(Cu0.4Al0.3)TaSe2: PREPARATION AND CRYSTAL STRUCTURE ANALYSIS FROM X-RAY POWDER DIFFRACTION
A new phase of the (CuAlSe2)1-x(TaSe)x alloy system was synthesized by the melt and annealingtechnique and studied by SEM, DTA, and XRPD techniques. Its structure has been refined by the Rietveld methodusing X-ray powder diffraction data. The new alloy corresponds with the stoichiometry Cu0.4Al0.3TaSe2. Thiscompound crystallizes in the hexagonal space group 𝑃6ത𝑚2 (Nº 187) with a MoS2-type structure, and unit cellparameters a = 3.455(2) Å, c = 13.423(4) Å, V = 138.7(1) Å3, Z =2. The crystal structure is based on the MoS2-type of stacking of TaSe2 layers with a partial ordering of Cu and Al cations over the tetrahedral sites. The powderpattern was composed of 63.1% of the principal phase Cu0.4Al0.3TaSe2 and 29.9% of CuAlSe2, 7.0% of TaSe3, asthe secondary phases.
Read ArticleHEAT DISSIPATION AT CEMENT HARDENING
During the construction of concrete structures of small cross-sections, the release of heat during cementhardening has no harmful effects. With the increasing temperature of the hardening cement mass, the rate ofcement hydration increases. This increases the rate of release of its heat of hydration of cement. Theconsequence of the accelerated process of hydration of the binder is a more intensive increase in the strengthof cement stone than in the case of hardening under normal conditions. This fact is widely used in practice forthe intensification of the hardening of concrete. When structures with small cross-sections are being built, theheat released during hardening is relatively quickly transferred to the surrounding space and does not cause asignificant increase in temperature. In structures made of massive concrete (with a large cross-section), thisheat is stored in the interior of the array for a long time, which causes a rather large rise in temperature and itsslow drop. This is due to the fact that heat transfer to the external environment is hampered here by theconsiderable thickness of the massif and the rapid rate of concreting, mechanized laying of large masses ofconcrete. As a result, a temperature difference is created between the internal and external parts of thestructure and harmful internal stresses arise that can cause cracking in the hardened concrete. This leads to aviolation of its solidity. The faster cement hydrates, the sooner and more heat is released. The types of cementswith a high content of tricalcium silicate and aluminate emit more heat and rather than types of cement with ahigh content of dicalcium silicate and tetra-calcium aluminoferrite. However, the latter has a lower strength. Theincrease in strength resulting from the hydration process is inevitably associated with the release of heat into theenvironment. C
Read ArticleE-SELECTIN AS A BIOMARKER IN FEMALE PATIENTS WITH Β-THALASSEMIA IN AL- NAJAF PROVENCE, IRAQ
E-selectin, as identified (CD62E), is expressed on endothelial cells after stimulation with inflammation cytokines. β-Thalassemia diseases (βT) and early diagnosis are of utmost significance in the entire world population. This study was performed in the Thalassemia Center of the Al-Zahraa Educational Hospital in Al-Najaf Province, Iraq, on sixty-nine with β-thalassemia (54 βT major and 15 βT Intermedia) aged 8-40 years who transfused blood. Compared to 20 healthy volunteers as a control group. In both βT patients and healthy groups were assessed serum E-selectin levels. It was investigated the relationship with RBC, Hb, PCV, WBC, PLT, BMI, splenic status, iron, and ferritin levels. The results revealed a significant (P<0.05) decreased values of HB, RBC, P.C.V, and BMI. In contrast, values of WBC, PLT, Iron, and Ferritin were significantly increased in βT patients as compared to the healthy control groups. A significant (P<0.05) increase in serum E- Selectin level in βT patients (20.55±0.47) ng/ml to compare with the healthy group (9.16±0.50) ng/ml. Furthermore, it was a significant decrease in groups of βT major (19.87±0.42) ng/ml more than in βT intermedia (23±1.42) ng/ml. E-Selectin revealed a significant increase (P<0.05) in progress age and associated with splenectomies and underweight groups compared to splenectomies and the normal weight groups, respectively. Also, E-Selectin levels significantly positively correlated with WBC, PLT value, iron, and Ferritin levels. However, it was no significant with RBC, PCV, Hb. As a conclusion from this study, E- Selectin is an important biomarker in β-thalassemia patients can be identified as the complications associated with iron overload, inflammatory process, and endothelial dysfunction in βT disease.
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