One and Two Way Packaging in the Dairy Sector

Choosing packaging material for dairy products and soft drinks is an interesting issue at the moment. Discussions arise on the costs impacts and environmental impacts of both one way packaging and reusable packaging. The aim of this article is to develop an evaluation tool providing costs and environmental impacts of the PC-bottle and the GT-packs in the dairy sector, considering forward and return flows. The evaluation tool enables the user to analyse the costs and environmental impacts of a supply chain with and without return flows using scenario analyses with respect to the use of various carrier types and the number of return loops. It appears that costs differences between PC-bottles and GT-pack are quite small. The PC bottle has a better environmental profile than the GT-pack. Scenario analysis on the carriers results in the advice to use preferably roll-in-containers with direct delivery, secondly roll-in-containers with delivery via distribution centers, thirdly in case of direct delivery either cartons or crates and cartons in case of delivery via distribution centers.pricing;supply chain management;reverse logistics;environment;life cycle assessment

Time gated fluorescence lifetime imaging and micro-volume spectroscopy using two-photon excitation

A scanning microscope utilizing two-photon excitation in combination with fluorescence lifetime contrast is presented. The microscope makes use of a tunable femtosecond titanium:sapphire laser enabling the two-photon excitation of a broad range of fluorescent molecules, including UV probes. Importantly, the penetration depth of the two-photon exciting (infra)red light is substantially greater than for the corresponding single-photon wavelength while photobleaching is significantly reduced. The time structure of the Ti:Sa laser can be employed in a straightforward way for the realization of fluorescence lifetime imaging. The fluorescence lifetime is sensitive to the local environment of the fluorescent molecule. This behaviour can be used for example to quantify concentrations of ions, such as pH and Ca2+, or pO2 and pCO2. In the set-up presented here the fluorescence lifetime imaging is accomplished by time-gated single photon counting. The performance and optical properties of the microscope are investigated by a number of test measurements on fluorescent test beads. Point-spread functions calculated from measurements on 230-nm beads using an iterative restoration procedure compare well with theoretical expectations. Lifetime imaging experiments on a test target containing two different types of test bead in a fluorescent buffer all with different lifetimes (2.15 ns, 2.56 ns and 3.34 ns) show excellent quantitative agreement with reference values obtained from time correlated single photon counting measurements. Moreover, the standard deviation in the results can be wholly ascribed to the photon statistics. Measurements of acridine orange stained biofilms are presented as an example of the potential of two-photon excitation combined with fluorescence lifetime contrast. Fluorescence lifetime and intensity images were recorded over the whole sample depth of 100 μm. Fluorescence intensity imaging is seriously hampered by the rapid decrease of the fluorescence signal as a function of the depth into the sample. Fluorescence lifetime imaging on the other hand is not affected by the decrease of the fluorescence intensity

Een Dijk van een Kwelder : een verkenning naar de golfreducerende werking van kwelders

Dit rapport geeft een samenvatting van relevant onderzoek naar de golfreducerende werking van kwelders en schetst de randvoorwaarden voor kweldervorming. Kwelders vormen een zone in het intergetijdengebied die de golven beïnvloeden door de weerstand van de bodem en de kweldervegetatie. De golfreducerende werking is afhankelijk van de hoogte en breedte van de kwelder, maar ook van de optredende waterstanden. Het is nog onduidelijk in hoeverre kwelders een bijdrage kunnen leveren aan de waterveiligheid in een veranderend klimaat. De studie is verricht in opdracht van het Deltaprogramma Deelprogramma Waddengebied en vormt een stap in het verkennen van geschikte waterveiligheidsstrategieën in het Waddengebied die zich naast waterveiligheid richten op doelstellingen voor natuur en ruimtelijke kwaliteit

Werktuigkundige Systemen

Het boek Werktuigkundige Systemen is een compacte inleiding op het systeemdenken in de werktuigbouwkunde, met nadruk op inzicht en grafische methoden, gelardeerd met prikkelende werkingsprincipes en constructie-elementen. Velen merken dat ze nog lang nadat ze het vak gedaan hebben dit boek als naslagwerk gebruiken en het steeds meer gaan waarderen, ook omdat het boek de basis legt voor veel vervolgvakken en projecten.Het boek is al jarenlang in gebruik bij eerstejaars studenten Werktuigbouwkunde aan de TU Delft. Diverse docenten gebruiken het bij vakken of ontwerp­projecten.De oorsprong van dit boek in de tachtiger jaren is een college geweest, waarin op eenvoudige wijze de werking van bestaande apparaten en machines werd geanalyseerd. In een later stadium is deze stof uitgebreid met een aantal constructieve bijzonderheden. Daarbij heeft de systeemleer en de modelvorming een belangrijke basis gevormd.Meer uitgebreid: De fundamentele principes bij ontwerpen komen in dit boek ‘Werktuigkundige Systemen’ naar voren. Zo wordt de systeemleer toegepast op werktuigkundige constructies en wordt in het hoofdstuk over modelvorming de weg aangegeven om de complexe fysische werkelijkheid om te zetten in een overzichtelijk werkingsinzicht. Ook onder meer mechanische versterkers komen aan bod en is een hoofdstuk gewijd aan de belangrijke begrippen sterkte en stijfheid. Er is ruim aandacht gegeven aan wrijving en weerstand, alsmede aan de middelen om deze te vergroten of te verkleinen. Omdat veren tot de essentiële werktuigonderdelen behoren is een hoofdstuk gewijd aan de toepassing van veren in een ontwerp. Hier is het belangrijke begrip voorspanning behandeld. Het onderwerp Aandrijving wordt behandeld en daarin wordt aangegeven op welke wijze een motor met een last moet worden gekoppeld. Het hoofdstuk over comparalogie laat de problemen zien bij het verkleinen of vergroten van reeds bestaande constructies en bij de vaak noodzakelijke modelproeven. Het hoofdstuk over energie ten slotte, geeft een inleiding in de ‘warme werktuigbouwkunde’. Hierin is een technologisch rendement beschreven dat aangeeft in welke mate een machine warmtetechnisch goed is geconstrueerd.Dit boek kan gebruikt worden bij verschillende soorten technisch hoger onderwijs; zowel door het globale overzicht van de gehele werktuigbouwkunde, de introductie van systeemleer en modelvorming, als door de specialistische behandeling van enkele bijzondere onderwerpen.Mechatronic Systems Desig

Paludiculture crops and nitrogen kick-start ecosystem service provisioning in rewetted peat soils

Purpose: Paludiculture (crop cultivation in wet peatlands) can prevent carbon and nutrient losses while enabling biomass production. As vegetation in rewetted peatlands is often nitrogen (N) limited, input of N-rich water may promote biomass production and nutrient removal. However, it is unclear how N loading and soil characteristics affect biomass yield, nutrient dynamics, and ecosystem service provisioning in paludiculture. Methods: We studied the influence of N loading (0, 50, 150, and 450 kg N ha−1 yr−1) on biomass production and nutrient sequestration of Typha latifolia (broadleaf cattail) and Phragmites australis (common reed) in mesocosms containing rewetted agricultural peat soil (intensively managed, near-neutral (IN)). To assess the interaction with soil characteristics T. latifolia was also grown on an extensively managed, acid (EA) peat soil. Results: N loading stimulated biomass production and nutrient uptake of both T. latifolia and P. australis, with T. latifolia showing the most pronounced response. Biomass yield of T. latifolia was higher on IN soil than on EA soil due to the higher pH, despite lower nutrient availability. N was largely taken up by the vegetation, whereas bare soils showed N accumulation in pore and surface water, and 80% loss through denitrification. Soil phosphorus was efficiently taken up by T. latifolia, especially at high N loads. Conclusion: N loading in paludiculture with T. latifolia and P. australis boosts biomass production while kick-starting peatland ecosystem services including nutrient removal. Nutrient availability and pH appear to be decisive soil characteristics when it comes to crop selection

Time gated fluorescence lifetime imaging and micro-volume spectroscopy using two-photon excitation

A scanning microscope utilizing two-photon excitation in combination with fluorescence lifetime contrast is presented. The microscope makes use of a tunable femtosecond titanium:sapphire laser enabling the two-photon excitation of a broad range of fluorescent molecules, including UV probes. Importantly, the penetration depth of the two-photon exciting (infra)red light is substantially greater than for the corresponding single-photon wavelength while photobleaching is significantly reduced. The time structure of the Ti:Sa laser can be employed in a straightforward way for the realization of fluorescence lifetime imaging. The fluorescence lifetime is sensitive to the local environment of the fluorescent molecule. This behaviour can be used for example to quantify concentrations of ions, such as pH and Ca2+, or pO2 and pCO2. In the set-up presented here the fluorescence lifetime imaging is accomplished by time-gated single photon counting. The performance and optical properties of the microscope are investigated by a number of test measurements on fluorescent test beads. Point-spread functions calculated from measurements on 230-nm beads using an iterative restoration procedure compare well with theoretical expectations. Lifetime imaging experiments on a test target containing two different types of test bead in a fluorescent buffer all with different lifetimes (2.15 ns, 2.56 ns and 3.34 ns) show excellent quantitative agreement with reference values obtained from time correlated single photon counting measurements. Moreover, the standard deviation in the results can be wholly ascribed to the photon statistics. Measurements of acridine orange stained biofilms are presented as an example of the potential of two-photon excitation combined with fluorescence lifetime contrast. Fluorescence lifetime and intensity images were recorded over the whole sample depth of 100 μm. Fluorescence intensity imaging is seriously hampered by the rapid decrease of the fluorescence signal as a function of the depth into the sample. Fluorescence lifetime imaging on the other hand is not affected by the decrease of the fluorescence intensity

Failure of lymphocyte-membrane HLA-A and -B expression in two siblings with combined immunodeficiency

A diagnosis of partial combined immunodeficiency was made in two Turkish siblings with a history of multiple pyogenic infections and persistent candidiasis. They demonstrated severe hypo-γ-globulinemia, with B-lymphocytes, but deficient plasma cell differentiation. T-Lymphocytes were decreased in number and did not respond to antigens, but did proliferate in cultures with lectins and allogeneic cells. HLA-A and -B determinants were not detected on blood lymphocytes, but they were expressed by cultured lymphoblasts, cultured fibroblasts, and were present in serum. MLR-Stimulatory capacity was intermediate and only two of six anti-HLA-DRw7 antisera demonstrated B-cell reactivity. β-2-Microglobulin (B2M) was not detected on the surface of T-lymphocytes, but was found in cross-sectioned T-cell membranes. B-lymphocytes carried B2M normally. The absence of HLA-A and -B determinants on lymphocytes of patients with similar immunodeficiency syndromes suggests a role for HLA determinants in lymphocyte differentiation