FEM based soil stress and strain analyses aimed at plant growth factors

During vehicular traffic on agricultural soils, the soil is subjected to a loading process which finally results into a change of micro-factors, such as the amount and distribution of water, solid parts or bounds, not arising from the soil water, between these solid parts in the soil. Derivations of the micro-factors are the so-called soil qualities like coefficient of oxygen diffusion and water permeability, moisture characteristic, root penetration resistance and the coefficient of heat conductivity. Seeds and plants need a specific set of values of these soil qualities to grow properly.The loading process of the soil is simulated through an impression of a strip into the soil with the help of a finite element method. Description is given of stress and strain theories with respect to a cubical soil body, the elastic-perfectly-plastic Mohr-Coulomb model, the soil-material interface and finite and interface elements of the used finite element program Plaxis. Derivation of soil model parameters for the finite element program Plaxis is given in case of a presented reference soil, a wet moderately heavy river clay with an entrapped air percentage of 5%. Beside soil model parameters of the Mohr-Coulomb model, attention is given to soil model parameters of the elastic region of the Plaxis-Cap model.A reference soil-load system is presented with corresponding finite element input. For handling the large amount of finite element output results, the stress and strain analysis program Trestana is developed. Characteristic of the program is that three-dimensional plots of quantities can be presented against the deformed mesh as ground surface, without loosing information through the use of smoothing procedures.Finally, single and composite quantities are presented which can serve as building blocks for constructing so-called kneading numbers of soil. This all in view of the idea that changes of kneading numbers correlate reasonably with the changes of the soil qualities.</p

Vervangingsopgave natte kunstwerken in het hoofdwatersysteem en hoofdvaarwegennet in Nederland

De vervangingsopgave natte kunstwerken: een strategische opgave voor Rijkswaterstaat – Rijkswaterstaat beheert als asset manager op duurzame wijze het Nederlandse hoofdwegennet, hoofdvaarwegennet en hoofdwatersysteem. Daarbij werkt Rijkswaterstaat aan de vlotte en veilige doorstroming van het (weg- en scheepvaart)verkeer, aan een veilig, schoon en gebruikersgericht watersysteem, aan de bescherming van Nederland tegen overstromingen en aan de leefbaarheid van Nederland. Rijkswaterstaat heeft in het verleden veel geïnvesteerd in de aanleg van infrastructuur in het watersysteem (het hoofdvaarwegennet en het hoofdwatersysteem)

The use of tools of data mining to decision making in engineering education—A systematic mapping study

In recent years, there has been an increasing amount of theoretical and applied research that has focused on educational data mining. The learning analytics is a discipline that uses techniques, methods, and algorithms that allow the user to discover and extract patterns in stored educational data, with the purpose of improving the teaching‐learning process. However, there are many requirements related to the use of new technologies in teaching‐learning processes that are practically unaddressed from the learning analytics. In an analysis of the literature, the existence of a systematic revision of the application of learning analytics in the field of engineering education is not evident. The study described in this article provides researchers with an overview of the progress made to date and identifies areas in which research is missing. To this end, a systematic mapping study has been carried out, oriented toward the classification of publications that focus on the type of research and the type of contribution. The results show a trend toward case study research that is mainly directed at software and computer science engineering. Furthermore, trends in the application of learning analytics are highlighted in the topics, such as student retention or dropout prediction, analysis of academic student data, student learning assessment and student behavior analysis. Although this systematic mapping study has focused on the application of learning analytics in engineering education, some of the results can also be applied to other educational areas

Higher education analytics: New trends in program assessments

© 2018, Springer International Publishing AG, part of Springer Nature. End of course evaluations technologies can provide critical analytics that can be used to improve the academic outcomes of almost any university. This paper presents key findings from a study conducted on more than twenty different academic degree-programs, regarding their use of end of course evaluation technology. Data was collected from an online survey instrument, in-depth interviews with academic administrators, and two case studies, one in the US and another in the UAE. The study reveals new trends including sectioning and categorization; questions standardization and benchmarking; alignment with key performance indicators and key learning outcomes; and grouping by course, program outcome, program, college, etc. in addition to those vertical structures, higher education institutions are vertically examining a specific question(s) across

Integrating evidence on patient preferences in healthcare policy decisions

Background: Despite a strong movement towards active patient involvement in healthcare policy decisions, systematic and explicit consideration of evidence of this research on patient preferences seems limited. Furthermore, little is known about the opinions of several stakeholders towards consideration of research evidence on patient preferences in healthcare policy decisions. This paper describes the protocol for an explorative study on the integration of research on patient preferences in healthcare policy decisions. The study questions: to what extent research evidence on patient preferences is considered in current procedures for healthcare policy decisions; opinions of stakeholders regarding the integration of this type of evidence in healthcare policy decisions; and what could be a decision framework for the integration of such research evidence in healthcare policy decisions. Methods/design: The study is divided in three sub-studies, predominantly using qualitative methods. The first sub-study is a scoping review in five European countries to investigate whether and how results of research on patient preferences are considered in current procedures for coverage decisions and clinical practice guideline development. The second sub-study is a qualitative study to explore the opinions of stakeholders with regard to the possibilities for integrating evidence on patient preferences in the process of healthcare decision-making in the Netherlands. The third sub-study is the development of a decision framework for research on patient preferences. The framework will consist of: a process description regarding the place of evidence on patient preferences in the decision-making process; and a taxonomy describing different terminologies and conceptualisations of ‘preferences’ and an overview of existing methodologies for investigating preferences. The concept framework will be presented to and discussed with experts. Discussion: This study will create awareness regarding the existence and potential value of research evidence on patient preferences for healthcare policy decision-making and provides insight in the methods for investigating patient preferences and the barriers and facilitators for integration of such research in healthcare policy decisions. Results of the study will be useful for researchers, clinical practice guideline developers, healthcare policy makers, and patient representatives

The right-to-manage default rule

We critically examine the right-to-manage as a legal default rule. We then assess the merits of alternative process and content defaults, as well as non-waivable terms and conditions. Finally, we suggest how various options might be combined in different circumstances

Evaluation of the finger wrinkling test: a pilot study

Purpose: Tilt table testing mainly evaluates the systemic cardiovascular part of the autonomic nervous system, while it is assumed that the finger wrinkling test assesses the peripheral part of the autonomic nervous system. In this study we explored whether the finger wrinkling test could be a useful test for autonomic dysfunction and whether the clinical evaluation of wrinkling can be improved by digital analysis of photographs. Methods: As much as 20 healthy subjects and 15 patients underwent tilt table testing and finger wrinkling testing. During the finger wrinkling test the right hand was immersed in water at 40°C. The degree of wrinkling was assessed with a 5-point clinical scale at baseline, 5, 15 and 30 min of immersion. Photographs were taken at the same intervals. Several features were evaluated using digital analysis: length and gradient of automatically detected wrinkle and mean, maximum, minimum, variance and derivative of grey value of pixels. Results: Clinical scoring of wrinkling allowed differentiation between healthy subjects and patients with a normal and an abnormal response to tilt table testing. Relevant features obtained with digital analysis were mean grey value and the gradient of automatically detected wrinkle. McNemar’s test showed no difference in test results between the tilt table test and the finger wrinkling test with a kappa of 0.68. Conclusion: The finger wrinkling test can be used as a screening test before tilt table testing. Visual evaluation of wrinkling is still superior to digital analysis of photographs

Observer Variation of 2-Deoxy-2-[F-18]fluoro-d-Glucose-Positron Emission Tomography in Mediastinal Staging of Non-Small Cell Lung Cancer as a Function of Experience, and its Potential Clinical Impact

Purpose: To test the extent of variation among nuclear medicine physicians with respect to staging non-small cell lung cancer with positron emission tomography (PET). Procedures: Two groups of nuclear medicine physicians with different levels of PET experience reviewed 30 PET scans. They were requested to identify and localize suspicious mediastinal lymph nodes (MLN) using standardized algorithms. Results were compared between the two groups, between individuals, and with expert reading. Results: Overall we found good interobserver agreement (kappa 0.65). Experience with PET translated into a better ability to localize MLN stations (68 % vs. 51%, respectively), and experienced readers appeared to be more familiar with translating PET readings into clinically useful statements. Conclusions: Although our results suggest that clinical experience with PET increases observers _ ability to read and interpret results from PET adequately, there is room for improvement. Experience with PET does not necessarily improve the accuracy of image interpretation

Impact of tissue adhesives on the prevention of anastomotic leakage of colonic anastomoses: an in vivo study

Background: Tissue adhesives (TA) may be useful to strengthen colorectal anastomoses, thereby preventing anastomotic leakage (AL). Previous studies have identified cyanoacrylate (CA) TAs as the most promising colonic anastomotic sealants. This stud