TECHNICAL NOTE. DESIGN OF SEA OUTFALLS - THE LOWER LIMIT CONCEPT OF INITIAL DILUTION.

The design of marine outfalls is often based on environmental criteria for a minimum initial dilution. Accordingly advanced diffuser arrangement are designed to fulfil these requirements. A large number of examples of malfunction and blocking in sea outfalls have occurred around the world as a result of this uncompromising consent to environmental demands. Two examples of unconventional design are given in this paper. Both cases involved risk of blockage of the diffuser section because of wave and current induced sediment transport. The paper also discusses how acceptable far field dilution conditions can be achieved even if normally accepted initial criteria are not fulfilled.

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THE INFLUENCE OF WAVES ON THE HYDRAULICS OF SEA OUTFALLS

Coastal Engineering Proceedings ◽

10.9753/icce.v20.190 ◽

1986 ◽

Vol 1 (20) ◽

pp. 190

Author(s):

Torben Larsen

Keyword(s):

Sediment Transport ◽

Initial Dilution ◽

Typical Data ◽

Concrete Blocks ◽

Sea Outfalls

Most of the larger cities in Denmark are located near the sea. About 60% of the sewage is therefore discharged through sea outfalls. Most of these sea outfalls were built in the seventies. In most cases a plastic pipeline were used, and the pipeline was ballasted with armoured concrete blocks and burried in a trench 1 - 2 m underneath the seabottom. To give the necessary initial dilution a diffusor with one or several contracted, horizontal outlets ends the pipeline. The Danish coasts are in general shallow and exposed to waves. The littoral sanddrift is considerably and the sea outfalls need to cross one or more bars. The diffusors are often placed outside the bars, but nevertheless sediment transport can occur around the diffusor. Figure 1 gives some typical data for Danish sea outfalls.

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Current U.K. Research into the Design and Operation of Long Sea Outfalls

Water Science & Technology ◽

10.2166/wst.1989.0005 ◽

1989 ◽

Vol 21 (1) ◽

pp. 47-54 ◽

Cited By ~ 1

Author(s):

D. Procter

Keyword(s):

Marine Environment ◽

Structural Design ◽

Performance Monitoring ◽

Research Programme ◽

Hydraulic Performance ◽

Initial Dilution ◽

Hydraulic Design ◽

Maintenance And Inspection ◽

The Uk ◽

Sea Outfalls

The paper describes the scale of the UK Water Industry's use of the marine environment for the treatment of sewage, and briefly outlines the comprehensive research programme it has instigated to ensure that its outfalls are designed and operated in such a way as to adequately protect the environment. Brief details are provided of the engineering content of the overall UK research programme including work on hydraulic design, initial dilution, structural design and operation, maintenance and inspection. Development of hydraulic performance monitoring procedures and equipment are dealt with in detail and typical results from early fieldvork described.

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DISCUSSION. TECHNICAL NOTE. MARINE OUTFALL DESIGN - COMPUTER MODELS FOR INITIAL DILUTION IN A CURRENT.

Proceedings of the Institution of Civil Engineers ◽

10.1680/iicep.1990.6848 ◽

1990 ◽

Vol 88 (3) ◽

pp. 481-486 ◽

Cited By ~ 1

Author(s):

JJ SHARP ◽

E MOORE

Keyword(s):

Computer Models ◽

Technical Note ◽

Initial Dilution ◽

Marine Outfall ◽

A Current

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Supernovae and interstellar gas dynamics

Symposium - International Astronomical Union ◽

10.1017/s0074180900100774 ◽

1967 ◽

Vol 31 ◽

pp. 117-119

Author(s):

F. D. Kahn ◽

L. Woltjer

Keyword(s):

Lower Limit ◽

High Velocity ◽

Gas Dynamics ◽

Interstellar Cloud ◽

Interstellar Gas ◽

Random Motions ◽

Relativistic Particles

The efficiency of the transfer of energy from supernovae into interstellar cloud motions is investigated. A lower limit of about 0·002 is obtained, but values near 0·01 are more likely. Taking all uncertainties in the theory and observations into account, the energy per supernova, in the form of relativistic particles or high-velocity matter, needed to maintain the random motions in the interstellar gas is estimated as 1051·4±1ergs.

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New AAC Access Strategy for Gesture Tracking: A Technical Note

Perspectives on Augmentative and Alternative Communication ◽

10.1044/aac21.1.11 ◽

2012 ◽

Vol 21 (1) ◽

pp. 11-16 ◽

Cited By ~ 1

Author(s):

Susan Fager ◽

Tom Jakobs ◽

David Beukelman ◽

Tricia Ternus ◽

Haylee Schley

Keyword(s):

Augmentative And Alternative Communication ◽

Technical Note ◽

Head Tracking ◽

Alternative Communication ◽

Access Methods ◽

Cord Injury ◽

Physical Limitations ◽

Gesture Tracking ◽

Communication Needs ◽

Tracking Device

Abstract This article summarizes the design and evaluation of a new augmentative and alternative communication (AAC) interface strategy for people with complex communication needs and severe physical limitations. This strategy combines typing, gesture recognition, and word prediction to input text into AAC software using touchscreen or head movement tracking access methods. Eight individuals with movement limitations due to spinal cord injury, amyotrophic lateral sclerosis, polio, and Guillain Barre syndrome participated in the evaluation of the prototype technology using a head-tracking device. Fourteen typical individuals participated in the evaluation of the prototype using a touchscreen.

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