calcium

Hamdallah Bearat's picture

Influence de NaCl sur la couleur et la composition chimique des pâtes céramiques calcaires au cours de leur cuisson, Revue d'Archéométrie 13, 43-53.

Journal Title, Volume, Page: 
Revue d'Archéométrie Year 1989 Volume 13 Issue 1 pp. 43-53
Year of Publication: 
1989
Authors: 
Béarat H
Current Affiliation: 
Department of Materials Science, Faculty of Engineering and Information Technology, An-Najah National University, Nablus. Palestine
Dufournier D
Ngyuen N
Raveau B
Preferred Abstract (Original): 
The whitening of calcareous ceramics was studied in Mössbauer spectroscopy and X-Rays diffraction. This phenomenon is similar to that which occurs in firing calcareous clays without chloride, but it appears at lower temperature : NaCl accelerates the formation of calcium aluminosilicates susceptible of Fe3+ -trapping. The alkali metals are lost, during firing, in the form of chlorides. Their loss percentage increases from Li to Rb ; it augments also in function of CaCO3 and NaCl proportions.
maather's picture

Sorption of Hazardous Metals From Single and Multi-Element Solutions by Saltbush Biomass In Batch and ‎Continuous Mode: Interference of Calcium and ‎Magnesium in Batch Mode

Journal Title, Volume, Page: 
Journal of Environmental Management Volume 90, Issue 2, Pages 1213–1218
Year of Publication: 
2009
Authors: 
Maather F. Sawalha
Environmental Science and Engineering Ph.D. Program, University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968, USA
Current Affiliation: 
Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine
Jose R. Peralta-Videa
Chemistry Department, University of Texas at El Paso, El Paso, TX 79968, USA
Blanca Sanchez-Salcido
Chemistry Department, University of Texas at El Paso, El Paso, TX 79968, USA
Jorge L. Gardea-Torresdey
Chemistry Department, University of Texas at El Paso, El Paso, TX 79968, USA
Preferred Abstract (Original): 

Batch studies were performed to determine the interference of calcium (Ca) and magnesium (Mg) on the sorption of Cu(II), Cd(II), Cr(III), Cr(VI), Pb(II), and Zn(II) [from CuSO4, K2Cr2O7, Pb(NO3)2, Cr(NO3)3, ZnCl2, and Cd(NO3)2] by saltbush (Atriplex canescens) biomass. The results demonstrated that Ca and Mg at concentrations of at least 20 times higher than the concentration of most of the target metals did not interfere with the metal binding. The data show that the batch binding capacity from a multimetal solution at pH 5.0 was (μmol/g) about 260 for Cr(III) and Pb, and about 117, 54, and 49 for Cu, Zn, and Cd, respectively. The use of 0.1 M HCl allowed the recovery of 85–100% of the bound Cu, Cr(III), and Pb, and more than 37% of the bound Cd and Zn. The column binding capacity for Pb was about 49 μmol/g from both the single and multimetal solutions, while it was, respectively about 35 and 23 μmol/g for Cr(III). The binding capacity for Cu and Zn from the single and multimetal column experiments was 35 μmol/g and less than 10 μmol/g, respectively. The stripping data from the single column experiment showed that 0.1 M HCl allowed the recovery of all the bound Cu and Zn, 90% and 74% of the bound Pb and Cr(VI), respectively, and less than 25% of the bound Cd and Cr(III), while the stripping from the multimetal experiment showed that 0.1 M HCl allowed the recovery of all the bound Cu and about 74%, 54%, 43%, and 40% of the bound Pb, Zn, Cd, and Cr(III), respectively.

2278's picture

Environmental Heat Stress Does Not Reduce Blood Ionized Calcium Concentration In Hens Acclimated To Elevated Temperatures

Journal Title, Volume, Page: 
Poultry Science 75: 97-200
Year of Publication: 
1996
Authors: 
Maen Samara
Department of Animal Science, The University of Tennessee, tenessee 37901-1071
Current Affiliation: 
Department of Agriculture, Faculty of Agriculture and Veterinary Medicine, An-Najah National University, Nablus, Palestine
K.R. Robbins
Department of Animal Science, The University of Tennessee, tenessee 37901-1071
M.O. Smith
Department of Animal Science, The University of Tennessee, tenessee 37901-1071
Preferred Abstract (Original): 
Changes in blood concentrations of ionized calcium and total calcium were measured in broiler breeder hens (42 wk old) relative to egg cycle and environmental temperatures. Two environmental temperature treatments were used: 1) temperature cycled daily from a low of 10 C at 0300 h to a high of 25 C at 1600 h; and 2) temperature cycled from a low of 21 C at 0300 h to a high of 39 C at 1600 h. Serial blood samples  were  collected  from  five   laying  hens   per temperature treatment via cutaneous ulnar vein cannula beginning at the time of oviposition and every 4 h thereafter until the next oviposition. Neither blood concentration of ionized calcium nor total plasma calcium was affected by temperature. Results suggest that the supply of calcium available in blood for shell deposition is not diminished in hens acclimated to high environmental temperatures.

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