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It is important that pastes and creames for skin treatment have suitable rheological properties and ability to establish a good contact with the tissues while retaining their tightness. Thixotropy is desired for providing fluidity when agitated and a suitably degree of stiffening thereafter. This requires low shear resistance in the coating phase and microstructural reorganization when leaving the paste to rest. Following the principle of using only mineral components for skin treatment, use of expandable hydrophilic clay minerals should be considered. They sorb cations and positively charged organic molecules and are impermeable to fluids and gas under low pressure, hence providing oxygen-free micro-environment. They can balance pH and are excellent agents for cleaning skin.
Iraq experienced two devastating wars in 1991 and 2003, during which massive amounts of new weapons and sophisticated manufactured nuclear weapons were used called Depleted Uranium (DU). As a consequence of the radioactive contamination; the humans are suffering from various disease like cancer and the environment is polluted. In practice, there is no strategy and/ or national program, not even well thought out plans and scientific personnel and technical equipment required to clean Iraq of these wastes. Reviewing the geological, topographical and hydrological data, it had been noticed that Umm Chaimin depression is a good candidate site to dump all contaminated radioactive scrap and soil. The suggested design of the landfill will ensure safe containment of the waste for hundreds of thousands of years even if significant climatic changes will take place.
properties of cement-based grouts containing talc or palygorskite were investigated for optimizing fluidity and quick strengthening at injection. The
fluidity controls the ability of grout to penetrate fractures and can be
determined by pipe flow tests, Marsh funnel tests, mini-slump cone tests and
rheometer tests. The grouts were 1) Talc for fluidity and strength by reacting
with cement, 2) Palygorskite (attapulgite) for early gelation by being
thixotropic, and 3) Powdered quartz for chemical integrity. The freshly
prepared grouts behaved as Bingham fluids with viscosities from 0.151 to 0.464
Pas and yield stresses 5.2 Pa to 36.7 Pa. Statistical analysis of the flow test
data converted Marsh flow time into viscosity. The pipe flow tests gave 26.5%
higher values than the viscometer for grout with Portland cement and talc, and
about 13.7% lower than the viscometer data for the grout with low-pH cement and
talc. The big Marsh funnel gave values differing by 5.2% - 5.3% from those of
the viscometer for grout with talc and Portland, and Merit 5000 cements. For
grout with palygorskite the viscosity was at least twice that of the other
grouts. Grout fluidity was positively affected by talc and negatively by
palygorskite and early cement hydration.