Synthesis and characterization of apatite silicated powders with wet precipitation method

The synthesis of apatite silicated Ca10(PO4)6-x(SiO4)x(OH)2-x (SiHA) with 0≤x≤2 was investigated using a wet precipitation method followed by heat treatment using calcium carbonate CaCO3 and phosphoric acid H3PO4 and silicon tetraacetate SiC8H20O4 (TEOS) in medium of water ethanol, with three different silicate concentrations. After drying, the samples are ground and then characterized by different analytical techniques like X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning electron Microscopy (SEM) and chemical analysis

Application of Statistical Experimental Design and Surface Plot Technique to Optimize Oxygenated Apatite Synthesis

This work deals with oxygenated apatite synthesis from calcium chloride and phosphoric acid using a wet precipitation method. An experimental design is applied to precise the influence of the synthesis parameters (pH of the reaction medium, atomic ratio Ca/P of the reagents, concentration of the calcium solution (Ca2+), temperature of the reaction medium (T), and duration of the reaction (D)) on the chemical composition (Ca/P molar ratio, % O2, and % O22−). An empirical model was developed and validated by applying the ANOVA analysis incorporating the interaction effects of all parameters and optimized using the response surface methodology. A reproducible synthesis of more oxygenated apatite with speed of dissolution adaptable to that of the osseous neoformation and allowing a progressive diffusion of oxygenated species (Ca/P = 1.575) is attained

OPTIMIZATION OF A PROCESS FOR DISCOLORATION OF LOW-GRADE SYRUP

L'amélioration de la couleur du sirop industriel de qualité inférieure, sur le charbon actif, a été optimisée à l'aide d'une conception composite centrale et d'une méthodologie de surface de réponse. Cette étude vérifie l'effet de trois paramètres expérimentaux : masse d'adsorbant (charbon actif), temps de contact adsorbat-adsorbant (sirop - charbon actif), rapport de masses des farines constituant le gâteau de filtration (m w /m b ) , et leurs interactions sur la réponse : ICUMSA Color. L'exploitation du modèle établi dans l'espace des variables a permis de définir des conditions économiques optimales d'obtention de sirop de classe claire selon la Commission Internationale pour les Méthodes Uniformes d'Analyse du Sucre (ICUMSA)

The possibility of establishing the dimensions of the quality of banking service: for the Rasheed and Rafidain bankers in Salah al-Din (model) Study: An exploratory

ملخص: يهدف البحث الحالي إلى التعرف على ابعاد جودة الخدمة المصرفية ومدى التزام المصارف المبحوثة بها لضمان الجودة في تقديم خدماتها , وتم وضع فرضية البحث الرئيسة تحقيقا لمقاصدها وتوجهاتها , ووزعت (39) استمارة استبانة على العاملين في مصرفي الرشيد والرافدين, وجرى اختبار فرضية البحث باستخدام مجموعة من الادوات الاحصائية بين ابعاد متغير البحث وخلص البحث إلى مجموعة من الاستنتاجات لعل من أهمها. وهناك تفاوتا في الاهتمام والالتزام من قبل المصارف المبحوثة بأبعاد جودة الخدمات المصرفية واستنادا إلى الاستنتاجات التي توصل اليها البحث , قدم الباحث مجموعة من التوصيات التي تنسجم مع هذه الاستنتاجات من اجل تطوير عمل المصارف المبحوثة ومن أهم هذه التوصيات ينبغي على المصارف المبحوثة الاهتمام الكافي والمتساوي بأبعاد جودة الخدمات المصرفية بغية تحقيق أهدافها في تحقيق المتميز على المنافسين .  Abstract: This study aims at identifying the quality dimensions of banking service and the extent to which the banks in question are committed to quality assurance in providing their services. The main research hypothesis was developed in accordance with research objectives. Hence, (39) copies of the questionnaire were distributed to employees of Al-Rasheed and Al-Rafidain banks. The hypothesis was tested using a set of statistical tools for research variables. The study concluded that there is a difference in attention and commitment of banks under study in terms of quality dimensions of banking services. According to the findings of this study, a set of recommendations were presented in order to develop the work of banks under study. The most important recommendation is that banks covered have to pay adequate and equal attention to the quality dimensions of banking services in order to accomplish their goals in achieving excellence over competitors

Characterization of antiseptic apatite powders prepared at biomimetics temperature and pH

Antiseptic apatite-based calcium phosphates were prepared as the single-phase powders. Phosphocalcic oxygenated apatites were synthesized from calcium salts and orthophosphate dissolved in oxygenated water solution at 30%, under the biomimetic conditions of 37 °C and pH 7.4. The characterization and chemical analysis of the synthesized biomimetic apatite powders were performed by scanning electron microscopy (SEM), powder X ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR) and chemical analysis. The obtained materials are a calcium deficient apatites with different morphologies

Natural Phosphate K09 as a New Reusable Catalyst for the Synthesis of Dihydropyrano[2,3-c]Pyrazole Derivatives at Room Temperature

International audienceIn this study, we report a simple, efficient and green protocol for the synthesis of pyrano[2,3-c]pyrazole derivatives by the use of the natural phosphate K09 as a mild and efficient heterogeneous catalyst. The catalytic efficiency of K09 was compared with other heterogeneous catalysts to determine the best catalyst for said conversion. Easy recovery of the catalyst and its reusability, room temperature reaction conditions, short reaction time, excellent yields, are some of the important features of this protocol

Advanced statistical optimization of parameters of synthesis process of oxygenated carbonated apatite

International audienceThe synthesis process of oxygenated carbonated apatite was optimized by an advanced statistical planning of experiments. Full factorial design of 24 experiments was used to find the effects of five principal parameters: pH of the reaction medium, atomic ratio Ca/P of the reagents, concentration of the calcium solution (Ca2+), temperature of the reaction medium (T) and duration of the reaction (D), with fixing the H2O2 composition at 30% and stirring to 600 turns/min. Studied responses were the atomic ratio Ca/P, % O2, % O2 2− and % CO3 2−. Optimum synthesis parameters were found to be pH = 7.38, Ca/P = 1.647, [Ca2+] = 0.636 M, T = 40°C and D = 1 h. The prediction responses were Ca/P = 1.575, % O2 = 0.76, % O2 2− = 0.50 and % CO3 2−= 1.84. The actual experimental results were in agreement with the prediction

One-Pot Synthesis of Dihydropyrimidinones/Thiones Catalyzed by White Marble a Metamorphic Rock an Efficient and Reusable Catalyst for the Biginelli Reaction

International audienceIn this work, we report a simple, efficient and green protocol for the synthesis of dihydropyrimidinones/thiones (products of Biginelli reaction) by the use of white marble as an effective heterogeneous catalyst. Short reaction times, high product yields, simple processing procedure and reusability of the catalyst are the superior characteristics of this protocol

Synthesis, characterization and thermal behaviour of a Phosphocalcic Oxygenated Apatite

A new route for preparing an antiseptic biomaterial has been described. An oxygenated apatite-based calcium phosphate powder that had a Ca/P ratio of 1.55 was synthesized from calcium nitrate and phosphoric acid in oxygenated water via a precipitation method. The X-ray diffraction and FTIR analysis of the as-dried powder reveals that the apatite is poorly crystalline and is converted into a biphasic calcium phosphate (HAP/beta TCP) when calcined at a temperature higher than 600°C. The chemical analysis of oxygenated species shows the disappearance of these species at 400°C