A review of UAE native seaweed as potential bio-refinery feedstock for jet fuel and high value chemicals

The UAE government has hosted several initiatives to produce sustainable jet fuel from locally available feedstock to support its sustainable energy strategy and vision. With more than 2000 km of coastline UAE is home to a large variety of aquatic biomass, such as seaweed. The local seaweed strains can act as ultimate candidate feedstock for not only bioenergy (jet fuel) but also a source for high value chemicals. Seaweed contains high carbohydrates and rapid growth rates and low lignin content. Several seaweed biomasses strains have been identified along the shores of the Emirate of Abu Dhabi amongst which one strain Ulva Sp. was the most dominant in terms of occurrence and availability. A bio refinery utilizing the local UAE seaweed strains could provide many advantages for the commercial viability the due to the fact that seaweed has potential to other high value product such as active components for pharmaceutical products as their market value is much higher that sustainable jet fuel. The preliminary chemical characterization showed significant glucan contents which indicate fermentable sugar content in these biomass samples. This make the local aquatic biomass an interesting research project both to fulfill the sustainable jet fuel initiative and establish further knowledge in the local aquatic biomass biorefinery capabilities

Experimental design of a system to investigate chaotic dripping

We report here the construction of a system designed to investigate chaotic dripping behaviour. The benchtop system has been designed for the purpose of measuring chaotic dripping in a microgravity test facility, although measurements under normal gravity only are reported here. The results confirm the main predictions of a simple 1-D mass-spring-damper theoretical model of the system, including the formation of point attractors and associated limit cycles, although there are significant departures from this model within specific flow rate regions resulting in the formation of what are termed here 'mid' drops (drops of a smaller size than normal). It is hypothesized that the origin of these mid drops arises from the development of a 'wetting' mass, namely a mass of liquid that is evacuated from the delivery tube from the previous drop excision

Design and test firing of a dual bidirectional double vortex bipropellant rocket engine

It is widely recognised that there is a global need for cheaper launchers for small satellites, and there is considerable global effort led primarily by private enterprise to develop these. One way to achieve these lower costs is to use cheaper materials, usually by sacrificing some of the performance benefit. A dual birectional double vortex bipropellant engine has been designed that confines combustion to the core of the rocket engine, thereby maintaining much cooler wall temperatures, enabling the employment of cheaper materials with lower melting temperatures. This paper reports on the design and successful test firing of such an engine with a nominal thrust of 20N, the first time that such an engine has been developed in an educational setting

Development of a high flow rate piston pump for rocket engines

There is a need for cheaper small satellite rocket launchers. One way of reducing costs is to reduce the cost of individual components. We describe here the development of an inexpensive piston pump for rocket engine applications. It demonstrates that it can deal with the combined requirements of high flow rate and operating speed at cryogenic temperatures without incurring the costs normally associated with such performance

A new diversity index

We introduce here a new index of diversity based on consideration of reasonable propositions that such an index should have in order to represent diversity. The behaviour of the index is compared with that of the Gini-Simpson diversity index, and is found to predict more realistic values of diversity for small communities, in particular when each species is equally represented and for small communities. The index correctly provides a measure of true diversity that is equal to the species richness across all values of species and organism numbers when all species are equally represented, as well as Hill's more stringent 'doubling' criterion when they are not. In addition, a new graphical interpretation is introduced that permits a straightforward visual comparison of pairs of indices across a wide range within a parameter space based on species and organism numbers

A comment on 'Comparative analysis of the isovolume calibration method for non-invasive respiratory monitoring techniques based on area transduction versus circumference transduction using the connected cylinders model' (2011 Pysiol. Meas. 32 1265-74)

An analysis introduced by the authors in 2011 examining the robustness of the isovolume method for the calibration of the respiratory inductive plethysmograph based on the connected cylinders particular model of Konno and Mead's generalized two-compartment model of respiration is extended. It is demonstrated that extending this to a more physically realistic geometrical model, termed the connected prismatic elliptical segments model, does not enhance the earlier analysis, and that the analysis can easily be proven to cover all area-based transduction sensors, irrespective of the actual geometry of the compartments

A theoretical study of the robustness of the isovolume calibration method for a two-compartment model of breathing, based on an analysis of the connected cylinders model

The use of the isovolume manoeuvre method as a calibration technique for respiratory monitoring instrumentation that detects the movement of the ribcage and the abdominal wall is analysed based on a model of two connected cylinders whose radii and heights may vary, and evidence is presented which suggests that this calibration method is robust in most circumstances. Some possible functional forms relating the variations in cylinder radius and height are examined, and methods for obtaining calibration constants based on these functional forms, purely from measurements of variations in the cylinder radius, are presented