Evaluation of Various Methods for Determining Bulk Compositions of Chondrules and Other Objects in Petrographic Thin Sections

Studies of many objects in petrographic thin section, such as melt inclusions in igneous rocks, chondrules and Ca-Al rich inclusions in chondritic meteorites, or clasts in lunar and other breccias, require or can benefit from knowledge of their bulk compositions. Given the scarcity of these materials, the reluctance of curators to provide more abundant material, and the extreme difficulty of cleanly separating such objects from their rock matrices, geochemical and cosmochemical studies need the ability to determine their bulk compositions from in situ methods, such as defocused beam analysis, or quantitative chemical mapping by electron beam methods

Printing Accuracy of Large Scale Melt Electrospinning 3D Printer in a Direct-Writing Mode

Melt Electrospinning is a method used to produce continuous micro to nanoscale fibres. Although it has been nearly a century since its discovery, the potential for Melt Electrospinning applications has just begun to garner attention. When combined with the Direct-Writing process it was realised that normally random fibre deposits could be controlled and 3D constructs formed and a new technology was born known as Melt Electrospinning 3D Printing. Currently this technology is being utilized in medical research to produce scaffolds for cellular growth. Key setbacks to this technology are the excessive time it takes for suitable scaffolds to be produced. This problem could be overcome through the up-scaling of MEW printers. This report aimed to test the printing accuracy of a simple up-scaled device to prove the feasibility of this technology for industrial use. An up-scaled prototype based on a smaller MEW printer was designed and constructed by students at Queensland University of Technology. The new machine included eight printing heads instead of one, a larger Collector and larger range of motion. These upscaled features were analysed to determine potential sources of inaccuracy. Several printing experiments were performed to show scaffolds met certain requirements for use in medical research. First that fibre diameter is consistent and below 25μm. Pore size control must be demonstrated and a minimal pore size of 40000μm 2 achieved. Finally, as an additional benefit of a multi-headed device it was desired to show that a single large scaffold could be produced using all four heads on one side. The fibre diameters produced show a high level of accuracy and fell below the maximum allowable size. Pore control could be seen but was not consistent in all scaffolds produced. Similarly the 40000μm 2 pore size was also demonstrated but not uniformly across scaffolds. A single large scaffold was successfully produced using multiple heads. The results showed that the successful up-scaling MEW is achievable. The small alterations in fibre diameter were attributed to small inaccuracy in the alignment of the U-Frame. Inconsistencies in pore control were identified as being related to design. Areas on the Collector that were nearer to secured foundations or the centre of mass showed excellent pore control as they were less prone vibrations. It is recommended that future up-scaled designs using laser alignment tools in construction. It is also suggested that a larger, stronger frame replace the U-Frame so that all corners of the Collector and Head Assemblies are securely fastened as well as damping incorporated to minimise vibrations

Screening and Engineering of Geobacillus spp. for Consolidated Bioprocessing of Lignocellulosic Biomass

Current lignocellulosic fermentation depend on complex and expensive enzymatic hydrolysis of cellulose and hemicellulose. In order to make bioprocessing of lignocellulose economically competitive this study has selected and engineered a host for degradation of cellulose, into simple monomeric sugars. Geobacillus thermoglucosidans DSM 2542 was engineered to individually express four cellulase proteins. The proteins chosen were CelA, CelB Cel6B and Cel9A from Caldicellulosciruptor bescii, Thermotoga neopolitania and Thermobifida fusca respectively. CelA, CelB and Cel9A were shown to be active against carboxymethylcellulose (CMC). CelA is of particular interest as the protein has been shown to be multifunctional, thermostable at 55 ºC, has a novel mode of action and able to degrade biomass through surface ablation and cavity formation. The cellulase genes were placed under the control of an inducible promoter (ParaE) to facilitate regulation of gene expression with arabinose. This study represents considerable progress in the engineering of G. thermoglucosidans for use in a consolidated bioprocessing system.Shell US Hosting Compan

The Effect of a Low-Fat, Plant-Based Lifestyle Intervention (CHIP) on Serum HDL Subfraction Levels - A Cohort Study

This conference abstract discusses a low-fat plant-based diet and the effect it has on HDL level

Making Mercury's Core with Light Elements

Recent results obtained from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging spacecraft showed the surface of Mercury has low FeO abundances (less than 2 wt%) and high S abundances (approximately 4 wt%), suggesting the oxygen fugacity of Mercury's surface materials is somewhere between 3 to 7 log10 units below the IW buffer. The highly reducing nature of Mercury has resulted in a relatively thin mantle and a large core that has the potential to exhibit an exotic composition in comparison to the other terrestrial planets. This exotic composition may extend to include light elements (e.g., Si, C, S). Furthermore, has argued for a possible primary floatation crust on Mercury composed of graphite, which may require a core that is C-saturated. In order to investigate mercurian core compositions, we conducted piston cylinder experiments at 1 GPa, from 1300 C to 1700 C, using a range of starting compositions consisting of various Si-Fe metal mixtures (Si5Fe95, Si10Fe90, Si22Fe78, and Si35Fe65). All metals were loaded into graphite capsules used to ensure C-saturation during the duration of each experimental run. Our experiments show that Fe-Si metallic alloys exclude carbon relative to more Fe-rich metal. This exclusion of carbon commences within the range of 5 to 10 wt% Si. These results indicate that if Mercury has a Si-rich core (having more than approximately 5 wt% silicon), it would have saturated in carbon at low C abundances allowing for the possible formation of a graphite floatation crust as suggested by. These results have important implications for the thermal and magmatic evolution of Mercury

Ultrasonic Inspection of Wooden Pallet Parts Using Time of Flight

Wooden pallets exceed furniture and other solid wood products as the largest single use of sawn hardwood logs in the USA. Most wooden pallets are constructed from two types of pallet parts (Figure 1): (1) stringers—the structural center members that support the pallet load and (2) deckboards—the top and bottom facing members that provide dimensional stability and product placement. There are many variants of this basic design, but most pallets contain solid wood components that are produced from lumber or from the center cant material of logs. Cant material has a high percentage of defect area and is generally not highly valuable for other solid wood products. Therefore, the pallet manufacturing industry must make use of low-quality raw materials and yet produce a product that remains in service for many trips

HDL Subfraction Changes with a Low-fat, Plant-based Complete Health Improvement Program (CHIP)

Background and Objectives: Low HDL concentrations are considered an important risk factor for cardiovascular disease. Interventions promoting a low-fat, plant-based eating pattern appear to reduce CVD risk while paradoxically also reducing HDL concentrations. Recent studies show HDL to comprise a range of subfractions, but the role these play in ameliorating the risk of CVD is unclear. The purpose of this study was to characterise changes in HDL subfractions in participants where HDL decreased following the CHIP intervention which promotes a low-fat, plant-based diet, with physical activity. Methods and Study Design: Individuals (n=22; mean age=55.4±16.3 years; 45.5% men, 54.5% women) participating in a CHIP intervention were assessed at baseline and 30 days for changes in BMI, blood pressure, lipid profile, (including large-, intermediate- and small-HDL subfractions) and fasting glucose. Results: HDL significantly decreased (10.6%, pConclusions: This paper discusses specific changes in HDL subfractions when overall-HDL decreases as a response to low fat, whole-food, plant-based eating and exercise. Additional research is required to elucidate the reasons through which behavioural therapies remodel the HDL particle and how this impacts the functional properties of HDL and CVD risk