One-dimensional nanomaterials synthesized using high-energy ball milling and annealing process

One-dimensional (1D) nanomaterials including nanotubes, nanowires and nanorods have many new properties, functionalities and a large range of promising applications. A major challenge for these future industrial applications is the large-quantity production. We report that the ball milling and annealing process has the potential to achieve the mass production. Several examples including C, BN nanotubes and SiC, Zn nanowires are presented to demonstrate such capability. In addition, both size and structure of 1D nanomaterials can be controlled by varying processing conditions. New growth mechanisms involved in the process have been investigated and the high-energy ball milling has an important role in the formation of these 1D nanomaterials.

Stochastic optimization models for energy management in carbonization process of carbon fiber production

Industrial producers face the task of optimizing production process in an attempt to achieve the desired quality such as mechanical properties with the lowest energy consumption. In industrial carbon fiber production, the fibers are processed in bundles containing (batches) several thousand filaments and consequently the energy optimization will be a stochastic process as it involves uncertainty, imprecision or randomness. This paper presents a stochastic optimization model to reduce energy consumption a given range of desired mechanical properties. Several processing condition sets are developed and for each set of conditions, 50 samples of fiber are analyzed for their tensile strength and modulus. The energy consumption during production of the samples is carefully monitored on the processing equipment. Then, five standard distribution functions are examined to determine those which can best describe the distribution of mechanical properties of filaments. To verify the distribution goodness of fit and correlation statistics, the Kolmogorov-Smirnov test is used. In order to estimate the selected distribution (Weibull) parameters, the maximum likelihood, least square and genetic algorithm methods are compared. An array of factors including the sample size, the confidence level, and relative error of estimated parameters are used for evaluating the tensile strength and modulus properties. The energy consumption and N2 gas cost are modeled by Convex Hull method. Finally, in order to optimize the carbon fiber production quality and its energy consumption and total cost, mixed integer linear programming is utilized. The results show that using the stochastic optimization models, we are able to predict the production quality in a given range and minimize the energy consumption of its industrial process.

A study on energy and environmental management techniques used in petroleum process industries

Petroleum process industries are one of the most energy and emission intensive sectors throughout the world.There are natural gas processing plant, crude oils and condensate fractionation plant, liquefied natural gas plantand liquefied petroleum gas plant etc. creates environmental pollution by processing and handling of petroleumproducts. The study critically reviewed and discussed the energy and environmental management includingpollution control of petroleum process industries of Bangladesh. They produce both gaseous (process gas, wastegas etc.) and liquid (produced water, waste oil and grease etc.) pollutants. The study found that the liquid pollutantlike waste water is more hazardous and its treatment process is highly complicated due to its higher salinity, morecorrosivity and grease contain characteristics. As part of energy management, the rational use of energy and energyflow diagram of the petroleum industry is presented. Finally, a time frame measures which can be implemented inorder to save energy is outlined. The study concluded that the rational use of energy and proper environmentalmanagement are essential for achieving energy and environmental sustainability of process industries.

Grassroots energy: a case study of active citizenship and public communication in risk society

In 2001, the Victorian state government approved the construction of a 500-megawatt power station at Stonehaven by US multinational corporation, AES Power One. In 2002 plans had stalled and the company had withdrawn from the process. By March, 2002 the state government flagged that the power station was no longer required to meet power supply demands. This paper applies Beck’s theories of risk society and reflexive modernisation to a case study. It asks to what extent is Australia a risk society? Is the Stonehaven case part of a larger-scale cultural and political movement and if so what are the consequences for corporate and civil citizenship and public communication in Australia?

Thermal simulation studies of a low energy university building in Australia

A key criterion by which any building will be judged when its environmental impact is assessed is its thermal performance. This paper describes the simulation of an office module in a three-storey university building in south eastern Australia. The module, located at the north-west corner of the top floor of the building, was chosen because it is likely to have the highest cooling load - a primary concern of energy conscious designers of commercial buildings for most parts of Australia.

In the paper, the initial key assumptions are stated, together with a description of a "reference" or base case, against which improvements in thermal performance were measured. The simulation process identified the major influences on thermal performance. This enabled changes in materials and construction, as well as basic design concepts to be evaluated. Features incorporated into the base case such as a metal roof and glazed walkway were found to have adverse influence on energy consumption, and were consequently rejected in preference for an improved design which included a hypocaust slab system on the roof of the office module. The final design was predicted to reduce the annual energy consumption for heating and cooling by 72% and 76% respectively.

La performance thermique est l'un des critegraveres cleacutes de l'eacutevaluation environnementale de tout bacirctiment. Cet article deacutecrit la simulation d'un module de bureau appartenant agrave un immeuble de trois eacutetages d'une universiteacute du sud-est de l'Australie. Ce module, situeacute agrave l'angle nord-ouest de l'eacutetage supeacuterieur du bacirctiment a eacuteteacute choisi car c'eacutetait lui qui, vraisemblablement, avait la charge de refroidissement la plus eacuteleveacutee, ce qui est une preacuteoccupation majeure des concepteurs conscients des problegravemes d'eacutenergie des bacirctiments commerciaux dans la plus grande partie du pays. Le processus de simulation a fait apparaicirctre trois influences principales sur la performance thermique par rapport agrave un cas de base. Cela a permis d'eacutevaluer les modifications apporteacutees aux mateacuteriaux et agrave la construction ainsi qu'aux avant-projets. Les caracteacuteristiques inteacutegreacutees dans le cas de base comme le toit meacutetallique et la passerelle vitreacutee avaient une influence neacutefaste sur la consommation d'eacutenergie et ont donc eacuteteacute rejeteacutees au beacuteneacutefice d'un concept ameacutelioreacute qui comprenait une dalle de type hypocauste sur le toit du module de bureau. Le concept final devrait reacuteduire la consommation annuelle d'eacutenergie pour le chauffage et le refroidissement de 72 % et 76 % respectivement, ce qui donne une ideacutee de la valeur ajouteacutee au processus de production agrave partir de proceacutedures avanceacutees de modeacutelisation et de simulation.

Effect of the manufacturing process on the interlaminar fracture toughness of 2/2 twill weave fabric carbon/epoxy composites

A 2/2 twill weave fabric carbon fibre reinforced epoxy matrix composite MTM56/CF0300 was used to investigate the effect of different manufacturing processes on the interlaminar fracture toughness. Double cantilever beam tests were performed on composites manufactured by hot press, autoclave and 'Quickstep' processes. The 'Quickstep' process was recently developed in Perth, Western Australia for the manufacture of advanced composite components. The values of the mode I critical strain energy release rate (G1d were compared and the results showed that the composite specimens manufactured by the autoclave and the 'Quickstep' process had much higher interlaminar fracture toughness than the specimen produced by the hot press. When compared to specimens manufactured by the hot press, the interlaminar fracture toughness values of the Quickstep and autoclave samples were 38% and 49% higher respectively. The 'Quickstep' process produced composite specimens that had comparable interlaminar fracture toughness to autoclave manufactured composites. Scanning electron microscopy (SEM) was employed to study the topography of the mode I interlaminar fracture surface and dynamic mechanical analysis (DMA) was performed to investigate the fibre/matrix interphase. SEM micrography and DMA spectra indicated that autoclave and 'Quickstep' produced composites with stronger fibre/matrix adhesion than hot press.

Validation of the use of input-output data for embodied energy analysis of the Australian construction industry

This paper evaluates a recently developed hybrid method for the embodied energy analysis of the Australian construction industry. It was found that the truncation associated with process analysis can be up to 80%, whilst the use of input-output analysis alone does not always provide a perfect model for replacing process data. There is also a considerable lack in the quantity and possibly quality of process data currently available. These findings suggest that current best-practice methods are sufficiently accurate for most typical applications, but this is heavily dependant upon data quality and availability. The hybrid method evaluated can be used for the optimisation of embodied energy and for identifying opportunities for improvements in energy efficiency.

CH2 energy harvesting systems : economic use and efficiency

This paper looks at the City of Melbourne's new office development CH₂ as a case study of world class energy performance. In particular, the integrated design of conventionally independent systems has led to the potential to deliver significant savings to the Council and to deliver better environmental conditions to building occupants that in turn may contribute to satisfaction, well-being and Productivity. It is concluded that this project has the potential
to be an iconic example of effective implementation of ESD (environmental sustainable design) principles and therefore act as a demonstration project to others. Energy efficiency of more than 50% of current benchmarks for Melbourne is effected. Energy harvesting is defined as arising from squander, waste and nature, which is a new concept introduced in this paper to better describe the design decision process.

An experimental study of low velocity impact response in 2/2 twill weave composite laminates manufactured by a novel fabrication process

A novel fabrication process for advanced composite components—the QuicktepTM process was described. 2/2 twill weave MTM56/CF0300 carbon epoxy composite laminates were manufactured by the Quickstep and the autoclave processes. The response of these laminates to drop-weight low velocity impact at energy levels ranging from 5 to 30 J was investigated. It was found that the laminates fabricated by the Quickstep had better impact damage tolerance than those fabricated by the autoclave. Optical microscopy revealed extensive matrix fracture in the center of the backside of the autoclave laminates indicating the more brittle property of the epoxy matrix cured by the autoclave process. Interfacial shear strength (IFSS) for two composite systems were measured by micro–debond experiments. The MTM56/CF0300 material cured by the Quickstep showed stronger fibre matrix adhesion. Since the thickness and density of the impact targets produced by two processes were different, finite element analysis (FEA) was performed to study the effect of these factors on the impact response. The simulation results showed that the difference in thickness and density affects the stress distribution under impact loading. Higher thickness and lower density caused by processing lead to less endurance to drop weight impact loading. Therefore the better performance of Quickstep laminates under impact loading was not due to the thickness and density change, but resulted from stronger mechanical properties.

Recent studies on yarn tension and energy consumption in ring spinning

High energy consumption remains a key challenge for the widely used ring spinning system. Tackling this challenge requires a full understanding of the various factors that contribute to yarn tension and energy consumption during ring spinning. In this paper, we report our recent experimental and theoretical research on air drag, yarn tension and energy consumption in ring spinning. A specially constructed rig was used to simulate the ring spinning process; and yarn tension at the guide-eye was measured for different yarns under different conditions. The effect of yarn hairiness on the air drag acting on a rotating yarn package and on a ballooning yarn was examined. Models of the power requirements for overcoming the air drag, increasing the kinetic energy of the yarn package (bobbin and wound yarn) and overcoming the yarn wind-on tension were developed. The ratio of energy-consumption to yarn-production over a full yarn package was discussed. A program to simulate yarn winding in ring spinning was implemented, which can generate the balloon shape and predict yarn tension under a given spinning condition. The simulation results were verified with experimental results obtained from spinning cotton and wool yarns.

Rapid composite tube manufacture utilizing the quickstep™ process

In this study, a novel method for manufacturing composite tubes utilizing the Quickstep^TM process has been developed. Tubes manufactured from `quick-cure' Toray G83C prepreg have demonstrated highly repeatable axial crush behavior with an average specific energy absorption (SEA) of 86 kJ/kg. The cure cycle is optimized by comparing the results from compression, dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), and porosity testing. The tube lay-up is optimized using compression and porosity test results. The effect of changes in fiber-orientation on SEA is also investigated. Process development has resulted in a robust manufacturing method capable of producing fully cured, high performance composite tubes with a cure cycle of 7 min. This corresponds to a 95% reduction in time compared to an equivalent autoclave cycle.

Validation of the use of Australian input-output data for building embodied energy simulation

Traditional!y, the simulation of buildings has focused 011 operational energy consumption in an attempt to determine the potential for energy savings. Whilst operational energy of Australian buildings accounts for around 20% of total energy consumption nationally, embodied energy represents 20 to 50 times the annual operational energy of 1110st Australian buildings. Lower values have been shown through a number of studies that have analysed the embodied energy of buildings and their products, however these have now shown to be incomplete in system boundary. Many of these studies have used traditional embodied energy analysis methods, such as process analysis and input-output analysis, Hybrid embodied energy analysis methods have been developed, but these need to be compared and validated. This paper reports on preliminary work on this topic. The findings so far suggest that current best-practice methods are sufficiently accurate for most typical applications, but this is heavily dependant upon data quality and availability.

Solar photocatalytic oxidation (PCO) process with a flat-plate reactor

An experimental rig with a flat-plate solar reactor was built to study the effectiveness of degradation using the reactive methylene blue as sensitive objective. The factors that affect the degradation performance, such as dosages of photocatalyst (Ti0₂), initial concentration of reactive methylene blue, flow rate through the flat-plate reactor, solar UV radiation intensity and decolourising efficiency of the solution, have been investigated. The results showed that the solar PCO process with a Flat-plate Reactor could degrade the methylene blue and decolour in methylene blue solution efficiently.

Assessment of embodied energy analysis methods for the Australian construction industry

Environmental assessment of buildings typically focuses on operational energy consumption in an attempt to minimise building energy consumption. Whilst the operation of Australian buildings accounts for around 20% of total energy consumption nationally, the energy embodied in these buildings represents up to 20 times their annual operational energy. Many previous studies, now shown to be incomplete in system boundary or unreliable, have provided much lower values for the embodied energy of buildings and their products. Many of these studies have used traditional embodied energy analysis methods, such as process analysis and input-output (1-0) analysis. More recently, hybrid embodied energy analysis methods have been developed, combining these two traditional methods. These hybrid methods need to be compared and validated, as these too have been considered to have several limitations. This paper aims to evaluate a recently developed hybrid method for the embodied energy analysis of the Australian construction industry, relative to traditional methods. Recent improvements to this hybrid method include the use of more recent 1-0 data and th.fl inclusion of capital energy data. These significant systemic changes mean that a previous assessment of the methods needs to be reviewed. It was found that the incompleteness associated with process analysis has increased from 49% to 87%. These findings suggest that current best-practice methods of embodied energy analysis are sufficiently accurate for most typical applications. This finding is strengthened by recent improvements to the 1-0 model.

An assessment of the energy and water embodied in commercial building construction

Growing global concern regarding the rapid rate at which humans are consuming the earth’s precious natural resources is leading to greater emphasis on more effective means of providing for our current and future needs. Energy and fresh water are the most crucial of these basic human needs. The energy and water required in the operation of buildings is fairly well known. Much less is known about the energy and water embodied in construction materials and products. It has been suggested that embodied energy typically represents 20 times the annual operational energy of current Australian buildings. Studies have suggested that the water embodied in buildings may be just as significant as that of energy. As for embodied energy, these studies have been based on traditional analysis methods, such as process and input-output analysis. These methods have been shown to suffer from errors relating to the availability of data and its reliability. Hybrid methods have been developed in an attempt to provide a more reliable assessment of the embodied energy and water associated with the construction of buildings. This paper evaluates the energy and water resources embodied in a commercial office building using a hybrid analysis method based on input-output data. It was found that the use of this hybrid analysis method increases the reliability and completeness of an embodied energy and water analysis of a typical commercial building by 45% and 64% respectively, over traditional analysis methods. The embodied energy and water associated with building construction is significant and thus represents an area where considerable energy and water savings are possible over the building life-cycle. These findings suggest that current best-practice methods of embodied energy and water analysis are sufficiently accurate for most typical applications, but this is heavily dependent upon data quality and availability.