bluuebunny/crossref_metadata_2025 huggingface dataset:
SPH MODELING OF VORTICITY GENERATION BY SHORT-CRESTED WAVE BREAKING
Authors: Wei Zhangping , Dalrymple Robert A
Published: June 2017

This study investigates vorticity generation by short-crested wave breaking by using the mesh-free Smoothed Particle Hydrodynamics model, GPUSPH. The short-crested waves are created by generating intersecting wave trains in a numerical wave basin with a beach. The capability of GPUSPH to simulate short-crested waves is first validated by laboratory measurements. Then we examine short-crested wave breaking with two incident wave heights H = 0.2 m and 0.3 m. The larger incident wave breaks at the toe of the planar beach, while the smaller incident wave breaks above the planar beach. The breaking wave profile, current field, nearshore circulation pattern, and vertical vorticity field due to short-crested wave breaking are carefully compared between two incident waves.
A GENERALIZED KDV TYPE EQUATION FOR UNEVEN DEPTHS
Authors: Beji Serdar
Published: June 2017

A Korteweg & de Vries type equation with improved dispersion characteristics for uneven water depths is presented. The new KdV type equation contains mixed dispersion and shoaling terms, which extend its applicable range of relative depths to virtually deep waters. The wave equation also satisfies an important consistency condition that there is an exact agreement between the shoaling rate of the equation itself and the rate obtained from the constancy of energy flux. A finite-difference scheme is devised for simulating several linear and nonlinear cases over varying bathymetry. The performance the new KdV type equation is observed to be quite satisfactory.
PERFORMANCE OF POROUS MARINE STRUCTURES OF SINGLE AND DOUBLE PERFORATED SEAWALLS IN REGULAR OBLIQUE WAVES
Authors: Chioukh Nadji , Boukhari Mohamed , YÃ¼ksel YalÃ§Ä±n , Hamoudi Benameur
Published: June 2017

In the present paper we examine the performance of two very common types of wave absorbing porous marine structures under regular oblique waves. The first structure consists of a single perforated vertical seawall, whereas the second consists of two perforated vertical seawalls creating what is called a chamber system (Jarlan type breakwater). The structures are surface piercing thus eliminating wave overtopping. Two methods are used for the present investigation. In the first method the problem of the interaction of obliquely incident linear waves upon a pair of porous vertical seawalls is first formulated in the context of the linear diffraction theory. The resulting boundary integral equation, which is matched with far-field solutions represented in terms of analytical series with unknown coefficients, and appropriate boundary conditions at the free surface, seabed and seawalls, is then solved numerically using the multi-domain boundary element method. In the second method a semi-analytical solution is developed by means of the eigenfunction expansions and a minimization approach using a least square method. In both methods the dissipation of the wave energy due to the presence of the perforated seawalls is represented by a simple yet effective relation in terms of the porosity parameter appropriate for thin perforated walls. The results are presented in terms of reflection and transmission coefficients, and the wave energy dissipation. Effects of the incident wave angles, porosities and depths of the walls and other major parameters of interest are explored.
CHARACTERISTICS OF NATURAL BEACHES
Authors: Bascom Willard N.
Published: June 2017

The subject of beach characteristics is a complex one which is obviously worthy of book-length treatment. The object of this paper is to describe briefly the shapes which groups of beach-forming particles take and the mechanisms by which the forces of nature have so arranged them. Using these reactions as criteria, the coastal engineer who is confronted with the problem of replenishing beach materials or of altering some existing sand flow with a shoreline structure will be able to understand (and predict) the rapid readjustment of the particles to their new environment. There are, of course, no unnatural beaches; the implication is that artificially created or nourished beaches and otherwise altered shorelines will respond in the same manner as those untouched beaches which were studied to assemble the information presented here.
LOW COST SHORE PROTECTION USED ON THE GREAT LAKES
Authors: Brater E F.
Published: June 2017

The purpose of this paper is to present the results of three years of field observations on low cost beach protection structures in use on the Great Lakes. The structures were studied in regard to their effectiveness as beach building and protective devices and with respect to their durability in resisting ice and wave forces. The term "low cost" refers to structures which cost between $10 and $50 per foot of frontage at 1952 prices.
FILLING PATTERN OF THE FORT SHERIDAN GROIN SYSTEM
Authors: Lee Charles E.
Published: June 2017

An analysis of the action of a groin system through the 14 months following construction is reported herein. Six surveys were made during this period which included onshore elevations to the bluff line and offshore soundings to approximately the seven foot depth contour. Wind records during the period of record were studied and hindcasts of wave conditions made. Analysis of the basic data reveals that the cumulative volume of impoundment at the system may be expressed approximately by K(Icos B)^0.97.
THE INFLUENCE OF SUBSURFACE CONDITIONS ON THE DESIGN OF FOUNDATIONS FOR WATERFRONT STRUCTURES IN THE GREAT LAKES AREA
Authors: Peck Ralph B.
Published: June 2017

The purpose of this paper is to describe subsurface conditions beneath the principal waterfront areas in the Great Lakes region and to discuss certain foundation problems associated with waterfront structures in this locality.
THE MAIN ORE UNLOADING DOCK FAILURES AND THEIR CORRECTION 1909-1925, GREAT LAKES REGION
Authors: Fucik E. James
Published: June 2017

To start at the beginning of Chicago's lake structures (and first attempts to hold back ware action) we will go back about 120 years, to the year 1833. At that time an Illinois Congressman put through Congress an appropriation of $25,000 to construct a harbor at the south end of Lake Michigan (Fig. 1). At that time the Chicago River was navigable only by canoes. That Congressman, however, argued that the harbor should be located eleven miles south at the Calumet River. He was out-argued by a Captain of the Corps of Engineers, U.S. Army, who prevailed, and two 500 foot piers were built at the mouth of the Chicago River. The Congressman's name was Stephen A. Douglass and the Captain's name was Jefferson Davis, who evidently was a very persuasive fellow. These piers were either wooden cribs filled with stone, or stone-filled pile piers.
HYDRAULIC MODEL TESTS FOR INDIANA HARBOR DEVELOPMENT
Authors: Straub Lorenz G. , Hudson Robert Y.
Published: June 2017

Plant facilities of the Inland Steel Company, East Chicago, Indiana, and the East Chicago plant of the Youngstown Sheet and Tube Company, occupy the entire perimeter and adjacent shoreline of Indiana Harbor (Figs. 1, 2, and 3) Major changes in the plants of these companies required revisions in the shoreline and the building of various bulkheads within the harbor and in Lake Michigan outside the harbor breakwater. Small scale hydraulic model studies of the harbor and portions of certain harbor structures were conducted to aid in the solution in the wave action problems arising from the construction programs of the two steel companies. Investigations concerned construction projects recently completed, projects under construction during the course of the model studies, and proposed future plans for plant expansion and harbor development.
GEOLOGIC HISTORY OF GREAT LAKES BEACHES
Authors: Hough Jack L.
Published: June 2017

The locations of the Great Lakes and many details of the lake bottom topography bear a distinct relationship to the bed rock structure. Normal stream erosion in pre-glacial time probably etched out the major topographic relief of the region, forming the major basins and even some of the present bays, in the weak rock belts.

Glacial ice, advancing over the region in several stages, followed the lowlands but reshaped them and probably deepened most of them.

The known lake history, beginning with the last retreat of the ice from the southern rims of the Michigan and Erie basins, involves a number of stages at different levels in each of the basins. These lakes discharged at various places at different times, because of readvancement or retreat of the glacial ice front and because of tilting of the earth's surface. The writer's summary of this history is illustrated by a series of sixteen maps. The practical importance of two extremely low lake stages is pointed out. These have affected foundation conditions in the vicinity of many river mouths. The newly established recency of some of the higher lake stages (Nipissing and Algoma), and the revision of the elevations attained by them, affect estimates of the intensity of beach action and they affect conclusions regarding the time of last discharge of water through the Chicago outlet.
SOME CHARACTERISTICS OF BOTTOM SEDIMENTS ALONG THE ILLINOIS SHORE LINE OF LAKE MICHIGAN
Authors: Fisher R. O.
Published: June 2017

The State of Illinois is engaged in a long range study of shore erosion phenomena along the Illinois shore of Lake Michigan in order to obtain more definite information on the numerous engineering, geologic and meteorologic factors involved in the erosion process.
WAVE-MEASURING BY MEANS OF THE INTEGRATOR
Authors: Wemelsfelder P.J.
Published: June 2017

Civil engineers concerned with problems of coastal engineering or with harbours, shipping, carrying out of work, are at present more interested in waves than ten or more years ago.

It is possible to gather data about waves by means of wave recorders of which several types have been developed. Some of them work quite satisfactorily.
THE GENERATION OF WAVES, TIDES AND CURRENTS IN MODELS
Authors: Gridel H.
Published: June 2017

The author describes the technique and apparatus used at Chatou for the generation of waves, tides and currents in models of hydraulic structures.
WAVE DIFFRACTION IN FRONT OF A PLANE WAVE PADDLE
Authors: Bouyssou Roland
Published: June 2017

In an installation specially designed for the purpose, the Laboratoire Dauphinois d'Hydraulique has, made numerous systematic measurements of the distribution of wave amplitude across the face of the paddle from which the wave originates.

It is known that a wave produced by a wave machine of finite width diffracts. At first sight, it may appear possible to compare this diffraction to that of a wave passing through a breach of the same width as the wave paddle and cut in a breakwater of infinite length.

When laying out a harbour model, it ia important to know this "diffraction" so that the wave machine can be made to produce a wave having the appropriate amplitude in the essential sections of the model binder consideration (structures, harbour entry channel, etc...).

Our tests were carried out with a normal, simple articulation, plane wave paddle, 10 metres wide.

A continuous recording of amplitude was made along lines parallel to the wave machine and very close to one another inside a 12 metres long- and 5 metres wide rectangle. The measuring instrument used was the "graphic wave recorder" developed in the Laboratory, the principle of which is reviewed in the paper.

Special precautions were taken to avoid the effects of parasites,(unequal amplitude at the beginning, reflections caused by the basin walls, constancy of waves produced, etc..).

Three waves were studied. For each of these, nearly a thousand measurements have been selected and recorded on a plan of the measuring area. The results obtained in this way are compared to those obtainable from theories on wave diffraction. The results show the need for the precautions taken in the Laboratory when designing wave machines.
MIGRATING SAND WAVES OR SAND HUMPS, WITH SPECIAL REFERENCE TO INVESTIGATIONS CARRIED OUT ON THE DANISH NORTH SEA COAST
Authors: Bruun Per
Published: June 2017

The transport of sediment by flowing water commands great interest in connection with the control of floods, land reclamation, and the construction of harbours and coast protection works. A distinction can be drawn between littoral drift in rivers and in the sea.

The sediment transportation in rivers has been investigated by several authors, e.g. Shields, Meyer Peter, Kalinske, and Einstein, see (16) pp,, 769-83*+. Einstein's latest theories have given reliable results in practice (9).

As pointed out by Einstein (7), there cannot be much difference, physically, between transportation of sediment in rivers and longshore drift at sea shores, apart from the littoral zone with its extremely complex conditions.

In the attempt to understand the complex problem of sea shores the practice so far has been to split them up into several reaches and investigate them separately. This work has given a number of results of practical interest in connection with littoral drift and coastal protection technology, see (2), (3), (5)» (6), (11), (13), and (16).

According to Einstein, Johnson and Chien (8) there exist two types of sediment load, one that bears a certain relationship with the discharge (bed-material load), and the other which does not (wash load). The result of flume study indicates that the transport rate of wash load, just as that of the bed-material load, can be calculated according to the Einstein bed-load function (9), if the instantaneous bed composition is known. On the other hand, the bedmaterial load is equally available'in the entire bed, but only the surface bed layer contains any significant amount of wash-load material. Any change of flow or of sediment supply may immediately change the composition of the wash-load material in the bed. The bed composition as determined from the instantaneous condition of the channel has no lasting significance so far as the wash load is concerned, and this makes the prediction of the wash-load rate from.the bed-load function impossible.

The following deals with a mode of bed-load transportation which, as far as can be seen, takes place in large "waves" or humps.

Introductorily are mentioned investigations made in the United States on migrating sand bars and sand waves in rivers, and investigations in Holland on migrating sand bars on the bottom of the sea.

The major part of the paper deal with migrating sand humps along the North Sea coast of the peninsula of Jutland, Denmark, see Fig. 3.
THE CONDITION OF TANGIER BAY
Authors: Laurent Jean
Published: June 2017

During recent years, the spectacular growth of the sand deposit has made a great beach located at the base of the town of Tangier, and created a problem for local authorities. They are afraid that this deposition may endanger the harbor accessibility. Before beginning correcting or protecting works, the International Zone Administration of Tangier has asked the Laboratoire Central d'Hydraulique de France to study the conditions of Tangier Bay, and to determine the mechanism of sand deposition; and also to define on a reduced scale model the best arrangements to be taken in the near future for an extension of the harbor. This paper aims to present the results of field observations on the prototype.
SEA-DEFENSE PROBLEMS - SUCCESS AND FAILURE OF SOME STRUCTURES
Authors: Dreyfous-Duoas M. Dreyfous-Duoas
Published: June 2017

Considering the studies which have been published and the tests which have been made on models in past years, the author analyzes the reasons of failure or success on various defense works against the action of the sea. Groins and dry-wall breakwaters built since 1830 in the southwest of France are discussed.

Discussed first are the cases where the failure of the structure resulted from the nature of the construction. Structures of wood, masonry shell, and reinforced concrete are discussed, with solid masonry being considered as the most durable. Next these same types of construction are considered from the standpoint of their cross section. For groins, some permeability to sand is desirable; for dry wall breakwaters, a. small reflection of the waves is effective in causing a flattening of the beach. A flat rough slope is desirable as the face of a breakwater. Low permeability is also desirable.

With regard to the general layout of structures, the danger of long groins in the vicinity of channels , and of open type construction with longitudinal structures is shown.

The attention of engineers is directed to the importance of the ends of structures where the most critical conditions often, occur. In conclusion, construction features which are effective on a sandy coast are shown, and the difficult problems of a clay soil coast are considered.
THE SHOALING AND BREAKING OF THE SOLITARY WAVE
Authors: Ippen Arthur T. , Kulin Gershon
Published: June 2017

The solitary wave is ordinarily defined as a single disturbance of the water surface, which is relatively concentrated and symmetrical and which is propagated, neglecting damping, without change of form. Although it can be readily produced in the laboratory, in what appears to the observer a pure form, its existence (first noted in the field by J. Scott Russell (1) in 183U) as a wave of permanent shape has not yet been established by rigorous mathematical methods. This wave has been the subject of intermittent theoretical and experimental investigation since the days of Russell. In more recent years, additional attention has been given to the solitary wave, since it seemed to exhibit characteristics related to those of long-period oscillatory waves approaching the surf zone. In this connection, an experimental program for the precise measurement of the characteristics of the solitary wave was undertaken at the Hydrodynamics Laboratory of the Massachusetts Institute of Technology. The results of the first phase of this work, including celerity, profile, internal motion and smooth-bottom damping, were reported by J. W. Daily and S. C. Stephan, Jr., to the Third Conference on Coastal Engineering in 1952 (2). The present paper is concerned principally with the results of an experimental study of the shoaling and breaking behavior of solitary waves.
SEDIMENT MOVEMENT AT SOUTH INDIAN PORTS
Authors: Manohar Madhav
Published: June 2017

The movement of sedimentary matter along the coastal regions of the land has always been a problem in coastal and harbour engineering. Erosion and accretion of the shore and the sea bottom and the silt charge from the rivers discharging into the sea contribute the necessary sediment that moves along the coast.
WASTE DISPOSAL IN MARINE WATERS
Authors: Hood Donald W.
Published: June 2017

Waste disposal in marine waters is of importance to coastal engineers because of the ever-increasing requirements for an effective means of dilution of both municipal and industrial wastes. There are many considerations that enter into a satisfactory waste disposal method by dilution, but to the engineer two major considerations must be made. These are, first, the rate of diffusion and, second, the level of dilution necessary to effect disposal. These considerations become quite involved because of the varying conditions which influence dilution or diffusion processes and the uses of the water, which determines the criteria for a satisfactory dilution level. Thus, the dilution levels necessary will be dependent on the nature of the material and the area of dispersal.
GENERAL ASPECTS OF A STUDY ON THE REGIMEN OF LAKE MARACAIBO
Authors: McCammon G. A.
Published: June 2017

Maracaibo Basin in Western Venezuela, Figure 1, has an area of 90,000 square kilometers. It is isolated from the rest of Venezuela on the East and South, and from Columbia on the West, by mountain ranges which reach a height of 5,000 meters at the southern boundary of the Basin. Lake Maracaibo and its marginal swamps cover 17,700 square kilometers of the Basin. The Lake proper, approximately 150 kilometers long by 110 kilometers wide, is connected to the Gulf of Venezuela by the Straits of Maracaibo and broad shallow Tablazo Bay. It is about 50 kilometers from the lake proper to the gulf. Tablazo Bay is separated from the Gulf of Venezuela by a series of shifting sand islands and bars.
PROBLEMS WITH SMALL CRAFT HARBORS
Authors: Noble H. Morgan
Published: June 2017

Administration of a small craft harbor includes, among its problems, those of finance, law, public relations, policing, and engineering. This paper will relate experiences in all of these categories, but as it is written for Coastal Engineers, it will cover the engineering category most completely.
AN EXPERIMENTAL STUDY OF HYDRAULIC BREAKWATERS
Authors: Straub Lorenz G. , Herbich John B. , Bowers C. E.
Published: June 2017

A hydraulic or water-jet breakwater is formed by- forcing water through a series of nozzles mounted on a pipe which is installed perpendicular to the direction of the incident waves. The jets create a surface current which results in breaking of the incident wave. Apparently, this effect is primarily responsible for attenuation of the incident wave. An earlier development, the pneumatic breakwater, operates on a similar principle with a horizontal surface current induced by rising air bubbles.
WIND WAVES AND SWELL
Authors: Wiegel R. L.
Published: June 2017

Winds blowing over the water surface generate waves. In general the higher the wind velocity, the larger the fetch over which it blows, and the longer it blows the higher and longer will be the average waves . Waves still under the action of the winds that created them are called wind waves, or a sea. They are forced waves rather than free waves. They are variable in their direction of advance (Arthur, 1949). They are irregular in the direction of propagation. The flow is rotational due to the shear stress of the wind on the water surface and it is quite turbulent as observations of dye in the water indicates. After the waves leave the generating area their characteristics become somewhat different, principally they are smoother, losing the rough appearance due to the disappearance of the multitude of smaller waves on top of the bigger ones and the whitecaps and spray. When running free of the storm the waves are known as swell. In Fig. 1 are shown some photographs taken in the laboratory of waves still rising under the action of wind and this same wave system after it has left the windy section of the wind-wave tunnel. It can be seen thati-the freely running swell has a smoother appearance than the waves in the windy section. The motion of the swell is nearly irrotational and nonturbulent, unless the swell runs into other regions where the water is in turbulent motion. Turbulence is a property of the fluid rather than of the wave motion. After the waves have travelled a distance from the generating area they have lost some energy due to air resistance, internal friction, and by large scale turbulent scattering if they run into other storm areas, and the rest of the energy has become spread over a larger area due to the dispersive and angular spreading characteristics of water gravity waves. All of these mechanisms lead to a decrease in energy density. Thus, the waves become lower in height. In addition, due to their dispersive characteristic the component wave periods tend to segregate in such a way that the longest waves lead the main body of waves and the shortest waves form the tail of the main body of waves. Finally, the swell may travel through areas where winds are present, adding new wind waves to old swell, and perhaps directly increasing or decreasing the size of the old swell.
RESEARCH ON WAVE ACTION ON LAKE SHORES AND UNLINED SLOPES OF ARTIFICIAL EARTH STRUCTURES
Authors: Pichoughkin A.A.
Published: June 2017

The construction of big modern hydro-electric plants makes it necessary to create large reservoirs, of which the surface area can be on the order of some hundreds or even thousands square kilometers. As for example, the surface area of the Kuibyshev reservoir is 5600 km 2 that one of the Sherbakov reservoir - 4500 km^, of the Stalingrad reservoir - 3470 km2, of Kahovka reservoir - 2155 km2. The dimensions of reservoirs in plan being so considerable, the waves of 3-3,5m height can appear on the water surface. The shoreline of reservoirs created on U.S.S.R. plain rivers exceeds the length of 13000 km. The problem of the protection of the upstream slopes of artificial earth structures and natural shores against wave action is of extreme importance under these conditions.
SUR DEVALUATION DE CERTAINES CARACTERISTIQUES DU TRANSPORT LITTORAL A LA BASE DES DONNEES METEOROLOGIQUES
Authors: Slomianko Pawel
Published: June 2017

Les transports littoraux de sables ou de graviers qui s'effectuent le long des cotes marines donnent lieu a un certain nombre de processus interessants et importants, tant du point de vue scientifique que du point de vue des solutions pratiques. Ne citerais-je ici que les phenomenes de la formation de depots de sables, de 1'ensablement des ports et des estuaires fluviaux, ainsi que de l'abrasion des ootes marines. L'intensite et la direction du transport littoral en sont les traits oaracteristiques essentiels. les deux oaracteristiques en quantite majeure et en premier lieu dependent des courants de la houle agissant sur la zone cotiere, ainsi que de la force et de la frequence des vagues. Afin de pouvoir determiner d'une maniere exacte les caraoteristiques precitees du transport littoral, on est tenu de poursuivre des etudes dont les methodes, cependant, ne sont pas encore elaborees d'une maniere.definitive, quant aux etudes memes - - elles sont en general couteuses et presentent des difficultes en cours d'essais.

Parmi lesdites etudes on peut citer la determination du volume de 1'apport de sable du cote au vent de l'obstacle transversal, ainsi que la methode, assez reoente d'ailleurs, d'usage de sable marque a l'aide d'isotopes [4,7] , ou bien encore a l'aide de colorants luminophores [1,8] f Lesdites methodes, cependant, comme il l'a ete signale plus haut, sont assez onereuses dans leur application. Les necessites pratiques imposent souvent des solutions, concernant la caracteristique generale des transports littoraux il se peut moins precises, mais plus promptes.
USE OF A RADIO-ACTIVE TRACER FOR THE MEASUREMENT OF SEDIMENT TRANSPORT IN THE NETHERLANDS
Authors: Svasek J.N. , Engel H.
Published: June 2017

The "Rijkswaterstaat" has developed a method based on the use of radio-active tracers for the evaluation of sediment transport due to the combined action of waves and currents. The results of preparatory studies and a laboratory test were published in a previous report by J.J. Arlman, P. Santema and J.N. Svasek [1]. The main principles of the method were 1. Detection by a sledge-mounted unit towed by a survey vessel and continuous registration on board of the radio-activity measured on the sea bottom. 2. Employment of low specific radio-activity of tracer material and a large quantity thereof. 5> Use of a long-life isotope and high radio-activity. k. Measurement of the vertical distribution of radioactivity in core samples or if possible by discrimination. In March 1958 the first lot of tracer material was placed on the sea bed. The tracer material consisted of the radio-active isotope Scandium^" emitting 2 curies incorporated in 100 kg "greensand". Scandium^" has a half-life of 8^ days and emits strong gramma radiations with energies of 0.89 and 1.12 MeV. Afterwards, in 1959, two series of measurements were taken near the entrance to the Rotterdam Waterway. Four droppings formed one series; they were generally carried out in the following manner: 50 kg greensand labeled with 2 Curies Scandium was dropped in k places at a safe distance from each other. 2 of the 8 portions consisted of smaller quantities of both radio-activity and greensand. In the following paragraphs the preparation, dropping and detection of the tracer, the working out of the registrations and the interpretation of the results of the 1959 measurements are discussed.
A STUDY OF DIFFUSION IN AN ESTUARY
Authors: Maloney W.E. , Cline C.H.
Published: June 2017

The problem of dispersion and flushing of contaminants from estuarine waters is of ever-increasing importance to engineers. To determine this reduction in concentration and removal of contaminants from estuarine water, several basic methods have been established. They are: (1) the classical tidal prism method, where the flushing is a function of the amount of water brought in and removed on each tide; (2) Ketchum's modified tidal prism method, where flushing is a function of tidal action and river discharge; and (3) a diffusion-advection method which may be based on a coefficient of eddy diffusivity. This third method, diffusion-advection, would seem to give the most realistic answer provided that confidence can be had in the coefficient of eddy diffusivity. This discussion will be confined to the third method. Furthermore, we will concern ourselves only with that portion of a contaminant that goes into solution and partakes of the motion of the water. Such factors as absorption onto particulate matter, settling out onto the bottom, and uptake of the contaminant by marine organisms will be neglected.
EXPERIMENTAL STUDIES OF SPECIALLY SHAPED CONCRETE BLOCKS FOR ABSORBING WAVE ENERGY
Authors: Nagai Shoshichiro
Published: June 2017

Laboratory tests were performed to determine wave energy absorbing ability of and stability characteristics against breaking waves of various shaped pre-cast concrete armor units used for protective cover layers on the seaward slopes of rubblemound breakwaters and for parallel dykes placed the offshore sides of seawalls. A new shape of armor units, a hollow tetrahedron concrete block with a porosity of 25 percentages in the body was proved to have better characteristics for wave energy absorbing ability and attenuation of wave run-up, as well as for stability against breaking waves also than tetrapod or other armor units used up-to-date.
ISLAND HARBOURS AND THEIR INFLUENCE ON ADJACENT SHORES
Authors: Shirdan Leon
Published: June 2017

The purpose of this paper is to put forward an alternative solution to the problem of reconstitution of existing ports, generally too shallow for the large tankers and ore carriers. Usually, the existing moles are extended to deep water fairways and approaches to berths, docks and basins, dredged and adapted to the draught of the new giants. This is connected with enormous expenses. Sometimes completely new port units, as for instance Europort, are built. The Island Harbours, with their seaward position, will reduce the length of the shipway to the berths and thus provide a speedier turn-out of vessels. The cost of erection and maintenance of such a harbour is in most cases lower than in that of a conventional solution, due to short breakwaters and limited quantities of primary and maintenance dredging operations. Different alternatives of island ports can be adapted in most sandy coasts over the world. The changes in coastal regime which may result from erecting an island harbour connected with the mainland by a bridge or a causeway can turn out profitable for general cargo ships, and even fisherboats, especially on the coasts where till now cutting the sea approaches through the shallows and bars was often unacceptable, due to the enormous expenses involved.
SAFETY OF SEA-WALLS
Authors: Edelman Tr.T.
Published: June 2017

The disastrous stormflood of 1953 has caused in the Netherlands an intensive research on the mechanism of damages of sea-walls and on the problem of safety. It was rather quickly understood that the damages of the sea-walls must have been caused by overflowing water only. The overtopping water, flowing down along the inner slope, penetrated into this slope. The resulting groundwater flow in the section of-the bank-body just beneath*"this slope must have reduced the friction resistance of the soil, m consequence of which slides occurred in the inner slopes, in many cases resulting m a total destruction of the bank-body. Obviously there was something wrong with our sea-walls, but at first it was not very clear in which way they had to be improved, rfe could distinguish two different ways, two different principles. Either vie should design our sea-walls so high, that overtopping would never occur, or we should construct a bank-body, that would be wholly proof against the action of overflowing water.
SHORELINE ADVANCEMENT BY SEA WALL AND GROYNES AT COCHIN
Authors: Hiranandani M.G. , Gole C.V.
Published: June 2017

In the paper "Some coastal engineering problems in India" presented at the Vlth Conference on Coastal Engineering, a mention has been made about experimental protective measures consisting of one mile long sea wall and groynes adopted for giving protection to the coast near Cochin. The protective works mentioned in the above paper are now in operation for the last five years. As there are no major rivers there is very little littoral drift along this coast. The material eroded from the coast forms the main source of littoral transport. The data regarding high water and low water marks along the coast have been recorded, and statistically analysed to assess the efficiency of these measures in respect of shoreline advancement. Results are discussed in the paper. Some experiments have also been carried out in the prototype for a sea wall with bituminous grouting. Behaviour of this type of sea wall has also been discussed in the paper. Since the construction of the experimental measures, protective measures in the shape of either sea wall or sea walls with groynes have been further extended to a 10 mile long reach of the coast. The results of these new works, experiments carried out in a model for evolving the design of protective measures and model limitations have also been included. Fig. 1 shows the plan of the sea wall and groynes in one mile experimental reach.
COASTAL PROTECTION WORKS AND RELATED PROBLEMS IN JAPAN
Authors: Hom-ma Masashi , Horikawa Kiyoshi
Published: June 2017

Japan consists of 4 main islands named Hokkaido, Honshu, Shikoku and Kyushu, which, together with numerous smaller islands scattered around, are so aligned as to form a slightly bent arc off the eastern fringe of the Asiatic Continent. (See Fig. 1.) The dominant geographies of these islands are represented by relatively high mountains located in the center and narrow strips of plane lands lying along the coastlines. It is in these coastal planes that the cores of the Japanese industrial and other economical activities are deployed with swarming population. The entire area of Japan is approximately 320,000 km2 and the surrounding coastlines are 14,560 km long. Traditionally the economy of Japan depended heavily on agriculture and fishery, which necessitated active reclamation works around the estuarine lowlands as well as establishment of small fishery ports in great numbers at various parts of Japan. The growth of her economical potency came to cast floodlight on the importance of marine transportation, and the commercial ports came to thrive at numerous estuary harbors. The land extension works along the coast line are even flourishing today, but they are aimed at creating the sites for modern industries. It should be emphasized that Japan has been utilizing the coastal areas to an utmost extent for survival as well as prosperity, and further that this trend is destined to persist also in the future in order to keep pace with her economical development.
ETUDE THEORIQUE DE L'EXPLOITATION DES ENREGISTREMENTS DE HOULE
Authors: Caseau P.
Published: June 2017

L'e'tude de la houle en un point, c'est-a-dire 1!exploitation d'un enregistrement de houle, consiste a obtenir, a. partir de cet enregistrement, le plus de renseignements possible sur le "spectre" de la houle. Nous excluons le cas ou la donnee -|-(t) se presente sous la forme d'un tableau chiffre' ou d'un courant electrique. Ces deux representations ont en conmun la proprie'te que 1' addition de deux fonctions et l1 operation 4, / f(t) oU y sont faciles a realiser. L*exploitation passera done naturellement par la fonction de correlation YC*-) = =T / TW|(trt) 1ui es^ "tres facile a obteni] Au contraire, si 1'enregistrement se pre'sente sous forme de courbes sur film ou sur papier, aucune de ces deux operations n'est facile a realiser, ce qui enleve a *Jf(f) beaucoup de son intere*t. Pour 1' exploitation des enregistrements effectues par 1'enregistreur autonome de Chatou, qui consistent en des courbes sur film de 35 mm, une methode simplifiee est actuellement utilise'e ji5_7° Cette methode ne donne cependant pas tous les renseignements que l'on voudrait, et elle est moins rapide d'emploi qu'il ne serait necessaire pour permettre le depouillement des tres nombreux enregistrements effectues avec les divers appareils en service. En modifiant un peu la methode, M,, Kowalski, de l*Instytut Morski, a Gdansk, en Pologne, a pu la mecaniser et la rendre plus pratique, sans cependant augmenter le nombre des renseignements obtenus. En s'inspirant du procede utilis^ par M, Kowalski, M. Valembois a imagine le procede que 1ious etudions ici. Ce proce'de consiste a faire defiler le film devant un appareil qui compti au moyen de cellules photoelectriques, le nombre de points dsintersection de . courbe u = ^(t) avec les droites u- etc , pour diverses valeurs de la constanti Mo Larras a propose", au lieu de coTiipter des nombres de points d1 intersection, de totaliser des intervalles horizontaux (fig. t). L1etude mathematique de ces procedes conduit naturellement a considerer les "distributions" associees a ^(t), a voir leurs relations avec le spectre, et a selectionner celles qui sont le plus faciles a obtenir et qui donnent le plus de renseignements sur celui-ci. Apres avoir passe en revue les hypotheses mathematiques et les resultats ne'eessaires au calcul, nous aborderons done l'^tude de ces distributions, et nous indiquerons quelques-unes de celles que l'on peut utiliser.
TRACING COASTAL SEDIMENT MOVEMENT BY NATURALLY RADIOACTIVE MINERALS
Authors: Kamel A.M. , Johnson J.W.
Published: June 2017

The process by which sediments are moved along the shore is known as littoral drift and it includes beach drifting and longshore drift (Johnson, 1919). Coarse material is moved along a foreshore in zig-zag paths under the influence of swash and backwash of the waves. The process of longshore drift is due to longshore currents set up within the breaker zone by breaking waves approaching the shoreline at an angle. Although the waves tend to become parallel to the coast as a result of refraction, they usually break at a slight angle to the shore with the result that a littoral current is induced and is effective in moving a mass of water (and the sediment placed in suspension by the breaking waves) slowly along the coast. It is this current combined with the agitating action of the breaking waves, that is the primary factor in causing movement of sand along a coastline. It is believed that the largest percentage of the littoral transport occurs shoreward of the breaking point of the waves .
DYNAMIC ANALYSIS OF OFFSHORE STRUCTURES
Authors: Harleman Donald R.F. , Nolan William C. , Honsinger Vernon C.
Published: June 2017

Analytical procedures are presented for calculation of the dynamic displacements of fixed offshore structures in oscillatory waves. The structure considered has four legs in a square configuration with waves impinging normal to one side; however, the procedures are general and may be applied to other configurations and wave directions. The horizontal displacement of the deck is determined as a function of time by application of vibration theory for a damped, spring-mass system subject to a harmonic force. The instantaneous wave force on each leg is composed of a hydrodynamic drag component and an inertial component as in the usual "statical" wave force analysis. The wave force expression is approximated by a Fourier series which permits calculation of the platform displacement by superposition of solutions of the equation of motion for the platform. Depending on the ratio of the wave frequency to the natural frequency of the platform, the structural stresses may be considerably high* than those found by methods which neglect the elastic behavior of the structure. The highest wave to be expected in a given locality is not necessarily the critical design wave. Maximum displacements and structural stresses may occur for smaller waves having periods producing a resonant response of the platform. Displacement measurements in a wave tank using a platform constructed of plastic are presented to show the validity of the analytical method. Both small and finite amplitude waves are used over a wide range of frequency ratios. A digital computer program (7090 FORTRAN) is used for the displacement calculation.
ACRECENTAMIENTOS Y EROSIONES COMO CONSECUENCIA DE OBRAS MARITIMAS CONSTRUIDAS EN EL LITORAL CENTRAL DEL DISTRITO FEDERAL DE VENEZUELA
Authors: Nouel Bernardo A.
Published: June 2017

En la costa Norte y Central de Venezuela, en el sector del Distrito Federal, se nan construldo obras maritimas, habiendose registrado deposiciones de sedimentos, erosiones y cambios interesantes en la linea de costa, siendo el ob^e to del presente trabajo, recopilar la informaci6n, analizar los fen6menos y establecer conclusiones en aquellos casos - en que el material informativo disponible y el analisis de los mismos, permitieron llegar a ellas. Se pudieron deermi nar volumenes de rellenos y erosiones en lapsos definidos - como consecuencia de las obras construidas. As£ mismo se pu do establecer una inter-relaci6n entre las caracteristicas" del oleaje en un sitio definido, su profundidad y la veloci dad de decantaci6n del sedimento, caracterizada por la de - su diametro medio, en un intento de verificar en la naturaleza, los estudios de Ippen y Eagleson sobre distribuci6n - de sedimentos por efecto de las olas (7)» Por el contrario, no se pudo establecer relaciones definidas entre el coeficiente de uniformidad del sedimento y la profundidad (8).
INVESTIGATION OF SEICHE ACTIVITY IN WEST COAST HARBORS
Authors: Ellis Glen E. , Collins Joseph L.
Published: June 2017

The seiche activity in several West Coast harbors has been investigated during the past two years. This investigation has been oriented mainly as an experimental problem in which a new oceanographic instrument, the solion infrasonic hydrophone, is used to detect bottom pressure fluctuations over a range of 5 sec to 1800 sec periods.

A limited theoretical consideration of this problem is presented in an attempt to correlate the seiche phenomenon to the harbor geometry. The data presented in this paper are for San Diego Bay and Long Beach Harbor. These data were recorded on magnetic tape and returned to the laboratory for analysis. This analysis consists of prewhitening the data with bandpass filters and then computing the power spectra by the method of Blackman and Tukey. A short discussion is presented to relate the use of this type of data to the study of two harbor engineering problems, ship mooring and close quarter navigation.
Efficient and Highly Selective Solvent‐Free Oxidation of Primary Alcohols to Aldehydes Using Bucky Nanodiamond
Authors: Lin Yangming , Wu Kuang‐Hsu (Tim) , Yu Linhui , Heumann Saskia , Su Dang Sheng
Published: June 2017

Selective oxidation of alcohols to aldehydes is widely applicable to the synthesis of various green chemicals. The poor chemoselectivity for complicated primary aldehydes over state‐of‐the‐art metal‐free or metal‐based catalysts represents a major obstacle for industrial application. Bucky nanodiamond is a potential green catalyst that exhibits excellent chemoselectivity and cycling stability for the selective oxidation of primary alcohols in diverse structures (22 examples, including aromatic, substituted aromatic, unsaturated, heterocyclic, and linear chain alcohols) to their corresponding aldehydes. The results are comparable to reported transition‐metal catalysts including conventional Pt/C and Ru/C catalysts for certain substrates under solvent‐free conditions. The possible activation process of the oxidant and substrates by the surface oxygen groups and defect species are revealed with model catalysts, ex situ electrochemical measurements, and ex situ attenuated total reflectance. The zigzag edges of sp2 carbon planes are shown to play a key role in these reactions.
Stabilization Mechanism of Micropore in High‐Density Polyethylene: A Comparison between Thermal and Mechanical Pathways
Authors: Li Xueyu , Lin Yuanfei , Su Fengmei , Chen Xiaowei , Lv Fei , Meng Lingpu , Zhang Qianlei , Li Liangbin
Published: June 2017

Aiming to reveal the stabilization mechanism of micropore embryos formed during cold stretching in high‐density polyethylene films, samples are subsequently subjected to temperature elevation and strain holding at 25 °C, respectively. The corresponding structure evolution is tracked. It is found that after strain holding at 25 °C and subsequent strain recovery, inhomogeneously distributed cavities are produced, most of which can be healed as temperature is elevated to 110 °C. Consequently, only a small number of nonevenly distributed micropores are formed during the subsequent hot stretching. While for thermal pathway, micropores and fibrils can be formed as temperature is elevated. The hot stretching membrane exhibits uniformly distributed micropores and the micropores are well interconnected, indicating that micropores stabilized via temperature elevation are permanent and homogeneous. The results reveal different stabilization mechanisms of micropores via the thermal and mechanical pathways with regard to the distribution as well as the amount of permanent micropores.
The expanding role of the clinical pharmacist
Authors: David Felix
Published: June 2017

The Clinical Pharmacy Congress held in London in May focused on the ever‐growing importance of pharmacists in a variety of healthcare settings. The presentations covered a diverse range of subject areas, from tackling issues of antimicrobial resistance in urinary tract infections to the management of long‐term conditions.
Pro
Authors: Gaebel W.
Published: June 2017

The concept of schizophrenia has undergone many changes since its first inception in the early 20th century. Basically, the concept has stood the tests of time, as it provides useful information about the clinical picture, the clinical course and the available treatment modalities. Any alternative concept will need to show that it provides similar information. The concept has also been useful to establish evidence–based guidelines for diagnosis and treatment, and to provide valuable information as regards psychosocial outcomes. In addition, recent genetic and neurophysiological studies have shown that common grounds of aetiopathogenesis can be identified, in that schizophrenia is a mental disorder with some genetic influences and a common pathway in complex disturbances of brain circuits due to altered neurotranmission. Current research focuses on identifying biomarkers for early detection, another area of mental healthcare in which a staging model of schizophrenia proved useful. This presentation will highlight the most pertinent arguments for keeping schizophrenia as a useful diagnostic and therapeutic concept of a mental disorder.