Lifting Operations for Subsea Installations Using Small Construction Vessels and Active Heave Compensation Systems: A Simulation Approach

Author(s):  
Karl H. Halse ◽  
Vilmar Æsøy ◽  
Dmitriy Ponkratov ◽  
Yingguang Chu ◽  
Jiafeng Xu ◽  
...  

Sub-sea installation operations require a high level of accuracy and control in order to avoid misalignment and possible collisions between modules on the sea bed. To reduce costs, smaller and lighter construction vessels are now performing these operations. The most critical parts of the operation are lift-off from the deck, passing through the splash zone, and landing sensitive equipment on the sea bed. The hazards are: high dynamic loads, resonance effects, and slack line snap. Therefore, in this study, modeling and simulation are applied to optimize design parameters and develop operational procedures for each operation to reduce risk of failure. Further, the same models can be used in operator simulator training. Modeling and simulation of interactive multi body systems is a rather complex task, involving the vessel as a moving platform, lifting equipment such as cranes and winches, guiding devices, lifting cables and payload behavior in air, all while partly to fully submerged. It is a multi-physics problem involving hydrodynamics, mechanics, hydraulics, electronics, and control systems. This paper describes an approach to link the different models to simulate the operations including interactions between the sub-systems. The paper focuses on the modeling approach used to connect the various dynamic systems into the complete operating system. The work is in its initial phase, and some of the sub-systems models are not complete. The models are described in this paper and will be included in future work. Some initial operational examples are included, to show how the models work together.

2004 ◽  
Vol 50 (4) ◽  
pp. 225-232 ◽  
Author(s):  
S. Bouzalakos ◽  
B. Jefferson ◽  
P.J. Longhurst ◽  
R.M. Stuetz

An economical and practical alternative to the standard end-of-pipe odour control methods is the application of liquid odour control products. Currently, there are no established product-testing methods. The data that are available are often of questionable quality and may have limited relevance to waste management. Waste facilities receive differing streams of waste at varying loading volumes. Whilst in operation this exposes control products to a wide variety of environmental conditions, further increasing the difficulty of selecting an effective means of control. The current study initially identifies commercially available odour control products applicable for solid and liquid waste management operations. Bench-scale batch absorption tests have been carried out to investigate odorous gas abatement for a range of selected commercial products and water at a range of pH values. Hydrogen sulphide was the test odorous gas, as it is commonly associated with waste processes. Gas-phase volumetric mass-transfer coefficients (KGa) have been calculated to determine mass-transfer performance. The development of a pilot-scale spray tower is then presented as the testing apparatus for future work. This is an attempt to construct a repeatable testing method for evaluating abatement performance of odour control products, and control the problems encountered when applying odour control products to open sites. KGa values and data collected from tests in this study will be considered in future work as design parameters for the rig.


Author(s):  
Roger Magnusson

Non-communicable diseases (NCDs), including cardiovascular disease, cancer, chronic respiratory diseases, and diabetes, are responsible for around 70 percent of global deaths each year. This chapter describes how NCDs have become prevalent and critically evaluates global efforts to address NCDs and their risk factors, with a particular focus on the World Health Organization (WHO) and United Nations (UN) system. It explores the factors that have prevented those addressing NCDs from achieving access to resources and a priority commensurate with their impact on people’s lives. The chapter evaluates the global response to NCDs both prior to and since the UN High-Level Meeting on Prevention and Control of Non-communicable Diseases, held in 2011, and considers opportunities for strengthening that response in future.


Author(s):  
Laura Vieten ◽  
Anne Marit Wöhrmann ◽  
Alexandra Michel

Abstract Objective Due to recent trends such as globalization and digitalization, more and more employees tend to have flexible working time arrangements, including boundaryless working hours. The aim of this study was to investigate the relationships of various aspects of boundaryless working hours (overtime, Sunday work, and extended work availability) with employees’ state of recovery. Besides, we examined the mediating and moderating role of recovery experiences (psychological detachment, relaxation, mastery, and control) in these relationships. Methods We used data from 8586 employees (48% women; average age of 48 years) who took part in the 2017 BAuA-Working Time Survey, a representative study of the German working population. Regression analyses were conducted to test main effects as well as mediation and moderation. Results Overtime work, Sunday work, and extended work availability were negatively related to state of recovery. Psychological detachment mediated these relationships. Furthermore, we found that relaxation and control mediated the association between extended work availability and state of recovery. However, no relevant moderating effects were found. Conclusions Altogether, our findings indicate that various aspects of boundaryless working hours pose a risk to employees’ state of recovery and that especially psychological detachment is a potential mechanism in these relationships. In addition, the results suggest that a high level of recovery experiences cannot attenuate these negative relationships in leisure time. Therefore, employers and employees alike should try to avoid or minimize boundaryless working hours.


Author(s):  
Kiona Hagen Niehaus ◽  
Rebecca Fiebrink

This paper describes the process of developing a software tool for digital artistic exploration of 3D human figures. Previously available software for modeling mesh-based 3D human figures restricts user output based on normative assumptions about the form that a body might take, particularly in terms of gender, race, and disability status, which are reinforced by ubiquitous use of range-limited sliders mapped to singular high-level design parameters. CreatorCustom, the software prototype created during this research, is designed to foreground an exploratory approach to modeling 3D human bodies, treating the digital body as a sculptural landscape rather than a presupposed form for rote technical representation. Building on prior research into serendipity in Human-Computer Interaction and 3D modeling systems for users at various levels of proficiency, among other areas, this research comprises two qualitative studies and investigation of the impact on the first author's artistic practice. Study 1 uses interviews and practice sessions to explore the practices of six queer artists working with the body and the language, materials, and actions they use in their practice; these then informed the design of the software tool. Study 2 investigates the usability, creativity support, and bodily implications of the software when used by thirteen artists in a workshop. These studies reveal the importance of exploration and unexpectedness in artistic practice, and a desire for experimental digital approaches to the human form.


Author(s):  
Ya-Fang Hu ◽  
Li-Ping Jia ◽  
Fang-Yuan Yu ◽  
Li-Ying Liu ◽  
Qin-Wei Song ◽  
...  

Abstract Background Coxsackievirus A16 (CVA16) is one of the major etiological agents of hand, foot and mouth disease (HFMD). This study aimed to investigate the molecular epidemiology and evolutionary characteristics of CVA16. Methods Throat swabs were collected from children with HFMD and suspected HFMD during 2010–2019. Enteroviruses (EVs) were detected and typed by real-time reverse transcription-polymerase chain reaction (RT-PCR) and RT-PCR. The genotype, evolutionary rate, the most recent common ancestor, population dynamics and selection pressure of CVA16 were analyzed based on viral protein gene (VP1) by bioinformatics software. Results A total of 4709 throat swabs were screened. EVs were detected in 3180 samples and 814 were CVA16 positive. More than 81% of CVA16-positive children were under 5 years old. The prevalence of CVA16 showed obvious periodic fluctuations with a high level during 2010–2012 followed by an apparent decline during 2013–2017. However, the activities of CVA16 increased gradually during 2018–2019. All the Beijing CVA16 strains belonged to sub-genotype B1, and B1b was the dominant strain. One B1c strain was detected in Beijing for the first time in 2016. The estimated mean evolutionary rate of VP1 gene was 4.49 × 10–3 substitution/site/year. Methionine gradually fixed at site-23 of VP1 since 2012. Two sites were detected under episodic positive selection, one of which (site-223) located in neutralizing linear epitope PEP71. Conclusions The dominant strains of CVA16 belonged to clade B1b and evolved in a fast evolutionary rate during 2010–2019 in Beijing. To provide more favorable data for HFMD prevention and control, it is necessary to keep attention on molecular epidemiological and evolutionary characteristics of CVA16.


Author(s):  
Umar Ibrahim Minhas ◽  
Roger Woods ◽  
Georgios Karakonstantis

AbstractWhilst FPGAs have been used in cloud ecosystems, it is still extremely challenging to achieve high compute density when mapping heterogeneous multi-tasks on shared resources at runtime. This work addresses this by treating the FPGA resource as a service and employing multi-task processing at the high level, design space exploration and static off-line partitioning in order to allow more efficient mapping of heterogeneous tasks onto the FPGA. In addition, a new, comprehensive runtime functional simulator is used to evaluate the effect of various spatial and temporal constraints on both the existing and new approaches when varying system design parameters. A comprehensive suite of real high performance computing tasks was implemented on a Nallatech 385 FPGA card and show that our approach can provide on average 2.9 × and 2.3 × higher system throughput for compute and mixed intensity tasks, while 0.2 × lower for memory intensive tasks due to external memory access latency and bandwidth limitations. The work has been extended by introducing a novel scheduling scheme to enhance temporal utilization of resources when using the proposed approach. Additional results for large queues of mixed intensity tasks (compute and memory) show that the proposed partitioning and scheduling approach can provide higher than 3 × system speedup over previous schemes.


2021 ◽  
Vol 9 (5) ◽  
pp. 1050
Author(s):  
Jing Zhu ◽  
Xiang Sun ◽  
Zhi-Dong Zhang ◽  
Qi-Yong Tang ◽  
Mei-Ying Gu ◽  
...  

Endophytic bacteria and fungi colonize plants that grow in various types of terrestrial and aquatic ecosystems. Our study investigates the communities of endophytic bacteria and fungi of halophyte Kalidium schrenkianum growing in stressed habitats with ionizing radiation. The geochemical factors and radiation (at low, medium, high level and control) both affected the structure of endophytic communities. The bacterial class Actinobacteria and the fungal class Dothideomycetes predominated the endophytic communities of K. schrenkianum. Aerial tissues of K. schrenkianum had higher fungal diversity, while roots had higher bacterial diversity. Radiation had no significant effect on the abundance of bacterial classes. Soil pH, total nitrogen, and organic matter showed significant effects on the diversity of root endophytes. Radiation affected bacterial and fungal community structure in roots but not in aerial tissues, and had a strong effect on fungal co-occurrence networks. Overall, the genetic diversity of both endophytic bacteria and fungi was higher in radioactive environments, however negative correlations were found between endophytic bacteria and fungi in the plant. The genetic diversity of both endophytic bacteria and fungi was higher in radioactive environments. Our findings suggest that radiation affects root endophytes, and that the endophytes associated with aerial tissues and roots of K. schrenkianum follow different mechanisms for community assembly and different paradigms in stress response.


2021 ◽  
Vol 13 (9) ◽  
pp. 4829
Author(s):  
Ahmed Hosny Saleh Metwally ◽  
Maiga Chang ◽  
Yining Wang ◽  
Ahmed Mohamed Fahmy Yousef

There is a growing body of literature that recognizes the importance of applying gamification in educational settings. This research developed an application to gamify students’ homework to address the concern of the students’ inability to complete their homework. This research aims to investigate students’ performance in doing their homework, and reflections and perceptions of the gameful experience in gamified homework exercises. Based on the data gathered from experimental and control groups (N = 84) via learning analytics, survey, and interview, the results show a high level of satisfaction according to students’ feedback. The most noticeable finding to extract from the analysis is that students can take on a persona, earn points, and experience a deeper sense of achievement through doing the gamified homework. Moreover, the students, on the whole, are likely to be intrinsically motivated whenever the homework is attributed to factors under their own control, when they consider that they have the expertise to be successful learners to achieve their desired objectives, and when they are interested in dealing with the homework for learning, not just achieving high grades.


2012 ◽  
Vol 48 (Special Issue) ◽  
pp. S43-S48 ◽  
Author(s):  
J. Polák ◽  
J. Kumar ◽  
B. Krška ◽  
M. Ravelonandro

Commercialisation of Biotech/GM (Biotech) crops started in 1995. Not only field crops, but also horticultural transgenic crops are under development and are beginning to be commercialised. Genetic engineering has the potential to revolutionise fruit tree breeding. The development of transgenic fruit cultivars is in progress. Over the past 20 years an international public sector research team has collaborated in the development of HoneySweet plum which is highly resistant to Plum pox virus (PPV) the most devastating disease of plums and other stone fruits. HoneySweet was deregulated in the USA in 2010. HoneySweet (aka C5) has been evaluated for eleven years (2002–2012) in a regulated field trial in the CzechRepublic for the resistance to PPV, Prune dwarf virus (PDV), and Apple chlorotic leaf spot virus (ACLSV), all of them being serious diseases of plum. Even under the high and permanent infection pressure produced through grafting, PPV has only been detected in HoneySweet trees in several leaves and fruits situated close to the point of inoculum grafting. The lack of infection spread in HoneySweet demonstrates its high level of PPV resistance. Co-infections of PPV with PDV and/or ACLSV had practically no influence on the quantity and quality of HoneySweet fruit which are large, sweet, and of a high eating quality. In many respects, they are superior to the fruits of the well-known cultivar Stanley. Many fruit growers and fruit tree nurseries in the CzechRepublic are supportive of the deregulation of HoneySweet plum to help improve the plum production and control the spread of PPV.


2017 ◽  
Vol 24 (14) ◽  
pp. 3206-3218
Author(s):  
Yohei Kushida ◽  
Hiroaki Umehara ◽  
Susumu Hara ◽  
Keisuke Yamada

Momentum exchange impact dampers (MEIDs) were proposed to control the shock responses of mechanical structures. They were applied to reduce floor shock vibrations and control lunar/planetary exploration spacecraft landings. MEIDs are required to control an object’s velocity and displacement, especially for applications involving spacecraft landing. Previous studies verified numerous MEID performances through various types of simulations and experiments. However, previous studies discussing the optimal design methodology for MEIDs are limited. This study explicitly derived the optimal design parameters of MEIDs, which control the controlled object’s displacement and velocity to zero in one-dimensional motion. In addition, the study derived sub-optimal design parameters to control the controlled object’s velocity within a reasonable approximation to derive a practical design methodology for MEIDs. The derived sub-optimal design methodology could also be applied to MEIDs in two-dimensional motion. Furthermore, simulations conducted in the study verified the performances of MEIDs with optimal/sub-optimal design parameters.


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