Authors:Z. Xiao, D. Liu, C. Wang, Z. Cao, X. Zhan, Z. Yin, Q. Chen, H. Liu, F. Xu, and L. Sun
The effect of mechanical alloying on Zn-Sb alloy system is investigated with X-ray diffraction (XRD), laser grain size analysis
and differential scanning calorimetry (DSC) respectively. The results of laser particle size analysis shows that the particle
size decreases with increasing of the grinding time between 0 and 24 h. XRD and DSC results indicate that longer the grinding
time of Zn-Sb is, the more content of Zn4Sb3 become in the product in this process.
Authors:A. Olariu, C. Besliu, M. Belc, I. Popescu, T. Badica, and Gh. Lazarovici
Ancient copper objects from Romanian territories have been analyzed by neutron activation analysis. A series of elements is determined: Au, Ag, As, Co, Cr, Fe, Hg, Ni, Zn, Sb, Sc, Se, Sn. Using mathematical dendograms some classifications and correlation have been established.
Authors:X. Mao, C. Chai, S. Ma, Z. Yang, D. Xu, Y. Sun, and Q. Zhang
The concentrations of 14 elements, including Ir, Au, Co, Cr, Fe, Sr, Rb, K, Ta, Zn, Sb, Ba, Sc and Se, in the Wuxi fallen ice were determined by neutron activation analysis. The experimental results show that the relative concentration ratios of Ir/Co, Ir/Cr and Ir/Sc etc. in the ice water (0.0069, 0.00024 and 0.11, respectively) are quite close to those of Type C1 chondrite (0.0102, 0.00021 and 0.092, respectively), which implies that the fallen ice might be a piece of extraterrestrial substance.
A preliminary study to evaluate the use of neutron activation analysis for the characterization of six groups of man-made
fibers for forensic purposes has been made. A total of 81 samples of acetate, acrylic, modacrylic, nylon, polyester and rayon
were analyzed. Small samples, approximately the size typically found during a crime scene search, were analyzed using a Ge(Li)
detector system following a 20 min irradiation at a flux of 5·1013 n·cm−2·sec−1. The following elements were determined quantitatively in one or more of the samples: Ti, Sr, Au, Zn, Sb, Br. Mn, Mg, Cu,
In, Co, Cu, V, K, Al, Cl, Na, Ca, and S. Significant qualitative and quantitative differences were found both between and
within the six groups. However, within certain groups some fibers from different manufacturers showed marked similarities
in qualitative and quantitative composition.
Instrumental neutron activation analysis (INAA) have been used for the determination of some major, minor and trace elements (As, Cr, Co, Ni, Zn, Sb, Sc, Ce, Ti, Fe, Mn and V) in various plant leaves together with their soil. The accuracy of the measurements have been evaluated by analyzing a number of plant and soil reference materials, precision have been estimated by triplicate analysis of the sample as well as that of the reference material. The obtained accurate and reliable data of some trace elements on microgram level for plants and soil will serve as baseline values and will be helpful to monitor the changes in the trace element content of soil and plant leaves.
Human, animal (cow, buffalo and goat) and commercial milk powders (for infants and adults) have been analyzed for 5 minor (Na, K, Mg, Cl and P) and 13 trace elements (Cr, Mn, Fe, Co, Cu, Zn, Cd, Hg, As, Se, Sb, Cs and Br) by instrumental and radiochemical neutron activation. Milk standards NIST SRM 1549 and IAEA A-11 along with diet standards RM 8431 a and IAEA H-9 were also analyzed for quality assurance. The method involves thermal neutron irradiation for 10 m, 1 h, 6 h and 1 week in a reactor followed by high resolution -spectrometry. Concentrations of Fe, Co, Zn, Sb, and Se were also determined by radiochemical solvent extraction. Mean concentrations of Na, K, Mg, P, Cl, Fe, Mn and Cu in human milk (colostrum) are comparable with that of a WHO/IAEA study. It has, however, lower contents of toxic trace elements (Cr, Cd, Hg, Br, Se, Sb and As) compared to breast tissue from the same area. Cow milk is richer in Na, K, Cl, Mn and Se but it has comparable amounts of Mg, Zn, Br, Fe and Sb with respect to breast milk. Significant differences have been observed for elemental concentrations of Na, K, P and Fe in commercial formula milk powders for infants and adults. Infant's milk powders contain all the nutrient elements in balanced amounts required for the higher growth rate of a child.
In this paper are presented the theoretical approaches and some considerations of the TE-role in biological processes of diseases development in HCM-specific diagnostic series (N, CCH, CU, AT and ACa) and the influence of the pathological alterations on the numerical changes of CE (contents of elements) and D (distribution coefficient) parameter values in the mentionend serier. The CE and D parameters for elements, Cr, Fe, Co, Zn, Sb and Sc are obtained by INAA of HCM and were verified and evaluated by statistical treatments in parts 1 and 2 of this communication. The following can be concluated by statistical treatments in parts 1 and 2 of this communication. The following can be concluded: — the CE parameters can still not be used as the absoloute measure of the pathological alterations in HCM-DS (insufficient knowledge of TE-role in living matter); — the D parameters could be used as the relative measure of pathological alterations in such DS, and — numerical changes of CE and D parameters in DS could be explained on the basis of biological/biochemical behaviour of the TE found in HCM-DS and on the possible variations of D parameters (as a function of CE parameters) for the cases: (1) CE
CE¨' and (2)CE
CE¨' presented in this paper.
In this paper are presented the results of statistical vertification and evaluation of the CE (content of element) and D (distribution coefficient) parameters of Cr, Fe, Co, Zn, Sb and Sc in HCM-diagnostic series (N, CCh, CU, AT and ACa) by statistical treatments (SRCC, F and T testing, regression analysis). The following data have been determined: recirocal dependence (D parameters) of pairs of contents of elements CCr/CCo, CFe/CCo, CCr/CFe, CSc/CoFe, CSc/CCr and CSc/CCo on different LS (1.5 and 10%) by SRCC testing; dependence of CE parameters for Sc, Co and Sb in all diagnostic groups on different LS-F-testing; reciprocal dependence of CE parameters for some of the elements found (Sc, Co, Sb) in HCM DS on different LS-T-testing, and depedence of CE=F (CE¨') functions for some pairs of elements found in all DG with R2 MAX>0.8. Regression analysis type functions: Pow, POLYP and POLYC. These investigations indicate the possiblities of CE and D parameter application for specific numerical diagnosis (Medical Elementology).
Authors:D. Gouveia, R. Rosenhaim, M. de Maurera, S. Lima, C. Paskocimas, E. Longo, A. Souza, and I. Santos
With the aim of obtaining materials with applications in pigments, CoxZn7-xSb2O12 spinels were synthesized using the Pechini method. This method consists in the formation of a polymeric net, where the metallic
cations are homogeneously distributed. In this work, two types of alcohol (ethyl glycol and ethylene glycol) were used for
the synthesis of a zinc antimoniate spinel, CoxZn7-xSb2O12 (x=0-7). The materials were characterized by termogravimetry (TG) and differential thermal analysis (DTA). TG results indicated
a decrease in total mass loss when cobalt was added to the solution substituting zinc, for samples prepared using the two
different alcohols. Decomposition temperatures, obtained by TG and DTA, presented a decreasing behavior as cobalt was added
to the material. In relation to the alcohols, all results indicated a better polymerization of the resin when ethylene glycol
was used, being the most indicated one for cation immobilization. X-ray diffraction did not show differences between the two
alcohols - both presented the spinel phase (Co, Zn)2.33Sb0.67O4. Samples with higher quantity of cobalt also presented ilmenite phase (Co, Zn)Sb2O6.
the zinc-rich corner: L → AlSb + (Al), L → AlSb + (Sb) [ 8 ].
The Al–Zn–Sb system was investigated by Zhu et al. [ 9 ] at 450 °C, a typical galvanizing temperature. In the Zn–AlSb–Sb 2 Zn 3 region, two intermetallic phases were found at 450 °C