The growing demands for energy coupled with ever increasing environmental concerns have allowed the global production of biofuels to rise significantly in recent years. Many countries across the world have begun utilising biofuels on a national scale, while many more are in the process of planning and implementing similar steps. While Australia has an abundance of fossil fuels in the form of coal, natural gas, and oil, and currently employs a variety of alternative energy sources, the technology to produce and implement biofuels in Australia is in its embryonic stage. Today, Australia is using first generation feedstock as the main source for the production of biofuel, but is progressively broadening into second-generation biofuel production technology. Australia has an enormous amount of biomass available in the form of agricultural and forestry residues, bagasse and feedstock currently unused for the production of biofuels. The technology for the conversion of lignocellulosic biomass into biofuels warrants further research to maximise yield to the point of industrial feasibility. This review discusses the current state of ethanol production in Australia, the key technological challenges involved in the production of second-generation biofuel and the availability of various kinds of lignocellulosic biomass for biofuel production. 相似文献
We present the electronic properties of tungsten carbide (WC) nano-compound using the Compton scattering technique. We have measured the Compton profile (CP) of nano-powder using our 137Cs Compton spectrometer. To determine the theoretical CPs of WC nano-compound, we have employed linear combination of atomic orbitals (LCAO) with Hartree-Fock and density functional theory. Although all the LCAO-based calculations show similar agreement with the experiment, the second-order generalised gradient approximation gives a marginally better agreement with the measured CP data. Layered structures and slight over-lapping in energy bands show a small role of exchange and correlation potentials in case of WC nano-compound, which is in contrast to bulk WC. 相似文献
Previous studies have shown influence of aliphatic side chain length and type on the transport properties of naphthalenediimide (NDI) materials by affecting molecular arrangement. There is lack of comparative study on the presence or absence of unsaturation in side chain and its effect on optical and electronic properties of NDI. The present work focuses on the structure–property relationship of four NDI derivatives bearing octyl (C8, OctA-NDI), hexadecyl (C16, HD-NDI), octadecyl (C18, ODA-NDI) and oleyl (C18-un, unsaturated, OLA-NDI) chain on imide-nitrogen. The self-assembling behaviour of the molecules is studied in concentrated solutions as fresh and aged samples in four different solvents by absorbance and emission spectroscopy. With increase in alkyl chain length, the aggregation behaviour is observed to increase. Very interestingly introduction of unsaturation in side chain reduces aggregation and restores the monomeric properties. Self-assembled microstructures formation was studied by scanning electron microscopy where all the four materials show different types of self-assembly formation. Finally, we compared the thermally activated electron conductivity and electron mobility of NDI derivatives, where also the side chain structure clearly influences the electron transport. Electron mobility decreases on increasing chain length from C8 to C18 and again increases in C18-un. A rationale for the structure–property relationship has been given based on the molecular packing and intermolecular π–π interactions. This study contributes significantly towards designing new NDI derivatives bearing long side chains with hampered aggregation for niche applications.
In this research work, an effort has been made to develop fused deposition modelling (FDM), feed stock filament wire from recycled low-density polyethylene (LDPE) with different particle sizes (i.e. single particle size (SPS), double particle size (DPS) and triple particle size (TPS) in different proportions) of SiC/Al2O3 as reinforcement. After evaluation of melt flow index (MFI), the best combinations were selected and used for filament wire preparation on twin screw extruder. The results of the study highlight that Al2O3-based DPS reinforcement resulted in better mechanical properties of the feed stock filament. Finally, the non-functional prototypes have been printed with feed stock filament prepared on open-source FDM. The Al2O3-based DPS reinforcement in LDPE resulted in better dimensional stability with improved surface hardness. The results have been supported by SEM-based photomicrographs and differential scanning calorimetry (DSC). 相似文献
Editor's note:This article shows how design space exploration can be realized through high-level synthesis. It presents a case study of a hardware implementation of the Advanced Encryption Standard (AES) Rijndael algorithm. Starting from the algorithmic specification, the authors generate various architectures by using the C2R compiler.—Philippe Coussy, Université de Bretagne-Sud 相似文献
A desired P2P file sharing system is expected to achieve the following design goals: scalability, routing efficiency and complex
query support. In this paper, we propose a powerful P2P file sharing system, PSON, which can satisfy all the three desired
properties. PSON is essentially a semantic overlay network of logical nodes. Each logical node represents a cluster of peers
that are close to each other. A powerful peer is selected in each cluster to support query routing on the overlay network
while the less powerful peers are responsible for the maintenance of shared contents. To facilitate query routing, super peers
are organized in form of a balanced binary search tree. By exploiting the concept of semantics, PSON can support complex queries
in a scalable and efficient way. In this paper, we present the basic system design such as the semantic overlay construction,
query routing and system dynamics. A load balancing scheme is proposed to further enhance the system performance. By simulation
experiments, we show that PSON is scalable, efficient and is able to support complex queries. 相似文献
Dimensionality reduction has recently been extensively studied for computer vision applications. We present a novel multilinear
algebra based approach to reduced dimensionality representation of multidimensional data, such as image ensembles, video sequences
and volume data. Before reducing the dimensionality we do not convert it into a vector as is done by traditional dimensionality
reduction techniques like PCA. Our approach works directly on the multidimensional form of the data (matrix in 2D and tensor
in higher dimensions) to yield what we call a Datum-as-Is representation. This helps exploit spatio-temporal redundancies
with less information loss than image-as-vector methods. An efficient rank-R tensor approximation algorithm is presented to
approximate higher-order tensors. We show that rank-R tensor approximation using Datum-as-Is representation generalizes many
existing approaches that use image-as-matrix representation, such as generalized low rank approximation of matrices (GLRAM) (Ye,
Y. in Mach. Learn. 61:167–191, 2005), rank-one decomposition of matrices (RODM) (Shashua, A., Levin, A. in CVPR’01: Proceedings of the 2001 IEEE computer society
conference on computer vision and pattern recognition, p. 42, 2001) and rank-one decomposition of tensors (RODT) (Wang, H., Ahuja, N. in ICPR ’04: ICPR ’04: Proceedings of the 17th international
conference on pattern recognition (ICPR’04), vol. 1, pp. 44–47, 2004). Our approach yields the most compact data representation among all known image-as-matrix methods. In addition, we propose
another rank-R tensor approximation algorithm based on slice projection of third-order tensors, which needs fewer iterations
for convergence for the important special case of 2D image ensembles, e.g., video. We evaluated the performance of our approach
vs. other approaches on a number of datasets with the following two main results. First, for a fixed compression ratio, the
proposed algorithm yields the best representation of image ensembles visually as well as in the least squares sense. Second,
proposed representation gives the best performance for object classification.
A shorter version of this paper was published at IEEE CVPR 2005 (Wang and Ahuja 2005). 相似文献
Thermolysis of cesium hexa(carboxylato)ferrate(III) precursors, Cs3[Fe(L)6].xH2O (L = formate, acetate, propionate, butyrate), has been carried out in flowing air atmosphere from ambient temperature to 1000°C. Various physico‐chemical techniques, that is, simultaneous TG‐DTG‐DTA, XRD, TEM, IR, Mössbauer spectroscopy, have been employed to characterize the intermediates and end products. After dehydration, the anhydrous precursors undergo exothermic decomposition to yield various intermediates, that is, cesium carbonate/propionate/butyrate and α‐Fe2O3. A subsequent decomposition of these intermediates leads to the formation of cesium ferrite above 800°C. Similar ferrite has been prepared by the combustion method at comparatively lower temperature (600°C) and in less time than that of conventional ceramic method. 相似文献