition and the perception of safety and comfort outdoors are presented. The results consistently show that at comparable illuminances, people perceive areas illuminated with white light to be brighter, safer and more comfortable than the same neighbourhood illuminated with yellowish light.
Reservoir Characterization from Insufficient Static Data Using Gradual Deformation Method with Ensemble Kalman Filter

Abstract Reservoir characterization is critical in order to estimate reserves and optimize oil and gas production. Ensemble Kalman filter characterizes the spatial distribution of reservoir parameters using covariances between static and dynamic data. Ensemble Kalman filter can rapidly provide results reflecting its overall tendency of parameter distribution, but may not characterize them in detail because ensemble Kalman filter does not minimize an objective function. Gradual deformation method is one of the well known non-gradient-based methods, which guarantees a global minimum theoretically. However, if permeability samples available do not represent the whole distribution, it can be hard for gradual deformation method to reduce the objective function sufficiently. In this study, results of ensemble Kalman filter are utilized as input permeability fields in gradual deformation method so that the demerit of each method is compensated by the merit. Although samples from a reservoir have no information on extreme permeability values, the developed gradual deformation method model with ensemble Kalman filter reliably characterizes hidden extreme values.
Lowering desalination costs by alternative desalination and water reuse scenarios

AbstractReverse osmosis (RO) has contributed to a large extent in positioning membrane desalination as one of the best available technologies to meet water demand in dry coastal areas. However, membrane desalination may still be perceived as an energy consuming and high cost desalination technology. Seawater Osmotic Dilution (SOD) may lower the energy consumption and the water cost by decreasing the salt content of seawater; and, at the same time SOD can become a sustainable technology that does not impact marine environments considering that less concentrated brines are discharged into the sea. The main objective of this study was the economical evaluation of SOD for the purpose of decreasing desalination costs. The authors have investigated the attractiveness and viability of SOD opportunities compared with standard RO membrane desalination. Three process configurations (desalination, desalination and reuse, SOD) were defined for a coastal area location, where the possibilities of water availability are.