Soils are aggregates of mineral particles, and together with air and/or water
in the void spaces, they form three-phase systems. A large portion of the
earth’s surface is covered by soils, and they are widely used as construction
and foundation materials. Soil mechanics is the branch of engineering that
deals with the engineering properties of soils and their behavior under
Soil erosion is a hazard traditionally associated with agriculture in tropical and semi-arid areas
and is important for its long-term effects on soil productivity and sustainable agriculture. It is,
however, a problem of wider significance occurring additionally on land devoted to forestry, transport
and recreation. Erosion also leads to environmental damage through sedimentation, pollution
and increased flooding. The costs associated with the movement and deposition of sediment
in the landscape frequently outweigh those arising from the long-term loss of soil in eroding fields.
The Guest Editors of this volume agreed in advance on the order listed on the title page, although equal editorial effort
should be recognized. Vadim Birstein, Robert Boyle and John Waldman convened the 1994 conference that was the source
for the original drafts of most of the manuscripts included in this collection. William Bemis put the volume in final shape;
he is also responsible for safeguarding the standards of all contributions as the editorial representative of Environmental
Biology of Fishes.
Toe erosion, especially in stormy conditions, is one of the common mechanism causing the failure and instability of the sea dikes and revetments. The erosion intensity becomes more serious at the beaches which is under the impacts of typhoons. Reliable forecasts about the intensity of toe erosion of sea dikes in stormy conditions have important ecnomomic and technical meaning in the design and construction of sea dikes.
Wastes are very process-specific but the key pollutants can be derived from
knowledge of: the process, construction materials, corrosion / erosion mechanisms and
maintenance materials. Waste audits are used to gather information on the source, composition,
quantity and variability of all wastes. Waste prevention typically involves preventing the
arising of waste at source, minimising the arisings and recycling any waste that is generated.
Inflammation can also be found in the intervertebral disks resulting in discitis and
spondylitis, which can be seen as narrowing of the intervertebral space and destruction of
the adjacent cover plates. Seldom synovitis and osteitis can be found in the atlantoaxial area
leading to erosions and destruction of the lateral atlantoaxial joint. At the worst the joint is
destabilized, this may cause cord compression and neurological loss of function.
The return on a nominal bond can be decomposed into two components: a real rate of return and a
compensation for the erosion of purchasing power arising from inflation. For conventional
government nominal zero coupon bonds, such as those in the example above, the nominal return is
certain (provided it is held to maturity) but the real return is not (because inflation is uncertain). An
index-linked zero coupon bond would have its value linked to movements in a suitable price index to
prevent inflation eroding its purchasing power (so its ‘real value’ is protected).
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học General Psychiatry cung cấp cho các bạn kiến thức về ngành y đề tài: Intraarticular injection of hyaluronan prevents cartilage erosion, periarticular fibrosis and mechanical allodynia and normalizes stance time in murine knee osteoarthritis...
Today, the ultrasonic signal is being used for predicting material behavior,
characterizing (detecting internal anomalies in) a variety of engineering structures,
as well as for inspecting human body parts like tumors, bones, and unborn fetuses.
Because of the ever-increasing popularity of the ultrasonic techniques in a wide
range of applications, this technology has received a lot of attention from the
research community. This book presents some new developments in ultrasonic
research for material and structure inspection. Application areas cover both
engineering and biological materials....
Gate valves are available with a variety of disks. Classification of gate valves is usually made
by the type disk used: solid wedge, flexible wedge, split wedge, or parallel disk.
Solid wedges, flexible wedges, and split wedges are used in valves having inclined seats. Parallel
disks are used in valves having parallel seats.
Regardless of the style of wedge or disk used, the disk is usually replaceable.
Whereas spark erosion and lasermachining
are suitable for any metal, the use of mechanical precision machining and the tools
suitable for this type depend on the stability of the alloy. For brass and copper, natural
diamondmicrotools are suitable and widely used, while for stainless steel and nickel-
based alloys, hardmetal tools are needed. Figure 1.3 shows a natural diamond cutter,
whereas Figure 1.4 shows a hard metal drill. Figure 1.5 shows photos of a rhodium
honeycombmicrochannel catalyst system.
The search for oil occurs in geological sediments, as opposed to volcanic rocks. Several
processes are involved in the creation of sediments. First, the inland continental volcanic rock is
continuously being weakened and eroded by weathering processes (mechanical (through water,
ice and wind) and chemical erosion). Secondly and simultaneously, the eroded material is being
transported by water, ice and wind and gradually the material may be broken down into smaller
pieces (from boulders to gravel, to sand, to silt and finally to clay).
Not all materials can be etched in an easy and cheap way. Especially, noble metals or
tantalum are stable against most of these corrosive structuring methods. Hence,
precision machining may be used to generate microstructures from these metals as
well as from standard metal alloys such as stainless steel or hastelloy. Depending on
the material, precision machining can be performed by spark erosion (wire spark
erosion and countersunk spark erosion), laser machining or mechanical precision