Influence of the dry/wet ratio on the chloride convection zone of concrete in a marine environment

The accumulation characteristics of surface chloride in concrete in different zones are different in the marine environment. A series of laboratory experiments were conducted to investigate the surface chloride and permeation characteristics of concrete in a simulated marine environment. The experimental results indicated that the surface chloride and chloride profiles of concrete in different zones of marine environment decreased in the following order: tidal zone > splash zone > submerged zone > atmospheric zone. The width of the ascent zone of Cl− concentration at tidal and splash zones was far less than that of the influential depth of moisture transport (IDMT), and the range of convection zone was dependent on the IDMT. Cl− at splash and tidal zones penetrated into concrete as a bulk liquid by non-saturated permeation driven by a humidity gradient. The change of chloride profiles in concrete along the altitudinal gradient was consistent with that of the cyclic water absorption amount (CWAA). The transport rate of chloride was the highest at the highest point of the tide.

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Alpha-Effect, Current and Kinetic Helicities for Magnetically Driven Turbulence, and Solar Dynamo

International Astronomical Union Colloquium ◽

10.1017/s0252921100064885 ◽

2000 ◽

Vol 179 ◽

pp. 387-388

Author(s):

Gaetano Belvedere ◽

V. V. Pipin ◽

G. Rüdiger

Keyword(s):

Southern Hemisphere ◽

Northern Hemisphere ◽

Convection Zone ◽

Solar Surface ◽

Momentum Transport ◽

Angular Momentum Transport ◽

Magnetic Buoyancy ◽

Alpha Effect ◽

Current Helicity

Extended AbstractRecent numerical simulations lead to the result that turbulence is much more magnetically driven than believed. In particular the role ofmagnetic buoyancyappears quite important for the generation ofα-effect and angular momentum transport (Brandenburg & Schmitt 1998). We present results obtained for a turbulence field driven by a (given) Lorentz force in a non-stratified but rotating convection zone. The main result confirms the numerical findings of Brandenburg & Schmitt that in the northern hemisphere theα-effect and the kinetic helicityℋkin= 〈u′ · rotu′〉 are positive (and negative in the northern hemisphere), this being just opposite to what occurs for the current helicityℋcurr= 〈j′ ·B′〉, which is negative in the northern hemisphere (and positive in the southern hemisphere). There has been an increasing number of papers presenting observations of current helicity at the solar surface, all showing that it isnegativein the northern hemisphere and positive in the southern hemisphere (see Rüdigeret al. 2000, also for a review).

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Solar Internal Rotation and Dynamo Waves: A Two-Dimensional Asymptotic Solution in the Convection Zone

International Astronomical Union Colloquium ◽

10.1017/s0252921100064861 ◽

2000 ◽

Vol 179 ◽

pp. 379-380

Author(s):

Gaetano Belvedere ◽

Kirill Kuzanyan ◽

Dmitry Sokoloff

Keyword(s):

Magnetic Field ◽

Asymptotic Solution ◽

Internal Rotation ◽

Convection Zone ◽

General Idea ◽

Dynamo Model ◽

Axially Symmetric ◽

Dynamo Action ◽

Regeneration Rate ◽

Dynamo Waves

Extended abstractHere we outline how asymptotic models may contribute to the investigation of mean field dynamos applied to the solar convective zone. We calculate here a spatial 2-D structure of the mean magnetic field, adopting real profiles of the solar internal rotation (the Ω-effect) and an extended prescription of the turbulent α-effect. In our model assumptions we do not prescribe any meridional flow that might seriously affect the resulting generated magnetic fields. We do not assume apriori any region or layer as a preferred site for the dynamo action (such as the overshoot zone), but the location of the α- and Ω-effects results in the propagation of dynamo waves deep in the convection zone. We consider an axially symmetric magnetic field dynamo model in a differentially rotating spherical shell. The main assumption, when using asymptotic WKB methods, is that the absolute value of the dynamo number (regeneration rate) |D| is large, i.e., the spatial scale of the solution is small. Following the general idea of an asymptotic solution for dynamo waves (e.g., Kuzanyan & Sokoloff 1995), we search for a solution in the form of a power series with respect to the small parameter |D|–1/3(short wavelength scale). This solution is of the order of magnitude of exp(i|D|1/3S), where S is a scalar function of position.

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Meridional Circulation, Turbulence, and Diffusion Processes in Stars

International Astronomical Union Colloquium ◽

10.1017/s0252921100080477 ◽

1976 ◽

Vol 32 ◽

pp. 109-116 ◽

Cited By ~ 1

Author(s):

S. Vauclair

Keyword(s):

Convection Zone ◽

Diffusion Processes ◽

Meridional Circulation ◽

Diffusion Time ◽

Work In Progress ◽

First Results ◽

Stellar Envelopes ◽

And Diffusion ◽

Turbulence And Diffusion ◽

Hr Diagram

This paper gives the first results of a work in progress, in collaboration with G. Michaud and G. Vauclair. It is a first attempt to compute the effects of meridional circulation and turbulence on diffusion processes in stellar envelopes. Computations have been made for a 2 Mʘstar, which lies in the Am - δ Scuti region of the HR diagram.Let us recall that in Am stars diffusion cannot occur between the two outer convection zones, contrary to what was assumed by Watson (1970, 1971) and Smith (1971), since they are linked by overshooting (Latour, 1972; Toomre et al., 1975). But diffusion may occur at the bottom of the second convection zone. According to Vauclair et al. (1974), the second convection zone, due to He II ionization, disappears after a time equal to the helium diffusion time, and then diffusion may happen at the bottom of the first convection zone, so that the arguments by Watson and Smith are preserved.

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Petroleum in the Marine Environment

Chemical & Engineering News ◽

10.1021/cen-v058n033.p022 ◽

1980 ◽

Vol 58 (33) ◽

pp. 22

Keyword(s):

Marine Environment

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Miocene of the S.E. United States A Model for Chemical Sedimentation in A Peri-Marine Environment

10.1016/s0070-4571(08)x7031-1 ◽

1977 ◽

Keyword(s):

United States ◽

Marine Environment

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Spatial assemblage structure of shallow-water reef fish in Southwest Australia

Marine Ecology Progress Series ◽

10.3354/meps13445 ◽

2020 ◽

Vol 649 ◽

pp. 125-140

Author(s):

DS Goldsworthy ◽

BJ Saunders ◽

JRC Parker ◽

ES Harvey

Keyword(s):

Shallow Water ◽

Reef Fish ◽

Marine Environment ◽

Fish Assemblages ◽

Canopy Cover ◽

Reef Fishes ◽

Reef Fish Assemblage ◽

Reef Type ◽

Present Distribution ◽

Southwest Australia

Bioregional categorisation of the Australian marine environment is essential to conserve and manage entire ecosystems, including the biota and associated habitats. It is important that these regions are optimally positioned to effectively plan for the protection of distinct assemblages. Recent climatic variation and changes to the marine environment in Southwest Australia (SWA) have resulted in shifts in species ranges and changes to the composition of marine assemblages. The goal of this study was to determine if the current bioregionalisation of SWA accurately represents the present distribution of shallow-water reef fishes across 2000 km of its subtropical and temperate coastline. Data was collected in 2015 using diver-operated underwater stereo-video surveys from 7 regions between Port Gregory (north of Geraldton) to the east of Esperance. This study indicated that (1) the shallow-water reef fish of SWA formed 4 distinct assemblages along the coast: one Midwestern, one Central and 2 Southern Assemblages; (2) differences between these fish assemblages were primarily driven by sea surface temperature, Ecklonia radiata cover, non-E. radiata (canopy) cover, understorey algae cover, reef type and reef height; and (3) each of the 4 assemblages were characterised by a high number of short-range Australian and Western Australian endemic species. The findings from this study suggest that 4, rather than the existing 3 bioregions would more effectively capture the shallow-water reef fish assemblage patterns, with boundaries having shifted southwards likely associated with ocean warming.

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PERAN DESIGNATED PERSON ASHORE (DPA) DALAM PENGOPERASIAN KAPAL YANG AMAN SESUAI KETENTUAN NASIONAL DAN INTERNASIONAL

JURNAL SAINS DAN TEKNOLOGI MARITIM ◽

10.33556/jstm.v20i1.212 ◽

2019 ◽

Vol 20 (1) ◽

Author(s):

Suganjar Suganjar ◽

Renny Hermawati

Keyword(s):

Marine Environment ◽

Emergency Preparedness ◽

Safety Management ◽

Shipping Industry ◽

Safe Operation ◽

International Regulation ◽

Loss Of Life ◽

Shipping Company ◽

Environmental Protection Policy ◽

Human Injury

Safety management in the shipping industry is based on an international regulation. It is International Safety Management Code (ISM-Code) which is a translation of SOLAS ‘74 Chapter IX. It stated that the objectives of the Code are to ensure safety at sea, prevention of human injury or loss of life, and avoidance of damage to the environment, in particular, to the marine environment, and to property.it is also requires commitment from top management to implementation on both company and on board. The implementation of the ISM-Code is expected to make the ship’s safety is more secure. The ISM-Code fulfillment refers to 16 elements, there are; General; Safety and Environmental Protection Policy; Company Responsibility and Authority; Designated Person(s); Master Responsibility and Authority; Resources and Personnel; Shipboard Operation; Emergency Preparedness; Report and Analysis of Non-conformities, Accidents and Hazardous Occurrences; Maintenance of the Ship and Equipment; Documentation; Company Verification, Review, and Evaluation; Certification and Periodical Verification; Interim Certification; Verification; Forms of Certificate. The responsibility and authority of Designated Person Ashore / DPA in a shipping company is regulated in the ISM-Code. So, it is expected that DPA can carry out its role well, than can minimize the level of accidents in each vessels owned/operated by each shipping company.Keywords : ISM Code, Safety management, Designated Person Ashore Manajemen keselamatan di bidang pelayaran saat ini diimplementasikan dalam suatu peraturan internasional yaitu International Safety Management Code (ISM-Code) yang merupakan penjabaran dari SOLAS 74 Chapter IX-Management for the safe operation of ships. Tujuan dari ISM-Code “The objectives of the Code are to ensure safety at sea, prevention of human injury or loss of life, and avoidance of damage to the environment, in particular, to the marine environment, and to property” dan ISM-Code menghendaki adanya komitmen dari manajemen tingkat puncak sampai pelaksanaan, baik di darat maupun di kapal. Pemberlakuan ISM-Code tersebut diharapkan akan membuat keselamatan kapal menjadi lebih terjamin. Pemenuhan ISM-Code mengacu kepada 16 elemen yang terdiri dari ; umum; kebijakan keselamatan dan perlindungan lingkungan; tanggung jawab dan wewenang perusahaan; petugas yang ditunjuk didarat; tanggung jawab dan wewenang nahkoda; sumber daya dan personil; pengopersian kapal; kesiapan menghadapi keadaan darurat; pelaporan dan analisis ketidaksesuaian, kecelakaan dan kejadian berbahaya; pemeliharaan kapal dan perlengkapan; Dokumentasi; verifikasi, tinjauan ulang, dan evaluasi oleh perusahaan; sertifikasi dan verifikasi berkala; sertifikasi sementara; verifikasi; bentuk sertifikat. Tugas dan tanggungjawab Designated Person Ashore/DPA didalam suatu perusahaan pelayaran, telah diatur di dalam ISM-Code. Sehingga diharapkan agar DPA dapat melaksanakan peranannya dengan baik, sehingga dapat menekan tingkat kecelakaan di setiap armada kapal yang dimiliki oleh setiap perusahaan pelayaran.Kata kunci : ISM Code, Manajemen keselamatan, Designated Person Ashore

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