scholarly journals A Flexible Chain Proposal for Winch Based Point Absorbers

2018 ◽  
Author(s):  
Kjell Andersson ◽  
Anders Hagnestål ◽  
Ulf Sellgren
Keyword(s):  
Wave Energy ◽  
Low Cost ◽  
Weight Ratio ◽  
Cost Effective ◽  
Preliminary Test ◽  
Design Solution ◽  
Strength Analysis ◽  
Wave Power ◽  
Elastomeric Bearings ◽  
Elastomeric Bearing

Ocean wave power is a promising renewable energy source for future energy production. It has however been difficult to find a cost-effective solution to convert the wave energy into electricity. The harsh marine environment and the fact that wave power is delivered with high forces at low speeds makes design of durable mechanical structures and efficient energy conversion challenging. The dimensioning forces strongly depend on the wave power concept, the Wave Energy Converter (WEC) implementation and the actual Power Take-Off (PTO) system. A WEC using a winch as a Power Take-Off system, i.e. a Winch Based Point Absorber (WBPA), could potentially accomplish a low Levelized Cost Of Energy (LCOE) if a key component — a low-cost, durable and efficient winch that can deal with high loads — can be developed. A key problem for achieving a durable winch is to find a force transmitting solution that can deal with these high loads and handle up to 80 million cycles. In this article we propose a design solution for a force transmitting chain in a WBPA system where elastomeric bearings are used as a means to achieve the relative motion between the links in the chain. With this solution no sliding is present and the angular motion is achieved as a deformation in the elastomeric bearing when the chain is winded on a drum. The link was designed primarily to minimize the number of joints in the chain: Thereby the maximum allowed relative angle between the links when rolled up over the drum should be as large as possible within practical limits. The angle is to be handled by the elastomeric bearing. A detailed strength analysis of the link has been performed as well as topology optimization to increase the strength to weight ratio. A test rig for a first proof of concept testing has been developed and the first preliminary test results indicate that this concept with using elastomeric bearings can be a potential solution for a durable chain and should be analyzed further for fatigue conditions and under water operations.

scholarly journals A Flexible Chain Proposal for Winch-Based Point Absorbers

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Kjell Andersson ◽  
Anders Hagnestål ◽  
Ulf Sellgren
Keyword(s):  
Wave Energy ◽  
Low Cost ◽  
Weight Ratio ◽  
Shear Stiffness ◽  
Cost Effective ◽  
Preliminary Test ◽  
Topological Optimization ◽  
Design Solution ◽  
Wave Power ◽  
Peak Loads

Ocean wave power is a promising renewable energy source. It has, however, been difficult to find a cost-effective solution to convert wave energy into electricity. The harsh marine environment and the fact that wave power is delivered with large forces at low speed make design of durable mechanical structures and efficient energy conversion challenging. The dimensioning forces strongly depend on the wave power concept, the wave energy converter (WEC) implementation, and the actual power take-off (PTO) system. A WEC with a winch as a power take-off system, i.e., a winch-based point absorber (WBPA), could potentially enable a low levelized cost of energy (LCOE) if a low-cost, durable and efficient winch that can deal with peak loads can be developed. A key challenge for realizing such a winch is to find a force transmitting solution that can deal with these peak loads and that can handle up to 80 million cycles during its life. In this article, we propose a design solution for a force transmitting chain with elastomer bearings connecting the links of the chain. With this solution no sliding is present, and the angular motion is realized as elastic shear deformations in the elastomer bearings when the chain is wound onto the winch drum. The elastomer bearings were designed for low shear stiffness and high compression stiffness, and the links were designed primarily to minimize the number of joints in the chain. Thereby, the maximum allowed relative angle between the links when rolled up over the drum should be as large as possible within practical limits. Finite element-based topological optimization was performed with the aim to increase the link strength to weight ratio. A test rig for a first proof of concept testing has been developed, and preliminary test results indicate that this chain concept with elastomer bearings can be a potential solution for a durable chain and should be analyzed and tested further for fatigue and sea operations.

scholarly journals Wave Energy Converter Power Take-Off System Scaling and Physical Modelling

2020 ◽  
Vol 8 (9) ◽  
pp. 632
Author(s):  
Gianmaria Giannini ◽  
Irina Temiz ◽  
Paulo Rosa-Santos ◽  
Zahra Shahroozi ◽  
Victor Ramos ◽  
...  
Keyword(s):  
Wave Energy ◽  
Experimental Testing ◽  
Experimental Studies ◽  
Physical Modelling ◽  
Cost Effective ◽  
Estimation Methods ◽  
Small Scale ◽  
Wave Power ◽  
Energy Converter ◽  
Energy Device

Absorbing wave power from oceans for producing a usable form of energy represents an attractive challenge, which for the most part concerns the development and integration, in a wave energy device, of a reliable, efficient and cost-effective power take-off mechanism. During the various stages of progress, for assessing a wave energy device, it is convenient to carry out experimental testing that, opportunely, takes into account the realistic behaviour of the power take-off mechanism at a small scale. To successfully replicate and assess the power take-off, good practices need to be implemented aiming to correctly scale and evaluate the power take-off mechanism and its behaviour. The present paper aims to explore and propose solutions that can be applied for reproducing and assessing the power take-off element during experimental studies, namely experimental set-ups enhancements, calibration practices, and error estimation methods. A series of recommendations on how to practically organize and carry out experiments were identified and three case studies are briefly covered. It was found that, despite specific options that can be strictly technology-dependent, various recommendations could be universally applicable.

Formation and Characteristics of Bentonite/Cationic Starch Composite as Adsorbent for Acid Red G Dye

2013 ◽  
Vol 821-822 ◽  
pp. 535-539
Author(s):  
Zhi Cai Yu ◽  
Hua Ling He ◽  
Jie Lin
Keyword(s):  
Aqueous Solution ◽  
Low Cost ◽  
Weight Ratio ◽  
Cost Effective ◽  
X Ray Diffraction ◽  
Cationic Starch ◽  
Composite Matrix ◽  
X Ray ◽  
Batch Technique ◽  
Acid Red G

In order to increase the adsorption capacity of bentonite, a novel and cost-effective cationic starch (CS) intercalated raw bentonite (RB) composite matrix was prepared by controlling the weight ratio of RB and CS. The intercalated microstructure of the RB/CS composite was then characterized by Fourier transform infrared spectroscopy (FTIR), X-ray-diffraction (XRD), respectively. The acid red G adsorption from aqueous solution on RB/CS composite was studied using batch technique and compared with the adsorption onto RB under various parameters such as weight ratio of RB to CS, initial dye concentration, contact time, pH, and adsorbent dosage. It was found that more than 90% of the dye from 100 ml L-1solution was removed by RB/CS composite under the optimal conditions and it had a higher color removal efficiency and a shorter adsorption equilibrium time compared with the RB as the adsorbent for acid red G dye. In summary, the result showed that RB/CS could be as a kind of low-cost material for the removal of acid red G from aqueous solution.

scholarly journals μSmartScope – Towards a low-cost microscopic medical device for cervical cancer screening using additive manufacturing and optimization

2021 ◽  
pp. 146442072110227
Author(s):  
Pedro Brandão ◽  
Paulo T Silva ◽  
Marco Parente ◽  
Luís Rosado
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Medical Device ◽  
Low Cost ◽  
Weight Ratio ◽  
Cost Effective ◽  
Automated Analysis ◽  
Tensile Tests ◽  
Design Tool ◽  
Manufacturing Technologies

Developing a low-cost medical device requires numerous stages of prototyping, where using traditional manufacturing technologies can increase development costs. The current study presents the development of a critical component for a low-cost microscope whose goal is to confer an inexpensive solution for automated analysis of microscopic smears. A novel design methodology was developed to optimize the achieved solution. During the exploration of this methodology, it is asked: how can an additive-manufactured prototype be cost-effective for accurate examination of cervical cytology smears? To understand the effect on cost and tensile strength that infill density and perimeter wall count, tensile tests were conducted. These results combined with the developed methodology achieved the most cost-effective solution. To achieve this, topology optimization was used to improve the stiffness-per-weight ratio of different parts. Finally, design for additive manufacturing and topology optimization was proven as an effective design tool.

A Preliminary Assessment of the Competitiveness of Wave Energy Technologies: A Regionally Detailed Analysis

2013 ◽  
Vol 431 ◽  
pp. 356-364
Author(s):  
Takayuki Takeshita
Keyword(s):  
Wave Energy ◽  
Seasonal Variability ◽  
Low Cost ◽  
Energy System ◽  
Wave Power ◽  
Global Energy ◽  
Power Sources ◽  
Energy System Model ◽  
Energy Technologies ◽  
The Uk

In this paper, a regionally disaggregated global energy system model treating the electricity supply sector in detail is used to examine the competitiveness of wave energy technologies for each of 48 world regions over the period to 2050 under a constraint of halving global energy-related CO2 emissions in 2050 compared to the 2000 level. It is first found that wave energy continues to be uncompetitive until 2050 due to (1) its high cost and (2) the large seasonal variability of wave power. Even if the reference wave electricity generation costs are assumed to be reduced by 90%, the latter factor severely limits the market penetration of wave energy technologies. It is then found that the UK and Ireland, Australia and New Zealand, Japan, South Africa, the western US, Latin America, Canada, and Spain and Portugal are the regions promising for wave energy deployment. Not only low-cost and abundant wave energy resources, but also the peak electric load in winter, the relatively small seasonal variability of wave power, and/or the low competitiveness of power sources substitutable by wave energy are the reasons for this.

scholarly journals First Report on Cyanotoxin (MC-LR) Removal from Surface Water by Multi-Soil-Layering (MSL) Eco-Technology: Preliminary Results

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1403
Author(s):  
Roseline Prisca Aba ◽  
Richard Mugani ◽  
Abdessamad Hejjaj ◽  
Nelly Brugerolle de Fraissinette ◽  
Brahim Oudra ◽  
...  
Keyword(s):  
Low Cost ◽  
Weight Ratio ◽  
Cost Effective ◽  
Dry Weight ◽  
Distilled Water ◽  
Treatment Methods ◽  
Preliminary Results ◽  
Early Results ◽  
The World ◽  
Soil Layering

Cyanobacteria blooms occur frequently in freshwaters around the world. Some can produce and release toxic compounds called cyanotoxins, which represent a danger to both the environment and human health. Microcystin-LR (MC-LR) is the most toxic variant reported all over the world. Conventional water treatment methods are expensive and require specialized personnel and equipment. Recently, a multi-soil-layering (MSL) system, a natural and low-cost technology, has been introduced as an attractive cost-effective, and environmentally friendly technology that is likely to be an alternative to conventional wastewater treatment methods. This study aims to evaluate, for the first time, the efficiency of MSL eco-technology to remove MC-LR on a laboratory scale using local materials. To this end, an MSL pilot plant was designed to treat distilled water contaminated with MC-LR. The pilot was composed of an alternation of permeable layers (pozzolan) and soil mixture layers (local sandy soil, sawdust, charcoal, and metallic iron on a dry weight ratio of 70, 10, 10, and 10%, respectively) arranged in a brick-layer-like pattern. MSL pilot was continuously fed with synthetic water containing distilled water contaminated with increasing concentrations of MC-LR (0.18–10 µg/L) at a hydraulic loading rate (HLR) of 200 L m−2 day−1. The early results showed MC-LR removal of above 99%. Based on these preliminary results, the multi-soil-layering eco-technology could be considered as a promising solution to treat water contaminated by MC-LR in order to produce quality water for irrigation or recreational activities.

ASSESSMENT OF THE PLATELET COUNT IN THE PREGNANT WOMEN IN IGIMS, PATNA, BIHAR

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Tanwi Singh ◽  
Anshuman Sinha
Keyword(s):  
Platelet Count ◽  
Pregnant Women ◽  
Screening Test ◽  
Low Cost ◽  
Medical Science ◽  
Cost Effective ◽  
Platelet Indices ◽  
Increased Risk ◽  
Low Platelet Count ◽  
Severity Of The Disease

The major risk associated with low platelet count in pregnancy is the increased risk of bleeding during the childbirth or post that. There is an increased blood supply to the uterus during pregnancy and the surgical procedure requires cutting of major blood vessels. Women with thrombocytopenia are at increased risk of losing excessive blood. The risk is more in case of caesarean delivery as compared to vaginal delivery. Hence based on above findings the present study was planned for Assessment of the Platelet Count in the Pregnant Women in IGIMS, Patna, Bihar. The present study was planned in Department of Pathology, Indira Gandhi Institute of Medical Science, Patna, Bihar, India. The present study was planned from duration of January 2019 to June 2019. In the present study 200 pregnant females samples received for the platelet estimation were enrolled in the present study. Clinically platelet indices can be a useful screening test for early identification of preeclampsia and eclampsia. Also platelet indices can assess the prognosis of this disease in pregnant women and can be used as an effective prognostic marker because it correlates with severity of the disease. Platelet count is a simple, low cost, and rapid routine screening test. Hence the data generated from the present study concludes that platelet count can be used as a simple and cost effective tool to monitor the progression of preeclampsia, thereby preventing complications to develop during the gestational period. Keywords: Platelet Count, Pregnant Women, IGIMS, Patna, Bihar, etc.

Janus – A New Approach to Air Combat Pilot Training

2019 ◽  
Vol 2019 (4) ◽  
pp. 7-22
Author(s):  
Georges Bridel ◽  
Zdobyslaw Goraj ◽  
Lukasz Kiszkowiak ◽  
Jean-Georges Brévot ◽  
Jean-Pierre Devaux ◽  
...  
Keyword(s):  
Low Cost ◽  
Cost Effective ◽  
High Energy ◽  
Training System ◽  
Embedded Sensors ◽  
Pilot Training ◽  
New Approach ◽  
Combat Aircraft ◽  
Air Combat ◽  
The Cost

Abstract Advanced jet training still relies on old concepts and solutions that are no longer efficient when considering the current and forthcoming changes in air combat. The cost of those old solutions to develop and maintain combat pilot skills are important, adding even more constraints to the training limitations. The requirement of having a trainer aircraft able to perform also light combat aircraft operational mission is adding unnecessary complexity and cost without any real operational advantages to air combat mission training. Thanks to emerging technologies, the JANUS project will study the feasibility of a brand-new concept of agile manoeuvrable training aircraft and an integrated training system, able to provide a live, virtual and constructive environment. The JANUS concept is based on a lightweight, low-cost, high energy aircraft associated to a ground based Integrated Training System providing simulated and emulated signals, simulated and real opponents, combined with real-time feedback on pilot’s physiological characteristics: traditionally embedded sensors are replaced with emulated signals, simulated opponents are proposed to the pilot, enabling out of sight engagement. JANUS is also providing new cost effective and more realistic solutions for “Red air aircraft” missions, organised in so-called “Aggressor Squadrons”.

Motivating Compliance: Firm Response to Mandatory Disclosure Policies

2018 ◽  
Vol 32 (2) ◽  
pp. 103-119
Author(s):  
Colleen M. Boland ◽  
Chris E. Hogan ◽  
Marilyn F. Johnson
Keyword(s):  
Conflict Of Interest ◽  
Low Cost ◽  
Cost Effective ◽  
Data Availability ◽  
Policy Adoption ◽  
Future Research ◽  
Regulated Firms ◽  
Firm Response ◽  
Disclosure Rules ◽  
The Impact

SYNOPSIS Mandatory existence disclosure rules require an organization to disclose a policy's existence, but not its content. We examine policy adoption frequencies in the year immediately after the IRS required mandatory existence disclosure by nonprofits of various governance policies. We also examine adoption frequencies in the year of the subsequent change from mandatory existence disclosure to a disclose-and-explain regime that required supplemental disclosures about the content and implementation of conflict of interest policies. Our results suggest that in areas where there is unclear regulatory authority, mandatory existence disclosure is an effective and low cost regulatory device for encouraging the adoption of policies desired by regulators, provided those policies are cost-effective for regulated firms to implement. In addition, we find that disclose-and-explain regulatory regimes provide stronger incentives for policy adoption than do mandatory existence disclosure regimes and also discourage “check the box” behavior. Future research should examine the impact of mandatory existence disclosure rules in the year that the regulation is implemented. Data Availability: Data are available from sources cited in the text.

scholarly journals End-of-Life Alternatives of Glass Reinforced Polyester Boat Hulls Compared by LCA

2018 ◽  
Vol 27 (4) ◽  
pp. 096369351802700 ◽  
Author(s):  
Mehmet Önal ◽  
Gökdeniz Neşer
Keyword(s):  
End Of Life ◽  
Environmental Impacts ◽  
Raw Materials ◽  
Weight Ratio ◽  
Cost Effective ◽  
Raw Material ◽  
Photochemical Oxidation ◽  
Human Toxicity ◽  
Vacuum Infusion ◽  
Infusion Method

Glass reinforced polyester (GRP), as a thermoset polymer composites, dominates boat building industry with its several advantages such as high strength/weight ratio, cohesiveness, good resistance to environment. However, proper recovering and recycling of GRP boats is became a current environmental requirement that should be met by the related industry. In this study, to propose in a cost effective and environmentally friendly way, Life Cycle Assessment (LCA) has been carried out for six scenarios include two moulding methods (namely Hand Lay-up Method, HLM and Vacuum Infusion Method, VIM) and three End-of-Life (EoL) alternatives(namely Extruding, Incineration and Landfill) for a recreational boat's GRP hulls. A case study from raw materials purchasing phase to disposal/recycling stages has been established taking 11 m length GRP boat hull as the functional unit. Analysis show that in the production phase, the impacts are mainly due to the use of energy (electricity), transport and raw material manufacture. Largest differences between the methods considered (HLM and VIM) can be observed in the factors of marine aquatic ecotoxicity and eutrophication while the closest ones are abiotic depletion, ozon layer depletion and photochemical oxidation. The environmental impact of VIM is much higher than HLM due to its higher energy consumption while vacuum infusion method has lower risk than hand lay-up method in terms of occupational health by using less raw material (resin) in a closed mold. In the comparison of the three EoL techniques, the mechanical way of recycling (granule extruding) shows better environmental impacts except terrestrial ecotoxicity, photochemical oxidation and acidification. Among the EoL alternatives, landfill has the highest environmental impacts except ‘global warming potential’ and ‘human toxicity’ which are the highest in extrusion. The main cause of the impacts of landfill is the transportation needs between the EoL boats and the licenced landfill site. Although it has the higher impact on human toxicity, incineration is the second cleaner alternative of EoL techniques considered in this study. In fact that the similar trend has been observed both in production and EoL phases of the boat. It is obvious that using much more renewable energy mix and greener transportation alternative can reduce the overall impact of the all phases considerably.

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