1,603 research outputs found
A study on the effects of e-navigation on reducing vessel accidents
The dissertation aims to evaluate how and to what extent e-navigation contributes to reducing accidents for SOLAS ships as well as non-SOLAS ships, hoping that the results are referred to IMO Member States when they are implementing enavigation along with the maritime sectors such as shipping companies, crews on board ships and manufactures developing e-navigation related systems. The study focuses on the potential effects of e-navigation based on tool kits of the IMO e-navigation for SOLAS ships and services of SMART-navigation, which is the Korean approach to implementing the e-navigation concept for both SOLAS ships and non-SOLAS ships. The processes and the methodologies that are used by the IMO to assess the effects of e-navigation are investigated. The vessel accidents for all ships in Korean waters and all Korean-flagged ships worldwide during the 5 years from 2009 to 2013 are analyzed. The formula is proposed to calculate the effects of e-navigation on reducing accidents, which can also be used by other Member States of the IMO when they implement e-navigation in their waters. The direct causes of accidents, which are reducible by the risk control options (RCOs), and the RCOs, which are applicable to non-SOLAS ships, are identified. Additionally, an expert questionnaire survey is carried out with a view to supporting the validity of identifying the RCOs and the direct causes. The results are collated and evaluated for the potential effects of e-navigation on reducing accidents, in relation to type of accidents as well as type of ships, for comparison with the results obtained by the IMO and for reference of other Member States. The concluding chapter examines the results of analysis of e-navigation\u27s tool kits and methodologies to assess their effects on reducing accidents, and discusses the potential rate of accident reduction through e-navigation. A number of recommendations are made concerning the need for further investigation in quantifying the coefficient applied to the proposed formula for evaluating the effects of e-navigation
Experimental study on the effect of initial liquid droplet size on the evaporation in a heterogeneous droplet
[EN] In the present work, we experimentally investigated the effect of initial liquid droplet size on the evaporation in the
heterogeneous droplet. Spherical carbon and water were used for particle and liquid droplet comprising the
heterogeneous droplet. four initial droplet volumes of 1, 2, 3 and 4 μl were considered when the diameter of the
particle was 5 mm. The heterogeneous droplet was suspended with a rod at 20 cm away from the radiator which
surface temperature was fixed to 473 K. Ambient temperature and relative humidity remained 296 K and 40 %,
respectively, during the experiment.
As the results, the evaporation rate of 4 μl case increased about 1.8 times compared with that of 1 μl case. The
evaporation rate increased almost linearly with the volume ratio, and that is related closely with the contact surface
between particle and water droplet. Contact surface area remained almost constantly with time, whereas it
increased with the initial volume of water droplet. The energy from radiator can be accumulated at the contact
surface at the side of particle, thereby intensifying the evaporation of water droplet because more heat transfers
from particle to droplet through the contact surface. Consequently, the initial volume of liquid droplet is one of the
influence factors on the evaporation rate in the heterogenous droplet.This research was supported by the Fire Fighting Safety & 119 Rescue Technology Research and Development
Program funded by the Ministry of Public Safety and Security (NEMA-NG-2014-46) and Research Project of Air
Sampling Detector funded by Alllitelife co. Inc..Sung, KH.; Nam, JS.; Hong, GB.; Ryou, HS. (2017). Experimental study on the effect of initial liquid droplet size on the evaporation in a heterogeneous droplet. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 290-295. https://doi.org/10.4995/ILASS2017.2017.4744OCS29029
Oxygen nonstoichiometry and thermodynamic quantities of Perovskite-Type La1- xSrxFeO3-δ(x=0.2, 0.5, 0.8)
In this work, the defect structure analysis of La1-xSrxFeO3-δ (x=0.2, 0.5, 0.8) was presented. Thermogravimetric measurements were performed to determine the change in oxygen nonstoichiometry (Δδ) with oxygen partial pressure (pO2) in 10-19 ≤ (pO2/atm) ≤ 0.21 and temperature in 750 ≤ (T/℃) ≤ 900 range. La1-xSrxFeO3-δ showed a clear electronic stoichiometric point around δ»3-x/2. The relative partial molar enthalpy (ho-hoo) and entropy (so-soo) of oxygen were calculated from δ-pO2-T relation by using Gibbs-Helmholtz equation. The negative sign of ho-hoo and so-soo indicated that the incorporation of oxygen was an exothermic process and showed that the experimentally observed variations in ho-hoo and so-soo with δ matched well with the statistical thermodynamic model proposed by Mizusaki[1]. The defect diagram analysis showed that in n-type regime Fe2+ concentration varied with (pO2)-1/4 whereas in p-type regime Fe4+ concentration varied with (pO2)1/4.
Reference
[1] J. Mizusaki et al. J. Solid State Chem. 67 (1987) 1-8
Study of Full Controlled Green Time Roundabouts – An Intelligent Approach
When roundabouts face congestion problems, the transition to signalised roundabouts is considered a solution to the problem. The majority of studies have concentrated on how to calculate the optimal cycle length and signal timing to minimise congestion at roundabouts. To date, intelligence algorithms with multi-objectives such as queue length, number of stops, delay time, capacity and so on are widely used for calculating signal timing. Although roundabout congestion can be generated by the weaving zone reducing roundabout capacity, there have been minimal studies which take into account the density in the weaving zone. This study proposed a hybrid gravitational search algorithm – ABFO random forest regression with the following objectives: density, delay time and capacity to find the optimal cycle length and green time in each phase of Changwon city hall roundabout in South Korea as a case study. The optimal cycle length and green time were calculated in MATLAB and microscopic simulation VISSIM sought the effectiveness of a signalised roundabout. The result of the analysis demonstrated that signalised roundabouts with 102 seconds cycle length (phase 1 – 65 seconds of green time and phase 2 – 37 seconds of green time) can reduce density by 46.1%, delays by 32.8% and increase roundabout capacity by 14.8%
Bonghan Ducts as Possible Pathways for Cancer Metastasis
Objective: The present study has been designed to find a possible new route for the
metastasis of cancer cells on the fascia surrounding tumor tissue using a novel technique
of trypan blue staining.
Materials and Methods: Tumor tissues were grown in the skin of nude mice after subcutaneous
inoculation with human lung cancer cells. Trypan blue was recently identified
as a dye with specificity for Bonghan ducts (BHDs) and not other tissues, such as
blood or lymph vessels or nerves.
Results: We demonstrate that the trypan blue staining technique allows the first
visualization of BHDs which are connected to tumor tissues
Bonghan Ducts as Possible Pathways for Cancer Metastasis
Objective: The present study has been designed to find a possible new route for the
metastasis of cancer cells on the fascia surrounding tumor tissue using a novel technique
of trypan blue staining.
Materials and Methods: Tumor tissues were grown in the skin of nude mice after subcutaneous
inoculation with human lung cancer cells. Trypan blue was recently identified
as a dye with specificity for Bonghan ducts (BHDs) and not other tissues, such as
blood or lymph vessels or nerves.
Results: We demonstrate that the trypan blue staining technique allows the first
visualization of BHDs which are connected to tumor tissues
Transport properties of graphene with one-dimensional charge defects
We study the effect of extended charge defects in electronic transport
properties of graphene. Extended defects are ubiquitous in chemically and
epitaxially grown graphene samples due to internal strains associated with the
lattice mismatch. We show that at low energies these defects interact quite
strongly with the 2D Dirac fermions and have an important effect in the
DC-conductivity of these materials.Comment: 6 pages, 5 figures. published version: one figure, appendix and
references adde
Association between harmful alcohol use and periodontal status according to gender and smoking
BACKGROUND: the aim of this study is to assess the association of harmful alcohol use based on the alcohol use disorders identification test (AUDIT) score with periodontal status according to gender and smoking in a representative sample of Korean adults. METHODS: This study analyzed 5,291 participants older than 19 years whose data of harmful alcohol use and periodontal status were available. Harmful alcohol use was defined by the WHO guidelines for the administration of AUDIT. The periodontal status was assessed by the Community Periodontal Index (CPI). Multivariate logistic regression analysis was performed with adjustment for socio-demographic variables, oral and general health behavior, oral health status and systemic conditions. All analyses considered a complex sampling design, and multivariate analysis was also performed in the subgroups. RESULTS: Multivariate logistic regression analysis revealed a marginal association between harmful alcohol use and higher CPI in the total sample. The adjusted odds ratio (OR) of harmful alcohol use was 1.16 (0.97 to 1.38) for higher CPI. Higher CPI was significantly associated with harmful alcohol use in men (OR: 1.28; 95% CI: 1.03-1.60) and non-smokers (OR: 1.29; 95% CI: 1.06-1.57). CONCLUSION: Periodontal status is significantly associated with harmful alcohol use in men and non-smokers in a representative sample of Korean adults
- …