Advances in Conceptual Ship Design Accounting for the Risk of Environmental Pollution

The present paper provides a thorough analysis of the prerequisites in adopting a new paradigm in the conceptual ship design accounting for the environmental pollution driven by maritime transportations. A survey of presently issued IMO environmental requirements outlines the framework within ship design solutions. Identified and carefully examined are several competing optimal design solutions, based on the energy efficiency design index introduced for shipbuilding, operation cost, and the resale costs at the end of the service life, which are used as input variables in a risk-based analysis. Reviewed are the immediate steps taken in the risk-based conceptual ship design to minimise the risk of environmental pollution while considering the life cycle assessment and energy efficiency of the ship propulsion system. Brought forth in the current paper are the results of a study into the concept design of series of containerships operating in the Black Sea for transporting 20, 40 and 45-foot containers aimed at identifying the main dimensions, capacity, visibility, freeboard, stability, bow, and stern design, propulsion complex and propeller design, control and manoeuvrability, seakeeping, energy efficiency design index, capital, and operational expenditures, that leads to the required fright rate for the ships in the range of 4,000 to 14,000 DWT. Accordingly, a bulk carrier’s risk-based concept ship design methodology is employed for the ship life cycle assessment and energy efficiency in pursuance of the optimal design solution in reference to the energy efficiency design index as most applicable to shipbuilding, operation, and resale costs at the end of the service life, and used as input variables in the risk estimate

MULTIPURPOSE VESSEL FLEET FOR SHORT BLACK SEA SHIPPING THROUGH MULTIMODAL TRANSPORT CORRIDORS

A study about the requirements and cargo transportation demand in the Black Sea as part of a multimodal transportation frame is performed, estimating the potential need of a ship fleet of multipurpose ships. The study performs conceptual multipurpose vessel design and fleet sizing using the long-time experience and statistics in defining main dimensions of the ship and her hull form, resistance and propulsion, weights, stability, free-board, seakeeping and manoeuvrability, capital, operational and decommissioning expenditure, where the optimal design solution is obtained based on the energy efficiency, shipbuilding, operation, and resale costs at the end of the service life. A discussion about possible applications of a different fleet of ship sizes in improving the cargo transportation efficiency considers the vessel\u27s typical operational profile in such a way to maximise the economic impact conditional of the unsteady cargo flow and environmental impact

Retrofitting measure of an ageing multi-purpose ship exposed to short-sea LNG operation

The objective of the present study is to analyse the retrofitting measure needed for an ageing multi-purpose ship exposed to a short sea LNG operation in the Black Sea region. Different technical aspects of the retrofitting related to using LNG as fuel for short-sea shipping, including the required volume of the liquefied natural gas, the appropriate type of tanks and the location of tanks on the ship, changes in the main engine and needed additional equipment, are discussed. The cost-benefit feasibility analysis is performed considering the historical and current price of LNG fuel and different taxes related to the generated CO2, examining the Varna-Poti-Varna and Varna-Istanbul-Varna routes

Principal component analysis of containership traffic in the Black Sea

A novel quantitative analysis employing the Principal Component Analysis (PCA) of containership traffic in the Black Sea from 2018 to 2021 is performed. The study uses a matrix covering five ship size classes from A to E for four years of operation, from 2018 to 2021, accounting for ship traffic, CO2, fuel consumption (FC), shipping intensity, and eco and traffic efficiency. Only the first two principal factors are analysed because of their total variation weight. Shipping intensity, FC intensity, and CO2 intensity plays a significant role in the first factor, while Eco efficiency, FC efficiency, and Traffic efficiency are considered for the second factor. Notably, the set of parameters pertains to time and is strongly associated with DWT. Two principal components were identified, F1 and F2, where F1 integrates efficiency and intensity. At the same time, F2 separates the intensity from the efficiency conditional on the ship size and the year of operations. In the principal component F1 the activities of ships A and C differ from B, D and E, separating more efficiently from less efficiently used ships, and in F2, the activities of class sizes of ships C and D and E contrast A and B ships, distinguishing the big-size class ships from small ones. It was concluded that the most intensively used ships are the ship size classes C and D, and the most efficient are ship size classes A and B. The most intensive use of the ships was in 2020, followed by 2021, and the most efficient were in 2018, 2019. Based on the ship activities and using the Within-class variance, ships are grouped into two clusters of similar activities, where the first one, with lower variance and more homogeneous, includes only the ship size class A. The second one with a relatively large variance consists of the rest size of the ships. Linear relationships considering the intensity and efficiency are derived as a function of the main variables, where the factor loading represents the variable’s coefficient, given as a relative weight to any factor

A new precision measurement of the {\alpha}-decay half-life of 190Pt

A laboratory measurement of the $\alpha$-decay half-life of $^{190}$Pt has been performed using a low background Frisch grid ionisation chamber. A total amount of 216.60(17) mg of natural platinum has been measured for 75.9 days. The resulting half-life is $(4.97\pm0.16)\times 10^{11}$ years, with a total uncertainty of 3.2%. This number is in good agreement with the half-life obtained using the geological comparison method

Efekti betaina kao dodatka u ishrani na neke proizvodne osobine šarana (cyprinus carpio l.) gajenog u recirkulacionom sistemu

Cilj ovog istraživanja bio je da se ustanove efekti betaina kao dadatka u ishrani na stopu preživljavanja, prirast i konverziju hrane kod šarana (Cyprinus carpio L.), gajenog u recirkulacionom sistemu. Četrdeset i osam jedinki šarana čija je prosečna početna težina bila 1238.13±39.19 - 1241.25±29.73 g podeljeni su u tri grupe. Eksperiment je rađen u duplikatu. Ribe su gajene u betonskim tankovima zapremine 0.8 m3, koji su pripadali recirkulacionom sistemu. Riba je hranjena ekstrudiranom hranom ”Aqua VITAL“, koju proizvodi “Aqua garant“. Veličina peleta bila je 6 mm. 1% betaina dodat je hrani šarana koji je pripadao eksperimentalnoj grupi EG1, dok je hrana za drugu eksperimentalnu grupu (EG2) sadržala 3% betaina. Šaran iz kontrolne grupe (CG) nije dobijao betain u ishrani. Hrana kojom je riba hranjena predstavljala je 2% težine ribe. Ogled je trajao 60 dana, a kontrolni ulov obavljen je 30-og dana da bi se ispitao uticaj betaina kao dodatka u ishrani na prirast i odnos konverzije hrane kod šarana (Cyprinus carpio L.), koji se gaji u recirkulacionom sistemu. Težina ribe (g) na kontrolnom ulovu ustanovljena je tako što je svaka jedinka pojedinačno merena. Finalna težina šarana iz eksperimentalnih i kontrolnih grupa iznosila je: EG1 – 1727.50±40.52 g, EG2 – 1749.39±33.45 g and CG – 1646.88±26.51 g. Vrednosti ovog parametra kod ribe iz druge eksperimentalne grupe EG2 bile su više nego kod jedinki iz EG1 (1.27%) i CG (6.22%), međutim razlike nisu bile značajne (P>0.05). Prosečni individualni prirast kod šarana iz dve replikacione kontrolne grupe bio je 406.25±20.61 g, što je 20.46% i 25.08% niže nego kod riba koje su dobijale 1% i 3% betaina, dok su razlike bile značajne (P<0.001). Najbolji koeficijent konverzije hrane bio je kod šarana iz EG2 - 1.49. Ova osobina je imala niže vrednosti nego kod riba iz EG1 (3.36% ) i CG (24.16%) (P<0.001). Kada je reč o stopi preživljavanja riba iz svih grupa, diskrepance nisu uočene. Ekonomska efikasnost grupe koje je dobijala 1% betaina bila je 1.66, što je niže nego kod EG2 (10.34%) i CG (15.66%)

SOFT TISSUE DYSFUNCTIONS OF THE UPPER LIMB - PATHOKINESIOLOGICAL PREREQUISITE FOR THEIR OCCURRENCE

В спортове като, бокс, борба, карате се извършват специфични двигателни стереотипи, които ангажират динамичните и статични структури на опорно-двигателния апарат, определящи силата, издръжливостта, мобилността и постуралния контрол. Нормалното алиниране и конгруентността наставните компоненти определя балансираното разпределение на силите между медиално и латерално разположените структури на горните крайници. Улнарната девиация (отклонение) на киткена става преразтяга радиалния отдел и подлага на компресия структурите намиращи се от улнарната страна на китката. Това отклонение има отношение към травмите не само на китка и пръсти, но и към краниално разположените сегменти на горни крайници. Повтарящите се движения (прави удари, упражнения върху и на уреди), както движения свързани с рязка смяна на посоката и неправилното сгъване на ръката в юмрук водят до по-бързо изчерпване на механичната издръжливост и претоварване на мускулния и капсуло-лигаментарния апарат. Тази кинезиологична предпоставка променя линиите на теглене на мускулите, в резултат на което режещите, натисковите и торзионни сили се увеличаватвърху определени костни или мускулни компоненти. Целта на настоящата статия е да се посочат причини за поява на мекотъканни дисфункции на китка

Messgenauigkeit zweier verschiedener pulsoxymetrischer Sauerstoffmesssysteme im Vergleich zur arteriellen Sauerstoffsättigung bei Kindern mit angeborenen Herzfehlern

Häufig beruht die initiale Diagnose einer Hypoxämie auf der Pulsoxymetrie, die als nicht-invasives, schnelles und zuverlässiges Verfahren in mehreren Bereichen der Medizin etabliert ist. Die Pulsoxymeter sind in der Regel auf einen Sättigungsbereich von 70 % bis 100 % mit einer Messgenauigkeit von 2 % bis 4 % kalibriert.142 Die Kalibration erfolgt anhand erwachsener Patienten, die Gasgemische mit unterschiedlich niedriger Sauerstoffkonzentration einatmen. Trotz der kontinuierlichen Weiterentwicklung des Verfahrens, bestehen relevante Abweichungen vom Goldstandard besonders im unteren Sauerstoffsättigungsbereich. Es stellt sich die Frage, ob die Messgenauigkeit der Pulsoxymeter bei Patienten mit angeborenen zyanotischen Herzvitien ausreichend ist, um diese nicht ungewollt einer Hypoxämie oder einer Übertherapie mit Sauerstoff auszusetzen. Allein durch statistische Verfahren lässt sich diese Frage nicht sicher beantworten. Die Messgenauigkeit der in der vorliegenden Studie untersuchten Pulsoxymeter war in Abhängigkeit der aSO2-Werte unterschiedlich. Obwohl Nellcor Oximax eine bessere Übereinstimmung mit dem Goldstandard in allen Gruppen aufweist, überstieg der Arms-Wert im unteren Sauerstoffsättigungsbereich (70 – 85%) die von der FDA (Food and Drug Administration) empfohlene Grenze ≤ 3%. In diesem Bereich zeigte sich eine signifikante Überschätzung der aSO2 Werte bei beiden Geräten. So würde beispielsweise bei einer von Philips IntelliVue gemessenen Sauerstoffsättigung von 80%, in 50% der Fälle die tatsächliche Sauerstoffsättigung unter 71% oder über 83% liegen. Bei Nellcor Oximax würde in 50% der Fälle die tatsächliche Sauerstoffsättigung unter 75% oder über 81% liegen. Die Ergebnisse geben Anlass zur Sorge, dass eine kritische Hypoxämie unerkannt und untertherapiert bleiben könnte, wenn man sich nur auf die Pulsoxymetrie als primäres Mittel zur Beurteilung der Sauerstoffsättigung verlässt. Dies kann Konsequenzen für Kinder mit angeborenen zyanotischen Herzfehlern haben, die normalerweise Sättigungswerte im unteren Kalibrierungsbereich der Pulsoxymeter haben. Daher sollte es nach Möglichkeit regelmäßige Abgleichungen der im klinischen Alltag eingesetzten Messverfahren mit einer arteriellen Messung geben, um systematische Abweichungen des Messsystems zu erkennen. Der FDA zufolge, sollten bei den Pulsoxymetriemessungen die Diagnose und Therapieentscheidungen auf der Basis von Trendwerten im Zeitverlauf und nicht auf der Basis von Absolutwerten getroffen werden

Correlation of lithographic performance of the electron beam resists SML and ZEP with their chemical structure

Study of topographical and structural changes occurring in a positive resist known as SML after electron beam lithography are presented in this article. The authors also defined its chemical structure, which is very important for understanding the lithographic performance of the resist. The structural and lithographic properties of SML have been compared to the traditional ZEP resist. First, the change in the surface roughness with respect to the electron dose of SML and ZEP resists was measured. It was found that both resists start off with similar initial roughness values. However, ZEP was observed to have a higher roughness at the apex electron dose, thereafter a reduction in roughness was observed. The roughness variation in the two resists reflected on the resolution of the gratings that were patterned in both the resists. Gratings in SML showed smoother line edge roughness, and the patterns transferred using SML resist showed more even features than the ones transferred with ZEP. Subsequently, to understand the chemical composition of the new resist, Fourier transform infrared spectroscopy (FTIR) measurements were performed on both the resists as well as on poly(methyl methacrylate) (PMMA) and their spectra were compared. The FTIR spectra revealed that SML had a chemical structure similar to ZEP and PMMA polymers. The high sensitivity of ZEP is attributed to the Cl group in the compound, which is not present in SML and PMMA and can therefore explain their lower sensitivity to electron exposure in comparison to ZEP. Unlike PMMA but comparable to ZEP, SML shows an IR peak at a wavenumber close to 850 cm−1, suggesting the presence of α-methylstyrene group within its chemical structure, which accounts for the resist's high etch durability, similar to ZEP. Additional FTIR measurements of pre- and postexposed resists together with their attributions to the resolution of the SML and ZEP resists is also demonstrated in this article. The data presented in the study highlights the chemical properties of SML and ZEP resists polymers and correlates them to their lithographic performance

Attitude toward Professional Realization of Graduates in the Specialty Rehabilitator

Rehabilitation is a complex of therapeutic and restorative, preventive, pedagogical, and socio-economic activities aimed at preventing possible disability and restoring the anatomical integrity and functional balance of the body. The rehabilitator is a specialist with medical education who participates in the preparation of medical expertise for solving the professional and social problems of persons endangered by disability. Rehabilitators conduct therapeutic procedures such as electrotherapy, light therapy, inhalation therapy, kinesitherapy, therapeutic massage, extension therapy, and suspension therapy. The aim of the research is to study the attitudes toward professional realization of students studying in the specialty Rehabilitator at Medical College, Medical University of Varna. For the purpose of the research, we conducted a sociological survey. Among them are students graduating the specialty Rehabilitator at Medical University of Varna and Medical University of Sofia