bluuebunny/crossref_metadata_2025 huggingface dataset:
ISOPACHOUS MAPPING OF THE LOWER PATUXENT ESTUARY SEDIMENTS BY CONTINUOUS SEISMIC PROFILING TECHNIQUES
Authors: Stiles Newell T. , Wiesnet Donald R.
Published: February 2019

The thickness and extent of the sediment cover in the Patuxent Estuary has been determined using a high-frequency, high-spatial resolution, shallow penetration, continuous seismic profiling system. From these data, an isopachous map was prepared The isopachous map provides the subbottom information required to determine optimum locations for placing test equipment on the river bottom Mud filled depressions, acoustically transparent to 12-kHz sound pulses, occur mainly to the north of Half Pone Point, and east of the present channel Based on the identification of first subbottom reflectors, these depressions are as much as 16 feet thick The dominance of the thicker deposits east of the channel and evidence of a submerged terrace indicates that either the channel has migrated to the west, or that the channel of the Patuxent River at this location was larger in the past and has subsequently filled in much of the material in the eastern edge Maximum penetration at the scarp of the submerged terrace was 36 feet beneath the water-sediment interface This study demonstrates the use of seismic profiling techniques for collecting and presenting data required for coastal engineering applications.
TURBULENCE AND SEDIMENT CONCENTRATION DUE TO WAVES
Authors: Horikawa Kiyoshi , Watanabe Akira
Published: February 2019

A new electrolytic turbulence transducer has been developed in order to measure the turbulent velocity fluctuation superposed on the oscillatory flow velocity The aim of the present paper is firstly to describe the outline of this transducer and secondly to introduce some of the experimental results The main items of the results are, l) the vertical distribution of turbulence intensity averaged over one wave cycle, where the turbulence is induced by ripples which appear on the movable bed of wave flume, and 2) the correlation between the turbulence intensity and the characteristics of sediment particles at the same level such as their fall velocity and sediment concentration.
THE ANALYSIS OF WAVE RECORDS
Authors: Harris D. Lee
Published: February 2019

Data obtained from two surface profile wave gages and two pressure wave gages at the Steel Pier in Atlantic City, New Jersey, are used to check the consistency of the analysis variables obtained from a given set of records by several commonly used analysis procedures All estimates of the characteristic height tested are found to be correlated better than 86 The estimates of characteristic period are not so satisfactory and in some cases are below 25 Consideration of several proposed definitions of the characteristic period indicates that they are based more on convenience in data processing than on application of the derived data Consideration of the use of wave data in engineering design shows that no one definition of the period can be satisfactory for all applications The best definition of the characteristic wave period for a given engineering problem can be specified only when the dynamic aspects of the problem have been identified.
BEACH NOURISHMENT AT VIRGINIA BEACH, VIRGINIA
Authors: Bunch James W.
Published: February 2019

Aspects of the Federal beach erosion control project at Virginia Beach, Virginia are described with particular emphasis directed to the sources, characteristics, costs, methods of placement and quantities of material periodically placed on the beach following project inception The beach response to nourishment is analyzed on the basis of yearly survey records compiled from data gathered by the sea-sled direct leveling technique The quantity of annual nourishment material required to maintain present beach dimensions is determined to be approximately 141,000 cubic yards.
STUDY OF DURBAN HARBOR SILTING AMD BEACH EROSION
Authors: Jordaan Jan Malan
Published: February 2019

miles of coastline, including the major area of the port limits and the inner harbor, was constructed to study combined wave, tide and wind action on transport of sand along the coast. The effects of three predominant conditions of swell and wind-waves on the state of the ocean front beaches were studied by observing relative changes in shoreline contours. Fluorescentdyed sand tracers were also used in the model. The accumulation and dredging of sand near the harbor entrance was reproduced in the model and various dredging and storage proposals were carried out to scale on the model. The model study enabled the cause of beach erosion to be attributed to the existence of an offshore shoal produced by the localized dumping of sand dredged from the harbor approaches. This shoal caused selective wave action along the coastline, which was reproduced to scale in the model. It was found that wind and tidal action had a major effect on the redistribution of sand on the beaches as modeled but a minor effect on the permanence of the harbor entrance channel. Apart from the interaction of dredged sand at times being fed to the beaches, the problem of beach erosion could be studied independently of that of harbor silting on the same model. Sand was fed to maintain a state of equilibrium on the southern aooroach beach to the harbor to simulate the littoral sunply. The northern beach downdrift of the harbor entrance, where the erosion problem existed, was found to be essentially starved of littoral supply, due to maintenance of the harbor entrance by dredging and offshore dunroing. The requirements of the model study also gave rise to a program of field data collection on the governing environmental factors, which in itself aided considerably to the diagnosis of the causes of the state of unbalance in the shoreline. The model study led to several proposed remedial schemes, certain of which have been adopted since completion of the model study. The model study was conducted by the South African Council for Scientific and Industrial Research, for the South African Railways and the City Council of Durban.
MODEL TESTS AHD STUDIES FOE POET EASHID, DUBAI
Authors: Loewy Eric
Published: February 2019

This paper is a factual account of studies carried out for the design of a new deep water harbour As so often happens construction work had to be begun before many of the conclusions of the study were available so that alterations to the initial designs had to be made while work progressed The studies comprised tidal and wave recordings and analysis, model studies to determine residual wave conditions at the quays, studies to determine the extent of littoral drift, the effect of the proposed works upon this and possible measures to counter downdrift erosion In addition studies were made of the stability of the adjacent creek channel which had previously been the harbour and a mathematical model study was carried out of the effects on the creek regime of various proposed entrance works including the construction of an entirely new creek entrance channel through the new deep water harbor.
RESEARCHES ON SEA-WALLS
Authors: Nagal S.
Published: February 2019

In the recent decade, very wide areas of sea where the depths of water are from several meters to ten meters or more during storms have been reclaimed for industrial firms and port facilities in many places in Japan As the incident wave energy in such cases is very large at the sea-walls, the protection of the reclaimed lands from wave overtopping by the conventional sea-walls of vertical type or composite-slope«and-berai type is generally impossible from an economical point of view In Japan a special type of sea-wall, which is of such a type that a rubble-mound covered with specially shaped precast concrete armor blocks is built in front of the sea-wall to absorb most of the incident wave energy, has been constructed to protect the reclaimed lands from wave overtopping Most of the seawalls have been proved satisfactory after passing of typhoons over or near the sea-walls The design of the sea-walls is presented here in by showing the comparisons between the experiments and prototypes during typhoons.
THE INFLUENCE OF BREAKER TYPE ON RIPRAP STABILITY
Authors: Ahrens John P.
Published: February 2019

Test data related to the stability of dumped quarry stone riprap under wave action is presented The tests were conducted in the large 635-foot wave tank at the Coastal Engineering Research Center at near prototype scale The data indicate that the stability of the riprap is strongly influenced by the type of breaker The lowest riprap stability is associated with a breaker type intermediate between plunging and surging, sometimes referred to as a collapsing breaker.
LAND USE AND MITIGATION EFFECTS ON BARRIER BEACH EROSION IN STORMS: CASE STUDY IN RHODE ISLAND
Authors: Naser Naser Al , Grilli Annette , Grilli Stephan , Baxter Christopher , Bradshaw Aaron , Maggi Brian
Published: February 2019

Sea Level Rise (SLR) and storm intensification lead to re-evaluating inundation assessments along the North Atlantic US shoreline. A particular effort is devoted to assessing coastal community risk to â€œ100-year stormâ€ events in Rhode Island, US, using a chain of state-of-the-art storm surge, wave propagation, and coastal erosion 2D models. Damage risks imposed on infrastructures and services incited US federal and state agencies to come up with innovative engineering solutions to improve coastal resiliency while preserving natural coastal and marine environments. This study critically evaluates available design tools used to assess the performance of two types of Natural and Natural Based Features (NNBFs) for coastal protection: natural vegetated barrier islands and dunes reinforced with Geotextile Sand-filled Containers (GSCs), on urbanized barrier islands. Comparative analyses with field data identifies the capabilities and limitations of phase averaging and phase resolving hydro-morphodynamic models used for simulating bed level changes in dissipative beaches, during 3 Sallenger storm regimes. Recommendations are provided on modeling approaches for simulating effects of vegetation and using GSCs to limit coastal erosion.
APPLICATION OF OPEN BOUNDARIES WITHIN A TWO-WAY COUPLED SPH MODEL TO SIMULATE NON-LINEAR WAVE-STRUCTURE INTERACTIONS
Authors: Verbrugghe Tim , Dominguez José Manuel , Altomare Corrado , Tafuni Angelantonio , Troch Peter , Kortenhaus Andreas
Published: February 2019

A two-way coupling between the fully non-linear potential flow (FNPF) solver OceanWave3D and the Smoothed Particle Hydrodynamics (SPH) solver DualSPHysics is presented. At the coupling interfaces within the SPH domain, an open boundary formulation is applied. An inlet and outlet zone are filled with bu er particles. At the inlet, horizontal orbital velocities and surface elevations calculated with OceanWave3D are imposed on the bu er particles. At the outlet, horizontal orbital velocities are imposed, but the surface elevation is extrapolated from the fluid domain. Velocity corrections are applied to avoid unwanted reflections in the fluid domain. The SPH surface elevation can be coupled back to OceanWave3D, where the original solution is overwritten. The coupling methodology is validated using a 2-D test case of a floating box. Additionally, a 3-D proof of concept is shown where overtopping waves are acting on a heaving cylinder. The 2-way coupled model proofs to be capable of simulating wave propagation and wave-structure interaction problems with an acceptable accuracy with RMSE values remaining below the smoothing length h.
EXPLORING THE INFLUENCE OF LAND RECLAMATION ON SEDIMENT GRAIN SIZE DISTRIBUTION ON TIDAL FLATS: A NUMERICAL STUDY
Authors: Chen Lei , Zhou Zeng , Xu Mengpiao , Xu Fan , Tao Jianfeng , Zhang Changkuan
Published: February 2019

We explore the effects of land reclamation on the morphological evolution and sediment sorting on a tidal flat using a state-of-the-art numerical model (Delft3D). Consistent with existing field observations and analytical theories, model results indicate that the longitudinal profile adjusts itself converging to new equilibrium states (narrower and steeper) after a series of reclamations. Relatively fine sediments deposit adjacent to the sea dike, due to the flood-dominated tidal hydrodynamics. The amount of sediment deposition in front of the dike peaks when the dike is designed at mean sea level. After sequential reclamations, sediment grain size appears to be coarser offshore and on the tidal flat. Overall, this study suggests that land reclamation can lead to the readjustment of tidal flat profile shapes and coarsening of sediment grain size, which should be taken into account when reclamation projects are planned.
WAVE CLIMATE VARIABILITY AND RELATED CLIMATE INDICES
Authors: Mori Nobuhito , Kishimoto Risako , Shimura Tomoya
Published: February 2019

Climate change is highly expected to give significant impact on coastal hazards and environment. The future projections of wave climate under global warming scenarios have been carried out and shows changes in wave heights depending on the regions (e.g., Hemer et al., 2013). Beside the long-term trends of wave climate, annual to decadal changes are also important to understand variability. For example, the North Atlantic Oscillation (NAO) is highly correlated to monthly mean wave height along the western European coast. However, variability of wave climate is not well understood over the globe, quantitatively. Additionally, the standard coastal engineers regard stationary process for wave environment for solving coastal problems. This study analyzes global wave climate variability for the last half century based on principal component analysis of atmospheric forcing (sea surface winds U10 and sea level pressure P) and wave hindcast.
UNMANNED AERIAL SYSTEM LIDAR SURVEY OF TWO BREAKWATERS IN THE HAWAIIAN ISLANDS
Authors: Podoski Jessica H. , Smith Thomas D. , Finnegan David C. , LeWinter Adam L. , Gadomski Peter J.
Published: February 2019

The U.S. Army Corps of Engineers (USACE), Honolulu District (POH) is responsible for the operation and maintenance of 26 navigation projects within the State of Hawaii and the U.S. Pacific territories. The majority of these deep-draft and small-boat harbors include breakwaters that are consistently exposed to a substantial and varied Pacific Ocean wave climate, requiring POH to maintain a rigorous structure condition inspection program to ensure safe and efficient operations at all of its navigation projects. As part of its constant efforts to improve the quality and efficiency of this inspection program, POH has joined with the USACE Cold Regions Research and Engineering Laboratory (CRREL) Remote Sensing and GIS Center of Expertise to utilize an Unmanned LiDAR Scanning (ULS) system to collect LiDAR (Light Detection and Ranging) spatial data and co-registered imagery of breakwaters at Hilo Deep Draft Harbor on the island of Hawaii, and Kaumalapau Deep Draft Harbor on the island of Lanai.
THE NEED FOR PHYSICAL MODELS IN COASTAL ENGINEERING
Authors: Couriel Edward , Nielsen Lex , Jayewardene Indra , McPherson Bronson
Published: February 2019

Coastal process understanding is based on observations of physical processes in the field and laboratory from which theories are developed. Theories may be expressed mathematically and coded into numerical models. Compared with the cost of field data acquisition and laboratory experiments, the cost of numerical modelling is often perceived to be low. Therefore, there is a tendency to undertake coastal investigation and design using numerical modelling methods alone. However, there is still a need for physical modelling in coastal engineering.
EXTREME WAVE PRESSURES AND LOADS ON A PILE-SUPPORTED WHARF DECK - INFLUENCES OF AIR GAP AND WAVE DIRECTION
Authors: Cornett Andrew
Published: February 2019

Many deck-on-pile structures are located in shallow water depths at elevations low enough to be inundated by large waves during intense storms or tsunami. Many researchers have studied wave-in-deck loads over the past decade using a variety of theoretical, experimental, and numerical methods. Wave-in-deck loads on various pile supported coastal structures such as jetties, piers, wharves and bridges have been studied by Tirindelli et al. (2003), Cuomo et al. (2007, 2009), Murali et al. (2009), and Meng et al. (2010). All these authors analyzed data from scale model tests to investigate the pressures and loads on beam and deck elements subject to wave impact under various conditions. Wavein- deck loads on fixed offshore structures have been studied by Murray et al. (1997), Finnigan et al. (1997), Bea et al. (1999, 2001), Baarholm et al. (2004, 2009), and Raaij et al. (2007). These authors have studied both simplified and realistic deck structures using a mixture of theoretical analysis and model tests. Other researchers, including Kendon et al. (2010), Schellin et al. (2009), Lande et al. (2011) and Wemmenhove et al. (2011) have demonstrated that various CFD methods can be used to simulate the interaction of extreme waves with both simple and more realistic deck structures, and predict wave-in-deck pressures and loads.
CNOIDAL WAVES IN SHALLOW WATER
Authors: Masch Frank D.
Published: February 2019

The propagation of long waves of finite amplitude in water with depth to wavelength ratios less than about one-tenth and greater than about one-fiftieth can be described by cnoidal wave theory. To date little use has been made of the theory because of the difficulties involved in practical application. This paper presents the theory necessary for predicting the transforming characteristics of long waves based on cnoidal theory. Basically the method involves calculating the power transmission for a wave train m shallow water from cnoidal theory and equating this to the deep water power transmission assuming no reflections or loss of energy as the waves move into shoaling water. The equations for wave power have been programmed for the range of cnoidal waves, and the results are plotted in non-dimensional form.
ATTRITION TESTS OF NATURAL AND REDEPOCITED SHINGLE BEACHES
Authors: Duvivier J.
Published: February 2019

Administrative difficulties sometimes inhibit the transfer of beach shingle from areas where there is a surplus to areas where there is a shortage and it may be necessary to form an artificial beach of ballast dug from an inland pit or of quarried stone to reinforce the defense works or as a substitute for them. Coast erosion may be caused by a seasonal reversal of the prevailing drift, or by the protection of a previously eroding frontage up-drift, or by building harbour works, or by attrition of beach material, and the recharging of a beach with imported stone may be a cheaper and more satisfactory all round solution than the progressive underpinning of sea walls.

Nevertheless it can be a costly expedient and it is necessary to be able to compare the resistance of the imported material to loss by attrition with the behaviour of the natural beach material. The paper describes some simple tests which were carried out in an attempt to evaluate the relative resistance of various quarried stones and natural beaches to attrition,
EFFECTS OF HYDROGRAP'HIC CHANGES DUE TO NEARSHORE DREDGER DUMPING ON WAVE REFRACTION AND LITTORAL SAND BALANCE
Authors: Jordaan Jan M.
Published: February 2019

This paper presents a case where, in the development of a harbour, dredged material was dumped in a location where a large accumulation eventually formed. This changed the offshore topography sufficiently to affect the predominant wave refraction conditions. The wave environment along the principal bathing beaches was changed as a result, and a degree of beach erosion ensued which can be ascribed as partly due to the effects of continued dredger dumping in one area.
ON THE EFFECT OF AN OFFSHORE BREAKWATER ON THE MAINTENANCE OF A HARBOR CONSTRUCTED ON A SANDY BEACH
Authors: Ozaki Akira
Published: February 2019

In this paper the author describes an experimental attempt to prevent the rapid blocking of a harbor entrance caused by littoral drift in the summer period. This work was conducted at "Seppu", a fishing harbor constructed on a sandy beach in Hokkaido, Japan. This investigation was originally sponsored by the Harbor Section of the Hokkaido Prefectural Office One of the top priority objectives, at that time, was to determine the efficiency of two jetties constructed on the updrift side for the purpose of countering the sand drift. Detailed observations including preliminary model experiments, were made from 1961 to I963 on the general aspects (ie condition and phenomena) of the coast in question. Meteorological data were also compiled together with investigations as set forth by the government. Based on the above, the author finally suggested the utilization of natural forces ie waves, offshore currents etc, by constructing an offshore breakwater to curb the blockage of the harbor mouth. This idea was shown to be adequate at least qualitatively by model experiment with the exception of the troublesome time scale problem. These findings, however, have not been adopted as yet for actual improvement of the harbor at present.
RESIDENCE TIME OF SAND COMPOSING THE BEACHES AND BARS OF OUTER CAPE COD
Authors: Zeigler John M. , Tuttle Sherwood D. , Giese Graham S. , Tasha Herman J.
Published: February 2019

When a grain of sand is delivered to the sea by erosion it begins a journey being transported along beaches or bars, or offshore by waves and currents. The history of this journey can be extremely complex for the grain might spend a few seconds in one place and many years trapped in another before being released again for travel. It is therefore important at the outset to place some limitations upon our study. Firstly, our time scale is limited to the past seventy years, the time over which data were gathered. Secondly, the geographical position is limited to a strip of the east coast of Cape Cod 29,400 yards in length (Figure 1), extending seaward to where water depth is about forty feet. After a grain of sediment leaves this area we are no longer concerned with it. We define residence time as the average number of years a grain of eroded sediment is likely to spend in this prescribed area before it is transported elsewhere. We will further try to show that sediment takes a preferred path, some of it moving along the beach and some along the bars. It makes no difference to us if specific environments share grains; that is to say, some material will be on the beach one day and on the bar the next. In the end those grains which tend to be more stable in the beach environment will spend more time there and will travel with a characteristic velocity which is different from the velocity of those grains which are in hydrodynamic equilibrium on bars. The method used to compute residence time involves volume stability. We measured the volume of the beaches and bars in the definition area and assumed that these volumes have not changed within the time limits of our study. We also measured the yearly addition of sediment to the area. In-as-much as there is neither gain nor loss of the average volume of sand -built features, i.e., the beaches and bars, sand must be moving out of the study area at the same rate it is being introduced. Therefore, the residence time in years is the average volume of a beach or bar divided by the yearly volume of sediment added by erosion to the beach or bar.
A PROJECTION-TYPE SOUNDER
Authors: Ijima Takeshi
Published: February 2019

The Depth sounding is the fundamental process for the investigation of sand drift on sandy beach and has been carried out by means of echo-sounders. Although it is necessary to obtain the actual variations of bottom topography under the direct action of strong waves, the data even by the up-to-date method of soundings are limited to the case of calm sea conditions. Moreover, even in calm seas it is often difficult to measure the depth of water in the surf zone which has remarkable change of bottom topography due to wave action. The author has no information on the data of bottom topography under the direct action of waves on actual beaches in Japan, excepting those of Mr. Fujiki on the coast of Niigata along the Japan Sea, who, however, had measured the bottom profile along one fixed line which was set perpendicularly to the beach. At present we have no effective method of measuring the amount of drift sand, and therefore the measurement of dynamical variation of bottom topography is considered to be the possible primary and fundamental approach to the estimation of sand drift on sandy beach without any coast structure and also to be the final method of finding out the similarity law between model test and actual phenomena, through which model test may become a confiderable method of solving the sand drift problem. In order to observe the dynamical varation of bottom topography by wave action, it is necessary to develope newly any possible method without boat and echo-sounder. This is the purpose of study of projection type sounder.
EXEMPLE DE REALISATIONS DE MODELES MATHEMATIQUES A SOGREAH POUR DES ETUDES DE PROPAGATION DE HOULE
Authors: Barailler L , Gaillard P.
Published: February 2019

Cet article presente des applications du calcul sur ordinateur electronique a. I1 etude de la propagation de la houle dans les zones cStieres. Cette propagation peut mettre en jou deux phenomenes : l'effefc de la variation des fonds sur la cclerite de propagation et en consequence sur la courbure des fronts d'ondes, phenomene dit de "refraction" par analogic avec l'optique geometrique. le rayonnement de l'energic de la houle en arriere d'obstacles naturels ou artificiels, phenomene dit de "diffraction". Jusqu'a ces dermeres anneea, seule la refraction faisait l'objet de methodes de calcul relativement simples, consistant a tracer, soit des fronts d'ondes par application du principe de Huygens, soit les orthogonales a ces fronts par application do la loi do refraction de Descartes.
INTERLOCKING PRECAST CONCRETE BLOCK SEAWALL
Authors: Jachowski Robert A.
Published: February 2019

As a result of a survey of damage caused by the severe storm of March 1962 which affected the entire east coast of the United States, a new and specially-shaped interlocking concrete block was developed for use in shore protection. This block is designed to be used in a revetment-type seawall that will be both durable and economical as well as reduce wave run-up and overtopping, and scour at its base or toe. A description of model investigations conducted on the interlocking precast concrete block seawall and results there from are presented. It is shown that effective shore protection can be designed utilizing these units.
A GUIDE TO THE DESIGN OP AIR BUBBLERS FOR MELTING ICE
Authors: Ince Simon
Published: February 2019

The use of air bubblers for maintaining ice-free areas in lakes and in the sea has been reported abundantly in the technical literature. This author (1962) reported his observations on two air bubbler installations in the Canadian Arctic to the Eighth International Conference on Coastal Engineering. The results of these investigations were, at that time, still inconclusive. Today, some of the mystery is resolved and it is the author's opinion that the existence of a heat reserve is the answer to the problem. Based on this premise, an attempt is made here to develop some guide lines for the proper utilization of this thermal reserve.
SEA TESTS OF A SPREAD-MOORED LANDING CRAFT
Authors: O'Brien J.T. , Muga B.J.
Published: February 2019

Sea tests of motion and mooring force were conducted on an LST (Landing Ship Tank) of about 44O0 long tons displacement. The LST was spread-moored by six 2-1/16 inch and one 1-1/4 inch (port breast) stud-link chains in simple catenary configuration in about 45 feet of water in the open Gulf of Mexico about 65 air miles south of New Orleans, Louisiana. Water-level variations at a single location, ship rotations and accelerations, mooring force, and wind were measured in sea states of 2 and 4. Three recordings of 38, 62, 67 minutes duration were analyzed, using timeseries techniques to provide apparent amplitude-response operators for all of the ship's motions and seven mooring chains. Theoretical prediction of the operators using long crested regular waves was made also. In longitudinal plane, theory predicts motions 1/3 to 4 times and chain tensions 1/4 to 9 times those measured. The most probable maximum-motion amplitude responses in sea state 4 are found to be 1.7, 1.1, and 1.7 feet, respectively, in surge, sway and heave, and 3.4 and 0.5 degrees, respectively in pitch and yaw. Roll was measured only in sea-state 2 with a corresponding maximum of 2.1 degrees. Maximum wave-induced chain tensions in kips were: 85.1 and 48.0 in port and starboard bow chains respectively; 10.6 (sea state 2) and 19.7 in port and starboard breast chains; 13.9 and 4.3 in port and starboard quarter chains (sea state 2) and 9.7 in stem chain. Total tension in port bow chain was 116.1 kips (85.1 plus initial tension of 31.0 kips). Chain response operators vary directly with initial tension, whicl complicates design. It is concluded that: (i) moor was unbalanced, i.e., port bow chain took most of load; (ii) chains loaded lightly, e.g., maximum wave induced tension was 116 kips compared to new proof load of 300 kips for the particular chain, the port bow; (iii) water level should be measured at more than one point; (iv) discouragement over differences is balanced by encouragement over agreements between measurements and theoretical prediction of motion and chain tension; (v) toward improvement: Theory needs extension to include short crested waves and barge types; (vi) initial tension unique to problem of mooring design; (vii) propulsion devices may be needed toward maintaining design initial tension, especially in storm; (viii) if directional spectra had been measured and if theory involving short crested waves had been available and used, then discrepancies between observation and theory likely would have been less.
ON THE SHEAR STRESS AT THE INTERFACE AND ITS EFFECTS IN THE STRATIFIED FLOW
Authors: Iwasaki Toshio
Published: February 2019

At the moderate velocity of the pure water which lies on the quiet sal£ water stable internal waves appear at the interfac in the stratified flow, and these waves will break and violated surface will arise if the velocity of the pure water may be increased. In this phase of phenomena the shear stress at the interface has the most important part. However observed aalues of this shear stress have not been reported in the systematic style. Experiments have been conducted in our laboratory since i960. Some theoretical considerations could be served to get an empirical equation on the mterfacial shear using experimental results and data presented by other researchers.
O MERCADO DE TRABALHO NA PERCEPÇÃO DOS PROFISSIONAIS CONTÁBEIS
Authors: Machado Dirlei , Rosa Tuyane , Martins Zilton Bartolomeu
Published: February 2019

O presente artigo teve por objetivo analisar a percepção dos profissionais contábeis acerca do mercado de trabalho. Em relação aos procedimentos metodológicos, a pesquisa teve uma abordagem quantitativa, de tipologia descritiva e consistiu em uma pesquisa de levantamento. Como instrumento de coleta de dados, utilizou-se um questionário com 20 (vinte) questões fechadas, adaptado dos estudos de Santos (2007) e Rodrigues (2009). A população da presente pesquisa foram os 21.144 (vinte um mil, cento e quarenta e quatro) profissionais contábeis devidamente registrados no Conselho Regional de Contabilidade (CRC) do estado de Santa Catarina e a amostra compreendeu 260 respondentes. Os dados foram tabulados por meio do Google Formulários e a técnica utilizada para análise de dados foi a estatística descritiva, por meio da distribuição de frequência relativa. Os principais resultados revelaram que os profissionais contábeis devem estar preparados para atender as exigências do mercado, se esforçando para acompanhar as mudanças ocorridas nas áreas da contabilidade e sempre se atualizando para cumprimento das obrigatoriedades.
Diagnosis of Fibromyalgia: Disagreement Between Fibromyalgia Criteria and Clinician‐Based Fibromyalgia Diagnosis in a University Clinic
Authors: Wolfe Frederick , Schmukler Juan , Jamal Shakeel , Castrejon Isabel , Gibson Kathryn A. , Srinivasan Sachin , Häuser Winfried , Pincus Theodore
Published: February 2019

Objective

Recent studies have suggested that fibromyalgia is inaccurately diagnosed in the community, and that ~75% of persons reporting a physician diagnosis of fibromyalgia would not satisfy published criteria. To investigate possible diagnostic misclassification, we compared expert physician diagnosis with published criteria.

Methods

In a university rheumatology clinic, 497 patients completed the Multidimensional Health Assessment Questionnaire (MD‐HAQ) and the 2010 American College of Rheumatology preliminary diagnostic criteria modified for self‐administration during their ordinary medical visits. Patients were evaluated and diagnosed by university rheumatology staff.

Results

Of the 497 patients, 121 (24.3%) satisfied the fibromyalgia criteria, while 104 (20.9%) received a clinician International Classification of Diseases (ICD) diagnosis of fibromyalgia. The agreement between clinicians and criteria was 79.2%. However, agreement beyond chance was only fair (κ = 0.41). Physicians failed to identify 60 criteria‐positive patients (49.6%) and incorrectly identified 43 criteria‐negative patients (11.4%). In a subset of 88 patients with rheumatoid arthritis (RA), the kappa value was 0.32, indicating slight to fair agreement. Universally, higher polysymptomatic distress scores and criteria‐based diagnosis were associated with more abnormal MD‐HAQ clinical scores. Women and patients with more symptoms but fewer pain areas were more likely to receive a clinician's diagnosis than to satisfy fibromyalgia criteria.

Conclusion

There is considerable disagreement between ICD clinical diagnosis and criteria‐based diagnosis of fibromyalgia, calling into question ICD‐based studies. Fibromyalgia criteria were easy to use, but problems regarding clinician bias, meaning of a fibromyalgia diagnosis, and the validity of physician diagnosis were substantial.
Coupled Ion‐Gel Channel‐Width Gating and Piezotronic Interface Gating in ZnO Nanowire Devices
Authors: Yang Xixi , Hu Guofeng , Gao Guoyun , Chen Xuanyu , Sun Junlu , Wan Bensong , Zhang Qian , Qin Shanshan , Zhang Wenliang , Pan Caofeng , Sun Qijun , Wang Zhong Lin
Published: February 2019

The piezotronic effect has been extensively investigated and applied to the third generation of semiconductors. However, there currently is no effective method compatible with microelectronics techniques to harness the piezotronic effect. In this work, a facile and low‐energy‐consuming method to couple the channel‐width gating effect with piezotronic devices is developed by precisely patterning ion‐gel electrolyte on ZnO NW. The ultrahigh capacitance of ion gel resulting from electrical double layers allows efficient modulation of the charge carrier density in ZnO NW at low gate voltage (2 V) to compensate for the piezotronic effect. The obtained output current variation under negative gate voltage (420%, i.e., enhanced piezotronic effect) is two times higher than that under zero or positive gate biases (200%). Through quantifying the reverse‐biased Schottky barrier height and charge carrier density, it is found that the applied negative gate voltage depletes free electrons in ZnO NW and alleviates the screening effect on piezoelectric polarization charges, leading to enhanced piezotronic effect. Based on this, an ion‐gel‐gated piezotronic strain sensor is fabricated with enhanced gauge factor and tunable logic devices. It is believed that the coupled ion‐gel and piezotronic gating effect is of great significance to the design of sophisticated and practical piezotronic devices.
Advanced Catalysts Derived from Composition‐Segregated Platinum–Nickel Nanostructures: New Opportunities and Challenges
Authors: Zhang Nan , Shao Qi , Xiao Xiangheng , Huang Xiaoqing
Published: February 2019

Composition segregation, resulting from the rearrangement of atom positions and different enrichment behaviors of different atoms in alloys, has been linked to their enhanced performances in catalytic applications due to the strong electronic effect and largely improved number of available active sites. Hence, composition‐segregated metallic nanostructures have been actively pursued to prepare better‐performing nanocatalysts. Moreover, they also act as an emerging platform to develop unusual nanostructures with desirable functionalities. An overview about the recent advances in preparing unusual nanostructures with desirable functionalities such as highly open 3D structures (concave, frame, porous, etc.) and composites with suitable interfaces (metal–metal, metal–oxide, metal–sulfide, metal–boride, metal–organic, metal–hydroxide interfaces, etc.) based on composition‐segregated metallic nanostructures which can boost heterogeneous catalytic reactions with superior performances is provided here. The different strategies developed so far for the synthesis of composition‐segregated metallic nanostructures are also discussed. Finally, the challenges of the composition‐segregated nanostructure and their functionalized materials are discussed, as well as some perspectives are highlighted on the fine regulation and multifunctionalities of nanostructures, which provide a powerful material foundation for the potential electrocatalysis, organic catalysis, and energy conversion of multicomponent metal nanostructures.
Engineering Biomimetic Materials for Skeletal Muscle Repair and Regeneration
Authors: Nakayama Karina H. , Shayan Mahdis , Huang Ngan F.
Published: February 2019

Although skeletal muscle is highly regenerative following injury or disease, endogenous self‐regeneration is severely impaired in conditions of volume traumatic muscle loss. Consequently, tissue engineering approaches are a promising means to regenerate skeletal muscle. Biological scaffolds serve as not only structural support for the promotion of cellular ingrowth but also impart potent modulatory signaling cues that may be beneficial for tissue regeneration. In this work, the progress of tissue engineering approaches for skeletal muscle engineering and regeneration is overviewed, with a focus on the techniques to create biomimetic engineered tissue using extracellular cues. These factors include mechanical and electrical stimulation, geometric patterning, and delivery of growth factors or other bioactive molecules. The progress of evaluating the therapeutic efficacy of these approaches in preclinical models of muscle injury is further discussed.
Ultrathin MXene/Calcium Alginate Aerogel Film for High‐Performance Electromagnetic Interference Shielding
Authors: Zhou Zehang , Liu Jize , Zhang Xinxing , Tian Dong , Zhan Zeying , Lu Canhui
Published: February 2019

Ultrathin and high‐performance electromagnetic interference (EMI) shielding materials are urgently demanded for modern microelectronic devices. 2D metal carbides (MXenes) are considered as a promising EMI shielding material due to its metallic conductivity. In this study, sodium alginate is applied as interlayer spacer for Ti3C2Tx nanosheets, which not only prevents the restacking of lamella structure but also serves as building blocks for the sponge‐like structure. Ultrathin Ti3C2Tx/calcium alginate (CA) aerogel films with sponge‐like structure and only tens of microns thickness are prepared through divalent metal ion induced crosslinking, vacuum‐assisted‐filtration induced self‐assembly, and freeze‐drying. Taking advantage of its sponge‐like structure, which facilitates the dissipation of incident electromagnetic waves through multireflection and scattering Ti3C2Tx/CA aerogel film, presents excellent EMI shielding effectiveness (54.3 dB) at a very low thickness of 26 µm. Furthermore, Ti3C2Tx/CA aerogel film shows an outstanding specific EMI shielding efficiency (17586 dB cm2 g−1), which is superior to most reported synthetic materials. The preparation of ultrathin Ti3C2Tx/CA aerogel film provides facile strategy for designing and fabricating high‐performance MXene‐based EMI‐shielding materials, which is highly desirable for various applications including aerospace and smart electronic devices.
Regiodivergent Trifluoromethanesulfonic Acid‐Promoted Cycloisomerizations of Ynenamines to Fused Indoles
Authors: Alam Khyarul , Kim Jin Gyeong , Kang Dong Yun , Park Jin Kyoon
Published: February 2019

Trifluoromethanesulfonic acid (TfOH)‐mediated cycloisomerizations were controlled through the choice of the electron‐withdrawing functional group at C3 of indoles to provide pyrrolo[3,2,1‐ij]quinolines and benzo[3,4]azepino[1,2‐a]indoles via 6‐endo‐dig and 7‐endo‐dig cyclizations, respectively. The natures of the different cyclizations could be controlled by tuning the electronic influences; indole substrates with carbonyl groups (such as −CO2Et and −COMe) gave products with six‐membered rings, while substrates with sulfonyl groups (such as −Ts and −Ms) gave products with seven‐membered rings in moderate to good yields. By comparison, electronically‐neutral substituents (such as −Ph and −H) turned out to give seven‐membered products through different mechanism.

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Progress on PEDOT:PSS/Nanocrystal Thermoelectric Composites
Authors: Song Haijun , Meng Qiufeng , Lu Yao , Cai Kefeng
Published: February 2019

In recent years, poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)‐based nanocomposite thermoelectric (TE) materials are extensively investigated since they can take the advantages of both PEDOT:PSS (e.g., low thermal conductivity, high electrical conductivity, solution processability, and flexibility) and inorganic nanocrystals (e.g., high Seebeck Coefficient) to yield TE performance comparable to that of traditional inorganic TE materials. Besides, various preparation processes allow the mass fabrication of PEDOT:PSS‐based TE materials using some time‐saving and cost‐effective technologies, such as roll‐to‐roll and screen printing methods. This review focuses on the recent progress of PEDOT:PSS/inorganic nanocrystal composites for TE application. The relevant preparation strategies and TE properties are discussed intensively. In addition, the fabrication method, synergistic effect, and energy filtering effect involved in the composites, and flexible devices assembled from the composites are also discussed. Finally, challenges and prospects for future studies are summarized.
Within‐crown plasticity in leaf traits among the tallest conifers
Authors: Chin Alana R. O. , Sillett Stephen C.
Published: February 2019

Premise of the study

Leaves are the sites of greatest water stress in trees and a key means of acclimation to the environment. We considered phenotypic plasticity of Pseudotsuga menziesii leaves in their ecological context, exploring responsiveness to natural gradients in water stress (indicated by sample height) and light availability (measured from hemispherical photos) to understand how leaf structure is controlled by abiotic factors in tall tree crowns.

Methods

After measuring anatomy, morphology, and carbon isotope composition (δ13C) of leaves throughout crowns of P. menziesii >90 m tall, we compared structural plasticity of leaves among the three tallest conifer species using equivalent data from past work on Sequoia sempervirens and Picea sitchensis.

Key results

Leaf mass per projected area (LMA) and δ13C increased and mesoporosity (airspace/area) decreased along the water‐stress gradient, while light did not play a detectable role in leaf development. Overall, leaves of P. menziesii were far less phenotypically responsive to within‐crown abiotic gradients than either P. sitchensis, whose leaves responded strongly to light availability, or S. sempervirens, whose leaves responded equally strongly to water stress.

Conclusions

P. menziesii maintain remarkably consistent leaf structure despite pronounced vertical gradients in abiotic factors. Contrasting patterns of leaf structural plasticity underlie divergent ecological strategies of the three tallest conifer species, which coexist in Californian rainforests.
Comparative study on quick sequential organ failure assessment, systemic inflammatory response syndrome and the shock index in prehospital emergency patients: single‐site retrospective study
Authors: Harada Masahiro , Takahashi Takeshi , Haga Yoshio , Nishikawa Takeshi
Published: February 2019

Aim

The quick sequential organ failure assessment (qSOFA) score, shock index (SI), and systemic inflammatory response syndrome (SIRS) criteria are simple indicators for the mortality of patients in the emergency department (ED). These simple indicators using only vital signs might be more useful in prehospital care than in the ED due to their quick calculation. However, these indicators have not been compared in prehospital settings. The aim of the present study is to compare these indicators measured in prehospital care and verify whether the qSOFA score is useful for prehospital triage.

Methods

We undertook a single‐site retrospective study on patients transferred by ambulance to the Kumamoto Medical Center ED (Kumamoto, Japan) between January 2015 and December 2016. We compared areas under the receiver operating characteristic (AUROC) curves of the qSOFA score, SI, and SIRS criteria measured in prehospital care. We also carried out sensitivity and specificity analyses using the Youden index.

Results

A total of 4,827 patients were included in the present study. The AUROC (95% confidence interval) of the qSOFA score for in‐hospital mortality was 0.64 (0.61–0.67), which was significantly higher than those of the SIRS criteria (0.59 [0.56–0.62]) and SI (0.58 [0.54–0.62]). According to the optimal cut‐off values (qSOFA ≥ 2) decided on as the Youden index, the sensitivity of the qSOFA score was 52.3% and its specificity was 69.9%.

Conclusions

The qSOFA score had the highest AUROC among three indicators. However, it might not be practical in actual prehospital triage due to its low sensitivity.
Shared polygenic risk and causal inferences in amyotrophic lateral sclerosis
Authors: Bandres‐Ciga Sara , Noyce Alastair J. , Hemani Gibran , Nicolas Aude , Calvo Andrea , Mora Gabriele ,   The ITALSGEN Consortium,   The International ALS Genomics Consortium, Tienari Pentti J. , Stone David J. , Nalls Mike A. , Singleton Andrew B. , Chiò Adriano , Traynor Bryan J.
Published: February 2019

Objective

To identify shared polygenic risk and causal associations in amyotrophic lateral sclerosis (ALS).

Methods

Linkage disequilibrium score regression and Mendelian randomization were applied in a large‐scale, data‐driven manner to explore genetic correlations and causal relationships between >700 phenotypic traits and ALS. Exposures consisted of publicly available genome‐wide association studies (GWASes) summary statistics from MR Base and LD‐hub. The outcome data came from the recently published ALS GWAS involving 20,806 cases and 59,804 controls. Multivariate analyses, genetic risk profiling, and Bayesian colocalization analyses were also performed.

Results

We have shown, by linkage disequilibrium score regression, that ALS shares polygenic risk genetic factors with a number of traits and conditions, including positive correlations with smoking status and moderate levels of physical activity, and negative correlations with higher cognitive performance, higher educational attainment, and light levels of physical activity. Using Mendelian randomization, we found evidence that hyperlipidemia is a causal risk factor for ALS and localized putative functional signals within loci of interest.

Interpretation

Here, we have developed a public resource (https://lng-nia.shinyapps.io/mrshiny) which we hope will become a valuable tool for the ALS community, and that will be expanded and updated as new data become available. Shared polygenic risk exists between ALS and educational attainment, physical activity, smoking, and tenseness/restlessness. We also found evidence that elevated low‐desnity lipoprotein cholesterol is a causal risk factor for ALS. Future randomized controlled trials should be considered as a proof of causality. Ann Neurol 2019;85:470–481