Tensegrity Structures in the Design of Flexible Structures for Offshore Aquaculture

Aquaculture is the fastest growing food producing sector in the world. Considerable interest exists in developing open ocean aquaculture in response to a shortage of suitable, sheltered inshore locations. The harsh weather conditions experienced offshore lead to a focus on new structure concepts, remote monitoring and a higher degree of automation in order to keep the cost of structures and operations within an economically viable range. This paper proposes tensegrity structures in the design of flexible structures for offshore aquaculture. The finite element analysis program ABAQUS™ has been used to investigate stiffness properties and performance of tensegrity structures when subjected to various forced deformations and hydrodynamic load conditions. The suggested concept, the tensegrity beam, shows promising stiffness properties in tension, compression and bending, which are relevant for development of open ocean aquaculture construction for high energy environments. When designing a tensegrity beam, both pre-stress and spring stiffness should be considered to ensure the desired structural properties. A large strength to mass ratio and promising properties with respect to control of geometry, stiffness and vibration could make tensegrity an enabling technology for future developments.

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Finite element analysis of tensegrity structures in offshore aquaculture installations

Aquacultural Engineering ◽

10.1016/j.aquaeng.2007.01.001 ◽

2007 ◽

Vol 36 (3) ◽

pp. 272-284 ◽

Cited By ~ 14

Author(s):

Østen Jensen ◽

Anders Sunde Wroldsen ◽

Pål Furset Lader ◽

Arne Fredheim ◽

Mats Heide

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Element Analysis ◽

Tensegrity Structures ◽

Offshore Aquaculture

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Optimizing genotype-environment-management interactions to ensure silage maize production in the Chinese Maize Belt

Climate Research ◽

10.3354/cr01599 ◽

2020 ◽

Vol 80 (2) ◽

pp. 133-146

Author(s):

L Zhang ◽

Z Zhang ◽

J Cao ◽

Y Luo ◽

Z Li

Keyword(s):

Field Experiments ◽

Weather Conditions ◽

Growth Cycle ◽

High Energy ◽

Risk Level ◽

Energy Yield ◽

Maize Production ◽

Early Date ◽

Environment Management ◽

Silage Maize

Grain maize production exceeds the demand for grain maize in China. Methods for harvesting good-quality silage maize urgently need a theoretical basis and reference data in order to ensure its benefits to farmers. However, research on silage maize is limited, and very few studies have focused on its energetic value and quality. Here, we calibrated the CERES-Maize model for 24 cultivars with 93 field experiments and then performed a long-term (1980-2017) simulation to optimize genotype-environment-management (G-E-M) interactions in the 4 main agroecological zones across China. We found that CERES-Maize could reproduce the growth and development of maize well under various management and weather conditions with a phenology bias of <5 d and biomass relative root mean square error values of <5%. The simulated results showed that sowing long-growth-cycle cultivars approximately 10 d in advance could yield good-quality silage. The optimal sowing dates (from late May to July) and harvest dates (from early October to mid-November) gradually became later from north to south. A high-energy yield was expected when sowing at an early date and/or with late-maturing cultivars. We found that Northeast China and the North China Plain were potential silage maize growing areas, although these areas experienced a medium or even high frost risk. Southwestern maize experienced a low risk level, but the low soil fertility limited the attainable yield. The results of this paper provide information for designing an optimal G×E×M strategy to ensure silage maize production in the Chinese Maize Belt.

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Current progress and performance improvement of Pt/C catalysts for fuel cells

Journal of Materials Chemistry A ◽

10.1039/d0ta08312g ◽

2020 ◽

Vol 8 (46) ◽

pp. 24284-24306

Author(s):

Xuefeng Ren ◽

Yiran Wang ◽

Anmin Liu ◽

Zhihong Zhang ◽

Qianyuan Lv ◽

...

Keyword(s):

Fuel Cells ◽

Fuel Cell ◽

Energy Conversion ◽

Performance Improvement ◽

Electric Energy ◽

Energy Conversion Efficiency ◽

High Energy ◽

Carnot Cycle ◽

High Energy Conversion Efficiency ◽

And Performance

Fuel cell is an electrochemical device, which can directly convert the chemical energy of fuel into electric energy, without heat process, not limited by Carnot cycle, high energy conversion efficiency, no noise and pollution.

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Synthesis and Performance of Strained Multicyclic Hydrocarbons as Highly Potential High-Energy-Density Fuels

Industrial & Engineering Chemistry Research ◽

10.1021/acs.iecr.1c00734 ◽

2021 ◽

Author(s):

Chi Ma ◽

Chengxiang Shi ◽

Yakun Liu ◽

Lun Pan ◽

Xiangwen Zhang ◽

...

Keyword(s):

Energy Density ◽

High Energy ◽

High Energy Density ◽

And Performance

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Are Suprapectineal Quadrilateral Surface Buttressing Plates Performances Superior to Traditional Fixation? A Finite Element Analysis

Applied Sciences ◽

10.3390/app11020858 ◽

2021 ◽

Vol 11 (2) ◽

pp. 858

Author(s):

Mara Terzini ◽

Andrea Di Pietro ◽

Alessandro Aprato ◽

Stefano Artiaco ◽

Alessandro Massè ◽

...

Keyword(s):

Finite Element ◽

Movement Analysis ◽

High Energy ◽

Clinical Analysis ◽

Acetabular Fractures ◽

Element Analysis ◽

Bone Stress ◽

Interfragmentary Movement ◽

Element Approach ◽

Transverse Fractures

Acetabular fractures have a high impact on patient’s quality of life, and because acetabular fractures are high energy injuries, they often co-occur with other pathologies such as damage to cartilage that could increase related morbidity; thus, it appears of primary importance developing reliable treatments for this disease. This work aims at the evaluation of the biomechanical performances of non-conservative treatments of acetabular fractures through a finite element approach. Two pelvic plates models (the standard suprapectineal plate—SPP, and a suprapectineal quadrilateral surface buttressing plate—SQBP) were analyzed when implanted on transverse or T-shaped fractures. The plates geometries were adapted to the specific hemipelvis, mimicking the bending action that the surgeon performs on the plate intraoperatively. Implemented models were tested in a single leg stance condition. The obtained results show that using the SQBP plate in transverse and T-shaped acetabular fractures generates lower bone stress if compared to the SPP plate. Interfragmentary movement analysis shows that the SQBP plate guarantees greater stability in transverse fractures. In conclusion, the SQBP plate seems worthy of further clinical analysis, having resulted as a promising option in the treatment of transverse and T-shaped acetabular fractures, able to reduce bone stress values and to get performances comparable, and in some cases superior, to traditional fixation.

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Ship Handling in Unprotected Waters: A Review of New Technologies in Escort Tugs to Improve Safety

Applied Mechanics ◽

10.3390/applmech2010004 ◽

2021 ◽

Vol 2 (1) ◽

pp. 46-62

Author(s):

Santiago Iglesias-Baniela ◽

Juan Vinagre-Ríos ◽

José M. Pérez-Canosa

Keyword(s):

High Performance ◽

New Technologies ◽

Weather Conditions ◽

Hull Form ◽

Best Available Technologies ◽

Adverse Weather Conditions ◽

Adverse Weather ◽

New Type ◽

Technological Challenge ◽

And Performance

It is a well-known fact that the 1989 Exxon Valdez disaster caused the escort towing of laden tankers in many coastal areas of the world to become compulsory. In order to implement a new type of escort towing, specially designed to be employed in very adverse weather conditions, considerable changes in the hull form of escort tugs had to be made to improve their stability and performance. Since traditional winch and ropes technologies were only effective in calm waters, tugs had to be fitted with new devices. These improvements allowed the remodeled tugs to counterbalance the strong forces generated by the maneuvers in open waters. The aim of this paper is to perform a comprehensive literature review of the new high-performance automatic dynamic winches. Furthermore, a thorough analysis of the best available technologies regarding towline, essential to properly exploit the new winches, will be carried out. Through this review, the way in which the escort towing industry has faced this technological challenge is shown.

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Energy Intakes of Ultraendurance Cyclists During Competition, an Observational Study

International Journal of Sport Nutrition and Exercise Metabolism ◽

10.1123/ijsnem.22.1.19 ◽

2012 ◽

Vol 22 (1) ◽

pp. 19-23 ◽

Cited By ~ 17

Author(s):

Katherine E. Black ◽

Paula M.L. Skidmore ◽

Rachel C. Brown

Keyword(s):

Observational Study ◽

Energy Intake ◽

Energy Requirement ◽

Negative Relationship ◽

Computer Software ◽

High Energy ◽

Energy Deficit ◽

Food Diary ◽

Food And Drink ◽

And Performance

Endurance events >10 hr are becoming increasingly popular but provide numerous physiological challenges, several of which can be attenuated with optimal nutritional intakes. Previous studies in ultraendurance races have reported large energy deficits during events. The authors therefore aimed to assess nutritional intakes in relation to performance among ultraendurance cyclists. This observational study included 18 cyclists in a 384-km cycle race. At race registration each cyclist’s support crew was provided with a food diary for their cyclist. On completion of the race, cyclists were asked to recall their race food and drink intakes. All food and fluids were analyzed using a computer software package. Mean (SD) time to complete the race was 16 hr 21 min (2 hr 2 min). Mean (SD) energy intake was 18.7 (8.6) MJ, compared with an estimated energy requirement for the race of 25.5 (7.4) MJ. There was a significant negative relationship between energy intake and time taken to complete the race (p = .023, r2 = −.283). Mean (SD) carbohydrate, fat, and protein intakes were 52 (27), 15.84 (56.43), and 2.94 (7.25) g/hr, respectively. Only carbohydrate (p = .015, r2 = −.563) and fat intake (p = .037, r2 = −.494) were associated with time taken to complete the race. This study demonstrates the difficulties in meeting the high energy demands of ultraendurance cycling. The relationship between energy intake and performance suggests that reducing the energy deficit may be advantageous. Given the high carbohydrate intakes of these athletes, increasing energy intake from fat should be investigated as a means of decreasing energy deficits.

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