Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Meetprotocol voor lichttransmissie van materialen met condens
    Swinkels, Gert-Jan ; Breugel, Bram van; Tsafaras, Ilias - \ 2017
    Bleiswijk : Wageningen University & Research, BU Glastuinbouw (Rapport GTB 1438) - 42
    kassen - meettechnieken - lichtdoorlating - glas - diffuus glas - condenseren - greenhouses - measurement techniques - light transmission - glass - diffused glass - condensation
    Measuring the light transmittance of greenhouse covering materials has become a standard procedure for the
    horticultural industry. This measurement is based on dry materials. However, transmittance changes (strongly)
    when water condenses on the inside of the material. For example, transmittance of traditional clear non-diffusing
    greenhouse glass usually decreases because the condensed droplets tend to reflect the light instead of transmit
    it, while some varieties of diffuse glass could increase light transmittance. Because a greenhouse is wet on the
    inside during a large period of the year it is important to be able to measure transmission with a standardized
    protocol. In this research a measurement protocol and associated equipment are developed for determining the
    effect of condensation on the hemispherical light transmission in a standardized way.
    The protocol is based on natural condensation on a material under a slope according to common greenhouse roof
    slopes, which is forced by a combination of temperature and humidity. In this way the natural process of draining
    of condensate is taken into account. The results show that the transmission of traditional clear uncoated (new)
    horticultural glass drops with about 3%-points while the effects on the behaviour of the tested types of diffuse
    glass vary between -1%- point up to + 1.5%-point.
    Measurement methods to assess methane production of individual dairy cows in a barn
    Wu, L. - \ 2016
    Wageningen University. Promotor(en): Peter Groot Koerkamp, co-promotor(en): Nico Ogink. - Wageningen : Wageningen University - ISBN 9789462577312 - 190
    dairy cows - cows - methane production - barns - measurement techniques - modeling - breath - uncertainty analysis - greenhouse gases - cubicles - melkkoeien - koeien - methaanproductie - landbouwschuren - meettechnieken - modelleren - adem - onzekerheidsanalyse - broeikasgassen - ligboxen

    Mitigation of methane production from dairy cows is critical to reduce the dairy industry’s contribution to the production of greenhouse gases. None of current used methane measurement methods are flawless and application of the methods is limited to assess the effects of methane mitigation methods under practical conditions. The main objective of this thesis is to design, test, and validate methods to determine or rank the methane production of individual dairy cows at farm house level.

    As a start, I evaluated merits and drawbacks of existing methane measurement methods and discussed against 14 requirements of methane measurement methods to assess methane mitigation strategies. This review study revealed that none of existing methods meet all requirements, and pointed out that sampling of breath air during the lying period of cows in cubicles could be a practical direction to measure methane production of individual cows under farm conditions. Therefore, we first assessed methane concentration levels and variations in time, and around cubicles, explored effects of barn and management factors on them, and assessed the effect of the variation of the background methane concentrations on assessing methane production of individual dairy cows in cubicles. Then, we designed and constructed an artificial reference cow (ARC) that mimics the methane production of real cows with known pre-set methane production rates and dynamics of eructations. With the acquired background information and the developed ARC, we assessed the uncertainty of a breath methane concentration (BMC) method in a feeder and developed a cubicle hood sampler (CHS) that measures methane fluxes from lying cows in cubicles. The observed uncertainty related to random errors of the BMC method can be overcome by sufficient numbers of repetitions. However identified uncertainty with a systematic nature, related to inconsistent relation between concentration and production rate, cannot be compensated by repeated measurements and requires further investigation into the widely used BMC method before it can be used with confidence. Compared to the BMC method, the developed CHS is not subject to such systematic effects and allows prolonged measurement periods. Performance test under field conditions showed that the designed CHS accurately measured methane fluxes provided by the ARC.

    Overall, in this thesis I assessed the measurement error of current three methane measurement principles (flux, breath concentration & tracer gas), provided information to limit the measurement variation, and assessed the availability to determine or rank the methane production of individual dairy cows at farm house level. The newly developed ARC can be used as a known reference source to calibrate and develop practical methane measurement methods, and the CHS is sufficiently accurate to measure methane production of individual cows at farm house level.

    Beach sand dynamics : measurements, models and scales
    Poortinga, A. - \ 2015
    Wageningen University. Promotor(en): Coen Ritsema, co-promotor(en): Saskia Visser; Michel Riksen. - Wageningen : Wageningen University - ISBN 9789462575851 - 235
    stranden - zand - modellen - meettechnieken - eolisch zand - sediment - geologische sedimentatie - beaches - sand - models - measurement techniques - aeolian sands - sediment - geological sedimentation
    Snelle meettechnieken voor nutriëntenbenutting bij landbouwhuisdieren
    Vrolijk, M. ; Goselink, R.M.A. ; Veldkamp, T. - \ 2015
    Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 902) - 43
    vee - veevoeding - nutriëntengebruiksefficiëntie - voedingsstoffenopname (mens en dier) - meettechnieken - voedingsfysiologie - livestock - livestock feeding - nutrient use efficiency - nutrient intake - measurement techniques - nutrition physiology
    Efficient feeding of animals in livestock production deserves constant attention. Feed is input for milk, meat and egg production. It is a challenge to use nutrients as efficiently as possible, and produce ‘more with less’. Feeding the animals at their requirements can be improved if the effects of nutrient intake can be measured within a short time. This project made an overview of possible ‘rapid measuring techniques’ to be used in the near future. Each technique was scored for relevance, technical feasibility, practical application and the investment needed for development (time and money). From an expert workshop, measuring by means of sensor boluses or fluorescent markers as well as manure analysis, were defined as most promising for future research and practice.
    Techniques for evaluating nutrient status in farm animals
    Jansman, A.J.M. ; Pas, M.F.W. te - \ 2015
    Wageningen : Wageningen UR Livestock Research (Report / Wageningen UR Livestock Research 846) - 47
    voedingsstoffenbalans - voedingsstoffen - meettechnieken - varkens - herkauwers - pluimvee - wetenschappelijk onderzoek - nutrient balance - nutrients - measurement techniques - pigs - ruminants - poultry - scientific research
    It is the aim of the study to present a literature review on methods and techniques for determining nutrient status of different farm animal species (ruminants, pigs and poultry). The study focusses especially on the options to determine nutrient status in farm animals from a research perspective rather than on the possibilities for their practical application and related technical issues.
    Measuring fast-temporal sediment fluxes with an analogue acoustic sensor: a wind tunnel study
    Poortinga, A. ; Minnen, J. van; Keijsers, J.G.S. ; Riksen, M.J.P.M. ; Goossens, D. ; Seeger, K.M. - \ 2013
    PLoS ONE 8 (2013)9. - ISSN 1932-6203
    eolische processen - sediment - windtunnels - meettechnieken - aeolian processes - sediment - wind tunnels - measurement techniques - inland drift-sand - aeolian transport - erosion - velocity - cloud - soil - validation - efficiency - intensity - saltation
    In aeolian research, field measurements are important for studying complex wind-driven processes for land management evaluation and model validation. Consequently, there have been many devices developed, tested, and applied to investigate a range of aeolian-based phenomena. However, determining the most effective application and data analysis techniques is widely debated in the literature. Here we investigate the effectiveness of two different sediment traps (the BEST trap and the MWAC catcher) in measuring vertical sediment flux. The study was performed in a wind tunnel with sediment fluxes characterized using saltiphones. Contrary to most studies, we used the analogue output of five saltiphones mounted on top of each other to determine the total kinetic energy, which was then used to calculate aeolian sediment budgets. Absolute sediment losses during the experiments were determined using a balance located beneath the test tray. Test runs were conducted with different sand sizes and at different wind speeds. The efficiency of the two traps did not vary with the wind speed or sediment size but was affected by both the experimental setup (position of the lowest trap above the surface and number of traps in the saltation layer) and the technique used to calculate the sediment flux. Despite this, good agreement was found between sediment losses calculated from the saltiphone and those measured using the balance. The results of this study provide a framework for measuring sediment fluxes at small time resolution (seconds to milliseconds) in the field.
    In aeolian research, field measurements are important for studying complex wind-driven processes for land management evaluation and model validation. Consequently, there have been many devices developed, tested, and applied to investigate a range of aeolian-based phenomena. However, determining the most effective application and data analysis techniques is widely debated in the literature. Here we investigate the effectiveness of two different sediment traps (the BEST trap and the MWAC catcher) in measuring vertical sediment flux. The study was performed in a wind tunnel with sediment fluxes characterized using saltiphones. Contrary to most studies, we used the analogue output of five saltiphones mounted on top of each other to determine the total kinetic energy, which was then used to calculate aeolian sediment budgets. Absolute sediment losses during the experiments were determined using a balance located beneath the test tray. Test runs were conducted with different sand sizes and at different wind speeds. The efficiency of the two traps did not vary with the wind speed or sediment size but was affected by both the experimental setup (position of the lowest trap above the surface and number of traps in the saltation layer) and the technique used to calculate the sediment flux. Despite this, good agreement was found between sediment losses calculated from the saltiphone and those measured using the balance. The results of this study provide a framework for measuring sediment fluxes at small time resolution (seconds to milliseconds) in the field.
    Validatiemetingen kantdoppen ten behoeve van het driftmodel IDEFICS
    Stallinga, H. ; Zande, J.C. van de; Velde, P. van - \ 2013
    Wageningen : Plant Research International Wageningen UR, Business Unit Agrosystems (Rapport / Plant Research International 525) - 78
    spuiten - spuitdoppen - meting - meettechnieken - drift - reductie - landbouwkundig onderzoek - milieubescherming - spraying - fan nozzles - measurement - measurement techniques - drift - reduction - agricultural research - environmental protection
    Ter beperking van de drift is het verplicht met veldspuiten de buitenste 14 m van het veld te spuiten met driftarme spuitdoppen en een driftreducerende kantdop. Om het effect van kantdoppen op de depositie ‘over de rand van het gewas’ en de drift te meten zijn enkelsdopsbespuitingen en driftmetingen uitgevoerd. De drift van 15 kantdoppen (02 en 04 grootte) werd gemeten en vergeleken met de standaard spleetdop TeeJet XR 110.04 en de BCPC grensdop Fijn/ Midden de Lurmark 31 - 03 - F110
    Rheology and Fracture Mechanics of Foods
    Vliet, T. van - \ 2013
    Boca Raton, FL, USA : CRC Press - ISBN 9781439827031 - 363
    reologie - mechanische eigenschappen - voedingsmiddelen - mechanica - voedselproducten - meettechnieken - reologische eigenschappen - rheology - mechanical properties - foods - mechanics - food products - measurement techniques - rheological properties
    The mechanical properties of food play an important role during manufacturing, storage, handling, and last but not least, during consumption. For an adequate understanding of the mechanical properties of liquid, liquid-like, soft solid, and solid foods, a basic understanding of relevant aspects of rheology and fracture mechanics is essential. Focusing on basic principles, Rheology and Fracture Mechanics of Foods examines how rheological and fracture behavior in food relates to product structure. Divided into three parts, the book reviews basic concepts and emphasizes aspects relevant for studying food products, raw materials, and intermediate products. It then introduces measuring methods and the equipment used for studying mechanical properties of food products, highlighting tests that deliver reproducible and interpretable data. The final part investigates the relation between rheological and fracture behavior of matter and physical structure at the relevant molecular, mesoscopic, and macroscopic length scales. In addition to the basics of rheology and fracture mechanics, the book explores the relationship between measured mechanical properties and the structure of the different types of food and how they may determine texture perception
    Proximal soil sensors and data fusion for precision agriculture
    Mahmood, H.S. - \ 2013
    Wageningen University. Promotor(en): Eldert van Henten, co-promotor(en): Willem Hoogmoed. - S.l. : s.n. - ISBN 9789461735799 - 205
    meettechnieken - sensors - bodemeigenschappen - meetsystemen - precisielandbouw - vollegrondsteelt - akkerbouw - measurement techniques - sensors - soil properties - measurement systems - precision agriculture - outdoor cropping - arable farming
    different remote and proximal soil sensors are available today that can scan entire fields and give detailed information on various physical, chemical, mechanical and biological soil properties. The first objective of this thesis was to evaluate different proximal soil sensors available today and to identify their capacity of quantifying soil properties. The second objective of this thesis was to enhance the usefulness of a single sensor system by multiple sensor data fusion that can improve the performance of currently available soil sensors when a single sensor does not function optimally due to certain set of soil and environmental constraints.
    Rainfall variability in the Netherlands from radars, rain gauges, and disdrometers
    Beek, R. van de - \ 2013
    Wageningen University. Promotor(en): Remko Uijlenhoet, co-promotor(en): Hidde Leijnse. - S.l. : s.n. - ISBN 9789461736437 - 128
    regen - neerslag - radar - regenmeters - hydrologie - meteorologie - schattingen - schatting - meettechnieken - meetsystemen - nederland - rain - precipitation - radar - rain gauges - hydrology - meteorology - estimates - estimation - measurement techniques - measurement systems - netherlands

    Chapter 1. This thesis presents studies on the variability of precipitation in the Netherlands from datasets collected by radars, rain gauges and disdrometers. Accurate rainfall estimates are highly relevant in hydrology, meteorology and climatology as precipitation has a large impact on society. Precipitation has been studied extensively in the past, although it is impossible to describe all processes and behavior involved. This thesis attempts to add to the knowledge on precipitation. In the first chapter a short overview of rainfall variability at different scales is presented together with the most common instruments for measuring precipitation.

    Chapter 2. The spatial variability of daily rainfall accumulations is studied. Ninety-day averaged semi-variograms are created based on a 30-year data set gathered by automatic stations operated by the Royal Netherlands Meteorological Institute (KNMI). This is complemented by a one-year dataset of 10 gauges within a 5 km radius around CESAR (Cabauw Experimental Site for Atmospheric Research) in the center of the Netherlands. It is shown that it is possible to derive an average semi-variogram that describes the climatology of daily precipitation for each day of the year.

    Chapter 3. The study of chapter 2 is extended by investigating accumulation intervals shorter than daily scales. These are at 12, 8, 6, 4, 3, 2 and 1-hour accumulation intervals. It is shown that at shorter temporal scales the behavior of semi-variograms of precipitation still shows a clear seasonal trend. At hourly and two-hourly accumulation intervals the signal of the range becomes fairly constant during the summer due to the limited accumulation period, the frequent occurrence of convective precipitation, and measurement errors. This illustrates the lower limit of using cosine functions to describe variogram parameters. By fitting a power-law function through the different cosine parameters it is possible to describe the semi-variance of precipitation at scales between 1 and 24 hours using a limited set of equations.

    Chapter 4. Different sources of error affecting rainfall estimates by weather radar are identified. By focussing on precipitation near a C-band radar some of these sources are reduced, which allows to focus on a limited set of error sources. These are radar calibration, ground clutter, wet radome attenuation and variations in rain drop size distribution. An event that caused high precipitation amounts in a band along the center of the Netherlands and more than 50~mm near the radar between the 25th and the 27th of August 2010 is studied. Without any correction and by applying a standard Marshall-Palmer Z-R relation the radar is found to underestimate by approximately 50% with respect to the rain gauge measurements. Using the sun for calibration a correction of 1 dB is applied. Clutter is corrected by subtracting a clear sky clutter map as this proves to provide better results than the standard doppler filter. Wet-radome attenuation is corrected by looking at the amount of attenuation at a known strong clutter pixel near the radar. Disdrometer data near the radar are used to derive accurate Z-R relations specific to the precipitation of the event. These corrections combined provide very promising results with a slight overestimation of the quantitative precipitation estimates (QPE) from the radar by 5 to 8%.

    Chapter 5. An extensive dataset of 195 precipitation events measured by an X-band radar (SOLIDAR) is used to study precipitation at a high spatial resolution of 120 m and a high temporal resolution of 16 s. This study shows the benefit of using such high resolution X-band radars over flat terrain. The errors in the radar measurements are first assessed and corrected as well as possible by considering different techniques. These errors are calibration, ground clutter and attenuation. Finally, five strongly different precipitation events are studied in detail to illustrate the strengths and weaknesses of the X-band weather radar.

    Chapter 6. The variability and possible measurement methods of precipitation have been studied. It was shown that precipitation spatial and temporal variability has a clear statistical signal by analyzing variograms for different accumulation intervals. Weather radars were also shown to be able to give good estimates of precipitation at ground level as well as detailed information on the spatial variability. Some recommendations are given to perform follow up studies. For chapters 2 & 3 it is recommended to use a larger and more detailed dataset, which also incorporates Belgian and German data. This would allow the study of anisotropy in the semi-variograms as well as extending the analysis to accumulation times shorter than 1 hour and longer than 24 hours. For chapter 4 it is recommended to study pixels located further away from the radar. While other error sources would become more pronounced it would be possible to study the applicability of the proposed corrections at longer ranges. Studying the wet-radome attenuation with several strong clutter pixels near the radar would allow the study of wind-effects on wet-radome attenuation, possibly allowing corrections using measurements of (Doppler) wind-speed and direction. Finally, in chapter 5 it is recommended to study the successor of SOLIDAR, IDRA, which is currently operational at CESAR. This radar is a polarimetric radar, allowing a more detailed study of precipitation together with the data from other instruments at this location and the C-band radar of KNMI, which is located close to this location at approximately 23 km.

    Watersense eindrapport
    Buitenkamp, M. ; Veen, A. van der; Haan, J.J. de; PPO Akkerbouw, Groene Ruimte en Vollegrondsgroente, - \ 2012
    Assen : Watersense - 51
    waterbeheer - sensors - meettechnieken - beslissingsondersteunende systemen - grondwaterstand - oppervlaktewater - waterstand - akkerbouw - waterschappen - watervoorziening - veenkolonien - drenthe - water management - sensors - measurement techniques - decision support systems - groundwater level - surface water - water level - arable farming - polder boards - water supply - veenkolonien - drenthe
    Dit rapport beschrijft de resultaten van het project WaterSense, dat liep van 2008 tot en met 2012. In het project zijn de mogelijkheden van sensortechnologie onderzocht voor waterbeheer door landbouwers, waterschappen en drinkwaterbedrijven. Het doel van WaterSense was: - het onderzoeken en ontwikkelen van het concept van een beslissingsondersteunend systeem voor waterbeheer met behulp van sensortechnologie; - validatie van het concept aan de hand van een demonstratiesysteem. In WaterSense zijn diverse aspecten van meten, modelleren en sturen met betrekking tot waterkwantiteit, waterkwaliteit en landbouw onderzocht.
    Measuring water-vapour and carbon-dioxide fluxes at field scales with scintillometry
    Kesteren, A.J.H. van - \ 2012
    Wageningen University. Promotor(en): Bert Holtslag, co-promotor(en): Oscar Hartogensis. - [S.l.] : s.n. - ISBN 9789461734235 - 212
    scintillometrie - waterdamp - kooldioxide - meteorologie - meettechnieken - scintillometry - water vapour - carbon dioxide - meteorology - measurement techniques

    Scintillometry is a measurement technique that has proven itself to be of great value for measuring spatial-averaged fluxes of sensible heat, momentum, and evapotranspiration. Furthermore, for crop fields (field scales), scintillometry has been shown to accurately determine the sensible-heat and momentum flux over time intervals as short as 6 seconds. As a consequence, interests in scintillometry are growing and scintillometers that determine sensible-heat fluxes and momentum fluxes have become commercially available.

    This thesis deals with two aspects of scintillometry. First, after a general introduction of scintillometry, measurement errors that have been observed in the large-aperture scintillometer from Kipp&Zonen and in the SLS field-scale scintillometer from Scintec are evaluated. For both scintillometer types, we discuss the variability in the measurement errors among different instruments and, where possible, we give solutions to remove these errors. Furthermore, we present the results of a prototype scintillometer that was developed as part of the research project. With our proposed design, we aim to overcome the measurement errors in the Scintec scintillometer and extend the applicability of the field-scale scintillometer to paths that are longer than 200 m.

    Second, we extend the application of field-scale scintillometry to the flux measurements of latent-heat, carbon-dioxide, and other passive scalars. Until now, scintillometers could not be used for measuring passive-scalar fluxes over crop fields and we show that with our extended methodology these fluxes can be accurately determined over time intervals as short as 1 minute. The methodology is based on a combination of scintillometer measurements and additional high-frequency scalar measurements and works under conditions of homogeneous turbulence, i.e. single crop fields. We introduce four methods, notably the energy-balance method, the Bowen-variance method, the flux-variance method, and the structure-parameter method. Using several validation methods, we show that the energy-balance method is unsuitable for estimating scalar fluxes over 1-min averaging intervals. The Bowen-variance and flux-variance method perform better and the structure-parameter method accurately resolves 1-minute fluxes. Thus, with this methodology fluxes can be resolved with a high temporal resolution, making it possible to study vegetation in a natural environment under non-stationary conditions. This allows us to show that the wheat vegetation affects fluxes upon changes in solar radiation in time periods clearly shorter than 30 minutes and that the canopy resistance can change significantly within several minutes.


    Analyse Sorbisense metingen Watersense op proefbedrijf 't Kompas
    Haan, J.J. de; Wijnholds, K.H. ; Kooij, J. van der - \ 2012
    Lelystad : PPO AGV
    waterverontreiniging - meettechnieken - proefvelden - oppervlaktewaterkwaliteit - grondwaterkwaliteit - zandgronden - akkerbouw - pesticiden - fosfaten - stikstof - veenkolonien - water pollution - measurement techniques - experimental plots - surface water quality - groundwater quality - sandy soils - arable farming - pesticides - phosphates - nitrogen - veenkolonien
    Metingen naar concentraties van stikstof, fosfaat en gewasbeschermingsmiddelen zijn uitgevoerd in het Watersense proefveld op PPO-locatie ’t Kompas te Valthermond. Gedurende ruim een jaar is de waterkwaliteit gemeten. Voordeel van Sorbisense metingen ten opzichte van standaardmetingen is dat over een lange tijd bemonsterd wordt. De techniek is echter niet bruikbaar voor operationele metingen waarop direct actie kan volgen omdat de analyse van de monsters in een laboratorium uitgevoerd moeten worden.
    Methaanemissie uit melkveedrijfmest bij gebruik van drijvende ballen = Reduction methane emission from dairy slurry using floating balls
    Dooren, H.J.C. van; Blanken, K. - \ 2012
    Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 495) - 13
    melkveehouderij - methaan - emissie - reductie - meettechnieken - dierlijke meststoffen - opslag - stalklimaat - voorwerpen - drijven - dairy farming - methane - emission - reduction - measurement techniques - animal manures - storage - stall climate - objects - floating
    The emission of methane from a slatted concrete floor with deep pits was measured using floating balls to reduce the emitting surface and compared with a reference without the balls.
    Inrichtingsontwerp van het bodemmeetnet voor de natuur in de provincie Gelderland
    Rietra, R.P.J.J. ; Brus, D.J. ; Wamelink, G.W.W. ; Kemmers, R.H. ; Voogd, J.C.H. - \ 2012
    Wageningen : Alterra (Alterra-rapport 2313) - 52
    bodemmonitoring - bodemkwaliteit - meettechnieken - meetsystemen - bemonsteren - natuurgebieden - gelderland - soil monitoring - soil quality - measurement techniques - measurement systems - sampling - natural areas - gelderland
    De kwaliteit en de ontwikkeling van de natuur dient gemonitord geworden volgens een nieuwe landelijke systematiek in het kader van het Subsidie Stelsel Natuur (SNL). Daarnaast speelt de monitoring voor Natura 2000-gebieden en specifiek voor de verdroging van de TOP-gebieden. In dit rapport wordt een ontwerp gegeven van het meetnet met de steekproefopzet in ruimte en tijd, de te meten parameters, bemonsterings- en analysemethode en meetlocaties. Hierbij is rekening gehouden met de verschillende beheertypen en hun oppervlakte en het belang van de bodemkwaliteit voor het type. Het ontwerp is zo opgezet dat het monitoringsprogramma over meerdere jaren kan worden uitgerold.
    Mogelijkheden van Ion Specifiek sturen van recirculatie water: Nota voor de projecten TOOLBOX en de EU Kader Richtlijn Water (substraten), 10 oktober 2011
    Blok, C. ; Lugt, G. van - \ 2011
    Wageningen UR Glastuinbouw/BLGG
    glastuinbouw - recirculatiesystemen - ionen - meettechnieken - instrumenten (meters) - greenhouse horticulture - recirculating systems - ions - measurement techniques - instruments
    Ion specifieke sensoren voor de glastuinbouw worden momenteel ontwikkeld door verschillende bedrijven. De normale praktijk is nu nog om drainwater monsters elke 7-14 dagen op te sturen naar een lab (terug binnen 24 uur in Holland). Enkele van de bestaande meetgegevens worden gepresenteerd.
    Voor bewerken de grond aftasten
    Doorn, D. van; Hoogmoed, W.B. - \ 2011
    Nieuwe oogst / Magazine gewas 7 (2011)18. - ISSN 1871-093X - p. 4 - 5.
    sensors - meettechnieken - grondbewerking - bodemstructuur - akkerbouw - precisielandbouw - landbouwtechniek - sensors - measurement techniques - tillage - soil structure - arable farming - precision agriculture - agricultural engineering
    Robotisering op het gebied van grondbewerking in de boerenpraktijk laat nog enkele jaren op zich wachten, verwacht Wageningen UR. Er is namelijk geen wettelijke basis voor
    Evaluatie van de CIGR methode voor de bepaling van het ventilatiedebiet uit stallen
    Mosquera Losada, J. ; Hol, J.M.G. ; Groenestein, C.M. - \ 2010
    Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 429)
    melkveehouderij - varkenshouderij - pluimveehouderij - vleeskuikens - stallen - ventilatie - broeikasgassen - ammoniakemissie - fijn stof - meettechnieken - stalklimaat - dairy farming - pig farming - poultry farming - broilers - stalls - ventilation - greenhouse gases - ammonia emission - particulate matter - measurement techniques - stall climate
    In this study the calculation method used by the CIGR to determine the ventilation rate from animal houses (CO2 mass balance method) was evaluated with measurement data for different animal categories.
    Precipitation measurement at CESAR, the Netherlands
    Leijnse, H. ; Uijlenhoet, R. ; Beek, C.Z. van de; Overeem, A. ; Otto, T. ; Unal, C.M.H. ; Dufournet, Y. ; Russchenberg, H.W. ; Figueras i Ventura, J. ; Klein Baltink, H. ; Holleman, I. - \ 2010
    Journal of Hydrometeorology 11 (2010)6. - ISSN 1525-755X - p. 1322 - 1329.
    neerslag - meettechnieken - weersvoorspelling - data-assimilatie - nederland - precipitation - measurement techniques - weather forecasting - data assimilation - netherlands - polarization spectral-analysis - dual-frequency retrieval - x-band frequencies - radar measurements - rainfall measurements - part i - reflectivity - resolution - rates - doppler
    The Cabauw Experimental Site for Atmospheric Research (CESAR) observatory hosts a unique collection of instruments related to precipitation measurement. The data collected by these instruments are stored in a database that is freely accessible through a Web interface. The instruments present at the CESAR site include three disdrometers (two on the ground and one at 200 mabove ground level), a dense network of rain gauges, three profiling radars (1.3, 3.3, and 35 GHz), and an X-band Doppler polarimetric scanning radar. In addition to these instruments, operational weather radar data from the nearby (;25 km) De Bilt C-band Doppler radar are also available. The richness of the datasets available is illustrated for a rainfall event, where the synergy of the different instruments provides insight into precipitation at multiple spatial and temporal scales. These datasets, which are freely available to the scientific community, can contribute greatly to our understanding of precipitation-related atmospheric and hydrologic processes.
    Beoordeling van de FSC 2000 als vervanger van de Leroux-meter voor het bepalen van de stroefheid van betonnen stalvloeren = Evaluation of the FSC 2000 as substitute for the Leroux apparatus for determination of skid resistance of concrete floors of animal houses
    Winkel, A. ; Blanken, K. ; Bokma, S. - \ 2010
    Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 315) - 21
    huisvesting, dieren - stallen - beton - vloeren - meettechnieken - animal housing - stalls - concrete - floors - measurement techniques
    In this study the FSC 2000 is evaluated as a substitute for the Leroux apparatus for determination of skid resistance of concrete floors of animal houses. This study shows that the FSC 2000 is well suitable for measurements of skid resistance of concrete slats and solid floors of animal houses.
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