University of Twente Publications
University of Twente Repository provides publications of UT scientific staff, in many cases full text and publicly available.
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Mostrando recursos 1 - 20 de 23,658
Exploring the success of an integrated primary care partnership: a longitudinal study of collaboration processes - Valentijn, Pim P.; Vrijhoef, Hubertus J.M.; Ruwaard, Dirk; Bont, Antoinette de; Arends, Rosa Y.; Bruijnzeels, Marc A.
Forming partnerships is a prominent strategy used to promote integrated service delivery across health and social service systems. Evidence about the collaboration process upon which partnerships evolve has rarely been addressed in an integrated-care setting. This study explores the longitudinal relationship of the collaboration process and the influence on the final perceived success of a partnership in such a setting. The collaboration process through which partnerships evolve is based on a conceptual framework which identifies five themes: shared ambition, interests and mutual gains, relationship dynamics, organisational dynamics and process management.
Fifty-nine out of 69 partnerships from a national programme in the...
Strong and Weak Rarity Value: Resource Games with Complex Price–Scarcity Relationships - Joosten, Reinoud
We analyze effects of rarity value on the sustainability of a natural resource. Rarity value means that under extreme scarcity of the resource unit profits increase ‘explosively.’ We focus on equilibrium behavior of very patient agents in a Small Fish War. Agents interacting on a body of water have two options: they can fish with restraint or without. Fishing with restraint allows the fish stock to recover; fishing without yields higher immediate but lower future catches. We distinguish weak and strong rarity value; for the strong (weak) variant, total symmetric Pareto-efficient rewards are higher (lower) than those obtained by keeping...
An interactive portal to empower cancer survivors: a qualitative study on user expectations - Kuijpers, Wilma; Groen, Wim G.; Loos, Romy; Oldenburg, Hester S.A.; Wouters, Michel W.J.M.; Aaronson, Neil K.; Harten, Wim H. van
Portals are increasingly used to improve patient empowerment, but are still uncommon in oncology. In this study, we explored cancer survivors’ and health professionals’ expectations of possible features of an interactive portal.
We conducted three focus groups with breast cancer survivors (n = 21), two with lung cancer survivors (n = 14), and four with health professionals (n = 31). Drafts of possible features of an interactive portal were presented as static screenshots: survivorship care plan (SCP), access to electronic medical record (EMR), appointments, e-consultation, online patient community, patient reported outcomes (PROs) plus feedback, telemonitoring service, online rehabilitation program, and online psychosocial self-management program. This presentation was...
Free-surface grease flow on a rotating plate - Westerberg, L.G.; Li, J.; Höglund, E.; Lugt, P.M.; Baart, P.
Grease lubrication is traditionally used in a great variety of mechanical systems such as rolling bearings, seals, and gears where it has been shown more advantageous than oil, mainly due to its consistency allowing the grease to stay inside the system and not leak out. Knowledge of the flow dynamics of grease is important for the understanding and prediction of grease distribution for optimum lubrication and for the migration of wear and contaminant particles. Free-surface effects play an important role in rolling bearings and open gears as the configuration normally is filled with about 30 % grease to avoid heavy...
Lubricating grease shear flow and boundary layers in a concentric cylinder configuration - Li, J.X.; Westerberg, L.G.; Höglund, E.; Lugt, P.M.; Baart, P.
Grease is extensively used to lubricate various machine elements such as rolling bearings, seals, and gears. Understanding the flow dynamics of grease is relevant for the prediction of grease distribution for optimum lubrication and for the migration of wear and contaminant particles. In this study, grease flow is visualized using microparticle image velocimetry (μPIV). The experimental setup includes a concentric cylinder configuration with a rotating shaft to simulate the grease flow in a double restriction seal geometry with two different grease pocket sizes. It is shown that the grease is partially yielded in the large grease pocket geometry and fully...
On the film thickness of grease-lubricated contacts at low speed - Cen, H.; Lugt, P.M.; Morales-Espejel, G.E.
The contribution of the thickener to the thickness of the lubricating film in grease-lubricated contacts is investigated. Four different types of greases were tested in a ball/spherical roller-on-disc machine, where the film thickness was measured using the interferometry method, varying the temperature, load, and slip. The test results show that there are two lubrication regimes. Below a transition speed the grease thickener plays an important role where the film thickness increases with decreasing speed. At higher speeds the film thickness is primarily governed by the base oil. This transition speed is a function of the temperature and not of the...
Film thickness of mechanically worked lubricating grease at very low speeds - Cen, H.; Lugt, P.M.; Morales-Espejel, G.E.
Several different types of commercially available greases, aged in a roll stability tester, have been tested in a ball-on-disc machine where the film thickness was measured using the interferometry method. The grease film thickness at very low speed is thicker than the base oil film thickness due to the contribution of the thickener in this regime, which practically vanishes at higher speeds. The (mechanical) aging process reduces the thickener material, decreasing the grease film thickness at very low speeds (entrainment speed less than 0.01 m/s) with aging time, whereas no significant difference was found at higher speeds where the grease...
On the normal stress effect in grease-lubricated bearing seals - Baart, P.; Lugt, P.M.; Prakash, B.
The film formation in lip seals, due to the non-Newtonian rheology of the lubricant, has been a topic of speculation. Earlier work suggests that normal stresses in grease would be favorable for the film buildup between the seal lip and shaft or bearing ring. In the current article, we evaluate this earlier work and our earlier theoretical seal lip model with a series of experiments. We use a modified concentric cylinder geometry and a model fluid to study the fluid pressure distribution in the seal-type geometry. The results are then related to grease-lubricated seals and our earlier theoretical predictions. The...
Onset of Flow Induced Tonal Noise in Corrugated Pipe Segments - Rudenko, O.; Nakiboglu, G.; Hirschberg, A.
Corrugated pipes combine small-scale rigidity and large-scale flexibility, which make them very useful in industrial applications. The flow through such a pipe can induce strong undesirable tonal noise (whistling) and even drive integrity threatening structural vibrations. Placing a corrugated segment along a smooth pipe reduces the whistling, while this composite pipe still retains some global flexibility. The whistling is reduced by thermoviscous damping in the smooth pipe segment. For a given corrugated segment and flow velocity, one would like to predict the smooth pipe length just sufficient to avoid tonal noise: the onset of whistling. A linear model based on...
Transition from Spherical to Irregular Dispersed Phase in Water/Oil Emulsions - Schmitt, M.; Limage, S.; Grigoriev, D.O.; Krägel, J.; Dutschk, V.; Vincent-Bonnieu, S.; Miller, R.; Antoni, M.
Bulk properties of transparent and dilute water in paraffin oil emulsions stabilized with sodium dodecyl sulfate (SDS) are analyzed by optical scanning tomography. Each scanning shot of the considered emulsions has a precision of 1 mu m. The influence of aluminum oxide nanoparticles in the structure of the water droplets is investigated. Depending on concentrations of SDS and nanoparticles, a transition occurs in their shape that changes from spherical to polymorphous. This transition is controlled by the SDS/alumina nanoparticles mixing ratio and is described using an identification procedure of the topology of the gray level contours extracted from each images....
Stability of colloidal silver nanoparticles trapped in lipid bilayer: effect of lecithin concentration and applied temperature - Barani, H.; Montazer, M.; Braun, H.G.; Dutschk, V.
The use of silver nanoparticle on various substrates has been widespread because of its good antibacterial properties that directly depend on the stability of the silver nanoparticles in a colloidal suspension. In this study, the colloidal solutions of the silver nanoparticles were synthesised by a simple and safe method by using lecithin as a stabilising agent and their stability was examined at various temperatures. The effect of the lecithin concentrations on the stability of the synthesised silver nanoparticles was examined from 25 to 80 degrees C at 5 degrees C intervals, by recording the changes in the UV-vis absorption spectra,...
Results of a survey among GP practices on how they manage patient safety aspects related to point-of-care testing in every day practice - Vries, Claudette de; Doggen, Carine; Hilbers, Ellen; Verheij, Robert; IJzerman, Maarten; Geertsma, Robert; Kusters, Ron
Point-of-care (POC) tests are devices or test strips that can be used near or at the site where care is delivered to patients, enabling a relatively fast diagnosis. Although many general practitioners (GPs) in the Netherlands are using POC tests in their practice, little is known on how they manage the corresponding patient safety aspects.
To obtain information on this aspect, an invitation to participate in a web-based questionnaire was sent to a random sample of 750 GP practices. Of this sample 111 GP practices returned a complete questionnaire. Data was analysed by using descriptive statistics.
Results show that there is not...
Gadolinium-enhanced MRI features of acute gouty arthritis on top of chronic gouty involvement in different joints - Emad, Yasser; Ragab, Yasser; El-Naggar, Ahmed; El-Shaarawy, Nashwa; Abd-Allah, Mayada A.; Gamal, Rania M.; Fathy, Ahmed; Hawass, Mona; Rasker, Johannes J.
The aims of the current study are to describe gadolinium-enhanced MRI features of an acute flare of established gouty arthritis in different joints and to examine a possible association between serum uric acid and MRI signs indicative of ongoing inflammation and/or structural joint damage as well as association with disease characteristics and laboratory findings. Twenty-seven male patients with established chronic gout agreed to participate, mean age 47.6 years, and mean disease duration in months 43.2 (±31.8). For all patients, detailed demographic, disease characteristics, and laboratory findings were obtained and correlated with MRI findings. In 27 patients with established gout, a...
Using diffusion of innovation theory to understand the factors impacting patient acceptance and use of consumer e-health innovations: a case study in a primary care clinic - Zhang, Xiaojun; Yu, Ping; Yan, Jun; Spil, Ton. A.M.
Consumer e-Health is a potential solution to the problems of accessibility, quality and costs of delivering public healthcare services to patients. Although consumer e-Health has proliferated in recent years, it remains unclear if patients are willing and able to accept and use this new and rapidly developing technology. Therefore, the aim of this research is to study the factors influencing patients’ acceptance and usage of consumer e-health innovations.
A simple but typical consumer e-health innovation – an e-appointment scheduling service – was developed and implemented in a primary health care clinic in a regional town in Australia. A longitudinal case study...
Effect of Multiwalled Carbon Nanotubes on the Properties of EPDM/NBR Dissimilar Elastomer Blends - Hoikkanen, M.; Poikelispää, M.; Das, A.; Honkanen, M.; Dierkes, W.K.; Vuorinen, J.
In the presence of multiwalled carbon nanotubes (MWCNT), polar nitrile-butadiene rubber (NBR) and nonpolar ethylene propylene diene rubber (EPDM) blends were prepared following a melt mixing method. For the preparation of MWCNT filled EPDM/NBR blends, two mixing methods were used: direct mixing and the masterbatch dilution method. Various physical, mechanical, and morphological properties are explored to elucidate the dispersion behavior of MWCNTs. It was concluded that the preparation method influences the dispersion of the nanotubes in different rubber phases and the properties of these blends are controlled by the degree of dispersion of the nanotubes in the two phases