Search results

The purpose of this paper is to present the results of interaction occurring during the exposition of some specific carbon textile materials obtained in laboratory conditions to beams of various laser types.

Carbon fabric materials – fiber, felt and cloth – obtained from different precursor materials and prepared at various process conditions (oxidized, partially carbonized, carbonized, graphitized), were exposed to pulses of various lasers (Nd3+: YAG, alexandrite, ruby).

Depending on the laser power, plasma and destructive phenomena occurred. In the case of an interaction between a Nd3+: YAG laser beam and specimens of thickness in millimeter range, the authors have estimated the threshold of the energy density for drilling and discussed the possible models of the interaction.

The results have implications in the estimations of quality as well as in the improvement of material processing, giving some new light to the changes of mechanical and optical constants of the material, as well as to the changes of carbon groups of the material, which would be useful for different types of modeling. Future research will be in the interaction of laser beams with various textile materials, where the investigation would cover the microstructure changes and the implications on cloth cutting and welding, concerning the damages as well as relief structures, specially renew for fs laser regimes.

The area of laser applications in the textile industry is supported by scientific and applicative exploration. However, fewer results are concerned with deep introspection into the microstructure of the damages considering the laser interaction with carbon fiber and other carbon-based textiles.

A multi-physics process model is developed to analyze reactive melt infiltration (RMI) fabrication of ceramic-matrix composite (CMC) materials and components. The paper aims to discuss this issue.

Within this model, the following key physical phenomena governing this process are accounted for: capillary and gravity-driven unsaturated flow of the molten silicon into the SiC/SiC CMC preform; chemical reactions between the silicon melt and carbon (either the one produced by the polymer-binder pyrolysis or the one residing within the dried matrix slurry); thermal-energy transfer and source/sink phenomena accompanying reactive-flow infiltration; volumetric changes accompanying chemical reactions of the molten silicon with the SiC preform and cooling of the as-fabricated CMC component to room temperature; development of residual stresses within, and thermal distortions of, the as-fabricated CMC component; and grain-microstructure development within the SiC matrix during RMI.

The model is validated, at the material level, by comparing its predictions with the experimental and modeling results available in the open literature. The model is subsequently applied to simulate RMI fabrication of a prototypical gas-turbine engine hot-section component, i.e. a shroud. The latter portion of the work revealed the utility of the present computational approach to model fabrication of complex-geometry CMC components via the RMI process.

To the authors’ knowledge, the present work constitutes the first reported attempt to apply a multi-physics RMI process model to a gas-turbine CMC component.

The mainstream of current research work in array tactile sensors concentrates on using a soft compliant membrane as a means of transmitting the effect of variable external stimuli to the discrete sensing elements. The soft compliant devices are usually made of a thin flexible substrate such as pressure sensitive pads, conductive materials, conductive coatings, piezoelectric polymers or elastomers. A large number of tactile sensor designs using these types of materials have been investigated by researchers. These include the use of anisotropically conductive silicone rubber (ACS), sponges containing carbon particles or felted carbon fibres, piezoelectric polymers such as polyvinylidene fluoride (PVF2) and conductive elastomers such as Dynacom materials consisting of silicone rubber mixed with metallic compounds.

The purpose of this paper is to investigate the effect of doping element on the microwave absorption performance of hexagonal nano boron nitride (h-nBN)-reinforced basalt fabric (BF)/epoxy composites. A new type of hybrid composite that will be produced by the use of boron nitride as an additive that leads to increased radar absorption capability will be developed and a new material that can be used in aeronautical radar applications.

This study is focused on the microwave absorption properties of h-nBN doped basalt fabric-reinforced epoxy composites. Basalt fabric (BF)/epoxy composites (pure composites) and the BF/h-nBN (1 Wt.% h-nBN doped composites) hybrid composites were fabricated by vacuum infusion method. Phase identification of the composites were performed using X-ray diffraction (XRD), the 2θ scan range was from 10 to 60 with the scanning speed of 3°/min and surface morphologies of the composites were investigated using scanning electron microscopy (SEM). Microwave properties of samples were investigated through transmission/reflection measurements in Agilent brand 2-Port PNA-L Network Analyzer in the frequency range of 3–18 GHz. The prepared sample is positioned between two horn antennas with and without metal plate.

Experimental results show that h-nBN doped composite was synthesized successfully and the produced hexagonal nano boron nitride-added fiber laminated composite material has good absorption behavior when they are used with metallic sheets and good for isolation applications at many points in the 3–18 GHz band.

This paper will contribute to the literature on the use of basalt fabric, which are new types of fibers, and hexagonal nano boron nitride and the effects of boron nitride on radar absorption properties of composite material. It presents detail characterization of each composite by using XRD and scanning electron microscopy.

This study aims to evaluate the practices of carbon management accounting (CMA) made by companies committed to sustainability in Australia’s four highest carbon-emitting industries, including electricity, transport, stationary energy and agriculture. The evaluation covers three CMA phases (i.e. data collection, interpretation and reporting).

This is a cross-sectional study using descriptive research. Data was collected using a questionnaire primarily derived from Burritt et al.’s (2002, 2011) CMA framework and suggestions from other references. The questionnaire includes a set of closed- and open-ended questions. Data was collected from 39 senior managers in the selected industries with direct knowledge and experience in their companies’ CMA practices.

The respondents disclose numerous different motivations for their companies to practise CMA and various ways of practising their CMA. This reflects diverse industry practices due to the absence of a generally accepted standard and different stages of organisational learning. The findings also show that the respondents perceived CMA practices as essential to enhancing their companies’ sustainability performance and overall reputation. However, the majority of the respondents showed little appetite for carbon emission disclosure.

The findings thoroughly describe the current CMA practices by companies committed to sustainability in Australia’s high carbon-emitting industries. Overall, the results show that while the respondents perceived CMA practices as essential for their companies’ sustainability performance and energy-saving, the CMA applications were inconsistent, along with some concerning results, such as a lack of assurance and accountability in the data validation and audit. These indicate the importance of policymakers to consider establishing CMA guidelines or standards to improve its practice. For any company, these findings can be used as learning materials to start or enhance CMA practice at their companies. A broader professional CMA community can strengthen the collective efforts to make CMA more robust.

The findings portray the perceptions of practitioners from Australia’s four highest carbon-emitting industries, indicating motivations to use CMA to understand their companies’ carbon footprint and reduce their companies’ environmental impacts.

The findings contribute to the limited literature in this area and offer several valuable insights regarding the current practice of CMA in Australia, focussing on high carbon-emission industries. It also encourages more research in this area using data from other industries or countries to develop comparative results and strengthen the literature. Future research using actual carbon emission information or a longitudinal approach could also evaluate the changes and progresses in CMA practices.

Low carbon solutions in infrastructure have been well documented and promoted in most areas of the UK except in the context of public sector Flood and Coastal Erosion Risk Management (FCERM) infrastructure. With the UK Government providing £2.5bn capital investment to reduce risk of flooding and coastal erosion between 2015 and 2020, the carbon impact of this construction programme will have a significant impact on the UK’s carbon targets. The purpose of this paper is to provide a comprehensive literature review focusing on the effect of carbon on climate change, the role of UK public sector FCERM construction and organisational cultural challenges in promoting low carbon.

An electronic survey of practising professionals in a leading government agency that procures major FCERM construction projects has been undertaken. The survey covers participants from the whole value chain within the project life cycle, since many authoritative sources call for integration, and for change to be implemented in partner organisations.

The survey shows that although carbon is considered, it is not yet at the level of importance nor is it prioritised to the extent at which cost is. This is for both public and private sector supply chain organisations. Low carbon, although included in discussions, does not feature as prominently throughout all project stages.

The utilisation of a survey for this research is limited as it merely supports current industry findings, albeit having focused on a specific infrastructure area. Further qualitative research is required to fully explore the findings within the survey, and to establish whether the implementation of a new whole life carbon calculator within FCERM construction will have an impact on the organisational culture and future successful implementation of low carbon construction.

The results of this research identify the specific areas in which industry practitioners involved in promoting and prioritising low carbon could focus on to facilitate the change required to fully embed low carbon into FCERM construction.

This research supports industry knowledge specifically for public sector FCERM construction, and the changes to organisational culture required to fully embed low carbon solutions in public sector construction. These changes may have an impact on the amount of carbon being used, which can positively affect climate change as a whole.

The literature review shows that carbon has a clear impact on climate change, and organisational culture and leadership can facilitate the successful implementation of new initiatives. However, previous attempts to embed low carbon into infrastructure construction practice have had limited success to date. The survey findings support the view that organisational culture and leadership can influence the successful embedding of low carbon solutions, and why this has been a challenge.

This paper aims to explore the pathways of carbon transfer in 200 US corporations along with the motivations that drive such transfers. The particular focus is on each firm’s embeddedness in the global value chain (GVC) and the influence of environmental law, operational costs and corporate social responsibility (CSR). The insights gleaned bridge a gap in the literature surrounding GVCs and corporate carbon transfer.

The methodology comprised a two-step research approach. First, the authors used a two-sided fixed regression to analyse the relationship between each firm’s embeddedness in the GVC and its carbon transfers. The sample consisted of 217 US firms. Next, the authors examined the influence of environmental law, operational costs and CSR on carbon transfers using a quantitative comparison analysis. These results were interpreted through the theoretical frameworks of the GVC and legitimacy theory.

The empirical results indicate positive relationships between carbon transfers and GVC embeddedness in terms of both a firm’s position and its degree. From the quantitative comparison, the authors find that the pressure of environmental law and operational costs motivate these transfers through the value chain. Furthermore, CSR does not help to mitigate transfers.

The findings offer insights for policymakers, industry and academia to understand that, with globalised production and greater value creation, transferring carbon to different parts of the GVC – largely to developing countries – will only become more common. The underdeveloped nature of environmental technology in these countries means that global emissions will likely rise instead of fall, further exacerbating global warming. Transferring carbon is not conducive to a sustainable global economy. Hence, firms should be closely regulated and given economic incentives to reduce emissions, not simply shunt them off to the developing world.

Carbon transfer is a major obstacle to effectively reducing carbon emissions. The responsibilities of carbon transfer via GVCs are difficult to define despite firms being a major consideration in such transfers. Understanding how and why corporations engage in carbon transfers can facilitate global cooperation among communities. This knowledge could pave the way to establishing a global carbon transfer monitoring network aimed at preventing corporate carbon transfer and, instead, encouraging emissions reduction.

This study extends the literature by investigating carbon transfers and the GVC at the firm level. The authors used two-step research approach including panel data and quantitative comparison analysis to address this important question. The authors are the primary study to explore the motivation and pathways by which firms transfer carbon through the GVC.

Certified emission reduction (CER) survey studies in the literature are quite restrictive in scope. These studies are based on convenience sampling and, therefore, cannot be relied upon. The current study comprehensively surveys the strengths, weaknesses and suggestive measures for clean development mechanism (CDM). This paper systematically aims to conduct the survey on top 50 companies in terms of CER volume.

The survey is aimed to target top 50 companies which account for 55 per cent of total number of CERs of all the Indian projects. The online survey link was sent to all 50 companies, and the finance managers were followed up regularly over a period of one year. Finally, 37 responses (a response rate of 72 per cent) have been received.

“CER is cheaper than EUA for Emission Compliance” is rated as topmost strength and “Methodology of Financial Additionality is Subjective” is rated as topmost weakness of CER mechanism. Removal of Quantitative Restrictions on CERs is rated as the topmost suggestive measure for stabilization of CER. Companies overwhelmingly favored continuation of banking and inclusion of carbon emission cost as one of the internal cost of business.

The current study throws light on future policy interventions for minimization of carbon footprint and efficient energy management.

This study gives vital reflections for stabilization of CDM. This will help sustainable development, generation of green energy, mitigation of carbon emission at the least cost and employment generation in developing countries because of CDM project development.

This study differs from earlier studies because it comprehensively surveys the pertinent issues relating to strengths, weaknesses and suggestive measures for CDM. It also differs from them because it is not based on convenience sampling. It conducts the survey systematically on top 50 companies in terms of CER volume. Therefore, unlike previous studies of questionable validities, the findings of this study can be safely considered for policy interventions

This paper aims to improve the tribological properties of aluminum alloys and reduce their wear rate.

Carbon is placed in the model at room temperature, pour 680°C of molten aluminum into the pressure chamber, and then pressed it into the mold containing carbon felt through a die casting machine, and waited for it to cool, which used an injection pressure of 52.8 MPa and held the same pressure for 15 s.

The result indicated that the mechanical properties of matrix and composite are similar, and the compressive strength of the composite is only 95% of the matrix alloy. However, the composite showed a low friction coefficient, the friction coefficient of Gr/Al composite is only 0.15, which just is two-third than that of the matrix alloy. Similarly, the wear rate of the composite is less than 4% of the matrix. In addition, the composite can avoid severe wear before 200°C, but the matrix alloy only 100°C.

This material has excellent friction properties and is able to maintain this excellent performance at high temperatures.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0454/

Cleanrooms are highly controlled enclosed rooms where air quality is monitored and ensured to have less contamination according to standard cleanliness level. Air filters are used to optimize indoor air quality and remove air pollutants. Filter media and filtering system are decided as per requirement. Depth filter media are mostly used in cleanroom filtrations. This paper aims to present a comprehensive review of the evolution of cleanroom filter media. It evaluates the advantages and disadvantages of air filter media. It is also studied which air filters have additional properties such as anti-microbial properties, anti-odour properties and chemical absorbent. Development and innovation of air filters and filtration techniques are necessary to improve the performance via the synergistic effect and it can be a possible avenue of future research.

This paper aims to drive the future of air filter research and development in achieving high-performance filtration with high filtration efficiency, low operational cost and high durability. Air pollutants are classified into three types: suspended particles, volatile organic pollutants and microorganisms. Technologies involved in purification are filtration, water washing purification, electrostatic precipitation and anion technology. They purify the air by running it through a filter medium that traps dust, hair, pet fur and debris. As air passes through the filter media, they function as a sieve, capturing particles. The fibres in the filter medium provide a winding path for airflow. There are different types of air filters such as the high-efficiency particulate air filter, fibreglass air filter and ultra-low particulate air filter.

Emerging filtration technologies and filters such as nanofibres, filters with polytetrafluoroethylene membrane are likely to become prevalent over the coming years globally. The introduction of indoor air filtration with thermal comfort can be a possible avenue of future research along with expanding indoor environment monitoring and improving air quality predictions. New air filters and filtration technologies having better performance with low cost and high durability must be developed which can restrict multiple types of pollutants at the same time.

The systematic literature review approach used in this paper highlights the emerging trends and issues in cleanroom filtration in a structured and thematic manner, enabling future work to progress as it will continue to develop and evolve.