156 research outputs found
A novel approach to developing effective maritime regulations : the case of LNG cargo filling limits
This paper introduces a novel approach to resolving a part of the fundamental problems encountered in the current practice of maritime regulatory frameworks. The novelty of the proposed method lies in a detailed and structured process that can examine and verify the appropriateness of a particular regulation in terms of integrating economic, environmental and safety impacts. Through its built-up database of approximately 440 LNG carriers in the world, the excellence of the proposed approach has been demonstrated by investigating the suitability of a controversial regulation related to the LNG cargo filling limit set forth in โthe International code for the construction & Equipment of Ships carrying liquefied gases in Bulk.โ A series of case studies have confirmed 169 LNG carriers currently are subjected to being placed under this issue. In this study, we identified shipsโ key characteristics which would contribute to the increase in total costs associated with economic, environmental and safety impacts and presented the threshold between the opportunity costs and the severity of the regulation. The research findings have provided a managerial insight that may increase the reliability of maritime regulations by applying this pragmatic/analytical regulatory framework model developed in this research
Regulatory gaps between LNG carriers and LNG fuelled ships
Given a number of marine vessels treating the liquefied natural gas either as cargo or fuel, this paper examined the regulatory gaps of two different international Codes โ the InternationalCodeof the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk and the International Code of Safety for Ships Using Gases or Other Low-flashpoint Fuels โ from the regulatory standpoint. Results of the gap analysis have identified and discussed the key areas encountered with regulatory discrepancies or ambiguities that might interrupt the proper design, construction and operation of LNG carrier and LNG fuelled ship. A systematic investigation and harmonisation process across the Codes was proposed to mitigate the potential issues that may arise from the discordant regulations. Also, the International Maritime Organization was suggested to take proactive action to improve such dissonances while a general insight into the importance of filling those gaps was provided for rule-makers and stakeholders
Determination of safety exclusion zone for LNG bunkering at fuel-supplying point
With strong environmental and economic driving forces for using LNG as a marine fuel over the last decade, an increasing number of local/international ports, mainly in Europe, have initiated LNG fuel providing service to LNG-fuelled ships. This trend is now spreading throughout the world. The LNG bunkering methods currently in use are truck-to-ship (TTS), ship-to-ship (STS) and pipeline-to-ship (PTS). This paper describes a study conducted to identify potential risks associated with LNG bunkering with particular emphasis on the fuel-supplying side. A series of parametric analyses were also carried out to identify the sensitivity to some parameters with the aid of a purpose-built computer program, Integrated Quantitative Risk Assessment (IQRA). Through the parametric analyses, general relationships between the risk and various parameters could be established from which the importance of the selected parameters might be evaluated. This paper also proposes a new approach of establishing realistic safety exclusion zones in LNG bunkering process. Research findings demonstrate that the implied hypothesis that the current practice of the probabilistic risk assessment focused on the population-independent analysis only is somewhat inadequate when applied to determining the safety exclusion zones as showing that the extent of safety exclusion zones tends to be set up unpractically wide. Instead, the proposed approach designed with the combination of population-dependant and independent analyses is proven to be useful in determining the zones more realistically. It may form a basis on which more useful safety-related standards and regulations on LNG bunkering can be built
Quantitative risk assessment of medium-sized floating regasification units using system hierarchical modelling
Currently there are no sufficiently detailed and specific regulations and guidelines applicable to Floating Regasification Units. In view of the fact that these units are likely to become more popular in the near future, their safety needs to be examined urgently. During the design of the world's first medium-sized floating regasification unit a qualitative risk assessment was carried out. Although the results are useful, they cannot be used for developing rules and regulations directly. For such purposes some detailed quantitative studies are essential. This paper addresses this gap and introduces a hierarchical system modelling method to overcome the problem of the lack of direct statistical accident data of novel systems. The method was implemented in IQRA (integrated quantitative risk assessment), a piece of software developed in-house for quantitative risk assessment. The safety of the floating regasification unit mentioned above was assessed using this software and the results were compared against the results obtained from conventional qualitative and the quantitative risk assessment. It was found that the qualitative risk assessment had a tendency to overestimate the frequency of the accidents but to underestimate their consequence, while the quantitative risk assessment based on the result of the qualitative assessment inherently underestimated both the frequency and the consequence of hazards. The hierarchical modelling was found to be an excellent method of dealing with complex systems with short operational history
Association between humidifier disinfectant exposure during infancy and subsequent neuropsychiatric outcomes during childhood: a nation-wide cross-sectional study
Background
The purpose was to determine the association between infant exposure to humidifier disinfectant (HD) with neuropsychiatric problems in pre-school children.
Methods
A total of 2,150 children (age 4โ11 months) were enrolled in the Panel Study of Korean Children (PSKC) study. The Korean version of the Child Behavior Checklist (CBCL) was used for assessments of neuropsychiatric problems. 1,113 children who participated in all the first to third PSKC studies and answered a question about HD exposure were finally enrolled.
Results
There were 717 (64.5%) children in non-HD group who were not exposed to HD and 396 (35.5%) in HD group with former exposure to HD. Exposure to HD was associated with total neuropsychiatric problems (adjusted odds ratio, aOR = 1.54, 95% CI = 1.15โ2.06), being emotionally reactive (aOR = 1.55, 95% CI = 1.00โ2.39), having attention problems (aOR = 1.96, 95% CI = 1.10โ3.47), having oppositional defiant problems (aOR = 1.70, 95% CI = 1.07โ2.71), and having attention deficit/hyperactivity problems (aOR = 11.57, 95% CI = 1.03โ2.38). The risks for neuropsychiatric problems were clearly increased in boy, firstborn, and secondary smoker.
Conclusions
Exposure to HD during early childhood had a potential association with subsequent behavioral abnormalities.This study was supported by a grant from the Seongnam Atopy Project of the Seongnam City Government, Republic of Korea
Elective Laparoscopic Repair after Colonoscopic Decompression for Incarcerated Morgagni Hernia
Plain radiographs of an 88-year-old woman who had experienced vomiting and abdominal distention for 3 days revealed a severely obstructed ileus, and abdominopelvic computed tomography revealed an incarcerated Morgagni hernia. The endoscope was passed through the constrictions from the diaphragmatic indentations and a thin catheter was placed for decompression. The obstructive ileus regressed markedly after the procedure; the patient underwent elective laparoscopic repair of the hernia 1 week later. This is believed to be the first case of endoscopic preoperative decompression for an incarcerated Morgagni hernia
Prefoldin 6 mediates longevity response from heat shock factor 1 to FOXO in C-elegans
Heat shock factor 1 (HSF-1) and forkhead box O (FOXO) are key transcription factors that protect cells from various stresses. In Caenorhabditis elegans, HSF-1 and FOXO together promote a long life span when insulin/IGF-1 signaling (IIS) is reduced. However, it remains poorly understood how HSF-1 and FOXO cooperate to confer IIS-mediated longevity. Here, we show that prefoldin 6 (PFD-6), a component of the molecular chaperone prefoldin-like complex, relays longevity response from HSF-1 to FOXO under reduced IIS. We found that PFD-6 was specifically required for reduced IIS-mediated longevity by acting in the intestine and hypodermis. We showed that HSF-1 increased the levels of PFD-6 proteins, which in turn directly bound FOXO and enhanced its transcriptional activity. Our work suggests that the prefoldin-like chaperone complex mediates longevity response from HSF-1 to FOXO to increase the life span in animals with reduced IIS.11Ysciescopu
New de-ubiquitinating enzyme, ubiquitin C-terminal hydrolase 8, in chick skeletal muscle
Sex differences in body composition affect total airway resistance during puberty
Abstract
Background
During puberty, changes in body composition due to sex hormones are associated with lung mechanics. However, little is known about the mediation effect of sex differences in body composition during puberty with total airway resistance.
Methods
We prospectively recruited 620 children (10โ12years old) from the general population and conducted a cross-sectional study. This study assessed pubertal status according to the five Tanner stages using a questionnaire, line drawings, and each subjects blood sex hormone profile. Both the impulse oscillation system for total lung mechanics and multifrequency bioelectrical impedance for body composition analyses were conducted. The effects of puberty on body composition and subsequent total lung resistance were evaluated using mediation analysis.
Results
Among the 503 children enrolled, there were 261 males (51.9%) and 242 females (48.1%). In males, higher testosterone levels corresponded with reduced total lung resistance (ฮฒโ=โโ0.13, 95% CIโ=โโ0.21 to โ0.05, pโ<โ0.001), and the proportion of the mediating effect through the muscle-fat ratio was 19% (95% CIโ=โ4 to 59, pโ=โ0.02). In contrast, in females, pubertal status reduced total lung resistance (ฮฒโ=โโ0.27, 95% CIโ=โโ0.58 to โ0.05, pโ=โ0.04), however, the proportion of the mediating effect through the body mass index was โ51% (95% CIโ=โโ244 to โ4%, pโ=โ0.04).
Conclusion
The muscle-fat ratio in adolescent males had a synergistic effect with testosterone on improving total airway resistance, whereas improvements in lung resistance by pubertal status were partially masked by body mass index in adolescent females. In conclusion, body composition changes during puberty between males and females have differing effects on total airway resistance
The Effect of Aging and Severity of Sleep Apnea on Heart Rate Variability Indices in Obstructive Sleep Apnea Syndrome
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