74 research outputs found
The impact of slow steaming on refrigerated exports from New Zealand
The practice of slow steaming has had a significant impact on New Zealand export industries with increased transit times in some cases causing significant reductions in shelf life once the product has reached the retail stage. The longer transit times also impose the extra cost to exporters of having more inventory tied up in transit. While there is clear evidence to suggest slow steaming has reduced fuel consumption and hence fuel emissions and fuel costs, these savings have not been passed on by the liners to their customers. However, there is no indication that slow-steaming has caused a significant reduction in export earnings for New Zealand (at least up to the middle of 2014). A predicted move to super-slow steaming would put extra strain on the New Zealand meat industry especially, with their lucrative European chilled lamb market under particular threat
A facile one step route that introduces functionality to polymer powders for laser sintering
Laser Sintering (LS) is a type of Additive Manufacturing (AM) exploiting laser processing of polymeric particles to produce 3D objects. Because of its ease of processability and thermo-physical properties, polyamide-12 (PA-12) represents ~95% of the polymeric materials used in LS. This constrains the functionality of the items produced, including limited available colours. Moreover, PA-12 objects tend to biofoul in wet environments. Therefore, a key challenge is to develop an inexpensive route to introduce desirable functionality to PA-12. We report a facile, clean, and scalable approach to modification of PA-12, exploiting supercritical carbon dioxide (scCO2) and free radical polymerizations to yield functionalised PA-12 materials. These can be easily printed using commercial apparatus. We demonstrate the potential by creating coloured PA-12 materials and show that the same approach can be utilized to create anti-biofouling objects. Our approach to functionalise materials could open significant new applications for AM
Recommended from our members
Kinetics of coal pyrolysis
This report contains results of a coordinated, multi-laboratory investigation of coal devolatilization. Data is reported pertaining to the devolatilization for bituminous coals over three orders of magnitude in apparent heating rate (100 to 100,000 + {degree}C/sec), over two orders of magnitude in particle size (20 to 700 microns), final particle temperatures from 400 to 1600{degree}C, heat transfer modes ranging from convection to radiative, ambient pressure ranging from near vacuum to one atmosphere pressure. The heat transfer characteristics of the reactors are reported in detail. It is assumed the experimental results are to form the basis of a devolatilization data base. Empirical rate expressions are developed for each phase of devolatilization which, when coupled to an awareness of the heat transfer rate potential of a particular devolatilization reactor, indicate the kinetics emphasized by a particular system reactor plus coal sample. The analysis indicates the particular phase of devolatilization that will be emphasized by a particular reactor type and, thereby, the kinetic expressions appropriate to that devolatilization system. Engineering rate expressions are developed from the empirical rate expressions in the context of a fundamental understanding of coal devolatilization developed in the course of the investigation. 164 refs., 223 figs., 44 tabs
Optimum control system design in the presence of large parameter variations
SIGLELD:D50283/84 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
BIOPROCESSING - PERSPECTIVE ON BIOPROCESSING
Insects as Sources of Novel Bioprocessing Acitvities The insects are a
large and diverse group of eukaryotes that have successfully colonised
most of the environmental niches on the Earth. In doing so, they have
evolved physical tolerances that adapt them to various extremes of
moisture availability, temperature stress, nutritional balance and so
on. It has long been assumed that these tolerances imply the existence
of a corresponding breadth of molecular pathways and capabilities that
derive either from the insects themselves, from their microbial
associates, or from a combination of both; investigations using
methodologies of functional genomics and environmental genomics are now
providing increasing evidence to support this view. As yet, these
metabolic strategies and capabilities remain both poorly understood,
and essentially untapped for human purposes. Nevertheless, there are
strong grounds for believing that in the future they will provide means
to significantly expand our capabilities in the field of bioprocessing
Silver Halide Colloid Precursors for the Synthesis of Monolayer-Protected Clusters
A new method for the synthesis of monolayer-protected silver clusters (MPCs) based on the two-phase reduction of a stable negatively charged silver bromide sol is described. Phase transfer of the colloid to toluene is accomplished using tetra-n-octylammonium bromide as the phase transfer reagent. The advantage of this synthesis is to uncouple the formation of the silver halide colloid from its transfer and reduction in the organic phase, thus allowing control over each reaction step. The silver colloid in toluene was reduced with aqueous borohydride in the presence of 4-bromobenzenethiol as the passivating agent. The UV-visible absorption spectra indicate the intermediate formation of Ag coreAgBr shell clusters during reduction. The resulting MPCs have been characterized by optical and transmission electron microscopy, energy-dispersive X-ray analysis, thermogravimetry, and UV-vis absorption spectroscopy. The formation of spiral cracks in the nanoparticulate agglomerates on solvent evaporation was observed. The spectra of thin films obtained by solvent evaporation have been analyzed using an effective medium theory
- …