scholarly journals An Overview on Bonded Marine Hoses for Sustainable Fluid Transfer and (Un)Loading Operations via Floating Offshore Structures (FOS)

2021 ◽  
Vol 9 (11) ◽  
pp. 1236
Author(s):  
Chiemela Victor Amaechi ◽  
Cole Chesterton ◽  
Harrison Obed Butler ◽  
Facheng Wang ◽  
Jianqiao Ye
Keyword(s):  
Single Point ◽  
Offshore Structures ◽  
Test Methods ◽  
Test Models ◽  
Industry Standards ◽  
Pros And Cons ◽  
The Subject ◽  
Loading And Unloading ◽  
Fluid Transfer ◽  
Novel Design

Due to the demand for oil production in varying water depth regions, the advantage of flexible buoyant conduits has led to an increase in bonded marine hoses for fluid transfer and (un)loading operations. The fluid transfer system for bonded marine hoses is dependent on floating offshore structures (FOS). This paper presents an overview of different systems for sustainable fluid transfer and (un)loading operations via FOS, such as Single Point Mooring (SPM) systems. SPMs are component aspects of the techno-economic design and FOS operation. This review aims to present sustainable fluid transfer technologies while addressing the subject of bonded marine hoses based on application, configuration, test models, hose selection criteria, hose-mooring configurations and operational views. This paper also includes an overview of the hose dynamics, with the loading and unloading (or discharging) techniques for sustainable fluid transfer via marine bonded hoses, based on operational challenges encountered. To dynamically present the hose performance in this review, an overview of the test methods’ guidance as specified in available industry standards was conducted. The pros and cons of marine hose application were also presented. Finally, this study presents different marine hose types and novel design configurations applied in implementing hose-mooring systems. Some concluding remarks with recommended solutions on the technology were presented in this review.

Flow Field on Helodeck of a Frigate: A Review

2019 ◽  
Vol 161 (A4) ◽  
Keyword(s):  
Flow Field ◽  
Numerical Solutions ◽  
Offshore Structures ◽  
High Speeds ◽  
High Turbulence ◽  
The Subject ◽  
Offshore Industry ◽  
The Military ◽  
Very High ◽  
Made In

The various functions desired from a frontline warship such as a frigate, corvette or a destroyer, coupled with the requirement of very high speeds and economic viability restricting the size, necessitates a very dense arrangement of weapons and sensors on the top deck and superstructure. Accordingly, Navies across the world have faced several problems with respect to functions for which a good aerodynamic design for these structures is essential. Major issues include smoke nuisance created due to impinging of the ship's exhaust gases on to the top deck leading to possible suction by engine intakes and high turbulence in the ship's air-wake leading to ship aircraft interface concerns. The flow field on the helodeck is extremely complex due to its geometry and interaction with the wake of the ship’s superstructure. A knowledge of this complexity is essential for ensuring safe helo operations on the helodeck. The problem of ship helicopter interaction has hogged the lime light in recent times, due to rising demand for design of warships for increased stealth, especially in the past two decades. Consequently, several researchers in countries with advanced Navies have invested considerable resources towards evolving both experimental and numerical solutions for the problem. However, given the military nature of the operations, open literature on the subject containing details of such research, which can be used as reference material for present work, are limited. Considering the complexities involved in the problem, an attempt has been made in this paper to holistically review the widely scattered and limited literature in this field. A good amount of literature on marine helo applications emerge from the offshore industry. Keeping in mind that the fields of warship design and offshore structures are dissimilar and have their peculiar problems, informed conclusions have been made in drawing lessons from available literature.

Cumulative Damage Mechanics: Characterization, Modeling, and Interpretation of Progressive Failure in Ceramics and Composites

2004 ◽  
Author(s):  
Michael G. Jenkins ◽  
Paul E. Labossie`re ◽  
Jonathan A. Salem
Keyword(s):  
Damage Mechanics ◽  
Progressive Failure ◽  
Ceramic Matrix Composites ◽  
Test Methods ◽  
Cumulative Damage ◽  
Material Behavior ◽  
Matrix Composites ◽  
Damage Models ◽  
Novel Design ◽  
Nonlinear Energy

Ceramic matrix composites (CMCs) have evolved to exhibit inherent damage tolerance through nonlinear energy absorption mechanisms while retaining the desirable attributes of their monolithic structural ceramic counterparts. Mathematical (analytic and numeric) models together with experimental measurements of this damage absorption have aided in understanding the thermomechanical behavior of CMCs. This understanding has led to improved test methods, better predictive modeling of material behavior, appropriate processing methods, and finally novel design methodologies for implementing CMCs. In this paper, background on CMC damage is presented, damage measurement and damage models are discussed and finally probabilistic aspects of constituent materials that can be used to illustrate the cumulative damage behavior of CMCs are described.

scholarly journals Hybrid Finite Element Method Development for Offshore Structures’ Calculation with the Implementation of Industry Standards

2019 ◽  
Vol 26 (4) ◽  
pp. 90-100
Author(s):  
Jacek Łubiński ◽  
Henryk Olszewski
Keyword(s):  
Finite Element ◽  
Method Development ◽  
Structural Model ◽  
Model Development ◽  
Steel Structures ◽  
Cost Effective ◽  
Offshore Structures ◽  
Wind Loading ◽  
Hybrid Finite Element Method ◽  
Industry Standards

Abstract In the design process of offshore steel structures, it is typical to employ commercial calculation codes in which simulation and evaluation of results are performed on the basis of the available standards (e.g. API, DNV, Lloyds). The modeling and solution rely on finite element methods and cover the simulation of the structure’s properties along with the influence of the marine environment – sea currents, wave and wind loading, as well as the influence of vibrations, buoyancy and accompanying mass of water. Both commercial and open source mathematical modeling software which is available nowadays allows for cost effective and flexible implementation of advanced models for offshore industrial structures with high level of credibility and safety. The models can be built to suit task-specific requirements and evaluated on the basis of the selected criterial system best suited to the needs of the customer. Examples of methodology for environmental and structural model development are presented, along with simulation results covering a wide scope of data, ranging from stress and deformation to resonant characteristics and issues of technological feasibility.

scholarly journals The pros and cons of working from home

2020 ◽  
Vol 8 (12) ◽  
pp. 133-145
Author(s):  
Vinicius Mitchell ◽  
Luiza Novaes
Keyword(s):  
Multidisciplinary Teams ◽  
Original Research ◽  
Professional Collaboration ◽  
Remote Work ◽  
Main Research ◽  
Face To Face ◽  
Open Questions ◽  
Pros And Cons ◽  
The Subject ◽  
Fitting In

In July 2020, a group of illustrators were contacted so we could hear if their views on remote work and professional collaboration had changed, in light of the covid-19 pandemic scenario. These illustrators participated in a previous research conducted with Brazilian newspaper illustrators between 2016-2018. The main research objective was to understand how illustrators were fitting in newspaper's routines and production, considering the multiplatform publishing trend led by the rise in mobile and digital readership. As it was observed then, illustrators were already used to working remotely. The investigation focused in assessing how these professionals viewed the pros and cons of face-to-face working way compared to working remotely. Also their views on the interaction with other fields’ professionals, in projects involving Illustration & Design were considered. Illustrators of Brazilian newspapers answered a query and an interview with open questions. Although the original research had not been motivated by a pandemic scene, we believe that by renewing the subject with new data collected in 2020, the study can contribute to the ongoing broader discussions over reorganizing workflows for remote work, especially those involving designers and projects with multidisciplinary teams. This paper aims at presenting and discussing qualitative data regarding these issues.

scholarly journals Pragmatisme Kepemimpinan Debora bagi Kepemimpinan Wanita Kristen di Masa Kini

2020 ◽  
Vol 4 (2) ◽  
pp. 94-107
Author(s):  
Elkana Chrisna Wijaya
Keyword(s):  
Qualitative Methodology ◽  
Women's Leadership ◽  
Research Subjects ◽  
Contemporary Issue ◽  
The World ◽  
Pros And Cons ◽  
The Subject ◽  
Biblical Texts ◽  
Conducting Research ◽  
Growing Conditions

Deborah's Leadership Pragmatism for Today's Christian Women's Leadership. The discussion on women's leadership is a contemporary issue that always brings polemic almost in various fields. The pros and cons of this matter from the beginning until the present remain a hot issue, while the freedom and involvement of women in the world of leadership, both in the spiritual and non-spiritual realms, is increasingly widespread and growing. Conditions and situations, of course, need to get a solution in the form of the contribution of thought, both theological and pragmatic. Conducting research on the subject, using a qualitative methodology, so that not only refers to the biblical texts that are directly related, but also refers to other texts relating to the research subjects, as well as using literature that is closely related to leadership. Thus, it is hoped that the results of this study will enlighten various parties and can be accounted for. Abstrak: Pragmatisme Kepemimpinan Debora bagi Kepemimpinan Wanita Kristen di Masa Kini. Pembahasan mengenai kepemimpinan wanita merupakan isu kontemporer yang senantiasa mendatangkan polemik hampir di berbagai bidang. Pro dan kontra mengenai hal tersebut dari dulu hingga kekinian tetap menjadi isu hangat, sementara kebebasan dan keterlibatan kaum wanita dalam dunia kepemimpinan, baik itu di dunia keagamaan maupun sekular semakin luas dan terus berkembang. Kondisi itu, tentunya perlu mendapatkan solusi dalam bentuk sebut penelitian teologis yang dapat menjadi acuan dalam menyelesaikan masalah tersebut. Pelaksanaan penelitian terhadap subyek tersebut, menggunakan metodologi penelitian kualitatif, sehingga tidak hanya mengacu pada teks Alkitab yang berkaitan langsung, namun juga mengacu pada teks-teks lainnya yang berkaitan dengan subyek penelitian, di samping juga menggunakan literatur-literatur yang berkaitan erat dengan kepemimpinan. Dengan demikian, diharapkan hasil penelitian ini berupa sebuah penelitian Alkitabiah yang dapat memberikan pemecahan masalah dan dapat diaplikasikan dalam kepemimpinan wanita Kristen di masa kini.

Model-Based Testing of Embedded Systems Exemplified for the Automotive Domain

2010 ◽  
pp. 377-413 ◽  
Author(s):  
Justyna Zander ◽  
Ina Schieferdecker
Keyword(s):  
Embedded Systems ◽  
Embedded System ◽  
Reference Signal ◽  
Test Methods ◽  
Domain Model ◽  
Test Method ◽  
Model Based ◽  
Test Models ◽  
Black Box Testing ◽  
Weak Points

The purpose of this chapter is to introduce the test methods applied for embedded systems addressing selected problems in the automotive domain. Model-based test approaches are reviewed and categorized. Weak points are identified and a novel test method is proposed. It is called model-in-the-loop for embedded system test (MiLEST) and is realized in MATLAB®/Simulink®/Stateflow® environment. Its main contribution refers to functional black-box testing based on the system and test models. It is contrasted with the test methods currently applied in the industry that form dedicated solutions, usually specialized in a concrete testing context. The developed signal-feature-oriented paradigm developed herewith allows the abstract description of signals and their properties. It addresses the problem of missing reference signal flows and allows for a systematic and automatic test data selection. Processing of both discrete and continuous signals is possible, so that the hybrid behavior of embedded systems can be handled.

Combining Data-Driven and User-Driven Evaluation Measures to Identify Interesting Rules

2009 ◽  
pp. 38-55 ◽  
Author(s):  
Solange Oliveira Rezende ◽  
Edson Augusto Melanda ◽  
Magaly Lika Fujimoto ◽  
Roberta Akemi Sinoara ◽  
Veronica Oliveira de Carvalho
Keyword(s):  
Data Mining ◽  
Data Driven ◽  
Objective Measures ◽  
Post Processing ◽  
Rule Mining ◽  
Evaluation Measures ◽  
Combining Data ◽  
Pros And Cons ◽  
The Subject

Association rule mining is a data mining task that is applied in several real problems. However, due to the huge number of association rules that can be generated, the knowledge post-processing phase becomes very complex and challenging. There are several evaluation measures that can be used in this phase to assist users in finding interesting rules. These measures, which can be divided into data-driven (or objective measures) and user-driven (or subjective measures), are first discussed and then analyzed for their pros and cons. A new methodology that combines them, aiming to use the advantages of each kind of measure and to make user’s participation easier, is presented. In this way, data-driven measures can be used to select some potentially interesting rules for the user’s evaluation. These rules and the knowledge obtained during the evaluation can be used to calculate user-driven measures, which are used to aid the user in identifying interesting rules. In order to identify interesting rules that use our methodology, an approach is described, as well as an exploratory environment and a case study to show that the proposed methodology is feasible. Interesting results were obtained. In the end of the chapter tendencies related to the subject are discussed.

scholarly journals An Overview of Lidar Imaging Systems for Autonomous Vehicles

2019 ◽  
Vol 9 (19) ◽  
pp. 4093 ◽  
Author(s):  
Santiago Royo ◽  
Maria Ballesta-Garcia
Keyword(s):  
Autonomous Vehicles ◽  
State Of The Art ◽  
Autonomous Vehicle ◽  
Single Point ◽  
Imaging Systems ◽  
Light Sources ◽  
Final Solution ◽  
Large Uncertainty ◽  
Current State ◽  
The Subject

Lidar imaging systems are one of the hottest topics in the optronics industry. The need to sense the surroundings of every autonomous vehicle has pushed forward a race dedicated to deciding the final solution to be implemented. However, the diversity of state-of-the-art approaches to the solution brings a large uncertainty on the decision of the dominant final solution. Furthermore, the performance data of each approach often arise from different manufacturers and developers, which usually have some interest in the dispute. Within this paper, we intend to overcome the situation by providing an introductory, neutral overview of the technology linked to lidar imaging systems for autonomous vehicles, and its current state of development. We start with the main single-point measurement principles utilized, which then are combined with different imaging strategies, also described in the paper. An overview of the features of the light sources and photodetectors specific to lidar imaging systems most frequently used in practice is also presented. Finally, a brief section on pending issues for lidar development in autonomous vehicles has been included, in order to present some of the problems which still need to be solved before implementation may be considered as final. The reader is provided with a detailed bibliography containing both relevant books and state-of-the-art papers for further progress in the subject.

scholarly journals Biodegradability standards for carrier bags and plastic films in aquatic environments: a critical review

2018 ◽  
Vol 5 (5) ◽  
pp. 171792 ◽  
Author(s):  
Jesse P. Harrison ◽  
Carl Boardman ◽  
Kenneth O'Callaghan ◽  
Anne-Marie Delort ◽  
Jim Song
Keyword(s):  
Degradation Products ◽  
Toxicity Testing ◽  
Test Methods ◽  
Ecological Impacts ◽  
Aquatic Environments ◽  
Natural Ecosystems ◽  
Marine Habitats ◽  
Industry Standards ◽  
Plastic Bag ◽  
Chemical Conditions

Plastic litter is encountered in aquatic ecosystems across the globe, including polar environments and the deep sea. To mitigate the adverse societal and ecological impacts of this waste, there has been debate on whether ‘biodegradable' materials should be granted exemptions from plastic bag bans and levies. However, great care must be exercised when attempting to define this term, due to the broad and complex range of physical and chemical conditions encountered within natural ecosystems. Here, we review existing international industry standards and regional test methods for evaluating the biodegradability of plastics within aquatic environments (wastewater, unmanaged freshwater and marine habitats). We argue that current standards and test methods are insufficient in their ability to realistically predict the biodegradability of carrier bags in these environments, due to several shortcomings in experimental procedures and a paucity of information in the scientific literature. Moreover, existing biodegradability standards and test methods for aquatic environments do not involve toxicity testing or account for the potentially adverse ecological impacts of carrier bags, plastic additives, polymer degradation products or small (microscopic) plastic particles that can arise via fragmentation. Successfully addressing these knowledge gaps is a key requirement for developing new biodegradability standard(s) for lightweight carrier bags.

Experimental, Numerical and Analytical Evaluation of a Helical-Turbine Performance

2019 ◽  
Author(s):  
Donghyuk Kang ◽  
Hiromasa Tsutsumi ◽  
Hiroyuki Hirahara
Keyword(s):  
The Other ◽  
Speed Ratio ◽  
Analytical Evaluation ◽  
Tip Speed Ratio ◽  
Momentum Theory ◽  
Turbine Performance ◽  
The Subject ◽  
Design Protocol ◽  
Novel Design ◽  
Blade Element

Abstract A helical wind turbine has been analyzed experimentally and numerically and a novel design protocol has been proposed by means of blade element and momentum theory. The subject of the present analysis is to discuss the effect of low tip speed ratio and high one, respectively. In the low tip speed ratio, the turbine is driven by the torque generated from the flow turning radially after colliding with the runner. On the other hand, in the high tip speed ratio, the turbine is operated by the torque generated from the flow passing through axially the turbine.

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