University of Adger
University of Adger
Azevedo R.,New University of Lisbon |
Roja-Solorzano L.R.,Nazarbayev University |
Bento Leal J.,New University of Lisbon |
Bento Leal J.,University of Adger
Flow Measurement and Instrumentation | Year: 2017
In the present study, high data rate measurements were obtained for the streamwise and vertical velocity components using 2D Laser Doppler Velocimeter. The turbulent field in a straight compound-channel flow was characterized for three different uniform flow water depths, corresponding to “deep flows”, “intermediate flows” and “shallow flows” conditions. Several methodologies were studied to process the data and to obtain autocorrelation functions, integral length scale and turbulence kinetic energy (TKE) dissipation rate. The Sample and Hold method was adopted to interpolate the unevenly spaced record and calculate the autocorrelation function; the integral-stop-value 1/e was used to estimate the integral length scale; and the TKE dissipation rate was estimated through the velocity energy spectrum. A double shear layer composed of two counter-rotating vertical oriented vortices, interacting with the secondary currents, is observed in the interface region for deep flow conditions. By decreasing the water depth, the interface region becomes dominated by a strong mixing layer of vertical oriented vortices with high TKE dissipation rate and large integral length scale, acting as a vertical wall to the weak secondary currents that develop at the main channel. The determination of the integral length scale permits to confirm the existence and the strength of these turbulence structures, unveiling the strong mixing layer as the origin of the largest integral length scales, even larger than the flow depth, and as the most efficient mechanism to redistribute turbulence generated at the bottom towards upper flow regions. Despite the high complexity of turbulence structures present in the flow, for all water depths, a linear dependence is depicted between integral length scale, TKE dissipation rate, and streamwise turbulence intensity. © 2017 Elsevier Ltd
Kirkevold O.,Norwegian Center for Dementia Research |
Kirkevold O.,University of Adger |
Engedal K.,University of Oslo
International Journal of Nursing Practice | Year: 2010
This study aims to map out to what degree medication is being crushed and mixed into the patients' food and beverages and how often this practice included medication, which has a statement in the Norwegian pharmaceutical compendium that this should not be done (inappropriately altered medication (IAM)). Data from a total of 2108 patients in 151 wards in 65 nursing homes were collected. The data contained information about the kind of drugs the patient received, in which form it was given and how it was given. Patient characteristics and ward characteristics were also recorded. Twenty-three per cent were given at least one drug mixed into their food or beverages and 10% were given at least one IAM. This study shows a malpractice regarding one aspect of medication in nursing homes. Even though we need more knowledge, we know enough to take action to raise the quality of the administration of medicines in nursing homes. © 2010 Blackwell Publishing Asia Pty Ltd.
Palacios-Quinonero F.,Polytechnic University of Catalonia |
Rossell J.M.,Polytechnic University of Catalonia |
Rodellar J.,Polytechnic University of Catalonia |
Karimi H.R.,University of Adger
IFAC Proceedings Volumes (IFAC-PapersOnline) | Year: 2011
In this paper, a control strategy to reduce the vibrational response of adjacent buildings under seismic excitation is presented. The proposed strategy combines passive linking elements with an active decentralized H∞ control system. The overall active-passive control system admits decentralized design and operation, and achieves an excellent vibrational reduction when the active control system works; in case of a full or partial failure of the active control system, a remarkable reduction in the vibrational response is guaranteed by the passive linking elements. For adjacent buildings that require different levels of seismic protection, the implementation of an active H∞ control system in just one of the buildings is also considered. The main ideas are presented by means of a simplified two-building model. Numerical simulations have been carried out to assess the performance of the proposed methodology with promising results. © 2011 IFAC.
Brito M.,University of Lisbon |
Fernandes J.,National Laboratory for Civil Engineering |
Leal J.B.,University of Adger |
Leal J.B.,New University of Lisbon
Environmental Fluid Mechanics | Year: 2016
The main goal of this study is the 3D numerical simulation of river flows with submerged vegetated floodplains. Since, vegetation layers are usually dense and present a large spatial heterogeneity they are here represented as a porous media. Standard semi-empirical relations drawn for porous beds packed with non-spherical particles are used to estimate the porous media parameters based on the averaged geometry of the vegetation elements. Thus, eliminating the uncertainty arising from a bulk drag coefficient approach and allowing the use of a coarser mesh. The free flow is described by Reynolds-averaged Navier–Stokes (RANS) equations, whereas the porous media flow is described by the volumetric-average of RANS equations. The volume-of-fluid method and an anisotropic explicit algebraic Reynolds stress model are used for free-surface and turbulence closure, respectively. The simulation approach is validated against results by other authors featuring vegetated flows in horizontal and rectangular open-channel. The computed results show that the time-averaged streamwise velocity and Reynolds shear stress vertical profiles are properly simulated. The validated approach was applied to simulate compound open-channel flows with submerged vegetated floodplains and compared with data obtained in an experimental facility. The results show that the proposed porous media approach is adequate to simulate flows with submerged vegetation on the floodplains. © 2016 Springer Science+Business Media Dordrecht
Palacios-Quinonero F.,University Polite |
Rossell J.M.,University Polite |
Rodellar J.,University Polite |
Karimi H.R.,University of Adger
Proceedings of the American Control Conference | Year: 2011
In this paper, a control strategy to mitigate the vibrational response of adjacent buildings under seismic excitation is presented. The proposed strategy combines inter-building passive actuators with active actuators placed in the building stories. The main ideas are presented by means of a simplified two-building model; however, a semi-decentralized overlapping approach via the inclusion principle has been used to impose a proper information exchange structure suitable for wireless control of large buildings. Numerical simulations have been carried out to assess the performance of the proposed methodology with promising results. The overall control system exhibits some degree of fault-tolerance since only partial degradation of the control performance results from partial failures of the control system. © 2011 AACC American Automatic Control Council.
Djokoto S.S.,University of Adger |
Karimi H.R.,University of Adger
Recent Researches in Geography, Geology, Energy, Environment and Biomedicine - Proc. of the 4th WSEAS Int. Conf. on EMESEG'11, 2nd Int. Conf. on WORLD-GEO'11, 5th Int. Conf. on EDEB'11 | Year: 2011
This paper describes the modeling, simulation and the instrumentation of High Pressure Roller Crusher (HPRC) for the production of silicon carbide grains. The study is to make a model and then simulate a High Pressure Roller Crusher. Selection of sensors for the HPRC is also important in this study. A High Pressure Roller Crusher (HPRC) is an important part in the production of silicon carbide, where the grains are crushed into powder form and then sieved into specified sizes based on its usage. This paper will present a model based on Johanson's theory for roller compactors, considering all the delays. The non-linearity or delays were handled in matlab using. Conclusions were drawn at end of the paper.
Zach O.,University of Adger |
Munkvold B.E.,University of Adger
Journal of Enterprise Information Management | Year: 2012
Purpose: The purpose of this paper is to investigate possible reasons for enterprise resource planning (ERP) system customization in small and medium-sized enterprises (SMEs), with a particular focus on distinguishing influential factors of the SME context. Design/methodology/approach: An exploratory qualitative research approach was employed, to identify new insights within the SME context. A multiple case study of four SMEs was conducted. Data were collected through 34 qualitative interviews with multiple informants across the four cases. Findings: The paper reports findings from four SMEs where ERP customization has been applied to match organizational needs. First, the level and type of ERP system customization applied by the case organizations were investigated. Then, the reasons for ERP system customization were explored. The analysis identified seven possible reasons leading to ERP system customization, classified according to two phases of the ERP life-cycle (prior to "going-live" and after "going-live"). Reasons specific to the SME context include unique business processes, ownership type, and organizational stage of growth. Research limitations/implications: The study is based on four cases only. Further research is needed to investigate the applicability of the findings in different contexts. Practical implications: The study findings are believed to be valuable for organizations about to implement an ERP system, as well as for ERP vendors. By identifying the reasons leading to ERP system customization and investigating the effect of the SME context, the study contributes to a better understanding of ERP system implementation in SMEs. Originality/value: The paper contributes to the scarce literature on reasons for ERP system customization in SMEs. By classifying the reasons into two phases of the ERP life-cycle, the study also contributes by exploring ERP system customization practice in different phases of the ERP life-cycle. © Emerald Group Publishing Limited.
Hartarska V.,Auburn University |
Nadolnyak D.,Auburn University |
Mersland R.,University of Adger
American Journal of Agricultural Economics | Year: 2014
Microfinance Institutions (MFIs) provide financial services to the poor and in many ways resemble both banks and non-profit organizations. Many MFIs target women because more women than men are poor, especially in rural areas. Studies show that women manage money differently from men and have different leadership styles. Thus, in credit unions and financial firms, female and male managers achieve different results. In microfinance, gender diversity on the board of MFIs is beneficial, and loans authorized by female loan officers have lower default rates. Motivated by these findings, we ask whether MFIs with a female Chief Executive Officer (CEO) are more efficient at serving the poor without jeopardizing financial sustainability. We adapt the banking approach to managerial (in)efficiency to account for the outreach and sustainability goals of the MFIs, and evaluate whether MFIs' outreach efficiency differs by the gender of their respective CEOs. We estimate a stochastic frontier cost function using the Battese-Coelli (1995) model and the "true" random effects estimators using panel data from over 250 MFIs. We find that MFIs with female CEOs have significantly higher outreach efficiency than MFIs with male CEOs. Similar results are found with a two-step stochastic frontier approach. Overall, the results suggest that promoting gender diversity at the top levels of MFI management is likely to have both social and financial benefits. © The Author (2014).
Karimi H.R.,University of Adger |
Djokoto S.S.,University of Adger
International Journal of Advanced Manufacturing Technology | Year: 2012
This paper describes the modeling, simulation, and the instrumentation of a high-pressure roller crusher (HPRC) for the production of silicon carbide grains. The study is to make a model and then simulate a high-pressure roller crusher. An HPRC is an important part in the production of silicon carbide, where the grains are crushed into powder form and then sieved into specified sizes based on their usage. The selection of sensors for the HPRC is also considered in this study. This paper presents a model based on Johanson's theory for roller compactors by considering the delay process. The simulation result is done using Matlab tools and Simulink to verify the approach proposed in the paper. Conclusions are drawn at the end of the paper. © Springer-Verlag London Limited 2012.