Insight into the Flow Within the Well Dock of a Mothership During Feeder Vessel Docking Manoeuvres

2020 ◽  
Vol 162 (A1) ◽  
Author(s):  
N T M Johnson ◽  
G J Macfarlane ◽  
J T Duffy ◽  
I Penesis ◽  
R J Ballantyne
Keyword(s):  
Measurement Techniques ◽  
Confined Water ◽  
Operational Parameters ◽  
Complex Flows ◽  
Sea Transport ◽  
Experimental Campaign ◽  
Feeder Vessel ◽  
Novel Concept ◽  
Optimum Solution ◽  
Insight Into

An experimental campaign has been undertaken to explore the flow around a feeder vessel as it manoeuvres in and out of the well dock of a mothership. The parent hulls for this study are drawn from the floating harbour transhipper concept created by Sea Transport Corporation. Laser measurement techniques have been employed to analyse the flow field within the well dock while the feeder vessel both enters and departs. For the Master of the feeder vessel to safely perform these manoeuvres, the complex flows resulting from the highly confined nature of the well dock concept need to be understood and potentially mitigated. It is shown that the inclusion of vents in the well dock can significantly influence the flow and that their effectiveness is determined by the size of the vents. This study further progresses the authors’ recent work on the same novel concept where the confined water effect of the well dock and inclusion of vents is quantified for both the seakeeping behaviour and the docking/departure performance. It is concluded that the use of vents is very beneficial when a feeder vessel docks or departs the well dock, however a compromise on the vent size must be reached in order to reduce adverse effects on feeder vessel motions when docked and exposed to a seaway. It is likely that the optimum solution, that covers all operational parameters, only requires the inclusion of relatively small vents.

INSIGHTS INTO THE FLOW WITHIN THE WELL DOCK OF A MOTHERSHIP DURING FEEDER VESSEL DOCKING MANOEUVRES

2021 ◽  
Vol 162 (A1) ◽  
Author(s):  
N T M Johnson ◽  
G J Macfarlane ◽  
J T Duffy ◽  
I Penesis ◽  
R J Ballantyne
Keyword(s):  
Measurement Techniques ◽  
Confined Water ◽  
Water Effect ◽  
Operational Parameters ◽  
Complex Flows ◽  
Sea Transport ◽  
Experimental Campaign ◽  
Feeder Vessel ◽  
Novel Concept ◽  
Optimum Solution

An experimental campaign has been undertaken to explore the flow around a feeder vessel as it manoeuvres in and out of the well dock of a mothership. The parent hulls for this study are drawn from the floating harbour transhipper concept created by Sea Transport Corporation. Laser measurement techniques have been employed to analyse the flow field within the well dock while the feeder vessel both enters and departs. For the Master of the feeder vessel to safely perform these manoeuvres, the complex flows resulting from the highly confined nature of the well dock concept need to be understood and potentially mitigated. It is shown that the inclusion of vents in the well dock can significantly influence the flow and that their effectiveness is determined by the size of the vents. This study further progresses the authors’ recent work on the same novel concept where the confined water effect of the well dock and inclusion of vents is quantified for both the seakeeping behaviour and the docking/departure performance. It is concluded that the use of vents is very beneficial when a feeder vessel docks or departs the well dock, however a compromise on the vent size must be reached in order to reduce adverse effects on feeder vessel motions when docked and exposed to a seaway. It is likely that the optimum solution, that covers all operational parameters, only requires the inclusion of relatively small vents.

A Fresh Insight into Film Morphology Measurement Techniques for Advanced Ulsi Manufacturing

1993 ◽  
Vol 309 ◽  
Author(s):  
Seshadri Ramaswami
Keyword(s):  
Grain Size ◽  
Integrated Circuit ◽  
Measurement Techniques ◽  
Film Morphology ◽  
Integrated Circuit Fabrication ◽  
Circuit Fabrication ◽  
Non Destructive ◽  
Fresh Insight ◽  
Insight Into

AbstractA laser based non-destructive technique has been used to study the morphology of sputterdeposited aluminum alloy films. The data emanating from the Therma-wave Imager that makes use of this principle, has been correlated with reflectivity, grain size and micro-roughness of the film. In addition, through the use of a case study, this paper demonstrates the utility of this application as an in-line monitor in an integrated circuit fabrication line.

The Three-Dimensional Surface Topographic Characterisation of Diamond Grinding Wheels

2010 ◽  
Vol 126-128 ◽  
pp. 690-695
Author(s):  
David Lee Butler
Keyword(s):  
Measurement Techniques ◽  
Three Dimensional ◽  
Surface Measurement ◽  
Grinding Wheel ◽  
Profile Measurement ◽  
Detailed Knowledge ◽  
Grinding Wheels ◽  
Diamond Grinding ◽  
Insight Into ◽  
Dimensional Surface

Surface measurement using three-dimensional stylus instruments is a relatively new technique that offers numerous advantages over more traditional profilometry methods. The information generated is, unlike profile measurement, less subjective and more statistical providing additional insight into the surface structure. One application of surface measurement that has encountered problems when using the profilometry method is that of grinding wheel characterisation. The wheel surface texture (topography) and the conditions under which it is generated have a profound effect upon the grinding performance as characterised by the grinding forces, power consumption, temperature, and surface integrity of components. A detailed knowledge of the nature of the topography of the grinding wheel would provide further insight into surface interactions between the wheel and workpiece as well as enabling improved control of the grinding process in general. In this paper four diamond grinding wheels of 91 and 181 micron grit size were subjected to differing dressing conditions to produce varying final wheel topographies. Three-dimensional surface measurement techniques were employed to quantitatively characterise the topographic change and provide an aerial estimation of the number of cutting grains. The results demonstrate that the techniques can distinguish between a worn and dressed wheel. In addition, the parametric values generated from the various surfaces can aid the user in determining when re-dressing is required.

scholarly journals MEASUREMENT TECHNIQUES FOR MOORED SHIP DYNAMICS

1982 ◽  
Vol 1 (18) ◽  
pp. 160
Author(s):  
J. Moes ◽  
S.G. Holroyd
Keyword(s):  
Measurement System ◽  
Measurement Techniques ◽  
Long Waves ◽  
Mooring Line ◽  
Mooring Lines ◽  
Preliminary Results ◽  
Ship Dynamics ◽  
Extensive Measurement ◽  
Horizontal Oscillation ◽  
Insight Into

Problems arise during adverse sea conditions with ships moored to the ore loading jetty at Saldanha Bay. Under certain wave conditions moored ships undergo large motions which cause breakage of mooring lines. In order to obtain a quantitative insight into the problem an extensive measurement system was installed at Saldanha Bay. This system comprises instrumentation for the measurement of short and long waves, currents and wind, mooring line and fender forces and the motions of the moored ships. Preliminary results show that during storm conditions long waves with periods between 50 and 150 s occur at the jetty. These periods fall within the same range as the observed natural periods of horizontal oscillation of the moored ships.

scholarly journals Biosorption of Pb2+ and Cd2+ from Simulated Wastewater Using Melina (Gmelina arborea) Tree Leaves Powder

2018 ◽  
pp. 1-12
Author(s):  
N. O. Ilelaboye ◽  
A. A. Oderinde
Keyword(s):  
Metal Ions ◽  
Waste Treatment ◽  
Anthropogenic Activities ◽  
Freundlich Isotherm ◽  
Solution Concentration ◽  
Isotherm Models ◽  
Operational Parameters ◽  
Solution Ph ◽  
Separation Parameter ◽  
Optimum Solution

Increased anthropogenic activities have led to serious environmental problems due to pollution caused by toxic materials such as heavy metals whose levels are rising in the environment. The inefficiency and high cost of conventional methods of waste treatment have prompted the investigation of environmentally friendly and cheaper methods of treatment using natural products. In this study, G. arborea leaves powder was investigated with a view of using it as cheap material for the biosorption of Pb2+ and Cd2+   from wastewater. The effects of operational parameters like pH, biosorbent dose [g/L], initial metal ions concentration [mg/L], contact time [minutes] and stirring speed [rpm] on the biosorption efficiency [%] were determined. The optimum solution pH for Pb2+ and Cd2+adsorption was 5.0 and peak adsorption of 91.33% and 82.53% for Pb2+ and Cd2+, respectively. 5 g/L Melina leaves were enough to achieve peak removal of both metal ions. The removal of the metal ions was comparatively quick, and stability was achieved after 30 minutes. The optimum stirring speed was 250 rpm for both metal ions. The uptake efficiency of the biosorbent was determined by Langmuir and Freundlich isotherm models. The value of Langmuir isotherm separation parameter [RL] of Pb2+ ion [0.0446 - 0.78125] and Cd2+ [0.1005- 0.9482] were within range of 0 -1 indicating favorable biosorption for both metal ions. The degree of non-linearity [n] values between Pb2+ [12.79] and Cd2+ [11.79] solution concentration and biosorption in Freundlich equation were greater than 1, indicating physical biosorption of Pb2+ and Cd2+ on to G. arborea leaves. G. arborea can serve as efficient biosorbent not only for Pb2+ and Cd2+ ions but also for other heavy metal ions in a wastewater stream

scholarly journals Russian and Negative Prefixing: A Cognitive-Semantic Approach to the Negative Adjective Prefixing in Russian, Spanish, Persian, and English

2018 ◽  
Vol 7 (4) ◽  
pp. 15
Author(s):  
Rajdeep Singh
Keyword(s):  
Cognitive Processing ◽  
The Novel ◽  
Semantic Approach ◽  
Morphological Process ◽  
Slavic Languages ◽  
Cognitive Context ◽  
Negative Adjective ◽  
Cognitive Semantic ◽  
Novel Concept ◽  
Insight Into

Negative prefixing has always been an important and intriguing morphological process, through which adjectives are formed in many different languages. However, there are limits to negative prefixing. In this study, we introduce the novel concept of Polarity Flexibility, through which the limitations for the negative prefixing are accounted for. Furthermore, we conducted an experiment to investigate whether the PF is an active cognitive process. The results of the experiment confirm our hypothesis and the fact that Polarity Flexibility does indeed influence the cognitive processing. In our study, we introduce the notion of the syntactic arrangement which influences the negative prefixing. Therefore, we compare Russian, Persian, Spanish and English in negative prefixing to show how much the cognitive processes are influenced by the syntactic formations. Russian as a representative of Slavic languages brings an important insight into the way syntax plays role in the semantic-cognitive context.

Centrifugal Flow in a Rotor-Stator Cavity

2005 ◽  
Vol 127 (4) ◽  
pp. 787-794 ◽  
Author(s):  
Sébastien Poncet ◽  
Roland Schiestel ◽  
Marie-Pierre Chauve
Keyword(s):  
Laser Doppler Anemometer ◽  
Second Order ◽  
Control Parameters ◽  
Complex Flows ◽  
Order Model ◽  
Pressure Transducers ◽  
Numerical Predictions ◽  
Two Component ◽  
First Time ◽  
Insight Into

The present work considers the turbulent flow inside an annular rotor-stator cavity with and without centrifugal throughflow. Extensive measurements performed using a two-component laser-Doppler anemometer technique, and pressure transducers are compared to numerical predictions based on one-point statistical modeling using a low-Reynolds-number second-order full-stress transport closure. A study of the flow control parameters is performed, and, for the first time, a better insight into the transition from Batchelor to Stewartson types of flow is gained from this study. The advanced second-order model is confirmed to be the adequate level of closure to describe such complex flows.

The Floating Harbour Transhipper: New-Generation Transhipment of Bulk Ore Products

2015 ◽  
Author(s):  
Gregor J. Macfarlane ◽  
Nicholas T. M. Johnson ◽  
Lauchlan J. Clarke ◽  
Ross J. Ballantyne ◽  
Kevin A. McTaggart
Keyword(s):  
Deep Water ◽  
Scale Model ◽  
Experimental Program ◽  
Material Transfer ◽  
Mining Operations ◽  
Sea Transport ◽  
Large Bulk ◽  
Physical Scale ◽  
Seakeeping Performance ◽  
Feeder Vessel

Bulk products such as iron ore and coal are usually shipped directly from shore facilities using large bulk carriers. This often involves significant cost due to major dredging operations, long jetties, large storage sheds and the acquisition of large tracts of coastal land. The costs of direct shore to an ocean-going export vessel (OGV) loading often run into billions of dollars — prohibitive for small- to medium-scale mining operations, particularly in remote regions with only distant access to deep water ports. The current industry standard for mitigating these issues is transhipping; the bulk cargo is transported from a smaller shore based facility to the export vessel moored in deep water by a small feeder vessel. Transhipment, while mitigating many of these issues, does introduce other concerns with respect to limiting seastate, environmentally harmful dust and potential spillage during materials transfer. The Australian company Sea Transport Corporation and the Australian Maritime College at the University of Tasmania are developing new technology for bulk ore transhipment: the floating harbour transhipper (FHT). The FHT is essentially a large floating warehouse with an aft well dock to support material transfer operations from the feeder vessel. The major advantages to the mining export industry are in the form of environmental and economic improvements, in some cases completely avoiding expensive dredging while minimising the environmentally invasive onshore infrastructure. In addition, the whole process is enclosed, therefore eliminating grab spillage and dust transport issues common to other transhipping methods. This paper presents an overview of the main hydrodynamic issues currently being investigated: primarily the interaction between multiple floating bodies close to one another in a seaway. The two primary ship-to-ship interactions that are being investigated are the effects experienced by the feeder vessel when it is docking or undocking within the FHT well dock and the interactions between the three vessels when operating in close proximity in an open seaway. A combination of physical scale model experiments and numerical techniques is employed, with a significant portion of the experimental program dedicated to the validation of the numerical simulation codes used to investigate the behaviour of the vessels. ShipMo3D is an object based library developed by DRDC for the purpose of analysing the seakeeping performance of vessels operating in a seaway in either the frequency or time domain. The capabilities of ShipMo3D are applied to this novel application in an attempt to provide realistic simulations of the interaction between the vessels of the FHT system. DualSPHysics, an open source Smoothed Particle Hydrodynamics (SPH) code, is being applied to the domain within the very restricted water environment of the FHT well dock to investigate the fluid flow behaviour and the effect that this has on the feeder vessel when entering/exiting.

Mass transfer in falling film microreactors: measurement techniques and effect of operational parameters

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Ali Alhafiz Mohammed ◽  
David Lokhat
Keyword(s):  
Mass Transfer ◽  
Measurement Techniques ◽  
Process Intensification ◽  
Liquid Films ◽  
Falling Film ◽  
Operational Parameters ◽  
Transfer Enhancement ◽  
Mass Transfer Enhancement ◽  
The Relationship ◽  
Common Target

Abstract Falling film microreactors have contributed to the pursuit of process intensification strategies and have, over the years, been recognized for their potential in performing demanding reactions. In the last few decades, modifications in the measurement techniques and operational parameters of these microstructured devices have been the focus of many research studies with a common target on process improvement. In this work, we present a review dedicated to falling film microreactors, focusing on the recent advances in their design and operation, with particular emphasis on mass transfer enhancement. Analysis of the recent techniques for the measurement of mass transfer as well as the operational parameters used and their effect on the target objective, particularly in the liquid phase (being the limiting phase reactant), are included in the review. The relationship between the hydrodynamics of falling thin liquid films and the microreactor design, the discrepancies between measured and model results, the major challenges, and the future outlook for these promising microreactors are also presented.

Variations in the Measured Carrier Lifetimes of n- 4H-SiC Epilayers

2008 ◽  
Vol 600-603 ◽  
pp. 489-492
Author(s):  
Paul B. Klein ◽  
Joshua D. Caldwell ◽  
Amitesh Shrivastava ◽  
Tangali S. Sudarshan
Keyword(s):  
Measurement Technique ◽  
Reasonable Agreement ◽  
Optical Measurement ◽  
Measurement Techniques ◽  
Carrier Dynamics ◽  
Injection Level ◽  
Carrier Lifetimes ◽  
Dynamics Simulations ◽  
Recombination Kinetics ◽  
Insight Into

The effects of measurement technique and measurement conditions (injection level, temperature) on the measured carrier lifetimes in n- 4H-SiC epilayers are investigated. For three optical measurement techniques, it is shown that the high and low injection lifetimes can vary dramatically. Differences in the lifetime for varying injection level and temperature are approached both experimentally and via carrier dynamics simulations, assuming Z1/Z2 as the dominant defect. Reasonable agreement between measured and calculated behavior is obtained, as is insight into the recombination kinetics associated with the lifetime limiting defect.

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