bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Study on Forced Vibration of Double Bottom Structure due to Whipping on an Ultra Large Container Ship
Authors: Kawasaki Yohei , Okada Tetsuo , Kobayakawa Hiroaki , Amaya Ichiro , Miyashita Tetsuji , Nagashima Tomoki , Neki Isao 
Published: October 2017

Worldwide expansion of economy has brought about prominent and rapid enlargement of container ships. Their greater beam has caused more flexible double bottom structure, giving rise to concerns about its adverse effect to the ultimate strength of hull girder. To accurately assess the ultimate strength of hull girder, it is essential to precisely grasp how the double bottom structures behave in the actual sea state, in terms of whipping and vibratory response as well as wave frequency response.
In this paper, the authors investigated structural behavior of the double bottom of a 14,000 TEU ultra large container ship in long-crested irregular head seas. Firstly, time domain ship motion and wave pressure on the hull surface was obtained through numerical analysis using Rankine source method. Subsequently, the obtained loads were applied to 3-dimensional whole ship finite element model, and time domain elastic responses of all over the hull structures were analyzed using Newmark-β method in terms of both whipping and wave frequency responses.
As a result, regarding the wave frequency response, it was found that maximum wave induced upward bending of the midship double bottom structures is exerted almost simultaneously with the maximum wave induced hogging hull girder bending moment. The correlation factors between the double bottom bending and the hull girder bending were about 0.94 around the midship region, and they decreased in the fore and aft region.
Regarding the whipping and vibratory response, it was found that large whipping response induces forced vibration of the double bottom structures, especially in the midship region. Because of the higher natural frequencies of the double bottom structures compared with that of whipping, the double bottom structures are excited in the same phase as the hull girder whipping, resulting in superimposed longitudinal stresses in way of the bottom shell plating.
From these observations, it can be concluded that the local bending behavior of the double bottom structures adversely affects the hull girder ultimate strength, both in terms of wave loads and whipping loads, and it is necessary to take sufficient care to the double bottom rigidity.
Improved In-Line VIV Prediction for Combined In-Line and Cross-Flow VIV Responses
Authors: Yin Decao , Passano Elizabeth , Larsen Carl M. 
Published: October 2017

Slender marine structures are subjected to ocean currents, which can cause vortex-induced vibrations (VIV). Accumulated damage due to VIV can shorten the fatigue life of marine structures, so it needs to be considered in the design and operation phase.
VIV prediction tools are based on hydrodynamic coefficients, which are obtained from forced motion experiments on a circular cylinder. Most of the forced motion experiments apply harmonic motions in either in-line (IL) or cross-flow (CF) direction. Combined IL and CF forced motion experiments are also reported. However, measured motions from flexible pipe VIV tests contain higher order harmonic components, which have not yet been extensively studied.
This paper presents results from conventional forced motion VIV experiments, but using measured motions taken from a flexible pipe undergoing VIV. The IL excitation coefficients were used by semi-empirical VIV prediction software VIVANA to perform combined IL and CF VIV calculation. The key IL results are compared with NDP flexible pipe model test results. By using present IL excitation coefficients, the prediction of IL responses for combined IL and CF VIV responses is improved.
Tension-Tension Testing of a Novel Mooring Rope Construction
Authors: Weller S. D. , Halswell P. , Johanning L. , Kosaka T. , Nakatsuka H. , Yamamoto I. 
Published: October 2017

Synthetic fibre ropes are in widespread use in maritime applications ranging from lifting to temporary and permanent mooring systems for vessels, offshore equipment and platforms. The selection of synthetic ropes over conventional steel components is motivated by several key advantages including selectable axial stiffness, energy absorption (and hence load mitigation), fatigue resistance and low unit cost. The long-term use of ropes as safety critical components in potentially high dynamic loading environments necessitates that new designs are verified using stringent qualification procedures. The International Organization for Standardization (ISO) is one certification body that has produced several guidelines for the testing of synthetic ropes encompassing quasi-static and dynamic loading as well as fatigue cycling.
This paper presents the results of tension-tension tests carried out to ISO 2307:2010, ISO 18692:2007(E) and ISO/TS 19336:2015(E) on three different 12-strand rope constructions manufactured by Ashimori Industry Co. Ltd from polyester and Vectran® fibres. The purpose of the tests was to characterise the performance of a novel 12-strand construction and compare this to a conventional 12-strand construction. Utilising the Dynamic Marine Component test facility (DMaC) at the University of Exeter several key performance metrics were determined including; elongation, minimum break load (MBL) and quasi-static and dynamic stiffness. During the ISO 2307:2010(E) test programme the samples were tested dry and during the ISO 18692:2007(E) and ISO/TS 19336:2015(E) test programmes the samples were fully submerged in tap water after being soaked for at least 24 hours. Two methods were used to quantify sample extension: i) an optical tracking system and ii) a draw-wire potentiometer. Axial compression fatigue and cyclic loading endurance tests were also carried out on two Vectran® samples. Further load-to-failure tests and sample analysis were also carried out by Ashimori Industry Co. Ltd.
It was found that the MBL of the samples exceeded the values specified by the manufacturer (by 7.7–29.5% for the polyester samples) with failure occurring at the splices in all cases and minor abrasion noted in several locations. The measured MBL of the novel polyester Straight Strand Rope (SSR) construction was up to 16% higher than the conventional construction with increases of quasi-static and dynamic stiffness of up to 6.8%. Differences between the viscoelastic and viscoplastic behaviour of the samples were also noted. The data obtained during these tests will provide insight into the behaviour of these materials and different rope constructions which will be of use to rope manufacturers, mooring system designers in addition to offshore equipment and vessel operators.
Prediction of Offshore Platform Mooring Line Tensions Using Artificial Neural Network
Authors: Sidarta Djoni E. , Kyoung Johyun , O’Sullivan Jim , Lambrakos Kostas F. 
Published: October 2017

Station-keeping is one of the important factors in the design of offshore platforms. Some offshore platforms, such as Spar, Semi-submersible and FPSO, use mooring lines as a mean for station-keeping. Tensions in the mooring lines are one of the key factors in station-keeping. The design of an offshore platform and its mooring lines is based on computed motions of the platform and associated mooring line tensions from numerical simulations using a software code on the basis of metocean criteria.
This paper presents an Artificial Neural Network (ANN) model for the prediction of mooring line tensions based on the motions of the platform. This ANN model is trained with time histories of vessel motions and corresponding mooring line tensions for a range of sea states from the results of numerical simulations. After the model is trained, it can reproduce with great fidelity and very fast the mooring line tensions. In addition, it can generate accurate mooring line tensions for sea states that were not included in the training, and this demonstrates that the model has captured the knowledge for the underlying physics between vessel motions and mooring line tensions. The paper presents an example of the training and the validation of the model for a semi-submersible offshore platform for a range of sea states.
The training of the ANN model employed a back-propagation learning algorithm. In this algorithm the computed output error is back-propagated through the neural network to modify the connection weights between neurons. The training started with a small number of hidden neurons, and the model grew adaptively by adding hidden neurons until either the target output convergence is achieved or a maximum number of additional hidden neurons is reached. The ANN model discovers nonlinear relationships between the input and output variables during training.
The paper presents comparison of time series of mooring line tensions for sea states that were and were not included in the training between those from the numerical simulations and those computed by the trained ANN model. Fatigue assessment is also used to quantitatively measure the accuracy of the ANN model prediction of the time series of mooring line tensions. The paper presents the results of fatigue assessment using various stages of the ANN models with different number of hidden neurons. This shows that the additional hidden neurons improve the prediction of the ANN model of the mooring line tensions for sea states that were and were not included in the training.
This approach of prediction of mooring line tensions based on vessel motions using ANN model paves the way to the development of an ANN-based monitoring system. Also, this ANN study demonstrates a great potential for the use of a more general and comprehensive ANN model to help monitor the dynamic behavior of floating systems and forecast problems before they occur by detecting deviations in historic patterns.
Molecular and Physiological Logics of the Pyruvate-Induced Response of a Novel Transporter in
Bacillus subtilis
Authors: Charbonnier Teddy , Le Coq Dominique , McGovern Stephen , Calabre Magali , Delumeau Olivier , Aymerich Stéphane , Jules Matthieu 
Published: October 2017

ABSTRACT

At the heart of central carbon metabolism, pyruvate is a pivotal metabolite in all living cells.
Bacillus subtilis
is able to excrete pyruvate as well as to use it as the sole carbon source. We herein reveal that
ysbAB
(renamed
pftAB
), the only operon specifically induced in pyruvate-grown
B. subtilis
cells, encodes a hetero-oligomeric membrane complex which operates as a facilitated transport system specific for pyruvate, thereby defining a novel class of transporter. We demonstrate that the LytST two-component system is responsible for the induction of
pftAB
in the presence of pyruvate by binding of the LytT response regulator to a palindromic region upstream of
pftAB
. We show that both glucose and malate, the preferred carbon sources for
B. subtilis
, trigger the binding of CcpA upstream of
pftAB
, which results in its catabolite repression. However, an additional CcpA-independent mechanism represses
pftAB
in the presence of malate. Screening a genome-wide transposon mutant library, we find that an active malic enzyme replenishing the pyruvate pool is required for this repression. We next reveal that the higher the influx of pyruvate, the stronger the CcpA-independent repression of
pftAB
, which suggests that intracellular pyruvate retroinhibits
pftAB
induction via LytST. Such a retroinhibition challenges the rational design of novel nature-inspired sensors and synthetic switches but undoubtedly offers new possibilities for the development of integrated sensor/controller circuitry. Overall, we provide evidence for a complete system of sensors, feed-forward and feedback controllers that play a major role in environmental growth of
B. subtilis
.

IMPORTANCE
Pyruvate is a small-molecule metabolite ubiquitous in living cells. Several species also use it as a carbon source as well as excrete it into the environment. The bacterial systems for pyruvate import/export have yet to be discovered. Here, we identified in the model bacterium
Bacillus subtilis
the first import/export system specific for pyruvate, PftAB, which defines a novel class of transporter. In this bacterium, extracellular pyruvate acts as the signal molecule for the LytST two-component system (TCS), which in turn induces expression of PftAB. However, when the pyruvate influx is high, LytST activity is drastically retroinhibited. Such a retroinhibition challenges the rational design of novel nature-inspired sensors and synthetic switches but undoubtedly offers new possibilities for the development of integrated sensor/controller circuitry.
Murine Cytomegalovirus Spreads by Dendritic Cell Recirculation
Authors: Farrell Helen E. , Bruce Kimberley , Lawler Clara , Oliveira Martha , Cardin Rhonda , Davis-Poynter Nicholas , Stevenson Philip G. 
Published: October 2017

ABSTRACT

Herpesviruses have coevolved with their hosts over hundreds of millions of years and exploit fundamental features of their biology. Cytomegaloviruses (CMVs) colonize blood-borne myeloid cells, and it has been hypothesized that systemic dissemination arises from infected stem cells in bone marrow. However, poor CMV transfer by stem cell transplantation argues against this being the main reservoir. To identify alternative pathways for CMV spread, we tracked murine CMV (MCMV) colonization after mucosal entry. We show that following intranasal MCMV infection, lung CD11c
+
dendritic cells (DC) migrated sequentially to lymph nodes (LN), blood, and then salivary glands. Replication-deficient virus followed the same route, and thus, DC infected peripherally traversed LN to enter the blood. Given that DC are thought to die locally following their arrival and integration into LN, recirculation into blood represents a new pathway. We examined host and viral factors that facilitated this LN traverse. We show that MCMV-infected DC exited LN by a distinct route to lymphocytes, entering high endothelial venules and bypassing the efferent lymph. LN exit required CD44 and the viral M33 chemokine receptor, without which infected DC accumulated in LN and systemic spread was greatly reduced. Taken together, our studies provide the first demonstration of virus-driven DC recirculation. As viruses follow host-defined pathways, high endothelial venules may normally allow DC to pass from LN back into blood.

IMPORTANCE
Human cytomegalovirus (HCMV) causes devastating disease in the unborn fetus and in the immunocompromised. There is no licensed vaccine, and preventive measures are impeded by our poor understanding of early events in host colonization. HCMV and murine CMV (MCMV) both infect blood-borne myeloid cells. HCMV-infected blood cells are thought to derive from infected bone marrow stem cells. However, infected stem cells have not been visualized
in vivo
nor shown to produce virus
ex vivo
, and hematopoietic transplants poorly transfer infection. We show that MCMV-infected dendritic cells in the lungs reach the blood via lymph nodes, surprisingly migrating into high endothelial venules. Dissemination did not require viral replication. It depended on the constitutively active viral chemokine receptor M33 and on the host hyaluronan receptor CD44. Thus, viral chemokine receptors are a possible target to limit systemic CMV infections.
Sexual health clinic attendance and non-attendance in Britain: findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3)
Authors: Tanton Clare , Geary Rebecca S , Clifton Soazig , Field Nigel , Heap Katie L , Mapp Fiona , Hughes Gwenda , Johnson Anne M , Cassell Jackie A , Sonnenberg Pam , Mercer Catherine H 
Published: October 2017

ObjectivesIn Britain, sexual health clinics (SHCs) are the most common location for STI diagnosis but many people with STI risk behaviours do not attend. We estimate prevalence of SHC attendance and how this varies by sociodemographic and behavioural factors (including unsafe sex) and describe hypothetical service preferences for those reporting unsafe sex.MethodsComplex survey analyses of data from Britain’s third National Survey of Sexual Attitudes and Lifestyles, a probability survey of 15 162 people aged 16–74 years, undertaken 2010–2012.ResultsOverall, recent attendance (past year) was highest among those aged 16–24 years (16.6% men, 22.4% women), decreasing with age (<1.5% among those 45–74 years). Approximately 15% of sexually-active 16–74 year olds (n=1002 men; n=1253 women) reported ‘unsafe sex’ (condomless first sex with a new partner and/or ≥2 partners and no condom use, past year); >75% of these had not attended a SHC (past year). However, of non-attenders aged 16–44 years, 18.7% of men and 39.0% of women reported chlamydia testing (past year) with testing highest in women aged <25 years. Of those aged 16–44 years reporting unsafe sex, the majority who reported previous SHC attendance would seek STI care there, whereas the majority who had not would use general practice.ConclusionWhile most reporting unsafe sex had not attended a SHC, many, particularly younger women, had tested for chlamydia suggesting engagement with sexual health services more broadly. Effective, diverse service provision is needed to engage those at-risk and ensure that they can attend services appropriate to their needs.
Mass-balance modelling of Gangotri glacier
Authors: Agrawal A. , Thayyen R. J. , Dimri A. P. 
Published: October 2017

Abstract

The sensitivity of glacier mass balance (MB) in response to climatic perturbations has made it an important parameter of study from hydrological, climatological and glaciological point of view. To monitor the health of any glacier system, long-term MB observations are required. These observations among Himalayan glaciers are not available consistently and large glaciers are not often monitored for mass balance due to logistical challenges. One such glacier is the Gangotri, situated in the western Himalaya. In the present study an attempt is made to model the MB over the Gangotri glacier, the biggest glacier in the Ganga basin and also the point of origin of the River Ganges. The mass balance of the Gangotri glacier is estimated during the time period 1985–2014 using two different methods: ice-flow velocity; and energy balance modelling using regional model (REMO) outputs and
in situ
automatic weather station (AWS) data. The geodetic method is used for the nearby Dokriani glacier, where field-based MB measurements are available. MB of Gangotri glacier estimated for 2001–14 using the ice-flow velocity method is −0.92 ± 0.36 m w.e. a
−1
; for 2006–07, MB using AWS and Tropical Rainfall Monitoring Mission (TRMM) data with the energy balance modelling approach is −0.82 m w.e. a
−1
; and for 1985–2005, MB using REMO data with the energy balance modelling approach is −0.98 ± 0.23 m w.e. a
−1
. Using the surface velocity method, it is estimated that the glacier lost 9% of its volume during the period 2001–14. The glacier vacated an area of 0.152 km
2
from the snout region, and retreated by 200 m in the last 14 years. MB values estimated for the Gangotri glacier from different methodologies are remarkably close, suggesting them to be suitable methods of MB estimation. TRMM, High Asia Refined (HAR-10) and Asian Precipitation Highly Resolved Observational Data Integration Towards Evaluation of water resources (APHRODITE) data are used to estimate the precipitation over the glacier. The study suggests that the glacier-wide estimation of weather parameters needs to be improved for more accurate estimation of glacier mass balance.
Geomorphic evolution of glacier-fed Baspa Valley, NW Himalaya: record of Late Quaternary climate change, monsoon dynamics and glacial fluctuations
Authors: Dutta S. , Mujtaba S. A. I. , Saini H. S. , Chunchekar R. , Kumar P. 
Published: October 2017

Abstract

In glacier-fed Baspa River valley, Late Quaternary climatic changes are archived in the terraces, fan and landslide deposits. An initial optically stimulated luminescence (OSL) based stratigraphy of these deposits is developed to deduce geomorphic evolution and palaeoclimatic changes. The data show large alluvial fan progradation around Sangla till
c.
45 ka (middle of marine isotope stage 3 or MIS-3) due to glacial retreat and readjustment of glacigenic sediment under warm and humid conditions followed by incision. During the end phase of MIS-3 (>23 ka), intensified precipitation blocked the river course near Sangla and Kharogla by rock avalanches and imposed lacustrine conditions which recorded sedimentation until the beginning of Holocene (
c.
11.4 ka). Reduced sedimentation in these lakes during the last glacial maximum (LGM)
c.
23–18 ka suggests a cold and arid climate, whereas increased sedimentation during
c.
18–11.5 ka indicates a warm and humid climate post-LGM. A palaeolake breach occurred during early Holocene and incision continued throughout the Holocene, with a pulse of fluvial aggradation during
c.
9.1–6.5 ka over lacustrine remnant. In the upper reach of the valley (Chitkul area), coeval aggradation continued from >28 ka until
c.
19 ka (MIS-3 to LGM) under cold and relatively arid conditions. This study emphasizes that Late Quaternary geomorphic evolution of Baspa valley is well synchronous with glacial fluctuations and the rapid response of the glacifluvial system to Indian summer monsoon (ISM) dynamics.
Global-scale abrupt climate events and black swans: an ice-core-derived palaeoclimate perspective from Earth's highest mountains
Authors: Thompson Lonnie G. , Mosley-Thompson Ellen , Davis Mary E. , Porter Stacy E. , Kenny Donald V. , Lin Ping-Nan 
Published: October 2017

Abstract
High-elevation tropical glaciers provide records of past climate from which current changes can be assessed. Comparisons among three ice-core records from tropical mountains on opposite sides of the Pacific Ocean reveal how climatic events are linked through large-scale processes such as El Niño–Southern Oscillation. Two distinctive trans-Pacific events in the mid-fourteenth and late-eighteenth centuries are distinguished by elevated aerosol concentrations in cores from the Peruvian Andes and the Tibetan Himalaya. Today aerosol sources for these areas are enhanced by droughts accompanying El Niños. In both locations, large-scale atmospheric circulation supports aerosol transport from likely source regions. Oxygen isotopic ratios from the ice cores are significantly linked with tropical Pacific sea-surface temperatures, especially in the NIÑO3.4 region. The arid periods in the fourteenth and eighteenth centuries reflect droughts that were possibly connected to strong and/or persistent El Niño conditions and Intertropical Convergence Zone migration. These ‘black swans’ are contemporaneous with climate-related population disruptions. Recent warming, particularly at high elevations, is posing a threat to tropical glaciers, many of which have been retreating at unprecedented rates over the last several thousand years. The diminishing ice in these alpine regions endangers water resources for populations in South Asia and South America.