Karel de Grote-University College

Antwerpen, Belgium
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Patients suffering from sensori-neural hearing loss caused by damaged hair cells in the cochlea and diagnosed as being profoundly deaf, are potential candidates for cochlear implantation. Today, there are a number of important limitations with respect to the optimal use of these devices in deaf patients. Firstly, cochlear implant speech processors need to be adjusted so that sounds perceived by the patient are representational and at a comfortable level. Manual fitting, currently the norm, is technically demanding and time consuming and clearly suboptimal, as it involves only two of the many electrical parameters in the speech processor. Secondly, manipulation of the implant settings is based on subjective judgments of the patient , which are often inconsistent and do not reflect the outcomes on psychoacoustic measures. For the last few years, experts in the field have expressed the need for a new fitting process that optimizes the patients hearing in a more efficient and accurate way. For this to happen, the fitting procedure should change from a comfort-driven approach to an outcome-driven one. It should also address as many electrical parameters as possible. Ideally, a cochlear implant should come with an assisted or (semi-)automated fitting procedure in which a large number of parameters may be adjusted, based on measured psycho-acoustic feedback from the implant user. Such an assisted fitting process would drastically reduce the number of man-hours of fitting during the lifetime of the device with qualitative with qualitatively better outcomes. The main objectives of the proposed research project are therefore (i) to turn an existing theoretical automated fitting model into a clinical application by means of various techniques from statistics, machine learning and optimisation; (ii) to develop an evaluation tool to measure functional hearing capacities, in casu the ability to understand speech-in-noise, representative for day-to-day listening situations.

Duker M.H.,University of Bremen | Gomez R.,Complutense University of Madrid | Vande Velde C.M.L.,Karel de Grote-University College | Azov V.A.,University of Bremen
Tetrahedron Letters | Year: 2011

The synthesis of novel upper rim calix[4]arene-tetrathiafulvalene conjugates 1a-d has been performed by bridging the tetrachloromethylated calix[4]arene derivative 4 with the corresponding tetrathiafulvalene- dithiolates. The cyclic voltammetry of 1a-d shows a two-step oxidation behavior, whereas NMR binding titrations showed their binding affinity to pyridinium salts. X-ray structure of 4 features calixarene fixed in the pinched cone conformation; its crystal packing is defined by the network of C-H⋯Cl weak hydrogen bonds. © 2011 Elsevier Ltd. All rights reserved.

Verhelst S.,Ghent University | Demuynck J.,Ghent University | Sierens R.,Ghent University | Huyskens P.,Karel de Grote-University College
International Journal of Hydrogen Energy | Year: 2010

Hydrogen-fueled internal combustion engines are a possible solution to make transportation more ecological. Apart from difficulties in production and storage of hydrogen, there are three major bottlenecks in the operation of hydrogen-powered engines: reaching a high power output, reducing NOx emissions at high loads and avoiding backfire. This paper presents an experimental study of the influence of continuously variable valve timing of the intake valves on these bottlenecks. Measurements were performed on a four-cylinder engine that can run on gasoline as well as on hydrogen. The measurements on hydrogen are compared to those on gasoline. For hydrogen, the effects of the cam phasing were investigated at wide open throttle, where load is controlled by the quality of the mixture (equivalence ratio) as well as in throttled mode, where load is defined by the quantity of mixture. Results show that it is possible to optimize the applied control strategy by using variable valve timing as a means to increase the range of both the qualitative and quantitative load control methods, which contributes to an easier switch between both methods. © 2010 Professor T. Nejat Veziroglu.

Hoorens V.,Catholic University of Leuven | Takano K.,Catholic University of Leuven | Franck E.,University of Antwerp | Franck E.,Karel de Grote-University College | And 2 more authors.
Psychological Assessment | Year: 2015

We tested the usefulness of name-letter preference scores as indirect indicators of self-esteem by exploring whether multiple unsupervised self-administrations of letter rating tasks within a short period of time yield useful data. We also examined whether preferences for initials and noninitial name-letters tap different aspects of self-esteem. Participants from a community sample (N = 164; 58 men and 106 women, 17-67 years, Mage = 34.57, SD = 13.28) completed daily letter rating tasks and state self-esteem questionnaires for 7 consecutive days. They also completed a trait self-esteem questionnaire on the first measurement day as well as 6 months later. Preference scores for first-name initials were stronger but more unstable than preference scores for other name-letters. Preferences for first-name initials were primarily associated with directly measured state self-esteem whereas preferences for noninitials were primarily associated with directly measured trait self-esteem even if the latter was measured 6 months later. Thus, we showed that preferences for initials and noninitials are not simply interchangeable. Previous letter rating studies, which almost exclusively used initial preferences, should be interpreted in terms of state rather than trait self-esteem. In future studies, researchers should focus on the name-letter preference that reflects the aspect of self-esteem they wish to address. © 2015 American Psychological Association.

Smits M.,University of Antwerp | Huygh D.,Karel de Grote-University College | Craeye B.,University of Antwerp | Lenaerts S.,University of Antwerp
Catalysis Today | Year: 2014

Soot deposition has the negative ability to devalue the aesthetic appearance of buildings. Titanium dioxide applied on the building material is one way to counteract this problem as it provides air-purifying and self-cleaning properties due to its photocatalytic activity. In literature, photocatalytic soot oxidation was described, but until now, little information was available about the influence of process parameters on the photocatalytic degradation efficiency. The influence of three process parameters was tested in this study, namely TiO2 concentration, soot concentration and water-to-cement ratio (W/C-ratio) of the mortar substrates. The results revealed 50 μg TiO2 cm-2 is better to use on the cementitious materials than 250 μg TiO2 cm-2. The soot concentrations occurring in real-world situations will not inhibit the photocatalyst to be activated by light. Furthermore, the photonic efficiency increases slightly for lower W/C-ratios. This can be of interest for structural building applications, since a lower W/C-ratio results in a lower porosity of the samples and consequently in an increase in mortar strength. © 2013 Elsevier B.V.

Jaeken L.,Karel de Grote-University College | Matveev V.V.,Russian Academy of Sciences
Open Biochemistry Journal | Year: 2012

Observations of coherent cellular behavior cannot be integrated into widely accepted membrane (pump) theory (MT) and its steady state energetics because of the thermal noise of assumed ordinary cell water and freely soluble cyto-plasmic K+. However, Ling disproved MT and proposed an alternative based on coherence, showing that rest (R) and action (A) are two different phases of protoplasm with different energy levels. The R-state is a coherent metastable low-entropy state as water and K+ are bound to unfolded proteins. The A-state is the higher-entropy state because water and K+ are free. The R-to-A phase transition is regarded as a mechanism to release energy for biological work, replacing the classical concept of high-energy bonds. Subsequent inactivation during the endergonic A-to-R phase transition needs an input of metabolic energy to restore the low entropy R-state. Matveev's native aggregation hypothesis allows to integrate the energetic details of globular proteins into this view. © Jaeken and Matveev.

Van Bogaert P.,University of Antwerp | Timmermans O.,University of Antwerp | Timmermans O.,Health Science University | Weeks S.M.,Texas Christian University | And 4 more authors.
International Journal of Nursing Studies | Year: 2014

Aim: To investigate the impact of nurse practice environment factors, nurse work characteristics, and burnout on nurse reported job outcomes, quality of care, and patient adverse events variables at the nursing unit level. Background: Nurse practice environment studies show growing insights and knowledge about determining factors for nurse workforce stability, quality of care, and patient safety. Until now, international studies have primarily focused on variability at the hospital level; however, insights at the nursing unit level can reveal key factors in the nurse practice environment. Design: A cross-sectional design with a survey. Method: In a cross-sectional survey, a sample of 1108 nurses assigned to 96 nursing units completed a structured questionnaire composed of various validated instruments measuring nurse practice environment factors, nurse work characteristics, burnout, nurse reported job outcomes, quality of care, and patient adverse events. Associations between the variables were examined using multilevel modelling techniques. Results: Various unit-level associations (simple models) were identified between nurse practice environment factors, nurse work characteristics, burnout dimensions, and nurse reported outcome variables. Multiple multilevel models showed various independent variables such as nursing management at the unit level, social capital, emotional exhaustion, and depersonalization as important predictors of nurse reported outcome variables such job satisfaction, turnover intentions, quality of care (at the unit, the last shift, and in the hospital within the last year), patient and family complaints, patient and family verbal abuse, patient falls, nosocomial infections, and medications errors. Conclusion: Results suggested a stable nurse work force, with the capability to achieve superior quality and patient safety outcomes, is associated with unit-level favourable perceptions of nurse work environment factors, workload, decision latitude, and social capital, as well low levels of burnout. Nurses, physicians, nursing leaders, and executives share responsibility to create an environment supportive of interdisciplinary team development. © 2013 Elsevier Ltd.

Penne R.,Karel de Grote-University College
European Journal of Combinatorics | Year: 2010

This paper characterizes the dead-center positions of a planar mechanism in terms of implicit bars, that can be described in their turn in terms of relative motion centers. Consequently, a graphical procedure for finding motion centers leads to a geometric description for dead-point positions. We give a survey of existing geometric constructions for motion centers, and we illustrate a new technique that makes use of the "Baracs construction". © 2010 Elsevier Ltd.

Tylleman B.,Free University of Colombia | Velde C.M.L.V.,Free University of Colombia | Velde C.M.L.V.,Karel de Grote-University College | Balandier J.-Y.,Free University of Colombia | And 4 more authors.
Organic Letters | Year: 2011

The regiospecific total synthesis and characterization of anti-isomers of 2,8-dialkylanthradithiophenes are described. The "anti" structure of the ADT derivatives is demonstrated by 13C NMR as well as single crystal X-ray diffraction. © 2011 American Chemical Society.

University of Antwerp and Karel de Grote-University College | Date: 2010-12-29

Phase separator comprising a housing (2) with an inlet (5) for a multi-phase mixture, a first outlet (6) and a second outlet (7), where inside said housing (2) are provided partition walls (8) providing in the space enclosed by the said housing (2) different zones respectively, an inlet zone (9), at least one intermediate zone (10) between two of said walls (8), and an outlet zone (11), whereby each of said walls (8) is provided with at least one opening (12), the circumferential edge of each of said openings (12) in mainly all directions being positioned at a distance (D) from the circumferential edge of the wall (8) through which these openings (12) extend.

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