Clashing of Risers and Umbilicals With Tension Leg Platform Tendons

2007 ◽  
Author(s):  
Ghiath Mansour
Keyword(s):  
Drag Coefficient ◽  
Light Weight ◽  
Tension Leg Platform ◽  
Mooring Lines ◽  
Design Issue ◽  
Course Of Action ◽  
The Difference

Clashing of risers and umbilicals with other risers, umbilicals, mooring lines, tendons, the hull, or other objects is a major design issue. Preventing clashing is the preferred course of action; however, clashing between catenary risers or catenary umbilicals and tension leg platform (TLP) tendons is typically more challenging to prevent due to the difference in configuration/stiffness and the light weight in the case of umbilicals. In this article, the effect of parameters such as the hang-off angle, hang-off location, azimuth heading, Drag coefficient and weight on the clashing between TLP tendons and umbilicals is considered. Alternatives to preventing such clashing are also discussed.

scholarly journals Sacrificing Oneself or Another: The Difference Between Prescriptive and Normative Judgments in Moral Evaluation

2020 ◽  
pp. 003329411989606
Author(s):  
Štěpán Bahník ◽  
Emir Efendic ◽  
Marek A. Vranka
Keyword(s):  
Moral Judgment ◽  
Moral Evaluation ◽  
Normative Judgment ◽  
Question Wording ◽  
Judgment Type ◽  
Course Of Action ◽  
The Difference ◽  
The Right ◽  
The Sacrifice ◽  
Normative Judgments

When asked whether to sacrifice oneself or another person to save others, one might think that people would consider sacrificing themselves rather than someone else as the right and appropriate course of action—thus showing an other-serving bias. So far however, most studies found instances of a self-serving bias—people say they would rather sacrifice others. In three experiments using trolley-like dilemmas, we tested whether an other-serving bias might appear as a function of judgment type. That is, participants were asked to make a prescriptive judgment (whether the described action should or should not be done) or a normative judgment (whether the action is right or wrong). We found that participants exhibited an other-serving bias only when asked whether self- or other-sacrifice is wrong. That is, when the judgment was normative and in a negative frame (in contrast to the positive frame asking whether the sacrifice is right). Otherwise, participants tended to exhibit a self-serving bias; that is, they approved sacrificing others more. The results underscore the importance of question wording and suggest that some effects on moral judgment might depend on the type of judgment.

Communiqué Issues in MANET and VANET Protocols With Network Security Disquiet

2020 ◽  
pp. 195-220 ◽  
Author(s):  
Mamata Rath ◽  
Bibudhendu Pati ◽  
Jhum Swain
Keyword(s):  
Ad Hoc Networks ◽  
Mobile Ad Hoc Networks ◽  
Network Topology ◽  
Mobile Networks ◽  
Vehicular Ad Hoc Networks ◽  
Ad Hoc ◽  
Course Of Action ◽  
Mobile Stations ◽  
The Difference ◽  
Hoc Networks

With faster expansion of mobile networks and quicker increment of web clients, more individuals approach worldwide data and communication innovation, because of which the issues of utilizing web as a worldwide stage and empowering the savvy protests and machines to coordinate, discuss, register, and ascertain slowly develops. In mobile ad-hoc networks (MANETs) and vehicular ad-hoc networks (VANET), the mobile stations and vehicles are self-reconfigurable as per the difference in network topology. Joint action between convenient centers is more basic because of the way that they confront significant difficulties, for example, frailty to work securely while protecting its advantages and performing secure guiding among center points. In the presence of vindictive hubs, one of the rule challenges in MANET is to plot ground-breaking security course of action that can shield MANET from different routing assaults.

scholarly journals Power Relations in the Force Field of Academia: A Close Reading of Srividya Natarajan’s No Onions Nor Garlic

SAGE Open ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 215824401983744
Author(s):  
Averi Mukhopadhyay
Keyword(s):  
Power Relations ◽  
Daily Life ◽  
Code Of Conduct ◽  
Close Reading ◽  
Men And Women ◽  
University Campuses ◽  
Second Homes ◽  
Course Of Action ◽  
The Difference ◽  
The One

University campuses serve as second homes for students, teachers, administrators, and parents coming from diverse regions, religions, classes, castes, and different genders. Interaction and camaraderie between the major characters in the academe develop. The bonhomie that exists between the stakeholders of the academe has its own rules, rules that are marked by the interference of power. The one wielding more power by virtue of one’s position, class, caste, or gender tries to dictate the terms of a particular relationship. Relations evolve as power relations, whereby a specific code of conduct regarding speech, behavior, thought, writing, love, and life is laid down for all—from administrators and professors to students and parents. This article studies how in a location as specific as Chennai University as described in Srividya Natarajan’s No Onions Nor Garlic, the ideological prejudices and hierarchical divisions highlighted by the play of power affect the daily life of the academe and chart out the course of action for everyone, from professors, students, high caste, low caste to men and women, involved in power relations. On the basis of that, this article suggests power in general serves not only to suppress the powerless but is productive also, as countering power with power creates a proper kind of resistance that blurs the difference between the agent and the target of power in power relations.

Design and implementation of atmospheric multi-parameter sensor for UAV-based aerosol distribution detection

Sensor Review ◽  
2017 ◽  
Vol 37 (2) ◽  
pp. 196-210 ◽  
Author(s):  
Fangjie Yu ◽  
Yunfei Liu ◽  
Longqing Fan ◽  
Linhua Li ◽  
Yong Han ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Embedded System ◽  
Low Power ◽  
Aerosol Particle ◽  
Particle Concentration ◽  
Pressure Probe ◽  
Light Weight ◽  
Content Type ◽  
The Difference ◽  
Pm2.5 And Pm10

Purpose In this paper, a light-weight, low-power atmospheric multi-parameter sensor (AMPS), which could be mounted on small flying platforms such as a tethered balloon, a quad-rotor unmanned aerial vehicle (UAV), a UAV helicopter, etc., is implemented and integrated to sample vertical distribution of aerosols with integrated parameters of aerosol particle concentration, temperature, relative humidity and atmospheric pressure. Design/methodology/approach The AMPS integrates three kinds of probes in an embedded system. A synchronous method based on GPS is proposed to drive the laser aerosol particle sensor, the temperature and humidity probe and the pressure probe to sample four channels approximately simultaneously. Different kinds of housing are designed to accommodate various flying platforms, and the weight is controlled to adapt the payload of each platform. Findings A series of validation tests show that while the AMPS achieves high precision, its power consumption is less than 1.3 W, which is essential for light flying platforms. The AMPS was mounted on different flying platforms and the difference was evaluated. For three times every five days, vertical profiles of PM2.5 and PM10 concentrations were observed by the AMPS mounted on a quad-rotor UAV, which revealed the significant correlation between the aerosol particle concentration and atmospheric parameters. Originality/value A new light-weight and low-power AMPS for small flying platforms is designed and tested, which provides an effective way to explore the properties of aerosol vertical distribution, and to monitor pollutants flexibly.

scholarly journals Study of Floating Wind Turbine with Modified Tension Leg Platform Placed in Regular Waves

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 703 ◽  
Author(s):  
Juhun Song ◽  
Hee-Chang Lim
Keyword(s):  
Wind Turbine ◽  
Real Data ◽  
Offshore Wind ◽  
Scale Model ◽  
Offshore Wind Turbine ◽  
Wave Loads ◽  
Tension Leg Platform ◽  
Mooring Lines ◽  
Floating Wind Turbine ◽  
Wave Conditions

In this study, the typical ocean environment was simulated with the aim to investigate the dynamic response under various environmental conditions of a Tension Leg Platform (TLP) type floating offshore wind turbine system. By applying Froude scaling, a scale model with a scale of 1:200 was designed and model experiments were carried out in a lab-scale wave flume that generated regular periodic waves by means of a piston-type wave generator while a wave absorber dissipated wave energy on the other side of the channel. The model was designed and manufactured based on the standard prototype of the National Renewable Energy Laboratory (NREL) 5 MW offshore wind turbine. In the first half of the study, the motion and structural responses for operational wave conditions of the North Sea near Scotland were considered to investigate the performance of a traditional TLP floating wind turbine compared with that of a newly designed TLP with added mooring lines. The new mooring lines were attached with the objective of increasing the horizontal stiffness of the system and thereby reducing the dominant motion of the TLP platform (i.e., the surge motion). The results of surge translational motions were obtained both in the frequency domain, using the response amplitude operator (RAO), and in the time domain, using the omega arithmetic method for the relative velocity. The results obtained show that our suggested concept improves the stability of the platform and reduces the overall motion of the system in all degrees-of-freedom. Moreover, the modified design was verified to enable operation in extreme wave conditions based on real data for a 100-year return period of the Northern Sea of California. The loads applied by the waves on the structure were also measured experimentally using modified Morison equation—the formula most frequently used to estimate wave-induced forces on offshore floating structures. The corresponding results obtained show that the wave loads applied on the new design TLP had less amplitude than the initial model and confirmed the significant contribution of the mooring lines in improving the performance of the system.

Sensitivity of Mooring Line Pretension in the Design Cycle for Floating Caissons

2004 ◽  
Author(s):  
Adinarayana Mukkamala ◽  
Partha Chakrabarti ◽  
Subrata K. Chakrabarti
Keyword(s):  
Reinforced Concrete ◽  
System Design ◽  
Mooring Line ◽  
Mooring System ◽  
Mooring Lines ◽  
Design Cycle ◽  
Overall Performance ◽  
The Difference ◽  
Tacoma Narrows Bridge ◽  
System Layout

The new parallel Tacoma Narrows Bridge being constructed by Tacoma Narrows Constructors will be mounted on two towers and these towers in turn will be supported by reinforced concrete caissons referred to as East Caisson (Tacoma side) and West Caisson (Gig Harbor side). Each Caisson is towed to the location and several stages of construction will take place at the actual site. During construction, the floating caissons will be moored in place to hold it against the flood and ebb currents in the Narrows. During the mooring system design, a desired pretension is established for the lines at each draft. However, due to practical limitations in the field some variations to this design pretension value may be expected. It is important to study the effect of this variation on the overall performance of the mooring system. In this paper, the sensitivity of the mooring line pretension on the overall performance of the mooring system for the above caisson is presented. During this study, all the variables that affect the mooring system design such as mooring system layout, mooring line makeup, anchor positions, fairlead departure angles, and fairlead locations are kept constant. The only variable changed is the pretension of the mooring lines. Two approaches for defining the variations in the pretension have been studied in this paper. In the first approach, the pretension is changed in a systematic way (predicted approach). In the second method the pretension is changed randomly. The latter is considered more likely to occur in the field for this type of complex mooring system. Both sets of results are presented for some selected drafts attained by the caisson during its construction. The difference in the results from the two methods is discussed.

Drag coefficient of a sphere in a non-stationary flow: new results

2007 ◽  
Vol 463 (2088) ◽  
pp. 3323-3345 ◽  
Author(s):  
G Jourdan ◽  
L Houas ◽  
O Igra ◽  
J.-L Estivalezes ◽  
C Devals ◽  
...  
Keyword(s):  
Drag Coefficient ◽  
Stationary Flow ◽  
Reynolds Numbers ◽  
Spherical Particles ◽  
Steady Flows ◽  
Two Phase ◽  
Spider Web ◽  
Wide Range ◽  
The Difference ◽  
Sphere Drag

The drag coefficient of a sphere placed in a non-stationary flow is studied experimentally over a wide range of Reynolds numbers in subsonic and supersonic flows. Experiments were conducted in a shock tube where the investigated balls were suspended, far from all the tube walls, on a very thin wire taken from a spider web. During each experiment, many shadowgraph photos were taken to enable an accurate construction of the sphere's trajectory. Based on the sphere's trajectory, its drag coefficient was evaluated. It was shown that a large difference exists between the sphere drag coefficient in steady and non-steady flows. In the investigated range of Reynolds numbers, the difference exceeds 50%. Based on the obtained results, a correlation for the non-stationary drag coefficient of a sphere is given. This correlation can be used safely in simulating two-phase flows composed of small spherical particles immersed in a gaseous medium.

scholarly journals Efektifitas Teknik Relaksasi Nafas Dalam dan Pijatan Effleurage terhadap penurunan skala nyeri pada post sectio caesarea

2019 ◽  
Vol 1 (1) ◽  
pp. 61-69
Author(s):  
Siti Rochimatul Lailiyah
Keyword(s):  
Sampling Technique ◽  
Pain Scale ◽  
Sectio Caesarea ◽  
Relaxation Techniques ◽  
Light Weight ◽  
Deep Breathing ◽  
Moderate Pain ◽  
Test Results ◽  
Post Operative Pain ◽  
The Difference

 Deep breathing relaxation techniques and massagetechniques is an act that can reduce the pain inpostpartum mother sectio caesarea. The purpose ofthis study was to determine the difference in theintensity of post operative pain sectio caesarea withthe technique of deep breathing relaxation andmassage at irna C RSUD Syarifah Ambami RatoEbu Bangkalan. This study uses an experimental quasiapproach. The population is patients who havesevere pain, moderate pain, and mild pain aftersurgery sectio caesarea in irna C RSUD SyarifahAmbami Rato Ebu Bangkalan as many as 57patients. 10-19 year old girls. the sample of 9respondents who taught the technique of deepbreathing relaxation and 9 respondents in givingmassage techniques. sampling technique that isused is probability sampling. Data collection usingSOP and pain scale sheets. Data analysis usingpaired t-test. The results showed that of the 9 respondentsmost respondents after the technique of breathrelaxation in light weight scale as much as 7 (77.8%)postpartum. And from 9 respondents most ofrespondent after done massage technique of lightweight scale as much as 8 (89.9) postpartum.Wilcoxon test results show probability value greaterthan expected significant value (0.317 <0.05). Thismeans there is no difference in the intensity ofpostoperative postoperative pain of caesarea withthe application of deep breathing relaxation andmassage Effleurage. Deep breathing relaxation techniquesand massage techniques are important factors inpreventing the occurrence of severe pain.postpartum is expected to post sectio caesarea tofamiliarize with the technique of deep breathingrelaxation and massage techniques to reduce pain..  

scholarly journals ANALYSIS OF THE USE OF SPOILER ONE LEVEL AND TWO LEVELS IN CONDITIONS OF STEADY AGAINST THE DRAG AND LIFT COEFFICIENTS ON A SEDAN TYPE CAR BY USING CFD (COMPUTATIONAL FLUID DYNAMIC)

2019 ◽  
Vol 1 (2) ◽  
pp. 58
Author(s):  
Fajar Frihdianto ◽  
Nyeyep Sri Wardani ◽  
Indah Widiastuti
Keyword(s):  
Drag Coefficient ◽  
Steady Flow ◽  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Lift Coefficient ◽  
Color Difference ◽  
Lower Surface ◽  
Significant Difference ◽  
The Difference ◽  
Drag And Lift

<p><em>This research was simulation analyzing the condition of steady flow in around of body car made and analized computly using CFD program (Computational Fluid Dynamic). The model used was Sedan car designed with different rear end body by adding spoiler. Analyzing in this research was done by using Software 18.2–CFD Student Version. Design of the three models were compared to find out the difference in magnitude of Coefficient of Drag, Coefficient of Lift, pressure distribution, velocity distribution, and behavioral character of flow around the rear end of car in the condition of steady flow. Model was made in appropriate scale with model of Honda city 2008 sedan car</em><em>. </em><em>Observation was made to look at the behavior of fluida flows both in front and back the car in different fluid speed ranges in steady condition.</em></p><p><em>The simulation results obtained from packet CFD on each condition were; model without spoiler, model with 1 level spoiler, and model with 2 level spoiler. Where this simulation showed that CD and CL were decrease</em><em>. </em><em>One of the example was at speed 40km/hour obtained the coefficient of drag (CD) of 0.31061, 0.28603, and 0.2054, it proved that 1 level spoiler could reduce the value of drag coefficient about 7.9135% of the sedan car without spoiler, while the car with 2 level spoiler could reduce the value of drag coefficient about 33.8592% without spoiler. For the coefficient of lift (CL) on each model was -0.38487, -0.54624, and -0.62097 proved that spoiler 1 level could reduce the value of lift coeffient about 41.92845% of the sedan car without spoiler, while the car with 2 level spoiler could reduce the value of lift coefficient about 61.35984% without spoiler. On the result of pressure distrubution and relative velocity give little affect to the upper and lower surface where this was indicated by almost no color difference contours. Then, if it was indicated from streamline and the formation of vortex, there was a significant difference so that it was very influential on the size of CD and CL occoured. By changing geometric proved that the spoiler car 1 and 2 level were more aerodynamic than the car without spoiler.</em></p>

Experimental and Numerical Study of the Influence of Drag Coefficient on Snap Loads in Mooring Lines of a Floating Offshore Wind Turbine

2021 ◽  
Author(s):  
Brendan Guillouzouic ◽  
François Pétrié ◽  
Vincent Lafon ◽  
Fabien Fremont
Keyword(s):  
Numerical Simulations ◽  
Drag Coefficient ◽  
Wind Turbine ◽  
Scale Effects ◽  
Numerical Study ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Floating Bodies ◽  
Mooring Lines ◽  
Floating Offshore Wind Turbine

Abstract Mooring is one of the key components of a floating offshore wind turbine since the mooring rupture may lead to the total loss of one or even several turbines in a farm. Even if a large experience in moorings of floating bodies was gained in the oil & gas industry, the renewable energies face new challenges such as reducing the cost as much as possible, reducing the footprint to limit environmental impact or avoid any interference between mooring lines and electrical cables in a farm composed of several tens of turbines. Those constraints may lead to designs suffering snap loads which shall be avoided as far as practicable or addressed with a particular attention, as this quasi-instantaneous stretching of the mooring lines may lead to very high tensions governing the design. This paper presents the results of physical model tests and numerical simulations performed on a typical floating wind turbine concept of semi-submersible type. Both qualitative and quantitative comparisons are performed. The objective is to provide guidelines for FOWT mooring designers regarding the selection of the drag coefficient to consider. A very significant influence of the line’s drag coefficient, on both the probability of occurrence and the magnitude of snap loads, was found. This subject is hereby fully documented on a given case study and general discussions on scale effects, marine growth effects and other parameters are also made. The numerical simulations were performed using the dynamic analysis software ‘OrcaFlex’. The experiments have been carried out by Océanide, in south of France.

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