Thesis (doctoral)--Uppsala universitet, 1982. / Extra t.p. with thesis statement inserted. Summary in English. Includes bibliographical references (p. 220-239).

This thesis studies the historic encounter between United States Navy airship K-74 and Nazi submarine U-134 in World War II. The Battle of the Atlantic is examined through case study of this one U-boat and its voyage. In all things except her fight with the American blimp, the patrol was perfectly typical. Looked at from start to finish, both her reports and the reports of the Allies encountered, many realities of the war can be studied. U-134 sailed to attack shipping between Florida and Cuba. She was challenged by the attack of United States Navy airship K-74 over the Florida Straits. It is the only documented instance of battle between two such combatants in history. That merits attention. Thesis finding disprove historian William Eliot Morison’s contention that the K-74 airship bombs were not dropped and did not damage the U-boat. Study of this U-boat and its antagonist broadens our understanding of the Battle of the Atlantic. It is a contribution to our knowledge of military, naval, aviation, and local history.

The essence of this diploma work is to find suitable alternatives to the current situation in the river sightseeing vessels. The aim is to design an object that would offer passengers an adequate and attractive environment where they would spend their free time and which would also be appropriate supplement to the place where this vessel is located.

This thesis describes a method to generate new trajectories based on historic positiondata for a given geographical area. The thesis uses AIS-data from fishing boats to first describe a method that uses DBSCAN and OPTICS algorithms to cluster the data into clustersbased on routes where the boats travel and areas where the boats fish.Here bayesian optimization has been utilized to search for parameters for the clusteringalgorithms. In this given scenario it was shown DBSCAN is better in all fields, but it hasmany points where OPTICS has the potential to become better if it was modified a bit.This is followed by a method describing how to take the clusters and build a nodenetwork that then can be traversed using a path finding algorithm combined with internalrules to generate new routes that can be used in simulations to give a realistic enoughsituation picture. Finally a method to evaluate these generated routes are described andused to compare the routes to each other

Scallops have traditionally been blast or sharp frozen. This study compared the quality of at-sea cryogenically frozen scallops with fresh and mechanically frozen scallops. A liquid CO₂ batch freezer was installed on-board the scallop boat. Samples were analyzed for microbiological, physical, chemical and sensory qualities. Sample types included fresh scallops, mechanically frozen scallops and 4 hr and 24 hr (on ice) cryogenically frozen scallops. The thaw loss mean of 4 hr cryogenically frozen scallops was 2.41 percent compared to means of 4.21 percent for 24 hr (on ice) cryogenically frozen scallops and mechanically frozen scallops, P < 0.0001. Cook loss for the 4 hr cryogenic frozen scallop was also reduced (P < 0.01) by 27 percent when baked. Cook method did not affect cook loss. Color measurements on the CIE L* a* b* scale did not differ significantly for raw or baked scallops. Instron peak force measurements had a very high standard error and therefore were not be analyzed statistically. The 4 hr cryogenically frozen scallops met the French Moisture/Protein ratio test standard of 5 (P > 0.02) but higher ratios were observed for 24 hr (on ice) cryogenically frozen scallops and mechanically frozen scallops. Scallops meeting this standard have greater export potential and the ability to attract high value markets. Variations observed in proximate composition were minor and may be due to biological factors. Sensory panelists found a significant difference (P < 0.01 to P < 0.05) among the randomly presented pairs of scallops. Over a 5 month storage period, the sensory characteristics of odor and taste of the cryogenically frozen scallops diminished and the mechanically frozen scallops were consistently scored higher. Mechanically frozen scallops had significantly lower cfu/gm for aerobic, psychrotrophic and coliform counts compared to fresh and cryogenically frozen scallops. The 4 hr cryogenically frozen scallop had lower thaw and cook loss which could have a significant economic and nutritional significance. Mechanically frozen scallops had a lower microbiological population and frozen storage for 8 months did not affect its taste or odor. Improved Sanitation and process control could establish cryogenically frozen scallops as a premium product. / Master of Science

Three different species of fish (sea trout, Spanish mackerel and catfish) were studied. Samples undergoing normal spoilage were compared with samples which had undergone a sanitizing treatment with alcohol. Differential temperature storage studies were conducted at 290 °F (-1.7 °C) and 32 °F (0 °C). Fish quality was assessed by means of microbiological, chemical and sensory analyses. Quality assessment via measurement of proteolytic and lipolytic enzymes was attempted, but these enzyme activities were not detected in any of the samples. It was not possible to differentiate between the contributions of microbial and autolytic spoilage. Alcohol treated samples (reduced numbers of microorganisms) had shelf-lives extended by 6-10 days over untreated samples. The shelf-life of samples stored at 290 °F was extended by 6-10 days over the shelf-life of samples stored at 32 °F. Treated samples stored at 290 °F received highest sensory scores and untreated samples stored at 320 °F received the lowest scores. It was seen that the three fish species studied had different shelf-lives: sea trout-6 days, Spanish mackerel - 10 days and catfish - 16 days. Decomposition rates differed significantly between species and this factor must be taken into account when marketing strategies are developed by firms engaged in fresh fish sales. / Master of Science

In Old West Norse there is mention of an Arctic skin and osier boat, which was paddled with Old West Norse (húð)keipr, diminutive keipull, formed on Germanic *kaip- ’bend, unfold’ according to the construction method. In East Norse there was a corresponding wooden boat, e.g. Swedish själ-myndrick, formed on mynda verb ‘paddle’ (&lt; Primitive Norse *mundian ‘aim at a certain goal, take aim’). In the provinces south of this verb’s area of distribution there occurs instead svepa verb ’paddle’ (&lt; Primitive Germanic *swaipōn ‘swing’). The earliest instances of Nordic rowing navigation are found in Norway and Denmark. Instances of rowing in the Baltic area are found on some picture stones from about the 6th century. But oarlocks with a grommet were probably used already for the steering oar in the paddled boats of the Bronze Age. An early oarlock (with a grommet) is that made of a goose-necked piece of wood, Old Swedish hār, Old West Norse hár (&lt; *hanhu-, *hanha- ‘branching, fork of a branch’) and Old West Norse keipr (&lt; *kaip- ‘something with a crooked or bent (-back) shape’. The word hár exists as a first element in Old Swedish hā-band ‘oar-loop’, Old West Norse há-bora ‘oar-port’ etc. Old West Norse keipr ‘oarlock’ has no ancient compounds. East Nordic hamna (&gt; Finnish hamina), Old Danish hafnæ (Old Frisian hevene) and West Nordic hamla (Faroese homla, Old English hamele, hamule) ‘oar-loop’ occurred early on the oarlock with a grommet; hamna may be a derivation of the stem in Primitive Norse *haƀan verb ‘hold (fast)’, alternatively *hafna- ‘clasp something’; hamla derives from a Germanic *hamilōn with the meaning ‘bridling band’. Centrally in the Nordic area hamna (Danish havne) and hamla ‘oar-loop’ were also used denominatively with the meaning ‘row pushing in a hamna/hamla (oar-loop)’. In addition there is the Swedish dialectal sväva (~ sveva, svävja) ‘row (back, break etc.) with pushing rowing’ and in the group of older verbs for rowing there is East Swedish hopa &lt; Primitive Norse *hōƀian ‘fix one’s eyes upon a certain goal (in the distance)’. With word formations on Germanic *þulna- ‘wooden plug’ there arose from the Middle Ages and in the North Sea countries a new terminology for the oarlock: Norse tull, toll ‘oarlock with a thole pin’. Even younger concepts are tullgång ‘oarlock with two thole pins’, årklyka, årgaffel ‘oar crutch’. A distinctive trait of Old Swedish hār and hamna, Old West Norse hár and hamla and keipr and other common words for the oarlock is in these words the shift of meaning ‘oarlock of a specific kind’ &gt; ‘almost any kind of oarlock’. Finally, the question arises whether or not the word svear of a tribe by Lake Mälaren could be tied to the paddling through a connection to the stem of the verbs svepa and sväva. / <p>Ingår även i serie: Studier till en svensk dialektgeografisk atlas, 8</p>

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2008. / This study investigates practical passive methods to improve the seakeeping of a Hydrofoil Supported Catamaran (Hysucat). The Hysucat is a hybrid vessel combining hydrofoil efficiency with the stability of catamarans. The seakeeping of the Hysucat was initially investigated experimentally to determine what seakeeping improvements are inherent to the Hysucat design. The results showed that the seakeeping is improved by 5-30%. A passive suspension system for the main hydrofoil of the Hysucat was designed and tested. A concept development strategy was followed for the design of the suspension system as such a system had never been investigated previously. Detailed specifications for the design were developed and concepts that could satisfy the customer and engineering requirements were generated. Numerical simulation models for the Hysucat and the final concepts were derived assuming a simplified 2nd order system to describe the seakeeping dynamics of the demi-hulls. Unknown parameters were determined using parameter estimation techniques. Representative parameter values were calculated from multiple towing tank experiments. Theory describing the motion of a hydrofoil in an orbital velocity wave field was combined with the hull model to simulate the Hysucat as well as the suspension system concepts. The models indicated that the concept where the main hydrofoil was attached to a spring loaded arm, that was free to pivot in response to orbital waves, was the most feasible in damping out vertical transmitted accelerations. Experimental tests indicated that little improvement was achieved with the suspension system at low frequencies. At resonance the suspension system was effective in decreasing the heave of the vessel by up to 27%. The pitch and acceleration response results showed improvements at the higher encounter frequencies of up to 50%. The calm water resistance of the vessel increased by 10% over the Hysucat with rigidly attached hydrofoils; however was still 24% less than the hull without foils.

Thesis (PhD)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: This work is concerned with the hydrodynamic design of hydrofoil-assisted catamarans. Focus is placed on the development of new and suitable design methods and application of these to identify the most important geometric parameters of catamaran hulls and hydrofoil configurations that influence efficiency and performance. These goals are pursued by firstly gaining a thorough understanding of the governing hydrodynamic principles involved in the design process. This knowledge is then applied to develop new and improved experimental techniques and theoretical methods needed for design. Both are improved to the extent where they can be applied as design tools covering the important semi-displacement and semi-planing speeds, which are the focus of this study. The operational speed range of hydrofoil-assisted catamarans is shown to consist of three distinct hydrodynamic phases (displacement, transition and planing) and that different hydrodynamic principles govern vessel performance in each phase. The hydrodynamics are found to differ substantially from that of conventional high-speed craft, primarily due to the interaction between the hull and the hydrofoils, which is found to vary with speed and results in the need for more complex experimental procedures to be followed if accurate predictions of resistance are to be made. Experimental predictions based on scaled model tests of relatively small hydrofoilassisted catamaran models are found to be less accurate than that achievable for conventional ships because of the inability to correct for all scaling errors encountered during model testing. With larger models scaling errors are encountered to a lesser degree. The most important scale effect is found to be due to the lower Reynolds number of the flow over the scaled foils. The lower Reynolds number results in higher drag and lower lift coefficients for hydrofoils compared with those achieved at full scale. This effect can only be partially corrected for in the scaling procedure using the available theoretical scaling methods. Presently available theoretical methods commonly used for the design of conventional ships were found to be ill adapted for modeling the complex hydrodynamics of hydrofoil-assisted catamarans and required further development. Vortex lattice theory was chosen to model the flow around hydrofoil-assisted catamarans as vortex theory models the flow around lifting surfaces in the most natural way. The commercial code AUTOWING is further developed and generalized to be able to model the complex hull-hydrofoil interactions that change with speed. The method is shown to make good predictions of all hydrodynamic quantities with accuracies at least as good as that achievable through model testing and therefore fulfills the requirements for a suitable theoretical design tool. The developed theoretical and experimental design tools are used to investigate the design of hydrofoils for hydrofoil-assisted catamarans. It is found that the main parameter needing consideration in the hydrofoil design is selection of a suitable hydrofoil lift fraction. A foil lift fraction in the order of 20-30% of the displacement weight is needed if resistance improvements using hydrofoil assistance are to be obtained over the hull without foils. It is often more favorable to use higher foil lift fractions (50%+) as the resistance improvements are better, although careful attention should then be given to directional and pitch-heave instabilities. The Hysuwac hydrofoil system patented by the University of Stellenbosch is found to be hydrodynamically optimal for most hullforms. The hullform and in particular the curvature of the aft buttock lines of the hull are found to have an important influence on the achievable resistance improvements and behaviour of the hydrofoil-assisted hull at speed. Hull curvature is detrimental to hydrodynamic performance as the suction pressures resulting from the flow over the curved hull counter the hydrofoil lift. The hullform best suited to hydrofoil assistance is found to be one with relatively straight lines and hard chine deep- V sections. The main conclusion drawn from this study is that hydrofoil-assistance is indeed suitable for improving the performance and efficiency of catamarans. The design and optimization of such vessels nevertheless requires careful consideration of the various resistance components and hull-foil interactions and in particular, how these change with speed. The evaluation of resistance for design purposes requires some discipline between theoretical analysis and experimental measurements as the complexity of the hydrodynamics reduce the accuracies of both. Consideration of these factors allows hulls and hydrofoils to be designed that are efficient and also free of dynamic instabilities. / AFRIKAANSE OPSOMMING: Hierdie studie is gerig op die hidrodinamiese ontwerp van hidrovleuel-gesteunde katamarans. Daar word gefokus op die ontwikkeling van nuwe en geskikte ontwerpmetodes, asook die toepassing van hierdie metodes om die belangrikste geometriese parameters van katamaranrompe en hidrovleuel-konfigurasies wat 'n invloed op doeltreffendheid en werkverrigting het, te identifiseer. As aanloop tot die studie is 'n deeglike begrip van die onderliggende hidrodinamiese beginsels bekom. Hierdie kennis is toegepas om nuwe en verbeterde eksperimentele en teoretiese tegnieke te ontwikkel wat nodig is vir die ontwerp van hidrovleuel-gesteunde katamarans in die belangrike deels-verplasing en deels-planering spoedbereike. Daar word getoon dat die bedryfspoedbereik van 'n hidrovleuel-gesteunde katamaran uit drie onderskeibare hidrodinamiese fases bestaan, naamlik verplasing, oorgang en planering, en dat verskillende hidrodinamiese beginsels die vaartuig se werkverrigting in elke fase bepaal. Daar is ook gevind dat die hidrodinamika wesentlik verskil van dié van konvensionele hoëspoed-vaartuie, hoofsaaklik as gevolg van die interaksie tussen die romp en die hidrovleuels wat wissel na gelang van die spoed. Hierdie interaksies moet in ag geneem word gedurende die ontwerpproses en beide eksperimentele en teoretiese metodes is nuttig om die omvang daarvan te bepaal. Daar is gevind dat die eksperimentele voorspellings gebaseer op toetse met relatief klein skaalmodelle van hidrovleuelgesteunde katamarans minder akkuraat is as dié wat bereik kan word met konvensionele skepe. Dit is omdat al die skaalfoute wat tydens die toetsing met die model ontstaan, nie gekorrigeer kan word nie. Die belangrikste skaaleffek is as gevolg van die laer Reynoldsgetal van die vloei oor die afgeskaalde vleuels. Groter modele Die laer Reynoldsgetal lei tot hoër sleur- en hefkoëffisiënte in vergelyking met dié vir die volskaal-hidrovleuels. Wanneer die beskikbare teoretiese metodes gebruik word, kan daar slegs gedeeltelik vir hierdie effek in die skaalprosedure gekorrigeer word. Daar is ook vasgestel dat die skaaleffekte op die Reynoldsgetal verminder word wanneer die hidrovleuels baie nabyaan die vrye oppervlakte is. Dit lei daartoe dat eksperimentele voorspellings van werkverrigting meer akkuraat is vir die ontwerpe waar die hidrovleuels nie so diep onder die water is nie. Daar is gevind dat die teoretiese metodes wat tans beskikbaar is en algemeen vir die ontwerp van konvensionele skepe gebruik word nie die komplekse hidrodinamika van hidrovleuel-gesteunde katamarans kan modelleer nie. Die werwelroosterteorie is gekies om die vloei om hidrovleuel-gesteunde katamarans te modelleer aangesien dié teorie die vloei om hefvlakke op die natuurlikste manier weergee. Die kommersiële kode AUTOWING is verder ontwikkel en veralgemeen om ook die komplekse spoed-afhanklike interaksies van die romp en hidrovleuel te kan modelleer. Hierdie metode lewer goeie voorspellings van al die hidrodinamiese maatstawwe met akkuraathede wat ten minste so goed is soos di wat met modeltoetsing bereik word en voldoen daarom aan die vereistes vir 'n geskikte teoretiese ontwerpmetode. Die teoretiese en eksperimentele ontwerpmetode wat ontwikkel is, word gebruik om die ontwerp van hidrovleuels vir hidrovleuel-gesteunde katamarans te ondersoek. Daar is gevind dat die belangrikste parameter wat in die hidrovleuel-ontwerp in ag geneem moet word, die keuse van 'n geskikte hidrovleuelhefverhouding is. Om in rompe met hidrovleuelsteun verbeterings in die weerstand te kry in vergelyking met rompe sonder vleuels, is 'n vleuel-hef-verhouding van 20-30 persent van die verplasingsgewig nodig. Dit is dikwels beter om hoër vleuel-hef-verhoudings (van 50 persent of meer) te gebruik omdat die verbetering in weerstand dan groter is. Daar moet dan egter gewaak word teen rigtings- en hei-hef-onstabiliteite. Daar is gevind dat die Hysuwachidrovleuel- stelsel wat deur die Universiteit van Stellenbosch gepatenteer is, hidrodinamies optimaal is vir die meeste rompvorms. Daar is gevind dat die vorm van die romp en veral die kromming van die lyne gevorm deur vertikale snitte deur die romp (Engels: "aft buttock lines") van die romp 'n belangrike invloed het op die bereikbare weerstandsverbeterings en die gedrag van die hidrovleuel-gesteunde romp wat op spoed is. Die kromming van die romp is nadelig vir die hidrodinamiese werksverrigting aangesien die suigdruk as gevolg van die vloei oor die gekromde romp die hefkrag van die hidrovleuels teenwerk. Die rompvorm wat die geskikste is vir hidrovleuel-ondersteuning is 'n romp met relatiewe reguit lyne en skerp hoekige diep- V seksies. Die belangrikste gevolgtrekking waartoe tydens die studie gekom is, is dat hidrovleuelondersteuning wel geskik is vir die verbetering van die werkverrigting en die doeltreffendheid van katamarans. Die ontwerp en optimering van sodanige vaartuie verg nogtans die noukeurige oorweging van die verskeie weerstandskomponente en rompvleuel- interaksies en veral hoe hierdie interaksies verander met spoed. Die evaluering van die weerstand vir die doeleindes van ontwerp verg dissipline tussen die teoretiese analise en die eksperimentele metings aangesien die kompleksiteit van die hidrodinamika die akkuraatheid van die algemeen-gebruikte teoretiese en eksperimentele metodes vir die hidrodinamiese ontwerp verminder. As hierdie faktore in ag geneem word, kan rompe en hidrovleuels ontwerp word wat doeltreffend is en ook vry is van dinamiese onstabiliteite.

Made available in DSpace on 2014-12-17T15:37:23Z (GMT). No. of bitstreams: 1 CarolinaHT.pdf: 827980 bytes, checksum: a107e08846f0000f45730f83c3b8e2a4 (MD5) Previous issue date: 2007-09-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Synchronism is the efetivation of the same behavior at the same time by two or more individuals. In cetology only from 2000 we verify an increasing of efforts for studies of synchronic behaviors. The synchronism in cetaceans was reported for a variety of contexts, including feeding, socializing, parental care, while resting, traveling and play, during afilliation, in sexual behaviour and possible while teaching. The synchronism in behavior is influenced by environmental factors and can be modified during stress situations such as the presence of boats. The aim of this study is to explore behavior synchronism presented by the estuarine dolphin (Sotalia guianensis) in Pipa, Rio Grande do Norte state, Northeastern Brazil. A total of 414 hours of observation during the year 2006, using scan sampling method, from a land based sighting was conducted. Analyses were conducted in four steps. Firstly, we determined the pattern of activity of the groups within the bay, testing for the influence of bay configuration before and after rains periods on the activity of animals. Analyses show that forage occurs more frequently after the rainy period, but there was no change in the number of individuals or spatial cohesions between them. Secondly, we analysed the influence of turism boat traffic on the behavior of animals. We verified no changes on the bahavior of animals during the presence of boats. Finally, we tested seven hypotheses regarding the ecological and social dynamics of synchronic behavior. Environmental aspects were considered the main influence for the synchronism, no influences of age, and more selective exihibition of synchronic breathing in feeding and social displays were observed during the study period / Sincronismo ? a efetiva??o ao mesmo tempo de um determinado comportamento por dois ou mais indiv?duos. Nos cet?ceos, os comportamentos realizados de forma sincr?nica s?o pouco estudados, e somente a partir de 2000 verifica-se um maior esfor?o na cetologia para investiga??o deste sincronismo comportamental. O sincronismo em cet?ceos tem sido relatado para uma variedade de contextos incluindo alimenta??o, socializa??o, cuidada parental, enquanto descansam, viajam e brincam, durante a afilia??o, no comportamento sexual e possivelmente enquanto ensinam. O sincronismo de comportamento ? influenciado por vari?veis ambientais e pode modificar-se em resposta a situa??es estressantes como o tr?fego de embarca??es. Este estudo visa caracterizar o sincronismo de comportamento efetivado pelo boto cinza (Sotalia guianensis) na praia de Pipa/RN. Para tanto foram realizadas um total de 414h de observa??o durante o ano de 2006, com a varredura como m?todo de registro. Para a an?lise algumas etapas e objetivos espec?ficos foram determinados. Primeiramente, foi determinado o padr?o de atividades dos grupos que freq?entaram as enseadas na ?poca do estudo, verificando poss?veis diferen?as correlacionadas ? enseada e ao per?odo do ano. As an?lises mostraram que ocorreu maior forrageio no per?odo ap?s as chuvas, mas n?o houve modifica??o no n?mero de indiv?duos ou coes?o entre os mesmos. Em seguida, analisamos a influ?ncia do turismo de observa??o de golfinho sobre o comportamento geral (or?amento de atividades e coes?o entre os indiv?duos) e sincr?nico dos animais. Foi verificado que n?o houve influ?ncia do barco no comportamento dos golfinhos. Por fim, testamos sete hip?teses acerca da din?mica ecol?gica e social do sincronismo comportamental. Destacou-se a influ?ncia de fatores externos (ambientais) na apresenta??o do sincronismo, a aus?ncia de influ?ncia da faixa et?ria, e a exibi??o mais seletiva (individualizada) de respira??o sincr?nica em forrageio e socializa??o, dado o menor n?mero de indiv?duos que apresentam este sincronismo respirat?rio