713 research outputs found
Toward monitoring and estimating the size of the HFO-contaminated seabed around a shipwreck using MBES backscatter data
No full textFunding Information: The authors are grateful to three anonymous reviewers for their constructive criticism and valuable comments. The authors express their gratitude to the Maritime Institute in Gdansk for making the final version of the report (Maritime Institute in Gdansk, 2016) available. The second author appreciates the support of the Gdynia Maritime University in funding this research through internal grant WN/PZ/2021/02. Funding Information: The second author appreciates the support of the Gdynia Maritime University in funding this research through internal grant WN/PZ/2021/02 . Publisher Copyright: © 2021Despite a progressive reduction of oil spills caused by the activity of maritime transportation, the latent sources of pollution still exist. Although the harmful impact of heavy fuel oil (HFO) on the marine environment is widely known, many shipwrecks cause contamination of the surrounding areas. In this paper, an approach to monitor the area of the HFO spill around a shipwreck is made using a bottom backscattering strength (BBS) obtained by a multibeam echosounder (MBES). As a case study, the s/s Stuttgart wreck located in the Gulf of Gdansk (Poland) is verified. Two different measurement campaigns have been carried out in shallow waters using low (190 kHz) and high (420 kHz) MBES frequency. The results indicate that the polluted area around s/s Stuttgart was estimated at 49.1 ha, which is around 18.3% more in comparison to the geological surveys made four years earlier.Peer reviewe
The Weight and Hopcount of the Shortest Path in the Complete Graph with Exponential Weights
No full textBoth the hopcount HN (the number of links) and the weight WN (the sum of the weights on links) of the shortest path between two arbitrary nodes in the complete graph KN with i.i.d. exponential link weights is computed. We consider the joint distribution of the pair (HN,WN) and derive, after proper scaling, the joint limiting distribution. One of the results is that HN and WN, properly scaled, are asymptotically independent.Delft Institute of Applied MathematicsElectrical Engineering, Mathematics and Computer Scienc
Feasibility of abdominoplasty with Cesarean section [Retraction]
No full textThe Editor-in-Chief and Publisher of the International Journal of Women’s Health have been alerted by Dr Nadine Sherif, the corresponding author, to unacceptable levels of duplication with a previously published paper: Ali A, Essam A. Abdominoplasty Combined with Cesarean Delivery: Evaluation of the Practice. Aesthetic Plastic Surgery. 2011;35(1):80–86.It is worth noting that this paper was peer-reviewed by two peer-reviewers and the Editor-in-Chief of the International Journal of Women’s Health before publication. The paper concerned is: Thabet WN, Hossny AS, Sherif NA. Feasibility of abdominoplasty with Cesarean section. International Journal of Women’s Health. 2012;4:115–121
A concept of critical safety area applicable for an obstacle-avoidance process for manned and autonomous ships
No full textFunding Information: This research work was supported by the Gdynia Maritime University internal grant WN/PZ/2021/02. Funding Information: The author is grateful to three anonymous reviewers for their constructive criticism and valuable comments. The author expresses his gratitude to Prof. Jerzy Matusiak of Aalto University for making the LaiDyn code available, as well as to Dr. Tomasz Hinz of Waterborne Transport Innovation Foundation for preparing LaiDyn output files containing ship trajectories. This research work was supported by the Gdynia Maritime University internal grant WN/PZ/2021/02. Publisher Copyright: © 2021 The Author(s)In times of increased automation of maritime transportation, ship collision with a stationary obstacle (allision) remains a significant problem. There are many existing solutions rooted primarily in the concept of ship domain and path-planning algorithms. However, among these, a geometrical approach to the determination of a required maneuvering area considering the dynamic nature of ship operations in close-quarters situations is still missing. Therefore, an improved concept of the CADCA (Collision Avoidance Dynamic Critical Area) is introduced for the case of ship allision. The CADCA is a deterministic zone that geometrically delimits required maneuvering space of a vessel. Its shape changes depending on the operational parameters of a ship, such as the magnitude of rudder angle, initial forward speed, or planned alteration of the course. In contrast to ship domain, the CADCA is determined using the critical distance between two objects called MDTC (Minimum Distance to Collision). Therefore, the CADCA concept can be used to appoint a position of no-return in a close-quarters situation, so as to determine the time and distance of the last-minute maneuver. An improved method of CADCA determination is introduced, along with an investigation of operational factors influencing the ship's critical area in allision scenarios. The simulations have been conducted for large passenger and container ship in encounters with various stationary obstacles differing in size and shape. The results indicate that from the operational point of view, a deflection of the rudder is the most influencing factor on the size of the CADCA, while the impact of ship speed is negligible for the investigated vessels. Besides, various applications of the CADCA are proposed and discussed for both manned and prospective autonomous vessels.Peer reviewe
TGF-alpha and IL-6 plasma levels selectively identify CML patients who fail to achieve an early molecular response or progress in the first year of therapy
No full textData source: Supplementary data, http://www.nature.com/leu/journal/v30/n6/suppinfo/leu201634s1.htmlEarly molecular response (EMR, BCR-ABL1 (IS)⩽10% at 3 months) is a strong predictor of outcome in imatinib-treated chronic phase chronic myeloid leukemia (CP-CML) patients, but for patients who transform early, 3 months may be too late for effective therapeutic intervention. Here, we employed multiplex cytokine profiling of plasma samples to test newly diagnosed CP-CML patients who subsequently received imatinib treatment. A wide range of pro-inflammatory and angiogenesis-promoting cytokines, chemokines and growth factors were elevated in the plasma of CML patients compared with that of healthy donors. Most of these normalized after tyrosine kinase inhibitor treatment while others remained high in remission samples. Importantly, we identified TGF-α and IL-6 as novel biomarkers with high diagnostic plasma levels strongly predictive of subsequent failure to achieve EMR and deep molecular response, as well as transformation to blast crisis and event-free survival. Interestingly, high TGF-α alone can also delineate a poor response group raising the possibility of a pathogenic role. This suggests that the incorporation of these simple measurements to the diagnostic work-up of CP-CML patients may enable therapy intensity to be individualized early according to the cytokine-risk profile of the patient.E Nievergall, J Reynolds, CH Kok, DB Watkins, M Biondo, SJ Busfield, G Vairo, K Fuller, WN Erber, T Sadras, R Grose, DT Yeung, AF Lopez, DK Hiwase, TP Hughes and DL Whit
Corrosion prevention of stell structures for Sri Lanka Author Premachandrasiri, W.N.
No full textSri Lanka has made a significant development in the design and construction sector during the last 10 years. The use of steel is one of the governing construction materials in the industries. One of the major concerns of existing steel structures is the durability. Corrosion and deterioration have become major challenges in the lifetime of the structure, as it is one of the major public focuses on the structures.
Standards are intended to assist engineers and corrosion experts in adopting best practice in corrosion protection of structural steel at new constructions with proper identification of an actual exposure. There are six environmental corrosivity categories according to BS ISO 12944 as C1, C2 C3, C4, C5 and C5 –M. Those are according to BS standard and they should be adapted for Sri Lanka. In this research environmental corrosivity category of SC1, SC2, SC3 and SC4 are classified for Sri Lanka considering corrosion affecting factors temperature, rainfall, coastal region and industrial zones. A field survey was carried out in different locations of the structure in the country to identify the pattern of corrosion according to variation of corrosion affecting factors.
Among the methods used to clean the surface of the steel before applying corrosion protection, sand blasting cleans best. However, it cannot be carried out in every location due to environmental issues and equipment required. Steel surface is difficult to clean using light tools because temporary stabilized corroded layer on the steel surface. If we change this surface (Convert surface grade A to Surface grade B), the light tools can be used for the surface preparation. Therefore a new method is proposed to change this surface grade. Firstly, sea water is sprayed on to the surface to increase the rate of corrosion and left for a day for rust to appear. Then it is cleaned by fresh water and surface salinity level should be checked using salinity meter. Then the surface can be prepared using “Cup-Brush application” method without using sand blasting. By this method well cleaned surface can be obtained and then the surface protection primer is applied on it immediately. This surface protection primer type and primer and paint thickness should be defined according to environmental corrosivity category
My Favorite Integer Sequences
No full textAbstract. This paper gives a brief description of the author's database of integer sequences, now over 35 years old, together with a selection of a few of the most interesting sequences in the table. Many unsolved problems are mentioned
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