bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reliability Assessment of Fatigue Critical Welded Details in Wind Turbine Jacket Support Structures
Authors: Branner Kim , Toft Henrik Stensgaard , Haselbach Philipp , Natarajan Anand , Sørensen John D. 
Published: November 2013

This paper describes a probabilistic approach to reliability assessment of fatigue critical welded details in jacket support structures for offshore wind turbines. The analysis of the jacket response to the operational loads is performed using Finite Element Method (FEM) simulations in SIMULIA Abaqus. Fatigue stress cycles are computed on the jacket members by applying tower top loads from an aeroelastic simulation with superimposed marine loads and in accordance to the IEC-61400-3 guidelines for operational conditions. The combined effect of the hydrodynamic loads and the rotor loads on the jacket structure is analyzed in a de-coupled scheme, but including the structural dynamics of the support structure.
The failure prediction of the welded joints, connecting the individual members of the support structure is based on SN-curves and Miners rule according to ISO 19902 and DNV-RP-C203/DNV-OS-J101. Probabilistic SN-curves and a stochastic model for Miners rule is used to estimate the reliability of selected critical welded details in the jacket structure taken into account the uncertainty in the fatigue stresses.
Safety Analysis at Conceptual Design of Marine Structures
Authors: Valdman Nikolai A. 
Published: November 2013

The results of conceptual design of safety system elements for exploitation of offshore platforms, off-loading berths and terminals of liquid hydrocarbon in the Russian shelf seas are considered in the paper.
The methodical approaches used at substantiation of technical decisions on storage, offloading and liquid hydrocarbon transportation on objects of marine transport-technological systems (MTTS) are presented. The results of development of both a complex of measures on decrease of accident risk and using of safety criteria and factors are given.
Assessment of Fatigue Reliability for Jacket-Type Offshore Platforms Considering Dynamic Behavior
Authors: Khedmati Mohammad Reza , Rigo Philippe , Amrane Amirouche , Nazari Masoud 
Published: November 2013

In order to traditionally investigate the strength of marine structures, the structure is subjected to a maximum static load. However, the marine structures are usually suffering environmental forces varying with time. Wave forces are the most important time dependent loading that causes fatigue in structural elements and joints. In this paper different methods base on S-N curve and linear elastic failure mechanics are presented. The governing equations and theories that are used in each method are expressed and the application of each method will be discussed.
The two main methods of deterministic analyses are: stress-based approach (S-N curve approach) and linear elastic fracture mechanics (LEFM) approaches. These approaches are applicable to different analyzing strategies, ie the first approach is used for cases in which general form of fatigue is dominant, but the latter involves the calculations of reliability as functions of crack geometry and its boundary conditions.
The SPD12C jacket platform in South Pars Oil Field is also modeled as a case study and the results of fatigue reliability analysis are presented.
In this paper a comprehensive method is presented to accurately predict the reliability of offshore platforms. This method is based on S-N curve and the results are compared with the fatigue life of joints.
Due to nonlinear interaction of soil and piles and the other affecting parameters such as flexibility of joints, non Gaussian procedure of loading, and nonlinearity of reaction force, the precise analyzing of stress levels will be impossible and a complex numerical analysis could only give limited information about the statistical properties of stress. In order to perform the fatigue analysis and predicting the cycles of stress SACS was used which is known as a powerful software in designing and analyzing offshore structures [1].
In this paper the whole structure was modeled subjected to different forces such as wave and sea currents. The effects of parameters such as marine growth and interaction of soil and piles are also included. The latter is shown to have a significant effect on determination of fatigue life of the platform.
Towards a Different View on Ship Design: The Development of Ships Observed Through a Social-Technological Perspective
Authors: van Bruinessen Ties , Hopman Hans , Smulders Frido 
Published: November 2013

Designing large, innovative ships is a complex assignment and an interesting one for every company: Ship designers are capable of supporting the client’s requests and deliver a design quicker than any other related industry involved in the design of complex objects. However, at the same time it is felt that the industry could improve their innovative output by applying a more focused method to design these innovative and complex ships. Existing methods either mitigate the complex relations between systems of a ship, or concentrate on the design of a single object.
The design models evaluated in this paper, amongst others, the design spiral and system engineering, do not describe these important aspects of the ship-design cycle: To evolve beyond the current innovations, current design models do not suffice. The model presented in this paper takes the complex relations through different levels of decomposition into account and presents the possibility to track and support change during the design process. In future research, the model will be applied and developed further towards approaches and tools to support innovative design.
Suppressing Full-Scale Riser VIV With the VT Suppressor
Authors: King Roger , Brown Andrew , Braaten Henning , Russo Massimiliano , Baarholm Rolf , Lie Halvor 
Published: November 2013

The paper reports on recent full scale experimental tests with The Ventilated Trouser (VT), a novel device for VIV suppression of cylindrical structures exposed to external fluid flow. The VT suppressor is a loose fitting sleeve in the form of a light flexible net with integral bobbins in a special arrangement (Fig 1). It is omni-directional, rugged, and made from materials compatible with the offshore environment.
The tests reported here, originated in an invitation from Statoil to test the VT on a slick riser section. They were undertaken at Marintek, Norway, with a 0.53m diameter riser in current velocities up to 2.3m/s, equivalent to post-Critical Reynolds Numbers of up to 1.2 × 106.
The VT suppressed the maximum VIV amplitude of the slick joint by over 90%. This was consistent with the suppression performance of the VT from previous tests with model risers varying in size from 0.1m diameter to 0.3m diameter.
The test results suggest the VT is a candidate suppressor fully capable of competing with conventional suppression devices.
Verification of Gamma Knife extend system based fractionated treatment planning using EBT2 film
Authors: Natanasabapathi Gopishankar , Bisht Raj Kishor 
Published: November 2013

Purpose:This paper presents EBT2 film verification of fractionated treatment planning with the Gamma Knife (GK) extend system, a relocatable frame system for multiple‐fraction or serial multiple‐session radiosurgery.Methods:A human head shaped phantom simulated the verification process for fractionated Gamma Knife treatment. Phantom preparation for Extend Frame based treatment planning involved creating a dental impression, fitting the phantom to the frame system, and acquiring a stereotactic computed tomography (CT) scan. A CT scan (Siemens, Emotion 6) of the phantom was obtained with following parameters: Tube voltage—110 kV, tube current—280 mA, pixel size—0.5 × 0.5 and 1 mm slice thickness. A treatment plan with two 8 mm collimator shots and three sectors blocking in each shot was made. Dose prescription of 4 Gy at 100% was delivered for the first fraction out of the two fractions planned. Gafchromic EBT2 film (ISP Wayne, NJ) was used as 2D verification dosimeter in this process. Films were cut and placed inside the film insert of the phantom for treatment dose delivery. Meanwhile a set of films from the same batch were exposed from 0 to 12 Gy doses for calibration purposes. An EPSON (Expression 10000 XL) scanner was used for scanning the exposed films in transparency mode. Scanned films were analyzed with inhouse written MATLAB codes.Results:Gamma index analysis of film measurement in comparison with TPS calculated dose resulted in high pass rates >90% for tolerance criteria of 1%/1 mm. The isodose overlay and linear dose profiles of film measured and computed dose distribution on sagittal and coronal plane were in close agreement.Conclusions:Through this study, the authors propose treatment verification QA method for Extend frame based fractionated Gamma Knife radiosurgery using EBT2 film.
In Vitro
Pharmacodynamics of Polymyxin B and Tigecycline Alone and in Combination against Carbapenem-Resistant Acinetobacter baumannii
Authors: Hagihara Mao , Housman Seth T. , Nicolau David P. , Kuti Joseph L. 
Published: November 2013

ABSTRACT

Carbapenem-resistant
Acinetobacter baumannii
is increasing in prevalence. Polymyxin B and tigecycline are among the most active antibiotics used against this pathogen
in vitro
. Past
in vitro
studies, however, neglected the importance of simulating exposures observed in humans to determine their antibacterial effects. In this study, four carbapenem-resistant
A. baumannii
isolates were evaluated using an
in vitro
pharmacodynamic model. Free-drug exposures using 1 mg/kg of body weight of polymyxin B every 12 h (q12h), 100 and 200 mg tigecycline q12h, and the combination of these regimens were simulated. The microbiological responses to these treatments were measured by the change in log
10
CFU/ml over 24 h and the area under the bacterial killing and regrowth curve (AUBC). Resistance was assessed by a population analysis profile (PAP) conducted after 24 h of treatment. Polymyxin B achieved a reduction on the order of −2.05 ± 0.68 log
10
CFU/ml against these
A. baumannii
isolates, while all isolates grew to control levels with tigecycline monotherapy. Combination therapy with polymyxin B plus 200 mg tigecycline q12h achieved a greater reduction in bacterial density than did therapy with polymyxin B alone (−3.31 ± 0.71 versus −2.05 ± 0.68 log
10
CFU/ml,
P
< 0.001) but not significantly different than combination therapy with 100 mg tigecycline q12h (−2.45 ± 1.00 log
10
CFU/ml,
P
= 0.370). Likewise, combination therapy with polymyxin B plus 200 mg tigecycline q12h significantly reduced the AUBC compared to that with polymyxin B alone (62.8 ± 8.9 versus 79.4 ± 10.5 log
10
CFU/ml,
P
< 0.05). No changes in the PAP from baseline were observed for either antibiotic alone. In this study, combination therapy with simulated exposures of polymyxin B and tigecycline at an aggressive dose of 200 mg q12h produced synergistic or additive effects on humans against these multidrug-resistant
A. baumannii
strains.
Severe Sepsis Facilitates Intestinal Colonization by Extended-Spectrum-β-Lactamase-Producing Klebsiella pneumoniae and Transfer of the SHV-18 Resistance Gene to Escherichia coli during Antimicrobial Treatment
Authors: Guan Jun , Liu Shaoze , Lin Zhaofen , Li Wenfang , Liu Xuefeng , Chen Dechang 
Published: November 2013

ABSTRACT

Infections caused by multidrug-resistant pathogens are frequent and life threatening in critically ill patients. To investigate whether severe sepsis affects gut colonization by resistant pathogens and genetic exchange between opportunistic pathogens, we tested the intestinal-colonization ability of an extended-spectrum beta-lactamase-producing
Klebsiella pneumoniae
strain carrying the SHV-18 resistance gene and the transfer ability of the resistance gene to endogenous
Escherichia coli
under ceftriaxone treatment in rats with burn injury only or severe sepsis induced by burns plus endotoxin exposure. Without ceftriaxone treatment, the
K. pneumoniae
strain colonized the intestine in both septic and burned rats for a short time, with clearance occurring earlier in burn-only rats but never in sham burn rats. In both burned and septic rats, the colonization level of the challenge strain dropped at the beginning and then later increased during ceftriaxone treatment, after which it declined gradually. This pattern coincided with the change in resistance of
K. pneumoniae
to ceftriaxone during and after ceftriaxone treatment. Compared with burn-only injury, severe sepsis had a more significant effect on the change in antimicrobial resistance to ceftriaxone. Only in septic rats was the resistance gene successfully transferred from the challenge strain to endogenous
E. coli
during ceftriaxone treatment; the gene persisted for at least 4 weeks after ceftriaxone treatment. We concluded that severe sepsis can facilitate intestinal colonization by an exogenous resistant pathogen and the transfer of the resistance gene to a potential endogenous pathogen during antimicrobial treatment.
Metronidazole and Hydroxymetronidazole Central Nervous System Distribution: 1. Microdialysis Assessment of Brain Extracellular Fluid Concentrations in Patients with Acute Brain Injury
Authors: Frasca Denis , Dahyot-Fizelier Claire , Adier Christophe , Mimoz Olivier , Debaene Bertrand , Couet William , Marchand Sandrine 
Published: November 2013

ABSTRACT

The distribution of metronidazole in the central nervous system has only been described based on cerebrospinal fluid data. However, extracellular fluid (ECF) concentrations may better predict its antimicrobial effect and/or side effects. We sought to explore by microdialysis brain ECF metronidazole distribution in patients with acute brain injury. Four brain-injured patients monitored by cerebral microdialysis received 500 mg of metronidazole over 0.5 h every 8 h. Brain dialysates and blood samples were collected at steady state over 8 h. Probe recoveries were evaluated by
in vivo
retrodialysis in each patient for metronidazole. Metronidazole and OH-metronidazole were assayed by high-pressure liquid chromatography, and a noncompartmental pharmacokinetic analysis was performed. Probe recovery was equal to 78.8% ± 1.3% for metronidazole in patients. Unbound brain metronidazole concentration-time curves were delayed compared to unbound plasma concentration-time curves but with a mean metronidazole unbound brain/plasma AUC
0–τ
ratio equal to 102% ± 19% (ranging from 87 to 124%). The unbound plasma concentration-time profiles for OH-metronidazole were flat, with mean average steady-state concentrations equal to 4.0 ± 0.7 μg ml
−1
. This microdialysis study describes the steady-state brain distribution of metronidazole in patients and confirms its extensive distribution.
A Novel Staphylococcal Cassette Chromosomal Element, SCC
fusC
, Carrying
fusC
and
speG
in Fusidic Acid-Resistant Methicillin-Resistant Staphylococcus aureus
Authors: Lin Yu-Tzu , Tsai Jui-Chang , Chen Hsiao-Jan , Hung Wei-Chun , Hsueh Po-Ren , Teng Lee-Jene 
Published: November 2013

ABSTRACT

A high prevalence of
fusC
(16/46, 59%) was found in fusidic acid-resistant methicillin-resistant
Staphylococcus aureus
isolates collected from 2008 to 2010. Nucleotide sequencing of
fusC
and flanking regions revealed a novel staphylococcal cassette chromosome (SCC) structure, SCC
fusC
, which was integrated into
rlmH
and located upstream from SCC
mec
. The SCC
fusC
element contained
speG
, which may contribute to the polyamine resistance.
Clinical and genetic aspects of hypophosphatasia in Japanese patients
Authors: Taketani Takeshi , Onigata Kazumichi , Kobayashi Hironori , Mushimoto Yuichi , Fukuda Seiji , Yamaguchi Seiji 
Published: November 2013

ObjectiveWe examined the clinical and genetic features of hypophosphatasia (HPP) in Japanese patients. HPP is a rare metabolic bone disorder of bone mineralisation caused by mutations in the liver/bone/kidney alkaline phosphatase (ALPL) gene, which encodes tissue-non-specific alkaline phosphatase isoenzyme. MethodsWe retrospectively investigate the incidence and clinical features of 52 patients with paediatric HPP who were born between 1999 and 2010. Mutations of the ALPL gene were analysed in 31 patients.ResultsThe annual incidence of perinatal lethal HPP (PLH) was estimated to be 2–3/1 000 000 births. The most frequent clinical type was PLH followed by prenatal benign. In addition to bone symptoms, cerebral manifestations were frequently observed including convulsion, mental retardation, deafness and short stature with growth hormone deficiency. Respiratory failure was the most significant predictor of a poor prognosis for PLH. The first and second most frequent mutations in the ALPL gene were c.1559delT and c.T979C (p.F327L), respectively. The c.1559delT homozygous mutation was lethal with respiratory failure. Patients with the p.F327L compound heterozygous mutation had the different non-lethal type with short stature and a gradual improvement in ALP level and bone mineralisation.ConclusionsThe most frequent clinical type was the PLH type with prognosis related to respiratory failure, biochemical/radiological changes and ALPL mutations. Cerebral manifestations frequently occurred. Genotype–phenotype correlations were associated with specific outcomes in the PLH type, whereas different clinical features were associated with the same genotype in the non-lethal type.
Ten days of simulated live high:train low altitude training increases Hbmass in elite water polo players
Authors: Garvican-Lewis Laura A , Clark Sally A , Polglaze Ted , McFadden Greg , Gore Christopher J 
Published: November 2013

ObjectivesWater polo requires high aerobic power to meet the demands of match play. Live high:train low (LHTL) may enhance aerobic capacity at sea level. Before the Olympics, the Australian women's water polo team utilised LHTL in an attempt to enhance aerobic fitness.MethodsOver 6 months, 11 players completed three normobaric LHTL exposures (block 1:11 days at 3000 m; block 2+3:9 days at 2500 m, 11 days normoxia, 10 days at 2800 m). Haemoglobin mass (Hbmass) was measured through carbon monoxide-rebreathing. Before each block, the relationship between Hbmass and water polo-specific aerobic fitness was investigated using the Multistage Shuttle Swim Test (MSST). Effect size statistics were adopted with likely, highly likely and almost certainly results being >75%, >95%, >99%, respectively. A Pearson product moment correlation was used to characterise the association between pooled data of Hbmass and MSST.ResultsHbmass (mean±SD, pre 721±66 g) likely increased after block 1 and almost certainly after block 2+3 (% change; 90% confidence limits: block 1: 3.7%; 1.3–6.2%, block 2+3: 4.5%; 3.8–5.1%) and the net effect was almost certainly higher after block 2+3 than before block 1 (pre) by 8.5%; 7.3–9.7%. There was a very large correlation between Hbmass (g/kg) and MSST score (r=0.73).ConclusionsLHTL exposures of <2 weeks induced approximately 4% increase in Hbmass of water polo players. Extra Hbmass may increase aerobic power, but since match performance is nuanced by many factors it is impossible to ascertain whether the increased Hbmass contributed to Australia's Bronze medal.
Wellness, fatigue and physical performance acclimatisation to a 2-week soccer camp at 3600 m (ISA3600)
Authors: Buchheit Martin , Simpson Ben M , Garvican-Lewis Laura A , Hammond Kristal , Kley Marlen , Schmidt Walter F , Aughey Robert J , Soria Rudy , Sargent Charli , Roach Gregory D , Claros Jesus C Jimenez , Wachsmuth Nadine , Gore Christopher J , Bourdon Pitre C 
Published: November 2013

ObjectivesTo examine the time course of wellness, fatigue and performance during an altitude training camp (La Paz, 3600 m) in two groups of either sea-level (Australian) or altitude (Bolivian) native young soccer players.MethodsWellness and fatigue were assessed using questionnaires and resting heart rate (HR) and HR variability. Physical performance was assessed using HR responses to a submaximal run, a Yo-Yo Intermittent recovery test level 1 (Yo-YoIR1) and a 20 m sprint. Most measures were performed daily, with the exception of Yo-YoIR1 and 20 m sprints, which were performed near sea level and on days 3 and 10 at altitude.ResultsCompared with near sea level, Australians had moderate-to-large impairments in wellness and Yo-YoIR1 relative to the Bolivians on arrival at altitude. The acclimatisation of most measures to altitude was substantially slower in Australians than Bolivians, with only Bolivians reaching near sea-level baseline high-intensity running by the end of the camp. Both teams had moderately impaired 20 m sprinting at the end of the camp. Exercise HR had large associations (r>0.5–0.7) with changes in Yo-YoIR1 in both groups.ConclusionsDespite partial physiological and perceptual acclimatisation, 2 weeks is insufficient for restoration of physical performance in young sea-level native soccer players. Because of the possible decrement in 20 m sprint time, a greater emphasis on speed training may be required during and after altitude training. The specific time course of restoration for each variable suggests that they measure different aspects of acclimatisation to 3600 m; they should therefore be used in combination to assess adaptation to altitude.
Altitude training and haemoglobin mass from the optimised carbon monoxide rebreathing method determined by a meta-analysis
Authors: Gore Christopher J , Sharpe Ken , Garvican-Lewis Laura A , Saunders Philo U , Humberstone Clare E , Robertson Eileen Y , Wachsmuth Nadine B , Clark Sally A , McLean Blake D , Friedmann-Bette Birgit , Neya Mitsuo , Pottgiesser Torben , Schumacher Yorck O , Schmidt Walter F 
Published: November 2013

ObjectiveTo characterise the time course of changes in haemoglobin mass (Hbmass) in response to altitude exposure.MethodsThis meta-analysis uses raw data from 17 studies that used carbon monoxide rebreathing to determine Hbmass prealtitude, during altitude and postaltitude. Seven studies were classic altitude training, eight were live high train low (LHTL) and two mixed classic and LHTL. Separate linear-mixed models were fitted to the data from the 17 studies and the resultant estimates of the effects of altitude used in a random effects meta-analysis to obtain an overall estimate of the effect of altitude, with separate analyses during altitude and postaltitude. In addition, within-subject differences from the prealtitude phase for altitude participant and all the data on control participants were used to estimate the analytical SD. The ‘true’ between-subject response to altitude was estimated from the within-subject differences on altitude participants, between the prealtitude and during-altitude phases, together with the estimated analytical SD.ResultsDuring-altitude Hbmass was estimated to increase by ∼1.1%/100 h for LHTL and classic altitude. Postaltitude Hbmass was estimated to be 3.3% higher than prealtitude values for up to 20 days. The within-subject SD was constant at ∼2% for up to 7 days between observations, indicative of analytical error. A 95% prediction interval for the ‘true’ response of an athlete exposed to 300 h of altitude was estimated to be 1.1–6%.ConclusionsCamps as short as 2 weeks of classic and LHTL altitude will quite likely increase Hbmass and most athletes can expect benefit.