bluuebunny/crossref_metadata_2025_split huggingface dataset:
A One-Hundred-Ton Oil Recovery Vessel for Bantry Bay
Authors: Neal R.W. , Bianchi R.A. , Marcus E.W. 
Published: October 2008

ABSTRACT
As part of a world-wide program. to provide complete oil-spill response capabilities to its operating facilities, the Gulf Oil Corporation has acquired a newly developed oil recovery ship for its deep-water oil terminal in Bantry Bay, Ireland. Besides requiring a highly effective oil recovery unit, Gulf also required a ship to patrol the waters near Whiddy Island, where the terminal is located, and periodically to patrol the full length of Bantry Bay, a round trip of about 50 miles.
Located on the southwest coast of Ireland, the Bay is exposed to the North Atlantic Ocean, and sea conditions are frequently severe the year round. In winter, rough to high seas (5 to 20 feet in height) are at a maximum., occurring 33 to 67 percent of the time. During spring, rough seas are at a minimum., but still occur 18 to 24 percent of the time.
Half-scale oil recovery tests were conducted in Boston Harbor and at EPA I s oil spill control test facility. A description of the facility, the procedures used and surface and underwater photography of several of the tests -are presented in the paper.
Seakeeping properties of the ship designed for use in Bantry Bay, Ireland, were investigated using the "5-D Seakeeping Program.". The program. was run for nine wave spectra which fully covered the range of sea conditions in which the vessel could expect to operate.
The vessel christened the "Bay Skimmer", is a fully equipped, 68 foot, 100-ton ship designed to patrol at speeds up to nine knots and to recover oil up to three knots.

INTRODUCTION
Gulf Oil Terminals (Ireland) Ltd., operates a deep-water oil terminal located on Whiddy Island in Bantry Bay, Ireland. Very large tankers (VLCC?s in excess of 250,000 DWT) unload crude oil from. the Middle East here, and smaller tankers are loaded for shipments to refineries throughout Europe.
Bantry Bay is located on the southwest coast of Ireland, which is characterized by bold mountainous peninsulas. Bantry itself is a minor port, significant primarily as a local fishing harbor and port of call for small. coastal vessels. The entire area, which is picturesque and unspoiled, is becoming increasingly attractive to tourists.
The Gulf terminal was built in 1968. Great care was taken to assure that storage tanks were strategically placed to avoid visual "pollution" altogether. Operations of the terminal have been conducted with equally great care to prevent accidental oil spills, and an excellent safety record has been established. Nevertheless, because of the number and size of the ships handled here, Gulf selected Bantry as one of the terminals worldwide to be equipped with a complete oil-spill response capability.
After evaluating several alternatives, Gulf selected the type of skimmer which it felt would be best suited to the needs in Bantry Bay. An oil recovery ship, which is the subject of this paper, was then developed to meet the specific requirements of this location and service.
Simultaneous Passive And Active Microwave Observations Of Near-Shore Beaufort Sea Ice
Authors: Campbell W.J. , Gloersen P.J. , Zwally H.J. , Ramseier R.O. , Elachi C.J. 
Published: October 2008

ABSTRACT
The use of active and passive microwave imagery in combination is the optimum way to observe the morphology and dynamics of near shore ice. Active and passive microwave data from aircraft that are described in this paper are also compared to the ESMR (Electrically Scanning Microwave Radiometer) imagery of the Nimbus-5 satellite. The information thus obtained shows how the data to be received from the SAR (Synthetic Aperture Radar) and SMMR (Scanning Multichannel Microwave Radiometer) and on Seasat A and Nimbus G have the potential of providing a vastly increased understanding of the near shore ice of the Beaufort Sea.

BACKGROUND
The current need for sea ice information has occurred at a time of rapid-evolution of both remote sensing platforms and sensors. These timely technical advances are beginning to eliminate the observational barriers that have limited our knowledge of a natural phenomenon existing in areas that are dark and/or cloud-covered much of the year. Furthermore, since sea ice undergoes large spatial variations on short time scales, the new sensing techniques are for the first time acquiring the sequential synoptic observations needed for cause and effect studies.
Considerable emphasis has in recent years been placed on the microwave remote sensing of sea ice because it offers the possibility of an all-weather, day-or-night, capability. Both passive and active microwave remote sensing techniques have been explored. An overview of these activities has been given in Campbell et ala (1975). Early work in this area utilized passive microwave techniques since such techniques were the first to be incorporated on board earth-viewing satellites.
The most important series of aircraft flights which demonstrated the feasibility and usefulness of ice observations by means of passive microwave sensors were those that occurred during the NASAAIDJEX (Arctic Ice Dynamics Joint Experiment) joint program. A series-of three AIDJEX pilot field experiments were performed during the springs of 1970, 1971 and 1972 in the southern Beaufort Sea. During each of these experiments, the NASA CV-990 "Galileo I " performed a variety of flights ranging in altitude from 150 m to 11 km. A wide variety of visual and infrared sensors were operated in addition to an imaging radiometer operated at a wavelength of 1.55cm and fixed-beam radiometers operated at wavelengths of 0.81, 2.8, 6.0, and 2lcm.
The 1970 data (Wilheit et al, 1972) showed that it was possible to distinguish sea-ice from liquid water both through the clouds and in the dark. This finding was useful because it pointed the way to an "all-time" ability to observe leads and polynyas. These data also showed that strong microwave emissivity differences occur on the ice surface itself. However, the lack of sufficient ground truth data prevented a determination of the reason for these differences.
New Marine Seismic Source Of The Gas Exploder Type
Authors: Reed Dale H. , Hardison Jack E. 
Published: October 2008

ABSTRACT
This new marine seismic source is a gas exploder of the DINOSEIS ® class. The principle of cavitation is built upon to obtain an improved acoustic output. Previous sources of this general type were designed to produce a direct compressional pulse while suppressing cavitation. In the new device a contained detonation drives a single plate through the water at high velocity, forming a cavitation bubble. The natural collapse results in a sharp acoustic pulse with several bar-meters peak amplitude. Such a pulse is ideal for seismic surveys. Several sources can be combined in an array for greater penetration.
Underwater photographs are displayed to illustrate the mechanism of pulse generation by bubble collapse. Calibrated far-field acoustic signatures are shown. In addition, waveforms from a downhole geophone in a Gulf of Mexico well velocity survey are displayed. A preliminary single channel marine reflection survey is shown.

INTRODUCTION
Marine seismic sources of the gas exploder type have traditionally been designed to create a compressional pulse from detonation of oxygen propane mixtures. This process requires rapid volume-acceleration and usually results in relatively low peak pressures. A study of the literature on cavitation shows that high peak pressures are obtained when vapor bubbles collapse in water. Peak pressures in excess of 104 atmospheres have been reported.1
Building on the concept of cavitation we have designed, built, and tested a new broad-band seismic source. Figures 1 and 2 show pictures of current working models.

BASIC DESIGN
Cavitation of water is a well known phenomenon. Usually cavitation happens in such a way that it is destructive and undesirable. For example, pumps and propellers are designed to avoid cavitation.
Since water cannot sustain stress in tension, it will change to vapor at low pressures. Accurate theories of cavitation do not exist, but it is fairly certain that dissolved gases come out of solution and form nuclei for water vapor bubble growth. It has long been observed that when the ambient water pressure returns to normal an inward flow collapses the bubble with little or no rebound. Coincident with this collapse a transient pressure of extremely high magnitude is created which radiates as a sound wave of high intensity.
If we assume a vapor or cavitation sphere in a body of water, we can calculate the potential energy. Figure 3 shows this energy, which on collapse is suddenly converted into compressive force and acoustic radiation. The conversion is quite efficient and offers an attractive method for seismic wave generation.
The concept for creating a large cavitation bubble is shown in Figure 4. A piston and cylinder is arranged so that the explosion of a propane-oxygen mixture drives a plate rapidly through the water, leaving a cavity behind. As will be shown later, a second pulse is generated as the piston rebounds from compression in the air box.
On The Strength Of New Composite Steelconcrete Material For Offshore Structure
Authors: Matsuishi M. , Nishimaki K. , Takeshita H. , Iwata S. , Suhara T. 
Published: October 2008

ABSTRACT
The authors have developed a new composite steel-concrete material for the strength members of huge offshore structures, where concrete is placed between steel plates. This paper contains the results of both experimental and theoretical investigations into the strength of the new composite material. Experiments under static and repeated loadings were carried out. Four types of test models of the composite material were subjected to shear, bending or combined shear and bending. It was found that the ultimate strength of the composite material is very high and it can absorb a great deal of energy at failure. A method for the ultimate strength analysis of the composite material is developed. The calculated results are in good agreements with experimental ones. Nonlinear analysis is carried out using the finite element method. In the analysis, the material nonlinearities of both concrete and steel are fully taken into account; the propagation of a crack in concrete caused by tension, plastification and crush of concrete by compression, and plastification of steel plate. Geometrical nonlinearity caused by gaps between concrete and steel is, also considered. The analysis accurately represented the behavior of the composite material under tests.
The new composite material is found to be desirable for the construction of offshore structures because of their excellent properties; large energy absorption and strength carrying capacity.

INTRODUCTION
The utilization of concrete and/or composite steel-concrete material for offshore structures gives the advantages of low initial cost, low maintenance cost and good impact resistance. Many projects using concrete are in various stages of design for offshore structures of near future such as an offshore power station.
A huge offshore structure, if made of steel, necessitates a great deal of dead load to offset its big bouyancy, whether it is of the floating type or the gravity type. The concrete may be employed as ballast and strength members in such an offshore structure. Drawbacks of concrete associate with low tensile strength and low ductility. It is difficult to secure watertightness, once concrete cracking develops in an offshore structure used in deep water, where the pressure is very high. And this may cause serious troubles. If ordinary composite steel-concrete material, such as reinforced concrete or prestressed concrete, are employed, crack starts on the surface of concrete by bending. Drawbacks of concrete require a design with an excessive margin as the exact estimation of the external forces acting upon an offshore structure is nearly impossible.
The authors have developed a new composite steel-concrete material for offshore structures to cover up the various drawbacks of the concrete. The new composite material endures large deformation and absorb a great deal of energy at failure, because the steel plate with high strength and ductility suppresses the development of surface cracks.
Procedure For Analyzing The Fatigue And Slow Crack Growth Behavior Of a Ship Structure
Authors: Marchica Nicholas V. , Beach Jeffrey E. 
Published: October 2008

ABSTRACT
A procedure for analyzing the fatigue and slow crack growth behavior of any ship structure is presented. Particular emphasis is placed on high performance ships such as hydrofoils, surface effect ships, and planning craft. Stress analyses determine the allowable fatigue design stress. A fatigue load spectrum for any particular detail is determined using in-service trials data if available or analytical techniques. An operating area analysis is performed establishing the percentage time the ship will be operating in various sea states. A fatigue analysis, using laboratory data, is performed as if the ship was operating 100 percent of the time in each sea state, the results indicating which sea states caused the greatest damage to the structure. The fatigue life of the critical area is found by summing the life predictions in each sea state based on the operating area analysis. A slow crack growth analysis, based on laboratory data, is performed using linear elastic fracture mechanics. The results of the procedure are used to determine if the structural detail analyzed should be accepted or redesigned.

INTRODUCTION
Ship structures, particularly hydrofoils, surface effect ships, and planning craft, are being built of new high strength-to-weight materials. Unfortunately, these materials are susceptible to fatigue and slow crack growth that may cause premature structural failure. An analysis approach or method is necessary to minimize this risk and insure the structural integrity of the ship structure.
This paper presents a procedure for analyzing the fatigue and slow crack growth behavior of a ship structure. A stress analysis is performed on a potential fatigue critical area of the structure to determine the allowable fatigue design stress. A fatigue load spectrum for any particular detail is determined using in-service trials data if available, or using analytical techniques. An operating area analysis is performed based on the ship's assumed deployment area, establishing the percentage time the ship will be operating in the various sea states. A fatigue analysis, using laboratory data, is performed as if the ship was operating 100 percent of the time in each sea state, the results indicating which sea states caused the greatest damage to the structure. The fatigue life of the critical area is found by summing the life predictions in each sea state based on the operational spectrum. A slow crack growth analysis, based on laboratory data, is performed using linear elastic fracture mechanics. The results of the procedure are used to determine if the structural detail analyzed should be accepted or redesigned.

STRESS ANALYSIS
A stress analysis is first performed on a critical area of the structure where fatigue and slow crack growth are of concern. This stress analysis may take many forms from the most simplified strength-of material approach to a sophisticated finite-element analysis or photoelastic analysis.
The Dynamic Behavior Of Mooring Lines
Authors: van Sluijs M.F. , Blok J.J. 
Published: October 2008

ABSTRACT
In this paper the results are presented of ＿a model study into the behaviour of anchor lines as used in the offshore mooring of a wide variety of floating structures. For this study model tests have been carried out with a buoy moored to four chains. The effect of model scale, pre-tension in the lines, wave height and wave period on the line tensions is discussed. Special attention is given to the dynamic behaviour of the mooring system, resulting into higher tensions than would follow from-calculations based upon the static catenary theory. The existence and significance of dynamic effects is confirmed by the results of forced oscillation tests with model anchor-chains in calm water.

INTRODUCTION
For offshore floating structures, which are exposed to environmental conditions, station keeping above a fixed point is an important requirement. To resist the resulting external forces these structures are, in the majority of cases, anchored to the sea bottom. It will be clear that a proper design of the anchoring system is of great importance. Inaccuracies in the design of the system and in the estimation of line tensions can have serious consequences [1].
In analysing forces and tensions in anchor lines a static and a dynamic part can be discerned. The static part covers the calculation based upon the classic catenary theory, a method which is generally applied in the design of systems capable to balance the external forces- [21 and [3]. According to Alexandrov [4], this procedure yields reliable results. Also field tests have indicated that the results of such static calculations conform very well to the measurements [5], which implies that cable dynamics have a negligible contribution to the total forces.
The approximation of anchor line forces based on statics is generally valid for lines attached to structures, whose motions come close to the static case. To meet this condition it is essential for the structure to have large natural periods of motion and small amplitude responses in the frequency range of wave components. For certain structures, however, the behaviour in waves is much different. Owing to small natural periods the relatively high :frequencies of the wave components cause large amplitudes of motion.
Recent model tests in waves, carried out at the Netherlands Ship Model Basin, showed that the resulting behaviour of the mooring lines may no longer be approximated statically. Larger mooring line tensions were observed than would follow from static catenary calculations, particularly for the weather-side lines.
Dynamic effects may be analysed mathematically through application of a finite difference method, [6], [7] and [8]. Although some insight might be obtained in this way, the sensitivity of the dynamic effect to the various mooring line parameters is still not fully explained.
Therefore, two series of systematic model experiments were carried out. The first series comprised tests in waves with a cylindrical buoy moored to four chains.
The Evolution of the Earth's Crust and Sedimentary Basin Development
Authors: Green A.R. 
Published: October 2008

ABSTRACT
The earth's crust is a thin, dynamic shell that changes in both thickness and composition through time. It is postulated that the changes that alter the crust are primarily the result of subcrustal processes and lateral interactions of crustal plates. The type of crust that underlies a sedimentary basin determines the physical framework, stability, manner of structuring, and conditions of sedimentation and environment throughout the evolution of the basin. Thus, as sediments are deposited, they record the tectonic history of the basin. These stratigraphic data can be used to develop conceptual, genetic models that put the evolution of oceanic, continental, and transitional types of crust into perspective. An orderly cycle of crustal evolution is proposed which suggests that oceanic crust is thick end and continental crust is thickened and thinned by a number of natural processes. The resulting transitional crustal types, which represent intermediate steps in the continuum, occupy a realm between thin, basic oceanic crust and thick, acidic continental crust. These transitional, somewhat unstable crustal types host most of the world's sedimentary basins. An attempt is made to step back from the detail of the complex interplay involved in the process of crustal genesis and sedimentary basin development and' look at the overall natural system. A set of hypothetical, genetic models depicting the proposed origin of various crustal types is presented so that geophysical data can be compared and tested against them.

THE CRUSTAL SETTING OF SEDIMENTARY BASINS
Sedimentary deposits greater than 2000 meters thick accumulate in depressions within the major continents or adjacent to their margins (Fig. 1). Basins within the major continents contain a large percentage of Precambrian, Paleozoic, and Mesozoic sediment, which furnishes a record of crustal evolution during these earlier periods of the earth's development. Some of these older rocks have been metamorphosed to such a degree that they can no longer be considered part of the sedimentary section, but rather are more closely related to the underlying crystalline crust. Basins on the marginal shelves, slopes, and rises of the Atlantic and Indian Oceans contain sediments of Mesozoic and Tertiary age and form some of the thickest sediment accumulations in the world. Most of the sedimentary basins around the margins of the Pacific Ocean have formed more recently and furbish valuable clues concerning the Tertiary crustal history of that part of the world. Indeed, many of the Pacific margins are presently in an active stage of basin formation and provide modern analogs to ancient mechanisms of crustal evolution.
Most of the world's sedimentary basins overlie crustal types that are neither purely continental nor purely oceanic in terms of thickness and composition. They generally develop upon thinned continental crust or upon accreted, constructed continental crust (Fig. 2).