3D inkjet printing of tablets exploiting bespoke complex geometries for controlled and tuneable drug release

A hot melt 3D inkjet printing method with the potential to manufacture formulations in complex and adaptable geometries for the controlled loading and release of medicines is presented. This first use of a precisely controlled solvent free inkjet printing to produce drug loaded solid dosage forms is demonstrated using a naturally derived FDA approved material (beeswax) as the drug carrier and fenofibrate as the drug. Tablets with bespoke geometries (honeycomb architecture) were fabricated. The honeycomb architecture was modified by control of the honeycomb cell size, and hence surface area to enable control of drug release profiles without the need to alter the formulation. Analysis of the formed tablets showed the drug to be evenly distributed within the beeswax at the bulk scale with evidence of some localization at the micron scale. An analytical model utilizing a Fickian description of diffusion was developed to allow the prediction of drug release. A comparison of experimental and predicted drug release data revealed that in addition to surface area, other factors such as the cell diameter in the case of the honeycomb geometry and material wettability must be considered in practical dosage form design. This information when combined with the range of achievable geometries could allow the bespoke production of optimized personalised medicines for a variety of delivery vehicles in addition to tablets, such as medical devices for example

Investment strategies in the crude oil futures market : an empirical analysis of its return and its causes

We show that while a passive investment strategy going long in WTI oil futures yields an annual excess return of 8.1% between January 1985 and June 2010, an active but very simple investment strategy going long in backwardation markets (spot price above futures prices) and short in contango markets (spot price below futures prices) yields an annual excess return of 20 % for the same period. Its statistical significance is also high with a t-value of 3.36 compared to the long only strategy with a t-value of only 1.34. A supplementary investment strategy, where we leave the market for one month after a prior monthly negative return, yields an annual excess return of 22% between 1985 and 2010. We also show that although the risk is relatively high in oil futures, investors with a perspective of more than 5 years made at least 12% annually after June 1991. Investors entering the market in 2000 and in 2005 made respectively 24.5% and 22.2 % annually. Between 1985 and 2004, backwardation markets account for more than 66% of the months. In addition, returns are much higher during backwardation months than during contango months. After 2005, however, contango markets have become the norm in oil futures; yet, the excess return has remained high. Roll return, whether in backwardation markets or contango markets is a very stable and safe excess return and accounts for almost all the return compared to spot return. Several explanations have been put forward regarding the drivers of the return in commodity futures. No explanation seems to fully account for the high returns. However, we do show that risk premium is connected to hedging pressure where short hedgers and long speculators are the most volatile and seem to adjust their volume according to price changes

Fjernmøte ved begjæring om førstegangsfengsling etter midlertidig lov om tilpasninger i prosessregelverket som følge av utbruddet av covid-19 mv. § 3, med fokus på EMK artikkel 5 nr. 3.

MasteroppgaveJUS399MAJUR-2MAJU

Onderzoek naar een geschikte combinatie toetsmethoden ter bepaling van de aquatische toxiciteit van milieugevaarlijke stoffen. Bijl.4: Verder onderzoek naar de gevoeligheid van cyanobacterien en diatomeeen voor chemische stoffen en evaluatie van algentoxiciteitstoetsen

Als aanvulling op vroeger onderzoek werden toxiciteitstoetsen uitgevoerd met drie algensoorten, met name de cyanobacterien Microcystis aeruginose (de stammen RID-2, CCAP 1405/1 en SAG 46/80) en Oscillatoria agardhii (RID-4) en de diatomee Gomphonema parvulum (SAG 1032-1). Voor het onderzoek werden zes toetsverbindingen gebruikt (kaliumdichromaat, diisopropylamine, 2,4-dinitrotolueen, 2,6,- dimethylquinoline, 2,4,-dichlooraniline en tetrapropyleenbenzeensulfonaat). Het doel van het onderzoek was het nagaan van de gevoeligheid van cyanobacterien en van diatomeeen voor resp. stikstofhoudende organische verbindingen en zeswaardig chroom. Daarnaast werd de invloed van enkele experimentele factoren op de toxiciteit onderzocht. In het algemeen konden de resultaten van het eerder uitgevoerde onderzoek worden bevestigd. De cyanobacterien en diatomeeen blijken echter minder gevoelig dan in het vroegere onderzoek werd gevonden.Abstract not availableDGMH/BWS-

Aluminium 3D Printing with KUKA Robot

This thesis work aims to identify how additive manufacturing of aluminium can be carried out with the help of an industrial robot. The nature of aluminium means that it needs to be melted in an inert gas zone, filled with argon, to prevent the formation of aluminium oxide. Also, industrial robots offer high repeatability and more degrees of freedom than a traditional Cartesian gantry. This could improve additive manufacturing by eliminating the need for support materials when manufacturing large overhangs. The development starts off with a brief literature survey and identifying existing technology on the market. Based on these finds a system for additive manufacturing is developed. This system consists of both off-the-shelf parts as well as custom designs of our own. A product development process is then carried out in multiple iterative phases, including conceptual designs, prototyping and detail designs. In addition, a brief investigation on possible strategies for a product platform and a potential business model is also addressed. A control system to connect and operate the various subsystems is developed and the digital process from initial design to finished physical product is investigated. Results from the working prototype is presented, a system that is fully capable of 3D-printing polymers in a multiaxis manner. A final business model and budget is also presented. Results from tests carried out with the prototype are presented. Later the results are discussed together with technical reflections from various parts of the thesis. Bottlenecks, such as the lack of software for multiaxis slicing is discussed in detail. Finally, the thesis is concluded together with recommendations for further work

Effects of nutrient trace metal speciation on algal growth in the presence of the chelator [S,S]-EDDS

This study tests the hypothesis that the apparent toxicity of strong chelators in standard algal growth inhibition tests (e.g. method OECD 201, EC C.3., ISO 8692) is related to essential trace metal bioavailability. This hypothesis was investigated for the chelator [S,S]-ethylene diamine disuccinate ([S,S]-EDDS) and the green alga Chlorella vulgaris. Metal speciation calculations were used to help design the algal growth experiments and interpret the data. Results suggest that interaction of the chelator with trace metals alters the free metal concentration and affects algal population growth, as opposed to a direct interaction between the alga and the chelator (toxicity sensu stricto). Even low levels of [S,S]-EDDS (i.e. 3 mg l-1 or less) reduce the free p(Cu) and p(Zn) (p(Metal) = -log[Metal]) in standard OECD medium below 16 and 11, respectively, which are the minimum levels required to support algal growth. Nutrient deficiency was overcome by supplementing the medium with appropriate amounts of the trace metals Cu, Zn and Co, but not by increasing the hardness of the medium. A short-term photosynthesis inhibition experiment with the alga Selenastrum capricornutum in metal-free medium showed only a minimal effect of[S,S]-EDDS on the 14C-CO2 fixation rate. About 10% inhibition was observed at 100 mg [S,S]-EDDS l-1, i.e. the EC50 for CO2 fixation is greater than 100 mg l-1. Results from this study illustrate that the standard algal growth inhibition test is not well suited to the assessment of algal toxicity (sensu stricto) of strong chelators. The no-effect level and EC50 value are probably overestimated by at least one order of magnitude for [S,S]-EDDS. The study also illustrates the importance of speciation calculations when assessing algal inhibition by chelators