360 research outputs found
De bodemgesteldheid van het ritsenlandschap en van de oude kustvlakte in Suriname
Full text linkAgriculture developed remarkably in the old and especially in the young coastal plain of Surinam in the 17th, 18th and 19th century and produced such crops as sugar, cotton, tobacco, cocoa and coffee. In the second half of the 19th century activity decreased severely. With the modern sciences including soil science and survey the Surinam government was now trying to extent agriculture.The author surveyed some areas in the coastal plain, where there were sandy beachridges, some rich in shells. In the old coastal plain, he studied clay soils and eroded sand ridges of very fine sands, classified them and considered their suitability for fruit crops. Soil genesis was discussed. In the young beach ridges brown to reddish brown, biologically homogenized deep loamy sand soils were formed with favourable drainage and groundwater podsols with poor drainage. There were all intermediates.- In the older coastal- clay soils textural B horizons developed in planosol-like soils. Also plinthite was present. Better drained soils were well homogenized, giving physically good brown soils suitable for many fruit crops such as citrus, cocos, oilpalm and coffee. These soils are also very suitable for grassland.<p/
De bodemgesteldheid van het ritsenlandschap en van de oude kustvlakte in Suriname
No full textAgriculture developed remarkably in the old and especially in the young coastal plain of Surinam in the 17th, 18th and 19th century and produced such crops as sugar, cotton, tobacco, cocoa and coffee. In the second half of the 19th century activity decreased severely. With the modern sciences including soil science and survey the Surinam government was now trying to extent agriculture.The author surveyed some areas in the coastal plain, where there were sandy beachridges, some rich in shells. In the old coastal plain, he studied clay soils and eroded sand ridges of very fine sands, classified them and considered their suitability for fruit crops. Soil genesis was discussed. In the young beach ridges brown to reddish brown, biologically homogenized deep loamy sand soils were formed with favourable drainage and groundwater podsols with poor drainage. There were all intermediates.- In the older coastal- clay soils textural B horizons developed in planosol-like soils. Also plinthite was present. Better drained soils were well homogenized, giving physically good brown soils suitable for many fruit crops such as citrus, cocos, oilpalm and coffee. These soils are also very suitable for grassland
Ondergrond Hogesnelheids Goederenvervoer in Noordwest Europa: Een verkeerskundige studie naar de kostenvoordelen van ondergronds hogesnelheids goederenvervoer in Noordwest Europa
No full textAls afgeleide van de groei van de vervoervraag is het goederenverkeer in Europa sterk toegenomen, waarbij de nadelige gevolgen in conflict zijn met de eisen ten aanzien van bereikbaarheid, veiligheid en leefbaarheid. Ondergronds hogesnelheids goederenvervoer is een innovatief transportsysteem dat deze nadelige gevolgen niet of nauwelijks heeft en dat kostenvoordelen zou kunnen bieden voor een verlader/vervoerder ten opzichte van bestaande vervoerwijzen. De doelstelling van het onderzoek is om een ondergronds hogesnelheids goederenvervoemetwerk te ontwerpen in Europa, waarbij er kostenvoordelen optreden voor verladers/vervoerders, ten opzichte van bestaande vervoerwijzen. Hierbij spelen drie vragen een rol: Voor welke goederen zou een ondergronds hogesnelheids goederenvervoersysteem een beter alternatief kunnen zijn dan bestaande transportmodaliteiten (voornamelijk wegvervoer en luchtvaart)? Op welke afstandsklasse(n) kan ondergronds hogesnelheids goederenvervoer een alternatief zijn voor bestaande modaliteiten? hl welke regio's in Noordwest Europa bestaat voldoende potentieel om te investeren in ondergronds hogesnelheids goederenvervoerinfrastructuur? Het ondergronds hogesnelheids goederenvervoer wordt vergeleken met de bestaande vervoerwijzen door middel van het modelleren van het keuzegedrag van een verlader/vervoerder in de logistiek op basis van de transportweerstand. De transportweerstand is gedefinieerd door de gegeneraliseerde kosten. Deze zijn afhankelijk van de kenmerken van het bestaande multimodale netwerk, via de transporttijden en transportkosten van de verschillende vervoerwijzen en de kenmerken van de te vervoeren goederen, via de tijdwaardering. Er is een indeling gemaakt van de goederen in 13 goederengroepen, waarbij voor elke goederengroep de gemiddelde tijdwaardering is berekend. De goederengroepen geven marktsegmenten aan, waarop vervoerwijzen een verschillende rol spelen. Het keuzegedrag van de verlader/vervoerder is gemodelleerd aan de hand van een simultaan vervoerwijzekeuze/routekeuzemodel, waarbij een stochastisch routekeuzemodel is toegepast. Aan de hand van een break-even afstandsanalyse, waarin vervoerwijzen over afstanden met elkaar worden vergeleken op basis van gegeneraliseerde kosten, wordt bestudeerd voor welk transporttarief, op welke afstand en voor welke goederen, ondergronds hogesnelheids goederenvervoer concurrerend kan zijn met bestaande vervoerwijzen. Om te achterhalen in welke regio's in Noordwest Europa ondergronds hogesnelheids goederenvervoer kostenvoordelen kan bieden, is het model gebruikt om zestien ontworpen alternatieve ondergronds hogesnelheids goederenvervoemetwerken voor zes situaties te evalueren. Hierbii is het Geoffrafisch Informatie svsteem (GIS) TransCAD gebruikt. Het minimale netwerk (dit is de minimaal opspannende boom) presteert gemiddeld het beste per netwerkkilometer investeringskosten. Er is een globale kostenberekening gemaakt, waarbij de potentie van het minimale netwerk, oftewel de "winst" in gegeneraliseerde kosten die het minimale OHSG netwerk kan behalen per jaar, ten opzichte van de basissituatie is berekend. Deze is vergeleken met de aanlegkosten en de jaarlijkse kosten van onderhoud en beheer van het minimale OHSG netwerk. Hieruit is voor twee scenario's de Netto Contante Waarde (NCW) (dit zijn de netto contante baten minus de netto contante kosten) berekend. In scenario I is de NCW waarde groter dan nul en is het minimale netwerk haalbaar. In scenario I I is het minimale netwerk niet haalbaar; de NCW waarde is negatief.Transport & PlanningCivil Engineering and Geoscience
Nemo condicit rem suam: over de samenloop tussen de rei vindicatio en de condictio
Full text linkIn
current Dutch law, a concurrence of actions is possible between the rei
vindicatio and the action to recover an undue payment (‘vordering uit
onverschuldigde betaling’). From a historical point of view, though, this
concurrence is remarkable. In Roman law, the rei vindicatio and the
condictio—the historical precursor of the modern actio to recover an undue
payment—were opposites: whereas the rei vindicatio was based on the plaintiff’s
ownership of an object, the condictio was based on the defendant’s obligation
to transfer ownership to the plaintiff. Consequently, concurrence of these
actions was, barring a few—but noteworthy—exceptions, impossible. This book
explores the development of the condictio in relation to the rei vindicatio. As
part of this development, the requirement that transfer of ownership is only
possible when a valid title (iusta causa) is present—and the question what
actually constitutes a iusta causa—plays an important role. Consecutively,
attention is given to Roman law, the ius commune, and the enactment of the
modern codifications in Germany, Switzerland, France, and the Netherlands.
(Contains a summary in German; Mit einer Zusammenfassung auf Deutsch.)Coherent privaatrech
The composition of wax and oil in green coffee beans
No full textMethods for the isolation of wax and oil from green coffee beans were studied and a method for the quantitative extraction of coffee oil from the beans was introduced. Coffee wax, coffee oil and wax-free coffee oil as well as the unsaponifiable matter prepared from each were fractionated by column chromatography. The chemical composition of the fractions was studied by thin-layer chromatography, gas-liquid chromatography, ultraviolet, infrared, nuclear magnetic resonance and mass spectrometry. The results include qualitative and quantitative data on (1) the total fatty acid composition as well as the composition of the fatty acids in triglycerides and diterpene alcohol esters, (2) the positional distribution of the fatty acids in the triglycerides, (3) the unsaponifiable matter and (4) Nβ -alkanoyl-5-hydroxy-tryptamines (C-5-HT) and other C-5-HT-like phenolic compounds.The unsaponifiable matter (3) was fractionated into diterpene alcohols, sterols and hydrocarbons (including squalene and n -alkanes from C 16 to C 31 ). Moreover the presence of α-tocopherol and (β+ γ)-tocopherol in green coffee beans was described for the first time.In view of the results of this study the removal of coffee wax by industrial processes, which are claimed to have a beneficial effect on the digestibility of coffee, was discussed. The current literature on the lipids of green coffee beans was extensively reviewed
Emergence and Evolution of Endogenous Water Institutions in an African River Basin: Local Water Governance and State Intervention in the Pangani River Basin, Tanzania
No full textWater management challenges in basins of Sub-Saharan Africa and in other parts of the world are increasing due to rapid urbanisation, poverty and food insecurity, energy demands, and climate change. Nearly half of the world population live in cities, and this is estimated to reach two-thirds of the world's population by the year 2050. The need to improve water services in cities poses new challenges to river basin management. Water transfer from other sectors to cities is an obvious way of reallocating the uses and users of the available water but this may have far reaching upstream-downstream consequences in a catchment. In addition there is an increasing trend in rural poverty, hunger, and food insecurity in Sub-Saharan Africa. To reduce and/or reverse the increasing trend of rural poverty and generate employment requires substantial investment in irrigated agriculture in Sub-Saharan Africa. However, transforming Sub-Saharan Africa's agriculture also implies intervention in water control as lack of access to reliable water supply is one of the major limitation to crop production. Coupled with the above problems are the rising global food and energy prices which have attracted foreign investment in agricultural land in Sub-Saharan Africa. Foreign direct investment in agriculture in Sub-Saharan Africa is likely to increase agricultural water use and this could lead to further enhancement of an already stressed water situation.Water ManagementCivil Engineering and Geoscience
Home and Mortgage Ownership of the Dutch Elderly: Explaining Cohort, Time and Age Effects
Full text linkThe relationship between home ownership of Dutch elderly households and age is strongly negative. Other studies suggest that this age gradient should be attributed to a cohort effect. In this paper we investigate where those cohort effects come from. We also observe that mortgage ownership among elderly home-owners increased considerably during the nineties. Using panel data we estimate models explaining home and mortgage ownership by age, cohort, and time effects, as well as other factors. Cohort and time effects are modelled explicitly using macro economic and housing market related variables. We find that the level of GDP per capita when the household head was young is the main factor explaining generation effects in home ownership among the elderly. After accounting for cohort effects it also appears that home ownership decreases slightly with age. Mortgage ownership among elderly home owners rose considerably during the nineties due to house price increases and due to financial innovation in the mortgage market. Cohort effects are also important. A supplementary analysis suggests that those cohort effects are due to the fact that the accidental bequest motive is becoming less important.home ownership, mortgages, cohort effects
Onderzoekingen betreffende besturingseigenschappen van vliegers aan het Forrestal Research Center van de Universiteit van Princeton. (Verslag van werkzaamheden gedurende de periode van 1 april '56 tot 15 april '57)
No full textAerospace Engineerin
Quantum superposition of charge states on capacitively coupled superconducting islands
Full text linkWe investigate the ground state properties of a system containing two superconducting islands coupled capacitively by a wire. The ground state is a macroscopic superposition of charge states, even though the islands cannot exchange charge carriers. The ground state of the system is probed by measuring the switching current of a Bloch transistor containing one of the islands. Calculations based on superpositions of charge states on both islands show good agreement with the experiments. The ability to couple quantum mechanical charge fluctuations in two neighboring devices using a wire is relevant for realizing quantum computation with this kind of circuit
Using a novel application for Mixed Reality navigated orthopaedic implant placement: a pilot study
No full textIntroductionAugmented Reality (AR) and Mixed Reality (MR) can be used for surgical navigation to execute the pre-operative plan. HoloMA is a novel AR/MR application which can guide the user to place surgical instruments on the planned location within the patient. In this pilot study, the AR/MR-guidance of HoloMA was used to place personalized canine acetabular roof implants on the pre-planned location on the iliac bone. MethodsDedicated tools to perform the AR/MR patient registration and surgical guidance were developed. An in silico patient registration test was conducted to assess if the available bony surface during the acetabular roof surgery was suitable to perform the patient registration accurately. Pilot tests to place implants using the AR/MR-guidance of HoloMA were conducted on phantoms, a cadaver and in an in vivo dog patient. The translational and angulation error between the planned and the post-operative implant positions were determined. The aim was to achieve implant placement with a maximum translational error of 4.0 mm and a maximum angulation error of 5.0° relative to the pre-operative plan.ResultsThe in silico patient registration test demonstrated a mean translational error of 0.94 ± 0.23 mm and a mean angulation error of 2.49 ± 0.34°. In the phantom tests, implants (n=6) were placed with a mean translational error of 1.94 ± 0.79 mm. The mean angulation errors in this test were: 2.87 ± 1.81° (transversal plane), 1.72 ± 1.64° (dorsal plane) and 3.10 ± 2.52° (sagittal plane). Two of the implants of the phantom test and both implants of the cadaveric test (n=2) were positioned with a translational error exceeding 4.0 mm and/or angulation error exceeding 5.0° from the planned positions. No implants were placed using AR/MR-guidance in the in vivo dog patient test. ConclusionThe results of the in silico patient registration test hold promise for the use of AR/MR-guidance in positioning personalized acetabular roof implants. However, the moderate outcomes observed in the phantom and cadaveric test suggest the need for further testing and improvements before deploying this AR/MR technology in a clinical setting. Technical Medicin
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