Clusters of calcium carbonate with palladium atoms can be considered the minimum catalytic unit Lindlar catalyst, and they are here prepared in solution or supported on alumina, to catalyze selective semi-hydrogenation internal alkynes at higher rates than terminal alkynes. This uncommon reactivity trend arises from a better accessibility sterically hindered alkyne tiny cluster catalyst. • Emer...

Investigations of precipitation reactions in equilibrium self-assembled structures like vesicles, micelles, microemulsions, etc. is an active area of research, but growing biological systems are not equilibrium systems. Here we propose the use of a well-characterized nonequilibrium system of myelins in AOT/water to carry out precipitation reaction of CaCO3. It is found that the micro-flow patte...

Abstraet--A method for the determination of the cations of Na, K, Mg and Ca adsorbed on clay minerals mixed with CaCO3 and MgCO3 is described. An ethanolic solution of LiC1-CsC1 is used to displace the exchangeable cations. Blank determinations performed using either a second ethanolic leach or a second LiC1-CsC1 leach, are used to correct for carbonate dissolution. Details of the methods devel...

The effect of polymer, plasticizer, and surfactant additives on stress development during drying of calcium carbonate particulate coatings was studied using a controlled-environment apparatus that simultaneously monitors drying stress, weight loss, and relative humidity. We found that the calcium carbonate coatings display a drying stress evolution typical of granular films, which is characteri...

Basin-scale calcification rates are highly important in assessments of the global oceanic carbon cycle. Traditionally, such estimates were based on rates of sedimentation measured with sediment traps or in deep sea cores. Here we estimated CaCO3 precipitation rates in the surface water of the Red Sea from total alkalinity depletion along their axial flow using the water flux in the straits of B...

This aim of this study was to observe the effects of the application of low calcium dialysate (LCD) combined with oral administration of CaCO3 in the treatment of hyperphosphatemia, as well as blood Ca2+, calcium-phosphate product (CPP), parathyroid hormone (PTH) and blood pressure in patients undergoing hemodialysis. Thirty-one maintenance hemodialysis (MHD) patients with hyperphosphatemia, bu...

Development of efficient substrate formulas to improve yield and shorten production time is one of the prerequisites for commercial cultivation of edible mushrooms. In this study, fifteen substrate formulas consisting of varying ratios of palm press fibre (PPF), mahogany sawdust (MS), Gmelina sawdust, wheat bran (WB), and fixed proportions of 1% calcium carbonate (CaCO3) and 1% sucrose were ass...

While it is generally accepted that water hardness affects copper toxicity, the major ions that contribute to water hardness (calcium [Ca] and magnesium [Mg]) may affect copper toxicity differently. This is important because the Ca:Mg ratio in standard laboratory-reconstituted waters often differs from the ratio in natural surface waters. Copper toxicity was assessed for five different aquatic ...

The alluvial plain of the Ceyhan River (SE Turkey) has been populated since the Neolithic. In 1954, Marjory Veronica Seton-Williams described for this area several archeological mounds (höyük), which are the remains of ancient settlements. Today, according to the archeological research carried out in the area, some of these mounds result to have been leveled by agricultural activities. In this ...

DSDP/ODP porewater profiles in organic carbon-bearing (< 5% org. C) sediments commonly show decreases in Ca concentrations and increases in alkalinity over depths where sulphate is being removed by microbial reduction. These Ca depletion profiles represent the combined effect of diffusion, advection and reaction (addition by ion exchange and removal by precipitation mainly as CaCO3 and/or dolom...