Search results
1 – 10 of 12Siddharth Kulkarni, Craig Chapman, Hanifa Shah, Erika Anneli Parn and David John Edwards
This paper aims to conduct a comprehensive literature review in the tidal energy physics, the ocean environment, hydrodynamics of horizontal axis tidal turbines and bio-mimicry.
Abstract
Purpose
This paper aims to conduct a comprehensive literature review in the tidal energy physics, the ocean environment, hydrodynamics of horizontal axis tidal turbines and bio-mimicry.
Design/methodology/approach
The paper provides an insight of the tidal turbine blade design and need for renewable energy sources to generate electricity through clean energy sources and less CO2 emission. The ocean environment, along with hydrodynamic design principles of a horizontal axis tidal turbine blade, is described, including theoretical maximum efficiency, blade element momentum theory and non-dimensional forces acting on tidal turbine blades.
Findings
This review gives an overview of fish locomotion identifying the attributes of the swimming like lift-based thrust propulsion, the locomotion driving factors: dorsal fins, caudal fins in propulsion, which enable the fish to be efficient even at low tidal velocities.
Originality/value
Finally, after understanding the phenomenon of caudal fin propulsion and its relationship with tidal turbine blade hydrodynamics, this review focuses on the implications of bio-mimicking a curved caudal fin to design an efficient horizontal axis tidal turbine.
Details
Keywords
Siddharth Suhas Kulkarni, Craig Chapman, Hanifa Shah and David John Edwards
The purpose of this paper is to conduct a comparative analysis between a straight blade (SB) and a curved caudal-fin tidal turbine blade (CB) and to examine the aspects relating…
Abstract
Purpose
The purpose of this paper is to conduct a comparative analysis between a straight blade (SB) and a curved caudal-fin tidal turbine blade (CB) and to examine the aspects relating to geometry, turbulence modelling, non-dimensional forces lift and power coefficients.
Design/methodology/approach
The comparison utilises results obtained from a default horizontal axis tidal turbine with turbine models available from the literature. A computational design method was then developed and implemented for “horizontal axis tidal turbine blade”. Computational fluid dynamics (CFD) results for the blade design are presented in terms of lift coefficient distribution at mid-height blades, power coefficients and blade surface pressure distributions. Moving the CB back towards the SB ensures that the total blade height stays constant for all geometries. A 3D mesh independency study of a “straight blade horizontal axis tidal turbine blade” modelled using CFD was carried out. The grid convergence study was produced by employing two turbulence models, the standard k-ε model and shear stress transport (SST) in ANSYS CFX. Three parameters were investigated: mesh resolution, turbulence model, and power coefficient in the initial CFD, analysis.
Findings
It was found that the mesh resolution and the turbulence model affect the power coefficient results. The power coefficients obtained from the standard k-ε model are 15 to 20 per cent lower than the accuracy of the SST model. Further analysis was performed on both the designed blades using ANSYS CFX and SST turbulence model. The variation in pressure distributions yields to the varying lift coefficient distribution across blade spans. The lift coefficient reached its peak between 0.75 and 0.8 of the blade span where the total lift accelerates with increasing pressure before drastically dropping down at 0.9 onwards due to the escalating rotational velocity of the blades.
Originality/value
The work presents a computational design methodological approach that is entirely original. While this numerical method has proven to be accurate and robust for many traditional tidal turbines, it has now been verified further for CB tidal turbines.
Details
Keywords
The chapter discusses two aspects of the theory of the firm. One is the question of what is a regenerative firm, and how the traditional view of the firm changed when one adopts…
Abstract
The chapter discusses two aspects of the theory of the firm. One is the question of what is a regenerative firm, and how the traditional view of the firm changed when one adopts an integral transdisciplinary worldview. The second is what are the consequences when we leave the assumption of the extrinsic value of the nature.
The central question is: How can firms transform themselves from a mainly extrinsic to a more intrinsic value orientation to nature? She is defending the necessity to transform anthropocentric business models into more ecocentric ones. Shifts to business models in which nature has an intrinsic value have fundamental consequences for the theory of the firm.
The chapter compares ‘creative destruction’ in which the value creation follows out of destruction of other values with the ‘law of seed’ where the natural cycles of continuous creation and regeneration carry out life. The latter can contribute creating value-based spiritual economic structures which bring together the rich diversity of man and nature. The regenerative firm can be an important driver for building an integral transdisciplinary world.
Details
Keywords
Deepak Doreswamy, Abhijay B.R., Jeane Marina D’Souza, Sachidananda H.K. and Subraya Krishna Bhat
Soft actuators using pneumatic-chamber (PneuNet)-based designs have been of interest in the area of soft robotics with scope of application in the area of biomedical assistance…
Abstract
Purpose
Soft actuators using pneumatic-chamber (PneuNet)-based designs have been of interest in the area of soft robotics with scope of application in the area of biomedical assistance and smart agriculture. Researchers have attempted to investigate multiple chambers in parallel to examine their deformation characteristics. However, there is a lacuna for investigation of the deformation characteristics of four parallel chambered soft actuators. The purpose of this study is to comprehensively investigate the different possible actuation scenarios and the resulting bending/deformation behaviours.
Design/methodology/approach
Therefore, in this study, a four-chambered PneuNet actuator is numerically investigated to evaluate the effects of pressurization scenarios and pressure levels on its performance, operating reaching and working volume.
Findings
The results of this study revealed that two-adjacent chamber equal pressurization and three-chamber pressurizations result in increased bending. However, two-opposite chamber pressurization reduces the bending angle with pressure levels in the lower pressure chamber. The maximum bending angle of 97° was achieved for single-chamber pressurization of 300 kPa. The two-adjacent chamber unequal pressurization can achieve a sweeping motion in the actuator along with bending. The working volume and reaching capability analysis revealed that the actuator can reach around 71% of the dimensional operating space.
Practical implications
The results provide fundamental guidance on the output nature of motion which can be obtained under different pressurization scenarios using the four-chambered design soft actuator, thereby making it a practical guide for implementation for useful applications.
Originality/value
The comprehensive pressurization scenarios and pressure level variations reported in this study will serve as fundamental operating guidelines for any practical implementation of the four-chambered PneuNet actuator.
Details
Keywords
R. Rathinamoorthy and S. Raja Balasaraswathi
Synthetic textile materials are noted as one of the major contributors to microfiber pollution through laundry. Though many research works evaluated microfiber pollution, the…
Abstract
Purpose
Synthetic textile materials are noted as one of the major contributors to microfiber pollution through laundry. Though many research works evaluated microfiber pollution, the solutions provided to control microfiber shedding are meager. The existing products collect or filter the microfiber from laundry effluent and restrict the direct leaching. However, no methods were proposed to effectively reduce the shedding from the textile itself.
Design/methodology/approach
This research is aimed to analyze the influence of surface modification of polyester knitted textiles by sodium hydroxide, on microfiber shedding. Response surface methodology was adapted to optimize different treatment parameters (alkali concentration, treatment time and temperature).
Findings
The results show that the sodium hydroxide concentration and treatment time had a negative correlation with microfiber shedding reduction. Whereas, treatment temperature had a positive correlation with microfiber shedding reduction. The statistical analysis revealed that 0.4 M concentration, 90°C temperature and 24 min of treatment time was the best process condition for minimum microfiber release. The same was confirmed with a practical experiment and a significant reduction of 80.63% in microfiber shedding after alkali treatment was found.
Originality/value
Alkali treatment of different knitted polyester fabrics with various knit structures and mass per square meter showed a significant reduction in microfiber shedding. The repeated laundry performed for 20 washes with surface-modified samples showed a significant reduction in microfiber release at every wash cycle and ensured the longevity of the effect.
Details
Keywords
Shirley Vincent and Will Focht
This study is the first of a five‐phase research project sponsored by the Council of Environmental Deans and Directors (CEDD), an organization of environmental program managers…
Abstract
Purpose
This study is the first of a five‐phase research project sponsored by the Council of Environmental Deans and Directors (CEDD), an organization of environmental program managers operating under the umbrella of the National Council for Science and the Environment. The purpose of the project is to determine if a consensus on core competencies for environmental program graduates is achievable, and if so, to make recommendations for consideration by program managers.
Design/methodology/approach
Q methodology was used to discern the perspectives of program managers at 42 CEDD member institutions on environmental curriculum design. An online survey preceded the Q sort exercise to elicit managers' curricular views and program characteristics. Survey responses were analyzed to select statements for the Q‐sorting exercise and categorized according to emergent themes. Multiple regression analysis was used to explore the relationship between perspectives (factor loadings) and host institution Carnegie classifications.
Findings
Three distinct, but not opposing, perspectives were identified from the initial Q‐factor rotation, which suggests the possibility of agreement on core competencies. The perspectives differ in their views of: curriculum orientation (professional training versus liberal arts), curriculum breadth versus depth, and flexible versus fixed core competencies. Host institution classification (Carnegie) is a small but significant predictor for two of the three perspectives. A second Q‐factor rotation reveals a consensus perspective that accommodates most respondents and aligns well with principles of sustainability, thus suggesting that sustainability may serve as a guiding paradigm for defining areas of core competence.
Originality/value
No national study of program managers' views of curriculum design and the identification of core competencies has been conducted in the USA.
Details
Keywords
AMM Ahsan, Ruinan Xie and Bashir Khoda
The purpose of this paper is to present a topology-based tissue scaffold design methodology to accurately represent the heterogeneous internal architecture of tissues/organs.
Abstract
Purpose
The purpose of this paper is to present a topology-based tissue scaffold design methodology to accurately represent the heterogeneous internal architecture of tissues/organs.
Design/methodology/approach
An image analysis technique is used that digitizes the topology information contained in medical images of tissues/organs. A weighted topology reconstruction algorithm is implemented to represent the heterogeneity with parametric functions. The parametric functions are then used to map the spatial material distribution following voxelization. The generated chronological information yields hierarchical tool-path points which are directly transferred to the three-dimensional (3D) bio-printer through a proposed generic platform called Application Program Interface (API). This seamless data corridor between design (virtual) and fabrication (physical) ensures the manufacturability of personalized heterogeneous porous scaffold structure without any CAD/STL file.
Findings
The proposed methodology is implemented to verify the effectiveness of the approach and the designed example structures are bio-fabricated with a deposition-based bio-additive manufacturing system. The designed and fabricated heterogeneous structures are evaluated which shows conforming porosity distribution compared to uniform method.
Originality/value
In bio-fabrication process, the generated bio-models with boundary representation (B-rep) or surface tessellation (mesh) do not capture the internal architectural information. This paper provides a design methodology for scaffold structure mimicking the native tissue/organ architecture and direct fabricating the structure without reconstructing the CAD model. Therefore, designing and direct bio-printing the heterogeneous topology of tissue scaffolds from medical images minimize the disparity between the internal architecture of target tissue and its scaffold.
Details
Keywords
Nataraj Poomathi, Sunpreet Singh, Chander Prakash, Rajkumar V. Patil, P.T. Perumal, Veluchamy Amutha Barathi, Kalpattu K. Balasubramanian, Seeram Ramakrishna and N.U. Maheshwari
Bioprinting is a promising technology, which has gained a recent attention, for application in all aspects of human life and has specific advantages in different areas of…
Abstract
Purpose
Bioprinting is a promising technology, which has gained a recent attention, for application in all aspects of human life and has specific advantages in different areas of medicines, especially in ophthalmology. The three-dimensional (3D) printing tools have been widely used in different applications, from surgical planning procedures to 3D models for certain highly delicate organs (such as: eye and heart). The purpose of this paper is to review the dedicated research efforts that so far have been made to highlight applications of 3D printing in the field of ophthalmology.
Design/methodology/approach
In this paper, the state-of-the-art review has been summarized for bioprinters, biomaterials and methodologies adopted to cure eye diseases. This paper starts with fundamental discussions and gradually leads toward the summary and future trends by covering almost all the research insights. For better understanding of the readers, various tables and figures have also been incorporated.
Findings
The usages of bioprinted surgical models have shown to be helpful in shortening the time of operation and decreasing the risk of donor, and hence, it could boost certain surgical effects. This demonstrates the wide use of bioprinting to design more precise biological research models for research in broader range of applications such as in generating blood vessels and cardiac tissue. Although bioprinting has not created a significant impact in ophthalmology, in recent times, these technologies could be helpful in treating several ocular disorders in the near future.
Originality/value
This review work emphasizes the understanding of 3D printing technologies, in the light of which these can be applied in ophthalmology to achieve successful treatment of eye diseases.
Details
Keywords
Markus J. Milne, Helen Tregidga and Sara Walton
Through an analysis of corporate sustainable development reporting, this paper seeks to examine critically language use and other visual (re)presentations of sustainable…
Abstract
Purpose
Through an analysis of corporate sustainable development reporting, this paper seeks to examine critically language use and other visual (re)presentations of sustainable development within the business context. It aims to provide a framework to interpret and tease out business representations of sustainable development. Such representations are argued to be constitutive of the way that business has come to “know” and “do” sustainable development and, therefore, to constrain and enable particular actions and developments.
Design/methodology/approach
The study uses a mix of synthesis, interpretive and discourse analysis to locate, interpret and critically analyse a corpus of written and presentational texts produced by a New Zealand business association and eight of its founding members' early triple bottom line reports.
Findings
The business association and its members' reports are shown to present a pragmatic and middle‐way discourse on business and the environment. Through the use of rhetorical claims to pragmatism and action, this discourse suggests that businesses are “doing” sustainability. But critical analysis and interpretation within a wider framework reveal a narrow, largely economic and instrumental approach to the natural environment.
Originality/value
This paper offers a diagrammatic synthesis of the contested “middle ground” of the sustainable development debate, and thereby provides a frame of reference for further interpretational work on organisations and sustainable development.
Details