High quality fill material

The shear strength of a reclamation area is primarily related to the type of fill material used. Distinction is made between high quality fill material and poor quality fill material . 

It should be noted that the terms high quality and poor quality do not refer to the quality of the resulting reclamation area. Even with poor quahty fill material, a high quality reclamation area can be achieved, given a proper design. 

The shear strength of a soil is defined by the Mohr-Coulomb equation  

For a granular material, factors affecting the shear strength are particle size distribution, particle shape, mineralogy, angularity, degree of compaction and stress 

Critical state shear strength of residual shear strength 

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In some cases, poor quality fill material will have to be used. Reference is also made to section 9.1 Cohesive or fine-grained fill materials for a more detailed description on the use of poor quality fill material. A shortage of sand sources in the close vicinity of a project or environmental constraints may have as a consequence that one is forced to work with cohesive materials for the land reclamation. In these cases the shear strength of the fill, and its increase in time, is much more difficult to predict compared to the use of high quality fill materials. A good knowledge of dredging and deposition methods is necessary. 

Based on the particle size distribution and the mineralogy of a high quality fill material, its shear strength can be predicted following methods such as described in section 8.4.2.1. Bear in mind that most of the literature data apphes for sihca sand only. 

High quality fill Material (sand, gravel)... 

Capital dredging works often involve the dredging of rocky material. Dredged rock can be used as a high quality fill material. 

The main purpose of a borrow area is to provide suitable fill material. Generally the required properties of the material can be split up per area or depth below the siuface. High quality fill materials (as may be required for the top layers of a land reclamation) are often referred to as selected fill . Bulk material is referred to as general fill . 

Economic reasons generally play an important role. It may be cheaper to use low quality fill material from a borrow area located at a close distance from the reclamation site instead of high quality fill material from a borrow area at a long sailing distance. The use of low quality fill material will require a different approach towards the technical specifications. Specifications usually adopted for high quality fill material may not be applicable. In order to comply with the performance requirements, more intensive ground improvement works will be required. 

The extra costs for the ground improvement and/or modifications of foundation design should be balanced against the extra costs for the longer sailing distance of the high quality fill material. 

The assessment of the shear strength of a fill is an evolving process during the design and execution of a hydrauhc fill project. A different approach is followed for high and poor quality fill materials. Generally, following phases can be identified ... 

Manufacturers of TLC materials and accessories are well prepared to satisfy the needs for professionally performed PLC. High-quality precoated preparative plates are available from a number of eommercial sources. Alternatively, less expensive or specialty preparative plates ean be homemade in the laboratory, and loose sorbents and coating devices ean be purehased for this purpose. More-or-less-automated devices can also be purehased for band application of higher quantities of sample solutions to preparative layers. At least for some users, sophisticated densitometric and other instrumental techniques are available as nondestructive tools for preliminary detention and identification of separated compounds in order to enhance the effieiency of their isolation. The only aid still missing, and maybe the most important of all, is a comprehensive monograph on PLC that might encourage and instruct many potential users on how to fully benefit from this very versatile, efficient, relatively inexpensive, and rather easy to use isolation and purification technique. This book was planned to fill that void. 

As with traditional aseptic filling, in order to comply with pharmaceutical GMP, it is important to minimize contamination at all stages of manufacture. Raw materials should be of a high quality and tested for microbial contamination. Water used for product manufacture should be of low bioburden and high purity (preferably water-for-injection quality, although this requirement is dependent upon the nature of the product being manufactured). 

With filled, re-inforced, and composite products the separation of unwanted material can present special problems, particularly if fibres or fibrous substances are incorporated there may be a tendency for the fibres to hold unwanted portions, while attempts at cutting or smoothing with abrasives can take away resin, filler, and re-inforcement selectively. Because of this it is difficult with such products to obtain finish of high quality unless a suitable film or some other coating is applied later. 

Beyond the abundant natural sources of quartz and other silicas, techniques for synthetic production of these materials have provided a significantly wider range of applications [27,34], Large, high-quality crystals of quartz can be grown by the well-established technique of hydrothermal growth in an autoclave filled with a solution of... 

The dimensions and properties of the lamp envelope are based on the discovery that the volume of Hg is critical for effective UV operation [50]. Higher Hg pressures result in the need to use higher microwave power levels. To focus the MW field efficiently into the EDL, a special Cd low-pressure lamp with a metal antenna (a molybdenum foil) was developed for experiments in MW-absorbing liquids [51]. The envelope material must be impermeable to gases, an electrical insulator, and chemically resistant to the filling compounds at the temperature of operation. High quality quartz is the most widely used lamp envelope material but early manufacturers of EDL used glass, Vycor, or Pyrex [52]. 

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